1/* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 2, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING. If not, write to
20the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21Boston, MA 02110-1301, USA. */
22
23
24/* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
28
29#include "config.h"
30#include "system.h"
31#include "coretypes.h"
32#include "tm.h"
33#include "tree.h"
34#include "rtl.h"
35#include "expr.h"
36#include "cp-tree.h"
37#include "tm_p.h"
38#include "flags.h"
39#include "output.h"
40#include "toplev.h"
41#include "diagnostic.h"
42#include "target.h"
43#include "convert.h"
44#include "c-common.h"
45
46static tree pfn_from_ptrmemfunc (tree);
47static tree convert_for_assignment (tree, tree, const char *, tree, int);
48static tree cp_pointer_int_sum (enum tree_code, tree, tree);
49static tree rationalize_conditional_expr (enum tree_code, tree);
50static int comp_ptr_ttypes_real (tree, tree, int);
51static bool comp_except_types (tree, tree, bool);
52static bool comp_array_types (tree, tree, bool);
53static tree common_base_type (tree, tree);
54static tree pointer_diff (tree, tree, tree);
55static tree get_delta_difference (tree, tree, bool, bool);
56static void casts_away_constness_r (tree *, tree *);
57static bool casts_away_constness (tree, tree);
58static void maybe_warn_about_returning_address_of_local (tree);
59static tree lookup_destructor (tree, tree, tree);
60static tree convert_arguments (tree, tree, tree, int);
61
62/* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
66
67tree
68require_complete_type (tree value)
69{
70 tree type;
71
72 if (processing_template_decl || value == error_mark_node)
73 return value;
74
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
77 else
78 type = TREE_TYPE (value);
79
80 if (type == error_mark_node)
81 return error_mark_node;
82
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
85 return value;
86
87 if (complete_type_or_else (type, value))
88 return value;
89 else
90 return error_mark_node;
91}
92
93/* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
97
98tree
99complete_type (tree type)
100{
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
103 at some point. */
104 return error_mark_node;
105
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
107 ;
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
109 {
110 tree t = complete_type (TREE_TYPE (type));
111 unsigned int needs_constructing, has_nontrivial_dtor;
112 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
113 layout_type (type);
114 needs_constructing
115 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
116 has_nontrivial_dtor
117 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
119 {
120 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
121 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
122 }
123 }
124 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
125 instantiate_class_template (TYPE_MAIN_VARIANT (type));
126
127 return type;
128}
129
130/* Like complete_type, but issue an error if the TYPE cannot be completed.
131 VALUE is used for informative diagnostics.
132 Returns NULL_TREE if the type cannot be made complete. */
133
134tree
135complete_type_or_else (tree type, tree value)
136{
137 type = complete_type (type);
138 if (type == error_mark_node)
139 /* We already issued an error. */
140 return NULL_TREE;
141 else if (!COMPLETE_TYPE_P (type))
142 {
143 cxx_incomplete_type_diagnostic (value, type, 0);
144 return NULL_TREE;
145 }
146 else
147 return type;
148}
149
150/* Return truthvalue of whether type of EXP is instantiated. */
151
152int
153type_unknown_p (tree exp)
154{
155 return (TREE_CODE (exp) == TREE_LIST
156 || TREE_TYPE (exp) == unknown_type_node);
157}
158
159
160/* Return the common type of two parameter lists.
161 We assume that comptypes has already been done and returned 1;
162 if that isn't so, this may crash.
163
164 As an optimization, free the space we allocate if the parameter
165 lists are already common. */
166
167static tree
168commonparms (tree p1, tree p2)
169{
170 tree oldargs = p1, newargs, n;
171 int i, len;
172 int any_change = 0;
173
174 len = list_length (p1);
175 newargs = tree_last (p1);
176
177 if (newargs == void_list_node)
178 i = 1;
179 else
180 {
181 i = 0;
182 newargs = 0;
183 }
184
185 for (; i < len; i++)
186 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
187
188 n = newargs;
189
190 for (i = 0; p1;
191 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
192 {
193 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
194 {
195 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
196 any_change = 1;
197 }
198 else if (! TREE_PURPOSE (p1))
199 {
200 if (TREE_PURPOSE (p2))
201 {
202 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
203 any_change = 1;
204 }
205 }
206 else
207 {
208 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
209 any_change = 1;
210 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
211 }
212 if (TREE_VALUE (p1) != TREE_VALUE (p2))
213 {
214 any_change = 1;
215 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
216 }
217 else
218 TREE_VALUE (n) = TREE_VALUE (p1);
219 }
220 if (! any_change)
221 return oldargs;
222
223 return newargs;
224}
225
226/* Given a type, perhaps copied for a typedef,
227 find the "original" version of it. */
228static tree
229original_type (tree t)
230{
231 int quals = cp_type_quals (t);
232 while (t != error_mark_node
233 && TYPE_NAME (t) != NULL_TREE)
234 {
235 tree x = TYPE_NAME (t);
236 if (TREE_CODE (x) != TYPE_DECL)
237 break;
238 x = DECL_ORIGINAL_TYPE (x);
239 if (x == NULL_TREE)
240 break;
241 t = x;
242 }
243 return cp_build_qualified_type (t, quals);
244}
245
246/* T1 and T2 are arithmetic or enumeration types. Return the type
247 that will result from the "usual arithmetic conversions" on T1 and
248 T2 as described in [expr]. */
249
250tree
251type_after_usual_arithmetic_conversions (tree t1, tree t2)
252{
253 enum tree_code code1 = TREE_CODE (t1);
254 enum tree_code code2 = TREE_CODE (t2);
255 tree attributes;
256
257 /* FIXME: Attributes. */
258 gcc_assert (ARITHMETIC_TYPE_P (t1)
259 || TREE_CODE (t1) == VECTOR_TYPE
260 || TREE_CODE (t1) == ENUMERAL_TYPE);
261 gcc_assert (ARITHMETIC_TYPE_P (t2)
262 || TREE_CODE (t2) == VECTOR_TYPE
263 || TREE_CODE (t2) == ENUMERAL_TYPE);
264
265 /* In what follows, we slightly generalize the rules given in [expr] so
266 as to deal with `long long' and `complex'. First, merge the
267 attributes. */
268 attributes = (*targetm.merge_type_attributes) (t1, t2);
269
270 /* If one type is complex, form the common type of the non-complex
271 components, then make that complex. Use T1 or T2 if it is the
272 required type. */
273 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
274 {
275 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
276 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
277 tree subtype
278 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
279
280 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
281 return build_type_attribute_variant (t1, attributes);
282 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
283 return build_type_attribute_variant (t2, attributes);
284 else
285 return build_type_attribute_variant (build_complex_type (subtype),
286 attributes);
287 }
288
289 if (code1 == VECTOR_TYPE)
290 {
291 /* When we get here we should have two vectors of the same size.
292 Just prefer the unsigned one if present. */
293 if (TYPE_UNSIGNED (t1))
294 return build_type_attribute_variant (t1, attributes);
295 else
296 return build_type_attribute_variant (t2, attributes);
297 }
298
299 /* If only one is real, use it as the result. */
300 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
301 return build_type_attribute_variant (t1, attributes);
302 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
303 return build_type_attribute_variant (t2, attributes);
304
305 /* Perform the integral promotions. */
306 if (code1 != REAL_TYPE)
307 {
308 t1 = type_promotes_to (t1);
309 t2 = type_promotes_to (t2);
310 }
311
312 /* Both real or both integers; use the one with greater precision. */
313 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
314 return build_type_attribute_variant (t1, attributes);
315 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
316 return build_type_attribute_variant (t2, attributes);
317
318 /* The types are the same; no need to do anything fancy. */
319 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
320 return build_type_attribute_variant (t1, attributes);
321
322 if (code1 != REAL_TYPE)
323 {
324 /* If one is a sizetype, use it so size_binop doesn't blow up. */
325 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
326 return build_type_attribute_variant (t1, attributes);
327 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
328 return build_type_attribute_variant (t2, attributes);
329
330 /* If one is unsigned long long, then convert the other to unsigned
331 long long. */
332 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
333 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
334 return build_type_attribute_variant (long_long_unsigned_type_node,
335 attributes);
336 /* If one is a long long, and the other is an unsigned long, and
337 long long can represent all the values of an unsigned long, then
338 convert to a long long. Otherwise, convert to an unsigned long
339 long. Otherwise, if either operand is long long, convert the
340 other to long long.
341
342 Since we're here, we know the TYPE_PRECISION is the same;
343 therefore converting to long long cannot represent all the values
344 of an unsigned long, so we choose unsigned long long in that
345 case. */
346 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
347 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 {
349 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
350 ? long_long_unsigned_type_node
351 : long_long_integer_type_node);
352 return build_type_attribute_variant (t, attributes);
353 }
354
355 /* Go through the same procedure, but for longs. */
356 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
357 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
358 return build_type_attribute_variant (long_unsigned_type_node,
359 attributes);
360 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
361 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 {
363 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
364 ? long_unsigned_type_node : long_integer_type_node);
365 return build_type_attribute_variant (t, attributes);
366 }
367 /* Otherwise prefer the unsigned one. */
368 if (TYPE_UNSIGNED (t1))
369 return build_type_attribute_variant (t1, attributes);
370 else
371 return build_type_attribute_variant (t2, attributes);
372 }
373 else
374 {
375 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
376 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
377 return build_type_attribute_variant (long_double_type_node,
378 attributes);
379 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
380 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
381 return build_type_attribute_variant (double_type_node,
382 attributes);
383 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
384 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
385 return build_type_attribute_variant (float_type_node,
386 attributes);
387
388 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
389 the standard C++ floating-point types. Logic earlier in this
390 function has already eliminated the possibility that
391 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
392 compelling reason to choose one or the other. */
393 return build_type_attribute_variant (t1, attributes);
394 }
395}
396
397/* Subroutine of composite_pointer_type to implement the recursive
398 case. See that function for documentation fo the parameters. */
399
400static tree
401composite_pointer_type_r (tree t1, tree t2, const char* location)
402{
403 tree pointee1;
404 tree pointee2;
405 tree result_type;
406 tree attributes;
407
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
410 {
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
413 }
414 else
415 {
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
418 }
419
420 /* [expr.rel]
421
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
426 types. */
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location);
434 else
435 {
436 pedwarn ("%s between distinct pointer types %qT and %qT "
437 "lacks a cast",
438 location, t1, t2);
439 result_type = void_type_node;
440 }
441 result_type = cp_build_qualified_type (result_type,
442 (cp_type_quals (pointee1)
443 | cp_type_quals (pointee2)));
444 /* If the original types were pointers to members, so is the
445 result. */
446 if (TYPE_PTR_TO_MEMBER_P (t1))
447 {
448 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
449 TYPE_PTRMEM_CLASS_TYPE (t2)))
450 pedwarn ("%s between distinct pointer types %qT and %qT "
451 "lacks a cast",
452 location, t1, t2);
453 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
454 result_type);
455 }
456 else
457 result_type = build_pointer_type (result_type);
458
459 /* Merge the attributes. */
460 attributes = (*targetm.merge_type_attributes) (t1, t2);
461 return build_type_attribute_variant (result_type, attributes);
462}
463
464/* Return the composite pointer type (see [expr.rel]) for T1 and T2.
465 ARG1 and ARG2 are the values with those types. The LOCATION is a
466 string describing the current location, in case an error occurs.
467
468 This routine also implements the computation of a common type for
469 pointers-to-members as per [expr.eq]. */
470
471tree
472composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
473 const char* location)
474{
475 tree class1;
476 tree class2;
477
478 /* [expr.rel]
479
480 If one operand is a null pointer constant, the composite pointer
481 type is the type of the other operand. */
482 if (null_ptr_cst_p (arg1))
483 return t2;
484 if (null_ptr_cst_p (arg2))
485 return t1;
486
487 /* We have:
488
489 [expr.rel]
490
491 If one of the operands has type "pointer to cv1 void*", then
492 the other has type "pointer to cv2T", and the composite pointer
493 type is "pointer to cv12 void", where cv12 is the union of cv1
494 and cv2.
495
496 If either type is a pointer to void, make sure it is T1. */
497 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
498 {
499 tree t;
500 t = t1;
501 t1 = t2;
502 t2 = t;
503 }
504
505 /* Now, if T1 is a pointer to void, merge the qualifiers. */
506 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
507 {
508 tree attributes;
509 tree result_type;
510
511 if (pedantic && TYPE_PTRFN_P (t2))
512 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
513 "and pointer-to-function", location);
514 result_type
515 = cp_build_qualified_type (void_type_node,
516 (cp_type_quals (TREE_TYPE (t1))
517 | cp_type_quals (TREE_TYPE (t2))));
518 result_type = build_pointer_type (result_type);
519 /* Merge the attributes. */
520 attributes = (*targetm.merge_type_attributes) (t1, t2);
521 return build_type_attribute_variant (result_type, attributes);
522 }
523
524 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
525 && TREE_CODE (t2) == POINTER_TYPE)
526 {
527 if (objc_compare_types (t1, t2, -3, NULL_TREE))
528 return t1;
529 }
530
531 /* [expr.eq] permits the application of a pointer conversion to
532 bring the pointers to a common type. */
533 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
534 && CLASS_TYPE_P (TREE_TYPE (t1))
535 && CLASS_TYPE_P (TREE_TYPE (t2))
536 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
537 TREE_TYPE (t2)))
538 {
539 class1 = TREE_TYPE (t1);
540 class2 = TREE_TYPE (t2);
541
542 if (DERIVED_FROM_P (class1, class2))
543 t2 = (build_pointer_type
544 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
545 else if (DERIVED_FROM_P (class2, class1))
546 t1 = (build_pointer_type
547 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
548 else
549 {
550 error ("%s between distinct pointer types %qT and %qT "
551 "lacks a cast", location, t1, t2);
552 return error_mark_node;
553 }
554 }
555 /* [expr.eq] permits the application of a pointer-to-member
556 conversion to change the class type of one of the types. */
557 else if (TYPE_PTR_TO_MEMBER_P (t1)
558 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
559 TYPE_PTRMEM_CLASS_TYPE (t2)))
560 {
561 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
562 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
563
564 if (DERIVED_FROM_P (class1, class2))
565 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
566 else if (DERIVED_FROM_P (class2, class1))
567 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
568 else
569 {
570 error ("%s between distinct pointer-to-member types %qT and %qT "
571 "lacks a cast", location, t1, t2);
572 return error_mark_node;
573 }
574 }
575
576 return composite_pointer_type_r (t1, t2, location);
577}
578
579/* Return the merged type of two types.
580 We assume that comptypes has already been done and returned 1;
581 if that isn't so, this may crash.
582
583 This just combines attributes and default arguments; any other
584 differences would cause the two types to compare unalike. */
585
586tree
587merge_types (tree t1, tree t2)
588{
589 enum tree_code code1;
590 enum tree_code code2;
591 tree attributes;
592
593 /* Save time if the two types are the same. */
594 if (t1 == t2)
595 return t1;
596 if (original_type (t1) == original_type (t2))
597 return t1;
598
599 /* If one type is nonsense, use the other. */
600 if (t1 == error_mark_node)
601 return t2;
602 if (t2 == error_mark_node)
603 return t1;
604
605 /* Merge the attributes. */
606 attributes = (*targetm.merge_type_attributes) (t1, t2);
607
608 if (TYPE_PTRMEMFUNC_P (t1))
609 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
610 if (TYPE_PTRMEMFUNC_P (t2))
611 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
612
613 code1 = TREE_CODE (t1);
614 code2 = TREE_CODE (t2);
615
616 switch (code1)
617 {
618 case POINTER_TYPE:
619 case REFERENCE_TYPE:
620 /* For two pointers, do this recursively on the target type. */
621 {
622 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
623 int quals = cp_type_quals (t1);
624
625 if (code1 == POINTER_TYPE)
626 t1 = build_pointer_type (target);
627 else
628 t1 = build_reference_type (target);
629 t1 = build_type_attribute_variant (t1, attributes);
630 t1 = cp_build_qualified_type (t1, quals);
631
632 if (TREE_CODE (target) == METHOD_TYPE)
633 t1 = build_ptrmemfunc_type (t1);
634
635 return t1;
636 }
637
638 case OFFSET_TYPE:
639 {
640 int quals;
641 tree pointee;
642 quals = cp_type_quals (t1);
643 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
644 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
645 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
646 pointee);
647 t1 = cp_build_qualified_type (t1, quals);
648 break;
649 }
650
651 case ARRAY_TYPE:
652 {
653 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
654 /* Save space: see if the result is identical to one of the args. */
655 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
656 return build_type_attribute_variant (t1, attributes);
657 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
658 return build_type_attribute_variant (t2, attributes);
659 /* Merge the element types, and have a size if either arg has one. */
660 t1 = build_cplus_array_type
661 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
662 break;
663 }
664
665 case FUNCTION_TYPE:
666 /* Function types: prefer the one that specified arg types.
667 If both do, merge the arg types. Also merge the return types. */
668 {
669 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
670 tree p1 = TYPE_ARG_TYPES (t1);
671 tree p2 = TYPE_ARG_TYPES (t2);
672 tree rval, raises;
673
674 /* Save space: see if the result is identical to one of the args. */
675 if (valtype == TREE_TYPE (t1) && ! p2)
676 return cp_build_type_attribute_variant (t1, attributes);
677 if (valtype == TREE_TYPE (t2) && ! p1)
678 return cp_build_type_attribute_variant (t2, attributes);
679
680 /* Simple way if one arg fails to specify argument types. */
681 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
682 {
683 rval = build_function_type (valtype, p2);
684 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
685 rval = build_exception_variant (rval, raises);
686 return cp_build_type_attribute_variant (rval, attributes);
687 }
688 raises = TYPE_RAISES_EXCEPTIONS (t1);
689 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
690 {
691 rval = build_function_type (valtype, p1);
692 if (raises)
693 rval = build_exception_variant (rval, raises);
694 return cp_build_type_attribute_variant (rval, attributes);
695 }
696
697 rval = build_function_type (valtype, commonparms (p1, p2));
698 t1 = build_exception_variant (rval, raises);
699 break;
700 }
701
702 case METHOD_TYPE:
703 {
704 /* Get this value the long way, since TYPE_METHOD_BASETYPE
705 is just the main variant of this. */
706 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
707 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
708 tree t3;
709
710 /* If this was a member function type, get back to the
711 original type of type member function (i.e., without
712 the class instance variable up front. */
713 t1 = build_function_type (TREE_TYPE (t1),
714 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
715 t2 = build_function_type (TREE_TYPE (t2),
716 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
717 t3 = merge_types (t1, t2);
718 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
719 TYPE_ARG_TYPES (t3));
720 t1 = build_exception_variant (t3, raises);
721 break;
722 }
723
724 case TYPENAME_TYPE:
725 /* There is no need to merge attributes into a TYPENAME_TYPE.
726 When the type is instantiated it will have whatever
727 attributes result from the instantiation. */
728 return t1;
729
730 default:;
731 }
732
733 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
734 return t1;
735 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
736 return t2;
737 else
738 return cp_build_type_attribute_variant (t1, attributes);
739}
740
741/* Return the common type of two types.
742 We assume that comptypes has already been done and returned 1;
743 if that isn't so, this may crash.
744
745 This is the type for the result of most arithmetic operations
746 if the operands have the given two types. */
747
748tree
749common_type (tree t1, tree t2)
750{
751 enum tree_code code1;
752 enum tree_code code2;
753
754 /* If one type is nonsense, bail. */
755 if (t1 == error_mark_node || t2 == error_mark_node)
756 return error_mark_node;
757
758 code1 = TREE_CODE (t1);
759 code2 = TREE_CODE (t2);
760
761 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
762 || code1 == VECTOR_TYPE)
763 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
764 || code2 == VECTOR_TYPE))
765 return type_after_usual_arithmetic_conversions (t1, t2);
766
767 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
768 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
769 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
770 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
771 "conversion");
772 else
773 gcc_unreachable ();
774}
775
776/* Compare two exception specifier types for exactness or subsetness, if
777 allowed. Returns false for mismatch, true for match (same, or
778 derived and !exact).
779
780 [except.spec] "If a class X ... objects of class X or any class publicly
781 and unambiguously derived from X. Similarly, if a pointer type Y * ...
782 exceptions of type Y * or that are pointers to any type publicly and
783 unambiguously derived from Y. Otherwise a function only allows exceptions
784 that have the same type ..."
785 This does not mention cv qualifiers and is different to what throw
786 [except.throw] and catch [except.catch] will do. They will ignore the
787 top level cv qualifiers, and allow qualifiers in the pointer to class
788 example.
789
790 We implement the letter of the standard. */
791
792static bool
793comp_except_types (tree a, tree b, bool exact)
794{
795 if (same_type_p (a, b))
796 return true;
797 else if (!exact)
798 {
799 if (cp_type_quals (a) || cp_type_quals (b))
800 return false;
801
802 if (TREE_CODE (a) == POINTER_TYPE
803 && TREE_CODE (b) == POINTER_TYPE)
804 {
805 a = TREE_TYPE (a);
806 b = TREE_TYPE (b);
807 if (cp_type_quals (a) || cp_type_quals (b))
808 return false;
809 }
810
811 if (TREE_CODE (a) != RECORD_TYPE
812 || TREE_CODE (b) != RECORD_TYPE)
813 return false;
814
815 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
816 return true;
817 }
818 return false;
819}
820
821/* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
822 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
823 otherwise it must be exact. Exception lists are unordered, but
824 we've already filtered out duplicates. Most lists will be in order,
825 we should try to make use of that. */
826
827bool
828comp_except_specs (tree t1, tree t2, bool exact)
829{
830 tree probe;
831 tree base;
832 int length = 0;
833
834 if (t1 == t2)
835 return true;
836
837 if (t1 == NULL_TREE) /* T1 is ... */
838 return t2 == NULL_TREE || !exact;
839 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
840 return t2 != NULL_TREE && !TREE_VALUE (t2);
841 if (t2 == NULL_TREE) /* T2 is ... */
842 return false;
843 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
844 return !exact;
845
846 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
847 Count how many we find, to determine exactness. For exact matching and
848 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
849 O(nm). */
850 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
851 {
852 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
853 {
854 tree a = TREE_VALUE (probe);
855 tree b = TREE_VALUE (t2);
856
857 if (comp_except_types (a, b, exact))
858 {
859 if (probe == base && exact)
860 base = TREE_CHAIN (probe);
861 length++;
862 break;
863 }
864 }
865 if (probe == NULL_TREE)
866 return false;
867 }
868 return !exact || base == NULL_TREE || length == list_length (t1);
869}
870
871/* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
872 [] can match [size]. */
873
874static bool
875comp_array_types (tree t1, tree t2, bool allow_redeclaration)
876{
877 tree d1;
878 tree d2;
879 tree max1, max2;
880
881 if (t1 == t2)
882 return true;
883
884 /* The type of the array elements must be the same. */
885 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
886 return false;
887
888 d1 = TYPE_DOMAIN (t1);
889 d2 = TYPE_DOMAIN (t2);
890
891 if (d1 == d2)
892 return true;
893
894 /* If one of the arrays is dimensionless, and the other has a
895 dimension, they are of different types. However, it is valid to
896 write:
897
898 extern int a[];
899 int a[3];
900
901 by [basic.link]:
902
903 declarations for an array object can specify
904 array types that differ by the presence or absence of a major
905 array bound (_dcl.array_). */
906 if (!d1 || !d2)
907 return allow_redeclaration;
908
909 /* Check that the dimensions are the same. */
910
911 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
912 return false;
913 max1 = TYPE_MAX_VALUE (d1);
914 max2 = TYPE_MAX_VALUE (d2);
915 if (processing_template_decl && !abi_version_at_least (2)
916 && !value_dependent_expression_p (max1)
917 && !value_dependent_expression_p (max2))
918 {
919 /* With abi-1 we do not fold non-dependent array bounds, (and
920 consequently mangle them incorrectly). We must therefore
921 fold them here, to verify the domains have the same
922 value. */
923 max1 = fold (max1);
924 max2 = fold (max2);
925 }
926
927 if (!cp_tree_equal (max1, max2))
928 return false;
929
930 return true;
931}
932
933/* Return true if T1 and T2 are related as allowed by STRICT. STRICT
934 is a bitwise-or of the COMPARE_* flags. */
935
936bool
937comptypes (tree t1, tree t2, int strict)
938{
939 if (t1 == t2)
940 return true;
941
942 /* Suppress errors caused by previously reported errors. */
943 if (t1 == error_mark_node || t2 == error_mark_node)
944 return false;
945
946 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
947
948 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
949 current instantiation. */
950 if (TREE_CODE (t1) == TYPENAME_TYPE)
951 {
952 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
953
954 if (resolved != error_mark_node)
955 t1 = resolved;
956 }
957
958 if (TREE_CODE (t2) == TYPENAME_TYPE)
959 {
960 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
961
962 if (resolved != error_mark_node)
963 t2 = resolved;
964 }
965
966 /* If either type is the internal version of sizetype, use the
967 language version. */
968 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
969 && TYPE_ORIG_SIZE_TYPE (t1))
970 t1 = TYPE_ORIG_SIZE_TYPE (t1);
971
972 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
973 && TYPE_ORIG_SIZE_TYPE (t2))
974 t2 = TYPE_ORIG_SIZE_TYPE (t2);
975
976 if (TYPE_PTRMEMFUNC_P (t1))
977 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
978 if (TYPE_PTRMEMFUNC_P (t2))
979 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
980
981 /* Different classes of types can't be compatible. */
982 if (TREE_CODE (t1) != TREE_CODE (t2))
983 return false;
984
985 /* Qualifiers must match. For array types, we will check when we
986 recur on the array element types. */
987 if (TREE_CODE (t1) != ARRAY_TYPE
988 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
989 return false;
990 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
991 return false;
992
993 /* Allow for two different type nodes which have essentially the same
994 definition. Note that we already checked for equality of the type
995 qualifiers (just above). */
996
997 if (TREE_CODE (t1) != ARRAY_TYPE
998 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
999 return true;
1000
1001 /* Compare the types. Break out if they could be the same. */
1002 switch (TREE_CODE (t1))
1003 {
1004 case TEMPLATE_TEMPLATE_PARM:
1005 case BOUND_TEMPLATE_TEMPLATE_PARM:
1006 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1007 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1008 return false;
1009 if (!comp_template_parms
1010 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1011 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1012 return false;
1013 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1014 break;
1015 /* Don't check inheritance. */
1016 strict = COMPARE_STRICT;
1017 /* Fall through. */
1018
1019 case RECORD_TYPE:
1020 case UNION_TYPE:
1021 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1022 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1023 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1024 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1025 break;
1026
1027 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1028 break;
1029 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1030 break;
1031
1032 return false;
1033
1034 case OFFSET_TYPE:
1035 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1036 strict & ~COMPARE_REDECLARATION))
1037 return false;
1038 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 return false;
1040 break;
1041
1042 case POINTER_TYPE:
1043 case REFERENCE_TYPE:
1044 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1045 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1046 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1047 return false;
1048 break;
1049
1050 case METHOD_TYPE:
1051 case FUNCTION_TYPE:
1052 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1053 return false;
1054 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1055 return false;
1056 break;
1057
1058 case ARRAY_TYPE:
1059 /* Target types must match incl. qualifiers. */
1060 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1061 return false;
1062 break;
1063
1064 case TEMPLATE_TYPE_PARM:
1065 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1066 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1067 return false;
1068 break;
1069
1070 case TYPENAME_TYPE:
1071 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1072 TYPENAME_TYPE_FULLNAME (t2)))
1073 return false;
1074 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1075 return false;
1076 break;
1077
1078 case UNBOUND_CLASS_TEMPLATE:
1079 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1080 return false;
1081 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1082 return false;
1083 break;
1084
1085 case COMPLEX_TYPE:
1086 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 return false;
1088 break;
1089
1090 case VECTOR_TYPE:
1091 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1092 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1093 return false;
1094 break;
1095
1096 default:
1097 return false;
1098 }
1099
1100 /* If we get here, we know that from a target independent POV the
1101 types are the same. Make sure the target attributes are also
1102 the same. */
1103 return targetm.comp_type_attributes (t1, t2);
1104}
1105
1106/* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1107
1108bool
1109at_least_as_qualified_p (tree type1, tree type2)
1110{
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1113
1114 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1115 return (q1 & q2) == q2;
1116}
1117
1118/* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1119 more cv-qualified that TYPE1, and 0 otherwise. */
1120
1121int
1122comp_cv_qualification (tree type1, tree type2)
1123{
1124 int q1 = cp_type_quals (type1);
1125 int q2 = cp_type_quals (type2);
1126
1127 if (q1 == q2)
1128 return 0;
1129
1130 if ((q1 & q2) == q2)
1131 return 1;
1132 else if ((q1 & q2) == q1)
1133 return -1;
1134
1135 return 0;
1136}
1137
1138/* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1139 subset of the cv-qualification signature of TYPE2, and the types
1140 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1141
1142int
1143comp_cv_qual_signature (tree type1, tree type2)
1144{
1145 if (comp_ptr_ttypes_real (type2, type1, -1))
1146 return 1;
1147 else if (comp_ptr_ttypes_real (type1, type2, -1))
1148 return -1;
1149 else
1150 return 0;
1151}
1152
1153/* If two types share a common base type, return that basetype.
1154 If there is not a unique most-derived base type, this function
1155 returns ERROR_MARK_NODE. */
1156
1157static tree
1158common_base_type (tree tt1, tree tt2)
1159{
1160 tree best = NULL_TREE;
1161 int i;
1162
1163 /* If one is a baseclass of another, that's good enough. */
1164 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1165 return tt1;
1166 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1167 return tt2;
1168
1169 /* Otherwise, try to find a unique baseclass of TT1
1170 that is shared by TT2, and follow that down. */
1171 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1172 {
1173 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1174 tree trial = common_base_type (basetype, tt2);
1175
1176 if (trial)
1177 {
1178 if (trial == error_mark_node)
1179 return trial;
1180 if (best == NULL_TREE)
1181 best = trial;
1182 else if (best != trial)
1183 return error_mark_node;
1184 }
1185 }
1186
1187 /* Same for TT2. */
1188 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1189 {
1190 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1191 tree trial = common_base_type (tt1, basetype);
1192
1193 if (trial)
1194 {
1195 if (trial == error_mark_node)
1196 return trial;
1197 if (best == NULL_TREE)
1198 best = trial;
1199 else if (best != trial)
1200 return error_mark_node;
1201 }
1202 }
1203 return best;
1204}
1205
1206/* Subroutines of `comptypes'. */
1207
1208/* Return true if two parameter type lists PARMS1 and PARMS2 are
1209 equivalent in the sense that functions with those parameter types
1210 can have equivalent types. The two lists must be equivalent,
1211 element by element. */
1212
1213bool
1214compparms (tree parms1, tree parms2)
1215{
1216 tree t1, t2;
1217
1218 /* An unspecified parmlist matches any specified parmlist
1219 whose argument types don't need default promotions. */
1220
1221 for (t1 = parms1, t2 = parms2;
1222 t1 || t2;
1223 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1224 {
1225 /* If one parmlist is shorter than the other,
1226 they fail to match. */
1227 if (!t1 || !t2)
1228 return false;
1229 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1230 return false;
1231 }
1232 return true;
1233}
1234
1235
1236/* Process a sizeof or alignof expression where the operand is a
1237 type. */
1238
1239tree
1240cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1241{
1242 tree value;
1243 bool dependent_p;
1244
1245 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1246 if (type == error_mark_node)
1247 return error_mark_node;
1248
1249 type = non_reference (type);
1250 if (TREE_CODE (type) == METHOD_TYPE)
1251 {
1252 if (complain && (pedantic || warn_pointer_arith))
1253 pedwarn ("invalid application of %qs to a member function",
1254 operator_name_info[(int) op].name);
1255 value = size_one_node;
1256 }
1257
1258 dependent_p = dependent_type_p (type);
1259 if (!dependent_p)
1260 complete_type (type);
1261 if (dependent_p
1262 /* VLA types will have a non-constant size. In the body of an
1263 uninstantiated template, we don't need to try to compute the
1264 value, because the sizeof expression is not an integral
1265 constant expression in that case. And, if we do try to
1266 compute the value, we'll likely end up with SAVE_EXPRs, which
1267 the template substitution machinery does not expect to see. */
1268 || (processing_template_decl
1269 && COMPLETE_TYPE_P (type)
1270 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1271 {
1272 value = build_min (op, size_type_node, type);
1273 TREE_READONLY (value) = 1;
1274 return value;
1275 }
1276
1277 return c_sizeof_or_alignof_type (complete_type (type),
1278 op == SIZEOF_EXPR,
1279 complain);
1280}
1281
1282/* Process a sizeof expression where the operand is an expression. */
1283
1284static tree
1285cxx_sizeof_expr (tree e)
1286{
1287 if (e == error_mark_node)
1288 return error_mark_node;
1289
1290 if (processing_template_decl)
1291 {
1292 e = build_min (SIZEOF_EXPR, size_type_node, e);
1293 TREE_SIDE_EFFECTS (e) = 0;
1294 TREE_READONLY (e) = 1;
1295
1296 return e;
1297 }
1298
1299 if (TREE_CODE (e) == COMPONENT_REF
1300 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1301 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1302 {
1303 error ("invalid application of %<sizeof%> to a bit-field");
1304 e = char_type_node;
1305 }
1306 else if (is_overloaded_fn (e))
1307 {
1308 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1309 "function type");
1310 e = char_type_node;
1311 }
1312 else if (type_unknown_p (e))
1313 {
1314 cxx_incomplete_type_error (e, TREE_TYPE (e));
1315 e = char_type_node;
1316 }
1317 else
1318 e = TREE_TYPE (e);
1319
1320 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1321}
1322
1323/* Implement the __alignof keyword: Return the minimum required
1324 alignment of E, measured in bytes. For VAR_DECL's and
1325 FIELD_DECL's return DECL_ALIGN (which can be set from an
1326 "aligned" __attribute__ specification). */
1327
1328static tree
1329cxx_alignof_expr (tree e)
1330{
1331 tree t;
1332
1333 if (e == error_mark_node)
1334 return error_mark_node;
1335
1336 if (processing_template_decl)
1337 {
1338 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1339 TREE_SIDE_EFFECTS (e) = 0;
1340 TREE_READONLY (e) = 1;
1341
1342 return e;
1343 }
1344
1345 if (TREE_CODE (e) == VAR_DECL)
1346 t = size_int (DECL_ALIGN_UNIT (e));
1347 else if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1349 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1350 {
1351 error ("invalid application of %<__alignof%> to a bit-field");
1352 t = size_one_node;
1353 }
1354 else if (TREE_CODE (e) == COMPONENT_REF
1355 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1356 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1357 else if (is_overloaded_fn (e))
1358 {
1359 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1360 "function type");
1361 if (TREE_CODE (e) == FUNCTION_DECL)
1362 t = size_int (DECL_ALIGN_UNIT (e));
1363 else
1364 t = size_one_node;
1365 }
1366 else if (type_unknown_p (e))
1367 {
1368 cxx_incomplete_type_error (e, TREE_TYPE (e));
1369 t = size_one_node;
1370 }
1371 else
1372 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1373
1374 return fold_convert (size_type_node, t);
1375}
1376
1377/* Process a sizeof or alignof expression E with code OP where the operand
1378 is an expression. */
1379
1380tree
1381cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1382{
1383 if (op == SIZEOF_EXPR)
1384 return cxx_sizeof_expr (e);
1385 else
1386 return cxx_alignof_expr (e);
1387}
1388
1389/* EXPR is being used in a context that is not a function call.
1390 Enforce:
1391
1392 [expr.ref]
1393
1394 The expression can be used only as the left-hand operand of a
1395 member function call.
1396
1397 [expr.mptr.operator]
1398
1399 If the result of .* or ->* is a function, then that result can be
1400 used only as the operand for the function call operator ().
1401
1402 by issuing an error message if appropriate. Returns true iff EXPR
1403 violates these rules. */
1404
1405bool
1406invalid_nonstatic_memfn_p (tree expr)
1407{
1408 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1409 {
1410 error ("invalid use of non-static member function");
1411 return true;
1412 }
1413 return false;
1414}
1415
1416/* If EXP is a reference to a bitfield, and the type of EXP does not
1417 match the declared type of the bitfield, return the declared type
1418 of the bitfield. Otherwise, return NULL_TREE. */
1419
1420tree
1421is_bitfield_expr_with_lowered_type (tree exp)
1422{
1423 switch (TREE_CODE (exp))
1424 {
1425 case COND_EXPR:
1426 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1427 return NULL_TREE;
1428 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1429
1430 case COMPOUND_EXPR:
1431 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1432
1433 case MODIFY_EXPR:
1434 case SAVE_EXPR:
1435 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1436
1437 case COMPONENT_REF:
1438 {
1439 tree field;
1440
1441 field = TREE_OPERAND (exp, 1);
1442 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1443 return NULL_TREE;
1444 if (same_type_ignoring_top_level_qualifiers_p
1445 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1446 return NULL_TREE;
1447 return DECL_BIT_FIELD_TYPE (field);
1448 }
1449
1450 default:
1451 return NULL_TREE;
1452 }
1453}
1454
1455/* Like is_bitfield_with_lowered_type, except that if EXP is not a
1456 bitfield with a lowered type, the type of EXP is returned, rather
1457 than NULL_TREE. */
1458
1459tree
1460unlowered_expr_type (tree exp)
1461{
1462 tree type;
1463
1464 type = is_bitfield_expr_with_lowered_type (exp);
1465 if (!type)
1466 type = TREE_TYPE (exp);
1467
1468 return type;
1469}
1470
1471/* Perform the conversions in [expr] that apply when an lvalue appears
1472 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1473 function-to-pointer conversions. In addition, manifest constants
1474 are replaced by their values, and bitfield references are converted
1475 to their declared types.
1476
1477 Although the returned value is being used as an rvalue, this
1478 function does not wrap the returned expression in a
1479 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1480 that the return value is no longer an lvalue. */
1481
1482tree
1483decay_conversion (tree exp)
1484{
1485 tree type;
1486 enum tree_code code;
1487
1488 type = TREE_TYPE (exp);
1489 if (type == error_mark_node)
1490 return error_mark_node;
1491
1492 if (type_unknown_p (exp))
1493 {
1494 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1495 return error_mark_node;
1496 }
1497
1498 exp = decl_constant_value (exp);
1499 if (error_operand_p (exp))
1500 return error_mark_node;
1501
1502 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1503 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1504 code = TREE_CODE (type);
1505 if (code == VOID_TYPE)
1506 {
1507 error ("void value not ignored as it ought to be");
1508 return error_mark_node;
1509 }
1510 if (invalid_nonstatic_memfn_p (exp))
1511 return error_mark_node;
1512 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1513 return build_unary_op (ADDR_EXPR, exp, 0);
1514 if (code == ARRAY_TYPE)
1515 {
1516 tree adr;
1517 tree ptrtype;
1518
1519 if (TREE_CODE (exp) == INDIRECT_REF)
1520 return build_nop (build_pointer_type (TREE_TYPE (type)),
1521 TREE_OPERAND (exp, 0));
1522
1523 if (TREE_CODE (exp) == COMPOUND_EXPR)
1524 {
1525 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1526 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1527 TREE_OPERAND (exp, 0), op1);
1528 }
1529
1530 if (!lvalue_p (exp)
1531 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1532 {
1533 error ("invalid use of non-lvalue array");
1534 return error_mark_node;
1535 }
1536
1537 ptrtype = build_pointer_type (TREE_TYPE (type));
1538
1539 if (TREE_CODE (exp) == VAR_DECL)
1540 {
1541 if (!cxx_mark_addressable (exp))
1542 return error_mark_node;
1543 adr = build_nop (ptrtype, build_address (exp));
1544 return adr;
1545 }
1546 /* This way is better for a COMPONENT_REF since it can
1547 simplify the offset for a component. */
1548 adr = build_unary_op (ADDR_EXPR, exp, 1);
1549 return cp_convert (ptrtype, adr);
1550 }
1551
1552 /* If a bitfield is used in a context where integral promotion
1553 applies, then the caller is expected to have used
1554 default_conversion. That function promotes bitfields correctly
1555 before calling this function. At this point, if we have a
1556 bitfield referenced, we may assume that is not subject to
1557 promotion, and that, therefore, the type of the resulting rvalue
1558 is the declared type of the bitfield. */
1559 exp = convert_bitfield_to_declared_type (exp);
1560
1561 /* We do not call rvalue() here because we do not want to wrap EXP
1562 in a NON_LVALUE_EXPR. */
1563
1564 /* [basic.lval]
1565
1566 Non-class rvalues always have cv-unqualified types. */
1567 type = TREE_TYPE (exp);
1568 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1569 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1570
1571 return exp;
1572}
1573
1574/* Perform prepatory conversions, as part of the "usual arithmetic
1575 conversions". In particular, as per [expr]:
1576
1577 Whenever an lvalue expression appears as an operand of an
1578 operator that expects the rvalue for that operand, the
1579 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1580 standard conversions are applied to convert the expression to an
1581 rvalue.
1582
1583 In addition, we perform integral promotions here, as those are
1584 applied to both operands to a binary operator before determining
1585 what additional conversions should apply. */
1586
1587tree
1588default_conversion (tree exp)
1589{
1590 /* Perform the integral promotions first so that bitfield
1591 expressions (which may promote to "int", even if the bitfield is
1592 declared "unsigned") are promoted correctly. */
1593 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1594 exp = perform_integral_promotions (exp);
1595 /* Perform the other conversions. */
1596 exp = decay_conversion (exp);
1597
1598 return exp;
1599}
1600
1601/* EXPR is an expression with an integral or enumeration type.
1602 Perform the integral promotions in [conv.prom], and return the
1603 converted value. */
1604
1605tree
1606perform_integral_promotions (tree expr)
1607{
1608 tree type;
1609 tree promoted_type;
1610
1611 /* [conv.prom]
1612
1613 If the bitfield has an enumerated type, it is treated as any
1614 other value of that type for promotion purposes. */
1615 type = is_bitfield_expr_with_lowered_type (expr);
1616 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1617 type = TREE_TYPE (expr);
1618 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1619 promoted_type = type_promotes_to (type);
1620 if (type != promoted_type)
1621 expr = cp_convert (promoted_type, expr);
1622 return expr;
1623}
1624
1625/* Take the address of an inline function without setting TREE_ADDRESSABLE
1626 or TREE_USED. */
1627
1628tree
1629inline_conversion (tree exp)
1630{
1631 if (TREE_CODE (exp) == FUNCTION_DECL)
1632 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1633
1634 return exp;
1635}
1636
1637/* Returns nonzero iff exp is a STRING_CST or the result of applying
1638 decay_conversion to one. */
1639
1640int
1641string_conv_p (tree totype, tree exp, int warn)
1642{
1643 tree t;
1644
1645 if (TREE_CODE (totype) != POINTER_TYPE)
1646 return 0;
1647
1648 t = TREE_TYPE (totype);
1649 if (!same_type_p (t, char_type_node)
1650 && !same_type_p (t, wchar_type_node))
1651 return 0;
1652
1653 if (TREE_CODE (exp) == STRING_CST)
1654 {
1655 /* Make sure that we don't try to convert between char and wchar_t. */
1656 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1657 return 0;
1658 }
1659 else
1660 {
1661 /* Is this a string constant which has decayed to 'const char *'? */
1662 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1663 if (!same_type_p (TREE_TYPE (exp), t))
1664 return 0;
1665 STRIP_NOPS (exp);
1666 if (TREE_CODE (exp) != ADDR_EXPR
1667 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1668 return 0;
1669 }
1670
1671 /* This warning is not very useful, as it complains about printf. */
1672 if (warn)
1673 warning (OPT_Wwrite_strings,
1674 "deprecated conversion from string constant to %qT",
1675 totype);
1676
1677 return 1;
1678}
1679
1680/* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1681 can, for example, use as an lvalue. This code used to be in
1682 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1683 expressions, where we're dealing with aggregates. But now it's again only
1684 called from unary_complex_lvalue. The case (in particular) that led to
1685 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1686 get it there. */
1687
1688static tree
1689rationalize_conditional_expr (enum tree_code code, tree t)
1690{
1691 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1692 the first operand is always the one to be used if both operands
1693 are equal, so we know what conditional expression this used to be. */
1694 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1695 {
1696 tree op0 = TREE_OPERAND (t, 0);
1697 tree op1 = TREE_OPERAND (t, 1);
1698
1699 /* The following code is incorrect if either operand side-effects. */
1700 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1701 && !TREE_SIDE_EFFECTS (op1));
1702 return
1703 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1704 ? LE_EXPR : GE_EXPR),
1705 op0, TREE_CODE (op0),
1706 op1, TREE_CODE (op1),
1707 /*overloaded_p=*/NULL),
1708 build_unary_op (code, op0, 0),
1709 build_unary_op (code, op1, 0));
1710 }
1711
1712 return
1713 build_conditional_expr (TREE_OPERAND (t, 0),
1714 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1715 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1716}
1717
1718/* Given the TYPE of an anonymous union field inside T, return the
1719 FIELD_DECL for the field. If not found return NULL_TREE. Because
1720 anonymous unions can nest, we must also search all anonymous unions
1721 that are directly reachable. */
1722
1723tree
1724lookup_anon_field (tree t, tree type)
1725{
1726 tree field;
1727
1728 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1729 {
1730 if (TREE_STATIC (field))
1731 continue;
1732 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1733 continue;
1734
1735 /* If we find it directly, return the field. */
1736 if (DECL_NAME (field) == NULL_TREE
1737 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1738 {
1739 return field;
1740 }
1741
1742 /* Otherwise, it could be nested, search harder. */
1743 if (DECL_NAME (field) == NULL_TREE
1744 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1745 {
1746 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1747 if (subfield)
1748 return subfield;
1749 }
1750 }
1751 return NULL_TREE;
1752}
1753
1754/* Build an expression representing OBJECT.MEMBER. OBJECT is an
1755 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1756 non-NULL, it indicates the path to the base used to name MEMBER.
