adding GNU dc ("desk calculator")

[unix-history] / gnu / usr.bin / gcc1 / cc1 / c-decl.c

/*-
 * This code is derived from software copyrighted by the Free Software
 * Foundation.
 *
 * Modified 1991 by Donn Seeley at UUNET Technologies, Inc.
 */

#ifndef lint
static char sccsid[] = "@(#)c-decl.c	6.3 (Berkeley) 5/8/91";
#endif /* not lint */

/* Process declarations and variables for C compiler.
   Copyright (C) 1988 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */


/* Process declarations and symbol lookup for C front end.
   Also constructs types; the standard scalar types at initialization,
   and structure, union, array and enum types when they are declared.  */

/* ??? not all decl nodes are given the most useful possible
   line numbers.  For example, the CONST_DECLs for enum values.  */

#include "config.h"
#include "tree.h"
#include "flags.h"
#include "c-tree.h"
#include "c-parse.h"

#include <stdio.h>

/* In grokdeclarator, distinguish syntactic contexts of declarators.  */
enum decl_context
{ NORMAL,			/* Ordinary declaration */
  FUNCDEF,			/* Function definition */
  PARM,				/* Declaration of parm before function body */
  FIELD,			/* Declaration inside struct or union */
  TYPENAME};			/* Typename (inside cast or sizeof)  */

#define NULL 0
#define MIN(X,Y) ((X) < (Y) ? (X) : (Y))
#define MAX(X,Y) ((X) > (Y) ? (X) : (Y))

#ifndef CHAR_TYPE_SIZE
#define CHAR_TYPE_SIZE BITS_PER_UNIT
#endif

#ifndef SHORT_TYPE_SIZE
#define SHORT_TYPE_SIZE (BITS_PER_UNIT * MIN ((UNITS_PER_WORD + 1) / 2, 2))
#endif

#ifndef INT_TYPE_SIZE
#define INT_TYPE_SIZE BITS_PER_WORD
#endif

#ifndef LONG_TYPE_SIZE
#define LONG_TYPE_SIZE BITS_PER_WORD
#endif

#ifndef LONG_LONG_TYPE_SIZE
#define LONG_LONG_TYPE_SIZE (BITS_PER_WORD * 2)
#endif

#ifndef FLOAT_TYPE_SIZE
#define FLOAT_TYPE_SIZE BITS_PER_WORD
#endif

#ifndef DOUBLE_TYPE_SIZE
#define DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
#endif

#ifndef LONG_DOUBLE_TYPE_SIZE
#define LONG_DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
#endif
\f
/* a node which has tree code ERROR_MARK, and whose type is itself.
   All erroneous expressions are replaced with this node.  All functions
   that accept nodes as arguments should avoid generating error messages
   if this node is one of the arguments, since it is undesirable to get
   multiple error messages from one error in the input.  */

tree error_mark_node;

/* INTEGER_TYPE and REAL_TYPE nodes for the standard data types */

tree short_integer_type_node;
tree integer_type_node;
tree long_integer_type_node;
tree long_long_integer_type_node;

tree short_unsigned_type_node;
tree unsigned_type_node;
tree long_unsigned_type_node;
tree long_long_unsigned_type_node;

tree unsigned_char_type_node;
tree signed_char_type_node;
tree char_type_node;

tree float_type_node;
tree double_type_node;
tree long_double_type_node;

/* a VOID_TYPE node.  */

tree void_type_node;

/* A node for type `void *'.  */

tree ptr_type_node;

/* A node for type `char *'.  */

tree string_type_node;

/* Type `char[256]' or something like it.
   Used when an array of char is needed and the size is irrelevant.  */

tree char_array_type_node;

/* Type `int[256]' or something like it.
   Used when an array of int needed and the size is irrelevant.  */

tree int_array_type_node;

/* type `int ()' -- used for implicit declaration of functions.  */

tree default_function_type;

/* function types `double (double)' and `double (double, double)', etc.  */

tree double_ftype_double, double_ftype_double_double;
tree int_ftype_int, long_ftype_long;

/* Function type `void (void *, void *, int)' and similar ones */

tree void_ftype_ptr_ptr_int, int_ftype_ptr_ptr_int, void_ftype_ptr_int_int;

/* Two expressions that are constants with value zero.
   The first is of type `int', the second of type `void *'.  */

tree integer_zero_node;
tree null_pointer_node;

/* A node for the integer constant 1.  */

tree integer_one_node;

/* An identifier whose name is <value>.  This is used as the "name"
   of the RESULT_DECLs for values of functions.  */

tree value_identifier;

/* While defining an enum type, this is 1 plus the last enumerator
   constant value.  */

static tree enum_next_value;

/* Parsing a function declarator leaves a list of parameter names
   or a chain or parameter decls here.  */

static tree last_function_parms;

/* Parsing a function declarator leaves here a chain of structure
   and enum types declared in the parmlist.  */

static tree last_function_parm_tags;

/* After parsing the declarator that starts a function definition,
   `start_function' puts here the list of parameter names or chain of decls.
   `store_parm_decls' finds it here.  */

static tree current_function_parms;

/* Similar, for last_function_parm_tags.  */
static tree current_function_parm_tags;

/* A list (chain of TREE_LIST nodes) of all LABEL_STMTs in the function
   that have names.  Here so we can clear out their names' definitions
   at the end of the function.  */

static tree named_labels;

/* The FUNCTION_DECL for the function currently being compiled,
   or 0 if between functions.  */
tree current_function_decl;

/* Set to 0 at beginning of a function definition, set to 1 if
   a return statement that specifies a return value is seen.  */

int current_function_returns_value;

/* Set to 0 at beginning of a function definition, set to 1 if
   a return statement with no argument is seen.  */

int current_function_returns_null;

/* Set to nonzero by `grokdeclarator' for a function
   whose return type is defaulted, if warnings for this are desired.  */

static int warn_about_return_type;

/* Nonzero when starting a function delcared `extern inline'.  */

static int current_extern_inline;
\f
/* For each binding contour we allocate a binding_level structure
 * which records the names defined in that contour.
 * Contours include:
 *  0) the global one
 *  1) one for each function definition,
 *     where internal declarations of the parameters appear.
 *  2) one for each compound statement,
 *     to record its declarations.
 *
 * The current meaning of a name can be found by searching the levels from
 * the current one out to the global one.
 */

/* Note that the information in the `names' component of the global contour
   is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers.  */

struct binding_level
  {
    /* A chain of _DECL nodes for all variables, constants, functions,
       and typedef types.  These are in the reverse of the order supplied.
     */
    tree names;

    /* A list of structure, union and enum definitions,
     * for looking up tag names.
     * It is a chain of TREE_LIST nodes, each of whose TREE_PURPOSE is a name,
     * or NULL_TREE; and whose TREE_VALUE is a RECORD_TYPE, UNION_TYPE,
     * or ENUMERAL_TYPE node.
     */
    tree tags;

    /* For each level, a list of shadowed outer-level local definitions
       to be restored when this level is popped.
       Each link is a TREE_LIST whose TREE_PURPOSE is an identifier and
       whose TREE_VALUE is its old definition (a kind of ..._DECL node).  */
    tree shadowed;

    /* For each level (except not the global one),
       a chain of LET_STMT nodes for all the levels
       that were entered and exited one level down.  */
    tree blocks;

    /* The binding level which this one is contained in (inherits from).  */
    struct binding_level *level_chain;

    /* Nonzero for the level that holds the parameters of a function.  */
    char parm_flag;

    /* Nonzero if this level "doesn't exist" for tags.  */
    char tag_transparent;

    /* Nonzero means make a LET_STMT for this level regardless of all else.  */
    char keep;

    /* Nonzero means make a LET_STMT if this level has any subblocks.  */
    char keep_if_subblocks;

    /* Number of decls in `names' that have incomplete 
       structure or union types.  */
    int n_incomplete;
  };

#define NULL_BINDING_LEVEL (struct binding_level *) NULL
  
/* The binding level currently in effect.  */

static struct binding_level *current_binding_level;

/* A chain of binding_level structures awaiting reuse.  */

static struct binding_level *free_binding_level;

/* The outermost binding level, for names of file scope.
   This is created when the compiler is started and exists
   through the entire run.  */

static struct binding_level *global_binding_level;

/* Binding level structures are initialized by copying this one.  */

static struct binding_level clear_binding_level
  = {NULL, NULL, NULL, NULL, NULL, 0, 0, 0};

/* Nonzero means unconditionally make a LET_STMT for the next level pushed.  */

static int keep_next_level_flag;

/* Nonzero means make a LET_STMT for the next level pushed
   if it has subblocks.  */

static int keep_next_if_subblocks;

/* Forward declarations.  */

static tree grokparms (), grokdeclarator ();
tree pushdecl ();
static void builtin_function ();

static tree lookup_tag ();
static tree lookup_tag_reverse ();
static tree lookup_name_current_level ();
static char *redeclaration_error_message ();
static void layout_array_type ();
\f
/* C-specific option variables.  */

/* Nonzero means allow type mismatches in conditional expressions;
   just make their values `void'.   */

int flag_cond_mismatch;

/* Nonzero means don't recognize the keyword `asm'.  */

int flag_no_asm;

/* Nonzero means do some things the same way PCC does.  */

int flag_traditional;

/* Nonzero means warn about implicit declarations.  */

int warn_implicit;

/* Nonzero means warn about function definitions that default the return type
   or that use a null return and have a return-type other than void.  */

int warn_return_type;

/* Nonzero means give string constants the type `const char *'
   to get extra warnings from them.  These warnings will be too numerous
   to be useful, except in thoroughly ANSIfied programs.  */

int warn_write_strings;

/* Nonzero means warn about pointer casts that can drop a type qualifier
   from the pointer target type.  */

int warn_cast_qual;

/* Nonzero means warn about sizeof(function) or addition/subtraction
   of function pointers.  */

int warn_pointer_arith;

/* Nonzero means warn for all old-style non-prototype function decls.  */

int warn_strict_prototypes;

/* Nonzero means `$' can be in an identifier.
   See cccp.c for reasons why this breaks some obscure ANSI C programs.  */

#ifndef DOLLARS_IN_IDENTIFIERS
#define DOLLARS_IN_IDENTIFIERS 0
#endif
int dollars_in_ident = DOLLARS_IN_IDENTIFIERS;

char *language_string = "GNU C";

/* Decode the string P as a language-specific option.
   Return 1 if it is recognized (and handle it);
   return 0 if not recognized.  */
   
int
lang_decode_option (p)
     char *p;
{
  if (!strcmp (p, "-ftraditional") || !strcmp (p, "-traditional"))
    flag_traditional = 1, dollars_in_ident = 1, flag_writable_strings = 1;
  else if (!strcmp (p, "-fsigned-char"))
    flag_signed_char = 1;
  else if (!strcmp (p, "-funsigned-char"))
    flag_signed_char = 0;
  else if (!strcmp (p, "-fno-signed-char"))
    flag_signed_char = 0;
  else if (!strcmp (p, "-fno-unsigned-char"))
    flag_signed_char = 1;
  else if (!strcmp (p, "-fshort-enums"))
    flag_short_enums = 1;
  else if (!strcmp (p, "-fno-short-enums"))
    flag_short_enums = 0;
  else if (!strcmp (p, "-fcond-mismatch"))
    flag_cond_mismatch = 1;
  else if (!strcmp (p, "-fno-cond-mismatch"))
    flag_cond_mismatch = 0;
  else if (!strcmp (p, "-fasm"))
    flag_no_asm = 0;
  else if (!strcmp (p, "-fno-asm"))
    flag_no_asm = 1;
  else if (!strcmp (p, "-ansi"))
    flag_no_asm = 1, dollars_in_ident = 0;
  else if (!strcmp (p, "-Wimplicit"))
    warn_implicit = 1;
  else if (!strcmp (p, "-Wreturn-type"))
    warn_return_type = 1;
  else if (!strcmp (p, "-Wwrite-strings"))
    warn_write_strings = 1;
  else if (!strcmp (p, "-Wcast-qual"))
    warn_cast_qual = 1;
  else if (!strcmp (p, "-Wpointer-arith"))
    warn_pointer_arith = 1;
  else if (!strcmp (p, "-Wstrict-prototypes"))
    warn_strict_prototypes = 1;
  else if (!strcmp (p, "-Wcomment"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wcomments"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wtrigraphs"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wall"))
    {
      extra_warnings = 1;
      warn_implicit = 1;
      warn_return_type = 1;
      warn_unused = 1;
      warn_switch = 1;
    }
  else
    return 0;

  return 1;
}

void
print_lang_identifier (file, node, indent)
     FILE *file;
     tree node;
     int indent;
{
  print_node (file, "global", IDENTIFIER_GLOBAL_VALUE (node), indent + 4);
  print_node (file, "local", IDENTIFIER_LOCAL_VALUE (node), indent + 4);
  print_node (file, "label", IDENTIFIER_LABEL_VALUE (node), indent + 4);
  print_node (file, "implicit", IDENTIFIER_IMPLICIT_DECL (node), indent + 4);
  print_node (file, "error locus", IDENTIFIER_ERROR_LOCUS (node), indent + 4);
}
\f
/* Create a new `struct binding_level'.  */

static
struct binding_level *
make_binding_level ()
{
  /* NOSTRICT */
  return (struct binding_level *) xmalloc (sizeof (struct binding_level));
}

/* Nonzero if we are currently in the global binding level.  */

int
global_bindings_p ()
{
  return current_binding_level == global_binding_level;
}

void
keep_next_level ()
{
  keep_next_level_flag = 1;
}

/* Nonzero if the current level needs to have a LET_STMT made.  */

int
kept_level_p ()
{
  return ((current_binding_level->keep_if_subblocks
	   && current_binding_level->blocks != 0)
	  || current_binding_level->keep
	  || current_binding_level->names != 0);
}

/* Identify this binding level as a level of parameters.  */

void
declare_parm_level ()
{
  current_binding_level->parm_flag = 1;
}

/* Nonzero if currently making parm declarations.  */

in_parm_level_p ()
{
  return current_binding_level->parm_flag;
}

/* Enter a new binding level.
   If TAG_TRANSPARENT is nonzero, do so only for the name space of variables,
   not for that of tags.  */

void
pushlevel (tag_transparent)
     int tag_transparent;
{
  register struct binding_level *newlevel = NULL_BINDING_LEVEL;

  /* If this is the top level of a function,
     just make sure that NAMED_LABELS is 0.
     They should have been set to 0 at the end of the previous function.  */

  if (current_binding_level == global_binding_level)
    {
      if (named_labels)
	abort ();
    }

  /* Reuse or create a struct for this binding level.  */

  if (free_binding_level)
    {
      newlevel = free_binding_level;
      free_binding_level = free_binding_level->level_chain;
    }
  else
    {
      newlevel = make_binding_level ();
    }

  /* Add this level to the front of the chain (stack) of levels that
     are active.  */

  *newlevel = clear_binding_level;
  newlevel->level_chain = current_binding_level;
  current_binding_level = newlevel;
  newlevel->tag_transparent = tag_transparent;
  newlevel->keep = keep_next_level_flag;
  keep_next_level_flag = 0;
  newlevel->keep_if_subblocks = keep_next_if_subblocks;
  keep_next_if_subblocks = 0;
}

/* Exit a binding level.
   Pop the level off, and restore the state of the identifier-decl mappings
   that were in effect when this level was entered.

   If KEEP is nonzero, this level had explicit declarations, so
   and create a "block" (a LET_STMT node) for the level
   to record its declarations and subblocks for symbol table output.

   If FUNCTIONBODY is nonzero, this level is the body of a function,
   so create a block as if KEEP were set and also clear out all
   label names.

