c-decl.c revision 259269
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: stable/9/contrib/gcc/c-decl.c 259269 2013-12-12 18:16:46Z pfg $ */
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
3935/* Print warning about variable length array if necessary.  */
3936
3937static void
3938warn_variable_length_array (const char *name, tree size)
3939{
3940  int ped = !flag_isoc99 && pedantic && warn_vla != 0;
3941  int const_size = TREE_CONSTANT (size);
3942
3943  if (ped)
3944    {
3945      if (const_size)
3946	{
3947	  if (name)
3948	    pedwarn ("ISO C90 forbids array %qs whose size "
3949		     "can%'t be evaluated",
3950		     name);
3951	  else
3952	    pedwarn ("ISO C90 forbids array whose size "
3953		     "can%'t be evaluated");
3954	}
3955      else
3956	{
3957	  if (name)
3958	    pedwarn ("ISO C90 forbids variable length array %qs",
3959		     name);
3960	  else
3961	    pedwarn ("ISO C90 forbids variable length array");
3962	}
3963    }
3964  else if (warn_vla > 0)
3965    {
3966      if (const_size)
3967        {
3968	  if (name)
3969	    warning (OPT_Wvla,
3970		     "the size of array %qs can"
3971		     "%'t be evaluated", name);
3972	  else
3973	    warning (OPT_Wvla,
3974		     "the size of array can %'t be evaluated");
3975	}
3976      else
3977	{
3978	  if (name)
3979	    warning (OPT_Wvla,
3980		     "variable length array %qs is used",
3981		     name);
3982	  else
3983	    warning (OPT_Wvla,
3984		     "variable length array is used");
3985	}
3986    }
3987}
3988
3989/* Given declspecs and a declarator,
3990   determine the name and type of the object declared
3991   and construct a ..._DECL node for it.
3992   (In one case we can return a ..._TYPE node instead.
3993    For invalid input we sometimes return 0.)
3994
3995   DECLSPECS is a c_declspecs structure for the declaration specifiers.
3996
3997   DECL_CONTEXT says which syntactic context this declaration is in:
3998     NORMAL for most contexts.  Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL.
3999     FUNCDEF for a function definition.  Like NORMAL but a few different
4000      error messages in each case.  Return value may be zero meaning
4001      this definition is too screwy to try to parse.
4002     PARM for a parameter declaration (either within a function prototype
4003      or before a function body).  Make a PARM_DECL, or return void_type_node.
4004     TYPENAME if for a typename (in a cast or sizeof).
4005      Don't make a DECL node; just return the ..._TYPE node.
4006     FIELD for a struct or union field; make a FIELD_DECL.
4007   INITIALIZED is true if the decl has an initializer.
4008   WIDTH is non-NULL for bit-fields, and is a pointer to an INTEGER_CST node
4009   representing the width of the bit-field.
4010
4011   In the TYPENAME case, DECLARATOR is really an absolute declarator.
4012   It may also be so in the PARM case, for a prototype where the
4013   argument type is specified but not the name.
4014
4015   This function is where the complicated C meanings of `static'
4016   and `extern' are interpreted.  */
4017
4018static tree
4019grokdeclarator (const struct c_declarator *declarator,
4020		struct c_declspecs *declspecs,
4021		enum decl_context decl_context, bool initialized, tree *width)
4022{
4023  tree type = declspecs->type;
4024  bool threadp = declspecs->thread_p;
4025  enum c_storage_class storage_class = declspecs->storage_class;
4026  int constp;
4027  int restrictp;
4028  int volatilep;
4029  int type_quals = TYPE_UNQUALIFIED;
4030  const char *name, *orig_name;
4031  tree typedef_type = 0;
4032  bool funcdef_flag = false;
4033  bool funcdef_syntax = false;
4034  int size_varies = 0;
4035  tree decl_attr = declspecs->decl_attr;
4036  int array_ptr_quals = TYPE_UNQUALIFIED;
4037  tree array_ptr_attrs = NULL_TREE;
4038  int array_parm_static = 0;
4039  bool array_parm_vla_unspec_p = false;
4040  tree returned_attrs = NULL_TREE;
4041  bool bitfield = width != NULL;
4042  tree element_type;
4043  struct c_arg_info *arg_info = 0;
4044
4045  if (decl_context == FUNCDEF)
4046    funcdef_flag = true, decl_context = NORMAL;
4047
4048  /* Look inside a declarator for the name being declared
4049     and get it as a string, for an error message.  */
4050  {
4051    const struct c_declarator *decl = declarator;
4052    name = 0;
4053
4054    while (decl)
4055      switch (decl->kind)
4056	{
4057	case cdk_function:
4058	case cdk_array:
4059	case cdk_pointer:
4060	  funcdef_syntax = (decl->kind == cdk_function);
4061	  decl = decl->declarator;
4062	  break;
4063
4064	case cdk_attrs:
4065	  decl = decl->declarator;
4066	  break;
4067
4068	case cdk_id:
4069	  if (decl->u.id)
4070	    name = IDENTIFIER_POINTER (decl->u.id);
4071	  decl = 0;
4072	  break;
4073
4074	default:
4075	  gcc_unreachable ();
4076	}
4077    orig_name = name;
4078    if (name == 0)
4079      name = "type name";
4080  }
4081
4082  /* A function definition's declarator must have the form of
4083     a function declarator.  */
4084
4085  if (funcdef_flag && !funcdef_syntax)
4086    return 0;
4087
4088  /* If this looks like a function definition, make it one,
4089     even if it occurs where parms are expected.
4090     Then store_parm_decls will reject it and not use it as a parm.  */
4091  if (decl_context == NORMAL && !funcdef_flag && current_scope->parm_flag)
4092    decl_context = PARM;
4093
4094  if (declspecs->deprecated_p && deprecated_state != DEPRECATED_SUPPRESS)
4095    warn_deprecated_use (declspecs->type);
4096
4097  if ((decl_context == NORMAL || decl_context == FIELD)
4098      && current_scope == file_scope
4099      && variably_modified_type_p (type, NULL_TREE))
4100    {
4101      error ("variably modified %qs at file scope", name);
4102      type = integer_type_node;
4103    }
4104
4105  typedef_type = type;
4106  size_varies = C_TYPE_VARIABLE_SIZE (type);
4107
4108  /* Diagnose defaulting to "int".  */
4109
4110  if (declspecs->default_int_p && !in_system_header)
4111    {
4112      /* Issue a warning if this is an ISO C 99 program or if
4113	 -Wreturn-type and this is a function, or if -Wimplicit;
4114	 prefer the former warning since it is more explicit.  */
4115      if ((warn_implicit_int || warn_return_type || flag_isoc99)
4116	  && funcdef_flag)
4117	warn_about_return_type = 1;
4118      else if (warn_implicit_int || flag_isoc99)
4119	pedwarn_c99 ("type defaults to %<int%> in declaration of %qs", name);
4120    }
4121
4122  /* Adjust the type if a bit-field is being declared,
4123     -funsigned-bitfields applied and the type is not explicitly
4124     "signed".  */
4125  if (bitfield && !flag_signed_bitfields && !declspecs->explicit_signed_p
4126      && TREE_CODE (type) == INTEGER_TYPE)
4127    type = c_common_unsigned_type (type);
4128
4129  /* Figure out the type qualifiers for the declaration.  There are
4130     two ways a declaration can become qualified.  One is something
4131     like `const int i' where the `const' is explicit.  Another is
4132     something like `typedef const int CI; CI i' where the type of the
4133     declaration contains the `const'.  A third possibility is that
4134     there is a type qualifier on the element type of a typedefed
4135     array type, in which case we should extract that qualifier so
4136     that c_apply_type_quals_to_decls receives the full list of
4137     qualifiers to work with (C90 is not entirely clear about whether
4138     duplicate qualifiers should be diagnosed in this case, but it
4139     seems most appropriate to do so).  */
4140  element_type = strip_array_types (type);
4141  constp = declspecs->const_p + TYPE_READONLY (element_type);
4142  restrictp = declspecs->restrict_p + TYPE_RESTRICT (element_type);
4143  volatilep = declspecs->volatile_p + TYPE_VOLATILE (element_type);
4144  if (pedantic && !flag_isoc99)
4145    {
4146      if (constp > 1)
4147	pedwarn ("duplicate %<const%>");
4148      if (restrictp > 1)
4149	pedwarn ("duplicate %<restrict%>");
4150      if (volatilep > 1)
4151	pedwarn ("duplicate %<volatile%>");
4152    }
4153  if (!flag_gen_aux_info && (TYPE_QUALS (element_type)))
4154    type = TYPE_MAIN_VARIANT (type);
4155  type_quals = ((constp ? TYPE_QUAL_CONST : 0)
4156		| (restrictp ? TYPE_QUAL_RESTRICT : 0)
4157		| (volatilep ? TYPE_QUAL_VOLATILE : 0));
4158
4159  /* Warn about storage classes that are invalid for certain
4160     kinds of declarations (parameters, typenames, etc.).  */
4161
4162  if (funcdef_flag
4163      && (threadp
4164	  || storage_class == csc_auto
4165	  || storage_class == csc_register
4166	  || storage_class == csc_typedef))
4167    {
4168      if (storage_class == csc_auto
4169	  && (pedantic || current_scope == file_scope))
4170	pedwarn ("function definition declared %<auto%>");
4171      if (storage_class == csc_register)
4172	error ("function definition declared %<register%>");
4173      if (storage_class == csc_typedef)
4174	error ("function definition declared %<typedef%>");
4175      if (threadp)
4176	error ("function definition declared %<__thread%>");
4177      threadp = false;
4178      if (storage_class == csc_auto
4179	  || storage_class == csc_register
4180	  || storage_class == csc_typedef)
4181	storage_class = csc_none;
4182    }
4183  else if (decl_context != NORMAL && (storage_class != csc_none || threadp))
4184    {
4185      if (decl_context == PARM && storage_class == csc_register)
4186	;
4187      else
4188	{
4189	  switch (decl_context)
4190	    {
4191	    case FIELD:
4192	      error ("storage class specified for structure field %qs",
4193		     name);
4194	      break;
4195	    case PARM:
4196	      error ("storage class specified for parameter %qs", name);
4197	      break;
4198	    default:
4199	      error ("storage class specified for typename");
4200	      break;
4201	    }
4202	  storage_class = csc_none;
4203	  threadp = false;
4204	}
4205    }
4206  else if (storage_class == csc_extern
4207	   && initialized
4208	   && !funcdef_flag)
4209    {
4210      /* 'extern' with initialization is invalid if not at file scope.  */
4211       if (current_scope == file_scope)
4212         {
4213           /* It is fine to have 'extern const' when compiling at C
4214              and C++ intersection.  */
4215           if (!(warn_cxx_compat && constp))
4216             warning (0, "%qs initialized and declared %<extern%>", name);
4217         }
4218      else
4219	error ("%qs has both %<extern%> and initializer", name);
4220    }
4221  else if (current_scope == file_scope)
4222    {
4223      if (storage_class == csc_auto)
4224	error ("file-scope declaration of %qs specifies %<auto%>", name);
4225      if (pedantic && storage_class == csc_register)
4226	pedwarn ("file-scope declaration of %qs specifies %<register%>", name);
4227    }
4228  else
4229    {
4230      if (storage_class == csc_extern && funcdef_flag)
4231	error ("nested function %qs declared %<extern%>", name);
4232      else if (threadp && storage_class == csc_none)
4233	{
4234	  error ("function-scope %qs implicitly auto and declared "
4235		 "%<__thread%>",
4236		 name);
4237	  threadp = false;
4238	}
4239    }
4240
4241  /* Now figure out the structure of the declarator proper.
4242     Descend through it, creating more complex types, until we reach
4243     the declared identifier (or NULL_TREE, in an absolute declarator).
4244     At each stage we maintain an unqualified version of the type
4245     together with any qualifiers that should be applied to it with
4246     c_build_qualified_type; this way, array types including
4247     multidimensional array types are first built up in unqualified
4248     form and then the qualified form is created with
4249     TYPE_MAIN_VARIANT pointing to the unqualified form.  */
4250
4251  while (declarator && declarator->kind != cdk_id)
4252    {
4253      if (type == error_mark_node)
4254	{
4255	  declarator = declarator->declarator;
4256	  continue;
4257	}
4258
4259      /* Each level of DECLARATOR is either a cdk_array (for ...[..]),
4260	 a cdk_pointer (for *...),
4261	 a cdk_function (for ...(...)),
4262	 a cdk_attrs (for nested attributes),
4263	 or a cdk_id (for the name being declared
4264	 or the place in an absolute declarator
4265	 where the name was omitted).
4266	 For the last case, we have just exited the loop.
4267
4268	 At this point, TYPE is the type of elements of an array,
4269	 or for a function to return, or for a pointer to point to.
4270	 After this sequence of ifs, TYPE is the type of the
4271	 array or function or pointer, and DECLARATOR has had its
4272	 outermost layer removed.  */
4273
4274      if (array_ptr_quals != TYPE_UNQUALIFIED
4275	  || array_ptr_attrs != NULL_TREE
4276	  || array_parm_static)
4277	{
4278	  /* Only the innermost declarator (making a parameter be of
4279	     array type which is converted to pointer type)
4280	     may have static or type qualifiers.  */
4281	  error ("static or type qualifiers in non-parameter array declarator");
4282	  array_ptr_quals = TYPE_UNQUALIFIED;
4283	  array_ptr_attrs = NULL_TREE;
4284	  array_parm_static = 0;
4285	}
4286
4287      switch (declarator->kind)
4288	{
4289	case cdk_attrs:
4290	  {
4291	    /* A declarator with embedded attributes.  */
4292	    tree attrs = declarator->u.attrs;
4293	    const struct c_declarator *inner_decl;
4294	    int attr_flags = 0;
4295	    declarator = declarator->declarator;
4296	    inner_decl = declarator;
4297	    while (inner_decl->kind == cdk_attrs)
4298	      inner_decl = inner_decl->declarator;
4299	    if (inner_decl->kind == cdk_id)
4300	      attr_flags |= (int) ATTR_FLAG_DECL_NEXT;
4301	    else if (inner_decl->kind == cdk_function)
4302	      attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT;
4303	    else if (inner_decl->kind == cdk_array)
4304	      attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT;
4305	    returned_attrs = decl_attributes (&type,
4306					      chainon (returned_attrs, attrs),
4307					      attr_flags);
4308	    break;
4309	  }
4310	case cdk_array:
4311	  {
4312	    tree itype = NULL_TREE;
4313	    tree size = declarator->u.array.dimen;
4314	    /* The index is a signed object `sizetype' bits wide.  */
4315	    tree index_type = c_common_signed_type (sizetype);
4316
4317	    array_ptr_quals = declarator->u.array.quals;
4318	    array_ptr_attrs = declarator->u.array.attrs;
4319	    array_parm_static = declarator->u.array.static_p;
4320	    array_parm_vla_unspec_p = declarator->u.array.vla_unspec_p;
4321
4322	    declarator = declarator->declarator;
4323
4324	    /* Check for some types that there cannot be arrays of.  */
4325
4326	    if (VOID_TYPE_P (type))
4327	      {
4328		error ("declaration of %qs as array of voids", name);
4329		type = error_mark_node;
4330	      }
4331
4332	    if (TREE_CODE (type) == FUNCTION_TYPE)
4333	      {
4334		error ("declaration of %qs as array of functions", name);
4335		type = error_mark_node;
4336	      }
4337
4338	    if (pedantic && !in_system_header && flexible_array_type_p (type))
4339	      pedwarn ("invalid use of structure with flexible array member");
4340
4341	    if (size == error_mark_node)
4342	      type = error_mark_node;
4343
4344	    if (type == error_mark_node)
4345	      continue;
4346
4347	    /* If size was specified, set ITYPE to a range-type for
4348	       that size.  Otherwise, ITYPE remains null.  finish_decl
4349	       may figure it out from an initial value.  */
4350
4351	    if (size)
4352	      {
4353		/* Strip NON_LVALUE_EXPRs since we aren't using as an
4354		   lvalue.  */
4355		STRIP_TYPE_NOPS (size);
4356
4357		if (!INTEGRAL_TYPE_P (TREE_TYPE (size)))
4358		  {
4359		    error ("size of array %qs has non-integer type", name);
4360		    size = integer_one_node;
4361		  }
4362
4363		if (pedantic && integer_zerop (size))
4364		  pedwarn ("ISO C forbids zero-size array %qs", name);
4365
4366		if (TREE_CODE (size) == INTEGER_CST)
4367		  {
4368		    constant_expression_warning (size);
4369		    if (tree_int_cst_sgn (size) < 0)
4370		      {
4371			error ("size of array %qs is negative", name);
4372			size = integer_one_node;
4373		      }
4374		  }
4375		else if ((decl_context == NORMAL || decl_context == FIELD)
4376			 && current_scope == file_scope)
4377		  {
4378		    error ("variably modified %qs at file scope", name);
4379		    size = integer_one_node;
4380		  }
4381		else
4382		  {
4383		    /* Make sure the array size remains visibly
4384		       nonconstant even if it is (eg) a const variable
4385		       with known value.  */
4386		    size_varies = 1;
4387		    warn_variable_length_array (orig_name, size);
4388		    if (warn_variable_decl)
4389		      warning (0, "variable-sized array %qs", name);
4390		  }
4391
4392		if (integer_zerop (size))
4393		  {
4394		    /* A zero-length array cannot be represented with
4395		       an unsigned index type, which is what we'll
4396		       get with build_index_type.  Create an
4397		       open-ended range instead.  */
4398		    itype = build_range_type (sizetype, size, NULL_TREE);
4399		  }
4400		else
4401		  {
4402		    /* Arrange for the SAVE_EXPR on the inside of the
4403		       MINUS_EXPR, which allows the -1 to get folded
4404		       with the +1 that happens when building TYPE_SIZE.  */
4405		    if (size_varies)
4406		      size = variable_size (size);
4407
4408		    /* Compute the maximum valid index, that is, size
4409		       - 1.  Do the calculation in index_type, so that
4410		       if it is a variable the computations will be
4411		       done in the proper mode.  */
4412		    itype = fold_build2 (MINUS_EXPR, index_type,
4413					 convert (index_type, size),
4414					 convert (index_type,
4415						  size_one_node));
4416
4417		    /* If that overflowed, the array is too big.  ???