1757 If PRESERVE_REFERENCE is true, the expression returned will have
1758 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1759 returned will have the type referred to by the reference.
1760
1761 This function does not perform access control; that is either done
1762 earlier by the parser when the name of MEMBER is resolved to MEMBER
1763 itself, or later when overload resolution selects one of the
1764 functions indicated by MEMBER. */
1765
1766tree
1767build_class_member_access_expr (tree object, tree member,
1768 tree access_path, bool preserve_reference)
1769{
1770 tree object_type;
1771 tree member_scope;
1772 tree result = NULL_TREE;
1773
1774 if (error_operand_p (object) || error_operand_p (member))
1775 return error_mark_node;
1776
1777 gcc_assert (DECL_P (member) || BASELINK_P (member));
1778
1779 /* [expr.ref]
1780
1781 The type of the first expression shall be "class object" (of a
1782 complete type). */
1783 object_type = TREE_TYPE (object);
1784 if (!currently_open_class (object_type)
1785 && !complete_type_or_else (object_type, object))
1786 return error_mark_node;
1787 if (!CLASS_TYPE_P (object_type))
1788 {
1789 error ("request for member %qD in %qE, which is of non-class type %qT",
1790 member, object, object_type);
1791 return error_mark_node;
1792 }
1793
1794 /* The standard does not seem to actually say that MEMBER must be a
1795 member of OBJECT_TYPE. However, that is clearly what is
1796 intended. */
1797 if (DECL_P (member))
1798 {
1799 member_scope = DECL_CLASS_CONTEXT (member);
1800 mark_used (member);
1801 if (TREE_DEPRECATED (member))
1802 warn_deprecated_use (member);
1803 }
1804 else
1805 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1806 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1807 presently be the anonymous union. Go outwards until we find a
1808 type related to OBJECT_TYPE. */
1809 while (ANON_AGGR_TYPE_P (member_scope)
1810 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1811 object_type))
1812 member_scope = TYPE_CONTEXT (member_scope);
1813 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1814 {
1815 if (TREE_CODE (member) == FIELD_DECL)
1816 error ("invalid use of nonstatic data member %qE", member);
1817 else
1818 error ("%qD is not a member of %qT", member, object_type);
1819 return error_mark_node;
1820 }
1821
1822 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1823 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1824 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1825 {
1826 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1827 if (temp)
1828 object = build_indirect_ref (temp, NULL);
1829 }
1830
1831 /* In [expr.ref], there is an explicit list of the valid choices for
1832 MEMBER. We check for each of those cases here. */
1833 if (TREE_CODE (member) == VAR_DECL)
1834 {
1835 /* A static data member. */
1836 result = member;
1837 /* If OBJECT has side-effects, they are supposed to occur. */
1838 if (TREE_SIDE_EFFECTS (object))
1839 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1840 }
1841 else if (TREE_CODE (member) == FIELD_DECL)
1842 {
1843 /* A non-static data member. */
1844 bool null_object_p;
1845 int type_quals;
1846 tree member_type;
1847
1848 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1849 && integer_zerop (TREE_OPERAND (object, 0)));
1850
1851 /* Convert OBJECT to the type of MEMBER. */
1852 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1853 TYPE_MAIN_VARIANT (member_scope)))
1854 {
1855 tree binfo;
1856 base_kind kind;
1857
1858 binfo = lookup_base (access_path ? access_path : object_type,
1859 member_scope, ba_unique, &kind);
1860 if (binfo == error_mark_node)
1861 return error_mark_node;
1862
1863 /* It is invalid to try to get to a virtual base of a
1864 NULL object. The most common cause is invalid use of
1865 offsetof macro. */
1866 if (null_object_p && kind == bk_via_virtual)
1867 {
1868 error ("invalid access to non-static data member %qD of "
1869 "NULL object",
1870 member);
1871 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1872 return error_mark_node;
1873 }
1874
1875 /* Convert to the base. */
1876 object = build_base_path (PLUS_EXPR, object, binfo,
1877 /*nonnull=*/1);
1878 /* If we found the base successfully then we should be able
1879 to convert to it successfully. */
1880 gcc_assert (object != error_mark_node);
1881 }
1882
1883 /* Complain about other invalid uses of offsetof, even though they will
1884 give the right answer. Note that we complain whether or not they
1885 actually used the offsetof macro, since there's no way to know at this
1886 point. So we just give a warning, instead of a pedwarn. */
1887 /* Do not produce this warning for base class field references, because
1888 we know for a fact that didn't come from offsetof. This does occur
1889 in various testsuite cases where a null object is passed where a
1890 vtable access is required. */
1891 if (null_object_p && warn_invalid_offsetof
1892 && CLASSTYPE_NON_POD_P (object_type)
1893 && !DECL_FIELD_IS_BASE (member)
1894 && !skip_evaluation)
1895 {
1896 warning (0, "invalid access to non-static data member %qD of NULL object",
1897 member);
1898 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1899 }
1900
1901 /* If MEMBER is from an anonymous aggregate, we have converted
1902 OBJECT so that it refers to the class containing the
1903 anonymous union. Generate a reference to the anonymous union
1904 itself, and recur to find MEMBER. */
1905 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1906 /* When this code is called from build_field_call, the
1907 object already has the type of the anonymous union.
1908 That is because the COMPONENT_REF was already
1909 constructed, and was then disassembled before calling
1910 build_field_call. After the function-call code is
1911 cleaned up, this waste can be eliminated. */
1912 && (!same_type_ignoring_top_level_qualifiers_p
1913 (TREE_TYPE (object), DECL_CONTEXT (member))))
1914 {
1915 tree anonymous_union;
1916
1917 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1918 DECL_CONTEXT (member));
1919 object = build_class_member_access_expr (object,
1920 anonymous_union,
1921 /*access_path=*/NULL_TREE,
1922 preserve_reference);
1923 }
1924
1925 /* Compute the type of the field, as described in [expr.ref]. */
1926 type_quals = TYPE_UNQUALIFIED;
1927 member_type = TREE_TYPE (member);
1928 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1929 {
1930 type_quals = (cp_type_quals (member_type)
1931 | cp_type_quals (object_type));
1932
1933 /* A field is const (volatile) if the enclosing object, or the
1934 field itself, is const (volatile). But, a mutable field is
1935 not const, even within a const object. */
1936 if (DECL_MUTABLE_P (member))
1937 type_quals &= ~TYPE_QUAL_CONST;
1938 member_type = cp_build_qualified_type (member_type, type_quals);
1939 }
1940
1941 result = build3 (COMPONENT_REF, member_type, object, member,
1942 NULL_TREE);
1943 result = fold_if_not_in_template (result);
1944
1945 /* Mark the expression const or volatile, as appropriate. Even
1946 though we've dealt with the type above, we still have to mark the
1947 expression itself. */
1948 if (type_quals & TYPE_QUAL_CONST)
1949 TREE_READONLY (result) = 1;
1950 if (type_quals & TYPE_QUAL_VOLATILE)
1951 TREE_THIS_VOLATILE (result) = 1;
1952 }
1953 else if (BASELINK_P (member))
1954 {
1955 /* The member is a (possibly overloaded) member function. */
1956 tree functions;
1957 tree type;
1958
1959 /* If the MEMBER is exactly one static member function, then we
1960 know the type of the expression. Otherwise, we must wait
1961 until overload resolution has been performed. */
1962 functions = BASELINK_FUNCTIONS (member);
1963 if (TREE_CODE (functions) == FUNCTION_DECL
1964 && DECL_STATIC_FUNCTION_P (functions))
1965 type = TREE_TYPE (functions);
1966 else
1967 type = unknown_type_node;
1968 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1969 base. That will happen when the function is called. */
1970 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1971 }
1972 else if (TREE_CODE (member) == CONST_DECL)
1973 {
1974 /* The member is an enumerator. */
1975 result = member;
1976 /* If OBJECT has side-effects, they are supposed to occur. */
1977 if (TREE_SIDE_EFFECTS (object))
1978 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1979 object, result);
1980 }
1981 else
1982 {
1983 error ("invalid use of %qD", member);
1984 return error_mark_node;
1985 }
1986
1987 if (!preserve_reference)
1988 /* [expr.ref]
1989
1990 If E2 is declared to have type "reference to T", then ... the
1991 type of E1.E2 is T. */
1992 result = convert_from_reference (result);
1993
1994 return result;
1995}
1996
1997/* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1998 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1999
2000static tree
2001lookup_destructor (tree object, tree scope, tree dtor_name)
2002{
2003 tree object_type = TREE_TYPE (object);
2004 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2005 tree expr;
2006
2007 if (scope && !check_dtor_name (scope, dtor_type))
2008 {
2009 error ("qualified type %qT does not match destructor name ~%qT",
2010 scope, dtor_type);
2011 return error_mark_node;
2012 }
2013 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2014 {
2015 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2016 TYPE_MAIN_VARIANT (object_type), dtor_type);
2017 return error_mark_node;
2018 }
2019 expr = lookup_member (dtor_type, complete_dtor_identifier,
2020 /*protect=*/1, /*want_type=*/false);
2021 expr = (adjust_result_of_qualified_name_lookup
2022 (expr, dtor_type, object_type));
2023 return expr;
2024}
2025
2026/* An expression of the form "A::template B" has been resolved to
2027 DECL. Issue a diagnostic if B is not a template or template
2028 specialization. */
2029
2030void
2031check_template_keyword (tree decl)
2032{
2033 /* The standard says:
2034
2035 [temp.names]
2036
2037 If a name prefixed by the keyword template is not a member
2038 template, the program is ill-formed.
2039
2040 DR 228 removed the restriction that the template be a member
2041 template.
2042
2043 DR 96, if accepted would add the further restriction that explicit
2044 template arguments must be provided if the template keyword is
2045 used, but, as of 2005-10-16, that DR is still in "drafting". If
2046 this DR is accepted, then the semantic checks here can be
2047 simplified, as the entity named must in fact be a template
2048 specialization, rather than, as at present, a set of overloaded
2049 functions containing at least one template function. */
2050 if (TREE_CODE (decl) != TEMPLATE_DECL
2051 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2052 {
2053 if (!is_overloaded_fn (decl))
2054 pedwarn ("%qD is not a template", decl);
2055 else
2056 {
2057 tree fns;
2058 fns = decl;
2059 if (BASELINK_P (fns))
2060 fns = BASELINK_FUNCTIONS (fns);
2061 while (fns)
2062 {
2063 tree fn = OVL_CURRENT (fns);
2064 if (TREE_CODE (fn) == TEMPLATE_DECL
2065 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2066 break;
2067 if (TREE_CODE (fn) == FUNCTION_DECL
2068 && DECL_USE_TEMPLATE (fn)
2069 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2070 break;
2071 fns = OVL_NEXT (fns);
2072 }
2073 if (!fns)
2074 pedwarn ("%qD is not a template", decl);
2075 }
2076 }
2077}
2078
2079/* This function is called by the parser to process a class member
2080 access expression of the form OBJECT.NAME. NAME is a node used by
2081 the parser to represent a name; it is not yet a DECL. It may,
2082 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2083 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2084 there is no reason to do the lookup twice, so the parser keeps the
2085 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2086 be a template via the use of the "A::template B" syntax. */
2087
2088tree
2089finish_class_member_access_expr (tree object, tree name, bool template_p)
2090{
2091 tree expr;
2092 tree object_type;
2093 tree member;
2094 tree access_path = NULL_TREE;
2095 tree orig_object = object;
2096 tree orig_name = name;
2097
2098 if (object == error_mark_node || name == error_mark_node)
2099 return error_mark_node;
2100
2101 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2102 if (!objc_is_public (object, name))
2103 return error_mark_node;
2104
2105 object_type = TREE_TYPE (object);
2106
2107 if (processing_template_decl)
2108 {
2109 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2110 dependent_type_p (object_type)
2111 /* If NAME is just an IDENTIFIER_NODE, then the expression
2112 is dependent. */
2113 || TREE_CODE (object) == IDENTIFIER_NODE
2114 /* If NAME is "f<args>", where either 'f' or 'args' is
2115 dependent, then the expression is dependent. */
2116 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2117 && dependent_template_id_p (TREE_OPERAND (name, 0),
2118 TREE_OPERAND (name, 1)))
2119 /* If NAME is "T::X" where "T" is dependent, then the
2120 expression is dependent. */
2121 || (TREE_CODE (name) == SCOPE_REF
2122 && TYPE_P (TREE_OPERAND (name, 0))
2123 && dependent_type_p (TREE_OPERAND (name, 0))))
2124 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2125 object = build_non_dependent_expr (object);
2126 }
2127
2128 /* [expr.ref]
2129
2130 The type of the first expression shall be "class object" (of a
2131 complete type). */
2132 if (!currently_open_class (object_type)
2133 && !complete_type_or_else (object_type, object))
2134 return error_mark_node;
2135 if (!CLASS_TYPE_P (object_type))
2136 {
2137 error ("request for member %qD in %qE, which is of non-class type %qT",
2138 name, object, object_type);
2139 return error_mark_node;
2140 }
2141
2142 if (BASELINK_P (name))
2143 /* A member function that has already been looked up. */
2144 member = name;
2145 else
2146 {
2147 bool is_template_id = false;
2148 tree template_args = NULL_TREE;
2149 tree scope;
2150
2151 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2152 {
2153 is_template_id = true;
2154 template_args = TREE_OPERAND (name, 1);
2155 name = TREE_OPERAND (name, 0);
2156
2157 if (TREE_CODE (name) == OVERLOAD)
2158 name = DECL_NAME (get_first_fn (name));
2159 else if (DECL_P (name))
2160 name = DECL_NAME (name);
2161 }
2162
2163 if (TREE_CODE (name) == SCOPE_REF)
2164 {
2165 /* A qualified name. The qualifying class or namespace `S'
2166 has already been looked up; it is either a TYPE or a
2167 NAMESPACE_DECL. */
2168 scope = TREE_OPERAND (name, 0);
2169 name = TREE_OPERAND (name, 1);
2170
2171 /* If SCOPE is a namespace, then the qualified name does not
2172 name a member of OBJECT_TYPE. */
2173 if (TREE_CODE (scope) == NAMESPACE_DECL)
2174 {
2175 error ("%<%D::%D%> is not a member of %qT",
2176 scope, name, object_type);
2177 return error_mark_node;
2178 }
2179
2180 gcc_assert (CLASS_TYPE_P (scope));
2181 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2182 || TREE_CODE (name) == BIT_NOT_EXPR);
2183
2184 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2185 access_path = lookup_base (object_type, scope, ba_check, NULL);
2186 if (access_path == error_mark_node)
2187 return error_mark_node;
2188 if (!access_path)
2189 {
2190 error ("%qT is not a base of %qT", scope, object_type);
2191 return error_mark_node;
2192 }
2193 }
2194 else
2195 {
2196 scope = NULL_TREE;
2197 access_path = object_type;
2198 }
2199
2200 if (TREE_CODE (name) == BIT_NOT_EXPR)
2201 member = lookup_destructor (object, scope, name);
2202 else
2203 {
2204 /* Look up the member. */
2205 member = lookup_member (access_path, name, /*protect=*/1,
2206 /*want_type=*/false);
2207 if (member == NULL_TREE)
2208 {
2209 error ("%qD has no member named %qE", object_type, name);
2210 return error_mark_node;
2211 }
2212 if (member == error_mark_node)
2213 return error_mark_node;
2214 }
2215
2216 if (is_template_id)
2217 {
2218 tree template = member;
2219
2220 if (BASELINK_P (template))
2221 template = lookup_template_function (template, template_args);
2222 else
2223 {
2224 error ("%qD is not a member template function", name);
2225 return error_mark_node;
2226 }
2227 }
2228 }
2229
2230 if (TREE_DEPRECATED (member))
2231 warn_deprecated_use (member);
2232
2233 if (template_p)
2234 check_template_keyword (member);
2235
2236 expr = build_class_member_access_expr (object, member, access_path,
2237 /*preserve_reference=*/false);
2238 if (processing_template_decl && expr != error_mark_node)
2239 {
2240 if (BASELINK_P (member))
2241 {
2242 if (TREE_CODE (orig_name) == SCOPE_REF)
2243 BASELINK_QUALIFIED_P (member) = 1;
2244 orig_name = member;
2245 }
2246 return build_min_non_dep (COMPONENT_REF, expr,
2247 orig_object, orig_name,
2248 NULL_TREE);
2249 }
2250
2251 return expr;
2252}
2253
2254/* Return an expression for the MEMBER_NAME field in the internal
2255 representation of PTRMEM, a pointer-to-member function. (Each
2256 pointer-to-member function type gets its own RECORD_TYPE so it is
2257 more convenient to access the fields by name than by FIELD_DECL.)
2258 This routine converts the NAME to a FIELD_DECL and then creates the
2259 node for the complete expression. */
2260
2261tree
2262build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2263{
2264 tree ptrmem_type;
2265 tree member;
2266 tree member_type;
2267
2268 /* This code is a stripped down version of
2269 build_class_member_access_expr. It does not work to use that
2270 routine directly because it expects the object to be of class
2271 type. */
2272 ptrmem_type = TREE_TYPE (ptrmem);
2273 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2274 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2275 /*want_type=*/false);
2276 member_type = cp_build_qualified_type (TREE_TYPE (member),
2277 cp_type_quals (ptrmem_type));
2278 return fold_build3 (COMPONENT_REF, member_type,
2279 ptrmem, member, NULL_TREE);
2280}
2281
2282/* Given an expression PTR for a pointer, return an expression
2283 for the value pointed to.
2284 ERRORSTRING is the name of the operator to appear in error messages.
2285
2286 This function may need to overload OPERATOR_FNNAME.
2287 Must also handle REFERENCE_TYPEs for C++. */
2288
2289tree
2290build_x_indirect_ref (tree expr, const char *errorstring)
2291{
2292 tree orig_expr = expr;
2293 tree rval;
2294
2295 if (processing_template_decl)
2296 {
2297 if (type_dependent_expression_p (expr))
2298 return build_min_nt (INDIRECT_REF, expr);
2299 expr = build_non_dependent_expr (expr);
2300 }
2301
2302 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2303 NULL_TREE, /*overloaded_p=*/NULL);
2304 if (!rval)
2305 rval = build_indirect_ref (expr, errorstring);
2306
2307 if (processing_template_decl && rval != error_mark_node)
2308 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2309 else
2310 return rval;
2311}
2312
2313tree
2314build_indirect_ref (tree ptr, const char *errorstring)
2315{
2316 tree pointer, type;
2317
2318 if (ptr == error_mark_node)
2319 return error_mark_node;
2320
2321 if (ptr == current_class_ptr)
2322 return current_class_ref;
2323
2324 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2325 ? ptr : decay_conversion (ptr));
2326 type = TREE_TYPE (pointer);
2327
2328 if (POINTER_TYPE_P (type))
2329 {
2330 /* [expr.unary.op]
2331
2332 If the type of the expression is "pointer to T," the type
2333 of the result is "T."
2334
2335 We must use the canonical variant because certain parts of
2336 the back end, like fold, do pointer comparisons between
2337 types. */
2338 tree t = canonical_type_variant (TREE_TYPE (type));
2339
2340 if (TREE_CODE (ptr) == CONVERT_EXPR
2341 || TREE_CODE (ptr) == NOP_EXPR
2342 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2343 {
2344 /* If a warning is issued, mark it to avoid duplicates from
2345 the backend. This only needs to be done at
2346 warn_strict_aliasing > 2. */
2347 if (warn_strict_aliasing > 2)
2348 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2349 type, TREE_OPERAND (ptr, 0)))
2350 TREE_NO_WARNING (ptr) = 1;
2351 }
2352
2353 if (VOID_TYPE_P (t))
2354 {
2355 /* A pointer to incomplete type (other than cv void) can be
2356 dereferenced [expr.unary.op]/1 */
2357 error ("%qT is not a pointer-to-object type", type);
2358 return error_mark_node;
2359 }
2360 else if (TREE_CODE (pointer) == ADDR_EXPR
2361 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2362 /* The POINTER was something like `&x'. We simplify `*&x' to
2363 `x'. */
2364 return TREE_OPERAND (pointer, 0);
2365 else
2366 {
2367 tree ref = build1 (INDIRECT_REF, t, pointer);
2368
2369 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2370 so that we get the proper error message if the result is used
2371 to assign to. Also, &* is supposed to be a no-op. */
2372 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2373 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2374 TREE_SIDE_EFFECTS (ref)
2375 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2376 return ref;
2377 }
2378 }
2379 /* `pointer' won't be an error_mark_node if we were given a
2380 pointer to member, so it's cool to check for this here. */
2381 else if (TYPE_PTR_TO_MEMBER_P (type))
2382 error ("invalid use of %qs on pointer to member", errorstring);
2383 else if (pointer != error_mark_node)
2384 {
2385 if (errorstring)
2386 error ("invalid type argument of %qs", errorstring);
2387 else
2388 error ("invalid type argument");
2389 }
2390 return error_mark_node;
2391}
2392
2393/* This handles expressions of the form "a[i]", which denotes
2394 an array reference.
2395
2396 This is logically equivalent in C to *(a+i), but we may do it differently.
2397 If A is a variable or a member, we generate a primitive ARRAY_REF.
2398 This avoids forcing the array out of registers, and can work on
2399 arrays that are not lvalues (for example, members of structures returned
2400 by functions).
2401
2402 If INDEX is of some user-defined type, it must be converted to
2403 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2404 will inherit the type of the array, which will be some pointer type. */
2405
2406tree
2407build_array_ref (tree array, tree idx)
2408{
2409 if (idx == 0)
2410 {
2411 error ("subscript missing in array reference");
2412 return error_mark_node;
2413 }
2414
2415 if (TREE_TYPE (array) == error_mark_node
2416 || TREE_TYPE (idx) == error_mark_node)
2417 return error_mark_node;
2418
2419 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2420 inside it. */
2421 switch (TREE_CODE (array))
2422 {
2423 case COMPOUND_EXPR:
2424 {
2425 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2426 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2427 TREE_OPERAND (array, 0), value);
2428 }
2429
2430 case COND_EXPR:
2431 return build_conditional_expr
2432 (TREE_OPERAND (array, 0),
2433 build_array_ref (TREE_OPERAND (array, 1), idx),
2434 build_array_ref (TREE_OPERAND (array, 2), idx));
2435
2436 default:
2437 break;
2438 }
2439
2440 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2441 {
2442 tree rval, type;
2443
2444 warn_array_subscript_with_type_char (idx);
2445
2446 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2447 {
2448 error ("array subscript is not an integer");
2449 return error_mark_node;
2450 }
2451
2452 /* Apply integral promotions *after* noticing character types.
2453 (It is unclear why we do these promotions -- the standard
2454 does not say that we should. In fact, the natural thing would
2455 seem to be to convert IDX to ptrdiff_t; we're performing
2456 pointer arithmetic.) */
2457 idx = perform_integral_promotions (idx);
2458
2459 /* An array that is indexed by a non-constant
2460 cannot be stored in a register; we must be able to do
2461 address arithmetic on its address.
2462 Likewise an array of elements of variable size. */
2463 if (TREE_CODE (idx) != INTEGER_CST
2464 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2465 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2466 != INTEGER_CST)))
2467 {
2468 if (!cxx_mark_addressable (array))
2469 return error_mark_node;
2470 }
2471
2472 /* An array that is indexed by a constant value which is not within
2473 the array bounds cannot be stored in a register either; because we
2474 would get a crash in store_bit_field/extract_bit_field when trying
2475 to access a non-existent part of the register. */
2476 if (TREE_CODE (idx) == INTEGER_CST
2477 && TYPE_DOMAIN (TREE_TYPE (array))
2478 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2479 {
2480 if (!cxx_mark_addressable (array))
2481 return error_mark_node;
2482 }
2483
2484 if (pedantic && !lvalue_p (array))
2485 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2486
2487 /* Note in C++ it is valid to subscript a `register' array, since
2488 it is valid to take the address of something with that
2489 storage specification. */
2490 if (extra_warnings)
2491 {
2492 tree foo = array;
2493 while (TREE_CODE (foo) == COMPONENT_REF)
2494 foo = TREE_OPERAND (foo, 0);
2495 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2496 warning (OPT_Wextra, "subscripting array declared %<register%>");
2497 }
2498
2499 type = TREE_TYPE (TREE_TYPE (array));
2500 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2501 /* Array ref is const/volatile if the array elements are
2502 or if the array is.. */
2503 TREE_READONLY (rval)
2504 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2505 TREE_SIDE_EFFECTS (rval)
2506 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2507 TREE_THIS_VOLATILE (rval)
2508 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2509 return require_complete_type (fold_if_not_in_template (rval));
2510 }
2511
2512 {
2513 tree ar = default_conversion (array);
2514 tree ind = default_conversion (idx);
2515
2516 /* Put the integer in IND to simplify error checking. */
2517 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2518 {
2519 tree temp = ar;
2520 ar = ind;
2521 ind = temp;
2522 }
2523
2524 if (ar == error_mark_node)
2525 return ar;
2526
2527 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2528 {
2529 error ("subscripted value is neither array nor pointer");
2530 return error_mark_node;
2531 }
2532 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2533 {
2534 error ("array subscript is not an integer");
2535 return error_mark_node;
2536 }
2537
2538 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2539 "array indexing");
2540 }
2541}
2542
2543/* Resolve a pointer to member function. INSTANCE is the object
2544 instance to use, if the member points to a virtual member.
2545
2546 This used to avoid checking for virtual functions if basetype
2547 has no virtual functions, according to an earlier ANSI draft.
2548 With the final ISO C++ rules, such an optimization is
2549 incorrect: A pointer to a derived member can be static_cast
2550 to pointer-to-base-member, as long as the dynamic object
2551 later has the right member. */
2552
2553tree
2554get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2555{
2556 if (TREE_CODE (function) == OFFSET_REF)
2557 function = TREE_OPERAND (function, 1);
2558
2559 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2560 {
2561 tree idx, delta, e1, e2, e3, vtbl, basetype;
2562 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2563
2564 tree instance_ptr = *instance_ptrptr;
2565 tree instance_save_expr = 0;
2566 if (instance_ptr == error_mark_node)
2567 {
2568 if (TREE_CODE (function) == PTRMEM_CST)
2569 {
2570 /* Extracting the function address from a pmf is only
2571 allowed with -Wno-pmf-conversions. It only works for
2572 pmf constants. */
2573 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2574 e1 = convert (fntype, e1);
2575 return e1;
2576 }
2577 else
2578 {
2579 error ("object missing in use of %qE", function);
2580 return error_mark_node;
2581 }
2582 }
2583
2584 if (TREE_SIDE_EFFECTS (instance_ptr))
2585 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2586
2587 if (TREE_SIDE_EFFECTS (function))
2588 function = save_expr (function);
2589
2590 /* Start by extracting all the information from the PMF itself. */
2591 e3 = pfn_from_ptrmemfunc (function);
2592 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2593 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2594 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2595 {
2596 case ptrmemfunc_vbit_in_pfn:
2597 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2598 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2599 break;
2600
2601 case ptrmemfunc_vbit_in_delta:
2602 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2603 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2604 break;
2605
2606 default:
2607 gcc_unreachable ();
2608 }
2609
2610 /* Convert down to the right base before using the instance. A
2611 special case is that in a pointer to member of class C, C may
2612 be incomplete. In that case, the function will of course be
2613 a member of C, and no conversion is required. In fact,
2614 lookup_base will fail in that case, because incomplete
2615 classes do not have BINFOs. */
2616 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2617 if (!same_type_ignoring_top_level_qualifiers_p
2618 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2619 {
2620 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2621 basetype, ba_check, NULL);
2622 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2623 1);
2624 if (instance_ptr == error_mark_node)
2625 return error_mark_node;
2626 }
2627 /* ...and then the delta in the PMF. */
2628 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2629 instance_ptr, delta);
2630
2631 /* Hand back the adjusted 'this' argument to our caller. */
2632 *instance_ptrptr = instance_ptr;
2633
2634 /* Next extract the vtable pointer from the object. */
2635 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2636 instance_ptr);
2637 vtbl = build_indirect_ref (vtbl, NULL);
2638
2639 /* Finally, extract the function pointer from the vtable. */
2640 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2641 e2 = build_indirect_ref (e2, NULL);
2642 TREE_CONSTANT (e2) = 1;
2643 TREE_INVARIANT (e2) = 1;
2644
2645 /* When using function descriptors, the address of the
2646 vtable entry is treated as a function pointer. */
2647 if (TARGET_VTABLE_USES_DESCRIPTORS)
2648 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2649 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2650
2651 TREE_TYPE (e2) = TREE_TYPE (e3);
2652 e1 = build_conditional_expr (e1, e2, e3);
2653
2654 /* Make sure this doesn't get evaluated first inside one of the
2655 branches of the COND_EXPR. */
2656 if (instance_save_expr)
2657 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2658 instance_save_expr, e1);
2659
2660 function = e1;
2661 }
2662 return function;
2663}
2664
2665tree
2666build_function_call (tree function, tree params)
2667{
2668 tree fntype, fndecl;
2669 tree coerced_params;
2670 tree name = NULL_TREE;
2671 int is_method;
2672 tree original = function;
2673
2674 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2675 expressions, like those used for ObjC messenger dispatches. */
2676 function = objc_rewrite_function_call (function, params);
2677
2678 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2679 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2680 if (TREE_CODE (function) == NOP_EXPR
2681 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2682 function = TREE_OPERAND (function, 0);
2683
2684 if (TREE_CODE (function) == FUNCTION_DECL)
2685 {
2686 name = DECL_NAME (function);
2687
2688 mark_used (function);
2689 fndecl = function;
2690
2691 /* Convert anything with function type to a pointer-to-function. */
2692 if (pedantic && DECL_MAIN_P (function))
2693 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2694
2695 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2696 (because calling an inline function does not mean the function
2697 needs to be separately compiled). */
2698
2699 if (DECL_INLINE (function))
2700 function = inline_conversion (function);
2701 else
2702 function = build_addr_func (function);
2703 }
2704 else
2705 {
2706 fndecl = NULL_TREE;
2707
2708 function = build_addr_func (function);
2709 }
2710
2711 if (function == error_mark_node)
2712 return error_mark_node;
2713
2714 fntype = TREE_TYPE (function);
2715
2716 if (TYPE_PTRMEMFUNC_P (fntype))
2717 {
2718 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2719 "function in %<%E (...)%>",
2720 original);
2721 return error_mark_node;
2722 }
2723
2724 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2725 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2726
2727 if (!((TREE_CODE (fntype) == POINTER_TYPE
2728 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2729 || is_method
2730 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2731 {
2732 error ("%qE cannot be used as a function", original);
2733 return error_mark_node;
2734 }
2735
2736 /* fntype now gets the type of function pointed to. */
2737 fntype = TREE_TYPE (fntype);
2738
2739 /* Convert the parameters to the types declared in the
2740 function prototype, or apply default promotions. */
2741
2742 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2743 params, fndecl, LOOKUP_NORMAL);
2744 if (coerced_params == error_mark_node)
2745 return error_mark_node;
2746
2747 /* Check for errors in format strings and inappropriately
2748 null parameters. */
2749
2750 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2751 TYPE_ARG_TYPES (fntype));
2752
2753 return build_cxx_call (function, coerced_params);
2754}
2755
2756/* Convert the actual parameter expressions in the list VALUES
2757 to the types in the list TYPELIST.
2758 If parmdecls is exhausted, or when an element has NULL as its type,
2759 perform the default conversions.
2760
2761 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2762
2763 This is also where warnings about wrong number of args are generated.
2764
2765 Return a list of expressions for the parameters as converted.
2766
2767 Both VALUES and the returned value are chains of TREE_LIST nodes
2768 with the elements of the list in the TREE_VALUE slots of those nodes.
2769
2770 In C++, unspecified trailing parameters can be filled in with their
2771 default arguments, if such were specified. Do so here. */
2772
2773static tree
2774convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2775{
2776 tree typetail, valtail;
2777 tree result = NULL_TREE;
2778 const char *called_thing = 0;
2779 int i = 0;
2780
2781 /* Argument passing is always copy-initialization. */
2782 flags |= LOOKUP_ONLYCONVERTING;
2783
2784 if (fndecl)
2785 {
2786 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2787 {
2788 if (DECL_NAME (fndecl) == NULL_TREE
2789 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2790 called_thing = "constructor";
2791 else
2792 called_thing = "member function";
2793 }
2794 else
2795 called_thing = "function";
2796 }
2797
2798 for (valtail = values, typetail = typelist;
2799 valtail;
2800 valtail = TREE_CHAIN (valtail), i++)
2801 {
2802 tree type = typetail ? TREE_VALUE (typetail) : 0;
2803 tree val = TREE_VALUE (valtail);
2804
2805 if (val == error_mark_node || type == error_mark_node)
2806 return error_mark_node;
2807
2808 if (type == void_type_node)
2809 {
2810 if (fndecl)
2811 {
2812 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2813 error ("at this point in file");
2814 }
2815 else
2816 error ("too many arguments to function");
2817 /* In case anybody wants to know if this argument
2818 list is valid. */
2819 if (result)
2820 TREE_TYPE (tree_last (result)) = error_mark_node;
2821 break;
2822 }
2823
2824 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2825 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2826 if (TREE_CODE (val) == NOP_EXPR
2827 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2828 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2829 val = TREE_OPERAND (val, 0);
2830
2831 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2832 {
2833 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2834 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2835 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2836 val = decay_conversion (val);
2837 }
2838
2839 if (val == error_mark_node)
2840 return error_mark_node;
2841
2842 if (type != 0)
2843 {
2844 /* Formal parm type is specified by a function prototype. */
2845 tree parmval;
2846
2847 if (!COMPLETE_TYPE_P (complete_type (type)))
2848 {
2849 if (fndecl)
2850 error ("parameter %P of %qD has incomplete type %qT",
2851 i, fndecl, type);
2852 else
2853 error ("parameter %P has incomplete type %qT", i, type);
2854 parmval = error_mark_node;
2855 }
2856 else
2857 {
2858 parmval = convert_for_initialization
2859 (NULL_TREE, type, val, flags,
2860 "argument passing", fndecl, i);
2861 parmval = convert_for_arg_passing (type, parmval);
2862 }
2863
2864 if (parmval == error_mark_node)
2865 return error_mark_node;
2866
2867 result = tree_cons (NULL_TREE, parmval, result);
2868 }
2869 else
2870 {
2871 if (fndecl && DECL_BUILT_IN (fndecl)
2872 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2873 /* Don't do ellipsis conversion for __built_in_constant_p
2874 as this will result in spurious warnings for non-POD
2875 types. */
2876 val = require_complete_type (val);
2877 else
2878 val = convert_arg_to_ellipsis (val);
2879
2880 result = tree_cons (NULL_TREE, val, result);
2881 }
2882
2883 if (typetail)
2884 typetail = TREE_CHAIN (typetail);
2885 }
2886
2887 if (typetail != 0 && typetail != void_list_node)
2888 {
2889 /* See if there are default arguments that can be used. */
2890 if (TREE_PURPOSE (typetail)
2891 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2892 {
2893 for (; typetail != void_list_node; ++i)
2894 {
2895 tree parmval
2896 = convert_default_arg (TREE_VALUE (typetail),
2897 TREE_PURPOSE (typetail),
2898 fndecl, i);
2899
2900 if (parmval == error_mark_node)
2901 return error_mark_node;
2902
2903 result = tree_cons (0, parmval, result);
2904 typetail = TREE_CHAIN (typetail);
2905 /* ends with `...'. */
2906 if (typetail == NULL_TREE)
2907 break;
2908 }
2909 }
2910 else
2911 {
2912 if (fndecl)
2913 {
2914 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2915 error ("at this point in file");
2916 }
2917 else
2918 error ("too few arguments to function");
2919 return error_mark_node;
2920 }
2921 }
2922
2923 return nreverse (result);
2924}
2925
2926/* Build a binary-operation expression, after performing default
2927 conversions on the operands. CODE is the kind of expression to build. */
2928
2929tree
2930build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2931 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2932{
2933 tree orig_arg1;
2934 tree orig_arg2;
2935 tree expr;
2936
2937 orig_arg1 = arg1;
2938 orig_arg2 = arg2;
2939
2940 if (processing_template_decl)
2941 {
2942 if (type_dependent_expression_p (arg1)
2943 || type_dependent_expression_p (arg2))
2944 return build_min_nt (code, arg1, arg2);
2945 arg1 = build_non_dependent_expr (arg1);
2946 arg2 = build_non_dependent_expr (arg2);
2947 }
2948
2949 if (code == DOTSTAR_EXPR)
2950 expr = build_m_component_ref (arg1, arg2);
2951 else
2952 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2953 overloaded_p);
2954
2955 /* Check for cases such as x+y<<z which users are likely to
2956 misinterpret. But don't warn about obj << x + y, since that is a
2957 common idiom for I/O. */
2958 if (warn_parentheses
2959 && !processing_template_decl
2960 && !error_operand_p (arg1)
2961 && !error_operand_p (arg2)
2962 && (code != LSHIFT_EXPR
2963 || !IS_AGGR_TYPE (TREE_TYPE (arg1))))
2964 warn_about_parentheses (code, arg1_code, arg2_code);
2965
2966 if (processing_template_decl && expr != error_mark_node)
2967 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2968
2969 return expr;
2970}
2971
2972/* Build a binary-operation expression without default conversions.
2973 CODE is the kind of expression to build.
2974 This function differs from `build' in several ways:
2975 the data type of the result is computed and recorded in it,
2976 warnings are generated if arg data types are invalid,
2977 special handling for addition and subtraction of pointers is known,
2978 and some optimization is done (operations on narrow ints
2979 are done in the narrower type when that gives the same result).
2980 Constant folding is also done before the result is returned.
2981
2982 Note that the operands will never have enumeral types
2983 because either they have just had the default conversions performed
2984 or they have both just been converted to some other type in which
2985 the arithmetic is to be done.
2986
2987 C++: must do special pointer arithmetic when implementing
2988 multiple inheritance, and deal with pointer to member functions. */
2989
2990tree
2991build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2992 int convert_p ATTRIBUTE_UNUSED)
2993{
2994 tree op0, op1;
2995 enum tree_code code0, code1;
2996 tree type0, type1;
2997 const char *invalid_op_diag;
2998
2999 /* Expression code to give to the expression when it is built.
3000 Normally this is CODE, which is what the caller asked for,
3001 but in some special cases we change it. */
3002 enum tree_code resultcode = code;
3003
3004 /* Data type in which the computation is to be performed.
3005 In the simplest cases this is the common type of the arguments. */
3006 tree result_type = NULL;
3007
3008 /* Nonzero means operands have already been type-converted
3009 in whatever way is necessary.
3010 Zero means they need to be converted to RESULT_TYPE. */
3011 int converted = 0;
3012
3013 /* Nonzero means create the expression with this type, rather than
3014 RESULT_TYPE. */
3015 tree build_type = 0;
3016
3017 /* Nonzero means after finally constructing the expression
3018 convert it to this type. */
3019 tree final_type = 0;
3020
3021 tree result;
3022
3023 /* Nonzero if this is an operation like MIN or MAX which can
3024 safely be computed in short if both args are promoted shorts.
3025 Also implies COMMON.
3026 -1 indicates a bitwise operation; this makes a difference
3027 in the exact conditions for when it is safe to do the operation
3028 in a narrower mode. */
3029 int shorten = 0;
3030
3031 /* Nonzero if this is a comparison operation;
3032 if both args are promoted shorts, compare the original shorts.
3033 Also implies COMMON. */
3034 int short_compare = 0;
3035
3036 /* Nonzero if this is a right-shift operation, which can be computed on the
3037 original short and then promoted if the operand is a promoted short. */
3038 int short_shift = 0;
3039
3040 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3041 int common = 0;
3042
3043 /* True if both operands have arithmetic type. */
3044 bool arithmetic_types_p;
3045
3046 /* Apply default conversions. */
3047 op0 = orig_op0;
3048 op1 = orig_op1;
3049
3050 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3051 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3052 || code == TRUTH_XOR_EXPR)
3053 {
3054 if (!really_overloaded_fn (op0))
3055 op0 = decay_conversion (op0);
3056 if (!really_overloaded_fn (op1))
3057 op1 = decay_conversion (op1);
3058 }
3059 else
3060 {
3061 if (!really_overloaded_fn (op0))
3062 op0 = default_conversion (op0);
3063 if (!really_overloaded_fn (op1))
3064 op1 = default_conversion (op1);
3065 }
3066
3067 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3068 STRIP_TYPE_NOPS (op0);
3069 STRIP_TYPE_NOPS (op1);
3070
3071 /* DTRT if one side is an overloaded function, but complain about it. */
3072 if (type_unknown_p (op0))
3073 {
3074 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3075 if (t != error_mark_node)
3076 {
3077 pedwarn ("assuming cast to type %qT from overloaded function",
3078 TREE_TYPE (t));
3079 op0 = t;
3080 }
3081 }
3082 if (type_unknown_p (op1))
3083 {
3084 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3085 if (t != error_mark_node)
3086 {
3087 pedwarn ("assuming cast to type %qT from overloaded function",
3088 TREE_TYPE (t));
3089 op1 = t;
3090 }
3091 }
3092
3093 type0 = TREE_TYPE (op0);
3094 type1 = TREE_TYPE (op1);
3095
3096 /* The expression codes of the data types of the arguments tell us
3097 whether the arguments are integers, floating, pointers, etc. */
3098 code0 = TREE_CODE (type0);
3099 code1 = TREE_CODE (type1);
3100
3101 /* If an error was already reported for one of the arguments,
3102 avoid reporting another error. */
3103
3104 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3105 return error_mark_node;
3106
3107 if ((invalid_op_diag
3108 = targetm.invalid_binary_op (code, type0, type1)))
3109 {
3110 error (invalid_op_diag, "");
3111 return error_mark_node;
3112 }
3113
3114 switch (code)
3115 {
3116 case MINUS_EXPR:
3117 /* Subtraction of two similar pointers.
3118 We must subtract them as integers, then divide by object size. */
3119 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3120 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3121 TREE_TYPE (type1)))
3122 return pointer_diff (op0, op1, common_type (type0, type1));
3123 /* In all other cases except pointer - int, the usual arithmetic
3124 rules aply. */
3125 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3126 {
3127 common = 1;
3128 break;
3129 }
3130 /* The pointer - int case is just like pointer + int; fall
3131 through. */
3132 case PLUS_EXPR:
3133 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3134 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3135 {
3136 tree ptr_operand;
3137 tree int_operand;
3138 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3139 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3140 if (processing_template_decl)
3141 {
3142 result_type = TREE_TYPE (ptr_operand);
3143 break;
3144 }
3145 return cp_pointer_int_sum (code,
3146 ptr_operand,
3147 int_operand);
3148 }
3149 common = 1;
3150 break;
3151
3152 case MULT_EXPR:
3153 common = 1;
3154 break;
3155
3156 case TRUNC_DIV_EXPR:
3157 case CEIL_DIV_EXPR:
3158 case FLOOR_DIV_EXPR:
3159 case ROUND_DIV_EXPR:
3160 case EXACT_DIV_EXPR:
3161 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3162 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3163 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3164 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3165 {
3166 enum tree_code tcode0 = code0, tcode1 = code1;
3167
3168 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3169 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3170 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3171 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3172
3173 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3174 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3175 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3176 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3177
3178 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3179 resultcode = RDIV_EXPR;
3180 else
3181 /* When dividing two signed integers, we have to promote to int.
3182 unless we divide by a constant != -1. Note that default
3183 conversion will have been performed on the operands at this
3184 point, so we have to dig out the original type to find out if
3185 it was unsigned. */
3186 shorten = ((TREE_CODE (op0) == NOP_EXPR
3187 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3188 || (TREE_CODE (op1) == INTEGER_CST
3189 && ! integer_all_onesp (op1)));
3190
3191 common = 1;
3192 }
3193 break;
3194
3195 case BIT_AND_EXPR:
3196 case BIT_IOR_EXPR:
3197 case BIT_XOR_EXPR:
3198 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3199 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3200 shorten = -1;
3201 break;
3202
3203 case TRUNC_MOD_EXPR:
3204 case FLOOR_MOD_EXPR:
3205 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3206 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3207 else if (code1 == REAL_TYPE && real_zerop (op1))
3208 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3209
3210 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3211 {
3212 /* Although it would be tempting to shorten always here, that loses
3213 on some targets, since the modulo instruction is undefined if the
3214 quotient can't be represented in the computation mode. We shorten
3215 only if unsigned or if dividing by something we know != -1. */
3216 shorten = ((TREE_CODE (op0) == NOP_EXPR
3217 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3218 || (TREE_CODE (op1) == INTEGER_CST
3219 && ! integer_all_onesp (op1)));
3220 common = 1;
3221 }
3222 break;
3223
3224 case TRUTH_ANDIF_EXPR:
3225 case TRUTH_ORIF_EXPR:
3226 case TRUTH_AND_EXPR:
3227 case TRUTH_OR_EXPR:
3228 result_type = boolean_type_node;
3229 break;
3230
3231 /* Shift operations: result has same type as first operand;
3232 always convert second operand to int.