   If REVERSE is nonzero, reverse the order of decls before putting
   them into the LET_STMT.  */

tree
poplevel (keep, reverse, functionbody)
     int keep;
     int reverse;
     int functionbody;
{
  register tree link;
  /* The chain of decls was accumulated in reverse order.
     Put it into forward order, just for cleanliness.  */
  tree decls;
  tree tags = current_binding_level->tags;
  tree subblocks = current_binding_level->blocks;
  tree block = 0;

  keep |= current_binding_level->keep;

  /* This warning is turned off because it causes warnings for
     declarations like `extern struct foo *x'.  */
#if 0
  /* Warn about incomplete structure types in this level.  */
  for (link = tags; link; link = TREE_CHAIN (link))
    if (TYPE_SIZE (TREE_VALUE (link)) == 0)
      {
	tree type = TREE_VALUE (link);
	char *errmsg;
	switch (TREE_CODE (type))
	  {
	  case RECORD_TYPE:
	    errmsg = "`struct %s' incomplete in scope ending here";
	    break;
	  case UNION_TYPE:
	    errmsg = "`union %s' incomplete in scope ending here";
	    break;
	  case ENUMERAL_TYPE:
	    errmsg = "`enum %s' incomplete in scope ending here";
	    break;
	  }
	if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
	  error (errmsg, IDENTIFIER_POINTER (TYPE_NAME (type)));
	else
	  /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL.  */
	  error (errmsg, IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))));
      }
#endif /* 0 */

  /* Get the decls in the order they were written.
     Usually current_binding_level->names is in reverse order.
     But parameter decls were previously put in forward order.  */

  if (reverse)
    current_binding_level->names
      = decls = nreverse (current_binding_level->names);
  else
    decls = current_binding_level->names;

  /* If there were any declarations or structure tags in that level,
     or if this level is a function body,
     create a LET_STMT to record them for the life of this function.  */

  if (keep || functionbody
      || (current_binding_level->keep_if_subblocks && subblocks != 0))
    block = build_let (0, 0, keep ? decls : 0,
		       subblocks, 0, keep ? tags : 0);

  /* In each subblock, record that this is its superior.  */

  for (link = subblocks; link; link = TREE_CHAIN (link))
    STMT_SUPERCONTEXT (link) = block;

  /* Clear out the meanings of the local variables of this level;
     also record in each decl which block it belongs to.  */

  for (link = decls; link; link = TREE_CHAIN (link))
    {
      if (DECL_NAME (link) != 0)
	{
	  /* If the ident. was used via a local extern decl,
	     don't forget that fact.  */
	  if (TREE_USED (link) && TREE_EXTERNAL (link))
	    TREE_USED (DECL_NAME (link)) = 1;
	  IDENTIFIER_LOCAL_VALUE (DECL_NAME (link)) = 0;
	}
      DECL_CONTEXT (link) = block;
    }

  /* Restore all name-meanings of the outer levels
     that were shadowed by this level.  */

  for (link = current_binding_level->shadowed; link; link = TREE_CHAIN (link))
    IDENTIFIER_LOCAL_VALUE (TREE_PURPOSE (link)) = TREE_VALUE (link);

  /* If the level being exited is the top level of a function,
     check over all the labels.  */

  if (functionbody)
    {
      /* Clear out the definitions of all label names,
	 since their scopes end here.  */

      for (link = named_labels; link; link = TREE_CHAIN (link))
	{
	  if (DECL_SOURCE_LINE (TREE_VALUE (link)) == 0)
	    {
	      error ("label `%s' used somewhere above but not defined",
		     IDENTIFIER_POINTER (DECL_NAME (TREE_VALUE (link))));
	      /* Avoid crashing later.  */
	      define_label (input_filename, 1, DECL_NAME (TREE_VALUE (link)));
	    }
	  else if (warn_unused && !TREE_USED (TREE_VALUE (link)))
	    warning_with_decl (TREE_VALUE (link), 
			       "label `%s' defined but not used");
	  IDENTIFIER_LABEL_VALUE (DECL_NAME (TREE_VALUE (link))) = 0;
	}

      named_labels = 0;
    }

  /* Pop the current level, and free the structure for reuse.  */

  {
    register struct binding_level *level = current_binding_level;
    current_binding_level = current_binding_level->level_chain;

    level->level_chain = free_binding_level;
    free_binding_level = level;
  }

  if (functionbody)
    {
      DECL_INITIAL (current_function_decl) = block;
      /* If this is the top level block of a function,
	 the vars are the function's parameters.
	 Don't leave them in the LET_STMT because they are
	 found in the FUNCTION_DECL instead.  */
      STMT_VARS (block) = 0;
    }
  else if (block)
    current_binding_level->blocks
      = chainon (current_binding_level->blocks, block);
  /* If we did not make a block for the level just exited,
     any blocks made for inner levels
     (since they cannot be recorded as subblocks in that level)
     must be carried forward so they will later become subblocks
     of something else.  */
  else if (subblocks)
    current_binding_level->blocks
      = chainon (current_binding_level->blocks, subblocks);

  if (block)
    TREE_USED (block) = 1;
  return block;
}
\f
/* Push a definition of struct, union or enum tag "name".
   "type" should be the type node.
   We assume that the tag "name" is not already defined.

   Note that the definition may really be just a forward reference.
   In that case, the TYPE_SIZE will be zero.  */

void
pushtag (name, type)
     tree name, type;
{
  register struct binding_level *b = current_binding_level;
  while (b->tag_transparent) b = b->level_chain;

  if (name)
    {
      /* Record the identifier as the type's name if it has none.  */

      if (TYPE_NAME (type) == 0)
	TYPE_NAME (type) = name;

      if (b == global_binding_level)
	b->tags = perm_tree_cons (name, type, b->tags);
      else
	b->tags = saveable_tree_cons (name, type, b->tags);
    }
}
\f
/* Handle when a new declaration NEWDECL
   has the same name as an old one OLDDECL
   in the same binding contour.
   Prints an error message if appropriate.

   If safely possible, alter OLDDECL to look like NEWDECL, and return 1.
   Otherwise, return 0.  */

static int
duplicate_decls (newdecl, olddecl)
     register tree newdecl, olddecl;
{
  int types_match = comptypes (TREE_TYPE (newdecl), TREE_TYPE (olddecl));

  if (TREE_CODE (TREE_TYPE (newdecl)) == ERROR_MARK
      || TREE_CODE (TREE_TYPE (olddecl)) == ERROR_MARK)
    types_match = 0;

  /* If this decl has linkage, and the old one does too, maybe no error.  */
  if (TREE_CODE (olddecl) != TREE_CODE (newdecl))
    {
      error_with_decl (newdecl, "`%s' redeclared as different kind of symbol");
      error_with_decl (olddecl, "previous declaration of `%s'");
    }
  else
    {
      if (flag_traditional && TREE_CODE (newdecl) == FUNCTION_DECL
	  && IDENTIFIER_IMPLICIT_DECL (DECL_NAME (newdecl)) == olddecl
	  && DECL_INITIAL (olddecl) == 0)
	/* If -traditional, avoid error for redeclaring fcn
	   after implicit decl.  */
	;
      else if (TREE_CODE (olddecl) == FUNCTION_DECL
	       && DECL_FUNCTION_CODE (olddecl) != NOT_BUILT_IN)
 	{
 	  if (!types_match)
 	    error_with_decl (newdecl, "conflicting types for built-in function `%s'");
 	  else if (extra_warnings)
 	    warning_with_decl (newdecl, "built-in function `%s' redeclared");
 	}
      else if (!types_match)
	{
	  error_with_decl (newdecl, "conflicting types for `%s'");
	  /* Check for function type mismatch
	     involving an empty arglist vs a nonempty one.  */
	  if (TREE_CODE (olddecl) == FUNCTION_DECL
	      && comptypes (TREE_TYPE (TREE_TYPE (olddecl)),
			    TREE_TYPE (TREE_TYPE (newdecl)))
	      && ((TYPE_ARG_TYPES (TREE_TYPE (olddecl)) == 0
		   && DECL_INITIAL (olddecl) == 0)
		  ||
		  (TYPE_ARG_TYPES (TREE_TYPE (newdecl)) == 0
		   && DECL_INITIAL (newdecl) == 0)))
	    {
	      /* Classify the problem further.  */
	      register tree t = TYPE_ARG_TYPES (TREE_TYPE (olddecl));
	      if (t == 0)
		t = TYPE_ARG_TYPES (TREE_TYPE (newdecl));
	      for (; t; t = TREE_CHAIN (t))
		{
		  register tree type = TREE_VALUE (t);

		  if (TREE_CHAIN (t) == 0 && type != void_type_node)
		    {
		      error ("A parameter list with an ellipsis can't match");
		      error ("an empty parameter name list declaration.");
		      break;
		    }

		  if (type == float_type_node
		      || (TREE_CODE (type) == INTEGER_TYPE
			  && (TYPE_PRECISION (type)
			      < TYPE_PRECISION (integer_type_node))))
		    {
		      error ("An argument type that has a default promotion");
		      error ("can't match an empty parameter name list declaration.");
		      break;
		    }
		}
	    }
	  error_with_decl (olddecl, "previous declaration of `%s'");
	}
      else
	{
	  char *errmsg = redeclaration_error_message (newdecl, olddecl);
	  if (errmsg)
	    {
	      error_with_decl (newdecl, errmsg);
	      error_with_decl (olddecl,
			       "here is the previous declaration of `%s'");
	    }
	  else if (TREE_CODE (olddecl) == FUNCTION_DECL
		   && DECL_INITIAL (olddecl) != 0
		   && TYPE_ARG_TYPES (TREE_TYPE (olddecl)) == 0
		   && TYPE_ARG_TYPES (TREE_TYPE (newdecl)) != 0)
	    {
	      /* Prototype decl follows defn w/o prototype.  */
	      warning_with_decl (newdecl, "prototype for `%s'");
	      warning_with_decl (olddecl,
				 "follows non-prototype definition here");
	    }

	  /* These bits are logically part of the type.  */
	  if (pedantic
	      && (TREE_READONLY (newdecl) != TREE_READONLY (olddecl)
		  || TREE_THIS_VOLATILE (newdecl) != TREE_THIS_VOLATILE (olddecl)))
	    warning_with_decl (newdecl, "type qualifiers for `%s' conflict with previous decl");
	}
    }

  if (TREE_CODE (olddecl) == TREE_CODE (newdecl))
    {
      int new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL
			       && DECL_INITIAL (newdecl) != 0);

      /* Copy all the DECL_... slots specified in the new decl
	 except for any that we copy here from the old type.  */

      if (types_match)
	{
	  tree oldtype = TREE_TYPE (olddecl);
	  /* Merge the data types specified in the two decls.  */
	  TREE_TYPE (newdecl)
	    = TREE_TYPE (olddecl)
	      = commontype (TREE_TYPE (newdecl), TREE_TYPE (olddecl));

	  /* Lay the type out, unless already done.  */
	  if (oldtype != TREE_TYPE (newdecl))
	    {
	      if (TREE_TYPE (newdecl) != error_mark_node)
		layout_type (TREE_TYPE (newdecl));
	      if (TREE_CODE (newdecl) != FUNCTION_DECL
		  && TREE_CODE (newdecl) != TYPE_DECL
		  && TREE_CODE (newdecl) != CONST_DECL)
		layout_decl (newdecl, 0);
	    }
	  else
	    {
	      /* Since the type is OLDDECL's, make OLDDECL's size go with.  */
	      DECL_SIZE (newdecl) = DECL_SIZE (olddecl);
	      DECL_SIZE_UNIT (newdecl) = DECL_SIZE_UNIT (olddecl);
	      if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl))
		DECL_ALIGN (newdecl) = DECL_ALIGN (olddecl);
	    }

	  /* Merge the type qualifiers.  */
	  if (TREE_READONLY (newdecl))
	    TREE_READONLY (olddecl) = 1;
	  if (TREE_THIS_VOLATILE (newdecl))
	    TREE_THIS_VOLATILE (olddecl) = 1;

	  /* Merge the initialization information.  */
	  if (DECL_INITIAL (newdecl) == 0)
	    DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
	  /* Keep the old rtl since we can safely use it.  */
	  DECL_RTL (newdecl) = DECL_RTL (olddecl);
	}
      /* If cannot merge, then use the new type and qualifiers,
	 and don't preserve the old rtl.  */
      else
	{
	  TREE_TYPE (olddecl) = TREE_TYPE (newdecl);
	  TREE_READONLY (olddecl) = TREE_READONLY (newdecl);
	  TREE_THIS_VOLATILE (olddecl) = TREE_THIS_VOLATILE (newdecl);
	  TREE_VOLATILE (olddecl) = TREE_VOLATILE (newdecl);
	}

      /* Merge the storage class information.  */
      if (TREE_EXTERNAL (newdecl))
	{
	  TREE_STATIC (newdecl) = TREE_STATIC (olddecl);
	  TREE_EXTERNAL (newdecl) = TREE_EXTERNAL (olddecl);

	  /* For functions, static overrides non-static.  */
	  if (TREE_CODE (newdecl) == FUNCTION_DECL)
	    {
	      TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl);
	      /* This is since we don't automatically
		 copy the attributes of NEWDECL into OLDDECL.  */
	      TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
	      /* If this clears `static', clear it in the identifier too.  */
	      if (! TREE_PUBLIC (olddecl))
		TREE_PUBLIC (DECL_NAME (olddecl)) = 0;
	    }
	  else
	    TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl);
	}
      else
	{
	  TREE_STATIC (olddecl) = TREE_STATIC (newdecl);
	  TREE_EXTERNAL (olddecl) = 0;
	  TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
	}

      /* If either decl says `inline', this fn is inline,
	 unless its definition was passed already.  */
      if (TREE_INLINE (newdecl) && DECL_INITIAL (olddecl) == 0)
	TREE_INLINE (olddecl) = 1;

      /* If redeclaring a builtin function, and not a definition,
	 it stays built in.
	 Also preserve various other info from the definition.  */
      if (TREE_CODE (newdecl) == FUNCTION_DECL && !new_is_definition)
	{
	  DECL_SET_FUNCTION_CODE (newdecl, DECL_FUNCTION_CODE (olddecl));
	  DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
	  DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
	  DECL_SAVED_INSNS (newdecl) = DECL_SAVED_INSNS (olddecl);
	  DECL_RESULT_TYPE (newdecl) = DECL_RESULT_TYPE (olddecl);
	  DECL_ARGUMENTS (newdecl) = DECL_ARGUMENTS (olddecl);
	  DECL_FRAME_SIZE (newdecl) = DECL_FRAME_SIZE (olddecl);
	}

      /* Don't lose track of having output OLDDECL as GDB symbol.  */
      DECL_BLOCK_SYMTAB_ADDRESS (newdecl)
	= DECL_BLOCK_SYMTAB_ADDRESS (olddecl);

      bcopy ((char *) newdecl + sizeof (struct tree_common),
	     (char *) olddecl + sizeof (struct tree_common),
	     sizeof (struct tree_decl) - sizeof (struct tree_common));

      return 1;
    }

  /* New decl is completely inconsistent with the old one =>
     tell caller to replace the old one.  */
  return 0;
}

/* Record a decl-node X as belonging to the current lexical scope.
   Check for errors (such as an incompatible declaration for the same
   name already seen in the same scope).

   Returns either X or an old decl for the same name.
   If an old decl is returned, it may have been smashed
   to agree with what X says.  */

tree
pushdecl (x)
     tree x;
{
  register tree t;
  register tree name = DECL_NAME (x);
  register struct binding_level *b = current_binding_level;

  if (name)
    {
      char *file;
      int line;

      t = lookup_name_current_level (name);
      if (t != 0 && t == error_mark_node)
	/* error_mark_node is 0 for a while during initialization!  */
	{
	  t = 0;
	  error_with_decl (x, "`%s' used prior to declaration");
	}

      if (t != 0)
	{
	  file = DECL_SOURCE_FILE (t);
	  line = DECL_SOURCE_LINE (t);
	}

      if (t != 0 && duplicate_decls (x, t))
	{
	  /* If this decl is `static' and an implicit decl was seen previously,
	     warn.  But don't complain if -traditional,
	     since traditional compilers don't complain.  */
	  if (!flag_traditional && TREE_PUBLIC (name)
	      && ! TREE_PUBLIC (x) && ! TREE_EXTERNAL (x)
	      /* We used to warn also for explicit extern followed by static,
		 but sometimes you need to do it that way.  */
	      && IDENTIFIER_IMPLICIT_DECL (name) != 0)
	    {
	      warning ("`%s' was declared implicitly `extern' and later `static'",
		       IDENTIFIER_POINTER (name));
	      warning_with_file_and_line (file, line,
					  "previous declaration of `%s'",
					  IDENTIFIER_POINTER (name));
	    }
	  return t;
	}

      /* If declaring a type as a typedef, and the type has no known
	 typedef name, install this TYPE_DECL as its typedef name.  */
      if (TREE_CODE (x) == TYPE_DECL)
	if (TYPE_NAME (TREE_TYPE (x)) == 0)
	  TYPE_NAME (TREE_TYPE (x)) = x;

      /* Multiple external decls of the same identifier ought to match.  */

      if (TREE_EXTERNAL (x) && IDENTIFIER_GLOBAL_VALUE (name) != 0
	  && (TREE_EXTERNAL (IDENTIFIER_GLOBAL_VALUE (name))
	      || TREE_PUBLIC (IDENTIFIER_GLOBAL_VALUE (name))))
	{
	  if (! comptypes (TREE_TYPE (x),
			   TREE_TYPE (IDENTIFIER_GLOBAL_VALUE (name))))
	    {
	      warning_with_decl (x,
				 "type mismatch with previous external decl");
	      warning_with_decl (IDENTIFIER_GLOBAL_VALUE (name),
				 "previous external decl of `%s'");
	    }
	}

      /* In PCC-compatibility mode, extern decls of vars with no current decl
	 take effect at top level no matter where they are.  */
      if (flag_traditional && TREE_EXTERNAL (x)
	  && lookup_name (name) == 0)
	b = global_binding_level;

      /* This name is new in its binding level.
	 Install the new declaration and return it.  */
      if (b == global_binding_level)
	{
	  /* Install a global value.  */
	  
