c-decl.c revision 122196
168349Sobrien/* Process declarations and variables for C compiler.
2133359Sobrien   Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3133359Sobrien   2001, 2002 Free Software Foundation, Inc.
4133359Sobrien
5226048SobrienThis file is part of GCC.
6133359Sobrien
7133359SobrienGCC is free software; you can redistribute it and/or modify it under
8133359Sobrienthe terms of the GNU General Public License as published by the Free
9133359SobrienSoftware Foundation; either version 2, or (at your option) any later
10133359Sobrienversion.
11133359Sobrien
12133359SobrienGCC is distributed in the hope that it will be useful, but WITHOUT ANY
13133359SobrienWARRANTY; without even the implied warranty of MERCHANTABILITY or
14133359SobrienFITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15226048Sobrienfor more details.
16133359Sobrien
17133359SobrienYou should have received a copy of the GNU General Public License
18133359Sobrienalong with GCC; see the file COPYING.  If not, write to the Free
19133359SobrienSoftware Foundation, 59 Temple Place - Suite 330, Boston, MA
20133359Sobrien02111-1307, USA.  */
21133359Sobrien
22133359Sobrien/* $FreeBSD: head/contrib/gcc/c-decl.c 122196 2003-11-07 03:21:29Z kan $ */
23133359Sobrien
24133359Sobrien/* Process declarations and symbol lookup for C front end.
25133359Sobrien   Also constructs types; the standard scalar types at initialization,
26133359Sobrien   and structure, union, array and enum types when they are declared.  */
27133359Sobrien
28133359Sobrien/* ??? not all decl nodes are given the most useful possible
2968349Sobrien   line numbers.  For example, the CONST_DECLs for enum values.  */
3068349Sobrien
3168349Sobrien#include "config.h"
3268349Sobrien#include "system.h"
3368349Sobrien#include "intl.h"
3468349Sobrien#include "tree.h"
3568349Sobrien#include "tree-inline.h"
3668349Sobrien#include "rtl.h"
3768349Sobrien#include "flags.h"
3868349Sobrien#include "function.h"
3968349Sobrien#include "output.h"
40103373Sobrien#include "expr.h"
41191736Sobrien#include "c-tree.h"
42191736Sobrien#include "toplev.h"
43330569Sgordon#include "ggc.h"
44191736Sobrien#include "tm_p.h"
45191736Sobrien#include "cpplib.h"
46133359Sobrien#include "target.h"
4768349Sobrien#include "debug.h"
4868349Sobrien#include "timevar.h"
4968349Sobrien#include "c-common.h"
5068349Sobrien#include "c-pragma.h"
5168349Sobrien#include "libfuncs.h"
5268349Sobrien#include "except.h"
53133359Sobrien
54330569Sgordon/* In grokdeclarator, distinguish syntactic contexts of declarators.  */
5568349Sobrienenum decl_context
56186690Sobrien{ NORMAL,			/* Ordinary declaration */
57175296Sobrien  FUNCDEF,			/* Function definition */
58175296Sobrien  PARM,				/* Declaration of parm before function body */
59175296Sobrien  FIELD,			/* Declaration inside struct or union */
60175296Sobrien  BITFIELD,			/* Likewise but with specified width */
61175296Sobrien  TYPENAME};			/* Typename (inside cast or sizeof)  */
62133359Sobrien
63133359Sobrien
64133359Sobrien/* Nonzero if we have seen an invalid cross reference
65133359Sobrien   to a struct, union, or enum, but not yet printed the message.  */
66133359Sobrien
67133359Sobrientree pending_invalid_xref;
68133359Sobrien/* File and line to appear in the eventual error message.  */
69191736Sobrienconst char *pending_invalid_xref_file;
70175296Sobrienint pending_invalid_xref_line;
71175296Sobrien
72284778Sdelphij/* While defining an enum type, this is 1 plus the last enumerator
73133359Sobrien   constant value.  Note that will do not have to save this or `enum_overflow'
74175296Sobrien   around nested function definition since such a definition could only
75191736Sobrien   occur in an enum value expression and we don't use these variables in
76191736Sobrien   that case.  */
77175296Sobrien
78175296Sobrienstatic tree enum_next_value;
79191736Sobrien
80175296Sobrien/* Nonzero means that there was overflow computing enum_next_value.  */
81175296Sobrien
82175296Sobrienstatic int enum_overflow;
83133359Sobrien
84133359Sobrien/* Parsing a function declarator leaves a list of parameter names
8568349Sobrien   or a chain or parameter decls here.  */
86226048Sobrien
87226048Sobrienstatic tree last_function_parms;
8868349Sobrien
89186690Sobrien/* Parsing a function declarator leaves here a chain of structure
90186690Sobrien   and enum types declared in the parmlist.  */
9168349Sobrien
92133359Sobrienstatic tree last_function_parm_tags;
93133359Sobrien
9468349Sobrien/* After parsing the declarator that starts a function definition,
95133359Sobrien   `start_function' puts here the list of parameter names or chain of decls.
96330569Sgordon   `store_parm_decls' finds it here.  */
97330569Sgordon
98330569Sgordonstatic tree current_function_parms;
9968349Sobrien
100330569Sgordon/* Similar, for last_function_parm_tags.  */
10168349Sobrienstatic tree current_function_parm_tags;
10268349Sobrien
103330569Sgordon/* Similar, for the file and line that the prototype came from if this is
10468349Sobrien   an old-style definition.  */
10568349Sobrienstatic const char *current_function_prototype_file;
10668349Sobrienstatic int current_function_prototype_line;
107330569Sgordon
108330569Sgordon/* The current statement tree.  */
109226048Sobrien
11068349Sobrienstatic GTY(()) struct stmt_tree_s c_stmt_tree;
11168349Sobrien
112330569Sgordon/* The current scope statement stack.  */
113226048Sobrien
114330569Sgordonstatic GTY(()) tree c_scope_stmt_stack;
11568349Sobrien
11668349Sobrien/* A list (chain of TREE_LIST nodes) of all LABEL_DECLs in the function
11768349Sobrien   that have names.  Here so we can clear out their names' definitions
118226048Sobrien   at the end of the function.  */
119330569Sgordon
120330569Sgordonstatic GTY(()) tree named_labels;
121169942Sobrien
122330569Sgordon/* A list of LABEL_DECLs from outer contexts that are currently shadowed.  */
123330569Sgordon
124330569Sgordonstatic GTY(()) tree shadowed_labels;
12568349Sobrien
12668349Sobrien/* Set to 0 at beginning of a function definition, set to 1 if
12768349Sobrien   a return statement that specifies a return value is seen.  */
12868349Sobrien
12968349Sobrienint current_function_returns_value;
13068349Sobrien
13168349Sobrien/* Set to 0 at beginning of a function definition, set to 1 if
13268349Sobrien   a return statement with no argument is seen.  */
13368349Sobrien
134226048Sobrienint current_function_returns_null;
13568349Sobrien
136133359Sobrien/* Set to 0 at beginning of a function definition, set to 1 if
137330569Sgordon   a call to a noreturn function is seen.  */
13868349Sobrien
13968349Sobrienint current_function_returns_abnormally;
14068349Sobrien
141330569Sgordon/* Set to nonzero by `grokdeclarator' for a function
142330569Sgordon   whose return type is defaulted, if warnings for this are desired.  */
143330569Sgordon
14468349Sobrienstatic int warn_about_return_type;
14568349Sobrien
146330569Sgordon/* Nonzero when starting a function declared `extern inline'.  */
14768349Sobrien
14868349Sobrienstatic int current_extern_inline;
14968349Sobrien
150226048Sobrien/* For each binding contour we allocate a binding_level structure
15168349Sobrien * which records the names defined in that contour.
152330569Sgordon * Contours include:
15368349Sobrien *  0) the global one
15468349Sobrien *  1) one for each function definition,
15568349Sobrien *     where internal declarations of the parameters appear.
156226048Sobrien *  2) one for each compound statement,
15768349Sobrien *     to record its declarations.
15868349Sobrien *
15968349Sobrien * The current meaning of a name can be found by searching the levels from
160 * the current one out to the global one.
161 */
162
163/* Note that the information in the `names' component of the global contour
164   is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */
165
166struct binding_level GTY(())
167  {
168    /* A chain of _DECL nodes for all variables, constants, functions,
169       and typedef types.  These are in the reverse of the order supplied.
170     */
171    tree names;
172
173    /* A list of structure, union and enum definitions,
174     * for looking up tag names.
175     * It is a chain of TREE_LIST nodes, each of whose TREE_PURPOSE is a name,
176     * or NULL_TREE; and whose TREE_VALUE is a RECORD_TYPE, UNION_TYPE,
177     * or ENUMERAL_TYPE node.
178     */
179    tree tags;
180
181    /* For each level, a list of shadowed outer-level local definitions
182       to be restored when this level is popped.
183       Each link is a TREE_LIST whose TREE_PURPOSE is an identifier and
184       whose TREE_VALUE is its old definition (a kind of ..._DECL node).  */
185    tree shadowed;
186
187    /* For each level (except not the global one),
188       a chain of BLOCK nodes for all the levels
189       that were entered and exited one level down.  */
190    tree blocks;
191
192    /* The BLOCK node for this level, if one has been preallocated.
193       If 0, the BLOCK is allocated (if needed) when the level is popped.  */
194    tree this_block;
195
196    /* The binding level which this one is contained in (inherits from).  */
197    struct binding_level *level_chain;
198
199    /* Nonzero for the level that holds the parameters of a function.  */
200    char parm_flag;
201
202    /* Nonzero if this level "doesn't exist" for tags.  */
203    char tag_transparent;
204
205    /* Nonzero if sublevels of this level "don't exist" for tags.
206       This is set in the parm level of a function definition
207       while reading the function body, so that the outermost block
208       of the function body will be tag-transparent.  */
209    char subblocks_tag_transparent;
210
211    /* Nonzero means make a BLOCK for this level regardless of all else.  */
212    char keep;
213
214    /* Nonzero means make a BLOCK if this level has any subblocks.  */
215    char keep_if_subblocks;
216
217    /* List of decls in `names' that have incomplete structure or
218       union types.  */
219    tree incomplete_list;
220
221    /* A list of decls giving the (reversed) specified order of parms,
222       not including any forward-decls in the parmlist.
223       This is so we can put the parms in proper order for assign_parms.  */
224    tree parm_order;
225  };
226
227#define NULL_BINDING_LEVEL (struct binding_level *) NULL
228
229/* The binding level currently in effect.  */
230
231static GTY(()) struct binding_level *current_binding_level;
232
233/* A chain of binding_level structures awaiting reuse.  */
234
235static GTY((deletable (""))) struct binding_level *free_binding_level;
236
237/* The outermost binding level, for names of file scope.
238   This is created when the compiler is started and exists
239   through the entire run.  */
240
241static GTY(()) struct binding_level *global_binding_level;
242
243/* Binding level structures are initialized by copying this one.  */
244
245static struct binding_level clear_binding_level
246  = {NULL, NULL, NULL, NULL, NULL, NULL_BINDING_LEVEL, 0, 0, 0, 0, 0, NULL,
247     NULL};
248
249/* Nonzero means unconditionally make a BLOCK for the next level pushed.  */
250
251static int keep_next_level_flag;
252
253/* Nonzero means make a BLOCK for the next level pushed
254   if it has subblocks.  */
255
256static int keep_next_if_subblocks;
257
258/* The chain of outer levels of label scopes.
259   This uses the same data structure used for binding levels,
260   but it works differently: each link in the chain records
261   saved values of named_labels and shadowed_labels for
262   a label binding level outside the current one.  */
263
264static GTY(()) struct binding_level *label_level_chain;
265
266/* Functions called automatically at the beginning and end of execution.  */
267
268tree static_ctors, static_dtors;
269
270/* Forward declarations.  */
271
272static struct binding_level * make_binding_level	PARAMS ((void));
273static void pop_binding_level		PARAMS ((struct binding_level **));
274static void clear_limbo_values		PARAMS ((tree));
275static int duplicate_decls		PARAMS ((tree, tree, int));
276static int redeclaration_error_message	PARAMS ((tree, tree));
277static void storedecls			PARAMS ((tree));
278static void storetags			PARAMS ((tree));
279static tree lookup_tag			PARAMS ((enum tree_code, tree,
280						 struct binding_level *, int));
281static tree lookup_tag_reverse		PARAMS ((tree));
282static tree grokdeclarator		PARAMS ((tree, tree, enum decl_context,
283						 int));
284static tree grokparms			PARAMS ((tree, int));
285static void layout_array_type		PARAMS ((tree));
286static tree c_make_fname_decl           PARAMS ((tree, int));
287static void c_expand_body               PARAMS ((tree, int, int));
288static void warn_if_shadowing		PARAMS ((tree, tree));
289static bool flexible_array_type_p	PARAMS ((tree));
290static int field_decl_cmp		PARAMS ((const PTR, const PTR));
291static tree set_save_expr_context	PARAMS ((tree *, int *, void *));
292
293/* States indicating how grokdeclarator() should handle declspecs marked
294   with __attribute__((deprecated)).  An object declared as
295   __attribute__((deprecated)) suppresses warnings of uses of other
296   deprecated items.  */
297
298enum deprecated_states {
299  DEPRECATED_NORMAL,
300  DEPRECATED_SUPPRESS
301};
302
303static enum deprecated_states deprecated_state = DEPRECATED_NORMAL;
304
305void
306c_print_identifier (file, node, indent)
307     FILE *file;
308     tree node;
309     int indent;
310{
311  print_node (file, "global", IDENTIFIER_GLOBAL_VALUE (node), indent + 4);
312  print_node (file, "local", IDENTIFIER_LOCAL_VALUE (node), indent + 4);
313  print_node (file, "label", IDENTIFIER_LABEL_VALUE (node), indent + 4);
314  print_node (file, "implicit", IDENTIFIER_IMPLICIT_DECL (node), indent + 4);
315  print_node (file, "error locus", IDENTIFIER_ERROR_LOCUS (node), indent + 4);
316  print_node (file, "limbo value", IDENTIFIER_LIMBO_VALUE (node), indent + 4);
317  if (C_IS_RESERVED_WORD (node))
318    {
319      tree rid = ridpointers[C_RID_CODE (node)];
320      indent_to (file, indent + 4);
321      fprintf (file, "rid ");
322      fprintf (file, HOST_PTR_PRINTF, (void *)rid);
323      fprintf (file, " \"%s\"", IDENTIFIER_POINTER (rid));
324    }
325}
326
327/* Hook called at end of compilation to assume 1 elt
328   for a top-level tentative array defn that wasn't complete before.  */
329
330void
331c_finish_incomplete_decl (decl)
332     tree decl;
333{
334  if (TREE_CODE (decl) == VAR_DECL)
335    {
336      tree type = TREE_TYPE (decl);
337      if (type != error_mark_node
338	  && TREE_CODE (type) == ARRAY_TYPE
339	  && ! DECL_EXTERNAL (decl)
340	  && TYPE_DOMAIN (type) == 0)
341	{
342	  warning_with_decl (decl, "array `%s' assumed to have one element");
343
344	  complete_array_type (type, NULL_TREE, 1);
345
346	  layout_decl (decl, 0);
347	}
348    }
349}
350
351/* Reuse or create a struct for this binding level.  */
352
353static struct binding_level *
354make_binding_level ()
355{
356  if (free_binding_level)
357    {
358      struct binding_level *result = free_binding_level;
359      free_binding_level = result->level_chain;
360      return result;
361    }
362  else
363    return (struct binding_level *) ggc_alloc (sizeof (struct binding_level));
364}
365
366/* Remove a binding level from a list and add it to the level chain.  */
367
368static void
369pop_binding_level (lp)
370     struct binding_level **lp;
371{
372  struct binding_level *l = *lp;
373  *lp = l->level_chain;
374
375  memset (l, 0, sizeof (struct binding_level));
376  l->level_chain = free_binding_level;
377  free_binding_level = l;
378}
379
380/* Nonzero if we are currently in the global binding level.  */
381
382int
383global_bindings_p ()
384{
385  return current_binding_level == global_binding_level;
386}
387
388void
389keep_next_level ()
390{
391  keep_next_level_flag = 1;
392}
393
394/* Nonzero if the current level needs to have a BLOCK made.  */
395
396int
397kept_level_p ()
398{
399  return ((current_binding_level->keep_if_subblocks
400	   && current_binding_level->blocks != 0)
401	  || current_binding_level->keep
402	  || current_binding_level->names != 0
403	  || (current_binding_level->tags != 0
404	      && !current_binding_level->tag_transparent));
405}
406
407/* Identify this binding level as a level of parameters.
408   DEFINITION_FLAG is 1 for a definition, 0 for a declaration.
409   But it turns out there is no way to pass the right value for
410   DEFINITION_FLAG, so we ignore it.  */
411
412void
413declare_parm_level (definition_flag)
414     int definition_flag ATTRIBUTE_UNUSED;
415{
416  current_binding_level->parm_flag = 1;
417}
418
419/* Nonzero if currently making parm declarations.  */
420
421int
422in_parm_level_p ()
423{
424  return current_binding_level->parm_flag;
425}
426
427/* Enter a new binding level.
428   If TAG_TRANSPARENT is nonzero, do so only for the name space of variables,
429   not for that of tags.  */
430
431void
432pushlevel (tag_transparent)
433     int tag_transparent;
434{
435  struct binding_level *newlevel = NULL_BINDING_LEVEL;
436
437  /* If this is the top level of a function,
438     just make sure that NAMED_LABELS is 0.  */
439
440  if (current_binding_level == global_binding_level)
441    {
442      named_labels = 0;
443    }
444
445  newlevel = make_binding_level ();
446
447  /* Add this level to the front of the chain (stack) of levels that
448     are active.  */
449
450  *newlevel = clear_binding_level;
451  newlevel->tag_transparent
452    = (tag_transparent
453       || (current_binding_level
454	   ? current_binding_level->subblocks_tag_transparent
455	   : 0));
456  newlevel->level_chain = current_binding_level;
457  current_binding_level = newlevel;
458  newlevel->keep = keep_next_level_flag;
459  keep_next_level_flag = 0;
460  newlevel->keep_if_subblocks = keep_next_if_subblocks;
461  keep_next_if_subblocks = 0;
462}
463
464/* Clear the limbo values of all identifiers defined in BLOCK or a subblock.  */
465
466static void
467clear_limbo_values (block)
468     tree block;
469{
470  tree tem;
471
472  for (tem = BLOCK_VARS (block); tem; tem = TREE_CHAIN (tem))
473    if (DECL_NAME (tem) != 0)
474      IDENTIFIER_LIMBO_VALUE (DECL_NAME (tem)) = 0;
475
476  for (tem = BLOCK_SUBBLOCKS (block); tem; tem = TREE_CHAIN (tem))
477    clear_limbo_values (tem);
478}
479
480/* Exit a binding level.
481   Pop the level off, and restore the state of the identifier-decl mappings
482   that were in effect when this level was entered.
483
484   If KEEP is nonzero, this level had explicit declarations, so
485   and create a "block" (a BLOCK node) for the level
486   to record its declarations and subblocks for symbol table output.
487
488   If FUNCTIONBODY is nonzero, this level is the body of a function,
489   so create a block as if KEEP were set and also clear out all
490   label names.
491
492   If REVERSE is nonzero, reverse the order of decls before putting
493   them into the BLOCK.  */
494
495tree
496poplevel (keep, reverse, functionbody)
497     int keep;
498     int reverse;
499     int functionbody;
500{
501  tree link;
502  /* The chain of decls was accumulated in reverse order.
503     Put it into forward order, just for cleanliness.  */
504  tree decls;
505  tree tags = current_binding_level->tags;
506  tree subblocks = current_binding_level->blocks;
507  tree block = 0;
508  tree decl;
509  int block_previously_created;
510
511  keep |= current_binding_level->keep;
512
513  /* This warning is turned off because it causes warnings for
514     declarations like `extern struct foo *x'.  */
515#if 0
516  /* Warn about incomplete structure types in this level.  */
517  for (link = tags; link; link = TREE_CHAIN (link))
518    if (!COMPLETE_TYPE_P (TREE_VALUE (link)))
519      {
520	tree type = TREE_VALUE (link);
521	tree type_name = TYPE_NAME (type);
522	char *id = IDENTIFIER_POINTER (TREE_CODE (type_name) == IDENTIFIER_NODE
523				       ? type_name
524				       : DECL_NAME (type_name));
525	switch (TREE_CODE (type))
526	  {
527	  case RECORD_TYPE:
528	    error ("`struct %s' incomplete in scope ending here", id);
529	    break;
530	  case UNION_TYPE:
531	    error ("`union %s' incomplete in scope ending here", id);
532	    break;
533	  case ENUMERAL_TYPE:
534	    error ("`enum %s' incomplete in scope ending here", id);
535	    break;
536	  }
537      }
538#endif /* 0 */
539
540  /* Get the decls in the order they were written.
541     Usually current_binding_level->names is in reverse order.
542     But parameter decls were previously put in forward order.  */
543
544  if (reverse)
545    current_binding_level->names
546      = decls = nreverse (current_binding_level->names);
547  else
548    decls = current_binding_level->names;
549
550  /* Output any nested inline functions within this block
551     if they weren't already output.  */
552
553  for (decl = decls; decl; decl = TREE_CHAIN (decl))
554    if (TREE_CODE (decl) == FUNCTION_DECL
555	&& ! TREE_ASM_WRITTEN (decl)
556	&& DECL_INITIAL (decl) != 0
557	&& TREE_ADDRESSABLE (decl))
558      {
559	/* If this decl was copied from a file-scope decl
560	   on account of a block-scope extern decl,
561	   propagate TREE_ADDRESSABLE to the file-scope decl.
562
563	   DECL_ABSTRACT_ORIGIN can be set to itself if warn_return_type is
564	   true, since then the decl goes through save_for_inline_copying.  */
565	if (DECL_ABSTRACT_ORIGIN (decl) != 0
566	    && DECL_ABSTRACT_ORIGIN (decl) != decl)
567	  TREE_ADDRESSABLE (DECL_ABSTRACT_ORIGIN (decl)) = 1;
568      }
569
570  /* We used to warn about unused variables in expand_end_bindings,
571     i.e. while generating RTL.  But in function-at-a-time mode we may
572     choose to never expand a function at all (e.g. auto inlining), so
573     we do this explicitly now.  */
574  warn_about_unused_variables (getdecls ());
575
576  /* If there were any declarations or structure tags in that level,
577     or if this level is a function body,
578     create a BLOCK to record them for the life of this function.  */
579
580  block = 0;
581  block_previously_created = (current_binding_level->this_block != 0);
582  if (block_previously_created)
583    block = current_binding_level->this_block;
584  else if (keep || functionbody
585	   || (current_binding_level->keep_if_subblocks && subblocks != 0))
586    block = make_node (BLOCK);
587  if (block != 0)
588    {
589      BLOCK_VARS (block) = decls;
590      BLOCK_SUBBLOCKS (block) = subblocks;
591    }
592
593  /* In each subblock, record that this is its superior.  */
594
595  for (link = subblocks; link; link = TREE_CHAIN (link))
596    BLOCK_SUPERCONTEXT (link) = block;
597
598  /* Clear out the meanings of the local variables of this level.  */
599
600  for (link = decls; link; link = TREE_CHAIN (link))
601    {
602      if (DECL_NAME (link) != 0)
603	{
604	  /* If the ident. was used or addressed via a local extern decl,
605	     don't forget that fact.  */
606	  if (DECL_EXTERNAL (link))
607	    {
608	      if (TREE_USED (link))
609		TREE_USED (DECL_NAME (link)) = 1;
610	      if (TREE_ADDRESSABLE (link))
611		TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (link)) = 1;
612	    }
613	  IDENTIFIER_LOCAL_VALUE (DECL_NAME (link)) = 0;
614	}
615    }
616
617  /* Restore all name-meanings of the outer levels
618     that were shadowed by this level.  */
619
620  for (link = current_binding_level->shadowed; link; link = TREE_CHAIN (link))
621    IDENTIFIER_LOCAL_VALUE (TREE_PURPOSE (link)) = TREE_VALUE (link);
622
623  /* If the level being exited is the top level of a function,
624     check over all the labels, and clear out the current
625     (function local) meanings of their names.  */
626
627  if (functionbody)
628    {
629      clear_limbo_values (block);
630
631      /* If this is the top level block of a function,
632	 the vars are the function's parameters.
633	 Don't leave them in the BLOCK because they are
634	 found in the FUNCTION_DECL instead.  */
635
636      BLOCK_VARS (block) = 0;
637
638      /* Clear out the definitions of all label names,
639	 since their scopes end here,
640	 and add them to BLOCK_VARS.  */
641
642      for (link = named_labels; link; link = TREE_CHAIN (link))
643	{
644	  tree label = TREE_VALUE (link);
645
646	  if (DECL_INITIAL (label) == 0)
647	    {
648	      error_with_decl (label, "label `%s' used but not defined");
649	      /* Avoid crashing later.  */
650	      define_label (input_filename, lineno,
651			    DECL_NAME (label));
652	    }
653	  else if (warn_unused_label && !TREE_USED (label))
654	    warning_with_decl (label, "label `%s' defined but not used");
655	  IDENTIFIER_LABEL_VALUE (DECL_NAME (label)) = 0;
656
657	  /* Put the labels into the "variables" of the
658	     top-level block, so debugger can see them.  */
659	  TREE_CHAIN (label) = BLOCK_VARS (block);
660	  BLOCK_VARS (block) = label;
661	}
662    }
663
664  /* Pop the current level, and free the structure for reuse.  */
665
666  pop_binding_level (&current_binding_level);
667
668  /* Dispose of the block that we just made inside some higher level.  */
669  if (functionbody)
670    DECL_INITIAL (current_function_decl) = block;
671  else if (block)
672    {
673      if (!block_previously_created)
674	current_binding_level->blocks
675	  = chainon (current_binding_level->blocks, block);
676    }
677  /* If we did not make a block for the level just exited,
678     any blocks made for inner levels
679     (since they cannot be recorded as subblocks in that level)
680     must be carried forward so they will later become subblocks
681     of something else.  */
682  else if (subblocks)
683    current_binding_level->blocks
684      = chainon (current_binding_level->blocks, subblocks);
685
686  /* Set the TYPE_CONTEXTs for all of the tagged types belonging to this
687     binding contour so that they point to the appropriate construct, i.e.
688     either to the current FUNCTION_DECL node, or else to the BLOCK node
689     we just constructed.
690
691     Note that for tagged types whose scope is just the formal parameter
692     list for some function type specification, we can't properly set
693     their TYPE_CONTEXTs here, because we don't have a pointer to the
694     appropriate FUNCTION_TYPE node readily available to us.  For those
695     cases, the TYPE_CONTEXTs of the relevant tagged type nodes get set
696     in `grokdeclarator' as soon as we have created the FUNCTION_TYPE
697     node which will represent the "scope" for these "parameter list local"
698     tagged types.  */
699
700  if (functionbody)
701    for (link = tags; link; link = TREE_CHAIN (link))
702      TYPE_CONTEXT (TREE_VALUE (link)) = current_function_decl;
703  else if (block)
704    for (link = tags; link; link = TREE_CHAIN (link))
705      TYPE_CONTEXT (TREE_VALUE (link)) = block;
706
707  if (block)
708    TREE_USED (block) = 1;
709
710  return block;
711}
712
713/* Insert BLOCK at the end of the list of subblocks of the
714   current binding level.  This is used when a BIND_EXPR is expanded,
715   to handle the BLOCK node inside the BIND_EXPR.  */
716
717void
718insert_block (block)
719     tree block;
720{
721  TREE_USED (block) = 1;
722  current_binding_level->blocks
723    = chainon (current_binding_level->blocks, block);
724}
725
726/* Set the BLOCK node for the innermost scope
727   (the one we are currently in).  */
728
729void
730set_block (block)
731     tree block;
732{
733  current_binding_level->this_block = block;
734  current_binding_level->names = chainon (current_binding_level->names,
735					  BLOCK_VARS (block));
736  current_binding_level->blocks = chainon (current_binding_level->blocks,
737					   BLOCK_SUBBLOCKS (block));
738}
739
740void
741push_label_level ()
742{
743  struct binding_level *newlevel;
744
745  newlevel = make_binding_level ();
746
747  /* Add this level to the front of the chain (stack) of label levels.  */
748
749  newlevel->level_chain = label_level_chain;
750  label_level_chain = newlevel;
751
752  newlevel->names = named_labels;
753  newlevel->shadowed = shadowed_labels;
754  named_labels = 0;
755  shadowed_labels = 0;
756}
757
758void
759pop_label_level ()
760{
761  struct binding_level *level = label_level_chain;
762  tree link, prev;
763
764  /* Clear out the definitions of the declared labels in this level.
765     Leave in the list any ordinary, non-declared labels.  */
766  for (link = named_labels, prev = 0; link;)
767    {
768      if (C_DECLARED_LABEL_FLAG (TREE_VALUE (link)))
769	{
770	  if (DECL_SOURCE_LINE (TREE_VALUE (link)) == 0)
771	    {
772	      error_with_decl (TREE_VALUE (link),
773			       "label `%s' used but not defined");
774	      /* Avoid crashing later.  */
775	      define_label (input_filename, lineno,
776			    DECL_NAME (TREE_VALUE (link)));
777	    }
778	  else if (warn_unused_label && !TREE_USED (TREE_VALUE (link)))
779	    warning_with_decl (TREE_VALUE (link),
780			       "label `%s' defined but not used");
781	  IDENTIFIER_LABEL_VALUE (DECL_NAME (TREE_VALUE (link))) = 0;
782
783	  /* Delete this element from the list.  */
784	  link = TREE_CHAIN (link);
785	  if (prev)
786	    TREE_CHAIN (prev) = link;
787	  else
788	    named_labels = link;
789	}
790      else
791	{
792	  prev = link;
793	  link = TREE_CHAIN (link);
794	}
795    }
796
797  /* Bring back all the labels that were shadowed.  */
798  for (link = shadowed_labels; link; link = TREE_CHAIN (link))
799    if (DECL_NAME (TREE_VALUE (link)) != 0)
800      IDENTIFIER_LABEL_VALUE (DECL_NAME (TREE_VALUE (link)))
801	= TREE_VALUE (link);
802
803  named_labels = chainon (named_labels, level->names);
804  shadowed_labels = level->shadowed;
805
806  /* Pop the current level, and free the structure for reuse.  */
807  pop_binding_level (&label_level_chain);
808}
809
810/* Push a definition or a declaration of struct, union or enum tag "name".
811   "type" should be the type node.
812   We assume that the tag "name" is not already defined.
813
814   Note that the definition may really be just a forward reference.
815   In that case, the TYPE_SIZE will be zero.  */
816
817void
818pushtag (name, type)
819     tree name, type;
820{
821  struct binding_level *b;
822
823  /* Find the proper binding level for this type tag.  */
824
825  for (b = current_binding_level; b->tag_transparent; b = b->level_chain)
826    continue;
827
828  if (name)
829    {
830      /* Record the identifier as the type's name if it has none.  */
831
832      if (TYPE_NAME (type) == 0)
833	TYPE_NAME (type) = name;
834    }
835
836  b->tags = tree_cons (name, type, b->tags);
837
838  /* Create a fake NULL-named TYPE_DECL node whose TREE_TYPE will be the
839     tagged type we just added to the current binding level.  This fake
840     NULL-named TYPE_DECL node helps dwarfout.c to know when it needs
841     to output a representation of a tagged type, and it also gives
842     us a convenient place to record the "scope start" address for the
843     tagged type.  */
844
845  TYPE_STUB_DECL (type) = pushdecl (build_decl (TYPE_DECL, NULL_TREE, type));
846
847  /* An approximation for now, so we can tell this is a function-scope tag.
848     This will be updated in poplevel.  */
849  TYPE_CONTEXT (type) = DECL_CONTEXT (TYPE_STUB_DECL (type));
850}
851
852/* Handle when a new declaration NEWDECL
853   has the same name as an old one OLDDECL
854   in the same binding contour.
855   Prints an error message if appropriate.
856
857   If safely possible, alter OLDDECL to look like NEWDECL, and return 1.
858   Otherwise, return 0.
859
860   When DIFFERENT_BINDING_LEVEL is true, NEWDECL is an external declaration,
861   and OLDDECL is in an outer binding level and should thus not be changed.  */
862
863static int
864duplicate_decls (newdecl, olddecl, different_binding_level)
865     tree newdecl, olddecl;
866     int different_binding_level;
867{
868  int types_match = comptypes (TREE_TYPE (newdecl), TREE_TYPE (olddecl));
869  int new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL
870			   && DECL_INITIAL (newdecl) != 0);
871  tree oldtype = TREE_TYPE (olddecl);
872  tree newtype = TREE_TYPE (newdecl);
873  int errmsg = 0;
874
875  if (DECL_P (olddecl))
876    {
877      if (TREE_CODE (newdecl) == FUNCTION_DECL
878	  && TREE_CODE (olddecl) == FUNCTION_DECL
879	  && (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl)))
880	{
881	  if (DECL_DECLARED_INLINE_P (newdecl)
882	      && DECL_UNINLINABLE (newdecl)
883	      && lookup_attribute ("noinline", DECL_ATTRIBUTES (newdecl)))
884	    /* Already warned elsewhere.  */;
885	  else if (DECL_DECLARED_INLINE_P (olddecl)
886		   && DECL_UNINLINABLE (olddecl)
887		   && lookup_attribute ("noinline", DECL_ATTRIBUTES (olddecl)))
888	    /* Already warned.  */;
889	  else if (DECL_DECLARED_INLINE_P (newdecl)
890		   && ! DECL_DECLARED_INLINE_P (olddecl)
891		   && DECL_UNINLINABLE (olddecl)
892		   && lookup_attribute ("noinline", DECL_ATTRIBUTES (olddecl)))
893	    {
894	      warning_with_decl (newdecl,
895				 "function `%s' redeclared as inline");
896	      warning_with_decl (olddecl,
897				 "previous declaration of function `%s' with attribute noinline");
898	    }
899	  else if (DECL_DECLARED_INLINE_P (olddecl)
900		   && DECL_UNINLINABLE (newdecl)
901		   && lookup_attribute ("noinline", DECL_ATTRIBUTES (newdecl)))
902	    {
903	      warning_with_decl (newdecl,
904				 "function `%s' redeclared with attribute noinline");
905	      warning_with_decl (olddecl,
906				 "previous declaration of function `%s' was inline");
907	    }
908	}
909
910      DECL_ATTRIBUTES (newdecl)
911	= (*targetm.merge_decl_attributes) (olddecl, newdecl);
912    }
913
914  if (TREE_CODE (newtype) == ERROR_MARK
915      || TREE_CODE (oldtype) == ERROR_MARK)
916    types_match = 0;
917
918  /* New decl is completely inconsistent with the old one =>
919     tell caller to replace the old one.
