c-decl.c revision 190404
1/* Process declarations and variables for C compiler.
2   Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3   2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING.  If not, write to the Free
19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2002110-1301, USA.  */
21
22/* $FreeBSD: head/contrib/gcc/c-decl.c 190404 2009-03-25 05:10:32Z das $ */
23/* Merged C99 inline changes from gcc trunk 122565 2007-03-05 */
24/* Fixed problems with compiling inline-25.c and inline-26.c */
25/* XXX still fails inline-29.c, inline-31.c, and inline-32.c */
26
27/* Process declarations and symbol lookup for C front end.
28   Also constructs types; the standard scalar types at initialization,
29   and structure, union, array and enum types when they are declared.  */
30
31/* ??? not all decl nodes are given the most useful possible
32   line numbers.  For example, the CONST_DECLs for enum values.  */
33
34#include "config.h"
35#include "system.h"
36#include "coretypes.h"
37#include "input.h"
38#include "tm.h"
39#include "intl.h"
40#include "tree.h"
41#include "tree-inline.h"
42#include "rtl.h"
43#include "flags.h"
44#include "function.h"
45#include "output.h"
46#include "expr.h"
47#include "c-tree.h"
48#include "toplev.h"
49#include "ggc.h"
50#include "tm_p.h"
51#include "cpplib.h"
52#include "target.h"
53#include "debug.h"
54#include "opts.h"
55#include "timevar.h"
56#include "c-common.h"
57#include "c-pragma.h"
58#include "langhooks.h"
59#include "tree-mudflap.h"
60#include "tree-gimple.h"
61#include "diagnostic.h"
62#include "tree-dump.h"
63#include "cgraph.h"
64#include "hashtab.h"
65#include "libfuncs.h"
66#include "except.h"
67#include "langhooks-def.h"
68#include "pointer-set.h"
69
70/* In grokdeclarator, distinguish syntactic contexts of declarators.  */
71enum decl_context
72{ NORMAL,			/* Ordinary declaration */
73  FUNCDEF,			/* Function definition */
74  PARM,				/* Declaration of parm before function body */
75  FIELD,			/* Declaration inside struct or union */
76  TYPENAME};			/* Typename (inside cast or sizeof)  */
77
78
79/* Nonzero if we have seen an invalid cross reference
80   to a struct, union, or enum, but not yet printed the message.  */
81tree pending_invalid_xref;
82
83/* File and line to appear in the eventual error message.  */
84location_t pending_invalid_xref_location;
85
86/* True means we've initialized exception handling.  */
87bool c_eh_initialized_p;
88
89/* While defining an enum type, this is 1 plus the last enumerator
90   constant value.  Note that will do not have to save this or `enum_overflow'
91   around nested function definition since such a definition could only
92   occur in an enum value expression and we don't use these variables in
93   that case.  */
94
95static tree enum_next_value;
96
97/* Nonzero means that there was overflow computing enum_next_value.  */
98
99static int enum_overflow;
100
101/* The file and line that the prototype came from if this is an
102   old-style definition; used for diagnostics in
103   store_parm_decls_oldstyle.  */
104
105static location_t current_function_prototype_locus;
106
107/* Whether this prototype was built-in.  */
108
109static bool current_function_prototype_built_in;
110
111/* The argument type information of this prototype.  */
112
113static tree current_function_prototype_arg_types;
114
115/* The argument information structure for the function currently being
116   defined.  */
117
118static struct c_arg_info *current_function_arg_info;
119
120/* The obstack on which parser and related data structures, which are
121   not live beyond their top-level declaration or definition, are
122   allocated.  */
123struct obstack parser_obstack;
124
125/* The current statement tree.  */
126
127static GTY(()) struct stmt_tree_s c_stmt_tree;
128
129/* State saving variables.  */
130tree c_break_label;
131tree c_cont_label;
132
133/* Linked list of TRANSLATION_UNIT_DECLS for the translation units
134   included in this invocation.  Note that the current translation
135   unit is not included in this list.  */
136
137static GTY(()) tree all_translation_units;
138
139/* A list of decls to be made automatically visible in each file scope.  */
140static GTY(()) tree visible_builtins;
141
142/* Set to 0 at beginning of a function definition, set to 1 if
143   a return statement that specifies a return value is seen.  */
144
145int current_function_returns_value;
146
147/* Set to 0 at beginning of a function definition, set to 1 if
148   a return statement with no argument is seen.  */
149
150int current_function_returns_null;
151
152/* Set to 0 at beginning of a function definition, set to 1 if
153   a call to a noreturn function is seen.  */
154
155int current_function_returns_abnormally;
156
157/* Set to nonzero by `grokdeclarator' for a function
158   whose return type is defaulted, if warnings for this are desired.  */
159
160static int warn_about_return_type;
161
162/* Nonzero when the current toplevel function contains a declaration
163   of a nested function which is never defined.  */
164
165static bool undef_nested_function;
166
167/* True means global_bindings_p should return false even if the scope stack
168   says we are in file scope.  */
169bool c_override_global_bindings_to_false;
170
171
172/* Each c_binding structure describes one binding of an identifier to
173   a decl.  All the decls in a scope - irrespective of namespace - are
174   chained together by the ->prev field, which (as the name implies)
175   runs in reverse order.  All the decls in a given namespace bound to
176   a given identifier are chained by the ->shadowed field, which runs
177   from inner to outer scopes.
178
179   The ->decl field usually points to a DECL node, but there are two
180   exceptions.  In the namespace of type tags, the bound entity is a
181   RECORD_TYPE, UNION_TYPE, or ENUMERAL_TYPE node.  If an undeclared
182   identifier is encountered, it is bound to error_mark_node to
183   suppress further errors about that identifier in the current
184   function.
185
186   The ->type field stores the type of the declaration in this scope;
187   if NULL, the type is the type of the ->decl field.  This is only of
188   relevance for objects with external or internal linkage which may
189   be redeclared in inner scopes, forming composite types that only
190   persist for the duration of those scopes.  In the external scope,
191   this stores the composite of all the types declared for this
192   object, visible or not.  The ->inner_comp field (used only at file
193   scope) stores whether an incomplete array type at file scope was
194   completed at an inner scope to an array size other than 1.
195
196   The depth field is copied from the scope structure that holds this
197   decl.  It is used to preserve the proper ordering of the ->shadowed
198   field (see bind()) and also for a handful of special-case checks.
199   Finally, the invisible bit is true for a decl which should be
200   ignored for purposes of normal name lookup, and the nested bit is
201   true for a decl that's been bound a second time in an inner scope;
202   in all such cases, the binding in the outer scope will have its
203   invisible bit true.  */
204
205struct c_binding GTY((chain_next ("%h.prev")))
206{
207  tree decl;			/* the decl bound */
208  tree type;			/* the type in this scope */
209  tree id;			/* the identifier it's bound to */
210  struct c_binding *prev;	/* the previous decl in this scope */
211  struct c_binding *shadowed;	/* the innermost decl shadowed by this one */
212  unsigned int depth : 28;      /* depth of this scope */
213  BOOL_BITFIELD invisible : 1;  /* normal lookup should ignore this binding */
214  BOOL_BITFIELD nested : 1;     /* do not set DECL_CONTEXT when popping */
215  BOOL_BITFIELD inner_comp : 1; /* incomplete array completed in inner scope */
216  /* one free bit */
217};
218#define B_IN_SCOPE(b1, b2) ((b1)->depth == (b2)->depth)
219#define B_IN_CURRENT_SCOPE(b) ((b)->depth == current_scope->depth)
220#define B_IN_FILE_SCOPE(b) ((b)->depth == 1 /*file_scope->depth*/)
221#define B_IN_EXTERNAL_SCOPE(b) ((b)->depth == 0 /*external_scope->depth*/)
222
223#define I_SYMBOL_BINDING(node) \
224  (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->symbol_binding)
225#define I_SYMBOL_DECL(node) \
226 (I_SYMBOL_BINDING(node) ? I_SYMBOL_BINDING(node)->decl : 0)
227
228#define I_TAG_BINDING(node) \
229  (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->tag_binding)
230#define I_TAG_DECL(node) \
231 (I_TAG_BINDING(node) ? I_TAG_BINDING(node)->decl : 0)
232
233#define I_LABEL_BINDING(node) \
234  (((struct lang_identifier *) IDENTIFIER_NODE_CHECK(node))->label_binding)
235#define I_LABEL_DECL(node) \
236 (I_LABEL_BINDING(node) ? I_LABEL_BINDING(node)->decl : 0)
237
238/* Each C symbol points to three linked lists of c_binding structures.
239   These describe the values of the identifier in the three different
240   namespaces defined by the language.  */
241
242struct lang_identifier GTY(())
243{
244  struct c_common_identifier common_id;
245  struct c_binding *symbol_binding; /* vars, funcs, constants, typedefs */
246  struct c_binding *tag_binding;    /* struct/union/enum tags */
247  struct c_binding *label_binding;  /* labels */
248};
249
250/* Validate c-lang.c's assumptions.  */
251extern char C_SIZEOF_STRUCT_LANG_IDENTIFIER_isnt_accurate
252[(sizeof(struct lang_identifier) == C_SIZEOF_STRUCT_LANG_IDENTIFIER) ? 1 : -1];
253
254/* The resulting tree type.  */
255
256union lang_tree_node
257  GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
258       chain_next ("TREE_CODE (&%h.generic) == INTEGER_TYPE ? (union lang_tree_node *) TYPE_NEXT_VARIANT (&%h.generic) : (union lang_tree_node *) TREE_CHAIN (&%h.generic)")))
259{
260  union tree_node GTY ((tag ("0"),
261			desc ("tree_node_structure (&%h)")))
262    generic;
263  struct lang_identifier GTY ((tag ("1"))) identifier;
264};
265
266/* Each c_scope structure describes the complete contents of one
267   scope.  Four scopes are distinguished specially: the innermost or
268   current scope, the innermost function scope, the file scope (always
269   the second to outermost) and the outermost or external scope.
270
271   Most declarations are recorded in the current scope.
272
273   All normal label declarations are recorded in the innermost
274   function scope, as are bindings of undeclared identifiers to
275   error_mark_node.  (GCC permits nested functions as an extension,
276   hence the 'innermost' qualifier.)  Explicitly declared labels
277   (using the __label__ extension) appear in the current scope.
278
279   Being in the file scope (current_scope == file_scope) causes
280   special behavior in several places below.  Also, under some
281   conditions the Objective-C front end records declarations in the
282   file scope even though that isn't the current scope.
283
284   All declarations with external linkage are recorded in the external
285   scope, even if they aren't visible there; this models the fact that
286   such declarations are visible to the entire program, and (with a
287   bit of cleverness, see pushdecl) allows diagnosis of some violations
288   of C99 6.2.2p7 and 6.2.7p2:
289
290     If, within the same translation unit, the same identifier appears
291     with both internal and external linkage, the behavior is
292     undefined.
293
294     All declarations that refer to the same object or function shall
295     have compatible type; otherwise, the behavior is undefined.
296
297   Initially only the built-in declarations, which describe compiler
298   intrinsic functions plus a subset of the standard library, are in
299   this scope.
300
301   The order of the blocks list matters, and it is frequently appended
302   to.  To avoid having to walk all the way to the end of the list on
303   each insertion, or reverse the list later, we maintain a pointer to
304   the last list entry.  (FIXME: It should be feasible to use a reversed
305   list here.)
306
307   The bindings list is strictly in reverse order of declarations;
308   pop_scope relies on this.  */
309
310
311struct c_scope GTY((chain_next ("%h.outer")))
312{
313  /* The scope containing this one.  */
314  struct c_scope *outer;
315
316  /* The next outermost function scope.  */
317  struct c_scope *outer_function;
318
319  /* All bindings in this scope.  */
320  struct c_binding *bindings;
321
322  /* For each scope (except the global one), a chain of BLOCK nodes
323     for all the scopes that were entered and exited one level down.  */
324  tree blocks;
325  tree blocks_last;
326
327  /* The depth of this scope.  Used to keep the ->shadowed chain of
328     bindings sorted innermost to outermost.  */
329  unsigned int depth : 28;
330
331  /* True if we are currently filling this scope with parameter
332     declarations.  */
333  BOOL_BITFIELD parm_flag : 1;
334
335  /* True if we saw [*] in this scope.  Used to give an error messages
336     if these appears in a function definition.  */
337  BOOL_BITFIELD had_vla_unspec : 1;
338
339  /* True if we already complained about forward parameter decls
340     in this scope.  This prevents double warnings on
341     foo (int a; int b; ...)  */
342  BOOL_BITFIELD warned_forward_parm_decls : 1;
343
344  /* True if this is the outermost block scope of a function body.
345     This scope contains the parameters, the local variables declared
346     in the outermost block, and all the labels (except those in
347     nested functions, or declared at block scope with __label__).  */
348  BOOL_BITFIELD function_body : 1;
349
350  /* True means make a BLOCK for this scope no matter what.  */
351  BOOL_BITFIELD keep : 1;
352};
353
354/* The scope currently in effect.  */
355
356static GTY(()) struct c_scope *current_scope;
357
358/* The innermost function scope.  Ordinary (not explicitly declared)
359   labels, bindings to error_mark_node, and the lazily-created
360   bindings of __func__ and its friends get this scope.  */
361
362static GTY(()) struct c_scope *current_function_scope;
363
364/* The C file scope.  This is reset for each input translation unit.  */
365
366static GTY(()) struct c_scope *file_scope;
367
368/* The outermost scope.  This is used for all declarations with
369   external linkage, and only these, hence the name.  */
370
371static GTY(()) struct c_scope *external_scope;
372
373/* A chain of c_scope structures awaiting reuse.  */
374
375static GTY((deletable)) struct c_scope *scope_freelist;
376
377/* A chain of c_binding structures awaiting reuse.  */
378
379static GTY((deletable)) struct c_binding *binding_freelist;
380
381/* Append VAR to LIST in scope SCOPE.  */
382#define SCOPE_LIST_APPEND(scope, list, decl) do {	\
383  struct c_scope *s_ = (scope);				\
384  tree d_ = (decl);					\
385  if (s_->list##_last)					\
386    TREE_CHAIN (s_->list##_last) = d_;			\
387  else							\
388    s_->list = d_;					\
389  s_->list##_last = d_;					\
390} while (0)
391
392/* Concatenate FROM in scope FSCOPE onto TO in scope TSCOPE.  */
393#define SCOPE_LIST_CONCAT(tscope, to, fscope, from) do {	\
394  struct c_scope *t_ = (tscope);				\
395  struct c_scope *f_ = (fscope);				\
396  if (t_->to##_last)						\
397    TREE_CHAIN (t_->to##_last) = f_->from;			\
398  else								\
399    t_->to = f_->from;						\
400  t_->to##_last = f_->from##_last;				\
401} while (0)
402
403/* True means unconditionally make a BLOCK for the next scope pushed.  */
404
405static bool keep_next_level_flag;
406
407/* True means the next call to push_scope will be the outermost scope
408   of a function body, so do not push a new scope, merely cease
409   expecting parameter decls.  */
410
411static bool next_is_function_body;
412
413/* Functions called automatically at the beginning and end of execution.  */
414
415static GTY(()) tree static_ctors;
416static GTY(()) tree static_dtors;
417
418/* Forward declarations.  */
419static tree lookup_name_in_scope (tree, struct c_scope *);
420static tree c_make_fname_decl (tree, int);
421static tree grokdeclarator (const struct c_declarator *,
422			    struct c_declspecs *,
423			    enum decl_context, bool, tree *);
424static tree grokparms (struct c_arg_info *, bool);
425static void layout_array_type (tree);
426
427/* T is a statement.  Add it to the statement-tree.  This is the
428   C/ObjC version--C++ has a slightly different version of this
429   function.  */
430
431tree
432add_stmt (tree t)
433{
434  enum tree_code code = TREE_CODE (t);
435
436  if (EXPR_P (t) && code != LABEL_EXPR)
437    {
438      if (!EXPR_HAS_LOCATION (t))
439	SET_EXPR_LOCATION (t, input_location);
440    }
441
442  if (code == LABEL_EXPR || code == CASE_LABEL_EXPR)
443    STATEMENT_LIST_HAS_LABEL (cur_stmt_list) = 1;
444
445  /* Add T to the statement-tree.  Non-side-effect statements need to be
446     recorded during statement expressions.  */
447  append_to_statement_list_force (t, &cur_stmt_list);
448
449  return t;
450}
451
452/* States indicating how grokdeclarator() should handle declspecs marked
453   with __attribute__((deprecated)).  An object declared as
454   __attribute__((deprecated)) suppresses warnings of uses of other
455   deprecated items.  */
456
457enum deprecated_states {
458  DEPRECATED_NORMAL,
459  DEPRECATED_SUPPRESS
460};
461
462static enum deprecated_states deprecated_state = DEPRECATED_NORMAL;
463
464void
465c_print_identifier (FILE *file, tree node, int indent)
466{
467  print_node (file, "symbol", I_SYMBOL_DECL (node), indent + 4);
468  print_node (file, "tag", I_TAG_DECL (node), indent + 4);
469  print_node (file, "label", I_LABEL_DECL (node), indent + 4);
470  if (C_IS_RESERVED_WORD (node))
471    {
472      tree rid = ridpointers[C_RID_CODE (node)];
473      indent_to (file, indent + 4);
474      fprintf (file, "rid %p \"%s\"",
475	       (void *) rid, IDENTIFIER_POINTER (rid));
476    }
477}
478
479/* Establish a binding between NAME, an IDENTIFIER_NODE, and DECL,
480   which may be any of several kinds of DECL or TYPE or error_mark_node,
481   in the scope SCOPE.  */
482static void
483bind (tree name, tree decl, struct c_scope *scope, bool invisible, bool nested)
484{
485  struct c_binding *b, **here;
486
487  if (binding_freelist)
488    {
489      b = binding_freelist;
490      binding_freelist = b->prev;
491    }
492  else
493    b = GGC_NEW (struct c_binding);
494
495  b->shadowed = 0;
496  b->decl = decl;
497  b->id = name;
498  b->depth = scope->depth;
499  b->invisible = invisible;
500  b->nested = nested;
501  b->inner_comp = 0;
502
503  b->type = 0;
504
505  b->prev = scope->bindings;
506  scope->bindings = b;
507
508  if (!name)
509    return;
510
511  switch (TREE_CODE (decl))
512    {
513    case LABEL_DECL:     here = &I_LABEL_BINDING (name);   break;
514    case ENUMERAL_TYPE:
515    case UNION_TYPE:
516    case RECORD_TYPE:    here = &I_TAG_BINDING (name);     break;
517    case VAR_DECL:
518    case FUNCTION_DECL:
519    case TYPE_DECL:
520    case CONST_DECL:
521    case PARM_DECL:
522    case ERROR_MARK:     here = &I_SYMBOL_BINDING (name);  break;
523
524    default:
525      gcc_unreachable ();
526    }
527
528  /* Locate the appropriate place in the chain of shadowed decls
529     to insert this binding.  Normally, scope == current_scope and
530     this does nothing.  */
531  while (*here && (*here)->depth > scope->depth)
532    here = &(*here)->shadowed;
533
534  b->shadowed = *here;
535  *here = b;
536}
537
538/* Clear the binding structure B, stick it on the binding_freelist,
539   and return the former value of b->prev.  This is used by pop_scope
540   and get_parm_info to iterate destructively over all the bindings
541   from a given scope.  */
542static struct c_binding *
543free_binding_and_advance (struct c_binding *b)
544{
545  struct c_binding *prev = b->prev;
546
547  memset (b, 0, sizeof (struct c_binding));
548  b->prev = binding_freelist;
549  binding_freelist = b;
550
551  return prev;
552}
553
554
555/* Hook called at end of compilation to assume 1 elt
556   for a file-scope tentative array defn that wasn't complete before.  */
557
558void
559c_finish_incomplete_decl (tree decl)
560{
561  if (TREE_CODE (decl) == VAR_DECL)
562    {
563      tree type = TREE_TYPE (decl);
564      if (type != error_mark_node
565	  && TREE_CODE (type) == ARRAY_TYPE
566	  && !DECL_EXTERNAL (decl)
567	  && TYPE_DOMAIN (type) == 0)
568	{
569	  warning (0, "array %q+D assumed to have one element", decl);
570
571	  complete_array_type (&TREE_TYPE (decl), NULL_TREE, true);
572
573	  layout_decl (decl, 0);
574	}
575    }
576}
577
578/* The Objective-C front-end often needs to determine the current scope.  */
579
580void *
581objc_get_current_scope (void)
582{
583  return current_scope;
584}
585
586/* The following function is used only by Objective-C.  It needs to live here
587   because it accesses the innards of c_scope.  */
588
589void
590objc_mark_locals_volatile (void *enclosing_blk)
591{
592  struct c_scope *scope;
593  struct c_binding *b;
594
595  for (scope = current_scope;
596       scope && scope != enclosing_blk;
597       scope = scope->outer)
598    {
599      for (b = scope->bindings; b; b = b->prev)
600	objc_volatilize_decl (b->decl);
601
602      /* Do not climb up past the current function.  */
603      if (scope->function_body)
604	break;
605    }
606}
607
608/* Nonzero if we are currently in file scope.  */
609
610int
611global_bindings_p (void)
612{
613  return current_scope == file_scope && !c_override_global_bindings_to_false;
614}
615
616void
617keep_next_level (void)
618{
619  keep_next_level_flag = true;
620}
621
622/* Identify this scope as currently being filled with parameters.  */
623
624void
625declare_parm_level (void)
626{
627  current_scope->parm_flag = true;
628}
629
630void
631push_scope (void)
632{
633  if (next_is_function_body)
634    {
635      /* This is the transition from the parameters to the top level
636	 of the function body.  These are the same scope
637	 (C99 6.2.1p4,6) so we do not push another scope structure.
638	 next_is_function_body is set only by store_parm_decls, which
639	 in turn is called when and only when we are about to
640	 encounter the opening curly brace for the function body.
641
642	 The outermost block of a function always gets a BLOCK node,
643	 because the debugging output routines expect that each
644	 function has at least one BLOCK.  */
645      current_scope->parm_flag         = false;
646      current_scope->function_body     = true;
647      current_scope->keep              = true;
648      current_scope->outer_function    = current_function_scope;
649      current_function_scope           = current_scope;
650
651      keep_next_level_flag = false;
652      next_is_function_body = false;
653    }
654  else
655    {
656      struct c_scope *scope;
657      if (scope_freelist)
658	{
659	  scope = scope_freelist;
660	  scope_freelist = scope->outer;
661	}
662      else
663	scope = GGC_CNEW (struct c_scope);
664
665      scope->keep          = keep_next_level_flag;
666      scope->outer         = current_scope;
667      scope->depth	   = current_scope ? (current_scope->depth + 1) : 0;
668
669      /* Check for scope depth overflow.  Unlikely (2^28 == 268,435,456) but
670	 possible.  */
671      if (current_scope && scope->depth == 0)
672	{
673	  scope->depth--;
674	  sorry ("GCC supports only %u nested scopes", scope->depth);
675	}
676
677      current_scope        = scope;
678      keep_next_level_flag = false;
679    }
680}
681
682/* Set the TYPE_CONTEXT of all of TYPE's variants to CONTEXT.  */
683
684static void
685set_type_context (tree type, tree context)
686{
687  for (type = TYPE_MAIN_VARIANT (type); type;
688       type = TYPE_NEXT_VARIANT (type))
689    TYPE_CONTEXT (type) = context;
690}
691
692/* Exit a scope.  Restore the state of the identifier-decl mappings
693   that were in effect when this scope was entered.  Return a BLOCK
694   node containing all the DECLs in this scope that are of interest
695   to debug info generation.  */
696
697tree
698pop_scope (void)
699{
700  struct c_scope *scope = current_scope;
701  tree block, context, p;
702  struct c_binding *b;
703
704  bool functionbody = scope->function_body;
705  bool keep = functionbody || scope->keep || scope->bindings;
706
707  c_end_vm_scope (scope->depth);
708
709  /* If appropriate, create a BLOCK to record the decls for the life
710     of this function.  */
711  block = 0;
712  if (keep)
713    {
714      block = make_node (BLOCK);
715      BLOCK_SUBBLOCKS (block) = scope->blocks;
716      TREE_USED (block) = 1;
717
718      /* In each subblock, record that this is its superior.  */
719      for (p = scope->blocks; p; p = TREE_CHAIN (p))
720	BLOCK_SUPERCONTEXT (p) = block;
721
722      BLOCK_VARS (block) = 0;
723    }
724
725  /* The TYPE_CONTEXTs for all of the tagged types belonging to this
726     scope must be set so that they point to the appropriate
727     construct, i.e.  either to the current FUNCTION_DECL node, or
728     else to the BLOCK node we just constructed.
729
730     Note that for tagged types whose scope is just the formal
731     parameter list for some function type specification, we can't
732     properly set their TYPE_CONTEXTs here, because we don't have a
733     pointer to the appropriate FUNCTION_TYPE node readily available
734     to us.  For those cases, the TYPE_CONTEXTs of the relevant tagged
735     type nodes get set in `grokdeclarator' as soon as we have created
736     the FUNCTION_TYPE node which will represent the "scope" for these
737     "parameter list local" tagged types.  */
738  if (scope->function_body)
739    context = current_function_decl;
740  else if (scope == file_scope)
741    {
742      tree file_decl = build_decl (TRANSLATION_UNIT_DECL, 0, 0);
743      TREE_CHAIN (file_decl) = all_translation_units;
744      all_translation_units = file_decl;
745      context = file_decl;
746    }
747  else
748    context = block;
749
750  /* Clear all bindings in this scope.  */
751  for (b = scope->bindings; b; b = free_binding_and_advance (b))
752    {
753      p = b->decl;
754      switch (TREE_CODE (p))
755	{
756	case LABEL_DECL:
757	  /* Warnings for unused labels, errors for undefined labels.  */
758	  if (TREE_USED (p) && !DECL_INITIAL (p))
759	    {
760	      error ("label %q+D used but not defined", p);
761	      DECL_INITIAL (p) = error_mark_node;
762	    }
763	  else if (!TREE_USED (p) && warn_unused_label)
764	    {
765	      if (DECL_INITIAL (p))
766		warning (0, "label %q+D defined but not used", p);
767	      else
768		warning (0, "label %q+D declared but not defined", p);
769	    }
770	  /* Labels go in BLOCK_VARS.  */
771	  TREE_CHAIN (p) = BLOCK_VARS (block);
772	  BLOCK_VARS (block) = p;
773	  gcc_assert (I_LABEL_BINDING (b->id) == b);
774	  I_LABEL_BINDING (b->id) = b->shadowed;
775	  break;
776
777	case ENUMERAL_TYPE:
778	case UNION_TYPE:
779	case RECORD_TYPE:
780	  set_type_context (p, context);
781
782	  /* Types may not have tag-names, in which case the type
783	     appears in the bindings list with b->id NULL.  */
784	  if (b->id)
785	    {
786	      gcc_assert (I_TAG_BINDING (b->id) == b);
787	      I_TAG_BINDING (b->id) = b->shadowed;
788	    }
789	  break;
790
791	case FUNCTION_DECL:
792	  /* Propagate TREE_ADDRESSABLE from nested functions to their
793	     containing functions.  */
794	  if (!TREE_ASM_WRITTEN (p)
795	      && DECL_INITIAL (p) != 0
796	      && TREE_ADDRESSABLE (p)
797	      && DECL_ABSTRACT_ORIGIN (p) != 0
798	      && DECL_ABSTRACT_ORIGIN (p) != p)
799	    TREE_ADDRESSABLE (DECL_ABSTRACT_ORIGIN (p)) = 1;
800	  if (!DECL_EXTERNAL (p)
801	      && DECL_INITIAL (p) == 0
802	      && scope != file_scope
803	      && scope != external_scope)
804	    {
805	      error ("nested function %q+D declared but never defined", p);
806	      undef_nested_function = true;
807	    }
808	  /* C99 6.7.4p6: "a function with external linkage... declared
809	     with an inline function specifier ... shall also be defined in the
810	     same translation unit."  */
811	  else if (DECL_DECLARED_INLINE_P (p)
812		   && TREE_PUBLIC (p)
813		   && !DECL_INITIAL (p)
814		   && !flag_gnu89_inline)
815	    pedwarn ("inline function %q+D declared but never defined", p);
816
817	  goto common_symbol;
818
819	case VAR_DECL:
820	  /* Warnings for unused variables.  */
821	  if (!TREE_USED (p)
822	      && !TREE_NO_WARNING (p)
823	      && !DECL_IN_SYSTEM_HEADER (p)
824	      && DECL_NAME (p)
825	      && !DECL_ARTIFICIAL (p)
826	      && scope != file_scope
827	      && scope != external_scope)
828	    warning (OPT_Wunused_variable, "unused variable %q+D", p);
829
830	  if (b->inner_comp)
831	    {
832	      error ("type of array %q+D completed incompatibly with"
833		     " implicit initialization", p);
834	    }
835
836	  /* Fall through.  */
837	case TYPE_DECL:
838	case CONST_DECL:
839	common_symbol:
840	  /* All of these go in BLOCK_VARS, but only if this is the
841	     binding in the home scope.  */
842	  if (!b->nested)
843	    {
844	      TREE_CHAIN (p) = BLOCK_VARS (block);
845	      BLOCK_VARS (block) = p;
846	    }
847	  /* If this is the file scope, and we are processing more
848	     than one translation unit in this compilation, set
849	     DECL_CONTEXT of each decl to the TRANSLATION_UNIT_DECL.
850	     This makes same_translation_unit_p work, and causes
851	     static declarations to be given disambiguating suffixes.  */
852	  if (scope == file_scope && num_in_fnames > 1)
853	    {
854	      DECL_CONTEXT (p) = context;
855	      if (TREE_CODE (p) == TYPE_DECL)
856		set_type_context (TREE_TYPE (p), context);
857	    }
858
859	  /* Fall through.  */
860	  /* Parameters go in DECL_ARGUMENTS, not BLOCK_VARS, and have
861	     already been put there by store_parm_decls.  Unused-
862	     parameter warnings are handled by function.c.
863	     error_mark_node obviously does not go in BLOCK_VARS and
864	     does not get unused-variable warnings.  */
865	case PARM_DECL:
866	case ERROR_MARK:
867	  /* It is possible for a decl not to have a name.  We get
868	     here with b->id NULL in this case.  */
869	  if (b->id)
870	    {
871	      gcc_assert (I_SYMBOL_BINDING (b->id) == b);
872	      I_SYMBOL_BINDING (b->id) = b->shadowed;
873	      if (b->shadowed && b->shadowed->type)
874		TREE_TYPE (b->shadowed->decl) = b->shadowed->type;
875	    }
876	  break;
877
878	default:
879	  gcc_unreachable ();
880	}
881    }
882
883
884  /* Dispose of the block that we just made inside some higher level.  */
885  if ((scope->function_body || scope == file_scope) && context)
886    {
887      DECL_INITIAL (context) = block;
888      BLOCK_SUPERCONTEXT (block) = context;
889    }
890  else if (scope->outer)
891    {
892      if (block)
893	SCOPE_LIST_APPEND (scope->outer, blocks, block);
894      /* If we did not make a block for the scope just exited, any
895	 blocks made for inner scopes must be carried forward so they
896	 will later become subblocks of something else.  */
897      else if (scope->blocks)
898	SCOPE_LIST_CONCAT (scope->outer, blocks, scope, blocks);
899    }
900
901  /* Pop the current scope, and free the structure for reuse.  */
902  current_scope = scope->outer;
903  if (scope->function_body)
904    current_function_scope = scope->outer_function;
905
906  memset (scope, 0, sizeof (struct c_scope));
907  scope->outer = scope_freelist;
908  scope_freelist = scope;
909
910  return block;
911}
912
913void
914push_file_scope (void)
915{
916  tree decl;
917
918  if (file_scope)
919    return;
920
921  push_scope ();
922  file_scope = current_scope;
923
924  start_fname_decls ();
925
926  for (decl = visible_builtins; decl; decl = TREE_CHAIN (decl))
927    bind (DECL_NAME (decl), decl, file_scope,
928	  /*invisible=*/false, /*nested=*/true);
929}
930
931void
932pop_file_scope (void)
933{
934  /* In case there were missing closebraces, get us back to the global
935     binding level.  */
936  while (current_scope != file_scope)
937    pop_scope ();
938
939  /* __FUNCTION__ is defined at file scope ("").  This
940     call may not be necessary as my tests indicate it
941     still works without it.  */
942  finish_fname_decls ();
943
944  /* This is the point to write out a PCH if we're doing that.
945     In that case we do not want to do anything else.  */
946  if (pch_file)
947    {
948      c_common_write_pch ();
949      return;
950    }
951
952  /* Pop off the file scope and close this translation unit.  */
953  pop_scope ();
954  file_scope = 0;
955
956  maybe_apply_pending_pragma_weaks ();
957  cgraph_finalize_compilation_unit ();
958}
959
960/* Insert BLOCK at the end of the list of subblocks of the current
961   scope.  This is used when a BIND_EXPR is expanded, to handle the
962   BLOCK node inside the BIND_EXPR.  */
963
964void
965insert_block (tree block)
966{
967  TREE_USED (block) = 1;
968  SCOPE_LIST_APPEND (current_scope, blocks, block);
969}
970
971/* Push a definition or a declaration of struct, union or enum tag "name".
972   "type" should be the type node.
973   We assume that the tag "name" is not already defined.
974
975   Note that the definition may really be just a forward reference.
976   In that case, the TYPE_SIZE will be zero.  */
977
978static void
979pushtag (tree name, tree type)
980{
981  /* Record the identifier as the type's name if it has none.  */
982  if (name && !TYPE_NAME (type))
983    TYPE_NAME (type) = name;
984  bind (name, type, current_scope, /*invisible=*/false, /*nested=*/false);
985
986  /* Create a fake NULL-named TYPE_DECL node whose TREE_TYPE will be the
987     tagged type we just added to the current scope.  This fake
988     NULL-named TYPE_DECL node helps dwarfout.c to know when it needs
989     to output a representation of a tagged type, and it also gives
990     us a convenient place to record the "scope start" address for the
991     tagged type.  */
992
993  TYPE_STUB_DECL (type) = pushdecl (build_decl (TYPE_DECL, NULL_TREE, type));
994
995  /* An approximation for now, so we can tell this is a function-scope tag.
996     This will be updated in pop_scope.  */
997  TYPE_CONTEXT (type) = DECL_CONTEXT (TYPE_STUB_DECL (type));
998}
999
1000/* Subroutine of compare_decls.  Allow harmless mismatches in return
1001   and argument types provided that the type modes match.  This function
1002   return a unified type given a suitable match, and 0 otherwise.  */
1003
1004static tree
1005match_builtin_function_types (tree newtype, tree oldtype)
1006{
1007  tree newrettype, oldrettype;
1008  tree newargs, oldargs;
1009  tree trytype, tryargs;
1010
1011  /* Accept the return type of the new declaration if same modes.  */
1012  oldrettype = TREE_TYPE (oldtype);
1013  newrettype = TREE_TYPE (newtype);
1014
1015  if (TYPE_MODE (oldrettype) != TYPE_MODE (newrettype))
1016    return 0;
1017
1018  oldargs = TYPE_ARG_TYPES (oldtype);
1019  newargs = TYPE_ARG_TYPES (newtype);
1020  tryargs = newargs;
1021
1022  while (oldargs || newargs)
1023    {
1024      if (!oldargs
1025	  || !newargs
1026	  || !TREE_VALUE (oldargs)
1027	  || !TREE_VALUE (newargs)
1028	  || TYPE_MODE (TREE_VALUE (oldargs))
1029	     != TYPE_MODE (TREE_VALUE (newargs)))
1030	return 0;
1031
1032      oldargs = TREE_CHAIN (oldargs);
1033      newargs = TREE_CHAIN (newargs);
1034    }
1035
1036  trytype = build_function_type (newrettype, tryargs);
1037  return build_type_attribute_variant (trytype, TYPE_ATTRIBUTES (oldtype));
1038}
1039
1040/* Subroutine of diagnose_mismatched_decls.  Check for function type
1041   mismatch involving an empty arglist vs a nonempty one and give clearer
1042   diagnostics.  */
1043static void
1044diagnose_arglist_conflict (tree newdecl, tree olddecl,
1045			   tree newtype, tree oldtype)
1046{
1047  tree t;
1048
1049  if (TREE_CODE (olddecl) != FUNCTION_DECL
1050      || !comptypes (TREE_TYPE (oldtype), TREE_TYPE (newtype))
1051      || !((TYPE_ARG_TYPES (oldtype) == 0 && DECL_INITIAL (olddecl) == 0)
1052	   ||
1053	   (TYPE_ARG_TYPES (newtype) == 0 && DECL_INITIAL (newdecl) == 0)))
1054    return;
1055
1056  t = TYPE_ARG_TYPES (oldtype);
1057  if (t == 0)
1058    t = TYPE_ARG_TYPES (newtype);
1059  for (; t; t = TREE_CHAIN (t))
1060    {
1061      tree type = TREE_VALUE (t);
1062
1063      if (TREE_CHAIN (t) == 0
1064	  && TYPE_MAIN_VARIANT (type) != void_type_node)
1065	{
1066	  inform ("a parameter list with an ellipsis can%'t match "
1067		  "an empty parameter name list declaration");
1068	  break;
1069	}
1070
1071      if (c_type_promotes_to (type) != type)
1072	{
1073	  inform ("an argument type that has a default promotion can%'t match "
1074		  "an empty parameter name list declaration");
1075	  break;
1076	}
1077    }
1078}
1079
1080/* Another subroutine of diagnose_mismatched_decls.  OLDDECL is an
1081   old-style function definition, NEWDECL is a prototype declaration.