	  /* If the first global decl has external linkage,
	     warn if we later see static one.  */
	  if (IDENTIFIER_GLOBAL_VALUE (name) == 0 && TREE_PUBLIC (x))
	    TREE_PUBLIC (name) = 1;

	  IDENTIFIER_GLOBAL_VALUE (name) = x;

	  /* Don't forget if the function was used via an implicit decl.  */
	  if (IDENTIFIER_IMPLICIT_DECL (name)
	      && TREE_USED (IDENTIFIER_IMPLICIT_DECL (name)))
	    TREE_USED (x) = 1, TREE_USED (name) = 1;

	  /* Don't forget if its address was taken in that way.  */
	  if (IDENTIFIER_IMPLICIT_DECL (name)
	      && TREE_ADDRESSABLE (IDENTIFIER_IMPLICIT_DECL (name)))
	    TREE_ADDRESSABLE (x) = 1;

	  /* Warn about mismatches against previous implicit decl.  */
	  if (IDENTIFIER_IMPLICIT_DECL (name) != 0
	      /* If this real decl matches the implicit, don't complain.  */
	      && ! (TREE_CODE (x) == FUNCTION_DECL
		    && TREE_TYPE (TREE_TYPE (x)) == integer_type_node))
	    warning ("`%s' was previously implicitly declared to return `int'",
		     IDENTIFIER_POINTER (name));

	  /* If this decl is `static' and an `extern' was seen previously,
	     that is erroneous.  */
	  if (TREE_PUBLIC (name)
	      && ! TREE_PUBLIC (x) && ! TREE_EXTERNAL (x))
	    {
	      if (IDENTIFIER_IMPLICIT_DECL (name))
		warning ("`%s' was declared implicitly `extern' and later `static'",
			 IDENTIFIER_POINTER (name));
	      else
		warning ("`%s' was declared `extern' and later `static'",
			 IDENTIFIER_POINTER (name));
	    }
	}
      else
	{
	  /* Here to install a non-global value.  */
	  tree oldlocal = IDENTIFIER_LOCAL_VALUE (name);
	  tree oldglobal = IDENTIFIER_GLOBAL_VALUE (name);
	  IDENTIFIER_LOCAL_VALUE (name) = x;

	  /* If this is an extern function declaration, see if we
	     have a global definition for the function.  */
	  if (oldlocal == 0
	      && oldglobal != 0
	      && TREE_CODE (x) == FUNCTION_DECL
	      && TREE_CODE (oldglobal) == FUNCTION_DECL)
	    {
	      /* We have one.  Their types must agree.  */
	      if (! comptypes (TREE_TYPE (x),
			       TREE_TYPE (IDENTIFIER_GLOBAL_VALUE (name))))
		warning_with_decl (x, "local declaration of `%s' doesn't match global one");
	      /* If the global one is inline, make the local one inline.  */
	      else if (TREE_INLINE (oldglobal)
		       || DECL_FUNCTION_CODE (oldglobal) != NOT_BUILT_IN
		       || (TYPE_ARG_TYPES (TREE_TYPE (oldglobal)) != 0
			   && TYPE_ARG_TYPES (TREE_TYPE (x)) == 0))
		IDENTIFIER_LOCAL_VALUE (name) = oldglobal;
	    }
	  /* If we have a local external declaration,
	     and no file-scope declaration has yet been seen,
	     then if we later have a file-scope decl it must not be static.  */
	  if (oldlocal == 0
	      && oldglobal == 0
	      && TREE_EXTERNAL (x)
	      && TREE_PUBLIC (x))
	    {
	      TREE_PUBLIC (name) = 1;
	    }

	  /* Warn if shadowing an argument at the top level of the body.  */
	  if (oldlocal != 0 && !TREE_EXTERNAL (x)
	      && TREE_CODE (oldlocal) == PARM_DECL
	      && TREE_CODE (x) != PARM_DECL
	      && current_binding_level->level_chain->parm_flag)
	    warning ("declaration of `%s' shadows a parameter",
		     IDENTIFIER_POINTER (name));

	  /* Maybe warn if shadowing something else.  */
	  else if (warn_shadow && !TREE_EXTERNAL (x)
		   /* No shadow warnings for vars made for inlining.  */
		   && !TREE_INLINE (x))
	    {
	      char *warnstring = 0;

	      if (oldlocal != 0 && TREE_CODE (oldlocal) == PARM_DECL)
		warnstring = "declaration of `%s' shadows a parameter";
	      else if (oldlocal != 0)
		warnstring = "declaration of `%s' shadows previous local";
	      else if (IDENTIFIER_GLOBAL_VALUE (name) != 0)
		warnstring = "declaration of `%s' shadows global declaration";

	      if (warnstring)
		warning (warnstring, IDENTIFIER_POINTER (name));
	    }

	  /* If storing a local value, there may already be one (inherited).
	     If so, record it for restoration when this binding level ends.  */
	  if (oldlocal != 0)
	    b->shadowed = tree_cons (name, oldlocal, b->shadowed);
	}

      /* Keep count of variables in this level with incomplete type.  */
      if (TYPE_SIZE (TREE_TYPE (x)) == 0)
	++b->n_incomplete;
    }

  /* Put decls on list in reverse order.
     We will reverse them later if necessary.  */
  TREE_CHAIN (x) = b->names;
  b->names = x;

  return x;
}
\f
/* Generate an implicit declaration for identifier FUNCTIONID
   as a function of type int ().  Print a warning if appropriate.  */

tree
implicitly_declare (functionid)
     tree functionid;
{
  register tree decl;

  /* Save the decl permanently so we can warn if definition follows.  */
#if 0  /* A temporary implicit decl causes a crash in pushdecl.
	  In 1.38, fix pushdecl.  */
  if (flag_traditional || !warn_implicit
      || current_binding_level == global_binding_level)
#endif
    end_temporary_allocation ();

  /* We used to reuse an old implicit decl here,
     but this loses with inline functions because it can clobber
     the saved decl chains.  */
/*  if (IDENTIFIER_IMPLICIT_DECL (functionid) != 0)
    decl = IDENTIFIER_IMPLICIT_DECL (functionid);
  else  */
    decl = build_decl (FUNCTION_DECL, functionid, default_function_type);

  TREE_EXTERNAL (decl) = 1;
  TREE_PUBLIC (decl) = 1;

  /* ANSI standard says implicit declarations are in the innermost block.
     So we record the decl in the standard fashion.
     If flag_traditional is set, pushdecl does it top-level.  */
  pushdecl (decl);
  rest_of_decl_compilation (decl, 0, 0, 0);

  if (warn_implicit
      /* Only one warning per identifier.  */
      && IDENTIFIER_IMPLICIT_DECL (functionid) == 0)
    warning ("implicit declaration of function `%s'",
	     IDENTIFIER_POINTER (functionid));

  IDENTIFIER_IMPLICIT_DECL (functionid) = decl;

#if 0
  if (flag_traditional || ! warn_implicit
      || current_binding_level == global_binding_level)
#endif
    resume_temporary_allocation ();

  return decl;
}

/* Return zero if the declaration NEWDECL is valid
   when the declaration OLDDECL (assumed to be for the same name)
   has already been seen.
   Otherwise return an error message format string with a %s
   where the identifier should go.  */

static char *
redeclaration_error_message (newdecl, olddecl)
     tree newdecl, olddecl;
{
  if (TREE_CODE (newdecl) == TYPE_DECL)
    {
      if (flag_traditional && TREE_TYPE (newdecl) == TREE_TYPE (olddecl))
	return 0;
      return "redefinition of `%s'";
    }
  else if (TREE_CODE (newdecl) == FUNCTION_DECL)
    {
      /* Declarations of functions can insist on internal linkage
	 but they can't be inconsistent with internal linkage,
	 so there can be no error on that account.
	 However defining the same name twice is no good.  */
      if (DECL_INITIAL (olddecl) != 0 && DECL_INITIAL (newdecl) != 0
	  /* However, defining once as extern inline and a second
	     time in another way is ok.  */
	  && !(TREE_INLINE (olddecl) && TREE_EXTERNAL (olddecl)
	       && !(TREE_INLINE (newdecl) && TREE_EXTERNAL (newdecl))))
	return "redefinition of `%s'";
      return 0;
    }
  else if (current_binding_level == global_binding_level)
    {
      /* Objects declared at top level:  */
      /* If at least one is a reference, it's ok.  */
      if (TREE_EXTERNAL (newdecl) || TREE_EXTERNAL (olddecl))
	return 0;
      /* Reject two definitions.  */
      if (DECL_INITIAL (olddecl) != 0 && DECL_INITIAL (newdecl) != 0)
	return "redefinition of `%s'";
      /* Now we have two tentative defs, or one tentative and one real def.  */
      /* Insist that the linkage match.  */
      if (TREE_PUBLIC (olddecl) != TREE_PUBLIC (newdecl))
	return "conflicting declarations of `%s'";
      return 0;
    }
  else
    {
      /* Objects declared with block scope:  */
      /* Reject two definitions, and reject a definition
	 together with an external reference.  */
       if (!(TREE_EXTERNAL (newdecl) && TREE_EXTERNAL (olddecl)))
	return "redeclaration of `%s'";
      return 0;
    }
}
\f
/* Get the LABEL_DECL corresponding to identifier ID as a label.
   Create one if none exists so far for the current function.
   This function is called for both label definitions and label references.  */

tree
lookup_label (id)
     tree id;
{
  register tree decl = IDENTIFIER_LABEL_VALUE (id);

  if (decl != 0)
    return decl;

  decl = build_decl (LABEL_DECL, id, NULL_TREE);
  DECL_MODE (decl) = VOIDmode;
  /* Mark that the label's definition has not been seen.  */
  DECL_SOURCE_LINE (decl) = 0;

  IDENTIFIER_LABEL_VALUE (id) = decl;

  named_labels
    = tree_cons (NULL_TREE, decl, named_labels);

  return decl;
}

/* Define a label, specifying the location in the source file.
   Return the LABEL_DECL node for the label, if the definition is valid.
   Otherwise return 0.  */

tree
define_label (filename, line, name)
     char *filename;
     int line;
     tree name;
{
  tree decl = lookup_label (name);
  if (DECL_SOURCE_LINE (decl) != 0)
    {
      error_with_decl (decl, "duplicate label `%s'");
      return 0;
    }
  else
    {
      /* Mark label as having been defined.  */
      DECL_SOURCE_FILE (decl) = filename;
      DECL_SOURCE_LINE (decl) = line;
      return decl;
    }
}
\f
/* Return the list of declarations of the current level.
   Note that this list is in reverse order unless/until
   you nreverse it; and when you do nreverse it, you must
   store the result back using `storedecls' or you will lose.  */

tree
getdecls ()
{
  return current_binding_level->names;
}

/* Return the list of type-tags (for structs, etc) of the current level.  */

tree
gettags ()
{
  return current_binding_level->tags;
}

/* Store the list of declarations of the current level.
   This is done for the parameter declarations of a function being defined,
   after they are modified in the light of any missing parameters.  */

static void
storedecls (decls)
     tree decls;
{
  current_binding_level->names = decls;
}

/* Similarly, store the list of tags of the current level.  */

static void
storetags (tags)
     tree tags;
{
  current_binding_level->tags = tags;
}
\f
/* Given NAME, an IDENTIFIER_NODE,
   return the structure (or union or enum) definition for that name.
   Searches binding levels from BINDING_LEVEL up to the global level.
   If THISLEVEL_ONLY is nonzero, searches only the specified context
   (but skips any tag-transparent contexts to find one that is
   meaningful for tags).
   FORM says which kind of type the caller wants;
   it is RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE.
   If the wrong kind of type is found, an error is reported.  */

static tree
lookup_tag (form, name, binding_level, thislevel_only)
     enum tree_code form;
     struct binding_level *binding_level;
     tree name;
     int thislevel_only;
{
  register struct binding_level *level;

  for (level = binding_level; level; level = level->level_chain)
    {
      register tree tail;
      for (tail = level->tags; tail; tail = TREE_CHAIN (tail))
	{
	  if (TREE_PURPOSE (tail) == name)
	    {
	      if (TREE_CODE (TREE_VALUE (tail)) != form)
		{
		  /* Definition isn't the kind we were looking for.  */
		  error ("`%s' defined as wrong kind of tag",
			 IDENTIFIER_POINTER (name));
		}
	      return TREE_VALUE (tail);
	    }
	}
      if (thislevel_only && ! level->tag_transparent)
	return NULL_TREE;
    }
  return NULL_TREE;
}

/* Given a type, find the tag that was defined for it and return the tag name.
   Otherwise return 0.  However, the value can never be 0
   in the cases in which this is used.  */

static tree
lookup_tag_reverse (type)
     tree type;
{
  register struct binding_level *level;

  for (level = current_binding_level; level; level = level->level_chain)
    {
      register tree tail;
      for (tail = level->tags; tail; tail = TREE_CHAIN (tail))
	{
	  if (TREE_VALUE (tail) == type)
	    return TREE_PURPOSE (tail);
	}
    }
  return NULL_TREE;
}
\f
/* Look up NAME in the current binding level and its superiors
   in the namespace of variables, functions and typedefs.
   Return a ..._DECL node of some kind representing its definition,
   or return 0 if it is undefined.  */

tree
lookup_name (name)
     tree name;
{
  register tree val;
  if (current_binding_level != global_binding_level
      && IDENTIFIER_LOCAL_VALUE (name))
    val = IDENTIFIER_LOCAL_VALUE (name);
  else
    val = IDENTIFIER_GLOBAL_VALUE (name);
  if (val && TREE_TYPE (val) == error_mark_node)
    return error_mark_node;
  return val;
}

/* Similar to `lookup_name' but look only at current binding level.  */

static tree
lookup_name_current_level (name)
     tree name;
{
  register tree t;

  if (current_binding_level == global_binding_level)
    return IDENTIFIER_GLOBAL_VALUE (name);

  if (IDENTIFIER_LOCAL_VALUE (name) == 0)
    return 0;

  for (t = current_binding_level->names; t; t = TREE_CHAIN (t))
    if (DECL_NAME (t) == name)
      break;

  return t;
}
\f
/* Create the predefined scalar types of C,
   and some nodes representing standard constants (0, 1, (void *)0).
   Initialize the global binding level.
   Make definitions for built-in primitive functions.  */

void
init_decl_processing ()
{
  register tree endlink;

  /* Make identifier nodes long enough for the language-specific slots.  */
  set_identifier_size (sizeof (struct lang_identifier));

  current_function_decl = NULL;
  named_labels = NULL;
  current_binding_level = NULL_BINDING_LEVEL;
  free_binding_level = NULL_BINDING_LEVEL;
  pushlevel (0);	/* make the binding_level structure for global names */
  global_binding_level = current_binding_level;

  value_identifier = get_identifier ("<value>");

  /* Define `int' and `char' first so that dbx will output them first.  */

  integer_type_node = make_signed_type (INT_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, ridpointers[(int) RID_INT],
			integer_type_node));

  /* Define `char', which is like either `signed char' or `unsigned char'
     but not the same as either.  */

  char_type_node =
    (flag_signed_char
     ? make_signed_type (CHAR_TYPE_SIZE)
     : make_unsigned_type (CHAR_TYPE_SIZE));
  pushdecl (build_decl (TYPE_DECL, get_identifier ("char"),
			char_type_node));

  long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("long int"),
			long_integer_type_node));

  unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned int"),
			unsigned_type_node));

  long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("long unsigned int"),
			long_unsigned_type_node));

  /* `unsigned long' or `unsigned int' is the standard type for sizeof.
     Traditionally, use a signed type.  */
  if (INT_TYPE_SIZE != LONG_TYPE_SIZE)
    sizetype = flag_traditional ? long_integer_type_node : long_unsigned_type_node;
  else
    sizetype = flag_traditional ? integer_type_node : unsigned_type_node;

  TREE_TYPE (TYPE_SIZE (integer_type_node)) = sizetype;
  TREE_TYPE (TYPE_SIZE (char_type_node)) = sizetype;
  TREE_TYPE (TYPE_SIZE (unsigned_type_node)) = sizetype;
  TREE_TYPE (TYPE_SIZE (long_unsigned_type_node)) = sizetype;
  TREE_TYPE (TYPE_SIZE (long_integer_type_node)) = sizetype;

  error_mark_node = make_node (ERROR_MARK);
  TREE_TYPE (error_mark_node) = error_mark_node;

  short_integer_type_node = make_signed_type (SHORT_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("short int"),
			short_integer_type_node));

  long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("long long int"),
			long_long_integer_type_node));

  short_unsigned_type_node = make_unsigned_type (SHORT_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("short unsigned int"),
			short_unsigned_type_node));

  long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("long long unsigned int"),
			long_long_unsigned_type_node));