3233 Also set SHORT_SHIFT if shifting rightward. */
3234
3235 case RSHIFT_EXPR:
3236 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3237 {
3238 result_type = type0;
3239 if (TREE_CODE (op1) == INTEGER_CST)
3240 {
3241 if (tree_int_cst_lt (op1, integer_zero_node))
3242 warning (0, "right shift count is negative");
3243 else
3244 {
3245 if (! integer_zerop (op1))
3246 short_shift = 1;
3247 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3248 warning (0, "right shift count >= width of type");
3249 }
3250 }
3251 /* Convert the shift-count to an integer, regardless of
3252 size of value being shifted. */
3253 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3254 op1 = cp_convert (integer_type_node, op1);
3255 /* Avoid converting op1 to result_type later. */
3256 converted = 1;
3257 }
3258 break;
3259
3260 case LSHIFT_EXPR:
3261 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3262 {
3263 result_type = type0;
3264 if (TREE_CODE (op1) == INTEGER_CST)
3265 {
3266 if (tree_int_cst_lt (op1, integer_zero_node))
3267 warning (0, "left shift count is negative");
3268 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3269 warning (0, "left shift count >= width of type");
3270 }
3271 /* Convert the shift-count to an integer, regardless of
3272 size of value being shifted. */
3273 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3274 op1 = cp_convert (integer_type_node, op1);
3275 /* Avoid converting op1 to result_type later. */
3276 converted = 1;
3277 }
3278 break;
3279
3280 case RROTATE_EXPR:
3281 case LROTATE_EXPR:
3282 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3283 {
3284 result_type = type0;
3285 if (TREE_CODE (op1) == INTEGER_CST)
3286 {
3287 if (tree_int_cst_lt (op1, integer_zero_node))
3288 warning (0, "%s rotate count is negative",
3289 (code == LROTATE_EXPR) ? "left" : "right");
3290 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3291 warning (0, "%s rotate count >= width of type",
3292 (code == LROTATE_EXPR) ? "left" : "right");
3293 }
3294 /* Convert the shift-count to an integer, regardless of
3295 size of value being shifted. */
3296 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3297 op1 = cp_convert (integer_type_node, op1);
3298 }
3299 break;
3300
3301 case EQ_EXPR:
3302 case NE_EXPR:
3303 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3304 warning (OPT_Wfloat_equal,
3305 "comparing floating point with == or != is unsafe");
3306 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3307 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3308 warning (OPT_Waddress,
3309 "comparison with string literal results in unspecified behaviour");
3310
3311 build_type = boolean_type_node;
3312 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3313 || code0 == COMPLEX_TYPE)
3314 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3315 || code1 == COMPLEX_TYPE))
3316 short_compare = 1;
3317 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3318 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3319 result_type = composite_pointer_type (type0, type1, op0, op1,
3320 "comparison");
3321 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3322 && null_ptr_cst_p (op1))
3323 result_type = type0;
3324 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3325 && null_ptr_cst_p (op0))
3326 result_type = type1;
3327 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3328 {
3329 result_type = type0;
3330 error ("ISO C++ forbids comparison between pointer and integer");
3331 }
3332 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3333 {
3334 result_type = type1;
3335 error ("ISO C++ forbids comparison between pointer and integer");
3336 }
3337 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3338 {
3339 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3340 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3341 result_type = TREE_TYPE (op0);
3342 }
3343 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3344 return cp_build_binary_op (code, op1, op0);
3345 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3346 && same_type_p (type0, type1))
3347 {
3348 /* E will be the final comparison. */
3349 tree e;
3350 /* E1 and E2 are for scratch. */
3351 tree e1;
3352 tree e2;
3353 tree pfn0;
3354 tree pfn1;
3355 tree delta0;
3356 tree delta1;
3357
3358 if (TREE_SIDE_EFFECTS (op0))
3359 op0 = save_expr (op0);
3360 if (TREE_SIDE_EFFECTS (op1))
3361 op1 = save_expr (op1);
3362
3363 /* We generate:
3364
3365 (op0.pfn == op1.pfn
3366 && (!op0.pfn || op0.delta == op1.delta))
3367
3368 The reason for the `!op0.pfn' bit is that a NULL
3369 pointer-to-member is any member with a zero PFN; the
3370 DELTA field is unspecified. */
3371 pfn0 = pfn_from_ptrmemfunc (op0);
3372 pfn1 = pfn_from_ptrmemfunc (op1);
3373 delta0 = build_ptrmemfunc_access_expr (op0,
3374 delta_identifier);
3375 delta1 = build_ptrmemfunc_access_expr (op1,
3376 delta_identifier);
3377 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3378 e2 = cp_build_binary_op (EQ_EXPR,
3379 pfn0,
3380 cp_convert (TREE_TYPE (pfn0),
3381 integer_zero_node));
3382 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3383 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3384 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3385 if (code == EQ_EXPR)
3386 return e;
3387 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3388 }
3389 else
3390 {
3391 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3392 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3393 type1));
3394 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3395 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3396 type0));
3397 }
3398
3399 break;
3400
3401 case MAX_EXPR:
3402 case MIN_EXPR:
3403 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3404 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3405 shorten = 1;
3406 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3407 result_type = composite_pointer_type (type0, type1, op0, op1,
3408 "comparison");
3409 break;
3410
3411 case LE_EXPR:
3412 case GE_EXPR:
3413 case LT_EXPR:
3414 case GT_EXPR:
3415 if (TREE_CODE (orig_op0) == STRING_CST
3416 || TREE_CODE (orig_op1) == STRING_CST)
3417 warning (OPT_Waddress,
3418 "comparison with string literal results in unspecified behaviour");
3419
3420 build_type = boolean_type_node;
3421 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3422 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3423 short_compare = 1;
3424 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3425 result_type = composite_pointer_type (type0, type1, op0, op1,
3426 "comparison");
3427 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3428 && integer_zerop (op1))
3429 result_type = type0;
3430 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3431 && integer_zerop (op0))
3432 result_type = type1;
3433 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3434 {
3435 result_type = type0;
3436 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3437 }
3438 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3439 {
3440 result_type = type1;
3441 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3442 }
3443 break;
3444
3445 case UNORDERED_EXPR:
3446 case ORDERED_EXPR:
3447 case UNLT_EXPR:
3448 case UNLE_EXPR:
3449 case UNGT_EXPR:
3450 case UNGE_EXPR:
3451 case UNEQ_EXPR:
3452 build_type = integer_type_node;
3453 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3454 {
3455 error ("unordered comparison on non-floating point argument");
3456 return error_mark_node;
3457 }
3458 common = 1;
3459 break;
3460
3461 default:
3462 break;
3463 }
3464
3465 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3466 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3467 || code1 == COMPLEX_TYPE)))
3468 arithmetic_types_p = 1;
3469 else
3470 {
3471 arithmetic_types_p = 0;
3472 /* Vector arithmetic is only allowed when both sides are vectors. */
3473 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3474 {
3475 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3476 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3477 TREE_TYPE (type1)))
3478 {
3479 binary_op_error (code, type0, type1);
3480 return error_mark_node;
3481 }
3482 arithmetic_types_p = 1;
3483 }
3484 }
3485 /* Determine the RESULT_TYPE, if it is not already known. */
3486 if (!result_type
3487 && arithmetic_types_p
3488 && (shorten || common || short_compare))
3489 result_type = common_type (type0, type1);
3490
3491 if (!result_type)
3492 {
3493 error ("invalid operands of types %qT and %qT to binary %qO",
3494 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3495 return error_mark_node;
3496 }
3497
3498 /* If we're in a template, the only thing we need to know is the
3499 RESULT_TYPE. */
3500 if (processing_template_decl)
3501 return build2 (resultcode,
3502 build_type ? build_type : result_type,
3503 op0, op1);
3504
3505 if (arithmetic_types_p)
3506 {
3507 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3508
3509 /* For certain operations (which identify themselves by shorten != 0)
3510 if both args were extended from the same smaller type,
3511 do the arithmetic in that type and then extend.
3512
3513 shorten !=0 and !=1 indicates a bitwise operation.
3514 For them, this optimization is safe only if
3515 both args are zero-extended or both are sign-extended.
3516 Otherwise, we might change the result.
3517 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3518 but calculated in (unsigned short) it would be (unsigned short)-1. */
3519
3520 if (shorten && none_complex)
3521 {
3522 int unsigned0, unsigned1;
3523 tree arg0 = get_narrower (op0, &unsigned0);
3524 tree arg1 = get_narrower (op1, &unsigned1);
3525 /* UNS is 1 if the operation to be done is an unsigned one. */
3526 int uns = TYPE_UNSIGNED (result_type);
3527 tree type;
3528
3529 final_type = result_type;
3530
3531 /* Handle the case that OP0 does not *contain* a conversion
3532 but it *requires* conversion to FINAL_TYPE. */
3533
3534 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3535 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3536 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3537 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3538
3539 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3540
3541 /* For bitwise operations, signedness of nominal type
3542 does not matter. Consider only how operands were extended. */
3543 if (shorten == -1)
3544 uns = unsigned0;
3545
3546 /* Note that in all three cases below we refrain from optimizing
3547 an unsigned operation on sign-extended args.
3548 That would not be valid. */
3549
3550 /* Both args variable: if both extended in same way
3551 from same width, do it in that width.
3552 Do it unsigned if args were zero-extended. */
3553 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3554 < TYPE_PRECISION (result_type))
3555 && (TYPE_PRECISION (TREE_TYPE (arg1))
3556 == TYPE_PRECISION (TREE_TYPE (arg0)))
3557 && unsigned0 == unsigned1
3558 && (unsigned0 || !uns))
3559 result_type = c_common_signed_or_unsigned_type
3560 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3561 else if (TREE_CODE (arg0) == INTEGER_CST
3562 && (unsigned1 || !uns)
3563 && (TYPE_PRECISION (TREE_TYPE (arg1))
3564 < TYPE_PRECISION (result_type))
3565 && (type = c_common_signed_or_unsigned_type
3566 (unsigned1, TREE_TYPE (arg1)),
3567 int_fits_type_p (arg0, type)))
3568 result_type = type;
3569 else if (TREE_CODE (arg1) == INTEGER_CST
3570 && (unsigned0 || !uns)
3571 && (TYPE_PRECISION (TREE_TYPE (arg0))
3572 < TYPE_PRECISION (result_type))
3573 && (type = c_common_signed_or_unsigned_type
3574 (unsigned0, TREE_TYPE (arg0)),
3575 int_fits_type_p (arg1, type)))
3576 result_type = type;
3577 }
3578
3579 /* Shifts can be shortened if shifting right. */
3580
3581 if (short_shift)
3582 {
3583 int unsigned_arg;
3584 tree arg0 = get_narrower (op0, &unsigned_arg);
3585
3586 final_type = result_type;
3587
3588 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3589 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3590
3591 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3592 /* We can shorten only if the shift count is less than the
3593 number of bits in the smaller type size. */
3594 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3595 /* If arg is sign-extended and then unsigned-shifted,
3596 we can simulate this with a signed shift in arg's type
3597 only if the extended result is at least twice as wide
3598 as the arg. Otherwise, the shift could use up all the
3599 ones made by sign-extension and bring in zeros.
3600 We can't optimize that case at all, but in most machines
3601 it never happens because available widths are 2**N. */
3602 && (!TYPE_UNSIGNED (final_type)
3603 || unsigned_arg
3604 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3605 <= TYPE_PRECISION (result_type))))
3606 {
3607 /* Do an unsigned shift if the operand was zero-extended. */
3608 result_type
3609 = c_common_signed_or_unsigned_type (unsigned_arg,
3610 TREE_TYPE (arg0));
3611 /* Convert value-to-be-shifted to that type. */
3612 if (TREE_TYPE (op0) != result_type)
3613 op0 = cp_convert (result_type, op0);
3614 converted = 1;
3615 }
3616 }
3617
3618 /* Comparison operations are shortened too but differently.
3619 They identify themselves by setting short_compare = 1. */
3620
3621 if (short_compare)
3622 {
3623 /* Don't write &op0, etc., because that would prevent op0
3624 from being kept in a register.
3625 Instead, make copies of the our local variables and
3626 pass the copies by reference, then copy them back afterward. */
3627 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3628 enum tree_code xresultcode = resultcode;
3629 tree val
3630 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3631 if (val != 0)
3632 return cp_convert (boolean_type_node, val);
3633 op0 = xop0, op1 = xop1;
3634 converted = 1;
3635 resultcode = xresultcode;
3636 }
3637
3638 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3639 && warn_sign_compare
3640 /* Do not warn until the template is instantiated; we cannot
3641 bound the ranges of the arguments until that point. */
3642 && !processing_template_decl)
3643 {
3644 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3645 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3646
3647 int unsignedp0, unsignedp1;
3648 tree primop0 = get_narrower (op0, &unsignedp0);
3649 tree primop1 = get_narrower (op1, &unsignedp1);
3650
3651 /* Check for comparison of different enum types. */
3652 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3653 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3654 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3655 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3656 {
3657 warning (0, "comparison between types %q#T and %q#T",
3658 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3659 }
3660
3661 /* Give warnings for comparisons between signed and unsigned
3662 quantities that may fail. */
3663 /* Do the checking based on the original operand trees, so that
3664 casts will be considered, but default promotions won't be. */
3665
3666 /* Do not warn if the comparison is being done in a signed type,
3667 since the signed type will only be chosen if it can represent
3668 all the values of the unsigned type. */
3669 if (!TYPE_UNSIGNED (result_type))
3670 /* OK */;
3671 /* Do not warn if both operands are unsigned. */
3672 else if (op0_signed == op1_signed)
3673 /* OK */;
3674 /* Do not warn if the signed quantity is an unsuffixed
3675 integer literal (or some static constant expression
3676 involving such literals or a conditional expression
3677 involving such literals) and it is non-negative. */
3678 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3679 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3680 /* OK */;
3681 /* Do not warn if the comparison is an equality operation,
3682 the unsigned quantity is an integral constant and it does
3683 not use the most significant bit of result_type. */
3684 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3685 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3686 && int_fits_type_p (orig_op1, c_common_signed_type
3687 (result_type)))
3688 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3689 && int_fits_type_p (orig_op0, c_common_signed_type
3690 (result_type)))))
3691 /* OK */;
3692 else
3693 warning (0, "comparison between signed and unsigned integer expressions");
3694
3695 /* Warn if two unsigned values are being compared in a size
3696 larger than their original size, and one (and only one) is the
3697 result of a `~' operator. This comparison will always fail.
3698
3699 Also warn if one operand is a constant, and the constant does not
3700 have all bits set that are set in the ~ operand when it is
3701 extended. */
3702
3703 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3704 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3705 {
3706 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3707 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3708 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3709 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3710
3711 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3712 {
3713 tree primop;
3714 HOST_WIDE_INT constant, mask;
3715 int unsignedp;
3716 unsigned int bits;
3717
3718 if (host_integerp (primop0, 0))
3719 {
3720 primop = primop1;
3721 unsignedp = unsignedp1;
3722 constant = tree_low_cst (primop0, 0);
3723 }
3724 else
3725 {
3726 primop = primop0;
3727 unsignedp = unsignedp0;
3728 constant = tree_low_cst (primop1, 0);
3729 }
3730
3731 bits = TYPE_PRECISION (TREE_TYPE (primop));
3732 if (bits < TYPE_PRECISION (result_type)
3733 && bits < HOST_BITS_PER_LONG && unsignedp)
3734 {
3735 mask = (~ (HOST_WIDE_INT) 0) << bits;
3736 if ((mask & constant) != mask)
3737 warning (0, "comparison of promoted ~unsigned with constant");
3738 }
3739 }
3740 else if (unsignedp0 && unsignedp1
3741 && (TYPE_PRECISION (TREE_TYPE (primop0))
3742 < TYPE_PRECISION (result_type))
3743 && (TYPE_PRECISION (TREE_TYPE (primop1))
3744 < TYPE_PRECISION (result_type)))
3745 warning (0, "comparison of promoted ~unsigned with unsigned");
3746 }
3747 }
3748 }
3749
3750 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3751 Then the expression will be built.
3752 It will be given type FINAL_TYPE if that is nonzero;
3753 otherwise, it will be given type RESULT_TYPE. */
3754
3755 /* Issue warnings about peculiar, but valid, uses of NULL. */
3756 if (/* It's reasonable to use pointer values as operands of &&
3757 and ||, so NULL is no exception. */
3758 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3759 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3760 (orig_op0 == null_node
3761 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3762 /* Or vice versa. */
3763 || (orig_op1 == null_node
3764 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3765 /* Or, both are NULL and the operation was not a comparison. */
3766 || (orig_op0 == null_node && orig_op1 == null_node
3767 && code != EQ_EXPR && code != NE_EXPR)))
3768 /* Some sort of arithmetic operation involving NULL was
3769 performed. Note that pointer-difference and pointer-addition
3770 have already been handled above, and so we don't end up here in
3771 that case. */
3772 warning (0, "NULL used in arithmetic");
3773
3774 if (! converted)
3775 {
3776 if (TREE_TYPE (op0) != result_type)
3777 op0 = cp_convert (result_type, op0);
3778 if (TREE_TYPE (op1) != result_type)
3779 op1 = cp_convert (result_type, op1);
3780
3781 if (op0 == error_mark_node || op1 == error_mark_node)
3782 return error_mark_node;
3783 }
3784
3785 if (build_type == NULL_TREE)
3786 build_type = result_type;
3787
3788 result = build2 (resultcode, build_type, op0, op1);
3789 result = fold_if_not_in_template (result);
3790 if (final_type != 0)
3791 result = cp_convert (final_type, result);
3792
3793 if (TREE_OVERFLOW_P (result)
3794 && !TREE_OVERFLOW_P (op0)
3795 && !TREE_OVERFLOW_P (op1))
3796 overflow_warning (result);
3797
3798 return result;
3799}
3800
3801/* Return a tree for the sum or difference (RESULTCODE says which)
3802 of pointer PTROP and integer INTOP. */
3803
3804static tree
3805cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3806{
3807 tree res_type = TREE_TYPE (ptrop);
3808
3809 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3810 in certain circumstance (when it's valid to do so). So we need
3811 to make sure it's complete. We don't need to check here, if we
3812 can actually complete it at all, as those checks will be done in
3813 pointer_int_sum() anyway. */
3814 complete_type (TREE_TYPE (res_type));
3815
3816 return pointer_int_sum (resultcode, ptrop,
3817 fold_if_not_in_template (intop));
3818}
3819
3820/* Return a tree for the difference of pointers OP0 and OP1.
3821 The resulting tree has type int. */
3822
3823static tree
3824pointer_diff (tree op0, tree op1, tree ptrtype)
3825{
3826 tree result;
3827 tree restype = ptrdiff_type_node;
3828 tree target_type = TREE_TYPE (ptrtype);
3829
3830 if (!complete_type_or_else (target_type, NULL_TREE))
3831 return error_mark_node;
3832
3833 if (pedantic || warn_pointer_arith)
3834 {
3835 if (TREE_CODE (target_type) == VOID_TYPE)
3836 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3837 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3838 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3839 if (TREE_CODE (target_type) == METHOD_TYPE)
3840 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3841 }
3842
3843 /* First do the subtraction as integers;
3844 then drop through to build the divide operator. */
3845
3846 op0 = cp_build_binary_op (MINUS_EXPR,
3847 cp_convert (restype, op0),
3848 cp_convert (restype, op1));
3849
3850 /* This generates an error if op1 is a pointer to an incomplete type. */
3851 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3852 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3853
3854 op1 = (TYPE_PTROB_P (ptrtype)
3855 ? size_in_bytes (target_type)
3856 : integer_one_node);
3857
3858 /* Do the division. */
3859
3860 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3861 return fold_if_not_in_template (result);
3862}
3863
3864/* Construct and perhaps optimize a tree representation
3865 for a unary operation. CODE, a tree_code, specifies the operation
3866 and XARG is the operand. */
3867
3868tree
3869build_x_unary_op (enum tree_code code, tree xarg)
3870{
3871 tree orig_expr = xarg;
3872 tree exp;
3873 int ptrmem = 0;
3874
3875 if (processing_template_decl)
3876 {
3877 if (type_dependent_expression_p (xarg))
3878 return build_min_nt (code, xarg, NULL_TREE);
3879
3880 xarg = build_non_dependent_expr (xarg);
3881 }
3882
3883 exp = NULL_TREE;
3884
3885 /* [expr.unary.op] says:
3886
3887 The address of an object of incomplete type can be taken.
3888
3889 (And is just the ordinary address operator, not an overloaded
3890 "operator &".) However, if the type is a template
3891 specialization, we must complete the type at this point so that
3892 an overloaded "operator &" will be available if required. */
3893 if (code == ADDR_EXPR
3894 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3895 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3896 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3897 || (TREE_CODE (xarg) == OFFSET_REF)))
3898 /* Don't look for a function. */;
3899 else
3900 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3901 /*overloaded_p=*/NULL);
3902 if (!exp && code == ADDR_EXPR)
3903 {
3904 /* A pointer to member-function can be formed only by saying
3905 &X::mf. */
3906 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3907 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3908 {
3909 if (TREE_CODE (xarg) != OFFSET_REF
3910 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3911 {
3912 error ("invalid use of %qE to form a pointer-to-member-function",
3913 xarg);
3914 if (TREE_CODE (xarg) != OFFSET_REF)
3915 inform (" a qualified-id is required");
3916 return error_mark_node;
3917 }
3918 else
3919 {
3920 error ("parentheses around %qE cannot be used to form a"
3921 " pointer-to-member-function",
3922 xarg);
3923 PTRMEM_OK_P (xarg) = 1;
3924 }
3925 }
3926
3927 if (TREE_CODE (xarg) == OFFSET_REF)
3928 {
3929 ptrmem = PTRMEM_OK_P (xarg);
3930
3931 if (!ptrmem && !flag_ms_extensions
3932 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3933 {
3934 /* A single non-static member, make sure we don't allow a
3935 pointer-to-member. */
3936 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3937 TREE_OPERAND (xarg, 0),
3938 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3939 PTRMEM_OK_P (xarg) = ptrmem;
3940 }
3941 }
3942 else if (TREE_CODE (xarg) == TARGET_EXPR)
3943 warning (0, "taking address of temporary");
3944 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3945 }
3946
3947 if (processing_template_decl && exp != error_mark_node)
3948 exp = build_min_non_dep (code, exp, orig_expr,
3949 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3950 if (TREE_CODE (exp) == ADDR_EXPR)
3951 PTRMEM_OK_P (exp) = ptrmem;
3952 return exp;
3953}
3954
3955/* Like c_common_truthvalue_conversion, but handle pointer-to-member
3956 constants, where a null value is represented by an INTEGER_CST of
3957 -1. */
3958
3959tree
3960cp_truthvalue_conversion (tree expr)
3961{
3962 tree type = TREE_TYPE (expr);
3963 if (TYPE_PTRMEM_P (type))
3964 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3965 else
3966 return c_common_truthvalue_conversion (expr);
3967}
3968
3969/* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3970
3971tree
3972condition_conversion (tree expr)
3973{
3974 tree t;
3975 if (processing_template_decl)
3976 return expr;
3977 t = perform_implicit_conversion (boolean_type_node, expr);
3978 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3979 return t;
3980}
3981
3982/* Return an ADDR_EXPR giving the address of T. This function
3983 attempts no optimizations or simplifications; it is a low-level
3984 primitive. */
3985
3986tree
3987build_address (tree t)
3988{
3989 tree addr;
3990
3991 if (error_operand_p (t) || !cxx_mark_addressable (t))
3992 return error_mark_node;
3993
3994 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3995
3996 return addr;
3997}
3998
3999/* Return a NOP_EXPR converting EXPR to TYPE. */
4000
4001tree
4002build_nop (tree type, tree expr)
4003{
4004 if (type == error_mark_node || error_operand_p (expr))
4005 return expr;
4006 return build1 (NOP_EXPR, type, expr);
4007}
4008
4009/* C++: Must handle pointers to members.
4010
4011 Perhaps type instantiation should be extended to handle conversion
4012 from aggregates to types we don't yet know we want? (Or are those
4013 cases typically errors which should be reported?)
4014
4015 NOCONVERT nonzero suppresses the default promotions
4016 (such as from short to int). */
4017
4018tree
4019build_unary_op (enum tree_code code, tree xarg, int noconvert)
4020{
4021 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4022 tree arg = xarg;
4023 tree argtype = 0;
4024 const char *errstring = NULL;
4025 tree val;
4026 const char *invalid_op_diag;
4027
4028 if (arg == error_mark_node)
4029 return error_mark_node;
4030
4031 if ((invalid_op_diag
4032 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4033 ? CONVERT_EXPR
4034 : code),
4035 TREE_TYPE (xarg))))
4036 {
4037 error (invalid_op_diag, "");
4038 return error_mark_node;
4039 }
4040
4041 switch (code)
4042 {
4043 case UNARY_PLUS_EXPR:
4044 case NEGATE_EXPR:
4045 {
4046 int flags = WANT_ARITH | WANT_ENUM;
4047 /* Unary plus (but not unary minus) is allowed on pointers. */
4048 if (code == UNARY_PLUS_EXPR)
4049 flags |= WANT_POINTER;
4050 arg = build_expr_type_conversion (flags, arg, true);
4051 if (!arg)
4052 errstring = (code == NEGATE_EXPR
4053 ? "wrong type argument to unary minus"
4054 : "wrong type argument to unary plus");
4055 else
4056 {
4057 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4058 arg = perform_integral_promotions (arg);
4059
4060 /* Make sure the result is not an lvalue: a unary plus or minus
4061 expression is always a rvalue. */
4062 arg = rvalue (arg);
4063 }
4064 }
4065 break;
4066
4067 case BIT_NOT_EXPR:
4068 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4069 {
4070 code = CONJ_EXPR;
4071 if (!noconvert)
4072 arg = default_conversion (arg);
4073 }
4074 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4075 | WANT_VECTOR,
4076 arg, true)))
4077 errstring = "wrong type argument to bit-complement";
4078 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4079 arg = perform_integral_promotions (arg);
4080 break;
4081
4082 case ABS_EXPR:
4083 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4084 errstring = "wrong type argument to abs";
4085 else if (!noconvert)
4086 arg = default_conversion (arg);
4087 break;
4088
4089 case CONJ_EXPR:
4090 /* Conjugating a real value is a no-op, but allow it anyway. */
4091 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4092 errstring = "wrong type argument to conjugation";
4093 else if (!noconvert)
4094 arg = default_conversion (arg);
4095 break;
4096
4097 case TRUTH_NOT_EXPR:
4098 arg = perform_implicit_conversion (boolean_type_node, arg);
4099 val = invert_truthvalue (arg);
4100 if (arg != error_mark_node)
4101 return val;
4102 errstring = "in argument to unary !";
4103 break;
4104
4105 case NOP_EXPR:
4106 break;
4107
4108 case REALPART_EXPR:
4109 if (TREE_CODE (arg) == COMPLEX_CST)
4110 return TREE_REALPART (arg);
4111 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4112 {
4113 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4114 return fold_if_not_in_template (arg);
4115 }
4116 else
4117 return arg;
4118
4119 case IMAGPART_EXPR:
4120 if (TREE_CODE (arg) == COMPLEX_CST)
4121 return TREE_IMAGPART (arg);
4122 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4123 {
4124 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4125 return fold_if_not_in_template (arg);
4126 }
4127 else
4128 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4129
4130 case PREINCREMENT_EXPR:
4131 case POSTINCREMENT_EXPR:
4132 case PREDECREMENT_EXPR:
4133 case POSTDECREMENT_EXPR:
4134 /* Handle complex lvalues (when permitted)
4135 by reduction to simpler cases. */
4136
4137 val = unary_complex_lvalue (code, arg);
4138 if (val != 0)
4139 return val;
4140
4141 /* Increment or decrement the real part of the value,
4142 and don't change the imaginary part. */
4143 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4144 {
4145 tree real, imag;
4146
4147 arg = stabilize_reference (arg);
4148 real = build_unary_op (REALPART_EXPR, arg, 1);
4149 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4150 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4151 build_unary_op (code, real, 1), imag);
4152 }
4153
4154 /* Report invalid types. */
4155
4156 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4157 arg, true)))
4158 {
4159 if (code == PREINCREMENT_EXPR)
4160 errstring ="no pre-increment operator for type";
4161 else if (code == POSTINCREMENT_EXPR)
4162 errstring ="no post-increment operator for type";
4163 else if (code == PREDECREMENT_EXPR)
4164 errstring ="no pre-decrement operator for type";
4165 else
4166 errstring ="no post-decrement operator for type";
4167 break;
4168 }
4169
4170 /* Report something read-only. */
4171
4172 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4173 || TREE_READONLY (arg))
4174 readonly_error (arg, ((code == PREINCREMENT_EXPR
4175 || code == POSTINCREMENT_EXPR)
4176 ? "increment" : "decrement"),
4177 0);
4178
4179 {
4180 tree inc;
4181 tree declared_type;
4182 tree result_type = TREE_TYPE (arg);
4183
4184 declared_type = unlowered_expr_type (arg);
4185
4186 arg = get_unwidened (arg, 0);
4187 argtype = TREE_TYPE (arg);
4188
4189 /* ARM $5.2.5 last annotation says this should be forbidden. */
4190 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4191 pedwarn ("ISO C++ forbids %sing an enum",
4192 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4193 ? "increment" : "decrement");
4194
4195 /* Compute the increment. */
4196
4197 if (TREE_CODE (argtype) == POINTER_TYPE)
4198 {
4199 tree type = complete_type (TREE_TYPE (argtype));
4200
4201 if (!COMPLETE_OR_VOID_TYPE_P (type))
4202 error ("cannot %s a pointer to incomplete type %qT",
4203 ((code == PREINCREMENT_EXPR
4204 || code == POSTINCREMENT_EXPR)
4205 ? "increment" : "decrement"), TREE_TYPE (argtype));
4206 else if ((pedantic || warn_pointer_arith)
4207 && !TYPE_PTROB_P (argtype))
4208 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4209 ((code == PREINCREMENT_EXPR
4210 || code == POSTINCREMENT_EXPR)
4211 ? "increment" : "decrement"), argtype);
4212 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4213 }
4214 else
4215 inc = integer_one_node;
4216
4217 inc = cp_convert (argtype, inc);
4218
4219 /* Handle incrementing a cast-expression. */
4220
4221 switch (TREE_CODE (arg))
4222 {
4223 case NOP_EXPR:
4224 case CONVERT_EXPR:
4225 case FLOAT_EXPR:
4226 case FIX_TRUNC_EXPR:
4227 case FIX_FLOOR_EXPR:
4228 case FIX_ROUND_EXPR:
4229 case FIX_CEIL_EXPR:
4230 {
4231 tree incremented, modify, value, compound;
4232 if (! lvalue_p (arg) && pedantic)
4233 pedwarn ("cast to non-reference type used as lvalue");
4234 arg = stabilize_reference (arg);
4235 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4236 value = arg;
4237 else
4238 value = save_expr (arg);
4239 incremented = build2 (((code == PREINCREMENT_EXPR
4240 || code == POSTINCREMENT_EXPR)
4241 ? PLUS_EXPR : MINUS_EXPR),
4242 argtype, value, inc);
4243
4244 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4245 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4246 modify, value);
4247
4248 /* Eliminate warning about unused result of + or -. */
4249 TREE_NO_WARNING (compound) = 1;
4250 return compound;
4251 }
4252
4253 default:
4254 break;
4255 }
4256
4257 /* Complain about anything else that is not a true lvalue. */
4258 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4259 || code == POSTINCREMENT_EXPR)
4260 ? lv_increment : lv_decrement)))
4261 return error_mark_node;
4262
4263 /* Forbid using -- on `bool'. */
4264 if (same_type_p (declared_type, boolean_type_node))
4265 {
4266 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4267 {
4268 error ("invalid use of %<--%> on bool variable %qD", arg);
4269 return error_mark_node;
4270 }
4271 val = boolean_increment (code, arg);
4272 }
4273 else
4274 val = build2 (code, TREE_TYPE (arg), arg, inc);
4275
4276 TREE_SIDE_EFFECTS (val) = 1;
4277 return cp_convert (result_type, val);
4278 }
4279
4280 case ADDR_EXPR:
4281 /* Note that this operation never does default_conversion
4282 regardless of NOCONVERT. */
4283
4284 argtype = lvalue_type (arg);
4285
4286 if (TREE_CODE (arg) == OFFSET_REF)
4287 goto offset_ref;
4288
4289 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4290 {
4291 tree type = build_pointer_type (TREE_TYPE (argtype));
4292 arg = build1 (CONVERT_EXPR, type, arg);
4293 return arg;
4294 }
4295 else if (pedantic && DECL_MAIN_P (arg))
4296 /* ARM $3.4 */
4297 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4298
4299 /* Let &* cancel out to simplify resulting code. */
4300 if (TREE_CODE (arg) == INDIRECT_REF)
4301 {
4302 /* We don't need to have `current_class_ptr' wrapped in a
4303 NON_LVALUE_EXPR node. */
4304 if (arg == current_class_ref)
4305 return current_class_ptr;
4306
4307 arg = TREE_OPERAND (arg, 0);
4308 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4309 {
4310 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4311 arg = build1 (CONVERT_EXPR, type, arg);
4312 }
4313 else
4314 /* Don't let this be an lvalue. */
4315 arg = rvalue (arg);
4316 return arg;
4317 }
4318
4319 /* Uninstantiated types are all functions. Taking the
4320 address of a function is a no-op, so just return the
4321 argument. */
4322
4323 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4324 || !IDENTIFIER_OPNAME_P (arg));
4325
4326 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4327 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4328 {
4329 /* They're trying to take the address of a unique non-static
4330 member function. This is ill-formed (except in MS-land),
4331 but let's try to DTRT.
4332 Note: We only handle unique functions here because we don't
4333 want to complain if there's a static overload; non-unique
4334 cases will be handled by instantiate_type. But we need to
4335 handle this case here to allow casts on the resulting PMF.
4336 We could defer this in non-MS mode, but it's easier to give
4337 a useful error here. */
4338
4339 /* Inside constant member functions, the `this' pointer
4340 contains an extra const qualifier. TYPE_MAIN_VARIANT
4341 is used here to remove this const from the diagnostics
4342 and the created OFFSET_REF. */
4343 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4344 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4345 mark_used (fn);
4346
4347 if (! flag_ms_extensions)
4348 {
4349 tree name = DECL_NAME (fn);
4350 if (current_class_type
4351 && TREE_OPERAND (arg, 0) == current_class_ref)
4352 /* An expression like &memfn. */
4353 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4354 " or parenthesized non-static member function to form"
4355 " a pointer to member function. Say %<&%T::%D%>",
4356 base, name);
4357 else
4358 pedwarn ("ISO C++ forbids taking the address of a bound member"
4359 " function to form a pointer to member function."
4360 " Say %<&%T::%D%>",
4361 base, name);
4362 }
4363 arg = build_offset_ref (base, fn, /*address_p=*/true);
4364 }
4365
4366 offset_ref:
4367 if (type_unknown_p (arg))
4368 return build1 (ADDR_EXPR, unknown_type_node, arg);
4369
4370 /* Handle complex lvalues (when permitted)
4371 by reduction to simpler cases. */
4372 val = unary_complex_lvalue (code, arg);
4373 if (val != 0)
4374 return val;
4375
4376 switch (TREE_CODE (arg))
4377 {
4378 case NOP_EXPR:
4379 case CONVERT_EXPR:
4380 case FLOAT_EXPR:
4381 case FIX_TRUNC_EXPR:
4382 case FIX_FLOOR_EXPR:
4383 case FIX_ROUND_EXPR:
4384 case FIX_CEIL_EXPR:
4385 if (! lvalue_p (arg) && pedantic)
4386 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4387 break;
4388
4389 case BASELINK:
4390 arg = BASELINK_FUNCTIONS (arg);
4391 /* Fall through. */
4392
4393 case OVERLOAD:
4394 arg = OVL_CURRENT (arg);
4395 break;
4396
4397 case OFFSET_REF:
4398 /* Turn a reference to a non-static data member into a
4399 pointer-to-member. */
4400 {
4401 tree type;
4402 tree t;
4403
4404 if (!PTRMEM_OK_P (arg))
4405 return build_unary_op (code, arg, 0);
4406
4407 t = TREE_OPERAND (arg, 1);
4408 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4409 {
4410 error ("cannot create pointer to reference member %qD", t);
4411 return error_mark_node;
4412 }
4413
4414 type = build_ptrmem_type (context_for_name_lookup (t),
4415 TREE_TYPE (t));
4416 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4417 return t;
4418 }
4419
4420 default:
4421 break;
4422 }
4423
4424 /* Anything not already handled and not a true memory reference
4425 is an error. */
4426 if (TREE_CODE (argtype) != FUNCTION_TYPE
4427 && TREE_CODE (argtype) != METHOD_TYPE
4428 && TREE_CODE (arg) != OFFSET_REF
4429 && !lvalue_or_else (arg, lv_addressof))
4430 return error_mark_node;
4431
4432 if (argtype != error_mark_node)
4433 argtype = build_pointer_type (argtype);
4434
4435 /* In a template, we are processing a non-dependent expression
4436 so we can just form an ADDR_EXPR with the correct type. */
4437 if (processing_template_decl)
4438 {
4439 val = build_address (arg);
4440 if (TREE_CODE (arg) == OFFSET_REF)
4441 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4442 return val;
4443 }
4444
4445 if (TREE_CODE (arg) != COMPONENT_REF)
4446 {
4447 val = build_address (arg);
4448 if (TREE_CODE (arg) == OFFSET_REF)
4449 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4450 }
4451 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4452 {
4453 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4454
4455 /* We can only get here with a single static member
4456 function. */
4457 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4458 && DECL_STATIC_FUNCTION_P (fn));
4459 mark_used (fn);
4460 val = build_address (fn);
4461 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4462 /* Do not lose object's side effects. */
4463 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4464 TREE_OPERAND (arg, 0), val);
4465 }
4466 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4467 {
4468 error ("attempt to take address of bit-field structure member %qD",
4469 TREE_OPERAND (arg, 1));
4470 return error_mark_node;
4471 }
4472 else
4473 {
4474 tree object = TREE_OPERAND (arg, 0);
4475 tree field = TREE_OPERAND (arg, 1);
4476 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4477 (TREE_TYPE (object), decl_type_context (field)));
4478 val = build_address (arg);
4479 }
4480
4481 if (TREE_CODE (argtype) == POINTER_TYPE
4482 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4483 {
4484 build_ptrmemfunc_type (argtype);
4485 val = build_ptrmemfunc (argtype, val, 0,
4486 /*c_cast_p=*/false);
4487 }
4488
4489 return val;
4490
4491 default:
4492 break;
4493 }
4494
4495 if (!errstring)
4496 {
4497 if (argtype == 0)
4498 argtype = TREE_TYPE (arg);
4499 return fold_if_not_in_template (build1 (code, argtype, arg));
4500 }
4501
4502 error ("%s", errstring);
4503 return error_mark_node;
4504}
4505
4506/* Apply unary lvalue-demanding operator CODE to the expression ARG
4507 for certain kinds of expressions which are not really lvalues
4508 but which we can accept as lvalues.
4509
4510 If ARG is not a kind of expression we can handle, return
4511 NULL_TREE. */
4512
4513tree
4514unary_complex_lvalue (enum tree_code code, tree arg)
4515{
4516 /* Inside a template, making these kinds of adjustments is
4517 pointless; we are only concerned with the type of the
4518 expression. */
4519 if (processing_template_decl)
4520 return NULL_TREE;
4521
4522 /* Handle (a, b) used as an "lvalue". */
4523 if (TREE_CODE (arg) == COMPOUND_EXPR)
4524 {
4525 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4526 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4527 TREE_OPERAND (arg, 0), real_result);
4528 }
4529
4530 /* Handle (a ? b : c) used as an "lvalue". */
4531 if (TREE_CODE (arg) == COND_EXPR
4532 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4533 return rationalize_conditional_expr (code, arg);
4534
4535 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4536 if (TREE_CODE (arg) == MODIFY_EXPR
4537 || TREE_CODE (arg) == PREINCREMENT_EXPR
4538 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4539 {
4540 tree lvalue = TREE_OPERAND (arg, 0);
4541 if (TREE_SIDE_EFFECTS (lvalue))
4542 {
4543 lvalue = stabilize_reference (lvalue);
4544 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4545 lvalue, TREE_OPERAND (arg, 1));
4546 }
4547 return unary_complex_lvalue
4548 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4549 }
4550
4551 if (code != ADDR_EXPR)
4552 return NULL_TREE;
4553
4554 /* Handle (a = b) used as an "lvalue" for `&'. */
4555 if (TREE_CODE (arg) == MODIFY_EXPR
4556 || TREE_CODE (arg) == INIT_EXPR)
4557 {
4558 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4559 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4560 arg, real_result);
4561 TREE_NO_WARNING (arg) = 1;
4562 return arg;
4563 }
4564
4565 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4566 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4567 || TREE_CODE (arg) == OFFSET_REF)
4568 return NULL_TREE;
4569
4570 /* We permit compiler to make function calls returning
4571 objects of aggregate type look like lvalues. */
4572 {
4573 tree targ = arg;
4574
4575 if (TREE_CODE (targ) == SAVE_EXPR)
4576 targ = TREE_OPERAND (targ, 0);
4577
4578 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4579 {
4580 if (TREE_CODE (arg) == SAVE_EXPR)
4581 targ = arg;
4582 else
4583 targ = build_cplus_new (TREE_TYPE (arg), arg);
4584 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4585 }
4586
4587 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4588 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4589 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4590 }
4591
4592 /* Don't let anything else be handled specially. */
4593 return NULL_TREE;
4594}
4595
4596/* Mark EXP saying that we need to be able to take the
4597 address of it; it should not be allocated in a register.