1082   Diagnose inconsistencies in the argument list.  Returns TRUE if
1083   the prototype is compatible, FALSE if not.  */
1084static bool
1085validate_proto_after_old_defn (tree newdecl, tree newtype, tree oldtype)
1086{
1087  tree newargs, oldargs;
1088  int i;
1089
1090#define END_OF_ARGLIST(t) ((t) == void_type_node)
1091
1092  oldargs = TYPE_ACTUAL_ARG_TYPES (oldtype);
1093  newargs = TYPE_ARG_TYPES (newtype);
1094  i = 1;
1095
1096  for (;;)
1097    {
1098      tree oldargtype = TREE_VALUE (oldargs);
1099      tree newargtype = TREE_VALUE (newargs);
1100
1101      if (oldargtype == error_mark_node || newargtype == error_mark_node)
1102	return false;
1103
1104      oldargtype = TYPE_MAIN_VARIANT (oldargtype);
1105      newargtype = TYPE_MAIN_VARIANT (newargtype);
1106
1107      if (END_OF_ARGLIST (oldargtype) && END_OF_ARGLIST (newargtype))
1108	break;
1109
1110      /* Reaching the end of just one list means the two decls don't
1111	 agree on the number of arguments.  */
1112      if (END_OF_ARGLIST (oldargtype))
1113	{
1114	  error ("prototype for %q+D declares more arguments "
1115		 "than previous old-style definition", newdecl);
1116	  return false;
1117	}
1118      else if (END_OF_ARGLIST (newargtype))
1119	{
1120	  error ("prototype for %q+D declares fewer arguments "
1121		 "than previous old-style definition", newdecl);
1122	  return false;
1123	}
1124
1125      /* Type for passing arg must be consistent with that declared
1126	 for the arg.  */
1127      else if (!comptypes (oldargtype, newargtype))
1128	{
1129	  error ("prototype for %q+D declares argument %d"
1130		 " with incompatible type",
1131		 newdecl, i);
1132	  return false;
1133	}
1134
1135      oldargs = TREE_CHAIN (oldargs);
1136      newargs = TREE_CHAIN (newargs);
1137      i++;
1138    }
1139
1140  /* If we get here, no errors were found, but do issue a warning
1141     for this poor-style construct.  */
1142  warning (0, "prototype for %q+D follows non-prototype definition",
1143	   newdecl);
1144  return true;
1145#undef END_OF_ARGLIST
1146}
1147
1148/* Subroutine of diagnose_mismatched_decls.  Report the location of DECL,
1149   first in a pair of mismatched declarations, using the diagnostic
1150   function DIAG.  */
1151static void
1152locate_old_decl (tree decl, void (*diag)(const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2))
1153{
1154  if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1155    ;
1156  else if (DECL_INITIAL (decl))
1157    diag (G_("previous definition of %q+D was here"), decl);
1158  else if (C_DECL_IMPLICIT (decl))
1159    diag (G_("previous implicit declaration of %q+D was here"), decl);
1160  else
1161    diag (G_("previous declaration of %q+D was here"), decl);
1162}
1163
1164/* Subroutine of duplicate_decls.  Compare NEWDECL to OLDDECL.
1165   Returns true if the caller should proceed to merge the two, false
1166   if OLDDECL should simply be discarded.  As a side effect, issues
1167   all necessary diagnostics for invalid or poor-style combinations.
1168   If it returns true, writes the types of NEWDECL and OLDDECL to
1169   *NEWTYPEP and *OLDTYPEP - these may have been adjusted from
1170   TREE_TYPE (NEWDECL, OLDDECL) respectively.  */
1171
1172static bool
1173diagnose_mismatched_decls (tree newdecl, tree olddecl,
1174			   tree *newtypep, tree *oldtypep)
1175{
1176  tree newtype, oldtype;
1177  bool pedwarned = false;
1178  bool warned = false;
1179  bool retval = true;
1180
1181#define DECL_EXTERN_INLINE(DECL) (DECL_DECLARED_INLINE_P (DECL)  \
1182				  && DECL_EXTERNAL (DECL))
1183
1184  /* If we have error_mark_node for either decl or type, just discard
1185     the previous decl - we're in an error cascade already.  */
1186  if (olddecl == error_mark_node || newdecl == error_mark_node)
1187    return false;
1188  *oldtypep = oldtype = TREE_TYPE (olddecl);
1189  *newtypep = newtype = TREE_TYPE (newdecl);
1190  if (oldtype == error_mark_node || newtype == error_mark_node)
1191    return false;
1192
1193  /* Two different categories of symbol altogether.  This is an error
1194     unless OLDDECL is a builtin.  OLDDECL will be discarded in any case.  */
1195  if (TREE_CODE (olddecl) != TREE_CODE (newdecl))
1196    {
1197      if (!(TREE_CODE (olddecl) == FUNCTION_DECL
1198	    && DECL_BUILT_IN (olddecl)
1199	    && !C_DECL_DECLARED_BUILTIN (olddecl)))
1200	{
1201	  error ("%q+D redeclared as different kind of symbol", newdecl);
1202	  locate_old_decl (olddecl, error);
1203	}
1204      else if (TREE_PUBLIC (newdecl))
1205	warning (0, "built-in function %q+D declared as non-function",
1206		 newdecl);
1207      else
1208	warning (OPT_Wshadow, "declaration of %q+D shadows "
1209		 "a built-in function", newdecl);
1210      return false;
1211    }
1212
1213  /* Enumerators have no linkage, so may only be declared once in a
1214     given scope.  */
1215  if (TREE_CODE (olddecl) == CONST_DECL)
1216    {
1217      error ("redeclaration of enumerator %q+D", newdecl);
1218      locate_old_decl (olddecl, error);
1219      return false;
1220    }
1221
1222  if (!comptypes (oldtype, newtype))
1223    {
1224      if (TREE_CODE (olddecl) == FUNCTION_DECL
1225	  && DECL_BUILT_IN (olddecl) && !C_DECL_DECLARED_BUILTIN (olddecl))
1226	{
1227	  /* Accept harmless mismatch in function types.
1228	     This is for the ffs and fprintf builtins.  */
1229	  tree trytype = match_builtin_function_types (newtype, oldtype);
1230
1231	  if (trytype && comptypes (newtype, trytype))
1232	    *oldtypep = oldtype = trytype;
1233	  else
1234	    {
1235	      /* If types don't match for a built-in, throw away the
1236		 built-in.  No point in calling locate_old_decl here, it
1237		 won't print anything.  */
1238	      warning (0, "conflicting types for built-in function %q+D",
1239		       newdecl);
1240	      return false;
1241	    }
1242	}
1243      else if (TREE_CODE (olddecl) == FUNCTION_DECL
1244	       && DECL_IS_BUILTIN (olddecl))
1245	{
1246	  /* A conflicting function declaration for a predeclared
1247	     function that isn't actually built in.  Objective C uses
1248	     these.  The new declaration silently overrides everything
1249	     but the volatility (i.e. noreturn) indication.  See also
1250	     below.  FIXME: Make Objective C use normal builtins.  */
1251	  TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl);
1252	  return false;
1253	}
1254      /* Permit void foo (...) to match int foo (...) if the latter is
1255	 the definition and implicit int was used.  See
1256	 c-torture/compile/920625-2.c.  */
1257      else if (TREE_CODE (newdecl) == FUNCTION_DECL && DECL_INITIAL (newdecl)
1258	       && TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == void_type_node
1259	       && TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == integer_type_node
1260	       && C_FUNCTION_IMPLICIT_INT (newdecl) && !DECL_INITIAL (olddecl))
1261	{
1262	  pedwarn ("conflicting types for %q+D", newdecl);
1263	  /* Make sure we keep void as the return type.  */
1264	  TREE_TYPE (newdecl) = *newtypep = newtype = oldtype;
1265	  C_FUNCTION_IMPLICIT_INT (newdecl) = 0;
1266	  pedwarned = true;
1267	}
1268      /* Permit void foo (...) to match an earlier call to foo (...) with
1269	 no declared type (thus, implicitly int).  */
1270      else if (TREE_CODE (newdecl) == FUNCTION_DECL
1271	       && TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == void_type_node
1272	       && TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == integer_type_node
1273	       && C_DECL_IMPLICIT (olddecl) && !DECL_INITIAL (olddecl))
1274	{
1275	  pedwarn ("conflicting types for %q+D", newdecl);
1276	  /* Make sure we keep void as the return type.  */
1277	  TREE_TYPE (olddecl) = *oldtypep = oldtype = newtype;
1278	  pedwarned = true;
1279	}
1280      else
1281	{
1282	  if (TYPE_QUALS (newtype) != TYPE_QUALS (oldtype))
1283	    error ("conflicting type qualifiers for %q+D", newdecl);
1284	  else
1285	    error ("conflicting types for %q+D", newdecl);
1286	  diagnose_arglist_conflict (newdecl, olddecl, newtype, oldtype);
1287	  locate_old_decl (olddecl, error);
1288	  return false;
1289	}
1290    }
1291
1292  /* Redeclaration of a type is a constraint violation (6.7.2.3p1),
1293     but silently ignore the redeclaration if either is in a system
1294     header.  (Conflicting redeclarations were handled above.)  */
1295  if (TREE_CODE (newdecl) == TYPE_DECL)
1296    {
1297      if (DECL_IN_SYSTEM_HEADER (newdecl) || DECL_IN_SYSTEM_HEADER (olddecl))
1298	return true;  /* Allow OLDDECL to continue in use.  */
1299
1300      error ("redefinition of typedef %q+D", newdecl);
1301      locate_old_decl (olddecl, error);
1302      return false;
1303    }
1304
1305  /* Function declarations can either be 'static' or 'extern' (no
1306     qualifier is equivalent to 'extern' - C99 6.2.2p5) and therefore
1307     can never conflict with each other on account of linkage
1308     (6.2.2p4).  Multiple definitions are not allowed (6.9p3,5) but
1309     gnu89 mode permits two definitions if one is 'extern inline' and
1310     one is not.  The non- extern-inline definition supersedes the
1311     extern-inline definition.  */
1312
1313  else if (TREE_CODE (newdecl) == FUNCTION_DECL)
1314    {
1315      /* If you declare a built-in function name as static, or
1316	 define the built-in with an old-style definition (so we
1317	 can't validate the argument list) the built-in definition is
1318	 overridden, but optionally warn this was a bad choice of name.  */
1319      if (DECL_BUILT_IN (olddecl)
1320	  && !C_DECL_DECLARED_BUILTIN (olddecl)
1321	  && (!TREE_PUBLIC (newdecl)
1322	      || (DECL_INITIAL (newdecl)
1323		  && !TYPE_ARG_TYPES (TREE_TYPE (newdecl)))))
1324	{
1325	  warning (OPT_Wshadow, "declaration of %q+D shadows "
1326		   "a built-in function", newdecl);
1327	  /* Discard the old built-in function.  */
1328	  return false;
1329	}
1330
1331      if (DECL_INITIAL (newdecl))
1332	{
1333	  if (DECL_INITIAL (olddecl))
1334	    {
1335	      /* If both decls are in the same TU and the new declaration
1336		 isn't overriding an extern inline reject the new decl.
1337		 In c99, no overriding is allowed in the same translation
1338		 unit.  */
1339	      if ((!DECL_EXTERN_INLINE (olddecl)
1340		   || DECL_EXTERN_INLINE (newdecl)
1341		   || (!flag_gnu89_inline
1342		       && (!DECL_DECLARED_INLINE_P (olddecl)
1343			   || !lookup_attribute ("gnu_inline",
1344						 DECL_ATTRIBUTES (olddecl)))
1345		       && (!DECL_DECLARED_INLINE_P (newdecl)
1346			   || !lookup_attribute ("gnu_inline",
1347						 DECL_ATTRIBUTES (newdecl))))
1348		  )
1349		  && same_translation_unit_p (newdecl, olddecl))
1350		{
1351		  error ("redefinition of %q+D", newdecl);
1352		  locate_old_decl (olddecl, error);
1353		  return false;
1354		}
1355	    }
1356	}
1357      /* If we have a prototype after an old-style function definition,
1358	 the argument types must be checked specially.  */
1359      else if (DECL_INITIAL (olddecl)
1360	       && !TYPE_ARG_TYPES (oldtype) && TYPE_ARG_TYPES (newtype)
1361	       && TYPE_ACTUAL_ARG_TYPES (oldtype)
1362	       && !validate_proto_after_old_defn (newdecl, newtype, oldtype))
1363	{
1364	  locate_old_decl (olddecl, error);
1365	  return false;
1366	}
1367      /* A non-static declaration (even an "extern") followed by a
1368	 static declaration is undefined behavior per C99 6.2.2p3-5,7.
1369	 The same is true for a static forward declaration at block
1370	 scope followed by a non-static declaration/definition at file
1371	 scope.  Static followed by non-static at the same scope is
1372	 not undefined behavior, and is the most convenient way to get
1373	 some effects (see e.g.  what unwind-dw2-fde-glibc.c does to
1374	 the definition of _Unwind_Find_FDE in unwind-dw2-fde.c), but
1375	 we do diagnose it if -Wtraditional.  */
1376      if (TREE_PUBLIC (olddecl) && !TREE_PUBLIC (newdecl))
1377	{
1378	  /* Two exceptions to the rule.  If olddecl is an extern
1379	     inline, or a predeclared function that isn't actually
1380	     built in, newdecl silently overrides olddecl.  The latter
1381	     occur only in Objective C; see also above.  (FIXME: Make
1382	     Objective C use normal builtins.)  */
1383	  if (!DECL_IS_BUILTIN (olddecl)
1384	      && !DECL_EXTERN_INLINE (olddecl))
1385	    {
1386	      error ("static declaration of %q+D follows "
1387		     "non-static declaration", newdecl);
1388	      locate_old_decl (olddecl, error);
1389	    }
1390	  return false;
1391	}
1392      else if (TREE_PUBLIC (newdecl) && !TREE_PUBLIC (olddecl))
1393	{
1394	  if (DECL_CONTEXT (olddecl))
1395	    {
1396	      error ("non-static declaration of %q+D follows "
1397		     "static declaration", newdecl);
1398	      locate_old_decl (olddecl, error);
1399	      return false;
1400	    }
1401	  else if (warn_traditional)
1402	    {
1403	      warning (OPT_Wtraditional, "non-static declaration of %q+D "
1404		       "follows static declaration", newdecl);
1405	      warned = true;
1406	    }
1407	}
1408
1409      /* Make sure gnu_inline attribute is either not present, or
1410	 present on all inline decls.  */
1411      if (DECL_DECLARED_INLINE_P (olddecl)
1412	  && DECL_DECLARED_INLINE_P (newdecl))
1413	{
1414	  bool newa = lookup_attribute ("gnu_inline",
1415					DECL_ATTRIBUTES (newdecl)) != NULL;
1416	  bool olda = lookup_attribute ("gnu_inline",
1417					DECL_ATTRIBUTES (olddecl)) != NULL;
1418	  if (newa != olda)
1419	    {
1420	      error ("%<gnu_inline%> attribute present on %q+D",
1421		     newa ? newdecl : olddecl);
1422	      error ("%Jbut not here", newa ? olddecl : newdecl);
1423	    }
1424	}
1425    }
1426  else if (TREE_CODE (newdecl) == VAR_DECL)
1427    {
1428      /* Only variables can be thread-local, and all declarations must
1429	 agree on this property.  */
1430      if (C_DECL_THREADPRIVATE_P (olddecl) && !DECL_THREAD_LOCAL_P (newdecl))
1431	{
1432	  /* Nothing to check.  Since OLDDECL is marked threadprivate
1433	     and NEWDECL does not have a thread-local attribute, we
1434	     will merge the threadprivate attribute into NEWDECL.  */
1435	  ;
1436	}
1437      else if (DECL_THREAD_LOCAL_P (newdecl) != DECL_THREAD_LOCAL_P (olddecl))
1438	{
1439	  if (DECL_THREAD_LOCAL_P (newdecl))
1440	    error ("thread-local declaration of %q+D follows "
1441		   "non-thread-local declaration", newdecl);
1442	  else
1443	    error ("non-thread-local declaration of %q+D follows "
1444		   "thread-local declaration", newdecl);
1445
1446	  locate_old_decl (olddecl, error);
1447	  return false;
1448	}
1449
1450      /* Multiple initialized definitions are not allowed (6.9p3,5).  */
1451      if (DECL_INITIAL (newdecl) && DECL_INITIAL (olddecl))
1452	{
1453	  error ("redefinition of %q+D", newdecl);
1454	  locate_old_decl (olddecl, error);
1455	  return false;
1456	}
1457
1458      /* Objects declared at file scope: if the first declaration had
1459	 external linkage (even if it was an external reference) the
1460	 second must have external linkage as well, or the behavior is
1461	 undefined.  If the first declaration had internal linkage, then
1462	 the second must too, or else be an external reference (in which
1463	 case the composite declaration still has internal linkage).
1464	 As for function declarations, we warn about the static-then-
1465	 extern case only for -Wtraditional.  See generally 6.2.2p3-5,7.  */
1466      if (DECL_FILE_SCOPE_P (newdecl)
1467	  && TREE_PUBLIC (newdecl) != TREE_PUBLIC (olddecl))
1468	{
1469	  if (DECL_EXTERNAL (newdecl))
1470	    {
1471	      if (!DECL_FILE_SCOPE_P (olddecl))
1472		{
1473		  error ("extern declaration of %q+D follows "
1474			 "declaration with no linkage", newdecl);
1475		  locate_old_decl (olddecl, error);
1476		  return false;
1477		}
1478	      else if (warn_traditional)
1479		{
1480		  warning (OPT_Wtraditional, "non-static declaration of %q+D "
1481			   "follows static declaration", newdecl);
1482		  warned = true;
1483		}
1484	    }
1485	  else
1486	    {
1487	      if (TREE_PUBLIC (newdecl))
1488		error ("non-static declaration of %q+D follows "
1489		       "static declaration", newdecl);
1490	      else
1491		error ("static declaration of %q+D follows "
1492		       "non-static declaration", newdecl);
1493
1494	      locate_old_decl (olddecl, error);
1495	      return false;
1496	    }
1497	}
1498      /* Two objects with the same name declared at the same block
1499	 scope must both be external references (6.7p3).  */
1500      else if (!DECL_FILE_SCOPE_P (newdecl))
1501	{
1502	  if (DECL_EXTERNAL (newdecl))
1503	    {
1504	      /* Extern with initializer at block scope, which will
1505		 already have received an error.  */
1506	    }
1507	  else if (DECL_EXTERNAL (olddecl))
1508	    {
1509	      error ("declaration of %q+D with no linkage follows "
1510		     "extern declaration", newdecl);
1511	      locate_old_decl (olddecl, error);
1512	    }
1513	  else
1514	    {
1515	      error ("redeclaration of %q+D with no linkage", newdecl);
1516	      locate_old_decl (olddecl, error);
1517	    }
1518
1519	  return false;
1520	}
1521    }
1522
1523  /* warnings */
1524  /* All decls must agree on a visibility.  */
1525  if (CODE_CONTAINS_STRUCT (TREE_CODE (newdecl), TS_DECL_WITH_VIS)
1526      && DECL_VISIBILITY_SPECIFIED (newdecl) && DECL_VISIBILITY_SPECIFIED (olddecl)
1527      && DECL_VISIBILITY (newdecl) != DECL_VISIBILITY (olddecl))
1528    {
1529      warning (0, "redeclaration of %q+D with different visibility "
1530	       "(old visibility preserved)", newdecl);
1531      warned = true;
1532    }
1533
1534  if (TREE_CODE (newdecl) == FUNCTION_DECL)
1535    {
1536      /* Diagnose inline __attribute__ ((noinline)) which is silly.  */
1537      if (DECL_DECLARED_INLINE_P (newdecl)
1538	  && lookup_attribute ("noinline", DECL_ATTRIBUTES (olddecl)))
1539	{
1540	  warning (OPT_Wattributes, "inline declaration of %qD follows "
1541		   "declaration with attribute noinline", newdecl);
1542	  warned = true;
1543	}
1544      else if (DECL_DECLARED_INLINE_P (olddecl)
1545	       && lookup_attribute ("noinline", DECL_ATTRIBUTES (newdecl)))
1546	{
1547	  warning (OPT_Wattributes, "declaration of %q+D with attribute "
1548		   "noinline follows inline declaration ", newdecl);
1549	  warned = true;
1550	}
1551
1552      /* Inline declaration after use or definition.
1553	 ??? Should we still warn about this now we have unit-at-a-time
1554	 mode and can get it right?
1555	 Definitely don't complain if the decls are in different translation
1556	 units.
1557	 C99 permits this, so don't warn in that case.  (The function
1558	 may not be inlined everywhere in function-at-a-time mode, but
1559	 we still shouldn't warn.)  */
1560      if (DECL_DECLARED_INLINE_P (newdecl) && !DECL_DECLARED_INLINE_P (olddecl)
1561	  && same_translation_unit_p (olddecl, newdecl)
1562	  && flag_gnu89_inline)
1563	{
1564	  if (TREE_USED (olddecl))
1565	    {
1566	      warning (0, "%q+D declared inline after being called", olddecl);
1567	      warned = true;
1568	    }
1569	  else if (DECL_INITIAL (olddecl))
1570	    {
1571	      warning (0, "%q+D declared inline after its definition", olddecl);
1572	      warned = true;
1573	    }
1574	}
1575    }
1576  else /* PARM_DECL, VAR_DECL */
1577    {
1578      /* Redeclaration of a parameter is a constraint violation (this is
1579	 not explicitly stated, but follows from C99 6.7p3 [no more than
1580	 one declaration of the same identifier with no linkage in the
1581	 same scope, except type tags] and 6.2.2p6 [parameters have no
1582	 linkage]).  We must check for a forward parameter declaration,
1583	 indicated by TREE_ASM_WRITTEN on the old declaration - this is
1584	 an extension, the mandatory diagnostic for which is handled by
1585	 mark_forward_parm_decls.  */
1586
1587      if (TREE_CODE (newdecl) == PARM_DECL
1588	  && (!TREE_ASM_WRITTEN (olddecl) || TREE_ASM_WRITTEN (newdecl)))
1589	{
1590	  error ("redefinition of parameter %q+D", newdecl);
1591	  locate_old_decl (olddecl, error);
1592	  return false;
1593	}
1594    }
1595
1596  /* Optional warning for completely redundant decls.  */
1597  if (!warned && !pedwarned
1598      && warn_redundant_decls
1599      /* Don't warn about a function declaration followed by a
1600	 definition.  */
1601      && !(TREE_CODE (newdecl) == FUNCTION_DECL
1602	   && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl))
1603      /* Don't warn about redundant redeclarations of builtins.  */
1604      && !(TREE_CODE (newdecl) == FUNCTION_DECL
1605	   && !DECL_BUILT_IN (newdecl)
1606	   && DECL_BUILT_IN (olddecl)
1607	   && !C_DECL_DECLARED_BUILTIN (olddecl))
1608      /* Don't warn about an extern followed by a definition.  */
1609      && !(DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl))
1610      /* Don't warn about forward parameter decls.  */
1611      && !(TREE_CODE (newdecl) == PARM_DECL
1612	   && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl))
1613      /* Don't warn about a variable definition following a declaration.  */
1614      && !(TREE_CODE (newdecl) == VAR_DECL
1615	   && DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl)))
1616    {
1617      warning (OPT_Wredundant_decls, "redundant redeclaration of %q+D",
1618	       newdecl);
1619      warned = true;
1620    }
1621
1622  /* Report location of previous decl/defn in a consistent manner.  */
1623  if (warned || pedwarned)
1624    locate_old_decl (olddecl, pedwarned ? pedwarn : warning0);
1625
1626#undef DECL_EXTERN_INLINE
1627
1628  return retval;
1629}
1630
1631/* Subroutine of duplicate_decls.  NEWDECL has been found to be
1632   consistent with OLDDECL, but carries new information.  Merge the
1633   new information into OLDDECL.  This function issues no
1634   diagnostics.  */
1635
1636static void
1637merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
1638{
1639  bool new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL
1640			    && DECL_INITIAL (newdecl) != 0);
1641  bool new_is_prototype = (TREE_CODE (newdecl) == FUNCTION_DECL
1642			   && TYPE_ARG_TYPES (TREE_TYPE (newdecl)) != 0);
1643  bool old_is_prototype = (TREE_CODE (olddecl) == FUNCTION_DECL
1644			   && TYPE_ARG_TYPES (TREE_TYPE (olddecl)) != 0);
1645  bool extern_changed = false;
1646
1647  /* For real parm decl following a forward decl, rechain the old decl
1648     in its new location and clear TREE_ASM_WRITTEN (it's not a
1649     forward decl anymore).  */
1650  if (TREE_CODE (newdecl) == PARM_DECL
1651      && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl))
1652    {
1653      struct c_binding *b, **here;
1654
1655      for (here = &current_scope->bindings; *here; here = &(*here)->prev)
1656	if ((*here)->decl == olddecl)
1657	  goto found;
1658      gcc_unreachable ();
1659
1660    found:
1661      b = *here;
1662      *here = b->prev;
1663      b->prev = current_scope->bindings;
1664      current_scope->bindings = b;
1665
1666      TREE_ASM_WRITTEN (olddecl) = 0;
1667    }
1668
1669  DECL_ATTRIBUTES (newdecl)
1670    = targetm.merge_decl_attributes (olddecl, newdecl);
1671
1672  /* Merge the data types specified in the two decls.  */
1673  TREE_TYPE (newdecl)
1674    = TREE_TYPE (olddecl)
1675    = composite_type (newtype, oldtype);
1676
1677  /* Lay the type out, unless already done.  */
1678  if (!comptypes (oldtype, TREE_TYPE (newdecl)))
1679    {
1680      if (TREE_TYPE (newdecl) != error_mark_node)
1681	layout_type (TREE_TYPE (newdecl));
1682      if (TREE_CODE (newdecl) != FUNCTION_DECL
1683	  && TREE_CODE (newdecl) != TYPE_DECL
1684	  && TREE_CODE (newdecl) != CONST_DECL)
1685	layout_decl (newdecl, 0);
1686    }
1687  else
1688    {
1689      /* Since the type is OLDDECL's, make OLDDECL's size go with.  */
1690      DECL_SIZE (newdecl) = DECL_SIZE (olddecl);
1691      DECL_SIZE_UNIT (newdecl) = DECL_SIZE_UNIT (olddecl);
1692      DECL_MODE (newdecl) = DECL_MODE (olddecl);
1693      if (TREE_CODE (olddecl) != FUNCTION_DECL)
1694	if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl))
1695	  {
1696	    DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl);
1697	    DECL_USER_ALIGN (newdecl) |= DECL_ALIGN (olddecl);
1698	  }
1699    }
1700
1701
1702  /* Merge the type qualifiers.  */
1703  if (TREE_READONLY (newdecl))
1704    TREE_READONLY (olddecl) = 1;
1705
1706  if (TREE_THIS_VOLATILE (newdecl))
1707    TREE_THIS_VOLATILE (olddecl) = 1;
1708
1709  /* Merge deprecatedness.  */
1710  if (TREE_DEPRECATED (newdecl))
1711    TREE_DEPRECATED (olddecl) = 1;
1712
1713  /* Keep source location of definition rather than declaration and of
1714     prototype rather than non-prototype unless that prototype is
1715     built-in.  */
1716  if ((DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0)
1717      || (old_is_prototype && !new_is_prototype
1718	  && !C_DECL_BUILTIN_PROTOTYPE (olddecl)))
1719    DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl);
1720
1721  /* Merge the initialization information.  */
1722   if (DECL_INITIAL (newdecl) == 0)
1723    DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
1724
1725  /* Merge the threadprivate attribute.  */
1726  if (TREE_CODE (olddecl) == VAR_DECL && C_DECL_THREADPRIVATE_P (olddecl))
1727    {
1728      DECL_TLS_MODEL (newdecl) = DECL_TLS_MODEL (olddecl);
1729      C_DECL_THREADPRIVATE_P (newdecl) = 1;
1730    }
1731
1732  if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS))
1733    {
1734      /* Merge the unused-warning information.  */
1735      if (DECL_IN_SYSTEM_HEADER (olddecl))
1736	DECL_IN_SYSTEM_HEADER (newdecl) = 1;
1737      else if (DECL_IN_SYSTEM_HEADER (newdecl))
1738	DECL_IN_SYSTEM_HEADER (olddecl) = 1;
1739
1740      /* Merge the section attribute.
1741	 We want to issue an error if the sections conflict but that
1742	 must be done later in decl_attributes since we are called
1743	 before attributes are assigned.  */
1744      if (DECL_SECTION_NAME (newdecl) == NULL_TREE)
1745	DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl);
1746
1747      /* Copy the assembler name.
1748	 Currently, it can only be defined in the prototype.  */
1749      COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl);
1750
1751      /* Use visibility of whichever declaration had it specified */
1752      if (DECL_VISIBILITY_SPECIFIED (olddecl))
1753	{
1754	  DECL_VISIBILITY (newdecl) = DECL_VISIBILITY (olddecl);
1755	  DECL_VISIBILITY_SPECIFIED (newdecl) = 1;
1756	}
1757
1758      if (TREE_CODE (newdecl) == FUNCTION_DECL)
1759	{
1760	  DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl);
1761	  DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl);
1762	  DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl);
1763	  DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl)
1764	    |= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl);
1765	  TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl);
1766	  TREE_READONLY (newdecl) |= TREE_READONLY (olddecl);
1767	  DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl);
1768	  DECL_IS_PURE (newdecl) |= DECL_IS_PURE (olddecl);
1769	  DECL_IS_NOVOPS (newdecl) |= DECL_IS_NOVOPS (olddecl);
1770	}
1771
1772      /* Merge the storage class information.  */
1773      merge_weak (newdecl, olddecl);
1774
1775      /* For functions, static overrides non-static.  */
1776      if (TREE_CODE (newdecl) == FUNCTION_DECL)
1777	{
1778	  TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl);
1779	  /* This is since we don't automatically
1780	     copy the attributes of NEWDECL into OLDDECL.  */
1781	  TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
1782	  /* If this clears `static', clear it in the identifier too.  */
1783	  if (!TREE_PUBLIC (olddecl))
1784	    TREE_PUBLIC (DECL_NAME (olddecl)) = 0;
1785	}
1786    }
1787
1788  /* In c99, 'extern' declaration before (or after) 'inline' means this
1789     function is not DECL_EXTERNAL, unless 'gnu_inline' attribute
1790     is present.  */
1791  if (TREE_CODE (newdecl) == FUNCTION_DECL
1792      && !flag_gnu89_inline
1793      && (DECL_DECLARED_INLINE_P (newdecl)
1794	  || DECL_DECLARED_INLINE_P (olddecl))
1795      && (!DECL_DECLARED_INLINE_P (newdecl)
1796	  || !DECL_DECLARED_INLINE_P (olddecl)
1797	  || !DECL_EXTERNAL (olddecl))
1798      && DECL_EXTERNAL (newdecl)
1799      && !lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (newdecl)))
1800    DECL_EXTERNAL (newdecl) = 0;
1801
1802  if (DECL_EXTERNAL (newdecl))
1803    {
1804      TREE_STATIC (newdecl) = TREE_STATIC (olddecl);
1805      DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl);
1806
1807      /* An extern decl does not override previous storage class.  */
1808      TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl);
1809      if (!DECL_EXTERNAL (newdecl))
1810	{
1811	  DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl);
1812	  DECL_COMMON (newdecl) = DECL_COMMON (olddecl);
1813	}
1814    }
1815  else
1816    {
1817      TREE_STATIC (olddecl) = TREE_STATIC (newdecl);
1818      TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
1819    }
1820
1821  if (TREE_CODE (newdecl) == FUNCTION_DECL)
1822    {
1823      /* If we're redefining a function previously defined as extern
1824	 inline, make sure we emit debug info for the inline before we
1825	 throw it away, in case it was inlined into a function that
1826	 hasn't been written out yet.  */
1827      if (new_is_definition && DECL_INITIAL (olddecl))
1828	{
1829	  if (TREE_USED (olddecl)
1830	      /* In unit-at-a-time mode we never inline re-defined extern
1831		 inline functions.  */
1832	      && !flag_unit_at_a_time
1833	      && cgraph_function_possibly_inlined_p (olddecl))
1834	    (*debug_hooks->outlining_inline_function) (olddecl);
1835
1836	  /* The new defn must not be inline.  */
1837	  DECL_INLINE (newdecl) = 0;
1838	  DECL_UNINLINABLE (newdecl) = 1;
1839	}
1840      else
1841	{
1842	  /* If either decl says `inline', this fn is inline, unless
1843	     its definition was passed already.  */
1844	  if (DECL_DECLARED_INLINE_P (newdecl)
1845	      || DECL_DECLARED_INLINE_P (olddecl))
1846	    DECL_DECLARED_INLINE_P (newdecl) = 1;
1847
1848	  DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl)
1849	    = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl));
1850	}
1851
1852      if (DECL_BUILT_IN (olddecl))
1853	{
1854	  /* If redeclaring a builtin function, it stays built in.
1855	     But it gets tagged as having been declared.  */
1856	  DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl);
1857	  DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl);
1858	  C_DECL_DECLARED_BUILTIN (newdecl) = 1;
1859	  if (new_is_prototype)
1860	    C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0;
1861	  else
1862	    C_DECL_BUILTIN_PROTOTYPE (newdecl)
1863	      = C_DECL_BUILTIN_PROTOTYPE (olddecl);
1864	}
1865
1866      /* Also preserve various other info from the definition.  */
1867      if (!new_is_definition)
1868	{
1869	  DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
1870	  DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
1871	  DECL_STRUCT_FUNCTION (newdecl) = DECL_STRUCT_FUNCTION (olddecl);
1872	  DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl);
1873	  DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl);
1874
1875	  /* Set DECL_INLINE on the declaration if we've got a body
1876	     from which to instantiate.  */
1877	  if (DECL_INLINE (olddecl) && !DECL_UNINLINABLE (newdecl))
1878	    {
1879	      DECL_INLINE (newdecl) = 1;
1880	      DECL_ABSTRACT_ORIGIN (newdecl)
1881		= DECL_ABSTRACT_ORIGIN (olddecl);
1882	    }
1883	}
1884      else
1885	{
1886	  /* If a previous declaration said inline, mark the
1887	     definition as inlinable.  */
1888	  if (DECL_DECLARED_INLINE_P (newdecl)
1889	      && !DECL_UNINLINABLE (newdecl))
1890	    DECL_INLINE (newdecl) = 1;
1891	}
1892    }
1893
1894   extern_changed = DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl);
1895
1896  /* Copy most of the decl-specific fields of NEWDECL into OLDDECL.
1897     But preserve OLDDECL's DECL_UID and DECL_CONTEXT.  */
1898  {
1899    unsigned olddecl_uid = DECL_UID (olddecl);
1900    tree olddecl_context = DECL_CONTEXT (olddecl);
1901
1902    memcpy ((char *) olddecl + sizeof (struct tree_common),
1903	    (char *) newdecl + sizeof (struct tree_common),
1904	    sizeof (struct tree_decl_common) - sizeof (struct tree_common));
1905    switch (TREE_CODE (olddecl))
1906      {
1907      case FIELD_DECL:
1908      case VAR_DECL:
1909      case PARM_DECL:
1910      case LABEL_DECL:
1911      case RESULT_DECL:
1912      case CONST_DECL:
1913      case TYPE_DECL:
1914      case FUNCTION_DECL:
1915	memcpy ((char *) olddecl + sizeof (struct tree_decl_common),
1916		(char *) newdecl + sizeof (struct tree_decl_common),
1917		tree_code_size (TREE_CODE (olddecl)) - sizeof (struct tree_decl_common));
1918	break;
1919
1920      default:
1921
1922	memcpy ((char *) olddecl + sizeof (struct tree_decl_common),
1923		(char *) newdecl + sizeof (struct tree_decl_common),
1924		sizeof (struct tree_decl_non_common) - sizeof (struct tree_decl_common));
1925      }
1926    DECL_UID (olddecl) = olddecl_uid;
1927    DECL_CONTEXT (olddecl) = olddecl_context;
1928  }
1929
1930  /* If OLDDECL had its DECL_RTL instantiated, re-invoke make_decl_rtl
1931     so that encode_section_info has a chance to look at the new decl
1932     flags and attributes.  */
1933  if (DECL_RTL_SET_P (olddecl)
1934      && (TREE_CODE (olddecl) == FUNCTION_DECL
1935	  || (TREE_CODE (olddecl) == VAR_DECL
1936	      && TREE_STATIC (olddecl))))
1937    make_decl_rtl (olddecl);
1938
1939  /* If we changed a function from DECL_EXTERNAL to !DECL_EXTERNAL,
1940     and the definition is coming from the old version, cgraph needs
1941     to be called again.  */
1942  if (extern_changed && !new_is_definition
1943      && TREE_CODE (olddecl) == FUNCTION_DECL && DECL_INITIAL (olddecl))
1944    cgraph_finalize_function (olddecl, false);
1945}
1946
1947/* Handle when a new declaration NEWDECL has the same name as an old
1948   one OLDDECL in the same binding contour.  Prints an error message
1949   if appropriate.