  /* Define both `signed char' and `unsigned char'.  */
  signed_char_type_node = make_signed_type (CHAR_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("signed char"),
			signed_char_type_node));

  unsigned_char_type_node = make_unsigned_type (CHAR_TYPE_SIZE);
  pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned char"),
			unsigned_char_type_node));

  float_type_node = make_node (REAL_TYPE);
  TYPE_PRECISION (float_type_node) = FLOAT_TYPE_SIZE;
  pushdecl (build_decl (TYPE_DECL, ridpointers[(int) RID_FLOAT],
			float_type_node));
  layout_type (float_type_node);

  double_type_node = make_node (REAL_TYPE);
  TYPE_PRECISION (double_type_node) = DOUBLE_TYPE_SIZE;
  pushdecl (build_decl (TYPE_DECL, ridpointers[(int) RID_DOUBLE],
			double_type_node));
  layout_type (double_type_node);

  long_double_type_node = make_node (REAL_TYPE);
  TYPE_PRECISION (long_double_type_node) = LONG_DOUBLE_TYPE_SIZE;
  pushdecl (build_decl (TYPE_DECL, get_identifier ("long double"),
			long_double_type_node));
  layout_type (long_double_type_node);

  integer_zero_node = build_int_2 (0, 0);
  TREE_TYPE (integer_zero_node) = integer_type_node;
  integer_one_node = build_int_2 (1, 0);
  TREE_TYPE (integer_one_node) = integer_type_node;

  size_zero_node = build_int_2 (0, 0);
  TREE_TYPE (size_zero_node) = sizetype;
  size_one_node = build_int_2 (1, 0);
  TREE_TYPE (size_one_node) = sizetype;

  void_type_node = make_node (VOID_TYPE);
  pushdecl (build_decl (TYPE_DECL,
			ridpointers[(int) RID_VOID], void_type_node));
  layout_type (void_type_node);	/* Uses integer_zero_node */

  null_pointer_node = build_int_2 (0, 0);
  TREE_TYPE (null_pointer_node) = build_pointer_type (void_type_node);
  layout_type (TREE_TYPE (null_pointer_node));

  string_type_node = build_pointer_type (char_type_node);

  /* make a type for arrays of 256 characters.
     256 is picked randomly because we have a type for integers from 0 to 255.
     With luck nothing will ever really depend on the length of this
     array type.  */
  char_array_type_node
    = build_array_type (char_type_node, unsigned_char_type_node);
  /* Likewise for arrays of ints.  */
  int_array_type_node
    = build_array_type (integer_type_node, unsigned_char_type_node);

  default_function_type
    = build_function_type (integer_type_node, NULL_TREE);

  ptr_type_node = build_pointer_type (void_type_node);
  endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE);

  double_ftype_double
    = build_function_type (double_type_node,
			   tree_cons (NULL_TREE, double_type_node, endlink));

  double_ftype_double_double
    = build_function_type (double_type_node,
			   tree_cons (NULL_TREE, double_type_node,
				      tree_cons (NULL_TREE,
						 double_type_node, endlink)));

  int_ftype_int
    = build_function_type (integer_type_node,
			   tree_cons (NULL_TREE, integer_type_node, endlink));

  long_ftype_long
    = build_function_type (long_integer_type_node,
			   tree_cons (NULL_TREE,
				      long_integer_type_node, endlink));

  void_ftype_ptr_ptr_int
    = build_function_type (void_type_node,
			   tree_cons (NULL_TREE, ptr_type_node,
				      tree_cons (NULL_TREE, ptr_type_node,
						 tree_cons (NULL_TREE,
							    integer_type_node,
							    endlink))));

  int_ftype_ptr_ptr_int
    = build_function_type (integer_type_node,
			   tree_cons (NULL_TREE, ptr_type_node,
				      tree_cons (NULL_TREE, ptr_type_node,
						 tree_cons (NULL_TREE,
							    integer_type_node,
							    endlink))));

  void_ftype_ptr_int_int
    = build_function_type (void_type_node,
			   tree_cons (NULL_TREE, ptr_type_node,
				      tree_cons (NULL_TREE, integer_type_node,
						 tree_cons (NULL_TREE,
							    integer_type_node,
							    endlink))));

  builtin_function ("__builtin_alloca",
		    build_function_type (ptr_type_node,
					 tree_cons (NULL_TREE,
						    integer_type_node,
						    endlink)),
		    BUILT_IN_ALLOCA);

  builtin_function ("__builtin_abs", int_ftype_int, BUILT_IN_ABS);
  builtin_function ("__builtin_fabs", double_ftype_double, BUILT_IN_FABS);
  builtin_function ("__builtin_labs", long_ftype_long, BUILT_IN_LABS);
  builtin_function ("__builtin_ffs", int_ftype_int, BUILT_IN_FFS);
  builtin_function ("__builtin_saveregs", default_function_type,
		    BUILT_IN_SAVEREGS);
  builtin_function ("__builtin_classify_type", default_function_type,
		    BUILT_IN_CLASSIFY_TYPE);
  builtin_function ("__builtin_next_arg",
		    build_function_type (ptr_type_node, endlink),
		    BUILT_IN_NEXT_ARG);
#if 0
  /* Support for these has not been written in either expand_builtin
     or build_function_call.  */
  builtin_function ("__builtin_div", default_ftype, BUILT_IN_DIV);
  builtin_function ("__builtin_ldiv", default_ftype, BUILT_IN_LDIV);
  builtin_function ("__builtin_ffloor", double_ftype_double, BUILT_IN_FFLOOR);
  builtin_function ("__builtin_fceil", double_ftype_double, BUILT_IN_FCEIL);
  builtin_function ("__builtin_fmod", double_ftype_double_double, BUILT_IN_FMOD);
  builtin_function ("__builtin_frem", double_ftype_double_double, BUILT_IN_FREM);
  builtin_function ("__builtin_memcpy", void_ftype_ptr_ptr_int, BUILT_IN_MEMCPY);
  builtin_function ("__builtin_memcmp", int_ftype_ptr_ptr_int, BUILT_IN_MEMCMP);
  builtin_function ("__builtin_memset", void_ftype_ptr_int_int, BUILT_IN_MEMSET);
  builtin_function ("__builtin_fsqrt", double_ftype_double, BUILT_IN_FSQRT);
  builtin_function ("__builtin_getexp", double_ftype_double, BUILT_IN_GETEXP);
  builtin_function ("__builtin_getman", double_ftype_double, BUILT_IN_GETMAN);
#endif

  start_identifier_warnings ();
}

/* Make a definition for a builtin function named NAME and whose data type
   is TYPE.  TYPE should be a function type with argument types.
   FUNCTION_CODE tells later passes how to compile calls to this function.
   See tree.h for its possible values.  */

static void
builtin_function (name, type, function_code)
     char *name;
     tree type;
     enum built_in_function function_code;
{
  tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type);
  TREE_EXTERNAL (decl) = 1;
  TREE_PUBLIC (decl) = 1;
  make_decl_rtl (decl, 0, 1);
  pushdecl (decl);
  DECL_SET_FUNCTION_CODE (decl, function_code);
}
\f
/* Called when a declaration is seen that contains no names to declare.
   If its type is a reference to a structure, union or enum inherited
   from a containing scope, shadow that tag name for the current scope
   with a forward reference.
   If its type defines a new named structure or union
   or defines an enum, it is valid but we need not do anything here.
   Otherwise, it is an error.  */

void
shadow_tag (declspecs)
     tree declspecs;
{
  int found_tag = 0;
  int warned = 0;
  register tree link;

  for (link = declspecs; link; link = TREE_CHAIN (link))
    {
      register tree value = TREE_VALUE (link);
      register enum tree_code code = TREE_CODE (value);
      int ok = 0;

      if (code == RECORD_TYPE || code == UNION_TYPE || code == ENUMERAL_TYPE)
	/* Used to test also that TYPE_SIZE (value) != 0.
	   That caused warning for `struct foo;' at top level in the file.  */
	{
	  register tree name = lookup_tag_reverse (value);
	  register tree t = lookup_tag (code, name, current_binding_level, 1);

	  if (t == 0)
	    {
	      t = make_node (code);
	      pushtag (name, t);
	      ok = 1;
	    }
	  else if (name != 0 || code == ENUMERAL_TYPE)
	    ok = 1;
	}

      if (ok)
	found_tag++;
      else
	{
	  if (!warned)
	    warning ("useless keyword or type name in declaration");
	  warned = 1;
	}
    }

  if (!warned)
    {
      if (found_tag > 1)
	warning ("multiple types in one declaration");
      if (found_tag == 0)
	warning ("empty declaration");
    }
}
\f
/* Decode a "typename", such as "int **", returning a ..._TYPE node.  */

tree
groktypename (typename)
     tree typename;
{
  if (TREE_CODE (typename) != TREE_LIST)
    return typename;
  return grokdeclarator (TREE_VALUE (typename),
			 TREE_PURPOSE (typename),
			 TYPENAME, 0);
}

/* Decode a declarator in an ordinary declaration or data definition.
   This is called as soon as the type information and variable name
   have been parsed, before parsing the initializer if any.
   Here we create the ..._DECL node, fill in its type,
   and put it on the list of decls for the current context.
   The ..._DECL node is returned as the value.

   Exception: for arrays where the length is not specified,
   the type is left null, to be filled in by `finish_decl'.

   Function definitions do not come here; they go to start_function
   instead.  However, external and forward declarations of functions
   do go through here.  Structure field declarations are done by
   grokfield and not through here.  */

/* Set this to zero to debug not using the temporary obstack
   to parse initializers.  */
int debug_temp_inits = 1;

tree
start_decl (declarator, declspecs, initialized)
     tree declspecs, declarator;
     int initialized;
{
  register tree decl = grokdeclarator (declarator, declspecs,
				       NORMAL, initialized);
  register tree tem;
  int init_written = initialized;

  if (initialized)
    /* Is it valid for this decl to have an initializer at all?
       If not, set INITIALIZED to zero, which will indirectly
       tell `finish_decl' to ignore the initializer once it is parsed.  */
    switch (TREE_CODE (decl))
      {
      case TYPE_DECL:
	/* typedef foo = bar  means give foo the same type as bar.
	   We haven't parsed bar yet, so `finish_decl' will fix that up.
	   Any other case of an initialization in a TYPE_DECL is an error.  */
	if (pedantic || list_length (declspecs) > 1)
	  {
	    error ("typedef `%s' is initialized",
		   IDENTIFIER_POINTER (DECL_NAME (decl)));
	    initialized = 0;
	  }
	break;

      case FUNCTION_DECL:
	error ("function `%s' is initialized like a variable",
	       IDENTIFIER_POINTER (DECL_NAME (decl)));
	initialized = 0;
	break;

      default:
	/* Don't allow initializations for incomplete types
	   except for arrays which might be completed by the initialization.  */
	if (TYPE_SIZE (TREE_TYPE (decl)) != 0)
	  ;			/* A complete type is ok.  */
	else if (TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE)
	  {
	    error ("variable `%s' has initializer but incomplete type",
		   IDENTIFIER_POINTER (DECL_NAME (decl)));
	    initialized = 0;
	  }
	else if (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))) == 0)
	  {
	    error ("elements of array `%s' have incomplete type",
		   IDENTIFIER_POINTER (DECL_NAME (decl)));
	    initialized = 0;
	  }
      }

  if (initialized)
    {
#if 0  /* Seems redundant.  */
      if (current_binding_level != global_binding_level
	  && TREE_EXTERNAL (decl)
	  && TREE_CODE (decl) != FUNCTION_DECL)
	warning ("declaration of `%s' has `extern' and is initialized",
		 IDENTIFIER_POINTER (DECL_NAME (decl)));
#endif
      TREE_EXTERNAL (decl) = 0;
      if (current_binding_level == global_binding_level)
	TREE_STATIC (decl) = 1;

      /* Tell `pushdecl' this is an initialized decl
	 even though we don't yet have the initializer expression.
	 Also tell `finish_decl' it may store the real initializer.  */
      DECL_INITIAL (decl) = error_mark_node;
    }

  /* Add this decl to the current binding level.
     TEM may equal DECL or it may be a previous decl of the same name.  */
  tem = pushdecl (decl);

  /* For a local variable, define the RTL now.  */
  if (current_binding_level != global_binding_level
      /* But not if this is a duplicate decl
	 and we preserved the rtl from the previous one
	 (which may or may not happen).  */
      && DECL_RTL (tem) == 0)
    {
      if (TYPE_SIZE (TREE_TYPE (tem)) != 0)
	expand_decl (tem, NULL_TREE);
      else if (TREE_CODE (TREE_TYPE (tem)) == ARRAY_TYPE
	       && DECL_INITIAL (tem) != 0)
	expand_decl (tem, NULL_TREE);
    }

  if (init_written)
    {
      /* When parsing and digesting the initializer,
	 use temporary storage.  Do this even if we will ignore the value.  */
      if (current_binding_level == global_binding_level && debug_temp_inits)
	temporary_allocation ();
    }

  return tem;
}

/* Finish processing of a declaration;
   install its line number and initial value.
   If the length of an array type is not known before,
   it must be determined now, from the initial value, or it is an error.  */

void
finish_decl (decl, init, asmspec_tree)
     tree decl, init;
     tree asmspec_tree;
{
  register tree type = TREE_TYPE (decl);
  int was_incomplete = (DECL_SIZE (decl) == 0);
  int temporary = allocation_temporary_p ();
  char *asmspec = 0;

  if (asmspec_tree)
    asmspec = TREE_STRING_POINTER (asmspec_tree);

  /* If `start_decl' didn't like having an initialization, ignore it now.  */

  if (init != 0 && DECL_INITIAL (decl) == 0)
    init = 0;

  if (init)
    {
      if (TREE_CODE (decl) != TYPE_DECL)
	store_init_value (decl, init);
      else
	{
	  /* typedef foo = bar; store the type of bar as the type of foo.  */
	  TREE_TYPE (decl) = TREE_TYPE (init);
	  DECL_INITIAL (decl) = init = 0;
	}
    }

  /* For top-level declaration, the initial value was read in
     the temporary obstack.  MAXINDEX, rtl, etc. to be made below
     must go in the permanent obstack; but don't discard the
     temporary data yet.  */

  if (current_binding_level == global_binding_level && temporary)
    end_temporary_allocation ();

  /* Deduce size of array from initialization, if not already known */

  if (TREE_CODE (type) == ARRAY_TYPE
      && TYPE_DOMAIN (type) == 0
      && TREE_CODE (decl) != TYPE_DECL)
    {
#if 0
      int do_default = ! ((!pedantic && TREE_STATIC (decl))
			  || TREE_EXTERNAL (decl));
#endif
      int do_default
	= (TREE_STATIC (decl)
	   /* Even if pedantic, an external linkage array
	      may have incomplete type at first.  */
	   ? pedantic && !TREE_PUBLIC (decl)
	   : !TREE_EXTERNAL (decl));
      int failure
	= complete_array_type (type, DECL_INITIAL (decl), do_default);

      if (failure == 1)
	error_with_decl (decl, "initializer fails to determine size of `%s'");

      if (failure == 2)
	{
	  if (do_default)
	    {
	      if (! TREE_PUBLIC (decl))
		error_with_decl (decl, "array size missing in `%s'");
	    }
	  else if (!pedantic && TREE_STATIC (decl))
	    TREE_EXTERNAL (decl) = 1;
	}

      if (pedantic && TYPE_DOMAIN (type) != 0
	  && tree_int_cst_lt (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
			      integer_zero_node))
	error_with_decl (decl, "zero-size array `%s'");

      layout_decl (decl, 0);
    }

  if (TREE_CODE (decl) == VAR_DECL)
    {
      if (TREE_STATIC (decl) && DECL_SIZE (decl) == 0)
	{
	  /* A static variable with an incomplete type:
	     that is an error if it is initialized or `static'.
	     Otherwise, let it through, but if it is not `extern'
	     then it may cause an error message later.  */
	  if (! (TREE_PUBLIC (decl) && DECL_INITIAL (decl) == 0))
	    error_with_decl (decl, "storage size of `%s' isn't known");
	}
      else if (!TREE_EXTERNAL (decl) && DECL_SIZE (decl) == 0)
	{
	  /* An automatic variable with an incomplete type:
	     that is an error.  */
	  error_with_decl (decl, "storage size of `%s' isn't known");
	  TREE_TYPE (decl) = error_mark_node;
	}

      if ((TREE_EXTERNAL (decl) || TREE_STATIC (decl))
	  && DECL_SIZE (decl) != 0 && ! TREE_LITERAL (DECL_SIZE (decl)))
	error_with_decl (decl, "storage size of `%s' isn't constant");
    }