920     This is always an error except in the case of shadowing a builtin.  */
921  if (TREE_CODE (olddecl) != TREE_CODE (newdecl))
922    {
923      if (TREE_CODE (olddecl) == FUNCTION_DECL
924	  && (DECL_BUILT_IN (olddecl)
925	      || DECL_BUILT_IN_NONANSI (olddecl)))
926	{
927	  /* If you declare a built-in or predefined function name as static,
928	     the old definition is overridden,
929	     but optionally warn this was a bad choice of name.  */
930	  if (!TREE_PUBLIC (newdecl))
931	    {
932	      if (!warn_shadow)
933		;
934	      else if (DECL_BUILT_IN (olddecl))
935		warning_with_decl (newdecl, "shadowing built-in function `%s'");
936	      else
937		warning_with_decl (newdecl, "shadowing library function `%s'");
938	    }
939	  /* Likewise, if the built-in is not ansi, then programs can
940	     override it even globally without an error.  */
941	  else if (! DECL_BUILT_IN (olddecl))
942	    warning_with_decl (newdecl,
943			       "library function `%s' declared as non-function");
944
945	  else if (DECL_BUILT_IN_NONANSI (olddecl))
946	    warning_with_decl (newdecl,
947			       "built-in function `%s' declared as non-function");
948	  else
949	    warning_with_decl (newdecl,
950			       "built-in function `%s' declared as non-function");
951	}
952      else
953	{
954	  error_with_decl (newdecl, "`%s' redeclared as different kind of symbol");
955	  error_with_decl (olddecl, "previous declaration of `%s'");
956	}
957
958      return 0;
959    }
960
961  /* For real parm decl following a forward decl,
962     return 1 so old decl will be reused.  */
963  if (types_match && TREE_CODE (newdecl) == PARM_DECL
964      && TREE_ASM_WRITTEN (olddecl) && ! TREE_ASM_WRITTEN (newdecl))
965    return 1;
966
967  /* The new declaration is the same kind of object as the old one.
968     The declarations may partially match.  Print warnings if they don't
969     match enough.  Ultimately, copy most of the information from the new
970     decl to the old one, and keep using the old one.  */
971
972  if (TREE_CODE (olddecl) == FUNCTION_DECL && DECL_BUILT_IN (olddecl))
973    {
974      /* A function declaration for a built-in function.  */
975      if (!TREE_PUBLIC (newdecl))
976	{
977	  /* If you declare a built-in function name as static, the
978	     built-in definition is overridden,
979	     but optionally warn this was a bad choice of name.  */
980	  if (warn_shadow)
981	    warning_with_decl (newdecl, "shadowing built-in function `%s'");
982	  /* Discard the old built-in function.  */
983	  return 0;
984	}
985      else if (!types_match)
986	{
987	  /* Accept the return type of the new declaration if same modes.  */
988	  tree oldreturntype = TREE_TYPE (oldtype);
989	  tree newreturntype = TREE_TYPE (newtype);
990
991	  if (TYPE_MODE (oldreturntype) == TYPE_MODE (newreturntype))
992	    {
993	      /* Function types may be shared, so we can't just modify
994		 the return type of olddecl's function type.  */
995	      tree trytype
996		= build_function_type (newreturntype,
997				       TYPE_ARG_TYPES (oldtype));
998	      trytype = build_type_attribute_variant (trytype,
999						      TYPE_ATTRIBUTES (oldtype));
1000
1001              types_match = comptypes (newtype, trytype);
1002	      if (types_match)
1003		oldtype = trytype;
1004	    }
1005	  /* Accept harmless mismatch in first argument type also.
1006	     This is for the ffs and fprintf builtins.  */
1007	  if (TYPE_ARG_TYPES (TREE_TYPE (newdecl)) != 0
1008	      && TYPE_ARG_TYPES (oldtype) != 0
1009	      && TREE_VALUE (TYPE_ARG_TYPES (newtype)) != 0
1010	      && TREE_VALUE (TYPE_ARG_TYPES (oldtype)) != 0
1011	      && (TYPE_MODE (TREE_VALUE (TYPE_ARG_TYPES (newtype)))
1012		  == TYPE_MODE (TREE_VALUE (TYPE_ARG_TYPES (oldtype)))))
1013	    {
1014	      /* Function types may be shared, so we can't just modify
1015		 the return type of olddecl's function type.  */
1016	      tree trytype
1017		= build_function_type (TREE_TYPE (oldtype),
1018				       tree_cons (NULL_TREE,
1019						  TREE_VALUE (TYPE_ARG_TYPES (newtype)),
1020						  TREE_CHAIN (TYPE_ARG_TYPES (oldtype))));
1021	      trytype = build_type_attribute_variant (trytype,
1022						      TYPE_ATTRIBUTES (oldtype));
1023
1024	      types_match = comptypes (newtype, trytype);
1025	      if (types_match)
1026		oldtype = trytype;
1027	    }
1028	  if (! different_binding_level)
1029	    TREE_TYPE (olddecl) = oldtype;
1030	}
1031      else if (TYPE_ARG_TYPES (oldtype) == NULL
1032	       && TYPE_ARG_TYPES (newtype) != NULL)
1033	{
1034	  /* For bcmp, bzero, fputs the builtin type has arguments not
1035	     specified.  Use the ones from the prototype so that type checking
1036	     is done for them.  */
1037	  tree trytype
1038	    = build_function_type (TREE_TYPE (oldtype),
1039				   TYPE_ARG_TYPES (newtype));
1040	  trytype = build_type_attribute_variant (trytype,
1041						  TYPE_ATTRIBUTES (oldtype));
1042
1043	  oldtype = trytype;
1044	  if (! different_binding_level)
1045	    TREE_TYPE (olddecl) = oldtype;
1046	}
1047      if (!types_match)
1048	{
1049	  /* If types don't match for a built-in, throw away the built-in.  */
1050	  warning_with_decl (newdecl, "conflicting types for built-in function `%s'");
1051	  return 0;
1052	}
1053    }
1054  else if (TREE_CODE (olddecl) == FUNCTION_DECL
1055	   && DECL_SOURCE_LINE (olddecl) == 0)
1056    {
1057      /* A function declaration for a predeclared function
1058	 that isn't actually built in.  */
1059      if (!TREE_PUBLIC (newdecl))
1060	{
1061	  /* If you declare it as static, the
1062	     default definition is overridden.  */
1063	  return 0;
1064	}
1065      else if (!types_match)
1066	{
1067	  /* If the types don't match, preserve volatility indication.
1068	     Later on, we will discard everything else about the
1069	     default declaration.  */
1070	  TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl);
1071	}
1072    }
1073  /* Permit char *foo () to match void *foo (...) if not pedantic,
1074     if one of them came from a system header file.  */
1075  else if (!types_match
1076	   && TREE_CODE (olddecl) == FUNCTION_DECL
1077	   && TREE_CODE (newdecl) == FUNCTION_DECL
1078	   && TREE_CODE (TREE_TYPE (oldtype)) == POINTER_TYPE
1079	   && TREE_CODE (TREE_TYPE (newtype)) == POINTER_TYPE
1080	   && (DECL_IN_SYSTEM_HEADER (olddecl)
1081	       || DECL_IN_SYSTEM_HEADER (newdecl))
1082	   && ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (newtype))) == void_type_node
1083		&& TYPE_ARG_TYPES (oldtype) == 0
1084		&& self_promoting_args_p (TYPE_ARG_TYPES (newtype))
1085		&& TREE_TYPE (TREE_TYPE (oldtype)) == char_type_node)
1086	       ||
1087	       (TREE_TYPE (TREE_TYPE (newtype)) == char_type_node
1088		&& TYPE_ARG_TYPES (newtype) == 0
1089		&& self_promoting_args_p (TYPE_ARG_TYPES (oldtype))
1090		&& TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (oldtype))) == void_type_node)))
1091    {
1092      if (pedantic)
1093	pedwarn_with_decl (newdecl, "conflicting types for `%s'");
1094      /* Make sure we keep void * as ret type, not char *.  */
1095      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (oldtype))) == void_type_node)
1096	TREE_TYPE (newdecl) = newtype = oldtype;
1097
1098      /* Set DECL_IN_SYSTEM_HEADER, so that if we see another declaration
1099	 we will come back here again.  */
1100      DECL_IN_SYSTEM_HEADER (newdecl) = 1;
1101    }
1102  else if (!types_match
1103	   /* Permit char *foo (int, ...); followed by char *foo ();
1104	      if not pedantic.  */
1105	   && ! (TREE_CODE (olddecl) == FUNCTION_DECL
1106		 && ! pedantic
1107		 /* Return types must still match.  */
1108		 && comptypes (TREE_TYPE (oldtype),
1109			       TREE_TYPE (newtype))
1110		 && TYPE_ARG_TYPES (newtype) == 0))
1111    {
1112      error_with_decl (newdecl, "conflicting types for `%s'");
1113      /* Check for function type mismatch
1114	 involving an empty arglist vs a nonempty one.  */
1115      if (TREE_CODE (olddecl) == FUNCTION_DECL
1116	  && comptypes (TREE_TYPE (oldtype),
1117			TREE_TYPE (newtype))
1118	  && ((TYPE_ARG_TYPES (oldtype) == 0
1119	       && DECL_INITIAL (olddecl) == 0)
1120	      ||
1121	      (TYPE_ARG_TYPES (newtype) == 0
1122	       && DECL_INITIAL (newdecl) == 0)))
1123	{
1124	  /* Classify the problem further.  */
1125	  tree t = TYPE_ARG_TYPES (oldtype);
1126	  if (t == 0)
1127	    t = TYPE_ARG_TYPES (newtype);
1128	  for (; t; t = TREE_CHAIN (t))
1129	    {
1130	      tree type = TREE_VALUE (t);
1131
1132	      if (TREE_CHAIN (t) == 0
1133		  && TYPE_MAIN_VARIANT (type) != void_type_node)
1134		{
1135		  error ("a parameter list with an ellipsis can't match an empty parameter name list declaration");
1136		  break;
1137		}
1138
1139	      if (c_type_promotes_to (type) != type)
1140		{
1141		  error ("an argument type that has a default promotion can't match an empty parameter name list declaration");
1142		  break;
1143		}
1144	    }
1145	}
1146      error_with_decl (olddecl, "previous declaration of `%s'");
1147
1148      /* This is safer because the initializer might contain references
1149	 to variables that were declared between olddecl and newdecl. This
1150	 will make the initializer invalid for olddecl in case it gets
1151	 assigned to olddecl below.  */
1152      if (TREE_CODE (newdecl) == VAR_DECL)
1153	DECL_INITIAL (newdecl) = 0;
1154    }
1155  /* TLS cannot follow non-TLS declaration.  */
1156  else if (TREE_CODE (olddecl) == VAR_DECL && TREE_CODE (newdecl) == VAR_DECL
1157	   && !DECL_THREAD_LOCAL (olddecl) && DECL_THREAD_LOCAL (newdecl))
1158    {
1159      error_with_decl (newdecl, "thread-local declaration of `%s' follows non thread-local declaration");
1160      error_with_decl (olddecl, "previous declaration of `%s'");
1161    }
1162  /* non-TLS declaration cannot follow TLS declaration.  */
1163  else if (TREE_CODE (olddecl) == VAR_DECL && TREE_CODE (newdecl) == VAR_DECL
1164	   && DECL_THREAD_LOCAL (olddecl) && !DECL_THREAD_LOCAL (newdecl))
1165    {
1166      error_with_decl (newdecl, "non thread-local declaration of `%s' follows thread-local declaration");
1167      error_with_decl (olddecl, "previous declaration of `%s'");
1168    }
1169  else
1170    {
1171      errmsg = redeclaration_error_message (newdecl, olddecl);
1172      if (errmsg)
1173	{
1174	  switch (errmsg)
1175	    {
1176	    case 1:
1177	      error_with_decl (newdecl, "redefinition of `%s'");
1178	      break;
1179	    case 2:
1180	      error_with_decl (newdecl, "redeclaration of `%s'");
1181	      break;
1182	    case 3:
1183	      error_with_decl (newdecl, "conflicting declarations of `%s'");
1184	      break;
1185	    default:
1186	      abort ();
1187	    }
1188
1189	  error_with_decl (olddecl,
1190			   ((DECL_INITIAL (olddecl)
1191			     && current_binding_level == global_binding_level)
1192			    ? "`%s' previously defined here"
1193			    : "`%s' previously declared here"));
1194	  return 0;
1195	}
1196      else if (TREE_CODE (newdecl) == TYPE_DECL
1197               && (DECL_IN_SYSTEM_HEADER (olddecl)
1198                   || DECL_IN_SYSTEM_HEADER (newdecl)))
1199	{
1200	  warning_with_decl (newdecl, "redefinition of `%s'");
1201	  warning_with_decl
1202	    (olddecl,
1203	     ((DECL_INITIAL (olddecl)
1204	       && current_binding_level == global_binding_level)
1205	      ? "`%s' previously defined here"
1206	      : "`%s' previously declared here"));
1207	}
1208      else if (TREE_CODE (olddecl) == FUNCTION_DECL
1209	       && DECL_INITIAL (olddecl) != 0
1210	       && TYPE_ARG_TYPES (oldtype) == 0
1211	       && TYPE_ARG_TYPES (newtype) != 0
1212	       && TYPE_ACTUAL_ARG_TYPES (oldtype) != 0)
1213	{
1214	  tree type, parm;
1215	  int nargs;
1216	  /* Prototype decl follows defn w/o prototype.  */
1217
1218	  for (parm = TYPE_ACTUAL_ARG_TYPES (oldtype),
1219	       type = TYPE_ARG_TYPES (newtype),
1220	       nargs = 1;
1221	       ;
1222	       parm = TREE_CHAIN (parm), type = TREE_CHAIN (type), nargs++)
1223	    {
1224	      if (TYPE_MAIN_VARIANT (TREE_VALUE (parm)) == void_type_node
1225		  && TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node)
1226		{
1227		  warning_with_decl (newdecl, "prototype for `%s' follows");
1228		  warning_with_decl (olddecl, "non-prototype definition here");
1229		  break;
1230		}
1231	      if (TYPE_MAIN_VARIANT (TREE_VALUE (parm)) == void_type_node
1232		  || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node)
1233		{
1234		  error_with_decl (newdecl,
1235				   "prototype for `%s' follows and number of arguments doesn't match");
1236		  error_with_decl (olddecl, "non-prototype definition here");
1237		  errmsg = 1;
1238		  break;
1239		}
1240	      /* Type for passing arg must be consistent
1241		 with that declared for the arg.  */
1242	      if (! comptypes (TREE_VALUE (parm), TREE_VALUE (type)))
1243		{
1244		  error_with_decl (newdecl,
1245				   "prototype for `%s' follows and argument %d doesn't match",
1246				   nargs);
1247		  error_with_decl (olddecl, "non-prototype definition here");
1248		  errmsg = 1;
1249		  break;
1250		}
1251	    }
1252	}
1253      /* Warn about mismatches in various flags.  */
1254      else
1255	{
1256	  /* Warn if function is now inline
1257	     but was previously declared not inline and has been called.  */
1258	  if (TREE_CODE (olddecl) == FUNCTION_DECL
1259	      && ! DECL_DECLARED_INLINE_P (olddecl)
1260	      && DECL_DECLARED_INLINE_P (newdecl)
1261	      && TREE_USED (olddecl))
1262	    warning_with_decl (newdecl,
1263			       "`%s' declared inline after being called");
1264	  if (TREE_CODE (olddecl) == FUNCTION_DECL
1265	      && ! DECL_DECLARED_INLINE_P (olddecl)
1266	      && DECL_DECLARED_INLINE_P (newdecl)
1267	      && DECL_INITIAL (olddecl) != 0)
1268	    warning_with_decl (newdecl,
1269			       "`%s' declared inline after its definition");
1270
1271	  /* If pedantic, warn when static declaration follows a non-static
1272	     declaration.  Otherwise, do so only for functions.  */
1273	  if ((pedantic || TREE_CODE (olddecl) == FUNCTION_DECL)
1274	      && TREE_PUBLIC (olddecl)
1275	      && !TREE_PUBLIC (newdecl))
1276	    warning_with_decl (newdecl, "static declaration for `%s' follows non-static");
1277
1278	  /* If warn_traditional, warn when a non-static function
1279	     declaration follows a static one.  */
1280	  if (warn_traditional && !in_system_header
1281	      && TREE_CODE (olddecl) == FUNCTION_DECL
1282	      && !TREE_PUBLIC (olddecl)
1283	      && TREE_PUBLIC (newdecl))
1284	    warning_with_decl (newdecl, "non-static declaration for `%s' follows static");
1285
1286	  /* Warn when const declaration follows a non-const
1287	     declaration, but not for functions.  */
1288	  if (TREE_CODE (olddecl) != FUNCTION_DECL
1289	      && !TREE_READONLY (olddecl)
1290	      && TREE_READONLY (newdecl))
1291	    warning_with_decl (newdecl, "const declaration for `%s' follows non-const");
1292	  /* These bits are logically part of the type, for variables.
1293	     But not for functions
1294	     (where qualifiers are not valid ANSI anyway).  */
1295	  else if (pedantic && TREE_CODE (olddecl) != FUNCTION_DECL
1296	      && (TREE_READONLY (newdecl) != TREE_READONLY (olddecl)
1297		  || TREE_THIS_VOLATILE (newdecl) != TREE_THIS_VOLATILE (olddecl)))
1298	    pedwarn_with_decl (newdecl, "type qualifiers for `%s' conflict with previous decl");
1299	}
1300    }
1301
1302  /* Optionally warn about more than one declaration for the same name.  */
1303  if (errmsg == 0 && warn_redundant_decls && DECL_SOURCE_LINE (olddecl) != 0
1304      /* Don't warn about a function declaration
1305	 followed by a definition.  */
1306      && !(TREE_CODE (newdecl) == FUNCTION_DECL && DECL_INITIAL (newdecl) != 0
1307	   && DECL_INITIAL (olddecl) == 0)
1308      /* Don't warn about extern decl followed by (tentative) definition.  */
1309      && !(DECL_EXTERNAL (olddecl) && ! DECL_EXTERNAL (newdecl)))
1310    {
1311      warning_with_decl (newdecl, "redundant redeclaration of `%s' in same scope");
1312      warning_with_decl (olddecl, "previous declaration of `%s'");
1313    }
1314
1315  /* Copy all the DECL_... slots specified in the new decl
1316     except for any that we copy here from the old type.
1317
1318     Past this point, we don't change OLDTYPE and NEWTYPE
1319     even if we change the types of NEWDECL and OLDDECL.  */
1320
1321  if (types_match)
1322    {
1323      /* When copying info to olddecl, we store into write_olddecl
1324	 instead.  This allows us to avoid modifying olddecl when
1325	 different_binding_level is true.  */
1326      tree write_olddecl = different_binding_level ? newdecl : olddecl;
1327
1328      /* Merge the data types specified in the two decls.  */
1329      if (TREE_CODE (newdecl) != FUNCTION_DECL || !DECL_BUILT_IN (olddecl))
1330	{
1331	  if (different_binding_level)
1332	    {
1333	      if (TYPE_ARG_TYPES (oldtype) != 0
1334		  && TYPE_ARG_TYPES (newtype) == 0)
1335		TREE_TYPE (newdecl) = common_type (newtype, oldtype);
1336	      else
1337		TREE_TYPE (newdecl)
1338		  = build_type_attribute_variant
1339		    (newtype,
1340		     merge_attributes (TYPE_ATTRIBUTES (newtype),
1341				       TYPE_ATTRIBUTES (oldtype)));
1342	    }
1343	  else
1344	    TREE_TYPE (newdecl)
1345	      = TREE_TYPE (olddecl)
1346		= common_type (newtype, oldtype);
1347	}
1348
1349      /* Lay the type out, unless already done.  */
1350      if (oldtype != TREE_TYPE (newdecl))
1351	{
1352	  if (TREE_TYPE (newdecl) != error_mark_node)
1353	    layout_type (TREE_TYPE (newdecl));
1354	  if (TREE_CODE (newdecl) != FUNCTION_DECL
1355	      && TREE_CODE (newdecl) != TYPE_DECL
1356	      && TREE_CODE (newdecl) != CONST_DECL)
1357	    layout_decl (newdecl, 0);
1358	}
1359      else
1360	{
1361	  /* Since the type is OLDDECL's, make OLDDECL's size go with.  */
1362	  DECL_SIZE (newdecl) = DECL_SIZE (olddecl);
1363	  DECL_SIZE_UNIT (newdecl) = DECL_SIZE_UNIT (olddecl);
1364	  DECL_MODE (newdecl) = DECL_MODE (olddecl);
1365	  if (TREE_CODE (olddecl) != FUNCTION_DECL)
1366	    if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl))
1367	      {
1368		DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl);
1369		DECL_USER_ALIGN (newdecl) |= DECL_ALIGN (olddecl);
1370	      }
1371	}
1372
1373      /* Keep the old rtl since we can safely use it.  */
1374      COPY_DECL_RTL (olddecl, newdecl);
1375
1376      /* Merge the type qualifiers.  */
1377      if (TREE_READONLY (newdecl))
1378	TREE_READONLY (write_olddecl) = 1;
1379
1380      if (TREE_THIS_VOLATILE (newdecl))
1381	{
1382	  TREE_THIS_VOLATILE (write_olddecl) = 1;
1383	  if (TREE_CODE (newdecl) == VAR_DECL
1384	      /* If an automatic variable is re-declared in the same
1385		 function scope, but the old declaration was not
1386		 volatile, make_var_volatile() would crash because the
1387		 variable would have been assigned to a pseudo, not a
1388		 MEM.  Since this duplicate declaration is invalid
1389		 anyway, we just skip the call.  */
1390	      && errmsg == 0)
1391	    make_var_volatile (newdecl);
1392	}
1393
1394      /* Keep source location of definition rather than declaration.  */
1395      /* When called with different_binding_level set, keep the old
1396	 information so that meaningful diagnostics can be given.  */
1397      if (DECL_INITIAL (newdecl) == 0 && DECL_INITIAL (olddecl) != 0
1398	  && ! different_binding_level)
1399	{
1400	  DECL_SOURCE_LINE (newdecl) = DECL_SOURCE_LINE (olddecl);
1401	  DECL_SOURCE_FILE (newdecl) = DECL_SOURCE_FILE (olddecl);
1402	}
1403
1404      /* Merge the unused-warning information.  */
1405      if (DECL_IN_SYSTEM_HEADER (olddecl))
1406	DECL_IN_SYSTEM_HEADER (newdecl) = 1;
1407      else if (DECL_IN_SYSTEM_HEADER (newdecl))
1408	DECL_IN_SYSTEM_HEADER (write_olddecl) = 1;
1409
1410      /* Merge the initialization information.  */
1411      /* When called with different_binding_level set, don't copy over
1412	 DECL_INITIAL, so that we don't accidentally change function
1413	 declarations into function definitions.  */
1414      if (DECL_INITIAL (newdecl) == 0 && ! different_binding_level)
1415	DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
1416
1417      /* Merge the section attribute.
1418         We want to issue an error if the sections conflict but that must be
1419	 done later in decl_attributes since we are called before attributes
1420	 are assigned.  */
1421      if (DECL_SECTION_NAME (newdecl) == NULL_TREE)
1422	DECL_SECTION_NAME (newdecl) = DECL_SECTION_NAME (olddecl);
1423
1424      /* Copy the assembler name.
1425	 Currently, it can only be defined in the prototype.  */
1426      COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl);
1427
1428      if (TREE_CODE (newdecl) == FUNCTION_DECL)
1429	{
1430	  DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl);
1431	  DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl);
1432	  DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl);
1433	  DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl)
1434	    |= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl);
1435	}
1436    }
1437  /* If cannot merge, then use the new type and qualifiers,
1438     and don't preserve the old rtl.  */
1439  else if (! different_binding_level)
1440    {
1441      TREE_TYPE (olddecl) = TREE_TYPE (newdecl);
1442      TREE_READONLY (olddecl) = TREE_READONLY (newdecl);
1443      TREE_THIS_VOLATILE (olddecl) = TREE_THIS_VOLATILE (newdecl);
1444      TREE_SIDE_EFFECTS (olddecl) = TREE_SIDE_EFFECTS (newdecl);
1445    }
1446
1447  /* Merge the storage class information.  */
1448  merge_weak (newdecl, olddecl);
1449
1450  /* For functions, static overrides non-static.  */
1451  if (TREE_CODE (newdecl) == FUNCTION_DECL)
1452    {
1453      TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl);
1454      /* This is since we don't automatically
1455	 copy the attributes of NEWDECL into OLDDECL.  */
1456      /* No need to worry about different_binding_level here because
1457	 then TREE_PUBLIC (newdecl) was true.  */
1458      TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
1459      /* If this clears `static', clear it in the identifier too.  */
1460      if (! TREE_PUBLIC (olddecl))
1461	TREE_PUBLIC (DECL_NAME (olddecl)) = 0;
1462    }
1463  if (DECL_EXTERNAL (newdecl))
1464    {
1465      if (! different_binding_level)
1466	{
1467	  /* Don't mess with these flags on local externs; they remain
1468	     external even if there's a declaration at file scope which
1469	     isn't.  */
1470	  TREE_STATIC (newdecl) = TREE_STATIC (olddecl);
1471	  DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl);
1472	}
1473      /* An extern decl does not override previous storage class.  */
1474      TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl);
1475      if (! DECL_EXTERNAL (newdecl))
1476	DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl);
1477    }
1478  else
1479    {
1480      TREE_STATIC (olddecl) = TREE_STATIC (newdecl);
1481      TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
1482    }
1483
1484  if (TREE_CODE (newdecl) == FUNCTION_DECL)
1485    {
1486      /* If we're redefining a function previously defined as extern
1487	 inline, make sure we emit debug info for the inline before we
1488	 throw it away, in case it was inlined into a function that hasn't
1489	 been written out yet.  */
1490      if (new_is_definition && DECL_INITIAL (olddecl))
1491	{
1492	  if (TREE_USED (olddecl))
1493	    (*debug_hooks->outlining_inline_function) (olddecl);
1494
1495	  /* The new defn must not be inline.  */
1496	  DECL_INLINE (newdecl) = 0;
1497	  DECL_UNINLINABLE (newdecl) = 1;
1498	}
1499      else
1500	{
1501	  /* If either decl says `inline', this fn is inline,
1502	     unless its definition was passed already.  */
1503	  if (DECL_DECLARED_INLINE_P (newdecl)
1504	      || DECL_DECLARED_INLINE_P (olddecl))
1505	    DECL_DECLARED_INLINE_P (newdecl) = 1;
1506
1507	  DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl)
1508	    = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl));
1509	}
1510
1511      if (DECL_BUILT_IN (olddecl))
1512	{
1513	  /* Get rid of any built-in function if new arg types don't match it
1514	     or if we have a function definition.  */
1515	  if (! types_match || new_is_definition)
1516	    {
1517	      if (! different_binding_level)
1518		{
1519		  TREE_TYPE (olddecl) = TREE_TYPE (newdecl);
1520		  DECL_BUILT_IN_CLASS (olddecl) = NOT_BUILT_IN;
1521		}
1522	    }
1523	  else
1524	    {
1525	      /* If redeclaring a builtin function, and not a definition,
1526		 it stays built in.  */
1527	      DECL_BUILT_IN_CLASS (newdecl) = DECL_BUILT_IN_CLASS (olddecl);
1528	      DECL_FUNCTION_CODE (newdecl) = DECL_FUNCTION_CODE (olddecl);
1529	    }
1530	}
1531
1532      /* Also preserve various other info from the definition.  */
1533      if (! new_is_definition)
1534	{
1535	  DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
1536	  /* When called with different_binding_level set, don't copy over
1537	     DECL_INITIAL, so that we don't accidentally change function
1538	     declarations into function definitions.  */
1539	  if (! different_binding_level)
1540	    DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
1541	  DECL_SAVED_INSNS (newdecl) = DECL_SAVED_INSNS (olddecl);
1542	  DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl);
1543	  DECL_NUM_STMTS (newdecl) = DECL_NUM_STMTS (olddecl);
1544	  DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl);
1545
1546	  /* Set DECL_INLINE on the declaration if we've got a body
1547	     from which to instantiate.  */
1548	  if (DECL_INLINE (olddecl) && ! DECL_UNINLINABLE (newdecl))
1549	    {
1550	      DECL_INLINE (newdecl) = 1;
1551	      DECL_ABSTRACT_ORIGIN (newdecl)
1552		= (different_binding_level
1553		   ? DECL_ORIGIN (olddecl)
1554		   : DECL_ABSTRACT_ORIGIN (olddecl));
1555	    }
1556	}
1557      else
1558	{
1559	  /* If a previous declaration said inline, mark the
1560	     definition as inlinable.  */
1561	  if (DECL_DECLARED_INLINE_P (newdecl)
1562	      && ! DECL_UNINLINABLE (newdecl))
1563	    DECL_INLINE (newdecl) = 1;
1564	}
1565    }
1566  if (different_binding_level)
1567    return 0;
1568
1569  /* Copy most of the decl-specific fields of NEWDECL into OLDDECL.
1570     But preserve OLDDECL's DECL_UID.  */
1571  {
1572    unsigned olddecl_uid = DECL_UID (olddecl);
1573
1574    memcpy ((char *) olddecl + sizeof (struct tree_common),
1575	    (char *) newdecl + sizeof (struct tree_common),
1576	    sizeof (struct tree_decl) - sizeof (struct tree_common));
1577    DECL_UID (olddecl) = olddecl_uid;
1578  }
1579
1580  /* NEWDECL contains the merged attribute lists.
1581     Update OLDDECL to be the same.  */
1582  DECL_ATTRIBUTES (olddecl) = DECL_ATTRIBUTES (newdecl);
1583
1584 /* If OLDDECL had its DECL_RTL instantiated, re-invoke make_decl_rtl
1585     so that encode_section_info has a chance to look at the new decl
1586     flags and attributes.  */
1587  if (DECL_RTL_SET_P (olddecl)
1588      && (TREE_CODE (olddecl) == FUNCTION_DECL
1589	  || (TREE_CODE (olddecl) == VAR_DECL
1590	      && TREE_STATIC (olddecl))))
1591    make_decl_rtl (olddecl, NULL);
1592
1593  return 1;
1594}
1595
1596/* Check whether decl-node X shadows an existing declaration.
1597   OLDLOCAL is the old IDENTIFIER_LOCAL_VALUE of the DECL_NAME of X,
1598   which might be a NULL_TREE.  */
1599static void
1600warn_if_shadowing (x, oldlocal)
1601     tree x, oldlocal;
1602{
1603  tree name;
1604
1605  if (DECL_EXTERNAL (x))
1606    return;
1607
1608  name = DECL_NAME (x);
1609
1610  /* Warn if shadowing an argument at the top level of the body.  */
1611  if (oldlocal != 0
1612      /* This warning doesn't apply to the parms of a nested fcn.  */
1613      && ! current_binding_level->parm_flag
1614      /* Check that this is one level down from the parms.  */
1615      && current_binding_level->level_chain->parm_flag
1616      /* Check that the decl being shadowed
1617	 comes from the parm level, one level up.  */
1618      && chain_member (oldlocal, current_binding_level->level_chain->names))
1619    {
1620      if (TREE_CODE (oldlocal) == PARM_DECL)
1621	pedwarn ("declaration of `%s' shadows a parameter",
1622		 IDENTIFIER_POINTER (name));
1623      else
1624	pedwarn ("declaration of `%s' shadows a symbol from the parameter list",
1625		 IDENTIFIER_POINTER (name));
1626    }
1627  /* Maybe warn if shadowing something else.  */
1628  else if (warn_shadow
1629	   /* No shadow warnings for internally generated vars.  */
1630	   && DECL_SOURCE_LINE (x) != 0
1631	   /* No shadow warnings for vars made for inlining.  */
1632	   && ! DECL_FROM_INLINE (x))
1633    {
1634      if (TREE_CODE (x) == PARM_DECL
1635	  && current_binding_level->level_chain->parm_flag)
1636	/* Don't warn about the parm names in function declarator
1637	   within a function declarator.
1638	   It would be nice to avoid warning in any function
1639	   declarator in a declaration, as opposed to a definition,
1640	   but there is no way to tell it's not a definition.  */
1641	;
1642      else if (oldlocal)
1643	{
1644	  if (TREE_CODE (oldlocal) == PARM_DECL)
1645	    shadow_warning ("a parameter", name, oldlocal);
1646	  else
1647	    shadow_warning ("a previous local", name, oldlocal);
1648	}
1649      else if (IDENTIFIER_GLOBAL_VALUE (name) != 0
1650	       && IDENTIFIER_GLOBAL_VALUE (name) != error_mark_node)
1651	shadow_warning ("a global declaration", name,
1652			IDENTIFIER_GLOBAL_VALUE (name));
1653    }
1654}
1655
1656/* Record a decl-node X as belonging to the current lexical scope.
1657   Check for errors (such as an incompatible declaration for the same
1658   name already seen in the same scope).
1659
1660   Returns either X or an old decl for the same name.
1661   If an old decl is returned, it may have been smashed
1662   to agree with what X says.  */
1663
1664tree
1665pushdecl (x)
1666     tree x;
1667{
1668  tree t;
1669  tree name = DECL_NAME (x);
1670  struct binding_level *b = current_binding_level;
1671
1672  /* Functions need the lang_decl data.  */
1673  if (TREE_CODE (x) == FUNCTION_DECL && ! DECL_LANG_SPECIFIC (x))
1674    DECL_LANG_SPECIFIC (x) = (struct lang_decl *)
1675      ggc_alloc_cleared (sizeof (struct lang_decl));
1676
1677  DECL_CONTEXT (x) = current_function_decl;
1678  /* A local extern declaration for a function doesn't constitute nesting.