4598 Value is true if successful.
4599
4600 C++: we do not allow `current_class_ptr' to be addressable. */
4601
4602bool
4603cxx_mark_addressable (tree exp)
4604{
4605 tree x = exp;
4606
4607 while (1)
4608 switch (TREE_CODE (x))
4609 {
4610 case ADDR_EXPR:
4611 case COMPONENT_REF:
4612 case ARRAY_REF:
4613 case REALPART_EXPR:
4614 case IMAGPART_EXPR:
4615 x = TREE_OPERAND (x, 0);
4616 break;
4617
4618 case PARM_DECL:
4619 if (x == current_class_ptr)
4620 {
4621 error ("cannot take the address of %<this%>, which is an rvalue expression");
4622 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4623 return true;
4624 }
4625 /* Fall through. */
4626
4627 case VAR_DECL:
4628 /* Caller should not be trying to mark initialized
4629 constant fields addressable. */
4630 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4631 || DECL_IN_AGGR_P (x) == 0
4632 || TREE_STATIC (x)
4633 || DECL_EXTERNAL (x));
4634 /* Fall through. */
4635
4636 case CONST_DECL:
4637 case RESULT_DECL:
4638 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4639 && !DECL_ARTIFICIAL (x))
4640 {
4641 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4642 {
4643 error
4644 ("address of explicit register variable %qD requested", x);
4645 return false;
4646 }
4647 else if (extra_warnings)
4648 warning
4649 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4650 }
4651 TREE_ADDRESSABLE (x) = 1;
4652 return true;
4653
4654 case FUNCTION_DECL:
4655 TREE_ADDRESSABLE (x) = 1;
4656 return true;
4657
4658 case CONSTRUCTOR:
4659 TREE_ADDRESSABLE (x) = 1;
4660 return true;
4661
4662 case TARGET_EXPR:
4663 TREE_ADDRESSABLE (x) = 1;
4664 cxx_mark_addressable (TREE_OPERAND (x, 0));
4665 return true;
4666
4667 default:
4668 return true;
4669 }
4670}
4671
4672/* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4673
4674tree
4675build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4676{
4677 tree orig_ifexp = ifexp;
4678 tree orig_op1 = op1;
4679 tree orig_op2 = op2;
4680 tree expr;
4681
4682 if (processing_template_decl)
4683 {
4684 /* The standard says that the expression is type-dependent if
4685 IFEXP is type-dependent, even though the eventual type of the
4686 expression doesn't dependent on IFEXP. */
4687 if (type_dependent_expression_p (ifexp)
4688 /* As a GNU extension, the middle operand may be omitted. */
4689 || (op1 && type_dependent_expression_p (op1))
4690 || type_dependent_expression_p (op2))
4691 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4692 ifexp = build_non_dependent_expr (ifexp);
4693 if (op1)
4694 op1 = build_non_dependent_expr (op1);
4695 op2 = build_non_dependent_expr (op2);
4696 }
4697
4698 expr = build_conditional_expr (ifexp, op1, op2);
4699 if (processing_template_decl && expr != error_mark_node)
4700 return build_min_non_dep (COND_EXPR, expr,
4701 orig_ifexp, orig_op1, orig_op2);
4702 return expr;
4703}
4704
4705/* Given a list of expressions, return a compound expression
4706 that performs them all and returns the value of the last of them. */
4707
4708tree build_x_compound_expr_from_list (tree list, const char *msg)
4709{
4710 tree expr = TREE_VALUE (list);
4711
4712 if (TREE_CHAIN (list))
4713 {
4714 if (msg)
4715 pedwarn ("%s expression list treated as compound expression", msg);
4716
4717 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4718 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4719 }
4720
4721 return expr;
4722}
4723
4724/* Handle overloading of the ',' operator when needed. */
4725
4726tree
4727build_x_compound_expr (tree op1, tree op2)
4728{
4729 tree result;
4730 tree orig_op1 = op1;
4731 tree orig_op2 = op2;
4732
4733 if (processing_template_decl)
4734 {
4735 if (type_dependent_expression_p (op1)
4736 || type_dependent_expression_p (op2))
4737 return build_min_nt (COMPOUND_EXPR, op1, op2);
4738 op1 = build_non_dependent_expr (op1);
4739 op2 = build_non_dependent_expr (op2);
4740 }
4741
4742 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4743 /*overloaded_p=*/NULL);
4744 if (!result)
4745 result = build_compound_expr (op1, op2);
4746
4747 if (processing_template_decl && result != error_mark_node)
4748 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4749
4750 return result;
4751}
4752
4753/* Build a compound expression. */
4754
4755tree
4756build_compound_expr (tree lhs, tree rhs)
4757{
4758 lhs = convert_to_void (lhs, "left-hand operand of comma");
4759
4760 if (lhs == error_mark_node || rhs == error_mark_node)
4761 return error_mark_node;
4762
4763 if (TREE_CODE (rhs) == TARGET_EXPR)
4764 {
4765 /* If the rhs is a TARGET_EXPR, then build the compound
4766 expression inside the target_expr's initializer. This
4767 helps the compiler to eliminate unnecessary temporaries. */
4768 tree init = TREE_OPERAND (rhs, 1);
4769
4770 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4771 TREE_OPERAND (rhs, 1) = init;
4772
4773 return rhs;
4774 }
4775
4776 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4777}
4778
4779/* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4780 casts away constness. DIAG_FN gives the function to call if we
4781 need to issue a diagnostic; if it is NULL, no diagnostic will be
4782 issued. DESCRIPTION explains what operation is taking place. */
4783
4784static void
4785check_for_casting_away_constness (tree src_type, tree dest_type,
4786 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4787 const char *description)
4788{
4789 if (diag_fn && casts_away_constness (src_type, dest_type))
4790 diag_fn ("%s from type %qT to type %qT casts away constness",
4791 description, src_type, dest_type);
4792}
4793
4794/* Convert EXPR (an expression with pointer-to-member type) to TYPE
4795 (another pointer-to-member type in the same hierarchy) and return
4796 the converted expression. If ALLOW_INVERSE_P is permitted, a
4797 pointer-to-derived may be converted to pointer-to-base; otherwise,
4798 only the other direction is permitted. If C_CAST_P is true, this
4799 conversion is taking place as part of a C-style cast. */
4800
4801tree
4802convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4803 bool c_cast_p)
4804{
4805 if (TYPE_PTRMEM_P (type))
4806 {
4807 tree delta;
4808
4809 if (TREE_CODE (expr) == PTRMEM_CST)
4810 expr = cplus_expand_constant (expr);
4811 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4812 TYPE_PTRMEM_CLASS_TYPE (type),
4813 allow_inverse_p,
4814 c_cast_p);
4815 if (!integer_zerop (delta))
4816 expr = cp_build_binary_op (PLUS_EXPR,
4817 build_nop (ptrdiff_type_node, expr),
4818 delta);
4819 return build_nop (type, expr);
4820 }
4821 else
4822 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4823 allow_inverse_p, c_cast_p);
4824}
4825
4826/* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4827 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4828 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4829
4830static tree
4831ignore_overflows (tree expr, tree orig)
4832{
4833 if (TREE_CODE (expr) == INTEGER_CST
4834 && CONSTANT_CLASS_P (orig)
4835 && TREE_CODE (orig) != STRING_CST
4836 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4837 || TREE_CONSTANT_OVERFLOW (expr)
4838 != TREE_CONSTANT_OVERFLOW (orig)))
4839 {
4840 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4841 /* Ensure constant sharing. */
4842 expr = build_int_cst_wide (TREE_TYPE (expr),
4843 TREE_INT_CST_LOW (expr),
4844 TREE_INT_CST_HIGH (expr));
4845 else
4846 {
4847 /* Avoid clobbering a shared constant. */
4848 expr = copy_node (expr);
4849 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4850 TREE_CONSTANT_OVERFLOW (expr)
4851 = TREE_CONSTANT_OVERFLOW (orig);
4852 }
4853 }
4854 return expr;
4855}
4856
4857/* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4858 this static_cast is being attempted as one of the possible casts
4859 allowed by a C-style cast. (In that case, accessibility of base
4860 classes is not considered, and it is OK to cast away
4861 constness.) Return the result of the cast. *VALID_P is set to
4862 indicate whether or not the cast was valid. */
4863
4864static tree
4865build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4866 bool *valid_p)
4867{
4868 tree intype;
4869 tree result;
4870 tree orig;
4871 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4872 const char *desc;
4873
4874 /* Assume the cast is valid. */
4875 *valid_p = true;
4876
4877 intype = TREE_TYPE (expr);
4878
4879 /* Save casted types in the function's used types hash table. */
4880 used_types_insert (type);
4881
4882 /* Determine what to do when casting away constness. */
4883 if (c_cast_p)
4884 {
4885 /* C-style casts are allowed to cast away constness. With
4886 WARN_CAST_QUAL, we still want to issue a warning. */
4887 diag_fn = warn_cast_qual ? warning0 : NULL;
4888 desc = "cast";
4889 }
4890 else
4891 {
4892 /* A static_cast may not cast away constness. */
4893 diag_fn = error;
4894 desc = "static_cast";
4895 }
4896
4897 /* [expr.static.cast]
4898
4899 An lvalue of type "cv1 B", where B is a class type, can be cast
4900 to type "reference to cv2 D", where D is a class derived (clause
4901 _class.derived_) from B, if a valid standard conversion from
4902 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4903 same cv-qualification as, or greater cv-qualification than, cv1,
4904 and B is not a virtual base class of D. */
4905 /* We check this case before checking the validity of "TYPE t =
4906 EXPR;" below because for this case:
4907
4908 struct B {};
4909 struct D : public B { D(const B&); };
4910 extern B& b;
4911 void f() { static_cast<const D&>(b); }
4912
4913 we want to avoid constructing a new D. The standard is not
4914 completely clear about this issue, but our interpretation is
4915 consistent with other compilers. */
4916 if (TREE_CODE (type) == REFERENCE_TYPE
4917 && CLASS_TYPE_P (TREE_TYPE (type))
4918 && CLASS_TYPE_P (intype)
4919 && real_lvalue_p (expr)
4920 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4921 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4922 build_pointer_type (TYPE_MAIN_VARIANT
4923 (TREE_TYPE (type))))
4924 && (c_cast_p
4925 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4926 {
4927 tree base;
4928
4929 /* There is a standard conversion from "D*" to "B*" even if "B"
4930 is ambiguous or inaccessible. If this is really a
4931 static_cast, then we check both for inaccessibility and
4932 ambiguity. However, if this is a static_cast being performed
4933 because the user wrote a C-style cast, then accessibility is
4934 not considered. */
4935 base = lookup_base (TREE_TYPE (type), intype,
4936 c_cast_p ? ba_unique : ba_check,
4937 NULL);
4938
4939 /* Convert from "B*" to "D*". This function will check that "B"
4940 is not a virtual base of "D". */
4941 expr = build_base_path (MINUS_EXPR, build_address (expr),
4942 base, /*nonnull=*/false);
4943 /* Convert the pointer to a reference -- but then remember that
4944 there are no expressions with reference type in C++. */
4945 return convert_from_reference (build_nop (type, expr));
4946 }
4947
4948 orig = expr;
4949
4950 /* [expr.static.cast]
4951
4952 An expression e can be explicitly converted to a type T using a
4953 static_cast of the form static_cast<T>(e) if the declaration T
4954 t(e);" is well-formed, for some invented temporary variable
4955 t. */
4956 result = perform_direct_initialization_if_possible (type, expr,
4957 c_cast_p);
4958 if (result)
4959 {
4960 result = convert_from_reference (result);
4961
4962 /* Ignore any integer overflow caused by the cast. */
4963 result = ignore_overflows (result, orig);
4964
4965 /* [expr.static.cast]
4966
4967 If T is a reference type, the result is an lvalue; otherwise,
4968 the result is an rvalue. */
4969 if (TREE_CODE (type) != REFERENCE_TYPE)
4970 result = rvalue (result);
4971 return result;
4972 }
4973
4974 /* [expr.static.cast]
4975
4976 Any expression can be explicitly converted to type cv void. */
4977 if (TREE_CODE (type) == VOID_TYPE)
4978 return convert_to_void (expr, /*implicit=*/NULL);
4979
4980 /* [expr.static.cast]
4981
4982 The inverse of any standard conversion sequence (clause _conv_),
4983 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4984 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4985 (_conv.bool_) conversions, can be performed explicitly using
4986 static_cast subject to the restriction that the explicit
4987 conversion does not cast away constness (_expr.const.cast_), and
4988 the following additional rules for specific cases: */
4989 /* For reference, the conversions not excluded are: integral
4990 promotions, floating point promotion, integral conversions,
4991 floating point conversions, floating-integral conversions,
4992 pointer conversions, and pointer to member conversions. */
4993 /* DR 128
4994
4995 A value of integral _or enumeration_ type can be explicitly
4996 converted to an enumeration type. */
4997 /* The effect of all that is that any conversion between any two
4998 types which are integral, floating, or enumeration types can be
4999 performed. */
5000 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5001 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5002 {
5003 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5004
5005 /* Ignore any integer overflow caused by the cast. */
5006 expr = ignore_overflows (expr, orig);
5007 return expr;
5008 }
5009
5010 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5011 && CLASS_TYPE_P (TREE_TYPE (type))
5012 && CLASS_TYPE_P (TREE_TYPE (intype))
5013 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5014 (TREE_TYPE (intype))),
5015 build_pointer_type (TYPE_MAIN_VARIANT
5016 (TREE_TYPE (type)))))
5017 {
5018 tree base;
5019
5020 if (!c_cast_p)
5021 check_for_casting_away_constness (intype, type, diag_fn, desc);
5022 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5023 c_cast_p ? ba_unique : ba_check,
5024 NULL);
5025 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5026 }
5027
5028 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5029 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5030 {
5031 tree c1;
5032 tree c2;
5033 tree t1;
5034 tree t2;
5035
5036 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5037 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5038
5039 if (TYPE_PTRMEM_P (type))
5040 {
5041 t1 = (build_ptrmem_type
5042 (c1,
5043 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5044 t2 = (build_ptrmem_type
5045 (c2,
5046 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5047 }
5048 else
5049 {
5050 t1 = intype;
5051 t2 = type;
5052 }
5053 if (can_convert (t1, t2))
5054 {
5055 if (!c_cast_p)
5056 check_for_casting_away_constness (intype, type, diag_fn,
5057 desc);
5058 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5059 c_cast_p);
5060 }
5061 }
5062
5063 /* [expr.static.cast]
5064
5065 An rvalue of type "pointer to cv void" can be explicitly
5066 converted to a pointer to object type. A value of type pointer
5067 to object converted to "pointer to cv void" and back to the
5068 original pointer type will have its original value. */
5069 if (TREE_CODE (intype) == POINTER_TYPE
5070 && VOID_TYPE_P (TREE_TYPE (intype))
5071 && TYPE_PTROB_P (type))
5072 {
5073 if (!c_cast_p)
5074 check_for_casting_away_constness (intype, type, diag_fn, desc);
5075 return build_nop (type, expr);
5076 }
5077
5078 *valid_p = false;
5079 return error_mark_node;
5080}
5081
5082/* Return an expression representing static_cast<TYPE>(EXPR). */
5083
5084tree
5085build_static_cast (tree type, tree expr)
5086{
5087 tree result;
5088 bool valid_p;
5089
5090 if (type == error_mark_node || expr == error_mark_node)
5091 return error_mark_node;
5092
5093 if (processing_template_decl)
5094 {
5095 expr = build_min (STATIC_CAST_EXPR, type, expr);
5096 /* We don't know if it will or will not have side effects. */
5097 TREE_SIDE_EFFECTS (expr) = 1;
5098 return convert_from_reference (expr);
5099 }
5100
5101 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5102 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5103 if (TREE_CODE (type) != REFERENCE_TYPE
5104 && TREE_CODE (expr) == NOP_EXPR
5105 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5106 expr = TREE_OPERAND (expr, 0);
5107
5108 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5109 if (valid_p)
5110 return result;
5111
5112 error ("invalid static_cast from type %qT to type %qT",
5113 TREE_TYPE (expr), type);
5114 return error_mark_node;
5115}
5116
5117/* EXPR is an expression with member function or pointer-to-member
5118 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5119 not permitted by ISO C++, but we accept it in some modes. If we
5120 are not in one of those modes, issue a diagnostic. Return the
5121 converted expression. */
5122
5123tree
5124convert_member_func_to_ptr (tree type, tree expr)
5125{
5126 tree intype;
5127 tree decl;
5128
5129 intype = TREE_TYPE (expr);
5130 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5131 || TREE_CODE (intype) == METHOD_TYPE);
5132
5133 if (pedantic || warn_pmf2ptr)
5134 pedwarn ("converting from %qT to %qT", intype, type);
5135
5136 if (TREE_CODE (intype) == METHOD_TYPE)
5137 expr = build_addr_func (expr);
5138 else if (TREE_CODE (expr) == PTRMEM_CST)
5139 expr = build_address (PTRMEM_CST_MEMBER (expr));
5140 else
5141 {
5142 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5143 decl = build_address (decl);
5144 expr = get_member_function_from_ptrfunc (&decl, expr);
5145 }
5146
5147 return build_nop (type, expr);
5148}
5149
5150/* Return a representation for a reinterpret_cast from EXPR to TYPE.
5151 If C_CAST_P is true, this reinterpret cast is being done as part of
5152 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5153 indicate whether or not reinterpret_cast was valid. */
5154
5155static tree
5156build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5157 bool *valid_p)
5158{
5159 tree intype;
5160
5161 /* Assume the cast is invalid. */
5162 if (valid_p)
5163 *valid_p = true;
5164
5165 if (type == error_mark_node || error_operand_p (expr))
5166 return error_mark_node;
5167
5168 intype = TREE_TYPE (expr);
5169
5170 /* Save casted types in the function's used types hash table. */
5171 used_types_insert (type);
5172
5173 /* [expr.reinterpret.cast]
5174 An lvalue expression of type T1 can be cast to the type
5175 "reference to T2" if an expression of type "pointer to T1" can be
5176 explicitly converted to the type "pointer to T2" using a
5177 reinterpret_cast. */
5178 if (TREE_CODE (type) == REFERENCE_TYPE)
5179 {
5180 if (! real_lvalue_p (expr))
5181 {
5182 error ("invalid cast of an rvalue expression of type "
5183 "%qT to type %qT",
5184 intype, type);
5185 return error_mark_node;
5186 }
5187
5188 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5189 "B" are related class types; the reinterpret_cast does not
5190 adjust the pointer. */
5191 if (TYPE_PTR_P (intype)
5192 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5193 COMPARE_BASE | COMPARE_DERIVED)))
5194 warning (0, "casting %qT to %qT does not dereference pointer",
5195 intype, type);
5196
5197 expr = build_unary_op (ADDR_EXPR, expr, 0);
5198 if (expr != error_mark_node)
5199 expr = build_reinterpret_cast_1
5200 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5201 valid_p);
5202 if (expr != error_mark_node)
5203 expr = build_indirect_ref (expr, 0);
5204 return expr;
5205 }
5206
5207 /* As a G++ extension, we consider conversions from member
5208 functions, and pointers to member functions to
5209 pointer-to-function and pointer-to-void types. If
5210 -Wno-pmf-conversions has not been specified,
5211 convert_member_func_to_ptr will issue an error message. */
5212 if ((TYPE_PTRMEMFUNC_P (intype)
5213 || TREE_CODE (intype) == METHOD_TYPE)
5214 && TYPE_PTR_P (type)
5215 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5216 || VOID_TYPE_P (TREE_TYPE (type))))
5217 return convert_member_func_to_ptr (type, expr);
5218
5219 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5220 array-to-pointer, and function-to-pointer conversions are
5221 performed. */
5222 expr = decay_conversion (expr);
5223
5224 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5225 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5226 if (TREE_CODE (expr) == NOP_EXPR
5227 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5228 expr = TREE_OPERAND (expr, 0);
5229
5230 if (error_operand_p (expr))
5231 return error_mark_node;
5232
5233 intype = TREE_TYPE (expr);
5234
5235 /* [expr.reinterpret.cast]
5236 A pointer can be converted to any integral type large enough to
5237 hold it. */
5238 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5239 {
5240 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5241 pedwarn ("cast from %qT to %qT loses precision",
5242 intype, type);
5243 }
5244 /* [expr.reinterpret.cast]
5245 A value of integral or enumeration type can be explicitly
5246 converted to a pointer. */
5247 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5248 /* OK */
5249 ;
5250 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5251 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5252 return fold_if_not_in_template (build_nop (type, expr));
5253 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5254 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5255 {
5256 tree sexpr = expr;
5257
5258 if (!c_cast_p)
5259 check_for_casting_away_constness (intype, type, error,
5260 "reinterpret_cast");
5261 /* Warn about possible alignment problems. */
5262 if (STRICT_ALIGNMENT && warn_cast_align
5263 && !VOID_TYPE_P (type)
5264 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5265 && COMPLETE_TYPE_P (TREE_TYPE (type))
5266 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5267 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5268 warning (0, "cast from %qT to %qT increases required alignment of "
5269 "target type",
5270 intype, type);
5271
5272 /* We need to strip nops here, because the frontend likes to
5273 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5274 STRIP_NOPS (sexpr);
5275 if (warn_strict_aliasing <= 2)
5276 strict_aliasing_warning (intype, type, sexpr);
5277
5278 return fold_if_not_in_template (build_nop (type, expr));
5279 }
5280 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5281 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5282 {
5283 if (pedantic)
5284 /* Only issue a warning, as we have always supported this
5285 where possible, and it is necessary in some cases. DR 195
5286 addresses this issue, but as of 2004/10/26 is still in
5287 drafting. */
5288 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5289 return fold_if_not_in_template (build_nop (type, expr));
5290 }
5291 else if (TREE_CODE (type) == VECTOR_TYPE)
5292 return fold_if_not_in_template (convert_to_vector (type, expr));
5293 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5294 return fold_if_not_in_template (convert_to_integer (type, expr));
5295 else
5296 {
5297 if (valid_p)
5298 *valid_p = false;
5299 error ("invalid cast from type %qT to type %qT", intype, type);
5300 return error_mark_node;
5301 }
5302
5303 return cp_convert (type, expr);
5304}
5305
5306tree
5307build_reinterpret_cast (tree type, tree expr)
5308{
5309 if (type == error_mark_node || expr == error_mark_node)
5310 return error_mark_node;
5311
5312 if (processing_template_decl)
5313 {
5314 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5315
5316 if (!TREE_SIDE_EFFECTS (t)
5317 && type_dependent_expression_p (expr))
5318 /* There might turn out to be side effects inside expr. */
5319 TREE_SIDE_EFFECTS (t) = 1;
5320 return convert_from_reference (t);
5321 }
5322
5323 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5324 /*valid_p=*/NULL);
5325}
5326
5327/* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5328 return an appropriate expression. Otherwise, return
5329 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5330 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5331 performing a C-style cast, its value upon return will indicate
5332 whether or not the conversion succeeded. */
5333
5334static tree
5335build_const_cast_1 (tree dst_type, tree expr, bool complain,
5336 bool *valid_p)
5337{
5338 tree src_type;
5339 tree reference_type;
5340
5341 /* Callers are responsible for handling error_mark_node as a
5342 destination type. */
5343 gcc_assert (dst_type != error_mark_node);
5344 /* In a template, callers should be building syntactic
5345 representations of casts, not using this machinery. */
5346 gcc_assert (!processing_template_decl);
5347
5348 /* Assume the conversion is invalid. */
5349 if (valid_p)
5350 *valid_p = false;
5351
5352 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5353 {
5354 if (complain)
5355 error ("invalid use of const_cast with type %qT, "
5356 "which is not a pointer, "
5357 "reference, nor a pointer-to-data-member type", dst_type);
5358 return error_mark_node;
5359 }
5360
5361 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5362 {
5363 if (complain)
5364 error ("invalid use of const_cast with type %qT, which is a pointer "
5365 "or reference to a function type", dst_type);
5366 return error_mark_node;
5367 }
5368
5369 /* Save casted types in the function's used types hash table. */
5370 used_types_insert (dst_type);
5371
5372 src_type = TREE_TYPE (expr);
5373 /* Expressions do not really have reference types. */
5374 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5375 src_type = TREE_TYPE (src_type);
5376
5377 /* [expr.const.cast]
5378
5379 An lvalue of type T1 can be explicitly converted to an lvalue of
5380 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5381 types) if a pointer to T1 can be explicitly converted to the type
5382 pointer to T2 using a const_cast. */
5383 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5384 {
5385 reference_type = dst_type;
5386 if (! real_lvalue_p (expr))
5387 {
5388 if (complain)
5389 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5390 src_type, dst_type);
5391 return error_mark_node;
5392 }
5393 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5394 src_type = build_pointer_type (src_type);
5395 }
5396 else
5397 {
5398 reference_type = NULL_TREE;
5399 /* If the destination type is not a reference type, the
5400 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5401 conversions are performed. */
5402 src_type = type_decays_to (src_type);
5403 if (src_type == error_mark_node)
5404 return error_mark_node;
5405 }
5406
5407 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5408 && comp_ptr_ttypes_const (dst_type, src_type))
5409 {
5410 if (valid_p)
5411 {
5412 *valid_p = true;
5413 /* This cast is actually a C-style cast. Issue a warning if
5414 the user is making a potentially unsafe cast. */
5415 if (warn_cast_qual)
5416 check_for_casting_away_constness (src_type, dst_type,
5417 warning0,
5418 "cast");
5419 }
5420 if (reference_type)
5421 {
5422 expr = build_unary_op (ADDR_EXPR, expr, 0);
5423 expr = build_nop (reference_type, expr);
5424 return convert_from_reference (expr);
5425 }
5426 else
5427 {
5428 expr = decay_conversion (expr);
5429 /* build_c_cast puts on a NOP_EXPR to make the result not an
5430 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5431 non-lvalue context. */
5432 if (TREE_CODE (expr) == NOP_EXPR
5433 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5434 expr = TREE_OPERAND (expr, 0);
5435 return build_nop (dst_type, expr);
5436 }
5437 }
5438
5439 if (complain)
5440 error ("invalid const_cast from type %qT to type %qT",
5441 src_type, dst_type);
5442 return error_mark_node;
5443}
5444
5445tree
5446build_const_cast (tree type, tree expr)
5447{
5448 if (type == error_mark_node || error_operand_p (expr))
5449 return error_mark_node;
5450
5451 if (processing_template_decl)
5452 {
5453 tree t = build_min (CONST_CAST_EXPR, type, expr);
5454
5455 if (!TREE_SIDE_EFFECTS (t)
5456 && type_dependent_expression_p (expr))
5457 /* There might turn out to be side effects inside expr. */
5458 TREE_SIDE_EFFECTS (t) = 1;
5459 return convert_from_reference (t);
5460 }
5461
5462 return build_const_cast_1 (type, expr, /*complain=*/true,
5463 /*valid_p=*/NULL);
5464}
5465
5466/* Build an expression representing an explicit C-style cast to type
5467 TYPE of expression EXPR. */
5468
5469tree
5470build_c_cast (tree type, tree expr)
5471{
5472 tree value = expr;
5473 tree result;
5474 bool valid_p;
5475
5476 if (type == error_mark_node || error_operand_p (expr))
5477 return error_mark_node;
5478
5479 if (processing_template_decl)
5480 {
5481 tree t = build_min (CAST_EXPR, type,
5482 tree_cons (NULL_TREE, value, NULL_TREE));
5483 /* We don't know if it will or will not have side effects. */
5484 TREE_SIDE_EFFECTS (t) = 1;
5485 return convert_from_reference (t);
5486 }
5487
5488 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5489 'Class') should always be retained, because this information aids
5490 in method lookup. */
5491 if (objc_is_object_ptr (type)
5492 && objc_is_object_ptr (TREE_TYPE (expr)))
5493 return build_nop (type, expr);
5494
5495 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5496 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5497 if (TREE_CODE (type) != REFERENCE_TYPE
5498 && TREE_CODE (value) == NOP_EXPR
5499 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5500 value = TREE_OPERAND (value, 0);
5501
5502 if (TREE_CODE (type) == ARRAY_TYPE)
5503 {
5504 /* Allow casting from T1* to T2[] because Cfront allows it.
5505 NIHCL uses it. It is not valid ISO C++ however. */
5506 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5507 {
5508 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5509 type = build_pointer_type (TREE_TYPE (type));
5510 }
5511 else
5512 {
5513 error ("ISO C++ forbids casting to an array type %qT", type);
5514 return error_mark_node;
5515 }
5516 }
5517
5518 if (TREE_CODE (type) == FUNCTION_TYPE
5519 || TREE_CODE (type) == METHOD_TYPE)
5520 {
5521 error ("invalid cast to function type %qT", type);
5522 return error_mark_node;
5523 }
5524
5525 /* A C-style cast can be a const_cast. */
5526 result = build_const_cast_1 (type, value, /*complain=*/false,
5527 &valid_p);
5528 if (valid_p)
5529 return result;
5530
5531 /* Or a static cast. */
5532 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5533 &valid_p);
5534 /* Or a reinterpret_cast. */
5535 if (!valid_p)
5536 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5537 &valid_p);
5538 /* The static_cast or reinterpret_cast may be followed by a
5539 const_cast. */
5540 if (valid_p
5541 /* A valid cast may result in errors if, for example, a
5542 conversion to am ambiguous base class is required. */
5543 && !error_operand_p (result))
5544 {
5545 tree result_type;
5546
5547 /* Non-class rvalues always have cv-unqualified type. */
5548 if (!CLASS_TYPE_P (type))
5549 type = TYPE_MAIN_VARIANT (type);
5550 result_type = TREE_TYPE (result);
5551 if (!CLASS_TYPE_P (result_type))
5552 result_type = TYPE_MAIN_VARIANT (result_type);
5553 /* If the type of RESULT does not match TYPE, perform a
5554 const_cast to make it match. If the static_cast or
5555 reinterpret_cast succeeded, we will differ by at most
5556 cv-qualification, so the follow-on const_cast is guaranteed
5557 to succeed. */
5558 if (!same_type_p (non_reference (type), non_reference (result_type)))
5559 {
5560 result = build_const_cast_1 (type, result, false, &valid_p);
5561 gcc_assert (valid_p);
5562 }
5563 return result;
5564 }
5565
5566 return error_mark_node;
5567}
5568
5569/* Build an assignment expression of lvalue LHS from value RHS.
5570 MODIFYCODE is the code for a binary operator that we use
5571 to combine the old value of LHS with RHS to get the new value.
5572 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5573
5574 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5575
5576tree
5577build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5578{
5579 tree result;
5580 tree newrhs = rhs;
5581 tree lhstype = TREE_TYPE (lhs);
5582 tree olhstype = lhstype;
5583 tree olhs = NULL_TREE;
5584 bool plain_assign = (modifycode == NOP_EXPR);
5585
5586 /* Avoid duplicate error messages from operands that had errors. */
5587 if (error_operand_p (lhs) || error_operand_p (rhs))
5588 return error_mark_node;
5589
5590 /* Handle control structure constructs used as "lvalues". */
5591 switch (TREE_CODE (lhs))
5592 {
5593 /* Handle --foo = 5; as these are valid constructs in C++. */
5594 case PREDECREMENT_EXPR:
5595 case PREINCREMENT_EXPR:
5596 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5597 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5598 stabilize_reference (TREE_OPERAND (lhs, 0)),
5599 TREE_OPERAND (lhs, 1));
5600 return build2 (COMPOUND_EXPR, lhstype,
5601 lhs,
5602 build_modify_expr (TREE_OPERAND (lhs, 0),
5603 modifycode, rhs));
5604
5605 /* Handle (a, b) used as an "lvalue". */
5606 case COMPOUND_EXPR:
5607 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5608 modifycode, rhs);
5609 if (newrhs == error_mark_node)
5610 return error_mark_node;
5611 return build2 (COMPOUND_EXPR, lhstype,
5612 TREE_OPERAND (lhs, 0), newrhs);
5613
5614 case MODIFY_EXPR:
5615 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5616 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5617 stabilize_reference (TREE_OPERAND (lhs, 0)),
5618 TREE_OPERAND (lhs, 1));
5619 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5620 if (newrhs == error_mark_node)
5621 return error_mark_node;
5622 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5623
5624 case MIN_EXPR:
5625 case MAX_EXPR:
5626 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5627 when neither operand has side-effects. */
5628 if (!lvalue_or_else (lhs, lv_assign))
5629 return error_mark_node;
5630
5631 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5632 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5633
5634 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5635 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5636 boolean_type_node,
5637 TREE_OPERAND (lhs, 0),
5638 TREE_OPERAND (lhs, 1)),
5639 TREE_OPERAND (lhs, 0),
5640 TREE_OPERAND (lhs, 1));
5641 /* Fall through. */
5642
5643 /* Handle (a ? b : c) used as an "lvalue". */
5644 case COND_EXPR:
5645 {
5646 /* Produce (a ? (b = rhs) : (c = rhs))
5647 except that the RHS goes through a save-expr
5648 so the code to compute it is only emitted once. */
5649 tree cond;
5650 tree preeval = NULL_TREE;
5651
5652 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5653 {
5654 error ("void value not ignored as it ought to be");
5655 return error_mark_node;
5656 }
5657
5658 rhs = stabilize_expr (rhs, &preeval);
5659
5660 /* Check this here to avoid odd errors when trying to convert
5661 a throw to the type of the COND_EXPR. */
5662 if (!lvalue_or_else (lhs, lv_assign))
5663 return error_mark_node;
5664
5665 cond = build_conditional_expr
5666 (TREE_OPERAND (lhs, 0),
5667 build_modify_expr (TREE_OPERAND (lhs, 1),
5668 modifycode, rhs),
5669 build_modify_expr (TREE_OPERAND (lhs, 2),
5670 modifycode, rhs));
5671
5672 if (cond == error_mark_node)
5673 return cond;
5674 /* Make sure the code to compute the rhs comes out
5675 before the split. */
5676 if (preeval)
5677 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5678 return cond;
5679 }
5680
5681 default:
5682 break;
5683 }
5684
5685 if (modifycode == INIT_EXPR)
5686 {
5687 if (TREE_CODE (rhs) == CONSTRUCTOR)
5688 {
5689 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5690 /* Call convert to generate an error; see PR 11063. */
5691 rhs = convert (lhstype, rhs);
5692 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5693 TREE_SIDE_EFFECTS (result) = 1;
5694 return result;
5695 }
5696 else if (! IS_AGGR_TYPE (lhstype))
5697 /* Do the default thing. */;
5698 else
5699 {
5700 result = build_special_member_call (lhs, complete_ctor_identifier,
5701 build_tree_list (NULL_TREE, rhs),
5702 lhstype, LOOKUP_NORMAL);
5703 if (result == NULL_TREE)
5704 return error_mark_node;
5705 return result;
5706 }
5707 }
5708 else
5709 {
5710 lhs = require_complete_type (lhs);
5711 if (lhs == error_mark_node)
5712 return error_mark_node;
5713
5714 if (modifycode == NOP_EXPR)
5715 {
5716 /* `operator=' is not an inheritable operator. */
5717 if (! IS_AGGR_TYPE (lhstype))
5718 /* Do the default thing. */;
5719 else
5720 {
5721 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5722 lhs, rhs, make_node (NOP_EXPR),
5723 /*overloaded_p=*/NULL);
5724 if (result == NULL_TREE)
5725 return error_mark_node;
5726 return result;
5727 }
5728 lhstype = olhstype;
5729 }
5730 else
5731 {
5732 /* A binary op has been requested. Combine the old LHS
5733 value with the RHS producing the value we should actually
5734 store into the LHS. */
5735
5736 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5737 lhs = stabilize_reference (lhs);
5738 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5739 if (newrhs == error_mark_node)
5740 {
5741 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5742 TREE_TYPE (lhs), TREE_TYPE (rhs));
5743 return error_mark_node;
5744 }
5745
5746 /* Now it looks like a plain assignment. */
5747 modifycode = NOP_EXPR;
5748 }
5749 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5750 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5751 }
5752
5753 /* The left-hand side must be an lvalue. */
5754 if (!lvalue_or_else (lhs, lv_assign))
5755 return error_mark_node;
5756
5757 /* Warn about modifying something that is `const'. Don't warn if
5758 this is initialization. */
5759 if (modifycode != INIT_EXPR
5760 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5761 /* Functions are not modifiable, even though they are
5762 lvalues. */
5763 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5764 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5765 /* If it's an aggregate and any field is const, then it is
5766 effectively const. */
5767 || (CLASS_TYPE_P (lhstype)
5768 && C_TYPE_FIELDS_READONLY (lhstype))))
5769 readonly_error (lhs, "assignment", 0);
5770
5771 /* If storing into a structure or union member, it has probably been
5772 given type `int'. Compute the type that would go with the actual
5773 amount of storage the member occupies. */
5774
5775 if (TREE_CODE (lhs) == COMPONENT_REF
5776 && (TREE_CODE (lhstype) == INTEGER_TYPE
5777 || TREE_CODE (lhstype) == REAL_TYPE
5778 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5779 {
5780 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5781
5782 /* If storing in a field that is in actuality a short or narrower
5783 than one, we must store in the field in its actual type. */
5784
5785 if (lhstype != TREE_TYPE (lhs))
5786 {
5787 /* Avoid warnings converting integral types back into enums for
5788 enum bit fields. */
5789 if (TREE_CODE (lhstype) == INTEGER_TYPE
5790 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5791 {
5792 if (TREE_SIDE_EFFECTS (lhs))
5793 lhs = stabilize_reference (lhs);
5794 olhs = lhs;
5795 }
5796 lhs = copy_node (lhs);
5797 TREE_TYPE (lhs) = lhstype;
5798 }
5799 }
5800
5801 /* Convert new value to destination type. */
5802
5803 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5804 {
5805 int from_array;
5806
5807 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5808 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5809 {
5810 error ("incompatible types in assignment of %qT to %qT",
5811 TREE_TYPE (rhs), lhstype);
5812 return error_mark_node;
5813 }
5814
5815 /* Allow array assignment in compiler-generated code. */
5816 if (! DECL_ARTIFICIAL (current_function_decl))
5817 {
5818 /* This routine is used for both initialization and assignment.
5819 Make sure the diagnostic message differentiates the context. */
5820 if (modifycode == INIT_EXPR)
5821 error ("array used as initializer");
5822 else
5823 error ("invalid array assignment");
5824 return error_mark_node;
5825 }
5826
5827 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5828 ? 1 + (modifycode != INIT_EXPR): 0;
5829 return build_vec_init (lhs, NULL_TREE, newrhs,
5830 /*explicit_default_init_p=*/false,
5831 from_array);
5832 }
5833
5834 if (modifycode == INIT_EXPR)
5835 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5836 "initialization", NULL_TREE, 0);
5837 else
5838 {
5839 /* Avoid warnings on enum bit fields. */
5840 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5841 && TREE_CODE (lhstype) == INTEGER_TYPE)
5842 {
5843 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5844 NULL_TREE, 0);
5845 newrhs = convert_force (lhstype, newrhs, 0);
5846 }
5847 else
5848 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5849 NULL_TREE, 0);
5850 if (TREE_CODE (newrhs) == CALL_EXPR
5851 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5852 newrhs = build_cplus_new (lhstype, newrhs);
5853
5854 /* Can't initialize directly from a TARGET_EXPR, since that would
5855 cause the lhs to be constructed twice, and possibly result in
5856 accidental self-initialization. So we force the TARGET_EXPR to be
5857 expanded without a target. */
5858 if (TREE_CODE (newrhs) == TARGET_EXPR)
5859 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5860 TREE_OPERAND (newrhs, 0));
5861 }
5862
5863 if (newrhs == error_mark_node)
5864 return error_mark_node;
5865
5866 if (c_dialect_objc () && flag_objc_gc)
5867 {
5868 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5869
5870 if (result)
5871 return result;
5872 }
5873
5874 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5875 lhstype, lhs, newrhs);
5876
5877 TREE_SIDE_EFFECTS (result) = 1;
5878 if (!plain_assign)
5879 TREE_NO_WARNING (result) = 1;
5880
5881 /* If we got the LHS in a different type for storing in,
5882 convert the result back to the nominal type of LHS
5883 so that the value we return always has the same type
5884 as the LHS argument. */
5885
5886 if (olhstype == TREE_TYPE (result))
5887 return result;
5888 if (olhs)
5889 {
5890 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5891 TREE_NO_WARNING (result) = 1;
5892 return result;
5893 }
5894 return convert_for_assignment (olhstype, result, "assignment",
5895 NULL_TREE, 0);
5896}
5897
5898tree
5899build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5900{
5901 if (processing_template_decl)
5902 return build_min_nt (MODOP_EXPR, lhs,
5903 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5904
5905 if (modifycode != NOP_EXPR)
5906 {
5907 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5908 make_node (modifycode),
5909 /*overloaded_p=*/NULL);
5910 if (rval)
5911 {
5912 TREE_NO_WARNING (rval) = 1;
5913 return rval;
5914 }
5915 }
5916 return build_modify_expr (lhs, modifycode, rhs);
5917}
5918
5919
5920/* Get difference in deltas for different pointer to member function
5921 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5922 the conversion is invalid, the constant is zero. If
5923 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5924 If C_CAST_P is true this conversion is taking place as part of a
5925 C-style cast.
5926
5927 Note that the naming of FROM and TO is kind of backwards; the return
5928 value is what we add to a TO in order to get a FROM. They are named
5929 this way because we call this function to find out how to convert from
5930 a pointer to member of FROM to a pointer to member of TO. */
5931
5932static tree
5933get_delta_difference (tree from, tree to,
5934 bool allow_inverse_p,
5935 bool c_cast_p)
5936{
5937 tree binfo;
5938 base_kind kind;
5939 tree result;
5940
5941 /* Assume no conversion is required. */
5942 result = integer_zero_node;
5943 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5944 if (kind == bk_inaccessible || kind == bk_ambig)
5945 error (" in pointer to member function conversion");
5946 else if (binfo)
5947 {
5948 if (kind != bk_via_virtual)
5949 result = BINFO_OFFSET (binfo);
5950 else
5951 {
5952 tree virt_binfo = binfo_from_vbase (binfo);
5953
5954 /* This is a reinterpret cast, we choose to do nothing. */
5955 if (allow_inverse_p)
5956 warning (0, "pointer to member cast via virtual base %qT",
5957 BINFO_TYPE (virt_binfo));
5958 else
5959 error ("pointer to member conversion via virtual base %qT",
5960 BINFO_TYPE (virt_binfo));
5961 }
5962 }
5963 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5964 /* Pointer to member of incomplete class is permitted*/;
5965 else if (!allow_inverse_p)
5966 {
5967 error_not_base_type (from, to);
5968 error (" in pointer to member conversion");
5969 }
5970 else
5971 {
5972 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5973 if (binfo)
5974 {
5975 if (kind != bk_via_virtual)
5976 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5977 else
5978 {
5979 /* This is a reinterpret cast, we choose to do nothing. */
5980 tree virt_binfo = binfo_from_vbase (binfo);
5981
5982 warning (0, "pointer to member cast via virtual base %qT",
5983 BINFO_TYPE (virt_binfo));
5984 }
5985 }
5986 }
5987
5988 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5989 result));
5990}
5991
5992/* Return a constructor for the pointer-to-member-function TYPE using
5993 the other components as specified. */
5994
5995tree
5996build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5997{
5998 tree u = NULL_TREE;
5999 tree delta_field;
6000 tree pfn_field;
6001 VEC(constructor_elt, gc) *v;
6002
6003 /* Pull the FIELD_DECLs out of the type. */
6004 pfn_field = TYPE_FIELDS (type);
6005 delta_field = TREE_CHAIN (pfn_field);
6006
6007 /* Make sure DELTA has the type we want. */
6008 delta = convert_and_check (delta_type_node, delta);
6009
6010 /* Finish creating the initializer. */
6011 v = VEC_alloc(constructor_elt, gc, 2);
6012 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6013 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6014 u = build_constructor (type, v);
6015 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6016 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6017 TREE_STATIC (u) = (TREE_CONSTANT (u)
6018 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6019 != NULL_TREE)
6020 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6021 != NULL_TREE));
6022 return u;
6023}
6024
6025/* Build a constructor for a pointer to member function. It can be
6026 used to initialize global variables, local variable, or used
6027 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6028 want to be.
6029
6030 If FORCE is nonzero, then force this conversion, even if
6031 we would rather not do it. Usually set when using an explicit
6032 cast. A C-style cast is being processed iff C_CAST_P is true.
6033
6034 Return error_mark_node, if something goes wrong. */
6035
6036tree
6037build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6038{
6039 tree fn;
6040 tree pfn_type;
6041 tree to_type;
6042
6043 if (error_operand_p (pfn))
6044 return error_mark_node;
6045
6046 pfn_type = TREE_TYPE (pfn);
6047 to_type = build_ptrmemfunc_type (type);
6048
6049 /* Handle multiple conversions of pointer to member functions. */
6050 if (TYPE_PTRMEMFUNC_P (pfn_type))
6051 {
6052 tree delta = NULL_TREE;
6053 tree npfn = NULL_TREE;
6054 tree n;
6055
6056 if (!force
6057 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6058 error ("invalid conversion to type %qT from type %qT",
6059 to_type, pfn_type);
6060
6061 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6062 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6063 force,
6064 c_cast_p);
6065
6066 /* We don't have to do any conversion to convert a
6067 pointer-to-member to its own type. But, we don't want to
6068 just return a PTRMEM_CST if there's an explicit cast; that
6069 cast should make the expression an invalid template argument. */
6070 if (TREE_CODE (pfn) != PTRMEM_CST)
6071 {
6072 if (same_type_p (to_type, pfn_type))
6073 return pfn;
6074 else if (integer_zerop (n))
6075 return build_reinterpret_cast (to_type, pfn);
6076 }
6077
6078 if (TREE_SIDE_EFFECTS (pfn))
6079 pfn = save_expr (pfn);
6080
6081 /* Obtain the function pointer and the current DELTA. */
6082 if (TREE_CODE (pfn) == PTRMEM_CST)
6083 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6084 else
6085 {
6086 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6087 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6088 }
6089
6090 /* Just adjust the DELTA field. */
6091 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6092 (TREE_TYPE (delta), ptrdiff_type_node));
6093 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6094 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6095 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6096 return build_ptrmemfunc1 (to_type, delta, npfn);
6097 }
6098
6099 /* Handle null pointer to member function conversions. */
6100 if (integer_zerop (pfn))
6101 {
6102 pfn = build_c_cast (type, integer_zero_node);
6103 return build_ptrmemfunc1 (to_type,
6104 integer_zero_node,
6105 pfn);
6106 }
6107
6108 if (type_unknown_p (pfn))
6109 return instantiate_type (type, pfn, tf_warning_or_error);
6110
6111 fn = TREE_OPERAND (pfn, 0);
6112 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6113 /* In a template, we will have preserved the
6114 OFFSET_REF. */
6115 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6116 return make_ptrmem_cst (to_type, fn);
6117}
6118
6119/* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6120 given by CST.
6121
6122 ??? There is no consistency as to the types returned for the above
6123 values. Some code acts as if it were a sizetype and some as if it were
6124 integer_type_node. */
6125
6126void
6127expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6128{
6129 tree type = TREE_TYPE (cst);
6130 tree fn = PTRMEM_CST_MEMBER (cst);
6131 tree ptr_class, fn_class;
6132
6133 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6134
6135 /* The class that the function belongs to. */
6136 fn_class = DECL_CONTEXT (fn);
6137
6138 /* The class that we're creating a pointer to member of. */
6139 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6140
6141 /* First, calculate the adjustment to the function's class. */
6142 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6143 /*c_cast_p=*/0);
6144
6145 if (!DECL_VIRTUAL_P (fn))
6146 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6147 else
6148 {
6149 /* If we're dealing with a virtual function, we have to adjust 'this'
6150 again, to point to the base which provides the vtable entry for
6151 fn; the call will do the opposite adjustment. */
6152 tree orig_class = DECL_CONTEXT (fn);
6153 tree binfo = binfo_or_else (orig_class, fn_class);
6154 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6155 *delta, BINFO_OFFSET (binfo));
6156 *delta = fold_if_not_in_template (*delta);
6157
6158 /* We set PFN to the vtable offset at which the function can be
6159 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6160 case delta is shifted left, and then incremented). */
6161 *pfn = DECL_VINDEX (fn);
6162 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6163 TYPE_SIZE_UNIT (vtable_entry_type));
6164 *pfn = fold_if_not_in_template (*pfn);
6165
6166 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6167 {
6168 case ptrmemfunc_vbit_in_pfn:
6169 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6170 integer_one_node);
6171 *pfn = fold_if_not_in_template (*pfn);
6172 break;
6173
6174 case ptrmemfunc_vbit_in_delta:
6175 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6176 *delta, integer_one_node);
6177 *delta = fold_if_not_in_template (*delta);
6178 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6179 *delta, integer_one_node);
6180 *delta = fold_if_not_in_template (*delta);
6181 break;
6182
6183 default:
6184 gcc_unreachable ();
6185 }
6186
6187 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6188 *pfn = fold_if_not_in_template (*pfn);
6189 }
6190}
6191
6192/* Return an expression for PFN from the pointer-to-member function
6193 given by T. */
6194
6195static tree
6196pfn_from_ptrmemfunc (tree t)
6197{
6198 if (TREE_CODE (t) == PTRMEM_CST)
6199 {
6200 tree delta;
6201 tree pfn;
6202
6203 expand_ptrmemfunc_cst (t, &delta, &pfn);
6204 if (pfn)
6205 return pfn;
6206 }
6207
6208 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6209}
6210
6211/* Convert value RHS to type TYPE as preparation for an assignment to
6212 an lvalue of type TYPE. ERRTYPE is a string to use in error
6213 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6214 are doing the conversion in order to pass the PARMNUMth argument of
6215 FNDECL. */
6216
6217static tree
6218convert_for_assignment (tree type, tree rhs,
6219 const char *errtype, tree fndecl, int parmnum)
6220{
6221 tree rhstype;
6222 enum tree_code coder;
6223
6224 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6225 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6226 rhs = TREE_OPERAND (rhs, 0);
6227
6228 rhstype = TREE_TYPE (rhs);
6229 coder = TREE_CODE (rhstype);
6230
6231 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
| 1/* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 2, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING. If not, write to
20the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21Boston, MA 02110-1301, USA. */
22
23
24/* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
28
29#include "config.h"
30#include "system.h"
31#include "coretypes.h"
32#include "tm.h"
33#include "tree.h"
34#include "rtl.h"
35#include "expr.h"
36#include "cp-tree.h"
37#include "tm_p.h"
38#include "flags.h"
39#include "output.h"
40#include "toplev.h"
41#include "diagnostic.h"
42#include "target.h"
43#include "convert.h"
44#include "c-common.h"
45
46static tree pfn_from_ptrmemfunc (tree);
47static tree convert_for_assignment (tree, tree, const char *, tree, int);
48static tree cp_pointer_int_sum (enum tree_code, tree, tree);
49static tree rationalize_conditional_expr (enum tree_code, tree);
50static int comp_ptr_ttypes_real (tree, tree, int);
51static bool comp_except_types (tree, tree, bool);
52static bool comp_array_types (tree, tree, bool);
53static tree common_base_type (tree, tree);
54static tree pointer_diff (tree, tree, tree);
55static tree get_delta_difference (tree, tree, bool, bool);
56static void casts_away_constness_r (tree *, tree *);
57static bool casts_away_constness (tree, tree);
58static void maybe_warn_about_returning_address_of_local (tree);
59static tree lookup_destructor (tree, tree, tree);
60static tree convert_arguments (tree, tree, tree, int);
61
62/* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
66
67tree
68require_complete_type (tree value)
69{
70 tree type;
71
72 if (processing_template_decl || value == error_mark_node)
73 return value;
74
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
77 else
78 type = TREE_TYPE (value);
79
80 if (type == error_mark_node)
81 return error_mark_node;
82
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
85 return value;
86
87 if (complete_type_or_else (type, value))
88 return value;
89 else
90 return error_mark_node;
91}
92
93/* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
97
98tree
99complete_type (tree type)
100{
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
103 at some point. */
104 return error_mark_node;
105
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
107 ;
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
109 {
110 tree t = complete_type (TREE_TYPE (type));
111 unsigned int needs_constructing, has_nontrivial_dtor;
112 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
113 layout_type (type);
114 needs_constructing
115 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
116 has_nontrivial_dtor
117 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
119 {
120 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
121 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
122 }
123 }
124 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
125 instantiate_class_template (TYPE_MAIN_VARIANT (type));
126
127 return type;
128}
129
130/* Like complete_type, but issue an error if the TYPE cannot be completed.