  /* Output the assembler code and/or RTL code for variables and functions,
     unless the type is an undefined structure or union.
     If not, it will get done when the type is completed.  */

  if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL)
    {
      if (flag_traditional && allocation_temporary_p ())
	{
	  end_temporary_allocation ();
	  rest_of_decl_compilation (decl, asmspec,
				    current_binding_level == global_binding_level,
				    0);
	  resume_temporary_allocation ();
	}
      else
	rest_of_decl_compilation (decl, asmspec,
				  current_binding_level == global_binding_level,
				  0);
      if (current_binding_level != global_binding_level)
	{
	  /* Recompute the RTL of a local array now
	     if it used to be an incomplete type.  */
	  if (was_incomplete
	      && ! TREE_STATIC (decl) && ! TREE_EXTERNAL (decl))
	    {
	      /* If we used it already as memory, it must stay in memory.  */
	      TREE_ADDRESSABLE (decl) = TREE_USED (decl);
	      /* If it's still incomplete now, no init will save it.  */
	      if (DECL_SIZE (decl) == 0)
		DECL_INITIAL (decl) = 0;
	      expand_decl (decl, NULL_TREE);
	    }
	  /* Compute and store the initial value.  */
	  expand_decl_init (decl);
	}
    }

  if (TREE_CODE (decl) == TYPE_DECL)
    rest_of_decl_compilation (decl, 0,
			      current_binding_level == global_binding_level,
			      0);

  /* Resume permanent allocation, if not within a function.  */
  if (temporary && current_binding_level == global_binding_level)
    {
      permanent_allocation ();
      /* We need to remember that this array HAD an initialization,
	 but discard the actual nodes, since they are temporary anyway.  */
      if (DECL_INITIAL (decl) != 0)
	DECL_INITIAL (decl) = error_mark_node;
    }

  /* At the end of a declaration, throw away any variable type sizes
     of types defined inside that declaration.  There is no use
     computing them in the following function definition.  */
  if (current_binding_level == global_binding_level)
    get_pending_sizes ();
}

/* Given a parsed parameter declaration,
   decode it into a PARM_DECL and push that on the current binding level.  */

void
push_parm_decl (parm)
     tree parm;
{
  register tree decl = grokdeclarator (TREE_VALUE (parm), TREE_PURPOSE (parm),
				       PARM, 0);

  /* Add this decl to the current binding level.  */
  finish_decl (pushdecl (decl), NULL_TREE, NULL_TREE);
}
\f
/* Make TYPE a complete type based on INITIAL_VALUE.
   Return 0 if successful, 1 if INITIAL_VALUE can't be decyphered,
   2 if there was no information (in which case assume 1 if DO_DEFAULT).  */

int
complete_array_type (type, initial_value, do_default)
     tree type;
     tree initial_value;
     int do_default;
{
  register tree maxindex = NULL_TREE;
  int value = 0;
  int temporary = (TREE_PERMANENT (type) && allocation_temporary_p ());

  /* Don't put temporary nodes in permanent type.  */
  if (temporary)
    end_temporary_allocation ();

  if (initial_value)
    {
      /* Note MAXINDEX  is really the maximum index,
	 one less than the size.  */
      if (TREE_CODE (initial_value) == STRING_CST)
	{
	  int eltsize = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (TREE_TYPE (initial_value))));
	  maxindex = build_int_2 (TREE_STRING_LENGTH (initial_value) / eltsize - 1, 0);
	}
      else if (TREE_CODE (initial_value) == CONSTRUCTOR)
	{
	  register int nelts
	    = list_length (CONSTRUCTOR_ELTS (initial_value));
	  maxindex = build_int_2 (nelts - 1, 0);
	}
      else
	{
	  /* Make an error message unless that happened already.  */
	  if (initial_value != error_mark_node)
	    value = 1;

	  /* Prevent further error messages.  */
	  maxindex = build_int_2 (1, 0);
	}
    }

  if (!maxindex)
    {
      if (do_default)
	maxindex = build_int_2 (1, 0);
      value = 2;
    }

  if (maxindex)
    {
      TYPE_DOMAIN (type) = build_index_type (maxindex);
      if (!TREE_TYPE (maxindex))
	TREE_TYPE (maxindex) = TYPE_DOMAIN (type);
    }

  /* Lay out the type now that we can get the real answer.  */

  layout_type (type);

  if (temporary)
    resume_temporary_allocation ();

  return value;
}
\f
/* Given declspecs and a declarator,
   determine the name and type of the object declared
   and construct a ..._DECL node for it.
   (In one case we can return a ..._TYPE node instead.
    For invalid input we sometimes return 0.)

   DECLSPECS is a chain of tree_list nodes whose value fields
    are the storage classes and type specifiers.

   DECL_CONTEXT says which syntactic context this declaration is in:
     NORMAL for most contexts.  Make a VAR_DECL or FUNCTION_DECL or TYPE_DECL.
     FUNCDEF for a function definition.  Like NORMAL but a few different
      error messages in each case.  Return value may be zero meaning
      this definition is too screwy to try to parse.
     PARM for a parameter declaration (either within a function prototype
      or before a function body).  Make a PARM_DECL, or return void_type_node.
     TYPENAME if for a typename (in a cast or sizeof).
      Don't make a DECL node; just return the ..._TYPE node.
     FIELD for a struct or union field; make a FIELD_DECL.
   INITIALIZED is 1 if the decl has an initializer.

   In the TYPENAME case, DECLARATOR is really an absolute declarator.
   It may also be so in the PARM case, for a prototype where the
   argument type is specified but not the name.

   This function is where the complicated C meanings of `static'
   and `extern' are intrepreted.  */

static tree
grokdeclarator (declarator, declspecs, decl_context, initialized)
     tree declspecs;
     tree declarator;
     enum decl_context decl_context;
     int initialized;
{
  int specbits = 0;
  tree spec;
  tree type = NULL_TREE;
  int longlong = 0;
  int constp;
  int volatilep;
  int inlinep;
  int explicit_int = 0;
  int explicit_char = 0;
  char *name;
  tree typedef_type = 0;
  int funcdef_flag = 0;
  int resume_temporary = 0;
  enum tree_code innermost_code = ERROR_MARK;

  if (decl_context == FUNCDEF)
    funcdef_flag = 1, decl_context = NORMAL;

  if (flag_traditional && allocation_temporary_p ())
    {
      resume_temporary = 1;
      end_temporary_allocation ();
    }

  /* Look inside a declarator for the name being declared
     and get it as a string, for an error message.  */
  {
    register tree decl = declarator;
    name = 0;

    while (decl)
      switch (TREE_CODE (decl))
	{
	case ARRAY_REF:
	case INDIRECT_REF:
	case CALL_EXPR:
	  innermost_code = TREE_CODE (decl);
	  decl = TREE_OPERAND (decl, 0);
	  break;

	case IDENTIFIER_NODE:
	  name = IDENTIFIER_POINTER (decl);
	  decl = 0;
	  break;

	default:
	  abort ();
	}
    if (name == 0)
      name = "type name";
  }

  /* A function definition's declarator must have the form of
     a function declarator.  */

  if (funcdef_flag && innermost_code != CALL_EXPR)
    return 0;

  /* Anything declared one level down from the top level
     must be one of the parameters of a function
     (because the body is at least two levels down).  */

  if (decl_context == NORMAL
      && current_binding_level->level_chain == global_binding_level)
    decl_context = PARM;

  /* Look through the decl specs and record which ones appear.
     Some typespecs are defined as built-in typenames.
     Others, the ones that are modifiers of other types,
     are represented by bits in SPECBITS: set the bits for
     the modifiers that appear.  Storage class keywords are also in SPECBITS.

     If there is a typedef name or a type, store the type in TYPE.
     This includes builtin typedefs such as `int'.

     Set EXPLICIT_INT if the type is `int' or `char' and did not
     come from a user typedef.

     Set LONGLONG if `long' is mentioned twice.  */

  for (spec = declspecs; spec; spec = TREE_CHAIN (spec))
    {
      register int i;
      register tree id = TREE_VALUE (spec);

      if (id == ridpointers[(int) RID_INT])
	explicit_int = 1;
      if (id == ridpointers[(int) RID_CHAR])
	explicit_char = 1;

      if (TREE_CODE (id) == IDENTIFIER_NODE)
	for (i = (int) RID_FIRST_MODIFIER; i < (int) RID_MAX; i++)
	  {
	    if (ridpointers[i] == id)
	      {
		if (i == (int) RID_LONG && specbits & (1<<i))
		  {
		    if (pedantic)
		      warning ("duplicate `%s'", IDENTIFIER_POINTER (id));
		    else if (longlong)
		      warning ("`long long long' is too long for GCC");
		    else
		      longlong = 1;
		  }
		else if (specbits & (1 << i))
		  warning ("duplicate `%s'", IDENTIFIER_POINTER (id));
		specbits |= 1 << i;
		goto found;
	      }
	  }
      if (type)
	error ("two or more data types in declaration of `%s'", name);
      else if (TREE_CODE (id) == IDENTIFIER_NODE)
	{
	  register tree t = lookup_name (id);
	  if (!t || TREE_CODE (t) != TYPE_DECL)
	    error ("`%s' fails to be a typedef or built in type",
		   IDENTIFIER_POINTER (id));
	  else type = TREE_TYPE (t);
	}
      else if (TREE_CODE (id) != ERROR_MARK)
	type = id;

    found: {}
    }

  typedef_type = type;

  /* No type at all: default to `int', and set EXPLICIT_INT
     because it was not a user-defined typedef.  */

  if (type == 0)
    {
      if (funcdef_flag && warn_return_type
	  && ! (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT)
			    | (1 << (int) RID_SIGNED) | (1 << (int) RID_UNSIGNED))))
	warn_about_return_type = 1;
      explicit_int = 1;
      type = integer_type_node;
    }

  /* Now process the modifiers that were specified
     and check for invalid combinations.  */

  /* Long double is a special combination.  */

  if ((specbits & 1 << (int) RID_LONG) && type == double_type_node)
    {
      specbits &= ~ (1 << (int) RID_LONG);
      type = long_double_type_node;
    }

  /* Check all other uses of type modifiers.  */

  if (specbits & ((1 << (int) RID_LONG) | (1 << (int) RID_SHORT)
		  | (1 << (int) RID_UNSIGNED) | (1 << (int) RID_SIGNED)))
    {
      if (!explicit_int && !explicit_char && !pedantic)
	error ("long, short, signed or unsigned used invalidly for `%s'", name);
      else if ((specbits & 1 << (int) RID_LONG) && (specbits & 1 << (int) RID_SHORT))
	error ("long and short specified together for `%s'", name);
      else if (((specbits & 1 << (int) RID_LONG) || (specbits & 1 << (int) RID_SHORT))
	       && explicit_char)
	error ("long or short specified with char for `%s'", name);
      else if ((specbits & 1 << (int) RID_SIGNED) && (specbits & 1 << (int) RID_UNSIGNED))
	error ("signed and unsigned given together for `%s'", name);
      else
	{
	  if (specbits & 1 << (int) RID_UNSIGNED)
	    {
	      if (longlong)
		type = long_long_unsigned_type_node;
	      else if (specbits & 1 << (int) RID_LONG)
	        type = long_unsigned_type_node;
	      else if (specbits & 1 << (int) RID_SHORT)
		type = short_unsigned_type_node;
	      else if (type == char_type_node)
		type = unsigned_char_type_node;
	      else
		type = unsigned_type_node;
	    }
	  else if ((specbits & 1 << (int) RID_SIGNED)
		   && type == char_type_node)
	    type = signed_char_type_node;
	  else if (longlong)
	    type = long_long_integer_type_node;
	  else if (specbits & 1 << (int) RID_LONG)
	    type = long_integer_type_node;
	  else if (specbits & 1 << (int) RID_SHORT)
	    type = short_integer_type_node;
	}
    }

  /* Set CONSTP if this declaration is `const', whether by
     explicit specification or via a typedef.
     Likewise for VOLATILEP.  */

  constp = !! (specbits & 1 << (int) RID_CONST) + TREE_READONLY (type);
  volatilep = !! (specbits & 1 << (int) RID_VOLATILE) + TREE_VOLATILE (type);
  inlinep = !! (specbits & (1 << (int) RID_INLINE));
  if (constp > 1)
    warning ("duplicate `const'");
  if (volatilep > 1)
    warning ("duplicate `volatile'");
  type = TYPE_MAIN_VARIANT (type);

  /* Warn if two storage classes are given. Default to `auto'.  */

  {
    int nclasses = 0;

    if (specbits & 1 << (int) RID_AUTO) nclasses++;
    if (specbits & 1 << (int) RID_STATIC) nclasses++;
    if (specbits & 1 << (int) RID_EXTERN) nclasses++;
    if (specbits & 1 << (int) RID_REGISTER) nclasses++;
    if (specbits & 1 << (int) RID_TYPEDEF) nclasses++;

    /* Warn about storage classes that are invalid for certain
       kinds of declarations (parameters, typenames, etc.).  */

    if (nclasses > 1)
      error ("multiple storage classes in declaration of `%s'", name);
    else if (funcdef_flag
	     && (specbits
		 & ((1 << (int) RID_REGISTER)
		    | (1 << (int) RID_AUTO)
		    | (1 << (int) RID_TYPEDEF))))
      {
	if (specbits & 1 << (int) RID_AUTO)
	  error ("function definition declared `auto'");
	if (specbits & 1 << (int) RID_REGISTER)
	  error ("function definition declared `auto'");
	if (specbits & 1 << (int) RID_TYPEDEF)
	  error ("function definition declared `typedef'");
	specbits &= ~ ((1 << (int) RID_TYPEDEF) | (1 << (int) RID_REGISTER)
		       | (1 << (int) RID_AUTO));
      }
    else if (decl_context != NORMAL && nclasses > 0)
      {
	if (decl_context == PARM && specbits & 1 << (int) RID_REGISTER)
	  ;
	else
	  {
	    error ((decl_context == FIELD
		    ? "storage class specified for structure field `%s'"
		    : (decl_context == PARM
		       ? "storage class specified for parameter `%s'"
		       : "storage class specified for typename")),
		   name);
	    specbits &= ~ ((1 << (int) RID_TYPEDEF) | (1 << (int) RID_REGISTER)
			   | (1 << (int) RID_AUTO) | (1 << (int) RID_STATIC)
			   | (1 << (int) RID_EXTERN));
	  }
      }
    else if (specbits & 1 << (int) RID_EXTERN && initialized
	     && ! funcdef_flag)
      warning ("`%s' initialized and declared `extern'", name);
    else if (current_binding_level == global_binding_level
	     && specbits & (1 << (int) RID_AUTO))
      error ("top-level declaration of `%s' specifies `auto'", name);
  }

  /* Now figure out the structure of the declarator proper.
     Descend through it, creating more complex types, until we reach
     the declared identifier (or NULL_TREE, in an absolute declarator).  */

  while (declarator && TREE_CODE (declarator) != IDENTIFIER_NODE)
    {
      if (type == error_mark_node)
	{
	  declarator = TREE_OPERAND (declarator, 0);
	  continue;
	}

      /* Each level of DECLARATOR is either an ARRAY_REF (for ...[..]),
	 an INDIRECT_REF (for *...),
	 a CALL_EXPR (for ...(...)),
	 an identifier (for the name being declared)
	 or a null pointer (for the place in an absolute declarator
	 where the name was omitted).
	 For the last two cases, we have just exited the loop.