4418		       While a size of INT_MAX+1 technically shouldn't
4419		       cause an overflow (because we subtract 1), the
4420		       overflow is recorded during the conversion to
4421		       index_type, before the subtraction.  Handling
4422		       this case seems like an unnecessary
4423		       complication.  */
4424		    if (TREE_CODE (itype) == INTEGER_CST
4425			&& TREE_OVERFLOW (itype))
4426		      {
4427			error ("size of array %qs is too large", name);
4428			type = error_mark_node;
4429			continue;
4430		      }
4431
4432		    itype = build_index_type (itype);
4433		  }
4434	      }
4435	    else if (decl_context == FIELD)
4436	      {
4437		if (pedantic && !flag_isoc99 && !in_system_header)
4438		  pedwarn ("ISO C90 does not support flexible array members");
4439
4440		/* ISO C99 Flexible array members are effectively
4441		   identical to GCC's zero-length array extension.  */
4442		itype = build_range_type (sizetype, size_zero_node, NULL_TREE);
4443	      }
4444	    else if (decl_context == PARM)
4445	      {
4446		if (array_parm_vla_unspec_p)
4447		  {
4448		    if (! orig_name)
4449		      {
4450			/* C99 6.7.5.2p4 */
4451			error ("%<[*]%> not allowed in other than a declaration");
4452		      }
4453
4454		    itype = build_range_type (sizetype, size_zero_node, NULL_TREE);
4455		    size_varies = 1;
4456		  }
4457	      }
4458	    else if (decl_context == TYPENAME)
4459	      {
4460		if (array_parm_vla_unspec_p)
4461		  {
4462		    /* The error is printed elsewhere.  We use this to
4463		       avoid messing up with incomplete array types of
4464		       the same type, that would otherwise be modified
4465		       below.  */
4466		    itype = build_range_type (sizetype, size_zero_node,
4467					      NULL_TREE);
4468		  }
4469	      }
4470
4471	     /* Complain about arrays of incomplete types.  */
4472	    if (!COMPLETE_TYPE_P (type))
4473	      {
4474		error ("array type has incomplete element type");
4475		type = error_mark_node;
4476	      }
4477	    else
4478	    /* When itype is NULL, a shared incomplete array type is
4479	       returned for all array of a given type.  Elsewhere we
4480	       make sure we don't complete that type before copying
4481	       it, but here we want to make sure we don't ever
4482	       modify the shared type, so we gcc_assert (itype)
4483	       below.  */
4484	      type = build_array_type (type, itype);
4485
4486	    if (type != error_mark_node)
4487	      {
4488		if (size_varies)
4489		  {
4490		    /* It is ok to modify type here even if itype is
4491		       NULL: if size_varies, we're in a
4492		       multi-dimensional array and the inner type has
4493		       variable size, so the enclosing shared array type
4494		       must too.  */
4495		    if (size && TREE_CODE (size) == INTEGER_CST)
4496		      type
4497			= build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4498		    C_TYPE_VARIABLE_SIZE (type) = 1;
4499		  }
4500
4501		/* The GCC extension for zero-length arrays differs from
4502		   ISO flexible array members in that sizeof yields
4503		   zero.  */
4504		if (size && integer_zerop (size))
4505		  {
4506		    gcc_assert (itype);
4507		    TYPE_SIZE (type) = bitsize_zero_node;
4508		    TYPE_SIZE_UNIT (type) = size_zero_node;
4509		  }
4510		if (array_parm_vla_unspec_p)
4511		  {
4512		    gcc_assert (itype);
4513		    /* The type is complete.  C99 6.7.5.2p4  */
4514		    TYPE_SIZE (type) = bitsize_zero_node;
4515		    TYPE_SIZE_UNIT (type) = size_zero_node;
4516		  }
4517	      }
4518
4519	    if (decl_context != PARM
4520		&& (array_ptr_quals != TYPE_UNQUALIFIED
4521		    || array_ptr_attrs != NULL_TREE
4522		    || array_parm_static))
4523	      {
4524		error ("static or type qualifiers in non-parameter array declarator");
4525		array_ptr_quals = TYPE_UNQUALIFIED;
4526		array_ptr_attrs = NULL_TREE;
4527		array_parm_static = 0;
4528	      }
4529	    break;
4530	  }
4531	case cdk_function:
4532	  {
4533	    /* Say it's a definition only for the declarator closest
4534	       to the identifier, apart possibly from some
4535	       attributes.  */
4536	    bool really_funcdef = false;
4537	    tree arg_types;
4538	    if (funcdef_flag)
4539	      {
4540		const struct c_declarator *t = declarator->declarator;
4541		while (t->kind == cdk_attrs)
4542		  t = t->declarator;
4543		really_funcdef = (t->kind == cdk_id);
4544	      }
4545
4546	    /* Declaring a function type.  Make sure we have a valid
4547	       type for the function to return.  */
4548	    if (type == error_mark_node)
4549	      continue;
4550
4551	    size_varies = 0;
4552
4553	    /* Warn about some types functions can't return.  */
4554	    if (TREE_CODE (type) == FUNCTION_TYPE)
4555	      {
4556		error ("%qs declared as function returning a function", name);
4557		type = integer_type_node;
4558	      }
4559	    if (TREE_CODE (type) == ARRAY_TYPE)
4560	      {
4561		error ("%qs declared as function returning an array", name);
4562		type = integer_type_node;
4563	      }
4564
4565	    /* Construct the function type and go to the next
4566	       inner layer of declarator.  */
4567	    arg_info = declarator->u.arg_info;
4568	    arg_types = grokparms (arg_info, really_funcdef);
4569	    if (really_funcdef)
4570	      put_pending_sizes (arg_info->pending_sizes);
4571
4572	    /* Type qualifiers before the return type of the function
4573	       qualify the return type, not the function type.  */
4574	    if (type_quals)
4575	      {
4576		/* Type qualifiers on a function return type are
4577		   normally permitted by the standard but have no
4578		   effect, so give a warning at -Wreturn-type.
4579		   Qualifiers on a void return type are banned on
4580		   function definitions in ISO C; GCC used to used
4581		   them for noreturn functions.  */
4582		if (VOID_TYPE_P (type) && really_funcdef)
4583		  pedwarn ("function definition has qualified void return type");
4584		else
4585		  warning (OPT_Wreturn_type,
4586			   "type qualifiers ignored on function return type");
4587
4588		type = c_build_qualified_type (type, type_quals);
4589	      }
4590	    type_quals = TYPE_UNQUALIFIED;
4591
4592	    type = build_function_type (type, arg_types);
4593	    declarator = declarator->declarator;
4594
4595	    /* Set the TYPE_CONTEXTs for each tagged type which is local to
4596	       the formal parameter list of this FUNCTION_TYPE to point to
4597	       the FUNCTION_TYPE node itself.  */
4598	    {
4599	      tree link;
4600
4601	      for (link = arg_info->tags;
4602		   link;
4603		   link = TREE_CHAIN (link))
4604		TYPE_CONTEXT (TREE_VALUE (link)) = type;
4605	    }
4606	    break;
4607	  }
4608	case cdk_pointer:
4609	  {
4610	    /* Merge any constancy or volatility into the target type
4611	       for the pointer.  */
4612
4613	    if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4614		&& type_quals)
4615	      pedwarn ("ISO C forbids qualified function types");
4616	    if (type_quals)
4617	      type = c_build_qualified_type (type, type_quals);
4618	    size_varies = 0;
4619
4620	    /* When the pointed-to type involves components of variable size,
4621	       care must be taken to ensure that the size evaluation code is
4622	       emitted early enough to dominate all the possible later uses
4623	       and late enough for the variables on which it depends to have
4624	       been assigned.
4625
4626	       This is expected to happen automatically when the pointed-to
4627	       type has a name/declaration of it's own, but special attention
4628	       is required if the type is anonymous.
4629
4630	       We handle the NORMAL and FIELD contexts here by attaching an
4631	       artificial TYPE_DECL to such pointed-to type.  This forces the
4632	       sizes evaluation at a safe point and ensures it is not deferred
4633	       until e.g. within a deeper conditional context.
4634
4635	       We expect nothing to be needed here for PARM or TYPENAME.
4636	       Pushing a TYPE_DECL at this point for TYPENAME would actually
4637	       be incorrect, as we might be in the middle of an expression
4638	       with side effects on the pointed-to type size "arguments" prior
4639	       to the pointer declaration point and the fake TYPE_DECL in the
4640	       enclosing context would force the size evaluation prior to the
4641	       side effects.  */
4642
4643	    if (!TYPE_NAME (type)
4644		&& (decl_context == NORMAL || decl_context == FIELD)
4645		&& variably_modified_type_p (type, NULL_TREE))
4646	      {
4647		tree decl = build_decl (TYPE_DECL, NULL_TREE, type);
4648		DECL_ARTIFICIAL (decl) = 1;
4649		pushdecl (decl);
4650		finish_decl (decl, NULL_TREE, NULL_TREE);
4651		TYPE_NAME (type) = decl;
4652	      }
4653
4654	    type = build_pointer_type (type);
4655
4656	    /* Process type qualifiers (such as const or volatile)
4657	       that were given inside the `*'.  */
4658	    type_quals = declarator->u.pointer_quals;
4659
4660	    declarator = declarator->declarator;
4661	    break;
4662	  }
4663	default:
4664	  gcc_unreachable ();
4665	}
4666    }
4667
4668  /* Now TYPE has the actual type, apart from any qualifiers in
4669     TYPE_QUALS.  */
4670
4671  /* Check the type and width of a bit-field.  */
4672  if (bitfield)
4673    check_bitfield_type_and_width (&type, width, orig_name);
4674
4675  /* Did array size calculations overflow?  */
4676
4677  if (TREE_CODE (type) == ARRAY_TYPE
4678      && COMPLETE_TYPE_P (type)
4679      && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST
4680      && TREE_OVERFLOW (TYPE_SIZE_UNIT (type)))
4681    {
4682      error ("size of array %qs is too large", name);
4683      /* If we proceed with the array type as it is, we'll eventually
4684	 crash in tree_low_cst().  */
4685      type = error_mark_node;
4686    }
4687
4688  /* If this is declaring a typedef name, return a TYPE_DECL.  */
4689
4690  if (storage_class == csc_typedef)
4691    {
4692      tree decl;
4693      if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4694	  && type_quals)
4695	pedwarn ("ISO C forbids qualified function types");
4696      if (type_quals)
4697	type = c_build_qualified_type (type, type_quals);
4698      decl = build_decl (TYPE_DECL, declarator->u.id, type);
4699      if (declspecs->explicit_signed_p)
4700	C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1;
4701      decl_attributes (&decl, returned_attrs, 0);
4702      if (declspecs->inline_p)
4703	pedwarn ("typedef %q+D declared %<inline%>", decl);
4704      return decl;
4705    }
4706
4707  /* If this is a type name (such as, in a cast or sizeof),
4708     compute the type and return it now.  */
4709
4710  if (decl_context == TYPENAME)
4711    {
4712      /* Note that the grammar rejects storage classes in typenames
4713	 and fields.  */
4714      gcc_assert (storage_class == csc_none && !threadp
4715		  && !declspecs->inline_p);
4716      if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4717	  && type_quals)
4718	pedwarn ("ISO C forbids const or volatile function types");
4719      if (type_quals)
4720	type = c_build_qualified_type (type, type_quals);
4721      decl_attributes (&type, returned_attrs, 0);
4722      return type;
4723    }
4724
4725  if (pedantic && decl_context == FIELD
4726      && variably_modified_type_p (type, NULL_TREE))
4727    {
4728      /* C99 6.7.2.1p8 */
4729      pedwarn ("a member of a structure or union cannot have a variably modified type");
4730    }
4731
4732  /* Aside from typedefs and type names (handle above),
4733     `void' at top level (not within pointer)
4734     is allowed only in public variables.
4735     We don't complain about parms either, but that is because
4736     a better error message can be made later.  */
4737
4738  if (VOID_TYPE_P (type) && decl_context != PARM
4739      && !((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE)
4740	    && (storage_class == csc_extern
4741		|| (current_scope == file_scope
4742		    && !(storage_class == csc_static
4743			 || storage_class == csc_register)))))
4744    {
4745      error ("variable or field %qs declared void", name);
4746      type = integer_type_node;
4747    }
4748
4749  /* Now create the decl, which may be a VAR_DECL, a PARM_DECL
4750     or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE.  */
4751
4752  {
4753    tree decl;
4754
4755    if (decl_context == PARM)
4756      {
4757	tree type_as_written;
4758	tree promoted_type;
4759
4760	/* A parameter declared as an array of T is really a pointer to T.
4761	   One declared as a function is really a pointer to a function.  */
4762
4763	if (TREE_CODE (type) == ARRAY_TYPE)
4764	  {
4765	    /* Transfer const-ness of array into that of type pointed to.  */
4766	    type = TREE_TYPE (type);
4767	    if (type_quals)
4768	      type = c_build_qualified_type (type, type_quals);
4769	    type = build_pointer_type (type);
4770	    type_quals = array_ptr_quals;
4771
4772	    /* We don't yet implement attributes in this context.  */
4773	    if (array_ptr_attrs != NULL_TREE)
4774	      warning (OPT_Wattributes,
4775		       "attributes in parameter array declarator ignored");
4776
4777	    size_varies = 0;
4778	  }
4779	else if (TREE_CODE (type) == FUNCTION_TYPE)
4780	  {
4781	    if (pedantic && type_quals)
4782	      pedwarn ("ISO C forbids qualified function types");
4783	    if (type_quals)
4784	      type = c_build_qualified_type (type, type_quals);
4785	    type = build_pointer_type (type);
4786	    type_quals = TYPE_UNQUALIFIED;
4787	  }
4788	else if (type_quals)
4789	  type = c_build_qualified_type (type, type_quals);
4790
4791	type_as_written = type;
4792
4793	decl = build_decl (PARM_DECL, declarator->u.id, type);
4794	if (size_varies)
4795	  C_DECL_VARIABLE_SIZE (decl) = 1;
4796
4797	/* Compute the type actually passed in the parmlist,
4798	   for the case where there is no prototype.
4799	   (For example, shorts and chars are passed as ints.)
4800	   When there is a prototype, this is overridden later.  */
4801
4802	if (type == error_mark_node)
4803	  promoted_type = type;
4804	else
4805	  promoted_type = c_type_promotes_to (type);
4806
4807	DECL_ARG_TYPE (decl) = promoted_type;
4808	if (declspecs->inline_p)
4809	  pedwarn ("parameter %q+D declared %<inline%>", decl);
4810      }
4811    else if (decl_context == FIELD)
4812      {
4813	/* Note that the grammar rejects storage classes in typenames
4814	   and fields.  */
4815	gcc_assert (storage_class == csc_none && !threadp
4816		    && !declspecs->inline_p);
4817
4818	/* Structure field.  It may not be a function.  */
4819
4820	if (TREE_CODE (type) == FUNCTION_TYPE)
4821	  {
4822	    error ("field %qs declared as a function", name);
4823	    type = build_pointer_type (type);
4824	  }
4825	else if (TREE_CODE (type) != ERROR_MARK
4826		 && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type))
4827	  {
4828	    error ("field %qs has incomplete type", name);
4829	    type = error_mark_node;
4830	  }
4831	type = c_build_qualified_type (type, type_quals);
4832	decl = build_decl (FIELD_DECL, declarator->u.id, type);
4833	DECL_NONADDRESSABLE_P (decl) = bitfield;
4834
4835	if (size_varies)
4836	  C_DECL_VARIABLE_SIZE (decl) = 1;
4837      }
4838    else if (TREE_CODE (type) == FUNCTION_TYPE)
4839      {
4840	if (storage_class == csc_register || threadp)
4841	  {
4842	    error ("invalid storage class for function %qs", name);
4843	   }
4844	else if (current_scope != file_scope)
4845	  {
4846	    /* Function declaration not at file scope.  Storage
4847	       classes other than `extern' are not allowed, C99
4848	       6.7.1p5, and `extern' makes no difference.  However,
4849	       GCC allows 'auto', perhaps with 'inline', to support
4850	       nested functions.  */
4851	    if (storage_class == csc_auto)
4852	      {
4853		if (pedantic)
4854		  pedwarn ("invalid storage class for function %qs", name);
4855	      }
4856	    else if (storage_class == csc_static)
4857	      {
4858		error ("invalid storage class for function %qs", name);
4859		if (funcdef_flag)
4860		  storage_class = declspecs->storage_class = csc_none;
4861		else
4862		  return 0;
4863	      }
4864	  }
4865
4866	decl = build_decl (FUNCTION_DECL, declarator->u.id, type);
4867	decl = build_decl_attribute_variant (decl, decl_attr);
4868
4869	DECL_LANG_SPECIFIC (decl) = GGC_CNEW (struct lang_decl);
4870
4871	if (pedantic && type_quals && !DECL_IN_SYSTEM_HEADER (decl))
4872	  pedwarn ("ISO C forbids qualified function types");
4873
4874	/* GNU C interprets a volatile-qualified function type to indicate
4875	   that the function does not return.  */
4876	if ((type_quals & TYPE_QUAL_VOLATILE)
4877	    && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
4878	  warning (0, "%<noreturn%> function returns non-void value");
4879
4880	/* Every function declaration is an external reference
4881	   (DECL_EXTERNAL) except for those which are not at file
4882	   scope and are explicitly declared "auto".  This is
4883	   forbidden by standard C (C99 6.7.1p5) and is interpreted by
4884	   GCC to signify a forward declaration of a nested function.  */
4885	if (storage_class == csc_auto && current_scope != file_scope)
4886	  DECL_EXTERNAL (decl) = 0;
4887	/* In C99, a function which is declared 'inline' with 'extern'
4888	   is not an external reference (which is confusing).  It
4889	   means that the later definition of the function must be output
4890	   in this file, C99 6.7.4p6.  In GNU C89, a function declared
4891	   'extern inline' is an external reference.  */
4892	else if (declspecs->inline_p && storage_class != csc_static)
4893	  DECL_EXTERNAL (decl) = ((storage_class == csc_extern)
4894				  == flag_gnu89_inline);
4895	else
4896	  DECL_EXTERNAL (decl) = !initialized;
4897
4898	/* Record absence of global scope for `static' or `auto'.  */
4899	TREE_PUBLIC (decl)
4900	  = !(storage_class == csc_static || storage_class == csc_auto);
4901
4902	/* For a function definition, record the argument information
4903	   block where store_parm_decls will look for it.  */
4904	if (funcdef_flag)
4905	  current_function_arg_info = arg_info;
4906
4907	if (declspecs->default_int_p)
4908	  C_FUNCTION_IMPLICIT_INT (decl) = 1;
4909
4910	/* Record presence of `inline', if it is reasonable.  */
4911	if (flag_hosted && MAIN_NAME_P (declarator->u.id))
4912	  {
4913	    if (declspecs->inline_p)
4914	      pedwarn ("cannot inline function %<main%>");
4915	  }
4916	else if (declspecs->inline_p)
4917	  {
4918	    /* Record that the function is declared `inline'.  */
4919	    DECL_DECLARED_INLINE_P (decl) = 1;
4920
4921	    /* Do not mark bare declarations as DECL_INLINE.  Doing so
4922	       in the presence of multiple declarations can result in
4923	       the abstract origin pointing between the declarations,
4924	       which will confuse dwarf2out.  */
4925	    if (initialized)
4926	      DECL_INLINE (decl) = 1;
4927	  }
4928	/* If -finline-functions, assume it can be inlined.  This does
4929	   two things: let the function be deferred until it is actually
4930	   needed, and let dwarf2 know that the function is inlinable.  */
4931	else if (flag_inline_trees == 2 && initialized)
4932	  DECL_INLINE (decl) = 1;
4933      }
4934    else
4935      {
4936	/* It's a variable.  */
4937	/* An uninitialized decl with `extern' is a reference.  */
4938	int extern_ref = !initialized && storage_class == csc_extern;
4939
4940	type = c_build_qualified_type (type, type_quals);
4941
4942	/* C99 6.2.2p7: It is invalid (compile-time undefined
4943	   behavior) to create an 'extern' declaration for a
4944	   variable if there is a global declaration that is
4945	   'static' and the global declaration is not visible.