1679     A local auto declaration does, since it's a forward decl
1680     for a nested function coming later.  */
1681  if ((TREE_CODE (x) == FUNCTION_DECL || TREE_CODE (x) == VAR_DECL)
1682      && DECL_INITIAL (x) == 0 && DECL_EXTERNAL (x))
1683    DECL_CONTEXT (x) = 0;
1684
1685  if (name)
1686    {
1687      int different_binding_level = 0;
1688
1689      if (warn_nested_externs
1690	  && DECL_EXTERNAL (x)
1691	  && b != global_binding_level
1692	  && x != IDENTIFIER_IMPLICIT_DECL (name)
1693	  /* No error messages for __FUNCTION__ and __PRETTY_FUNCTION__.  */
1694	  && !DECL_IN_SYSTEM_HEADER (x))
1695	warning ("nested extern declaration of `%s'",
1696		 IDENTIFIER_POINTER (name));
1697
1698      t = lookup_name_current_level (name);
1699      if (! t && DECL_EXTERNAL (x) && TREE_PUBLIC (x))
1700	{
1701	  t = IDENTIFIER_GLOBAL_VALUE (name);
1702	  /* Type decls at global scope don't conflict with externs declared
1703	     inside lexical blocks.  */
1704	  if (! t || TREE_CODE (t) == TYPE_DECL)
1705	    /* If there's no visible global declaration, try for an
1706               invisible one.  */
1707	    t = IDENTIFIER_LIMBO_VALUE (name);
1708	  different_binding_level = 1;
1709	}
1710      if (t != 0 && t == error_mark_node)
1711	/* error_mark_node is 0 for a while during initialization!  */
1712	{
1713	  t = 0;
1714	  error_with_decl (x, "`%s' used prior to declaration");
1715	}
1716
1717      /* If this decl is `static' and an implicit decl was seen previously,
1718	 warn.  */
1719      if (TREE_PUBLIC (name)
1720	  /* Don't test for DECL_EXTERNAL, because grokdeclarator
1721	     sets this for all functions.  */
1722	  && ! TREE_PUBLIC (x)
1723	  && (TREE_CODE (x) == FUNCTION_DECL || b == global_binding_level)
1724	  /* We used to warn also for explicit extern followed by static,
1725	     but sometimes you need to do it that way.  */
1726	  && IDENTIFIER_IMPLICIT_DECL (name) != 0)
1727	{
1728	  pedwarn ("`%s' was declared implicitly `extern' and later `static'",
1729		   IDENTIFIER_POINTER (name));
1730	  pedwarn_with_file_and_line
1731	    (DECL_SOURCE_FILE (IDENTIFIER_IMPLICIT_DECL (name)),
1732	     DECL_SOURCE_LINE (IDENTIFIER_IMPLICIT_DECL (name)),
1733	     "previous declaration of `%s'",
1734	     IDENTIFIER_POINTER (name));
1735	  TREE_THIS_VOLATILE (name) = 1;
1736	}
1737
1738      if (t != 0 && duplicate_decls (x, t, different_binding_level))
1739	{
1740	  if (TREE_CODE (t) == PARM_DECL)
1741	    {
1742	      /* Don't allow more than one "real" duplicate
1743		 of a forward parm decl.  */
1744	      TREE_ASM_WRITTEN (t) = TREE_ASM_WRITTEN (x);
1745	      return t;
1746	    }
1747	  return t;
1748	}
1749
1750      /* If we are processing a typedef statement, generate a whole new
1751	 ..._TYPE node (which will be just a variant of the existing
1752	 ..._TYPE node with identical properties) and then install the
1753	 TYPE_DECL node generated to represent the typedef name as the
1754	 TYPE_NAME of this brand new (duplicate) ..._TYPE node.
1755
1756	 The whole point here is to end up with a situation where each
1757	 and every ..._TYPE node the compiler creates will be uniquely
1758	 associated with AT MOST one node representing a typedef name.
1759	 This way, even though the compiler substitutes corresponding
1760	 ..._TYPE nodes for TYPE_DECL (i.e. "typedef name") nodes very
1761	 early on, later parts of the compiler can always do the reverse
1762	 translation and get back the corresponding typedef name.  For
1763	 example, given:
1764
1765		typedef struct S MY_TYPE;
1766		MY_TYPE object;
1767
1768	 Later parts of the compiler might only know that `object' was of
1769	 type `struct S' if it were not for code just below.  With this
1770	 code however, later parts of the compiler see something like:
1771
1772		struct S' == struct S
1773		typedef struct S' MY_TYPE;
1774		struct S' object;
1775
1776	 And they can then deduce (from the node for type struct S') that
1777	 the original object declaration was:
1778
1779		MY_TYPE object;
1780
1781	 Being able to do this is important for proper support of protoize,
1782	 and also for generating precise symbolic debugging information
1783	 which takes full account of the programmer's (typedef) vocabulary.
1784
1785         Obviously, we don't want to generate a duplicate ..._TYPE node if
1786	 the TYPE_DECL node that we are now processing really represents a
1787	 standard built-in type.
1788
1789         Since all standard types are effectively declared at line zero
1790         in the source file, we can easily check to see if we are working
1791         on a standard type by checking the current value of lineno.  */
1792
1793      if (TREE_CODE (x) == TYPE_DECL)
1794	{
1795	  if (DECL_SOURCE_LINE (x) == 0)
1796	    {
1797	      if (TYPE_NAME (TREE_TYPE (x)) == 0)
1798		TYPE_NAME (TREE_TYPE (x)) = x;
1799	    }
1800	  else if (TREE_TYPE (x) != error_mark_node
1801		   && DECL_ORIGINAL_TYPE (x) == NULL_TREE)
1802	    {
1803	      tree tt = TREE_TYPE (x);
1804	      DECL_ORIGINAL_TYPE (x) = tt;
1805	      tt = build_type_copy (tt);
1806	      TYPE_NAME (tt) = x;
1807	      TREE_USED (tt) = TREE_USED (x);
1808	      TREE_TYPE (x) = tt;
1809	    }
1810	}
1811
1812      /* Multiple external decls of the same identifier ought to match.
1813	 We get warnings about inline functions where they are defined.
1814	 Avoid duplicate warnings where they are used.  */
1815      if (TREE_PUBLIC (x)
1816	  && ! (TREE_CODE (x) == FUNCTION_DECL && DECL_INLINE (x)))
1817	{
1818	  tree decl;
1819
1820	  if (IDENTIFIER_LIMBO_VALUE (name) != 0)
1821	    /* Decls in limbo are always extern, so no need to check that.  */
1822	    decl = IDENTIFIER_LIMBO_VALUE (name);
1823	  else
1824	    decl = 0;
1825
1826	  if (decl && ! comptypes (TREE_TYPE (x), TREE_TYPE (decl))
1827	      /* If old decl is built-in, we already warned if we should.  */
1828	      && !DECL_BUILT_IN (decl))
1829	    {
1830	      pedwarn_with_decl (x,
1831				 "type mismatch with previous external decl");
1832	      pedwarn_with_decl (decl, "previous external decl of `%s'");
1833	    }
1834	}
1835
1836      /* If a function has had an implicit declaration, and then is defined,
1837	 make sure they are compatible.  */
1838
1839      if (IDENTIFIER_IMPLICIT_DECL (name) != 0
1840	  && IDENTIFIER_GLOBAL_VALUE (name) == 0
1841	  && TREE_CODE (x) == FUNCTION_DECL
1842	  && ! comptypes (TREE_TYPE (x),
1843			  TREE_TYPE (IDENTIFIER_IMPLICIT_DECL (name))))
1844	{
1845	  warning_with_decl (x, "type mismatch with previous implicit declaration");
1846	  warning_with_decl (IDENTIFIER_IMPLICIT_DECL (name),
1847			     "previous implicit declaration of `%s'");
1848	}
1849
1850      /* This name is new in its binding level.
1851	 Install the new declaration and return it.  */
1852      if (b == global_binding_level)
1853	{
1854	  /* Install a global value.  */
1855
1856	  /* If the first global decl has external linkage,
1857	     warn if we later see static one.  */
1858	  if (IDENTIFIER_GLOBAL_VALUE (name) == 0 && TREE_PUBLIC (x))
1859	    TREE_PUBLIC (name) = 1;
1860
1861	  IDENTIFIER_GLOBAL_VALUE (name) = x;
1862
1863	  /* We no longer care about any previous block level declarations.  */
1864	  IDENTIFIER_LIMBO_VALUE (name) = 0;
1865
1866	  /* Don't forget if the function was used via an implicit decl.  */
1867	  if (IDENTIFIER_IMPLICIT_DECL (name)
1868	      && TREE_USED (IDENTIFIER_IMPLICIT_DECL (name)))
1869	    TREE_USED (x) = 1, TREE_USED (name) = 1;
1870
1871	  /* Don't forget if its address was taken in that way.  */
1872	  if (IDENTIFIER_IMPLICIT_DECL (name)
1873	      && TREE_ADDRESSABLE (IDENTIFIER_IMPLICIT_DECL (name)))
1874	    TREE_ADDRESSABLE (x) = 1;
1875
1876	  /* Warn about mismatches against previous implicit decl.  */
1877	  if (IDENTIFIER_IMPLICIT_DECL (name) != 0
1878	      /* If this real decl matches the implicit, don't complain.  */
1879	      && ! (TREE_CODE (x) == FUNCTION_DECL
1880		    && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (x)))
1881			== integer_type_node)))
1882	    pedwarn ("`%s' was previously implicitly declared to return `int'",
1883		     IDENTIFIER_POINTER (name));
1884
1885	  /* If this decl is `static' and an `extern' was seen previously,
1886	     that is erroneous.  */
1887	  if (TREE_PUBLIC (name)
1888	      && ! TREE_PUBLIC (x) && ! DECL_EXTERNAL (x))
1889	    {
1890	      /* Okay to redeclare an ANSI built-in as static.  */
1891	      if (t != 0 && DECL_BUILT_IN (t))
1892		;
1893	      /* Okay to declare a non-ANSI built-in as anything.  */
1894	      else if (t != 0 && DECL_BUILT_IN_NONANSI (t))
1895		;
1896	      /* Okay to have global type decl after an earlier extern
1897		 declaration inside a lexical block.  */
1898	      else if (TREE_CODE (x) == TYPE_DECL)
1899		;
1900	      else if (IDENTIFIER_IMPLICIT_DECL (name))
1901		{
1902		  if (! TREE_THIS_VOLATILE (name))
1903		    pedwarn ("`%s' was declared implicitly `extern' and later `static'",
1904			     IDENTIFIER_POINTER (name));
1905		}
1906	      else
1907		pedwarn ("`%s' was declared `extern' and later `static'",
1908			 IDENTIFIER_POINTER (name));
1909	    }
1910	}
1911      else
1912	{
1913	  /* Here to install a non-global value.  */
1914	  tree oldlocal = IDENTIFIER_LOCAL_VALUE (name);
1915	  tree oldglobal = IDENTIFIER_GLOBAL_VALUE (name);
1916
1917	  IDENTIFIER_LOCAL_VALUE (name) = x;
1918
1919	  /* If this is an extern function declaration, see if we
1920	     have a global definition or declaration for the function.  */
1921	  if (oldlocal == 0
1922	      && oldglobal != 0
1923	      && TREE_CODE (x) == FUNCTION_DECL
1924	      && TREE_CODE (oldglobal) == FUNCTION_DECL
1925	      && DECL_EXTERNAL (x)
1926	      && ! DECL_DECLARED_INLINE_P (x))
1927	    {
1928	      /* We have one.  Their types must agree.  */
1929	      if (! comptypes (TREE_TYPE (x),
1930			       TREE_TYPE (IDENTIFIER_GLOBAL_VALUE (name))))
1931		pedwarn_with_decl (x, "extern declaration of `%s' doesn't match global one");
1932	      else
1933		{
1934		  /* Inner extern decl is inline if global one is.
1935		     Copy enough to really inline it.  */
1936		  if (DECL_DECLARED_INLINE_P (oldglobal))
1937		    {
1938		      DECL_DECLARED_INLINE_P (x)
1939		        = DECL_DECLARED_INLINE_P (oldglobal);
1940		      DECL_INLINE (x) = DECL_INLINE (oldglobal);
1941		      DECL_INITIAL (x) = (current_function_decl == oldglobal
1942					  ? 0 : DECL_INITIAL (oldglobal));
1943		      DECL_SAVED_INSNS (x) = DECL_SAVED_INSNS (oldglobal);
1944		      DECL_NUM_STMTS (x) = DECL_NUM_STMTS (oldglobal);
1945		      DECL_ARGUMENTS (x) = DECL_ARGUMENTS (oldglobal);
1946		      DECL_RESULT (x) = DECL_RESULT (oldglobal);
1947		      TREE_ASM_WRITTEN (x) = TREE_ASM_WRITTEN (oldglobal);
1948		      DECL_ABSTRACT_ORIGIN (x)
1949			= DECL_ABSTRACT_ORIGIN (oldglobal);
1950		    }
1951		  /* Inner extern decl is built-in if global one is.  */
1952		  if (DECL_BUILT_IN (oldglobal))
1953		    {
1954		      DECL_BUILT_IN_CLASS (x) = DECL_BUILT_IN_CLASS (oldglobal);
1955		      DECL_FUNCTION_CODE (x) = DECL_FUNCTION_CODE (oldglobal);
1956		    }
1957		  /* Keep the arg types from a file-scope fcn defn.  */
1958		  if (TYPE_ARG_TYPES (TREE_TYPE (oldglobal)) != 0
1959		      && DECL_INITIAL (oldglobal)
1960		      && TYPE_ARG_TYPES (TREE_TYPE (x)) == 0)
1961		    TREE_TYPE (x) = TREE_TYPE (oldglobal);
1962		}
1963	    }
1964
1965#if 0
1966	  /* This case is probably sometimes the right thing to do.  */
1967	  /* If we have a local external declaration,
1968	     then any file-scope declaration should not
1969	     have been static.  */
1970	  if (oldlocal == 0 && oldglobal != 0
1971	      && !TREE_PUBLIC (oldglobal)
1972	      && DECL_EXTERNAL (x) && TREE_PUBLIC (x))
1973	    warning ("`%s' locally external but globally static",
1974		     IDENTIFIER_POINTER (name));
1975#endif
1976
1977	  /* If we have a local external declaration,
1978	     and no file-scope declaration has yet been seen,
1979	     then if we later have a file-scope decl it must not be static.  */
1980	  if (oldlocal == 0
1981	      && DECL_EXTERNAL (x)
1982	      && TREE_PUBLIC (x))
1983	    {
1984	      if (oldglobal == 0)
1985		TREE_PUBLIC (name) = 1;
1986
1987	      /* Save this decl, so that we can do type checking against
1988		 other decls after it falls out of scope.
1989
1990		 Only save it once.  This prevents temporary decls created in
1991		 expand_inline_function from being used here, since this
1992		 will have been set when the inline function was parsed.
1993		 It also helps give slightly better warnings.  */
1994	      if (IDENTIFIER_LIMBO_VALUE (name) == 0)
1995		IDENTIFIER_LIMBO_VALUE (name) = x;
1996	    }
1997
1998	  warn_if_shadowing (x, oldlocal);
1999
2000	  /* If storing a local value, there may already be one (inherited).
2001	     If so, record it for restoration when this binding level ends.  */
2002	  if (oldlocal != 0)
2003	    b->shadowed = tree_cons (name, oldlocal, b->shadowed);
2004	}
2005
2006      /* Keep list of variables in this level with incomplete type.
2007	 If the input is erroneous, we can have error_mark in the type
2008	 slot (e.g. "f(void a, ...)") - that doesn't count as an
2009	 incomplete type.  */
2010      if (TREE_TYPE (x) != error_mark_node
2011	  && !COMPLETE_TYPE_P (TREE_TYPE (x)))
2012	{
2013	  tree element = TREE_TYPE (x);
2014
2015	  while (TREE_CODE (element) == ARRAY_TYPE)
2016	    element = TREE_TYPE (element);
2017	  if ((TREE_CODE (element) == RECORD_TYPE
2018	       || TREE_CODE (element) == UNION_TYPE)
2019	      && (TREE_CODE (x) != TYPE_DECL
2020		  || TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE))
2021	    b->incomplete_list = tree_cons (NULL_TREE, x, b->incomplete_list);
2022	}
2023    }
2024
2025  /* Put decls on list in reverse order.
2026     We will reverse them later if necessary.  */
2027  TREE_CHAIN (x) = b->names;
2028  b->names = x;
2029
2030  return x;
2031}
2032
2033/* Like pushdecl, only it places X in GLOBAL_BINDING_LEVEL, if appropriate.  */
2034
2035tree
2036pushdecl_top_level (x)
2037     tree x;
2038{
2039  tree t;
2040  struct binding_level *b = current_binding_level;
2041
2042  current_binding_level = global_binding_level;
2043  t = pushdecl (x);
2044  current_binding_level = b;
2045  return t;
2046}
2047
2048/* Generate an implicit declaration for identifier FUNCTIONID
2049   as a function of type int ().  Print a warning if appropriate.  */
2050
2051tree
2052implicitly_declare (functionid)
2053     tree functionid;
2054{
2055  tree decl;
2056  int traditional_warning = 0;
2057  /* Only one "implicit declaration" warning per identifier.  */
2058  int implicit_warning;
2059
2060  /* We used to reuse an old implicit decl here,
2061     but this loses with inline functions because it can clobber
2062     the saved decl chains.  */
2063#if 0
2064  if (IDENTIFIER_IMPLICIT_DECL (functionid) != 0)
2065    decl = IDENTIFIER_IMPLICIT_DECL (functionid);
2066  else
2067#endif
2068    decl = build_decl (FUNCTION_DECL, functionid, default_function_type);
2069
2070  /* Warn of implicit decl following explicit local extern decl.
2071     This is probably a program designed for traditional C.  */
2072  if (TREE_PUBLIC (functionid) && IDENTIFIER_GLOBAL_VALUE (functionid) == 0)
2073    traditional_warning = 1;
2074
2075  /* Warn once of an implicit declaration.  */
2076  implicit_warning = (IDENTIFIER_IMPLICIT_DECL (functionid) == 0);
2077
2078  DECL_EXTERNAL (decl) = 1;
2079  TREE_PUBLIC (decl) = 1;
2080
2081  /* Record that we have an implicit decl and this is it.  */
2082  IDENTIFIER_IMPLICIT_DECL (functionid) = decl;
2083
2084  /* ANSI standard says implicit declarations are in the innermost block.
2085     So we record the decl in the standard fashion.  */
2086  pushdecl (decl);
2087
2088  /* This is a no-op in c-lang.c or something real in objc-act.c.  */
2089  if (flag_objc)
2090    objc_check_decl (decl);
2091
2092  rest_of_decl_compilation (decl, NULL, 0, 0);
2093
2094  if (implicit_warning)
2095    implicit_decl_warning (functionid);
2096  else if (warn_traditional && traditional_warning)
2097    warning ("function `%s' was previously declared within a block",
2098	     IDENTIFIER_POINTER (functionid));
2099
2100  /* Write a record describing this implicit function declaration to the
2101     prototypes file (if requested).  */
2102
2103  gen_aux_info_record (decl, 0, 1, 0);
2104
2105  /* Possibly apply some default attributes to this implicit declaration.  */
2106  decl_attributes (&decl, NULL_TREE, 0);
2107
2108  return decl;
2109}
2110
2111void
2112implicit_decl_warning (id)
2113     tree id;
2114{
2115  const char *name = IDENTIFIER_POINTER (id);
2116  if (mesg_implicit_function_declaration == 2)
2117    error ("implicit declaration of function `%s'", name);
2118  else if (mesg_implicit_function_declaration == 1)
2119    warning ("implicit declaration of function `%s'", name);
2120}
2121
2122/* Return zero if the declaration NEWDECL is valid
2123   when the declaration OLDDECL (assumed to be for the same name)
2124   has already been seen.
2125   Otherwise return 1 if NEWDECL is a redefinition, 2 if it is a redeclaration,
2126   and 3 if it is a conflicting declaration.  */
2127
2128static int
2129redeclaration_error_message (newdecl, olddecl)
2130     tree newdecl, olddecl;
2131{
2132  if (TREE_CODE (newdecl) == TYPE_DECL)
2133    {
2134      /* Do not complain about type redeclarations where at least one
2135	 declaration was in a system header.  */
2136      if (DECL_IN_SYSTEM_HEADER (olddecl) || DECL_IN_SYSTEM_HEADER (newdecl))
2137	return 0;
2138      return 1;
2139    }
2140  else if (TREE_CODE (newdecl) == FUNCTION_DECL)
2141    {
2142      /* Declarations of functions can insist on internal linkage
2143	 but they can't be inconsistent with internal linkage,
2144	 so there can be no error on that account.
2145	 However defining the same name twice is no good.  */
2146      if (DECL_INITIAL (olddecl) != 0 && DECL_INITIAL (newdecl) != 0
2147	  /* However, defining once as extern inline and a second
2148	     time in another way is ok.  */
2149	  && ! (DECL_DECLARED_INLINE_P (olddecl) && DECL_EXTERNAL (olddecl)
2150	       && ! (DECL_DECLARED_INLINE_P (newdecl)
2151		     && DECL_EXTERNAL (newdecl))))
2152	return 1;
2153      return 0;
2154    }
2155  else if (DECL_CONTEXT (newdecl) == NULL_TREE)
2156    {
2157      /* Objects declared at top level:  */
2158      /* If at least one is a reference, it's ok.  */
2159      if (DECL_EXTERNAL (newdecl) || DECL_EXTERNAL (olddecl))
2160	return 0;
2161      /* Reject two definitions.  */
2162      if (DECL_INITIAL (olddecl) != 0 && DECL_INITIAL (newdecl) != 0)
2163	return 1;
2164      /* Now we have two tentative defs, or one tentative and one real def.  */
2165      /* Insist that the linkage match.  */
2166      if (TREE_PUBLIC (olddecl) != TREE_PUBLIC (newdecl))
2167	return 3;
2168      return 0;
2169    }
2170  else if (current_binding_level->parm_flag
2171	   && TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl))
2172    return 0;
2173  else
2174    {
2175      /* Newdecl has block scope.  If olddecl has block scope also, then
2176	 reject two definitions, and reject a definition together with an
2177	 external reference.  Otherwise, it is OK, because newdecl must
2178	 be an extern reference to olddecl.  */
2179      if (!(DECL_EXTERNAL (newdecl) && DECL_EXTERNAL (olddecl))
2180	  && DECL_CONTEXT (newdecl) == DECL_CONTEXT (olddecl))
2181	return 2;
2182      return 0;
2183    }
2184}
2185
2186/* Get the LABEL_DECL corresponding to identifier ID as a label.
2187   Create one if none exists so far for the current function.
2188   This function is called for both label definitions and label references.  */
2189
2190tree
2191lookup_label (id)
2192     tree id;
2193{
2194  tree decl = IDENTIFIER_LABEL_VALUE (id);
2195
2196  if (current_function_decl == 0)
2197    {
2198      error ("label %s referenced outside of any function",
2199	     IDENTIFIER_POINTER (id));
2200      return 0;
2201    }
2202
2203  /* Use a label already defined or ref'd with this name.  */
2204  if (decl != 0)
2205    {
2206      /* But not if it is inherited and wasn't declared to be inheritable.  */
2207      if (DECL_CONTEXT (decl) != current_function_decl
2208	  && ! C_DECLARED_LABEL_FLAG (decl))
2209	return shadow_label (id);
2210      return decl;
2211    }
2212
2213  decl = build_decl (LABEL_DECL, id, void_type_node);
2214
2215  /* A label not explicitly declared must be local to where it's ref'd.  */
2216  DECL_CONTEXT (decl) = current_function_decl;
2217
2218  DECL_MODE (decl) = VOIDmode;
2219
2220  /* Say where one reference is to the label,
2221     for the sake of the error if it is not defined.  */
2222  DECL_SOURCE_LINE (decl) = lineno;
2223  DECL_SOURCE_FILE (decl) = input_filename;
2224
2225  IDENTIFIER_LABEL_VALUE (id) = decl;
2226
2227  named_labels = tree_cons (NULL_TREE, decl, named_labels);
2228
2229  return decl;
2230}
2231
2232/* Make a label named NAME in the current function,
2233   shadowing silently any that may be inherited from containing functions
2234   or containing scopes.
2235
2236   Note that valid use, if the label being shadowed
2237   comes from another scope in the same function,
2238   requires calling declare_nonlocal_label right away.  */
2239
2240tree
2241shadow_label (name)
2242     tree name;
2243{
2244  tree decl = IDENTIFIER_LABEL_VALUE (name);
2245
2246  if (decl != 0)
2247    {
2248      tree dup;
2249
2250      /* Check to make sure that the label hasn't already been declared
2251	 at this label scope */
2252      for (dup = named_labels; dup; dup = TREE_CHAIN (dup))
2253	if (TREE_VALUE (dup) == decl)
2254	  {
2255	    error ("duplicate label declaration `%s'",
2256		   IDENTIFIER_POINTER (name));
2257	    error_with_decl (TREE_VALUE (dup),
2258			     "this is a previous declaration");
2259	    /* Just use the previous declaration.  */
2260	    return lookup_label (name);
2261	  }
2262
2263      shadowed_labels = tree_cons (NULL_TREE, decl, shadowed_labels);
2264      IDENTIFIER_LABEL_VALUE (name) = decl = 0;
2265    }
2266
2267  return lookup_label (name);
2268}
2269
2270/* Define a label, specifying the location in the source file.
2271   Return the LABEL_DECL node for the label, if the definition is valid.
2272   Otherwise return 0.  */
2273
2274tree
2275define_label (filename, line, name)
2276     const char *filename;
2277     int line;
2278     tree name;
2279{
2280  tree decl = lookup_label (name);
2281
2282  /* If label with this name is known from an outer context, shadow it.  */
2283  if (decl != 0 && DECL_CONTEXT (decl) != current_function_decl)
2284    {
2285      shadowed_labels = tree_cons (NULL_TREE, decl, shadowed_labels);
2286      IDENTIFIER_LABEL_VALUE (name) = 0;
2287      decl = lookup_label (name);
2288    }
2289
2290  if (warn_traditional && !in_system_header && lookup_name (name))
2291    warning_with_file_and_line (filename, line,
2292				"traditional C lacks a separate namespace for labels, identifier `%s' conflicts",
2293				IDENTIFIER_POINTER (name));
2294
2295  if (DECL_INITIAL (decl) != 0)
2296    {
2297      error_with_file_and_line (filename, line, "duplicate label `%s'",
2298				IDENTIFIER_POINTER (name));
2299      return 0;
2300    }
2301  else
2302    {
2303      /* Mark label as having been defined.  */
2304      DECL_INITIAL (decl) = error_mark_node;
2305      /* Say where in the source.  */
2306      DECL_SOURCE_FILE (decl) = filename;
2307      DECL_SOURCE_LINE (decl) = line;
2308      return decl;
2309    }
2310}
2311
2312/* Return the list of declarations of the current level.
2313   Note that this list is in reverse order unless/until
2314   you nreverse it; and when you do nreverse it, you must
2315   store the result back using `storedecls' or you will lose.  */
2316
2317tree
2318getdecls ()
2319{
2320  return current_binding_level->names;
2321}
2322
2323/* Return the list of type-tags (for structs, etc) of the current level.  */
2324
2325tree
2326gettags ()
2327{
2328  return current_binding_level->tags;
2329}
2330
2331/* Store the list of declarations of the current level.
2332   This is done for the parameter declarations of a function being defined,
2333   after they are modified in the light of any missing parameters.  */
2334
2335static void
2336storedecls (decls)
2337     tree decls;
2338{
2339  current_binding_level->names = decls;
2340}
2341
2342/* Similarly, store the list of tags of the current level.  */
2343
2344static void
2345storetags (tags)
2346     tree tags;
2347{
2348  current_binding_level->tags = tags;
2349}
2350
2351/* Given NAME, an IDENTIFIER_NODE,
2352   return the structure (or union or enum) definition for that name.
2353   Searches binding levels from BINDING_LEVEL up to the global level.
2354   If THISLEVEL_ONLY is nonzero, searches only the specified context
2355   (but skips any tag-transparent contexts to find one that is
2356   meaningful for tags).
2357   CODE says which kind of type the caller wants;
2358   it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE.
2359   If the wrong kind of type is found, an error is reported.  */
2360
2361static tree
2362lookup_tag (code, name, binding_level, thislevel_only)
2363     enum tree_code code;
2364     struct binding_level *binding_level;
2365     tree name;
2366     int thislevel_only;
2367{
2368  struct binding_level *level;
2369  int thislevel = 1;
2370
2371  for (level = binding_level; level; level = level->level_chain)
2372    {
2373      tree tail;
2374      for (tail = level->tags; tail; tail = TREE_CHAIN (tail))
2375	{
2376	  if (TREE_PURPOSE (tail) == name)
2377	    {
2378	      if (TREE_CODE (TREE_VALUE (tail)) != code)
2379		{
2380		  /* Definition isn't the kind we were looking for.  */
2381		  pending_invalid_xref = name;
2382		  pending_invalid_xref_file = input_filename;
2383		  pending_invalid_xref_line = lineno;
2384		  /* If in the same binding level as a declaration as a tag
2385		     of a different type, this must not be allowed to
2386		     shadow that tag, so give the error immediately.
2387		     (For example, "struct foo; union foo;" is invalid.)  */
2388		  if (thislevel)
2389		    pending_xref_error ();
2390		}
2391	      return TREE_VALUE (tail);
2392	    }
2393	}
2394      if (! level->tag_transparent)
2395	{
2396	  if (thislevel_only)
2397	    return NULL_TREE;
2398	  thislevel = 0;
2399	}
2400    }
2401  return NULL_TREE;
2402}
2403
2404/* Print an error message now
2405   for a recent invalid struct, union or enum cross reference.
2406   We don't print them immediately because they are not invalid
2407   when used in the `struct foo;' construct for shadowing.  */
2408
2409void
2410pending_xref_error ()
2411{
2412  if (pending_invalid_xref != 0)
2413    error_with_file_and_line (pending_invalid_xref_file,
2414			      pending_invalid_xref_line,
2415			      "`%s' defined as wrong kind of tag",
2416			      IDENTIFIER_POINTER (pending_invalid_xref));
2417  pending_invalid_xref = 0;
2418}
2419
2420/* Given a type, find the tag that was defined for it and return the tag name.
2421   Otherwise return 0.  */
2422
2423static tree
2424lookup_tag_reverse (type)
2425     tree type;
2426{
2427  struct binding_level *level;
2428
2429  for (level = current_binding_level; level; level = level->level_chain)
2430    {
2431      tree tail;
2432      for (tail = level->tags; tail; tail = TREE_CHAIN (tail))
2433	{
2434	  if (TREE_VALUE (tail) == type)
2435	    return TREE_PURPOSE (tail);
2436	}
2437    }
2438  return NULL_TREE;
2439}
2440
2441/* Look up NAME in the current binding level and its superiors
2442   in the namespace of variables, functions and typedefs.
2443   Return a ..._DECL node of some kind representing its definition,
2444   or return 0 if it is undefined.  */
2445
2446tree
2447lookup_name (name)
2448     tree name;
2449{
2450  tree val;
2451
2452  if (current_binding_level != global_binding_level
2453      && IDENTIFIER_LOCAL_VALUE (name))
2454    val = IDENTIFIER_LOCAL_VALUE (name);
2455  else
2456    val = IDENTIFIER_GLOBAL_VALUE (name);
2457  return val;
2458}
2459
2460/* Similar to `lookup_name' but look only at current binding level.  */
2461
2462tree
2463lookup_name_current_level (name)
2464     tree name;
2465{
2466  tree t;
2467
2468  if (current_binding_level == global_binding_level)
2469    return IDENTIFIER_GLOBAL_VALUE (name);
2470
2471  if (IDENTIFIER_LOCAL_VALUE (name) == 0)
2472    return 0;
2473
2474  for (t = current_binding_level->names; t; t = TREE_CHAIN (t))
2475    if (DECL_NAME (t) == name)
2476      break;
2477
2478  return t;
2479}
2480
2481/* Create the predefined scalar types of C,
2482   and some nodes representing standard constants (0, 1, (void *) 0).
2483   Initialize the global binding level.
2484   Make definitions for built-in primitive functions.  */
2485
2486void
2487c_init_decl_processing ()
2488{
2489  tree endlink;
2490  tree ptr_ftype_void, ptr_ftype_ptr;
2491
2492  /* Adds some ggc roots, and reserved words for c-parse.in.  */
2493  c_parse_init ();
2494
2495  current_function_decl = NULL;
2496  named_labels = NULL;
2497  current_binding_level = NULL_BINDING_LEVEL;
2498  free_binding_level = NULL_BINDING_LEVEL;
2499
2500  /* Make the binding_level structure for global names.  */
2501  pushlevel (0);
2502  global_binding_level = current_binding_level;
2503
2504  build_common_tree_nodes (flag_signed_char);
2505
2506  c_common_nodes_and_builtins ();
2507
2508  boolean_type_node = integer_type_node;
2509  boolean_true_node = integer_one_node;
2510  boolean_false_node = integer_zero_node;
2511
2512  c_bool_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
2513  TREE_SET_CODE (c_bool_type_node, BOOLEAN_TYPE);
2514  TYPE_MAX_VALUE (c_bool_type_node) = build_int_2 (1, 0);
2515  TREE_TYPE (TYPE_MAX_VALUE (c_bool_type_node)) = c_bool_type_node;
2516  TYPE_PRECISION (c_bool_type_node) = 1;
2517  pushdecl (build_decl (TYPE_DECL, get_identifier ("_Bool"),
2518			c_bool_type_node));
2519  c_bool_false_node = build_int_2 (0, 0);
2520  TREE_TYPE (c_bool_false_node) = c_bool_type_node;
2521  c_bool_true_node = build_int_2 (1, 0);
2522  TREE_TYPE (c_bool_true_node) = c_bool_type_node;
2523
2524  endlink = void_list_node;
2525  ptr_ftype_void = build_function_type (ptr_type_node, endlink);
2526  ptr_ftype_ptr
2527    = build_function_type (ptr_type_node,
2528			   tree_cons (NULL_TREE, ptr_type_node, endlink));
2529
2530  pedantic_lvalues = pedantic;
2531
2532  make_fname_decl = c_make_fname_decl;
2533  start_fname_decls ();
2534}
2535
2536/* Create the VAR_DECL for __FUNCTION__ etc. ID is the name to give the
2537   decl, NAME is the initialization string and TYPE_DEP indicates whether
2538   NAME depended on the type of the function.  As we don't yet implement
2539   delayed emission of static data, we mark the decl as emitted
2540   so it is not placed in the output.  Anything using it must therefore pull
2541   out the STRING_CST initializer directly.  This does mean that these names
2542   are string merging candidates, which is wrong for C99's __func__.  FIXME.  */
2543
2544static tree
2545c_make_fname_decl (id, type_dep)
2546     tree id;
2547     int type_dep;
2548{
2549  const char *name = fname_as_string (type_dep);
2550  tree decl, type, init;
2551  size_t length = strlen (name);
2552
2553  type =  build_array_type
2554          (build_qualified_type (char_type_node, TYPE_QUAL_CONST),
2555	   build_index_type (size_int (length)));
2556
2557  decl = build_decl (VAR_DECL, id, type);
2558  /* We don't push the decl, so have to set its context here.  */
2559  DECL_CONTEXT (decl) = current_function_decl;
2560
2561  TREE_STATIC (decl) = 1;
2562  TREE_READONLY (decl) = 1;
2563  DECL_ARTIFICIAL (decl) = 1;
2564
2565  init = build_string (length + 1, name);
2566  TREE_TYPE (init) = type;
2567  DECL_INITIAL (decl) = init;
2568
2569  TREE_USED (decl) = 1;
2570
2571  finish_decl (decl, init, NULL_TREE);
2572
2573  return decl;
2574}
2575
2576/* Return a definition for a builtin function named NAME and whose data type
2577   is TYPE.  TYPE should be a function type with argument types.