	 At this point, TYPE is the type of elements of an array,
	 or for a function to return, or for a pointer to point to.
	 After this sequence of ifs, TYPE is the type of the
	 array or function or pointer, and DECLARATOR has had its
	 outermost layer removed.  */

      if (TREE_CODE (declarator) == ARRAY_REF)
	{
	  register tree itype = NULL_TREE;
	  register tree size = TREE_OPERAND (declarator, 1);

	  declarator = TREE_OPERAND (declarator, 0);

	  /* Check for some types that there cannot be arrays of.  */

	  if (type == void_type_node)
	    {
	      error ("declaration of `%s' as array of voids", name);
	      type = error_mark_node;
	    }

	  if (TREE_CODE (type) == FUNCTION_TYPE)
	    {
	      error ("declaration of `%s' as array of functions", name);
	      type = error_mark_node;
	    }

	  if (size == error_mark_node)
	    type = error_mark_node;

	  if (type == error_mark_node)
	    continue;

	  /* If size was specified, set ITYPE to a range-type for that size.
	     Otherwise, ITYPE remains null.  finish_decl may figure it out
	     from an initial value.  */

	  if (size)
	    {
	      /* might be a cast */
	      if (TREE_CODE (size) == NOP_EXPR
		  && TREE_TYPE (size) == TREE_TYPE (TREE_OPERAND (size, 0)))
		size = TREE_OPERAND (size, 0);

	      if (TREE_CODE (TREE_TYPE (size)) != INTEGER_TYPE
		  && TREE_CODE (TREE_TYPE (size)) != ENUMERAL_TYPE)
		{
		  error ("size of array `%s' has non-integer type", name);
		  size = integer_one_node;
		}
	      if (pedantic && integer_zerop (size))
		warning ("ANSI C forbids zero-size array `%s'", name);
	      if (TREE_CODE (size) == INTEGER_CST)
		{
		  if (INT_CST_LT (size, integer_zero_node))
		    {
		      error ("size of array `%s' is negative", name);
		      size = integer_one_node;
		    }
		  itype = build_index_type (build_int_2 (TREE_INT_CST_LOW (size) - 1, 0));
		}
	      else
		{
		  if (pedantic)
		    warning ("ANSI C forbids variable-size array `%s'", name);
		  itype = build_binary_op (MINUS_EXPR, size, integer_one_node);
		  itype = build_index_type (itype);
		}
	    }

	  /* Complain about arrays of incomplete types, except in typedefs.  */

	  if (TYPE_SIZE (type) == 0
	      && !(specbits & (1 << (int) RID_TYPEDEF)))
	    warning ("array type has incomplete element type");

	  /* Build the array type itself.
	     Merge any constancy or volatility into the target type.  */

	  if (constp || volatilep)
	    type = c_build_type_variant (type, constp, volatilep);

#if 0	/* don't clear these; leave them set so that the array type
	   or the variable is itself const or volatile.  */
	  constp = 0;
	  volatilep = 0;
#endif

	  type = build_array_type (type, itype);
	}
      else if (TREE_CODE (declarator) == CALL_EXPR)
	{
	  tree arg_types;

	  /* Declaring a function type.
	     Make sure we have a valid type for the function to return.  */
	  if (type == error_mark_node)
	    continue;

          if (pedantic && (constp || volatilep))
            warning ("function declared to return const or volatile result");

	  /* Warn about some types functions can't return.  */

	  if (TREE_CODE (type) == FUNCTION_TYPE)
	    {
	      error ("`%s' declared as function returning a function", name);
	      type = integer_type_node;
	    }
	  if (TREE_CODE (type) == ARRAY_TYPE)
	    {
	      error ("`%s' declared as function returning an array", name);
	      type = integer_type_node;
	    }

	  /* Traditionally, declaring return type float means double.  */

	  if (flag_traditional && type == float_type_node)
	    type = double_type_node;

	  /* Construct the function type and go to the next
	     inner layer of declarator.  */

	  arg_types = grokparms (TREE_OPERAND (declarator, 1),
				 funcdef_flag
				 /* Say it's a definition
				    only for the CALL_EXPR
				    closest to the identifier.  */
				 && TREE_CODE (TREE_OPERAND (declarator, 0)) == IDENTIFIER_NODE);
#if 0 /* This seems to be false.  We turn off temporary allocation
	 above in this function if -traditional.
	 And this code caused inconsistent results with prototypes:
	 callers would ignore them, and pass arguments wrong.  */

	  /* Omit the arg types if -traditional, since the arg types
	     and the list links might not be permanent.  */
	  type = build_function_type (type, flag_traditional ? 0 : arg_types);
#endif
	  type = build_function_type (type, arg_types);
	  declarator = TREE_OPERAND (declarator, 0);
	}
      else if (TREE_CODE (declarator) == INDIRECT_REF)
	{
	  /* Merge any constancy or volatility into the target type
	     for the pointer.  */

	  if (constp || volatilep)
	    type = c_build_type_variant (type, constp, volatilep);
	  constp = 0;
	  volatilep = 0;

	  type = build_pointer_type (type);

	  /* Process a list of type modifier keywords
	     (such as const or volatile) that were given inside the `*'.  */

	  if (TREE_TYPE (declarator))
	    {
	      register tree typemodlist;
	      int erred = 0;
	      for (typemodlist = TREE_TYPE (declarator); typemodlist;
		   typemodlist = TREE_CHAIN (typemodlist))
		{
		  if (TREE_VALUE (typemodlist) == ridpointers[(int) RID_CONST])
		    constp++;
		  else if (TREE_VALUE (typemodlist) == ridpointers[(int) RID_VOLATILE])
		    volatilep++;
		  else if (!erred)
		    {
		      erred = 1;
		      error ("invalid type modifier within pointer declarator");
		    }
		}
	      if (constp > 1)
		warning ("duplicate `const'");
	      if (volatilep > 1)
		warning ("duplicate `volatile'");
	    }

	  declarator = TREE_OPERAND (declarator, 0);
	}
      else
	abort ();

/*      layout_type (type);  */

      /* @@ Should perhaps replace the following code by changes in
       * @@ stor_layout.c. */
      if (TREE_CODE (type) == FUNCTION_DECL)
	{
	  /* A function variable in C should be Pmode rather than EPmode
	     because it has just the address of a function, no static chain.*/
	  TYPE_MODE (type) = Pmode;
	}
    }

  /* Now TYPE has the actual type.  */

  /* If this is declaring a typedef name, return a TYPE_DECL.  */

  if (specbits & (1 << (int) RID_TYPEDEF))
    {
      /* Note that the grammar rejects storage classes
	 in typenames, fields or parameters */
      if (constp || volatilep)
	type = c_build_type_variant (type, constp, volatilep);
      if (resume_temporary)
	resume_temporary_allocation ();
      return build_decl (TYPE_DECL, declarator, type);
    }

  /* Detect the case of an array type of unspecified size
     which came, as such, direct from a typedef name.
     We must copy the type, so that each identifier gets
     a distinct type, so that each identifier's size can be
     controlled separately by its own initializer.  */

  if (type != 0 && typedef_type != 0
      && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (typedef_type)
      && TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == 0)
    type = build_array_type (TREE_TYPE (type), 0);

  /* If this is a type name (such as, in a cast or sizeof),
     compute the type and return it now.  */

  if (decl_context == TYPENAME)
    {
      /* Note that the grammar rejects storage classes
	 in typenames, fields or parameters */
      if (constp || volatilep)
	type = c_build_type_variant (type, constp, volatilep);
      if (resume_temporary)
	resume_temporary_allocation ();
      return type;
    }

  /* `void' at top level (not within pointer)
     is allowed only in typedefs or type names.
     We don't complain about parms either, but that is because
     a better error message can be made later.  */

  if (type == void_type_node && decl_context != PARM)
    {
      error ("variable or field `%s' declared void",
	     IDENTIFIER_POINTER (declarator));
      type = integer_type_node;
    }

  /* Now create the decl, which may be a VAR_DECL, a PARM_DECL
     or a FUNCTION_DECL, depending on DECL_CONTEXT and TYPE.  */

  {
    register tree decl;

    if (decl_context == PARM)
      {
	/* A parameter declared as an array of T is really a pointer to T.
	   One declared as a function is really a pointer to a function.  */

	if (TREE_CODE (type) == ARRAY_TYPE)
	  {
	    /* Transfer const-ness of array into that of type pointed to.  */
	    type = build_pointer_type
		    (c_build_type_variant (TREE_TYPE (type), constp, volatilep));
	    volatilep = constp = 0;
	  }
	else if (TREE_CODE (type) == FUNCTION_TYPE)
	  {
	    if (pedantic && (constp || volatilep))
	      warning ("ANSI C forbids const or volatile function types");
	    type = build_pointer_type (c_build_type_variant (type, constp, volatilep));
	    volatilep = constp = 0;
	  }

	if (initialized)
	  error ("parameter `%s' is initialized", name);

	decl = build_decl (PARM_DECL, declarator, type);

	/* Compute the type actually passed in the parmlist,
	   for the case where there is no prototype.
	   (For example, shorts and chars are passed as ints.)
	   When there is a prototype, this is overridden later.  */

	DECL_ARG_TYPE (decl) = type;
	if (type == float_type_node)
	  DECL_ARG_TYPE (decl) = double_type_node;
	else if (TREE_CODE (type) == INTEGER_TYPE
		 /* ANSI C says short and char are promoted to int
		    or unsigned int, even if that is not wider.  */
		 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)
		     || type == short_integer_type_node
		     || type == short_unsigned_type_node))
	  {
	    if (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)
		&& TREE_UNSIGNED (type))
	      DECL_ARG_TYPE (decl) = unsigned_type_node;
	    else
	      DECL_ARG_TYPE (decl) = integer_type_node;
	  }
      }
    else if (decl_context == FIELD)
      {
	/* Structure field.  It may not be a function.  */

	if (TREE_CODE (type) == FUNCTION_TYPE)
	  {
	    error ("field `%s' declared as a function",
		   IDENTIFIER_POINTER (declarator));
	    type = build_pointer_type (type);
	  }
	else if (TREE_CODE (type) != ERROR_MARK && TYPE_SIZE (type) == 0)
	  {
	    error ("field `%s' has incomplete type",
		   IDENTIFIER_POINTER (declarator));
	    type = error_mark_node;
	  }
	/* Move type qualifiers down to element of an array.  */
	if (TREE_CODE (type) == ARRAY_TYPE && (constp || volatilep))
	  {
	    type = c_build_type_variant (type, constp, volatilep);
	    constp = volatilep = 0;
	  }
	/* Note that the grammar rejects storage classes
	   in typenames, fields or parameters */
	decl = build_decl (FIELD_DECL, declarator, type);
      }
    else if (TREE_CODE (type) == FUNCTION_TYPE)
      {
	if (specbits & ((1 << (int) RID_AUTO) | (1 << (int) RID_REGISTER)))
	  error ("invalid storage class for function `%s'",
		 IDENTIFIER_POINTER (declarator));
	/* Function declaration not at top level.
	   Storage classes other than `extern' are not allowed
	   and `extern' makes no difference.  */
	if (current_binding_level != global_binding_level
	    && (specbits & ((1 << (int) RID_STATIC) | (1 << (int) RID_INLINE)))
	    && pedantic)
	  warning ("invalid storage class for function `%s'",
		   IDENTIFIER_POINTER (declarator));
	decl = build_decl (FUNCTION_DECL, declarator, type);

	TREE_EXTERNAL (decl) = 1;
	/* Record presence of `static'.  */
	TREE_PUBLIC (decl) = !(specbits & (1 << (int) RID_STATIC));
	/* Record presence of `inline', if it is reasonable.  */
	if (inlinep)
	  {
	    tree last = tree_last (TYPE_ARG_TYPES (type));

	    if (! strcmp (IDENTIFIER_POINTER (declarator), "main"))
	      warning ("cannot inline function `main'");
	    else if (last && TREE_VALUE (last) != void_type_node)
	      warning ("inline declaration ignored for function with `...'");
	    else
	      /* Assume that otherwise the function can be inlined.  */
	      TREE_INLINE (decl) = 1;

	    if (specbits & (1 << (int) RID_EXTERN))
	      current_extern_inline = 1;
	  }
      }
    else
      {
	/* It's a variable.  */

	/* Move type qualifiers down to element of an array.  */
	if (TREE_CODE (type) == ARRAY_TYPE && (constp || volatilep))
	  {
	    type = c_build_type_variant (type, constp, volatilep);
#if 0 /* but a variable whose type is const should still have TREE_READONLY.  */
	    constp = volatilep = 0;
#endif
	  }

	decl = build_decl (VAR_DECL, declarator, type);

	if (inlinep)
	  warning_with_decl (decl, "variable `%s' declared `inline'");

	/* An uninitialized decl with `extern' is a reference.  */
	TREE_EXTERNAL (decl)
	  = !initialized && (specbits & (1 << (int) RID_EXTERN));
	/* At top level, either `static' or no s.c. makes a definition
	   (perhaps tentative), and absence of `static' makes it public.  */
	if (current_binding_level == global_binding_level)
	  {
	    TREE_PUBLIC (decl) = !(specbits & (1 << (int) RID_STATIC));
	    TREE_STATIC (decl) = ! TREE_EXTERNAL (decl);
	  }
	/* Not at top level, only `static' makes a static definition.  */
	else
	  {
	    TREE_STATIC (decl) = (specbits & (1 << (int) RID_STATIC)) != 0;
	    TREE_PUBLIC (decl) = TREE_EXTERNAL (decl);
	    /* `extern' with initialization is invalid if not at top level.  */
	    if ((specbits & (1 << (int) RID_EXTERN)) && initialized)
	      error ("`%s' has both `extern' and initializer", name);
	  }
      }

    /* Record `register' declaration for warnings on &
       and in case doing stupid register allocation.  */

    if (specbits & (1 << (int) RID_REGISTER))
      TREE_REGDECL (decl) = 1;

    /* Record constancy and volatility.  */

    if (constp)
      TREE_READONLY (decl) = 1;
    if (volatilep)
      {
	TREE_VOLATILE (decl) = 1;
	TREE_THIS_VOLATILE (decl) = 1;
      }

    if (resume_temporary)
      resume_temporary_allocation ();

    return decl;
  }
}
\f
/* Make a variant type in the proper way for C, propagating qualifiers
   down to the element type of an array.  */

tree
c_build_type_variant (type, constp, volatilep)
     tree type;
     int constp, volatilep;
{
  if (TREE_CODE (type) != ARRAY_TYPE)
    return build_type_variant (type, constp, volatilep);

  return build_array_type (c_build_type_variant (TREE_TYPE (type),
						 constp, volatilep),
			   TYPE_DOMAIN (type));
}
\f
/* Decode the parameter-list info for a function type or function definition.
   The argument is the value returned by `get_parm_info' (or made in parse.y
   if there is an identifier list instead of a parameter decl list).
   These two functions are separate because when a function returns
   or receives functions then each is called multiple times but the order
   of calls is different.  The last call to `grokparms' is always the one
   that contains the formal parameter names of a function definition.

   Store in `last_function_parms' a chain of the decls of parms.
   Also store in `last_function_parm_tags' a chain of the struct and union
   tags declared among the parms.

   Return a list of arg types to use in the FUNCTION_TYPE for this function.

   FUNCDEF_FLAG is nonzero for a function definition, 0 for
   a mere declaration.  A nonempty identifier-list gets an error message
   when FUNCDEF_FLAG is zero.  */

static tree
grokparms (parms_info, funcdef_flag)
     tree parms_info;
     int funcdef_flag;
{
  tree first_parm = TREE_CHAIN (parms_info);

  last_function_parms = TREE_PURPOSE (parms_info);
  last_function_parm_tags = TREE_VALUE (parms_info);

  if (warn_strict_prototypes && first_parm == 0 && !funcdef_flag)
    warning ("function declaration isn't a prototype");

  if (first_parm != 0
      && TREE_CODE (TREE_VALUE (first_parm)) == IDENTIFIER_NODE)
    {
      if (! funcdef_flag)
	warning ("parameter names (without types) in function declaration");

      last_function_parms = first_parm;
      return 0;
    }
  else
    {
      tree parm;
      tree typelt;
      /* We no longer test FUNCDEF_FLAG.
	 If the arg types are incomplete in a declaration,
	 they must include undefined tags.
	 These tags can never be defined in the scope of the declaration,
	 so the types can never be completed,
	 and no call can be compiled successfully.  */
#if 0
      /* In a fcn definition, arg types must be complete.  */
      if (funcdef_flag)
#endif
	for (parm = last_function_parms, typelt = first_parm;
	     parm;
	     parm = TREE_CHAIN (parm))
	  /* Skip over any enumeration constants declared here.  */
	  if (TREE_CODE (parm) == PARM_DECL)
	    {
	      /* Barf if the parameter itself has an incomplete type.  */
	      tree type = TREE_VALUE (typelt);
	      if (TYPE_SIZE (type) == 0)
		{
		  if (funcdef_flag && DECL_NAME (parm) != 0)
		    error ("parameter `%s' has incomplete type",
			   IDENTIFIER_POINTER (DECL_NAME (parm)));
		  else
		    warning ("parameter has incomplete type");
		  if (funcdef_flag)
		    {
		      TREE_VALUE (typelt) = error_mark_node;
		      TREE_TYPE (parm) = error_mark_node;
		    }
		}
#if 0  /* This has been replaced by parm_tags_warning
	  which uses a more accurate criterion for what to warn about.  */
	      else
		{
		  /* Now warn if is a pointer to an incomplete type.  */
		  while (TREE_CODE (type) == POINTER_TYPE
			 || TREE_CODE (type) == REFERENCE_TYPE)
		    type = TREE_TYPE (type);
		  type = TYPE_MAIN_VARIANT (type);
		  if (TYPE_SIZE (type) == 0)
		    {
		      if (DECL_NAME (parm) != 0)
			warning ("parameter `%s' points to incomplete type",
				 IDENTIFIER_POINTER (DECL_NAME (parm)));
		      else
			warning ("parameter points to incomplete type");
		    }
		}
#endif
	      typelt = TREE_CHAIN (typelt);
	    }

      return first_parm;
    }
}


/* Return a tree_list node with info on a parameter list just parsed.
   The TREE_PURPOSE is a chain of decls of those parms.
   The TREE_VALUE is a list of structure, union and enum tags defined.
   The TREE_CHAIN is a list of argument types to go in the FUNCTION_TYPE.
   This tree_list node is later fed to `grokparms'.