131 VALUE is used for informative diagnostics.
132 Returns NULL_TREE if the type cannot be made complete. */
133
134tree
135complete_type_or_else (tree type, tree value)
136{
137 type = complete_type (type);
138 if (type == error_mark_node)
139 /* We already issued an error. */
140 return NULL_TREE;
141 else if (!COMPLETE_TYPE_P (type))
142 {
143 cxx_incomplete_type_diagnostic (value, type, 0);
144 return NULL_TREE;
145 }
146 else
147 return type;
148}
149
150/* Return truthvalue of whether type of EXP is instantiated. */
151
152int
153type_unknown_p (tree exp)
154{
155 return (TREE_CODE (exp) == TREE_LIST
156 || TREE_TYPE (exp) == unknown_type_node);
157}
158
159
160/* Return the common type of two parameter lists.
161 We assume that comptypes has already been done and returned 1;
162 if that isn't so, this may crash.
163
164 As an optimization, free the space we allocate if the parameter
165 lists are already common. */
166
167static tree
168commonparms (tree p1, tree p2)
169{
170 tree oldargs = p1, newargs, n;
171 int i, len;
172 int any_change = 0;
173
174 len = list_length (p1);
175 newargs = tree_last (p1);
176
177 if (newargs == void_list_node)
178 i = 1;
179 else
180 {
181 i = 0;
182 newargs = 0;
183 }
184
185 for (; i < len; i++)
186 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
187
188 n = newargs;
189
190 for (i = 0; p1;
191 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
192 {
193 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
194 {
195 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
196 any_change = 1;
197 }
198 else if (! TREE_PURPOSE (p1))
199 {
200 if (TREE_PURPOSE (p2))
201 {
202 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
203 any_change = 1;
204 }
205 }
206 else
207 {
208 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
209 any_change = 1;
210 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
211 }
212 if (TREE_VALUE (p1) != TREE_VALUE (p2))
213 {
214 any_change = 1;
215 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
216 }
217 else
218 TREE_VALUE (n) = TREE_VALUE (p1);
219 }
220 if (! any_change)
221 return oldargs;
222
223 return newargs;
224}
225
226/* Given a type, perhaps copied for a typedef,
227 find the "original" version of it. */
228static tree
229original_type (tree t)
230{
231 int quals = cp_type_quals (t);
232 while (t != error_mark_node
233 && TYPE_NAME (t) != NULL_TREE)
234 {
235 tree x = TYPE_NAME (t);
236 if (TREE_CODE (x) != TYPE_DECL)
237 break;
238 x = DECL_ORIGINAL_TYPE (x);
239 if (x == NULL_TREE)
240 break;
241 t = x;
242 }
243 return cp_build_qualified_type (t, quals);
244}
245
246/* T1 and T2 are arithmetic or enumeration types. Return the type
247 that will result from the "usual arithmetic conversions" on T1 and
248 T2 as described in [expr]. */
249
250tree
251type_after_usual_arithmetic_conversions (tree t1, tree t2)
252{
253 enum tree_code code1 = TREE_CODE (t1);
254 enum tree_code code2 = TREE_CODE (t2);
255 tree attributes;
256
257 /* FIXME: Attributes. */
258 gcc_assert (ARITHMETIC_TYPE_P (t1)
259 || TREE_CODE (t1) == VECTOR_TYPE
260 || TREE_CODE (t1) == ENUMERAL_TYPE);
261 gcc_assert (ARITHMETIC_TYPE_P (t2)
262 || TREE_CODE (t2) == VECTOR_TYPE
263 || TREE_CODE (t2) == ENUMERAL_TYPE);
264
265 /* In what follows, we slightly generalize the rules given in [expr] so
266 as to deal with `long long' and `complex'. First, merge the
267 attributes. */
268 attributes = (*targetm.merge_type_attributes) (t1, t2);
269
270 /* If one type is complex, form the common type of the non-complex
271 components, then make that complex. Use T1 or T2 if it is the
272 required type. */
273 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
274 {
275 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
276 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
277 tree subtype
278 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
279
280 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
281 return build_type_attribute_variant (t1, attributes);
282 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
283 return build_type_attribute_variant (t2, attributes);
284 else
285 return build_type_attribute_variant (build_complex_type (subtype),
286 attributes);
287 }
288
289 if (code1 == VECTOR_TYPE)
290 {
291 /* When we get here we should have two vectors of the same size.
292 Just prefer the unsigned one if present. */
293 if (TYPE_UNSIGNED (t1))
294 return build_type_attribute_variant (t1, attributes);
295 else
296 return build_type_attribute_variant (t2, attributes);
297 }
298
299 /* If only one is real, use it as the result. */
300 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
301 return build_type_attribute_variant (t1, attributes);
302 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
303 return build_type_attribute_variant (t2, attributes);
304
305 /* Perform the integral promotions. */
306 if (code1 != REAL_TYPE)
307 {
308 t1 = type_promotes_to (t1);
309 t2 = type_promotes_to (t2);
310 }
311
312 /* Both real or both integers; use the one with greater precision. */
313 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
314 return build_type_attribute_variant (t1, attributes);
315 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
316 return build_type_attribute_variant (t2, attributes);
317
318 /* The types are the same; no need to do anything fancy. */
319 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
320 return build_type_attribute_variant (t1, attributes);
321
322 if (code1 != REAL_TYPE)
323 {
324 /* If one is a sizetype, use it so size_binop doesn't blow up. */
325 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
326 return build_type_attribute_variant (t1, attributes);
327 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
328 return build_type_attribute_variant (t2, attributes);
329
330 /* If one is unsigned long long, then convert the other to unsigned
331 long long. */
332 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
333 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
334 return build_type_attribute_variant (long_long_unsigned_type_node,
335 attributes);
336 /* If one is a long long, and the other is an unsigned long, and
337 long long can represent all the values of an unsigned long, then
338 convert to a long long. Otherwise, convert to an unsigned long
339 long. Otherwise, if either operand is long long, convert the
340 other to long long.
341
342 Since we're here, we know the TYPE_PRECISION is the same;
343 therefore converting to long long cannot represent all the values
344 of an unsigned long, so we choose unsigned long long in that
345 case. */
346 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
347 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 {
349 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
350 ? long_long_unsigned_type_node
351 : long_long_integer_type_node);
352 return build_type_attribute_variant (t, attributes);
353 }
354
355 /* Go through the same procedure, but for longs. */
356 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
357 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
358 return build_type_attribute_variant (long_unsigned_type_node,
359 attributes);
360 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
361 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 {
363 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
364 ? long_unsigned_type_node : long_integer_type_node);
365 return build_type_attribute_variant (t, attributes);
366 }
367 /* Otherwise prefer the unsigned one. */
368 if (TYPE_UNSIGNED (t1))
369 return build_type_attribute_variant (t1, attributes);
370 else
371 return build_type_attribute_variant (t2, attributes);
372 }
373 else
374 {
375 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
376 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
377 return build_type_attribute_variant (long_double_type_node,
378 attributes);
379 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
380 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
381 return build_type_attribute_variant (double_type_node,
382 attributes);
383 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
384 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
385 return build_type_attribute_variant (float_type_node,
386 attributes);
387
388 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
389 the standard C++ floating-point types. Logic earlier in this
390 function has already eliminated the possibility that
391 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
392 compelling reason to choose one or the other. */
393 return build_type_attribute_variant (t1, attributes);
394 }
395}
396
397/* Subroutine of composite_pointer_type to implement the recursive
398 case. See that function for documentation fo the parameters. */
399
400static tree
401composite_pointer_type_r (tree t1, tree t2, const char* location)
402{
403 tree pointee1;
404 tree pointee2;
405 tree result_type;
406 tree attributes;
407
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
410 {
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
413 }
414 else
415 {
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
418 }
419
420 /* [expr.rel]
421
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
426 types. */
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location);
434 else
435 {
436 pedwarn ("%s between distinct pointer types %qT and %qT "
437 "lacks a cast",
438 location, t1, t2);
439 result_type = void_type_node;
440 }
441 result_type = cp_build_qualified_type (result_type,
442 (cp_type_quals (pointee1)
443 | cp_type_quals (pointee2)));
444 /* If the original types were pointers to members, so is the
445 result. */
446 if (TYPE_PTR_TO_MEMBER_P (t1))
447 {
448 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
449 TYPE_PTRMEM_CLASS_TYPE (t2)))
450 pedwarn ("%s between distinct pointer types %qT and %qT "
451 "lacks a cast",
452 location, t1, t2);
453 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
454 result_type);
455 }
456 else
457 result_type = build_pointer_type (result_type);
458
459 /* Merge the attributes. */
460 attributes = (*targetm.merge_type_attributes) (t1, t2);
461 return build_type_attribute_variant (result_type, attributes);
462}
463
464/* Return the composite pointer type (see [expr.rel]) for T1 and T2.
465 ARG1 and ARG2 are the values with those types. The LOCATION is a
466 string describing the current location, in case an error occurs.
467
468 This routine also implements the computation of a common type for
469 pointers-to-members as per [expr.eq]. */
470
471tree
472composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
473 const char* location)
474{
475 tree class1;
476 tree class2;
477
478 /* [expr.rel]
479
480 If one operand is a null pointer constant, the composite pointer
481 type is the type of the other operand. */
482 if (null_ptr_cst_p (arg1))
483 return t2;
484 if (null_ptr_cst_p (arg2))
485 return t1;
486
487 /* We have:
488
489 [expr.rel]
490
491 If one of the operands has type "pointer to cv1 void*", then
492 the other has type "pointer to cv2T", and the composite pointer
493 type is "pointer to cv12 void", where cv12 is the union of cv1
494 and cv2.
495
496 If either type is a pointer to void, make sure it is T1. */
497 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
498 {
499 tree t;
500 t = t1;
501 t1 = t2;
502 t2 = t;
503 }
504
505 /* Now, if T1 is a pointer to void, merge the qualifiers. */
506 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
507 {
508 tree attributes;
509 tree result_type;
510
511 if (pedantic && TYPE_PTRFN_P (t2))
512 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
513 "and pointer-to-function", location);
514 result_type
515 = cp_build_qualified_type (void_type_node,
516 (cp_type_quals (TREE_TYPE (t1))
517 | cp_type_quals (TREE_TYPE (t2))));
518 result_type = build_pointer_type (result_type);
519 /* Merge the attributes. */
520 attributes = (*targetm.merge_type_attributes) (t1, t2);
521 return build_type_attribute_variant (result_type, attributes);
522 }
523
524 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
525 && TREE_CODE (t2) == POINTER_TYPE)
526 {
527 if (objc_compare_types (t1, t2, -3, NULL_TREE))
528 return t1;
529 }
530
531 /* [expr.eq] permits the application of a pointer conversion to
532 bring the pointers to a common type. */
533 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
534 && CLASS_TYPE_P (TREE_TYPE (t1))
535 && CLASS_TYPE_P (TREE_TYPE (t2))
536 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
537 TREE_TYPE (t2)))
538 {
539 class1 = TREE_TYPE (t1);
540 class2 = TREE_TYPE (t2);
541
542 if (DERIVED_FROM_P (class1, class2))
543 t2 = (build_pointer_type
544 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
545 else if (DERIVED_FROM_P (class2, class1))
546 t1 = (build_pointer_type
547 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
548 else
549 {
550 error ("%s between distinct pointer types %qT and %qT "
551 "lacks a cast", location, t1, t2);
552 return error_mark_node;
553 }
554 }
555 /* [expr.eq] permits the application of a pointer-to-member
556 conversion to change the class type of one of the types. */
557 else if (TYPE_PTR_TO_MEMBER_P (t1)
558 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
559 TYPE_PTRMEM_CLASS_TYPE (t2)))
560 {
561 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
562 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
563
564 if (DERIVED_FROM_P (class1, class2))
565 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
566 else if (DERIVED_FROM_P (class2, class1))
567 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
568 else
569 {
570 error ("%s between distinct pointer-to-member types %qT and %qT "
571 "lacks a cast", location, t1, t2);
572 return error_mark_node;
573 }
574 }
575
576 return composite_pointer_type_r (t1, t2, location);
577}
578
579/* Return the merged type of two types.
580 We assume that comptypes has already been done and returned 1;
581 if that isn't so, this may crash.
582
583 This just combines attributes and default arguments; any other
584 differences would cause the two types to compare unalike. */
585
586tree
587merge_types (tree t1, tree t2)
588{
589 enum tree_code code1;
590 enum tree_code code2;
591 tree attributes;
592
593 /* Save time if the two types are the same. */
594 if (t1 == t2)
595 return t1;
596 if (original_type (t1) == original_type (t2))
597 return t1;
598
599 /* If one type is nonsense, use the other. */
600 if (t1 == error_mark_node)
601 return t2;
602 if (t2 == error_mark_node)
603 return t1;
604
605 /* Merge the attributes. */
606 attributes = (*targetm.merge_type_attributes) (t1, t2);
607
608 if (TYPE_PTRMEMFUNC_P (t1))
609 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
610 if (TYPE_PTRMEMFUNC_P (t2))
611 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
612
613 code1 = TREE_CODE (t1);
614 code2 = TREE_CODE (t2);
615
616 switch (code1)
617 {
618 case POINTER_TYPE:
619 case REFERENCE_TYPE:
620 /* For two pointers, do this recursively on the target type. */
621 {
622 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
623 int quals = cp_type_quals (t1);
624
625 if (code1 == POINTER_TYPE)
626 t1 = build_pointer_type (target);
627 else
628 t1 = build_reference_type (target);
629 t1 = build_type_attribute_variant (t1, attributes);
630 t1 = cp_build_qualified_type (t1, quals);
631
632 if (TREE_CODE (target) == METHOD_TYPE)
633 t1 = build_ptrmemfunc_type (t1);
634
635 return t1;
636 }
637
638 case OFFSET_TYPE:
639 {
640 int quals;
641 tree pointee;
642 quals = cp_type_quals (t1);
643 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
644 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
645 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
646 pointee);
647 t1 = cp_build_qualified_type (t1, quals);
648 break;
649 }
650
651 case ARRAY_TYPE:
652 {
653 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
654 /* Save space: see if the result is identical to one of the args. */
655 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
656 return build_type_attribute_variant (t1, attributes);
657 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
658 return build_type_attribute_variant (t2, attributes);
659 /* Merge the element types, and have a size if either arg has one. */
660 t1 = build_cplus_array_type
661 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
662 break;
663 }
664
665 case FUNCTION_TYPE:
666 /* Function types: prefer the one that specified arg types.
667 If both do, merge the arg types. Also merge the return types. */
668 {
669 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
670 tree p1 = TYPE_ARG_TYPES (t1);
671 tree p2 = TYPE_ARG_TYPES (t2);
672 tree rval, raises;
673
674 /* Save space: see if the result is identical to one of the args. */
675 if (valtype == TREE_TYPE (t1) && ! p2)
676 return cp_build_type_attribute_variant (t1, attributes);
677 if (valtype == TREE_TYPE (t2) && ! p1)
678 return cp_build_type_attribute_variant (t2, attributes);
679
680 /* Simple way if one arg fails to specify argument types. */
681 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
682 {
683 rval = build_function_type (valtype, p2);
684 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
685 rval = build_exception_variant (rval, raises);
686 return cp_build_type_attribute_variant (rval, attributes);
687 }
688 raises = TYPE_RAISES_EXCEPTIONS (t1);
689 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
690 {
691 rval = build_function_type (valtype, p1);
692 if (raises)
693 rval = build_exception_variant (rval, raises);
694 return cp_build_type_attribute_variant (rval, attributes);
695 }
696
697 rval = build_function_type (valtype, commonparms (p1, p2));
698 t1 = build_exception_variant (rval, raises);
699 break;
700 }
701
702 case METHOD_TYPE:
703 {
704 /* Get this value the long way, since TYPE_METHOD_BASETYPE
705 is just the main variant of this. */
706 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
707 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
708 tree t3;
709
710 /* If this was a member function type, get back to the
711 original type of type member function (i.e., without
712 the class instance variable up front. */
713 t1 = build_function_type (TREE_TYPE (t1),
714 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
715 t2 = build_function_type (TREE_TYPE (t2),
716 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
717 t3 = merge_types (t1, t2);
718 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
719 TYPE_ARG_TYPES (t3));
720 t1 = build_exception_variant (t3, raises);
721 break;
722 }
723
724 case TYPENAME_TYPE:
725 /* There is no need to merge attributes into a TYPENAME_TYPE.
726 When the type is instantiated it will have whatever
727 attributes result from the instantiation. */
728 return t1;
729
730 default:;
731 }
732
733 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
734 return t1;
735 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
736 return t2;
737 else
738 return cp_build_type_attribute_variant (t1, attributes);
739}
740
741/* Return the common type of two types.
742 We assume that comptypes has already been done and returned 1;
743 if that isn't so, this may crash.
744
745 This is the type for the result of most arithmetic operations
746 if the operands have the given two types. */
747
748tree
749common_type (tree t1, tree t2)
750{
751 enum tree_code code1;
752 enum tree_code code2;
753
754 /* If one type is nonsense, bail. */
755 if (t1 == error_mark_node || t2 == error_mark_node)
756 return error_mark_node;
757
758 code1 = TREE_CODE (t1);
759 code2 = TREE_CODE (t2);
760
761 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
762 || code1 == VECTOR_TYPE)
763 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
764 || code2 == VECTOR_TYPE))
765 return type_after_usual_arithmetic_conversions (t1, t2);
766
767 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
768 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
769 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
770 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
771 "conversion");
772 else
773 gcc_unreachable ();
774}
775
776/* Compare two exception specifier types for exactness or subsetness, if
777 allowed. Returns false for mismatch, true for match (same, or
778 derived and !exact).
779
780 [except.spec] "If a class X ... objects of class X or any class publicly
781 and unambiguously derived from X. Similarly, if a pointer type Y * ...
782 exceptions of type Y * or that are pointers to any type publicly and
783 unambiguously derived from Y. Otherwise a function only allows exceptions
784 that have the same type ..."
785 This does not mention cv qualifiers and is different to what throw
786 [except.throw] and catch [except.catch] will do. They will ignore the
787 top level cv qualifiers, and allow qualifiers in the pointer to class
788 example.
789
790 We implement the letter of the standard. */
791
792static bool
793comp_except_types (tree a, tree b, bool exact)
794{
795 if (same_type_p (a, b))
796 return true;
797 else if (!exact)
798 {
799 if (cp_type_quals (a) || cp_type_quals (b))
800 return false;
801
802 if (TREE_CODE (a) == POINTER_TYPE
803 && TREE_CODE (b) == POINTER_TYPE)
804 {
805 a = TREE_TYPE (a);
806 b = TREE_TYPE (b);
807 if (cp_type_quals (a) || cp_type_quals (b))
808 return false;
809 }
810
811 if (TREE_CODE (a) != RECORD_TYPE
812 || TREE_CODE (b) != RECORD_TYPE)
813 return false;
814
815 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
816 return true;
817 }
818 return false;
819}
820
821/* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
822 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
823 otherwise it must be exact. Exception lists are unordered, but
824 we've already filtered out duplicates. Most lists will be in order,
825 we should try to make use of that. */
826
827bool
828comp_except_specs (tree t1, tree t2, bool exact)
829{
830 tree probe;
831 tree base;
832 int length = 0;
833
834 if (t1 == t2)
835 return true;
836
837 if (t1 == NULL_TREE) /* T1 is ... */
838 return t2 == NULL_TREE || !exact;
839 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
840 return t2 != NULL_TREE && !TREE_VALUE (t2);
841 if (t2 == NULL_TREE) /* T2 is ... */
842 return false;
843 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
844 return !exact;
845
846 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
847 Count how many we find, to determine exactness. For exact matching and
848 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
849 O(nm). */
850 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
851 {
852 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
853 {
854 tree a = TREE_VALUE (probe);
855 tree b = TREE_VALUE (t2);
856
857 if (comp_except_types (a, b, exact))
858 {
859 if (probe == base && exact)
860 base = TREE_CHAIN (probe);
861 length++;
862 break;
863 }
864 }
865 if (probe == NULL_TREE)
866 return false;
867 }
868 return !exact || base == NULL_TREE || length == list_length (t1);
869}
870
871/* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
872 [] can match [size]. */
873
874static bool
875comp_array_types (tree t1, tree t2, bool allow_redeclaration)
876{
877 tree d1;
878 tree d2;
879 tree max1, max2;
880
881 if (t1 == t2)
882 return true;
883
884 /* The type of the array elements must be the same. */
885 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
886 return false;
887
888 d1 = TYPE_DOMAIN (t1);
889 d2 = TYPE_DOMAIN (t2);
890
891 if (d1 == d2)
892 return true;
893
894 /* If one of the arrays is dimensionless, and the other has a
895 dimension, they are of different types. However, it is valid to
896 write:
897
898 extern int a[];
899 int a[3];
900
901 by [basic.link]:
902
903 declarations for an array object can specify
904 array types that differ by the presence or absence of a major
905 array bound (_dcl.array_). */
906 if (!d1 || !d2)
907 return allow_redeclaration;
908
909 /* Check that the dimensions are the same. */
910
911 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
912 return false;
913 max1 = TYPE_MAX_VALUE (d1);
914 max2 = TYPE_MAX_VALUE (d2);
915 if (processing_template_decl && !abi_version_at_least (2)
916 && !value_dependent_expression_p (max1)
917 && !value_dependent_expression_p (max2))
918 {
919 /* With abi-1 we do not fold non-dependent array bounds, (and
920 consequently mangle them incorrectly). We must therefore
921 fold them here, to verify the domains have the same
922 value. */
923 max1 = fold (max1);
924 max2 = fold (max2);
925 }
926
927 if (!cp_tree_equal (max1, max2))
928 return false;
929
930 return true;
931}
932
933/* Return true if T1 and T2 are related as allowed by STRICT. STRICT
934 is a bitwise-or of the COMPARE_* flags. */
935
936bool
937comptypes (tree t1, tree t2, int strict)
938{
939 if (t1 == t2)
940 return true;
941
942 /* Suppress errors caused by previously reported errors. */
943 if (t1 == error_mark_node || t2 == error_mark_node)
944 return false;
945
946 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
947
948 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
949 current instantiation. */
950 if (TREE_CODE (t1) == TYPENAME_TYPE)
951 {
952 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
953
954 if (resolved != error_mark_node)
955 t1 = resolved;
956 }
957
958 if (TREE_CODE (t2) == TYPENAME_TYPE)
959 {
960 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
961
962 if (resolved != error_mark_node)
963 t2 = resolved;
964 }
965
966 /* If either type is the internal version of sizetype, use the
967 language version. */
968 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
969 && TYPE_ORIG_SIZE_TYPE (t1))
970 t1 = TYPE_ORIG_SIZE_TYPE (t1);
971
972 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
973 && TYPE_ORIG_SIZE_TYPE (t2))
974 t2 = TYPE_ORIG_SIZE_TYPE (t2);
975
976 if (TYPE_PTRMEMFUNC_P (t1))
977 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
978 if (TYPE_PTRMEMFUNC_P (t2))
979 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
980
981 /* Different classes of types can't be compatible. */
982 if (TREE_CODE (t1) != TREE_CODE (t2))
983 return false;
984
985 /* Qualifiers must match. For array types, we will check when we
986 recur on the array element types. */
987 if (TREE_CODE (t1) != ARRAY_TYPE
988 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
989 return false;
990 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
991 return false;
992
993 /* Allow for two different type nodes which have essentially the same
994 definition. Note that we already checked for equality of the type
995 qualifiers (just above). */
996
997 if (TREE_CODE (t1) != ARRAY_TYPE
998 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
999 return true;
1000
1001 /* Compare the types. Break out if they could be the same. */
1002 switch (TREE_CODE (t1))
1003 {
1004 case TEMPLATE_TEMPLATE_PARM:
1005 case BOUND_TEMPLATE_TEMPLATE_PARM:
1006 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1007 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1008 return false;
1009 if (!comp_template_parms
1010 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1011 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1012 return false;
1013 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1014 break;
1015 /* Don't check inheritance. */
1016 strict = COMPARE_STRICT;
1017 /* Fall through. */
1018
1019 case RECORD_TYPE:
1020 case UNION_TYPE:
1021 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1022 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1023 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1024 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1025 break;
1026
1027 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1028 break;
1029 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1030 break;
1031
1032 return false;
1033
1034 case OFFSET_TYPE:
1035 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1036 strict & ~COMPARE_REDECLARATION))
1037 return false;
1038 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 return false;
1040 break;
1041
1042 case POINTER_TYPE:
1043 case REFERENCE_TYPE:
1044 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1045 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1046 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1047 return false;
1048 break;
1049
1050 case METHOD_TYPE:
1051 case FUNCTION_TYPE:
1052 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1053 return false;
1054 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1055 return false;
1056 break;
1057
1058 case ARRAY_TYPE:
1059 /* Target types must match incl. qualifiers. */
1060 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1061 return false;
1062 break;
1063
1064 case TEMPLATE_TYPE_PARM:
1065 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1066 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1067 return false;
1068 break;
1069
1070 case TYPENAME_TYPE:
1071 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1072 TYPENAME_TYPE_FULLNAME (t2)))
1073 return false;
1074 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1075 return false;
1076 break;
1077
1078 case UNBOUND_CLASS_TEMPLATE:
1079 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1080 return false;
1081 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1082 return false;
1083 break;
1084
1085 case COMPLEX_TYPE:
1086 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 return false;
1088 break;
1089
1090 case VECTOR_TYPE:
1091 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1092 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1093 return false;
1094 break;
1095
1096 default:
1097 return false;
1098 }
1099
1100 /* If we get here, we know that from a target independent POV the
1101 types are the same. Make sure the target attributes are also
1102 the same. */
1103 return targetm.comp_type_attributes (t1, t2);
1104}
1105
1106/* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1107
1108bool
1109at_least_as_qualified_p (tree type1, tree type2)
1110{
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1113
1114 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1115 return (q1 & q2) == q2;
1116}
1117
1118/* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1119 more cv-qualified that TYPE1, and 0 otherwise. */
1120
1121int
1122comp_cv_qualification (tree type1, tree type2)
1123{
1124 int q1 = cp_type_quals (type1);
1125 int q2 = cp_type_quals (type2);
1126
1127 if (q1 == q2)
1128 return 0;
1129
1130 if ((q1 & q2) == q2)
1131 return 1;
1132 else if ((q1 & q2) == q1)
1133 return -1;
1134
1135 return 0;
1136}
1137
1138/* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1139 subset of the cv-qualification signature of TYPE2, and the types
1140 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1141
1142int
1143comp_cv_qual_signature (tree type1, tree type2)
1144{
1145 if (comp_ptr_ttypes_real (type2, type1, -1))
1146 return 1;
1147 else if (comp_ptr_ttypes_real (type1, type2, -1))
1148 return -1;
1149 else
1150 return 0;
1151}
1152
1153/* If two types share a common base type, return that basetype.
1154 If there is not a unique most-derived base type, this function
1155 returns ERROR_MARK_NODE. */
1156
1157static tree
1158common_base_type (tree tt1, tree tt2)
1159{
1160 tree best = NULL_TREE;
1161 int i;
1162
1163 /* If one is a baseclass of another, that's good enough. */
1164 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1165 return tt1;
1166 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1167 return tt2;
1168
1169 /* Otherwise, try to find a unique baseclass of TT1
1170 that is shared by TT2, and follow that down. */
1171 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1172 {
1173 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1174 tree trial = common_base_type (basetype, tt2);
1175
1176 if (trial)
1177 {
1178 if (trial == error_mark_node)
1179 return trial;
1180 if (best == NULL_TREE)
1181 best = trial;
1182 else if (best != trial)
1183 return error_mark_node;
1184 }
1185 }
1186
1187 /* Same for TT2. */
1188 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1189 {
1190 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1191 tree trial = common_base_type (tt1, basetype);
1192
1193 if (trial)
1194 {
1195 if (trial == error_mark_node)
1196 return trial;
1197 if (best == NULL_TREE)
1198 best = trial;
1199 else if (best != trial)
1200 return error_mark_node;
1201 }
1202 }
1203 return best;
1204}
1205
1206/* Subroutines of `comptypes'. */
1207
1208/* Return true if two parameter type lists PARMS1 and PARMS2 are
1209 equivalent in the sense that functions with those parameter types
1210 can have equivalent types. The two lists must be equivalent,
1211 element by element. */
1212
1213bool
1214compparms (tree parms1, tree parms2)
1215{
1216 tree t1, t2;
1217
1218 /* An unspecified parmlist matches any specified parmlist
1219 whose argument types don't need default promotions. */
1220
1221 for (t1 = parms1, t2 = parms2;
1222 t1 || t2;
1223 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1224 {
1225 /* If one parmlist is shorter than the other,
1226 they fail to match. */
1227 if (!t1 || !t2)
1228 return false;
1229 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1230 return false;
1231 }
1232 return true;
1233}
1234
1235
1236/* Process a sizeof or alignof expression where the operand is a
1237 type. */
1238
1239tree
1240cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1241{
1242 tree value;
1243 bool dependent_p;
1244
1245 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1246 if (type == error_mark_node)
1247 return error_mark_node;
1248
1249 type = non_reference (type);
1250 if (TREE_CODE (type) == METHOD_TYPE)
1251 {
1252 if (complain && (pedantic || warn_pointer_arith))
1253 pedwarn ("invalid application of %qs to a member function",
1254 operator_name_info[(int) op].name);
1255 value = size_one_node;
1256 }
1257
1258 dependent_p = dependent_type_p (type);
1259 if (!dependent_p)
1260 complete_type (type);
1261 if (dependent_p
1262 /* VLA types will have a non-constant size. In the body of an
1263 uninstantiated template, we don't need to try to compute the
1264 value, because the sizeof expression is not an integral
1265 constant expression in that case. And, if we do try to
1266 compute the value, we'll likely end up with SAVE_EXPRs, which
1267 the template substitution machinery does not expect to see. */
1268 || (processing_template_decl
1269 && COMPLETE_TYPE_P (type)
1270 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1271 {
1272 value = build_min (op, size_type_node, type);
1273 TREE_READONLY (value) = 1;
1274 return value;
1275 }
1276
1277 return c_sizeof_or_alignof_type (complete_type (type),
1278 op == SIZEOF_EXPR,
1279 complain);
1280}
1281
1282/* Process a sizeof expression where the operand is an expression. */
1283
1284static tree
1285cxx_sizeof_expr (tree e)
1286{
1287 if (e == error_mark_node)
1288 return error_mark_node;
1289
1290 if (processing_template_decl)
1291 {
1292 e = build_min (SIZEOF_EXPR, size_type_node, e);
1293 TREE_SIDE_EFFECTS (e) = 0;
1294 TREE_READONLY (e) = 1;
1295
1296 return e;
1297 }
1298
1299 if (TREE_CODE (e) == COMPONENT_REF
1300 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1301 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1302 {
1303 error ("invalid application of %<sizeof%> to a bit-field");
1304 e = char_type_node;
1305 }
1306 else if (is_overloaded_fn (e))
1307 {
1308 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1309 "function type");
1310 e = char_type_node;
1311 }
1312 else if (type_unknown_p (e))
1313 {
1314 cxx_incomplete_type_error (e, TREE_TYPE (e));
1315 e = char_type_node;
1316 }
1317 else
1318 e = TREE_TYPE (e);
1319
1320 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1321}
1322
1323/* Implement the __alignof keyword: Return the minimum required
1324 alignment of E, measured in bytes. For VAR_DECL's and
1325 FIELD_DECL's return DECL_ALIGN (which can be set from an
1326 "aligned" __attribute__ specification). */
1327
1328static tree
1329cxx_alignof_expr (tree e)
1330{
1331 tree t;
1332
1333 if (e == error_mark_node)
1334 return error_mark_node;
1335
1336 if (processing_template_decl)
1337 {
1338 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1339 TREE_SIDE_EFFECTS (e) = 0;
1340 TREE_READONLY (e) = 1;
1341
1342 return e;
1343 }
1344
1345 if (TREE_CODE (e) == VAR_DECL)
1346 t = size_int (DECL_ALIGN_UNIT (e));
1347 else if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1349 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1350 {
1351 error ("invalid application of %<__alignof%> to a bit-field");
1352 t = size_one_node;
1353 }
1354 else if (TREE_CODE (e) == COMPONENT_REF
1355 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1356 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1357 else if (is_overloaded_fn (e))
1358 {
1359 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1360 "function type");
1361 if (TREE_CODE (e) == FUNCTION_DECL)
1362 t = size_int (DECL_ALIGN_UNIT (e));
1363 else
1364 t = size_one_node;
1365 }
1366 else if (type_unknown_p (e))
1367 {
1368 cxx_incomplete_type_error (e, TREE_TYPE (e));
1369 t = size_one_node;
1370 }
1371 else
1372 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1373
1374 return fold_convert (size_type_node, t);
1375}
1376
1377/* Process a sizeof or alignof expression E with code OP where the operand
1378 is an expression. */
1379
1380tree
1381cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1382{
1383 if (op == SIZEOF_EXPR)
1384 return cxx_sizeof_expr (e);
1385 else
1386 return cxx_alignof_expr (e);
1387}
1388
1389/* EXPR is being used in a context that is not a function call.
1390 Enforce:
1391
1392 [expr.ref]
1393
1394 The expression can be used only as the left-hand operand of a
1395 member function call.
1396
1397 [expr.mptr.operator]
1398
1399 If the result of .* or ->* is a function, then that result can be
1400 used only as the operand for the function call operator ().
1401
1402 by issuing an error message if appropriate. Returns true iff EXPR
1403 violates these rules. */
1404
1405bool
1406invalid_nonstatic_memfn_p (tree expr)
1407{
1408 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1409 {
1410 error ("invalid use of non-static member function");
1411 return true;
1412 }
1413 return false;
1414}
1415
1416/* If EXP is a reference to a bitfield, and the type of EXP does not
1417 match the declared type of the bitfield, return the declared type
1418 of the bitfield. Otherwise, return NULL_TREE. */
1419
1420tree
1421is_bitfield_expr_with_lowered_type (tree exp)
1422{
1423 switch (TREE_CODE (exp))
1424 {
1425 case COND_EXPR:
1426 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1427 return NULL_TREE;
1428 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1429
1430 case COMPOUND_EXPR:
1431 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1432
1433 case MODIFY_EXPR:
1434 case SAVE_EXPR:
1435 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1436
1437 case COMPONENT_REF:
1438 {
1439 tree field;
1440
1441 field = TREE_OPERAND (exp, 1);
1442 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1443 return NULL_TREE;
1444 if (same_type_ignoring_top_level_qualifiers_p
1445 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1446 return NULL_TREE;
1447 return DECL_BIT_FIELD_TYPE (field);
1448 }
1449
1450 default:
1451 return NULL_TREE;
1452 }
1453}
1454
1455/* Like is_bitfield_with_lowered_type, except that if EXP is not a
1456 bitfield with a lowered type, the type of EXP is returned, rather
1457 than NULL_TREE. */
1458
1459tree
1460unlowered_expr_type (tree exp)
1461{
1462 tree type;
1463
1464 type = is_bitfield_expr_with_lowered_type (exp);
1465 if (!type)
1466 type = TREE_TYPE (exp);
1467
1468 return type;
1469}
1470
1471/* Perform the conversions in [expr] that apply when an lvalue appears
1472 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1473 function-to-pointer conversions. In addition, manifest constants
1474 are replaced by their values, and bitfield references are converted
1475 to their declared types.
1476
1477 Although the returned value is being used as an rvalue, this
1478 function does not wrap the returned expression in a
1479 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1480 that the return value is no longer an lvalue. */
1481
1482tree
1483decay_conversion (tree exp)
1484{
1485 tree type;
1486 enum tree_code code;
1487
1488 type = TREE_TYPE (exp);
1489 if (type == error_mark_node)
1490 return error_mark_node;
1491
1492 if (type_unknown_p (exp))
1493 {
1494 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1495 return error_mark_node;
1496 }
1497
1498 exp = decl_constant_value (exp);
1499 if (error_operand_p (exp))
1500 return error_mark_node;
1501
1502 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1503 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1504 code = TREE_CODE (type);
1505 if (code == VOID_TYPE)
1506 {
1507 error ("void value not ignored as it ought to be");
1508 return error_mark_node;
1509 }
1510 if (invalid_nonstatic_memfn_p (exp))
1511 return error_mark_node;
1512 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1513 return build_unary_op (ADDR_EXPR, exp, 0);
1514 if (code == ARRAY_TYPE)
1515 {
1516 tree adr;
1517 tree ptrtype;
1518
1519 if (TREE_CODE (exp) == INDIRECT_REF)
1520 return build_nop (build_pointer_type (TREE_TYPE (type)),
1521 TREE_OPERAND (exp, 0));
1522
1523 if (TREE_CODE (exp) == COMPOUND_EXPR)
1524 {
1525 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1526 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1527 TREE_OPERAND (exp, 0), op1);
1528 }
1529
1530 if (!lvalue_p (exp)
1531 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1532 {
1533 error ("invalid use of non-lvalue array");
1534 return error_mark_node;
1535 }
1536
1537 ptrtype = build_pointer_type (TREE_TYPE (type));
1538
1539 if (TREE_CODE (exp) == VAR_DECL)
1540 {
1541 if (!cxx_mark_addressable (exp))
1542 return error_mark_node;
1543 adr = build_nop (ptrtype, build_address (exp));
1544 return adr;
1545 }
1546 /* This way is better for a COMPONENT_REF since it can
1547 simplify the offset for a component. */
1548 adr = build_unary_op (ADDR_EXPR, exp, 1);
1549 return cp_convert (ptrtype, adr);
1550 }
1551
1552 /* If a bitfield is used in a context where integral promotion
1553 applies, then the caller is expected to have used
1554 default_conversion. That function promotes bitfields correctly
1555 before calling this function. At this point, if we have a
1556 bitfield referenced, we may assume that is not subject to
1557 promotion, and that, therefore, the type of the resulting rvalue
1558 is the declared type of the bitfield. */
1559 exp = convert_bitfield_to_declared_type (exp);
1560
1561 /* We do not call rvalue() here because we do not want to wrap EXP
1562 in a NON_LVALUE_EXPR. */
1563
1564 /* [basic.lval]
1565
1566 Non-class rvalues always have cv-unqualified types. */
1567 type = TREE_TYPE (exp);
1568 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1569 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1570
1571 return exp;
1572}
1573
1574/* Perform prepatory conversions, as part of the "usual arithmetic
1575 conversions". In particular, as per [expr]:
1576
1577 Whenever an lvalue expression appears as an operand of an
1578 operator that expects the rvalue for that operand, the
1579 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1580 standard conversions are applied to convert the expression to an
1581 rvalue.
1582
1583 In addition, we perform integral promotions here, as those are
1584 applied to both operands to a binary operator before determining
1585 what additional conversions should apply. */
1586
1587tree
1588default_conversion (tree exp)
1589{
1590 /* Perform the integral promotions first so that bitfield
1591 expressions (which may promote to "int", even if the bitfield is
1592 declared "unsigned") are promoted correctly. */
1593 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1594 exp = perform_integral_promotions (exp);
1595 /* Perform the other conversions. */
1596 exp = decay_conversion (exp);
1597
1598 return exp;
1599}
1600
1601/* EXPR is an expression with an integral or enumeration type.
1602 Perform the integral promotions in [conv.prom], and return the
1603 converted value. */
1604
1605tree
1606perform_integral_promotions (tree expr)
1607{
1608 tree type;
1609 tree promoted_type;
1610
1611 /* [conv.prom]
1612
1613 If the bitfield has an enumerated type, it is treated as any
1614 other value of that type for promotion purposes. */
1615 type = is_bitfield_expr_with_lowered_type (expr);
1616 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1617 type = TREE_TYPE (expr);
1618 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1619 promoted_type = type_promotes_to (type);
1620 if (type != promoted_type)
1621 expr = cp_convert (promoted_type, expr);
1622 return expr;
1623}
1624
1625/* Take the address of an inline function without setting TREE_ADDRESSABLE
1626 or TREE_USED. */
1627
1628tree
1629inline_conversion (tree exp)
1630{
1631 if (TREE_CODE (exp) == FUNCTION_DECL)
1632 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1633
1634 return exp;
1635}
1636
1637/* Returns nonzero iff exp is a STRING_CST or the result of applying
1638 decay_conversion to one. */
1639
1640int
1641string_conv_p (tree totype, tree exp, int warn)
1642{
1643 tree t;
1644
1645 if (TREE_CODE (totype) != POINTER_TYPE)
1646 return 0;
1647
1648 t = TREE_TYPE (totype);
1649 if (!same_type_p (t, char_type_node)
1650 && !same_type_p (t, wchar_type_node))
1651 return 0;
1652
1653 if (TREE_CODE (exp) == STRING_CST)
1654 {
1655 /* Make sure that we don't try to convert between char and wchar_t. */
1656 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1657 return 0;
1658 }
1659 else
1660 {
1661 /* Is this a string constant which has decayed to 'const char *'? */
1662 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1663 if (!same_type_p (TREE_TYPE (exp), t))
1664 return 0;
1665 STRIP_NOPS (exp);
1666 if (TREE_CODE (exp) != ADDR_EXPR
1667 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1668 return 0;
1669 }
1670
1671 /* This warning is not very useful, as it complains about printf. */
1672 if (warn)
1673 warning (OPT_Wwrite_strings,
1674 "deprecated conversion from string constant to %qT",
1675 totype);
1676
1677 return 1;
1678}
1679
1680/* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1681 can, for example, use as an lvalue. This code used to be in
1682 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1683 expressions, where we're dealing with aggregates. But now it's again only
1684 called from unary_complex_lvalue. The case (in particular) that led to
1685 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1686 get it there. */
1687
1688static tree
1689rationalize_conditional_expr (enum tree_code code, tree t)
1690{
1691 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1692 the first operand is always the one to be used if both operands
1693 are equal, so we know what conditional expression this used to be. */
1694 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1695 {
1696 tree op0 = TREE_OPERAND (t, 0);
1697 tree op1 = TREE_OPERAND (t, 1);
1698
1699 /* The following code is incorrect if either operand side-effects. */
1700 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1701 && !TREE_SIDE_EFFECTS (op1));
1702 return
1703 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1704 ? LE_EXPR : GE_EXPR),
1705 op0, TREE_CODE (op0),
1706 op1, TREE_CODE (op1),
1707 /*overloaded_p=*/NULL),
1708 build_unary_op (code, op0, 0),
1709 build_unary_op (code, op1, 0));
1710 }
1711
1712 return
1713 build_conditional_expr (TREE_OPERAND (t, 0),
1714 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1715 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1716}
1717
1718/* Given the TYPE of an anonymous union field inside T, return the
1719 FIELD_DECL for the field. If not found return NULL_TREE. Because
1720 anonymous unions can nest, we must also search all anonymous unions
1721 that are directly reachable. */
1722
1723tree
1724lookup_anon_field (tree t, tree type)
1725{
1726 tree field;
1727
1728 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1729 {
1730 if (TREE_STATIC (field))
1731 continue;
1732 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1733 continue;
1734
1735 /* If we find it directly, return the field. */
1736 if (DECL_NAME (field) == NULL_TREE
1737 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1738 {
1739 return field;
1740 }
1741
1742 /* Otherwise, it could be nested, search harder. */
1743 if (DECL_NAME (field) == NULL_TREE
1744 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1745 {
1746 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1747 if (subfield)
1748 return subfield;
1749 }
1750 }
1751 return NULL_TREE;
1752}
1753
1754/* Build an expression representing OBJECT.MEMBER. OBJECT is an
1755 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1756 non-NULL, it indicates the path to the base used to name MEMBER.