2578   FUNCTION_CODE tells later passes how to compile calls to this function.
2579   See tree.h for its possible values.
2580
2581   If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
2582   the name to be called if we can't opencode the function.  If
2583   ATTRS is nonzero, use that for the function's attribute list.  */
2584
2585tree
2586builtin_function (name, type, function_code, class, library_name, attrs)
2587     const char *name;
2588     tree type;
2589     int function_code;
2590     enum built_in_class class;
2591     const char *library_name;
2592     tree attrs;
2593{
2594  tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type);
2595  DECL_EXTERNAL (decl) = 1;
2596  TREE_PUBLIC (decl) = 1;
2597  if (library_name)
2598    SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name));
2599  make_decl_rtl (decl, NULL);
2600  pushdecl (decl);
2601  DECL_BUILT_IN_CLASS (decl) = class;
2602  DECL_FUNCTION_CODE (decl) = function_code;
2603
2604  /* Warn if a function in the namespace for users
2605     is used without an occasion to consider it declared.  */
2606  if (name[0] != '_' || name[1] != '_')
2607    C_DECL_ANTICIPATED (decl) = 1;
2608
2609  /* Possibly apply some default attributes to this built-in function.  */
2610  if (attrs)
2611    decl_attributes (&decl, attrs, ATTR_FLAG_BUILT_IN);
2612  else
2613    decl_attributes (&decl, NULL_TREE, 0);
2614
2615  return decl;
2616}
2617
2618/* Apply default attributes to a function, if a system function with default
2619   attributes.  */
2620
2621void
2622c_insert_default_attributes (decl)
2623     tree decl;
2624{
2625  if (!TREE_PUBLIC (decl))
2626    return;
2627  c_common_insert_default_attributes (decl);
2628}
2629
2630/* Called when a declaration is seen that contains no names to declare.
2631   If its type is a reference to a structure, union or enum inherited
2632   from a containing scope, shadow that tag name for the current scope
2633   with a forward reference.
2634   If its type defines a new named structure or union
2635   or defines an enum, it is valid but we need not do anything here.
2636   Otherwise, it is an error.  */
2637
2638void
2639shadow_tag (declspecs)
2640     tree declspecs;
2641{
2642  shadow_tag_warned (declspecs, 0);
2643}
2644
2645void
2646shadow_tag_warned (declspecs, warned)
2647     tree declspecs;
2648     int warned;
2649     /* 1 => we have done a pedwarn.  2 => we have done a warning, but
2650	no pedwarn.  */
2651{
2652  int found_tag = 0;
2653  tree link;
2654  tree specs, attrs;
2655
2656  pending_invalid_xref = 0;
2657
2658  /* Remove the attributes from declspecs, since they will confuse the
2659     following code.  */
2660  split_specs_attrs (declspecs, &specs, &attrs);
2661
2662  for (link = specs; link; link = TREE_CHAIN (link))
2663    {
2664      tree value = TREE_VALUE (link);
2665      enum tree_code code = TREE_CODE (value);
2666
2667      if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE)
2668	/* Used to test also that TYPE_SIZE (value) != 0.
2669	   That caused warning for `struct foo;' at top level in the file.  */
2670	{
2671	  tree name = lookup_tag_reverse (value);
2672	  tree t;
2673
2674	  found_tag++;
2675
2676	  if (name == 0)
2677	    {
2678	      if (warned != 1 && code != ENUMERAL_TYPE)
2679		/* Empty unnamed enum OK */
2680		{
2681		  pedwarn ("unnamed struct/union that defines no instances");
2682		  warned = 1;
2683		}
2684	    }
2685	  else
2686	    {
2687	      t = lookup_tag (code, name, current_binding_level, 1);
2688
2689	      if (t == 0)
2690		{
2691		  t = make_node (code);
2692		  pushtag (name, t);
2693		}
2694	    }
2695	}
2696      else
2697	{
2698	  if (!warned && ! in_system_header)
2699	    {
2700	      warning ("useless keyword or type name in empty declaration");
2701	      warned = 2;
2702	    }
2703	}
2704    }
2705
2706  if (found_tag > 1)
2707    error ("two types specified in one empty declaration");
2708
2709  if (warned != 1)
2710    {
2711      if (found_tag == 0)
2712	pedwarn ("empty declaration");
2713    }
2714}
2715
2716/* Construct an array declarator.  EXPR is the expression inside [], or
2717   NULL_TREE.  QUALS are the type qualifiers inside the [] (to be applied
2718   to the pointer to which a parameter array is converted).  STATIC_P is
2719   nonzero if "static" is inside the [], zero otherwise.  VLA_UNSPEC_P
2720   is nonzero is the array is [*], a VLA of unspecified length which is
2721   nevertheless a complete type (not currently implemented by GCC),
2722   zero otherwise.  The declarator is constructed as an ARRAY_REF
2723   (to be decoded by grokdeclarator), whose operand 0 is what's on the
2724   left of the [] (filled by in set_array_declarator_type) and operand 1
2725   is the expression inside; whose TREE_TYPE is the type qualifiers and
2726   which has TREE_STATIC set if "static" is used.  */
2727
2728tree
2729build_array_declarator (expr, quals, static_p, vla_unspec_p)
2730     tree expr;
2731     tree quals;
2732     int static_p;
2733     int vla_unspec_p;
2734{
2735  tree decl;
2736  decl = build_nt (ARRAY_REF, NULL_TREE, expr);
2737  TREE_TYPE (decl) = quals;
2738  TREE_STATIC (decl) = (static_p ? 1 : 0);
2739  if (pedantic && !flag_isoc99)
2740    {
2741      if (static_p || quals != NULL_TREE)
2742	pedwarn ("ISO C90 does not support `static' or type qualifiers in parameter array declarators");
2743      if (vla_unspec_p)
2744	pedwarn ("ISO C90 does not support `[*]' array declarators");
2745    }
2746  if (vla_unspec_p)
2747    warning ("GCC does not yet properly implement `[*]' array declarators");
2748  return decl;
2749}
2750
2751/* Set the type of an array declarator.  DECL is the declarator, as
2752   constructed by build_array_declarator; TYPE is what appears on the left
2753   of the [] and goes in operand 0.  ABSTRACT_P is nonzero if it is an
2754   abstract declarator, zero otherwise; this is used to reject static and
2755   type qualifiers in abstract declarators, where they are not in the
2756   C99 grammar.  */
2757
2758tree
2759set_array_declarator_type (decl, type, abstract_p)
2760     tree decl;
2761     tree type;
2762     int abstract_p;
2763{
2764  TREE_OPERAND (decl, 0) = type;
2765  if (abstract_p && (TREE_TYPE (decl) != NULL_TREE || TREE_STATIC (decl)))
2766    error ("static or type qualifiers in abstract declarator");
2767  return decl;
2768}
2769
2770/* Decode a "typename", such as "int **", returning a ..._TYPE node.  */
2771
2772tree
2773groktypename (typename)
2774     tree typename;
2775{
2776  tree specs, attrs;
2777
2778  if (TREE_CODE (typename) != TREE_LIST)
2779    return typename;
2780
2781  split_specs_attrs (TREE_PURPOSE (typename), &specs, &attrs);
2782
2783  typename = grokdeclarator (TREE_VALUE (typename), specs, TYPENAME, 0);
2784
2785  /* Apply attributes.  */
2786  decl_attributes (&typename, attrs, 0);
2787
2788  return typename;
2789}
2790
2791/* Return a PARM_DECL node for a given pair of specs and declarator.  */
2792
2793tree
2794groktypename_in_parm_context (typename)
2795     tree typename;
2796{
2797  if (TREE_CODE (typename) != TREE_LIST)
2798    return typename;
2799  return grokdeclarator (TREE_VALUE (typename),
2800			 TREE_PURPOSE (typename),
2801			 PARM, 0);
2802}
2803
2804/* Decode a declarator in an ordinary declaration or data definition.
2805   This is called as soon as the type information and variable name
2806   have been parsed, before parsing the initializer if any.
2807   Here we create the ..._DECL node, fill in its type,
2808   and put it on the list of decls for the current context.
2809   The ..._DECL node is returned as the value.
2810
2811   Exception: for arrays where the length is not specified,
2812   the type is left null, to be filled in by `finish_decl'.
2813
2814   Function definitions do not come here; they go to start_function
2815   instead.  However, external and forward declarations of functions
2816   do go through here.  Structure field declarations are done by
2817   grokfield and not through here.  */
2818
2819tree
2820start_decl (declarator, declspecs, initialized, attributes)
2821     tree declarator, declspecs;
2822     int initialized;
2823     tree attributes;
2824{
2825  tree decl;
2826  tree tem;
2827
2828  /* An object declared as __attribute__((deprecated)) suppresses
2829     warnings of uses of other deprecated items.  */
2830  if (lookup_attribute ("deprecated", attributes))
2831    deprecated_state = DEPRECATED_SUPPRESS;
2832
2833  decl = grokdeclarator (declarator, declspecs,
2834			 NORMAL, initialized);
2835
2836  deprecated_state = DEPRECATED_NORMAL;
2837
2838  if (warn_main > 0 && TREE_CODE (decl) != FUNCTION_DECL
2839      && MAIN_NAME_P (DECL_NAME (decl)))
2840    warning_with_decl (decl, "`%s' is usually a function");
2841
2842  if (initialized)
2843    /* Is it valid for this decl to have an initializer at all?
2844       If not, set INITIALIZED to zero, which will indirectly
2845       tell `finish_decl' to ignore the initializer once it is parsed.  */
2846    switch (TREE_CODE (decl))
2847      {
2848      case TYPE_DECL:
2849	error ("typedef `%s' is initialized (use __typeof__ instead)",
2850	       IDENTIFIER_POINTER (DECL_NAME (decl)));
2851	initialized = 0;
2852	break;
2853
2854      case FUNCTION_DECL:
2855	error ("function `%s' is initialized like a variable",
2856	       IDENTIFIER_POINTER (DECL_NAME (decl)));
2857	initialized = 0;
2858	break;
2859
2860      case PARM_DECL:
2861	/* DECL_INITIAL in a PARM_DECL is really DECL_ARG_TYPE.  */
2862	error ("parameter `%s' is initialized",
2863	       IDENTIFIER_POINTER (DECL_NAME (decl)));
2864	initialized = 0;
2865	break;
2866
2867      default:
2868	/* Don't allow initializations for incomplete types
2869	   except for arrays which might be completed by the initialization.  */
2870
2871	/* This can happen if the array size is an undefined macro.  We already
2872	   gave a warning, so we don't need another one.  */
2873	if (TREE_TYPE (decl) == error_mark_node)
2874	  initialized = 0;
2875	else if (COMPLETE_TYPE_P (TREE_TYPE (decl)))
2876	  {
2877	    /* A complete type is ok if size is fixed.  */
2878
2879	    if (TREE_CODE (TYPE_SIZE (TREE_TYPE (decl))) != INTEGER_CST
2880		|| C_DECL_VARIABLE_SIZE (decl))
2881	      {
2882		error ("variable-sized object may not be initialized");
2883		initialized = 0;
2884	      }
2885	  }
2886	else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE)
2887	  {
2888	    error ("variable `%s' has initializer but incomplete type",
2889		   IDENTIFIER_POINTER (DECL_NAME (decl)));
2890	    initialized = 0;
2891	  }
2892	else if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
2893	  {
2894	    error ("elements of array `%s' have incomplete type",
2895		   IDENTIFIER_POINTER (DECL_NAME (decl)));
2896	    initialized = 0;
2897	  }
2898      }
2899
2900  if (initialized)
2901    {
2902#if 0
2903      /* Seems redundant with grokdeclarator.  */
2904      if (current_binding_level != global_binding_level
2905	  && DECL_EXTERNAL (decl)
2906	  && TREE_CODE (decl) != FUNCTION_DECL)
2907	warning ("declaration of `%s' has `extern' and is initialized",
2908		 IDENTIFIER_POINTER (DECL_NAME (decl)));
2909#endif
2910      DECL_EXTERNAL (decl) = 0;
2911      if (current_binding_level == global_binding_level)
2912	TREE_STATIC (decl) = 1;
2913
2914      /* Tell `pushdecl' this is an initialized decl
2915	 even though we don't yet have the initializer expression.
2916	 Also tell `finish_decl' it may store the real initializer.  */
2917      DECL_INITIAL (decl) = error_mark_node;
2918    }
2919
2920  /* If this is a function declaration, write a record describing it to the
2921     prototypes file (if requested).  */
2922
2923  if (TREE_CODE (decl) == FUNCTION_DECL)
2924    gen_aux_info_record (decl, 0, 0, TYPE_ARG_TYPES (TREE_TYPE (decl)) != 0);
2925
2926  /* ANSI specifies that a tentative definition which is not merged with
2927     a non-tentative definition behaves exactly like a definition with an
2928     initializer equal to zero.  (Section 3.7.2)
2929
2930     -fno-common gives strict ANSI behavior, though this tends to break
2931     a large body of code that grew up without this rule.
2932
2933     Thread-local variables are never common, since there's no entrenched
2934     body of code to break, and it allows more efficient variable references
2935     in the presense of dynamic linking.  */
2936
2937  if (TREE_CODE (decl) == VAR_DECL
2938      && !initialized
2939      && TREE_PUBLIC (decl)
2940      && !DECL_THREAD_LOCAL (decl)
2941      && !flag_no_common)
2942    DECL_COMMON (decl) = 1;
2943
2944  /* Set attributes here so if duplicate decl, will have proper attributes.  */
2945  decl_attributes (&decl, attributes, 0);
2946
2947  /* If #pragma weak was used, mark the decl weak now.  */
2948  if (current_binding_level == global_binding_level)
2949    maybe_apply_pragma_weak (decl);
2950
2951  if (TREE_CODE (decl) == FUNCTION_DECL
2952      && DECL_DECLARED_INLINE_P (decl)
2953      && DECL_UNINLINABLE (decl)
2954      && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl)))
2955    warning_with_decl (decl,
2956		       "inline function `%s' given attribute noinline");
2957
2958  /* Add this decl to the current binding level.
2959     TEM may equal DECL or it may be a previous decl of the same name.  */
2960  tem = pushdecl (decl);
2961
2962  /* For a local variable, define the RTL now.  */
2963  if (current_binding_level != global_binding_level
2964      /* But not if this is a duplicate decl
2965	 and we preserved the rtl from the previous one
2966	 (which may or may not happen).  */
2967      && !DECL_RTL_SET_P (tem)
2968      && !DECL_CONTEXT (tem))
2969    {
2970      if (TREE_TYPE (tem) != error_mark_node
2971	  && COMPLETE_TYPE_P (TREE_TYPE (tem)))
2972	expand_decl (tem);
2973      else if (TREE_CODE (TREE_TYPE (tem)) == ARRAY_TYPE
2974	       && DECL_INITIAL (tem) != 0)
2975	expand_decl (tem);
2976    }
2977
2978  return tem;
2979}
2980
2981/* Finish processing of a declaration;
2982   install its initial value.
2983   If the length of an array type is not known before,
2984   it must be determined now, from the initial value, or it is an error.  */
2985
2986void
2987finish_decl (decl, init, asmspec_tree)
2988     tree decl, init;
2989     tree asmspec_tree;
2990{
2991  tree type = TREE_TYPE (decl);
2992  int was_incomplete = (DECL_SIZE (decl) == 0);
2993  const char *asmspec = 0;
2994
2995  /* If a name was specified, get the string.  */
2996  if (current_binding_level == global_binding_level)
2997    asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree);
2998  if (asmspec_tree)
2999    asmspec = TREE_STRING_POINTER (asmspec_tree);
3000
3001  /* If `start_decl' didn't like having an initialization, ignore it now.  */
3002  if (init != 0 && DECL_INITIAL (decl) == 0)
3003    init = 0;
3004
3005  /* Don't crash if parm is initialized.  */
3006  if (TREE_CODE (decl) == PARM_DECL)
3007    init = 0;
3008
3009  if (init)
3010    store_init_value (decl, init);
3011
3012  /* Deduce size of array from initialization, if not already known */
3013  if (TREE_CODE (type) == ARRAY_TYPE
3014      && TYPE_DOMAIN (type) == 0
3015      && TREE_CODE (decl) != TYPE_DECL)
3016    {
3017      int do_default
3018	= (TREE_STATIC (decl)
3019	   /* Even if pedantic, an external linkage array
3020	      may have incomplete type at first.  */
3021	   ? pedantic && !TREE_PUBLIC (decl)
3022	   : !DECL_EXTERNAL (decl));
3023      int failure
3024	= complete_array_type (type, DECL_INITIAL (decl), do_default);
3025
3026      /* Get the completed type made by complete_array_type.  */
3027      type = TREE_TYPE (decl);
3028
3029      if (failure == 1)
3030	error_with_decl (decl, "initializer fails to determine size of `%s'");
3031
3032      else if (failure == 2)
3033	{
3034	  if (do_default)
3035	    error_with_decl (decl, "array size missing in `%s'");
3036	  /* If a `static' var's size isn't known,
3037	     make it extern as well as static, so it does not get
3038	     allocated.
3039	     If it is not `static', then do not mark extern;
3040	     finish_incomplete_decl will give it a default size
3041	     and it will get allocated.  */
3042	  else if (!pedantic && TREE_STATIC (decl) && ! TREE_PUBLIC (decl))
3043	    DECL_EXTERNAL (decl) = 1;
3044	}
3045
3046      /* TYPE_MAX_VALUE is always one less than the number of elements
3047	 in the array, because we start counting at zero.  Therefore,
3048	 warn only if the value is less than zero.  */
3049      else if (pedantic && TYPE_DOMAIN (type) != 0
3050	      && tree_int_cst_sgn (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) < 0)
3051	error_with_decl (decl, "zero or negative size array `%s'");
3052
3053      layout_decl (decl, 0);
3054    }
3055
3056  if (TREE_CODE (decl) == VAR_DECL)
3057    {
3058      if (DECL_SIZE (decl) == 0 && TREE_TYPE (decl) != error_mark_node
3059	  && COMPLETE_TYPE_P (TREE_TYPE (decl)))
3060	layout_decl (decl, 0);
3061
3062      if (DECL_SIZE (decl) == 0
3063	  /* Don't give an error if we already gave one earlier.  */
3064	  && TREE_TYPE (decl) != error_mark_node
3065	  && (TREE_STATIC (decl)
3066	      ?
3067		/* A static variable with an incomplete type
3068		   is an error if it is initialized.
3069		   Also if it is not file scope.
3070		   Otherwise, let it through, but if it is not `extern'
3071		   then it may cause an error message later.  */
3072		(DECL_INITIAL (decl) != 0
3073		 || DECL_CONTEXT (decl) != 0)
3074	      :
3075		/* An automatic variable with an incomplete type
3076		   is an error.  */
3077		!DECL_EXTERNAL (decl)))
3078	{
3079	  error_with_decl (decl, "storage size of `%s' isn't known");
3080	  TREE_TYPE (decl) = error_mark_node;
3081	}
3082
3083      if ((DECL_EXTERNAL (decl) || TREE_STATIC (decl))
3084	  && DECL_SIZE (decl) != 0)
3085	{
3086	  if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3087	    constant_expression_warning (DECL_SIZE (decl));
3088	  else
3089	    error_with_decl (decl, "storage size of `%s' isn't constant");
3090	}
3091
3092      if (TREE_USED (type))
3093	TREE_USED (decl) = 1;
3094    }
3095
3096  /* If this is a function and an assembler name is specified, it isn't
3097     builtin any more.  Also reset DECL_RTL so we can give it its new
3098     name.  */
3099  if (TREE_CODE (decl) == FUNCTION_DECL && asmspec)
3100    {
3101      DECL_BUILT_IN_CLASS (decl) = NOT_BUILT_IN;
3102      SET_DECL_RTL (decl, NULL_RTX);
3103      SET_DECL_ASSEMBLER_NAME (decl, get_identifier (asmspec));
3104    }
3105
3106  /* Output the assembler code and/or RTL code for variables and functions,
3107     unless the type is an undefined structure or union.
3108     If not, it will get done when the type is completed.  */
3109
3110  if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL)
3111    {
3112      /* This is a no-op in c-lang.c or something real in objc-act.c.  */
3113      if (flag_objc)
3114	objc_check_decl (decl);
3115
3116      if (!DECL_CONTEXT (decl))
3117	{
3118	  if (DECL_INITIAL (decl) == NULL_TREE
3119	      || DECL_INITIAL (decl) == error_mark_node)
3120	    /* Don't output anything
3121	       when a tentative file-scope definition is seen.
3122	       But at end of compilation, do output code for them.  */
3123	    DECL_DEFER_OUTPUT (decl) = 1;
3124	  rest_of_decl_compilation (decl, asmspec,
3125				    (DECL_CONTEXT (decl) == 0
3126				     || TREE_ASM_WRITTEN (decl)), 0);
3127	}
3128      else
3129	{
3130	  /* This is a local variable.  If there is an ASMSPEC, the
3131	     user has requested that we handle it specially.  */
3132	  if (asmspec)
3133	    {
3134	      /* In conjunction with an ASMSPEC, the `register'
3135		 keyword indicates that we should place the variable
3136		 in a particular register.  */
3137	      if (DECL_REGISTER (decl))
3138		DECL_C_HARD_REGISTER (decl) = 1;
3139
3140	      /* If this is not a static variable, issue a warning.
3141		 It doesn't make any sense to give an ASMSPEC for an
3142		 ordinary, non-register local variable.  Historically,
3143		 GCC has accepted -- but ignored -- the ASMSPEC in
3144		 this case.  */
3145	      if (TREE_CODE (decl) == VAR_DECL
3146		  && !DECL_REGISTER (decl)
3147		  && !TREE_STATIC (decl))
3148		warning_with_decl (decl,
3149				   "ignoring asm-specifier for non-static local variable `%s'");
3150	      else
3151		SET_DECL_ASSEMBLER_NAME (decl, get_identifier (asmspec));
3152	    }
3153
3154	  if (TREE_CODE (decl) != FUNCTION_DECL)
3155	    add_decl_stmt (decl);
3156	}
3157
3158      if (DECL_CONTEXT (decl) != 0)
3159	{
3160	  /* Recompute the RTL of a local array now
3161	     if it used to be an incomplete type.  */
3162	  if (was_incomplete
3163	      && ! TREE_STATIC (decl) && ! DECL_EXTERNAL (decl))
3164	    {
3165	      /* If we used it already as memory, it must stay in memory.  */
3166	      TREE_ADDRESSABLE (decl) = TREE_USED (decl);
3167	      /* If it's still incomplete now, no init will save it.  */
3168	      if (DECL_SIZE (decl) == 0)
3169		DECL_INITIAL (decl) = 0;
3170	    }
3171	}
3172    }
3173
3174  if (TREE_CODE (decl) == TYPE_DECL)
3175    {
3176      /* This is a no-op in c-lang.c or something real in objc-act.c.  */
3177      if (flag_objc)
3178	objc_check_decl (decl);
3179      rest_of_decl_compilation (decl, NULL, DECL_CONTEXT (decl) == 0, 0);
3180    }
3181
3182  /* At the end of a declaration, throw away any variable type sizes
3183     of types defined inside that declaration.  There is no use
3184     computing them in the following function definition.  */
3185  if (current_binding_level == global_binding_level)
3186    get_pending_sizes ();
3187
3188  /* Install a cleanup (aka destructor) if one was given.  */
3189  if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl))
3190    {
3191      tree attr = lookup_attribute ("cleanup", DECL_ATTRIBUTES (decl));
3192      if (attr)
3193	{
3194	  static bool eh_initialized_p;
3195
3196	  tree cleanup_id = TREE_VALUE (TREE_VALUE (attr));
3197	  tree cleanup_decl = lookup_name (cleanup_id);
3198	  tree cleanup;
3199
3200	  /* Build "cleanup(&decl)" for the destructor.  */
3201	  cleanup = build_unary_op (ADDR_EXPR, decl, 0);
3202	  cleanup = build_tree_list (NULL_TREE, cleanup);
3203	  cleanup = build_function_call (cleanup_decl, cleanup);
3204
3205	  /* Don't warn about decl unused; the cleanup uses it.  */
3206	  TREE_USED (decl) = 1;
3207
3208	  /* Initialize EH, if we've been told to do so.  */
3209	  if (flag_exceptions && !eh_initialized_p)
3210	    {
3211	      eh_initialized_p = true;
3212	      eh_personality_libfunc
3213		= init_one_libfunc (USING_SJLJ_EXCEPTIONS
3214				    ? "__gcc_personality_sj0"
3215				    : "__gcc_personality_v0");
3216	      using_eh_for_cleanups ();
3217	    }
3218
3219	  add_stmt (build_stmt (CLEANUP_STMT, decl, cleanup));
3220	}
3221    }
3222}
3223
3224/* Given a parsed parameter declaration,
3225   decode it into a PARM_DECL and push that on the current binding level.
3226   Also, for the sake of forward parm decls,
3227   record the given order of parms in `parm_order'.  */
3228
3229void
3230push_parm_decl (parm)
3231     tree parm;
3232{
3233  tree decl;
3234  int old_immediate_size_expand = immediate_size_expand;
3235  /* Don't try computing parm sizes now -- wait till fn is called.  */
3236  immediate_size_expand = 0;
3237
3238  decl = grokdeclarator (TREE_VALUE (TREE_PURPOSE (parm)),
3239			 TREE_PURPOSE (TREE_PURPOSE (parm)), PARM, 0);
3240  decl_attributes (&decl, TREE_VALUE (parm), 0);
3241
3242#if 0
3243  if (DECL_NAME (decl))
3244    {
3245      tree olddecl;
3246      olddecl = lookup_name (DECL_NAME (decl));
3247      if (pedantic && olddecl != 0 && TREE_CODE (olddecl) == TYPE_DECL)
3248	pedwarn_with_decl (decl,
3249			   "ISO C forbids parameter `%s' shadowing typedef");
3250    }
3251#endif
3252
3253  decl = pushdecl (decl);
3254
3255  immediate_size_expand = old_immediate_size_expand;
3256
3257  current_binding_level->parm_order
3258    = tree_cons (NULL_TREE, decl, current_binding_level->parm_order);
3259
3260  /* Add this decl to the current binding level.  */
3261  finish_decl (decl, NULL_TREE, NULL_TREE);
3262}
3263
3264/* Clear the given order of parms in `parm_order'.
3265   Used at start of parm list,
3266   and also at semicolon terminating forward decls.  */
3267
3268void
3269clear_parm_order ()
3270{
3271  current_binding_level->parm_order = NULL_TREE;
3272}
3273
3274/* Build a COMPOUND_LITERAL_EXPR.  TYPE is the type given in the compound
3275   literal, which may be an incomplete array type completed by the
3276   initializer; INIT is a CONSTRUCTOR that initializes the compound
3277   literal.  */
3278
3279tree
3280build_compound_literal (type, init)
3281     tree type;
3282     tree init;
3283{
3284  /* We do not use start_decl here because we have a type, not a declarator;
3285     and do not use finish_decl because the decl should be stored inside
3286     the COMPOUND_LITERAL_EXPR rather than added elsewhere as a DECL_STMT.  */
3287  tree decl = build_decl (VAR_DECL, NULL_TREE, type);
3288  tree complit;
3289  tree stmt;
3290  DECL_EXTERNAL (decl) = 0;
3291  TREE_PUBLIC (decl) = 0;
3292  TREE_STATIC (decl) = (current_binding_level == global_binding_level);
3293  DECL_CONTEXT (decl) = current_function_decl;
3294  TREE_USED (decl) = 1;
3295  TREE_TYPE (decl) = type;
3296  TREE_READONLY (decl) = TREE_READONLY (type);
3297  store_init_value (decl, init);
3298
3299  if (TREE_CODE (type) == ARRAY_TYPE && !COMPLETE_TYPE_P (type))
3300    {
3301      int failure = complete_array_type (type, DECL_INITIAL (decl), 1);
3302      if (failure)
3303	abort ();
3304    }
3305
3306  type = TREE_TYPE (decl);
3307  if (type == error_mark_node || !COMPLETE_TYPE_P (type))
3308    return error_mark_node;
3309
3310  stmt = build_stmt (DECL_STMT, decl);
3311  complit = build1 (COMPOUND_LITERAL_EXPR, TREE_TYPE (decl), stmt);
3312  TREE_SIDE_EFFECTS (complit) = 1;
3313
3314  layout_decl (decl, 0);
3315
3316  if (TREE_STATIC (decl))
3317    {
3318      /* This decl needs a name for the assembler output.  We also need
3319	 a unique suffix to be added to the name.  */
3320      char *name;
3321      extern int var_labelno;
3322
3323      ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal", var_labelno);
3324      var_labelno++;
3325      DECL_NAME (decl) = get_identifier (name);
3326      DECL_DEFER_OUTPUT (decl) = 1;
3327      DECL_COMDAT (decl) = 1;
3328      DECL_ARTIFICIAL (decl) = 1;
3329      pushdecl (decl);
3330      rest_of_decl_compilation (decl, NULL, 1, 0);
3331    }
3332
3333  return complit;
3334}
3335
3336/* Make TYPE a complete type based on INITIAL_VALUE.
3337   Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered,
3338   2 if there was no information (in which case assume 1 if DO_DEFAULT).  */
3339
3340int
3341complete_array_type (type, initial_value, do_default)
3342     tree type;
3343     tree initial_value;
3344     int do_default;
3345{
3346  tree maxindex = NULL_TREE;
3347  int value = 0;
3348
3349  if (initial_value)
3350    {
3351      /* Note MAXINDEX  is really the maximum index,
3352	 one less than the size.  */
3353      if (TREE_CODE (initial_value) == STRING_CST)
3354	{
3355	  int eltsize
3356	    = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value)));
3357	  maxindex = build_int_2 ((TREE_STRING_LENGTH (initial_value)
3358				   / eltsize) - 1, 0);
3359	}
3360      else if (TREE_CODE (initial_value) == CONSTRUCTOR)
3361	{
3362	  tree elts = CONSTRUCTOR_ELTS (initial_value);
3363	  maxindex = build_int_2 (-1, -1);
3364	  for (; elts; elts = TREE_CHAIN (elts))
3365	    {
3366	      if (TREE_PURPOSE (elts))
3367		maxindex = TREE_PURPOSE (elts);
3368	      else
3369		maxindex = fold (build (PLUS_EXPR, integer_type_node,
3370					maxindex, integer_one_node));
3371	    }
3372	  maxindex = copy_node (maxindex);
3373	}
3374      else
3375	{
3376	  /* Make an error message unless that happened already.  */
3377	  if (initial_value != error_mark_node)
3378	    value = 1;
3379
3380	  /* Prevent further error messages.  */
3381	  maxindex = build_int_2 (0, 0);
3382	}
3383    }
3384
3385  if (!maxindex)
3386    {
3387      if (do_default)
3388	maxindex = build_int_2 (0, 0);
3389      value = 2;
3390    }
3391
3392  if (maxindex)
3393    {
3394      TYPE_DOMAIN (type) = build_index_type (maxindex);
3395      if (!TREE_TYPE (maxindex))
3396	TREE_TYPE (maxindex) = TYPE_DOMAIN (type);
3397    }
3398
3399  /* Lay out the type now that we can get the real answer.  */
3400
3401  layout_type (type);
3402
3403  return value;
3404}
3405
3406/* Determine whether TYPE is a structure with a flexible array member,
3407   or a union containing such a structure (possibly recursively).  */
3408
3409static bool
3410flexible_array_type_p (type)
3411     tree type;
3412{
3413  tree x;
3414  switch (TREE_CODE (type))
3415    {
3416    case RECORD_TYPE:
3417      x = TYPE_FIELDS (type);
3418      if (x == NULL_TREE)
3419	return false;
3420      while (TREE_CHAIN (x) != NULL_TREE)
3421	x = TREE_CHAIN (x);
3422      if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE
3423	  && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE
3424	  && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE
3425	  && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE)
3426	return true;
3427      return false;
3428    case UNION_TYPE:
3429      for (x = TYPE_FIELDS (type); x != NULL_TREE; x = TREE_CHAIN (x))
3430	{
3431	  if (flexible_array_type_p (TREE_TYPE (x)))
3432	    return true;
3433	}
3434      return false;
3435    default:
3436    return false;
3437  }
3438}
3439
3440/* Given declspecs and a declarator,
3441   determine the name and type of the object declared
3442   and construct a ..._DECL node for it.
3443   (In one case we can return a ..._TYPE node instead.
3444    For invalid input we sometimes return 0.)
3445
3446   DECLSPECS is a chain of tree_list nodes whose value fields
3447    are the storage classes and type specifiers.
3448
3449   DECL_CONTEXT says which syntactic context this declaration is in:
3450     NORMAL for most contexts.  Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL.
3451     FUNCDEF for a function definition.  Like NORMAL but a few different
3452      error messages in each case.  Return value may be zero meaning
3453      this definition is too screwy to try to parse.
3454     PARM for a parameter declaration (either within a function prototype
3455      or before a function body).  Make a PARM_DECL, or return void_type_node.
3456     TYPENAME if for a typename (in a cast or sizeof).
3457      Don't make a DECL node; just return the ..._TYPE node.
3458     FIELD for a struct or union field; make a FIELD_DECL.
3459     BITFIELD for a field with specified width.
3460   INITIALIZED is 1 if the decl has an initializer.
3461
3462   In the TYPENAME case, DECLARATOR is really an absolute declarator.
3463   It may also be so in the PARM case, for a prototype where the
3464   argument type is specified but not the name.
3465
3466   This function is where the complicated C meanings of `static'
3467   and `extern' are interpreted.  */
3468
3469static tree
3470grokdeclarator (declarator, declspecs, decl_context, initialized)
3471     tree declspecs;
3472     tree declarator;
3473     enum decl_context decl_context;
3474     int initialized;
3475{
3476  int specbits = 0;
3477  tree spec;
3478  tree type = NULL_TREE;
3479  int longlong = 0;
3480  int constp;
3481  int restrictp;
3482  int volatilep;
3483  int type_quals = TYPE_UNQUALIFIED;
3484  int inlinep;
3485  int explicit_int = 0;
3486  int explicit_char = 0;
3487  int defaulted_int = 0;
3488  tree typedef_decl = 0;
3489  const char *name;
3490  tree typedef_type = 0;
3491  int funcdef_flag = 0;
3492  enum tree_code innermost_code = ERROR_MARK;
3493  int bitfield = 0;
3494  int size_varies = 0;
3495  tree decl_attr = NULL_TREE;
3496  tree array_ptr_quals = NULL_TREE;
3497  int array_parm_static = 0;
3498  tree returned_attrs = NULL_TREE;
3499
3500  if (decl_context == BITFIELD)
3501    bitfield = 1, decl_context = FIELD;
3502
3503  if (decl_context == FUNCDEF)
3504    funcdef_flag = 1, decl_context = NORMAL;
3505
3506  /* Look inside a declarator for the name being declared
3507     and get it as a string, for an error message.  */
3508  {
3509    tree decl = declarator;
3510    name = 0;
3511
3512    while (decl)
3513      switch (TREE_CODE (decl))
3514	{
3515	case ARRAY_REF:
3516	case INDIRECT_REF:
3517	case CALL_EXPR:
3518	  innermost_code = TREE_CODE (decl);
3519	  decl = TREE_OPERAND (decl, 0);
3520	  break;
3521
3522	case TREE_LIST:
3523	  decl = TREE_VALUE (decl);
3524	  break;
3525
3526	case IDENTIFIER_NODE:
3527	  name = IDENTIFIER_POINTER (decl);
3528	  decl = 0;
3529	  break;
3530
3531	default:
3532	  abort ();
3533	}
3534    if (name == 0)
3535      name = "type name";
3536  }
3537
3538  /* A function definition's declarator must have the form of
3539     a function declarator.  */
3540
3541  if (funcdef_flag && innermost_code != CALL_EXPR)
3542    return 0;
3543
3544  /* Anything declared one level down from the top level
3545     must be one of the parameters of a function
3546     (because the body is at least two levels down).  */
3547
3548  /* If this looks like a function definition, make it one,
3549     even if it occurs where parms are expected.