   VOID_AT_END nonzero means append `void' to the end of the type-list.
   Zero means the parmlist ended with an ellipsis so don't append `void'.  */

tree
get_parm_info (void_at_end)
     int void_at_end;
{
  register tree decl;
  register tree types = 0;
  int erred = 0;
  tree tags = gettags ();
  tree parms = nreverse (getdecls ());

  /* Just `void' (and no ellipsis) is special.  There are really no parms.  */
  if (void_at_end && parms != 0
      && TREE_CHAIN (parms) == 0
      && TREE_TYPE (parms) == void_type_node
      && DECL_NAME (parms) == 0)
    {
      parms = NULL_TREE;
      storedecls (NULL_TREE);
      return saveable_tree_cons (NULL_TREE, NULL_TREE,
				 saveable_tree_cons (NULL_TREE, void_type_node, NULL_TREE));
    }

  storedecls (parms);

  for (decl = parms; decl; decl = TREE_CHAIN (decl))
    /* There may also be declarations for enumerators if an enumeration
       type is declared among the parms.  Ignore them here.  */
    if (TREE_CODE (decl) == PARM_DECL)
      {
	/* Since there is a prototype,
	   args are passed in their declared types.  */
	tree type = TREE_TYPE (decl);
	DECL_ARG_TYPE (decl) = type;
#ifdef PROMOTE_PROTOTYPES
	if (TREE_CODE (type) == INTEGER_TYPE
	    && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))
	  DECL_ARG_TYPE (decl) = integer_type_node;
#endif

	types = saveable_tree_cons (NULL_TREE, TREE_TYPE (decl), types);
	if (TREE_VALUE (types) == void_type_node && ! erred
	    && DECL_NAME (decl) == 0)
	  {
	    error ("`void' in parameter list must be the entire list");
	    erred = 1;
	  }
      }

  if (void_at_end)
    return saveable_tree_cons (parms, tags,
			       nreverse (saveable_tree_cons (NULL_TREE, void_type_node, types)));

  return saveable_tree_cons (parms, tags, nreverse (types));
}

/* At end of parameter list, warn about any struct, union or enum tags
   defined within.  Do so because these types cannot ever become complete.  */

void
parmlist_tags_warning ()
{
  tree elt;
  static int already;

  for (elt = current_binding_level->tags; elt; elt = TREE_CHAIN (elt))
    {
      enum tree_code code = TREE_CODE (TREE_VALUE (elt));
      warning ("`%s %s' declared inside parameter list",
	       (code == RECORD_TYPE ? "struct"
		: code == UNION_TYPE ? "union"
		: "enum"),
	       IDENTIFIER_POINTER (TREE_PURPOSE (elt)));
      if (! already)
	{
	  warning ("its scope is only this definition or declaration,");
	  warning ("which is probably not what you want.");
	  already = 1;
	}
    }
}
\f
/* Get the struct, enum or union (CODE says which) with tag NAME.
   Define the tag as a forward-reference if it is not defined.  */

tree
xref_tag (code, name)
     enum tree_code code;
     tree name;
{
  int temporary = allocation_temporary_p ();

  /* If a cross reference is requested, look up the type
     already defined for this tag and return it.  */

  register tree ref = lookup_tag (code, name, current_binding_level, 0);
  if (ref) return ref;

  if (current_binding_level == global_binding_level && temporary)
    end_temporary_allocation ();

  /* If no such tag is yet defined, create a forward-reference node
     and record it as the "definition".
     When a real declaration of this type is found,
     the forward-reference will be altered into a real type.  */

  ref = make_node (code);
  if (code == ENUMERAL_TYPE)
    {
      /* (In ANSI, Enums can be referred to only if already defined.)  */
      if (pedantic)
	warning ("ANSI C forbids forward references to `enum' types");
      /* Give the type a default layout like unsigned int
	 to avoid crashing if it does not get defined.  */
      TYPE_MODE (ref) = SImode;
      TYPE_ALIGN (ref) = TYPE_ALIGN (unsigned_type_node);
      TREE_UNSIGNED (ref) = 1;
      TYPE_PRECISION (ref) = TYPE_PRECISION (unsigned_type_node);
      TYPE_MIN_VALUE (ref) = TYPE_MIN_VALUE (unsigned_type_node);
      TYPE_MAX_VALUE (ref) = TYPE_MAX_VALUE (unsigned_type_node);
    }

  pushtag (name, ref);

  if (current_binding_level == global_binding_level && temporary)
    resume_temporary_allocation ();

  return ref;
}
\f
/* Make sure that the tag NAME is defined *in the current binding level*
   at least as a forward reference.
   CODE says which kind of tag NAME ought to be.  */

tree
start_struct (code, name)
     enum tree_code code;
     tree name;
{
  /* If there is already a tag defined at this binding level
     (as a forward reference), just return it.  */

  register tree ref = 0;

  if (name != 0)
    ref = lookup_tag (code, name, current_binding_level, 1);
  if (ref && TREE_CODE (ref) == code)
    {
      if (TYPE_FIELDS (ref))
	error ((code == UNION_TYPE ? "redefinition of `union %s'"
		: "redefinition of `struct %s'"),
	       IDENTIFIER_POINTER (name));

      return ref;
    }

  /* Otherwise create a forward-reference just so the tag is in scope.  */

  ref = make_node (code);
  pushtag (name, ref);
  return ref;
}

/* Process the specs, declarator (NULL if omitted) and width (NULL if omitted)
   of a structure component, returning a FIELD_DECL node.
   WIDTH is non-NULL for bit fields only, and is an INTEGER_CST node.

   This is done during the parsing of the struct declaration.
   The FIELD_DECL nodes are chained together and the lot of them
   are ultimately passed to `build_struct' to make the RECORD_TYPE node.  */

tree
grokfield (filename, line, declarator, declspecs, width)
     char *filename;
     int line;
     tree declarator, declspecs, width;
{
  register tree value = grokdeclarator (declarator, declspecs, FIELD, 0);

  finish_decl (value, NULL, NULL);
  DECL_INITIAL (value) = width;

  return value;
}
\f
/* Fill in the fields of a RECORD_TYPE or UNION_TYPE node, T.
   FIELDLIST is a chain of FIELD_DECL nodes for the fields.  */

tree
finish_struct (t, fieldlist)
     register tree t, fieldlist;
{
  register tree x;
  int old_momentary;
  int round_up_size = 1;

  /* If this type was previously laid out as a forward reference,
     make sure we lay it out again.  */

  TYPE_SIZE (t) = 0;

  if (extra_warnings && in_parm_level_p ())
    warning ((TREE_CODE (t) == UNION_TYPE ? "union defined inside parms"
	      : "structure defined inside parms"));

  old_momentary = suspend_momentary ();

  if (fieldlist == 0 && pedantic)
    warning ((TREE_CODE (t) == UNION_TYPE ? "union has no members"
	      : "structure has no members"));

  /* Install struct as DECL_CONTEXT of each field decl.
     Also process specified field sizes.
     Set DECL_SIZE_UNIT to the specified size, or 0 if none specified.
     The specified size is found in the DECL_INITIAL.
     Store 0 there, except for ": 0" fields (so we can find them
     and delete them, below).  */

  for (x = fieldlist; x; x = TREE_CHAIN (x))
    {
      DECL_CONTEXT (x) = t;
      DECL_SIZE_UNIT (x) = 0;

      /* If any field is const, the structure type is pseudo-const.  */
      if (TREE_READONLY (x))
	C_TYPE_FIELDS_READONLY (t) = 1;
      else
	{
	  /* A field that is pseudo-const makes the structure likewise.  */
	  tree t1 = TREE_TYPE (x);
	  while (TREE_CODE (t1) == ARRAY_TYPE)
	    t1 = TREE_TYPE (t1);
	  if ((TREE_CODE (t1) == RECORD_TYPE || TREE_CODE (t1) == UNION_TYPE)
	      && C_TYPE_FIELDS_READONLY (t1))
	    C_TYPE_FIELDS_READONLY (t) = 1;
	}

      /* Detect invalid bit-field size.  */
      if (DECL_INITIAL (x) && TREE_CODE (DECL_INITIAL (x)) != INTEGER_CST)
	{
	  error_with_decl (x, "bit-field `%s' width not an integer constant");
	  DECL_INITIAL (x) = NULL;
	}

      /* Detect invalid bit-field type.  */
      if (DECL_INITIAL (x)
	  && TREE_CODE (TREE_TYPE (x)) != INTEGER_TYPE
	  && TREE_CODE (TREE_TYPE (x)) != ENUMERAL_TYPE)
	{
	  error_with_decl (x, "bit-field `%s' has invalid type");
	  DECL_INITIAL (x) = NULL;
	}
      if (DECL_INITIAL (x) && pedantic
	  && TREE_TYPE (x) != integer_type_node
	  && TREE_TYPE (x) != unsigned_type_node)
	warning_with_decl (x, "bit-field `%s' type invalid in ANSI C");

      /* Detect and ignore out of range field width.  */
      if (DECL_INITIAL (x))
	{
	  register int width = TREE_INT_CST_LOW (DECL_INITIAL (x));

	  if (width < 0)
	    {
	      DECL_INITIAL (x) = NULL;
	      warning_with_decl (x, "negative width in bit-field `%s'");
	    }
	  else if (width == 0 && DECL_NAME (x) != 0)
	    {
	      error_with_decl (x, "zero width for bit-field `%s'");
	      DECL_INITIAL (x) = NULL;
	    }
	  else if (width > TYPE_PRECISION (TREE_TYPE (x)))
	    {
	      DECL_INITIAL (x) = NULL;
	      warning_with_decl (x, "width of `%s' exceeds its type");
	    }
	}

      /* Process valid field width.  */
      if (DECL_INITIAL (x))
	{
	  register int width = TREE_INT_CST_LOW (DECL_INITIAL (x));

	  if (width == 0)
	    {
	      /* field size 0 => mark following field as "aligned" */
	      if (TREE_CHAIN (x))
		DECL_ALIGN (TREE_CHAIN (x))
		  = MAX (DECL_ALIGN (TREE_CHAIN (x)), EMPTY_FIELD_BOUNDARY);
	      /* field of size 0 at the end => round up the size.  */
	      else
		round_up_size = EMPTY_FIELD_BOUNDARY;
	    }
	  else
	    {
	      DECL_INITIAL (x) = NULL;
	      DECL_SIZE_UNIT (x) = width;
	      TREE_PACKED (x) = 1;
	      /* Traditionally a bit field is unsigned
		 even if declared signed.  */
	      if (flag_traditional
		  && TREE_CODE (TREE_TYPE (x)) == INTEGER_TYPE)
		TREE_TYPE (x) = unsigned_type_node;
	    }
	}
      else
	/* Non-bit-fields are aligned for their type.  */
	DECL_ALIGN (x) = MAX (DECL_ALIGN (x), TYPE_ALIGN (TREE_TYPE (x)));
    }

  /* Now DECL_INITIAL is null on all members except for zero-width bit-fields.
     And they have already done their work.  */

  /* Delete all zero-width bit-fields from the front of the fieldlist */
  while (fieldlist
	 && DECL_INITIAL (fieldlist))
    fieldlist = TREE_CHAIN (fieldlist);
  /* Delete all such members from the rest of the fieldlist */
  for (x = fieldlist; x;)
    {
      if (TREE_CHAIN (x) && DECL_INITIAL (TREE_CHAIN (x)))
	TREE_CHAIN (x) = TREE_CHAIN (TREE_CHAIN (x));
      else x = TREE_CHAIN (x);
    }

  /* Delete all duplicate fields from the fieldlist */
  for (x = fieldlist; x && TREE_CHAIN (x);)
    /* Anonymous fields aren't duplicates.  */
    if (DECL_NAME (TREE_CHAIN (x)) == 0)
      x = TREE_CHAIN (x);
    else
      {
	register tree y = fieldlist;
	  
	while (1)
	  {
	    if (DECL_NAME (y) == DECL_NAME (TREE_CHAIN (x)))
	      break;
	    if (y == x)
	      break;
	    y = TREE_CHAIN (y);
	  }
	if (DECL_NAME (y) == DECL_NAME (TREE_CHAIN (x)))
	  {
	    error_with_decl (TREE_CHAIN (x), "duplicate member `%s'");
	    TREE_CHAIN (x) = TREE_CHAIN (TREE_CHAIN (x));
	  }
	else x = TREE_CHAIN (x);
      }

  /* Now we have the final fieldlist.  Record it,
     then lay out the structure or union (including the fields).  */

  TYPE_FIELDS (t) = fieldlist;

  /* If there's a :0 field at the end, round the size to the
     EMPTY_FIELD_BOUNDARY.  */
  TYPE_ALIGN (t) = round_up_size;

  for (x = TYPE_MAIN_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x))
    {
      TYPE_FIELDS (x) = TYPE_FIELDS (t);
      TYPE_ALIGN (x) = TYPE_ALIGN (t);
    }

  layout_type (t);

  /* Promote each bit-field's type to int if it is narrower than that.  */
  for (x = fieldlist; x; x = TREE_CHAIN (x))
    if (TREE_PACKED (x)
	&& TREE_CODE (TREE_TYPE (x)) == INTEGER_TYPE
	&& (TREE_INT_CST_LOW (DECL_SIZE (x)) * DECL_SIZE_UNIT (x)
	    < TYPE_PRECISION (integer_type_node)))
      TREE_TYPE (x) = integer_type_node;

  /* If this structure or union completes the type of any previous
     variable declaration, lay it out and output its rtl.  */

  if (current_binding_level->n_incomplete != 0)
    {
      tree decl;
      for (decl = current_binding_level->names; decl; decl = TREE_CHAIN (decl))
	{
	  if (TREE_TYPE (decl) == t
	      && TREE_CODE (decl) != TYPE_DECL)
	    {
	      int toplevel = global_binding_level == current_binding_level;
	      layout_decl (decl, 0);
	      rest_of_decl_compilation (decl, 0, toplevel, 0);
	      if (! toplevel)
		expand_decl (decl, NULL_TREE);
	      --current_binding_level->n_incomplete;
	    }
	  else if (TYPE_SIZE (TREE_TYPE (decl)) == 0
		   && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
	    {
	      tree element = TREE_TYPE (decl);
	      while (TREE_CODE (element) == ARRAY_TYPE)
		element = TREE_TYPE (element);
	      if (element == t)
		layout_array_type (TREE_TYPE (decl));
	    }
	}
    }

  resume_momentary (old_momentary);

  return t;
}

/* Lay out the type T, and its element type, and so on.  */

static void
layout_array_type (t)
     tree t;
{
  if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE)
    layout_array_type (TREE_TYPE (t));
  layout_type (t);
}
\f
/* Begin compiling the definition of an enumeration type.
   NAME is its name (or null if anonymous).
   Returns the type object, as yet incomplete.
   Also records info about it so that build_enumerator
   may be used to declare the individual values as they are read.  */

tree
start_enum (name)
     tree name;
{
  register tree enumtype = 0;

  /* If this is the real definition for a previous forward reference,
     fill in the contents in the same object that used to be the
     forward reference.  */

  if (name != 0)
    enumtype = lookup_tag (ENUMERAL_TYPE, name, current_binding_level, 1);

  if (enumtype == 0 || TREE_CODE (enumtype) != ENUMERAL_TYPE)
    {
      enumtype = make_node (ENUMERAL_TYPE);
      pushtag (name, enumtype);
    }

  if (TYPE_VALUES (enumtype) != 0)
    {
      /* This enum is a named one that has been declared already.  */
      error ("redeclaration of `enum %s'", IDENTIFIER_POINTER (name));

      /* Completely replace its old definition.
	 The old enumerators remain defined, however.  */
      TYPE_VALUES (enumtype) = 0;
    }

  /* Initially, set up this enum as like `int'
     so that we can create the enumerators' declarations and values.
     Later on, the precision of the type may be changed and
     it may be laid out again.  */

  TYPE_PRECISION (enumtype) = TYPE_PRECISION (integer_type_node);
  TYPE_SIZE (enumtype) = 0;
  fixup_unsigned_type (enumtype);

  enum_next_value = integer_zero_node;

  return enumtype;
}

/* After processing and defining all the values of an enumeration type,
   install their decls in the enumeration type and finish it off.
   ENUMTYPE is the type object and VALUES a list of name-value pairs.
   Returns ENUMTYPE.  */

tree
finish_enum (enumtype, values)
     register tree enumtype, values;
{
  register tree pair;
  register long maxvalue = 0;
  register long minvalue = 0;
  register int i;

  if (in_parm_level_p ())
    warning ("enum defined inside parms");

  TYPE_VALUES (enumtype) = values;

  /* Calculate the maximum value of any enumerator in this type.  */

  for (pair = values; pair; pair = TREE_CHAIN (pair))
    {
      int value = TREE_INT_CST_LOW (TREE_VALUE (pair));
      if (pair == values)
	minvalue = maxvalue = value;
      else
	{
	  if (value > maxvalue)
	    maxvalue = value;
	  if (value < minvalue)
	    minvalue = value;
	}
    }

  if (flag_short_enums)
    {
      /* Determine the precision this type needs, lay it out, and define it.  */

      for (i = maxvalue; i; i >>= 1)
	TYPE_PRECISION (enumtype)++;

      if (!TYPE_PRECISION (enumtype))
	TYPE_PRECISION (enumtype) = 1;

      /* Cancel the laying out previously done for the enum type,
	 so that fixup_unsigned_type will do it over.  */
      TYPE_SIZE (enumtype) = 0;

      fixup_unsigned_type (enumtype);
    }

  TREE_INT_CST_LOW (TYPE_MAX_VALUE (enumtype)) = maxvalue;

  /* An enum can have some negative values; then it is signed.  */
  if (minvalue < 0)
    {
      TREE_INT_CST_LOW (TYPE_MIN_VALUE (enumtype)) = minvalue;
      TREE_INT_CST_HIGH (TYPE_MIN_VALUE (enumtype)) = -1;
      TREE_UNSIGNED (enumtype) = 0;
    }
  return enumtype;
}

/* Build and install a CONST_DECL for one value of the
   current enumeration type (one that was begun with start_enum).
   Return a tree-list containing the name and its value.
   Assignment of sequential values by default is handled here.  */

tree
build_enumerator (name, value)
     tree name, value;
{
  register tree decl;

  /* Validate and default VALUE.  */

  /* Remove no-op casts from the value.  */
  while (value != 0 && TREE_CODE (value) == NOP_EXPR)
    value = TREE_OPERAND (value, 0);

  if (value != 0 && TREE_CODE (value) != INTEGER_CST)
    {
      error ("enumerator value for `%s' not integer constant",
	     IDENTIFIER_POINTER (name));
      value = 0;
    }

  /* Default based on previous value.  */
  if (value == 0)
    value = enum_next_value;

  /* Might as well enforce the ANSI restriction, since
     values outside this range don't work in version 1.  */
  if (! int_fits_type_p (value, integer_type_node))
    {
      error ("enumerator value outside range of `int'");
      value = integer_zero_node;
    }

  /* Set basis for default for next value.  */
  enum_next_value = build_binary_op_nodefault (PLUS_EXPR, value,
					       integer_one_node, PLUS_EXPR);

  /* Now create a declaration for the enum value name.  */

  decl = build_decl (CONST_DECL, name, integer_type_node);
  DECL_INITIAL (decl) = value;
  TREE_TYPE (value) = integer_type_node;
  pushdecl (decl);

  return saveable_tree_cons (name, value, NULL);
}
\f
/* Create the FUNCTION_DECL for a function definition.
   DECLSPECS and DECLARATOR are the parts of the declaration;
   they describe the function's name and the type it returns,
   but twisted together in a fashion that parallels the syntax of C.