4946	   (If the static declaration _is_ currently visible,
4947	   the 'extern' declaration is taken to refer to that decl.) */
4948	if (extern_ref && current_scope != file_scope)
4949	  {
4950	    tree global_decl  = identifier_global_value (declarator->u.id);
4951	    tree visible_decl = lookup_name (declarator->u.id);
4952
4953	    if (global_decl
4954		&& global_decl != visible_decl
4955		&& TREE_CODE (global_decl) == VAR_DECL
4956		&& !TREE_PUBLIC (global_decl))
4957	      error ("variable previously declared %<static%> redeclared "
4958		     "%<extern%>");
4959	  }
4960
4961	decl = build_decl (VAR_DECL, declarator->u.id, type);
4962	DECL_SOURCE_LOCATION (decl) = declarator->id_loc;
4963	if (size_varies)
4964	  C_DECL_VARIABLE_SIZE (decl) = 1;
4965
4966	if (declspecs->inline_p)
4967	  pedwarn ("variable %q+D declared %<inline%>", decl);
4968
4969	/* At file scope, an initialized extern declaration may follow
4970	   a static declaration.  In that case, DECL_EXTERNAL will be
4971	   reset later in start_decl.  */
4972	DECL_EXTERNAL (decl) = (storage_class == csc_extern);
4973
4974	/* At file scope, the presence of a `static' or `register' storage
4975	   class specifier, or the absence of all storage class specifiers
4976	   makes this declaration a definition (perhaps tentative).  Also,
4977	   the absence of `static' makes it public.  */
4978	if (current_scope == file_scope)
4979	  {
4980	    TREE_PUBLIC (decl) = storage_class != csc_static;
4981	    TREE_STATIC (decl) = !extern_ref;
4982	  }
4983	/* Not at file scope, only `static' makes a static definition.  */
4984	else
4985	  {
4986	    TREE_STATIC (decl) = (storage_class == csc_static);
4987	    TREE_PUBLIC (decl) = extern_ref;
4988	  }
4989
4990	if (threadp)
4991	  {
4992	    if (targetm.have_tls)
4993	      DECL_TLS_MODEL (decl) = decl_default_tls_model (decl);
4994	    else
4995	      /* A mere warning is sure to result in improper semantics
4996		 at runtime.  Don't bother to allow this to compile.  */
4997	      error ("thread-local storage not supported for this target");
4998	  }
4999      }
5000
5001    if (storage_class == csc_extern
5002	&& variably_modified_type_p (type, NULL_TREE))
5003      {
5004	/* C99 6.7.5.2p2 */
5005	error ("object with variably modified type must have no linkage");
5006      }
5007
5008    /* Record `register' declaration for warnings on &
5009       and in case doing stupid register allocation.  */
5010
5011    if (storage_class == csc_register)
5012      {
5013	C_DECL_REGISTER (decl) = 1;
5014	DECL_REGISTER (decl) = 1;
5015      }
5016
5017    /* Record constancy and volatility.  */
5018    c_apply_type_quals_to_decl (type_quals, decl);
5019
5020    /* If a type has volatile components, it should be stored in memory.
5021       Otherwise, the fact that those components are volatile
5022       will be ignored, and would even crash the compiler.
5023       Of course, this only makes sense on  VAR,PARM, and RESULT decl's.   */
5024    if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl))
5025	&& (TREE_CODE (decl) == VAR_DECL ||  TREE_CODE (decl) == PARM_DECL
5026	  || TREE_CODE (decl) == RESULT_DECL))
5027      {
5028	/* It is not an error for a structure with volatile fields to
5029	   be declared register, but reset DECL_REGISTER since it
5030	   cannot actually go in a register.  */
5031	int was_reg = C_DECL_REGISTER (decl);
5032	C_DECL_REGISTER (decl) = 0;
5033	DECL_REGISTER (decl) = 0;
5034	c_mark_addressable (decl);
5035	C_DECL_REGISTER (decl) = was_reg;
5036      }
5037
5038  /* This is the earliest point at which we might know the assembler
5039     name of a variable.  Thus, if it's known before this, die horribly.  */
5040    gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl));
5041
5042    decl_attributes (&decl, returned_attrs, 0);
5043
5044    return decl;
5045  }
5046}
5047
5048/* Decode the parameter-list info for a function type or function definition.
5049   The argument is the value returned by `get_parm_info' (or made in c-parse.c
5050   if there is an identifier list instead of a parameter decl list).
5051   These two functions are separate because when a function returns
5052   or receives functions then each is called multiple times but the order
5053   of calls is different.  The last call to `grokparms' is always the one
5054   that contains the formal parameter names of a function definition.
5055
5056   Return a list of arg types to use in the FUNCTION_TYPE for this function.
5057
5058   FUNCDEF_FLAG is true for a function definition, false for
5059   a mere declaration.  A nonempty identifier-list gets an error message
5060   when FUNCDEF_FLAG is false.  */
5061
5062static tree
5063grokparms (struct c_arg_info *arg_info, bool funcdef_flag)
5064{
5065  tree arg_types = arg_info->types;
5066
5067  if (funcdef_flag && arg_info->had_vla_unspec)
5068    {
5069      /* A function definition isn't function prototype scope C99 6.2.1p4.  */
5070      /* C99 6.7.5.2p4 */
5071      error ("%<[*]%> not allowed in other than function prototype scope");
5072    }
5073
5074  if (arg_types == 0 && !funcdef_flag && !in_system_header)
5075    warning (OPT_Wstrict_prototypes,
5076	     "function declaration isn%'t a prototype");
5077
5078  if (arg_types == error_mark_node)
5079    return 0;  /* don't set TYPE_ARG_TYPES in this case */
5080
5081  else if (arg_types && TREE_CODE (TREE_VALUE (arg_types)) == IDENTIFIER_NODE)
5082    {
5083      if (!funcdef_flag)
5084	pedwarn ("parameter names (without types) in function declaration");
5085
5086      arg_info->parms = arg_info->types;
5087      arg_info->types = 0;
5088      return 0;
5089    }
5090  else
5091    {
5092      tree parm, type, typelt;
5093      unsigned int parmno;
5094
5095      /* If there is a parameter of incomplete type in a definition,
5096	 this is an error.  In a declaration this is valid, and a
5097	 struct or union type may be completed later, before any calls
5098	 or definition of the function.  In the case where the tag was
5099	 first declared within the parameter list, a warning has
5100	 already been given.  If a parameter has void type, then
5101	 however the function cannot be defined or called, so
5102	 warn.  */
5103
5104      for (parm = arg_info->parms, typelt = arg_types, parmno = 1;
5105	   parm;
5106	   parm = TREE_CHAIN (parm), typelt = TREE_CHAIN (typelt), parmno++)
5107	{
5108	  type = TREE_VALUE (typelt);
5109	  if (type == error_mark_node)
5110	    continue;
5111
5112	  if (!COMPLETE_TYPE_P (type))
5113	    {
5114	      if (funcdef_flag)
5115		{
5116		  if (DECL_NAME (parm))
5117		    error ("parameter %u (%q+D) has incomplete type",
5118			   parmno, parm);
5119		  else
5120		    error ("%Jparameter %u has incomplete type",
5121			   parm, parmno);
5122
5123		  TREE_VALUE (typelt) = error_mark_node;
5124		  TREE_TYPE (parm) = error_mark_node;
5125		}
5126	      else if (VOID_TYPE_P (type))
5127		{
5128		  if (DECL_NAME (parm))
5129		    warning (0, "parameter %u (%q+D) has void type",
5130			     parmno, parm);
5131		  else
5132		    warning (0, "%Jparameter %u has void type",
5133			     parm, parmno);
5134		}
5135	    }
5136
5137	  if (DECL_NAME (parm) && TREE_USED (parm))
5138	    warn_if_shadowing (parm);
5139	}
5140      return arg_types;
5141    }
5142}
5143
5144/* Take apart the current scope and return a c_arg_info structure with
5145   info on a parameter list just parsed.
5146
5147   This structure is later fed to 'grokparms' and 'store_parm_decls'.
5148
5149   ELLIPSIS being true means the argument list ended in '...' so don't
5150   append a sentinel (void_list_node) to the end of the type-list.  */
5151
5152struct c_arg_info *
5153get_parm_info (bool ellipsis)
5154{
5155  struct c_binding *b = current_scope->bindings;
5156  struct c_arg_info *arg_info = XOBNEW (&parser_obstack,
5157					struct c_arg_info);
5158  tree parms    = 0;
5159  tree tags     = 0;
5160  tree types    = 0;
5161  tree others   = 0;
5162
5163  static bool explained_incomplete_types = false;
5164  bool gave_void_only_once_err = false;
5165
5166  arg_info->parms = 0;
5167  arg_info->tags = 0;
5168  arg_info->types = 0;
5169  arg_info->others = 0;
5170  arg_info->pending_sizes = 0;
5171  arg_info->had_vla_unspec = current_scope->had_vla_unspec;
5172
5173  /* The bindings in this scope must not get put into a block.
5174     We will take care of deleting the binding nodes.  */
5175  current_scope->bindings = 0;
5176
5177  /* This function is only called if there was *something* on the
5178     parameter list.  */
5179  gcc_assert (b);
5180
5181  /* A parameter list consisting solely of 'void' indicates that the
5182     function takes no arguments.  But if the 'void' is qualified
5183     (by 'const' or 'volatile'), or has a storage class specifier
5184     ('register'), then the behavior is undefined; issue an error.
5185     Typedefs for 'void' are OK (see DR#157).  */
5186  if (b->prev == 0			    /* one binding */
5187      && TREE_CODE (b->decl) == PARM_DECL   /* which is a parameter */
5188      && !DECL_NAME (b->decl)               /* anonymous */
5189      && VOID_TYPE_P (TREE_TYPE (b->decl))) /* of void type */
5190    {
5191      if (TREE_THIS_VOLATILE (b->decl)
5192	  || TREE_READONLY (b->decl)
5193	  || C_DECL_REGISTER (b->decl))
5194	error ("%<void%> as only parameter may not be qualified");
5195
5196      /* There cannot be an ellipsis.  */
5197      if (ellipsis)
5198	error ("%<void%> must be the only parameter");
5199
5200      arg_info->types = void_list_node;
5201      return arg_info;
5202    }
5203
5204  if (!ellipsis)
5205    types = void_list_node;
5206
5207  /* Break up the bindings list into parms, tags, types, and others;
5208     apply sanity checks; purge the name-to-decl bindings.  */
5209  while (b)
5210    {
5211      tree decl = b->decl;
5212      tree type = TREE_TYPE (decl);
5213      const char *keyword;
5214
5215      switch (TREE_CODE (decl))
5216	{
5217	case PARM_DECL:
5218	  if (b->id)
5219	    {
5220	      gcc_assert (I_SYMBOL_BINDING (b->id) == b);
5221	      I_SYMBOL_BINDING (b->id) = b->shadowed;
5222	    }
5223
5224	  /* Check for forward decls that never got their actual decl.  */
5225	  if (TREE_ASM_WRITTEN (decl))
5226	    error ("parameter %q+D has just a forward declaration", decl);
5227	  /* Check for (..., void, ...) and issue an error.  */
5228	  else if (VOID_TYPE_P (type) && !DECL_NAME (decl))
5229	    {
5230	      if (!gave_void_only_once_err)
5231		{
5232		  error ("%<void%> must be the only parameter");
5233		  gave_void_only_once_err = true;
5234		}
5235	    }
5236	  else
5237	    {
5238	      /* Valid parameter, add it to the list.  */
5239	      TREE_CHAIN (decl) = parms;
5240	      parms = decl;
5241
5242	      /* Since there is a prototype, args are passed in their
5243		 declared types.  The back end may override this later.  */
5244	      DECL_ARG_TYPE (decl) = type;
5245	      types = tree_cons (0, type, types);
5246	    }
5247	  break;
5248
5249	case ENUMERAL_TYPE: keyword = "enum"; goto tag;
5250	case UNION_TYPE:    keyword = "union"; goto tag;
5251	case RECORD_TYPE:   keyword = "struct"; goto tag;
5252	tag:
5253	  /* Types may not have tag-names, in which case the type
5254	     appears in the bindings list with b->id NULL.  */
5255	  if (b->id)
5256	    {
5257	      gcc_assert (I_TAG_BINDING (b->id) == b);
5258	      I_TAG_BINDING (b->id) = b->shadowed;
5259	    }
5260
5261	  /* Warn about any struct, union or enum tags defined in a
5262	     parameter list.  The scope of such types is limited to
5263	     the parameter list, which is rarely if ever desirable
5264	     (it's impossible to call such a function with type-
5265	     correct arguments).  An anonymous union parm type is
5266	     meaningful as a GNU extension, so don't warn for that.  */
5267	  if (TREE_CODE (decl) != UNION_TYPE || b->id != 0)
5268	    {
5269	      if (b->id)
5270		/* The %s will be one of 'struct', 'union', or 'enum'.  */
5271		warning (0, "%<%s %E%> declared inside parameter list",
5272			 keyword, b->id);
5273	      else
5274		/* The %s will be one of 'struct', 'union', or 'enum'.  */
5275		warning (0, "anonymous %s declared inside parameter list",
5276			 keyword);
5277
5278	      if (!explained_incomplete_types)
5279		{
5280		  warning (0, "its scope is only this definition or declaration,"
5281			   " which is probably not what you want");
5282		  explained_incomplete_types = true;
5283		}
5284	    }
5285
5286	  tags = tree_cons (b->id, decl, tags);
5287	  break;
5288
5289	case CONST_DECL:
5290	case TYPE_DECL:
5291	case FUNCTION_DECL:
5292	  /* CONST_DECLs appear here when we have an embedded enum,
5293	     and TYPE_DECLs appear here when we have an embedded struct
5294	     or union.  No warnings for this - we already warned about the
5295	     type itself.  FUNCTION_DECLs appear when there is an implicit
5296	     function declaration in the parameter list.  */
5297
5298	  TREE_CHAIN (decl) = others;
5299	  others = decl;
5300	  /* fall through */
5301
5302	case ERROR_MARK:
5303	  /* error_mark_node appears here when we have an undeclared
5304	     variable.  Just throw it away.  */
5305	  if (b->id)
5306	    {
5307	      gcc_assert (I_SYMBOL_BINDING (b->id) == b);
5308	      I_SYMBOL_BINDING (b->id) = b->shadowed;
5309	    }
5310	  break;
5311
5312	  /* Other things that might be encountered.  */
5313	case LABEL_DECL:
5314	case VAR_DECL:
5315	default:
5316	  gcc_unreachable ();
5317	}
5318
5319      b = free_binding_and_advance (b);
5320    }
5321
5322  arg_info->parms = parms;
5323  arg_info->tags = tags;
5324  arg_info->types = types;
5325  arg_info->others = others;
5326  arg_info->pending_sizes = get_pending_sizes ();
5327  return arg_info;
5328}
5329
5330/* Get the struct, enum or union (CODE says which) with tag NAME.
5331   Define the tag as a forward-reference if it is not defined.
5332   Return a c_typespec structure for the type specifier.  */
5333
5334struct c_typespec
5335parser_xref_tag (enum tree_code code, tree name)
5336{
5337  struct c_typespec ret;
5338  /* If a cross reference is requested, look up the type
5339     already defined for this tag and return it.  */
5340
5341  tree ref = lookup_tag (code, name, 0);
5342  /* If this is the right type of tag, return what we found.
5343     (This reference will be shadowed by shadow_tag later if appropriate.)
5344     If this is the wrong type of tag, do not return it.  If it was the
5345     wrong type in the same scope, we will have had an error
5346     message already; if in a different scope and declaring
5347     a name, pending_xref_error will give an error message; but if in a
5348     different scope and not declaring a name, this tag should
5349     shadow the previous declaration of a different type of tag, and
5350     this would not work properly if we return the reference found.
5351     (For example, with "struct foo" in an outer scope, "union foo;"
5352     must shadow that tag with a new one of union type.)  */
5353  ret.kind = (ref ? ctsk_tagref : ctsk_tagfirstref);
5354  if (ref && TREE_CODE (ref) == code)
5355    {
5356      ret.spec = ref;
5357      return ret;
5358    }
5359
5360  /* If no such tag is yet defined, create a forward-reference node
5361     and record it as the "definition".
5362     When a real declaration of this type is found,
5363     the forward-reference will be altered into a real type.  */
5364
5365  ref = make_node (code);
5366  if (code == ENUMERAL_TYPE)
5367    {
5368      /* Give the type a default layout like unsigned int
5369	 to avoid crashing if it does not get defined.  */
5370      TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node);
5371      TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node);
5372      TYPE_USER_ALIGN (ref) = 0;
5373      TYPE_UNSIGNED (ref) = 1;
5374      TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node);
5375      TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node);
5376      TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node);
5377    }
5378
5379  pushtag (name, ref);
5380
5381  ret.spec = ref;
5382  return ret;
5383}
5384
5385/* Get the struct, enum or union (CODE says which) with tag NAME.
5386   Define the tag as a forward-reference if it is not defined.
5387   Return a tree for the type.  */
5388
5389tree
5390xref_tag (enum tree_code code, tree name)
5391{
5392  return parser_xref_tag (code, name).spec;
5393}
5394
5395/* Make sure that the tag NAME is defined *in the current scope*
5396   at least as a forward reference.
5397   CODE says which kind of tag NAME ought to be.  */
5398
5399tree
5400start_struct (enum tree_code code, tree name)
5401{
5402  /* If there is already a tag defined at this scope
5403     (as a forward reference), just return it.  */
5404
5405  tree ref = 0;
5406
5407  if (name != 0)
5408    ref = lookup_tag (code, name, 1);
5409  if (ref && TREE_CODE (ref) == code)
5410    {
5411      if (TYPE_SIZE (ref))
5412	{
5413	  if (code == UNION_TYPE)
5414	    error ("redefinition of %<union %E%>", name);
5415	  else
5416	    error ("redefinition of %<struct %E%>", name);
5417	}
5418      else if (C_TYPE_BEING_DEFINED (ref))
5419	{
5420	  if (code == UNION_TYPE)
5421	    error ("nested redefinition of %<union %E%>", name);
5422	  else
5423	    error ("nested redefinition of %<struct %E%>", name);
5424	  /* Don't create structures that contain themselves.  */
5425	  ref = NULL_TREE;
5426	}
5427    }
5428
5429  /* Otherwise create a forward-reference just so the tag is in scope.  */
5430
5431  if (ref == NULL_TREE || TREE_CODE (ref) != code)
5432    {
5433      ref = make_node (code);
5434      pushtag (name, ref);
5435    }
5436
5437  C_TYPE_BEING_DEFINED (ref) = 1;
5438  TYPE_PACKED (ref) = flag_pack_struct;
5439  return ref;
5440}
5441
5442/* Process the specs, declarator and width (NULL if omitted)
5443   of a structure component, returning a FIELD_DECL node.
5444   WIDTH is non-NULL for bit-fields only, and is an INTEGER_CST node.
5445
5446   This is done during the parsing of the struct declaration.
5447   The FIELD_DECL nodes are chained together and the lot of them
5448   are ultimately passed to `build_struct' to make the RECORD_TYPE node.  */
5449
5450tree
5451grokfield (struct c_declarator *declarator, struct c_declspecs *declspecs,
5452	   tree width)
5453{
5454  tree value;
5455
5456  if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE
5457      && width == NULL_TREE)
5458    {
5459      /* This is an unnamed decl.
5460
5461	 If we have something of the form "union { list } ;" then this
5462	 is the anonymous union extension.  Similarly for struct.
5463
5464	 If this is something of the form "struct foo;", then
5465	   If MS extensions are enabled, this is handled as an
5466	     anonymous struct.
5467	   Otherwise this is a forward declaration of a structure tag.
5468
5469	 If this is something of the form "foo;" and foo is a TYPE_DECL, then
5470	   If MS extensions are enabled and foo names a structure, then
5471	     again this is an anonymous struct.