1757 If PRESERVE_REFERENCE is true, the expression returned will have
1758 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1759 returned will have the type referred to by the reference.
1760
1761 This function does not perform access control; that is either done
1762 earlier by the parser when the name of MEMBER is resolved to MEMBER
1763 itself, or later when overload resolution selects one of the
1764 functions indicated by MEMBER. */
1765
1766tree
1767build_class_member_access_expr (tree object, tree member,
1768 tree access_path, bool preserve_reference)
1769{
1770 tree object_type;
1771 tree member_scope;
1772 tree result = NULL_TREE;
1773
1774 if (error_operand_p (object) || error_operand_p (member))
1775 return error_mark_node;
1776
1777 gcc_assert (DECL_P (member) || BASELINK_P (member));
1778
1779 /* [expr.ref]
1780
1781 The type of the first expression shall be "class object" (of a
1782 complete type). */
1783 object_type = TREE_TYPE (object);
1784 if (!currently_open_class (object_type)
1785 && !complete_type_or_else (object_type, object))
1786 return error_mark_node;
1787 if (!CLASS_TYPE_P (object_type))
1788 {
1789 error ("request for member %qD in %qE, which is of non-class type %qT",
1790 member, object, object_type);
1791 return error_mark_node;
1792 }
1793
1794 /* The standard does not seem to actually say that MEMBER must be a
1795 member of OBJECT_TYPE. However, that is clearly what is
1796 intended. */
1797 if (DECL_P (member))
1798 {
1799 member_scope = DECL_CLASS_CONTEXT (member);
1800 mark_used (member);
1801 if (TREE_DEPRECATED (member))
1802 warn_deprecated_use (member);
1803 }
1804 else
1805 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1806 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1807 presently be the anonymous union. Go outwards until we find a
1808 type related to OBJECT_TYPE. */
1809 while (ANON_AGGR_TYPE_P (member_scope)
1810 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1811 object_type))
1812 member_scope = TYPE_CONTEXT (member_scope);
1813 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1814 {
1815 if (TREE_CODE (member) == FIELD_DECL)
1816 error ("invalid use of nonstatic data member %qE", member);
1817 else
1818 error ("%qD is not a member of %qT", member, object_type);
1819 return error_mark_node;
1820 }
1821
1822 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1823 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1824 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1825 {
1826 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1827 if (temp)
1828 object = build_indirect_ref (temp, NULL);
1829 }
1830
1831 /* In [expr.ref], there is an explicit list of the valid choices for
1832 MEMBER. We check for each of those cases here. */
1833 if (TREE_CODE (member) == VAR_DECL)
1834 {
1835 /* A static data member. */
1836 result = member;
1837 /* If OBJECT has side-effects, they are supposed to occur. */
1838 if (TREE_SIDE_EFFECTS (object))
1839 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1840 }
1841 else if (TREE_CODE (member) == FIELD_DECL)
1842 {
1843 /* A non-static data member. */
1844 bool null_object_p;
1845 int type_quals;
1846 tree member_type;
1847
1848 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1849 && integer_zerop (TREE_OPERAND (object, 0)));
1850
1851 /* Convert OBJECT to the type of MEMBER. */
1852 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1853 TYPE_MAIN_VARIANT (member_scope)))
1854 {
1855 tree binfo;
1856 base_kind kind;
1857
1858 binfo = lookup_base (access_path ? access_path : object_type,
1859 member_scope, ba_unique, &kind);
1860 if (binfo == error_mark_node)
1861 return error_mark_node;
1862
1863 /* It is invalid to try to get to a virtual base of a
1864 NULL object. The most common cause is invalid use of
1865 offsetof macro. */
1866 if (null_object_p && kind == bk_via_virtual)
1867 {
1868 error ("invalid access to non-static data member %qD of "
1869 "NULL object",
1870 member);
1871 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1872 return error_mark_node;
1873 }
1874
1875 /* Convert to the base. */
1876 object = build_base_path (PLUS_EXPR, object, binfo,
1877 /*nonnull=*/1);
1878 /* If we found the base successfully then we should be able
1879 to convert to it successfully. */
1880 gcc_assert (object != error_mark_node);
1881 }
1882
1883 /* Complain about other invalid uses of offsetof, even though they will
1884 give the right answer. Note that we complain whether or not they
1885 actually used the offsetof macro, since there's no way to know at this
1886 point. So we just give a warning, instead of a pedwarn. */
1887 /* Do not produce this warning for base class field references, because
1888 we know for a fact that didn't come from offsetof. This does occur
1889 in various testsuite cases where a null object is passed where a
1890 vtable access is required. */
1891 if (null_object_p && warn_invalid_offsetof
1892 && CLASSTYPE_NON_POD_P (object_type)
1893 && !DECL_FIELD_IS_BASE (member)
1894 && !skip_evaluation)
1895 {
1896 warning (0, "invalid access to non-static data member %qD of NULL object",
1897 member);
1898 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1899 }
1900
1901 /* If MEMBER is from an anonymous aggregate, we have converted
1902 OBJECT so that it refers to the class containing the
1903 anonymous union. Generate a reference to the anonymous union
1904 itself, and recur to find MEMBER. */
1905 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1906 /* When this code is called from build_field_call, the
1907 object already has the type of the anonymous union.
1908 That is because the COMPONENT_REF was already
1909 constructed, and was then disassembled before calling
1910 build_field_call. After the function-call code is
1911 cleaned up, this waste can be eliminated. */
1912 && (!same_type_ignoring_top_level_qualifiers_p
1913 (TREE_TYPE (object), DECL_CONTEXT (member))))
1914 {
1915 tree anonymous_union;
1916
1917 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1918 DECL_CONTEXT (member));
1919 object = build_class_member_access_expr (object,
1920 anonymous_union,
1921 /*access_path=*/NULL_TREE,
1922 preserve_reference);
1923 }
1924
1925 /* Compute the type of the field, as described in [expr.ref]. */
1926 type_quals = TYPE_UNQUALIFIED;
1927 member_type = TREE_TYPE (member);
1928 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1929 {
1930 type_quals = (cp_type_quals (member_type)
1931 | cp_type_quals (object_type));
1932
1933 /* A field is const (volatile) if the enclosing object, or the
1934 field itself, is const (volatile). But, a mutable field is
1935 not const, even within a const object. */
1936 if (DECL_MUTABLE_P (member))
1937 type_quals &= ~TYPE_QUAL_CONST;
1938 member_type = cp_build_qualified_type (member_type, type_quals);
1939 }
1940
1941 result = build3 (COMPONENT_REF, member_type, object, member,
1942 NULL_TREE);
1943 result = fold_if_not_in_template (result);
1944
1945 /* Mark the expression const or volatile, as appropriate. Even
1946 though we've dealt with the type above, we still have to mark the
1947 expression itself. */
1948 if (type_quals & TYPE_QUAL_CONST)
1949 TREE_READONLY (result) = 1;
1950 if (type_quals & TYPE_QUAL_VOLATILE)
1951 TREE_THIS_VOLATILE (result) = 1;
1952 }
1953 else if (BASELINK_P (member))
1954 {
1955 /* The member is a (possibly overloaded) member function. */
1956 tree functions;
1957 tree type;
1958
1959 /* If the MEMBER is exactly one static member function, then we
1960 know the type of the expression. Otherwise, we must wait
1961 until overload resolution has been performed. */
1962 functions = BASELINK_FUNCTIONS (member);
1963 if (TREE_CODE (functions) == FUNCTION_DECL
1964 && DECL_STATIC_FUNCTION_P (functions))
1965 type = TREE_TYPE (functions);
1966 else
1967 type = unknown_type_node;
1968 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1969 base. That will happen when the function is called. */
1970 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1971 }
1972 else if (TREE_CODE (member) == CONST_DECL)
1973 {
1974 /* The member is an enumerator. */
1975 result = member;
1976 /* If OBJECT has side-effects, they are supposed to occur. */
1977 if (TREE_SIDE_EFFECTS (object))
1978 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1979 object, result);
1980 }
1981 else
1982 {
1983 error ("invalid use of %qD", member);
1984 return error_mark_node;
1985 }
1986
1987 if (!preserve_reference)
1988 /* [expr.ref]
1989
1990 If E2 is declared to have type "reference to T", then ... the
1991 type of E1.E2 is T. */
1992 result = convert_from_reference (result);
1993
1994 return result;
1995}
1996
1997/* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1998 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1999
2000static tree
2001lookup_destructor (tree object, tree scope, tree dtor_name)
2002{
2003 tree object_type = TREE_TYPE (object);
2004 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2005 tree expr;
2006
2007 if (scope && !check_dtor_name (scope, dtor_type))
2008 {
2009 error ("qualified type %qT does not match destructor name ~%qT",
2010 scope, dtor_type);
2011 return error_mark_node;
2012 }
2013 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2014 {
2015 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2016 TYPE_MAIN_VARIANT (object_type), dtor_type);
2017 return error_mark_node;
2018 }
2019 expr = lookup_member (dtor_type, complete_dtor_identifier,
2020 /*protect=*/1, /*want_type=*/false);
2021 expr = (adjust_result_of_qualified_name_lookup
2022 (expr, dtor_type, object_type));
2023 return expr;
2024}
2025
2026/* An expression of the form "A::template B" has been resolved to
2027 DECL. Issue a diagnostic if B is not a template or template
2028 specialization. */
2029
2030void
2031check_template_keyword (tree decl)
2032{
2033 /* The standard says:
2034
2035 [temp.names]
2036
2037 If a name prefixed by the keyword template is not a member
2038 template, the program is ill-formed.
2039
2040 DR 228 removed the restriction that the template be a member
2041 template.
2042
2043 DR 96, if accepted would add the further restriction that explicit
2044 template arguments must be provided if the template keyword is
2045 used, but, as of 2005-10-16, that DR is still in "drafting". If
2046 this DR is accepted, then the semantic checks here can be
2047 simplified, as the entity named must in fact be a template
2048 specialization, rather than, as at present, a set of overloaded
2049 functions containing at least one template function. */
2050 if (TREE_CODE (decl) != TEMPLATE_DECL
2051 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2052 {
2053 if (!is_overloaded_fn (decl))
2054 pedwarn ("%qD is not a template", decl);
2055 else
2056 {
2057 tree fns;
2058 fns = decl;
2059 if (BASELINK_P (fns))
2060 fns = BASELINK_FUNCTIONS (fns);
2061 while (fns)
2062 {
2063 tree fn = OVL_CURRENT (fns);
2064 if (TREE_CODE (fn) == TEMPLATE_DECL
2065 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2066 break;
2067 if (TREE_CODE (fn) == FUNCTION_DECL
2068 && DECL_USE_TEMPLATE (fn)
2069 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2070 break;
2071 fns = OVL_NEXT (fns);
2072 }
2073 if (!fns)
2074 pedwarn ("%qD is not a template", decl);
2075 }
2076 }
2077}
2078
2079/* This function is called by the parser to process a class member
2080 access expression of the form OBJECT.NAME. NAME is a node used by
2081 the parser to represent a name; it is not yet a DECL. It may,
2082 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2083 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2084 there is no reason to do the lookup twice, so the parser keeps the
2085 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2086 be a template via the use of the "A::template B" syntax. */
2087
2088tree
2089finish_class_member_access_expr (tree object, tree name, bool template_p)
2090{
2091 tree expr;
2092 tree object_type;
2093 tree member;
2094 tree access_path = NULL_TREE;
2095 tree orig_object = object;
2096 tree orig_name = name;
2097
2098 if (object == error_mark_node || name == error_mark_node)
2099 return error_mark_node;
2100
2101 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2102 if (!objc_is_public (object, name))
2103 return error_mark_node;
2104
2105 object_type = TREE_TYPE (object);
2106
2107 if (processing_template_decl)
2108 {
2109 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2110 dependent_type_p (object_type)
2111 /* If NAME is just an IDENTIFIER_NODE, then the expression
2112 is dependent. */
2113 || TREE_CODE (object) == IDENTIFIER_NODE
2114 /* If NAME is "f<args>", where either 'f' or 'args' is
2115 dependent, then the expression is dependent. */
2116 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2117 && dependent_template_id_p (TREE_OPERAND (name, 0),
2118 TREE_OPERAND (name, 1)))
2119 /* If NAME is "T::X" where "T" is dependent, then the
2120 expression is dependent. */
2121 || (TREE_CODE (name) == SCOPE_REF
2122 && TYPE_P (TREE_OPERAND (name, 0))
2123 && dependent_type_p (TREE_OPERAND (name, 0))))
2124 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2125 object = build_non_dependent_expr (object);
2126 }
2127
2128 /* [expr.ref]
2129
2130 The type of the first expression shall be "class object" (of a
2131 complete type). */
2132 if (!currently_open_class (object_type)
2133 && !complete_type_or_else (object_type, object))
2134 return error_mark_node;
2135 if (!CLASS_TYPE_P (object_type))
2136 {
2137 error ("request for member %qD in %qE, which is of non-class type %qT",
2138 name, object, object_type);
2139 return error_mark_node;
2140 }
2141
2142 if (BASELINK_P (name))
2143 /* A member function that has already been looked up. */
2144 member = name;
2145 else
2146 {
2147 bool is_template_id = false;
2148 tree template_args = NULL_TREE;
2149 tree scope;
2150
2151 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2152 {
2153 is_template_id = true;
2154 template_args = TREE_OPERAND (name, 1);
2155 name = TREE_OPERAND (name, 0);
2156
2157 if (TREE_CODE (name) == OVERLOAD)
2158 name = DECL_NAME (get_first_fn (name));
2159 else if (DECL_P (name))
2160 name = DECL_NAME (name);
2161 }
2162
2163 if (TREE_CODE (name) == SCOPE_REF)
2164 {
2165 /* A qualified name. The qualifying class or namespace `S'
2166 has already been looked up; it is either a TYPE or a
2167 NAMESPACE_DECL. */
2168 scope = TREE_OPERAND (name, 0);
2169 name = TREE_OPERAND (name, 1);
2170
2171 /* If SCOPE is a namespace, then the qualified name does not
2172 name a member of OBJECT_TYPE. */
2173 if (TREE_CODE (scope) == NAMESPACE_DECL)
2174 {
2175 error ("%<%D::%D%> is not a member of %qT",
2176 scope, name, object_type);
2177 return error_mark_node;
2178 }
2179
2180 gcc_assert (CLASS_TYPE_P (scope));
2181 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2182 || TREE_CODE (name) == BIT_NOT_EXPR);
2183
2184 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2185 access_path = lookup_base (object_type, scope, ba_check, NULL);
2186 if (access_path == error_mark_node)
2187 return error_mark_node;
2188 if (!access_path)
2189 {
2190 error ("%qT is not a base of %qT", scope, object_type);
2191 return error_mark_node;
2192 }
2193 }
2194 else
2195 {
2196 scope = NULL_TREE;
2197 access_path = object_type;
2198 }
2199
2200 if (TREE_CODE (name) == BIT_NOT_EXPR)
2201 member = lookup_destructor (object, scope, name);
2202 else
2203 {
2204 /* Look up the member. */
2205 member = lookup_member (access_path, name, /*protect=*/1,
2206 /*want_type=*/false);
2207 if (member == NULL_TREE)
2208 {
2209 error ("%qD has no member named %qE", object_type, name);
2210 return error_mark_node;
2211 }
2212 if (member == error_mark_node)
2213 return error_mark_node;
2214 }
2215
2216 if (is_template_id)
2217 {
2218 tree template = member;
2219
2220 if (BASELINK_P (template))
2221 template = lookup_template_function (template, template_args);
2222 else
2223 {
2224 error ("%qD is not a member template function", name);
2225 return error_mark_node;
2226 }
2227 }
2228 }
2229
2230 if (TREE_DEPRECATED (member))
2231 warn_deprecated_use (member);
2232
2233 if (template_p)
2234 check_template_keyword (member);
2235
2236 expr = build_class_member_access_expr (object, member, access_path,
2237 /*preserve_reference=*/false);
2238 if (processing_template_decl && expr != error_mark_node)
2239 {
2240 if (BASELINK_P (member))
2241 {
2242 if (TREE_CODE (orig_name) == SCOPE_REF)
2243 BASELINK_QUALIFIED_P (member) = 1;
2244 orig_name = member;
2245 }
2246 return build_min_non_dep (COMPONENT_REF, expr,
2247 orig_object, orig_name,
2248 NULL_TREE);
2249 }
2250
2251 return expr;
2252}
2253
2254/* Return an expression for the MEMBER_NAME field in the internal
2255 representation of PTRMEM, a pointer-to-member function. (Each
2256 pointer-to-member function type gets its own RECORD_TYPE so it is
2257 more convenient to access the fields by name than by FIELD_DECL.)
2258 This routine converts the NAME to a FIELD_DECL and then creates the
2259 node for the complete expression. */
2260
2261tree
2262build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2263{
2264 tree ptrmem_type;
2265 tree member;
2266 tree member_type;
2267
2268 /* This code is a stripped down version of
2269 build_class_member_access_expr. It does not work to use that
2270 routine directly because it expects the object to be of class
2271 type. */
2272 ptrmem_type = TREE_TYPE (ptrmem);
2273 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2274 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2275 /*want_type=*/false);
2276 member_type = cp_build_qualified_type (TREE_TYPE (member),
2277 cp_type_quals (ptrmem_type));
2278 return fold_build3 (COMPONENT_REF, member_type,
2279 ptrmem, member, NULL_TREE);
2280}
2281
2282/* Given an expression PTR for a pointer, return an expression
2283 for the value pointed to.
2284 ERRORSTRING is the name of the operator to appear in error messages.
2285
2286 This function may need to overload OPERATOR_FNNAME.
2287 Must also handle REFERENCE_TYPEs for C++. */
2288
2289tree
2290build_x_indirect_ref (tree expr, const char *errorstring)
2291{
2292 tree orig_expr = expr;
2293 tree rval;
2294
2295 if (processing_template_decl)
2296 {
2297 if (type_dependent_expression_p (expr))
2298 return build_min_nt (INDIRECT_REF, expr);
2299 expr = build_non_dependent_expr (expr);
2300 }
2301
2302 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2303 NULL_TREE, /*overloaded_p=*/NULL);
2304 if (!rval)
2305 rval = build_indirect_ref (expr, errorstring);
2306
2307 if (processing_template_decl && rval != error_mark_node)
2308 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2309 else
2310 return rval;
2311}
2312
2313tree
2314build_indirect_ref (tree ptr, const char *errorstring)
2315{
2316 tree pointer, type;
2317
2318 if (ptr == error_mark_node)
2319 return error_mark_node;
2320
2321 if (ptr == current_class_ptr)
2322 return current_class_ref;
2323
2324 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2325 ? ptr : decay_conversion (ptr));
2326 type = TREE_TYPE (pointer);
2327
2328 if (POINTER_TYPE_P (type))
2329 {
2330 /* [expr.unary.op]
2331
2332 If the type of the expression is "pointer to T," the type
2333 of the result is "T."
2334
2335 We must use the canonical variant because certain parts of
2336 the back end, like fold, do pointer comparisons between
2337 types. */
2338 tree t = canonical_type_variant (TREE_TYPE (type));
2339
2340 if (TREE_CODE (ptr) == CONVERT_EXPR
2341 || TREE_CODE (ptr) == NOP_EXPR
2342 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2343 {
2344 /* If a warning is issued, mark it to avoid duplicates from
2345 the backend. This only needs to be done at
2346 warn_strict_aliasing > 2. */
2347 if (warn_strict_aliasing > 2)
2348 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2349 type, TREE_OPERAND (ptr, 0)))
2350 TREE_NO_WARNING (ptr) = 1;
2351 }
2352
2353 if (VOID_TYPE_P (t))
2354 {
2355 /* A pointer to incomplete type (other than cv void) can be
2356 dereferenced [expr.unary.op]/1 */
2357 error ("%qT is not a pointer-to-object type", type);
2358 return error_mark_node;
2359 }
2360 else if (TREE_CODE (pointer) == ADDR_EXPR
2361 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2362 /* The POINTER was something like `&x'. We simplify `*&x' to
2363 `x'. */
2364 return TREE_OPERAND (pointer, 0);
2365 else
2366 {
2367 tree ref = build1 (INDIRECT_REF, t, pointer);
2368
2369 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2370 so that we get the proper error message if the result is used
2371 to assign to. Also, &* is supposed to be a no-op. */
2372 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2373 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2374 TREE_SIDE_EFFECTS (ref)
2375 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2376 return ref;
2377 }
2378 }
2379 /* `pointer' won't be an error_mark_node if we were given a
2380 pointer to member, so it's cool to check for this here. */
2381 else if (TYPE_PTR_TO_MEMBER_P (type))
2382 error ("invalid use of %qs on pointer to member", errorstring);
2383 else if (pointer != error_mark_node)
2384 {
2385 if (errorstring)
2386 error ("invalid type argument of %qs", errorstring);
2387 else
2388 error ("invalid type argument");
2389 }
2390 return error_mark_node;
2391}
2392
2393/* This handles expressions of the form "a[i]", which denotes
2394 an array reference.
2395
2396 This is logically equivalent in C to *(a+i), but we may do it differently.
2397 If A is a variable or a member, we generate a primitive ARRAY_REF.
2398 This avoids forcing the array out of registers, and can work on
2399 arrays that are not lvalues (for example, members of structures returned
2400 by functions).
2401
2402 If INDEX is of some user-defined type, it must be converted to
2403 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2404 will inherit the type of the array, which will be some pointer type. */
2405
2406tree
2407build_array_ref (tree array, tree idx)
2408{
2409 if (idx == 0)
2410 {
2411 error ("subscript missing in array reference");
2412 return error_mark_node;
2413 }
2414
2415 if (TREE_TYPE (array) == error_mark_node
2416 || TREE_TYPE (idx) == error_mark_node)
2417 return error_mark_node;
2418
2419 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2420 inside it. */
2421 switch (TREE_CODE (array))
2422 {
2423 case COMPOUND_EXPR:
2424 {
2425 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2426 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2427 TREE_OPERAND (array, 0), value);
2428 }
2429
2430 case COND_EXPR:
2431 return build_conditional_expr
2432 (TREE_OPERAND (array, 0),
2433 build_array_ref (TREE_OPERAND (array, 1), idx),
2434 build_array_ref (TREE_OPERAND (array, 2), idx));
2435
2436 default:
2437 break;
2438 }
2439
2440 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2441 {
2442 tree rval, type;
2443
2444 warn_array_subscript_with_type_char (idx);
2445
2446 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2447 {
2448 error ("array subscript is not an integer");
2449 return error_mark_node;
2450 }
2451
2452 /* Apply integral promotions *after* noticing character types.
2453 (It is unclear why we do these promotions -- the standard
2454 does not say that we should. In fact, the natural thing would
2455 seem to be to convert IDX to ptrdiff_t; we're performing
2456 pointer arithmetic.) */
2457 idx = perform_integral_promotions (idx);
2458
2459 /* An array that is indexed by a non-constant
2460 cannot be stored in a register; we must be able to do
2461 address arithmetic on its address.
2462 Likewise an array of elements of variable size. */
2463 if (TREE_CODE (idx) != INTEGER_CST
2464 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2465 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2466 != INTEGER_CST)))
2467 {
2468 if (!cxx_mark_addressable (array))
2469 return error_mark_node;
2470 }
2471
2472 /* An array that is indexed by a constant value which is not within
2473 the array bounds cannot be stored in a register either; because we
2474 would get a crash in store_bit_field/extract_bit_field when trying
2475 to access a non-existent part of the register. */
2476 if (TREE_CODE (idx) == INTEGER_CST
2477 && TYPE_DOMAIN (TREE_TYPE (array))
2478 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2479 {
2480 if (!cxx_mark_addressable (array))
2481 return error_mark_node;
2482 }
2483
2484 if (pedantic && !lvalue_p (array))
2485 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2486
2487 /* Note in C++ it is valid to subscript a `register' array, since
2488 it is valid to take the address of something with that
2489 storage specification. */
2490 if (extra_warnings)
2491 {
2492 tree foo = array;
2493 while (TREE_CODE (foo) == COMPONENT_REF)
2494 foo = TREE_OPERAND (foo, 0);
2495 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2496 warning (OPT_Wextra, "subscripting array declared %<register%>");
2497 }
2498
2499 type = TREE_TYPE (TREE_TYPE (array));
2500 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2501 /* Array ref is const/volatile if the array elements are
2502 or if the array is.. */
2503 TREE_READONLY (rval)
2504 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2505 TREE_SIDE_EFFECTS (rval)
2506 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2507 TREE_THIS_VOLATILE (rval)
2508 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2509 return require_complete_type (fold_if_not_in_template (rval));
2510 }
2511
2512 {
2513 tree ar = default_conversion (array);
2514 tree ind = default_conversion (idx);
2515
2516 /* Put the integer in IND to simplify error checking. */
2517 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2518 {
2519 tree temp = ar;
2520 ar = ind;
2521 ind = temp;
2522 }
2523
2524 if (ar == error_mark_node)
2525 return ar;
2526
2527 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2528 {
2529 error ("subscripted value is neither array nor pointer");
2530 return error_mark_node;
2531 }
2532 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2533 {
2534 error ("array subscript is not an integer");
2535 return error_mark_node;
2536 }
2537
2538 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2539 "array indexing");
2540 }
2541}
2542
2543/* Resolve a pointer to member function. INSTANCE is the object
2544 instance to use, if the member points to a virtual member.
2545
2546 This used to avoid checking for virtual functions if basetype
2547 has no virtual functions, according to an earlier ANSI draft.
2548 With the final ISO C++ rules, such an optimization is
2549 incorrect: A pointer to a derived member can be static_cast
2550 to pointer-to-base-member, as long as the dynamic object
2551 later has the right member. */
2552
2553tree
2554get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2555{
2556 if (TREE_CODE (function) == OFFSET_REF)
2557 function = TREE_OPERAND (function, 1);
2558
2559 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2560 {
2561 tree idx, delta, e1, e2, e3, vtbl, basetype;
2562 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2563
2564 tree instance_ptr = *instance_ptrptr;
2565 tree instance_save_expr = 0;
2566 if (instance_ptr == error_mark_node)
2567 {
2568 if (TREE_CODE (function) == PTRMEM_CST)
2569 {
2570 /* Extracting the function address from a pmf is only
2571 allowed with -Wno-pmf-conversions. It only works for
2572 pmf constants. */
2573 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2574 e1 = convert (fntype, e1);
2575 return e1;
2576 }
2577 else
2578 {
2579 error ("object missing in use of %qE", function);
2580 return error_mark_node;
2581 }
2582 }
2583
2584 if (TREE_SIDE_EFFECTS (instance_ptr))
2585 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2586
2587 if (TREE_SIDE_EFFECTS (function))
2588 function = save_expr (function);
2589
2590 /* Start by extracting all the information from the PMF itself. */
2591 e3 = pfn_from_ptrmemfunc (function);
2592 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2593 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2594 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2595 {
2596 case ptrmemfunc_vbit_in_pfn:
2597 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2598 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2599 break;
2600
2601 case ptrmemfunc_vbit_in_delta:
2602 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2603 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2604 break;
2605
2606 default:
2607 gcc_unreachable ();
2608 }
2609
2610 /* Convert down to the right base before using the instance. A
2611 special case is that in a pointer to member of class C, C may
2612 be incomplete. In that case, the function will of course be
2613 a member of C, and no conversion is required. In fact,
2614 lookup_base will fail in that case, because incomplete
2615 classes do not have BINFOs. */
2616 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2617 if (!same_type_ignoring_top_level_qualifiers_p
2618 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2619 {
2620 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2621 basetype, ba_check, NULL);
2622 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2623 1);
2624 if (instance_ptr == error_mark_node)
2625 return error_mark_node;
2626 }
2627 /* ...and then the delta in the PMF. */
2628 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2629 instance_ptr, delta);
2630
2631 /* Hand back the adjusted 'this' argument to our caller. */
2632 *instance_ptrptr = instance_ptr;
2633
2634 /* Next extract the vtable pointer from the object. */
2635 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2636 instance_ptr);
2637 vtbl = build_indirect_ref (vtbl, NULL);
2638
2639 /* Finally, extract the function pointer from the vtable. */
2640 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2641 e2 = build_indirect_ref (e2, NULL);
2642 TREE_CONSTANT (e2) = 1;
2643 TREE_INVARIANT (e2) = 1;
2644
2645 /* When using function descriptors, the address of the
2646 vtable entry is treated as a function pointer. */
2647 if (TARGET_VTABLE_USES_DESCRIPTORS)
2648 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2649 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2650
2651 TREE_TYPE (e2) = TREE_TYPE (e3);
2652 e1 = build_conditional_expr (e1, e2, e3);
2653
2654 /* Make sure this doesn't get evaluated first inside one of the
2655 branches of the COND_EXPR. */
2656 if (instance_save_expr)
2657 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2658 instance_save_expr, e1);
2659
2660 function = e1;
2661 }
2662 return function;
2663}
2664
2665tree
2666build_function_call (tree function, tree params)
2667{
2668 tree fntype, fndecl;
2669 tree coerced_params;
2670 tree name = NULL_TREE;
2671 int is_method;
2672 tree original = function;
2673
2674 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2675 expressions, like those used for ObjC messenger dispatches. */
2676 function = objc_rewrite_function_call (function, params);
2677
2678 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2679 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2680 if (TREE_CODE (function) == NOP_EXPR
2681 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2682 function = TREE_OPERAND (function, 0);
2683
2684 if (TREE_CODE (function) == FUNCTION_DECL)
2685 {
2686 name = DECL_NAME (function);
2687
2688 mark_used (function);
2689 fndecl = function;
2690
2691 /* Convert anything with function type to a pointer-to-function. */
2692 if (pedantic && DECL_MAIN_P (function))
2693 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2694
2695 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2696 (because calling an inline function does not mean the function
2697 needs to be separately compiled). */
2698
2699 if (DECL_INLINE (function))
2700 function = inline_conversion (function);
2701 else
2702 function = build_addr_func (function);
2703 }
2704 else
2705 {
2706 fndecl = NULL_TREE;
2707
2708 function = build_addr_func (function);
2709 }
2710
2711 if (function == error_mark_node)
2712 return error_mark_node;
2713
2714 fntype = TREE_TYPE (function);
2715
2716 if (TYPE_PTRMEMFUNC_P (fntype))
2717 {
2718 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2719 "function in %<%E (...)%>",
2720 original);
2721 return error_mark_node;
2722 }
2723
2724 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2725 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2726
2727 if (!((TREE_CODE (fntype) == POINTER_TYPE
2728 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2729 || is_method
2730 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2731 {
2732 error ("%qE cannot be used as a function", original);
2733 return error_mark_node;
2734 }
2735
2736 /* fntype now gets the type of function pointed to. */
2737 fntype = TREE_TYPE (fntype);
2738
2739 /* Convert the parameters to the types declared in the
2740 function prototype, or apply default promotions. */
2741
2742 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2743 params, fndecl, LOOKUP_NORMAL);
2744 if (coerced_params == error_mark_node)
2745 return error_mark_node;
2746
2747 /* Check for errors in format strings and inappropriately
2748 null parameters. */
2749
2750 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2751 TYPE_ARG_TYPES (fntype));
2752
2753 return build_cxx_call (function, coerced_params);
2754}
2755
2756/* Convert the actual parameter expressions in the list VALUES
2757 to the types in the list TYPELIST.
2758 If parmdecls is exhausted, or when an element has NULL as its type,
2759 perform the default conversions.
2760
2761 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2762
2763 This is also where warnings about wrong number of args are generated.
2764
2765 Return a list of expressions for the parameters as converted.
2766
2767 Both VALUES and the returned value are chains of TREE_LIST nodes
2768 with the elements of the list in the TREE_VALUE slots of those nodes.
2769
2770 In C++, unspecified trailing parameters can be filled in with their
2771 default arguments, if such were specified. Do so here. */
2772
2773static tree
2774convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2775{
2776 tree typetail, valtail;
2777 tree result = NULL_TREE;
2778 const char *called_thing = 0;
2779 int i = 0;
2780
2781 /* Argument passing is always copy-initialization. */
2782 flags |= LOOKUP_ONLYCONVERTING;
2783
2784 if (fndecl)
2785 {
2786 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2787 {
2788 if (DECL_NAME (fndecl) == NULL_TREE
2789 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2790 called_thing = "constructor";
2791 else
2792 called_thing = "member function";
2793 }
2794 else
2795 called_thing = "function";
2796 }
2797
2798 for (valtail = values, typetail = typelist;
2799 valtail;
2800 valtail = TREE_CHAIN (valtail), i++)
2801 {
2802 tree type = typetail ? TREE_VALUE (typetail) : 0;
2803 tree val = TREE_VALUE (valtail);
2804
2805 if (val == error_mark_node || type == error_mark_node)
2806 return error_mark_node;
2807
2808 if (type == void_type_node)
2809 {
2810 if (fndecl)
2811 {
2812 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2813 error ("at this point in file");
2814 }
2815 else
2816 error ("too many arguments to function");
2817 /* In case anybody wants to know if this argument
2818 list is valid. */
2819 if (result)
2820 TREE_TYPE (tree_last (result)) = error_mark_node;
2821 break;
2822 }
2823
2824 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2825 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2826 if (TREE_CODE (val) == NOP_EXPR
2827 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2828 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2829 val = TREE_OPERAND (val, 0);
2830
2831 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2832 {
2833 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2834 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2835 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2836 val = decay_conversion (val);
2837 }
2838
2839 if (val == error_mark_node)
2840 return error_mark_node;
2841
2842 if (type != 0)
2843 {
2844 /* Formal parm type is specified by a function prototype. */
2845 tree parmval;
2846
2847 if (!COMPLETE_TYPE_P (complete_type (type)))
2848 {
2849 if (fndecl)
2850 error ("parameter %P of %qD has incomplete type %qT",
2851 i, fndecl, type);
2852 else
2853 error ("parameter %P has incomplete type %qT", i, type);
2854 parmval = error_mark_node;
2855 }
2856 else
2857 {
2858 parmval = convert_for_initialization
2859 (NULL_TREE, type, val, flags,
2860 "argument passing", fndecl, i);
2861 parmval = convert_for_arg_passing (type, parmval);
2862 }
2863
2864 if (parmval == error_mark_node)
2865 return error_mark_node;
2866
2867 result = tree_cons (NULL_TREE, parmval, result);
2868 }
2869 else
2870 {
2871 if (fndecl && DECL_BUILT_IN (fndecl)
2872 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2873 /* Don't do ellipsis conversion for __built_in_constant_p
2874 as this will result in spurious warnings for non-POD
2875 types. */
2876 val = require_complete_type (val);
2877 else
2878 val = convert_arg_to_ellipsis (val);
2879
2880 result = tree_cons (NULL_TREE, val, result);
2881 }
2882
2883 if (typetail)
2884 typetail = TREE_CHAIN (typetail);
2885 }
2886
2887 if (typetail != 0 && typetail != void_list_node)
2888 {
2889 /* See if there are default arguments that can be used. */
2890 if (TREE_PURPOSE (typetail)
2891 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2892 {
2893 for (; typetail != void_list_node; ++i)
2894 {
2895 tree parmval
2896 = convert_default_arg (TREE_VALUE (typetail),
2897 TREE_PURPOSE (typetail),
2898 fndecl, i);
2899
2900 if (parmval == error_mark_node)
2901 return error_mark_node;
2902
2903 result = tree_cons (0, parmval, result);
2904 typetail = TREE_CHAIN (typetail);
2905 /* ends with `...'. */
2906 if (typetail == NULL_TREE)
2907 break;
2908 }
2909 }
2910 else
2911 {
2912 if (fndecl)
2913 {
2914 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2915 error ("at this point in file");
2916 }
2917 else
2918 error ("too few arguments to function");
2919 return error_mark_node;
2920 }
2921 }
2922
2923 return nreverse (result);
2924}
2925
2926/* Build a binary-operation expression, after performing default
2927 conversions on the operands. CODE is the kind of expression to build. */
2928
2929tree
2930build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2931 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2932{
2933 tree orig_arg1;
2934 tree orig_arg2;
2935 tree expr;
2936
2937 orig_arg1 = arg1;
2938 orig_arg2 = arg2;
2939
2940 if (processing_template_decl)
2941 {
2942 if (type_dependent_expression_p (arg1)
2943 || type_dependent_expression_p (arg2))
2944 return build_min_nt (code, arg1, arg2);
2945 arg1 = build_non_dependent_expr (arg1);
2946 arg2 = build_non_dependent_expr (arg2);
2947 }
2948
2949 if (code == DOTSTAR_EXPR)
2950 expr = build_m_component_ref (arg1, arg2);
2951 else
2952 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2953 overloaded_p);
2954
2955 /* Check for cases such as x+y<<z which users are likely to
2956 misinterpret. But don't warn about obj << x + y, since that is a
2957 common idiom for I/O. */
2958 if (warn_parentheses
2959 && !processing_template_decl
2960 && !error_operand_p (arg1)
2961 && !error_operand_p (arg2)
2962 && (code != LSHIFT_EXPR
2963 || !IS_AGGR_TYPE (TREE_TYPE (arg1))))
2964 warn_about_parentheses (code, arg1_code, arg2_code);
2965
2966 if (processing_template_decl && expr != error_mark_node)
2967 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2968
2969 return expr;
2970}
2971
2972/* Build a binary-operation expression without default conversions.
2973 CODE is the kind of expression to build.
2974 This function differs from `build' in several ways:
2975 the data type of the result is computed and recorded in it,
2976 warnings are generated if arg data types are invalid,
2977 special handling for addition and subtraction of pointers is known,
2978 and some optimization is done (operations on narrow ints
2979 are done in the narrower type when that gives the same result).
2980 Constant folding is also done before the result is returned.
2981
2982 Note that the operands will never have enumeral types
2983 because either they have just had the default conversions performed
2984 or they have both just been converted to some other type in which
2985 the arithmetic is to be done.
2986
2987 C++: must do special pointer arithmetic when implementing
2988 multiple inheritance, and deal with pointer to member functions. */
2989
2990tree
2991build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2992 int convert_p ATTRIBUTE_UNUSED)
2993{
2994 tree op0, op1;
2995 enum tree_code code0, code1;
2996 tree type0, type1;
2997 const char *invalid_op_diag;
2998
2999 /* Expression code to give to the expression when it is built.
3000 Normally this is CODE, which is what the caller asked for,
3001 but in some special cases we change it. */
3002 enum tree_code resultcode = code;
3003
3004 /* Data type in which the computation is to be performed.
3005 In the simplest cases this is the common type of the arguments. */
3006 tree result_type = NULL;
3007
3008 /* Nonzero means operands have already been type-converted
3009 in whatever way is necessary.
3010 Zero means they need to be converted to RESULT_TYPE. */
3011 int converted = 0;
3012
3013 /* Nonzero means create the expression with this type, rather than
3014 RESULT_TYPE. */
3015 tree build_type = 0;
3016
3017 /* Nonzero means after finally constructing the expression
3018 convert it to this type. */
3019 tree final_type = 0;
3020
3021 tree result;
3022
3023 /* Nonzero if this is an operation like MIN or MAX which can
3024 safely be computed in short if both args are promoted shorts.
3025 Also implies COMMON.
3026 -1 indicates a bitwise operation; this makes a difference
3027 in the exact conditions for when it is safe to do the operation
3028 in a narrower mode. */
3029 int shorten = 0;
3030
3031 /* Nonzero if this is a comparison operation;
3032 if both args are promoted shorts, compare the original shorts.
3033 Also implies COMMON. */
3034 int short_compare = 0;
3035
3036 /* Nonzero if this is a right-shift operation, which can be computed on the
3037 original short and then promoted if the operand is a promoted short. */
3038 int short_shift = 0;
3039
3040 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3041 int common = 0;
3042
3043 /* True if both operands have arithmetic type. */
3044 bool arithmetic_types_p;
3045
3046 /* Apply default conversions. */
3047 op0 = orig_op0;
3048 op1 = orig_op1;
3049
3050 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3051 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3052 || code == TRUTH_XOR_EXPR)
3053 {
3054 if (!really_overloaded_fn (op0))
3055 op0 = decay_conversion (op0);
3056 if (!really_overloaded_fn (op1))
3057 op1 = decay_conversion (op1);
3058 }
3059 else
3060 {
3061 if (!really_overloaded_fn (op0))
3062 op0 = default_conversion (op0);
3063 if (!really_overloaded_fn (op1))
3064 op1 = default_conversion (op1);
3065 }
3066
3067 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3068 STRIP_TYPE_NOPS (op0);
3069 STRIP_TYPE_NOPS (op1);
3070
3071 /* DTRT if one side is an overloaded function, but complain about it. */
3072 if (type_unknown_p (op0))
3073 {
3074 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3075 if (t != error_mark_node)
3076 {
3077 pedwarn ("assuming cast to type %qT from overloaded function",
3078 TREE_TYPE (t));
3079 op0 = t;
3080 }
3081 }
3082 if (type_unknown_p (op1))
3083 {
3084 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3085 if (t != error_mark_node)
3086 {
3087 pedwarn ("assuming cast to type %qT from overloaded function",
3088 TREE_TYPE (t));
3089 op1 = t;
3090 }
3091 }
3092
3093 type0 = TREE_TYPE (op0);
3094 type1 = TREE_TYPE (op1);
3095
3096 /* The expression codes of the data types of the arguments tell us
3097 whether the arguments are integers, floating, pointers, etc. */
3098 code0 = TREE_CODE (type0);
3099 code1 = TREE_CODE (type1);
3100
3101 /* If an error was already reported for one of the arguments,
3102 avoid reporting another error. */
3103
3104 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3105 return error_mark_node;
3106
3107 if ((invalid_op_diag
3108 = targetm.invalid_binary_op (code, type0, type1)))
3109 {
3110 error (invalid_op_diag, "");
3111 return error_mark_node;
3112 }
3113
3114 switch (code)
3115 {
3116 case MINUS_EXPR:
3117 /* Subtraction of two similar pointers.
3118 We must subtract them as integers, then divide by object size. */
3119 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3120 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3121 TREE_TYPE (type1)))
3122 return pointer_diff (op0, op1, common_type (type0, type1));
3123 /* In all other cases except pointer - int, the usual arithmetic
3124 rules aply. */
3125 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3126 {
3127 common = 1;
3128 break;
3129 }
3130 /* The pointer - int case is just like pointer + int; fall
3131 through. */
3132 case PLUS_EXPR:
3133 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3134 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3135 {
3136 tree ptr_operand;
3137 tree int_operand;
3138 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3139 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3140 if (processing_template_decl)
3141 {
3142 result_type = TREE_TYPE (ptr_operand);
3143 break;
3144 }
3145 return cp_pointer_int_sum (code,
3146 ptr_operand,
3147 int_operand);
3148 }
3149 common = 1;
3150 break;
3151
3152 case MULT_EXPR:
3153 common = 1;
3154 break;
3155
3156 case TRUNC_DIV_EXPR:
3157 case CEIL_DIV_EXPR:
3158 case FLOOR_DIV_EXPR:
3159 case ROUND_DIV_EXPR:
3160 case EXACT_DIV_EXPR:
3161 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3162 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3163 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3164 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3165 {
3166 enum tree_code tcode0 = code0, tcode1 = code1;
3167
3168 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3169 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3170 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3171 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3172
3173 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3174 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3175 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3176 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3177
3178 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3179 resultcode = RDIV_EXPR;
3180 else
3181 /* When dividing two signed integers, we have to promote to int.
3182 unless we divide by a constant != -1. Note that default
3183 conversion will have been performed on the operands at this
3184 point, so we have to dig out the original type to find out if
3185 it was unsigned. */
3186 shorten = ((TREE_CODE (op0) == NOP_EXPR
3187 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3188 || (TREE_CODE (op1) == INTEGER_CST
3189 && ! integer_all_onesp (op1)));
3190
3191 common = 1;
3192 }
3193 break;
3194
3195 case BIT_AND_EXPR:
3196 case BIT_IOR_EXPR:
3197 case BIT_XOR_EXPR:
3198 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3199 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3200 shorten = -1;
3201 break;
3202
3203 case TRUNC_MOD_EXPR:
3204 case FLOOR_MOD_EXPR:
3205 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3206 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3207 else if (code1 == REAL_TYPE && real_zerop (op1))
3208 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3209
3210 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3211 {
3212 /* Although it would be tempting to shorten always here, that loses
3213 on some targets, since the modulo instruction is undefined if the
3214 quotient can't be represented in the computation mode. We shorten
3215 only if unsigned or if dividing by something we know != -1. */
3216 shorten = ((TREE_CODE (op0) == NOP_EXPR
3217 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3218 || (TREE_CODE (op1) == INTEGER_CST
3219 && ! integer_all_onesp (op1)));
3220 common = 1;
3221 }
3222 break;
3223
3224 case TRUTH_ANDIF_EXPR:
3225 case TRUTH_ORIF_EXPR:
3226 case TRUTH_AND_EXPR:
3227 case TRUTH_OR_EXPR:
3228 result_type = boolean_type_node;
3229 break;
3230
3231 /* Shift operations: result has same type as first operand;
3232 always convert second operand to int.