1950
1951   If safely possible, alter OLDDECL to look like NEWDECL, and return
1952   true.  Otherwise, return false.  */
1953
1954static bool
1955duplicate_decls (tree newdecl, tree olddecl)
1956{
1957  tree newtype = NULL, oldtype = NULL;
1958
1959  if (!diagnose_mismatched_decls (newdecl, olddecl, &newtype, &oldtype))
1960    {
1961      /* Avoid `unused variable' and other warnings warnings for OLDDECL.  */
1962      TREE_NO_WARNING (olddecl) = 1;
1963      return false;
1964    }
1965
1966  merge_decls (newdecl, olddecl, newtype, oldtype);
1967  return true;
1968}
1969
1970
1971/* Check whether decl-node NEW_DECL shadows an existing declaration.  */
1972static void
1973warn_if_shadowing (tree new_decl)
1974{
1975  struct c_binding *b;
1976
1977  /* Shadow warnings wanted?  */
1978  if (!warn_shadow
1979      /* No shadow warnings for internally generated vars.  */
1980      || DECL_IS_BUILTIN (new_decl)
1981      /* No shadow warnings for vars made for inlining.  */
1982      || DECL_FROM_INLINE (new_decl))
1983    return;
1984
1985  /* Is anything being shadowed?  Invisible decls do not count.  */
1986  for (b = I_SYMBOL_BINDING (DECL_NAME (new_decl)); b; b = b->shadowed)
1987    if (b->decl && b->decl != new_decl && !b->invisible)
1988      {
1989	tree old_decl = b->decl;
1990
1991	if (old_decl == error_mark_node)
1992	  {
1993	    warning (OPT_Wshadow, "declaration of %q+D shadows previous "
1994		     "non-variable", new_decl);
1995	    break;
1996	  }
1997	else if (TREE_CODE (old_decl) == PARM_DECL)
1998	  warning (OPT_Wshadow, "declaration of %q+D shadows a parameter",
1999		   new_decl);
2000	else if (DECL_FILE_SCOPE_P (old_decl))
2001	  warning (OPT_Wshadow, "declaration of %q+D shadows a global "
2002		   "declaration", new_decl);
2003	else if (TREE_CODE (old_decl) == FUNCTION_DECL
2004		 && DECL_BUILT_IN (old_decl))
2005	  {
2006	    warning (OPT_Wshadow, "declaration of %q+D shadows "
2007		     "a built-in function", new_decl);
2008	    break;
2009	  }
2010	else
2011	  warning (OPT_Wshadow, "declaration of %q+D shadows a previous local",
2012		   new_decl);
2013
2014	warning (OPT_Wshadow, "%Jshadowed declaration is here", old_decl);
2015
2016	break;
2017      }
2018}
2019
2020
2021/* Subroutine of pushdecl.
2022
2023   X is a TYPE_DECL for a typedef statement.  Create a brand new
2024   ..._TYPE node (which will be just a variant of the existing
2025   ..._TYPE node with identical properties) and then install X
2026   as the TYPE_NAME of this brand new (duplicate) ..._TYPE node.
2027
2028   The whole point here is to end up with a situation where each
2029   and every ..._TYPE node the compiler creates will be uniquely
2030   associated with AT MOST one node representing a typedef name.
2031   This way, even though the compiler substitutes corresponding
2032   ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
2033   early on, later parts of the compiler can always do the reverse
2034   translation and get back the corresponding typedef name.  For
2035   example, given:
2036
2037	typedef struct S MY_TYPE;
2038	MY_TYPE object;
2039
2040   Later parts of the compiler might only know that `object' was of
2041   type `struct S' if it were not for code just below.  With this
2042   code however, later parts of the compiler see something like:
2043
2044	struct S' == struct S
2045	typedef struct S' MY_TYPE;
2046	struct S' object;
2047
2048    And they can then deduce (from the node for type struct S') that
2049    the original object declaration was:
2050
2051		MY_TYPE object;
2052
2053    Being able to do this is important for proper support of protoize,
2054    and also for generating precise symbolic debugging information
2055    which takes full account of the programmer's (typedef) vocabulary.
2056
2057    Obviously, we don't want to generate a duplicate ..._TYPE node if
2058    the TYPE_DECL node that we are now processing really represents a
2059    standard built-in type.
2060
2061    Since all standard types are effectively declared at line zero
2062    in the source file, we can easily check to see if we are working
2063    on a standard type by checking the current value of lineno.  */
2064
2065static void
2066clone_underlying_type (tree x)
2067{
2068  if (DECL_IS_BUILTIN (x))
2069    {
2070      if (TYPE_NAME (TREE_TYPE (x)) == 0)
2071	TYPE_NAME (TREE_TYPE (x)) = x;
2072    }
2073  else if (TREE_TYPE (x) != error_mark_node
2074	   && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
2075    {
2076      tree tt = TREE_TYPE (x);
2077      DECL_ORIGINAL_TYPE (x) = tt;
2078      tt = build_variant_type_copy (tt);
2079      TYPE_NAME (tt) = x;
2080      TREE_USED (tt) = TREE_USED (x);
2081      TREE_TYPE (x) = tt;
2082    }
2083}
2084
2085/* Record a decl-node X as belonging to the current lexical scope.
2086   Check for errors (such as an incompatible declaration for the same
2087   name already seen in the same scope).
2088
2089   Returns either X or an old decl for the same name.
2090   If an old decl is returned, it may have been smashed
2091   to agree with what X says.  */
2092
2093tree
2094pushdecl (tree x)
2095{
2096  tree name = DECL_NAME (x);
2097  struct c_scope *scope = current_scope;
2098  struct c_binding *b;
2099  bool nested = false;
2100
2101  /* Functions need the lang_decl data.  */
2102  if (TREE_CODE (x) == FUNCTION_DECL && !DECL_LANG_SPECIFIC (x))
2103    DECL_LANG_SPECIFIC (x) = GGC_CNEW (struct lang_decl);
2104
2105  /* Must set DECL_CONTEXT for everything not at file scope or
2106     DECL_FILE_SCOPE_P won't work.  Local externs don't count
2107     unless they have initializers (which generate code).  */
2108  if (current_function_decl
2109      && ((TREE_CODE (x) != FUNCTION_DECL && TREE_CODE (x) != VAR_DECL)
2110	  || DECL_INITIAL (x) || !DECL_EXTERNAL (x)))
2111    DECL_CONTEXT (x) = current_function_decl;
2112
2113  /* If this is of variably modified type, prevent jumping into its
2114     scope.  */
2115  if ((TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == TYPE_DECL)
2116      && variably_modified_type_p (TREE_TYPE (x), NULL_TREE))
2117    c_begin_vm_scope (scope->depth);
2118
2119  /* Anonymous decls are just inserted in the scope.  */
2120  if (!name)
2121    {
2122      bind (name, x, scope, /*invisible=*/false, /*nested=*/false);
2123      return x;
2124    }
2125
2126  /* First, see if there is another declaration with the same name in
2127     the current scope.  If there is, duplicate_decls may do all the
2128     work for us.  If duplicate_decls returns false, that indicates
2129     two incompatible decls in the same scope; we are to silently
2130     replace the old one (duplicate_decls has issued all appropriate
2131     diagnostics).  In particular, we should not consider possible
2132     duplicates in the external scope, or shadowing.  */
2133  b = I_SYMBOL_BINDING (name);
2134  if (b && B_IN_SCOPE (b, scope))
2135    {
2136      struct c_binding *b_ext, *b_use;
2137      tree type = TREE_TYPE (x);
2138      tree visdecl = b->decl;
2139      tree vistype = TREE_TYPE (visdecl);
2140      if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE
2141	  && COMPLETE_TYPE_P (TREE_TYPE (x)))
2142	b->inner_comp = false;
2143      b_use = b;
2144      b_ext = b;
2145      /* If this is an external linkage declaration, we should check
2146	 for compatibility with the type in the external scope before
2147	 setting the type at this scope based on the visible
2148	 information only.  */
2149      if (TREE_PUBLIC (x) && TREE_PUBLIC (visdecl))
2150	{
2151	  while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext))
2152	    b_ext = b_ext->shadowed;
2153	  if (b_ext)
2154	    {
2155	      b_use = b_ext;
2156	      if (b_use->type)
2157		TREE_TYPE (b_use->decl) = b_use->type;
2158	    }
2159	}
2160      if (duplicate_decls (x, b_use->decl))
2161	{
2162	  if (b_use != b)
2163	    {
2164	      /* Save the updated type in the external scope and
2165		 restore the proper type for this scope.  */
2166	      tree thistype;
2167	      if (comptypes (vistype, type))
2168		thistype = composite_type (vistype, type);
2169	      else
2170		thistype = TREE_TYPE (b_use->decl);
2171	      b_use->type = TREE_TYPE (b_use->decl);
2172	      if (TREE_CODE (b_use->decl) == FUNCTION_DECL
2173		  && DECL_BUILT_IN (b_use->decl))
2174		thistype
2175		  = build_type_attribute_variant (thistype,
2176						  TYPE_ATTRIBUTES
2177						  (b_use->type));
2178	      TREE_TYPE (b_use->decl) = thistype;
2179	    }
2180	  return b_use->decl;
2181	}
2182      else
2183	goto skip_external_and_shadow_checks;
2184    }
2185
2186  /* All declarations with external linkage, and all external
2187     references, go in the external scope, no matter what scope is
2188     current.  However, the binding in that scope is ignored for
2189     purposes of normal name lookup.  A separate binding structure is
2190     created in the requested scope; this governs the normal
2191     visibility of the symbol.
2192
2193     The binding in the externals scope is used exclusively for
2194     detecting duplicate declarations of the same object, no matter
2195     what scope they are in; this is what we do here.  (C99 6.2.7p2:
2196     All declarations that refer to the same object or function shall
2197     have compatible type; otherwise, the behavior is undefined.)  */
2198  if (DECL_EXTERNAL (x) || scope == file_scope)
2199    {
2200      tree type = TREE_TYPE (x);
2201      tree vistype = 0;
2202      tree visdecl = 0;
2203      bool type_saved = false;
2204      if (b && !B_IN_EXTERNAL_SCOPE (b)
2205	  && (TREE_CODE (b->decl) == FUNCTION_DECL
2206	      || TREE_CODE (b->decl) == VAR_DECL)
2207	  && DECL_FILE_SCOPE_P (b->decl))
2208	{
2209	  visdecl = b->decl;
2210	  vistype = TREE_TYPE (visdecl);
2211	}
2212      if (scope != file_scope
2213	  && !DECL_IN_SYSTEM_HEADER (x))
2214	warning (OPT_Wnested_externs, "nested extern declaration of %qD", x);
2215
2216      while (b && !B_IN_EXTERNAL_SCOPE (b))
2217	{
2218	  /* If this decl might be modified, save its type.  This is
2219	     done here rather than when the decl is first bound
2220	     because the type may change after first binding, through
2221	     being completed or through attributes being added.  If we
2222	     encounter multiple such decls, only the first should have
2223	     its type saved; the others will already have had their
2224	     proper types saved and the types will not have changed as
2225	     their scopes will not have been re-entered.  */
2226	  if (DECL_P (b->decl) && DECL_FILE_SCOPE_P (b->decl) && !type_saved)
2227	    {
2228	      b->type = TREE_TYPE (b->decl);
2229	      type_saved = true;
2230	    }
2231	  if (B_IN_FILE_SCOPE (b)
2232	      && TREE_CODE (b->decl) == VAR_DECL
2233	      && TREE_STATIC (b->decl)
2234	      && TREE_CODE (TREE_TYPE (b->decl)) == ARRAY_TYPE
2235	      && !TYPE_DOMAIN (TREE_TYPE (b->decl))
2236	      && TREE_CODE (type) == ARRAY_TYPE
2237	      && TYPE_DOMAIN (type)
2238	      && TYPE_MAX_VALUE (TYPE_DOMAIN (type))
2239	      && !integer_zerop (TYPE_MAX_VALUE (TYPE_DOMAIN (type))))
2240	    {
2241	      /* Array type completed in inner scope, which should be
2242		 diagnosed if the completion does not have size 1 and
2243		 it does not get completed in the file scope.  */
2244	      b->inner_comp = true;
2245	    }
2246	  b = b->shadowed;
2247	}
2248
2249      /* If a matching external declaration has been found, set its
2250	 type to the composite of all the types of that declaration.
2251	 After the consistency checks, it will be reset to the
2252	 composite of the visible types only.  */
2253      if (b && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl))
2254	  && b->type)
2255	TREE_TYPE (b->decl) = b->type;
2256
2257      /* The point of the same_translation_unit_p check here is,
2258	 we want to detect a duplicate decl for a construct like
2259	 foo() { extern bar(); } ... static bar();  but not if
2260	 they are in different translation units.  In any case,
2261	 the static does not go in the externals scope.  */
2262      if (b
2263	  && (TREE_PUBLIC (x) || same_translation_unit_p (x, b->decl))
2264	  && duplicate_decls (x, b->decl))
2265	{
2266	  tree thistype;
2267	  if (vistype)
2268	    {
2269	      if (comptypes (vistype, type))
2270		thistype = composite_type (vistype, type);
2271	      else
2272		thistype = TREE_TYPE (b->decl);
2273	    }
2274	  else
2275	    thistype = type;
2276	  b->type = TREE_TYPE (b->decl);
2277	  if (TREE_CODE (b->decl) == FUNCTION_DECL && DECL_BUILT_IN (b->decl))
2278	    thistype
2279	      = build_type_attribute_variant (thistype,
2280					      TYPE_ATTRIBUTES (b->type));
2281	  TREE_TYPE (b->decl) = thistype;
2282	  bind (name, b->decl, scope, /*invisible=*/false, /*nested=*/true);
2283	  return b->decl;
2284	}
2285      else if (TREE_PUBLIC (x))
2286	{
2287	  if (visdecl && !b && duplicate_decls (x, visdecl))
2288	    {
2289	      /* An external declaration at block scope referring to a
2290		 visible entity with internal linkage.  The composite
2291		 type will already be correct for this scope, so we
2292		 just need to fall through to make the declaration in
2293		 this scope.  */
2294	      nested = true;
2295	      x = visdecl;
2296	    }
2297	  else
2298	    {
2299	      bind (name, x, external_scope, /*invisible=*/true,
2300		    /*nested=*/false);
2301	      nested = true;
2302	    }
2303	}
2304    }
2305
2306  if (TREE_CODE (x) != PARM_DECL)
2307    warn_if_shadowing (x);
2308
2309 skip_external_and_shadow_checks:
2310  if (TREE_CODE (x) == TYPE_DECL)
2311    clone_underlying_type (x);
2312
2313  bind (name, x, scope, /*invisible=*/false, nested);
2314
2315  /* If x's type is incomplete because it's based on a
2316     structure or union which has not yet been fully declared,
2317     attach it to that structure or union type, so we can go
2318     back and complete the variable declaration later, if the
2319     structure or union gets fully declared.
2320
2321     If the input is erroneous, we can have error_mark in the type
2322     slot (e.g. "f(void a, ...)") - that doesn't count as an
2323     incomplete type.  */
2324  if (TREE_TYPE (x) != error_mark_node
2325      && !COMPLETE_TYPE_P (TREE_TYPE (x)))
2326    {
2327      tree element = TREE_TYPE (x);
2328
2329      while (TREE_CODE (element) == ARRAY_TYPE)
2330	element = TREE_TYPE (element);
2331      element = TYPE_MAIN_VARIANT (element);
2332
2333      if ((TREE_CODE (element) == RECORD_TYPE
2334	   || TREE_CODE (element) == UNION_TYPE)
2335	  && (TREE_CODE (x) != TYPE_DECL
2336	      || TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE)
2337	  && !COMPLETE_TYPE_P (element))
2338	C_TYPE_INCOMPLETE_VARS (element)
2339	  = tree_cons (NULL_TREE, x, C_TYPE_INCOMPLETE_VARS (element));
2340    }
2341  return x;
2342}
2343
2344/* Record X as belonging to file scope.
2345   This is used only internally by the Objective-C front end,
2346   and is limited to its needs.  duplicate_decls is not called;
2347   if there is any preexisting decl for this identifier, it is an ICE.  */
2348
2349tree
2350pushdecl_top_level (tree x)
2351{
2352  tree name;
2353  bool nested = false;
2354  gcc_assert (TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == CONST_DECL);
2355
2356  name = DECL_NAME (x);
2357
2358 gcc_assert (TREE_CODE (x) == CONST_DECL || !I_SYMBOL_BINDING (name));
2359
2360  if (TREE_PUBLIC (x))
2361    {
2362      bind (name, x, external_scope, /*invisible=*/true, /*nested=*/false);
2363      nested = true;
2364    }
2365  if (file_scope)
2366    bind (name, x, file_scope, /*invisible=*/false, nested);
2367
2368  return x;
2369}
2370
2371static void
2372implicit_decl_warning (tree id, tree olddecl)
2373{
2374  void (*diag) (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2);
2375  switch (mesg_implicit_function_declaration)
2376    {
2377    case 0: return;
2378    case 1: diag = warning0; break;
2379    case 2: diag = error;   break;
2380    default: gcc_unreachable ();
2381    }
2382
2383  diag (G_("implicit declaration of function %qE"), id);
2384  if (olddecl)
2385    locate_old_decl (olddecl, diag);
2386}
2387
2388/* Generate an implicit declaration for identifier FUNCTIONID as a
2389   function of type int ().  */
2390
2391tree
2392implicitly_declare (tree functionid)
2393{
2394  struct c_binding *b;
2395  tree decl = 0;
2396  tree asmspec_tree;
2397
2398  for (b = I_SYMBOL_BINDING (functionid); b; b = b->shadowed)
2399    {
2400      if (B_IN_SCOPE (b, external_scope))
2401	{
2402	  decl = b->decl;
2403	  break;
2404	}
2405    }
2406
2407  if (decl)
2408    {
2409      if (decl == error_mark_node)
2410	return decl;
2411
2412      /* FIXME: Objective-C has weird not-really-builtin functions
2413	 which are supposed to be visible automatically.  They wind up
2414	 in the external scope because they're pushed before the file
2415	 scope gets created.  Catch this here and rebind them into the
2416	 file scope.  */
2417      if (!DECL_BUILT_IN (decl) && DECL_IS_BUILTIN (decl))
2418	{
2419	  bind (functionid, decl, file_scope,
2420		/*invisible=*/false, /*nested=*/true);
2421	  return decl;
2422	}
2423      else
2424	{
2425	  tree newtype = default_function_type;
2426	  if (b->type)
2427	    TREE_TYPE (decl) = b->type;
2428	  /* Implicit declaration of a function already declared
2429	     (somehow) in a different scope, or as a built-in.
2430	     If this is the first time this has happened, warn;
2431	     then recycle the old declaration but with the new type.  */
2432	  if (!C_DECL_IMPLICIT (decl))
2433	    {
2434	      implicit_decl_warning (functionid, decl);
2435	      C_DECL_IMPLICIT (decl) = 1;
2436	    }
2437	  if (DECL_BUILT_IN (decl))
2438	    {
2439	      newtype = build_type_attribute_variant (newtype,
2440						      TYPE_ATTRIBUTES
2441						      (TREE_TYPE (decl)));
2442	      if (!comptypes (newtype, TREE_TYPE (decl)))
2443		{
2444		  warning (0, "incompatible implicit declaration of built-in"
2445			   " function %qD", decl);
2446		  newtype = TREE_TYPE (decl);
2447		}
2448	    }
2449	  else
2450	    {
2451	      if (!comptypes (newtype, TREE_TYPE (decl)))
2452		{
2453		  error ("incompatible implicit declaration of function %qD",
2454			 decl);
2455		  locate_old_decl (decl, error);
2456		}
2457	    }
2458	  b->type = TREE_TYPE (decl);
2459	  TREE_TYPE (decl) = newtype;
2460	  bind (functionid, decl, current_scope,
2461		/*invisible=*/false, /*nested=*/true);
2462	  return decl;
2463	}
2464    }
2465
2466  /* Not seen before.  */
2467  decl = build_decl (FUNCTION_DECL, functionid, default_function_type);
2468  DECL_EXTERNAL (decl) = 1;
2469  TREE_PUBLIC (decl) = 1;
2470  C_DECL_IMPLICIT (decl) = 1;
2471  implicit_decl_warning (functionid, 0);
2472  asmspec_tree = maybe_apply_renaming_pragma (decl, /*asmname=*/NULL);
2473  if (asmspec_tree)
2474    set_user_assembler_name (decl, TREE_STRING_POINTER (asmspec_tree));
2475
2476  /* C89 says implicit declarations are in the innermost block.
2477     So we record the decl in the standard fashion.  */
2478  decl = pushdecl (decl);
2479
2480  /* No need to call objc_check_decl here - it's a function type.  */
2481  rest_of_decl_compilation (decl, 0, 0);
2482
2483  /* Write a record describing this implicit function declaration
2484     to the prototypes file (if requested).  */
2485  gen_aux_info_record (decl, 0, 1, 0);
2486
2487  /* Possibly apply some default attributes to this implicit declaration.  */
2488  decl_attributes (&decl, NULL_TREE, 0);
2489
2490  return decl;
2491}
2492
2493/* Issue an error message for a reference to an undeclared variable
2494   ID, including a reference to a builtin outside of function-call
2495   context.  Establish a binding of the identifier to error_mark_node
2496   in an appropriate scope, which will suppress further errors for the
2497   same identifier.  The error message should be given location LOC.  */
2498void
2499undeclared_variable (tree id, location_t loc)
2500{
2501  static bool already = false;
2502  struct c_scope *scope;
2503
2504  if (current_function_decl == 0)
2505    {
2506      error ("%H%qE undeclared here (not in a function)", &loc, id);
2507      scope = current_scope;
2508    }
2509  else
2510    {
2511      error ("%H%qE undeclared (first use in this function)", &loc, id);
2512
2513      if (!already)
2514	{
2515	  error ("%H(Each undeclared identifier is reported only once", &loc);
2516	  error ("%Hfor each function it appears in.)", &loc);
2517	  already = true;
2518	}
2519
2520      /* If we are parsing old-style parameter decls, current_function_decl
2521	 will be nonnull but current_function_scope will be null.  */
2522      scope = current_function_scope ? current_function_scope : current_scope;
2523    }
2524  bind (id, error_mark_node, scope, /*invisible=*/false, /*nested=*/false);
2525}
2526
2527/* Subroutine of lookup_label, declare_label, define_label: construct a
2528   LABEL_DECL with all the proper frills.  */
2529
2530static tree
2531make_label (tree name, location_t location)
2532{
2533  tree label = build_decl (LABEL_DECL, name, void_type_node);
2534
2535  DECL_CONTEXT (label) = current_function_decl;
2536  DECL_MODE (label) = VOIDmode;
2537  DECL_SOURCE_LOCATION (label) = location;
2538
2539  return label;
2540}
2541
2542/* Get the LABEL_DECL corresponding to identifier NAME as a label.
2543   Create one if none exists so far for the current function.
2544   This is called when a label is used in a goto expression or
2545   has its address taken.  */
2546
2547tree
2548lookup_label (tree name)
2549{
2550  tree label;
2551
2552  if (current_function_decl == 0)
2553    {
2554      error ("label %qE referenced outside of any function", name);
2555      return 0;
2556    }
2557
2558  /* Use a label already defined or ref'd with this name, but not if
2559     it is inherited from a containing function and wasn't declared
2560     using __label__.  */
2561  label = I_LABEL_DECL (name);
2562  if (label && (DECL_CONTEXT (label) == current_function_decl
2563		|| C_DECLARED_LABEL_FLAG (label)))
2564    {
2565      /* If the label has only been declared, update its apparent
2566	 location to point here, for better diagnostics if it
2567	 turns out not to have been defined.  */
2568      if (!TREE_USED (label))
2569	DECL_SOURCE_LOCATION (label) = input_location;
2570      return label;
2571    }
2572
2573  /* No label binding for that identifier; make one.  */
2574  label = make_label (name, input_location);
2575
2576  /* Ordinary labels go in the current function scope.  */
2577  bind (name, label, current_function_scope,
2578	/*invisible=*/false, /*nested=*/false);
2579  return label;
2580}
2581
2582/* Make a label named NAME in the current function, shadowing silently
2583   any that may be inherited from containing functions or containing
2584   scopes.  This is called for __label__ declarations.  */
2585
2586tree
2587declare_label (tree name)
2588{
2589  struct c_binding *b = I_LABEL_BINDING (name);
2590  tree label;
2591
2592  /* Check to make sure that the label hasn't already been declared
2593     at this scope */
2594  if (b && B_IN_CURRENT_SCOPE (b))
2595    {
2596      error ("duplicate label declaration %qE", name);
2597      locate_old_decl (b->decl, error);
2598
2599      /* Just use the previous declaration.  */
2600      return b->decl;
2601    }
2602
2603  label = make_label (name, input_location);
2604  C_DECLARED_LABEL_FLAG (label) = 1;
2605
2606  /* Declared labels go in the current scope.  */
2607  bind (name, label, current_scope,
2608	/*invisible=*/false, /*nested=*/false);
2609  return label;
2610}
2611
2612/* Define a label, specifying the location in the source file.
2613   Return the LABEL_DECL node for the label, if the definition is valid.
2614   Otherwise return 0.  */
2615
2616tree
2617define_label (location_t location, tree name)
2618{
2619  /* Find any preexisting label with this name.  It is an error
2620     if that label has already been defined in this function, or
2621     if there is a containing function with a declared label with
2622     the same name.  */
2623  tree label = I_LABEL_DECL (name);
2624  struct c_label_list *nlist_se, *nlist_vm;
2625
2626  if (label
2627      && ((DECL_CONTEXT (label) == current_function_decl
2628	   && DECL_INITIAL (label) != 0)
2629	  || (DECL_CONTEXT (label) != current_function_decl
2630	      && C_DECLARED_LABEL_FLAG (label))))
2631    {
2632      error ("%Hduplicate label %qD", &location, label);
2633      locate_old_decl (label, error);
2634      return 0;
2635    }
2636  else if (label && DECL_CONTEXT (label) == current_function_decl)
2637    {
2638      /* The label has been used or declared already in this function,
2639	 but not defined.  Update its location to point to this
2640	 definition.  */
2641      if (C_DECL_UNDEFINABLE_STMT_EXPR (label))
2642	error ("%Jjump into statement expression", label);
2643      if (C_DECL_UNDEFINABLE_VM (label))
2644	error ("%Jjump into scope of identifier with variably modified type",
2645	       label);
2646      DECL_SOURCE_LOCATION (label) = location;
2647    }
2648  else
2649    {
2650      /* No label binding for that identifier; make one.  */
2651      label = make_label (name, location);
2652
2653      /* Ordinary labels go in the current function scope.  */
2654      bind (name, label, current_function_scope,
2655	    /*invisible=*/false, /*nested=*/false);
2656    }
2657
2658  if (!in_system_header && lookup_name (name))
2659    warning (OPT_Wtraditional, "%Htraditional C lacks a separate namespace "
2660	     "for labels, identifier %qE conflicts", &location, name);
2661
2662  nlist_se = XOBNEW (&parser_obstack, struct c_label_list);
2663  nlist_se->next = label_context_stack_se->labels_def;
2664  nlist_se->label = label;
2665  label_context_stack_se->labels_def = nlist_se;
2666
2667  nlist_vm = XOBNEW (&parser_obstack, struct c_label_list);
2668  nlist_vm->next = label_context_stack_vm->labels_def;
2669  nlist_vm->label = label;
2670  label_context_stack_vm->labels_def = nlist_vm;
2671
2672  /* Mark label as having been defined.  */
2673  DECL_INITIAL (label) = error_mark_node;
2674  return label;
2675}
2676
2677/* Given NAME, an IDENTIFIER_NODE,
2678   return the structure (or union or enum) definition for that name.
2679   If THISLEVEL_ONLY is nonzero, searches only the current_scope.
2680   CODE says which kind of type the caller wants;
2681   it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE.
2682   If the wrong kind of type is found, an error is reported.  */
2683
2684static tree
2685lookup_tag (enum tree_code code, tree name, int thislevel_only)
2686{
2687  struct c_binding *b = I_TAG_BINDING (name);
2688  int thislevel = 0;
2689
2690  if (!b || !b->decl)
2691    return 0;
2692
2693  /* We only care about whether it's in this level if
2694     thislevel_only was set or it might be a type clash.  */
2695  if (thislevel_only || TREE_CODE (b->decl) != code)
2696    {
2697      /* For our purposes, a tag in the external scope is the same as
2698	 a tag in the file scope.  (Primarily relevant to Objective-C
2699	 and its builtin structure tags, which get pushed before the
2700	 file scope is created.)  */
2701      if (B_IN_CURRENT_SCOPE (b)
2702	  || (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b)))
2703	thislevel = 1;
2704    }
2705
2706  if (thislevel_only && !thislevel)
2707    return 0;
2708
2709  if (TREE_CODE (b->decl) != code)
2710    {
2711      /* Definition isn't the kind we were looking for.  */
2712      pending_invalid_xref = name;
2713      pending_invalid_xref_location = input_location;
2714
2715      /* If in the same binding level as a declaration as a tag
2716	 of a different type, this must not be allowed to
2717	 shadow that tag, so give the error immediately.
2718	 (For example, "struct foo; union foo;" is invalid.)  */
2719      if (thislevel)
2720	pending_xref_error ();
2721    }
2722  return b->decl;
2723}
2724
2725/* Print an error message now
2726   for a recent invalid struct, union or enum cross reference.
2727   We don't print them immediately because they are not invalid
2728   when used in the `struct foo;' construct for shadowing.  */
2729
2730void
2731pending_xref_error (void)
2732{
2733  if (pending_invalid_xref != 0)
2734    error ("%H%qE defined as wrong kind of tag",
2735	   &pending_invalid_xref_location, pending_invalid_xref);
2736  pending_invalid_xref = 0;
2737}
2738
2739
2740/* Look up NAME in the current scope and its superiors
2741   in the namespace of variables, functions and typedefs.
2742   Return a ..._DECL node of some kind representing its definition,
2743   or return 0 if it is undefined.  */
2744
2745tree
2746lookup_name (tree name)
2747{
2748  struct c_binding *b = I_SYMBOL_BINDING (name);
2749  if (b && !b->invisible)
2750    return b->decl;
2751  return 0;
2752}
2753
2754/* Similar to `lookup_name' but look only at the indicated scope.  */
2755
2756static tree
2757lookup_name_in_scope (tree name, struct c_scope *scope)
2758{
2759  struct c_binding *b;
2760
2761  for (b = I_SYMBOL_BINDING (name); b; b = b->shadowed)
2762    if (B_IN_SCOPE (b, scope))
2763      return b->decl;
2764  return 0;
2765}
2766
2767/* Create the predefined scalar types of C,
2768   and some nodes representing standard constants (0, 1, (void *) 0).
2769   Initialize the global scope.
2770   Make definitions for built-in primitive functions.  */
2771
2772void
2773c_init_decl_processing (void)
2774{
2775  location_t save_loc = input_location;
2776
2777  /* Initialize reserved words for parser.  */
2778  c_parse_init ();
2779
2780  current_function_decl = 0;
2781
2782  gcc_obstack_init (&parser_obstack);
2783
2784  /* Make the externals scope.  */
2785  push_scope ();
2786  external_scope = current_scope;
2787
2788  /* Declarations from c_common_nodes_and_builtins must not be associated
2789     with this input file, lest we get differences between using and not
2790     using preprocessed headers.  */
2791#ifdef USE_MAPPED_LOCATION
2792  input_location = BUILTINS_LOCATION;
2793#else
2794  input_location.file = "<built-in>";
2795  input_location.line = 0;
2796#endif
2797
2798  build_common_tree_nodes (flag_signed_char, false);
2799
2800  c_common_nodes_and_builtins ();
2801
2802  /* In C, comparisons and TRUTH_* expressions have type int.  */
2803  truthvalue_type_node = integer_type_node;
2804  truthvalue_true_node = integer_one_node;
2805  truthvalue_false_node = integer_zero_node;
2806
2807  /* Even in C99, which has a real boolean type.  */
2808  pushdecl (build_decl (TYPE_DECL, get_identifier ("_Bool"),
2809			boolean_type_node));
2810
2811  input_location = save_loc;
2812
2813  pedantic_lvalues = true;
2814
2815  make_fname_decl = c_make_fname_decl;
2816  start_fname_decls ();
2817}
2818
2819/* Create the VAR_DECL for __FUNCTION__ etc. ID is the name to give the
2820   decl, NAME is the initialization string and TYPE_DEP indicates whether
2821   NAME depended on the type of the function.  As we don't yet implement
2822   delayed emission of static data, we mark the decl as emitted
2823   so it is not placed in the output.  Anything using it must therefore pull
2824   out the STRING_CST initializer directly.  FIXME.  */
2825
2826static tree
2827c_make_fname_decl (tree id, int type_dep)
2828{
2829  const char *name = fname_as_string (type_dep);
2830  tree decl, type, init;
2831  size_t length = strlen (name);
2832
2833  type = build_array_type (char_type_node,
2834			   build_index_type (size_int (length)));
2835  type = c_build_qualified_type (type, TYPE_QUAL_CONST);
2836
2837  decl = build_decl (VAR_DECL, id, type);
2838
2839  TREE_STATIC (decl) = 1;
2840  TREE_READONLY (decl) = 1;
2841  DECL_ARTIFICIAL (decl) = 1;
2842
2843  init = build_string (length + 1, name);
2844  free ((char *) name);
2845  TREE_TYPE (init) = type;
2846  DECL_INITIAL (decl) = init;
2847
2848  TREE_USED (decl) = 1;
2849
2850  if (current_function_decl
2851      /* For invalid programs like this:
2852
2853         void foo()
2854         const char* p = __FUNCTION__;
2855
2856	 the __FUNCTION__ is believed to appear in K&R style function
2857	 parameter declarator.  In that case we still don't have
2858	 function_scope.  */
2859      && (!errorcount || current_function_scope))
2860    {
2861      DECL_CONTEXT (decl) = current_function_decl;
2862      bind (id, decl, current_function_scope,
2863	    /*invisible=*/false, /*nested=*/false);
2864    }
2865
2866  finish_decl (decl, init, NULL_TREE);
2867
2868  return decl;
2869}
2870
2871/* Return a definition for a builtin function named NAME and whose data type
2872   is TYPE.  TYPE should be a function type with argument types.
2873   FUNCTION_CODE tells later passes how to compile calls to this function.
2874   See tree.h for its possible values.
2875
2876   If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
2877   the name to be called if we can't opencode the function.  If
2878   ATTRS is nonzero, use that for the function's attribute list.  */
2879
2880tree
2881builtin_function (const char *name, tree type, int function_code,
2882		  enum built_in_class cl, const char *library_name,
2883		  tree attrs)
2884{
2885  tree id = get_identifier (name);
2886  tree decl = build_decl (FUNCTION_DECL, id, type);
2887  TREE_PUBLIC (decl) = 1;
2888  DECL_EXTERNAL (decl) = 1;
2889  DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl);
2890  DECL_BUILT_IN_CLASS (decl) = cl;
2891  DECL_FUNCTION_CODE (decl) = function_code;
2892  C_DECL_BUILTIN_PROTOTYPE (decl) = (TYPE_ARG_TYPES (type) != 0);
2893  if (library_name)
2894    SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name));
2895
2896  /* Should never be called on a symbol with a preexisting meaning.  */
2897  gcc_assert (!I_SYMBOL_BINDING (id));
2898
2899  bind (id, decl, external_scope, /*invisible=*/true, /*nested=*/false);
2900
2901  /* Builtins in the implementation namespace are made visible without
2902     needing to be explicitly declared.  See push_file_scope.  */
2903  if (name[0] == '_' && (name[1] == '_' || ISUPPER (name[1])))
2904    {
2905      TREE_CHAIN (decl) = visible_builtins;
2906      visible_builtins = decl;
2907    }
2908
2909  /* Possibly apply some default attributes to this built-in function.  */
2910  if (attrs)
2911    decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
2912  else
2913    decl_attributes (&decl, NULL_TREE, 0);
2914
2915  return decl;
2916}
2917
2918/* Called when a declaration is seen that contains no names to declare.
2919   If its type is a reference to a structure, union or enum inherited
2920   from a containing scope, shadow that tag name for the current scope
2921   with a forward reference.
2922   If its type defines a new named structure or union
2923   or defines an enum, it is valid but we need not do anything here.
2924   Otherwise, it is an error.  */
2925
2926void
2927shadow_tag (const struct c_declspecs *declspecs)
2928{
2929  shadow_tag_warned (declspecs, 0);
2930}
2931
2932/* WARNED is 1 if we have done a pedwarn, 2 if we have done a warning,
2933   but no pedwarn.  */
2934void
2935shadow_tag_warned (const struct c_declspecs *declspecs, int warned)
2936{
2937  bool found_tag = false;
2938
2939  if (declspecs->type && !declspecs->default_int_p && !declspecs->typedef_p)
2940    {
2941      tree value = declspecs->type;
2942      enum tree_code code = TREE_CODE (value);
2943
2944      if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE)
2945	/* Used to test also that TYPE_SIZE (value) != 0.