5472	   Otherwise this is an error.
5473
5474	 Oh what a horrid tangled web we weave.  I wonder if MS consciously
5475	 took this from Plan 9 or if it was an accident of implementation
5476	 that took root before someone noticed the bug...  */
5477
5478      tree type = declspecs->type;
5479      bool type_ok = (TREE_CODE (type) == RECORD_TYPE
5480		      || TREE_CODE (type) == UNION_TYPE);
5481      bool ok = false;
5482
5483      if (type_ok
5484	  && (flag_ms_extensions || !declspecs->typedef_p))
5485	{
5486	  if (flag_ms_extensions)
5487	    ok = true;
5488	  else if (flag_iso)
5489	    ok = false;
5490	  else if (TYPE_NAME (type) == NULL)
5491	    ok = true;
5492	  else
5493	    ok = false;
5494	}
5495      if (!ok)
5496	{
5497	  pedwarn ("declaration does not declare anything");
5498	  return NULL_TREE;
5499	}
5500      if (pedantic)
5501	pedwarn ("ISO C doesn%'t support unnamed structs/unions");
5502    }
5503
5504  value = grokdeclarator (declarator, declspecs, FIELD, false,
5505			  width ? &width : NULL);
5506
5507  finish_decl (value, NULL_TREE, NULL_TREE);
5508  DECL_INITIAL (value) = width;
5509
5510  return value;
5511}
5512
5513/* Generate an error for any duplicate field names in FIELDLIST.  Munge
5514   the list such that this does not present a problem later.  */
5515
5516static void
5517detect_field_duplicates (tree fieldlist)
5518{
5519  tree x, y;
5520  int timeout = 10;
5521
5522  /* First, see if there are more than "a few" fields.
5523     This is trivially true if there are zero or one fields.  */
5524  if (!fieldlist)
5525    return;
5526  x = TREE_CHAIN (fieldlist);
5527  if (!x)
5528    return;
5529  do {
5530    timeout--;
5531    x = TREE_CHAIN (x);
5532  } while (timeout > 0 && x);
5533
5534  /* If there were "few" fields, avoid the overhead of allocating
5535     a hash table.  Instead just do the nested traversal thing.  */
5536  if (timeout > 0)
5537    {
5538      for (x = TREE_CHAIN (fieldlist); x ; x = TREE_CHAIN (x))
5539	if (DECL_NAME (x))
5540	  {
5541	    for (y = fieldlist; y != x; y = TREE_CHAIN (y))
5542	      if (DECL_NAME (y) == DECL_NAME (x))
5543		{
5544		  error ("duplicate member %q+D", x);
5545		  DECL_NAME (x) = NULL_TREE;
5546		}
5547	  }
5548    }
5549  else
5550    {
5551      htab_t htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL);
5552      void **slot;
5553
5554      for (x = fieldlist; x ; x = TREE_CHAIN (x))
5555	if ((y = DECL_NAME (x)) != 0)
5556	  {
5557	    slot = htab_find_slot (htab, y, INSERT);
5558	    if (*slot)
5559	      {
5560		error ("duplicate member %q+D", x);
5561		DECL_NAME (x) = NULL_TREE;
5562	      }
5563	    *slot = y;
5564	  }
5565
5566      htab_delete (htab);
5567    }
5568}
5569
5570/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T.
5571   FIELDLIST is a chain of FIELD_DECL nodes for the fields.
5572   ATTRIBUTES are attributes to be applied to the structure.  */
5573
5574tree
5575finish_struct (tree t, tree fieldlist, tree attributes)
5576{
5577  tree x;
5578  bool toplevel = file_scope == current_scope;
5579  int saw_named_field;
5580
5581  /* If this type was previously laid out as a forward reference,
5582     make sure we lay it out again.  */
5583
5584  TYPE_SIZE (t) = 0;
5585
5586  decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5587
5588  if (pedantic)
5589    {
5590      for (x = fieldlist; x; x = TREE_CHAIN (x))
5591	if (DECL_NAME (x) != 0)
5592	  break;
5593
5594      if (x == 0)
5595	{
5596	  if (TREE_CODE (t) == UNION_TYPE)
5597	    {
5598	      if (fieldlist)
5599		pedwarn ("union has no named members");
5600	      else
5601		pedwarn ("union has no members");
5602	    }
5603	  else
5604	    {
5605	      if (fieldlist)
5606		pedwarn ("struct has no named members");
5607	      else
5608		pedwarn ("struct has no members");
5609	    }
5610	}
5611    }
5612
5613  /* Install struct as DECL_CONTEXT of each field decl.
5614     Also process specified field sizes, found in the DECL_INITIAL,
5615     storing 0 there after the type has been changed to precision equal
5616     to its width, rather than the precision of the specified standard
5617     type.  (Correct layout requires the original type to have been preserved
5618     until now.)  */
5619
5620  saw_named_field = 0;
5621  for (x = fieldlist; x; x = TREE_CHAIN (x))
5622    {
5623      if (TREE_TYPE (x) == error_mark_node)
5624	continue;
5625
5626      DECL_CONTEXT (x) = t;
5627
5628      if (TYPE_PACKED (t) && TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
5629	DECL_PACKED (x) = 1;
5630
5631      /* If any field is const, the structure type is pseudo-const.  */
5632      if (TREE_READONLY (x))
5633	C_TYPE_FIELDS_READONLY (t) = 1;
5634      else
5635	{
5636	  /* A field that is pseudo-const makes the structure likewise.  */
5637	  tree t1 = TREE_TYPE (x);
5638	  while (TREE_CODE (t1) == ARRAY_TYPE)
5639	    t1 = TREE_TYPE (t1);
5640	  if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE)
5641	      && C_TYPE_FIELDS_READONLY (t1))
5642	    C_TYPE_FIELDS_READONLY (t) = 1;
5643	}
5644
5645      /* Any field that is volatile means variables of this type must be
5646	 treated in some ways as volatile.  */
5647      if (TREE_THIS_VOLATILE (x))
5648	C_TYPE_FIELDS_VOLATILE (t) = 1;
5649
5650      /* Any field of nominal variable size implies structure is too.  */
5651      if (C_DECL_VARIABLE_SIZE (x))
5652	C_TYPE_VARIABLE_SIZE (t) = 1;
5653
5654      if (DECL_INITIAL (x))
5655	{
5656	  unsigned HOST_WIDE_INT width = tree_low_cst (DECL_INITIAL (x), 1);
5657	  DECL_SIZE (x) = bitsize_int (width);
5658	  DECL_BIT_FIELD (x) = 1;
5659	  SET_DECL_C_BIT_FIELD (x);
5660	}
5661
5662      /* Detect flexible array member in an invalid context.  */
5663      if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE
5664	  && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE
5665	  && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE
5666	  && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE)
5667	{
5668	  if (TREE_CODE (t) == UNION_TYPE)
5669	    {
5670	      error ("%Jflexible array member in union", x);
5671	      TREE_TYPE (x) = error_mark_node;
5672	    }
5673	  else if (TREE_CHAIN (x) != NULL_TREE)
5674	    {
5675	      error ("%Jflexible array member not at end of struct", x);
5676	      TREE_TYPE (x) = error_mark_node;
5677	    }
5678	  else if (!saw_named_field)
5679	    {
5680	      error ("%Jflexible array member in otherwise empty struct", x);
5681	      TREE_TYPE (x) = error_mark_node;
5682	    }
5683	}
5684
5685      if (pedantic && !in_system_header && TREE_CODE (t) == RECORD_TYPE
5686	  && flexible_array_type_p (TREE_TYPE (x)))
5687	pedwarn ("%Jinvalid use of structure with flexible array member", x);
5688
5689      if (DECL_NAME (x))
5690	saw_named_field = 1;
5691    }
5692
5693  detect_field_duplicates (fieldlist);
5694
5695  /* Now we have the nearly final fieldlist.  Record it,
5696     then lay out the structure or union (including the fields).  */
5697
5698  TYPE_FIELDS (t) = fieldlist;
5699
5700  layout_type (t);
5701
5702  /* Give bit-fields their proper types.  */
5703  {
5704    tree *fieldlistp = &fieldlist;
5705    while (*fieldlistp)
5706      if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp)
5707	  && TREE_TYPE (*fieldlistp) != error_mark_node)
5708	{
5709	  unsigned HOST_WIDE_INT width
5710	    = tree_low_cst (DECL_INITIAL (*fieldlistp), 1);
5711	  tree type = TREE_TYPE (*fieldlistp);
5712	  if (width != TYPE_PRECISION (type))
5713	    {
5714	      TREE_TYPE (*fieldlistp)
5715		= c_build_bitfield_integer_type (width, TYPE_UNSIGNED (type));
5716	      DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp));
5717	    }
5718	  DECL_INITIAL (*fieldlistp) = 0;
5719	}
5720      else
5721	fieldlistp = &TREE_CHAIN (*fieldlistp);
5722  }
5723
5724  /* Now we have the truly final field list.
5725     Store it in this type and in the variants.  */
5726
5727  TYPE_FIELDS (t) = fieldlist;
5728
5729  /* If there are lots of fields, sort so we can look through them fast.
5730     We arbitrarily consider 16 or more elts to be "a lot".  */
5731
5732  {
5733    int len = 0;
5734
5735    for (x = fieldlist; x; x = TREE_CHAIN (x))
5736      {
5737	if (len > 15 || DECL_NAME (x) == NULL)
5738	  break;
5739	len += 1;
5740      }
5741
5742    if (len > 15)
5743      {
5744	tree *field_array;
5745	struct lang_type *space;
5746	struct sorted_fields_type *space2;
5747
5748	len += list_length (x);
5749
5750	/* Use the same allocation policy here that make_node uses, to
5751	  ensure that this lives as long as the rest of the struct decl.
5752	  All decls in an inline function need to be saved.  */
5753
5754	space = GGC_CNEW (struct lang_type);
5755	space2 = GGC_NEWVAR (struct sorted_fields_type,
5756			     sizeof (struct sorted_fields_type) + len * sizeof (tree));
5757
5758	len = 0;
5759	space->s = space2;
5760	field_array = &space2->elts[0];
5761	for (x = fieldlist; x; x = TREE_CHAIN (x))
5762	  {
5763	    field_array[len++] = x;
5764
5765	    /* If there is anonymous struct or union, break out of the loop.  */
5766	    if (DECL_NAME (x) == NULL)
5767	      break;
5768	  }
5769	/* Found no anonymous struct/union.  Add the TYPE_LANG_SPECIFIC.  */
5770	if (x == NULL)
5771	  {
5772	    TYPE_LANG_SPECIFIC (t) = space;
5773	    TYPE_LANG_SPECIFIC (t)->s->len = len;
5774	    field_array = TYPE_LANG_SPECIFIC (t)->s->elts;
5775	    qsort (field_array, len, sizeof (tree), field_decl_cmp);
5776	  }
5777      }
5778  }
5779
5780  for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x))
5781    {
5782      TYPE_FIELDS (x) = TYPE_FIELDS (t);
5783      TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t);
5784      C_TYPE_FIELDS_READONLY (x) = C_TYPE_FIELDS_READONLY (t);
5785      C_TYPE_FIELDS_VOLATILE (x) = C_TYPE_FIELDS_VOLATILE (t);
5786      C_TYPE_VARIABLE_SIZE (x) = C_TYPE_VARIABLE_SIZE (t);
5787    }
5788
5789  /* If this was supposed to be a transparent union, but we can't
5790     make it one, warn and turn off the flag.  */
5791  if (TREE_CODE (t) == UNION_TYPE
5792      && TYPE_TRANSPARENT_UNION (t)
5793      && (!TYPE_FIELDS (t) || TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t))))
5794    {
5795      TYPE_TRANSPARENT_UNION (t) = 0;
5796      warning (0, "union cannot be made transparent");
5797    }
5798
5799  /* If this structure or union completes the type of any previous
5800     variable declaration, lay it out and output its rtl.  */
5801  for (x = C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t));
5802       x;
5803       x = TREE_CHAIN (x))
5804    {
5805      tree decl = TREE_VALUE (x);
5806      if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
5807	layout_array_type (TREE_TYPE (decl));
5808      if (TREE_CODE (decl) != TYPE_DECL)
5809	{
5810	  layout_decl (decl, 0);
5811	  if (c_dialect_objc ())
5812	    objc_check_decl (decl);
5813	  rest_of_decl_compilation (decl, toplevel, 0);
5814	  if (!toplevel)
5815	    expand_decl (decl);
5816	}
5817    }
5818  C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0;
5819
5820  /* Finish debugging output for this type.  */
5821  rest_of_type_compilation (t, toplevel);
5822
5823  /* If we're inside a function proper, i.e. not file-scope and not still
5824     parsing parameters, then arrange for the size of a variable sized type
5825     to be bound now.  */
5826  if (cur_stmt_list && variably_modified_type_p (t, NULL_TREE))
5827    add_stmt (build_stmt (DECL_EXPR, build_decl (TYPE_DECL, NULL, t)));
5828
5829  return t;
5830}
5831
5832/* Lay out the type T, and its element type, and so on.  */
5833
5834static void
5835layout_array_type (tree t)
5836{
5837  if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE)
5838    layout_array_type (TREE_TYPE (t));
5839  layout_type (t);
5840}
5841
5842/* Begin compiling the definition of an enumeration type.
5843   NAME is its name (or null if anonymous).
5844   Returns the type object, as yet incomplete.
5845   Also records info about it so that build_enumerator
5846   may be used to declare the individual values as they are read.  */
5847
5848tree
5849start_enum (tree name)
5850{
5851  tree enumtype = 0;
5852
5853  /* If this is the real definition for a previous forward reference,
5854     fill in the contents in the same object that used to be the
5855     forward reference.  */
5856
5857  if (name != 0)
5858    enumtype = lookup_tag (ENUMERAL_TYPE, name, 1);
5859
5860  if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE)
5861    {
5862      enumtype = make_node (ENUMERAL_TYPE);
5863      pushtag (name, enumtype);
5864    }
5865
5866  if (C_TYPE_BEING_DEFINED (enumtype))
5867    error ("nested redefinition of %<enum %E%>", name);
5868
5869  C_TYPE_BEING_DEFINED (enumtype) = 1;
5870
5871  if (TYPE_VALUES (enumtype) != 0)
5872    {
5873      /* This enum is a named one that has been declared already.  */
5874      error ("redeclaration of %<enum %E%>", name);
5875
5876      /* Completely replace its old definition.
5877	 The old enumerators remain defined, however.  */
5878      TYPE_VALUES (enumtype) = 0;
5879    }
5880
5881  enum_next_value = integer_zero_node;
5882  enum_overflow = 0;
5883
5884  if (flag_short_enums)
5885    TYPE_PACKED (enumtype) = 1;
5886
5887  return enumtype;
5888}
5889
5890/* After processing and defining all the values of an enumeration type,
5891   install their decls in the enumeration type and finish it off.
5892   ENUMTYPE is the type object, VALUES a list of decl-value pairs,
5893   and ATTRIBUTES are the specified attributes.
5894   Returns ENUMTYPE.  */
5895
5896tree
5897finish_enum (tree enumtype, tree values, tree attributes)
5898{
5899  tree pair, tem;
5900  tree minnode = 0, maxnode = 0;
5901  int precision, unsign;
5902  bool toplevel = (file_scope == current_scope);
5903  struct lang_type *lt;
5904
5905  decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5906
5907  /* Calculate the maximum value of any enumerator in this type.  */
5908
5909  if (values == error_mark_node)
5910    minnode = maxnode = integer_zero_node;
5911  else
5912    {
5913      minnode = maxnode = TREE_VALUE (values);
5914      for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair))
5915	{
5916	  tree value = TREE_VALUE (pair);
5917	  if (tree_int_cst_lt (maxnode, value))
5918	    maxnode = value;
5919	  if (tree_int_cst_lt (value, minnode))
5920	    minnode = value;
5921	}
5922    }
5923
5924  /* Construct the final type of this enumeration.  It is the same
5925     as one of the integral types - the narrowest one that fits, except
5926     that normally we only go as narrow as int - and signed iff any of
5927     the values are negative.  */
5928  unsign = (tree_int_cst_sgn (minnode) >= 0);
5929  precision = MAX (min_precision (minnode, unsign),
5930		   min_precision (maxnode, unsign));
5931
5932  if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node))
5933    {
5934      tem = c_common_type_for_size (precision, unsign);
5935      if (tem == NULL)
5936	{
5937	  warning (0, "enumeration values exceed range of largest integer");
5938	  tem = long_long_integer_type_node;
5939	}
5940    }
5941  else
5942    tem = unsign ? unsigned_type_node : integer_type_node;
5943
5944  TYPE_MIN_VALUE (enumtype) = TYPE_MIN_VALUE (tem);
5945  TYPE_MAX_VALUE (enumtype) = TYPE_MAX_VALUE (tem);
5946  TYPE_UNSIGNED (enumtype) = TYPE_UNSIGNED (tem);
5947  TYPE_SIZE (enumtype) = 0;
5948
5949  /* If the precision of the type was specific with an attribute and it
5950     was too small, give an error.  Otherwise, use it.  */
5951  if (TYPE_PRECISION (enumtype))
5952    {
5953      if (precision > TYPE_PRECISION (enumtype))
5954	error ("specified mode too small for enumeral values");
5955    }
5956  else
5957    TYPE_PRECISION (enumtype) = TYPE_PRECISION (tem);
5958
5959  layout_type (enumtype);
5960
5961  if (values != error_mark_node)
5962    {
5963      /* Change the type of the enumerators to be the enum type.  We
5964	 need to do this irrespective of the size of the enum, for
5965	 proper type checking.  Replace the DECL_INITIALs of the
5966	 enumerators, and the value slots of the list, with copies
5967	 that have the enum type; they cannot be modified in place
5968	 because they may be shared (e.g.  integer_zero_node) Finally,
5969	 change the purpose slots to point to the names of the decls.  */
5970      for (pair = values; pair; pair = TREE_CHAIN (pair))
5971	{
5972	  tree enu = TREE_PURPOSE (pair);
5973	  tree ini = DECL_INITIAL (enu);
5974
5975	  TREE_TYPE (enu) = enumtype;
5976
5977	  /* The ISO C Standard mandates enumerators to have type int,
5978	     even though the underlying type of an enum type is
5979	     unspecified.  Here we convert any enumerators that fit in
5980	     an int to type int, to avoid promotions to unsigned types
5981	     when comparing integers with enumerators that fit in the
5982	     int range.  When -pedantic is given, build_enumerator()
5983	     would have already taken care of those that don't fit.  */
5984	  if (int_fits_type_p (ini, integer_type_node))
5985	    tem = integer_type_node;
5986	  else
5987	    tem = enumtype;
5988	  ini = convert (tem, ini);
5989
5990	  DECL_INITIAL (enu) = ini;
5991	  TREE_PURPOSE (pair) = DECL_NAME (enu);
5992	  TREE_VALUE (pair) = ini;
5993	}
5994
5995      TYPE_VALUES (enumtype) = values;
5996    }
5997
5998  /* Record the min/max values so that we can warn about bit-field
5999     enumerations that are too small for the values.  */
6000  lt = GGC_CNEW (struct lang_type);
6001  lt->enum_min = minnode;
6002  lt->enum_max = maxnode;
6003  TYPE_LANG_SPECIFIC (enumtype) = lt;
6004
6005  /* Fix up all variant types of this enum type.  */
6006  for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem))
6007    {
6008      if (tem == enumtype)
6009	continue;
6010      TYPE_VALUES (tem) = TYPE_VALUES (enumtype);
6011      TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype);
6012      TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype);
6013      TYPE_SIZE (tem) = TYPE_SIZE (enumtype);
6014      TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype);
6015      TYPE_MODE (tem) = TYPE_MODE (enumtype);
6016      TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype);
6017      TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype);
6018      TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype);
6019      TYPE_UNSIGNED (tem) = TYPE_UNSIGNED (enumtype);
6020      TYPE_LANG_SPECIFIC (tem) = TYPE_LANG_SPECIFIC (enumtype);
6021    }
6022
6023  /* Finish debugging output for this type.  */
6024  rest_of_type_compilation (enumtype, toplevel);
6025
6026  return enumtype;
6027}
6028
6029/* Build and install a CONST_DECL for one value of the
6030   current enumeration type (one that was begun with start_enum).