3550     Then store_parm_decls will reject it and not use it as a parm.  */
3551  if (decl_context == NORMAL && !funcdef_flag
3552      && current_binding_level->parm_flag)
3553    decl_context = PARM;
3554
3555  /* Look through the decl specs and record which ones appear.
3556     Some typespecs are defined as built-in typenames.
3557     Others, the ones that are modifiers of other types,
3558     are represented by bits in SPECBITS: set the bits for
3559     the modifiers that appear.  Storage class keywords are also in SPECBITS.
3560
3561     If there is a typedef name or a type, store the type in TYPE.
3562     This includes builtin typedefs such as `int'.
3563
3564     Set EXPLICIT_INT or EXPLICIT_CHAR if the type is `int' or `char'
3565     and did not come from a user typedef.
3566
3567     Set LONGLONG if `long' is mentioned twice.  */
3568
3569  for (spec = declspecs; spec; spec = TREE_CHAIN (spec))
3570    {
3571      tree id = TREE_VALUE (spec);
3572
3573      /* If the entire declaration is itself tagged as deprecated then
3574         suppress reports of deprecated items.  */
3575      if (id && TREE_DEPRECATED (id))
3576        {
3577	  if (deprecated_state != DEPRECATED_SUPPRESS)
3578	    warn_deprecated_use (id);
3579        }
3580
3581      if (id == ridpointers[(int) RID_INT])
3582	explicit_int = 1;
3583      if (id == ridpointers[(int) RID_CHAR])
3584	explicit_char = 1;
3585
3586      if (TREE_CODE (id) == IDENTIFIER_NODE && C_IS_RESERVED_WORD (id))
3587	{
3588	  enum rid i = C_RID_CODE (id);
3589	  if ((int) i <= (int) RID_LAST_MODIFIER)
3590	    {
3591	      if (i == RID_LONG && (specbits & (1 << (int) RID_LONG)))
3592		{
3593		  if (longlong)
3594		    error ("`long long long' is too long for GCC");
3595		  else
3596		    {
3597		      if (pedantic && !flag_isoc99 && ! in_system_header
3598			  && warn_long_long)
3599			pedwarn ("ISO C90 does not support `long long'");
3600		      longlong = 1;
3601		    }
3602		}
3603	      else if (specbits & (1 << (int) i))
3604		{
3605		  if (i == RID_CONST || i == RID_VOLATILE || i == RID_RESTRICT)
3606		    {
3607		      if (!flag_isoc99)
3608			pedwarn ("duplicate `%s'", IDENTIFIER_POINTER (id));
3609		    }
3610		  else
3611		    error ("duplicate `%s'", IDENTIFIER_POINTER (id));
3612		}
3613
3614	      /* Diagnose "__thread extern".  Recall that this list
3615		 is in the reverse order seen in the text.  */
3616	      if (i == RID_THREAD
3617		  && (specbits & (1 << (int) RID_EXTERN
3618				  | 1 << (int) RID_STATIC)))
3619		{
3620		  if (specbits & 1 << (int) RID_EXTERN)
3621		    error ("`__thread' before `extern'");
3622		  else
3623		    error ("`__thread' before `static'");
3624		}
3625
3626	      specbits |= 1 << (int) i;
3627	      goto found;
3628	    }
3629	}
3630      if (type)
3631	error ("two or more data types in declaration of `%s'", name);
3632      /* Actual typedefs come to us as TYPE_DECL nodes.  */
3633      else if (TREE_CODE (id) == TYPE_DECL)
3634	{
3635	  if (TREE_TYPE (id) == error_mark_node)
3636	    ; /* Allow the type to default to int to avoid cascading errors.  */
3637	  else
3638	    {
3639	      type = TREE_TYPE (id);
3640	      decl_attr = DECL_ATTRIBUTES (id);
3641	      typedef_decl = id;
3642	    }
3643	}
3644      /* Built-in types come as identifiers.  */
3645      else if (TREE_CODE (id) == IDENTIFIER_NODE)
3646	{
3647	  tree t = lookup_name (id);
3648	  if (TREE_TYPE (t) == error_mark_node)
3649	    ;
3650	  else if (!t || TREE_CODE (t) != TYPE_DECL)
3651	    error ("`%s' fails to be a typedef or built in type",
3652		   IDENTIFIER_POINTER (id));
3653	  else
3654	    {
3655	      type = TREE_TYPE (t);
3656	      typedef_decl = t;
3657	    }
3658	}
3659      else if (TREE_CODE (id) != ERROR_MARK)
3660	type = id;
3661
3662    found:
3663      ;
3664    }
3665
3666  typedef_type = type;
3667  if (type)
3668    size_varies = C_TYPE_VARIABLE_SIZE (type);
3669
3670  /* No type at all: default to `int', and set DEFAULTED_INT
3671     because it was not a user-defined typedef.  */
3672
3673  if (type == 0)
3674    {
3675      if ((! (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT)
3676			  | (1 << (int) RID_SIGNED)
3677			  | (1 << (int) RID_UNSIGNED)
3678			  | (1 << (int) RID_COMPLEX))))
3679	  /* Don't warn about typedef foo = bar.  */
3680	  && ! (specbits & (1 << (int) RID_TYPEDEF) && initialized)
3681	  && ! in_system_header)
3682	{
3683	  /* Issue a warning if this is an ISO C 99 program or if -Wreturn-type
3684	     and this is a function, or if -Wimplicit; prefer the former
3685	     warning since it is more explicit.  */
3686	  if ((warn_implicit_int || warn_return_type || flag_isoc99)
3687	      && funcdef_flag)
3688	    warn_about_return_type = 1;
3689	  else if (warn_implicit_int || flag_isoc99)
3690	    pedwarn_c99 ("type defaults to `int' in declaration of `%s'",
3691			 name);
3692	}
3693
3694      defaulted_int = 1;
3695      type = integer_type_node;
3696    }
3697
3698  /* Now process the modifiers that were specified
3699     and check for invalid combinations.  */
3700
3701  /* Long double is a special combination.  */
3702
3703  if ((specbits & 1 << (int) RID_LONG) && ! longlong
3704      && TYPE_MAIN_VARIANT (type) == double_type_node)
3705    {
3706      specbits &= ~(1 << (int) RID_LONG);
3707      type = long_double_type_node;
3708    }
3709
3710  /* Check all other uses of type modifiers.  */
3711
3712  if (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT)
3713		  | (1 << (int) RID_UNSIGNED) | (1 << (int) RID_SIGNED)))
3714    {
3715      int ok = 0;
3716
3717      if ((specbits & 1 << (int) RID_LONG)
3718	  && (specbits & 1 << (int) RID_SHORT))
3719	error ("both long and short specified for `%s'", name);
3720      else if (((specbits & 1 << (int) RID_LONG)
3721		|| (specbits & 1 << (int) RID_SHORT))
3722	       && explicit_char)
3723	error ("long or short specified with char for `%s'", name);
3724      else if (((specbits & 1 << (int) RID_LONG)
3725		|| (specbits & 1 << (int) RID_SHORT))
3726	       && TREE_CODE (type) == REAL_TYPE)
3727	{
3728	  static int already = 0;
3729
3730	  error ("long or short specified with floating type for `%s'", name);
3731	  if (! already && ! pedantic)
3732	    {
3733	      error ("the only valid combination is `long double'");
3734	      already = 1;
3735	    }
3736	}
3737      else if ((specbits & 1 << (int) RID_SIGNED)
3738	       && (specbits & 1 << (int) RID_UNSIGNED))
3739	error ("both signed and unsigned specified for `%s'", name);
3740      else if (TREE_CODE (type) != INTEGER_TYPE)
3741	error ("long, short, signed or unsigned invalid for `%s'", name);
3742      else
3743	{
3744	  ok = 1;
3745	  if (!explicit_int && !defaulted_int && !explicit_char)
3746	    {
3747	      error ("long, short, signed or unsigned used invalidly for `%s'",
3748		     name);
3749	      ok = 0;
3750	    }
3751	}
3752
3753      /* Discard the type modifiers if they are invalid.  */
3754      if (! ok)
3755	{
3756	  specbits &= ~((1 << (int) RID_LONG) | (1 << (int) RID_SHORT)
3757			| (1 << (int) RID_UNSIGNED) | (1 << (int) RID_SIGNED));
3758	  longlong = 0;
3759	}
3760    }
3761
3762  if ((specbits & (1 << (int) RID_COMPLEX))
3763      && TREE_CODE (type) != INTEGER_TYPE && TREE_CODE (type) != REAL_TYPE)
3764    {
3765      error ("complex invalid for `%s'", name);
3766      specbits &= ~(1 << (int) RID_COMPLEX);
3767    }
3768
3769  /* Decide whether an integer type is signed or not.
3770     Optionally treat bitfields as signed by default.  */
3771  if (specbits & 1 << (int) RID_UNSIGNED
3772      || (bitfield && ! flag_signed_bitfields
3773	  && (explicit_int || defaulted_int || explicit_char
3774	      /* A typedef for plain `int' without `signed'
3775		 can be controlled just like plain `int'.  */
3776	      || ! (typedef_decl != 0
3777		    && C_TYPEDEF_EXPLICITLY_SIGNED (typedef_decl)))
3778	  && TREE_CODE (type) != ENUMERAL_TYPE
3779	  && !(specbits & 1 << (int) RID_SIGNED)))
3780    {
3781      if (longlong)
3782	type = long_long_unsigned_type_node;
3783      else if (specbits & 1 << (int) RID_LONG)
3784	type = long_unsigned_type_node;
3785      else if (specbits & 1 << (int) RID_SHORT)
3786	type = short_unsigned_type_node;
3787      else if (type == char_type_node)
3788	type = unsigned_char_type_node;
3789      else if (typedef_decl)
3790	type = c_common_unsigned_type (type);
3791      else
3792	type = unsigned_type_node;
3793    }
3794  else if ((specbits & 1 << (int) RID_SIGNED)
3795	   && type == char_type_node)
3796    type = signed_char_type_node;
3797  else if (longlong)
3798    type = long_long_integer_type_node;
3799  else if (specbits & 1 << (int) RID_LONG)
3800    type = long_integer_type_node;
3801  else if (specbits & 1 << (int) RID_SHORT)
3802    type = short_integer_type_node;
3803
3804  if (specbits & 1 << (int) RID_COMPLEX)
3805    {
3806      if (pedantic && !flag_isoc99)
3807	pedwarn ("ISO C90 does not support complex types");
3808      /* If we just have "complex", it is equivalent to
3809	 "complex double", but if any modifiers at all are specified it is
3810	 the complex form of TYPE.  E.g, "complex short" is
3811	 "complex short int".  */
3812
3813      if (defaulted_int && ! longlong
3814	  && ! (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT)
3815			    | (1 << (int) RID_SIGNED)
3816			    | (1 << (int) RID_UNSIGNED))))
3817	{
3818	  if (pedantic)
3819	    pedwarn ("ISO C does not support plain `complex' meaning `double complex'");
3820	  type = complex_double_type_node;
3821	}
3822      else if (type == integer_type_node)
3823	{
3824	  if (pedantic)
3825	    pedwarn ("ISO C does not support complex integer types");
3826	  type = complex_integer_type_node;
3827	}
3828      else if (type == float_type_node)
3829	type = complex_float_type_node;
3830      else if (type == double_type_node)
3831	type = complex_double_type_node;
3832      else if (type == long_double_type_node)
3833	type = complex_long_double_type_node;
3834      else
3835	{
3836	  if (pedantic)
3837	    pedwarn ("ISO C does not support complex integer types");
3838	  type = build_complex_type (type);
3839	}
3840    }
3841
3842  /* Figure out the type qualifiers for the declaration.  There are
3843     two ways a declaration can become qualified.  One is something
3844     like `const int i' where the `const' is explicit.  Another is
3845     something like `typedef const int CI; CI i' where the type of the
3846     declaration contains the `const'.  */
3847  constp = !! (specbits & 1 << (int) RID_CONST) + TYPE_READONLY (type);
3848  restrictp = !! (specbits & 1 << (int) RID_RESTRICT) + TYPE_RESTRICT (type);
3849  volatilep = !! (specbits & 1 << (int) RID_VOLATILE) + TYPE_VOLATILE (type);
3850  inlinep = !! (specbits & (1 << (int) RID_INLINE));
3851  if (constp > 1 && ! flag_isoc99)
3852    pedwarn ("duplicate `const'");
3853  if (restrictp > 1 && ! flag_isoc99)
3854    pedwarn ("duplicate `restrict'");
3855  if (volatilep > 1 && ! flag_isoc99)
3856    pedwarn ("duplicate `volatile'");
3857  if (! flag_gen_aux_info && (TYPE_QUALS (type)))
3858    type = TYPE_MAIN_VARIANT (type);
3859  type_quals = ((constp ? TYPE_QUAL_CONST : 0)
3860		| (restrictp ? TYPE_QUAL_RESTRICT : 0)
3861		| (volatilep ? TYPE_QUAL_VOLATILE : 0));
3862
3863  /* Warn if two storage classes are given. Default to `auto'.  */
3864
3865  {
3866    int nclasses = 0;
3867
3868    if (specbits & 1 << (int) RID_AUTO) nclasses++;
3869    if (specbits & 1 << (int) RID_STATIC) nclasses++;
3870    if (specbits & 1 << (int) RID_EXTERN) nclasses++;
3871    if (specbits & 1 << (int) RID_REGISTER) nclasses++;
3872    if (specbits & 1 << (int) RID_TYPEDEF) nclasses++;
3873
3874    /* "static __thread" and "extern __thread" are allowed.  */
3875    if ((specbits & (1 << (int) RID_THREAD
3876		     | 1 << (int) RID_STATIC
3877		     | 1 << (int) RID_EXTERN)) == (1 << (int) RID_THREAD))
3878      nclasses++;
3879
3880    /* Warn about storage classes that are invalid for certain
3881       kinds of declarations (parameters, typenames, etc.).  */
3882
3883    if (nclasses > 1)
3884      error ("multiple storage classes in declaration of `%s'", name);
3885    else if (funcdef_flag
3886	     && (specbits
3887		 & ((1 << (int) RID_REGISTER)
3888		    | (1 << (int) RID_AUTO)
3889		    | (1 << (int) RID_TYPEDEF)
3890		    | (1 << (int) RID_THREAD))))
3891      {
3892	if (specbits & 1 << (int) RID_AUTO
3893	    && (pedantic || current_binding_level == global_binding_level))
3894	  pedwarn ("function definition declared `auto'");
3895	if (specbits & 1 << (int) RID_REGISTER)
3896	  error ("function definition declared `register'");
3897	if (specbits & 1 << (int) RID_TYPEDEF)
3898	  error ("function definition declared `typedef'");
3899	if (specbits & 1 << (int) RID_THREAD)
3900	  error ("function definition declared `__thread'");
3901	specbits &= ~((1 << (int) RID_TYPEDEF) | (1 << (int) RID_REGISTER)
3902		      | (1 << (int) RID_AUTO) | (1 << (int) RID_THREAD));
3903      }
3904    else if (decl_context != NORMAL && nclasses > 0)
3905      {
3906	if (decl_context == PARM && specbits & 1 << (int) RID_REGISTER)
3907	  ;
3908	else
3909	  {
3910	    switch (decl_context)
3911	      {
3912	      case FIELD:
3913		error ("storage class specified for structure field `%s'",
3914		       name);
3915		break;
3916	      case PARM:
3917		error ("storage class specified for parameter `%s'", name);
3918		break;
3919	      default:
3920		error ("storage class specified for typename");
3921		break;
3922	      }
3923	    specbits &= ~((1 << (int) RID_TYPEDEF) | (1 << (int) RID_REGISTER)
3924			  | (1 << (int) RID_AUTO) | (1 << (int) RID_STATIC)
3925			  | (1 << (int) RID_EXTERN) | (1 << (int) RID_THREAD));
3926	  }
3927      }
3928    else if (specbits & 1 << (int) RID_EXTERN && initialized && ! funcdef_flag)
3929      {
3930	/* `extern' with initialization is invalid if not at top level.  */
3931	if (current_binding_level == global_binding_level)
3932	  warning ("`%s' initialized and declared `extern'", name);
3933	else
3934	  error ("`%s' has both `extern' and initializer", name);
3935      }
3936    else if (current_binding_level == global_binding_level)
3937      {
3938	if (specbits & 1 << (int) RID_AUTO)
3939	  error ("top-level declaration of `%s' specifies `auto'", name);
3940      }
3941    else
3942      {
3943	if (specbits & 1 << (int) RID_EXTERN && funcdef_flag)
3944	  error ("nested function `%s' declared `extern'", name);
3945	else if ((specbits & (1 << (int) RID_THREAD
3946			       | 1 << (int) RID_EXTERN
3947			       | 1 << (int) RID_STATIC))
3948		 == (1 << (int) RID_THREAD))
3949	  {
3950	    error ("function-scope `%s' implicitly auto and declared `__thread'",
3951		   name);
3952	    specbits &= ~(1 << (int) RID_THREAD);
3953	  }
3954      }
3955  }
3956
3957  /* Now figure out the structure of the declarator proper.
3958     Descend through it, creating more complex types, until we reach
3959     the declared identifier (or NULL_TREE, in an absolute declarator).  */
3960
3961  while (declarator && TREE_CODE (declarator) != IDENTIFIER_NODE)
3962    {
3963      if (type == error_mark_node)
3964	{
3965	  declarator = TREE_OPERAND (declarator, 0);
3966	  continue;
3967	}
3968
3969      /* Each level of DECLARATOR is either an ARRAY_REF (for ...[..]),
3970	 an INDIRECT_REF (for *...),
3971	 a CALL_EXPR (for ...(...)),
3972	 a TREE_LIST (for nested attributes),
3973	 an identifier (for the name being declared)
3974	 or a null pointer (for the place in an absolute declarator
3975	 where the name was omitted).
3976	 For the last two cases, we have just exited the loop.
3977
3978	 At this point, TYPE is the type of elements of an array,
3979	 or for a function to return, or for a pointer to point to.
3980	 After this sequence of ifs, TYPE is the type of the
3981	 array or function or pointer, and DECLARATOR has had its
3982	 outermost layer removed.  */
3983
3984      if (array_ptr_quals != NULL_TREE || array_parm_static)
3985	{
3986	  /* Only the innermost declarator (making a parameter be of
3987	     array type which is converted to pointer type)
3988	     may have static or type qualifiers.  */
3989	  error ("static or type qualifiers in non-parameter array declarator");
3990	  array_ptr_quals = NULL_TREE;
3991	  array_parm_static = 0;
3992	}
3993
3994      if (TREE_CODE (declarator) == TREE_LIST)
3995	{
3996	  /* We encode a declarator with embedded attributes using
3997	     a TREE_LIST.  */
3998	  tree attrs = TREE_PURPOSE (declarator);
3999	  tree inner_decl;
4000	  int attr_flags = 0;
4001	  declarator = TREE_VALUE (declarator);
4002	  inner_decl = declarator;
4003	  while (inner_decl != NULL_TREE
4004		 && TREE_CODE (inner_decl) == TREE_LIST)
4005	    inner_decl = TREE_VALUE (inner_decl);
4006	  if (inner_decl == NULL_TREE
4007	      || TREE_CODE (inner_decl) == IDENTIFIER_NODE)
4008	    attr_flags |= (int) ATTR_FLAG_DECL_NEXT;
4009	  else if (TREE_CODE (inner_decl) == CALL_EXPR)
4010	    attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT;
4011	  else if (TREE_CODE (inner_decl) == ARRAY_REF)
4012	    attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT;
4013	  returned_attrs = decl_attributes (&type,
4014					    chainon (returned_attrs, attrs),
4015					    attr_flags);
4016	}
4017      else if (TREE_CODE (declarator) == ARRAY_REF)
4018	{
4019	  tree itype = NULL_TREE;
4020	  tree size = TREE_OPERAND (declarator, 1);
4021	  /* The index is a signed object `sizetype' bits wide.  */
4022	  tree index_type = c_common_signed_type (sizetype);
4023
4024	  array_ptr_quals = TREE_TYPE (declarator);
4025	  array_parm_static = TREE_STATIC (declarator);
4026
4027	  declarator = TREE_OPERAND (declarator, 0);
4028
4029	  /* Check for some types that there cannot be arrays of.  */
4030
4031	  if (VOID_TYPE_P (type))
4032	    {
4033	      error ("declaration of `%s' as array of voids", name);
4034	      type = error_mark_node;
4035	    }
4036
4037	  if (TREE_CODE (type) == FUNCTION_TYPE)
4038	    {
4039	      error ("declaration of `%s' as array of functions", name);
4040	      type = error_mark_node;
4041	    }
4042
4043	  if (pedantic && flexible_array_type_p (type))
4044	    pedwarn ("invalid use of structure with flexible array member");
4045
4046	  if (size == error_mark_node)
4047	    type = error_mark_node;
4048
4049	  if (type == error_mark_node)
4050	    continue;
4051
4052	  /* If size was specified, set ITYPE to a range-type for that size.
4053	     Otherwise, ITYPE remains null.  finish_decl may figure it out
4054	     from an initial value.  */
4055
4056	  if (size)
4057	    {
4058	      /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue.  */
4059	      STRIP_TYPE_NOPS (size);
4060
4061	      if (! INTEGRAL_TYPE_P (TREE_TYPE (size)))
4062		{
4063		  error ("size of array `%s' has non-integer type", name);
4064		  size = integer_one_node;
4065		}
4066
4067	      if (pedantic && integer_zerop (size))
4068		pedwarn ("ISO C forbids zero-size array `%s'", name);
4069
4070	      if (TREE_CODE (size) == INTEGER_CST)
4071		{
4072		  constant_expression_warning (size);
4073		  if (tree_int_cst_sgn (size) < 0)
4074		    {
4075		      error ("size of array `%s' is negative", name);
4076		      size = integer_one_node;
4077		    }
4078		}
4079	      else
4080		{
4081		  /* Make sure the array size remains visibly nonconstant
4082		     even if it is (eg) a const variable with known value.  */
4083		  size_varies = 1;
4084
4085		  if (!flag_isoc99 && pedantic)
4086		    {
4087		      if (TREE_CONSTANT (size))
4088			pedwarn ("ISO C90 forbids array `%s' whose size can't be evaluated",
4089				 name);
4090		      else
4091			pedwarn ("ISO C90 forbids variable-size array `%s'",
4092				 name);
4093		    }
4094		}
4095
4096	      if (integer_zerop (size))
4097		{
4098		  /* A zero-length array cannot be represented with an
4099		     unsigned index type, which is what we'll get with
4100		     build_index_type.  Create an open-ended range instead.  */
4101		  itype = build_range_type (sizetype, size, NULL_TREE);
4102		}
4103	      else
4104		{
4105		  /* Compute the maximum valid index, that is, size - 1.
4106		     Do the calculation in index_type, so that if it is
4107		     a variable the computations will be done in the
4108		     proper mode.  */
4109	          itype = fold (build (MINUS_EXPR, index_type,
4110				       convert (index_type, size),
4111				       convert (index_type, size_one_node)));
4112
4113	          /* If that overflowed, the array is too big.
4114		     ??? While a size of INT_MAX+1 technically shouldn't
4115		     cause an overflow (because we subtract 1), the overflow
4116		     is recorded during the conversion to index_type, before
4117		     the subtraction.  Handling this case seems like an
4118		     unnecessary complication.  */
4119		  if (TREE_OVERFLOW (itype))
4120		    {
4121		      error ("size of array `%s' is too large", name);
4122		      type = error_mark_node;
4123		      continue;
4124		    }
4125
4126		  if (size_varies)
4127		    {
4128		      /* We must be able to distinguish the
4129			 SAVE_EXPR_CONTEXT for the variably-sized type
4130			 so that we can set it correctly in
4131			 set_save_expr_context.  The convention is
4132			 that all SAVE_EXPRs that need to be reset
4133			 have NULL_TREE for their SAVE_EXPR_CONTEXT.  */
4134		      tree cfd = current_function_decl;
4135		      if (decl_context == PARM)
4136			current_function_decl = NULL_TREE;
4137		      itype = variable_size (itype);
4138		      if (decl_context == PARM)
4139			current_function_decl = cfd;
4140		    }
4141		  itype = build_index_type (itype);
4142		}
4143	    }
4144	  else if (decl_context == FIELD)
4145	    {
4146	      if (pedantic && !flag_isoc99 && !in_system_header)
4147		pedwarn ("ISO C90 does not support flexible array members");
4148
4149	      /* ISO C99 Flexible array members are effectively identical
4150		 to GCC's zero-length array extension.  */
4151	      itype = build_range_type (sizetype, size_zero_node, NULL_TREE);
4152	    }
4153
4154	  /* If pedantic, complain about arrays of incomplete types.  */
4155
4156	  if (pedantic && !COMPLETE_TYPE_P (type))
4157	    pedwarn ("array type has incomplete element type");
4158
4159#if 0
4160	  /* We shouldn't have a function type here at all!
4161	     Functions aren't allowed as array elements.  */
4162	  if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4163	      && (constp || volatilep))
4164	    pedwarn ("ISO C forbids const or volatile function types");
4165#endif
4166
4167	  /* Build the array type itself, then merge any constancy or
4168	     volatility into the target type.  We must do it in this order
4169	     to ensure that the TYPE_MAIN_VARIANT field of the array type
4170	     is set correctly.  */
4171
4172	  type = build_array_type (type, itype);
4173	  if (type_quals)
4174	    type = c_build_qualified_type (type, type_quals);
4175
4176	  if (size_varies)
4177	    C_TYPE_VARIABLE_SIZE (type) = 1;
4178
4179	  /* The GCC extension for zero-length arrays differs from
4180	     ISO flexible array members in that sizeof yields zero.  */
4181	  if (size && integer_zerop (size))
4182	    {
4183	      layout_type (type);
4184	      TYPE_SIZE (type) = bitsize_zero_node;
4185	      TYPE_SIZE_UNIT (type) = size_zero_node;
4186	    }
4187	  if (decl_context != PARM
4188	      && (array_ptr_quals != NULL_TREE || array_parm_static))
4189	    {
4190	      error ("static or type qualifiers in non-parameter array declarator");
4191	      array_ptr_quals = NULL_TREE;
4192	      array_parm_static = 0;
4193	    }
4194	}
4195      else if (TREE_CODE (declarator) == CALL_EXPR)
4196	{
4197	  tree arg_types;
4198
4199	  /* Declaring a function type.
4200	     Make sure we have a valid type for the function to return.  */
4201	  if (type == error_mark_node)
4202	    continue;
4203
4204	  size_varies = 0;
4205
4206	  /* Warn about some types functions can't return.  */
4207
4208	  if (TREE_CODE (type) == FUNCTION_TYPE)
4209	    {
4210	      error ("`%s' declared as function returning a function", name);
4211	      type = integer_type_node;
4212	    }
4213	  if (TREE_CODE (type) == ARRAY_TYPE)
4214	    {
4215	      error ("`%s' declared as function returning an array", name);
4216	      type = integer_type_node;
4217	    }
4218
4219	  /* Construct the function type and go to the next
4220	     inner layer of declarator.  */
4221
4222	  arg_types = grokparms (TREE_OPERAND (declarator, 1),
4223				 funcdef_flag
4224				 /* Say it's a definition
4225				    only for the CALL_EXPR
4226				    closest to the identifier.  */
4227				 && TREE_CODE (TREE_OPERAND (declarator, 0)) == IDENTIFIER_NODE);
4228	  /* Type qualifiers before the return type of the function
4229	     qualify the return type, not the function type.  */
4230	  if (type_quals)
4231	    {
4232	      /* Type qualifiers on a function return type are normally
4233		 permitted by the standard but have no effect, so give a
4234		 warning at -W.  Qualifiers on a void return type have
4235		 meaning as a GNU extension, and are banned on function
4236		 definitions in ISO C.  FIXME: strictly we shouldn't
4237		 pedwarn for qualified void return types except on function
4238		 definitions, but not doing so could lead to the undesirable
4239		 state of a "volatile void" function return type not being
4240		 warned about, and a use of the function being compiled
4241		 with GNU semantics, with no diagnostics under -pedantic.  */
4242	      if (VOID_TYPE_P (type) && pedantic && !in_system_header)
4243		pedwarn ("ISO C forbids qualified void function return type");
4244	      else if (extra_warnings
4245		       && !(VOID_TYPE_P (type)
4246			    && type_quals == TYPE_QUAL_VOLATILE))
4247		warning ("type qualifiers ignored on function return type");
4248
4249	      type = c_build_qualified_type (type, type_quals);
4250	    }
4251	  type_quals = TYPE_UNQUALIFIED;
4252
4253	  type = build_function_type (type, arg_types);
4254	  declarator = TREE_OPERAND (declarator, 0);
4255
4256	  /* Set the TYPE_CONTEXTs for each tagged type which is local to
4257	     the formal parameter list of this FUNCTION_TYPE to point to
4258	     the FUNCTION_TYPE node itself.  */
4259
4260	  {
4261	    tree link;
4262
4263	    for (link = last_function_parm_tags;
4264		 link;
4265		 link = TREE_CHAIN (link))
4266	      TYPE_CONTEXT (TREE_VALUE (link)) = type;
4267	  }
4268	}
4269      else if (TREE_CODE (declarator) == INDIRECT_REF)
4270	{
4271	  /* Merge any constancy or volatility into the target type
4272	     for the pointer.  */
4273
4274	  if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4275	      && type_quals)
4276	    pedwarn ("ISO C forbids qualified function types");
4277	  if (type_quals)
4278	    type = c_build_qualified_type (type, type_quals);
4279	  type_quals = TYPE_UNQUALIFIED;
4280	  size_varies = 0;
4281
4282	  type = build_pointer_type (type);
4283
4284	  /* Process a list of type modifier keywords
4285	     (such as const or volatile) that were given inside the `*'.  */
4286
4287	  if (TREE_TYPE (declarator))
4288	    {
4289	      tree typemodlist;
4290	      int erred = 0;
4291
4292	      constp = 0;
4293	      volatilep = 0;
4294	      restrictp = 0;
4295	      for (typemodlist = TREE_TYPE (declarator); typemodlist;
4296		   typemodlist = TREE_CHAIN (typemodlist))
4297		{
4298		  tree qualifier = TREE_VALUE (typemodlist);
4299
4300		  if (C_IS_RESERVED_WORD (qualifier))
4301		    {
4302		      if (C_RID_CODE (qualifier) == RID_CONST)
4303			constp++;
4304		      else if (C_RID_CODE (qualifier) == RID_VOLATILE)
4305			volatilep++;
4306		      else if (C_RID_CODE (qualifier) == RID_RESTRICT)
4307			restrictp++;
4308		      else
4309			erred++;
4310		    }
4311		  else
4312		    erred++;
4313		}
4314
4315	      if (erred)
4316		error ("invalid type modifier within pointer declarator");
4317	      if (constp > 1 && ! flag_isoc99)
4318		pedwarn ("duplicate `const'");
4319	      if (volatilep > 1 && ! flag_isoc99)
4320		pedwarn ("duplicate `volatile'");
4321	      if (restrictp > 1 && ! flag_isoc99)
4322		pedwarn ("duplicate `restrict'");
4323
4324	      type_quals = ((constp ? TYPE_QUAL_CONST : 0)
4325			    | (restrictp ? TYPE_QUAL_RESTRICT : 0)
4326			    | (volatilep ? TYPE_QUAL_VOLATILE : 0));
4327	    }
4328
4329	  declarator = TREE_OPERAND (declarator, 0);
4330	}
4331      else
4332	abort ();
4333
4334    }
4335
4336  /* Now TYPE has the actual type.  */
4337
4338  /* Did array size calculations overflow?  */
4339
4340  if (TREE_CODE (type) == ARRAY_TYPE
4341      && COMPLETE_TYPE_P (type)
4342      && TREE_OVERFLOW (TYPE_SIZE (type)))
4343    {
4344      error ("size of array `%s' is too large", name);
4345      /* If we proceed with the array type as it is, we'll eventually
4346	 crash in tree_low_cst().  */
4347      type = error_mark_node;
4348    }
4349
4350  /* If this is declaring a typedef name, return a TYPE_DECL.  */
4351
4352  if (specbits & (1 << (int) RID_TYPEDEF))
4353    {
4354      tree decl;
4355      /* Note that the grammar rejects storage classes
4356	 in typenames, fields or parameters */
4357      if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4358	  && type_quals)
4359	pedwarn ("ISO C forbids qualified function types");
4360      if (type_quals)
4361	type = c_build_qualified_type (type, type_quals);
4362      decl = build_decl (TYPE_DECL, declarator, type);
4363      if ((specbits & (1 << (int) RID_SIGNED))
4364	  || (typedef_decl && C_TYPEDEF_EXPLICITLY_SIGNED (typedef_decl)))
4365	C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1;
4366      decl_attributes (&decl, returned_attrs, 0);
4367      return decl;
4368    }
4369
4370  /* Detect the case of an array type of unspecified size
4371     which came, as such, direct from a typedef name.
4372     We must copy the type, so that each identifier gets
4373     a distinct type, so that each identifier's size can be
4374     controlled separately by its own initializer.  */
4375
4376  if (type != 0 && typedef_type != 0
4377      && TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == 0
4378      && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (typedef_type))
4379    {
4380      type = build_array_type (TREE_TYPE (type), 0);
4381      if (size_varies)
4382	C_TYPE_VARIABLE_SIZE (type) = 1;
4383    }
4384
4385  /* If this is a type name (such as, in a cast or sizeof),
4386     compute the type and return it now.  */
4387
4388  if (decl_context == TYPENAME)
4389    {
4390      /* Note that the grammar rejects storage classes
4391	 in typenames, fields or parameters */
4392      if (pedantic && TREE_CODE (type) == FUNCTION_TYPE
4393	  && type_quals)
4394	pedwarn ("ISO C forbids const or volatile function types");
4395      if (type_quals)
4396	type = c_build_qualified_type (type, type_quals);
4397      decl_attributes (&type, returned_attrs, 0);
4398      return type;
4399    }
4400
4401  /* Aside from typedefs and type names (handle above),
4402     `void' at top level (not within pointer)
4403     is allowed only in public variables.