2946	   That caused warning for `struct foo;' at top level in the file.  */
2947	{
2948	  tree name = TYPE_NAME (value);
2949	  tree t;
2950
2951	  found_tag = true;
2952
2953	  if (name == 0)
2954	    {
2955	      if (warned != 1 && code != ENUMERAL_TYPE)
2956		/* Empty unnamed enum OK */
2957		{
2958		  pedwarn ("unnamed struct/union that defines no instances");
2959		  warned = 1;
2960		}
2961	    }
2962	  else if (!declspecs->tag_defined_p
2963		   && declspecs->storage_class != csc_none)
2964	    {
2965	      if (warned != 1)
2966		pedwarn ("empty declaration with storage class specifier "
2967			 "does not redeclare tag");
2968	      warned = 1;
2969	      pending_xref_error ();
2970	    }
2971	  else if (!declspecs->tag_defined_p
2972		   && (declspecs->const_p
2973		       || declspecs->volatile_p
2974		       || declspecs->restrict_p))
2975	    {
2976	      if (warned != 1)
2977		pedwarn ("empty declaration with type qualifier "
2978			 "does not redeclare tag");
2979	      warned = 1;
2980	      pending_xref_error ();
2981	    }
2982	  else
2983	    {
2984	      pending_invalid_xref = 0;
2985	      t = lookup_tag (code, name, 1);
2986
2987	      if (t == 0)
2988		{
2989		  t = make_node (code);
2990		  pushtag (name, t);
2991		}
2992	    }
2993	}
2994      else
2995	{
2996	  if (warned != 1 && !in_system_header)
2997	    {
2998	      pedwarn ("useless type name in empty declaration");
2999	      warned = 1;
3000	    }
3001	}
3002    }
3003  else if (warned != 1 && !in_system_header && declspecs->typedef_p)
3004    {
3005      pedwarn ("useless type name in empty declaration");
3006      warned = 1;
3007    }
3008
3009  pending_invalid_xref = 0;
3010
3011  if (declspecs->inline_p)
3012    {
3013      error ("%<inline%> in empty declaration");
3014      warned = 1;
3015    }
3016
3017  if (current_scope == file_scope && declspecs->storage_class == csc_auto)
3018    {
3019      error ("%<auto%> in file-scope empty declaration");
3020      warned = 1;
3021    }
3022
3023  if (current_scope == file_scope && declspecs->storage_class == csc_register)
3024    {
3025      error ("%<register%> in file-scope empty declaration");
3026      warned = 1;
3027    }
3028
3029  if (!warned && !in_system_header && declspecs->storage_class != csc_none)
3030    {
3031      warning (0, "useless storage class specifier in empty declaration");
3032      warned = 2;
3033    }
3034
3035  if (!warned && !in_system_header && declspecs->thread_p)
3036    {
3037      warning (0, "useless %<__thread%> in empty declaration");
3038      warned = 2;
3039    }
3040
3041  if (!warned && !in_system_header && (declspecs->const_p
3042				       || declspecs->volatile_p
3043				       || declspecs->restrict_p))
3044    {
3045      warning (0, "useless type qualifier in empty declaration");
3046      warned = 2;
3047    }
3048
3049  if (warned != 1)
3050    {
3051      if (!found_tag)
3052	pedwarn ("empty declaration");
3053    }
3054}
3055
3056
3057/* Return the qualifiers from SPECS as a bitwise OR of TYPE_QUAL_*
3058   bits.  SPECS represents declaration specifiers that the grammar
3059   only permits to contain type qualifiers and attributes.  */
3060
3061int
3062quals_from_declspecs (const struct c_declspecs *specs)
3063{
3064  int quals = ((specs->const_p ? TYPE_QUAL_CONST : 0)
3065	       | (specs->volatile_p ? TYPE_QUAL_VOLATILE : 0)
3066	       | (specs->restrict_p ? TYPE_QUAL_RESTRICT : 0));
3067  gcc_assert (!specs->type
3068	      && !specs->decl_attr
3069	      && specs->typespec_word == cts_none
3070	      && specs->storage_class == csc_none
3071	      && !specs->typedef_p
3072	      && !specs->explicit_signed_p
3073	      && !specs->deprecated_p
3074	      && !specs->long_p
3075	      && !specs->long_long_p
3076	      && !specs->short_p
3077	      && !specs->signed_p
3078	      && !specs->unsigned_p
3079	      && !specs->complex_p
3080	      && !specs->inline_p
3081	      && !specs->thread_p);
3082  return quals;
3083}
3084
3085/* Construct an array declarator.  EXPR is the expression inside [],
3086   or NULL_TREE.  QUALS are the type qualifiers inside the [] (to be
3087   applied to the pointer to which a parameter array is converted).
3088   STATIC_P is true if "static" is inside the [], false otherwise.
3089   VLA_UNSPEC_P is true if the array is [*], a VLA of unspecified
3090   length which is nevertheless a complete type, false otherwise.  The
3091   field for the contained declarator is left to be filled in by
3092   set_array_declarator_inner.  */
3093
3094struct c_declarator *
3095build_array_declarator (tree expr, struct c_declspecs *quals, bool static_p,
3096			bool vla_unspec_p)
3097{
3098  struct c_declarator *declarator = XOBNEW (&parser_obstack,
3099					    struct c_declarator);
3100  declarator->kind = cdk_array;
3101  declarator->declarator = 0;
3102  declarator->u.array.dimen = expr;
3103  if (quals)
3104    {
3105      declarator->u.array.attrs = quals->attrs;
3106      declarator->u.array.quals = quals_from_declspecs (quals);
3107    }
3108  else
3109    {
3110      declarator->u.array.attrs = NULL_TREE;
3111      declarator->u.array.quals = 0;
3112    }
3113  declarator->u.array.static_p = static_p;
3114  declarator->u.array.vla_unspec_p = vla_unspec_p;
3115  if (pedantic && !flag_isoc99)
3116    {
3117      if (static_p || quals != NULL)
3118	pedwarn ("ISO C90 does not support %<static%> or type "
3119		 "qualifiers in parameter array declarators");
3120      if (vla_unspec_p)
3121	pedwarn ("ISO C90 does not support %<[*]%> array declarators");
3122    }
3123  if (vla_unspec_p)
3124    {
3125      if (!current_scope->parm_flag)
3126	{
3127	  /* C99 6.7.5.2p4 */
3128	  error ("%<[*]%> not allowed in other than function prototype scope");
3129	  declarator->u.array.vla_unspec_p = false;
3130	  return NULL;
3131	}
3132      current_scope->had_vla_unspec = true;
3133    }
3134  return declarator;
3135}
3136
3137/* Set the contained declarator of an array declarator.  DECL is the
3138   declarator, as constructed by build_array_declarator; INNER is what
3139   appears on the left of the [].  ABSTRACT_P is true if it is an
3140   abstract declarator, false otherwise; this is used to reject static
3141   and type qualifiers in abstract declarators, where they are not in
3142   the C99 grammar (subject to possible change in DR#289).  */
3143
3144struct c_declarator *
3145set_array_declarator_inner (struct c_declarator *decl,
3146			    struct c_declarator *inner, bool abstract_p)
3147{
3148  decl->declarator = inner;
3149  if (abstract_p && (decl->u.array.quals != TYPE_UNQUALIFIED
3150		     || decl->u.array.attrs != NULL_TREE
3151		     || decl->u.array.static_p))
3152    error ("static or type qualifiers in abstract declarator");
3153  return decl;
3154}
3155
3156/* INIT is a constructor that forms DECL's initializer.  If the final
3157   element initializes a flexible array field, add the size of that
3158   initializer to DECL's size.  */
3159
3160static void
3161add_flexible_array_elts_to_size (tree decl, tree init)
3162{
3163  tree elt, type;
3164
3165  if (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (init)))
3166    return;
3167
3168  elt = VEC_last (constructor_elt, CONSTRUCTOR_ELTS (init))->value;
3169  type = TREE_TYPE (elt);
3170  if (TREE_CODE (type) == ARRAY_TYPE
3171      && TYPE_SIZE (type) == NULL_TREE
3172      && TYPE_DOMAIN (type) != NULL_TREE
3173      && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL_TREE)
3174    {
3175      complete_array_type (&type, elt, false);
3176      DECL_SIZE (decl)
3177	= size_binop (PLUS_EXPR, DECL_SIZE (decl), TYPE_SIZE (type));
3178      DECL_SIZE_UNIT (decl)
3179	= size_binop (PLUS_EXPR, DECL_SIZE_UNIT (decl), TYPE_SIZE_UNIT (type));
3180    }
3181}
3182
3183/* Decode a "typename", such as "int **", returning a ..._TYPE node.  */
3184
3185tree
3186groktypename (struct c_type_name *type_name)
3187{
3188  tree type;
3189  tree attrs = type_name->specs->attrs;
3190
3191  type_name->specs->attrs = NULL_TREE;
3192
3193  type = grokdeclarator (type_name->declarator, type_name->specs, TYPENAME,
3194			 false, NULL);
3195
3196  /* Apply attributes.  */
3197  decl_attributes (&type, attrs, 0);
3198
3199  return type;
3200}
3201
3202/* Decode a declarator in an ordinary declaration or data definition.
3203   This is called as soon as the type information and variable name
3204   have been parsed, before parsing the initializer if any.
3205   Here we create the ..._DECL node, fill in its type,
3206   and put it on the list of decls for the current context.
3207   The ..._DECL node is returned as the value.
3208
3209   Exception: for arrays where the length is not specified,
3210   the type is left null, to be filled in by `finish_decl'.
3211
3212   Function definitions do not come here; they go to start_function
3213   instead.  However, external and forward declarations of functions
3214   do go through here.  Structure field declarations are done by
3215   grokfield and not through here.  */
3216
3217tree
3218start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs,
3219	    bool initialized, tree attributes)
3220{
3221  tree decl;
3222  tree tem;
3223
3224  /* An object declared as __attribute__((deprecated)) suppresses
3225     warnings of uses of other deprecated items.  */
3226  if (lookup_attribute ("deprecated", attributes))
3227    deprecated_state = DEPRECATED_SUPPRESS;
3228
3229  decl = grokdeclarator (declarator, declspecs,
3230			 NORMAL, initialized, NULL);
3231  if (!decl)
3232    return 0;
3233
3234  deprecated_state = DEPRECATED_NORMAL;
3235
3236  if (warn_main > 0 && TREE_CODE (decl) != FUNCTION_DECL
3237      && MAIN_NAME_P (DECL_NAME (decl)))
3238    warning (OPT_Wmain, "%q+D is usually a function", decl);
3239
3240  if (initialized)
3241    /* Is it valid for this decl to have an initializer at all?
3242       If not, set INITIALIZED to zero, which will indirectly
3243       tell 'finish_decl' to ignore the initializer once it is parsed.  */
3244    switch (TREE_CODE (decl))
3245      {
3246      case TYPE_DECL:
3247	error ("typedef %qD is initialized (use __typeof__ instead)", decl);
3248	initialized = 0;
3249	break;
3250
3251      case FUNCTION_DECL:
3252	error ("function %qD is initialized like a variable", decl);
3253	initialized = 0;
3254	break;
3255
3256      case PARM_DECL:
3257	/* DECL_INITIAL in a PARM_DECL is really DECL_ARG_TYPE.  */
3258	error ("parameter %qD is initialized", decl);
3259	initialized = 0;
3260	break;
3261
3262      default:
3263	/* Don't allow initializations for incomplete types except for
3264	   arrays which might be completed by the initialization.  */
3265
3266	/* This can happen if the array size is an undefined macro.
3267	   We already gave a warning, so we don't need another one.  */
3268	if (TREE_TYPE (decl) == error_mark_node)
3269	  initialized = 0;
3270	else if (COMPLETE_TYPE_P (TREE_TYPE (decl)))
3271	  {
3272	    /* A complete type is ok if size is fixed.  */
3273
3274	    if (TREE_CODE (TYPE_SIZE (TREE_TYPE (decl))) != INTEGER_CST
3275		|| C_DECL_VARIABLE_SIZE (decl))
3276	      {
3277		error ("variable-sized object may not be initialized");
3278		initialized = 0;
3279	      }
3280	  }
3281	else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE)
3282	  {
3283	    error ("variable %qD has initializer but incomplete type", decl);
3284	    initialized = 0;
3285	  }
3286	else if (C_DECL_VARIABLE_SIZE (decl))
3287	  {
3288	    /* Although C99 is unclear about whether incomplete arrays
3289	       of VLAs themselves count as VLAs, it does not make
3290	       sense to permit them to be initialized given that
3291	       ordinary VLAs may not be initialized.  */
3292	    error ("variable-sized object may not be initialized");
3293	    initialized = 0;
3294	  }
3295      }
3296
3297  if (initialized)
3298    {
3299      if (current_scope == file_scope)
3300	TREE_STATIC (decl) = 1;
3301
3302      /* Tell 'pushdecl' this is an initialized decl
3303	 even though we don't yet have the initializer expression.
3304	 Also tell 'finish_decl' it may store the real initializer.  */
3305      DECL_INITIAL (decl) = error_mark_node;
3306    }
3307
3308  /* If this is a function declaration, write a record describing it to the
3309     prototypes file (if requested).  */
3310
3311  if (TREE_CODE (decl) == FUNCTION_DECL)
3312    gen_aux_info_record (decl, 0, 0, TYPE_ARG_TYPES (TREE_TYPE (decl)) != 0);
3313
3314  /* ANSI specifies that a tentative definition which is not merged with
3315     a non-tentative definition behaves exactly like a definition with an
3316     initializer equal to zero.  (Section 3.7.2)
3317
3318     -fno-common gives strict ANSI behavior, though this tends to break
3319     a large body of code that grew up without this rule.
3320
3321     Thread-local variables are never common, since there's no entrenched
3322     body of code to break, and it allows more efficient variable references
3323     in the presence of dynamic linking.  */
3324
3325  if (TREE_CODE (decl) == VAR_DECL
3326      && !initialized
3327      && TREE_PUBLIC (decl)
3328      && !DECL_THREAD_LOCAL_P (decl)
3329      && !flag_no_common)
3330    DECL_COMMON (decl) = 1;
3331
3332  /* Set attributes here so if duplicate decl, will have proper attributes.  */
3333  decl_attributes (&decl, attributes, 0);
3334
3335  /* Handle gnu_inline attribute.  */
3336  if (declspecs->inline_p
3337      && !flag_gnu89_inline
3338      && TREE_CODE (decl) == FUNCTION_DECL
3339      && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl)))
3340    {
3341      if (declspecs->storage_class == csc_auto && current_scope != file_scope)
3342	;
3343      else if (declspecs->storage_class != csc_static)
3344	DECL_EXTERNAL (decl) = !DECL_EXTERNAL (decl);
3345    }
3346
3347  if (TREE_CODE (decl) == FUNCTION_DECL
3348      && targetm.calls.promote_prototypes (TREE_TYPE (decl)))
3349    {
3350      struct c_declarator *ce = declarator;
3351
3352      if (ce->kind == cdk_pointer)
3353	ce = declarator->declarator;
3354      if (ce->kind == cdk_function)
3355	{
3356	  tree args = ce->u.arg_info->parms;
3357	  for (; args; args = TREE_CHAIN (args))
3358	    {
3359	      tree type = TREE_TYPE (args);
3360	      if (type && INTEGRAL_TYPE_P (type)
3361		  && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))
3362		DECL_ARG_TYPE (args) = integer_type_node;
3363	    }
3364	}
3365    }
3366
3367  if (TREE_CODE (decl) == FUNCTION_DECL
3368      && DECL_DECLARED_INLINE_P (decl)
3369      && DECL_UNINLINABLE (decl)
3370      && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl)))
3371    warning (OPT_Wattributes, "inline function %q+D given attribute noinline",
3372	     decl);
3373
3374  /* C99 6.7.4p3: An inline definition of a function with external
3375     linkage shall not contain a definition of a modifiable object
3376     with static storage duration...  */
3377  if (TREE_CODE (decl) == VAR_DECL
3378      && current_scope != file_scope
3379      && TREE_STATIC (decl)
3380      && !TREE_READONLY (decl)
3381      && DECL_DECLARED_INLINE_P (current_function_decl)
3382      && DECL_EXTERNAL (current_function_decl))
3383    pedwarn ("%q+D is static but declared in inline function %qD "
3384	     "which is not static", decl, current_function_decl);
3385
3386  /* Add this decl to the current scope.
3387     TEM may equal DECL or it may be a previous decl of the same name.  */
3388  tem = pushdecl (decl);
3389
3390  if (initialized && DECL_EXTERNAL (tem))
3391    {
3392      DECL_EXTERNAL (tem) = 0;
3393      TREE_STATIC (tem) = 1;
3394    }
3395
3396  return tem;
3397}
3398
3399/* Initialize EH if not initialized yet and exceptions are enabled.  */
3400
3401void
3402c_maybe_initialize_eh (void)
3403{
3404  if (!flag_exceptions || c_eh_initialized_p)
3405    return;
3406
3407  c_eh_initialized_p = true;
3408  eh_personality_libfunc
3409    = init_one_libfunc (USING_SJLJ_EXCEPTIONS
3410			? "__gcc_personality_sj0"
3411			: "__gcc_personality_v0");
3412  default_init_unwind_resume_libfunc ();
3413  using_eh_for_cleanups ();
3414}
3415
3416/* Finish processing of a declaration;
3417   install its initial value.
3418   If the length of an array type is not known before,
3419   it must be determined now, from the initial value, or it is an error.  */
3420
3421void
3422finish_decl (tree decl, tree init, tree asmspec_tree)
3423{
3424  tree type;
3425  int was_incomplete = (DECL_SIZE (decl) == 0);
3426  const char *asmspec = 0;
3427
3428  /* If a name was specified, get the string.  */
3429  if ((TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL)
3430      && DECL_FILE_SCOPE_P (decl))
3431    asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree);
3432  if (asmspec_tree)
3433    asmspec = TREE_STRING_POINTER (asmspec_tree);
3434
3435  /* If `start_decl' didn't like having an initialization, ignore it now.  */
3436  if (init != 0 && DECL_INITIAL (decl) == 0)
3437    init = 0;
3438
3439  /* Don't crash if parm is initialized.  */
3440  if (TREE_CODE (decl) == PARM_DECL)
3441    init = 0;
3442
3443  if (init)
3444    store_init_value (decl, init);
3445
3446  if (c_dialect_objc () && (TREE_CODE (decl) == VAR_DECL
3447			    || TREE_CODE (decl) == FUNCTION_DECL
3448			    || TREE_CODE (decl) == FIELD_DECL))
3449    objc_check_decl (decl);
3450
3451  type = TREE_TYPE (decl);
3452
3453  /* Deduce size of array from initialization, if not already known.  */
3454  if (TREE_CODE (type) == ARRAY_TYPE
3455      && TYPE_DOMAIN (type) == 0
3456      && TREE_CODE (decl) != TYPE_DECL)
3457    {
3458      bool do_default
3459	= (TREE_STATIC (decl)
3460	   /* Even if pedantic, an external linkage array
3461	      may have incomplete type at first.  */
3462	   ? pedantic && !TREE_PUBLIC (decl)
3463	   : !DECL_EXTERNAL (decl));
3464      int failure
3465	= complete_array_type (&TREE_TYPE (decl), DECL_INITIAL (decl),
3466			       do_default);
3467
3468      /* Get the completed type made by complete_array_type.  */
3469      type = TREE_TYPE (decl);
3470
3471      switch (failure)
3472	{
3473	case 1:
3474	  error ("initializer fails to determine size of %q+D", decl);
3475	  break;
3476
3477	case 2:
3478	  if (do_default)
3479	    error ("array size missing in %q+D", decl);
3480	  /* If a `static' var's size isn't known,
3481	     make it extern as well as static, so it does not get
3482	     allocated.
3483	     If it is not `static', then do not mark extern;
3484	     finish_incomplete_decl will give it a default size
3485	     and it will get allocated.  */
3486	  else if (!pedantic && TREE_STATIC (decl) && !TREE_PUBLIC (decl))
3487	    DECL_EXTERNAL (decl) = 1;
3488	  break;
3489
3490	case 3:
3491	  error ("zero or negative size array %q+D", decl);
3492	  break;
3493
3494	case 0:
3495	  /* For global variables, update the copy of the type that
3496	     exists in the binding.  */
3497	  if (TREE_PUBLIC (decl))
3498	    {
3499	      struct c_binding *b_ext = I_SYMBOL_BINDING (DECL_NAME (decl));
3500	      while (b_ext && !B_IN_EXTERNAL_SCOPE (b_ext))
3501		b_ext = b_ext->shadowed;
3502	      if (b_ext)
3503		{
3504		  if (b_ext->type)
3505		    b_ext->type = composite_type (b_ext->type, type);
3506		  else
3507		    b_ext->type = type;
3508		}
3509	    }
3510	  break;
3511
3512	default:
3513	  gcc_unreachable ();
3514	}
3515
3516      if (DECL_INITIAL (decl))
3517	TREE_TYPE (DECL_INITIAL (decl)) = type;
3518
3519      layout_decl (decl, 0);
3520    }
3521
3522  if (TREE_CODE (decl) == VAR_DECL)
3523    {
3524      if (init && TREE_CODE (init) == CONSTRUCTOR)
3525	add_flexible_array_elts_to_size (decl, init);
3526
3527      if (DECL_SIZE (decl) == 0 && TREE_TYPE (decl) != error_mark_node
3528	  && COMPLETE_TYPE_P (TREE_TYPE (decl)))
3529	layout_decl (decl, 0);
3530
3531      if (DECL_SIZE (decl) == 0
3532	  /* Don't give an error if we already gave one earlier.  */
3533	  && TREE_TYPE (decl) != error_mark_node
3534	  && (TREE_STATIC (decl)
3535	      /* A static variable with an incomplete type
3536		 is an error if it is initialized.
3537		 Also if it is not file scope.
3538		 Otherwise, let it through, but if it is not `extern'
3539		 then it may cause an error message later.  */
3540	      ? (DECL_INITIAL (decl) != 0
3541		 || !DECL_FILE_SCOPE_P (decl))
3542	      /* An automatic variable with an incomplete type
3543		 is an error.  */
3544	      : !DECL_EXTERNAL (decl)))
3545	 {
3546	   error ("storage size of %q+D isn%'t known", decl);
3547	   TREE_TYPE (decl) = error_mark_node;
3548	 }
3549
3550      if ((DECL_EXTERNAL (decl) || TREE_STATIC (decl))
3551	  && DECL_SIZE (decl) != 0)
3552	{
3553	  if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3554	    constant_expression_warning (DECL_SIZE (decl));
3555	  else
3556	    error ("storage size of %q+D isn%'t constant", decl);
3557	}
3558
3559      if (TREE_USED (type))
3560	TREE_USED (decl) = 1;
3561    }
3562
3563  /* If this is a function and an assembler name is specified, reset DECL_RTL
3564     so we can give it its new name.  Also, update built_in_decls if it
3565     was a normal built-in.  */
3566  if (TREE_CODE (decl) == FUNCTION_DECL && asmspec)
3567    {
3568      if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
3569	set_builtin_user_assembler_name (decl, asmspec);
3570      set_user_assembler_name (decl, asmspec);
3571    }
3572
3573  /* If #pragma weak was used, mark the decl weak now.  */
3574  maybe_apply_pragma_weak (decl);
3575
3576  /* Output the assembler code and/or RTL code for variables and functions,
3577     unless the type is an undefined structure or union.
3578     If not, it will get done when the type is completed.  */
3579
3580  if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL)
3581    {
3582      /* Determine the ELF visibility.  */
3583      if (TREE_PUBLIC (decl))
3584	c_determine_visibility (decl);
3585
3586      /* This is a no-op in c-lang.c or something real in objc-act.c.  */
3587      if (c_dialect_objc ())
3588	objc_check_decl (decl);
3589
3590      if (asmspec)
3591	{
3592	  /* If this is not a static variable, issue a warning.
3593	     It doesn't make any sense to give an ASMSPEC for an
3594	     ordinary, non-register local variable.  Historically,
3595	     GCC has accepted -- but ignored -- the ASMSPEC in
3596	     this case.  */
3597	  if (!DECL_FILE_SCOPE_P (decl)
3598	      && TREE_CODE (decl) == VAR_DECL
3599	      && !C_DECL_REGISTER (decl)
3600	      && !TREE_STATIC (decl))
3601	    warning (0, "ignoring asm-specifier for non-static local "
3602		     "variable %q+D", decl);
3603	  else
3604	    set_user_assembler_name (decl, asmspec);
3605	}
3606
3607      if (DECL_FILE_SCOPE_P (decl))
3608	{
3609	  if (DECL_INITIAL (decl) == NULL_TREE
3610	      || DECL_INITIAL (decl) == error_mark_node)
3611	    /* Don't output anything
3612	       when a tentative file-scope definition is seen.
3613	       But at end of compilation, do output code for them.  */
3614	    DECL_DEFER_OUTPUT (decl) = 1;
3615	  rest_of_decl_compilation (decl, true, 0);
3616	}
3617      else
3618	{
3619	  /* In conjunction with an ASMSPEC, the `register'
3620	     keyword indicates that we should place the variable
3621	     in a particular register.  */
3622	  if (asmspec && C_DECL_REGISTER (decl))
3623	    {
3624	      DECL_HARD_REGISTER (decl) = 1;
3625	      /* This cannot be done for a structure with volatile
3626		 fields, on which DECL_REGISTER will have been
3627		 reset.  */
3628	      if (!DECL_REGISTER (decl))
3629		error ("cannot put object with volatile field into register");
3630	    }
3631
3632	  if (TREE_CODE (decl) != FUNCTION_DECL)
3633	    {
3634	      /* If we're building a variable sized type, and we might be
3635		 reachable other than via the top of the current binding
3636		 level, then create a new BIND_EXPR so that we deallocate
3637		 the object at the right time.  */
3638	      /* Note that DECL_SIZE can be null due to errors.  */
3639	      if (DECL_SIZE (decl)
3640		  && !TREE_CONSTANT (DECL_SIZE (decl))
3641		  && STATEMENT_LIST_HAS_LABEL (cur_stmt_list))
3642		{
3643		  tree bind;
3644		  bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
3645		  TREE_SIDE_EFFECTS (bind) = 1;
3646		  add_stmt (bind);
3647		  BIND_EXPR_BODY (bind) = push_stmt_list ();
3648		}
3649	      add_stmt (build_stmt (DECL_EXPR, decl));
3650	    }
3651	}
3652
3653
3654      if (!DECL_FILE_SCOPE_P (decl))
3655	{
3656	  /* Recompute the RTL of a local array now
3657	     if it used to be an incomplete type.  */
3658	  if (was_incomplete
3659	      && !TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
3660	    {
3661	      /* If we used it already as memory, it must stay in memory.  */
3662	      TREE_ADDRESSABLE (decl) = TREE_USED (decl);
3663	      /* If it's still incomplete now, no init will save it.  */
3664	      if (DECL_SIZE (decl) == 0)
3665		DECL_INITIAL (decl) = 0;
3666	    }
3667	}
3668    }
3669
3670  /* If this was marked 'used', be sure it will be output.  */
3671  if (!flag_unit_at_a_time && lookup_attribute ("used", DECL_ATTRIBUTES (decl)))
3672    mark_decl_referenced (decl);
3673
3674  if (TREE_CODE (decl) == TYPE_DECL)
3675    {
3676      if (!DECL_FILE_SCOPE_P (decl)
3677	  && variably_modified_type_p (TREE_TYPE (decl), NULL_TREE))
3678	add_stmt (build_stmt (DECL_EXPR, decl));
3679
3680      rest_of_decl_compilation (decl, DECL_FILE_SCOPE_P (decl), 0);
3681    }
3682
3683  /* At the end of a declaration, throw away any variable type sizes
3684     of types defined inside that declaration.  There is no use
3685     computing them in the following function definition.  */
3686  if (current_scope == file_scope)
3687    get_pending_sizes ();
3688
3689  /* Install a cleanup (aka destructor) if one was given.  */
3690  if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
3691    {
3692      tree attr = lookup_attribute ("cleanup", DECL_ATTRIBUTES (decl));
3693      if (attr)
3694	{
3695	  tree cleanup_id = TREE_VALUE (TREE_VALUE (attr));
3696	  tree cleanup_decl = lookup_name (cleanup_id);
3697	  tree cleanup;
3698
3699	  /* Build "cleanup(&decl)" for the destructor.  */
3700	  cleanup = build_unary_op (ADDR_EXPR, decl, 0);
3701	  cleanup = build_tree_list (NULL_TREE, cleanup);
3702	  cleanup = build_function_call (cleanup_decl, cleanup);
3703
3704	  /* Don't warn about decl unused; the cleanup uses it.  */
3705	  TREE_USED (decl) = 1;
3706	  TREE_USED (cleanup_decl) = 1;
3707
3708	  /* Initialize EH, if we've been told to do so.  */
3709	  c_maybe_initialize_eh ();
3710
3711	  push_cleanup (decl, cleanup, false);
3712	}
3713    }
3714}
3715
3716/* Given a parsed parameter declaration, decode it into a PARM_DECL.  */
3717
3718tree
3719grokparm (const struct c_parm *parm)
3720{
3721  tree decl = grokdeclarator (parm->declarator, parm->specs, PARM, false,
3722			      NULL);
3723
3724  decl_attributes (&decl, parm->attrs, 0);
3725
3726  return decl;
3727}
3728
3729/* Given a parsed parameter declaration, decode it into a PARM_DECL
3730   and push that on the current scope.  */
3731
3732void
3733push_parm_decl (const struct c_parm *parm)
3734{
3735  tree decl;
3736
3737  decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, NULL);
3738  decl_attributes (&decl, parm->attrs, 0);
3739
3740  decl = pushdecl (decl);
3741
3742  finish_decl (decl, NULL_TREE, NULL_TREE);
3743}
3744
3745/* Mark all the parameter declarations to date as forward decls.
3746   Also diagnose use of this extension.  */
3747
3748void
3749mark_forward_parm_decls (void)
3750{
3751  struct c_binding *b;
3752
3753  if (pedantic && !current_scope->warned_forward_parm_decls)
3754    {
3755      pedwarn ("ISO C forbids forward parameter declarations");
3756      current_scope->warned_forward_parm_decls = true;
3757    }
3758
3759  for (b = current_scope->bindings; b; b = b->prev)
3760    if (TREE_CODE (b->decl) == PARM_DECL)
3761      TREE_ASM_WRITTEN (b->decl) = 1;
3762}
3763
3764/* Build a COMPOUND_LITERAL_EXPR.  TYPE is the type given in the compound
3765   literal, which may be an incomplete array type completed by the
3766   initializer; INIT is a CONSTRUCTOR that initializes the compound
3767   literal.  */
3768
3769tree
3770build_compound_literal (tree type, tree init)
3771{
3772  /* We do not use start_decl here because we have a type, not a declarator;
3773     and do not use finish_decl because the decl should be stored inside
3774     the COMPOUND_LITERAL_EXPR rather than added elsewhere as a DECL_EXPR.  */
3775  tree decl;
3776  tree complit;
3777  tree stmt;
3778
3779  if (type == error_mark_node)
3780    return error_mark_node;
3781
3782  decl = build_decl (VAR_DECL, NULL_TREE, type);
3783  DECL_EXTERNAL (decl) = 0;
3784  TREE_PUBLIC (decl) = 0;
3785  TREE_STATIC (decl) = (current_scope == file_scope);
3786  DECL_CONTEXT (decl) = current_function_decl;
3787  TREE_USED (decl) = 1;
3788  TREE_TYPE (decl) = type;
3789  TREE_READONLY (decl) = TYPE_READONLY (type);
3790  store_init_value (decl, init);
3791
3792  if (TREE_CODE (type) == ARRAY_TYPE && !COMPLETE_TYPE_P (type))
3793    {
3794      int failure = complete_array_type (&TREE_TYPE (decl),
3795					 DECL_INITIAL (decl), true);
3796      gcc_assert (!failure);
3797
3798      type = TREE_TYPE (decl);
3799      TREE_TYPE (DECL_INITIAL (decl)) = type;
3800    }
3801
3802  if (type == error_mark_node || !COMPLETE_TYPE_P (type))
3803    return error_mark_node;
3804
3805  stmt = build_stmt (DECL_EXPR, decl);
3806  complit = build1 (COMPOUND_LITERAL_EXPR, type, stmt);
3807  TREE_SIDE_EFFECTS (complit) = 1;
3808
3809  layout_decl (decl, 0);
3810
3811  if (TREE_STATIC (decl))
3812    {
3813      /* This decl needs a name for the assembler output.  */
3814      set_compound_literal_name (decl);
3815      DECL_DEFER_OUTPUT (decl) = 1;
3816      DECL_COMDAT (decl) = 1;
3817      DECL_ARTIFICIAL (decl) = 1;
3818      DECL_IGNORED_P (decl) = 1;
3819      pushdecl (decl);
3820      rest_of_decl_compilation (decl, 1, 0);
3821    }
3822
3823  return complit;
3824}
3825
3826/* Determine whether TYPE is a structure with a flexible array member,
3827   or a union containing such a structure (possibly recursively).  */
3828
3829static bool
3830flexible_array_type_p (tree type)
3831{
3832  tree x;
3833  switch (TREE_CODE (type))
3834    {
3835    case RECORD_TYPE:
3836      x = TYPE_FIELDS (type);
3837      if (x == NULL_TREE)
3838	return false;
3839      while (TREE_CHAIN (x) != NULL_TREE)
3840	x = TREE_CHAIN (x);
3841      if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE
3842	  && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE
3843	  && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE
3844	  && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE)
3845	return true;
3846      return false;
3847    case UNION_TYPE:
3848      for (x = TYPE_FIELDS (type); x != NULL_TREE; x = TREE_CHAIN (x))
3849	{
3850	  if (flexible_array_type_p (TREE_TYPE (x)))
3851	    return true;
3852	}
3853      return false;
3854    default:
3855    return false;
3856  }
3857}
3858
3859/* Performs sanity checks on the TYPE and WIDTH of the bit-field NAME,
3860   replacing with appropriate values if they are invalid.  */
3861static void
3862check_bitfield_type_and_width (tree *type, tree *width, const char *orig_name)
3863{
3864  tree type_mv;
3865  unsigned int max_width;
3866  unsigned HOST_WIDE_INT w;
3867  const char *name = orig_name ? orig_name: _("<anonymous>");
3868
3869  /* Detect and ignore out of range field width and process valid
3870     field widths.  */
3871  if (!INTEGRAL_TYPE_P (TREE_TYPE (*width))
3872      || TREE_CODE (*width) != INTEGER_CST)
3873    {
3874      error ("bit-field %qs width not an integer constant", name);
3875      *width = integer_one_node;
3876    }
3877  else
3878    {
3879      constant_expression_warning (*width);
3880      if (tree_int_cst_sgn (*width) < 0)
3881	{
3882	  error ("negative width in bit-field %qs", name);
3883	  *width = integer_one_node;
3884	}
3885      else if (integer_zerop (*width) && orig_name)
3886	{
3887	  error ("zero width for bit-field %qs", name);
3888	  *width = integer_one_node;
3889	}
3890    }
3891
3892  /* Detect invalid bit-field type.  */
3893  if (TREE_CODE (*type) != INTEGER_TYPE
3894      && TREE_CODE (*type) != BOOLEAN_TYPE
3895      && TREE_CODE (*type) != ENUMERAL_TYPE)
3896    {
3897      error ("bit-field %qs has invalid type", name);
3898      *type = unsigned_type_node;
3899    }
3900
3901  type_mv = TYPE_MAIN_VARIANT (*type);
3902  if (pedantic
3903      && !in_system_header
3904      && type_mv != integer_type_node
3905      && type_mv != unsigned_type_node
3906      && type_mv != boolean_type_node)
3907    pedwarn ("type of bit-field %qs is a GCC extension", name);
3908
3909  if (type_mv == boolean_type_node)
3910    max_width = CHAR_TYPE_SIZE;
3911  else
3912    max_width = TYPE_PRECISION (*type);
3913
3914  if (0 < compare_tree_int (*width, max_width))
3915    {
3916      error ("width of %qs exceeds its type", name);
3917      w = max_width;
3918      *width = build_int_cst (NULL_TREE, w);
3919    }
3920  else
3921    w = tree_low_cst (*width, 1);
3922
3923  if (TREE_CODE (*type) == ENUMERAL_TYPE)
3924    {
3925      struct lang_type *lt = TYPE_LANG_SPECIFIC (*type);
3926      if (!lt
3927	  || w < min_precision (lt->enum_min, TYPE_UNSIGNED (*type))
3928	  || w < min_precision (lt->enum_max, TYPE_UNSIGNED (*type)))
3929	warning (0, "%qs is narrower than values of its type", name);
3930    }
3931}
3932
3933
3934/* Given declspecs and a declarator,
3935   determine the name and type of the object declared
3936   and construct a ..._DECL node for it.
3937   (In one case we can return a ..._TYPE node instead.
3938    For invalid input we sometimes return 0.)
3939
3940   DECLSPECS is a c_declspecs structure for the declaration specifiers.
3941
3942   DECL_CONTEXT says which syntactic context this declaration is in:
3943     NORMAL for most contexts.  Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL.
3944     FUNCDEF for a function definition.  Like NORMAL but a few different
3945      error messages in each case.  Return value may be zero meaning
3946      this definition is too screwy to try to parse.