6031   Return a tree-list containing the CONST_DECL and its value.
6032   Assignment of sequential values by default is handled here.  */
6033
6034tree
6035build_enumerator (tree name, tree value)
6036{
6037  tree decl, type;
6038
6039  /* Validate and default VALUE.  */
6040
6041  if (value != 0)
6042    {
6043      /* Don't issue more errors for error_mark_node (i.e. an
6044	 undeclared identifier) - just ignore the value expression.  */
6045      if (value == error_mark_node)
6046	value = 0;
6047      else if (!INTEGRAL_TYPE_P (TREE_TYPE (value))
6048	       || TREE_CODE (value) != INTEGER_CST)
6049	{
6050	  error ("enumerator value for %qE is not an integer constant", name);
6051	  value = 0;
6052	}
6053      else
6054	{
6055	  value = default_conversion (value);
6056	  constant_expression_warning (value);
6057	}
6058    }
6059
6060  /* Default based on previous value.  */
6061  /* It should no longer be possible to have NON_LVALUE_EXPR
6062     in the default.  */
6063  if (value == 0)
6064    {
6065      value = enum_next_value;
6066      if (enum_overflow)
6067	error ("overflow in enumeration values");
6068    }
6069
6070  if (pedantic && !int_fits_type_p (value, integer_type_node))
6071    {
6072      pedwarn ("ISO C restricts enumerator values to range of %<int%>");
6073      /* XXX This causes -pedantic to change the meaning of the program.
6074	 Remove?  -zw 2004-03-15  */
6075      value = convert (integer_type_node, value);
6076    }
6077
6078  /* Set basis for default for next value.  */
6079  enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0);
6080  enum_overflow = tree_int_cst_lt (enum_next_value, value);
6081
6082  /* Now create a declaration for the enum value name.  */
6083
6084  type = TREE_TYPE (value);
6085  type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
6086				      TYPE_PRECISION (integer_type_node)),
6087				 (TYPE_PRECISION (type)
6088				  >= TYPE_PRECISION (integer_type_node)
6089				  && TYPE_UNSIGNED (type)));
6090
6091  decl = build_decl (CONST_DECL, name, type);
6092  DECL_INITIAL (decl) = convert (type, value);
6093  pushdecl (decl);
6094
6095  return tree_cons (decl, value, NULL_TREE);
6096}
6097
6098
6099/* Create the FUNCTION_DECL for a function definition.
6100   DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of
6101   the declaration; they describe the function's name and the type it returns,
6102   but twisted together in a fashion that parallels the syntax of C.
6103
6104   This function creates a binding context for the function body
6105   as well as setting up the FUNCTION_DECL in current_function_decl.
6106
6107   Returns 1 on success.  If the DECLARATOR is not suitable for a function
6108   (it defines a datum instead), we return 0, which tells
6109   yyparse to report a parse error.  */
6110
6111int
6112start_function (struct c_declspecs *declspecs, struct c_declarator *declarator,
6113		tree attributes)
6114{
6115  tree decl1, old_decl;
6116  tree restype, resdecl;
6117  struct c_label_context_se *nstack_se;
6118  struct c_label_context_vm *nstack_vm;
6119
6120  current_function_returns_value = 0;  /* Assume, until we see it does.  */
6121  current_function_returns_null = 0;
6122  current_function_returns_abnormally = 0;
6123  warn_about_return_type = 0;
6124  c_switch_stack = NULL;
6125
6126  nstack_se = XOBNEW (&parser_obstack, struct c_label_context_se);
6127  nstack_se->labels_def = NULL;
6128  nstack_se->labels_used = NULL;
6129  nstack_se->next = label_context_stack_se;
6130  label_context_stack_se = nstack_se;
6131
6132  nstack_vm = XOBNEW (&parser_obstack, struct c_label_context_vm);
6133  nstack_vm->labels_def = NULL;
6134  nstack_vm->labels_used = NULL;
6135  nstack_vm->scope = 0;
6136  nstack_vm->next = label_context_stack_vm;
6137  label_context_stack_vm = nstack_vm;
6138
6139  /* Indicate no valid break/continue context by setting these variables
6140     to some non-null, non-label value.  We'll notice and emit the proper
6141     error message in c_finish_bc_stmt.  */
6142  c_break_label = c_cont_label = size_zero_node;
6143
6144  decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL);
6145
6146  /* If the declarator is not suitable for a function definition,
6147     cause a syntax error.  */
6148  if (decl1 == 0)
6149    {
6150      label_context_stack_se = label_context_stack_se->next;
6151      label_context_stack_vm = label_context_stack_vm->next;
6152      return 0;
6153    }
6154
6155  decl_attributes (&decl1, attributes, 0);
6156
6157  if (DECL_DECLARED_INLINE_P (decl1)
6158      && DECL_UNINLINABLE (decl1)
6159      && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1)))
6160    warning (OPT_Wattributes, "inline function %q+D given attribute noinline",
6161	     decl1);
6162
6163  /* Handle gnu_inline attribute.  */
6164  if (declspecs->inline_p
6165      && !flag_gnu89_inline
6166      && TREE_CODE (decl1) == FUNCTION_DECL
6167      && lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (decl1)))
6168    {
6169      if (declspecs->storage_class != csc_static)
6170	DECL_EXTERNAL (decl1) = !DECL_EXTERNAL (decl1);
6171    }
6172
6173  announce_function (decl1);
6174
6175  if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1))))
6176    {
6177      error ("return type is an incomplete type");
6178      /* Make it return void instead.  */
6179      TREE_TYPE (decl1)
6180	= build_function_type (void_type_node,
6181			       TYPE_ARG_TYPES (TREE_TYPE (decl1)));
6182    }
6183
6184  if (warn_about_return_type)
6185    pedwarn_c99 ("return type defaults to %<int%>");
6186
6187  /* Make the init_value nonzero so pushdecl knows this is not tentative.
6188     error_mark_node is replaced below (in pop_scope) with the BLOCK.  */
6189  DECL_INITIAL (decl1) = error_mark_node;
6190
6191  /* If this definition isn't a prototype and we had a prototype declaration
6192     before, copy the arg type info from that prototype.  */
6193  old_decl = lookup_name_in_scope (DECL_NAME (decl1), current_scope);
6194  if (old_decl && TREE_CODE (old_decl) != FUNCTION_DECL)
6195    old_decl = 0;
6196  current_function_prototype_locus = UNKNOWN_LOCATION;
6197  current_function_prototype_built_in = false;
6198  current_function_prototype_arg_types = NULL_TREE;
6199  if (TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0)
6200    {
6201      if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE
6202	  && comptypes (TREE_TYPE (TREE_TYPE (decl1)),
6203			TREE_TYPE (TREE_TYPE (old_decl))))
6204	{
6205	  TREE_TYPE (decl1) = composite_type (TREE_TYPE (old_decl),
6206					      TREE_TYPE (decl1));
6207	  current_function_prototype_locus = DECL_SOURCE_LOCATION (old_decl);
6208	  current_function_prototype_built_in
6209	    = C_DECL_BUILTIN_PROTOTYPE (old_decl);
6210	  current_function_prototype_arg_types
6211	    = TYPE_ARG_TYPES (TREE_TYPE (decl1));
6212	}
6213      if (TREE_PUBLIC (decl1))
6214	{
6215	  /* If there is an external prototype declaration of this
6216	     function, record its location but do not copy information
6217	     to this decl.  This may be an invisible declaration
6218	     (built-in or in a scope which has finished) or simply
6219	     have more refined argument types than any declaration
6220	     found above.  */
6221	  struct c_binding *b;
6222	  for (b = I_SYMBOL_BINDING (DECL_NAME (decl1)); b; b = b->shadowed)
6223	    if (B_IN_SCOPE (b, external_scope))
6224	      break;
6225	  if (b)
6226	    {
6227	      tree ext_decl, ext_type;
6228	      ext_decl = b->decl;
6229	      ext_type = b->type ? b->type : TREE_TYPE (ext_decl);
6230	      if (TREE_CODE (ext_type) == FUNCTION_TYPE
6231		  && comptypes (TREE_TYPE (TREE_TYPE (decl1)),
6232				TREE_TYPE (ext_type)))
6233		{
6234		  current_function_prototype_locus
6235		    = DECL_SOURCE_LOCATION (ext_decl);
6236		  current_function_prototype_built_in
6237		    = C_DECL_BUILTIN_PROTOTYPE (ext_decl);
6238		  current_function_prototype_arg_types
6239		    = TYPE_ARG_TYPES (ext_type);
6240		}
6241	    }
6242	}
6243    }
6244
6245  /* Optionally warn of old-fashioned def with no previous prototype.  */
6246  if (warn_strict_prototypes
6247      && old_decl != error_mark_node
6248      && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0
6249      && C_DECL_ISNT_PROTOTYPE (old_decl))
6250    warning (OPT_Wstrict_prototypes,
6251	     "function declaration isn%'t a prototype");
6252  /* Optionally warn of any global def with no previous prototype.  */
6253  else if (warn_missing_prototypes
6254	   && old_decl != error_mark_node
6255	   && TREE_PUBLIC (decl1)
6256	   && !MAIN_NAME_P (DECL_NAME (decl1))
6257	   && C_DECL_ISNT_PROTOTYPE (old_decl))
6258    warning (OPT_Wmissing_prototypes, "no previous prototype for %q+D", decl1);
6259  /* Optionally warn of any def with no previous prototype
6260     if the function has already been used.  */
6261  else if (warn_missing_prototypes
6262	   && old_decl != 0
6263	   && old_decl != error_mark_node
6264	   && TREE_USED (old_decl)
6265	   && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0)
6266    warning (OPT_Wmissing_prototypes,
6267	     "%q+D was used with no prototype before its definition", decl1);
6268  /* Optionally warn of any global def with no previous declaration.  */
6269  else if (warn_missing_declarations
6270	   && TREE_PUBLIC (decl1)
6271	   && old_decl == 0
6272	   && !MAIN_NAME_P (DECL_NAME (decl1)))
6273    warning (OPT_Wmissing_declarations, "no previous declaration for %q+D",
6274	     decl1);
6275  /* Optionally warn of any def with no previous declaration
6276     if the function has already been used.  */
6277  else if (warn_missing_declarations
6278	   && old_decl != 0
6279	   && old_decl != error_mark_node
6280	   && TREE_USED (old_decl)
6281	   && C_DECL_IMPLICIT (old_decl))
6282    warning (OPT_Wmissing_declarations,
6283	     "%q+D was used with no declaration before its definition", decl1);
6284
6285  /* This function exists in static storage.
6286     (This does not mean `static' in the C sense!)  */
6287  TREE_STATIC (decl1) = 1;
6288
6289  /* A nested function is not global.  */
6290  if (current_function_decl != 0)
6291    TREE_PUBLIC (decl1) = 0;
6292
6293  /* This is the earliest point at which we might know the assembler
6294     name of the function.  Thus, if it's set before this, die horribly.  */
6295  gcc_assert (!DECL_ASSEMBLER_NAME_SET_P (decl1));
6296
6297  /* If #pragma weak was used, mark the decl weak now.  */
6298  if (current_scope == file_scope)
6299    maybe_apply_pragma_weak (decl1);
6300
6301  /* Warn for unlikely, improbable, or stupid declarations of `main'.  */
6302  if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1)))
6303    {
6304      tree args;
6305      int argct = 0;
6306
6307      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1)))
6308	  != integer_type_node)
6309	pedwarn ("return type of %q+D is not %<int%>", decl1);
6310
6311      for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args;
6312	   args = TREE_CHAIN (args))
6313	{
6314	  tree type = args ? TREE_VALUE (args) : 0;
6315
6316	  if (type == void_type_node)
6317	    break;
6318
6319	  ++argct;
6320	  switch (argct)
6321	    {
6322	    case 1:
6323	      if (TYPE_MAIN_VARIANT (type) != integer_type_node)
6324		pedwarn ("first argument of %q+D should be %<int%>", decl1);
6325	      break;
6326
6327	    case 2:
6328	      if (TREE_CODE (type) != POINTER_TYPE
6329		  || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
6330		  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
6331		      != char_type_node))
6332		pedwarn ("second argument of %q+D should be %<char **%>",
6333			 decl1);
6334	      break;
6335
6336	    case 3:
6337	      if (TREE_CODE (type) != POINTER_TYPE
6338		  || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
6339		  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
6340		      != char_type_node))
6341		pedwarn ("third argument of %q+D should probably be "
6342			 "%<char **%>", decl1);
6343	      break;
6344	    }
6345	}
6346
6347      /* It is intentional that this message does not mention the third
6348	 argument because it's only mentioned in an appendix of the
6349	 standard.  */
6350      if (argct > 0 && (argct < 2 || argct > 3))
6351	pedwarn ("%q+D takes only zero or two arguments", decl1);
6352
6353      if (!TREE_PUBLIC (decl1))
6354	pedwarn ("%q+D is normally a non-static function", decl1);
6355    }
6356
6357  /* Record the decl so that the function name is defined.
6358     If we already have a decl for this name, and it is a FUNCTION_DECL,
6359     use the old decl.  */
6360
6361  current_function_decl = pushdecl (decl1);
6362
6363  push_scope ();
6364  declare_parm_level ();
6365
6366  restype = TREE_TYPE (TREE_TYPE (current_function_decl));
6367  /* Promote the value to int before returning it.  */
6368  if (c_promoting_integer_type_p (restype))
6369    {
6370      /* It retains unsignedness if not really getting wider.  */
6371      if (TYPE_UNSIGNED (restype)
6372	  && (TYPE_PRECISION (restype)
6373		  == TYPE_PRECISION (integer_type_node)))
6374	restype = unsigned_type_node;
6375      else
6376	restype = integer_type_node;
6377    }
6378
6379  resdecl = build_decl (RESULT_DECL, NULL_TREE, restype);
6380  DECL_ARTIFICIAL (resdecl) = 1;
6381  DECL_IGNORED_P (resdecl) = 1;
6382  DECL_RESULT (current_function_decl) = resdecl;
6383
6384  start_fname_decls ();
6385
6386  return 1;
6387}
6388
6389/* Subroutine of store_parm_decls which handles new-style function
6390   definitions (prototype format). The parms already have decls, so we
6391   need only record them as in effect and complain if any redundant
6392   old-style parm decls were written.  */
6393static void
6394store_parm_decls_newstyle (tree fndecl, const struct c_arg_info *arg_info)
6395{
6396  tree decl;
6397
6398  if (current_scope->bindings)
6399    {
6400      error ("%Jold-style parameter declarations in prototyped "
6401	     "function definition", fndecl);
6402
6403      /* Get rid of the old-style declarations.  */
6404      pop_scope ();
6405      push_scope ();
6406    }
6407  /* Don't issue this warning for nested functions, and don't issue this
6408     warning if we got here because ARG_INFO_TYPES was error_mark_node
6409     (this happens when a function definition has just an ellipsis in
6410     its parameter list).  */
6411  else if (!in_system_header && !current_function_scope
6412	   && arg_info->types != error_mark_node)
6413    warning (OPT_Wtraditional,
6414	     "%Jtraditional C rejects ISO C style function definitions",
6415	     fndecl);
6416
6417  /* Now make all the parameter declarations visible in the function body.
6418     We can bypass most of the grunt work of pushdecl.  */
6419  for (decl = arg_info->parms; decl; decl = TREE_CHAIN (decl))
6420    {
6421      DECL_CONTEXT (decl) = current_function_decl;
6422      if (DECL_NAME (decl))
6423	{
6424	  bind (DECL_NAME (decl), decl, current_scope,
6425		/*invisible=*/false, /*nested=*/false);
6426	  if (!TREE_USED (decl))
6427	    warn_if_shadowing (decl);
6428	}
6429      else
6430	error ("%Jparameter name omitted", decl);
6431    }
6432
6433  /* Record the parameter list in the function declaration.  */
6434  DECL_ARGUMENTS (fndecl) = arg_info->parms;
6435
6436  /* Now make all the ancillary declarations visible, likewise.  */
6437  for (decl = arg_info->others; decl; decl = TREE_CHAIN (decl))
6438    {
6439      DECL_CONTEXT (decl) = current_function_decl;
6440      if (DECL_NAME (decl))
6441	bind (DECL_NAME (decl), decl, current_scope,
6442	      /*invisible=*/false, /*nested=*/false);
6443    }
6444
6445  /* And all the tag declarations.  */
6446  for (decl = arg_info->tags; decl; decl = TREE_CHAIN (decl))
6447    if (TREE_PURPOSE (decl))
6448      bind (TREE_PURPOSE (decl), TREE_VALUE (decl), current_scope,
6449	    /*invisible=*/false, /*nested=*/false);
6450}
6451
6452/* Subroutine of store_parm_decls which handles old-style function
6453   definitions (separate parameter list and declarations).  */
6454
6455static void
6456store_parm_decls_oldstyle (tree fndecl, const struct c_arg_info *arg_info)
6457{
6458  struct c_binding *b;
6459  tree parm, decl, last;
6460  tree parmids = arg_info->parms;
6461  struct pointer_set_t *seen_args = pointer_set_create ();
6462
6463  if (!in_system_header)
6464    warning (OPT_Wold_style_definition, "%Jold-style function definition",
6465	     fndecl);
6466
6467  /* Match each formal parameter name with its declaration.  Save each
6468     decl in the appropriate TREE_PURPOSE slot of the parmids chain.  */
6469  for (parm = parmids; parm; parm = TREE_CHAIN (parm))
6470    {
6471      if (TREE_VALUE (parm) == 0)
6472	{
6473	  error ("%Jparameter name missing from parameter list", fndecl);
6474	  TREE_PURPOSE (parm) = 0;
6475	  continue;
6476	}
6477
6478      b = I_SYMBOL_BINDING (TREE_VALUE (parm));
6479      if (b && B_IN_CURRENT_SCOPE (b))
6480	{
6481	  decl = b->decl;
6482	  /* If we got something other than a PARM_DECL it is an error.  */
6483	  if (TREE_CODE (decl) != PARM_DECL)
6484	    error ("%q+D declared as a non-parameter", decl);
6485	  /* If the declaration is already marked, we have a duplicate
6486	     name.  Complain and ignore the duplicate.  */
6487	  else if (pointer_set_contains (seen_args, decl))
6488	    {
6489	      error ("multiple parameters named %q+D", decl);
6490	      TREE_PURPOSE (parm) = 0;
6491	      continue;
6492	    }
6493	  /* If the declaration says "void", complain and turn it into
6494	     an int.  */
6495	  else if (VOID_TYPE_P (TREE_TYPE (decl)))
6496	    {
6497	      error ("parameter %q+D declared with void type", decl);
6498	      TREE_TYPE (decl) = integer_type_node;
6499	      DECL_ARG_TYPE (decl) = integer_type_node;
6500	      layout_decl (decl, 0);
6501	    }
6502	  warn_if_shadowing (decl);
6503	}
6504      /* If no declaration found, default to int.  */
6505      else
6506	{
6507	  decl = build_decl (PARM_DECL, TREE_VALUE (parm), integer_type_node);
6508	  DECL_ARG_TYPE (decl) = TREE_TYPE (decl);
6509	  DECL_SOURCE_LOCATION (decl) = DECL_SOURCE_LOCATION (fndecl);
6510	  pushdecl (decl);
6511	  warn_if_shadowing (decl);
6512
6513	  if (flag_isoc99)
6514	    pedwarn ("type of %q+D defaults to %<int%>", decl);
6515	  else if (extra_warnings)
6516	    warning (OPT_Wextra, "type of %q+D defaults to %<int%>", decl);
6517	}
6518
6519      TREE_PURPOSE (parm) = decl;
6520      pointer_set_insert (seen_args, decl);
6521    }
6522
6523  /* Now examine the parms chain for incomplete declarations
6524     and declarations with no corresponding names.  */
6525
6526  for (b = current_scope->bindings; b; b = b->prev)
6527    {
6528      parm = b->decl;
6529      if (TREE_CODE (parm) != PARM_DECL)
6530	continue;
6531
6532      if (TREE_TYPE (parm) != error_mark_node
6533	  && !COMPLETE_TYPE_P (TREE_TYPE (parm)))
6534	{
6535	  error ("parameter %q+D has incomplete type", parm);
6536	  TREE_TYPE (parm) = error_mark_node;
6537	}
6538
6539      if (!pointer_set_contains (seen_args, parm))
6540	{
6541	  error ("declaration for parameter %q+D but no such parameter", parm);
6542
6543	  /* Pretend the parameter was not missing.