4404     We don't complain about parms either, but that is because
4405     a better error message can be made later.  */
4406
4407  if (VOID_TYPE_P (type) && decl_context != PARM
4408      && ! ((decl_context != FIELD && TREE_CODE (type) != FUNCTION_TYPE)
4409	    && ((specbits & (1 << (int) RID_EXTERN))
4410		|| (current_binding_level == global_binding_level
4411		    && !(specbits
4412			 & ((1 << (int) RID_STATIC) | (1 << (int) RID_REGISTER)))))))
4413    {
4414      error ("variable or field `%s' declared void", name);
4415      type = integer_type_node;
4416    }
4417
4418  /* Now create the decl, which may be a VAR_DECL, a PARM_DECL
4419     or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE.  */
4420
4421  {
4422    tree decl;
4423
4424    if (decl_context == PARM)
4425      {
4426	tree type_as_written;
4427	tree promoted_type;
4428
4429	/* A parameter declared as an array of T is really a pointer to T.
4430	   One declared as a function is really a pointer to a function.  */
4431
4432	if (TREE_CODE (type) == ARRAY_TYPE)
4433	  {
4434	    /* Transfer const-ness of array into that of type pointed to.  */
4435	    type = TREE_TYPE (type);
4436	    if (type_quals)
4437	      type = c_build_qualified_type (type, type_quals);
4438	    type = build_pointer_type (type);
4439	    type_quals = TYPE_UNQUALIFIED;
4440	    if (array_ptr_quals)
4441	      {
4442		tree new_ptr_quals, new_ptr_attrs;
4443		int erred = 0;
4444		split_specs_attrs (array_ptr_quals, &new_ptr_quals, &new_ptr_attrs);
4445		/* We don't yet implement attributes in this context.  */
4446		if (new_ptr_attrs != NULL_TREE)
4447		  warning ("attributes in parameter array declarator ignored");
4448
4449		constp = 0;
4450		volatilep = 0;
4451		restrictp = 0;
4452		for (; new_ptr_quals; new_ptr_quals = TREE_CHAIN (new_ptr_quals))
4453		  {
4454		    tree qualifier = TREE_VALUE (new_ptr_quals);
4455
4456		    if (C_IS_RESERVED_WORD (qualifier))
4457		      {
4458			if (C_RID_CODE (qualifier) == RID_CONST)
4459			  constp++;
4460			else if (C_RID_CODE (qualifier) == RID_VOLATILE)
4461			  volatilep++;
4462			else if (C_RID_CODE (qualifier) == RID_RESTRICT)
4463			  restrictp++;
4464			else
4465			  erred++;
4466		      }
4467		    else
4468		      erred++;
4469		  }
4470
4471		if (erred)
4472		  error ("invalid type modifier within array declarator");
4473
4474		type_quals = ((constp ? TYPE_QUAL_CONST : 0)
4475			      | (restrictp ? TYPE_QUAL_RESTRICT : 0)
4476			      | (volatilep ? TYPE_QUAL_VOLATILE : 0));
4477	      }
4478	    size_varies = 0;
4479	  }
4480	else if (TREE_CODE (type) == FUNCTION_TYPE)
4481	  {
4482	    if (pedantic && type_quals)
4483	      pedwarn ("ISO C forbids qualified function types");
4484	    if (type_quals)
4485	      type = c_build_qualified_type (type, type_quals);
4486	    type = build_pointer_type (type);
4487	    type_quals = TYPE_UNQUALIFIED;
4488	  }
4489	else if (type_quals)
4490	  type = c_build_qualified_type (type, type_quals);
4491
4492	type_as_written = type;
4493
4494	decl = build_decl (PARM_DECL, declarator, type);
4495	if (size_varies)
4496	  C_DECL_VARIABLE_SIZE (decl) = 1;
4497
4498	/* Compute the type actually passed in the parmlist,
4499	   for the case where there is no prototype.
4500	   (For example, shorts and chars are passed as ints.)
4501	   When there is a prototype, this is overridden later.  */
4502
4503	if (type == error_mark_node)
4504	  promoted_type = type;
4505	else
4506	  promoted_type = c_type_promotes_to (type);
4507
4508	DECL_ARG_TYPE (decl) = promoted_type;
4509	DECL_ARG_TYPE_AS_WRITTEN (decl) = type_as_written;
4510      }
4511    else if (decl_context == FIELD)
4512      {
4513	/* Structure field.  It may not be a function.  */
4514
4515	if (TREE_CODE (type) == FUNCTION_TYPE)
4516	  {
4517	    error ("field `%s' declared as a function", name);
4518	    type = build_pointer_type (type);
4519	  }
4520	else if (TREE_CODE (type) != ERROR_MARK
4521	         && !COMPLETE_OR_UNBOUND_ARRAY_TYPE_P (type))
4522	  {
4523	    error ("field `%s' has incomplete type", name);
4524	    type = error_mark_node;
4525	  }
4526	/* Move type qualifiers down to element of an array.  */
4527	if (TREE_CODE (type) == ARRAY_TYPE && type_quals)
4528	  {
4529	    type = build_array_type (c_build_qualified_type (TREE_TYPE (type),
4530							     type_quals),
4531				     TYPE_DOMAIN (type));
4532#if 0
4533	    /* Leave the field const or volatile as well.  */
4534	    type_quals = TYPE_UNQUALIFIED;
4535#endif
4536	  }
4537	decl = build_decl (FIELD_DECL, declarator, type);
4538	DECL_NONADDRESSABLE_P (decl) = bitfield;
4539
4540	if (size_varies)
4541	  C_DECL_VARIABLE_SIZE (decl) = 1;
4542      }
4543    else if (TREE_CODE (type) == FUNCTION_TYPE)
4544      {
4545	/* Every function declaration is "external"
4546	   except for those which are inside a function body
4547	   in which `auto' is used.
4548	   That is a case not specified by ANSI C,
4549	   and we use it for forward declarations for nested functions.  */
4550	int extern_ref = (!(specbits & (1 << (int) RID_AUTO))
4551			  || current_binding_level == global_binding_level);
4552
4553	if (specbits & (1 << (int) RID_AUTO)
4554	    && (pedantic || current_binding_level == global_binding_level))
4555	  pedwarn ("invalid storage class for function `%s'", name);
4556	if (specbits & (1 << (int) RID_REGISTER))
4557	  error ("invalid storage class for function `%s'", name);
4558	if (specbits & (1 << (int) RID_THREAD))
4559	  error ("invalid storage class for function `%s'", name);
4560	/* Function declaration not at top level.
4561	   Storage classes other than `extern' are not allowed
4562	   and `extern' makes no difference.  */
4563	if (current_binding_level != global_binding_level
4564	    && (specbits & ((1 << (int) RID_STATIC) | (1 << (int) RID_INLINE)))
4565	    && pedantic)
4566	  pedwarn ("invalid storage class for function `%s'", name);
4567
4568	decl = build_decl (FUNCTION_DECL, declarator, type);
4569	decl = build_decl_attribute_variant (decl, decl_attr);
4570
4571	DECL_LANG_SPECIFIC (decl) = (struct lang_decl *)
4572	  ggc_alloc_cleared (sizeof (struct lang_decl));
4573
4574	if (pedantic && type_quals && ! DECL_IN_SYSTEM_HEADER (decl))
4575	  pedwarn ("ISO C forbids qualified function types");
4576
4577	/* GNU C interprets a `volatile void' return type to indicate
4578	   that the function does not return.  */
4579	if ((type_quals & TYPE_QUAL_VOLATILE)
4580	    && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
4581	  warning ("`noreturn' function returns non-void value");
4582
4583	if (extern_ref)
4584	  DECL_EXTERNAL (decl) = 1;
4585	/* Record absence of global scope for `static' or `auto'.  */
4586	TREE_PUBLIC (decl)
4587	  = !(specbits & ((1 << (int) RID_STATIC) | (1 << (int) RID_AUTO)));
4588
4589	if (defaulted_int)
4590	  C_FUNCTION_IMPLICIT_INT (decl) = 1;
4591
4592	/* Record presence of `inline', if it is reasonable.  */
4593	if (MAIN_NAME_P (declarator))
4594	  {
4595	    if (inlinep)
4596	      warning ("cannot inline function `main'");
4597	  }
4598	else if (inlinep)
4599	  {
4600	    /* Assume that otherwise the function can be inlined.  */
4601	    DECL_DECLARED_INLINE_P (decl) = 1;
4602
4603	    /* Do not mark bare declarations as DECL_INLINE.  Doing so
4604	       in the presence of multiple declarations can result in
4605	       the abstract origin pointing between the declarations,
4606	       which will confuse dwarf2out.  */
4607	    if (initialized)
4608	      {
4609		DECL_INLINE (decl) = 1;
4610		if (specbits & (1 << (int) RID_EXTERN))
4611		  current_extern_inline = 1;
4612	      }
4613	  }
4614	/* If -finline-functions, assume it can be inlined.  This does
4615	   two things: let the function be deferred until it is actually
4616	   needed, and let dwarf2 know that the function is inlinable.  */
4617	else if (flag_inline_trees == 2 && initialized)
4618	  {
4619	    if (!DECL_INLINE (decl))
4620		DID_INLINE_FUNC (decl) = 1;
4621	    DECL_INLINE (decl) = 1;
4622	    DECL_DECLARED_INLINE_P (decl) = 0;
4623	  }
4624      }
4625    else
4626      {
4627	/* It's a variable.  */
4628	/* An uninitialized decl with `extern' is a reference.  */
4629	int extern_ref = !initialized && (specbits & (1 << (int) RID_EXTERN));
4630
4631	/* Move type qualifiers down to element of an array.  */
4632	if (TREE_CODE (type) == ARRAY_TYPE && type_quals)
4633	  {
4634	    int saved_align = TYPE_ALIGN(type);
4635	    type = build_array_type (c_build_qualified_type (TREE_TYPE (type),
4636							     type_quals),
4637				     TYPE_DOMAIN (type));
4638	    TYPE_ALIGN (type) = saved_align;
4639#if 0 /* Leave the variable const or volatile as well.  */
4640	    type_quals = TYPE_UNQUALIFIED;
4641#endif
4642	  }
4643	else if (type_quals)
4644	  type = c_build_qualified_type (type, type_quals);
4645
4646	decl = build_decl (VAR_DECL, declarator, type);
4647	if (size_varies)
4648	  C_DECL_VARIABLE_SIZE (decl) = 1;
4649
4650	if (inlinep)
4651	  pedwarn_with_decl (decl, "variable `%s' declared `inline'");
4652
4653	DECL_EXTERNAL (decl) = extern_ref;
4654
4655	/* At top level, the presence of a `static' or `register' storage
4656	   class specifier, or the absence of all storage class specifiers
4657	   makes this declaration a definition (perhaps tentative).  Also,
4658	   the absence of both `static' and `register' makes it public.  */
4659	if (current_binding_level == global_binding_level)
4660	  {
4661	    TREE_PUBLIC (decl) = !(specbits & ((1 << (int) RID_STATIC)
4662					       | (1 << (int) RID_REGISTER)));
4663	    TREE_STATIC (decl) = !extern_ref;
4664	  }
4665	/* Not at top level, only `static' makes a static definition.  */
4666	else
4667	  {
4668	    TREE_STATIC (decl) = (specbits & (1 << (int) RID_STATIC)) != 0;
4669	    TREE_PUBLIC (decl) = extern_ref;
4670	  }
4671
4672	if (specbits & 1 << (int) RID_THREAD)
4673	  {
4674	    if (targetm.have_tls)
4675	      DECL_THREAD_LOCAL (decl) = 1;
4676	    else
4677	      /* A mere warning is sure to result in improper semantics
4678		 at runtime.  Don't bother to allow this to compile.  */
4679	      error ("thread-local storage not supported for this target");
4680	  }
4681      }
4682
4683    /* Record `register' declaration for warnings on &
4684       and in case doing stupid register allocation.  */
4685
4686    if (specbits & (1 << (int) RID_REGISTER))
4687      DECL_REGISTER (decl) = 1;
4688
4689    /* Record constancy and volatility.  */
4690    c_apply_type_quals_to_decl (type_quals, decl);
4691
4692    /* If a type has volatile components, it should be stored in memory.
4693       Otherwise, the fact that those components are volatile
4694       will be ignored, and would even crash the compiler.  */
4695    if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (decl)))
4696      c_mark_addressable (decl);
4697
4698    decl_attributes (&decl, returned_attrs, 0);
4699
4700    return decl;
4701  }
4702}
4703
4704/* Decode the parameter-list info for a function type or function definition.
4705   The argument is the value returned by `get_parm_info' (or made in parse.y
4706   if there is an identifier list instead of a parameter decl list).
4707   These two functions are separate because when a function returns
4708   or receives functions then each is called multiple times but the order
4709   of calls is different.  The last call to `grokparms' is always the one
4710   that contains the formal parameter names of a function definition.
4711
4712   Store in `last_function_parms' a chain of the decls of parms.
4713   Also store in `last_function_parm_tags' a chain of the struct, union,
4714   and enum tags declared among the parms.
4715
4716   Return a list of arg types to use in the FUNCTION_TYPE for this function.
4717
4718   FUNCDEF_FLAG is nonzero for a function definition, 0 for
4719   a mere declaration.  A nonempty identifier-list gets an error message
4720   when FUNCDEF_FLAG is zero.  */
4721
4722static tree
4723grokparms (parms_info, funcdef_flag)
4724     tree parms_info;
4725     int funcdef_flag;
4726{
4727  tree first_parm = TREE_CHAIN (parms_info);
4728
4729  last_function_parms = TREE_PURPOSE (parms_info);
4730  last_function_parm_tags = TREE_VALUE (parms_info);
4731
4732  if (warn_strict_prototypes && first_parm == 0 && !funcdef_flag
4733      && !in_system_header)
4734    warning ("function declaration isn't a prototype");
4735
4736  if (first_parm != 0
4737      && TREE_CODE (TREE_VALUE (first_parm)) == IDENTIFIER_NODE)
4738    {
4739      if (! funcdef_flag)
4740	pedwarn ("parameter names (without types) in function declaration");
4741
4742      last_function_parms = first_parm;
4743      return 0;
4744    }
4745  else
4746    {
4747      tree parm;
4748      tree typelt;
4749      /* We no longer test FUNCDEF_FLAG.
4750	 If the arg types are incomplete in a declaration,
4751	 they must include undefined tags.
4752	 These tags can never be defined in the scope of the declaration,
4753	 so the types can never be completed,
4754	 and no call can be compiled successfully.  */
4755#if 0
4756      /* In a fcn definition, arg types must be complete.  */
4757      if (funcdef_flag)
4758#endif
4759	for (parm = last_function_parms, typelt = first_parm;
4760	     parm;
4761	     parm = TREE_CHAIN (parm))
4762	  /* Skip over any enumeration constants declared here.  */
4763	  if (TREE_CODE (parm) == PARM_DECL)
4764	    {
4765	      /* Barf if the parameter itself has an incomplete type.  */
4766	      tree type = TREE_VALUE (typelt);
4767	      if (type == error_mark_node)
4768		continue;
4769	      if (!COMPLETE_TYPE_P (type))
4770		{
4771		  if (funcdef_flag && DECL_NAME (parm) != 0)
4772		    error ("parameter `%s' has incomplete type",
4773			   IDENTIFIER_POINTER (DECL_NAME (parm)));
4774		  else
4775		    warning ("parameter has incomplete type");
4776		  if (funcdef_flag)
4777		    {
4778		      TREE_VALUE (typelt) = error_mark_node;
4779		      TREE_TYPE (parm) = error_mark_node;
4780		    }
4781		}
4782#if 0
4783	      /* This has been replaced by parm_tags_warning, which
4784		 uses a more accurate criterion for what to warn
4785		 about.  */
4786	      else
4787		{
4788		  /* Now warn if is a pointer to an incomplete type.  */
4789		  while (TREE_CODE (type) == POINTER_TYPE
4790			 || TREE_CODE (type) == REFERENCE_TYPE)
4791		    type = TREE_TYPE (type);
4792		  type = TYPE_MAIN_VARIANT (type);
4793		  if (!COMPLETE_TYPE_P (type))
4794		    {
4795		      if (DECL_NAME (parm) != 0)
4796			warning ("parameter `%s' points to incomplete type",
4797				 IDENTIFIER_POINTER (DECL_NAME (parm)));
4798		      else
4799			warning ("parameter points to incomplete type");
4800		    }
4801		}
4802#endif
4803	      typelt = TREE_CHAIN (typelt);
4804	    }
4805
4806      return first_parm;
4807    }
4808}
4809
4810/* Return a tree_list node with info on a parameter list just parsed.
4811   The TREE_PURPOSE is a chain of decls of those parms.
4812   The TREE_VALUE is a list of structure, union and enum tags defined.
4813   The TREE_CHAIN is a list of argument types to go in the FUNCTION_TYPE.
4814   This tree_list node is later fed to `grokparms'.
4815
4816   VOID_AT_END nonzero means append `void' to the end of the type-list.
4817   Zero means the parmlist ended with an ellipsis so don't append `void'.  */
4818
4819tree
4820get_parm_info (void_at_end)
4821     int void_at_end;
4822{
4823  tree decl, t;
4824  tree types = 0;
4825  int erred = 0;
4826  tree tags = gettags ();
4827  tree parms = getdecls ();
4828  tree new_parms = 0;
4829  tree order = current_binding_level->parm_order;
4830
4831  /* Just `void' (and no ellipsis) is special.  There are really no parms.
4832     But if the `void' is qualified (by `const' or `volatile') or has a
4833     storage class specifier (`register'), then the behavior is undefined;
4834     by not counting it as the special case of `void' we will cause an
4835     error later.  Typedefs for `void' are OK (see DR#157).  */
4836  if (void_at_end && parms != 0
4837      && TREE_CHAIN (parms) == 0
4838      && VOID_TYPE_P (TREE_TYPE (parms))
4839      && ! TREE_THIS_VOLATILE (parms)
4840      && ! TREE_READONLY (parms)
4841      && ! DECL_REGISTER (parms)
4842      && DECL_NAME (parms) == 0)
4843    {
4844      parms = NULL_TREE;
4845      storedecls (NULL_TREE);
4846      return tree_cons (NULL_TREE, NULL_TREE,
4847			tree_cons (NULL_TREE, void_type_node, NULL_TREE));
4848    }
4849
4850  /* Extract enumerator values and other non-parms declared with the parms.
4851     Likewise any forward parm decls that didn't have real parm decls.  */
4852  for (decl = parms; decl;)
4853    {
4854      tree next = TREE_CHAIN (decl);
4855
4856      if (TREE_CODE (decl) != PARM_DECL)
4857	{
4858	  TREE_CHAIN (decl) = new_parms;
4859	  new_parms = decl;
4860	}
4861      else if (TREE_ASM_WRITTEN (decl))
4862	{
4863	  error_with_decl (decl,
4864			   "parameter `%s' has just a forward declaration");
4865	  TREE_CHAIN (decl) = new_parms;
4866	  new_parms = decl;
4867	}
4868      decl = next;
4869    }
4870
4871  /* Put the parm decls back in the order they were in in the parm list.  */
4872  for (t = order; t; t = TREE_CHAIN (t))
4873    {
4874      if (TREE_CHAIN (t))
4875	TREE_CHAIN (TREE_VALUE (t)) = TREE_VALUE (TREE_CHAIN (t));
4876      else
4877	TREE_CHAIN (TREE_VALUE (t)) = 0;
4878    }
4879
4880  new_parms = chainon (order ? nreverse (TREE_VALUE (order)) : 0,
4881		       new_parms);
4882
4883  /* Store the parmlist in the binding level since the old one
4884     is no longer a valid list.  (We have changed the chain pointers.)  */
4885  storedecls (new_parms);
4886
4887  for (decl = new_parms; decl; decl = TREE_CHAIN (decl))
4888    /* There may also be declarations for enumerators if an enumeration
4889       type is declared among the parms.  Ignore them here.  */
4890    if (TREE_CODE (decl) == PARM_DECL)
4891      {
4892	/* Since there is a prototype,
4893	   args are passed in their declared types.  */
4894	tree type = TREE_TYPE (decl);
4895	DECL_ARG_TYPE (decl) = type;
4896	if (PROMOTE_PROTOTYPES
4897	    && INTEGRAL_TYPE_P (type)
4898	    && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))
4899	  DECL_ARG_TYPE (decl) = integer_type_node;
4900
4901	types = tree_cons (NULL_TREE, TREE_TYPE (decl), types);
4902	if (VOID_TYPE_P (TREE_VALUE (types)) && ! erred
4903	    && DECL_NAME (decl) == 0)
4904	  {
4905	    error ("`void' in parameter list must be the entire list");
4906	    erred = 1;
4907	  }
4908      }
4909
4910  if (void_at_end)
4911    return tree_cons (new_parms, tags,
4912		      nreverse (tree_cons (NULL_TREE, void_type_node, types)));
4913
4914  return tree_cons (new_parms, tags, nreverse (types));
4915}
4916
4917/* At end of parameter list, warn about any struct, union or enum tags
4918   defined within.  Do so because these types cannot ever become complete.  */
4919
4920void
4921parmlist_tags_warning ()
4922{
4923  tree elt;
4924  static int already;
4925
4926  for (elt = current_binding_level->tags; elt; elt = TREE_CHAIN (elt))
4927    {
4928      enum tree_code code = TREE_CODE (TREE_VALUE (elt));
4929      /* An anonymous union parm type is meaningful as a GNU extension.
4930	 So don't warn for that.  */
4931      if (code == UNION_TYPE && TREE_PURPOSE (elt) == 0 && !pedantic)
4932	continue;
4933      if (TREE_PURPOSE (elt) != 0)
4934        {
4935          if (code == RECORD_TYPE)
4936            warning ("`struct %s' declared inside parameter list",
4937                     IDENTIFIER_POINTER (TREE_PURPOSE (elt)));
4938          else if (code == UNION_TYPE)
4939            warning ("`union %s' declared inside parameter list",
4940                     IDENTIFIER_POINTER (TREE_PURPOSE (elt)));
4941          else
4942            warning ("`enum %s' declared inside parameter list",
4943                     IDENTIFIER_POINTER (TREE_PURPOSE (elt)));
4944        }
4945      else
4946	{
4947	  /* For translation these need to be separate warnings */
4948	  if (code == RECORD_TYPE)
4949	    warning ("anonymous struct declared inside parameter list");
4950	  else if (code == UNION_TYPE)
4951	    warning ("anonymous union declared inside parameter list");
4952	  else
4953	    warning ("anonymous enum declared inside parameter list");
4954	}
4955      if (! already)
4956	{
4957	  warning ("its scope is only this definition or declaration, which is probably not what you want");
4958	  already = 1;
4959	}
4960    }
4961}
4962
4963/* Get the struct, enum or union (CODE says which) with tag NAME.
4964   Define the tag as a forward-reference if it is not defined.  */
4965
4966tree
4967xref_tag (code, name)
4968     enum tree_code code;
4969     tree name;
4970{
4971  /* If a cross reference is requested, look up the type
4972     already defined for this tag and return it.  */
4973
4974  tree ref = lookup_tag (code, name, current_binding_level, 0);
4975  /* If this is the right type of tag, return what we found.
4976     (This reference will be shadowed by shadow_tag later if appropriate.)
4977     If this is the wrong type of tag, do not return it.  If it was the
4978     wrong type in the same binding level, we will have had an error
4979     message already; if in a different binding level and declaring
4980     a name, pending_xref_error will give an error message; but if in a
4981     different binding level and not declaring a name, this tag should
4982     shadow the previous declaration of a different type of tag, and
4983     this would not work properly if we return the reference found.
4984     (For example, with "struct foo" in an outer scope, "union foo;"
4985     must shadow that tag with a new one of union type.)  */
4986  if (ref && TREE_CODE (ref) == code)
4987    return ref;
4988
4989  /* If no such tag is yet defined, create a forward-reference node
4990     and record it as the "definition".
4991     When a real declaration of this type is found,
4992     the forward-reference will be altered into a real type.  */
4993
4994  ref = make_node (code);
4995  if (code == ENUMERAL_TYPE)
4996    {
4997      /* Give the type a default layout like unsigned int
4998	 to avoid crashing if it does not get defined.  */
4999      TYPE_MODE (ref) = TYPE_MODE (unsigned_type_node);
5000      TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node);
5001      TYPE_USER_ALIGN (ref) = 0;
5002      TREE_UNSIGNED (ref) = 1;
5003      TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node);
5004      TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node);
5005      TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node);
5006    }
5007
5008  pushtag (name, ref);
5009
5010  return ref;
5011}
5012
5013/* Make sure that the tag NAME is defined *in the current binding level*
5014   at least as a forward reference.
5015   CODE says which kind of tag NAME ought to be.  */
5016
5017tree
5018start_struct (code, name)
5019     enum tree_code code;
5020     tree name;
5021{
5022  /* If there is already a tag defined at this binding level
5023     (as a forward reference), just return it.  */
5024
5025  tree ref = 0;
5026
5027  if (name != 0)
5028    ref = lookup_tag (code, name, current_binding_level, 1);
5029  if (ref && TREE_CODE (ref) == code)
5030    {
5031      if (TYPE_FIELDS (ref))
5032        {
5033	  if (code == UNION_TYPE)
5034	    error ("redefinition of `union %s'", IDENTIFIER_POINTER (name));
5035          else
5036	    error ("redefinition of `struct %s'", IDENTIFIER_POINTER (name));
5037	}
5038    }
5039  else
5040    {
5041      /* Otherwise create a forward-reference just so the tag is in scope.  */
5042
5043      ref = make_node (code);
5044      pushtag (name, ref);
5045    }
5046
5047  C_TYPE_BEING_DEFINED (ref) = 1;
5048  TYPE_PACKED (ref) = flag_pack_struct;
5049  return ref;
5050}
5051
5052/* Process the specs, declarator (NULL if omitted) and width (NULL if omitted)
5053   of a structure component, returning a FIELD_DECL node.
5054   WIDTH is non-NULL for bit fields only, and is an INTEGER_CST node.
5055
5056   This is done during the parsing of the struct declaration.
5057   The FIELD_DECL nodes are chained together and the lot of them
5058   are ultimately passed to `build_struct' to make the RECORD_TYPE node.  */
5059
5060tree
5061grokfield (filename, line, declarator, declspecs, width)
5062     const char *filename ATTRIBUTE_UNUSED;
5063     int line ATTRIBUTE_UNUSED;
5064     tree declarator, declspecs, width;
5065{
5066  tree value;
5067
5068  if (declarator == NULL_TREE && width == NULL_TREE)
5069    {
5070      /* This is an unnamed decl.
5071
5072	 If we have something of the form "union { list } ;" then this
5073	 is the anonymous union extension.  Similarly for struct.
5074
5075	 If this is something of the form "struct foo;", then
5076	   If MS extensions are enabled, this is handled as an
5077	     anonymous struct.
5078	   Otherwise this is a forward declaration of a structure tag.
5079
5080	 If this is something of the form "foo;" and foo is a TYPE_DECL, then
5081	   If MS extensions are enabled and foo names a structure, then
5082	     again this is an anonymous struct.
5083	   Otherwise this is an error.
5084
5085	 Oh what a horrid tangled web we weave.  I wonder if MS consiously
5086	 took this from Plan 9 or if it was an accident of implementation
5087	 that took root before someone noticed the bug...  */
5088
5089      tree type = TREE_VALUE (declspecs);
5090
5091      if (flag_ms_extensions && TREE_CODE (type) == TYPE_DECL)
5092	type = TREE_TYPE (type);
5093      if (TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE)
5094	{
5095	  if (flag_ms_extensions)
5096	    ; /* ok */
5097	  else if (flag_iso)
5098	    goto warn_unnamed_field;
5099	  else if (TYPE_NAME (type) == NULL)
5100	    ; /* ok */
5101	  else
5102	    goto warn_unnamed_field;
5103	}
5104      else
5105	{
5106	warn_unnamed_field:
5107	  warning ("declaration does not declare anything");
5108	  return NULL_TREE;
5109	}
5110    }
5111
5112  value = grokdeclarator (declarator, declspecs, width ? BITFIELD : FIELD, 0);
5113
5114  finish_decl (value, NULL_TREE, NULL_TREE);
5115  DECL_INITIAL (value) = width;
5116
5117  if (flag_objc)
5118    objc_check_decl (value);
5119  return value;
5120}
5121
5122/* Function to help qsort sort FIELD_DECLs by name order.  */
5123
5124
5125static int
5126field_decl_cmp (xp, yp)
5127      const PTR xp;
5128      const PTR yp;
5129{
5130  tree *x = (tree *)xp, *y = (tree *)yp;
5131
5132  if (DECL_NAME (*x) == DECL_NAME (*y))
5133    return 0;
5134  if (DECL_NAME (*x) == NULL)
5135    return -1;
5136  if (DECL_NAME (*y) == NULL)
5137    return 1;
5138  if (DECL_NAME (*x) < DECL_NAME (*y))
5139    return -1;
5140  return 1;
5141}
5142
5143
5144/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T.
5145   FIELDLIST is a chain of FIELD_DECL nodes for the fields.
5146   ATTRIBUTES are attributes to be applied to the structure.  */
5147
5148tree
5149finish_struct (t, fieldlist, attributes)
5150     tree t;
5151     tree fieldlist;
5152     tree attributes;
5153{
5154  tree x;
5155  int toplevel = global_binding_level == current_binding_level;
5156  int saw_named_field;
5157
5158  /* If this type was previously laid out as a forward reference,
5159     make sure we lay it out again.  */
5160
5161  TYPE_SIZE (t) = 0;
5162
5163  decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5164
5165  /* Nameless union parm types are useful as GCC extension.  */
5166  if (! (TREE_CODE (t) == UNION_TYPE && TYPE_NAME (t) == 0) && !pedantic)
5167    /* Otherwise, warn about any struct or union def. in parmlist.  */
5168    if (in_parm_level_p ())
5169      {
5170	if (pedantic)
5171	  pedwarn ("%s defined inside parms",
5172		   TREE_CODE (t) == UNION_TYPE ? _("union") : _("structure"));
5173	else
5174	  warning ("%s defined inside parms",
5175		   TREE_CODE (t) == UNION_TYPE ? _("union") : _("structure"));
5176      }
5177
5178  if (pedantic)
5179    {
5180      for (x = fieldlist; x; x = TREE_CHAIN (x))
5181	if (DECL_NAME (x) != 0)
5182	  break;
5183
5184      if (x == 0)
5185	pedwarn ("%s has no %s",
5186		 TREE_CODE (t) == UNION_TYPE ? _("union") : _("struct"),
5187		 fieldlist ? _("named members") : _("members"));
5188    }
5189
5190  /* Install struct as DECL_CONTEXT of each field decl.