3947     PARM for a parameter declaration (either within a function prototype
3948      or before a function body).  Make a PARM_DECL, or return void_type_node.
3949     TYPENAME if for a typename (in a cast or sizeof).
3950      Don't make a DECL node; just return the ..._TYPE node.
3951     FIELD for a struct or union field; make a FIELD_DECL.
3952   INITIALIZED is true if the decl has an initializer.
3953   WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node
3954   representing the width of the bit-field.
3955
3956   In the TYPENAME case, DECLARATOR is really an absolute declarator.
3957   It may also be so in the PARM case, for a prototype where the
3958   argument type is specified but not the name.
3959
3960   This function is where the complicated C meanings of `static'
3961   and `extern' are interpreted.  */
3962
3963static tree
3964grokdeclarator (const struct c_declarator *declarator,
3965		struct c_declspecs *declspecs,
3966		enum decl_context decl_context, bool initialized, tree *width)
3967{
3968  tree type = declspecs->type;
3969  bool threadp = declspecs->thread_p;
3970  enum c_storage_class storage_class = declspecs->storage_class;
3971  int constp;
3972  int restrictp;
3973  int volatilep;
3974  int type_quals = TYPE_UNQUALIFIED;
3975  const char *name, *orig_name;
3976  tree typedef_type = 0;
3977  bool funcdef_flag = false;
3978  bool funcdef_syntax = false;
3979  int size_varies = 0;
3980  tree decl_attr = declspecs->decl_attr;
3981  int array_ptr_quals = TYPE_UNQUALIFIED;
3982  tree array_ptr_attrs = NULL_TREE;
3983  int array_parm_static = 0;
3984  bool array_parm_vla_unspec_p = false;
3985  tree returned_attrs = NULL_TREE;
3986  bool bitfield = width != NULL;
3987  tree element_type;
3988  struct c_arg_info *arg_info = 0;
3989
3990  if (decl_context == FUNCDEF)
3991    funcdef_flag = true, decl_context = NORMAL;
3992
3993  /* Look inside a declarator for the name being declared
3994     and get it as a string, for an error message.  */
3995  {
3996    const struct c_declarator *decl = declarator;
3997    name = 0;
3998
3999    while (decl)
4000      switch (decl->kind)
4001	{
4002	case cdk_function:
4003	case cdk_array:
4004	case cdk_pointer:
4005	  funcdef_syntax = (decl->kind == cdk_function);
4006	  decl = decl->declarator;
4007	  break;
4008
4009	case cdk_attrs:
4010	  decl = decl->declarator;
4011	  break;
4012
4013	case cdk_id:
4014	  if (decl->u.id)
4015	    name = IDENTIFIER_POINTER (decl->u.id);
4016	  decl = 0;
4017	  break;
4018
4019	default:
4020	  gcc_unreachable ();
4021	}
4022    orig_name = name;
4023    if (name == 0)
4024      name = "type name";
4025  }
4026
4027  /* A function definition's declarator must have the form of
4028     a function declarator.  */
4029
4030  if (funcdef_flag && !funcdef_syntax)
4031    return 0;
4032
4033  /* If this looks like a function definition, make it one,
4034     even if it occurs where parms are expected.
4035     Then store_parm_decls will reject it and not use it as a parm.  */
4036  if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag)
4037    decl_context = PARM;
4038
4039  if (declspecs->deprecated_p && deprecated_state != DEPRECATED_SUPPRESS)
4040    warn_deprecated_use (declspecs->type);
4041
4042  if ((decl_context == NORMAL || decl_context == FIELD)
4043      && current_scope == file_scope
4044      && variably_modified_type_p (type, NULL_TREE))
4045    {
4046      error ("variably modified %qs at file scope", name);
4047      type = integer_type_node;
4048    }
4049
4050  typedef_type = type;
4051  size_varies = C_TYPE_VARIABLE_SIZE (type);
4052
4053  /* Diagnose defaulting to "int".  */
4054
4055  if (declspecs->default_int_p && !in_system_header)
4056    {
4057      /* Issue a warning if this is an ISO C 99 program or if
4058	 -Wreturn-type and this is a function, or if -Wimplicit;
4059	 prefer the former warning since it is more explicit.  */
4060      if ((warn_implicit_int || warn_return_type || flag_isoc99)
4061	  && funcdef_flag)
4062	warn_about_return_type = 1;
4063      else if (warn_implicit_int || flag_isoc99)
4064	pedwarn_c99 ("type defaults to %<int%> in declaration of %qs", name);
4065    }
4066
4067  /* Adjust the type if a bit-field is being declared,
4068     -funsigned-bitfields applied and the type is not explicitly
4069     "signed".  */
4070  if (bitfield && !flag_signed_bitfields && !declspecs->explicit_signed_p
4071      && TREE_CODE (type) == INTEGER_TYPE)
4072    type = c_common_unsigned_type (type);
4073
4074  /* Figure out the type qualifiers for the declaration.  There are
4075     two ways a declaration can become qualified.  One is something
4076     like `const int i' where the `const' is explicit.  Another is
4077     something like `typedef const int CI; CI i' where the type of the
4078     declaration contains the `const'.  A third possibility is that
4079     there is a type qualifier on the element type of a typedefed
4080     array type, in which case we should extract that qualifier so
4081     that c_apply_type_quals_to_decls receives the full list of
4082     qualifiers to work with (C90 is not entirely clear about whether
4083     duplicate qualifiers should be diagnosed in this case, but it
4084     seems most appropriate to do so).  */
4085  element_type = strip_array_types (type);
4086  constp = declspecs->const_p + TYPE_READONLY (element_type);
4087  restrictp = declspecs->restrict_p + TYPE_RESTRICT (element_type);
4088  volatilep = declspecs->volatile_p + TYPE_VOLATILE (element_type);
4089  if (pedantic && !flag_isoc99)
4090    {
4091      if (constp > 1)
4092	pedwarn ("duplicate %<const%>");
4093      if (restrictp > 1)
4094	pedwarn ("duplicate %<restrict%>");
4095      if (volatilep > 1)
4096	pedwarn ("duplicate %<volatile%>");
4097    }
4098  if (!flag_gen_aux_info && (TYPE_QUALS (element_type)))
4099    type = TYPE_MAIN_VARIANT (type);
4100  type_quals = ((constp ? TYPE_QUAL_CONST : 0)
4101		| (restrictp ? TYPE_QUAL_RESTRICT : 0)
4102		| (volatilep ? TYPE_QUAL_VOLATILE : 0));
4103
4104  /* Warn about storage classes that are invalid for certain
4105     kinds of declarations (parameters, typenames, etc.).  */
4106
4107  if (funcdef_flag
4108      && (threadp
4109	  || storage_class == csc_auto
4110	  || storage_class == csc_register
4111	  || storage_class == csc_typedef))
4112    {
4113      if (storage_class == csc_auto
4114	  && (pedantic || current_scope == file_scope))
4115	pedwarn ("function definition declared %<auto%>");
4116      if (storage_class == csc_register)
4117	error ("function definition declared %<register%>");
4118      if (storage_class == csc_typedef)
4119	error ("function definition declared %<typedef%>");
4120      if (threadp)
4121	error ("function definition declared %<__thread%>");
4122      threadp = false;
4123      if (storage_class == csc_auto
4124	  || storage_class == csc_register
4125	  || storage_class == csc_typedef)
4126	storage_class = csc_none;
4127    }
4128  else if (decl_context != NORMAL && (storage_class != csc_none || threadp))
4129    {
4130      if (decl_context == PARM && storage_class == csc_register)
4131	;
4132      else
4133	{
4134	  switch (decl_context)
4135	    {
4136	    case FIELD:
4137	      error ("storage class specified for structure field %qs",
4138		     name);
4139	      break;
4140	    case PARM:
4141	      error ("storage class specified for parameter %qs", name);
4142	      break;
4143	    default:
4144	      error ("storage class specified for typename");
4145	      break;
4146	    }
4147	  storage_class = csc_none;
4148	  threadp = false;
4149	}
4150    }
4151  else if (storage_class == csc_extern
4152	   && initialized
4153	   && !funcdef_flag)
4154    {
4155      /* 'extern' with initialization is invalid if not at file scope.  */
4156       if (current_scope == file_scope)
4157         {
4158           /* It is fine to have 'extern const' when compiling at C
4159              and C++ intersection.  */
4160           if (!(warn_cxx_compat && constp))
4161             warning (0, "%qs initialized and declared %<extern%>", name);
4162         }
4163      else
4164	error ("%qs has both %<extern%> and initializer", name);
4165    }
4166  else if (current_scope == file_scope)
4167    {
4168      if (storage_class == csc_auto)
4169	error ("file-scope declaration of %qs specifies %<auto%>", name);
4170      if (pedantic && storage_class == csc_register)
4171	pedwarn ("file-scope declaration of %qs specifies %<register%>", name);
4172    }
4173  else
4174    {
4175      if (storage_class == csc_extern && funcdef_flag)
4176	error ("nested function %qs declared %<extern%>", name);
4177      else if (threadp && storage_class == csc_none)
4178	{
4179	  error ("function-scope %qs implicitly auto and declared "
4180		 "%<__thread%>",
4181		 name);
4182	  threadp = false;
4183	}
4184    }
4185
4186  /* Now figure out the structure of the declarator proper.
4187     Descend through it, creating more complex types, until we reach
4188     the declared identifier (or NULL_TREE, in an absolute declarator).
4189     At each stage we maintain an unqualified version of the type
4190     together with any qualifiers that should be applied to it with
4191     c_build_qualified_type; this way, array types including
4192     multidimensional array types are first built up in unqualified
4193     form and then the qualified form is created with
4194     TYPE_MAIN_VARIANT pointing to the unqualified form.  */
4195
4196  while (declarator && declarator->kind != cdk_id)
4197    {
4198      if (type == error_mark_node)
4199	{
4200	  declarator = declarator->declarator;
4201	  continue;
4202	}
4203
4204      /* Each level of DECLARATOR is either a cdk_array (for ...[..]),
4205	 a cdk_pointer (for *...),
4206	 a cdk_function (for ...(...)),
4207	 a cdk_attrs (for nested attributes),
4208	 or a cdk_id (for the name being declared
4209	 or the place in an absolute declarator
4210	 where the name was omitted).
4211	 For the last case, we have just exited the loop.
4212
4213	 At this point, TYPE is the type of elements of an array,
4214	 or for a function to return, or for a pointer to point to.
4215	 After this sequence of ifs, TYPE is the type of the
4216	 array or function or pointer, and DECLARATOR has had its
4217	 outermost layer removed.  */
4218
4219      if (array_ptr_quals != TYPE_UNQUALIFIED
4220	  || array_ptr_attrs != NULL_TREE
4221	  || array_parm_static)
4222	{
4223	  /* Only the innermost declarator (making a parameter be of
4224	     array type which is converted to pointer type)
4225	     may have static or type qualifiers.  */
4226	  error ("static or type qualifiers in non-parameter array declarator");
4227	  array_ptr_quals = TYPE_UNQUALIFIED;
4228	  array_ptr_attrs = NULL_TREE;
4229	  array_parm_static = 0;
4230	}
4231
4232      switch (declarator->kind)
4233	{
4234	case cdk_attrs:
4235	  {
4236	    /* A declarator with embedded attributes.  */
4237	    tree attrs = declarator->u.attrs;
4238	    const struct c_declarator *inner_decl;
4239	    int attr_flags = 0;
4240	    declarator = declarator->declarator;
4241	    inner_decl = declarator;
4242	    while (inner_decl->kind == cdk_attrs)
4243	      inner_decl = inner_decl->declarator;
4244	    if (inner_decl->kind == cdk_id)
4245	      attr_flags |= (int) ATTR_FLAG_DECL_NEXT;
4246	    else if (inner_decl->kind == cdk_function)
4247	      attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT;
4248	    else if (inner_decl->kind == cdk_array)
4249	      attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT;
4250	    returned_attrs = decl_attributes (&type,
4251					      chainon (returned_attrs, attrs),
4252					      attr_flags);
4253	    break;
4254	  }
4255	case cdk_array:
4256	  {
4257	    tree itype = NULL_TREE;
4258	    tree size = declarator->u.array.dimen;
4259	    /* The index is a signed object `sizetype' bits wide.  */
4260	    tree index_type = c_common_signed_type (sizetype);
4261
4262	    array_ptr_quals = declarator->u.array.quals;
4263	    array_ptr_attrs = declarator->u.array.attrs;
4264	    array_parm_static = declarator->u.array.static_p;
4265	    array_parm_vla_unspec_p = declarator->u.array.vla_unspec_p;
4266
4267	    declarator = declarator->declarator;
4268
4269	    /* Check for some types that there cannot be arrays of.  */
4270
4271	    if (VOID_TYPE_P (type))
4272	      {
4273		error ("declaration of %qs as array of voids", name);
4274		type = error_mark_node;
4275	      }
4276
4277	    if (TREE_CODE (type) == FUNCTION_TYPE)
4278	      {
4279		error ("declaration of %qs as array of functions", name);
4280		type = error_mark_node;
4281	      }
4282
4283	    if (pedantic && !in_system_header && flexible_array_type_p (type))
4284	      pedwarn ("invalid use of structure with flexible array member");
4285
4286	    if (size == error_mark_node)
4287	      type = error_mark_node;
4288
4289	    if (type == error_mark_node)
4290	      continue;
4291
4292	    /* If size was specified, set ITYPE to a range-type for
4293	       that size.  Otherwise, ITYPE remains null.  finish_decl
4294	       may figure it out from an initial value.  */
4295
4296	    if (size)
4297	      {
4298		/* Strip NON_LVALUE_EXPRs since we aren't using as an
4299		   lvalue.  */
4300		STRIP_TYPE_NOPS (size);
4301
4302		if (!INTEGRAL_TYPE_P (TREE_TYPE (size)))
4303		  {
4304		    error ("size of array %qs has non-integer type", name);
4305		    size = integer_one_node;
4306		  }
4307
4308		if (pedantic && integer_zerop (size))
4309		  pedwarn ("ISO C forbids zero-size array %qs", name);
4310
4311		if (TREE_CODE (size) == INTEGER_CST)
4312		  {
4313		    constant_expression_warning (size);
4314		    if (tree_int_cst_sgn (size) < 0)
4315		      {
4316			error ("size of array %qs is negative", name);
4317			size = integer_one_node;
4318		      }
4319		  }
4320		else if ((decl_context == NORMAL || decl_context == FIELD)
4321			 && current_scope == file_scope)
4322		  {
4323		    error ("variably modified %qs at file scope", name);
4324		    size = integer_one_node;
4325		  }
4326		else
4327		  {
4328		    /* Make sure the array size remains visibly
4329		       nonconstant even if it is (eg) a const variable
4330		       with known value.  */
4331		    size_varies = 1;
4332
4333		    if (!flag_isoc99 && pedantic)
4334		      {
4335			if (TREE_CONSTANT (size))
4336			  pedwarn ("ISO C90 forbids array %qs whose size "
4337				   "can%'t be evaluated",
4338				   name);
4339			else
4340			  pedwarn ("ISO C90 forbids variable-size array %qs",
4341				   name);
4342		      }
4343		  }
4344
4345		if (integer_zerop (size))
4346		  {
4347		    /* A zero-length array cannot be represented with
4348		       an unsigned index type, which is what we'll
4349		       get with build_index_type.  Create an
4350		       open-ended range instead.  */
4351		    itype = build_range_type (sizetype, size, NULL_TREE);
4352		  }
4353		else
4354		  {
4355		    /* Arrange for the SAVE_EXPR on the inside of the
4356		       MINUS_EXPR, which allows the -1 to get folded
4357		       with the +1 that happens when building TYPE_SIZE.  */
4358		    if (size_varies)
4359		      size = variable_size (size);
4360
4361		    /* Compute the maximum valid index, that is, size
4362		       - 1.  Do the calculation in index_type, so that
4363		       if it is a variable the computations will be
4364		       done in the proper mode.  */
4365		    itype = fold_build2 (MINUS_EXPR, index_type,
4366					 convert (index_type, size),
4367					 convert (index_type,
4368						  size_one_node));
4369
4370		    /* If that overflowed, the array is too big.  ???
4371		       While a size of INT_MAX+1 technically shouldn't
4372		       cause an overflow (because we subtract 1), the
4373		       overflow is recorded during the conversion to
4374		       index_type, before the subtraction.  Handling
4375		       this case seems like an unnecessary
4376		       complication.  */
4377		    if (TREE_CODE (itype) == INTEGER_CST
4378			&& TREE_OVERFLOW (itype))
4379		      {
4380			error ("size of array %qs is too large", name);
4381			type = error_mark_node;
4382			continue;
4383		      }
4384
4385		    itype = build_index_type (itype);
4386		  }
4387	      }
4388	    else if (decl_context == FIELD)
4389	      {
4390		if (pedantic && !flag_isoc99 && !in_system_header)
4391		  pedwarn ("ISO C90 does not support flexible array members");
4392
4393		/* ISO C99 Flexible array members are effectively
4394		   identical to GCC's zero-length array extension.  */
4395		itype = build_range_type (sizetype, size_zero_node, NULL_TREE);
4396	      }
4397	    else if (decl_context == PARM)
4398	      {
4399		if (array_parm_vla_unspec_p)
4400		  {
4401		    if (! orig_name)
4402		      {
4403			/* C99 6.7.5.2p4 */
4404			error ("%<[*]%> not allowed in other than a declaration");
4405		      }
4406
4407		    itype = build_range_type (sizetype, size_zero_node, NULL_TREE);
4408		    size_varies = 1;
4409		  }
4410	      }
4411	    else if (decl_context == TYPENAME)
4412	      {
4413		if (array_parm_vla_unspec_p)
4414		  {
4415		    /* The error is printed elsewhere.  We use this to
4416		       avoid messing up with incomplete array types of
4417		       the same type, that would otherwise be modified
4418		       below.  */
4419		    itype = build_range_type (sizetype, size_zero_node,
4420					      NULL_TREE);
4421		  }
4422	      }
4423
4424	     /* Complain about arrays of incomplete types.  */
4425	    if (!COMPLETE_TYPE_P (type))
4426	      {
4427		error ("array type has incomplete element type");
4428		type = error_mark_node;
4429	      }
4430	    else
4431	    /* When itype is NULL, a shared incomplete array type is
4432	       returned for all array of a given type.  Elsewhere we
4433	       make sure we don't complete that type before copying
4434	       it, but here we want to make sure we don't ever
4435	       modify the shared type, so we gcc_assert (itype)
4436	       below.  */
4437	      type = build_array_type (type, itype);
4438
4439	    if (type != error_mark_node)
4440	      {
4441		if (size_varies)
4442		  {
4443		    /* It is ok to modify type here even if itype is
4444		       NULL: if size_varies, we're in a
4445		       multi-dimensional array and the inner type has
4446		       variable size, so the enclosing shared array type
4447		       must too.  */
4448		    if (size && TREE_CODE (size) == INTEGER_CST)
4449		      type
4450			= build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4451		    C_TYPE_VARIABLE_SIZE (type) = 1;
4452		  }
4453
4454		/* The GCC extension for zero-length arrays differs from
4455		   ISO flexible array members in that sizeof yields
4456		   zero.  */
4457		if (size && integer_zerop (size))
4458		  {
4459		    gcc_assert (itype);
4460		    TYPE_SIZE (type) = bitsize_zero_node;
4461		    TYPE_SIZE_UNIT (type) = size_zero_node;
4462		  }
4463		if (array_parm_vla_unspec_p)
4464		  {
4465		    gcc_assert (itype);
4466		    /* The type is complete.  C99 6.7.5.2p4  */
4467		    TYPE_SIZE (type) = bitsize_zero_node;
4468		    TYPE_SIZE_UNIT (type) = size_zero_node;
4469		  }
4470	      }
4471
4472	    if (decl_context != PARM
4473		&& (array_ptr_quals != TYPE_UNQUALIFIED
4474		    || array_ptr_attrs != NULL_TREE
4475		    || array_parm_static))
4476	      {
4477		error ("static or type qualifiers in non-parameter array declarator");
4478		array_ptr_quals = TYPE_UNQUALIFIED;
4479		array_ptr_attrs = NULL_TREE;
4480		array_parm_static = 0;
4481	      }
4482	    break;
4483	  }
4484	case cdk_function:
4485	  {
4486	    /* Say it's a definition only for the declarator closest
4487	       to the identifier, apart possibly from some
4488	       attributes.  */
4489	    bool really_funcdef = false;
4490	    tree arg_types;
4491	    if (funcdef_flag)
4492	      {
4493		const struct c_declarator *t = declarator->declarator;
4494		while (t->kind == cdk_attrs)
4495		  t = t->declarator;
4496		really_funcdef = (t->kind == cdk_id);
4497	      }
4498
4499	    /* Declaring a function type.  Make sure we have a valid
4500	       type for the function to return.  */
4501	    if (type == error_mark_node)
4502	      continue;
4503
4504	    size_varies = 0;
4505
4506	    /* Warn about some types functions can't return.  */
4507	    if (TREE_CODE (type) == FUNCTION_TYPE)
4508	      {
4509		error ("%qs declared as function returning a function", name);
4510		type = integer_type_node;
4511	      }
4512	    if (TREE_CODE (type) == ARRAY_TYPE)
4513	      {
4514		error ("%qs declared as function returning an array", name);
4515		type = integer_type_node;
4516	      }
4517
4518	    /* Construct the function type and go to the next
4519	       inner layer of declarator.  */
4520	    arg_info = declarator->u.arg_info;
4521	    arg_types = grokparms (arg_info, really_funcdef);
4522	    if (really_funcdef)
4523	      put_pending_sizes (arg_info->pending_sizes);
4524
4525	    /* Type qualifiers before the return type of the function
4526	       qualify the return type, not the function type.  */
4527	    if (type_quals)
4528	      {
4529		/* Type qualifiers on a function return type are
4530		   normally permitted by the standard but have no
4531		   effect, so give a warning at -Wreturn-type.
4532		   Qualifiers on a void return type are banned on
4533		   function definitions in ISO C; GCC used to used
4534		   them for noreturn functions.  */
4535		if (VOID_TYPE_P (type) && really_funcdef)
4536		  pedwarn ("function definition has qualified void return type");
4537		else
4538		  warning (OPT_Wreturn_type,
4539			   "type qualifiers ignored on function return type");
4540
4541		type = c_build_qualified_type (type, type_quals);
4542	      }
4543	    type_quals = TYPE_UNQUALIFIED;
4544
4545	    type = build_function_type (type, arg_types);
4546	    declarator = declarator->declarator;
4547
4548	    /* Set the TYPE_CONTEXTs for each tagged type which is local to
4549	       the formal parameter list of this FUNCTION_TYPE to point to
4550	       the FUNCTION_TYPE node itself.  */
4551	    {
4552	      tree link;
4553
4554	      for (link = arg_info->tags;
4555		   link;
4556		   link = TREE_CHAIN (link))
4557		TYPE_CONTEXT (TREE_VALUE (link)) = type;
4558	    }
4559	    break;
4560	  }
4561	case cdk_pointer:
4562	  {
4563	    /* Merge any constancy or volatility into the target type
4564	       for the pointer.  */
4565
4566	    if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4567		&& type_quals)
4568	      pedwarn ("ISO C forbids qualified function types");
4569	    if (type_quals)
4570	      type = c_build_qualified_type (type, type_quals);
4571	    size_varies = 0;
4572
4573	    /* When the pointed-to type involves components of variable size,
4574	       care must be taken to ensure that the size evaluation code is
4575	       emitted early enough to dominate all the possible later uses
4576	       and late enough for the variables on which it depends to have
4577	       been assigned.
4578
4579	       This is expected to happen automatically when the pointed-to
4580	       type has a name/declaration of it's own, but special attention
4581	       is required if the type is anonymous.
4582
4583	       We handle the NORMAL and FIELD contexts here by attaching an
4584	       artificial TYPE_DECL to such pointed-to type.  This forces the
4585	       sizes evaluation at a safe point and ensures it is not deferred
4586	       until e.g. within a deeper conditional context.
4587
4588	       We expect nothing to be needed here for PARM or TYPENAME.
4589	       Pushing a TYPE_DECL at this point for TYPENAME would actually
4590	       be incorrect, as we might be in the middle of an expression
4591	       with side effects on the pointed-to type size "arguments" prior
4592	       to the pointer declaration point and the fake TYPE_DECL in the
4593	       enclosing context would force the size evaluation prior to the
4594	       side effects.  */
4595
4596	    if (!TYPE_NAME (type)
4597		&& (decl_context == NORMAL || decl_context == FIELD)
4598		&& variably_modified_type_p (type, NULL_TREE))
4599	      {
4600		tree decl = build_decl (TYPE_DECL, NULL_TREE, type);
4601		DECL_ARTIFICIAL (decl) = 1;
4602		pushdecl (decl);
4603		finish_decl (decl, NULL_TREE, NULL_TREE);
4604		TYPE_NAME (type) = decl;
4605	      }
4606
4607	    type = build_pointer_type (type);
4608
4609	    /* Process type qualifiers (such as const or volatile)
4610	       that were given inside the `*'.  */
4611	    type_quals = declarator->u.pointer_quals;
4612
4613	    declarator = declarator->declarator;
4614	    break;
4615	  }
4616	default:
4617	  gcc_unreachable ();
4618	}
4619    }
4620
4621  /* Now TYPE has the actual type, apart from any qualifiers in
4622     TYPE_QUALS.  */
4623
4624  /* Check the type and width of a bit-field.  */
4625  if (bitfield)
4626    check_bitfield_type_and_width (&type, width, orig_name);
4627
4628  /* Did array size calculations overflow?  */
4629
4630  if (TREE_CODE (type) == ARRAY_TYPE
4631      && COMPLETE_TYPE_P (type)
4632      && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
4633      && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
4634    {
4635      error ("size of array %qs is too large", name);
4636      /* If we proceed with the array type as it is, we'll eventually
4637	 crash in tree_low_cst().  */
4638      type = error_mark_node;
4639    }
4640
4641  /* If this is declaring a typedef name, return a TYPE_DECL.  */
4642
4643  if (storage_class == csc_typedef)
4644    {
4645      tree decl;
4646      if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4647	  && type_quals)
4648	pedwarn ("ISO C forbids qualified function types");
4649      if (type_quals)
4650	type = c_build_qualified_type (type, type_quals);
4651      decl = build_decl (TYPE_DECL, declarator->u.id, type);
4652      if (declspecs->explicit_signed_p)
4653	C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1;
4654      decl_attributes (&decl, returned_attrs, 0);
4655      if (declspecs->inline_p)
4656	pedwarn ("typedef %q+D declared %<inline%>", decl);
4657      return decl;
4658    }
4659
4660  /* If this is a type name (such as, in a cast or sizeof),
4661     compute the type and return it now.  */
4662
4663  if (decl_context == TYPENAME)
4664    {
4665      /* Note that the grammar rejects storage classes in typenames
4666	 and fields.  */
4667      gcc_assert (storage_class == csc_none && !threadp
4668		  && !declspecs->inline_p);
4669      if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4670	  && type_quals)
4671	pedwarn ("ISO C forbids const or volatile function types");
4672      if (type_quals)
4673	type = c_build_qualified_type (type, type_quals);
4674      decl_attributes (&type, returned_attrs, 0);
4675      return type;
4676    }
4677
4678  if (pedantic && decl_context == FIELD
4679      && variably_modified_type_p (type, NULL_TREE))
4680    {
4681      /* C99 6.7.2.1p8 */
4682      pedwarn ("a member of a structure or union cannot have a variably modified type");
4683    }
4684
4685  /* Aside from typedefs and type names (handle above),
4686     `void' at top level (not within pointer)
4687     is allowed only in public variables.
4688     We don't complain about parms either, but that is because
4689     a better error message can be made later.  */
4690
4691  if (VOID_TYPE_P (type) && decl_context != PARM
4692      && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE)
4693	    && (storage_class == csc_extern
4694		|| (current_scope == file_scope
4695		    && !(storage_class == csc_static
4696			 || storage_class == csc_register)))))
4697    {
4698      error ("variable or field %qs declared void", name);
4699      type = integer_type_node;
4700    }
4701
4702  /* Now create the decl, which may be a VAR_DECL, a PARM_DECL
4703     or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE.  */
4704
4705  {
4706    tree decl;
4707
4708    if (decl_context == PARM)
4709      {
4710	tree type_as_written;
4711	tree promoted_type;
4712
4713	/* A parameter declared as an array of T is really a pointer to T.
4714	   One declared as a function is really a pointer to a function.  */
4715
4716	if (TREE_CODE (type) == ARRAY_TYPE)
4717	  {
4718	    /* Transfer const-ness of array into that of type pointed to.  */
4719	    type = TREE_TYPE (type);
4720	    if (type_quals)
4721	      type = c_build_qualified_type (type, type_quals);
4722	    type = build_pointer_type (type);
4723	    type_quals = array_ptr_quals;
4724
4725	    /* We don't yet implement attributes in this context.  */
4726	    if (array_ptr_attrs != NULL_TREE)
4727	      warning (OPT_Wattributes,
4728		       "attributes in parameter array declarator ignored");
4729
4730	    size_varies = 0;
4731	  }
4732	else if (TREE_CODE (type) == FUNCTION_TYPE)
4733	  {
4734	    if (pedantic && type_quals)
4735	      pedwarn ("ISO C forbids qualified function types");
4736	    if (type_quals)
4737	      type = c_build_qualified_type (type, type_quals);
4738	    type = build_pointer_type (type);
4739	    type_quals = TYPE_UNQUALIFIED;
4740	  }
4741	else if (type_quals)
4742	  type = c_build_qualified_type (type, type_quals);
4743
4744	type_as_written = type;
4745
4746	decl = build_decl (PARM_DECL, declarator->u.id, type);
4747	if (size_varies)
4748	  C_DECL_VARIABLE_SIZE (decl) = 1;
4749
4750	/* Compute the type actually passed in the parmlist,
4751	   for the case where there is no prototype.
4752	   (For example, shorts and chars are passed as ints.)
4753	   When there is a prototype, this is overridden later.  */
4754
4755	if (type == error_mark_node)
4756	  promoted_type = type;
4757	else
4758	  promoted_type = c_type_promotes_to (type);
4759
4760	DECL_ARG_TYPE (decl) = promoted_type;
4761	if (declspecs->inline_p)
4762	  pedwarn ("parameter %q+D declared %<inline%>", decl);
4763      }
4764    else if (decl_context == FIELD)
4765      {
4766	/* Note that the grammar rejects storage classes in typenames
4767	   and fields.  */
4768	gcc_assert (storage_class == csc_none && !threadp
4769		    && !declspecs->inline_p);
4770
4771	/* Structure field.  It may not be a function.  */
4772
4773	if (TREE_CODE (type) == FUNCTION_TYPE)
4774	  {
4775	    error ("field %qs declared as a function", name);
4776	    type = build_pointer_type (type);
4777	  }
4778	else if (TREE_CODE (type) != ERROR_MARK
4779		 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type))
4780	  {
4781	    error ("field %qs has incomplete type", name);
4782	    type = error_mark_node;
4783	  }
4784	type = c_build_qualified_type (type, type_quals);
4785	decl = build_decl (FIELD_DECL, declarator->u.id, type);
4786	DECL_NONADDRESSABLE_P (decl) = bitfield;
4787
4788	if (size_varies)
4789	  C_DECL_VARIABLE_SIZE (decl) = 1;
4790      }
4791    else if (TREE_CODE (type) == FUNCTION_TYPE)
4792      {
4793	if (storage_class == csc_register || threadp)
4794	  {
4795	    error ("invalid storage class for function %qs", name);
4796	   }
4797	else if (current_scope != file_scope)
4798	  {
4799	    /* Function declaration not at file scope.  Storage
4800	       classes other than `extern' are not allowed, C99
4801	       6.7.1p5, and `extern' makes no difference.  However,
4802	       GCC allows 'auto', perhaps with 'inline', to support
4803	       nested functions.  */
4804	    if (storage_class == csc_auto)
4805	      {
4806		if (pedantic)
4807		  pedwarn ("invalid storage class for function %qs", name);
4808	      }
4809	    else if (storage_class == csc_static)
4810	      {
4811		error ("invalid storage class for function %qs", name);
4812		if (funcdef_flag)
4813		  storage_class = declspecs->storage_class = csc_none;
4814		else
4815		  return 0;
4816	      }
4817	  }
4818
4819	decl = build_decl (FUNCTION_DECL, declarator->u.id, type);
4820	decl = build_decl_attribute_variant (decl, decl_attr);
4821
4822	DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl);
4823
4824	if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl))
4825	  pedwarn ("ISO C forbids qualified function types");
4826
4827	/* GNU C interprets a volatile-qualified function type to indicate
4828	   that the function does not return.  */
4829	if ((type_quals & TYPE_QUAL_VOLATILE)
4830	    && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
4831	  warning (0, "%<noreturn%> function returns non-void value");
4832
4833	/* Every function declaration is an external reference
4834	   (DECL_EXTERNAL) except for those which are not at file
4835	   scope and are explicitly declared "auto".  This is
4836	   forbidden by standard C (C99 6.7.1p5) and is interpreted by
4837	   GCC to signify a forward declaration of a nested function.  */
4838	if (storage_class == csc_auto && current_scope != file_scope)
4839	  DECL_EXTERNAL (decl) = 0;
4840	/* In C99, a function which is declared 'inline' with 'extern'
4841	   is not an external reference (which is confusing).  It
4842	   means that the later definition of the function must be output
4843	   in this file, C99 6.7.4p6.  In GNU C89, a function declared
4844	   'extern inline' is an external reference.  */
4845	else if (declspecs->inline_p && storage_class != csc_static)
4846	  DECL_EXTERNAL (decl) = ((storage_class == csc_extern)
4847				  == flag_gnu89_inline);
4848	else
4849	  DECL_EXTERNAL (decl) = !initialized;
4850
4851	/* Record absence of global scope for `static' or `auto'.  */
4852	TREE_PUBLIC (decl)
4853	  = !(storage_class == csc_static || storage_class == csc_auto);
4854
4855	/* For a function definition, record the argument information
4856	   block where store_parm_decls will look for it.  */
4857	if (funcdef_flag)
4858	  current_function_arg_info = arg_info;
4859
4860	if (declspecs->default_int_p)
4861	  C_FUNCTION_IMPLICIT_INT (decl) = 1;
4862
4863	/* Record presence of `inline', if it is reasonable.  */
4864	if (flag_hosted && MAIN_NAME_P (declarator->u.id))
4865	  {
4866	    if (declspecs->inline_p)
4867	      pedwarn ("cannot inline function %<main%>");
4868	  }
4869	else if (declspecs->inline_p)
4870	  {
4871	    /* Record that the function is declared `inline'.  */
4872	    DECL_DECLARED_INLINE_P (decl) = 1;
4873
4874	    /* Do not mark bare declarations as DECL_INLINE.  Doing so
4875	       in the presence of multiple declarations can result in
4876	       the abstract origin pointing between the declarations,
4877	       which will confuse dwarf2out.  */
4878	    if (initialized)
4879	      DECL_INLINE (decl) = 1;
4880	  }
4881	/* If -finline-functions, assume it can be inlined.  This does
4882	   two things: let the function be deferred until it is actually
4883	   needed, and let dwarf2 know that the function is inlinable.  */
4884	else if (flag_inline_trees == 2 && initialized)
4885	  DECL_INLINE (decl) = 1;
4886      }
4887    else
4888      {
4889	/* It's a variable.  */
4890	/* An uninitialized decl with `extern' is a reference.  */
4891	int extern_ref = !initialized && storage_class == csc_extern;
4892
4893	type = c_build_qualified_type (type, type_quals);
4894
4895	/* C99 6.2.2p7: It is invalid (compile-time undefined
4896	   behavior) to create an 'extern' declaration for a
4897	   variable if there is a global declaration that is
4898	   'static' and the global declaration is not visible.