6544	     This gets us to a standard state and minimizes
6545	     further error messages.  */
6546	  parmids = chainon (parmids, tree_cons (parm, 0, 0));
6547	}
6548    }
6549
6550  /* Chain the declarations together in the order of the list of
6551     names.  Store that chain in the function decl, replacing the
6552     list of names.  Update the current scope to match.  */
6553  DECL_ARGUMENTS (fndecl) = 0;
6554
6555  for (parm = parmids; parm; parm = TREE_CHAIN (parm))
6556    if (TREE_PURPOSE (parm))
6557      break;
6558  if (parm && TREE_PURPOSE (parm))
6559    {
6560      last = TREE_PURPOSE (parm);
6561      DECL_ARGUMENTS (fndecl) = last;
6562
6563      for (parm = TREE_CHAIN (parm); parm; parm = TREE_CHAIN (parm))
6564	if (TREE_PURPOSE (parm))
6565	  {
6566	    TREE_CHAIN (last) = TREE_PURPOSE (parm);
6567	    last = TREE_PURPOSE (parm);
6568	  }
6569      TREE_CHAIN (last) = 0;
6570    }
6571
6572  pointer_set_destroy (seen_args);
6573
6574  /* If there was a previous prototype,
6575     set the DECL_ARG_TYPE of each argument according to
6576     the type previously specified, and report any mismatches.  */
6577
6578  if (current_function_prototype_arg_types)
6579    {
6580      tree type;
6581      for (parm = DECL_ARGUMENTS (fndecl),
6582	     type = current_function_prototype_arg_types;
6583	   parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type))
6584			     != void_type_node));
6585	   parm = TREE_CHAIN (parm), type = TREE_CHAIN (type))
6586	{
6587	  if (parm == 0 || type == 0
6588	      || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node)
6589	    {
6590	      if (current_function_prototype_built_in)
6591		warning (0, "number of arguments doesn%'t match "
6592			 "built-in prototype");
6593	      else
6594		{
6595		  error ("number of arguments doesn%'t match prototype");
6596		  error ("%Hprototype declaration",
6597			 &current_function_prototype_locus);
6598		}
6599	      break;
6600	    }
6601	  /* Type for passing arg must be consistent with that
6602	     declared for the arg.  ISO C says we take the unqualified
6603	     type for parameters declared with qualified type.  */
6604	  if (!comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)),
6605			  TYPE_MAIN_VARIANT (TREE_VALUE (type))))
6606	    {
6607	      if (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
6608		  == TYPE_MAIN_VARIANT (TREE_VALUE (type)))
6609		{
6610		  /* Adjust argument to match prototype.  E.g. a previous
6611		     `int foo(float);' prototype causes
6612		     `int foo(x) float x; {...}' to be treated like
6613		     `int foo(float x) {...}'.  This is particularly
6614		     useful for argument types like uid_t.  */
6615		  DECL_ARG_TYPE (parm) = TREE_TYPE (parm);
6616
6617		  if (targetm.calls.promote_prototypes (TREE_TYPE (current_function_decl))
6618		      && INTEGRAL_TYPE_P (TREE_TYPE (parm))
6619		      && TYPE_PRECISION (TREE_TYPE (parm))
6620		      < TYPE_PRECISION (integer_type_node))
6621		    DECL_ARG_TYPE (parm) = integer_type_node;
6622
6623		  if (pedantic)
6624		    {
6625		      /* ??? Is it possible to get here with a
6626			 built-in prototype or will it always have
6627			 been diagnosed as conflicting with an
6628			 old-style definition and discarded?  */
6629		      if (current_function_prototype_built_in)
6630			warning (0, "promoted argument %qD "
6631				 "doesn%'t match built-in prototype", parm);
6632		      else
6633			{
6634			  pedwarn ("promoted argument %qD "
6635				   "doesn%'t match prototype", parm);
6636			  pedwarn ("%Hprototype declaration",
6637				   &current_function_prototype_locus);
6638			}
6639		    }
6640		}
6641	      else
6642		{
6643		  if (current_function_prototype_built_in)
6644		    warning (0, "argument %qD doesn%'t match "
6645			     "built-in prototype", parm);
6646		  else
6647		    {
6648		      error ("argument %qD doesn%'t match prototype", parm);
6649		      error ("%Hprototype declaration",
6650			     &current_function_prototype_locus);
6651		    }
6652		}
6653	    }
6654	}
6655      TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0;
6656    }
6657
6658  /* Otherwise, create a prototype that would match.  */
6659
6660  else
6661    {
6662      tree actual = 0, last = 0, type;
6663
6664      for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm))
6665	{
6666	  type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE);
6667	  if (last)
6668	    TREE_CHAIN (last) = type;
6669	  else
6670	    actual = type;
6671	  last = type;
6672	}
6673      type = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
6674      if (last)
6675	TREE_CHAIN (last) = type;
6676      else
6677	actual = type;
6678
6679      /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES
6680	 of the type of this function, but we need to avoid having this
6681	 affect the types of other similarly-typed functions, so we must
6682	 first force the generation of an identical (but separate) type
6683	 node for the relevant function type.  The new node we create
6684	 will be a variant of the main variant of the original function
6685	 type.  */
6686
6687      TREE_TYPE (fndecl) = build_variant_type_copy (TREE_TYPE (fndecl));
6688
6689      TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual;
6690    }
6691}
6692
6693/* Store parameter declarations passed in ARG_INFO into the current
6694   function declaration.  */
6695
6696void
6697store_parm_decls_from (struct c_arg_info *arg_info)
6698{
6699  current_function_arg_info = arg_info;
6700  store_parm_decls ();
6701}
6702
6703/* Store the parameter declarations into the current function declaration.
6704   This is called after parsing the parameter declarations, before
6705   digesting the body of the function.
6706
6707   For an old-style definition, construct a prototype out of the old-style
6708   parameter declarations and inject it into the function's type.  */
6709
6710void
6711store_parm_decls (void)
6712{
6713  tree fndecl = current_function_decl;
6714  bool proto;
6715
6716  /* The argument information block for FNDECL.  */
6717  struct c_arg_info *arg_info = current_function_arg_info;
6718  current_function_arg_info = 0;
6719
6720  /* True if this definition is written with a prototype.  Note:
6721     despite C99 6.7.5.3p14, we can *not* treat an empty argument
6722     list in a function definition as equivalent to (void) -- an
6723     empty argument list specifies the function has no parameters,
6724     but only (void) sets up a prototype for future calls.  */
6725  proto = arg_info->types != 0;
6726
6727  if (proto)
6728    store_parm_decls_newstyle (fndecl, arg_info);
6729  else
6730    store_parm_decls_oldstyle (fndecl, arg_info);
6731
6732  /* The next call to push_scope will be a function body.  */
6733
6734  next_is_function_body = true;
6735
6736  /* Write a record describing this function definition to the prototypes
6737     file (if requested).  */
6738
6739  gen_aux_info_record (fndecl, 1, 0, proto);
6740
6741  /* Initialize the RTL code for the function.  */
6742  allocate_struct_function (fndecl);
6743
6744  /* Begin the statement tree for this function.  */
6745  DECL_SAVED_TREE (fndecl) = push_stmt_list ();
6746
6747  /* ??? Insert the contents of the pending sizes list into the function
6748     to be evaluated.  The only reason left to have this is
6749	void foo(int n, int array[n++])
6750     because we throw away the array type in favor of a pointer type, and
6751     thus won't naturally see the SAVE_EXPR containing the increment.  All
6752     other pending sizes would be handled by gimplify_parameters.  */
6753  {
6754    tree t;
6755    for (t = nreverse (get_pending_sizes ()); t ; t = TREE_CHAIN (t))
6756      add_stmt (TREE_VALUE (t));
6757  }
6758
6759  /* Even though we're inside a function body, we still don't want to
6760     call expand_expr to calculate the size of a variable-sized array.
6761     We haven't necessarily assigned RTL to all variables yet, so it's
6762     not safe to try to expand expressions involving them.  */
6763  cfun->x_dont_save_pending_sizes_p = 1;
6764}
6765
6766/* Emit diagnostics that require gimple input for detection.  Operate on
6767   FNDECL and all its nested functions.  */
6768
6769static void
6770c_gimple_diagnostics_recursively (tree fndecl)
6771{
6772  struct cgraph_node *cgn;
6773
6774  /* Handle attribute((warn_unused_result)).  Relies on gimple input.  */
6775  c_warn_unused_result (&DECL_SAVED_TREE (fndecl));
6776
6777  /* Notice when OpenMP structured block constraints are violated.  */
6778  if (flag_openmp)
6779    diagnose_omp_structured_block_errors (fndecl);
6780
6781  /* Finalize all nested functions now.  */
6782  cgn = cgraph_node (fndecl);
6783  for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
6784    c_gimple_diagnostics_recursively (cgn->decl);
6785}
6786
6787/* Finish up a function declaration and compile that function
6788   all the way to assembler language output.  The free the storage
6789   for the function definition.
6790
6791   This is called after parsing the body of the function definition.  */
6792
6793void
6794finish_function (void)
6795{
6796  tree fndecl = current_function_decl;
6797
6798  label_context_stack_se = label_context_stack_se->next;
6799  label_context_stack_vm = label_context_stack_vm->next;
6800
6801  if (TREE_CODE (fndecl) == FUNCTION_DECL
6802      && targetm.calls.promote_prototypes (TREE_TYPE (fndecl)))
6803    {
6804      tree args = DECL_ARGUMENTS (fndecl);
6805      for (; args; args = TREE_CHAIN (args))
6806	{
6807	  tree type = TREE_TYPE (args);
6808	  if (INTEGRAL_TYPE_P (type)
6809	      && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))
6810	    DECL_ARG_TYPE (args) = integer_type_node;
6811	}
6812    }
6813
6814  if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node)
6815    BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl;
6816
6817  /* Must mark the RESULT_DECL as being in this function.  */
6818
6819  if (DECL_RESULT (fndecl) && DECL_RESULT (fndecl) != error_mark_node)
6820    DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
6821
6822  if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted)
6823    {
6824      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl)))
6825	  != integer_type_node)
6826	{
6827	  /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned.
6828	     If warn_main is -1 (-Wno-main) we don't want to be warned.  */
6829	  if (!warn_main)
6830	    pedwarn ("return type of %q+D is not %<int%>", fndecl);
6831	}
6832      else
6833	{
6834	  if (flag_isoc99)
6835	    {
6836	      tree stmt = c_finish_return (integer_zero_node);
6837#ifdef USE_MAPPED_LOCATION
6838	      /* Hack.  We don't want the middle-end to warn that this return
6839		 is unreachable, so we mark its location as special.  Using
6840		 UNKNOWN_LOCATION has the problem that it gets clobbered in
6841		 annotate_one_with_locus.  A cleaner solution might be to
6842		 ensure ! should_carry_locus_p (stmt), but that needs a flag.
6843	      */
6844	      SET_EXPR_LOCATION (stmt, BUILTINS_LOCATION);
6845#else
6846	      /* Hack.  We don't want the middle-end to warn that this
6847		 return is unreachable, so put the statement on the
6848		 special line 0.  */
6849	      annotate_with_file_line (stmt, input_filename, 0);
6850#endif
6851	    }
6852	}
6853    }
6854
6855  /* Tie off the statement tree for this function.  */
6856  DECL_SAVED_TREE (fndecl) = pop_stmt_list (DECL_SAVED_TREE (fndecl));
6857
6858  finish_fname_decls ();
6859
6860  /* Complain if there's just no return statement.  */
6861  if (warn_return_type
6862      && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE
6863      && !current_function_returns_value && !current_function_returns_null
6864      /* Don't complain if we are no-return.  */
6865      && !current_function_returns_abnormally
6866      /* Don't warn for main().  */
6867      && !MAIN_NAME_P (DECL_NAME (fndecl))
6868      /* Or if they didn't actually specify a return type.  */
6869      && !C_FUNCTION_IMPLICIT_INT (fndecl)
6870      /* Normally, with -Wreturn-type, flow will complain.  Unless we're an
6871	 inline function, as we might never be compiled separately.  */
6872      && DECL_INLINE (fndecl))
6873    {
6874      warning (OPT_Wreturn_type,
6875	       "no return statement in function returning non-void");
6876      TREE_NO_WARNING (fndecl) = 1;
6877    }
6878
6879  /* With just -Wextra, complain only if function returns both with
6880     and without a value.  */
6881  if (extra_warnings
6882      && current_function_returns_value
6883      && current_function_returns_null)
6884    warning (OPT_Wextra, "this function may return with or without a value");
6885
6886  /* Store the end of the function, so that we get good line number
6887     info for the epilogue.  */
6888  cfun->function_end_locus = input_location;
6889
6890  /* If we don't have ctors/dtors sections, and this is a static
6891     constructor or destructor, it must be recorded now.  */
6892  if (DECL_STATIC_CONSTRUCTOR (fndecl)
6893      && !targetm.have_ctors_dtors)
6894    static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors);
6895  if (DECL_STATIC_DESTRUCTOR (fndecl)
6896      && !targetm.have_ctors_dtors)
6897    static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors);
6898
6899  /* Finalize the ELF visibility for the function.  */
6900  c_determine_visibility (fndecl);
6901
6902  /* Genericize before inlining.  Delay genericizing nested functions
6903     until their parent function is genericized.  Since finalizing
6904     requires GENERIC, delay that as well.  */
6905
6906  if (DECL_INITIAL (fndecl) && DECL_INITIAL (fndecl) != error_mark_node
6907      && !undef_nested_function)
6908    {
6909      if (!decl_function_context (fndecl))
6910	{
6911	  c_genericize (fndecl);
6912	  c_gimple_diagnostics_recursively (fndecl);
6913
6914	  /* ??? Objc emits functions after finalizing the compilation unit.
6915	     This should be cleaned up later and this conditional removed.  */
6916	  if (cgraph_global_info_ready)
6917	    {
6918	      c_expand_body (fndecl);
6919	      return;
6920	    }
6921
6922	  cgraph_finalize_function (fndecl, false);
6923	}
6924      else
6925	{
6926	  /* Register this function with cgraph just far enough to get it
6927	    added to our parent's nested function list.  Handy, since the
6928	    C front end doesn't have such a list.  */
6929	  (void) cgraph_node (fndecl);
6930	}
6931    }
6932
6933  if (!decl_function_context (fndecl))
6934    undef_nested_function = false;
6935
6936  /* We're leaving the context of this function, so zap cfun.
6937     It's still in DECL_STRUCT_FUNCTION, and we'll restore it in
6938     tree_rest_of_compilation.  */
6939  cfun = NULL;
6940  current_function_decl = NULL;
6941}
6942
6943/* Generate the RTL for the body of FNDECL.  */
6944
6945void
6946c_expand_body (tree fndecl)
6947{
6948
6949  if (!DECL_INITIAL (fndecl)
6950      || DECL_INITIAL (fndecl) == error_mark_node)
6951    return;
6952
6953  tree_rest_of_compilation (fndecl);
6954
6955  if (DECL_STATIC_CONSTRUCTOR (fndecl)
6956      && targetm.have_ctors_dtors)
6957    targetm.asm_out.constructor (XEXP (DECL_RTL (fndecl), 0),
6958				 DEFAULT_INIT_PRIORITY);
6959  if (DECL_STATIC_DESTRUCTOR (fndecl)
6960      && targetm.have_ctors_dtors)
6961    targetm.asm_out.destructor (XEXP (DECL_RTL (fndecl), 0),
6962				DEFAULT_INIT_PRIORITY);
6963}
6964
6965/* Check the declarations given in a for-loop for satisfying the C99
6966   constraints.  If exactly one such decl is found, return it.  */
6967
6968tree
6969check_for_loop_decls (void)
6970{
6971  struct c_binding *b;
6972  tree one_decl = NULL_TREE;
6973  int n_decls = 0;
6974
6975
6976  if (!flag_isoc99)
6977    {
6978      /* If we get here, declarations have been used in a for loop without
6979	 the C99 for loop scope.  This doesn't make much sense, so don't
6980	 allow it.  */
6981      error ("%<for%> loop initial declaration used outside C99 mode");
6982      return NULL_TREE;
6983    }
6984  /* C99 subclause 6.8.5 paragraph 3:
6985
6986       [#3]  The  declaration  part  of  a for statement shall only
6987       declare identifiers for objects having storage class auto or
6988       register.