5191     Also process specified field sizes,m which is found in the DECL_INITIAL.
5192     Store 0 there, except for ": 0" fields (so we can find them
5193     and delete them, below).  */
5194
5195  saw_named_field = 0;
5196  for (x = fieldlist; x; x = TREE_CHAIN (x))
5197    {
5198      DECL_CONTEXT (x) = t;
5199      DECL_PACKED (x) |= TYPE_PACKED (t);
5200
5201      /* If any field is const, the structure type is pseudo-const.  */
5202      if (TREE_READONLY (x))
5203	C_TYPE_FIELDS_READONLY (t) = 1;
5204      else
5205	{
5206	  /* A field that is pseudo-const makes the structure likewise.  */
5207	  tree t1 = TREE_TYPE (x);
5208	  while (TREE_CODE (t1) == ARRAY_TYPE)
5209	    t1 = TREE_TYPE (t1);
5210	  if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE)
5211	      && C_TYPE_FIELDS_READONLY (t1))
5212	    C_TYPE_FIELDS_READONLY (t) = 1;
5213	}
5214
5215      /* Any field that is volatile means variables of this type must be
5216	 treated in some ways as volatile.  */
5217      if (TREE_THIS_VOLATILE (x))
5218	C_TYPE_FIELDS_VOLATILE (t) = 1;
5219
5220      /* Any field of nominal variable size implies structure is too.  */
5221      if (C_DECL_VARIABLE_SIZE (x))
5222	C_TYPE_VARIABLE_SIZE (t) = 1;
5223
5224      /* Detect invalid nested redefinition.  */
5225      if (TREE_TYPE (x) == t)
5226	error ("nested redefinition of `%s'",
5227	       IDENTIFIER_POINTER (TYPE_NAME (t)));
5228
5229      /* Detect invalid bit-field size.  */
5230      if (DECL_INITIAL (x))
5231	STRIP_NOPS (DECL_INITIAL (x));
5232      if (DECL_INITIAL (x))
5233	{
5234	  if (TREE_CODE (DECL_INITIAL (x)) == INTEGER_CST)
5235	    constant_expression_warning (DECL_INITIAL (x));
5236	  else
5237	    {
5238	      error_with_decl (x,
5239			       "bit-field `%s' width not an integer constant");
5240	      DECL_INITIAL (x) = NULL;
5241	    }
5242	}
5243
5244      /* Detect invalid bit-field type.  */
5245      if (DECL_INITIAL (x)
5246	  && TREE_CODE (TREE_TYPE (x)) != INTEGER_TYPE
5247	  && TREE_CODE (TREE_TYPE (x)) != BOOLEAN_TYPE
5248	  && TREE_CODE (TREE_TYPE (x)) != ENUMERAL_TYPE)
5249	{
5250	  error_with_decl (x, "bit-field `%s' has invalid type");
5251	  DECL_INITIAL (x) = NULL;
5252	}
5253
5254      if (DECL_INITIAL (x) && pedantic
5255	  && TYPE_MAIN_VARIANT (TREE_TYPE (x)) != integer_type_node
5256	  && TYPE_MAIN_VARIANT (TREE_TYPE (x)) != unsigned_type_node
5257	  && TYPE_MAIN_VARIANT (TREE_TYPE (x)) != c_bool_type_node
5258	  /* Accept an enum that's equivalent to int or unsigned int.  */
5259	  && !(TREE_CODE (TREE_TYPE (x)) == ENUMERAL_TYPE
5260	       && (TYPE_PRECISION (TREE_TYPE (x))
5261		   == TYPE_PRECISION (integer_type_node))))
5262	pedwarn_with_decl (x, "bit-field `%s' type invalid in ISO C");
5263
5264      /* Detect and ignore out of range field width and process valid
5265	 field widths.  */
5266      if (DECL_INITIAL (x))
5267	{
5268	  int max_width
5269	    = (TYPE_MAIN_VARIANT (TREE_TYPE (x)) == c_bool_type_node
5270	       ? CHAR_TYPE_SIZE : TYPE_PRECISION (TREE_TYPE (x)));
5271
5272	  if (tree_int_cst_sgn (DECL_INITIAL (x)) < 0)
5273	    error_with_decl (x, "negative width in bit-field `%s'");
5274	  else if (0 < compare_tree_int (DECL_INITIAL (x), max_width))
5275	    pedwarn_with_decl (x, "width of `%s' exceeds its type");
5276	  else if (integer_zerop (DECL_INITIAL (x)) && DECL_NAME (x) != 0)
5277	    error_with_decl (x, "zero width for bit-field `%s'");
5278	  else
5279	    {
5280	      /* The test above has assured us that TREE_INT_CST_HIGH is 0.  */
5281	      unsigned HOST_WIDE_INT width
5282		= tree_low_cst (DECL_INITIAL (x), 1);
5283
5284	      if (TREE_CODE (TREE_TYPE (x)) == ENUMERAL_TYPE
5285		  && (width < min_precision (TYPE_MIN_VALUE (TREE_TYPE (x)),
5286					     TREE_UNSIGNED (TREE_TYPE (x)))
5287		      || (width
5288			  < min_precision (TYPE_MAX_VALUE (TREE_TYPE (x)),
5289					   TREE_UNSIGNED (TREE_TYPE (x))))))
5290		warning_with_decl (x,
5291				   "`%s' is narrower than values of its type");
5292
5293	      DECL_SIZE (x) = bitsize_int (width);
5294	      DECL_BIT_FIELD (x) = 1;
5295	      SET_DECL_C_BIT_FIELD (x);
5296
5297	      if (width == 0
5298		  && ! (* targetm.ms_bitfield_layout_p) (t))
5299		{
5300		  /* field size 0 => force desired amount of alignment.  */
5301#ifdef EMPTY_FIELD_BOUNDARY
5302		  DECL_ALIGN (x) = MAX (DECL_ALIGN (x), EMPTY_FIELD_BOUNDARY);
5303#endif
5304#ifdef PCC_BITFIELD_TYPE_MATTERS
5305		  if (PCC_BITFIELD_TYPE_MATTERS)
5306		    {
5307		      DECL_ALIGN (x) = MAX (DECL_ALIGN (x),
5308					    TYPE_ALIGN (TREE_TYPE (x)));
5309		      DECL_USER_ALIGN (x) |= TYPE_USER_ALIGN (TREE_TYPE (x));
5310		    }
5311#endif
5312		}
5313	    }
5314	}
5315
5316      DECL_INITIAL (x) = 0;
5317
5318      /* Detect flexible array member in an invalid context.  */
5319      if (TREE_CODE (TREE_TYPE (x)) == ARRAY_TYPE
5320	  && TYPE_SIZE (TREE_TYPE (x)) == NULL_TREE
5321	  && TYPE_DOMAIN (TREE_TYPE (x)) != NULL_TREE
5322	  && TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (x))) == NULL_TREE)
5323	{
5324	  if (TREE_CODE (t) == UNION_TYPE)
5325	    error_with_decl (x, "flexible array member in union");
5326	  else if (TREE_CHAIN (x) != NULL_TREE)
5327	    error_with_decl (x, "flexible array member not at end of struct");
5328	  else if (! saw_named_field)
5329	    error_with_decl (x, "flexible array member in otherwise empty struct");
5330	}
5331
5332      if (pedantic && TREE_CODE (t) == RECORD_TYPE
5333	  && flexible_array_type_p (TREE_TYPE (x)))
5334	pedwarn_with_decl (x, "invalid use of structure with flexible array member");
5335
5336      if (DECL_NAME (x))
5337	saw_named_field = 1;
5338    }
5339
5340  /* Delete all duplicate fields from the fieldlist */
5341  for (x = fieldlist; x && TREE_CHAIN (x);)
5342    /* Anonymous fields aren't duplicates.  */
5343    if (DECL_NAME (TREE_CHAIN (x)) == 0)
5344      x = TREE_CHAIN (x);
5345    else
5346      {
5347	tree y = fieldlist;
5348
5349	while (1)
5350	  {
5351	    if (DECL_NAME (y) == DECL_NAME (TREE_CHAIN (x)))
5352	      break;
5353	    if (y == x)
5354	      break;
5355	    y = TREE_CHAIN (y);
5356	  }
5357	if (DECL_NAME (y) == DECL_NAME (TREE_CHAIN (x)))
5358	  {
5359	    error_with_decl (TREE_CHAIN (x), "duplicate member `%s'");
5360	    TREE_CHAIN (x) = TREE_CHAIN (TREE_CHAIN (x));
5361	  }
5362	else
5363	  x = TREE_CHAIN (x);
5364      }
5365
5366  /* Now we have the nearly final fieldlist.  Record it,
5367     then lay out the structure or union (including the fields).  */
5368
5369  TYPE_FIELDS (t) = fieldlist;
5370
5371  layout_type (t);
5372
5373  /* Delete all zero-width bit-fields from the fieldlist */
5374  {
5375    tree *fieldlistp = &fieldlist;
5376    while (*fieldlistp)
5377      if (TREE_CODE (*fieldlistp) == FIELD_DECL && DECL_INITIAL (*fieldlistp))
5378	*fieldlistp = TREE_CHAIN (*fieldlistp);
5379      else
5380	fieldlistp = &TREE_CHAIN (*fieldlistp);
5381  }
5382
5383  /* Now we have the truly final field list.
5384     Store it in this type and in the variants.  */
5385
5386  TYPE_FIELDS (t) = fieldlist;
5387
5388  /* If there are lots of fields, sort so we can look through them fast.
5389    We arbitrarily consider 16 or more elts to be "a lot".  */
5390
5391  {
5392    int len = 0;
5393
5394    for (x = fieldlist; x; x = TREE_CHAIN (x))
5395      {
5396        if (len > 15 || DECL_NAME (x) == NULL)
5397          break;
5398        len += 1;
5399      }
5400
5401    if (len > 15)
5402      {
5403        tree *field_array;
5404        char *space;
5405
5406        len += list_length (x);
5407
5408        /* Use the same allocation policy here that make_node uses, to
5409          ensure that this lives as long as the rest of the struct decl.
5410          All decls in an inline function need to be saved.  */
5411
5412        space = ggc_alloc (sizeof (struct lang_type) + len * sizeof (tree));
5413
5414        len = 0;
5415	field_array = &(((struct lang_type *) space)->elts[0]);
5416        for (x = fieldlist; x; x = TREE_CHAIN (x))
5417          {
5418            field_array[len++] = x;
5419
5420            /* if there is anonymous struct or unoin break out of the loop */
5421            if (DECL_NAME (x) == NULL)
5422              break;
5423          }
5424        /* found no anonymous struct/union add the TYPE_LANG_SPECIFIC. */
5425        if (x == NULL)
5426          {
5427            TYPE_LANG_SPECIFIC (t) = (struct lang_type *) space;
5428            TYPE_LANG_SPECIFIC (t)->len = len;
5429            field_array = &TYPE_LANG_SPECIFIC (t)->elts[0];
5430            qsort (field_array, len, sizeof (tree), field_decl_cmp);
5431          }
5432      }
5433  }
5434
5435  for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x))
5436    {
5437      TYPE_FIELDS (x) = TYPE_FIELDS (t);
5438      TYPE_LANG_SPECIFIC (x) = TYPE_LANG_SPECIFIC (t);
5439      TYPE_ALIGN (x) = TYPE_ALIGN (t);
5440      TYPE_USER_ALIGN (x) = TYPE_USER_ALIGN (t);
5441    }
5442
5443  /* If this was supposed to be a transparent union, but we can't
5444     make it one, warn and turn off the flag.  */
5445  if (TREE_CODE (t) == UNION_TYPE
5446      && TYPE_TRANSPARENT_UNION (t)
5447      && TYPE_MODE (t) != DECL_MODE (TYPE_FIELDS (t)))
5448    {
5449      TYPE_TRANSPARENT_UNION (t) = 0;
5450      warning ("union cannot be made transparent");
5451    }
5452
5453  /* If this structure or union completes the type of any previous
5454     variable declaration, lay it out and output its rtl.  */
5455
5456  if (current_binding_level->incomplete_list != NULL_TREE)
5457    {
5458      tree prev = NULL_TREE;
5459
5460      for (x = current_binding_level->incomplete_list; x; x = TREE_CHAIN (x))
5461        {
5462	  tree decl = TREE_VALUE (x);
5463
5464	  if (TYPE_MAIN_VARIANT (TREE_TYPE (decl)) == TYPE_MAIN_VARIANT (t)
5465	      && TREE_CODE (decl) != TYPE_DECL)
5466	    {
5467	      layout_decl (decl, 0);
5468	      /* This is a no-op in c-lang.c or something real in
5469		 objc-act.c.  */
5470	      if (flag_objc)
5471		objc_check_decl (decl);
5472	      rest_of_decl_compilation (decl, NULL, toplevel, 0);
5473	      if (! toplevel)
5474		expand_decl (decl);
5475	      /* Unlink X from the incomplete list.  */
5476	      if (prev)
5477		TREE_CHAIN (prev) = TREE_CHAIN (x);
5478	      else
5479	        current_binding_level->incomplete_list = TREE_CHAIN (x);
5480	    }
5481	  else if (!COMPLETE_TYPE_P (TREE_TYPE (decl))
5482		   && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
5483	    {
5484	      tree element = TREE_TYPE (decl);
5485	      while (TREE_CODE (element) == ARRAY_TYPE)
5486		element = TREE_TYPE (element);
5487	      if (element == t)
5488		{
5489		  layout_array_type (TREE_TYPE (decl));
5490		  if (TREE_CODE (decl) != TYPE_DECL)
5491		    {
5492		      layout_decl (decl, 0);
5493		      if (flag_objc)
5494			objc_check_decl (decl);
5495		      rest_of_decl_compilation (decl, NULL, toplevel, 0);
5496		      if (! toplevel)
5497			expand_decl (decl);
5498		    }
5499		  /* Unlink X from the incomplete list.  */
5500		  if (prev)
5501		    TREE_CHAIN (prev) = TREE_CHAIN (x);
5502		  else
5503		    current_binding_level->incomplete_list = TREE_CHAIN (x);
5504		}
5505	      else
5506		prev = x;
5507	    }
5508	  else
5509	    prev = x;
5510	}
5511    }
5512
5513  /* Finish debugging output for this type.  */
5514  rest_of_type_compilation (t, toplevel);
5515
5516  return t;
5517}
5518
5519/* Lay out the type T, and its element type, and so on.  */
5520
5521static void
5522layout_array_type (t)
5523     tree t;
5524{
5525  if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE)
5526    layout_array_type (TREE_TYPE (t));
5527  layout_type (t);
5528}
5529
5530/* Begin compiling the definition of an enumeration type.
5531   NAME is its name (or null if anonymous).
5532   Returns the type object, as yet incomplete.
5533   Also records info about it so that build_enumerator
5534   may be used to declare the individual values as they are read.  */
5535
5536tree
5537start_enum (name)
5538     tree name;
5539{
5540  tree enumtype = 0;
5541
5542  /* If this is the real definition for a previous forward reference,
5543     fill in the contents in the same object that used to be the
5544     forward reference.  */
5545
5546  if (name != 0)
5547    enumtype = lookup_tag (ENUMERAL_TYPE, name, current_binding_level, 1);
5548
5549  if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE)
5550    {
5551      enumtype = make_node (ENUMERAL_TYPE);
5552      pushtag (name, enumtype);
5553    }
5554
5555  C_TYPE_BEING_DEFINED (enumtype) = 1;
5556
5557  if (TYPE_VALUES (enumtype) != 0)
5558    {
5559      /* This enum is a named one that has been declared already.  */
5560      error ("redeclaration of `enum %s'", IDENTIFIER_POINTER (name));
5561
5562      /* Completely replace its old definition.
5563	 The old enumerators remain defined, however.  */
5564      TYPE_VALUES (enumtype) = 0;
5565    }
5566
5567  enum_next_value = integer_zero_node;
5568  enum_overflow = 0;
5569
5570  if (flag_short_enums)
5571    TYPE_PACKED (enumtype) = 1;
5572
5573  return enumtype;
5574}
5575
5576/* After processing and defining all the values of an enumeration type,
5577   install their decls in the enumeration type and finish it off.
5578   ENUMTYPE is the type object, VALUES a list of decl-value pairs,
5579   and ATTRIBUTES are the specified attributes.
5580   Returns ENUMTYPE.  */
5581
5582tree
5583finish_enum (enumtype, values, attributes)
5584     tree enumtype;
5585     tree values;
5586     tree attributes;
5587{
5588  tree pair, tem;
5589  tree minnode = 0, maxnode = 0, enum_value_type;
5590  int precision, unsign;
5591  int toplevel = (global_binding_level == current_binding_level);
5592
5593  if (in_parm_level_p ())
5594    warning ("enum defined inside parms");
5595
5596  decl_attributes (&enumtype, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5597
5598  /* Calculate the maximum value of any enumerator in this type.  */
5599
5600  if (values == error_mark_node)
5601    minnode = maxnode = integer_zero_node;
5602  else
5603    {
5604      minnode = maxnode = TREE_VALUE (values);
5605      for (pair = TREE_CHAIN (values); pair; pair = TREE_CHAIN (pair))
5606	{
5607	  tree value = TREE_VALUE (pair);
5608	  if (tree_int_cst_lt (maxnode, value))
5609	    maxnode = value;
5610	  if (tree_int_cst_lt (value, minnode))
5611	    minnode = value;
5612	}
5613    }
5614
5615  /* Construct the final type of this enumeration.  It is the same
5616     as one of the integral types - the narrowest one that fits, except
5617     that normally we only go as narrow as int - and signed iff any of
5618     the values are negative.  */
5619  unsign = (tree_int_cst_sgn (minnode) >= 0);
5620  precision = MAX (min_precision (minnode, unsign),
5621		   min_precision (maxnode, unsign));
5622  if (TYPE_PACKED (enumtype) || precision > TYPE_PRECISION (integer_type_node))
5623    {
5624      tree narrowest = c_common_type_for_size (precision, unsign);
5625      if (narrowest == 0)
5626	{
5627	  warning ("enumeration values exceed range of largest integer");
5628	  narrowest = long_long_integer_type_node;
5629	}
5630
5631      precision = TYPE_PRECISION (narrowest);
5632    }
5633  else
5634    precision = TYPE_PRECISION (integer_type_node);
5635
5636  if (precision == TYPE_PRECISION (integer_type_node))
5637    enum_value_type = c_common_type_for_size (precision, 0);
5638  else
5639    enum_value_type = enumtype;
5640
5641  TYPE_MIN_VALUE (enumtype) = minnode;
5642  TYPE_MAX_VALUE (enumtype) = maxnode;
5643  TYPE_PRECISION (enumtype) = precision;
5644  TREE_UNSIGNED (enumtype) = unsign;
5645  TYPE_SIZE (enumtype) = 0;
5646  layout_type (enumtype);
5647
5648  if (values != error_mark_node)
5649    {
5650      /* Change the type of the enumerators to be the enum type.  We
5651	 need to do this irrespective of the size of the enum, for
5652	 proper type checking.  Replace the DECL_INITIALs of the
5653	 enumerators, and the value slots of the list, with copies
5654	 that have the enum type; they cannot be modified in place
5655	 because they may be shared (e.g.  integer_zero_node) Finally,
5656	 change the purpose slots to point to the names of the decls.  */
5657      for (pair = values; pair; pair = TREE_CHAIN (pair))
5658	{
5659	  tree enu = TREE_PURPOSE (pair);
5660
5661	  TREE_TYPE (enu) = enumtype;
5662	  DECL_SIZE (enu) = TYPE_SIZE (enumtype);
5663	  DECL_SIZE_UNIT (enu) = TYPE_SIZE_UNIT (enumtype);
5664	  DECL_ALIGN (enu) = TYPE_ALIGN (enumtype);
5665	  DECL_USER_ALIGN (enu) = TYPE_USER_ALIGN (enumtype);
5666	  DECL_MODE (enu) = TYPE_MODE (enumtype);
5667
5668	  /* The ISO C Standard mandates enumerators to have type int,
5669	     even though the underlying type of an enum type is
5670	     unspecified.  Here we convert any enumerators that fit in
5671	     an int to type int, to avoid promotions to unsigned types
5672	     when comparing integers with enumerators that fit in the
5673	     int range.  When -pedantic is given, build_enumerator()
5674	     would have already taken care of those that don't fit.  */
5675	  if (int_fits_type_p (DECL_INITIAL (enu), enum_value_type))
5676	    DECL_INITIAL (enu) = convert (enum_value_type, DECL_INITIAL (enu));
5677	  else
5678	    DECL_INITIAL (enu) = convert (enumtype, DECL_INITIAL (enu));
5679
5680	  TREE_PURPOSE (pair) = DECL_NAME (enu);
5681	  TREE_VALUE (pair) = DECL_INITIAL (enu);
5682	}
5683
5684      TYPE_VALUES (enumtype) = values;
5685    }
5686
5687  /* Fix up all variant types of this enum type.  */
5688  for (tem = TYPE_MAIN_VARIANT (enumtype); tem; tem = TYPE_NEXT_VARIANT (tem))
5689    {
5690      if (tem == enumtype)
5691	continue;
5692      TYPE_VALUES (tem) = TYPE_VALUES (enumtype);
5693      TYPE_MIN_VALUE (tem) = TYPE_MIN_VALUE (enumtype);
5694      TYPE_MAX_VALUE (tem) = TYPE_MAX_VALUE (enumtype);
5695      TYPE_SIZE (tem) = TYPE_SIZE (enumtype);
5696      TYPE_SIZE_UNIT (tem) = TYPE_SIZE_UNIT (enumtype);
5697      TYPE_MODE (tem) = TYPE_MODE (enumtype);
5698      TYPE_PRECISION (tem) = TYPE_PRECISION (enumtype);
5699      TYPE_ALIGN (tem) = TYPE_ALIGN (enumtype);
5700      TYPE_USER_ALIGN (tem) = TYPE_USER_ALIGN (enumtype);
5701      TREE_UNSIGNED (tem) = TREE_UNSIGNED (enumtype);
5702    }
5703
5704  /* Finish debugging output for this type.  */
5705  rest_of_type_compilation (enumtype, toplevel);
5706
5707  return enumtype;
5708}
5709
5710/* Build and install a CONST_DECL for one value of the
5711   current enumeration type (one that was begun with start_enum).
5712   Return a tree-list containing the CONST_DECL and its value.
5713   Assignment of sequential values by default is handled here.  */
5714
5715tree
5716build_enumerator (name, value)
5717     tree name, value;
5718{
5719  tree decl, type;
5720
5721  /* Validate and default VALUE.  */
5722
5723  /* Remove no-op casts from the value.  */
5724  if (value)
5725    STRIP_TYPE_NOPS (value);
5726
5727  if (value != 0)
5728    {
5729      if (TREE_CODE (value) == INTEGER_CST)
5730	{
5731	  value = default_conversion (value);
5732	  constant_expression_warning (value);
5733	}
5734      else
5735	{
5736	  error ("enumerator value for `%s' not integer constant",
5737		 IDENTIFIER_POINTER (name));
5738	  value = 0;
5739	}
5740    }
5741
5742  /* Default based on previous value.  */
5743  /* It should no longer be possible to have NON_LVALUE_EXPR
5744     in the default.  */
5745  if (value == 0)
5746    {
5747      value = enum_next_value;
5748      if (enum_overflow)
5749	error ("overflow in enumeration values");
5750    }
5751
5752  if (pedantic && ! int_fits_type_p (value, integer_type_node))
5753    {
5754      pedwarn ("ISO C restricts enumerator values to range of `int'");
5755      value = convert (integer_type_node, value);
5756    }
5757
5758  /* Set basis for default for next value.  */
5759  enum_next_value = build_binary_op (PLUS_EXPR, value, integer_one_node, 0);
5760  enum_overflow = tree_int_cst_lt (enum_next_value, value);
5761
5762  /* Now create a declaration for the enum value name.  */
5763
5764  type = TREE_TYPE (value);
5765  type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
5766				      TYPE_PRECISION (integer_type_node)),
5767				 (TYPE_PRECISION (type)
5768				  >= TYPE_PRECISION (integer_type_node)
5769				  && TREE_UNSIGNED (type)));
5770
5771  decl = build_decl (CONST_DECL, name, type);
5772  DECL_INITIAL (decl) = convert (type, value);
5773  pushdecl (decl);
5774
5775  return tree_cons (decl, value, NULL_TREE);
5776}
5777
5778
5779/* Create the FUNCTION_DECL for a function definition.
5780   DECLSPECS, DECLARATOR and ATTRIBUTES are the parts of
5781   the declaration; they describe the function's name and the type it returns,
5782   but twisted together in a fashion that parallels the syntax of C.
5783
5784   This function creates a binding context for the function body
5785   as well as setting up the FUNCTION_DECL in current_function_decl.
5786
5787   Returns 1 on success.  If the DECLARATOR is not suitable for a function
5788   (it defines a datum instead), we return 0, which tells
5789   yyparse to report a parse error.  */
5790
5791int
5792start_function (declspecs, declarator, attributes)
5793     tree declarator, declspecs, attributes;
5794{
5795  tree decl1, old_decl;
5796  tree restype;
5797  int old_immediate_size_expand = immediate_size_expand;
5798
5799  current_function_returns_value = 0;  /* Assume, until we see it does.  */
5800  current_function_returns_null = 0;
5801  current_function_returns_abnormally = 0;
5802  warn_about_return_type = 0;
5803  current_extern_inline = 0;
5804  named_labels = 0;
5805  shadowed_labels = 0;
5806
5807  /* Don't expand any sizes in the return type of the function.  */
5808  immediate_size_expand = 0;
5809
5810  decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, 1);
5811
5812  /* If the declarator is not suitable for a function definition,
5813     cause a syntax error.  */
5814  if (decl1 == 0)
5815    {
5816      immediate_size_expand = old_immediate_size_expand;
5817      return 0;
5818    }
5819
5820  decl_attributes (&decl1, attributes, 0);
5821
5822  /* If #pragma weak was used, mark the decl weak now.  */
5823  if (current_binding_level == global_binding_level)
5824    maybe_apply_pragma_weak (decl1);
5825
5826  if (DECL_DECLARED_INLINE_P (decl1)
5827      && DECL_UNINLINABLE (decl1)
5828      && lookup_attribute ("noinline", DECL_ATTRIBUTES (decl1)))
5829    warning_with_decl (decl1,
5830		       "inline function `%s' given attribute noinline");
5831
5832  announce_function (decl1);
5833
5834  if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl1))))
5835    {
5836      error ("return type is an incomplete type");
5837      /* Make it return void instead.  */
5838      TREE_TYPE (decl1)
5839	= build_function_type (void_type_node,
5840			       TYPE_ARG_TYPES (TREE_TYPE (decl1)));
5841    }
5842
5843  if (warn_about_return_type)
5844    pedwarn_c99 ("return type defaults to `int'");
5845
5846  /* Save the parm names or decls from this function's declarator
5847     where store_parm_decls will find them.  */
5848  current_function_parms = last_function_parms;
5849  current_function_parm_tags = last_function_parm_tags;
5850
5851  /* Make the init_value nonzero so pushdecl knows this is not tentative.
5852     error_mark_node is replaced below (in poplevel) with the BLOCK.  */
5853  DECL_INITIAL (decl1) = error_mark_node;
5854
5855  /* If this definition isn't a prototype and we had a prototype declaration
5856     before, copy the arg type info from that prototype.
5857     But not if what we had before was a builtin function.  */
5858  old_decl = lookup_name_current_level (DECL_NAME (decl1));
5859  if (old_decl != 0 && TREE_CODE (TREE_TYPE (old_decl)) == FUNCTION_TYPE
5860      && !DECL_BUILT_IN (old_decl)
5861      && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1)))
5862	  == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (old_decl))))
5863      && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0)
5864    {
5865      TREE_TYPE (decl1) = TREE_TYPE (old_decl);
5866      current_function_prototype_file = DECL_SOURCE_FILE (old_decl);
5867      current_function_prototype_line = DECL_SOURCE_LINE (old_decl);
5868    }
5869
5870  /* If there is no explicit declaration, look for any out-of-scope implicit
5871     declarations.  */
5872  if (old_decl == 0)
5873    old_decl = IDENTIFIER_IMPLICIT_DECL (DECL_NAME (decl1));
5874
5875  /* Optionally warn of old-fashioned def with no previous prototype.  */
5876  if (warn_strict_prototypes
5877      && TYPE_ARG_TYPES (TREE_TYPE (decl1)) == 0
5878      && !(old_decl != 0
5879	   && (TYPE_ARG_TYPES (TREE_TYPE (old_decl)) != 0
5880	       || (DECL_BUILT_IN (old_decl)
5881		   && ! C_DECL_ANTICIPATED (old_decl))))
5882		     && !(flag_bsd_no_warn_kr_main && 0 ==
5883			strcmp ("main", IDENTIFIER_POINTER (DECL_NAME (decl1)))))
5884    warning ("function declaration isn't a prototype");
5885  /* Optionally warn of any global def with no previous prototype.  */
5886  else if (warn_missing_prototypes
5887	   && TREE_PUBLIC (decl1)
5888	   && !(old_decl != 0
5889		&& (TYPE_ARG_TYPES (TREE_TYPE (old_decl)) != 0
5890		    || (DECL_BUILT_IN (old_decl)
5891			&& ! C_DECL_ANTICIPATED (old_decl))))
5892	   && ! MAIN_NAME_P (DECL_NAME (decl1)))
5893    warning_with_decl (decl1, "no previous prototype for `%s'");
5894  /* Optionally warn of any def with no previous prototype
5895     if the function has already been used.  */
5896  else if (warn_missing_prototypes
5897	   && old_decl != 0 && TREE_USED (old_decl)
5898	   && TYPE_ARG_TYPES (TREE_TYPE (old_decl)) == 0)
5899    warning_with_decl (decl1,
5900		       "`%s' was used with no prototype before its definition");
5901  /* Optionally warn of any global def with no previous declaration.  */
5902  else if (warn_missing_declarations
5903	   && TREE_PUBLIC (decl1)
5904	   && old_decl == 0
5905	   && ! MAIN_NAME_P (DECL_NAME (decl1)))
5906    warning_with_decl (decl1, "no previous declaration for `%s'");
5907  /* Optionally warn of any def with no previous declaration
5908     if the function has already been used.  */
5909  else if (warn_missing_declarations
5910	   && old_decl != 0 && TREE_USED (old_decl)
5911	   && old_decl == IDENTIFIER_IMPLICIT_DECL (DECL_NAME (decl1)))
5912    warning_with_decl (decl1,
5913		       "`%s' was used with no declaration before its definition");
5914
5915  /* This is a definition, not a reference.
5916     So normally clear DECL_EXTERNAL.
5917     However, `extern inline' acts like a declaration
5918     except for defining how to inline.  So set DECL_EXTERNAL in that case.  */
5919  DECL_EXTERNAL (decl1) = current_extern_inline;
5920
5921  /* This function exists in static storage.
5922     (This does not mean `static' in the C sense!)  */
5923  TREE_STATIC (decl1) = 1;
5924
5925  /* A nested function is not global.  */
5926  if (current_function_decl != 0)
5927    TREE_PUBLIC (decl1) = 0;
5928
5929  /* Warn for unlikely, improbable, or stupid declarations of `main'.  */
5930  if (warn_main > 0 && MAIN_NAME_P (DECL_NAME (decl1)))
5931    {
5932      tree args;
5933      int argct = 0;
5934
5935      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (decl1)))
5936	  != integer_type_node)
5937	pedwarn_with_decl (decl1, "return type of `%s' is not `int'");
5938
5939      for (args = TYPE_ARG_TYPES (TREE_TYPE (decl1)); args;
5940	   args = TREE_CHAIN (args))
5941	{
5942	  tree type = args ? TREE_VALUE (args) : 0;
5943
5944	  if (type == void_type_node)
5945	    break;
5946
5947	  ++argct;
5948	  switch (argct)
5949	    {
5950	    case 1:
5951	      if (TYPE_MAIN_VARIANT (type) != integer_type_node)
5952		pedwarn_with_decl (decl1,
5953				   "first argument of `%s' should be `int'");
5954	      break;
5955
5956	    case 2:
5957	      if (TREE_CODE (type) != POINTER_TYPE
5958		  || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
5959		  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
5960		      != char_type_node))
5961		pedwarn_with_decl (decl1,
5962				   "second argument of `%s' should be `char **'");
5963	      break;
5964
5965	    case 3:
5966	      if (TREE_CODE (type) != POINTER_TYPE
5967		  || TREE_CODE (TREE_TYPE (type)) != POINTER_TYPE
5968		  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (type)))
5969		      != char_type_node))
5970		pedwarn_with_decl (decl1,
5971				   "third argument of `%s' should probably be `char **'");
5972	      break;
5973	    }
5974	}
5975
5976      /* It is intentional that this message does not mention the third
5977	 argument because it's only mentioned in an appendix of the
5978	 standard.  */
5979      if (argct > 0 && (argct < 2 || argct > 3))
5980	pedwarn_with_decl (decl1, "`%s' takes only zero or two arguments");
5981
5982      if (! TREE_PUBLIC (decl1))
5983	pedwarn_with_decl (decl1, "`%s' is normally a non-static function");
5984    }
5985
5986  /* Record the decl so that the function name is defined.
5987     If we already have a decl for this name, and it is a FUNCTION_DECL,
5988     use the old decl.  */
5989
5990  current_function_decl = pushdecl (decl1);
5991
5992  pushlevel (0);
5993  declare_parm_level (1);
5994  current_binding_level->subblocks_tag_transparent = 1;
5995
5996  make_decl_rtl (current_function_decl, NULL);
5997
5998  restype = TREE_TYPE (TREE_TYPE (current_function_decl));
5999  /* Promote the value to int before returning it.  */
6000  if (c_promoting_integer_type_p (restype))
6001    {
6002      /* It retains unsignedness if not really getting wider.  */
6003      if (TREE_UNSIGNED (restype)
6004	  && (TYPE_PRECISION (restype)
6005		  == TYPE_PRECISION (integer_type_node)))
6006	restype = unsigned_type_node;
6007      else
6008	restype = integer_type_node;
6009    }
6010  DECL_RESULT (current_function_decl)
6011    = build_decl (RESULT_DECL, NULL_TREE, restype);
6012
6013  /* If this fcn was already referenced via a block-scope `extern' decl
6014     (or an implicit decl), propagate certain information about the usage.  */
6015  if (TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (current_function_decl)))
6016    TREE_ADDRESSABLE (current_function_decl) = 1;
6017
6018  immediate_size_expand = old_immediate_size_expand;
6019
6020  start_fname_decls ();
6021
6022  return 1;
6023}
6024
6025/* Store the parameter declarations into the current function declaration.
6026   This is called after parsing the parameter declarations, before
6027   digesting the body of the function.
6028
6029   For an old-style definition, modify the function's type
6030   to specify at least the number of arguments.  */
6031
6032void
6033store_parm_decls ()
6034{
6035  tree fndecl = current_function_decl;
6036  tree parm;
6037
6038  /* This is either a chain of PARM_DECLs (if a prototype was used)
6039     or a list of IDENTIFIER_NODEs (for an old-fashioned C definition).  */
6040  tree specparms = current_function_parms;
6041
6042  /* This is a list of types declared among parms in a prototype.  */
6043  tree parmtags = current_function_parm_tags;
6044
6045  /* This is a chain of PARM_DECLs from old-style parm declarations.  */
6046  tree parmdecls = getdecls ();
6047
6048  /* This is a chain of any other decls that came in among the parm
6049     declarations.  If a parm is declared with  enum {foo, bar} x;
6050     then CONST_DECLs for foo and bar are put here.  */
6051  tree nonparms = 0;
6052
6053  /* The function containing FNDECL, if any.  */
6054  tree context = decl_function_context (fndecl);
6055
6056  /* Nonzero if this definition is written with a prototype.  */
6057  int prototype = 0;
6058
6059  int saved_warn_shadow = warn_shadow;
6060
6061  /* Don't re-emit shadow warnings.  */
6062  warn_shadow = 0;
6063
6064  if (specparms != 0 && TREE_CODE (specparms) != TREE_LIST)
6065    {
6066      /* This case is when the function was defined with an ANSI prototype.
6067	 The parms already have decls, so we need not do anything here
6068	 except record them as in effect
6069	 and complain if any redundant old-style parm decls were written.  */
6070
6071      tree next;
6072      tree others = 0;
6073
6074      prototype = 1;
6075
6076      if (parmdecls != 0)
6077	{
6078	  tree decl, link;
6079
6080	  error_with_decl (fndecl,
6081			   "parm types given both in parmlist and separately");
6082	  /* Get rid of the erroneous decls; don't keep them on
6083	     the list of parms, since they might not be PARM_DECLs.  */
6084	  for (decl = current_binding_level->names;
6085	       decl; decl = TREE_CHAIN (decl))
6086	    if (DECL_NAME (decl))
6087	      IDENTIFIER_LOCAL_VALUE (DECL_NAME (decl)) = 0;
6088	  for (link = current_binding_level->shadowed;
6089	       link; link = TREE_CHAIN (link))
6090	    IDENTIFIER_LOCAL_VALUE (TREE_PURPOSE (link)) = TREE_VALUE (link);
6091	  current_binding_level->names = 0;
6092	  current_binding_level->shadowed = 0;
6093	}
6094
6095      specparms = nreverse (specparms);
6096      for (parm = specparms; parm; parm = next)
6097	{
6098	  next = TREE_CHAIN (parm);
6099	  if (TREE_CODE (parm) == PARM_DECL)
6100	    {
6101	      if (DECL_NAME (parm) == 0)
6102		error_with_decl (parm, "parameter name omitted");
6103	      else if (TREE_CODE (TREE_TYPE (parm)) != ERROR_MARK
6104		       && VOID_TYPE_P (TREE_TYPE (parm)))
6105		{
6106		  error_with_decl (parm, "parameter `%s' declared void");
6107		  /* Change the type to error_mark_node so this parameter
6108		     will be ignored by assign_parms.  */
6109		  TREE_TYPE (parm) = error_mark_node;
6110		}
6111	      pushdecl (parm);
6112	    }
6113	  else
6114	    {
6115	      /* If we find an enum constant or a type tag,
6116		 put it aside for the moment.  */
6117	      TREE_CHAIN (parm) = 0;
6118	      others = chainon (others, parm);
6119	    }
6120	}
6121
6122      /* Get the decls in their original chain order
6123	 and record in the function.  */
6124      DECL_ARGUMENTS (fndecl) = getdecls ();
6125
6126#if 0
6127      /* If this function takes a variable number of arguments,
6128	 add a phony parameter to the end of the parm list,
6129	 to represent the position of the first unnamed argument.  */
6130      if (TREE_VALUE (tree_last (TYPE_ARG_TYPES (TREE_TYPE (fndecl))))
6131	  != void_type_node)
6132	{
6133	  tree dummy = build_decl (PARM_DECL, NULL_TREE, void_type_node);
6134	  /* Let's hope the address of the unnamed parm
6135	     won't depend on its type.  */
6136	  TREE_TYPE (dummy) = integer_type_node;
6137	  DECL_ARG_TYPE (dummy) = integer_type_node;
6138	  DECL_ARGUMENTS (fndecl) = chainon (DECL_ARGUMENTS (fndecl), dummy);
6139	}
6140#endif
6141
6142      /* Now pushdecl the enum constants.  */
6143      for (parm = others; parm; parm = next)
6144	{
6145	  next = TREE_CHAIN (parm);
6146	  if (DECL_NAME (parm) == 0)
6147	    ;
6148	  else if (TYPE_MAIN_VARIANT (TREE_TYPE (parm)) == void_type_node)
6149	    ;
6150	  else if (TREE_CODE (parm) != PARM_DECL)
6151	    pushdecl (parm);
6152	}
6153
6154      storetags (chainon (parmtags, gettags ()));
6155    }
6156  else
6157    {
6158      /* SPECPARMS is an identifier list--a chain of TREE_LIST nodes
6159	 each with a parm name as the TREE_VALUE.