4899	   (If the static declaration _is_ currently visible,
4900	   the 'extern' declaration is taken to refer to that decl.) */
4901	if (extern_ref && current_scope != file_scope)
4902	  {
4903	    tree global_decl  = identifier_global_value (declarator->u.id);
4904	    tree visible_decl = lookup_name (declarator->u.id);
4905
4906	    if (global_decl
4907		&& global_decl != visible_decl
4908		&& TREE_CODE (global_decl) == VAR_DECL
4909		&& !TREE_PUBLIC (global_decl))
4910	      error ("variable previously declared %<static%> redeclared "
4911		     "%<extern%>");
4912	  }
4913
4914	decl = build_decl (VAR_DECL, declarator->u.id, type);
4915	DECL_SOURCE_LOCATION (decl) = declarator->id_loc;
4916	if (size_varies)
4917	  C_DECL_VARIABLE_SIZE (decl) = 1;
4918
4919	if (declspecs->inline_p)
4920	  pedwarn ("variable %q+D declared %<inline%>", decl);
4921
4922	/* At file scope, an initialized extern declaration may follow
4923	   a static declaration.  In that case, DECL_EXTERNAL will be
4924	   reset later in start_decl.  */
4925	DECL_EXTERNAL (decl) = (storage_class == csc_extern);
4926
4927	/* At file scope, the presence of a `static' or `register' storage
4928	   class specifier, or the absence of all storage class specifiers
4929	   makes this declaration a definition (perhaps tentative).  Also,
4930	   the absence of `static' makes it public.  */
4931	if (current_scope == file_scope)
4932	  {
4933	    TREE_PUBLIC (decl) = storage_class != csc_static;
4934	    TREE_STATIC (decl) = !extern_ref;
4935	  }
4936	/* Not at file scope, only `static' makes a static definition.  */
4937	else
4938	  {
4939	    TREE_STATIC (decl) = (storage_class == csc_static);
4940	    TREE_PUBLIC (decl) = extern_ref;
4941	  }
4942
4943	if (threadp)
4944	  {
4945	    if (targetm.have_tls)
4946	      DECL_TLS_MODEL (decl) = decl_default_tls_model (decl);
4947	    else
4948	      /* A mere warning is sure to result in improper semantics
4949		 at runtime.  Don't bother to allow this to compile.  */
4950	      error ("thread-local storage not supported for this target");
4951	  }
4952      }
4953
4954    if (storage_class == csc_extern
4955	&& variably_modified_type_p (type, NULL_TREE))
4956      {
4957	/* C99 6.7.5.2p2 */
4958	error ("object with variably modified type must have no linkage");
4959      }
4960
4961    /* Record `register' declaration for warnings on &
4962       and in case doing stupid register allocation.  */
4963
4964    if (storage_class == csc_register)
4965      {
4966	C_DECL_REGISTER (decl) = 1;
4967	DECL_REGISTER (decl) = 1;
4968      }
4969
4970    /* Record constancy and volatility.  */
4971    c_apply_type_quals_to_decl (type_quals, decl);
4972
4973    /* If a type has volatile components, it should be stored in memory.
4974       Otherwise, the fact that those components are volatile
4975       will be ignored, and would even crash the compiler.
4976       Of course, this only makes sense on  VAR,PARM, and RESULT decl's.   */
4977    if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl))
4978	&& (TREE_CODE (decl) == VAR_DECL ||  TREE_CODE (decl) == PARM_DECL
4979	  || TREE_CODE (decl) == RESULT_DECL))
4980      {
4981	/* It is not an error for a structure with volatile fields to
4982	   be declared register, but reset DECL_REGISTER since it
4983	   cannot actually go in a register.  */
4984	int was_reg = C_DECL_REGISTER (decl);
4985	C_DECL_REGISTER (decl) = 0;
4986	DECL_REGISTER (decl) = 0;
4987	c_mark_addressable (decl);
4988	C_DECL_REGISTER (decl) = was_reg;
4989      }
4990
4991  /* This is the earliest point at which we might know the assembler
4992     name of a variable.  Thus, if it's known before this, die horribly.  */
4993    gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl));
4994
4995    decl_attributes (&decl, returned_attrs, 0);
4996
4997    return decl;
4998  }
4999}
5000
5001/* Decode the parameter-list info for a function type or function definition.
5002   The argument is the value returned by `get_parm_info' (or made in c-parse.c
5003   if there is an identifier list instead of a parameter decl list).
5004   These two functions are separate because when a function returns
5005   or receives functions then each is called multiple times but the order
5006   of calls is different.  The last call to `grokparms' is always the one
5007   that contains the formal parameter names of a function definition.
5008
5009   Return a list of arg types to use in the FUNCTION_TYPE for this function.
5010
5011   FUNCDEF_FLAG is true for a function definition, false for
5012   a mere declaration.  A nonempty identifier-list gets an error message
5013   when FUNCDEF_FLAG is false.  */
5014
5015static tree
5016grokparms (struct c_arg_info *arg_info, bool funcdef_flag)
5017{
5018  tree arg_types = arg_info->types;
5019
5020  if (funcdef_flag && arg_info->had_vla_unspec)
5021    {
5022      /* A function definition isn't function prototype scope C99 6.2.1p4.  */
5023      /* C99 6.7.5.2p4 */
5024      error ("%<[*]%> not allowed in other than function prototype scope");
5025    }
5026
5027  if (arg_types == 0 && !funcdef_flag && !in_system_header)
5028    warning (OPT_Wstrict_prototypes,
5029	     "function declaration isn%'t a prototype");
5030
5031  if (arg_types == error_mark_node)
5032    return 0;  /* don't set TYPE_ARG_TYPES in this case */
5033
5034  else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE)
5035    {
5036      if (!funcdef_flag)
5037	pedwarn ("parameter names (without types) in function declaration");
5038
5039      arg_info->parms = arg_info->types;
5040      arg_info->types = 0;
5041      return 0;
5042    }
5043  else
5044    {
5045      tree parm, type, typelt;
5046      unsigned int parmno;
5047
5048      /* If there is a parameter of incomplete type in a definition,
5049	 this is an error.  In a declaration this is valid, and a
5050	 struct or union type may be completed later, before any calls
5051	 or definition of the function.  In the case where the tag was
5052	 first declared within the parameter list, a warning has
5053	 already been given.  If a parameter has void type, then
5054	 however the function cannot be defined or called, so
5055	 warn.  */
5056
5057      for (parm = arg_info->parms, typelt = arg_types, parmno = 1;
5058	   parm;
5059	   parm = TREE_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++)
5060	{
5061	  type = TREE_VALUE (typelt);
5062	  if (type == error_mark_node)
5063	    continue;
5064
5065	  if (!COMPLETE_TYPE_P (type))
5066	    {
5067	      if (funcdef_flag)
5068		{
5069		  if (DECL_NAME (parm))
5070		    error ("parameter %u (%q+D) has incomplete type",
5071			   parmno, parm);
5072		  else
5073		    error ("%Jparameter %u has incomplete type",
5074			   parm, parmno);
5075
5076		  TREE_VALUE (typelt) = error_mark_node;
5077		  TREE_TYPE (parm) = error_mark_node;
5078		}
5079	      else if (VOID_TYPE_P (type))
5080		{
5081		  if (DECL_NAME (parm))
5082		    warning (0, "parameter %u (%q+D) has void type",
5083			     parmno, parm);
5084		  else
5085		    warning (0, "%Jparameter %u has void type",
5086			     parm, parmno);
5087		}
5088	    }
5089
5090	  if (DECL_NAME (parm) && TREE_USED (parm))
5091	    warn_if_shadowing (parm);
5092	}
5093      return arg_types;
5094    }
5095}
5096
5097/* Take apart the current scope and return a c_arg_info structure with
5098   info on a parameter list just parsed.
5099
5100   This structure is later fed to 'grokparms' and 'store_parm_decls'.
5101
5102   ELLIPSIS being true means the argument list ended in '...' so don't
5103   append a sentinel (void_list_node) to the end of the type-list.  */
5104
5105struct c_arg_info *
5106get_parm_info (bool ellipsis)
5107{
5108  struct c_binding *b = current_scope->bindings;
5109  struct c_arg_info *arg_info = XOBNEW (&parser_obstack,
5110					struct c_arg_info);
5111  tree parms    = 0;
5112  tree tags     = 0;
5113  tree types    = 0;
5114  tree others   = 0;
5115
5116  static bool explained_incomplete_types = false;
5117  bool gave_void_only_once_err = false;
5118
5119  arg_info->parms = 0;
5120  arg_info->tags = 0;
5121  arg_info->types = 0;
5122  arg_info->others = 0;
5123  arg_info->pending_sizes = 0;
5124  arg_info->had_vla_unspec = current_scope->had_vla_unspec;
5125
5126  /* The bindings in this scope must not get put into a block.
5127     We will take care of deleting the binding nodes.  */
5128  current_scope->bindings = 0;
5129
5130  /* This function is only called if there was *something* on the
5131     parameter list.  */
5132  gcc_assert (b);
5133
5134  /* A parameter list consisting solely of 'void' indicates that the
5135     function takes no arguments.  But if the 'void' is qualified
5136     (by 'const' or 'volatile'), or has a storage class specifier
5137     ('register'), then the behavior is undefined; issue an error.
5138     Typedefs for 'void' are OK (see DR#157).  */
5139  if (b->prev == 0			    /* one binding */
5140      && TREE_CODE (b->decl) == PARM_DECL   /* which is a parameter */
5141      && !DECL_NAME (b->decl)               /* anonymous */
5142      && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */
5143    {
5144      if (TREE_THIS_VOLATILE (b->decl)
5145	  || TREE_READONLY (b->decl)
5146	  || C_DECL_REGISTER (b->decl))
5147	error ("%<void%> as only parameter may not be qualified");
5148
5149      /* There cannot be an ellipsis.  */
5150      if (ellipsis)
5151	error ("%<void%> must be the only parameter");
5152
5153      arg_info->types = void_list_node;
5154      return arg_info;
5155    }
5156
5157  if (!ellipsis)
5158    types = void_list_node;
5159
5160  /* Break up the bindings list into parms, tags, types, and others;
5161     apply sanity checks; purge the name-to-decl bindings.  */
5162  while (b)
5163    {
5164      tree decl = b->decl;
5165      tree type = TREE_TYPE (decl);
5166      const char *keyword;
5167
5168      switch (TREE_CODE (decl))
5169	{
5170	case PARM_DECL:
5171	  if (b->id)
5172	    {
5173	      gcc_assert (I_SYMBOL_BINDING (b->id) == b);
5174	      I_SYMBOL_BINDING (b->id) = b->shadowed;
5175	    }
5176
5177	  /* Check for forward decls that never got their actual decl.  */
5178	  if (TREE_ASM_WRITTEN (decl))
5179	    error ("parameter %q+D has just a forward declaration", decl);
5180	  /* Check for (..., void, ...) and issue an error.  */
5181	  else if (VOID_TYPE_P (type) && !DECL_NAME (decl))
5182	    {
5183	      if (!gave_void_only_once_err)
5184		{
5185		  error ("%<void%> must be the only parameter");
5186		  gave_void_only_once_err = true;
5187		}
5188	    }
5189	  else
5190	    {
5191	      /* Valid parameter, add it to the list.  */
5192	      TREE_CHAIN (decl) = parms;
5193	      parms = decl;
5194
5195	      /* Since there is a prototype, args are passed in their
5196		 declared types.  The back end may override this later.  */
5197	      DECL_ARG_TYPE (decl) = type;
5198	      types = tree_cons (0, type, types);
5199	    }
5200	  break;
5201
5202	case ENUMERAL_TYPE: keyword = "enum"; goto tag;
5203	case UNION_TYPE:    keyword = "union"; goto tag;
5204	case RECORD_TYPE:   keyword = "struct"; goto tag;
5205	tag:
5206	  /* Types may not have tag-names, in which case the type
5207	     appears in the bindings list with b->id NULL.  */
5208	  if (b->id)
5209	    {
5210	      gcc_assert (I_TAG_BINDING (b->id) == b);
5211	      I_TAG_BINDING (b->id) = b->shadowed;
5212	    }
5213
5214	  /* Warn about any struct, union or enum tags defined in a
5215	     parameter list.  The scope of such types is limited to
5216	     the parameter list, which is rarely if ever desirable
5217	     (it's impossible to call such a function with type-
5218	     correct arguments).  An anonymous union parm type is
5219	     meaningful as a GNU extension, so don't warn for that.  */
5220	  if (TREE_CODE (decl) != UNION_TYPE || b->id != 0)
5221	    {
5222	      if (b->id)
5223		/* The %s will be one of 'struct', 'union', or 'enum'.  */
5224		warning (0, "%<%s %E%> declared inside parameter list",
5225			 keyword, b->id);
5226	      else
5227		/* The %s will be one of 'struct', 'union', or 'enum'.  */
5228		warning (0, "anonymous %s declared inside parameter list",
5229			 keyword);
5230
5231	      if (!explained_incomplete_types)
5232		{
5233		  warning (0, "its scope is only this definition or declaration,"
5234			   " which is probably not what you want");
5235		  explained_incomplete_types = true;
5236		}
5237	    }
5238
5239	  tags = tree_cons (b->id, decl, tags);
5240	  break;
5241
5242	case CONST_DECL:
5243	case TYPE_DECL:
5244	case FUNCTION_DECL:
5245	  /* CONST_DECLs appear here when we have an embedded enum,
5246	     and TYPE_DECLs appear here when we have an embedded struct
5247	     or union.  No warnings for this - we already warned about the
5248	     type itself.  FUNCTION_DECLs appear when there is an implicit
5249	     function declaration in the parameter list.  */
5250
5251	  TREE_CHAIN (decl) = others;
5252	  others = decl;
5253	  /* fall through */
5254
5255	case ERROR_MARK:
5256	  /* error_mark_node appears here when we have an undeclared
5257	     variable.  Just throw it away.  */
5258	  if (b->id)
5259	    {
5260	      gcc_assert (I_SYMBOL_BINDING (b->id) == b);
5261	      I_SYMBOL_BINDING (b->id) = b->shadowed;
5262	    }
5263	  break;
5264
5265	  /* Other things that might be encountered.  */
5266	case LABEL_DECL:
5267	case VAR_DECL:
5268	default:
5269	  gcc_unreachable ();
5270	}
5271
5272      b = free_binding_and_advance (b);
5273    }
5274
5275  arg_info->parms = parms;
5276  arg_info->tags = tags;
5277  arg_info->types = types;
5278  arg_info->others = others;
5279  arg_info->pending_sizes = get_pending_sizes ();
5280  return arg_info;
5281}
5282
5283/* Get the struct, enum or union (CODE says which) with tag NAME.
5284   Define the tag as a forward-reference if it is not defined.
5285   Return a c_typespec structure for the type specifier.  */
5286
5287struct c_typespec
5288parser_xref_tag (enum tree_code code, tree name)
5289{
5290  struct c_typespec ret;
5291  /* If a cross reference is requested, look up the type
5292     already defined for this tag and return it.  */
5293
5294  tree ref = lookup_tag (code, name, 0);
5295  /* If this is the right type of tag, return what we found.
5296     (This reference will be shadowed by shadow_tag later if appropriate.)
5297     If this is the wrong type of tag, do not return it.  If it was the
5298     wrong type in the same scope, we will have had an error
5299     message already; if in a different scope and declaring
5300     a name, pending_xref_error will give an error message; but if in a
5301     different scope and not declaring a name, this tag should
5302     shadow the previous declaration of a different type of tag, and
5303     this would not work properly if we return the reference found.
5304     (For example, with "struct foo" in an outer scope, "union foo;"
5305     must shadow that tag with a new one of union type.)  */
5306  ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref);
5307  if (ref && TREE_CODE (ref) == code)
5308    {
5309      ret.spec = ref;
5310      return ret;
5311    }
5312
5313  /* If no such tag is yet defined, create a forward-reference node
5314     and record it as the "definition".
5315     When a real declaration of this type is found,
5316     the forward-reference will be altered into a real type.  */
5317
5318  ref = make_node (code);
5319  if (code == ENUMERAL_TYPE)
5320    {
5321      /* Give the type a default layout like unsigned int
5322	 to avoid crashing if it does not get defined.  */
5323      TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node);
5324      TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node);
5325      TYPE_USER_ALIGN (ref) = 0;
5326      TYPE_UNSIGNED (ref) = 1;
5327      TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node);
5328      TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node);
5329      TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node);
5330    }
5331
5332  pushtag (name, ref);
5333
5334  ret.spec = ref;
5335  return ret;
5336}
5337
5338/* Get the struct, enum or union (CODE says which) with tag NAME.
5339   Define the tag as a forward-reference if it is not defined.
5340   Return a tree for the type.  */
5341
5342tree
5343xref_tag (enum tree_code code, tree name)
5344{
5345  return parser_xref_tag (code, name).spec;
5346}
5347
5348/* Make sure that the tag NAME is defined *in the current scope*
5349   at least as a forward reference.
5350   CODE says which kind of tag NAME ought to be.  */
5351
5352tree
5353start_struct (enum tree_code code, tree name)
5354{
5355  /* If there is already a tag defined at this scope
5356     (as a forward reference), just return it.  */
5357
5358  tree ref = 0;
5359
5360  if (name != 0)
5361    ref = lookup_tag (code, name, 1);
5362  if (ref && TREE_CODE (ref) == code)
5363    {
5364      if (TYPE_SIZE (ref))
5365	{
5366	  if (code == UNION_TYPE)
5367	    error ("redefinition of %<union %E%>", name);
5368	  else
5369	    error ("redefinition of %<struct %E%>", name);
5370	}
5371      else if (C_TYPE_BEING_DEFINED (ref))
5372	{
5373	  if (code == UNION_TYPE)
5374	    error ("nested redefinition of %<union %E%>", name);
5375	  else
5376	    error ("nested redefinition of %<struct %E%>", name);
5377	  /* Don't create structures that contain themselves.  */
5378	  ref = NULL_TREE;
5379	}
5380    }
5381
5382  /* Otherwise create a forward-reference just so the tag is in scope.  */
5383
5384  if (ref == NULL_TREE || TREE_CODE (ref) != code)
5385    {
5386      ref = make_node (code);
5387      pushtag (name, ref);
5388    }
5389
5390  C_TYPE_BEING_DEFINED (ref) = 1;
5391  TYPE_PACKED (ref) = flag_pack_struct;
5392  return ref;
5393}
5394
5395/* Process the specs, declarator and width (NULL if omitted)
5396   of a structure component, returning a FIELD_DECL node.
5397   WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node.
5398
5399   This is done during the parsing of the struct declaration.
5400   The FIELD_DECL nodes are chained together and the lot of them
5401   are ultimately passed to `build_struct' to make the RECORD_TYPE node.  */
5402
5403tree
5404grokfield (struct c_declarator *declarator, struct c_declspecs *declspecs,
5405	   tree width)
5406{
5407  tree value;
5408
5409  if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE
5410      && width == NULL_TREE)
5411    {
5412      /* This is an unnamed decl.
5413
5414	 If we have something of the form "union { list } ;" then this
5415	 is the anonymous union extension.  Similarly for struct.
5416
5417	 If this is something of the form "struct foo;", then
5418	   If MS extensions are enabled, this is handled as an
5419	     anonymous struct.
5420	   Otherwise this is a forward declaration of a structure tag.
5421
5422	 If this is something of the form "foo;" and foo is a TYPE_DECL, then
5423	   If MS extensions are enabled and foo names a structure, then
5424	     again this is an anonymous struct.
5425	   Otherwise this is an error.
5426
5427	 Oh what a horrid tangled web we weave.  I wonder if MS consciously
5428	 took this from Plan 9 or if it was an accident of implementation
5429	 that took root before someone noticed the bug...  */
5430
5431      tree type = declspecs->type;
5432      bool type_ok = (TREE_CODE (type) == RECORD_TYPE
5433		      || TREE_CODE (type) == UNION_TYPE);
5434      bool ok = false;
5435
5436      if (type_ok
5437	  && (flag_ms_extensions || !declspecs->typedef_p))
5438	{
5439	  if (flag_ms_extensions)
5440	    ok = true;
5441	  else if (flag_iso)
5442	    ok = false;
5443	  else if (TYPE_NAME (type) == NULL)
5444	    ok = true;
5445	  else
5446	    ok = false;
5447	}
5448      if (!ok)
5449	{
5450	  pedwarn ("declaration does not declare anything");
5451	  return NULL_TREE;
5452	}
5453      if (pedantic)
5454	pedwarn ("ISO C doesn%'t support unnamed structs/unions");
5455    }
5456
5457  value = grokdeclarator (declarator, declspecs, FIELD, false,
5458			  width ? &width : NULL);
5459
5460  finish_decl (value, NULL_TREE, NULL_TREE);
5461  DECL_INITIAL (value) = width;
5462
5463  return value;
5464}
5465
5466/* Generate an error for any duplicate field names in FIELDLIST.  Munge
5467   the list such that this does not present a problem later.  */
5468
5469static void
5470detect_field_duplicates (tree fieldlist)
5471{
5472  tree x, y;
5473  int timeout = 10;
5474
5475  /* First, see if there are more than "a few" fields.
5476     This is trivially true if there are zero or one fields.  */
5477  if (!fieldlist)
5478    return;
5479  x = TREE_CHAIN (fieldlist);
5480  if (!x)
5481    return;
5482  do {
5483    timeout--;
5484    x = TREE_CHAIN (x);
5485  } while (timeout > 0 && x);
5486
5487  /* If there were "few" fields, avoid the overhead of allocating
5488     a hash table.  Instead just do the nested traversal thing.  */
5489  if (timeout > 0)
5490    {
5491      for (x = TREE_CHAIN (fieldlist); x ; x = TREE_CHAIN (x))
5492	if (DECL_NAME (x))
5493	  {
5494	    for (y = fieldlist; y != x; y = TREE_CHAIN (y))
5495	      if (DECL_NAME (y) == DECL_NAME (x))
5496		{
5497		  error ("duplicate member %q+D", x);
5498		  DECL_NAME (x) = NULL_TREE;
5499		}
5500	  }
5501    }
5502  else
5503    {
5504      htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL);
5505      void **slot;
5506
5507      for (x = fieldlist; x ; x = TREE_CHAIN (x))
5508	if ((y = DECL_NAME (x)) != 0)
5509	  {
5510	    slot = htab_find_slot (htab, y, INSERT);
5511	    if (*slot)
5512	      {
5513		error ("duplicate member %q+D", x);
5514		DECL_NAME (x) = NULL_TREE;
5515	      }
5516	    *slot = y;
5517	  }
5518
5519      htab_delete (htab);
5520    }
5521}
5522
5523/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T.
5524   FIELDLIST is a chain of FIELD_DECL nodes for the fields.
5525   ATTRIBUTES are attributes to be applied to the structure.  */
5526
5527tree
5528finish_struct (tree t, tree fieldlist, tree attributes)
5529{
5530  tree x;
5531  bool toplevel = file_scope == current_scope;
5532  int saw_named_field;
5533
5534  /* If this type was previously laid out as a forward reference,
5535     make sure we lay it out again.  */
5536
5537  TYPE_SIZE (t) = 0;
5538
5539  decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5540
5541  if (pedantic)
5542    {
5543      for (x = fieldlist; x; x = TREE_CHAIN (x))
5544	if (DECL_NAME (x) != 0)
5545	  break;
5546
5547      if (x == 0)
5548	{
5549	  if (TREE_CODE (t) == UNION_TYPE)
5550	    {
5551	      if (fieldlist)
5552		pedwarn ("union has no named members");
5553	      else
5554		pedwarn ("union has no members");
5555	    }
5556	  else
5557	    {
5558	      if (fieldlist)
5559		pedwarn ("struct has no named members");
5560	      else
5561		pedwarn ("struct has no members");
5562	    }
5563	}
5564    }
5565
5566  /* Install struct as DECL_CONTEXT of each field decl.
5567     Also process specified field sizes, found in the DECL_INITIAL,
5568     storing 0 there after the type has been changed to precision equal
5569     to its width, rather than the precision of the specified standard
5570     type.  (Correct layout requires the original type to have been preserved
5571     until now.)  */
5572
5573  saw_named_field = 0;
5574  for (x = fieldlist; x; x = TREE_CHAIN (x))
5575    {
5576      if (TREE_TYPE (x) == error_mark_node)
5577	continue;
5578
5579      DECL_CONTEXT (x) = t;
5580
5581      if (TYPE_PACKED (t) && TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
5582	DECL_PACKED (x) = 1;
5583
5584      /* If any field is const, the structure type is pseudo-const.  */
5585      if (TREE_READONLY (x))
5586	C_TYPE_FIELDS_READONLY (t) = 1;
5587      else
5588	{
5589	  /* A field that is pseudo-const makes the structure likewise.  */
5590	  tree t1 = TREE_TYPE (x);
5591	  while (TREE_CODE (t1) == ARRAY_TYPE)
5592	    t1 = TREE_TYPE (t1);
5593	  if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE)
5594	      && C_TYPE_FIELDS_READONLY (t1))
5595	    C_TYPE_FIELDS_READONLY (t) = 1;
5596	}
5597
5598      /* Any field that is volatile means variables of this type must be
5599	 treated in some ways as volatile.  */
5600      if (TREE_THIS_VOLATILE (x))
5601	C_TYPE_FIELDS_VOLATILE (t) = 1;
5602
5603      /* Any field of nominal variable size implies structure is too.  */
5604      if (C_DECL_VARIABLE_SIZE (x))
5605	C_TYPE_VARIABLE_SIZE (t) = 1;
5606
5607      if (DECL_INITIAL (x))
5608	{
5609	  unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1);
5610	  DECL_SIZE (x) = bitsize_int (width);
5611	  DECL_BIT_FIELD (x) = 1;
5612	  SET_DECL_C_BIT_FIELD (x);
5613	}
5614
5615      /* Detect flexible array member in an invalid context.  */
5616      if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE
5617	  && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE
5618	  && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE
5619	  && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE)
5620	{
5621	  if (TREE_CODE (t) == UNION_TYPE)
5622	    {
5623	      error ("%Jflexible array member in union", x);
5624	      TREE_TYPE (x) = error_mark_node;
5625	    }
5626	  else if (TREE_CHAIN (x) != NULL_TREE)
5627	    {
5628	      error ("%Jflexible array member not at end of struct", x);
5629	      TREE_TYPE (x) = error_mark_node;
5630	    }
5631	  else if (!saw_named_field)
5632	    {
5633	      error ("%Jflexible array member in otherwise empty struct", x);
5634	      TREE_TYPE (x) = error_mark_node;
5635	    }
5636	}
5637
5638      if (pedantic && !in_system_header && TREE_CODE (t) == RECORD_TYPE
5639	  && flexible_array_type_p (TREE_TYPE (x)))
5640	pedwarn ("%Jinvalid use of structure with flexible array member", x);
5641
5642      if (DECL_NAME (x))
5643	saw_named_field = 1;
5644    }
5645
5646  detect_field_duplicates (fieldlist);
5647
5648  /* Now we have the nearly final fieldlist.  Record it,
5649     then lay out the structure or union (including the fields).  */
5650
5651  TYPE_FIELDS (t) = fieldlist;
5652
5653  layout_type (t);
5654
5655  /* Give bit-fields their proper types.  */
5656  {
5657    tree *fieldlistp = &fieldlist;
5658    while (*fieldlistp)
5659      if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp)
5660	  && TREE_TYPE (*fieldlistp) != error_mark_node)
5661	{
5662	  unsigned HOST_WIDE_INT width
5663	    = tree_low_cst (DECL_INITIAL (*fieldlistp), 1);
5664	  tree type = TREE_TYPE (*fieldlistp);
5665	  if (width != TYPE_PRECISION (type))
5666	    {
5667	      TREE_TYPE (*fieldlistp)
5668		= c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type));
5669	      DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp));
5670	    }
5671	  DECL_INITIAL (*fieldlistp) = 0;
5672	}
5673      else
5674	fieldlistp = &TREE_CHAIN (*fieldlistp);
5675  }
5676
5677  /* Now we have the truly final field list.
5678     Store it in this type and in the variants.  */
5679
5680  TYPE_FIELDS (t) = fieldlist;
5681
5682  /* If there are lots of fields, sort so we can look through them fast.
5683     We arbitrarily consider 16 or more elts to be "a lot".  */
5684
5685  {
5686    int len = 0;
5687
5688    for (x = fieldlist; x; x = TREE_CHAIN (x))
5689      {
5690	if (len > 15 || DECL_NAME (x) == NULL)
5691	  break;
5692	len += 1;
5693      }
5694
5695    if (len > 15)
5696      {
5697	tree *field_array;
5698	struct lang_type *space;
5699	struct sorted_fields_type *space2;
5700
5701	len += list_length (x);
5702
5703	/* Use the same allocation policy here that make_node uses, to
5704	  ensure that this lives as long as the rest of the struct decl.
5705	  All decls in an inline function need to be saved.  */
5706
5707	space = GGC_CNEW (struct lang_type);
5708	space2 = GGC_NEWVAR (struct sorted_fields_type,
5709			     sizeof (struct sorted_fields_type) + len * sizeof (tree));
5710
5711	len = 0;
5712	space->s = space2;
5713	field_array = &space2->elts[0];
5714	for (x = fieldlist; x; x = TREE_CHAIN (x))
5715	  {
5716	    field_array[len++] = x;
5717
5718	    /* If there is anonymous struct or union, break out of the loop.  */
5719	    if (DECL_NAME (x) == NULL)
5720	      break;
5721	  }
5722	/* Found no anonymous struct/union.  Add the TYPE_LANG_SPECIFIC.  */
5723	if (x == NULL)
5724	  {
5725	    TYPE_LANG_SPECIFIC (t) = space;
5726	    TYPE_LANG_SPECIFIC (t)->s->len = len;
5727	    field_array = TYPE_LANG_SPECIFIC (t)->s->elts;
5728	    qsort (field_array, len, sizeof (tree), field_decl_cmp);
5729	  }
5730      }
5731  }
5732
5733  for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x))
5734    {
5735      TYPE_FIELDS (x) = TYPE_FIELDS (t);
5736      TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t);
5737      C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t);
5738      C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t);
5739      C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t);
5740    }
5741
5742  /* If this was supposed to be a transparent union, but we can't
5743     make it one, warn and turn off the flag.  */
5744  if (TREE_CODE (t) == UNION_TYPE
5745      && TYPE_TRANSPARENT_UNION (t)
5746      && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t))))
5747    {
5748      TYPE_TRANSPARENT_UNION (t) = 0;
5749      warning (0, "union cannot be made transparent");
5750    }
5751
5752  /* If this structure or union completes the type of any previous
5753     variable declaration, lay it out and output its rtl.  */
5754  for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t));
5755       x;
5756       x = TREE_CHAIN (x))
5757    {
5758      tree decl = TREE_VALUE (x);
5759      if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
5760	layout_array_type (TREE_TYPE (decl));
5761      if (TREE_CODE (decl) != TYPE_DECL)
5762	{
5763	  layout_decl (decl, 0);
5764	  if (c_dialect_objc ())
5765	    objc_check_decl (decl);
5766	  rest_of_decl_compilation (decl, toplevel, 0);
5767	  if (!toplevel)
5768	    expand_decl (decl);
5769	}
5770    }
5771  C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0;
5772
5773  /* Finish debugging output for this type.  */
5774  rest_of_type_compilation (t, toplevel);
5775
5776  /* If we're inside a function proper, i.e. not file-scope and not still
5777     parsing parameters, then arrange for the size of a variable sized type
5778     to be bound now.  */
5779  if (cur_stmt_list && variably_modified_type_p (t, NULL_TREE))
5780    add_stmt (build_stmt (DECL_EXPR, build_decl (TYPE_DECL, NULL, t)));
5781
5782  return t;
5783}
5784
5785/* Lay out the type T, and its element type, and so on.  */
5786
5787static void
5788layout_array_type (tree t)
5789{
5790  if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE)
5791    layout_array_type (TREE_TYPE (t));
5792  layout_type (t);
5793}
5794
5795/* Begin compiling the definition of an enumeration type.
5796   NAME is its name (or null if anonymous).
5797   Returns the type object, as yet incomplete.
5798   Also records info about it so that build_enumerator
5799   may be used to declare the individual values as they are read.  */
5800
5801tree
5802start_enum (tree name)
5803{
5804  tree enumtype = 0;
5805
5806  /* If this is the real definition for a previous forward reference,
5807     fill in the contents in the same object that used to be the
5808     forward reference.  */
5809
5810  if (name != 0)
5811    enumtype = lookup_tag (ENUMERAL_TYPE, name, 1);
5812
5813  if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE)
5814    {
5815      enumtype = make_node (ENUMERAL_TYPE);
5816      pushtag (name, enumtype);
5817    }
5818
5819  if (C_TYPE_BEING_DEFINED (enumtype))
5820    error ("nested redefinition of %<enum %E%>", name);
5821
5822  C_TYPE_BEING_DEFINED (enumtype) = 1;
5823
5824  if (TYPE_VALUES (enumtype) != 0)
5825    {
5826      /* This enum is a named one that has been declared already.  */
5827      error ("redeclaration of %<enum %E%>", name);
5828
5829      /* Completely replace its old definition.
5830	 The old enumerators remain defined, however.  */
5831      TYPE_VALUES (enumtype) = 0;
5832    }
5833
5834  enum_next_value = integer_zero_node;
5835  enum_overflow = 0;
5836
5837  if (flag_short_enums)
5838    TYPE_PACKED (enumtype) = 1;
5839
5840  return enumtype;
5841}
5842
5843/* After processing and defining all the values of an enumeration type,
5844   install their decls in the enumeration type and finish it off.
5845   ENUMTYPE is the type object, VALUES a list of decl-value pairs,
5846   and ATTRIBUTES are the specified attributes.
5847   Returns ENUMTYPE.  */
5848
5849tree
5850finish_enum (tree enumtype, tree values, tree attributes)
5851{
5852  tree pair, tem;
5853  tree minnode = 0, maxnode = 0;
5854  int precision, unsign;
5855  bool toplevel = (file_scope == current_scope);
5856  struct lang_type *lt;
5857
5858  decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5859
5860  /* Calculate the maximum value of any enumerator in this type.  */
5861
5862  if (values == error_mark_node)
5863    minnode = maxnode = integer_zero_node;
5864  else
5865    {
5866      minnode = maxnode = TREE_VALUE (values);
5867      for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair))
5868	{
5869	  tree value = TREE_VALUE (pair);
5870	  if (tree_int_cst_lt (maxnode, value))
5871	    maxnode = value;
5872	  if (tree_int_cst_lt (value, minnode))
5873	    minnode = value;
5874	}
5875    }
5876
5877  /* Construct the final type of this enumeration.  It is the same
5878     as one of the integral types - the narrowest one that fits, except
5879     that normally we only go as narrow as int - and signed iff any of
5880     the values are negative.  */
5881  unsign = (tree_int_cst_sgn (minnode) >= 0);
5882  precision = MAX (min_precision (minnode, unsign),
5883		   min_precision (maxnode, unsign));
5884
5885  if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node))
5886    {
5887      tem = c_common_type_for_size (precision, unsign);
5888      if (tem == NULL)
5889	{
5890	  warning (0, "enumeration values exceed range of largest integer");
5891	  tem = long_long_integer_type_node;
5892	}
5893    }
5894  else
5895    tem = unsign ? unsigned_type_node : integer_type_node;
5896
5897  TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem);
5898  TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem);
5899  TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem);
5900  TYPE_SIZE (enumtype) = 0;
5901
5902  /* If the precision of the type was specific with an attribute and it
5903     was too small, give an error.  Otherwise, use it.  */
5904  if (TYPE_PRECISION (enumtype))
5905    {
5906      if (precision > TYPE_PRECISION (enumtype))
5907	error ("specified mode too small for enumeral values");
5908    }
5909  else
5910    TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem);
5911
5912  layout_type (enumtype);
5913
5914  if (values != error_mark_node)
5915    {
5916      /* Change the type of the enumerators to be the enum type.  We
5917	 need to do this irrespective of the size of the enum, for
5918	 proper type checking.  Replace the DECL_INITIALs of the
5919	 enumerators, and the value slots of the list, with copies
5920	 that have the enum type; they cannot be modified in place
5921	 because they may be shared (e.g.  integer_zero_node) Finally,
5922	 change the purpose slots to point to the names of the decls.  */
5923      for (pair = values; pair; pair = TREE_CHAIN (pair))
5924	{
5925	  tree enu = TREE_PURPOSE (pair);
5926	  tree ini = DECL_INITIAL (enu);
5927
5928	  TREE_TYPE (enu) = enumtype;
5929
5930	  /* The ISO C Standard mandates enumerators to have type int,
5931	     even though the underlying type of an enum type is
5932	     unspecified.  Here we convert any enumerators that fit in
5933	     an int to type int, to avoid promotions to unsigned types
5934	     when comparing integers with enumerators that fit in the
5935	     int range.  When -pedantic is given, build_enumerator()
5936	     would have already taken care of those that don't fit.  */
5937	  if (int_fits_type_p (ini, integer_type_node))
5938	    tem = integer_type_node;
5939	  else
5940	    tem = enumtype;
5941	  ini = convert (tem, ini);
5942
5943	  DECL_INITIAL (enu) = ini;
5944	  TREE_PURPOSE (pair) = DECL_NAME (enu);
5945	  TREE_VALUE (pair) = ini;
5946	}
5947
5948      TYPE_VALUES (enumtype) = values;
5949    }
5950
5951  /* Record the min/max values so that we can warn about bit-field
5952     enumerations that are too small for the values.  */
5953  lt = GGC_CNEW (struct lang_type);
5954  lt->enum_min = minnode;
5955  lt->enum_max = maxnode;
5956  TYPE_LANG_SPECIFIC (enumtype) = lt;
5957
5958  /* Fix up all variant types of this enum type.  */
5959  for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem))
5960    {
5961      if (tem == enumtype)
5962	continue;
5963      TYPE_VALUES (tem) = TYPE_VALUES (enumtype);
5964      TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype);
5965      TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype);
5966      TYPE_SIZE (tem) = TYPE_SIZE (enumtype);
5967      TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype);
5968      TYPE_MODE (tem) = TYPE_MODE (enumtype);
5969      TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype);
5970      TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype);
5971      TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype);
5972      TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype);
5973      TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype);
5974    }
5975
5976  /* Finish debugging output for this type.  */
5977  rest_of_type_compilation (enumtype, toplevel);
5978
5979  return enumtype;
5980}
5981
5982/* Build and install a CONST_DECL for one value of the
5983   current enumeration type (one that was begun with start_enum).