   This function creates a binding context for the function body
   as well as setting up the FUNCTION_DECL in current_function_decl.

   Returns 1 on success.  If the DECLARATOR is not suitable for a function
   (it defines a datum instead), we return 0, which tells
   yyparse to report a parse error.  */

int
start_function (declspecs, declarator)
     tree declarator, declspecs;
{
  tree decl1, old_decl;
  tree restype;

  current_function_returns_value = 0;  /* Assume, until we see it does. */
  current_function_returns_null = 0;
  warn_about_return_type = 0;
  current_extern_inline = 0;

  decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, 1);

  /* If the declarator is not suitable for a function definition,
     cause a syntax error.  */
  if (decl1 == 0)
    return 0;

  current_function_decl = decl1;

  announce_function (current_function_decl);

  if (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl1))) == 0)
    {
      error ("return-type is an incomplete type");
      /* Make it return void instead.  */
      TREE_TYPE (decl1)
	= build_function_type (void_type_node,
			       TYPE_ARG_TYPES (TREE_TYPE (decl1)));
    }

  if (warn_about_return_type)
    warning ("return-type defaults to `int'");

  /* Save the parm names or decls from this function's declarator
     where store_parm_decls will find them.  */
  current_function_parms = last_function_parms;
  current_function_parm_tags = last_function_parm_tags;

  /* Make the init_value nonzero so pushdecl knows this is not tentative.
     error_mark_node is replaced below (in poplevel) with the LET_STMT.  */
  DECL_INITIAL (current_function_decl) = error_mark_node;

  /* If this definition isn't a prototype and we had a prototype declaration
     before, copy the arg type info from that prototype.  */
  old_decl = lookup_name_current_level (DECL_NAME (current_function_decl));
  if (old_decl != 0
      && TREE_TYPE (TREE_TYPE (current_function_decl)) == TREE_TYPE (TREE_TYPE (old_decl))
      && TYPE_ARG_TYPES (TREE_TYPE (current_function_decl)) == 0)
    TREE_TYPE (current_function_decl) = TREE_TYPE (old_decl);

  /* This is a definition, not a reference.
     So normally clear TREE_EXTERNAL.
     However, `extern inline' acts like a declaration
     except for defining how to inline.  So set TREE_EXTERNAL in that case.  */
  TREE_EXTERNAL (current_function_decl) = current_extern_inline;

  /* This function exists in static storage.
     (This does not mean `static' in the C sense!)  */
  TREE_STATIC (current_function_decl) = 1;

  /* Record the decl so that the function name is defined.
     If we already have a decl for this name, and it is a FUNCTION_DECL,
     use the old decl.  */

  current_function_decl = pushdecl (current_function_decl);

  pushlevel (0);
  declare_parm_level ();

  make_function_rtl (current_function_decl);

  restype = TREE_TYPE (TREE_TYPE (current_function_decl));
  /* Promote the value to int before returning it.  */
  if (TREE_CODE (restype) == INTEGER_TYPE
      && TYPE_PRECISION (restype) < TYPE_PRECISION (integer_type_node))
    restype = integer_type_node;
  DECL_RESULT_TYPE (current_function_decl) = restype;
  DECL_RESULT (current_function_decl)
    = build_decl (RESULT_DECL, value_identifier, restype);

  /* Allocate further tree nodes temporarily during compilation
     of this function only.  */
  temporary_allocation ();

  /* If this fcn was already referenced via a block-scope `extern' decl
     (or an implicit decl), propagate certain information about the usage.  */
  if (TREE_ADDRESSABLE (DECL_NAME (current_function_decl)))
    TREE_ADDRESSABLE (current_function_decl) = 1;

  return 1;
}
\f
/* Store the parameter declarations into the current function declaration.
   This is called after parsing the parameter declarations, before
   digesting the body of the function.  */

void
store_parm_decls ()
{
  register tree fndecl = current_function_decl;
  register tree parm;

  /* This is either a chain of PARM_DECLs (if a prototype was used)
     or a list of IDENTIFIER_NODEs (for an old-fashioned C definition).  */
  tree specparms = current_function_parms;

  /* This is a list of types declared among parms in a prototype.  */
  tree parmtags = current_function_parm_tags;

  /* This is a chain of PARM_DECLs from old-style parm declarations.  */
  register tree parmdecls = getdecls ();

  /* This is a chain of any other decls that came in among the parm
     declarations.  If a parm is declared with  enum {foo, bar} x;
     then CONST_DECLs for foo and bar are put here.  */
  tree nonparms = 0;

  if (specparms != 0 && TREE_CODE (specparms) != TREE_LIST)
    {
      /* This case is when the function was defined with an ANSI prototype.
	 The parms already have decls, so we need not do anything here
	 except record them as in effect
	 and complain if any redundant old-style parm decls were written.  */

      register tree next;
      tree others = 0;

      if (parmdecls != 0)
	error_with_decl (fndecl,
			 "parm types given both in parmlist and separately");

      specparms = nreverse (specparms);
      for (parm = specparms; parm; parm = next)
	{
	  next = TREE_CHAIN (parm);
	  if (DECL_NAME (parm) == 0)
	    error_with_decl (parm, "parameter name omitted");
	  else if (TREE_TYPE (parm) == void_type_node)
	    error_with_decl (parm, "parameter `%s' declared void");
	  else if (TREE_CODE (parm) == PARM_DECL)
	    pushdecl (parm);
	  else
	    {
	      /* If we find an enum constant, put it aside for the moment.  */
	      TREE_CHAIN (parm) = 0;
	      others = chainon (others, parm);
	    }
	}

      /* Get the decls in their original chain order
	 and record in the function.  */
      DECL_ARGUMENTS (fndecl) = getdecls ();

      /* Now pushdecl the enum constants.  */
      for (parm = others; parm; parm = next)
	{
	  next = TREE_CHAIN (parm);
	  if (DECL_NAME (parm) == 0)
	    ;
	  else if (TREE_TYPE (parm) == void_type_node)
	    ;
	  else if (TREE_CODE (parm) != PARM_DECL)
	    pushdecl (parm);
	}

      storetags (chainon (parmtags, gettags ()));
    }
  else
    {
      /* SPECPARMS is an identifier list--a chain of TREE_LIST nodes
	 each with a parm name as the TREE_VALUE.

	 PARMDECLS is a list of declarations for parameters.
	 Warning! It can also contain CONST_DECLs which are not parameters
	 but are names of enumerators of any enum types
	 declared among the parameters.

	 First match each formal parameter name with its declaration.
	 Associate decls with the names and store the decls
	 into the TREE_PURPOSE slots.  */

      for (parm = specparms; parm; parm = TREE_CHAIN (parm))
	{
	  register tree tail, found = NULL;

	  if (TREE_VALUE (parm) == 0)
	    {
	      error_with_decl (fndecl, "parameter name missing from parameter list");
	      TREE_PURPOSE (parm) = 0;
	      continue;
	    }

	  /* See if any of the parmdecls specifies this parm by name.
	     Ignore any enumerator decls.  */
	  for (tail = parmdecls; tail; tail = TREE_CHAIN (tail))
	    if (DECL_NAME (tail) == TREE_VALUE (parm)
		&& TREE_CODE (tail) == PARM_DECL)
	      {
		found = tail;
		break;
	      }

	  /* If declaration already marked, we have a duplicate name.
	     Complain, and don't use this decl twice.   */
	  if (found && DECL_CONTEXT (found) != 0)
	    {
	      error_with_decl (found, "multiple parameters named `%s'");
	      found = 0;
	    }

	  /* If the declaration says "void", complain and ignore it.  */
	  if (found && TREE_TYPE (found) == void_type_node)
	    {
	      error_with_decl (found, "parameter `%s' declared void");
	      TREE_TYPE (found) = integer_type_node;
	      DECL_ARG_TYPE (found) = integer_type_node;
	      layout_decl (found, 0);
	    }

	  /* If no declaration found, default to int.  */
	  if (!found)
	    {
	      found = build_decl (PARM_DECL, TREE_VALUE (parm),
				  integer_type_node);
	      DECL_ARG_TYPE (found) = TREE_TYPE (found);
	      DECL_SOURCE_LINE (found) = DECL_SOURCE_LINE (fndecl);
	      DECL_SOURCE_FILE (found) = DECL_SOURCE_FILE (fndecl);
	      if (extra_warnings)
		warning_with_decl (found, "type of `%s' defaults to `int'");
	      pushdecl (found);
	    }

	  TREE_PURPOSE (parm) = found;

	  /* Mark this decl as "already found" -- see test, above.
	     It is safe to clobber DECL_CONTEXT temporarily
	     because the final values are not stored until
	     the `poplevel' in `finish_function'.  */
	  DECL_CONTEXT (found) = error_mark_node;
	}

      /* Complain about declarations not matched with any names.
	 Put any enumerator constants onto the list NONPARMS.  */

      nonparms = 0;
      for (parm = parmdecls; parm; )
	{
	  tree next = TREE_CHAIN (parm);
	  TREE_CHAIN (parm) = 0;

	  /* Complain about args with incomplete types.  */
	  if (TYPE_SIZE (TREE_TYPE (parm)) == 0)
	    {
	      error_with_decl (parm, "parameter `%s' has incomplete type");
	      TREE_TYPE (parm) = error_mark_node;
	    }

	  if (TREE_CODE (parm) != PARM_DECL)
	    nonparms = chainon (nonparms, parm);

	  else if (DECL_CONTEXT (parm) == 0)
	    {
	      error_with_decl (parm,
			       "declaration for parameter `%s' but no such parameter");
	      /* Pretend the parameter was not missing.
		 This gets us to a standard state and minimizes
		 further error messages.  */
	      specparms
		= chainon (specparms,
			   tree_cons (parm, NULL_TREE, NULL_TREE));
	    }

	  parm = next;
	}

      /* Chain the declarations together in the order of the list of names.  */
      /* Store that chain in the function decl, replacing the list of names.  */
      parm = specparms;
      DECL_ARGUMENTS (fndecl) = 0;
      {
	register tree last;
	for (last = 0; parm; parm = TREE_CHAIN (parm))
	  if (TREE_PURPOSE (parm))
	    {
	      if (last == 0)
		DECL_ARGUMENTS (fndecl) = TREE_PURPOSE (parm);
	      else
		TREE_CHAIN (last) = TREE_PURPOSE (parm);
	      last = TREE_PURPOSE (parm);
	      TREE_CHAIN (last) = 0;
	      DECL_CONTEXT (last) = 0;
	    }
      }

      /* If there was a previous prototype,
	 set the DECL_ARG_TYPE of each argument according to
	 the type previously specified, and report any mismatches.  */

      if (TYPE_ARG_TYPES (TREE_TYPE (fndecl)))
	{
	  register tree type;
	  for (parm = DECL_ARGUMENTS (fndecl),
	       type = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
	       parm || (type && TREE_VALUE (type) != void_type_node);
	       parm = TREE_CHAIN (parm), type = TREE_CHAIN (type))
	    {
	      if (parm == 0 || type == 0
		  || TREE_VALUE (type) == void_type_node)
		{
		  error ("number of arguments doesn't match prototype");
		  break;
		}
	      /* Type for passing arg must be consistent
		 with that declared for the arg.  */
	      if (! comptypes (DECL_ARG_TYPE (parm), TREE_VALUE (type)))
		{
		  error ("argument `%s' doesn't match function prototype",
			 IDENTIFIER_POINTER (DECL_NAME (parm)));
		  if (DECL_ARG_TYPE (parm) == integer_type_node
		      && TREE_VALUE (type) == TREE_TYPE (parm))
		    {
		      error ("a formal parameter type that promotes to `int'");
		      error ("can match only `int' in the prototype");
		    }
		  if (DECL_ARG_TYPE (parm) == double_type_node
		      && TREE_VALUE (type) == TREE_TYPE (parm))
		    {
		      error ("a formal parameter type that promotes to `double'");
		      error ("can match only `double' in the prototype");
		    }
		}
	    }
	}

      /* Now store the final chain of decls for the arguments
	 as the decl-chain of the current lexical scope.
	 Put the enumerators in as well, at the front so that
	 DECL_ARGUMENTS is not modified.  */

      storedecls (chainon (nonparms, DECL_ARGUMENTS (fndecl)));
    }

  /* Make sure the binding level for the top of the function body
     gets a LET_STMT if there are any in the function.
     Otherwise, the dbx output is wrong.  */

  keep_next_if_subblocks = 1;

  /* Initialize the RTL code for the function.  */

  init_function_start (fndecl, input_filename, lineno);

  /* Set up parameters and prepare for return, for the function.  */

  expand_function_start (fndecl, 0);
}
\f
/* Finish up a function declaration and compile that function
   all the way to assembler language output.  The free the storage
   for the function definition.

   This is called after parsing the body of the function definition.
   LINENO is the current line number.  */

void
finish_function (lineno)
     int lineno;
{
  register tree fndecl = current_function_decl;

/*  TREE_READONLY (fndecl) = 1;
    This caused &foo to be of type ptr-to-const-function
    which then got a warning when stored in a ptr-to-function variable.  */

  poplevel (1, 0, 1);

  /* Must mark the RESULT_DECL as being in this function.  */

  DECL_CONTEXT (DECL_RESULT (fndecl)) = DECL_INITIAL (fndecl);

  /* Obey `register' declarations if `setjmp' is called in this fn.  */
  if (flag_traditional && current_function_calls_setjmp)
    setjmp_protect (DECL_INITIAL (fndecl));

  /* Generate rtl for function exit.  */
  expand_function_end (input_filename, lineno);

  /* So we can tell if jump_optimize sets it to 1.  */
  current_function_returns_null = 0;

  /* Run the optimizers and output the assembler code for this function.  */
  rest_of_compilation (fndecl);

  if (TREE_THIS_VOLATILE (fndecl) && current_function_returns_null)
    warning ("`volatile' function does return");
  else if (warn_return_type && current_function_returns_null
	   && TREE_TYPE (TREE_TYPE (fndecl)) != void_type_node)
    /* If this function returns non-void and control can drop through,
       complain.  */
    warning ("control reaches end of non-void function");
  /* With just -W, complain only if function returns both with
     and without a value.  */
  else if (extra_warnings
	   && current_function_returns_value && current_function_returns_null)
    warning ("this function may return with or without a value");

  /* Free all the tree nodes making up this function.  */
  /* Switch back to allocating nodes permanently
     until we start another function.  */
  permanent_allocation ();

  if (DECL_SAVED_INSNS (fndecl) == 0)
    {
      /* Stop pointing to the local nodes about to be freed.  */
      /* But DECL_INITIAL must remain nonzero so we know this
	 was an actual function definition.  */
      DECL_INITIAL (fndecl) = error_mark_node;
      DECL_ARGUMENTS (fndecl) = 0;
    }

  /* Let the error reporting routines know that we're outside a function.  */
  current_function_decl = NULL;
}