6160
6161	 PARMDECLS is a chain of declarations for parameters.
6162	 Warning! It can also contain CONST_DECLs which are not parameters
6163	 but are names of enumerators of any enum types
6164	 declared among the parameters.
6165
6166	 First match each formal parameter name with its declaration.
6167	 Associate decls with the names and store the decls
6168	 into the TREE_PURPOSE slots.  */
6169
6170      /* We use DECL_WEAK as a flag to show which parameters have been
6171	 seen already since it is not used on PARM_DECL or CONST_DECL.  */
6172      for (parm = parmdecls; parm; parm = TREE_CHAIN (parm))
6173	DECL_WEAK (parm) = 0;
6174
6175      for (parm = specparms; parm; parm = TREE_CHAIN (parm))
6176	{
6177	  tree tail, found = NULL;
6178
6179	  if (TREE_VALUE (parm) == 0)
6180	    {
6181	      error_with_decl (fndecl,
6182			       "parameter name missing from parameter list");
6183	      TREE_PURPOSE (parm) = 0;
6184	      continue;
6185	    }
6186
6187	  /* See if any of the parmdecls specifies this parm by name.
6188	     Ignore any enumerator decls.  */
6189	  for (tail = parmdecls; tail; tail = TREE_CHAIN (tail))
6190	    if (DECL_NAME (tail) == TREE_VALUE (parm)
6191		&& TREE_CODE (tail) == PARM_DECL)
6192	      {
6193		found = tail;
6194		break;
6195	      }
6196
6197	  /* If declaration already marked, we have a duplicate name.
6198	     Complain, and don't use this decl twice.  */
6199	  if (found && DECL_WEAK (found))
6200	    {
6201	      error_with_decl (found, "multiple parameters named `%s'");
6202	      found = 0;
6203	    }
6204
6205	  /* If the declaration says "void", complain and ignore it.  */
6206	  if (found && VOID_TYPE_P (TREE_TYPE (found)))
6207	    {
6208	      error_with_decl (found, "parameter `%s' declared void");
6209	      TREE_TYPE (found) = integer_type_node;
6210	      DECL_ARG_TYPE (found) = integer_type_node;
6211	      layout_decl (found, 0);
6212	    }
6213
6214	  /* If no declaration found, default to int.  */
6215	  if (!found)
6216	    {
6217	      found = build_decl (PARM_DECL, TREE_VALUE (parm),
6218				  integer_type_node);
6219	      DECL_ARG_TYPE (found) = TREE_TYPE (found);
6220	      DECL_SOURCE_LINE (found) = DECL_SOURCE_LINE (fndecl);
6221	      DECL_SOURCE_FILE (found) = DECL_SOURCE_FILE (fndecl);
6222	      if (flag_isoc99)
6223		pedwarn_with_decl (found, "type of `%s' defaults to `int'");
6224	      else if (extra_warnings)
6225		warning_with_decl (found, "type of `%s' defaults to `int'");
6226	      pushdecl (found);
6227	    }
6228
6229	  TREE_PURPOSE (parm) = found;
6230
6231	  /* Mark this decl as "already found".  */
6232	  DECL_WEAK (found) = 1;
6233	}
6234
6235      /* Put anything which is on the parmdecls chain and which is
6236	 not a PARM_DECL onto the list NONPARMS.  (The types of
6237	 non-parm things which might appear on the list include
6238	 enumerators and NULL-named TYPE_DECL nodes.) Complain about
6239	 any actual PARM_DECLs not matched with any names.  */
6240
6241      nonparms = 0;
6242      for (parm = parmdecls; parm;)
6243	{
6244	  tree next = TREE_CHAIN (parm);
6245	  TREE_CHAIN (parm) = 0;
6246
6247	  if (TREE_CODE (parm) != PARM_DECL)
6248	    nonparms = chainon (nonparms, parm);
6249	  else
6250	    {
6251	      /* Complain about args with incomplete types.  */
6252	      if (!COMPLETE_TYPE_P (TREE_TYPE (parm)))
6253		{
6254		  error_with_decl (parm, "parameter `%s' has incomplete type");
6255		  TREE_TYPE (parm) = error_mark_node;
6256		}
6257
6258	      if (! DECL_WEAK (parm))
6259		{
6260		  error_with_decl (parm,
6261				   "declaration for parameter `%s' but no such parameter");
6262	          /* Pretend the parameter was not missing.
6263		     This gets us to a standard state and minimizes
6264		     further error messages.  */
6265		  specparms
6266		    = chainon (specparms,
6267			       tree_cons (parm, NULL_TREE, NULL_TREE));
6268		}
6269	    }
6270
6271	  parm = next;
6272	}
6273
6274      /* Chain the declarations together in the order of the list of
6275         names.  Store that chain in the function decl, replacing the
6276         list of names.  */
6277      parm = specparms;
6278      DECL_ARGUMENTS (fndecl) = 0;
6279      {
6280	tree last;
6281	for (last = 0; parm; parm = TREE_CHAIN (parm))
6282	  if (TREE_PURPOSE (parm))
6283	    {
6284	      if (last == 0)
6285		DECL_ARGUMENTS (fndecl) = TREE_PURPOSE (parm);
6286	      else
6287		TREE_CHAIN (last) = TREE_PURPOSE (parm);
6288	      last = TREE_PURPOSE (parm);
6289	      TREE_CHAIN (last) = 0;
6290	    }
6291      }
6292
6293      /* If there was a previous prototype,
6294	 set the DECL_ARG_TYPE of each argument according to
6295	 the type previously specified, and report any mismatches.  */
6296
6297      if (TYPE_ARG_TYPES (TREE_TYPE (fndecl)))
6298	{
6299	  tree type;
6300	  for (parm = DECL_ARGUMENTS (fndecl),
6301	       type = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
6302	       parm || (type && (TYPE_MAIN_VARIANT (TREE_VALUE (type))
6303				 != void_type_node));
6304	       parm = TREE_CHAIN (parm), type = TREE_CHAIN (type))
6305	    {
6306	      if (parm == 0 || type == 0
6307		  || TYPE_MAIN_VARIANT (TREE_VALUE (type)) == void_type_node)
6308		{
6309		  error ("number of arguments doesn't match prototype");
6310		  error_with_file_and_line (current_function_prototype_file,
6311					    current_function_prototype_line,
6312					    "prototype declaration");
6313		  break;
6314		}
6315	      /* Type for passing arg must be consistent with that
6316		 declared for the arg.  ISO C says we take the unqualified
6317		 type for parameters declared with qualified type.  */
6318	      if (! comptypes (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm)),
6319			       TYPE_MAIN_VARIANT (TREE_VALUE (type))))
6320		{
6321		  if (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
6322		      == TYPE_MAIN_VARIANT (TREE_VALUE (type)))
6323		    {
6324		      /* Adjust argument to match prototype.  E.g. a previous
6325			 `int foo(float);' prototype causes
6326			 `int foo(x) float x; {...}' to be treated like
6327			 `int foo(float x) {...}'.  This is particularly
6328			 useful for argument types like uid_t.  */
6329		      DECL_ARG_TYPE (parm) = TREE_TYPE (parm);
6330
6331		      if (PROMOTE_PROTOTYPES
6332			  && INTEGRAL_TYPE_P (TREE_TYPE (parm))
6333			  && TYPE_PRECISION (TREE_TYPE (parm))
6334			  < TYPE_PRECISION (integer_type_node))
6335			DECL_ARG_TYPE (parm) = integer_type_node;
6336
6337		      if (pedantic)
6338			{
6339			  pedwarn ("promoted argument `%s' doesn't match prototype",
6340				   IDENTIFIER_POINTER (DECL_NAME (parm)));
6341			  warning_with_file_and_line
6342			    (current_function_prototype_file,
6343			     current_function_prototype_line,
6344			     "prototype declaration");
6345			}
6346		    }
6347		  else
6348		    {
6349		      error ("argument `%s' doesn't match prototype",
6350			     IDENTIFIER_POINTER (DECL_NAME (parm)));
6351		      error_with_file_and_line (current_function_prototype_file,
6352						current_function_prototype_line,
6353						"prototype declaration");
6354		    }
6355		}
6356	    }
6357	  TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = 0;
6358	}
6359
6360      /* Otherwise, create a prototype that would match.  */
6361
6362      else
6363	{
6364	  tree actual = 0, last = 0, type;
6365
6366	  for (parm = DECL_ARGUMENTS (fndecl); parm; parm = TREE_CHAIN (parm))
6367	    {
6368	      type = tree_cons (NULL_TREE, DECL_ARG_TYPE (parm), NULL_TREE);
6369	      if (last)
6370		TREE_CHAIN (last) = type;
6371	      else
6372		actual = type;
6373	      last = type;
6374	    }
6375	  type = tree_cons (NULL_TREE, void_type_node, NULL_TREE);
6376	  if (last)
6377	    TREE_CHAIN (last) = type;
6378	  else
6379	    actual = type;
6380
6381	  /* We are going to assign a new value for the TYPE_ACTUAL_ARG_TYPES
6382	     of the type of this function, but we need to avoid having this
6383	     affect the types of other similarly-typed functions, so we must
6384	     first force the generation of an identical (but separate) type
6385	     node for the relevant function type.  The new node we create
6386	     will be a variant of the main variant of the original function
6387	     type.  */
6388
6389	  TREE_TYPE (fndecl) = build_type_copy (TREE_TYPE (fndecl));
6390
6391	  TYPE_ACTUAL_ARG_TYPES (TREE_TYPE (fndecl)) = actual;
6392	}
6393
6394      /* Now store the final chain of decls for the arguments
6395	 as the decl-chain of the current lexical scope.
6396	 Put the enumerators in as well, at the front so that
6397	 DECL_ARGUMENTS is not modified.  */
6398
6399      storedecls (chainon (nonparms, DECL_ARGUMENTS (fndecl)));
6400    }
6401
6402  /* Make sure the binding level for the top of the function body
6403     gets a BLOCK if there are any in the function.
6404     Otherwise, the dbx output is wrong.  */
6405
6406  keep_next_if_subblocks = 1;
6407
6408  /* ??? This might be an improvement,
6409     but needs to be thought about some more.  */
6410#if 0
6411  keep_next_level_flag = 1;
6412#endif
6413
6414  /* Write a record describing this function definition to the prototypes
6415     file (if requested).  */
6416
6417  gen_aux_info_record (fndecl, 1, 0, prototype);
6418
6419  /* Initialize the RTL code for the function.  */
6420  init_function_start (fndecl, input_filename, lineno);
6421
6422  /* Begin the statement tree for this function.  */
6423  begin_stmt_tree (&DECL_SAVED_TREE (current_function_decl));
6424
6425  /* If this is a nested function, save away the sizes of any
6426     variable-size types so that we can expand them when generating
6427     RTL.  */
6428  if (context)
6429    {
6430      tree t;
6431
6432      DECL_LANG_SPECIFIC (fndecl)->pending_sizes
6433	= nreverse (get_pending_sizes ());
6434      for (t = DECL_LANG_SPECIFIC (fndecl)->pending_sizes;
6435	   t;
6436	   t = TREE_CHAIN (t))
6437	SAVE_EXPR_CONTEXT (TREE_VALUE (t)) = context;
6438    }
6439
6440  /* This function is being processed in whole-function mode.  */
6441  cfun->x_whole_function_mode_p = 1;
6442
6443  /* Even though we're inside a function body, we still don't want to
6444     call expand_expr to calculate the size of a variable-sized array.
6445     We haven't necessarily assigned RTL to all variables yet, so it's
6446     not safe to try to expand expressions involving them.  */
6447  immediate_size_expand = 0;
6448  cfun->x_dont_save_pending_sizes_p = 1;
6449
6450  warn_shadow = saved_warn_shadow;
6451}
6452
6453/* Finish up a function declaration and compile that function
6454   all the way to assembler language output.  The free the storage
6455   for the function definition.
6456
6457   This is called after parsing the body of the function definition.
6458
6459   NESTED is nonzero if the function being finished is nested in another.
6460   CAN_DEFER_P is nonzero if the function may be deferred.  */
6461
6462void
6463finish_function (nested, can_defer_p)
6464     int nested;
6465     int can_defer_p;
6466{
6467  tree fndecl = current_function_decl;
6468
6469#if 0
6470  /* This caused &foo to be of type ptr-to-const-function which then
6471     got a warning when stored in a ptr-to-function variable.  */
6472  TREE_READONLY (fndecl) = 1;
6473#endif
6474
6475  poplevel (1, 0, 1);
6476  BLOCK_SUPERCONTEXT (DECL_INITIAL (fndecl)) = fndecl;
6477
6478  /* Must mark the RESULT_DECL as being in this function.  */
6479
6480  DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl;
6481
6482  if (MAIN_NAME_P (DECL_NAME (fndecl)) && flag_hosted)
6483    {
6484      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl)))
6485	  != integer_type_node)
6486	{
6487	  /* If warn_main is 1 (-Wmain) or 2 (-Wall), we have already warned.
6488	     If warn_main is -1 (-Wno-main) we don't want to be warned.  */
6489	  if (! warn_main)
6490	    pedwarn_with_decl (fndecl, "return type of `%s' is not `int'");
6491	}
6492      else
6493	{
6494#ifdef DEFAULT_MAIN_RETURN
6495	  /* Make it so that `main' always returns success by default.  */
6496	  DEFAULT_MAIN_RETURN;
6497#else
6498	  if (flag_isoc99)
6499	    c_expand_return (integer_zero_node);
6500#endif
6501	}
6502    }
6503
6504  finish_fname_decls ();
6505
6506  /* Tie off the statement tree for this function.  */
6507  finish_stmt_tree (&DECL_SAVED_TREE (fndecl));
6508
6509  /* Complain if there's just no return statement.  */
6510  if (warn_return_type
6511      && TREE_CODE (TREE_TYPE (TREE_TYPE (fndecl))) != VOID_TYPE
6512      && !current_function_returns_value && !current_function_returns_null
6513      /* Don't complain if we abort.  */
6514      && !current_function_returns_abnormally
6515      /* Don't warn for main().  */
6516      && !MAIN_NAME_P (DECL_NAME (fndecl))
6517      /* Or if they didn't actually specify a return type.  */
6518      && !C_FUNCTION_IMPLICIT_INT (fndecl)
6519      /* Normally, with -Wreturn-type, flow will complain.  Unless we're an
6520	 inline function, as we might never be compiled separately.  */
6521      && DECL_INLINE (fndecl))
6522    warning ("no return statement in function returning non-void");
6523
6524  /* With just -W, complain only if function returns both with
6525     and without a value.  */
6526  if (extra_warnings
6527      && current_function_returns_value
6528      && current_function_returns_null)
6529    warning ("this function may return with or without a value");
6530
6531  /* Clear out memory we no longer need.  */
6532  free_after_parsing (cfun);
6533  /* Since we never call rest_of_compilation, we never clear
6534     CFUN.  Do so explicitly.  */
6535  free_after_compilation (cfun);
6536  cfun = NULL;
6537
6538  if (! nested)
6539    {
6540      /* Generate RTL for the body of this function.  */
6541      c_expand_body (fndecl, nested, can_defer_p);
6542
6543      /* Let the error reporting routines know that we're outside a
6544	 function.  For a nested function, this value is used in
6545	 c_pop_function_context and then reset via pop_function_context.  */
6546      current_function_decl = NULL;
6547    }
6548}
6549
6550/* Generate the RTL for a deferred function FNDECL.  */
6551
6552void
6553c_expand_deferred_function (fndecl)
6554     tree fndecl;
6555{
6556  /* DECL_INLINE or DECL_RESULT might got cleared after the inline
6557     function was deferred, e.g. in duplicate_decls.  */
6558  if (DECL_INLINE (fndecl) && DECL_RESULT (fndecl))
6559    {
6560      c_expand_body (fndecl, 0, 0);
6561      current_function_decl = NULL;
6562    }
6563}
6564
6565/* Called to move the SAVE_EXPRs for parameter declarations in a
6566   nested function into the nested function.  DATA is really the
6567   nested FUNCTION_DECL.  */
6568
6569static tree
6570set_save_expr_context (tp, walk_subtrees, data)
6571     tree *tp;
6572     int *walk_subtrees;
6573     void *data;
6574{
6575  if (TREE_CODE (*tp) == SAVE_EXPR && !SAVE_EXPR_CONTEXT (*tp))
6576    SAVE_EXPR_CONTEXT (*tp) = (tree) data;
6577  /* Do not walk back into the SAVE_EXPR_CONTEXT; that will cause
6578     circularity.  */
6579  else if (DECL_P (*tp))
6580    *walk_subtrees = 0;
6581
6582  return NULL_TREE;
6583}
6584
6585/* Generate the RTL for the body of FNDECL.  If NESTED_P is nonzero,
6586   then we are already in the process of generating RTL for another
6587   function.  If can_defer_p is zero, we won't attempt to defer the
6588   generation of RTL.  */
6589
6590static void
6591c_expand_body (fndecl, nested_p, can_defer_p)
6592     tree fndecl;
6593     int nested_p, can_defer_p;
6594{
6595  int uninlinable = 1;
6596  int saved_lineno;
6597  const char *saved_input_filename;
6598
6599  /* There's no reason to do any of the work here if we're only doing
6600     semantic analysis; this code just generates RTL.  */
6601  if (flag_syntax_only)
6602    return;
6603
6604  saved_lineno = lineno;
6605  saved_input_filename = input_filename;
6606  lineno = DECL_SOURCE_LINE (fndecl);
6607  input_filename = DECL_SOURCE_FILE (fndecl);
6608
6609  if (flag_inline_trees)
6610    {
6611      /* First, cache whether the current function is inlinable.  Some
6612         predicates depend on cfun and current_function_decl to
6613         function completely.  */
6614      timevar_push (TV_INTEGRATION);
6615      uninlinable = ! tree_inlinable_function_p (fndecl);
6616
6617      if (! uninlinable && can_defer_p
6618	  /* Save function tree for inlining.  Should return 0 if the
6619             language does not support function deferring or the
6620             function could not be deferred.  */
6621	  && defer_fn (fndecl))
6622	{
6623	  /* Let the back-end know that this function exists.  */
6624	  (*debug_hooks->deferred_inline_function) (fndecl);
6625          timevar_pop (TV_INTEGRATION);
6626          lineno = saved_lineno;
6627          input_filename = saved_input_filename;
6628	  return;
6629	}
6630
6631      /* Then, inline any functions called in it.  */
6632      optimize_inline_calls (fndecl);
6633      timevar_pop (TV_INTEGRATION);
6634    }
6635
6636  timevar_push (TV_EXPAND);
6637
6638  if (nested_p)
6639    {
6640      /* Make sure that we will evaluate variable-sized types involved
6641	 in our function's type.  */
6642      expand_pending_sizes (DECL_LANG_SPECIFIC (fndecl)->pending_sizes);
6643      /* Squirrel away our current state.  */
6644      push_function_context ();
6645    }
6646
6647  /* Initialize the RTL code for the function.  */
6648  current_function_decl = fndecl;
6649  init_function_start (fndecl, input_filename, DECL_SOURCE_LINE (fndecl));
6650
6651  /* This function is being processed in whole-function mode.  */
6652  cfun->x_whole_function_mode_p = 1;
6653
6654  /* Even though we're inside a function body, we still don't want to
6655     call expand_expr to calculate the size of a variable-sized array.
6656     We haven't necessarily assigned RTL to all variables yet, so it's
6657     not safe to try to expand expressions involving them.  */
6658  immediate_size_expand = 0;
6659  cfun->x_dont_save_pending_sizes_p = 1;
6660
6661  /* Set up parameters and prepare for return, for the function.  */
6662  expand_function_start (fndecl, 0);
6663
6664  /* If the function has a variably modified type, there may be
6665     SAVE_EXPRs in the parameter types.  Their context must be set to
6666     refer to this function; they cannot be expanded in the containing
6667     function.  */
6668  if (decl_function_context (fndecl)
6669      && variably_modified_type_p (TREE_TYPE (fndecl)))
6670    walk_tree (&TREE_TYPE (fndecl), set_save_expr_context, fndecl,
6671	       NULL);
6672
6673  /* If this function is `main', emit a call to `__main'
6674     to run global initializers, etc.  */
6675  if (DECL_NAME (fndecl)
6676      && MAIN_NAME_P (DECL_NAME (fndecl))
6677      && DECL_CONTEXT (fndecl) == NULL_TREE)
6678    expand_main_function ();
6679
6680  /* Generate the RTL for this function.  */
6681  expand_stmt (DECL_SAVED_TREE (fndecl));
6682
6683  /* Keep the function body if it's needed for inlining or dumping.  */
6684  if (uninlinable && !dump_enabled_p (TDI_all))
6685    {
6686      /* Allow the body of the function to be garbage collected.  */
6687      DECL_SAVED_TREE (fndecl) = NULL_TREE;
6688    }
6689
6690  /* We hard-wired immediate_size_expand to zero above.
6691     expand_function_end will decrement this variable.  So, we set the
6692     variable to one here, so that after the decrement it will remain
6693     zero.  */
6694  immediate_size_expand = 1;
6695
6696  /* Allow language dialects to perform special processing.  */
6697  if (lang_expand_function_end)
6698    (*lang_expand_function_end) ();
6699
6700  /* Generate rtl for function exit.  */
6701  expand_function_end (input_filename, lineno, 0);
6702
6703  /* If this is a nested function, protect the local variables in the stack
6704     above us from being collected while we're compiling this function.  */
6705  if (nested_p)
6706    ggc_push_context ();
6707
6708  /* Run the optimizers and output the assembler code for this function.  */
6709  rest_of_compilation (fndecl);
6710
6711  /* Undo the GC context switch.  */
6712  if (nested_p)
6713    ggc_pop_context ();
6714
6715  /* If requested, warn about function definitions where the function will
6716     return a value (usually of some struct or union type) which itself will
6717     take up a lot of stack space.  */
6718
6719  if (warn_larger_than && !DECL_EXTERNAL (fndecl) && TREE_TYPE (fndecl))
6720    {
6721      tree ret_type = TREE_TYPE (TREE_TYPE (fndecl));
6722
6723      if (ret_type && TYPE_SIZE_UNIT (ret_type)
6724	  && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
6725	  && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
6726				   larger_than_size))
6727	{
6728	  unsigned int size_as_int
6729	    = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
6730
6731	  if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
6732	    warning_with_decl (fndecl,
6733			       "size of return value of `%s' is %u bytes",
6734			       size_as_int);
6735	  else
6736	    warning_with_decl (fndecl,
6737			       "size of return value of `%s' is larger than %d bytes",
6738			       larger_than_size);
6739	}
6740    }
6741
6742  if (DECL_SAVED_INSNS (fndecl) == 0 && ! nested_p
6743      && ! flag_inline_trees)
6744    {
6745      /* Stop pointing to the local nodes about to be freed.
6746	 But DECL_INITIAL must remain nonzero so we know this
6747	 was an actual function definition.
6748	 For a nested function, this is done in c_pop_function_context.
6749	 If rest_of_compilation set this to 0, leave it 0.  */
6750      if (DECL_INITIAL (fndecl) != 0)
6751	DECL_INITIAL (fndecl) = error_mark_node;
6752
6753      DECL_ARGUMENTS (fndecl) = 0;
6754    }
6755
6756  if (DECL_STATIC_CONSTRUCTOR (fndecl))
6757    {
6758      if (targetm.have_ctors_dtors)
6759	(* targetm.asm_out.constructor) (XEXP (DECL_RTL (fndecl), 0),
6760				         DEFAULT_INIT_PRIORITY);
6761      else
6762	static_ctors = tree_cons (NULL_TREE, fndecl, static_ctors);
6763    }
6764
6765  if (DECL_STATIC_DESTRUCTOR (fndecl))
6766    {
6767      if (targetm.have_ctors_dtors)
6768	(* targetm.asm_out.destructor) (XEXP (DECL_RTL (fndecl), 0),
6769				        DEFAULT_INIT_PRIORITY);
6770      else
6771	static_dtors = tree_cons (NULL_TREE, fndecl, static_dtors);
6772    }
6773
6774  if (nested_p)
6775    /* Return to the enclosing function.  */
6776    pop_function_context ();
6777  timevar_pop (TV_EXPAND);
6778
6779  lineno = saved_lineno;
6780  input_filename = saved_input_filename;
6781}
6782
6783/* Check the declarations given in a for-loop for satisfying the C99
6784   constraints.  */
6785void
6786check_for_loop_decls ()
6787{
6788  tree t;
6789
6790  if (!flag_isoc99)
6791    {
6792      /* If we get here, declarations have been used in a for loop without
6793	 the C99 for loop scope.  This doesn't make much sense, so don't
6794	 allow it.  */
6795      error ("`for' loop initial declaration used outside C99 mode");
6796      return;
6797    }
6798  /* C99 subclause 6.8.5 paragraph 3:
6799
6800       [#3]  The  declaration  part  of  a for statement shall only
6801       declare identifiers for objects having storage class auto or
6802       register.
6803
6804     It isn't clear whether, in this sentence, "identifiers" binds to
6805     "shall only declare" or to "objects" - that is, whether all identifiers
6806     declared must be identifiers for objects, or whether the restriction
6807     only applies to those that are.  (A question on this in comp.std.c
6808     in November 2000 received no answer.)  We implement the strictest
6809     interpretation, to avoid creating an extension which later causes
6810     problems.  */
6811
6812  for (t = gettags (); t; t = TREE_CHAIN (t))
6813    {
6814      if (TREE_PURPOSE (t) != 0)
6815        {
6816          enum tree_code code = TREE_CODE (TREE_VALUE (t));
6817
6818          if (code == RECORD_TYPE)
6819            error ("`struct %s' declared in `for' loop initial declaration",
6820                   IDENTIFIER_POINTER (TREE_PURPOSE (t)));
6821          else if (code == UNION_TYPE)
6822            error ("`union %s' declared in `for' loop initial declaration",
6823                   IDENTIFIER_POINTER (TREE_PURPOSE (t)));
6824          else
6825            error ("`enum %s' declared in `for' loop initial declaration",
6826                   IDENTIFIER_POINTER (TREE_PURPOSE (t)));
6827        }
6828    }
6829
6830  for (t = getdecls (); t; t = TREE_CHAIN (t))
6831    {
6832      if (TREE_CODE (t) != VAR_DECL && DECL_NAME (t))
6833	error_with_decl (t, "declaration of non-variable `%s' in `for' loop initial declaration");
6834      else if (TREE_STATIC (t))
6835	error_with_decl (t, "declaration of static variable `%s' in `for' loop initial declaration");
6836      else if (DECL_EXTERNAL (t))
6837	error_with_decl (t, "declaration of `extern' variable `%s' in `for' loop initial declaration");
6838    }
6839}
6840
6841/* Save and restore the variables in this file and elsewhere
6842   that keep track of the progress of compilation of the current function.
6843   Used for nested functions.  */
6844
6845struct language_function GTY(())
6846{
6847  struct c_language_function base;
6848  tree named_labels;
6849  tree shadowed_labels;
6850  int returns_value;
6851  int returns_null;
6852  int returns_abnormally;
6853  int warn_about_return_type;
6854  int extern_inline;
6855  struct binding_level *binding_level;
6856};
6857
6858/* Save and reinitialize the variables
6859   used during compilation of a C function.  */
6860
6861void
6862c_push_function_context (f)
6863     struct function *f;
6864{
6865  struct language_function *p;
6866  p = ((struct language_function *)
6867       ggc_alloc (sizeof (struct language_function)));
6868  f->language = p;
6869
6870  p->base.x_stmt_tree = c_stmt_tree;
6871  p->base.x_scope_stmt_stack = c_scope_stmt_stack;
6872  p->named_labels = named_labels;
6873  p->shadowed_labels = shadowed_labels;
6874  p->returns_value = current_function_returns_value;
6875  p->returns_null = current_function_returns_null;
6876  p->returns_abnormally = current_function_returns_abnormally;
6877  p->warn_about_return_type = warn_about_return_type;
6878  p->extern_inline = current_extern_inline;
6879  p->binding_level = current_binding_level;
6880}
6881
6882/* Restore the variables used during compilation of a C function.  */
6883
6884void
6885c_pop_function_context (f)
6886     struct function *f;
6887{
6888  struct language_function *p = f->language;
6889  tree link;
6890
6891  /* Bring back all the labels that were shadowed.  */
6892  for (link = shadowed_labels; link; link = TREE_CHAIN (link))
6893    if (DECL_NAME (TREE_VALUE (link)) != 0)
6894      IDENTIFIER_LABEL_VALUE (DECL_NAME (TREE_VALUE (link)))
6895	= TREE_VALUE (link);
6896
6897  if (DECL_SAVED_INSNS (current_function_decl) == 0
6898      && DECL_SAVED_TREE (current_function_decl) == NULL_TREE)
6899    {
6900      /* Stop pointing to the local nodes about to be freed.  */
6901      /* But DECL_INITIAL must remain nonzero so we know this
6902	 was an actual function definition.  */
6903      DECL_INITIAL (current_function_decl) = error_mark_node;
6904      DECL_ARGUMENTS (current_function_decl) = 0;
6905    }
6906
6907  c_stmt_tree = p->base.x_stmt_tree;
6908  c_scope_stmt_stack = p->base.x_scope_stmt_stack;
6909  named_labels = p->named_labels;
6910  shadowed_labels = p->shadowed_labels;
6911  current_function_returns_value = p->returns_value;
6912  current_function_returns_null = p->returns_null;
6913  current_function_returns_abnormally = p->returns_abnormally;
6914  warn_about_return_type = p->warn_about_return_type;
6915  current_extern_inline = p->extern_inline;
6916  current_binding_level = p->binding_level;
6917
6918  f->language = NULL;
6919}
6920
6921/* Copy the DECL_LANG_SPECIFIC data associated with DECL.  */
6922
6923void
6924c_dup_lang_specific_decl (decl)
6925     tree decl;
6926{
6927  struct lang_decl *ld;
6928
6929  if (!DECL_LANG_SPECIFIC (decl))
6930    return;
6931
6932  ld = (struct lang_decl *) ggc_alloc (sizeof (struct lang_decl));
6933  memcpy ((char *) ld, (char *) DECL_LANG_SPECIFIC (decl),
6934	  sizeof (struct lang_decl));
6935  DECL_LANG_SPECIFIC (decl) = ld;
6936}
6937
6938/* The functions below are required for functionality of doing
6939   function at once processing in the C front end. Currently these
6940   functions are not called from anywhere in the C front end, but as
6941   these changes continue, that will change.  */
6942
6943/* Returns nonzero if the current statement is a full expression,
6944   i.e. temporaries created during that statement should be destroyed
6945   at the end of the statement.  */
6946
6947int
6948stmts_are_full_exprs_p ()
6949{
6950  return 0;
6951}
6952
6953/* Returns the stmt_tree (if any) to which statements are currently
6954   being added.  If there is no active statement-tree, NULL is
6955   returned.  */
6956
6957stmt_tree
6958current_stmt_tree ()
6959{
6960  return &c_stmt_tree;
6961}
6962
6963/* Returns the stack of SCOPE_STMTs for the current function.  */
6964
6965tree *
6966current_scope_stmt_stack ()
6967{
6968  return &c_scope_stmt_stack;
6969}
6970
6971/* Nonzero if TYPE is an anonymous union or struct type.  Always 0 in
6972   C.  */
6973
6974int
6975anon_aggr_type_p (node)
6976     tree node ATTRIBUTE_UNUSED;
6977{
6978  return 0;
6979}
6980
6981/* Dummy function in place of callback used by C++.  */
6982
6983void
6984extract_interface_info ()
6985{
6986}
6987
6988/* Return a new COMPOUND_STMT, after adding it to the current
6989   statement tree.  */
6990
6991tree
6992c_begin_compound_stmt ()
6993{
6994  tree stmt;
6995
6996  /* Create the COMPOUND_STMT.  */
6997  stmt = add_stmt (build_stmt (COMPOUND_STMT, NULL_TREE));
6998
6999  return stmt;
7000}
7001
7002/* Expand T (a DECL_STMT) if it declares an entity not handled by the
7003   common code.  */
7004
7005void
7006c_expand_decl_stmt (t)
7007     tree t;
7008{
7009  tree decl = DECL_STMT_DECL (t);
7010
7011  /* Expand nested functions.  */
7012  if (TREE_CODE (decl) == FUNCTION_DECL
7013      && DECL_CONTEXT (decl) == current_function_decl
7014      && DECL_SAVED_TREE (decl))
7015    c_expand_body (decl, /*nested_p=*/1, /*can_defer_p=*/0);
7016}
7017
7018/* Return the IDENTIFIER_GLOBAL_VALUE of T, for use in common code, since
7019   the definition of IDENTIFIER_GLOBAL_VALUE is different for C and C++.  */
7020
7021tree
7022identifier_global_value	(t)
7023     tree t;
7024{
7025  return IDENTIFIER_GLOBAL_VALUE (t);
7026}
7027
7028/* Record a builtin type for C.  If NAME is non-NULL, it is the name used;
7029   otherwise the name is found in ridpointers from RID_INDEX.  */
7030
7031void
7032record_builtin_type (rid_index, name, type)
7033     enum rid rid_index;
7034     const char *name;
7035     tree type;
7036{
7037  tree id;
7038  if (name == 0)
7039    id = ridpointers[(int) rid_index];
7040  else
7041    id = get_identifier (name);
7042  pushdecl (build_decl (TYPE_DECL, id, type));
7043}
7044
7045/* Build the void_list_node (void_type_node having been created).  */
7046tree
7047build_void_list_node ()
7048{
7049  tree t = build_tree_list (NULL_TREE, void_type_node);
7050  return t;
7051}
7052
7053/* Return something to represent absolute declarators containing a *.
7054   TARGET is the absolute declarator that the * contains.
7055   TYPE_QUALS_ATTRS is a list of modifiers such as const or volatile
7056   to apply to the pointer type, represented as identifiers, possible mixed
7057   with attributes.
7058
7059   We return an INDIRECT_REF whose "contents" are TARGET (inside a TREE_LIST,
7060   if attributes are present) and whose type is the modifier list.  */
7061
7062tree
7063make_pointer_declarator (type_quals_attrs, target)
7064     tree type_quals_attrs, target;
7065{
7066  tree quals, attrs;
7067  tree itarget = target;
7068  split_specs_attrs (type_quals_attrs, &quals, &attrs);
7069  if (attrs != NULL_TREE)
7070    itarget = tree_cons (attrs, target, NULL_TREE);
7071  return build1 (INDIRECT_REF, quals, itarget);
7072}
7073
7074#include "gt-c-decl.h"
7075