5984   Return a tree-list containing the CONST_DECL and its value.
5985   Assignment of sequential values by default is handled here.  */
5986
5987tree
5988build_enumerator (tree name, tree value)
5989{
5990  tree decl, type;
5991
5992  /* Validate and default VALUE.  */
5993
5994  if (value != 0)
5995    {
5996      /* Don't issue more errors for error_mark_node (i.e. an
5997	 undeclared identifier) - just ignore the value expression.  */
5998      if (value == error_mark_node)
5999	value = 0;
6000      else if (!INTEGRAL_TYPE_P (TREE_TYPE (value))
6001	       || TREE_CODE (value) != INTEGER_CST)
6002	{
6003	  error ("enumerator value for %qE is not an integer constant", name);
6004	  value = 0;
6005	}
6006      else
6007	{
6008	  value = default_conversion (value);
6009	  constant_expression_warning (value);
6010	}
6011    }
6012
6013  /* Default based on previous value.  */
6014  /* It should no longer be possible to have NON_LVALUE_EXPR
6015     in the default.  */
6016  if (value == 0)
6017    {
6018      value = enum_next_value;
6019      if (enum_overflow)
6020	error ("overflow in enumeration values");
6021    }
6022
6023  if (pedantic && !int_fits_type_p (value, integer_type_node))
6024    {
6025      pedwarn ("ISO C restricts enumerator values to range of %<int%>");
6026      /* XXX This causes -pedantic to change the meaning of the program.
6027	 Remove?  -zw 2004-03-15  */
6028      value = convert (integer_type_node, value);
6029    }
6030
6031  /* Set basis for default for next value.  */
6032  enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0);
6033  enum_overflow = tree_int_cst_lt (enum_next_value, value);
6034
6035  /* Now create a declaration for the enum value name.  */
6036
6037  type = TREE_TYPE (value);
6038  type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
6039				      TYPE_PRECISION (integer_type_node)),
6040				 (TYPE_PRECISION (type)
6041				  >= TYPE_PRECISION (integer_type_node)
6042				  && TYPE_UNSIGNED (type)));
6043
6044  decl = build_decl (CONST_DECL, name, type);
6045  DECL_INITIAL (decl) = convert (type, value);
6046  pushdecl (decl);
6047
6048  return tree_cons (decl, value, NULL_TREE);
6049}
6050
6051
6052/* Create the FUNCTION_DECL for a function definition.
6053   DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of
6054   the declaration; they describe the function's name and the type it returns,
6055   but twisted together in a fashion that parallels the syntax of C.
6056
6057   This function creates a binding context for the function body
6058   as well as setting up the FUNCTION_DECL in current_function_decl.
6059
6060   Returns 1 on success.  If the DECLARATOR is not suitable for a function
6061   (it defines a datum instead), we return 0, which tells
6062   yyparse to report a parse error.  */
6063
6064int
6065start_function (struct c_declspecs *declspecs, struct c_declarator *declarator,
6066		tree attributes)
6067{
6068  tree decl1, old_decl;
6069  tree restype, resdecl;
6070  struct c_label_context_se *nstack_se;
6071  struct c_label_context_vm *nstack_vm;
6072
6073  current_function_returns_value = 0;  /* Assume, until we see it does.  */
6074  current_function_returns_null = 0;
6075  current_function_returns_abnormally = 0;
6076  warn_about_return_type = 0;
6077  c_switch_stack = NULL;
6078
6079  nstack_se = XOBNEW (&parser_obstack, struct c_label_context_se);
6080  nstack_se->labels_def = NULL;
6081  nstack_se->labels_used = NULL;
6082  nstack_se->next = label_context_stack_se;
6083  label_context_stack_se = nstack_se;
6084
6085  nstack_vm = XOBNEW (&parser_obstack, struct c_label_context_vm);
6086  nstack_vm->labels_def = NULL;
6087  nstack_vm->labels_used = NULL;
6088  nstack_vm->scope = 0;
6089  nstack_vm->next = label_context_stack_vm;
6090  label_context_stack_vm = nstack_vm;
6091
6092  /* Indicate no valid break/continue context by setting these variables
6093     to some non-null, non-label value.  We'll notice and emit the proper
6094     error message in c_finish_bc_stmt.  */
6095  c_break_label = c_cont_label = size_zero_node;
6096
6097  decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL);
6098
6099  /* If the declarator is not suitable for a function definition,
6100     cause a syntax error.  */
6101  if (decl1 == 0)
6102    {
6103      label_context_stack_se = label_context_stack_se->next;
6104      label_context_stack_vm = label_context_stack_vm->next;
6105      return 0;
6106    }
6107
6108  decl_attributes (&decl1, attributes, 0);
6109
6110  if (DECL_DECLARED_INLINE_P (decl1)
6111      && DECL_UNINLINABLE (decl1)
6112      && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1)))
6113    warning (OPT_Wattributes, "inline function %q+D given attribute noinline",
6114	     decl1);
6115
6116  /* Handle gnu_inline attribute.  */
6117  if (declspecs->inline_p
6118      && !flag_gnu89_inline
6119      && TREE_CODE (decl1) == FUNCTION_DECL
6120      && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1)))
6121    {
6122      if (declspecs->storage_class != csc_static)
6123	DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1);
6124    }
6125
6126  announce_function (decl1);
6127
6128  if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1))))
6129    {
6130      error ("return type is an incomplete type");
6131      /* Make it return void instead.  */
6132      TREE_TYPE (decl1)
6133	= build_function_type (void_type_node,
6134			       TYPE_ARG_TYPES (TREE_TYPE (decl1)));
6135    }
6136
6137  if (warn_about_return_type)
6138    pedwarn_c99 ("return type defaults to %<int%>");
6139
6140  /* Make the init_value nonzero so pushdecl knows this is not tentative.
6141     error_mark_node is replaced below (in pop_scope) with the BLOCK.  */
6142  DECL_INITIAL (decl1) = error_mark_node;
6143
6144  /* If this definition isn't a prototype and we had a prototype declaration
6145     before, copy the arg type info from that prototype.  */
6146  old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope);
6147  if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL)
6148    old_decl = 0;
6149  current_function_prototype_locus = UNKNOWN_LOCATION;
6150  current_function_prototype_built_in = false;
6151  current_function_prototype_arg_types = NULL_TREE;
6152  if (TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0)
6153    {
6154      if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE
6155	  && comptypes (TREE_TYPE (TREE_TYPE (decl1)),
6156			TREE_TYPE (TREE_TYPE (old_decl))))
6157	{
6158	  TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl),
6159					      TREE_TYPE (decl1));
6160	  current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl);
6161	  current_function_prototype_built_in
6162	    = C_DECL_BUILTIN_PROTOTYPE (old_decl);
6163	  current_function_prototype_arg_types
6164	    = TYPE_ARG_TYPES (TREE_TYPE (decl1));
6165	}
6166      if (TREE_PUBLIC (decl1))
6167	{
6168	  /* If there is an external prototype declaration of this
6169	     function, record its location but do not copy information
6170	     to this decl.  This may be an invisible declaration
6171	     (built-in or in a scope which has finished) or simply
6172	     have more refined argument types than any declaration
6173	     found above.  */
6174	  struct c_binding *b;
6175	  for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed)
6176	    if (B_IN_SCOPE (b, external_scope))
6177	      break;
6178	  if (b)
6179	    {
6180	      tree ext_decl, ext_type;
6181	      ext_decl = b->decl;
6182	      ext_type = b->type ? b->type : TREE_TYPE (ext_decl);
6183	      if (TREE_CODE (ext_type) == FUNCTION_TYPE
6184		  && comptypes (TREE_TYPE (TREE_TYPE (decl1)),
6185				TREE_TYPE (ext_type)))
6186		{
6187		  current_function_prototype_locus
6188		    = DECL_SOURCE_LOCATION (ext_decl);
6189		  current_function_prototype_built_in
6190		    = C_DECL_BUILTIN_PROTOTYPE (ext_decl);
6191		  current_function_prototype_arg_types
6192		    = TYPE_ARG_TYPES (ext_type);
6193		}
6194	    }
6195	}
6196    }
6197
6198  /* Optionally warn of old-fashioned def with no previous prototype.  */
6199  if (warn_strict_prototypes
6200      && old_decl != error_mark_node
6201      && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0
6202      && C_DECL_ISNT_PROTOTYPE (old_decl))
6203    warning (OPT_Wstrict_prototypes,
6204	     "function declaration isn%'t a prototype");
6205  /* Optionally warn of any global def with no previous prototype.  */
6206  else if (warn_missing_prototypes
6207	   && old_decl != error_mark_node
6208	   && TREE_PUBLIC (decl1)
6209	   && !MAIN_NAME_P (DECL_NAME (decl1))
6210	   && C_DECL_ISNT_PROTOTYPE (old_decl))
6211    warning (OPT_Wmissing_prototypes, "no previous prototype for %q+D", decl1);
6212  /* Optionally warn of any def with no previous prototype
6213     if the function has already been used.  */
6214  else if (warn_missing_prototypes
6215	   && old_decl != 0
6216	   && old_decl != error_mark_node
6217	   && TREE_USED (old_decl)
6218	   && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0)
6219    warning (OPT_Wmissing_prototypes,
6220	     "%q+D was used with no prototype before its definition", decl1);
6221  /* Optionally warn of any global def with no previous declaration.  */
6222  else if (warn_missing_declarations
6223	   && TREE_PUBLIC (decl1)
6224	   && old_decl == 0
6225	   && !MAIN_NAME_P (DECL_NAME (decl1)))
6226    warning (OPT_Wmissing_declarations, "no previous declaration for %q+D",
6227	     decl1);
6228  /* Optionally warn of any def with no previous declaration
6229     if the function has already been used.  */
6230  else if (warn_missing_declarations
6231	   && old_decl != 0
6232	   && old_decl != error_mark_node
6233	   && TREE_USED (old_decl)
6234	   && C_DECL_IMPLICIT (old_decl))
6235    warning (OPT_Wmissing_declarations,
6236	     "%q+D was used with no declaration before its definition", decl1);
6237
6238  /* This function exists in static storage.
6239     (This does not mean `static' in the C sense!)  */
6240  TREE_STATIC (decl1) = 1;
6241
6242  /* A nested function is not global.  */
6243  if (current_function_decl != 0)
6244    TREE_PUBLIC (decl1) = 0;
6245
6246  /* This is the earliest point at which we might know the assembler
6247     name of the function.  Thus, if it's set before this, die horribly.  */
6248  gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1));
6249
6250  /* If #pragma weak was used, mark the decl weak now.  */
6251  if (current_scope == file_scope)
6252    maybe_apply_pragma_weak (decl1);
6253
6254  /* Warn for unlikely, improbable, or stupid declarations of `main'.  */
6255  if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1)))
6256    {
6257      tree args;
6258      int argct = 0;
6259
6260      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1)))
6261	  != integer_type_node)
6262	pedwarn ("return type of %q+D is not %<int%>", decl1);
6263
6264      for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args;
6265	   args = TREE_CHAIN (args))
6266	{
6267	  tree type = args ? TREE_VALUE (args) : 0;
6268
6269	  if (type == void_type_node)
6270	    break;
6271
6272	  ++argct;
6273	  switch (argct)
6274	    {
6275	    case 1:
6276	      if (TYPE_MAIN_VARIANT (type) != integer_type_node)
6277		pedwarn ("first argument of %q+D should be %<int%>", decl1);
6278	      break;
6279
6280	    case 2:
6281	      if (TREE_CODE (type) != POINTER_TYPE
6282		  || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
6283		  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
6284		      != char_type_node))
6285		pedwarn ("second argument of %q+D should be %<char **%>",
6286			 decl1);
6287	      break;
6288
6289	    case 3:
6290	      if (TREE_CODE (type) != POINTER_TYPE
6291		  || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
6292		  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
6293		      != char_type_node))
6294		pedwarn ("third argument of %q+D should probably be "
6295			 "%<char **%>", decl1);
6296	      break;
6297	    }
6298	}
6299
6300      /* It is intentional that this message does not mention the third
6301	 argument because it's only mentioned in an appendix of the
6302	 standard.  */
6303      if (argct > 0 && (argct < 2 || argct > 3))
6304	pedwarn ("%q+D takes only zero or two arguments", decl1);
6305
6306      if (!TREE_PUBLIC (decl1))
6307	pedwarn ("%q+D is normally a non-static function", decl1);
6308    }
6309
6310  /* Record the decl so that the function name is defined.
6311     If we already have a decl for this name, and it is a FUNCTION_DECL,
6312     use the old decl.  */
6313
6314  current_function_decl = pushdecl (decl1);
6315
6316  push_scope ();
6317  declare_parm_level ();
6318
6319  restype = TREE_TYPE (TREE_TYPE (current_function_decl));
6320  /* Promote the value to int before returning it.  */
6321  if (c_promoting_integer_type_p (restype))
6322    {
6323      /* It retains unsignedness if not really getting wider.  */
6324      if (TYPE_UNSIGNED (restype)
6325	  && (TYPE_PRECISION (restype)
6326		  == TYPE_PRECISION (integer_type_node)))
6327	restype = unsigned_type_node;
6328      else
6329	restype = integer_type_node;
6330    }
6331
6332  resdecl = build_decl (RESULT_DECL, NULL_TREE, restype);
6333  DECL_ARTIFICIAL (resdecl) = 1;
6334  DECL_IGNORED_P (resdecl) = 1;
6335  DECL_RESULT (current_function_decl) = resdecl;
6336
6337  start_fname_decls ();
6338
6339  return 1;
6340}
6341
6342/* Subroutine of store_parm_decls which handles new-style function
6343   definitions (prototype format). The parms already have decls, so we
6344   need only record them as in effect and complain if any redundant
6345   old-style parm decls were written.  */
6346static void
6347store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info)
6348{
6349  tree decl;
6350
6351  if (current_scope->bindings)
6352    {
6353      error ("%Jold-style parameter declarations in prototyped "
6354	     "function definition", fndecl);
6355
6356      /* Get rid of the old-style declarations.  */
6357      pop_scope ();
6358      push_scope ();
6359    }
6360  /* Don't issue this warning for nested functions, and don't issue this
6361     warning if we got here because ARG_INFO_TYPES was error_mark_node
6362     (this happens when a function definition has just an ellipsis in
6363     its parameter list).  */
6364  else if (!in_system_header && !current_function_scope
6365	   && arg_info->types != error_mark_node)
6366    warning (OPT_Wtraditional,
6367	     "%Jtraditional C rejects ISO C style function definitions",
6368	     fndecl);
6369
6370  /* Now make all the parameter declarations visible in the function body.
6371     We can bypass most of the grunt work of pushdecl.  */
6372  for (decl = arg_info->parms; decl; decl = TREE_CHAIN (decl))
6373    {
6374      DECL_CONTEXT (decl) = current_function_decl;
6375      if (DECL_NAME (decl))
6376	{
6377	  bind (DECL_NAME (decl), decl, current_scope,
6378		/*invisible=*/false, /*nested=*/false);
6379	  if (!TREE_USED (decl))
6380	    warn_if_shadowing (decl);
6381	}
6382      else
6383	error ("%Jparameter name omitted", decl);
6384    }
6385
6386  /* Record the parameter list in the function declaration.  */
6387  DECL_ARGUMENTS (fndecl) = arg_info->parms;
6388
6389  /* Now make all the ancillary declarations visible, likewise.  */
6390  for (decl = arg_info->others; decl; decl = TREE_CHAIN (decl))
6391    {
6392      DECL_CONTEXT (decl) = current_function_decl;
6393      if (DECL_NAME (decl))
6394	bind (DECL_NAME (decl), decl, current_scope,
6395	      /*invisible=*/false, /*nested=*/false);
6396    }
6397
6398  /* And all the tag declarations.  */
6399  for (decl = arg_info->tags; decl; decl = TREE_CHAIN (decl))
6400    if (TREE_PURPOSE (decl))
6401      bind (TREE_PURPOSE (decl), TREE_VALUE (decl), current_scope,
6402	    /*invisible=*/false, /*nested=*/false);
6403}
6404
6405/* Subroutine of store_parm_decls which handles old-style function
6406   definitions (separate parameter list and declarations).  */
6407
6408static void
6409store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info)
6410{
6411  struct c_binding *b;
6412  tree parm, decl, last;
6413  tree parmids = arg_info->parms;
6414  struct pointer_set_t *seen_args = pointer_set_create ();
6415
6416  if (!in_system_header)
6417    warning (OPT_Wold_style_definition, "%Jold-style function definition",
6418	     fndecl);
6419
6420  /* Match each formal parameter name with its declaration.  Save each
6421     decl in the appropriate TREE_PURPOSE slot of the parmids chain.  */
6422  for (parm = parmids; parm; parm = TREE_CHAIN (parm))
6423    {
6424      if (TREE_VALUE (parm) == 0)
6425	{
6426	  error ("%Jparameter name missing from parameter list", fndecl);
6427	  TREE_PURPOSE (parm) = 0;
6428	  continue;
6429	}
6430
6431      b = I_SYMBOL_BINDING (TREE_VALUE (parm));
6432      if (b && B_IN_CURRENT_SCOPE (b))
6433	{
6434	  decl = b->decl;
6435	  /* If we got something other than a PARM_DECL it is an error.  */
6436	  if (TREE_CODE (decl) != PARM_DECL)
6437	    error ("%q+D declared as a non-parameter", decl);
6438	  /* If the declaration is already marked, we have a duplicate
6439	     name.  Complain and ignore the duplicate.  */
6440	  else if (pointer_set_contains (seen_args, decl))
6441	    {
6442	      error ("multiple parameters named %q+D", decl);
6443	      TREE_PURPOSE (parm) = 0;
6444	      continue;
6445	    }
6446	  /* If the declaration says "void", complain and turn it into
6447	     an int.  */
6448	  else if (VOID_TYPE_P (TREE_TYPE (decl)))
6449	    {
6450	      error ("parameter %q+D declared with void type", decl);
6451	      TREE_TYPE (decl) = integer_type_node;
6452	      DECL_ARG_TYPE (decl) = integer_type_node;
6453	      layout_decl (decl, 0);
6454	    }
6455	  warn_if_shadowing (decl);
6456	}
6457      /* If no declaration found, default to int.  */
6458      else
6459	{
6460	  decl = build_decl (PARM_DECL, TREE_VALUE (parm), integer_type_node);
6461	  DECL_ARG_TYPE (decl) = TREE_TYPE (decl);
6462	  DECL_SOURCE_LOCATION (decl) = DECL_SOURCE_LOCATION (fndecl);
6463	  pushdecl (decl);
6464	  warn_if_shadowing (decl);
6465
6466	  if (flag_isoc99)
6467	    pedwarn ("type of %q+D defaults to %<int%>", decl);
6468	  else if (extra_warnings)
6469	    warning (OPT_Wextra, "type of %q+D defaults to %<int%>", decl);
6470	}
6471
6472      TREE_PURPOSE (parm) = decl;
6473      pointer_set_insert (seen_args, decl);
6474    }
6475
6476  /* Now examine the parms chain for incomplete declarations
6477     and declarations with no corresponding names.  */
6478
6479  for (b = current_scope->bindings; b; b = b->prev)
6480    {
6481      parm = b->decl;
6482      if (TREE_CODE (parm) != PARM_DECL)
6483	continue;
6484
6485      if (TREE_TYPE (parm) != error_mark_node
6486	  && !COMPLETE_TYPE_P (TREE_TYPE (parm)))
6487	{
6488	  error ("parameter %q+D has incomplete type", parm);
6489	  TREE_TYPE (parm) = error_mark_node;
6490	}
6491
6492      if (!pointer_set_contains (seen_args, parm))
6493	{
6494	  error ("declaration for parameter %q+D but no such parameter", parm);
6495
6496	  /* Pretend the parameter was not missing.
6497	     This gets us to a standard state and minimizes
6498	     further error messages.  */
6499	  parmids = chainon (parmids, tree_cons (parm, 0, 0));
6500	}
6501    }
6502
6503  /* Chain the declarations together in the order of the list of
6504     names.  Store that chain in the function decl, replacing the
6505     list of names.  Update the current scope to match.  */
6506  DECL_ARGUMENTS (fndecl) = 0;
6507
6508  for (parm = parmids; parm; parm = TREE_CHAIN (parm))
6509    if (TREE_PURPOSE (parm))
6510      break;
6511  if (parm && TREE_PURPOSE (parm))
6512    {
6513      last = TREE_PURPOSE (parm);
6514      DECL_ARGUMENTS (fndecl) = last;
6515
6516      for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm))
6517	if (TREE_PURPOSE (parm))
6518	  {
6519	    TREE_CHAIN (last) = TREE_PURPOSE (parm);
6520	    last = TREE_PURPOSE (parm);
6521	  }
6522      TREE_CHAIN (last) = 0;
6523    }
6524
6525  pointer_set_destroy (seen_args);
6526
6527  /* If there was a previous prototype,
6528     set the DECL_ARG_TYPE of each argument according to
6529     the type previously specified, and report any mismatches.  */
6530
6531  if (current_function_prototype_arg_types)
6532    {
6533      tree type;
6534      for (parm = DECL_ARGUMENTS (fndecl),
6535	     type = current_function_prototype_arg_types;
6536	   parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type))
6537			     != void_type_node));
6538	   parm = TREE_CHAIN (parm), type = TREE_CHAIN (type))
6539	{
6540	  if (parm == 0 || type == 0
6541	      || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node)
6542	    {
6543	      if (current_function_prototype_built_in)
6544		warning (0, "number of arguments doesn%'t match "
6545			 "built-in prototype");
6546	      else
6547		{
6548		  error ("number of arguments doesn%'t match prototype");
6549		  error ("%Hprototype declaration",
6550			 &current_function_prototype_locus);
6551		}
6552	      break;
6553	    }
6554	  /* Type for passing arg must be consistent with that
6555	     declared for the arg.  ISO C says we take the unqualified
6556	     type for parameters declared with qualified type.  */
6557	  if (!comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)),
6558			  TYPE_MAIN_VARIANT (TREE_VALUE (type))))
6559	    {
6560	      if (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
6561		  == TYPE_MAIN_VARIANT (TREE_VALUE (type)))
6562		{
6563		  /* Adjust argument to match prototype.  E.g. a previous
6564		     `int foo(float);' prototype causes
6565		     `int foo(x) float x; {...}' to be treated like
6566		     `int foo(float x) {...}'.  This is particularly
6567		     useful for argument types like uid_t.  */
6568		  DECL_ARG_TYPE (parm) = TREE_TYPE (parm);
6569
6570		  if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl))
6571		      && INTEGRAL_TYPE_P (TREE_TYPE (parm))
6572		      && TYPE_PRECISION (TREE_TYPE (parm))
6573		      < TYPE_PRECISION (integer_type_node))
6574		    DECL_ARG_TYPE (parm) = integer_type_node;
6575
6576		  if (pedantic)
6577		    {
6578		      /* ??? Is it possible to get here with a
6579			 built-in prototype or will it always have
6580			 been diagnosed as conflicting with an
6581			 old-style definition and discarded?  */
6582		      if (current_function_prototype_built_in)
6583			warning (0, "promoted argument %qD "
6584				 "doesn%'t match built-in prototype", parm);
6585		      else
6586			{
6587			  pedwarn ("promoted argument %qD "
6588				   "doesn%'t match prototype", parm);
6589			  pedwarn ("%Hprototype declaration",
6590				   &current_function_prototype_locus);
6591			}
6592		    }
6593		}
6594	      else
6595		{
6596		  if (current_function_prototype_built_in)
6597		    warning (0, "argument %qD doesn%'t match "
6598			     "built-in prototype", parm);
6599		  else
6600		    {
6601		      error ("argument %qD doesn%'t match prototype", parm);
6602		      error ("%Hprototype declaration",
6603			     &current_function_prototype_locus);
6604		    }
6605		}
6606	    }
6607	}
6608      TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0;
6609    }
6610
6611  /* Otherwise, create a prototype that would match.  */
6612
6613  else
6614    {
6615      tree actual = 0, last = 0, type;
6616
6617      for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm))
6618	{
6619	  type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE);
6620	  if (last)
6621	    TREE_CHAIN (last) = type;
6622	  else
6623	    actual = type;
6624	  last = type;
6625	}
6626      type = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
6627      if (last)
6628	TREE_CHAIN (last) = type;
6629      else
6630	actual = type;
6631
6632      /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES
6633	 of the type of this function, but we need to avoid having this
6634	 affect the types of other similarly-typed functions, so we must
6635	 first force the generation of an identical (but separate) type
6636	 node for the relevant function type.  The new node we create
6637	 will be a variant of the main variant of the original function
6638	 type.  */
6639
6640      TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl));
6641
6642      TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual;
6643    }
6644}
6645
6646/* Store parameter declarations passed in ARG_INFO into the current
6647   function declaration.  */
6648
6649void
6650store_parm_decls_from (struct c_arg_info *arg_info)
6651{
6652  current_function_arg_info = arg_info;
6653  store_parm_decls ();
6654}
6655
6656/* Store the parameter declarations into the current function declaration.
6657   This is called after parsing the parameter declarations, before
6658   digesting the body of the function.
6659
6660   For an old-style definition, construct a prototype out of the old-style
6661   parameter declarations and inject it into the function's type.  */
6662
6663void
6664store_parm_decls (void)
6665{
6666  tree fndecl = current_function_decl;
6667  bool proto;
6668
6669  /* The argument information block for FNDECL.  */
6670  struct c_arg_info *arg_info = current_function_arg_info;
6671  current_function_arg_info = 0;
6672
6673  /* True if this definition is written with a prototype.  Note:
6674     despite C99 6.7.5.3p14, we can *not* treat an empty argument
6675     list in a function definition as equivalent to (void) -- an
6676     empty argument list specifies the function has no parameters,
6677     but only (void) sets up a prototype for future calls.  */
6678  proto = arg_info->types != 0;
6679
6680  if (proto)
6681    store_parm_decls_newstyle (fndecl, arg_info);
6682  else
6683    store_parm_decls_oldstyle (fndecl, arg_info);
6684
6685  /* The next call to push_scope will be a function body.  */
6686
6687  next_is_function_body = true;
6688
6689  /* Write a record describing this function definition to the prototypes
6690     file (if requested).  */
6691
6692  gen_aux_info_record (fndecl, 1, 0, proto);
6693
6694  /* Initialize the RTL code for the function.  */
6695  allocate_struct_function (fndecl);
6696
6697  /* Begin the statement tree for this function.  */
6698  DECL_SAVED_TREE (fndecl) = push_stmt_list ();
6699
6700  /* ??? Insert the contents of the pending sizes list into the function
6701     to be evaluated.  The only reason left to have this is
6702	void foo(int n, int array[n++])
6703     because we throw away the array type in favor of a pointer type, and
6704     thus won't naturally see the SAVE_EXPR containing the increment.  All
6705     other pending sizes would be handled by gimplify_parameters.  */
6706  {
6707    tree t;
6708    for (t = nreverse (get_pending_sizes ()); t ; t = TREE_CHAIN (t))
6709      add_stmt (TREE_VALUE (t));
6710  }
6711
6712  /* Even though we're inside a function body, we still don't want to
6713     call expand_expr to calculate the size of a variable-sized array.
6714     We haven't necessarily assigned RTL to all variables yet, so it's
6715     not safe to try to expand expressions involving them.  */
6716  cfun->x_dont_save_pending_sizes_p = 1;
6717}
6718
6719/* Emit diagnostics that require gimple input for detection.  Operate on
6720   FNDECL and all its nested functions.  */
6721
6722static void
6723c_gimple_diagnostics_recursively (tree fndecl)
6724{
6725  struct cgraph_node *cgn;
6726
6727  /* Handle attribute((warn_unused_result)).  Relies on gimple input.  */
6728  c_warn_unused_result (&DECL_SAVED_TREE (fndecl));
6729
6730  /* Notice when OpenMP structured block constraints are violated.  */
6731  if (flag_openmp)
6732    diagnose_omp_structured_block_errors (fndecl);
6733
6734  /* Finalize all nested functions now.  */
6735  cgn = cgraph_node (fndecl);
6736  for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
6737    c_gimple_diagnostics_recursively (cgn->decl);
6738}
6739
6740/* Finish up a function declaration and compile that function
6741   all the way to assembler language output.  The free the storage
6742   for the function definition.
6743
6744   This is called after parsing the body of the function definition.  */
6745
6746void
6747finish_function (void)
6748{
6749  tree fndecl = current_function_decl;
6750
6751  label_context_stack_se = label_context_stack_se->next;
6752  label_context_stack_vm = label_context_stack_vm->next;
6753
6754  if (TREE_CODE (fndecl) == FUNCTION_DECL
6755      && targetm.calls.promote_prototypes (TREE_TYPE (fndecl)))
6756    {
6757      tree args = DECL_ARGUMENTS (fndecl);
6758      for (; args; args = TREE_CHAIN (args))
6759	{
6760	  tree type = TREE_TYPE (args);
6761	  if (INTEGRAL_TYPE_P (type)
6762	      && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))
6763	    DECL_ARG_TYPE (args) = integer_type_node;
6764	}
6765    }
6766
6767  if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node)
6768    BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl;
6769
6770  /* Must mark the RESULT_DECL as being in this function.  */
6771
6772  if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node)
6773    DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
6774
6775  if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted)
6776    {
6777      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl)))
6778	  != integer_type_node)
6779	{
6780	  /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned.
6781	     If warn_main is -1 (-Wno-main) we don't want to be warned.  */
6782	  if (!warn_main)
6783	    pedwarn ("return type of %q+D is not %<int%>", fndecl);
6784	}
6785      else
6786	{
6787	  if (flag_isoc99)
6788	    {
6789	      tree stmt = c_finish_return (integer_zero_node);
6790#ifdef USE_MAPPED_LOCATION
6791	      /* Hack.  We don't want the middle-end to warn that this return
6792		 is unreachable, so we mark its location as special.  Using
6793		 UNKNOWN_LOCATION has the problem that it gets clobbered in
6794		 annotate_one_with_locus.  A cleaner solution might be to
6795		 ensure ! should_carry_locus_p (stmt), but that needs a flag.
6796	      */
6797	      SET_EXPR_LOCATION (stmt, BUILTINS_LOCATION);
6798#else
6799	      /* Hack.  We don't want the middle-end to warn that this
6800		 return is unreachable, so put the statement on the
6801		 special line 0.  */
6802	      annotate_with_file_line (stmt, input_filename, 0);
6803#endif
6804	    }
6805	}
6806    }
6807
6808  /* Tie off the statement tree for this function.  */
6809  DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl));
6810
6811  finish_fname_decls ();
6812
6813  /* Complain if there's just no return statement.  */
6814  if (warn_return_type
6815      && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE
6816      && !current_function_returns_value && !current_function_returns_null
6817      /* Don't complain if we are no-return.  */
6818      && !current_function_returns_abnormally
6819      /* Don't warn for main().  */
6820      && !MAIN_NAME_P (DECL_NAME (fndecl))
6821      /* Or if they didn't actually specify a return type.  */
6822      && !C_FUNCTION_IMPLICIT_INT (fndecl)
6823      /* Normally, with -Wreturn-type, flow will complain.  Unless we're an
6824	 inline function, as we might never be compiled separately.  */
6825      && DECL_INLINE (fndecl))
6826    {
6827      warning (OPT_Wreturn_type,
6828	       "no return statement in function returning non-void");
6829      TREE_NO_WARNING (fndecl) = 1;
6830    }
6831
6832  /* With just -Wextra, complain only if function returns both with
6833     and without a value.  */
6834  if (extra_warnings
6835      && current_function_returns_value
6836      && current_function_returns_null)
6837    warning (OPT_Wextra, "this function may return with or without a value");
6838
6839  /* Store the end of the function, so that we get good line number
6840     info for the epilogue.  */
6841  cfun->function_end_locus = input_location;
6842
6843  /* If we don't have ctors/dtors sections, and this is a static
6844     constructor or destructor, it must be recorded now.  */
6845  if (DECL_STATIC_CONSTRUCTOR (fndecl)
6846      && !targetm.have_ctors_dtors)
6847    static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors);
6848  if (DECL_STATIC_DESTRUCTOR (fndecl)
6849      && !targetm.have_ctors_dtors)
6850    static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors);
6851
6852  /* Finalize the ELF visibility for the function.  */
6853  c_determine_visibility (fndecl);
6854
6855  /* Genericize before inlining.  Delay genericizing nested functions
6856     until their parent function is genericized.  Since finalizing
6857     requires GENERIC, delay that as well.  */
6858
6859  if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node
6860      && !undef_nested_function)
6861    {
6862      if (!decl_function_context (fndecl))
6863	{
6864	  c_genericize (fndecl);
6865	  c_gimple_diagnostics_recursively (fndecl);
6866
6867	  /* ??? Objc emits functions after finalizing the compilation unit.
6868	     This should be cleaned up later and this conditional removed.  */
6869	  if (cgraph_global_info_ready)
6870	    {
6871	      c_expand_body (fndecl);
6872	      return;
6873	    }
6874
6875	  cgraph_finalize_function (fndecl, false);
6876	}
6877      else
6878	{
6879	  /* Register this function with cgraph just far enough to get it
6880	    added to our parent's nested function list.  Handy, since the
6881	    C front end doesn't have such a list.  */
6882	  (void) cgraph_node (fndecl);
6883	}
6884    }
6885
6886  if (!decl_function_context (fndecl))
6887    undef_nested_function = false;
6888
6889  /* We're leaving the context of this function, so zap cfun.
6890     It's still in DECL_STRUCT_FUNCTION, and we'll restore it in
6891     tree_rest_of_compilation.  */
6892  cfun = NULL;
6893  current_function_decl = NULL;
6894}
6895
6896/* Generate the RTL for the body of FNDECL.  */
6897
6898void
6899c_expand_body (tree fndecl)
6900{
6901
6902  if (!DECL_INITIAL (fndecl)
6903      || DECL_INITIAL (fndecl) == error_mark_node)
6904    return;
6905
6906  tree_rest_of_compilation (fndecl);
6907
6908  if (DECL_STATIC_CONSTRUCTOR (fndecl)
6909      && targetm.have_ctors_dtors)
6910    targetm.asm_out.constructor (XEXP (DECL_RTL (fndecl), 0),
6911				 DEFAULT_INIT_PRIORITY);
6912  if (DECL_STATIC_DESTRUCTOR (fndecl)
6913      && targetm.have_ctors_dtors)
6914    targetm.asm_out.destructor (XEXP (DECL_RTL (fndecl), 0),
6915				DEFAULT_INIT_PRIORITY);
6916}
6917
6918/* Check the declarations given in a for-loop for satisfying the C99
6919   constraints.  If exactly one such decl is found, return it.  */
6920
6921tree
6922check_for_loop_decls (void)
6923{
6924  struct c_binding *b;
6925  tree one_decl = NULL_TREE;
6926  int n_decls = 0;
6927
6928
6929  if (!flag_isoc99)
6930    {
6931      /* If we get here, declarations have been used in a for loop without
6932	 the C99 for loop scope.  This doesn't make much sense, so don't
6933	 allow it.  */
6934      error ("%<for%> loop initial declaration used outside C99 mode");
6935      return NULL_TREE;
6936    }
6937  /* C99 subclause 6.8.5 paragraph 3:
6938
6939       [#3]  The  declaration  part  of  a for statement shall only
6940       declare identifiers for objects having storage class auto or
6941       register.