6989
6990     It isn't clear whether, in this sentence, "identifiers" binds to
6991     "shall only declare" or to "objects" - that is, whether all identifiers
6992     declared must be identifiers for objects, or whether the restriction
6993     only applies to those that are.  (A question on this in comp.std.c
6994     in November 2000 received no answer.)  We implement the strictest
6995     interpretation, to avoid creating an extension which later causes
6996     problems.  */
6997
6998  for (b = current_scope->bindings; b; b = b->prev)
6999    {
7000      tree id = b->id;
7001      tree decl = b->decl;
7002
7003      if (!id)
7004	continue;
7005
7006      switch (TREE_CODE (decl))
7007	{
7008	case VAR_DECL:
7009	  if (TREE_STATIC (decl))
7010	    error ("declaration of static variable %q+D in %<for%> loop "
7011		   "initial declaration", decl);
7012	  else if (DECL_EXTERNAL (decl))
7013	    error ("declaration of %<extern%> variable %q+D in %<for%> loop "
7014		   "initial declaration", decl);
7015	  break;
7016
7017	case RECORD_TYPE:
7018	  error ("%<struct %E%> declared in %<for%> loop initial declaration",
7019		 id);
7020	  break;
7021	case UNION_TYPE:
7022	  error ("%<union %E%> declared in %<for%> loop initial declaration",
7023		 id);
7024	  break;
7025	case ENUMERAL_TYPE:
7026	  error ("%<enum %E%> declared in %<for%> loop initial declaration",
7027		 id);
7028	  break;
7029	default:
7030	  error ("declaration of non-variable %q+D in %<for%> loop "
7031		 "initial declaration", decl);
7032	}
7033
7034      n_decls++;
7035      one_decl = decl;
7036    }
7037
7038  return n_decls == 1 ? one_decl : NULL_TREE;
7039}
7040
7041/* Save and reinitialize the variables
7042   used during compilation of a C function.  */
7043
7044void
7045c_push_function_context (struct function *f)
7046{
7047  struct language_function *p;
7048  p = GGC_NEW (struct language_function);
7049  f->language = p;
7050
7051  p->base.x_stmt_tree = c_stmt_tree;
7052  p->x_break_label = c_break_label;
7053  p->x_cont_label = c_cont_label;
7054  p->x_switch_stack = c_switch_stack;
7055  p->arg_info = current_function_arg_info;
7056  p->returns_value = current_function_returns_value;
7057  p->returns_null = current_function_returns_null;
7058  p->returns_abnormally = current_function_returns_abnormally;
7059  p->warn_about_return_type = warn_about_return_type;
7060}
7061
7062/* Restore the variables used during compilation of a C function.  */
7063
7064void
7065c_pop_function_context (struct function *f)
7066{
7067  struct language_function *p = f->language;
7068
7069  if (DECL_STRUCT_FUNCTION (current_function_decl) == 0
7070      && DECL_SAVED_TREE (current_function_decl) == NULL_TREE)
7071    {
7072      /* Stop pointing to the local nodes about to be freed.  */
7073      /* But DECL_INITIAL must remain nonzero so we know this
7074	 was an actual function definition.  */
7075      DECL_INITIAL (current_function_decl) = error_mark_node;
7076      DECL_ARGUMENTS (current_function_decl) = 0;
7077    }
7078
7079  c_stmt_tree = p->base.x_stmt_tree;
7080  c_break_label = p->x_break_label;
7081  c_cont_label = p->x_cont_label;
7082  c_switch_stack = p->x_switch_stack;
7083  current_function_arg_info = p->arg_info;
7084  current_function_returns_value = p->returns_value;
7085  current_function_returns_null = p->returns_null;
7086  current_function_returns_abnormally = p->returns_abnormally;
7087  warn_about_return_type = p->warn_about_return_type;
7088
7089  f->language = NULL;
7090}
7091
7092/* Copy the DECL_LANG_SPECIFIC data associated with DECL.  */
7093
7094void
7095c_dup_lang_specific_decl (tree decl)
7096{
7097  struct lang_decl *ld;
7098
7099  if (!DECL_LANG_SPECIFIC (decl))
7100    return;
7101
7102  ld = GGC_NEW (struct lang_decl);
7103  memcpy (ld, DECL_LANG_SPECIFIC (decl), sizeof (struct lang_decl));
7104  DECL_LANG_SPECIFIC (decl) = ld;
7105}
7106
7107/* The functions below are required for functionality of doing
7108   function at once processing in the C front end. Currently these
7109   functions are not called from anywhere in the C front end, but as
7110   these changes continue, that will change.  */
7111
7112/* Returns the stmt_tree (if any) to which statements are currently
7113   being added.  If there is no active statement-tree, NULL is
7114   returned.  */
7115
7116stmt_tree
7117current_stmt_tree (void)
7118{
7119  return &c_stmt_tree;
7120}
7121
7122/* Nonzero if TYPE is an anonymous union or struct type.  Always 0 in
7123   C.  */
7124
7125int
7126anon_aggr_type_p (tree ARG_UNUSED (node))
7127{
7128  return 0;
7129}
7130
7131/* Return the global value of T as a symbol.  */
7132
7133tree
7134identifier_global_value	(tree t)
7135{
7136  struct c_binding *b;
7137
7138  for (b = I_SYMBOL_BINDING (t); b; b = b->shadowed)
7139    if (B_IN_FILE_SCOPE (b) || B_IN_EXTERNAL_SCOPE (b))
7140      return b->decl;
7141
7142  return 0;
7143}
7144
7145/* Record a builtin type for C.  If NAME is non-NULL, it is the name used;
7146   otherwise the name is found in ridpointers from RID_INDEX.  */
7147
7148void
7149record_builtin_type (enum rid rid_index, const char *name, tree type)
7150{
7151  tree id, decl;
7152  if (name == 0)
7153    id = ridpointers[(int) rid_index];
7154  else
7155    id = get_identifier (name);
7156  decl = build_decl (TYPE_DECL, id, type);
7157  pushdecl (decl);
7158  if (debug_hooks->type_decl)
7159    debug_hooks->type_decl (decl, false);
7160}
7161
7162/* Build the void_list_node (void_type_node having been created).  */
7163tree
7164build_void_list_node (void)
7165{
7166  tree t = build_tree_list (NULL_TREE, void_type_node);
7167  return t;
7168}
7169
7170/* Return a c_parm structure with the given SPECS, ATTRS and DECLARATOR.  */
7171
7172struct c_parm *
7173build_c_parm (struct c_declspecs *specs, tree attrs,
7174	      struct c_declarator *declarator)
7175{
7176  struct c_parm *ret = XOBNEW (&parser_obstack, struct c_parm);
7177  ret->specs = specs;
7178  ret->attrs = attrs;
7179  ret->declarator = declarator;
7180  return ret;
7181}
7182
7183/* Return a declarator with nested attributes.  TARGET is the inner
7184   declarator to which these attributes apply.  ATTRS are the
7185   attributes.  */
7186
7187struct c_declarator *
7188build_attrs_declarator (tree attrs, struct c_declarator *target)
7189{
7190  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7191  ret->kind = cdk_attrs;
7192  ret->declarator = target;
7193  ret->u.attrs = attrs;
7194  return ret;
7195}
7196
7197/* Return a declarator for a function with arguments specified by ARGS
7198   and return type specified by TARGET.  */
7199
7200struct c_declarator *
7201build_function_declarator (struct c_arg_info *args,
7202			   struct c_declarator *target)
7203{
7204  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7205  ret->kind = cdk_function;
7206  ret->declarator = target;
7207  ret->u.arg_info = args;
7208  return ret;
7209}
7210
7211/* Return a declarator for the identifier IDENT (which may be
7212   NULL_TREE for an abstract declarator).  */
7213
7214struct c_declarator *
7215build_id_declarator (tree ident)
7216{
7217  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7218  ret->kind = cdk_id;
7219  ret->declarator = 0;
7220  ret->u.id = ident;
7221  /* Default value - may get reset to a more precise location. */
7222  ret->id_loc = input_location;
7223  return ret;
7224}
7225
7226/* Return something to represent absolute declarators containing a *.
7227   TARGET is the absolute declarator that the * contains.
7228   TYPE_QUALS_ATTRS is a structure for type qualifiers and attributes
7229   to apply to the pointer type.  */
7230
7231struct c_declarator *
7232make_pointer_declarator (struct c_declspecs *type_quals_attrs,
7233			 struct c_declarator *target)
7234{
7235  tree attrs;
7236  int quals = 0;
7237  struct c_declarator *itarget = target;
7238  struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
7239  if (type_quals_attrs)
7240    {
7241      attrs = type_quals_attrs->attrs;
7242      quals = quals_from_declspecs (type_quals_attrs);
7243      if (attrs != NULL_TREE)
7244	itarget = build_attrs_declarator (attrs, target);
7245    }
7246  ret->kind = cdk_pointer;
7247  ret->declarator = itarget;
7248  ret->u.pointer_quals = quals;
7249  return ret;
7250}
7251
7252/* Return a pointer to a structure for an empty list of declaration
7253   specifiers.  */
7254
7255struct c_declspecs *
7256build_null_declspecs (void)
7257{
7258  struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs);
7259  ret->type = 0;
7260  ret->decl_attr = 0;
7261  ret->attrs = 0;
7262  ret->typespec_word = cts_none;
7263  ret->storage_class = csc_none;
7264  ret->declspecs_seen_p = false;
7265  ret->type_seen_p = false;
7266  ret->non_sc_seen_p = false;
7267  ret->typedef_p = false;
7268  ret->tag_defined_p = false;
7269  ret->explicit_signed_p = false;
7270  ret->deprecated_p = false;
7271  ret->default_int_p = false;
7272  ret->long_p = false;
7273  ret->long_long_p = false;
7274  ret->short_p = false;
7275  ret->signed_p = false;
7276  ret->unsigned_p = false;
7277  ret->complex_p = false;
7278  ret->inline_p = false;
7279  ret->thread_p = false;
7280  ret->const_p = false;
7281  ret->volatile_p = false;
7282  ret->restrict_p = false;
7283  return ret;
7284}
7285
7286/* Add the type qualifier QUAL to the declaration specifiers SPECS,
7287   returning SPECS.  */
7288
7289struct c_declspecs *
7290declspecs_add_qual (struct c_declspecs *specs, tree qual)
7291{
7292  enum rid i;
7293  bool dupe = false;
7294  specs->non_sc_seen_p = true;
7295  specs->declspecs_seen_p = true;
7296  gcc_assert (TREE_CODE (qual) == IDENTIFIER_NODE
7297	      && C_IS_RESERVED_WORD (qual));
7298  i = C_RID_CODE (qual);
7299  switch (i)
7300    {
7301    case RID_CONST:
7302      dupe = specs->const_p;
7303      specs->const_p = true;
7304      break;
7305    case RID_VOLATILE:
7306      dupe = specs->volatile_p;
7307      specs->volatile_p = true;
7308      break;
7309    case RID_RESTRICT:
7310      dupe = specs->restrict_p;
7311      specs->restrict_p = true;
7312      break;
7313    default:
7314      gcc_unreachable ();
7315    }
7316  if (dupe && pedantic && !flag_isoc99)
7317    pedwarn ("duplicate %qE", qual);
7318  return specs;
7319}
7320
7321/* Add the type specifier TYPE to the declaration specifiers SPECS,
7322   returning SPECS.  */
7323
7324struct c_declspecs *
7325declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec)
7326{
7327  tree type = spec.spec;
7328  specs->non_sc_seen_p = true;
7329  specs->declspecs_seen_p = true;
7330  specs->type_seen_p = true;
7331  if (TREE_DEPRECATED (type))
7332    specs->deprecated_p = true;
7333
7334  /* Handle type specifier keywords.  */
7335  if (TREE_CODE (type) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (type))
7336    {
7337      enum rid i = C_RID_CODE (type);
7338      if (specs->type)
7339	{
7340	  error ("two or more data types in declaration specifiers");
7341	  return specs;
7342	}
7343      if ((int) i <= (int) RID_LAST_MODIFIER)
7344	{
7345	  /* "long", "short", "signed", "unsigned" or "_Complex".  */
7346	  bool dupe = false;
7347	  switch (i)
7348	    {
7349	    case RID_LONG:
7350	      if (specs->long_long_p)
7351		{
7352		  error ("%<long long long%> is too long for GCC");
7353		  break;
7354		}
7355	      if (specs->long_p)
7356		{
7357		  if (specs->typespec_word == cts_double)
7358		    {
7359		      error ("both %<long long%> and %<double%> in "
7360			     "declaration specifiers");
7361		      break;
7362		    }
7363		  if (pedantic && !flag_isoc99 && !in_system_header
7364		      && warn_long_long)
7365		    pedwarn ("ISO C90 does not support %<long long%>");
7366		  specs->long_long_p = 1;
7367		  break;
7368		}
7369	      if (specs->short_p)
7370		error ("both %<long%> and %<short%> in "
7371		       "declaration specifiers");
7372	      else if (specs->typespec_word == cts_void)
7373		error ("both %<long%> and %<void%> in "
7374		       "declaration specifiers");
7375	      else if (specs->typespec_word == cts_bool)
7376		error ("both %<long%> and %<_Bool%> in "
7377		       "declaration specifiers");
7378	      else if (specs->typespec_word == cts_char)
7379		error ("both %<long%> and %<char%> in "
7380		       "declaration specifiers");
7381	      else if (specs->typespec_word == cts_float)
7382		error ("both %<long%> and %<float%> in "
7383		       "declaration specifiers");
7384	      else if (specs->typespec_word == cts_dfloat32)
7385		error ("both %<long%> and %<_Decimal32%> in "
7386		       "declaration specifiers");
7387	      else if (specs->typespec_word == cts_dfloat64)
7388		error ("both %<long%> and %<_Decimal64%> in "
7389		       "declaration specifiers");
7390	      else if (specs->typespec_word == cts_dfloat128)
7391		error ("both %<long%> and %<_Decimal128%> in "
7392		       "declaration specifiers");
7393	      else
7394		specs->long_p = true;
7395	      break;
7396	    case RID_SHORT:
7397	      dupe = specs->short_p;
7398	      if (specs->long_p)
7399		error ("both %<long%> and %<short%> in "
7400		       "declaration specifiers");
7401	      else if (specs->typespec_word == cts_void)
7402		error ("both %<short%> and %<void%> in "
7403		       "declaration specifiers");
7404	      else if (specs->typespec_word == cts_bool)
7405		error ("both %<short%> and %<_Bool%> in "
7406		       "declaration specifiers");
7407	      else if (specs->typespec_word == cts_char)
7408		error ("both %<short%> and %<char%> in "
7409		       "declaration specifiers");
7410	      else if (specs->typespec_word == cts_float)
7411		error ("both %<short%> and %<float%> in "
7412		       "declaration specifiers");
7413	      else if (specs->typespec_word == cts_double)
7414		error ("both %<short%> and %<double%> in "
7415		       "declaration specifiers");
7416	      else if (specs->typespec_word == cts_dfloat32)
7417                error ("both %<short%> and %<_Decimal32%> in "
7418		       "declaration specifiers");
7419	      else if (specs->typespec_word == cts_dfloat64)
7420		error ("both %<short%> and %<_Decimal64%> in "
7421		                        "declaration specifiers");
7422	      else if (specs->typespec_word == cts_dfloat128)
7423		error ("both %<short%> and %<_Decimal128%> in "
7424		       "declaration specifiers");
7425	      else
7426		specs->short_p = true;
7427	      break;
7428	    case RID_SIGNED:
7429	      dupe = specs->signed_p;
7430	      if (specs->unsigned_p)
7431		error ("both %<signed%> and %<unsigned%> in "
7432		       "declaration specifiers");
7433	      else if (specs->typespec_word == cts_void)
7434		error ("both %<signed%> and %<void%> in "
7435		       "declaration specifiers");
7436	      else if (specs->typespec_word == cts_bool)
7437		error ("both %<signed%> and %<_Bool%> in "
7438		       "declaration specifiers");
7439	      else if (specs->typespec_word == cts_float)
7440		error ("both %<signed%> and %<float%> in "
7441		       "declaration specifiers");
7442	      else if (specs->typespec_word == cts_double)
7443		error ("both %<signed%> and %<double%> in "
7444		       "declaration specifiers");
7445	      else if (specs->typespec_word == cts_dfloat32)
7446		error ("both %<signed%> and %<_Decimal32%> in "
7447		       "declaration specifiers");
7448	      else if (specs->typespec_word == cts_dfloat64)
7449		error ("both %<signed%> and %<_Decimal64%> in "
7450		       "declaration specifiers");
7451	      else if (specs->typespec_word == cts_dfloat128)
7452		error ("both %<signed%> and %<_Decimal128%> in "
7453		       "declaration specifiers");
7454	      else
7455		specs->signed_p = true;
7456	      break;
7457	    case RID_UNSIGNED:
7458	      dupe = specs->unsigned_p;
7459	      if (specs->signed_p)
7460		error ("both %<signed%> and %<unsigned%> in "
7461		       "declaration specifiers");
7462	      else if (specs->typespec_word == cts_void)
7463		error ("both %<unsigned%> and %<void%> in "
7464		       "declaration specifiers");
7465	      else if (specs->typespec_word == cts_bool)
7466		error ("both %<unsigned%> and %<_Bool%> in "
7467		       "declaration specifiers");
7468	      else if (specs->typespec_word == cts_float)
7469		error ("both %<unsigned%> and %<float%> in "
7470		       "declaration specifiers");
7471	      else if (specs->typespec_word == cts_double)
7472		error ("both %<unsigned%> and %<double%> in "
7473		       "declaration specifiers");
7474              else if (specs->typespec_word == cts_dfloat32)
7475		error ("both %<unsigned%> and %<_Decimal32%> in "
7476		       "declaration specifiers");
7477	      else if (specs->typespec_word == cts_dfloat64)
7478		error ("both %<unsigned%> and %<_Decimal64%> in "
7479		       "declaration specifiers");
7480	      else if (specs->typespec_word == cts_dfloat128)
7481		error ("both %<unsigned%> and %<_Decimal128%> in "
7482		       "declaration specifiers");
7483	      else
7484		specs->unsigned_p = true;
7485	      break;
7486	    case RID_COMPLEX:
7487	      dupe = specs->complex_p;
7488	      if (pedantic && !flag_isoc99 && !in_system_header)
7489		pedwarn ("ISO C90 does not support complex types");
7490	      if (specs->typespec_word == cts_void)
7491		error ("both %<complex%> and %<void%> in "
7492		       "declaration specifiers");
7493	      else if (specs->typespec_word == cts_bool)
7494		error ("both %<complex%> and %<_Bool%> in "
7495		       "declaration specifiers");
7496              else if (specs->typespec_word == cts_dfloat32)
7497		error ("both %<complex%> and %<_Decimal32%> in "
7498		       "declaration specifiers");
7499	      else if (specs->typespec_word == cts_dfloat64)
7500		error ("both %<complex%> and %<_Decimal64%> in "
7501		       "declaration specifiers");
7502	      else if (specs->typespec_word == cts_dfloat128)
7503		error ("both %<complex%> and %<_Decimal128%> in "
7504		       "declaration specifiers");
7505	      else
7506		specs->complex_p = true;
7507	      break;
7508	    default:
7509	      gcc_unreachable ();
7510	    }
7511
7512	  if (dupe)
7513	    error ("duplicate %qE", type);
7514
7515	  return specs;
7516	}
7517      else
7518	{
7519	  /* "void", "_Bool", "char", "int", "float" or "double".  */
7520	  if (specs->typespec_word != cts_none)
7521	    {
7522	      error ("two or more data types in declaration specifiers");
7523	      return specs;
7524	    }
7525	  switch (i)
7526	    {
7527	    case RID_VOID:
7528	      if (specs->long_p)
7529		error ("both %<long%> and %<void%> in "
7530		       "declaration specifiers");
7531	      else if (specs->short_p)
7532		error ("both %<short%> and %<void%> in "
7533		       "declaration specifiers");
7534	      else if (specs->signed_p)
7535		error ("both %<signed%> and %<void%> in "
7536		       "declaration specifiers");