3233 Also set SHORT_SHIFT if shifting rightward. */
3234
3235 case RSHIFT_EXPR:
3236 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3237 {
3238 result_type = type0;
3239 if (TREE_CODE (op1) == INTEGER_CST)
3240 {
3241 if (tree_int_cst_lt (op1, integer_zero_node))
3242 warning (0, "right shift count is negative");
3243 else
3244 {
3245 if (! integer_zerop (op1))
3246 short_shift = 1;
3247 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3248 warning (0, "right shift count >= width of type");
3249 }
3250 }
3251 /* Convert the shift-count to an integer, regardless of
3252 size of value being shifted. */
3253 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3254 op1 = cp_convert (integer_type_node, op1);
3255 /* Avoid converting op1 to result_type later. */
3256 converted = 1;
3257 }
3258 break;
3259
3260 case LSHIFT_EXPR:
3261 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3262 {
3263 result_type = type0;
3264 if (TREE_CODE (op1) == INTEGER_CST)
3265 {
3266 if (tree_int_cst_lt (op1, integer_zero_node))
3267 warning (0, "left shift count is negative");
3268 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3269 warning (0, "left shift count >= width of type");
3270 }
3271 /* Convert the shift-count to an integer, regardless of
3272 size of value being shifted. */
3273 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3274 op1 = cp_convert (integer_type_node, op1);
3275 /* Avoid converting op1 to result_type later. */
3276 converted = 1;
3277 }
3278 break;
3279
3280 case RROTATE_EXPR:
3281 case LROTATE_EXPR:
3282 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3283 {
3284 result_type = type0;
3285 if (TREE_CODE (op1) == INTEGER_CST)
3286 {
3287 if (tree_int_cst_lt (op1, integer_zero_node))
3288 warning (0, "%s rotate count is negative",
3289 (code == LROTATE_EXPR) ? "left" : "right");
3290 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3291 warning (0, "%s rotate count >= width of type",
3292 (code == LROTATE_EXPR) ? "left" : "right");
3293 }
3294 /* Convert the shift-count to an integer, regardless of
3295 size of value being shifted. */
3296 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3297 op1 = cp_convert (integer_type_node, op1);
3298 }
3299 break;
3300
3301 case EQ_EXPR:
3302 case NE_EXPR:
3303 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3304 warning (OPT_Wfloat_equal,
3305 "comparing floating point with == or != is unsafe");
3306 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3307 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3308 warning (OPT_Waddress,
3309 "comparison with string literal results in unspecified behaviour");
3310
3311 build_type = boolean_type_node;
3312 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3313 || code0 == COMPLEX_TYPE)
3314 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3315 || code1 == COMPLEX_TYPE))
3316 short_compare = 1;
3317 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3318 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3319 result_type = composite_pointer_type (type0, type1, op0, op1,
3320 "comparison");
3321 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3322 && null_ptr_cst_p (op1))
3323 result_type = type0;
3324 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3325 && null_ptr_cst_p (op0))
3326 result_type = type1;
3327 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3328 {
3329 result_type = type0;
3330 error ("ISO C++ forbids comparison between pointer and integer");
3331 }
3332 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3333 {
3334 result_type = type1;
3335 error ("ISO C++ forbids comparison between pointer and integer");
3336 }
3337 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3338 {
3339 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3340 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3341 result_type = TREE_TYPE (op0);
3342 }
3343 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3344 return cp_build_binary_op (code, op1, op0);
3345 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3346 && same_type_p (type0, type1))
3347 {
3348 /* E will be the final comparison. */
3349 tree e;
3350 /* E1 and E2 are for scratch. */
3351 tree e1;
3352 tree e2;
3353 tree pfn0;
3354 tree pfn1;
3355 tree delta0;
3356 tree delta1;
3357
3358 if (TREE_SIDE_EFFECTS (op0))
3359 op0 = save_expr (op0);
3360 if (TREE_SIDE_EFFECTS (op1))
3361 op1 = save_expr (op1);
3362
3363 /* We generate:
3364
3365 (op0.pfn == op1.pfn
3366 && (!op0.pfn || op0.delta == op1.delta))
3367
3368 The reason for the `!op0.pfn' bit is that a NULL
3369 pointer-to-member is any member with a zero PFN; the
3370 DELTA field is unspecified. */
3371 pfn0 = pfn_from_ptrmemfunc (op0);
3372 pfn1 = pfn_from_ptrmemfunc (op1);
3373 delta0 = build_ptrmemfunc_access_expr (op0,
3374 delta_identifier);
3375 delta1 = build_ptrmemfunc_access_expr (op1,
3376 delta_identifier);
3377 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3378 e2 = cp_build_binary_op (EQ_EXPR,
3379 pfn0,
3380 cp_convert (TREE_TYPE (pfn0),
3381 integer_zero_node));
3382 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3383 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3384 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3385 if (code == EQ_EXPR)
3386 return e;
3387 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3388 }
3389 else
3390 {
3391 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3392 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3393 type1));
3394 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3395 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3396 type0));
3397 }
3398
3399 break;
3400
3401 case MAX_EXPR:
3402 case MIN_EXPR:
3403 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3404 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3405 shorten = 1;
3406 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3407 result_type = composite_pointer_type (type0, type1, op0, op1,
3408 "comparison");
3409 break;
3410
3411 case LE_EXPR:
3412 case GE_EXPR:
3413 case LT_EXPR:
3414 case GT_EXPR:
3415 if (TREE_CODE (orig_op0) == STRING_CST
3416 || TREE_CODE (orig_op1) == STRING_CST)
3417 warning (OPT_Waddress,
3418 "comparison with string literal results in unspecified behaviour");
3419
3420 build_type = boolean_type_node;
3421 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3422 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3423 short_compare = 1;
3424 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3425 result_type = composite_pointer_type (type0, type1, op0, op1,
3426 "comparison");
3427 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3428 && integer_zerop (op1))
3429 result_type = type0;
3430 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3431 && integer_zerop (op0))
3432 result_type = type1;
3433 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3434 {
3435 result_type = type0;
3436 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3437 }
3438 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3439 {
3440 result_type = type1;
3441 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3442 }
3443 break;
3444
3445 case UNORDERED_EXPR:
3446 case ORDERED_EXPR:
3447 case UNLT_EXPR:
3448 case UNLE_EXPR:
3449 case UNGT_EXPR:
3450 case UNGE_EXPR:
3451 case UNEQ_EXPR:
3452 build_type = integer_type_node;
3453 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3454 {
3455 error ("unordered comparison on non-floating point argument");
3456 return error_mark_node;
3457 }
3458 common = 1;
3459 break;
3460
3461 default:
3462 break;
3463 }
3464
3465 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3466 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3467 || code1 == COMPLEX_TYPE)))
3468 arithmetic_types_p = 1;
3469 else
3470 {
3471 arithmetic_types_p = 0;
3472 /* Vector arithmetic is only allowed when both sides are vectors. */
3473 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3474 {
3475 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3476 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3477 TREE_TYPE (type1)))
3478 {
3479 binary_op_error (code, type0, type1);
3480 return error_mark_node;
3481 }
3482 arithmetic_types_p = 1;
3483 }
3484 }
3485 /* Determine the RESULT_TYPE, if it is not already known. */
3486 if (!result_type
3487 && arithmetic_types_p
3488 && (shorten || common || short_compare))
3489 result_type = common_type (type0, type1);
3490
3491 if (!result_type)
3492 {
3493 error ("invalid operands of types %qT and %qT to binary %qO",
3494 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3495 return error_mark_node;
3496 }
3497
3498 /* If we're in a template, the only thing we need to know is the
3499 RESULT_TYPE. */
3500 if (processing_template_decl)
3501 return build2 (resultcode,
3502 build_type ? build_type : result_type,
3503 op0, op1);
3504
3505 if (arithmetic_types_p)
3506 {
3507 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3508
3509 /* For certain operations (which identify themselves by shorten != 0)
3510 if both args were extended from the same smaller type,
3511 do the arithmetic in that type and then extend.
3512
3513 shorten !=0 and !=1 indicates a bitwise operation.
3514 For them, this optimization is safe only if
3515 both args are zero-extended or both are sign-extended.
3516 Otherwise, we might change the result.
3517 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3518 but calculated in (unsigned short) it would be (unsigned short)-1. */
3519
3520 if (shorten && none_complex)
3521 {
3522 int unsigned0, unsigned1;
3523 tree arg0 = get_narrower (op0, &unsigned0);
3524 tree arg1 = get_narrower (op1, &unsigned1);
3525 /* UNS is 1 if the operation to be done is an unsigned one. */
3526 int uns = TYPE_UNSIGNED (result_type);
3527 tree type;
3528
3529 final_type = result_type;
3530
3531 /* Handle the case that OP0 does not *contain* a conversion
3532 but it *requires* conversion to FINAL_TYPE. */
3533
3534 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3535 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3536 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3537 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3538
3539 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3540
3541 /* For bitwise operations, signedness of nominal type
3542 does not matter. Consider only how operands were extended. */
3543 if (shorten == -1)
3544 uns = unsigned0;
3545
3546 /* Note that in all three cases below we refrain from optimizing
3547 an unsigned operation on sign-extended args.
3548 That would not be valid. */
3549
3550 /* Both args variable: if both extended in same way
3551 from same width, do it in that width.
3552 Do it unsigned if args were zero-extended. */
3553 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3554 < TYPE_PRECISION (result_type))
3555 && (TYPE_PRECISION (TREE_TYPE (arg1))
3556 == TYPE_PRECISION (TREE_TYPE (arg0)))
3557 && unsigned0 == unsigned1
3558 && (unsigned0 || !uns))
3559 result_type = c_common_signed_or_unsigned_type
3560 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3561 else if (TREE_CODE (arg0) == INTEGER_CST
3562 && (unsigned1 || !uns)
3563 && (TYPE_PRECISION (TREE_TYPE (arg1))
3564 < TYPE_PRECISION (result_type))
3565 && (type = c_common_signed_or_unsigned_type
3566 (unsigned1, TREE_TYPE (arg1)),
3567 int_fits_type_p (arg0, type)))
3568 result_type = type;
3569 else if (TREE_CODE (arg1) == INTEGER_CST
3570 && (unsigned0 || !uns)
3571 && (TYPE_PRECISION (TREE_TYPE (arg0))
3572 < TYPE_PRECISION (result_type))
3573 && (type = c_common_signed_or_unsigned_type
3574 (unsigned0, TREE_TYPE (arg0)),
3575 int_fits_type_p (arg1, type)))
3576 result_type = type;
3577 }
3578
3579 /* Shifts can be shortened if shifting right. */
3580
3581 if (short_shift)
3582 {
3583 int unsigned_arg;
3584 tree arg0 = get_narrower (op0, &unsigned_arg);
3585
3586 final_type = result_type;
3587
3588 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3589 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3590
3591 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3592 /* We can shorten only if the shift count is less than the
3593 number of bits in the smaller type size. */
3594 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3595 /* If arg is sign-extended and then unsigned-shifted,
3596 we can simulate this with a signed shift in arg's type
3597 only if the extended result is at least twice as wide
3598 as the arg. Otherwise, the shift could use up all the
3599 ones made by sign-extension and bring in zeros.
3600 We can't optimize that case at all, but in most machines
3601 it never happens because available widths are 2**N. */
3602 && (!TYPE_UNSIGNED (final_type)
3603 || unsigned_arg
3604 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3605 <= TYPE_PRECISION (result_type))))
3606 {
3607 /* Do an unsigned shift if the operand was zero-extended. */
3608 result_type
3609 = c_common_signed_or_unsigned_type (unsigned_arg,
3610 TREE_TYPE (arg0));
3611 /* Convert value-to-be-shifted to that type. */
3612 if (TREE_TYPE (op0) != result_type)
3613 op0 = cp_convert (result_type, op0);
3614 converted = 1;
3615 }
3616 }
3617
3618 /* Comparison operations are shortened too but differently.
3619 They identify themselves by setting short_compare = 1. */
3620
3621 if (short_compare)
3622 {
3623 /* Don't write &op0, etc., because that would prevent op0
3624 from being kept in a register.
3625 Instead, make copies of the our local variables and
3626 pass the copies by reference, then copy them back afterward. */
3627 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3628 enum tree_code xresultcode = resultcode;
3629 tree val
3630 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3631 if (val != 0)
3632 return cp_convert (boolean_type_node, val);
3633 op0 = xop0, op1 = xop1;
3634 converted = 1;
3635 resultcode = xresultcode;
3636 }
3637
3638 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3639 && warn_sign_compare
3640 /* Do not warn until the template is instantiated; we cannot
3641 bound the ranges of the arguments until that point. */
3642 && !processing_template_decl)
3643 {
3644 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3645 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3646
3647 int unsignedp0, unsignedp1;
3648 tree primop0 = get_narrower (op0, &unsignedp0);
3649 tree primop1 = get_narrower (op1, &unsignedp1);
3650
3651 /* Check for comparison of different enum types. */
3652 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3653 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3654 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3655 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3656 {
3657 warning (0, "comparison between types %q#T and %q#T",
3658 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3659 }
3660
3661 /* Give warnings for comparisons between signed and unsigned
3662 quantities that may fail. */
3663 /* Do the checking based on the original operand trees, so that
3664 casts will be considered, but default promotions won't be. */
3665
3666 /* Do not warn if the comparison is being done in a signed type,
3667 since the signed type will only be chosen if it can represent
3668 all the values of the unsigned type. */
3669 if (!TYPE_UNSIGNED (result_type))
3670 /* OK */;
3671 /* Do not warn if both operands are unsigned. */
3672 else if (op0_signed == op1_signed)
3673 /* OK */;
3674 /* Do not warn if the signed quantity is an unsuffixed
3675 integer literal (or some static constant expression
3676 involving such literals or a conditional expression
3677 involving such literals) and it is non-negative. */
3678 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3679 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3680 /* OK */;
3681 /* Do not warn if the comparison is an equality operation,
3682 the unsigned quantity is an integral constant and it does
3683 not use the most significant bit of result_type. */
3684 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3685 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3686 && int_fits_type_p (orig_op1, c_common_signed_type
3687 (result_type)))
3688 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3689 && int_fits_type_p (orig_op0, c_common_signed_type
3690 (result_type)))))
3691 /* OK */;
3692 else
3693 warning (0, "comparison between signed and unsigned integer expressions");
3694
3695 /* Warn if two unsigned values are being compared in a size
3696 larger than their original size, and one (and only one) is the
3697 result of a `~' operator. This comparison will always fail.
3698
3699 Also warn if one operand is a constant, and the constant does not
3700 have all bits set that are set in the ~ operand when it is
3701 extended. */
3702
3703 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3704 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3705 {
3706 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3707 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3708 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3709 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3710
3711 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3712 {
3713 tree primop;
3714 HOST_WIDE_INT constant, mask;
3715 int unsignedp;
3716 unsigned int bits;
3717
3718 if (host_integerp (primop0, 0))
3719 {
3720 primop = primop1;
3721 unsignedp = unsignedp1;
3722 constant = tree_low_cst (primop0, 0);
3723 }
3724 else
3725 {
3726 primop = primop0;
3727 unsignedp = unsignedp0;
3728 constant = tree_low_cst (primop1, 0);
3729 }
3730
3731 bits = TYPE_PRECISION (TREE_TYPE (primop));
3732 if (bits < TYPE_PRECISION (result_type)
3733 && bits < HOST_BITS_PER_LONG && unsignedp)
3734 {
3735 mask = (~ (HOST_WIDE_INT) 0) << bits;
3736 if ((mask & constant) != mask)
3737 warning (0, "comparison of promoted ~unsigned with constant");
3738 }
3739 }
3740 else if (unsignedp0 && unsignedp1
3741 && (TYPE_PRECISION (TREE_TYPE (primop0))
3742 < TYPE_PRECISION (result_type))
3743 && (TYPE_PRECISION (TREE_TYPE (primop1))
3744 < TYPE_PRECISION (result_type)))
3745 warning (0, "comparison of promoted ~unsigned with unsigned");
3746 }
3747 }
3748 }
3749
3750 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3751 Then the expression will be built.
3752 It will be given type FINAL_TYPE if that is nonzero;
3753 otherwise, it will be given type RESULT_TYPE. */
3754
3755 /* Issue warnings about peculiar, but valid, uses of NULL. */
3756 if (/* It's reasonable to use pointer values as operands of &&
3757 and ||, so NULL is no exception. */
3758 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3759 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3760 (orig_op0 == null_node
3761 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3762 /* Or vice versa. */
3763 || (orig_op1 == null_node
3764 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3765 /* Or, both are NULL and the operation was not a comparison. */
3766 || (orig_op0 == null_node && orig_op1 == null_node
3767 && code != EQ_EXPR && code != NE_EXPR)))
3768 /* Some sort of arithmetic operation involving NULL was
3769 performed. Note that pointer-difference and pointer-addition
3770 have already been handled above, and so we don't end up here in
3771 that case. */
3772 warning (0, "NULL used in arithmetic");
3773
3774 if (! converted)
3775 {
3776 if (TREE_TYPE (op0) != result_type)
3777 op0 = cp_convert (result_type, op0);
3778 if (TREE_TYPE (op1) != result_type)
3779 op1 = cp_convert (result_type, op1);
3780
3781 if (op0 == error_mark_node || op1 == error_mark_node)
3782 return error_mark_node;
3783 }
3784
3785 if (build_type == NULL_TREE)
3786 build_type = result_type;
3787
3788 result = build2 (resultcode, build_type, op0, op1);
3789 result = fold_if_not_in_template (result);
3790 if (final_type != 0)
3791 result = cp_convert (final_type, result);
3792
3793 if (TREE_OVERFLOW_P (result)
3794 && !TREE_OVERFLOW_P (op0)
3795 && !TREE_OVERFLOW_P (op1))
3796 overflow_warning (result);
3797
3798 return result;
3799}
3800
3801/* Return a tree for the sum or difference (RESULTCODE says which)
3802 of pointer PTROP and integer INTOP. */
3803
3804static tree
3805cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3806{
3807 tree res_type = TREE_TYPE (ptrop);
3808
3809 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3810 in certain circumstance (when it's valid to do so). So we need
3811 to make sure it's complete. We don't need to check here, if we
3812 can actually complete it at all, as those checks will be done in
3813 pointer_int_sum() anyway. */
3814 complete_type (TREE_TYPE (res_type));
3815
3816 return pointer_int_sum (resultcode, ptrop,
3817 fold_if_not_in_template (intop));
3818}
3819
3820/* Return a tree for the difference of pointers OP0 and OP1.
3821 The resulting tree has type int. */
3822
3823static tree
3824pointer_diff (tree op0, tree op1, tree ptrtype)
3825{
3826 tree result;
3827 tree restype = ptrdiff_type_node;
3828 tree target_type = TREE_TYPE (ptrtype);
3829
3830 if (!complete_type_or_else (target_type, NULL_TREE))
3831 return error_mark_node;
3832
3833 if (pedantic || warn_pointer_arith)
3834 {
3835 if (TREE_CODE (target_type) == VOID_TYPE)
3836 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3837 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3838 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3839 if (TREE_CODE (target_type) == METHOD_TYPE)
3840 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3841 }
3842
3843 /* First do the subtraction as integers;
3844 then drop through to build the divide operator. */
3845
3846 op0 = cp_build_binary_op (MINUS_EXPR,
3847 cp_convert (restype, op0),
3848 cp_convert (restype, op1));
3849
3850 /* This generates an error if op1 is a pointer to an incomplete type. */
3851 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3852 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3853
3854 op1 = (TYPE_PTROB_P (ptrtype)
3855 ? size_in_bytes (target_type)
3856 : integer_one_node);
3857
3858 /* Do the division. */
3859
3860 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3861 return fold_if_not_in_template (result);
3862}
3863
3864/* Construct and perhaps optimize a tree representation
3865 for a unary operation. CODE, a tree_code, specifies the operation
3866 and XARG is the operand. */
3867
3868tree
3869build_x_unary_op (enum tree_code code, tree xarg)
3870{
3871 tree orig_expr = xarg;
3872 tree exp;
3873 int ptrmem = 0;
3874
3875 if (processing_template_decl)
3876 {
3877 if (type_dependent_expression_p (xarg))
3878 return build_min_nt (code, xarg, NULL_TREE);
3879
3880 xarg = build_non_dependent_expr (xarg);
3881 }
3882
3883 exp = NULL_TREE;
3884
3885 /* [expr.unary.op] says:
3886
3887 The address of an object of incomplete type can be taken.
3888
3889 (And is just the ordinary address operator, not an overloaded
3890 "operator &".) However, if the type is a template
3891 specialization, we must complete the type at this point so that
3892 an overloaded "operator &" will be available if required. */
3893 if (code == ADDR_EXPR
3894 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3895 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3896 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3897 || (TREE_CODE (xarg) == OFFSET_REF)))
3898 /* Don't look for a function. */;
3899 else
3900 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3901 /*overloaded_p=*/NULL);
3902 if (!exp && code == ADDR_EXPR)
3903 {
3904 /* A pointer to member-function can be formed only by saying
3905 &X::mf. */
3906 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3907 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3908 {
3909 if (TREE_CODE (xarg) != OFFSET_REF
3910 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3911 {
3912 error ("invalid use of %qE to form a pointer-to-member-function",
3913 xarg);
3914 if (TREE_CODE (xarg) != OFFSET_REF)
3915 inform (" a qualified-id is required");
3916 return error_mark_node;
3917 }
3918 else
3919 {
3920 error ("parentheses around %qE cannot be used to form a"
3921 " pointer-to-member-function",
3922 xarg);
3923 PTRMEM_OK_P (xarg) = 1;
3924 }
3925 }
3926
3927 if (TREE_CODE (xarg) == OFFSET_REF)
3928 {
3929 ptrmem = PTRMEM_OK_P (xarg);
3930
3931 if (!ptrmem && !flag_ms_extensions
3932 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3933 {
3934 /* A single non-static member, make sure we don't allow a
3935 pointer-to-member. */
3936 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3937 TREE_OPERAND (xarg, 0),
3938 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3939 PTRMEM_OK_P (xarg) = ptrmem;
3940 }
3941 }
3942 else if (TREE_CODE (xarg) == TARGET_EXPR)
3943 warning (0, "taking address of temporary");
3944 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3945 }
3946
3947 if (processing_template_decl && exp != error_mark_node)
3948 exp = build_min_non_dep (code, exp, orig_expr,
3949 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3950 if (TREE_CODE (exp) == ADDR_EXPR)
3951 PTRMEM_OK_P (exp) = ptrmem;
3952 return exp;
3953}
3954
3955/* Like c_common_truthvalue_conversion, but handle pointer-to-member
3956 constants, where a null value is represented by an INTEGER_CST of
3957 -1. */
3958
3959tree
3960cp_truthvalue_conversion (tree expr)
3961{
3962 tree type = TREE_TYPE (expr);
3963 if (TYPE_PTRMEM_P (type))
3964 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3965 else
3966 return c_common_truthvalue_conversion (expr);
3967}
3968
3969/* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3970
3971tree
3972condition_conversion (tree expr)
3973{
3974 tree t;
3975 if (processing_template_decl)
3976 return expr;
3977 t = perform_implicit_conversion (boolean_type_node, expr);
3978 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3979 return t;
3980}
3981
3982/* Return an ADDR_EXPR giving the address of T. This function
3983 attempts no optimizations or simplifications; it is a low-level
3984 primitive. */
3985
3986tree
3987build_address (tree t)
3988{
3989 tree addr;
3990
3991 if (error_operand_p (t) || !cxx_mark_addressable (t))
3992 return error_mark_node;
3993
3994 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3995
3996 return addr;
3997}
3998
3999/* Return a NOP_EXPR converting EXPR to TYPE. */
4000
4001tree
4002build_nop (tree type, tree expr)
4003{
4004 if (type == error_mark_node || error_operand_p (expr))
4005 return expr;
4006 return build1 (NOP_EXPR, type, expr);
4007}
4008
4009/* C++: Must handle pointers to members.
4010
4011 Perhaps type instantiation should be extended to handle conversion
4012 from aggregates to types we don't yet know we want? (Or are those
4013 cases typically errors which should be reported?)
4014
4015 NOCONVERT nonzero suppresses the default promotions
4016 (such as from short to int). */
4017
4018tree
4019build_unary_op (enum tree_code code, tree xarg, int noconvert)
4020{
4021 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4022 tree arg = xarg;
4023 tree argtype = 0;
4024 const char *errstring = NULL;
4025 tree val;
4026 const char *invalid_op_diag;
4027
4028 if (arg == error_mark_node)
4029 return error_mark_node;
4030
4031 if ((invalid_op_diag
4032 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4033 ? CONVERT_EXPR
4034 : code),
4035 TREE_TYPE (xarg))))
4036 {
4037 error (invalid_op_diag, "");
4038 return error_mark_node;
4039 }
4040
4041 switch (code)
4042 {
4043 case UNARY_PLUS_EXPR:
4044 case NEGATE_EXPR:
4045 {
4046 int flags = WANT_ARITH | WANT_ENUM;
4047 /* Unary plus (but not unary minus) is allowed on pointers. */
4048 if (code == UNARY_PLUS_EXPR)
4049 flags |= WANT_POINTER;
4050 arg = build_expr_type_conversion (flags, arg, true);
4051 if (!arg)
4052 errstring = (code == NEGATE_EXPR
4053 ? "wrong type argument to unary minus"
4054 : "wrong type argument to unary plus");
4055 else
4056 {
4057 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4058 arg = perform_integral_promotions (arg);
4059
4060 /* Make sure the result is not an lvalue: a unary plus or minus
4061 expression is always a rvalue. */
4062 arg = rvalue (arg);
4063 }
4064 }
4065 break;
4066
4067 case BIT_NOT_EXPR:
4068 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4069 {
4070 code = CONJ_EXPR;
4071 if (!noconvert)
4072 arg = default_conversion (arg);
4073 }
4074 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4075 | WANT_VECTOR,
4076 arg, true)))
4077 errstring = "wrong type argument to bit-complement";
4078 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4079 arg = perform_integral_promotions (arg);
4080 break;
4081
4082 case ABS_EXPR:
4083 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4084 errstring = "wrong type argument to abs";
4085 else if (!noconvert)
4086 arg = default_conversion (arg);
4087 break;
4088
4089 case CONJ_EXPR:
4090 /* Conjugating a real value is a no-op, but allow it anyway. */
4091 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4092 errstring = "wrong type argument to conjugation";
4093 else if (!noconvert)
4094 arg = default_conversion (arg);
4095 break;
4096
4097 case TRUTH_NOT_EXPR:
4098 arg = perform_implicit_conversion (boolean_type_node, arg);
4099 val = invert_truthvalue (arg);
4100 if (arg != error_mark_node)
4101 return val;
4102 errstring = "in argument to unary !";
4103 break;
4104
4105 case NOP_EXPR:
4106 break;
4107
4108 case REALPART_EXPR:
4109 if (TREE_CODE (arg) == COMPLEX_CST)
4110 return TREE_REALPART (arg);
4111 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4112 {
4113 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4114 return fold_if_not_in_template (arg);
4115 }
4116 else
4117 return arg;
4118
4119 case IMAGPART_EXPR:
4120 if (TREE_CODE (arg) == COMPLEX_CST)
4121 return TREE_IMAGPART (arg);
4122 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4123 {
4124 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4125 return fold_if_not_in_template (arg);
4126 }
4127 else
4128 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4129
4130 case PREINCREMENT_EXPR:
4131 case POSTINCREMENT_EXPR:
4132 case PREDECREMENT_EXPR:
4133 case POSTDECREMENT_EXPR:
4134 /* Handle complex lvalues (when permitted)
4135 by reduction to simpler cases. */
4136
4137 val = unary_complex_lvalue (code, arg);
4138 if (val != 0)
4139 return val;
4140
4141 /* Increment or decrement the real part of the value,
4142 and don't change the imaginary part. */
4143 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4144 {
4145 tree real, imag;
4146
4147 arg = stabilize_reference (arg);
4148 real = build_unary_op (REALPART_EXPR, arg, 1);
4149 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4150 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4151 build_unary_op (code, real, 1), imag);
4152 }
4153
4154 /* Report invalid types. */
4155
4156 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4157 arg, true)))
4158 {
4159 if (code == PREINCREMENT_EXPR)
4160 errstring ="no pre-increment operator for type";
4161 else if (code == POSTINCREMENT_EXPR)
4162 errstring ="no post-increment operator for type";
4163 else if (code == PREDECREMENT_EXPR)
4164 errstring ="no pre-decrement operator for type";
4165 else
4166 errstring ="no post-decrement operator for type";
4167 break;
4168 }
4169
4170 /* Report something read-only. */
4171
4172 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4173 || TREE_READONLY (arg))
4174 readonly_error (arg, ((code == PREINCREMENT_EXPR
4175 || code == POSTINCREMENT_EXPR)
4176 ? "increment" : "decrement"),
4177 0);
4178
4179 {
4180 tree inc;
4181 tree declared_type;
4182 tree result_type = TREE_TYPE (arg);
4183
4184 declared_type = unlowered_expr_type (arg);
4185
4186 arg = get_unwidened (arg, 0);
4187 argtype = TREE_TYPE (arg);
4188
4189 /* ARM $5.2.5 last annotation says this should be forbidden. */
4190 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4191 pedwarn ("ISO C++ forbids %sing an enum",
4192 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4193 ? "increment" : "decrement");
4194
4195 /* Compute the increment. */
4196
4197 if (TREE_CODE (argtype) == POINTER_TYPE)
4198 {
4199 tree type = complete_type (TREE_TYPE (argtype));
4200
4201 if (!COMPLETE_OR_VOID_TYPE_P (type))
4202 error ("cannot %s a pointer to incomplete type %qT",
4203 ((code == PREINCREMENT_EXPR
4204 || code == POSTINCREMENT_EXPR)
4205 ? "increment" : "decrement"), TREE_TYPE (argtype));
4206 else if ((pedantic || warn_pointer_arith)
4207 && !TYPE_PTROB_P (argtype))
4208 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4209 ((code == PREINCREMENT_EXPR
4210 || code == POSTINCREMENT_EXPR)
4211 ? "increment" : "decrement"), argtype);
4212 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4213 }
4214 else
4215 inc = integer_one_node;
4216
4217 inc = cp_convert (argtype, inc);
4218
4219 /* Handle incrementing a cast-expression. */
4220
4221 switch (TREE_CODE (arg))
4222 {
4223 case NOP_EXPR:
4224 case CONVERT_EXPR:
4225 case FLOAT_EXPR:
4226 case FIX_TRUNC_EXPR:
4227 case FIX_FLOOR_EXPR:
4228 case FIX_ROUND_EXPR:
4229 case FIX_CEIL_EXPR:
4230 {
4231 tree incremented, modify, value, compound;
4232 if (! lvalue_p (arg) && pedantic)
4233 pedwarn ("cast to non-reference type used as lvalue");
4234 arg = stabilize_reference (arg);
4235 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4236 value = arg;
4237 else
4238 value = save_expr (arg);
4239 incremented = build2 (((code == PREINCREMENT_EXPR
4240 || code == POSTINCREMENT_EXPR)
4241 ? PLUS_EXPR : MINUS_EXPR),
4242 argtype, value, inc);
4243
4244 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4245 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4246 modify, value);
4247
4248 /* Eliminate warning about unused result of + or -. */
4249 TREE_NO_WARNING (compound) = 1;
4250 return compound;
4251 }
4252
4253 default:
4254 break;
4255 }
4256
4257 /* Complain about anything else that is not a true lvalue. */
4258 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4259 || code == POSTINCREMENT_EXPR)
4260 ? lv_increment : lv_decrement)))
4261 return error_mark_node;
4262
4263 /* Forbid using -- on `bool'. */
4264 if (same_type_p (declared_type, boolean_type_node))
4265 {
4266 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4267 {
4268 error ("invalid use of %<--%> on bool variable %qD", arg);
4269 return error_mark_node;
4270 }
4271 val = boolean_increment (code, arg);
4272 }
4273 else
4274 val = build2 (code, TREE_TYPE (arg), arg, inc);
4275
4276 TREE_SIDE_EFFECTS (val) = 1;
4277 return cp_convert (result_type, val);
4278 }
4279
4280 case ADDR_EXPR:
4281 /* Note that this operation never does default_conversion
4282 regardless of NOCONVERT. */
4283
4284 argtype = lvalue_type (arg);
4285
4286 if (TREE_CODE (arg) == OFFSET_REF)
4287 goto offset_ref;
4288
4289 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4290 {
4291 tree type = build_pointer_type (TREE_TYPE (argtype));
4292 arg = build1 (CONVERT_EXPR, type, arg);
4293 return arg;
4294 }
4295 else if (pedantic && DECL_MAIN_P (arg))
4296 /* ARM $3.4 */
4297 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4298
4299 /* Let &* cancel out to simplify resulting code. */
4300 if (TREE_CODE (arg) == INDIRECT_REF)
4301 {
4302 /* We don't need to have `current_class_ptr' wrapped in a
4303 NON_LVALUE_EXPR node. */
4304 if (arg == current_class_ref)
4305 return current_class_ptr;
4306
4307 arg = TREE_OPERAND (arg, 0);
4308 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4309 {
4310 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4311 arg = build1 (CONVERT_EXPR, type, arg);
4312 }
4313 else
4314 /* Don't let this be an lvalue. */
4315 arg = rvalue (arg);
4316 return arg;
4317 }
4318
4319 /* Uninstantiated types are all functions. Taking the
4320 address of a function is a no-op, so just return the
4321 argument. */
4322
4323 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4324 || !IDENTIFIER_OPNAME_P (arg));
4325
4326 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4327 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4328 {
4329 /* They're trying to take the address of a unique non-static
4330 member function. This is ill-formed (except in MS-land),
4331 but let's try to DTRT.
4332 Note: We only handle unique functions here because we don't
4333 want to complain if there's a static overload; non-unique
4334 cases will be handled by instantiate_type. But we need to
4335 handle this case here to allow casts on the resulting PMF.
4336 We could defer this in non-MS mode, but it's easier to give
4337 a useful error here. */
4338
4339 /* Inside constant member functions, the `this' pointer
4340 contains an extra const qualifier. TYPE_MAIN_VARIANT
4341 is used here to remove this const from the diagnostics
4342 and the created OFFSET_REF. */
4343 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4344 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4345 mark_used (fn);
4346
4347 if (! flag_ms_extensions)
4348 {
4349 tree name = DECL_NAME (fn);
4350 if (current_class_type
4351 && TREE_OPERAND (arg, 0) == current_class_ref)
4352 /* An expression like &memfn. */
4353 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4354 " or parenthesized non-static member function to form"
4355 " a pointer to member function. Say %<&%T::%D%>",
4356 base, name);
4357 else
4358 pedwarn ("ISO C++ forbids taking the address of a bound member"
4359 " function to form a pointer to member function."
4360 " Say %<&%T::%D%>",
4361 base, name);
4362 }
4363 arg = build_offset_ref (base, fn, /*address_p=*/true);
4364 }
4365
4366 offset_ref:
4367 if (type_unknown_p (arg))
4368 return build1 (ADDR_EXPR, unknown_type_node, arg);
4369
4370 /* Handle complex lvalues (when permitted)
4371 by reduction to simpler cases. */
4372 val = unary_complex_lvalue (code, arg);
4373 if (val != 0)
4374 return val;
4375
4376 switch (TREE_CODE (arg))
4377 {
4378 case NOP_EXPR:
4379 case CONVERT_EXPR:
4380 case FLOAT_EXPR:
4381 case FIX_TRUNC_EXPR:
4382 case FIX_FLOOR_EXPR:
4383 case FIX_ROUND_EXPR:
4384 case FIX_CEIL_EXPR:
4385 if (! lvalue_p (arg) && pedantic)
4386 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4387 break;
4388
4389 case BASELINK:
4390 arg = BASELINK_FUNCTIONS (arg);
4391 /* Fall through. */
4392
4393 case OVERLOAD:
4394 arg = OVL_CURRENT (arg);
4395 break;
4396
4397 case OFFSET_REF:
4398 /* Turn a reference to a non-static data member into a
4399 pointer-to-member. */
4400 {
4401 tree type;
4402 tree t;
4403
4404 if (!PTRMEM_OK_P (arg))
4405 return build_unary_op (code, arg, 0);
4406
4407 t = TREE_OPERAND (arg, 1);
4408 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4409 {
4410 error ("cannot create pointer to reference member %qD", t);
4411 return error_mark_node;
4412 }
4413
4414 type = build_ptrmem_type (context_for_name_lookup (t),
4415 TREE_TYPE (t));
4416 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4417 return t;
4418 }
4419
4420 default:
4421 break;
4422 }
4423
4424 /* Anything not already handled and not a true memory reference
4425 is an error. */
4426 if (TREE_CODE (argtype) != FUNCTION_TYPE
4427 && TREE_CODE (argtype) != METHOD_TYPE
4428 && TREE_CODE (arg) != OFFSET_REF
4429 && !lvalue_or_else (arg, lv_addressof))
4430 return error_mark_node;
4431
4432 if (argtype != error_mark_node)
4433 argtype = build_pointer_type (argtype);
4434
4435 /* In a template, we are processing a non-dependent expression
4436 so we can just form an ADDR_EXPR with the correct type. */
4437 if (processing_template_decl)
4438 {
4439 val = build_address (arg);
4440 if (TREE_CODE (arg) == OFFSET_REF)
4441 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4442 return val;
4443 }
4444
4445 if (TREE_CODE (arg) != COMPONENT_REF)
4446 {
4447 val = build_address (arg);
4448 if (TREE_CODE (arg) == OFFSET_REF)
4449 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4450 }
4451 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4452 {
4453 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4454
4455 /* We can only get here with a single static member
4456 function. */
4457 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4458 && DECL_STATIC_FUNCTION_P (fn));
4459 mark_used (fn);
4460 val = build_address (fn);
4461 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4462 /* Do not lose object's side effects. */
4463 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4464 TREE_OPERAND (arg, 0), val);
4465 }
4466 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4467 {
4468 error ("attempt to take address of bit-field structure member %qD",
4469 TREE_OPERAND (arg, 1));
4470 return error_mark_node;
4471 }
4472 else
4473 {
4474 tree object = TREE_OPERAND (arg, 0);
4475 tree field = TREE_OPERAND (arg, 1);
4476 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4477 (TREE_TYPE (object), decl_type_context (field)));
4478 val = build_address (arg);
4479 }
4480
4481 if (TREE_CODE (argtype) == POINTER_TYPE
4482 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4483 {
4484 build_ptrmemfunc_type (argtype);
4485 val = build_ptrmemfunc (argtype, val, 0,
4486 /*c_cast_p=*/false);
4487 }
4488
4489 return val;
4490
4491 default:
4492 break;
4493 }
4494
4495 if (!errstring)
4496 {
4497 if (argtype == 0)
4498 argtype = TREE_TYPE (arg);
4499 return fold_if_not_in_template (build1 (code, argtype, arg));
4500 }
4501
4502 error ("%s", errstring);
4503 return error_mark_node;
4504}
4505
4506/* Apply unary lvalue-demanding operator CODE to the expression ARG
4507 for certain kinds of expressions which are not really lvalues
4508 but which we can accept as lvalues.
4509
4510 If ARG is not a kind of expression we can handle, return
4511 NULL_TREE. */
4512
4513tree
4514unary_complex_lvalue (enum tree_code code, tree arg)
4515{
4516 /* Inside a template, making these kinds of adjustments is
4517 pointless; we are only concerned with the type of the
4518 expression. */
4519 if (processing_template_decl)
4520 return NULL_TREE;
4521
4522 /* Handle (a, b) used as an "lvalue". */
4523 if (TREE_CODE (arg) == COMPOUND_EXPR)
4524 {
4525 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4526 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4527 TREE_OPERAND (arg, 0), real_result);
4528 }
4529
4530 /* Handle (a ? b : c) used as an "lvalue". */
4531 if (TREE_CODE (arg) == COND_EXPR
4532 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4533 return rationalize_conditional_expr (code, arg);
4534
4535 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4536 if (TREE_CODE (arg) == MODIFY_EXPR
4537 || TREE_CODE (arg) == PREINCREMENT_EXPR
4538 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4539 {
4540 tree lvalue = TREE_OPERAND (arg, 0);
4541 if (TREE_SIDE_EFFECTS (lvalue))
4542 {
4543 lvalue = stabilize_reference (lvalue);
4544 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4545 lvalue, TREE_OPERAND (arg, 1));
4546 }
4547 return unary_complex_lvalue
4548 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4549 }
4550
4551 if (code != ADDR_EXPR)
4552 return NULL_TREE;
4553
4554 /* Handle (a = b) used as an "lvalue" for `&'. */
4555 if (TREE_CODE (arg) == MODIFY_EXPR
4556 || TREE_CODE (arg) == INIT_EXPR)
4557 {
4558 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4559 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4560 arg, real_result);
4561 TREE_NO_WARNING (arg) = 1;
4562 return arg;
4563 }
4564
4565 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4566 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4567 || TREE_CODE (arg) == OFFSET_REF)
4568 return NULL_TREE;
4569
4570 /* We permit compiler to make function calls returning
4571 objects of aggregate type look like lvalues. */
4572 {
4573 tree targ = arg;
4574
4575 if (TREE_CODE (targ) == SAVE_EXPR)
4576 targ = TREE_OPERAND (targ, 0);
4577
4578 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4579 {
4580 if (TREE_CODE (arg) == SAVE_EXPR)
4581 targ = arg;
4582 else
4583 targ = build_cplus_new (TREE_TYPE (arg), arg);
4584 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4585 }
4586
4587 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4588 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4589 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4590 }
4591
4592 /* Don't let anything else be handled specially. */
4593 return NULL_TREE;
4594}
4595
4596/* Mark EXP saying that we need to be able to take the
4597 address of it; it should not be allocated in a register.