6942
6943     It isn't clear whether, in this sentence, "identifiers" binds to
6944     "shall only declare" or to "objects" - that is, whether all identifiers
6945     declared must be identifiers for objects, or whether the restriction
6946     only applies to those that are.  (A question on this in comp.std.c
6947     in November 2000 received no answer.)  We implement the strictest
6948     interpretation, to avoid creating an extension which later causes
6949     problems.  */
6950
6951  for (b = current_scope->bindings; b; b = b->prev)
6952    {
6953      tree id = b->id;
6954      tree decl = b->decl;
6955
6956      if (!id)
6957	continue;
6958
6959      switch (TREE_CODE (decl))
6960	{
6961	case VAR_DECL:
6962	  if (TREE_STATIC (decl))
6963	    error ("declaration of static variable %q+D in %<for%> loop "
6964		   "initial declaration", decl);
6965	  else if (DECL_EXTERNAL (decl))
6966	    error ("declaration of %<extern%> variable %q+D in %<for%> loop "
6967		   "initial declaration", decl);
6968	  break;
6969
6970	case RECORD_TYPE:
6971	  error ("%<struct %E%> declared in %<for%> loop initial declaration",
6972		 id);
6973	  break;
6974	case UNION_TYPE:
6975	  error ("%<union %E%> declared in %<for%> loop initial declaration",
6976		 id);
6977	  break;
6978	case ENUMERAL_TYPE:
6979	  error ("%<enum %E%> declared in %<for%> loop initial declaration",
6980		 id);
6981	  break;
6982	default:
6983	  error ("declaration of non-variable %q+D in %<for%> loop "
6984		 "initial declaration", decl);
6985	}
6986
6987      n_decls++;
6988      one_decl = decl;
6989    }
6990
6991  return n_decls == 1 ? one_decl : NULL_TREE;
6992}
6993
6994/* Save and reinitialize the variables
6995   used during compilation of a C function.  */
6996
6997void
6998c_push_function_context (struct function *f)
6999{
7000  struct language_function *p;
7001  p = GGC_NEW (struct language_function);
7002  f->language = p;
7003
7004  p->base.x_stmt_tree = c_stmt_tree;
7005  p->x_break_label = c_break_label;
7006  p->x_cont_label = c_cont_label;
7007  p->x_switch_stack = c_switch_stack;
7008  p->arg_info = current_function_arg_info;
7009  p->returns_value = current_function_returns_value;
7010  p->returns_null = current_function_returns_null;
7011  p->returns_abnormally = current_function_returns_abnormally;
7012  p->warn_about_return_type = warn_about_return_type;
7013}
7014
7015/* Restore the variables used during compilation of a C function.  */
7016
7017void
7018c_pop_function_context (struct function *f)
7019{
7020  struct language_function *p = f->language;
7021
7022  if (DECL_STRUCT_FUNCTION (current_function_decl) == 0
7023      && DECL_SAVED_TREE (current_function_decl) == NULL_TREE)
7024    {
7025      /* Stop pointing to the local nodes about to be freed.  */
7026      /* But DECL_INITIAL must remain nonzero so we know this
7027	 was an actual function definition.  */
7028      DECL_INITIAL (current_function_decl) = error_mark_node;
7029      DECL_ARGUMENTS (current_function_decl) = 0;
7030    }
7031
7032  c_stmt_tree = p->base.x_stmt_tree;
7033  c_break_label = p->x_break_label;
7034  c_cont_label = p->x_cont_label;
7035  c_switch_stack = p->x_switch_stack;
7036  current_function_arg_info = p->arg_info;
7037  current_function_returns_value = p->returns_value;
7038  current_function_returns_null = p->returns_null;
7039  current_function_returns_abnormally = p->returns_abnormally;
7040  warn_about_return_type = p->warn_about_return_type;
7041
7042  f->language = NULL;
7043}
7044
7045/* Copy the DECL_LANG_SPECIFIC data associated with DECL.  */
7046
7047void
7048c_dup_lang_specific_decl (tree decl)
7049{
7050  struct lang_decl *ld;
7051
7052  if (!DECL_LANG_SPECIFIC (decl))
7053    return;
7054
7055  ld = GGC_NEW (struct lang_decl);
7056  memcpy (ld, DECL_LANG_SPECIFIC (decl), sizeof (struct lang_decl));
7057  DECL_LANG_SPECIFIC (decl) = ld;
7058}
7059
7060/* The functions below are required for functionality of doing
7061   function at once processing in the C front end. Currently these
7062   functions are not called from anywhere in the C front end, but as
7063   these changes continue, that will change.  */
7064
7065/* Returns the stmt_tree (if any) to which statements are currently
7066   being added.  If there is no active statement-tree, NULL is
7067   returned.  */
7068
7069stmt_tree
7070current_stmt_tree (void)
7071{
7072  return &c_stmt_tree;
7073}
7074
7075/* Nonzero if TYPE is an anonymous union or struct type.  Always 0 in
7076   C.  */
7077
7078int
7079anon_aggr_type_p (tree ARG_UNUSED (node))
7080{
7081  return 0;
7082}
7083
7084/* Return the global value of T as a symbol.  */
7085
7086tree
7087identifier_global_value	(tree t)
7088{
7089  struct c_binding *b;
7090
7091  for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed)
7092    if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b))
7093      return b->decl;
7094
7095  return 0;
7096}
7097
7098/* Record a builtin type for C.  If NAME is non-NULL, it is the name used;
7099   otherwise the name is found in ridpointers from RID_INDEX.  */
7100
7101void
7102record_builtin_type (enum rid rid_index, const char *name, tree type)
7103{
7104  tree id, decl;
7105  if (name == 0)
7106    id = ridpointers[(int) rid_index];
7107  else
7108    id = get_identifier (name);
7109  decl = build_decl (TYPE_DECL, id, type);
7110  pushdecl (decl);
7111  if (debug_hooks->type_decl)
7112    debug_hooks->type_decl (decl, false);
7113}
7114
7115/* Build the void_list_node (void_type_node having been created).  */
7116tree
7117build_void_list_node (void)
7118{
7119  tree t = build_tree_list (NULL_TREE, void_type_node);
7120  return t;
7121}
7122
7123/* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR.  */
7124
7125struct c_parm *
7126build_c_parm (struct c_declspecs *specs, tree attrs,
7127	      struct c_declarator *declarator)
7128{
7129  struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm);
7130  ret->specs = specs;
7131  ret->attrs = attrs;
7132  ret->declarator = declarator;
7133  return ret;
7134}
7135
7136/* Return a declarator with nested attributes.  TARGET is the inner
7137   declarator to which these attributes apply.  ATTRS are the
7138   attributes.  */
7139
7140struct c_declarator *
7141build_attrs_declarator (tree attrs, struct c_declarator *target)
7142{
7143  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7144  ret->kind = cdk_attrs;
7145  ret->declarator = target;
7146  ret->u.attrs = attrs;
7147  return ret;
7148}
7149
7150/* Return a declarator for a function with arguments specified by ARGS
7151   and return type specified by TARGET.  */
7152
7153struct c_declarator *
7154build_function_declarator (struct c_arg_info *args,
7155			   struct c_declarator *target)
7156{
7157  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7158  ret->kind = cdk_function;
7159  ret->declarator = target;
7160  ret->u.arg_info = args;
7161  return ret;
7162}
7163
7164/* Return a declarator for the identifier IDENT (which may be
7165   NULL_TREE for an abstract declarator).  */
7166
7167struct c_declarator *
7168build_id_declarator (tree ident)
7169{
7170  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7171  ret->kind = cdk_id;
7172  ret->declarator = 0;
7173  ret->u.id = ident;
7174  /* Default value - may get reset to a more precise location. */
7175  ret->id_loc = input_location;
7176  return ret;
7177}
7178
7179/* Return something to represent absolute declarators containing a *.
7180   TARGET is the absolute declarator that the * contains.
7181   TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes
7182   to apply to the pointer type.  */
7183
7184struct c_declarator *
7185make_pointer_declarator (struct c_declspecs *type_quals_attrs,
7186			 struct c_declarator *target)
7187{
7188  tree attrs;
7189  int quals = 0;
7190  struct c_declarator *itarget = target;
7191  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7192  if (type_quals_attrs)
7193    {
7194      attrs = type_quals_attrs->attrs;
7195      quals = quals_from_declspecs (type_quals_attrs);
7196      if (attrs != NULL_TREE)
7197	itarget = build_attrs_declarator (attrs, target);
7198    }
7199  ret->kind = cdk_pointer;
7200  ret->declarator = itarget;
7201  ret->u.pointer_quals = quals;
7202  return ret;
7203}
7204
7205/* Return a pointer to a structure for an empty list of declaration
7206   specifiers.  */
7207
7208struct c_declspecs *
7209build_null_declspecs (void)
7210{
7211  struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs);
7212  ret->type = 0;
7213  ret->decl_attr = 0;
7214  ret->attrs = 0;
7215  ret->typespec_word = cts_none;
7216  ret->storage_class = csc_none;
7217  ret->declspecs_seen_p = false;
7218  ret->type_seen_p = false;
7219  ret->non_sc_seen_p = false;
7220  ret->typedef_p = false;
7221  ret->tag_defined_p = false;
7222  ret->explicit_signed_p = false;
7223  ret->deprecated_p = false;
7224  ret->default_int_p = false;
7225  ret->long_p = false;
7226  ret->long_long_p = false;
7227  ret->short_p = false;
7228  ret->signed_p = false;
7229  ret->unsigned_p = false;
7230  ret->complex_p = false;
7231  ret->inline_p = false;
7232  ret->thread_p = false;
7233  ret->const_p = false;
7234  ret->volatile_p = false;
7235  ret->restrict_p = false;
7236  return ret;
7237}
7238
7239/* Add the type qualifier QUAL to the declaration specifiers SPECS,
7240   returning SPECS.  */
7241
7242struct c_declspecs *
7243declspecs_add_qual (struct c_declspecs *specs, tree qual)
7244{
7245  enum rid i;
7246  bool dupe = false;
7247  specs->non_sc_seen_p = true;
7248  specs->declspecs_seen_p = true;
7249  gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE
7250	      && C_IS_RESERVED_WORD (qual));
7251  i = C_RID_CODE (qual);
7252  switch (i)
7253    {
7254    case RID_CONST:
7255      dupe = specs->const_p;
7256      specs->const_p = true;
7257      break;
7258    case RID_VOLATILE:
7259      dupe = specs->volatile_p;
7260      specs->volatile_p = true;
7261      break;
7262    case RID_RESTRICT:
7263      dupe = specs->restrict_p;
7264      specs->restrict_p = true;
7265      break;
7266    default:
7267      gcc_unreachable ();
7268    }
7269  if (dupe && pedantic && !flag_isoc99)
7270    pedwarn ("duplicate %qE", qual);
7271  return specs;
7272}
7273
7274/* Add the type specifier TYPE to the declaration specifiers SPECS,
7275   returning SPECS.  */
7276
7277struct c_declspecs *
7278declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec)
7279{
7280  tree type = spec.spec;
7281  specs->non_sc_seen_p = true;
7282  specs->declspecs_seen_p = true;
7283  specs->type_seen_p = true;
7284  if (TREE_DEPRECATED (type))
7285    specs->deprecated_p = true;
7286
7287  /* Handle type specifier keywords.  */
7288  if (TREE_CODE (type) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (type))
7289    {
7290      enum rid i = C_RID_CODE (type);
7291      if (specs->type)
7292	{
7293	  error ("two or more data types in declaration specifiers");
7294	  return specs;
7295	}
7296      if ((int) i <= (int) RID_LAST_MODIFIER)
7297	{
7298	  /* "long", "short", "signed", "unsigned" or "_Complex".  */
7299	  bool dupe = false;
7300	  switch (i)
7301	    {
7302	    case RID_LONG:
7303	      if (specs->long_long_p)
7304		{
7305		  error ("%<long long long%> is too long for GCC");
7306		  break;
7307		}
7308	      if (specs->long_p)
7309		{
7310		  if (specs->typespec_word == cts_double)
7311		    {
7312		      error ("both %<long long%> and %<double%> in "
7313			     "declaration specifiers");
7314		      break;
7315		    }
7316		  if (pedantic && !flag_isoc99 && !in_system_header
7317		      && warn_long_long)
7318		    pedwarn ("ISO C90 does not support %<long long%>");
7319		  specs->long_long_p = 1;
7320		  break;
7321		}
7322	      if (specs->short_p)
7323		error ("both %<long%> and %<short%> in "
7324		       "declaration specifiers");
7325	      else if (specs->typespec_word == cts_void)
7326		error ("both %<long%> and %<void%> in "
7327		       "declaration specifiers");
7328	      else if (specs->typespec_word == cts_bool)
7329		error ("both %<long%> and %<_Bool%> in "
7330		       "declaration specifiers");
7331	      else if (specs->typespec_word == cts_char)
7332		error ("both %<long%> and %<char%> in "
7333		       "declaration specifiers");
7334	      else if (specs->typespec_word == cts_float)
7335		error ("both %<long%> and %<float%> in "
7336		       "declaration specifiers");
7337	      else if (specs->typespec_word == cts_dfloat32)
7338		error ("both %<long%> and %<_Decimal32%> in "
7339		       "declaration specifiers");
7340	      else if (specs->typespec_word == cts_dfloat64)
7341		error ("both %<long%> and %<_Decimal64%> in "
7342		       "declaration specifiers");
7343	      else if (specs->typespec_word == cts_dfloat128)
7344		error ("both %<long%> and %<_Decimal128%> in "
7345		       "declaration specifiers");
7346	      else
7347		specs->long_p = true;
7348	      break;
7349	    case RID_SHORT:
7350	      dupe = specs->short_p;
7351	      if (specs->long_p)
7352		error ("both %<long%> and %<short%> in "
7353		       "declaration specifiers");
7354	      else if (specs->typespec_word == cts_void)
7355		error ("both %<short%> and %<void%> in "
7356		       "declaration specifiers");
7357	      else if (specs->typespec_word == cts_bool)
7358		error ("both %<short%> and %<_Bool%> in "
7359		       "declaration specifiers");
7360	      else if (specs->typespec_word == cts_char)
7361		error ("both %<short%> and %<char%> in "
7362		       "declaration specifiers");
7363	      else if (specs->typespec_word == cts_float)
7364		error ("both %<short%> and %<float%> in "
7365		       "declaration specifiers");
7366	      else if (specs->typespec_word == cts_double)
7367		error ("both %<short%> and %<double%> in "
7368		       "declaration specifiers");
7369	      else if (specs->typespec_word == cts_dfloat32)
7370                error ("both %<short%> and %<_Decimal32%> in "
7371		       "declaration specifiers");
7372	      else if (specs->typespec_word == cts_dfloat64)
7373		error ("both %<short%> and %<_Decimal64%> in "
7374		                        "declaration specifiers");
7375	      else if (specs->typespec_word == cts_dfloat128)
7376		error ("both %<short%> and %<_Decimal128%> in "
7377		       "declaration specifiers");
7378	      else
7379		specs->short_p = true;
7380	      break;
7381	    case RID_SIGNED:
7382	      dupe = specs->signed_p;
7383	      if (specs->unsigned_p)
7384		error ("both %<signed%> and %<unsigned%> in "
7385		       "declaration specifiers");
7386	      else if (specs->typespec_word == cts_void)
7387		error ("both %<signed%> and %<void%> in "
7388		       "declaration specifiers");
7389	      else if (specs->typespec_word == cts_bool)
7390		error ("both %<signed%> and %<_Bool%> in "
7391		       "declaration specifiers");
7392	      else if (specs->typespec_word == cts_float)
7393		error ("both %<signed%> and %<float%> in "
7394		       "declaration specifiers");
7395	      else if (specs->typespec_word == cts_double)
7396		error ("both %<signed%> and %<double%> in "
7397		       "declaration specifiers");
7398	      else if (specs->typespec_word == cts_dfloat32)
7399		error ("both %<signed%> and %<_Decimal32%> in "
7400		       "declaration specifiers");
7401	      else if (specs->typespec_word == cts_dfloat64)
7402		error ("both %<signed%> and %<_Decimal64%> in "
7403		       "declaration specifiers");
7404	      else if (specs->typespec_word == cts_dfloat128)
7405		error ("both %<signed%> and %<_Decimal128%> in "
7406		       "declaration specifiers");
7407	      else
7408		specs->signed_p = true;
7409	      break;
7410	    case RID_UNSIGNED:
7411	      dupe = specs->unsigned_p;
7412	      if (specs->signed_p)
7413		error ("both %<signed%> and %<unsigned%> in "
7414		       "declaration specifiers");
7415	      else if (specs->typespec_word == cts_void)
7416		error ("both %<unsigned%> and %<void%> in "
7417		       "declaration specifiers");
7418	      else if (specs->typespec_word == cts_bool)
7419		error ("both %<unsigned%> and %<_Bool%> in "
7420		       "declaration specifiers");
7421	      else if (specs->typespec_word == cts_float)
7422		error ("both %<unsigned%> and %<float%> in "
7423		       "declaration specifiers");
7424	      else if (specs->typespec_word == cts_double)
7425		error ("both %<unsigned%> and %<double%> in "
7426		       "declaration specifiers");
7427              else if (specs->typespec_word == cts_dfloat32)
7428		error ("both %<unsigned%> and %<_Decimal32%> in "
7429		       "declaration specifiers");
7430	      else if (specs->typespec_word == cts_dfloat64)
7431		error ("both %<unsigned%> and %<_Decimal64%> in "
7432		       "declaration specifiers");
7433	      else if (specs->typespec_word == cts_dfloat128)
7434		error ("both %<unsigned%> and %<_Decimal128%> in "
7435		       "declaration specifiers");
7436	      else
7437		specs->unsigned_p = true;
7438	      break;
7439	    case RID_COMPLEX:
7440	      dupe = specs->complex_p;
7441	      if (pedantic && !flag_isoc99 && !in_system_header)
7442		pedwarn ("ISO C90 does not support complex types");
7443	      if (specs->typespec_word == cts_void)
7444		error ("both %<complex%> and %<void%> in "
7445		       "declaration specifiers");
7446	      else if (specs->typespec_word == cts_bool)
7447		error ("both %<complex%> and %<_Bool%> in "
7448		       "declaration specifiers");
7449              else if (specs->typespec_word == cts_dfloat32)
7450		error ("both %<complex%> and %<_Decimal32%> in "
7451		       "declaration specifiers");
7452	      else if (specs->typespec_word == cts_dfloat64)
7453		error ("both %<complex%> and %<_Decimal64%> in "
7454		       "declaration specifiers");
7455	      else if (specs->typespec_word == cts_dfloat128)
7456		error ("both %<complex%> and %<_Decimal128%> in "
7457		       "declaration specifiers");
7458	      else
7459		specs->complex_p = true;
7460	      break;
7461	    default:
7462	      gcc_unreachable ();
7463	    }
7464
7465	  if (dupe)
7466	    error ("duplicate %qE", type);
7467
7468	  return specs;
7469	}
7470      else
7471	{
7472	  /* "void", "_Bool", "char", "int", "float" or "double".  */
7473	  if (specs->typespec_word != cts_none)
7474	    {
7475	      error ("two or more data types in declaration specifiers");
7476	      return specs;
7477	    }
7478	  switch (i)
7479	    {
7480	    case RID_VOID:
7481	      if (specs->long_p)
7482		error ("both %<long%> and %<void%> in "
7483		       "declaration specifiers");
7484	      else if (specs->short_p)
7485		error ("both %<short%> and %<void%> in "
7486		       "declaration specifiers");
7487	      else if (specs->signed_p)
7488		error ("both %<signed%> and %<void%> in "
7489		       "declaration specifiers");
7490	      else if (specs->unsigned_p)
7491		error ("both %<unsigned%> and %<void%> in "
7492		       "declaration specifiers");
7493	      else if (specs->complex_p)
7494		error ("both %<complex%> and %<void%> in "
7495		       "declaration specifiers");
7496	      else
7497		specs->typespec_word = cts_void;
7498	      return specs;
7499	    case RID_BOOL:
7500	      if (specs->long_p)
7501		error ("both %<long%> and %<_Bool%> in "
7502		       "declaration specifiers");
7503	      else if (specs->short_p)
7504		error ("both %<short%> and %<_Bool%> in "
7505		       "declaration specifiers");
7506	      else if (specs->signed_p)
7507		error ("both %<signed%> and %<_Bool%> in "
7508		       "declaration specifiers");
7509	      else if (specs->unsigned_p)
7510		error ("both %<unsigned%> and %<_Bool%> in "
7511		       "declaration specifiers");
7512	      else if (specs->complex_p)
7513		error ("both %<complex%> and %<_Bool%> in "
7514		       "declaration specifiers");
7515	      else
7516		specs->typespec_word = cts_bool;
7517	      return specs;
7518	    case RID_CHAR:
7519	      if (specs->long_p)
7520		error ("both %<long%> and %<char%> in "
7521		       "declaration specifiers");
7522	      else if (specs->short_p)
7523		error ("both %<short%> and %<char%> in "
7524		       "declaration specifiers");
7525	      else
7526		specs->typespec_word = cts_char;
7527	      return specs;
7528	    case RID_INT:
7529	      specs->typespec_word = cts_int;
7530	      return specs;
7531	    case RID_FLOAT:
7532	      if (specs->long_p)
7533		error ("both %<long%> and %<float%> in "
7534		       "declaration specifiers");
7535	      else if (specs->short_p)
7536		error ("both %<short%> and %<float%> in "
7537		       "declaration specifiers");
7538	      else if (specs->signed_p)
7539		error ("both %<signed%> and %<float%> in "
7540		       "declaration specifiers");
7541	      else if (specs->unsigned_p)
7542		error ("both %<unsigned%> and %<float%> in "
7543		       "declaration specifiers");
7544	      else
7545		specs->typespec_word = cts_float;
7546	      return specs;
7547	    case RID_DOUBLE:
7548	      if (specs->long_long_p)
7549		error ("both %<long long%> and %<double%> in "
7550		       "declaration specifiers");
7551	      else if (specs->short_p)
7552		error ("both %<short%> and %<double%> in "
7553		       "declaration specifiers");
7554	      else if (specs->signed_p)
7555		error ("both %<signed%> and %<double%> in "
7556		       "declaration specifiers");
7557	      else if (specs->unsigned_p)
7558		error ("both %<unsigned%> and %<double%> in "
7559		       "declaration specifiers");
7560	      else
7561		specs->typespec_word = cts_double;
7562	      return specs;
7563	    case RID_DFLOAT32:
7564	    case RID_DFLOAT64:
7565	    case RID_DFLOAT128:
7566	      {
7567		const char *str;
7568		if (i == RID_DFLOAT32)
7569		  str = "_Decimal32";
7570		else if (i == RID_DFLOAT64)
7571		  str = "_Decimal64";
7572		else
7573		  str = "_Decimal128";
7574		if (specs->long_long_p)
7575		  error ("both %<long long%> and %<%s%> in "
7576			 "declaration specifiers", str);
7577		if (specs->long_p)
7578		  error ("both %<long%> and %<%s%> in "
7579			 "declaration specifiers", str);
7580		else if (specs->short_p)
7581		  error ("both %<short%> and %<%s%> in "
7582			 "declaration specifiers", str);
7583		else if (specs->signed_p)
7584		  error ("both %<signed%> and %<%s%> in "
7585			 "declaration specifiers", str);
7586		else if (specs->unsigned_p)
7587		  error ("both %<unsigned%> and %<%s%> in "
7588			 "declaration specifiers", str);
7589                else if (specs->complex_p)
7590                  error ("both %<complex%> and %<%s%> in "
7591                         "declaration specifiers", str);
7592		else if (i == RID_DFLOAT32)
7593		  specs->typespec_word = cts_dfloat32;
7594		else if (i == RID_DFLOAT64)
7595		  specs->typespec_word = cts_dfloat64;
7596		else
7597		  specs->typespec_word = cts_dfloat128;
7598	      }
7599	      if (!targetm.decimal_float_supported_p ())
7600		error ("decimal floating point not supported for this target");
7601	      if (pedantic)
7602		pedwarn ("ISO C does not support decimal floating point");
7603	      return specs;
7604	    default:
7605	      /* ObjC reserved word "id", handled below.  */
7606	      break;
7607	    }
7608	}
7609    }
7610
7611  /* Now we have a typedef (a TYPE_DECL node), an identifier (some
7612     form of ObjC type, cases such as "int" and "long" being handled
7613     above), a TYPE (struct, union, enum and typeof specifiers) or an
7614     ERROR_MARK.  In none of these cases may there have previously
7615     been any type specifiers.  */
7616  if (specs->type || specs->typespec_word != cts_none
7617      || specs->long_p || specs->short_p || specs->signed_p
7618      || specs->unsigned_p || specs->complex_p)
7619    error ("two or more data types in declaration specifiers");
7620  else if (TREE_CODE (type) == TYPE_DECL)
7621    {
7622      if (TREE_TYPE (type) == error_mark_node)
7623	; /* Allow the type to default to int to avoid cascading errors.  */
7624      else
7625	{
7626	  specs->type = TREE_TYPE (type);
7627	  specs->decl_attr = DECL_ATTRIBUTES (type);
7628	  specs->typedef_p = true;
7629	  specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type);
7630	}
7631    }
7632  else if (TREE_CODE (type) == IDENTIFIER_NODE)
7633    {
7634      tree t = lookup_name (type);
7635      if (!t || TREE_CODE (t) != TYPE_DECL)
7636	error ("%qE fails to be a typedef or built in type", type);
7637      else if (TREE_TYPE (t) == error_mark_node)
7638	;
7639      else
7640	specs->type = TREE_TYPE (t);
7641    }
7642  else if (TREE_CODE (type) != ERROR_MARK)
7643    {
7644      if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref)
7645	specs->tag_defined_p = true;
7646      if (spec.kind == ctsk_typeof)
7647	specs->typedef_p = true;
7648      specs->type = type;
7649    }
7650
7651  return specs;
7652}
7653
7654/* Add the storage class specifier or function specifier SCSPEC to the
7655   declaration specifiers SPECS, returning SPECS.  */
7656
7657struct c_declspecs *
7658declspecs_add_scspec (struct c_declspecs *specs, tree scspec)
7659{
7660  enum rid i;
7661  enum c_storage_class n = csc_none;
7662  bool dupe = false;
7663  specs->declspecs_seen_p = true;
7664  gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE
7665	      && C_IS_RESERVED_WORD (scspec));
7666  i = C_RID_CODE (scspec);
7667  if (extra_warnings && specs->non_sc_seen_p)
7668    warning (OPT_Wextra, "%qE is not at beginning of declaration", scspec);
7669  switch (i)
7670    {
7671    case RID_INLINE:
7672      /* C99 permits duplicate inline.  Although of doubtful utility,
7673	 it seems simplest to permit it in gnu89 mode as well, as
7674	 there is also little utility in maintaining this as a
7675	 difference between gnu89 and C99 inline.  */
7676      dupe = false;
7677      specs->inline_p = true;
7678      break;
7679    case RID_THREAD:
7680      dupe = specs->thread_p;
7681      if (specs->storage_class == csc_auto)
7682	error ("%<__thread%> used with %<auto%>");
7683      else if (specs->storage_class == csc_register)
7684	error ("%<__thread%> used with %<register%>");
7685      else if (specs->storage_class == csc_typedef)
7686	error ("%<__thread%> used with %<typedef%>");
7687      else
7688	specs->thread_p = true;
7689      break;
7690    case RID_AUTO:
7691      n = csc_auto;
7692      break;
7693    case RID_EXTERN:
7694      n = csc_extern;
7695      /* Diagnose "__thread extern".  */
7696      if (specs->thread_p)
7697	error ("%<__thread%> before %<extern%>");
7698      break;
7699    case RID_REGISTER:
7700      n = csc_register;
7701      break;
7702    case RID_STATIC:
7703      n = csc_static;
7704      /* Diagnose "__thread static".  */
7705      if (specs->thread_p)
7706	error ("%<__thread%> before %<static%>");
7707      break;
7708    case RID_TYPEDEF:
7709      n = csc_typedef;
7710      break;
7711    default:
7712      gcc_unreachable ();
7713    }
7714  if (n != csc_none && n == specs->storage_class)
7715    dupe = true;
7716  if (dupe)
7717    error ("duplicate %qE", scspec);
7718  if (n != csc_none)
7719    {
7720      if (specs->storage_class != csc_none && n != specs->storage_class)
7721	{
7722	  error ("multiple storage classes in declaration specifiers");
7723	}
7724      else
7725	{
7726	  specs->storage_class = n;
7727	  if (n != csc_extern && n != csc_static && specs->thread_p)
7728	    {
7729	      error ("%<__thread%> used with %qE", scspec);
7730	      specs->thread_p = false;
7731	    }
7732	}
7733    }
7734  return specs;
7735}
7736
7737/* Add the attributes ATTRS to the declaration specifiers SPECS,
7738   returning SPECS.  */
7739
7740struct c_declspecs *
7741declspecs_add_attrs (struct c_declspecs *specs, tree attrs)
7742{
7743  specs->attrs = chainon (attrs, specs->attrs);
7744  specs->declspecs_seen_p = true;
7745  return specs;
7746}
7747
7748/* Combine "long", "short", "signed", "unsigned" and "_Complex" type
7749   specifiers with any other type specifier to determine the resulting
7750   type.  This is where ISO C checks on complex types are made, since
7751   "_Complex long" is a prefix of the valid ISO C type "_Complex long
7752   double".  */
7753
7754struct c_declspecs *
7755finish_declspecs (struct c_declspecs *specs)
7756{
7757  /* If a type was specified as a whole, we have no modifiers and are
7758     done.  */
7759  if (specs->type != NULL_TREE)
7760    {
7761      gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p
7762		  && !specs->signed_p && !specs->unsigned_p
7763		  && !specs->complex_p);
7764      return specs;
7765    }
7766
7767  /* If none of "void", "_Bool", "char", "int", "float" or "double"
7768     has been specified, treat it as "int" unless "_Complex" is
7769     present and there are no other specifiers.  If we just have
7770     "_Complex", it is equivalent to "_Complex double", but e.g.
7771     "_Complex short" is equivalent to "_Complex short int".  */
7772  if (specs->typespec_word == cts_none)
7773    {
7774      if (specs->long_p || specs->short_p
7775	  || specs->signed_p || specs->unsigned_p)
7776	{
7777	  specs->typespec_word = cts_int;
7778	}
7779      else if (specs->complex_p)
7780	{
7781	  specs->typespec_word = cts_double;
7782	  if (pedantic)
7783	    pedwarn ("ISO C does not support plain %<complex%> meaning "
7784		     "%<double complex%>");
7785	}
7786      else
7787	{
7788	  specs->typespec_word = cts_int;
7789	  specs->default_int_p = true;
7790	  /* We don't diagnose this here because grokdeclarator will
7791	     give more specific diagnostics according to whether it is
7792	     a function definition.  */
7793	}
7794    }
7795
7796  /* If "signed" was specified, record this to distinguish "int" and
7797     "signed int" in the case of a bit-field with
7798     -funsigned-bitfields.  */
7799  specs->explicit_signed_p = specs->signed_p;
7800
7801  /* Now compute the actual type.  */
7802  switch (specs->typespec_word)
7803    {
7804    case cts_void:
7805      gcc_assert (!specs->long_p && !specs->short_p
7806		  && !specs->signed_p && !specs->unsigned_p
7807		  && !specs->complex_p);
7808      specs->type = void_type_node;
7809      break;
7810    case cts_bool:
7811      gcc_assert (!specs->long_p && !specs->short_p
7812		  && !specs->signed_p && !specs->unsigned_p
7813		  && !specs->complex_p);
7814      specs->type = boolean_type_node;
7815      break;
7816    case cts_char:
7817      gcc_assert (!specs->long_p && !specs->short_p);
7818      gcc_assert (!(specs->signed_p && specs->unsigned_p));
7819      if (specs->signed_p)
7820	specs->type = signed_char_type_node;
7821      else if (specs->unsigned_p)
7822	specs->type = unsigned_char_type_node;
7823      else
7824	specs->type = char_type_node;
7825      if (specs->complex_p)
7826	{
7827	  if (pedantic)
7828	    pedwarn ("ISO C does not support complex integer types");
7829	  specs->type = build_complex_type (specs->type);
7830	}
7831      break;
7832    case cts_int:
7833      gcc_assert (!(specs->long_p && specs->short_p));
7834      gcc_assert (!(specs->signed_p && specs->unsigned_p));
7835      if (specs->long_long_p)
7836	specs->type = (specs->unsigned_p
7837		       ? long_long_unsigned_type_node
7838		       : long_long_integer_type_node);
7839      else if (specs->long_p)
7840	specs->type = (specs->unsigned_p
7841		       ? long_unsigned_type_node
7842		       : long_integer_type_node);
7843      else if (specs->short_p)
7844	specs->type = (specs->unsigned_p
7845		       ? short_unsigned_type_node
7846		       : short_integer_type_node);
7847      else
7848	specs->type = (specs->unsigned_p
7849		       ? unsigned_type_node
7850		       : integer_type_node);
7851      if (specs->complex_p)
7852	{
7853	  if (pedantic)
7854	    pedwarn ("ISO C does not support complex integer types");
7855	  specs->type = build_complex_type (specs->type);
7856	}
7857      break;
7858    case cts_float:
7859      gcc_assert (!specs->long_p && !specs->short_p
7860		  && !specs->signed_p && !specs->unsigned_p);
7861      specs->type = (specs->complex_p
7862		     ? complex_float_type_node
7863		     : float_type_node);
7864      break;
7865    case cts_double:
7866      gcc_assert (!specs->long_long_p && !specs->short_p
7867		  && !specs->signed_p && !specs->unsigned_p);
7868      if (specs->long_p)
7869	{
7870	  specs->type = (specs->complex_p
7871			 ? complex_long_double_type_node
7872			 : long_double_type_node);
7873	}
7874      else
7875	{
7876	  specs->type = (specs->complex_p
7877			 ? complex_double_type_node
7878			 : double_type_node);
7879	}
7880      break;
7881    case cts_dfloat32:
7882    case cts_dfloat64:
7883    case cts_dfloat128:
7884      gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p
7885		  && !specs->signed_p && !specs->unsigned_p && !specs->complex_p);
7886      if (specs->typespec_word == cts_dfloat32)
7887	specs->type = dfloat32_type_node;
7888      else if (specs->typespec_word == cts_dfloat64)
7889	specs->type = dfloat64_type_node;
7890      else
7891	specs->type = dfloat128_type_node;
7892      break;
7893    default:
7894      gcc_unreachable ();
7895    }
7896
7897  return specs;
7898}
7899
7900/* Synthesize a function which calls all the global ctors or global
7901   dtors in this file.  This is only used for targets which do not
7902   support .ctors/.dtors sections.  FIXME: Migrate into cgraph.  */
7903static void
7904build_cdtor (int method_type, tree cdtors)
7905{
7906  tree body = 0;
7907
7908  if (!cdtors)
7909    return;
7910
7911  for (; cdtors; cdtors = TREE_CHAIN (cdtors))
7912    append_to_statement_list (build_function_call (TREE_VALUE (cdtors), 0),
7913			      &body);
7914
7915  cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY);
7916}
7917
7918/* A subroutine of c_write_global_declarations.  Perform final processing
7919   on one file scope's declarations (or the external scope's declarations),
7920   GLOBALS.  */
7921
7922static void
7923c_write_global_declarations_1 (tree globals)
7924{
7925  tree decl;
7926  bool reconsider;
7927
7928  /* Process the decls in the order they were written.  */
7929  for (decl = globals; decl; decl = TREE_CHAIN (decl))
7930    {
7931      /* Check for used but undefined static functions using the C
7932	 standard's definition of "used", and set TREE_NO_WARNING so
7933	 that check_global_declarations doesn't repeat the check.  */
7934      if (TREE_CODE (decl) == FUNCTION_DECL
7935	  && DECL_INITIAL (decl) == 0
7936	  && DECL_EXTERNAL (decl)
7937	  && !TREE_PUBLIC (decl)
7938	  && C_DECL_USED (decl))
7939	{
7940	  pedwarn ("%q+F used but never defined", decl);
7941	  TREE_NO_WARNING (decl) = 1;
7942	}
7943
7944      wrapup_global_declaration_1 (decl);
7945    }
7946
7947  do
7948    {
7949      reconsider = false;
7950      for (decl = globals; decl; decl = TREE_CHAIN (decl))
7951	reconsider |= wrapup_global_declaration_2 (decl);
7952    }
7953  while (reconsider);
7954
7955  for (decl = globals; decl; decl = TREE_CHAIN (decl))
7956    check_global_declaration_1 (decl);
7957}
7958
7959/* A subroutine of c_write_global_declarations Emit debug information for each
7960   of the declarations in GLOBALS.  */
7961
7962static void
7963c_write_global_declarations_2 (tree globals)
7964{
7965  tree decl;
7966
7967  for (decl = globals; decl ; decl = TREE_CHAIN (decl))
7968    debug_hooks->global_decl (decl);
7969}
7970
7971/* Preserve the external declarations scope across a garbage collect.  */
7972static GTY(()) tree ext_block;
7973
7974void
7975c_write_global_declarations (void)
7976{
7977  tree t;
7978
7979  /* We don't want to do this if generating a PCH.  */
7980  if (pch_file)
7981    return;
7982
7983  /* Don't waste time on further processing if -fsyntax-only or we've
7984     encountered errors.  */
7985  if (flag_syntax_only || errorcount || sorrycount || cpp_errors (parse_in))
7986    return;
7987
7988  /* Close the external scope.  */
7989  ext_block = pop_scope ();
7990  external_scope = 0;
7991  gcc_assert (!current_scope);
7992
7993  if (ext_block)
7994    {
7995      tree tmp = BLOCK_VARS (ext_block);
7996      int flags;
7997      FILE * stream = dump_begin (TDI_tu, &flags);
7998      if (stream && tmp)
7999	{
8000	  dump_node (tmp, flags & ~TDF_SLIM, stream);
8001	  dump_end (TDI_tu, stream);
8002	}
8003    }
8004
8005  /* Process all file scopes in this compilation, and the external_scope,
8006     through wrapup_global_declarations and check_global_declarations.  */
8007  for (t = all_translation_units; t; t = TREE_CHAIN (t))
8008    c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t)));
8009  c_write_global_declarations_1 (BLOCK_VARS (ext_block));
8010
8011  /* Generate functions to call static constructors and destructors
8012     for targets that do not support .ctors/.dtors sections.  These
8013     functions have magic names which are detected by collect2.  */
8014  build_cdtor ('I', static_ctors); static_ctors = 0;
8015  build_cdtor ('D', static_dtors); static_dtors = 0;
8016
8017  /* We're done parsing; proceed to optimize and emit assembly.
8018     FIXME: shouldn't be the front end's responsibility to call this.  */
8019  cgraph_optimize ();
8020
8021  /* After cgraph has had a chance to emit everything that's going to
8022     be emitted, output debug information for globals.  */
8023  if (errorcount == 0 && sorrycount == 0)
8024    {
8025      timevar_push (TV_SYMOUT);
8026      for (t = all_translation_units; t; t = TREE_CHAIN (t))
8027	c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t)));
8028      c_write_global_declarations_2 (BLOCK_VARS (ext_block));
8029      timevar_pop (TV_SYMOUT);
8030    }
8031
8032  ext_block = NULL;
8033}
8034
8035#include "gt-c-decl.h"
8036