7537	      else if (specs->unsigned_p)
7538		error ("both %<unsigned%> and %<void%> in "
7539		       "declaration specifiers");
7540	      else if (specs->complex_p)
7541		error ("both %<complex%> and %<void%> in "
7542		       "declaration specifiers");
7543	      else
7544		specs->typespec_word = cts_void;
7545	      return specs;
7546	    case RID_BOOL:
7547	      if (specs->long_p)
7548		error ("both %<long%> and %<_Bool%> in "
7549		       "declaration specifiers");
7550	      else if (specs->short_p)
7551		error ("both %<short%> and %<_Bool%> in "
7552		       "declaration specifiers");
7553	      else if (specs->signed_p)
7554		error ("both %<signed%> and %<_Bool%> in "
7555		       "declaration specifiers");
7556	      else if (specs->unsigned_p)
7557		error ("both %<unsigned%> and %<_Bool%> in "
7558		       "declaration specifiers");
7559	      else if (specs->complex_p)
7560		error ("both %<complex%> and %<_Bool%> in "
7561		       "declaration specifiers");
7562	      else
7563		specs->typespec_word = cts_bool;
7564	      return specs;
7565	    case RID_CHAR:
7566	      if (specs->long_p)
7567		error ("both %<long%> and %<char%> in "
7568		       "declaration specifiers");
7569	      else if (specs->short_p)
7570		error ("both %<short%> and %<char%> in "
7571		       "declaration specifiers");
7572	      else
7573		specs->typespec_word = cts_char;
7574	      return specs;
7575	    case RID_INT:
7576	      specs->typespec_word = cts_int;
7577	      return specs;
7578	    case RID_FLOAT:
7579	      if (specs->long_p)
7580		error ("both %<long%> and %<float%> in "
7581		       "declaration specifiers");
7582	      else if (specs->short_p)
7583		error ("both %<short%> and %<float%> in "
7584		       "declaration specifiers");
7585	      else if (specs->signed_p)
7586		error ("both %<signed%> and %<float%> in "
7587		       "declaration specifiers");
7588	      else if (specs->unsigned_p)
7589		error ("both %<unsigned%> and %<float%> in "
7590		       "declaration specifiers");
7591	      else
7592		specs->typespec_word = cts_float;
7593	      return specs;
7594	    case RID_DOUBLE:
7595	      if (specs->long_long_p)
7596		error ("both %<long long%> and %<double%> in "
7597		       "declaration specifiers");
7598	      else if (specs->short_p)
7599		error ("both %<short%> and %<double%> in "
7600		       "declaration specifiers");
7601	      else if (specs->signed_p)
7602		error ("both %<signed%> and %<double%> in "
7603		       "declaration specifiers");
7604	      else if (specs->unsigned_p)
7605		error ("both %<unsigned%> and %<double%> in "
7606		       "declaration specifiers");
7607	      else
7608		specs->typespec_word = cts_double;
7609	      return specs;
7610	    case RID_DFLOAT32:
7611	    case RID_DFLOAT64:
7612	    case RID_DFLOAT128:
7613	      {
7614		const char *str;
7615		if (i == RID_DFLOAT32)
7616		  str = "_Decimal32";
7617		else if (i == RID_DFLOAT64)
7618		  str = "_Decimal64";
7619		else
7620		  str = "_Decimal128";
7621		if (specs->long_long_p)
7622		  error ("both %<long long%> and %<%s%> in "
7623			 "declaration specifiers", str);
7624		if (specs->long_p)
7625		  error ("both %<long%> and %<%s%> in "
7626			 "declaration specifiers", str);
7627		else if (specs->short_p)
7628		  error ("both %<short%> and %<%s%> in "
7629			 "declaration specifiers", str);
7630		else if (specs->signed_p)
7631		  error ("both %<signed%> and %<%s%> in "
7632			 "declaration specifiers", str);
7633		else if (specs->unsigned_p)
7634		  error ("both %<unsigned%> and %<%s%> in "
7635			 "declaration specifiers", str);
7636                else if (specs->complex_p)
7637                  error ("both %<complex%> and %<%s%> in "
7638                         "declaration specifiers", str);
7639		else if (i == RID_DFLOAT32)
7640		  specs->typespec_word = cts_dfloat32;
7641		else if (i == RID_DFLOAT64)
7642		  specs->typespec_word = cts_dfloat64;
7643		else
7644		  specs->typespec_word = cts_dfloat128;
7645	      }
7646	      if (!targetm.decimal_float_supported_p ())
7647		error ("decimal floating point not supported for this target");
7648	      if (pedantic)
7649		pedwarn ("ISO C does not support decimal floating point");
7650	      return specs;
7651	    default:
7652	      /* ObjC reserved word "id", handled below.  */
7653	      break;
7654	    }
7655	}
7656    }
7657
7658  /* Now we have a typedef (a TYPE_DECL node), an identifier (some
7659     form of ObjC type, cases such as "int" and "long" being handled
7660     above), a TYPE (struct, union, enum and typeof specifiers) or an
7661     ERROR_MARK.  In none of these cases may there have previously
7662     been any type specifiers.  */
7663  if (specs->type || specs->typespec_word != cts_none
7664      || specs->long_p || specs->short_p || specs->signed_p
7665      || specs->unsigned_p || specs->complex_p)
7666    error ("two or more data types in declaration specifiers");
7667  else if (TREE_CODE (type) == TYPE_DECL)
7668    {
7669      if (TREE_TYPE (type) == error_mark_node)
7670	; /* Allow the type to default to int to avoid cascading errors.  */
7671      else
7672	{
7673	  specs->type = TREE_TYPE (type);
7674	  specs->decl_attr = DECL_ATTRIBUTES (type);
7675	  specs->typedef_p = true;
7676	  specs->explicit_signed_p = C_TYPEDEF_EXPLICITLY_SIGNED (type);
7677	}
7678    }
7679  else if (TREE_CODE (type) == IDENTIFIER_NODE)
7680    {
7681      tree t = lookup_name (type);
7682      if (!t || TREE_CODE (t) != TYPE_DECL)
7683	error ("%qE fails to be a typedef or built in type", type);
7684      else if (TREE_TYPE (t) == error_mark_node)
7685	;
7686      else
7687	specs->type = TREE_TYPE (t);
7688    }
7689  else if (TREE_CODE (type) != ERROR_MARK)
7690    {
7691      if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref)
7692	specs->tag_defined_p = true;
7693      if (spec.kind == ctsk_typeof)
7694	specs->typedef_p = true;
7695      specs->type = type;
7696    }
7697
7698  return specs;
7699}
7700
7701/* Add the storage class specifier or function specifier SCSPEC to the
7702   declaration specifiers SPECS, returning SPECS.  */
7703
7704struct c_declspecs *
7705declspecs_add_scspec (struct c_declspecs *specs, tree scspec)
7706{
7707  enum rid i;
7708  enum c_storage_class n = csc_none;
7709  bool dupe = false;
7710  specs->declspecs_seen_p = true;
7711  gcc_assert (TREE_CODE (scspec) == IDENTIFIER_NODE
7712	      && C_IS_RESERVED_WORD (scspec));
7713  i = C_RID_CODE (scspec);
7714  if (extra_warnings && specs->non_sc_seen_p)
7715    warning (OPT_Wextra, "%qE is not at beginning of declaration", scspec);
7716  switch (i)
7717    {
7718    case RID_INLINE:
7719      /* C99 permits duplicate inline.  Although of doubtful utility,
7720	 it seems simplest to permit it in gnu89 mode as well, as
7721	 there is also little utility in maintaining this as a
7722	 difference between gnu89 and C99 inline.  */
7723      dupe = false;
7724      specs->inline_p = true;
7725      break;
7726    case RID_THREAD:
7727      dupe = specs->thread_p;
7728      if (specs->storage_class == csc_auto)
7729	error ("%<__thread%> used with %<auto%>");
7730      else if (specs->storage_class == csc_register)
7731	error ("%<__thread%> used with %<register%>");
7732      else if (specs->storage_class == csc_typedef)
7733	error ("%<__thread%> used with %<typedef%>");
7734      else
7735	specs->thread_p = true;
7736      break;
7737    case RID_AUTO:
7738      n = csc_auto;
7739      break;
7740    case RID_EXTERN:
7741      n = csc_extern;
7742      /* Diagnose "__thread extern".  */
7743      if (specs->thread_p)
7744	error ("%<__thread%> before %<extern%>");
7745      break;
7746    case RID_REGISTER:
7747      n = csc_register;
7748      break;
7749    case RID_STATIC:
7750      n = csc_static;
7751      /* Diagnose "__thread static".  */
7752      if (specs->thread_p)
7753	error ("%<__thread%> before %<static%>");
7754      break;
7755    case RID_TYPEDEF:
7756      n = csc_typedef;
7757      break;
7758    default:
7759      gcc_unreachable ();
7760    }
7761  if (n != csc_none && n == specs->storage_class)
7762    dupe = true;
7763  if (dupe)
7764    error ("duplicate %qE", scspec);
7765  if (n != csc_none)
7766    {
7767      if (specs->storage_class != csc_none && n != specs->storage_class)
7768	{
7769	  error ("multiple storage classes in declaration specifiers");
7770	}
7771      else
7772	{
7773	  specs->storage_class = n;
7774	  if (n != csc_extern && n != csc_static && specs->thread_p)
7775	    {
7776	      error ("%<__thread%> used with %qE", scspec);
7777	      specs->thread_p = false;
7778	    }
7779	}
7780    }
7781  return specs;
7782}
7783
7784/* Add the attributes ATTRS to the declaration specifiers SPECS,
7785   returning SPECS.  */
7786
7787struct c_declspecs *
7788declspecs_add_attrs (struct c_declspecs *specs, tree attrs)
7789{
7790  specs->attrs = chainon (attrs, specs->attrs);
7791  specs->declspecs_seen_p = true;
7792  return specs;
7793}
7794
7795/* Combine "long", "short", "signed", "unsigned" and "_Complex" type
7796   specifiers with any other type specifier to determine the resulting
7797   type.  This is where ISO C checks on complex types are made, since
7798   "_Complex long" is a prefix of the valid ISO C type "_Complex long
7799   double".  */
7800
7801struct c_declspecs *
7802finish_declspecs (struct c_declspecs *specs)
7803{
7804  /* If a type was specified as a whole, we have no modifiers and are
7805     done.  */
7806  if (specs->type != NULL_TREE)
7807    {
7808      gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p
7809		  && !specs->signed_p && !specs->unsigned_p
7810		  && !specs->complex_p);
7811      return specs;
7812    }
7813
7814  /* If none of "void", "_Bool", "char", "int", "float" or "double"
7815     has been specified, treat it as "int" unless "_Complex" is
7816     present and there are no other specifiers.  If we just have
7817     "_Complex", it is equivalent to "_Complex double", but e.g.
7818     "_Complex short" is equivalent to "_Complex short int".  */
7819  if (specs->typespec_word == cts_none)
7820    {
7821      if (specs->long_p || specs->short_p
7822	  || specs->signed_p || specs->unsigned_p)
7823	{
7824	  specs->typespec_word = cts_int;
7825	}
7826      else if (specs->complex_p)
7827	{
7828	  specs->typespec_word = cts_double;
7829	  if (pedantic)
7830	    pedwarn ("ISO C does not support plain %<complex%> meaning "
7831		     "%<double complex%>");
7832	}
7833      else
7834	{
7835	  specs->typespec_word = cts_int;
7836	  specs->default_int_p = true;
7837	  /* We don't diagnose this here because grokdeclarator will
7838	     give more specific diagnostics according to whether it is
7839	     a function definition.  */
7840	}
7841    }
7842
7843  /* If "signed" was specified, record this to distinguish "int" and
7844     "signed int" in the case of a bit-field with
7845     -funsigned-bitfields.  */
7846  specs->explicit_signed_p = specs->signed_p;
7847
7848  /* Now compute the actual type.  */
7849  switch (specs->typespec_word)
7850    {
7851    case cts_void:
7852      gcc_assert (!specs->long_p && !specs->short_p
7853		  && !specs->signed_p && !specs->unsigned_p
7854		  && !specs->complex_p);
7855      specs->type = void_type_node;
7856      break;
7857    case cts_bool:
7858      gcc_assert (!specs->long_p && !specs->short_p
7859		  && !specs->signed_p && !specs->unsigned_p
7860		  && !specs->complex_p);
7861      specs->type = boolean_type_node;
7862      break;
7863    case cts_char:
7864      gcc_assert (!specs->long_p && !specs->short_p);
7865      gcc_assert (!(specs->signed_p && specs->unsigned_p));
7866      if (specs->signed_p)
7867	specs->type = signed_char_type_node;
7868      else if (specs->unsigned_p)
7869	specs->type = unsigned_char_type_node;
7870      else
7871	specs->type = char_type_node;
7872      if (specs->complex_p)
7873	{
7874	  if (pedantic)
7875	    pedwarn ("ISO C does not support complex integer types");
7876	  specs->type = build_complex_type (specs->type);
7877	}
7878      break;
7879    case cts_int:
7880      gcc_assert (!(specs->long_p && specs->short_p));
7881      gcc_assert (!(specs->signed_p && specs->unsigned_p));
7882      if (specs->long_long_p)
7883	specs->type = (specs->unsigned_p
7884		       ? long_long_unsigned_type_node
7885		       : long_long_integer_type_node);
7886      else if (specs->long_p)
7887	specs->type = (specs->unsigned_p
7888		       ? long_unsigned_type_node
7889		       : long_integer_type_node);
7890      else if (specs->short_p)
7891	specs->type = (specs->unsigned_p
7892		       ? short_unsigned_type_node
7893		       : short_integer_type_node);
7894      else
7895	specs->type = (specs->unsigned_p
7896		       ? unsigned_type_node
7897		       : integer_type_node);
7898      if (specs->complex_p)
7899	{
7900	  if (pedantic)
7901	    pedwarn ("ISO C does not support complex integer types");
7902	  specs->type = build_complex_type (specs->type);
7903	}
7904      break;
7905    case cts_float:
7906      gcc_assert (!specs->long_p && !specs->short_p
7907		  && !specs->signed_p && !specs->unsigned_p);
7908      specs->type = (specs->complex_p
7909		     ? complex_float_type_node
7910		     : float_type_node);
7911      break;
7912    case cts_double:
7913      gcc_assert (!specs->long_long_p && !specs->short_p
7914		  && !specs->signed_p && !specs->unsigned_p);
7915      if (specs->long_p)
7916	{
7917	  specs->type = (specs->complex_p
7918			 ? complex_long_double_type_node
7919			 : long_double_type_node);
7920	}
7921      else
7922	{
7923	  specs->type = (specs->complex_p
7924			 ? complex_double_type_node
7925			 : double_type_node);
7926	}
7927      break;
7928    case cts_dfloat32:
7929    case cts_dfloat64:
7930    case cts_dfloat128:
7931      gcc_assert (!specs->long_p && !specs->long_long_p && !specs->short_p
7932		  && !specs->signed_p && !specs->unsigned_p && !specs->complex_p);
7933      if (specs->typespec_word == cts_dfloat32)
7934	specs->type = dfloat32_type_node;
7935      else if (specs->typespec_word == cts_dfloat64)
7936	specs->type = dfloat64_type_node;
7937      else
7938	specs->type = dfloat128_type_node;
7939      break;
7940    default:
7941      gcc_unreachable ();
7942    }
7943
7944  return specs;
7945}
7946
7947/* Synthesize a function which calls all the global ctors or global
7948   dtors in this file.  This is only used for targets which do not
7949   support .ctors/.dtors sections.  FIXME: Migrate into cgraph.  */
7950static void
7951build_cdtor (int method_type, tree cdtors)
7952{
7953  tree body = 0;
7954
7955  if (!cdtors)
7956    return;
7957
7958  for (; cdtors; cdtors = TREE_CHAIN (cdtors))
7959    append_to_statement_list (build_function_call (TREE_VALUE (cdtors), 0),
7960			      &body);
7961
7962  cgraph_build_static_cdtor (method_type, body, DEFAULT_INIT_PRIORITY);
7963}
7964
7965/* A subroutine of c_write_global_declarations.  Perform final processing
7966   on one file scope's declarations (or the external scope's declarations),
7967   GLOBALS.  */
7968
7969static void
7970c_write_global_declarations_1 (tree globals)
7971{
7972  tree decl;
7973  bool reconsider;
7974
7975  /* Process the decls in the order they were written.  */
7976  for (decl = globals; decl; decl = TREE_CHAIN (decl))
7977    {
7978      /* Check for used but undefined static functions using the C
7979	 standard's definition of "used", and set TREE_NO_WARNING so
7980	 that check_global_declarations doesn't repeat the check.  */
7981      if (TREE_CODE (decl) == FUNCTION_DECL
7982	  && DECL_INITIAL (decl) == 0
7983	  && DECL_EXTERNAL (decl)
7984	  && !TREE_PUBLIC (decl)
7985	  && C_DECL_USED (decl))
7986	{
7987	  pedwarn ("%q+F used but never defined", decl);
7988	  TREE_NO_WARNING (decl) = 1;
7989	}
7990
7991      wrapup_global_declaration_1 (decl);
7992    }
7993
7994  do
7995    {
7996      reconsider = false;
7997      for (decl = globals; decl; decl = TREE_CHAIN (decl))
7998	reconsider |= wrapup_global_declaration_2 (decl);
7999    }
8000  while (reconsider);
8001
8002  for (decl = globals; decl; decl = TREE_CHAIN (decl))
8003    check_global_declaration_1 (decl);
8004}
8005
8006/* A subroutine of c_write_global_declarations Emit debug information for each
8007   of the declarations in GLOBALS.  */
8008
8009static void
8010c_write_global_declarations_2 (tree globals)
8011{
8012  tree decl;
8013
8014  for (decl = globals; decl ; decl = TREE_CHAIN (decl))
8015    debug_hooks->global_decl (decl);
8016}
8017
8018/* Preserve the external declarations scope across a garbage collect.  */
8019static GTY(()) tree ext_block;
8020
8021void
8022c_write_global_declarations (void)
8023{
8024  tree t;
8025
8026  /* We don't want to do this if generating a PCH.  */
8027  if (pch_file)
8028    return;
8029
8030  /* Don't waste time on further processing if -fsyntax-only or we've
8031     encountered errors.  */
8032  if (flag_syntax_only || errorcount || sorrycount || cpp_errors (parse_in))
8033    return;
8034
8035  /* Close the external scope.  */
8036  ext_block = pop_scope ();
8037  external_scope = 0;
8038  gcc_assert (!current_scope);
8039
8040  if (ext_block)
8041    {
8042      tree tmp = BLOCK_VARS (ext_block);
8043      int flags;
8044      FILE * stream = dump_begin (TDI_tu, &flags);
8045      if (stream && tmp)
8046	{
8047	  dump_node (tmp, flags & ~TDF_SLIM, stream);
8048	  dump_end (TDI_tu, stream);
8049	}
8050    }
8051
8052  /* Process all file scopes in this compilation, and the external_scope,
8053     through wrapup_global_declarations and check_global_declarations.  */
8054  for (t = all_translation_units; t; t = TREE_CHAIN (t))
8055    c_write_global_declarations_1 (BLOCK_VARS (DECL_INITIAL (t)));
8056  c_write_global_declarations_1 (BLOCK_VARS (ext_block));
8057
8058  /* Generate functions to call static constructors and destructors
8059     for targets that do not support .ctors/.dtors sections.  These
8060     functions have magic names which are detected by collect2.  */
8061  build_cdtor ('I', static_ctors); static_ctors = 0;
8062  build_cdtor ('D', static_dtors); static_dtors = 0;
8063
8064  /* We're done parsing; proceed to optimize and emit assembly.
8065     FIXME: shouldn't be the front end's responsibility to call this.  */
8066  cgraph_optimize ();
8067
8068  /* After cgraph has had a chance to emit everything that's going to
8069     be emitted, output debug information for globals.  */
8070  if (errorcount == 0 && sorrycount == 0)
8071    {
8072      timevar_push (TV_SYMOUT);
8073      for (t = all_translation_units; t; t = TREE_CHAIN (t))
8074	c_write_global_declarations_2 (BLOCK_VARS (DECL_INITIAL (t)));
8075      c_write_global_declarations_2 (BLOCK_VARS (ext_block));
8076      timevar_pop (TV_SYMOUT);
8077    }
8078
8079  ext_block = NULL;
8080}
8081
8082#include "gt-c-decl.h"
8083