4598 Value is true if successful.
4599
4600 C++: we do not allow `current_class_ptr' to be addressable. */
4601
4602bool
4603cxx_mark_addressable (tree exp)
4604{
4605 tree x = exp;
4606
4607 while (1)
4608 switch (TREE_CODE (x))
4609 {
4610 case ADDR_EXPR:
4611 case COMPONENT_REF:
4612 case ARRAY_REF:
4613 case REALPART_EXPR:
4614 case IMAGPART_EXPR:
4615 x = TREE_OPERAND (x, 0);
4616 break;
4617
4618 case PARM_DECL:
4619 if (x == current_class_ptr)
4620 {
4621 error ("cannot take the address of %<this%>, which is an rvalue expression");
4622 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4623 return true;
4624 }
4625 /* Fall through. */
4626
4627 case VAR_DECL:
4628 /* Caller should not be trying to mark initialized
4629 constant fields addressable. */
4630 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4631 || DECL_IN_AGGR_P (x) == 0
4632 || TREE_STATIC (x)
4633 || DECL_EXTERNAL (x));
4634 /* Fall through. */
4635
4636 case CONST_DECL:
4637 case RESULT_DECL:
4638 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4639 && !DECL_ARTIFICIAL (x))
4640 {
4641 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4642 {
4643 error
4644 ("address of explicit register variable %qD requested", x);
4645 return false;
4646 }
4647 else if (extra_warnings)
4648 warning
4649 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4650 }
4651 TREE_ADDRESSABLE (x) = 1;
4652 return true;
4653
4654 case FUNCTION_DECL:
4655 TREE_ADDRESSABLE (x) = 1;
4656 return true;
4657
4658 case CONSTRUCTOR:
4659 TREE_ADDRESSABLE (x) = 1;
4660 return true;
4661
4662 case TARGET_EXPR:
4663 TREE_ADDRESSABLE (x) = 1;
4664 cxx_mark_addressable (TREE_OPERAND (x, 0));
4665 return true;
4666
4667 default:
4668 return true;
4669 }
4670}
4671
4672/* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4673
4674tree
4675build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4676{
4677 tree orig_ifexp = ifexp;
4678 tree orig_op1 = op1;
4679 tree orig_op2 = op2;
4680 tree expr;
4681
4682 if (processing_template_decl)
4683 {
4684 /* The standard says that the expression is type-dependent if
4685 IFEXP is type-dependent, even though the eventual type of the
4686 expression doesn't dependent on IFEXP. */
4687 if (type_dependent_expression_p (ifexp)
4688 /* As a GNU extension, the middle operand may be omitted. */
4689 || (op1 && type_dependent_expression_p (op1))
4690 || type_dependent_expression_p (op2))
4691 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4692 ifexp = build_non_dependent_expr (ifexp);
4693 if (op1)
4694 op1 = build_non_dependent_expr (op1);
4695 op2 = build_non_dependent_expr (op2);
4696 }
4697
4698 expr = build_conditional_expr (ifexp, op1, op2);
4699 if (processing_template_decl && expr != error_mark_node)
4700 return build_min_non_dep (COND_EXPR, expr,
4701 orig_ifexp, orig_op1, orig_op2);
4702 return expr;
4703}
4704
4705/* Given a list of expressions, return a compound expression
4706 that performs them all and returns the value of the last of them. */
4707
4708tree build_x_compound_expr_from_list (tree list, const char *msg)
4709{
4710 tree expr = TREE_VALUE (list);
4711
4712 if (TREE_CHAIN (list))
4713 {
4714 if (msg)
4715 pedwarn ("%s expression list treated as compound expression", msg);
4716
4717 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4718 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4719 }
4720
4721 return expr;
4722}
4723
4724/* Handle overloading of the ',' operator when needed. */
4725
4726tree
4727build_x_compound_expr (tree op1, tree op2)
4728{
4729 tree result;
4730 tree orig_op1 = op1;
4731 tree orig_op2 = op2;
4732
4733 if (processing_template_decl)
4734 {
4735 if (type_dependent_expression_p (op1)
4736 || type_dependent_expression_p (op2))
4737 return build_min_nt (COMPOUND_EXPR, op1, op2);
4738 op1 = build_non_dependent_expr (op1);
4739 op2 = build_non_dependent_expr (op2);
4740 }
4741
4742 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4743 /*overloaded_p=*/NULL);
4744 if (!result)
4745 result = build_compound_expr (op1, op2);
4746
4747 if (processing_template_decl && result != error_mark_node)
4748 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4749
4750 return result;
4751}
4752
4753/* Build a compound expression. */
4754
4755tree
4756build_compound_expr (tree lhs, tree rhs)
4757{
4758 lhs = convert_to_void (lhs, "left-hand operand of comma");
4759
4760 if (lhs == error_mark_node || rhs == error_mark_node)
4761 return error_mark_node;
4762
4763 if (TREE_CODE (rhs) == TARGET_EXPR)
4764 {
4765 /* If the rhs is a TARGET_EXPR, then build the compound
4766 expression inside the target_expr's initializer. This
4767 helps the compiler to eliminate unnecessary temporaries. */
4768 tree init = TREE_OPERAND (rhs, 1);
4769
4770 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4771 TREE_OPERAND (rhs, 1) = init;
4772
4773 return rhs;
4774 }
4775
4776 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4777}
4778
4779/* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4780 casts away constness. DIAG_FN gives the function to call if we
4781 need to issue a diagnostic; if it is NULL, no diagnostic will be
4782 issued. DESCRIPTION explains what operation is taking place. */
4783
4784static void
4785check_for_casting_away_constness (tree src_type, tree dest_type,
4786 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4787 const char *description)
4788{
4789 if (diag_fn && casts_away_constness (src_type, dest_type))
4790 diag_fn ("%s from type %qT to type %qT casts away constness",
4791 description, src_type, dest_type);
4792}
4793
4794/* Convert EXPR (an expression with pointer-to-member type) to TYPE
4795 (another pointer-to-member type in the same hierarchy) and return
4796 the converted expression. If ALLOW_INVERSE_P is permitted, a
4797 pointer-to-derived may be converted to pointer-to-base; otherwise,
4798 only the other direction is permitted. If C_CAST_P is true, this
4799 conversion is taking place as part of a C-style cast. */
4800
4801tree
4802convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4803 bool c_cast_p)
4804{
4805 if (TYPE_PTRMEM_P (type))
4806 {
4807 tree delta;
4808
4809 if (TREE_CODE (expr) == PTRMEM_CST)
4810 expr = cplus_expand_constant (expr);
4811 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4812 TYPE_PTRMEM_CLASS_TYPE (type),
4813 allow_inverse_p,
4814 c_cast_p);
4815 if (!integer_zerop (delta))
4816 expr = cp_build_binary_op (PLUS_EXPR,
4817 build_nop (ptrdiff_type_node, expr),
4818 delta);
4819 return build_nop (type, expr);
4820 }
4821 else
4822 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4823 allow_inverse_p, c_cast_p);
4824}
4825
4826/* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4827 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4828 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4829
4830static tree
4831ignore_overflows (tree expr, tree orig)
4832{
4833 if (TREE_CODE (expr) == INTEGER_CST
4834 && CONSTANT_CLASS_P (orig)
4835 && TREE_CODE (orig) != STRING_CST
4836 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4837 || TREE_CONSTANT_OVERFLOW (expr)
4838 != TREE_CONSTANT_OVERFLOW (orig)))
4839 {
4840 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4841 /* Ensure constant sharing. */
4842 expr = build_int_cst_wide (TREE_TYPE (expr),
4843 TREE_INT_CST_LOW (expr),
4844 TREE_INT_CST_HIGH (expr));
4845 else
4846 {
4847 /* Avoid clobbering a shared constant. */
4848 expr = copy_node (expr);
4849 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4850 TREE_CONSTANT_OVERFLOW (expr)
4851 = TREE_CONSTANT_OVERFLOW (orig);
4852 }
4853 }
4854 return expr;
4855}
4856
4857/* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4858 this static_cast is being attempted as one of the possible casts
4859 allowed by a C-style cast. (In that case, accessibility of base
4860 classes is not considered, and it is OK to cast away
4861 constness.) Return the result of the cast. *VALID_P is set to
4862 indicate whether or not the cast was valid. */
4863
4864static tree
4865build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4866 bool *valid_p)
4867{
4868 tree intype;
4869 tree result;
4870 tree orig;
4871 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4872 const char *desc;
4873
4874 /* Assume the cast is valid. */
4875 *valid_p = true;
4876
4877 intype = TREE_TYPE (expr);
4878
4879 /* Save casted types in the function's used types hash table. */
4880 used_types_insert (type);
4881
4882 /* Determine what to do when casting away constness. */
4883 if (c_cast_p)
4884 {
4885 /* C-style casts are allowed to cast away constness. With
4886 WARN_CAST_QUAL, we still want to issue a warning. */
4887 diag_fn = warn_cast_qual ? warning0 : NULL;
4888 desc = "cast";
4889 }
4890 else
4891 {
4892 /* A static_cast may not cast away constness. */
4893 diag_fn = error;
4894 desc = "static_cast";
4895 }
4896
4897 /* [expr.static.cast]
4898
4899 An lvalue of type "cv1 B", where B is a class type, can be cast
4900 to type "reference to cv2 D", where D is a class derived (clause
4901 _class.derived_) from B, if a valid standard conversion from
4902 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4903 same cv-qualification as, or greater cv-qualification than, cv1,
4904 and B is not a virtual base class of D. */
4905 /* We check this case before checking the validity of "TYPE t =
4906 EXPR;" below because for this case:
4907
4908 struct B {};
4909 struct D : public B { D(const B&); };
4910 extern B& b;
4911 void f() { static_cast<const D&>(b); }
4912
4913 we want to avoid constructing a new D. The standard is not
4914 completely clear about this issue, but our interpretation is
4915 consistent with other compilers. */
4916 if (TREE_CODE (type) == REFERENCE_TYPE
4917 && CLASS_TYPE_P (TREE_TYPE (type))
4918 && CLASS_TYPE_P (intype)
4919 && real_lvalue_p (expr)
4920 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4921 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4922 build_pointer_type (TYPE_MAIN_VARIANT
4923 (TREE_TYPE (type))))
4924 && (c_cast_p
4925 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4926 {
4927 tree base;
4928
4929 /* There is a standard conversion from "D*" to "B*" even if "B"
4930 is ambiguous or inaccessible. If this is really a
4931 static_cast, then we check both for inaccessibility and
4932 ambiguity. However, if this is a static_cast being performed
4933 because the user wrote a C-style cast, then accessibility is
4934 not considered. */
4935 base = lookup_base (TREE_TYPE (type), intype,
4936 c_cast_p ? ba_unique : ba_check,
4937 NULL);
4938
4939 /* Convert from "B*" to "D*". This function will check that "B"
4940 is not a virtual base of "D". */
4941 expr = build_base_path (MINUS_EXPR, build_address (expr),
4942 base, /*nonnull=*/false);
4943 /* Convert the pointer to a reference -- but then remember that
4944 there are no expressions with reference type in C++. */
4945 return convert_from_reference (build_nop (type, expr));
4946 }
4947
4948 orig = expr;
4949
4950 /* [expr.static.cast]
4951
4952 An expression e can be explicitly converted to a type T using a
4953 static_cast of the form static_cast<T>(e) if the declaration T
4954 t(e);" is well-formed, for some invented temporary variable
4955 t. */
4956 result = perform_direct_initialization_if_possible (type, expr,
4957 c_cast_p);
4958 if (result)
4959 {
4960 result = convert_from_reference (result);
4961
4962 /* Ignore any integer overflow caused by the cast. */
4963 result = ignore_overflows (result, orig);
4964
4965 /* [expr.static.cast]
4966
4967 If T is a reference type, the result is an lvalue; otherwise,
4968 the result is an rvalue. */
4969 if (TREE_CODE (type) != REFERENCE_TYPE)
4970 result = rvalue (result);
4971 return result;
4972 }
4973
4974 /* [expr.static.cast]
4975
4976 Any expression can be explicitly converted to type cv void. */
4977 if (TREE_CODE (type) == VOID_TYPE)
4978 return convert_to_void (expr, /*implicit=*/NULL);
4979
4980 /* [expr.static.cast]
4981
4982 The inverse of any standard conversion sequence (clause _conv_),
4983 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4984 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4985 (_conv.bool_) conversions, can be performed explicitly using
4986 static_cast subject to the restriction that the explicit
4987 conversion does not cast away constness (_expr.const.cast_), and
4988 the following additional rules for specific cases: */
4989 /* For reference, the conversions not excluded are: integral
4990 promotions, floating point promotion, integral conversions,
4991 floating point conversions, floating-integral conversions,
4992 pointer conversions, and pointer to member conversions. */
4993 /* DR 128
4994
4995 A value of integral _or enumeration_ type can be explicitly
4996 converted to an enumeration type. */
4997 /* The effect of all that is that any conversion between any two
4998 types which are integral, floating, or enumeration types can be
4999 performed. */
5000 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5001 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5002 {
5003 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5004
5005 /* Ignore any integer overflow caused by the cast. */
5006 expr = ignore_overflows (expr, orig);
5007 return expr;
5008 }
5009
5010 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5011 && CLASS_TYPE_P (TREE_TYPE (type))
5012 && CLASS_TYPE_P (TREE_TYPE (intype))
5013 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5014 (TREE_TYPE (intype))),
5015 build_pointer_type (TYPE_MAIN_VARIANT
5016 (TREE_TYPE (type)))))
5017 {
5018 tree base;
5019
5020 if (!c_cast_p)
5021 check_for_casting_away_constness (intype, type, diag_fn, desc);
5022 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5023 c_cast_p ? ba_unique : ba_check,
5024 NULL);
5025 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5026 }
5027
5028 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5029 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5030 {
5031 tree c1;
5032 tree c2;
5033 tree t1;
5034 tree t2;
5035
5036 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5037 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5038
5039 if (TYPE_PTRMEM_P (type))
5040 {
5041 t1 = (build_ptrmem_type
5042 (c1,
5043 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5044 t2 = (build_ptrmem_type
5045 (c2,
5046 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5047 }
5048 else
5049 {
5050 t1 = intype;
5051 t2 = type;
5052 }
5053 if (can_convert (t1, t2))
5054 {
5055 if (!c_cast_p)
5056 check_for_casting_away_constness (intype, type, diag_fn,
5057 desc);
5058 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5059 c_cast_p);
5060 }
5061 }
5062
5063 /* [expr.static.cast]
5064
5065 An rvalue of type "pointer to cv void" can be explicitly
5066 converted to a pointer to object type. A value of type pointer
5067 to object converted to "pointer to cv void" and back to the
5068 original pointer type will have its original value. */
5069 if (TREE_CODE (intype) == POINTER_TYPE
5070 && VOID_TYPE_P (TREE_TYPE (intype))
5071 && TYPE_PTROB_P (type))
5072 {
5073 if (!c_cast_p)
5074 check_for_casting_away_constness (intype, type, diag_fn, desc);
5075 return build_nop (type, expr);
5076 }
5077
5078 *valid_p = false;
5079 return error_mark_node;
5080}
5081
5082/* Return an expression representing static_cast<TYPE>(EXPR). */
5083
5084tree
5085build_static_cast (tree type, tree expr)
5086{
5087 tree result;
5088 bool valid_p;
5089
5090 if (type == error_mark_node || expr == error_mark_node)
5091 return error_mark_node;
5092
5093 if (processing_template_decl)
5094 {
5095 expr = build_min (STATIC_CAST_EXPR, type, expr);
5096 /* We don't know if it will or will not have side effects. */
5097 TREE_SIDE_EFFECTS (expr) = 1;
5098 return convert_from_reference (expr);
5099 }
5100
5101 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5102 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5103 if (TREE_CODE (type) != REFERENCE_TYPE
5104 && TREE_CODE (expr) == NOP_EXPR
5105 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5106 expr = TREE_OPERAND (expr, 0);
5107
5108 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5109 if (valid_p)
5110 return result;
5111
5112 error ("invalid static_cast from type %qT to type %qT",
5113 TREE_TYPE (expr), type);
5114 return error_mark_node;
5115}
5116
5117/* EXPR is an expression with member function or pointer-to-member
5118 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5119 not permitted by ISO C++, but we accept it in some modes. If we
5120 are not in one of those modes, issue a diagnostic. Return the
5121 converted expression. */
5122
5123tree
5124convert_member_func_to_ptr (tree type, tree expr)
5125{
5126 tree intype;
5127 tree decl;
5128
5129 intype = TREE_TYPE (expr);
5130 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5131 || TREE_CODE (intype) == METHOD_TYPE);
5132
5133 if (pedantic || warn_pmf2ptr)
5134 pedwarn ("converting from %qT to %qT", intype, type);
5135
5136 if (TREE_CODE (intype) == METHOD_TYPE)
5137 expr = build_addr_func (expr);
5138 else if (TREE_CODE (expr) == PTRMEM_CST)
5139 expr = build_address (PTRMEM_CST_MEMBER (expr));
5140 else
5141 {
5142 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5143 decl = build_address (decl);
5144 expr = get_member_function_from_ptrfunc (&decl, expr);
5145 }
5146
5147 return build_nop (type, expr);
5148}
5149
5150/* Return a representation for a reinterpret_cast from EXPR to TYPE.
5151 If C_CAST_P is true, this reinterpret cast is being done as part of
5152 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5153 indicate whether or not reinterpret_cast was valid. */
5154
5155static tree
5156build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5157 bool *valid_p)
5158{
5159 tree intype;
5160
5161 /* Assume the cast is invalid. */
5162 if (valid_p)
5163 *valid_p = true;
5164
5165 if (type == error_mark_node || error_operand_p (expr))
5166 return error_mark_node;
5167
5168 intype = TREE_TYPE (expr);
5169
5170 /* Save casted types in the function's used types hash table. */
5171 used_types_insert (type);
5172
5173 /* [expr.reinterpret.cast]
5174 An lvalue expression of type T1 can be cast to the type
5175 "reference to T2" if an expression of type "pointer to T1" can be
5176 explicitly converted to the type "pointer to T2" using a
5177 reinterpret_cast. */
5178 if (TREE_CODE (type) == REFERENCE_TYPE)
5179 {
5180 if (! real_lvalue_p (expr))
5181 {
5182 error ("invalid cast of an rvalue expression of type "
5183 "%qT to type %qT",
5184 intype, type);
5185 return error_mark_node;
5186 }
5187
5188 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5189 "B" are related class types; the reinterpret_cast does not
5190 adjust the pointer. */
5191 if (TYPE_PTR_P (intype)
5192 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5193 COMPARE_BASE | COMPARE_DERIVED)))
5194 warning (0, "casting %qT to %qT does not dereference pointer",
5195 intype, type);
5196
5197 expr = build_unary_op (ADDR_EXPR, expr, 0);
5198 if (expr != error_mark_node)
5199 expr = build_reinterpret_cast_1
5200 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5201 valid_p);
5202 if (expr != error_mark_node)
5203 expr = build_indirect_ref (expr, 0);
5204 return expr;
5205 }
5206
5207 /* As a G++ extension, we consider conversions from member
5208 functions, and pointers to member functions to
5209 pointer-to-function and pointer-to-void types. If
5210 -Wno-pmf-conversions has not been specified,
5211 convert_member_func_to_ptr will issue an error message. */
5212 if ((TYPE_PTRMEMFUNC_P (intype)
5213 || TREE_CODE (intype) == METHOD_TYPE)
5214 && TYPE_PTR_P (type)
5215 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5216 || VOID_TYPE_P (TREE_TYPE (type))))
5217 return convert_member_func_to_ptr (type, expr);
5218
5219 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5220 array-to-pointer, and function-to-pointer conversions are
5221 performed. */
5222 expr = decay_conversion (expr);
5223
5224 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5225 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5226 if (TREE_CODE (expr) == NOP_EXPR
5227 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5228 expr = TREE_OPERAND (expr, 0);
5229
5230 if (error_operand_p (expr))
5231 return error_mark_node;
5232
5233 intype = TREE_TYPE (expr);
5234
5235 /* [expr.reinterpret.cast]
5236 A pointer can be converted to any integral type large enough to
5237 hold it. */
5238 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5239 {
5240 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5241 pedwarn ("cast from %qT to %qT loses precision",
5242 intype, type);
5243 }
5244 /* [expr.reinterpret.cast]
5245 A value of integral or enumeration type can be explicitly
5246 converted to a pointer. */
5247 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5248 /* OK */
5249 ;
5250 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5251 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5252 return fold_if_not_in_template (build_nop (type, expr));
5253 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5254 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5255 {
5256 tree sexpr = expr;
5257
5258 if (!c_cast_p)
5259 check_for_casting_away_constness (intype, type, error,
5260 "reinterpret_cast");
5261 /* Warn about possible alignment problems. */
5262 if (STRICT_ALIGNMENT && warn_cast_align
5263 && !VOID_TYPE_P (type)
5264 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5265 && COMPLETE_TYPE_P (TREE_TYPE (type))
5266 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5267 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5268 warning (0, "cast from %qT to %qT increases required alignment of "
5269 "target type",
5270 intype, type);
5271
5272 /* We need to strip nops here, because the frontend likes to
5273 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5274 STRIP_NOPS (sexpr);
5275 if (warn_strict_aliasing <= 2)
5276 strict_aliasing_warning (intype, type, sexpr);
5277
5278 return fold_if_not_in_template (build_nop (type, expr));
5279 }
5280 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5281 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5282 {
5283 if (pedantic)
5284 /* Only issue a warning, as we have always supported this
5285 where possible, and it is necessary in some cases. DR 195
5286 addresses this issue, but as of 2004/10/26 is still in
5287 drafting. */
5288 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5289 return fold_if_not_in_template (build_nop (type, expr));
5290 }
5291 else if (TREE_CODE (type) == VECTOR_TYPE)
5292 return fold_if_not_in_template (convert_to_vector (type, expr));
5293 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5294 return fold_if_not_in_template (convert_to_integer (type, expr));
5295 else
5296 {
5297 if (valid_p)
5298 *valid_p = false;
5299 error ("invalid cast from type %qT to type %qT", intype, type);
5300 return error_mark_node;
5301 }
5302
5303 return cp_convert (type, expr);
5304}
5305
5306tree
5307build_reinterpret_cast (tree type, tree expr)
5308{
5309 if (type == error_mark_node || expr == error_mark_node)
5310 return error_mark_node;
5311
5312 if (processing_template_decl)
5313 {
5314 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5315
5316 if (!TREE_SIDE_EFFECTS (t)
5317 && type_dependent_expression_p (expr))
5318 /* There might turn out to be side effects inside expr. */
5319 TREE_SIDE_EFFECTS (t) = 1;
5320 return convert_from_reference (t);
5321 }
5322
5323 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5324 /*valid_p=*/NULL);
5325}
5326
5327/* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5328 return an appropriate expression. Otherwise, return
5329 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5330 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5331 performing a C-style cast, its value upon return will indicate
5332 whether or not the conversion succeeded. */
5333
5334static tree
5335build_const_cast_1 (tree dst_type, tree expr, bool complain,
5336 bool *valid_p)
5337{
5338 tree src_type;
5339 tree reference_type;
5340
5341 /* Callers are responsible for handling error_mark_node as a
5342 destination type. */
5343 gcc_assert (dst_type != error_mark_node);
5344 /* In a template, callers should be building syntactic
5345 representations of casts, not using this machinery. */
5346 gcc_assert (!processing_template_decl);
5347
5348 /* Assume the conversion is invalid. */
5349 if (valid_p)
5350 *valid_p = false;
5351
5352 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5353 {
5354 if (complain)
5355 error ("invalid use of const_cast with type %qT, "
5356 "which is not a pointer, "
5357 "reference, nor a pointer-to-data-member type", dst_type);
5358 return error_mark_node;
5359 }
5360
5361 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5362 {
5363 if (complain)
5364 error ("invalid use of const_cast with type %qT, which is a pointer "
5365 "or reference to a function type", dst_type);
5366 return error_mark_node;
5367 }
5368
5369 /* Save casted types in the function's used types hash table. */
5370 used_types_insert (dst_type);
5371
5372 src_type = TREE_TYPE (expr);
5373 /* Expressions do not really have reference types. */
5374 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5375 src_type = TREE_TYPE (src_type);
5376
5377 /* [expr.const.cast]
5378
5379 An lvalue of type T1 can be explicitly converted to an lvalue of
5380 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5381 types) if a pointer to T1 can be explicitly converted to the type
5382 pointer to T2 using a const_cast. */
5383 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5384 {
5385 reference_type = dst_type;
5386 if (! real_lvalue_p (expr))
5387 {
5388 if (complain)
5389 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5390 src_type, dst_type);
5391 return error_mark_node;
5392 }
5393 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5394 src_type = build_pointer_type (src_type);
5395 }
5396 else
5397 {
5398 reference_type = NULL_TREE;
5399 /* If the destination type is not a reference type, the
5400 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5401 conversions are performed. */
5402 src_type = type_decays_to (src_type);
5403 if (src_type == error_mark_node)
5404 return error_mark_node;
5405 }
5406
5407 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5408 && comp_ptr_ttypes_const (dst_type, src_type))
5409 {
5410 if (valid_p)
5411 {
5412 *valid_p = true;
5413 /* This cast is actually a C-style cast. Issue a warning if
5414 the user is making a potentially unsafe cast. */
5415 if (warn_cast_qual)
5416 check_for_casting_away_constness (src_type, dst_type,
5417 warning0,
5418 "cast");
5419 }
5420 if (reference_type)
5421 {
5422 expr = build_unary_op (ADDR_EXPR, expr, 0);
5423 expr = build_nop (reference_type, expr);
5424 return convert_from_reference (expr);
5425 }
5426 else
5427 {
5428 expr = decay_conversion (expr);
5429 /* build_c_cast puts on a NOP_EXPR to make the result not an
5430 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5431 non-lvalue context. */
5432 if (TREE_CODE (expr) == NOP_EXPR
5433 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5434 expr = TREE_OPERAND (expr, 0);
5435 return build_nop (dst_type, expr);
5436 }
5437 }
5438
5439 if (complain)
5440 error ("invalid const_cast from type %qT to type %qT",
5441 src_type, dst_type);
5442 return error_mark_node;
5443}
5444
5445tree
5446build_const_cast (tree type, tree expr)
5447{
5448 if (type == error_mark_node || error_operand_p (expr))
5449 return error_mark_node;
5450
5451 if (processing_template_decl)
5452 {
5453 tree t = build_min (CONST_CAST_EXPR, type, expr);
5454
5455 if (!TREE_SIDE_EFFECTS (t)
5456 && type_dependent_expression_p (expr))
5457 /* There might turn out to be side effects inside expr. */
5458 TREE_SIDE_EFFECTS (t) = 1;
5459 return convert_from_reference (t);
5460 }
5461
5462 return build_const_cast_1 (type, expr, /*complain=*/true,
5463 /*valid_p=*/NULL);
5464}
5465
5466/* Build an expression representing an explicit C-style cast to type
5467 TYPE of expression EXPR. */
5468
5469tree
5470build_c_cast (tree type, tree expr)
5471{
5472 tree value = expr;
5473 tree result;
5474 bool valid_p;
5475
5476 if (type == error_mark_node || error_operand_p (expr))
5477 return error_mark_node;
5478
5479 if (processing_template_decl)
5480 {
5481 tree t = build_min (CAST_EXPR, type,
5482 tree_cons (NULL_TREE, value, NULL_TREE));
5483 /* We don't know if it will or will not have side effects. */
5484 TREE_SIDE_EFFECTS (t) = 1;
5485 return convert_from_reference (t);
5486 }
5487
5488 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5489 'Class') should always be retained, because this information aids
5490 in method lookup. */
5491 if (objc_is_object_ptr (type)
5492 && objc_is_object_ptr (TREE_TYPE (expr)))
5493 return build_nop (type, expr);
5494
5495 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5496 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5497 if (TREE_CODE (type) != REFERENCE_TYPE
5498 && TREE_CODE (value) == NOP_EXPR
5499 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5500 value = TREE_OPERAND (value, 0);
5501
5502 if (TREE_CODE (type) == ARRAY_TYPE)
5503 {
5504 /* Allow casting from T1* to T2[] because Cfront allows it.
5505 NIHCL uses it. It is not valid ISO C++ however. */
5506 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5507 {
5508 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5509 type = build_pointer_type (TREE_TYPE (type));
5510 }
5511 else
5512 {
5513 error ("ISO C++ forbids casting to an array type %qT", type);
5514 return error_mark_node;
5515 }
5516 }
5517
5518 if (TREE_CODE (type) == FUNCTION_TYPE
5519 || TREE_CODE (type) == METHOD_TYPE)
5520 {
5521 error ("invalid cast to function type %qT", type);
5522 return error_mark_node;
5523 }
5524
5525 /* A C-style cast can be a const_cast. */
5526 result = build_const_cast_1 (type, value, /*complain=*/false,
5527 &valid_p);
5528 if (valid_p)
5529 return result;
5530
5531 /* Or a static cast. */
5532 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5533 &valid_p);
5534 /* Or a reinterpret_cast. */
5535 if (!valid_p)
5536 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5537 &valid_p);
5538 /* The static_cast or reinterpret_cast may be followed by a
5539 const_cast. */
5540 if (valid_p
5541 /* A valid cast may result in errors if, for example, a
5542 conversion to am ambiguous base class is required. */
5543 && !error_operand_p (result))
5544 {
5545 tree result_type;
5546
5547 /* Non-class rvalues always have cv-unqualified type. */
5548 if (!CLASS_TYPE_P (type))
5549 type = TYPE_MAIN_VARIANT (type);
5550 result_type = TREE_TYPE (result);
5551 if (!CLASS_TYPE_P (result_type))
5552 result_type = TYPE_MAIN_VARIANT (result_type);
5553 /* If the type of RESULT does not match TYPE, perform a
5554 const_cast to make it match. If the static_cast or
5555 reinterpret_cast succeeded, we will differ by at most
5556 cv-qualification, so the follow-on const_cast is guaranteed
5557 to succeed. */
5558 if (!same_type_p (non_reference (type), non_reference (result_type)))
5559 {
5560 result = build_const_cast_1 (type, result, false, &valid_p);
5561 gcc_assert (valid_p);
5562 }
5563 return result;
5564 }
5565
5566 return error_mark_node;
5567}
5568
5569/* Build an assignment expression of lvalue LHS from value RHS.
5570 MODIFYCODE is the code for a binary operator that we use
5571 to combine the old value of LHS with RHS to get the new value.
5572 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5573
5574 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5575
5576tree
5577build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5578{
5579 tree result;
5580 tree newrhs = rhs;
5581 tree lhstype = TREE_TYPE (lhs);
5582 tree olhstype = lhstype;
5583 tree olhs = NULL_TREE;
5584 bool plain_assign = (modifycode == NOP_EXPR);
5585
5586 /* Avoid duplicate error messages from operands that had errors. */
5587 if (error_operand_p (lhs) || error_operand_p (rhs))
5588 return error_mark_node;
5589
5590 /* Handle control structure constructs used as "lvalues". */
5591 switch (TREE_CODE (lhs))
5592 {
5593 /* Handle --foo = 5; as these are valid constructs in C++. */
5594 case PREDECREMENT_EXPR:
5595 case PREINCREMENT_EXPR:
5596 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5597 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5598 stabilize_reference (TREE_OPERAND (lhs, 0)),
5599 TREE_OPERAND (lhs, 1));
5600 return build2 (COMPOUND_EXPR, lhstype,
5601 lhs,
5602 build_modify_expr (TREE_OPERAND (lhs, 0),
5603 modifycode, rhs));
5604
5605 /* Handle (a, b) used as an "lvalue". */
5606 case COMPOUND_EXPR:
5607 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5608 modifycode, rhs);
5609 if (newrhs == error_mark_node)
5610 return error_mark_node;
5611 return build2 (COMPOUND_EXPR, lhstype,
5612 TREE_OPERAND (lhs, 0), newrhs);
5613
5614 case MODIFY_EXPR:
5615 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5616 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5617 stabilize_reference (TREE_OPERAND (lhs, 0)),
5618 TREE_OPERAND (lhs, 1));
5619 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5620 if (newrhs == error_mark_node)
5621 return error_mark_node;
5622 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5623
5624 case MIN_EXPR:
5625 case MAX_EXPR:
5626 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5627 when neither operand has side-effects. */
5628 if (!lvalue_or_else (lhs, lv_assign))
5629 return error_mark_node;
5630
5631 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5632 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5633
5634 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5635 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5636 boolean_type_node,
5637 TREE_OPERAND (lhs, 0),
5638 TREE_OPERAND (lhs, 1)),
5639 TREE_OPERAND (lhs, 0),
5640 TREE_OPERAND (lhs, 1));
5641 /* Fall through. */
5642
5643 /* Handle (a ? b : c) used as an "lvalue". */
5644 case COND_EXPR:
5645 {
5646 /* Produce (a ? (b = rhs) : (c = rhs))
5647 except that the RHS goes through a save-expr
5648 so the code to compute it is only emitted once. */
5649 tree cond;
5650 tree preeval = NULL_TREE;
5651
5652 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5653 {
5654 error ("void value not ignored as it ought to be");
5655 return error_mark_node;
5656 }
5657
5658 rhs = stabilize_expr (rhs, &preeval);
5659
5660 /* Check this here to avoid odd errors when trying to convert
5661 a throw to the type of the COND_EXPR. */
5662 if (!lvalue_or_else (lhs, lv_assign))
5663 return error_mark_node;
5664
5665 cond = build_conditional_expr
5666 (TREE_OPERAND (lhs, 0),
5667 build_modify_expr (TREE_OPERAND (lhs, 1),
5668 modifycode, rhs),
5669 build_modify_expr (TREE_OPERAND (lhs, 2),
5670 modifycode, rhs));
5671
5672 if (cond == error_mark_node)
5673 return cond;
5674 /* Make sure the code to compute the rhs comes out
5675 before the split. */
5676 if (preeval)
5677 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5678 return cond;
5679 }
5680
5681 default:
5682 break;
5683 }
5684
5685 if (modifycode == INIT_EXPR)
5686 {
5687 if (TREE_CODE (rhs) == CONSTRUCTOR)
5688 {
5689 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5690 /* Call convert to generate an error; see PR 11063. */
5691 rhs = convert (lhstype, rhs);
5692 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5693 TREE_SIDE_EFFECTS (result) = 1;
5694 return result;
5695 }
5696 else if (! IS_AGGR_TYPE (lhstype))
5697 /* Do the default thing. */;
5698 else
5699 {
5700 result = build_special_member_call (lhs, complete_ctor_identifier,
5701 build_tree_list (NULL_TREE, rhs),
5702 lhstype, LOOKUP_NORMAL);
5703 if (result == NULL_TREE)
5704 return error_mark_node;
5705 return result;
5706 }
5707 }
5708 else
5709 {
5710 lhs = require_complete_type (lhs);
5711 if (lhs == error_mark_node)
5712 return error_mark_node;
5713
5714 if (modifycode == NOP_EXPR)
5715 {
5716 /* `operator=' is not an inheritable operator. */
5717 if (! IS_AGGR_TYPE (lhstype))
5718 /* Do the default thing. */;
5719 else
5720 {
5721 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5722 lhs, rhs, make_node (NOP_EXPR),
5723 /*overloaded_p=*/NULL);
5724 if (result == NULL_TREE)
5725 return error_mark_node;
5726 return result;
5727 }
5728 lhstype = olhstype;
5729 }
5730 else
5731 {
5732 /* A binary op has been requested. Combine the old LHS
5733 value with the RHS producing the value we should actually
5734 store into the LHS. */
5735
5736 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5737 lhs = stabilize_reference (lhs);
5738 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5739 if (newrhs == error_mark_node)
5740 {
5741 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5742 TREE_TYPE (lhs), TREE_TYPE (rhs));
5743 return error_mark_node;
5744 }
5745
5746 /* Now it looks like a plain assignment. */
5747 modifycode = NOP_EXPR;
5748 }
5749 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5750 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5751 }
5752
5753 /* The left-hand side must be an lvalue. */
5754 if (!lvalue_or_else (lhs, lv_assign))
5755 return error_mark_node;
5756
5757 /* Warn about modifying something that is `const'. Don't warn if
5758 this is initialization. */
5759 if (modifycode != INIT_EXPR
5760 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5761 /* Functions are not modifiable, even though they are
5762 lvalues. */
5763 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5764 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5765 /* If it's an aggregate and any field is const, then it is
5766 effectively const. */
5767 || (CLASS_TYPE_P (lhstype)
5768 && C_TYPE_FIELDS_READONLY (lhstype))))
5769 readonly_error (lhs, "assignment", 0);
5770
5771 /* If storing into a structure or union member, it has probably been
5772 given type `int'. Compute the type that would go with the actual
5773 amount of storage the member occupies. */
5774
5775 if (TREE_CODE (lhs) == COMPONENT_REF
5776 && (TREE_CODE (lhstype) == INTEGER_TYPE
5777 || TREE_CODE (lhstype) == REAL_TYPE
5778 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5779 {
5780 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5781
5782 /* If storing in a field that is in actuality a short or narrower
5783 than one, we must store in the field in its actual type. */
5784
5785 if (lhstype != TREE_TYPE (lhs))
5786 {
5787 /* Avoid warnings converting integral types back into enums for
5788 enum bit fields. */
5789 if (TREE_CODE (lhstype) == INTEGER_TYPE
5790 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5791 {
5792 if (TREE_SIDE_EFFECTS (lhs))
5793 lhs = stabilize_reference (lhs);
5794 olhs = lhs;
5795 }
5796 lhs = copy_node (lhs);
5797 TREE_TYPE (lhs) = lhstype;
5798 }
5799 }
5800
5801 /* Convert new value to destination type. */
5802
5803 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5804 {
5805 int from_array;
5806
5807 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5808 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5809 {
5810 error ("incompatible types in assignment of %qT to %qT",
5811 TREE_TYPE (rhs), lhstype);
5812 return error_mark_node;
5813 }
5814
5815 /* Allow array assignment in compiler-generated code. */
5816 if (! DECL_ARTIFICIAL (current_function_decl))
5817 {
5818 /* This routine is used for both initialization and assignment.
5819 Make sure the diagnostic message differentiates the context. */
5820 if (modifycode == INIT_EXPR)
5821 error ("array used as initializer");
5822 else
5823 error ("invalid array assignment");
5824 return error_mark_node;
5825 }
5826
5827 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5828 ? 1 + (modifycode != INIT_EXPR): 0;
5829 return build_vec_init (lhs, NULL_TREE, newrhs,
5830 /*explicit_default_init_p=*/false,
5831 from_array);
5832 }
5833
5834 if (modifycode == INIT_EXPR)
5835 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5836 "initialization", NULL_TREE, 0);
5837 else
5838 {
5839 /* Avoid warnings on enum bit fields. */
5840 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5841 && TREE_CODE (lhstype) == INTEGER_TYPE)
5842 {
5843 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5844 NULL_TREE, 0);
5845 newrhs = convert_force (lhstype, newrhs, 0);
5846 }
5847 else
5848 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5849 NULL_TREE, 0);
5850 if (TREE_CODE (newrhs) == CALL_EXPR
5851 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5852 newrhs = build_cplus_new (lhstype, newrhs);
5853
5854 /* Can't initialize directly from a TARGET_EXPR, since that would
5855 cause the lhs to be constructed twice, and possibly result in
5856 accidental self-initialization. So we force the TARGET_EXPR to be
5857 expanded without a target. */
5858 if (TREE_CODE (newrhs) == TARGET_EXPR)
5859 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5860 TREE_OPERAND (newrhs, 0));
5861 }
5862
5863 if (newrhs == error_mark_node)
5864 return error_mark_node;
5865
5866 if (c_dialect_objc () && flag_objc_gc)
5867 {
5868 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5869
5870 if (result)
5871 return result;
5872 }
5873
5874 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5875 lhstype, lhs, newrhs);
5876
5877 TREE_SIDE_EFFECTS (result) = 1;
5878 if (!plain_assign)
5879 TREE_NO_WARNING (result) = 1;
5880
5881 /* If we got the LHS in a different type for storing in,
5882 convert the result back to the nominal type of LHS
5883 so that the value we return always has the same type
5884 as the LHS argument. */
5885
5886 if (olhstype == TREE_TYPE (result))
5887 return result;
5888 if (olhs)
5889 {
5890 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5891 TREE_NO_WARNING (result) = 1;
5892 return result;
5893 }
5894 return convert_for_assignment (olhstype, result, "assignment",
5895 NULL_TREE, 0);
5896}
5897
5898tree
5899build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5900{
5901 if (processing_template_decl)
5902 return build_min_nt (MODOP_EXPR, lhs,
5903 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5904
5905 if (modifycode != NOP_EXPR)
5906 {
5907 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5908 make_node (modifycode),
5909 /*overloaded_p=*/NULL);
5910 if (rval)
5911 {
5912 TREE_NO_WARNING (rval) = 1;
5913 return rval;
5914 }
5915 }
5916 return build_modify_expr (lhs, modifycode, rhs);
5917}
5918
5919
5920/* Get difference in deltas for different pointer to member function
5921 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5922 the conversion is invalid, the constant is zero. If
5923 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5924 If C_CAST_P is true this conversion is taking place as part of a
5925 C-style cast.
5926
5927 Note that the naming of FROM and TO is kind of backwards; the return
5928 value is what we add to a TO in order to get a FROM. They are named
5929 this way because we call this function to find out how to convert from
5930 a pointer to member of FROM to a pointer to member of TO. */
5931
5932static tree
5933get_delta_difference (tree from, tree to,
5934 bool allow_inverse_p,
5935 bool c_cast_p)
5936{
5937 tree binfo;
5938 base_kind kind;
5939 tree result;
5940
5941 /* Assume no conversion is required. */
5942 result = integer_zero_node;
5943 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5944 if (kind == bk_inaccessible || kind == bk_ambig)
5945 error (" in pointer to member function conversion");
5946 else if (binfo)
5947 {
5948 if (kind != bk_via_virtual)
5949 result = BINFO_OFFSET (binfo);
5950 else
5951 {
5952 tree virt_binfo = binfo_from_vbase (binfo);
5953
5954 /* This is a reinterpret cast, we choose to do nothing. */
5955 if (allow_inverse_p)
5956 warning (0, "pointer to member cast via virtual base %qT",
5957 BINFO_TYPE (virt_binfo));
5958 else
5959 error ("pointer to member conversion via virtual base %qT",
5960 BINFO_TYPE (virt_binfo));
5961 }
5962 }
5963 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5964 /* Pointer to member of incomplete class is permitted*/;
5965 else if (!allow_inverse_p)
5966 {
5967 error_not_base_type (from, to);
5968 error (" in pointer to member conversion");
5969 }
5970 else
5971 {
5972 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5973 if (binfo)
5974 {
5975 if (kind != bk_via_virtual)
5976 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5977 else
5978 {
5979 /* This is a reinterpret cast, we choose to do nothing. */
5980 tree virt_binfo = binfo_from_vbase (binfo);
5981
5982 warning (0, "pointer to member cast via virtual base %qT",
5983 BINFO_TYPE (virt_binfo));
5984 }
5985 }
5986 }
5987
5988 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5989 result));
5990}
5991
5992/* Return a constructor for the pointer-to-member-function TYPE using
5993 the other components as specified. */
5994
5995tree
5996build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5997{
5998 tree u = NULL_TREE;
5999 tree delta_field;
6000 tree pfn_field;
6001 VEC(constructor_elt, gc) *v;
6002
6003 /* Pull the FIELD_DECLs out of the type. */
6004 pfn_field = TYPE_FIELDS (type);
6005 delta_field = TREE_CHAIN (pfn_field);
6006
6007 /* Make sure DELTA has the type we want. */
6008 delta = convert_and_check (delta_type_node, delta);
6009
6010 /* Finish creating the initializer. */
6011 v = VEC_alloc(constructor_elt, gc, 2);
6012 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6013 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6014 u = build_constructor (type, v);
6015 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6016 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6017 TREE_STATIC (u) = (TREE_CONSTANT (u)
6018 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6019 != NULL_TREE)
6020 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6021 != NULL_TREE));
6022 return u;
6023}
6024
6025/* Build a constructor for a pointer to member function. It can be
6026 used to initialize global variables, local variable, or used
6027 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6028 want to be.
6029
6030 If FORCE is nonzero, then force this conversion, even if
6031 we would rather not do it. Usually set when using an explicit
6032 cast. A C-style cast is being processed iff C_CAST_P is true.
6033
6034 Return error_mark_node, if something goes wrong. */
6035
6036tree
6037build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6038{
6039 tree fn;
6040 tree pfn_type;
6041 tree to_type;
6042
6043 if (error_operand_p (pfn))
6044 return error_mark_node;
6045
6046 pfn_type = TREE_TYPE (pfn);
6047 to_type = build_ptrmemfunc_type (type);
6048
6049 /* Handle multiple conversions of pointer to member functions. */
6050 if (TYPE_PTRMEMFUNC_P (pfn_type))
6051 {
6052 tree delta = NULL_TREE;
6053 tree npfn = NULL_TREE;
6054 tree n;
6055
6056 if (!force
6057 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6058 error ("invalid conversion to type %qT from type %qT",
6059 to_type, pfn_type);
6060
6061 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6062 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6063 force,
6064 c_cast_p);
6065
6066 /* We don't have to do any conversion to convert a
6067 pointer-to-member to its own type. But, we don't want to
6068 just return a PTRMEM_CST if there's an explicit cast; that
6069 cast should make the expression an invalid template argument. */
6070 if (TREE_CODE (pfn) != PTRMEM_CST)
6071 {
6072 if (same_type_p (to_type, pfn_type))
6073 return pfn;
6074 else if (integer_zerop (n))
6075 return build_reinterpret_cast (to_type, pfn);
6076 }
6077
6078 if (TREE_SIDE_EFFECTS (pfn))
6079 pfn = save_expr (pfn);
6080
6081 /* Obtain the function pointer and the current DELTA. */
6082 if (TREE_CODE (pfn) == PTRMEM_CST)
6083 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6084 else
6085 {
6086 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6087 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6088 }
6089
6090 /* Just adjust the DELTA field. */
6091 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6092 (TREE_TYPE (delta), ptrdiff_type_node));
6093 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6094 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6095 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6096 return build_ptrmemfunc1 (to_type, delta, npfn);
6097 }
6098
6099 /* Handle null pointer to member function conversions. */
6100 if (integer_zerop (pfn))
6101 {
6102 pfn = build_c_cast (type, integer_zero_node);
6103 return build_ptrmemfunc1 (to_type,
6104 integer_zero_node,
6105 pfn);
6106 }
6107
6108 if (type_unknown_p (pfn))
6109 return instantiate_type (type, pfn, tf_warning_or_error);
6110
6111 fn = TREE_OPERAND (pfn, 0);
6112 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6113 /* In a template, we will have preserved the
6114 OFFSET_REF. */
6115 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6116 return make_ptrmem_cst (to_type, fn);
6117}
6118
6119/* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6120 given by CST.
6121
6122 ??? There is no consistency as to the types returned for the above
6123 values. Some code acts as if it were a sizetype and some as if it were
6124 integer_type_node. */
6125
6126void
6127expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6128{
6129 tree type = TREE_TYPE (cst);
6130 tree fn = PTRMEM_CST_MEMBER (cst);
6131 tree ptr_class, fn_class;
6132
6133 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6134
6135 /* The class that the function belongs to. */
6136 fn_class = DECL_CONTEXT (fn);
6137
6138 /* The class that we're creating a pointer to member of. */
6139 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6140
6141 /* First, calculate the adjustment to the function's class. */
6142 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6143 /*c_cast_p=*/0);
6144
6145 if (!DECL_VIRTUAL_P (fn))
6146 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6147 else
6148 {
6149 /* If we're dealing with a virtual function, we have to adjust 'this'
6150 again, to point to the base which provides the vtable entry for
6151 fn; the call will do the opposite adjustment. */
6152 tree orig_class = DECL_CONTEXT (fn);
6153 tree binfo = binfo_or_else (orig_class, fn_class);
6154 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6155 *delta, BINFO_OFFSET (binfo));
6156 *delta = fold_if_not_in_template (*delta);
6157
6158 /* We set PFN to the vtable offset at which the function can be
6159 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6160 case delta is shifted left, and then incremented). */
6161 *pfn = DECL_VINDEX (fn);
6162 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6163 TYPE_SIZE_UNIT (vtable_entry_type));
6164 *pfn = fold_if_not_in_template (*pfn);
6165
6166 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6167 {
6168 case ptrmemfunc_vbit_in_pfn:
6169 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6170 integer_one_node);
6171 *pfn = fold_if_not_in_template (*pfn);
6172 break;
6173
6174 case ptrmemfunc_vbit_in_delta:
6175 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6176 *delta, integer_one_node);
6177 *delta = fold_if_not_in_template (*delta);
6178 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6179 *delta, integer_one_node);
6180 *delta = fold_if_not_in_template (*delta);
6181 break;
6182
6183 default:
6184 gcc_unreachable ();
6185 }
6186
6187 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6188 *pfn = fold_if_not_in_template (*pfn);
6189 }
6190}
6191
6192/* Return an expression for PFN from the pointer-to-member function
6193 given by T. */
6194
6195static tree
6196pfn_from_ptrmemfunc (tree t)
6197{
6198 if (TREE_CODE (t) == PTRMEM_CST)
6199 {
6200 tree delta;
6201 tree pfn;
6202
6203 expand_ptrmemfunc_cst (t, &delta, &pfn);
6204 if (pfn)
6205 return pfn;
6206 }
6207
6208 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6209}
6210
6211/* Convert value RHS to type TYPE as preparation for an assignment to
6212 an lvalue of type TYPE. ERRTYPE is a string to use in error
6213 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6214 are doing the conversion in order to pass the PARMNUMth argument of
6215 FNDECL. */
6216
6217static tree
6218convert_for_assignment (tree type, tree rhs,
6219 const char *errtype, tree fndecl, int parmnum)
6220{
6221 tree rhstype;
6222 enum tree_code coder;
6223
6224 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6225 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6226 rhs = TREE_OPERAND (rhs, 0);
6227
6228 rhstype = TREE_TYPE (rhs);
6229 coder = TREE_CODE (rhstype);
6230
6231 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
|