c-decl.c

gcc库的原代码,对编程有很大帮助.

tree static_ctors, static_dtors;

/* Forward declarations.  */

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

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

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

int flag_cond_mismatch;

/* Nonzero means give `double' the same size as `float'.  */

int flag_short_double;

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

int flag_no_asm;

/* Nonzero means don't recognize any builtin functions.  */

int flag_no_builtin;

/* Nonzero means don't recognize the non-ANSI builtin functions.
   -ansi sets this.  */

int flag_no_nonansi_builtin;

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

int flag_traditional;

/* Nonzero means to allow single precision math even if we're generally
   being traditional. */
int flag_allow_single_precision = 0;

/* Nonzero means to treat bitfields as signed unless they say `unsigned'.  */

int flag_signed_bitfields = 1;
int explicit_flag_signed_bitfields = 0;

/* Nonzero means handle `#ident' directives.  0 means ignore them.  */

int flag_no_ident = 0;

/* Nonzero means warn about implicit declarations.  */

int warn_implicit;

/* 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 when casting a function call to a type that does
   not match the return type (e.g. (float)sqrt() or (anything*)malloc()
   when there is no previous declaration of sqrt or malloc.  */

int warn_bad_function_cast;

/* Warn about traditional constructs whose meanings changed in ANSI C.  */

int warn_traditional;

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

int warn_pointer_arith;

/* Nonzero means warn for non-prototype function decls
   or non-prototyped defs without previous prototype.  */

int warn_strict_prototypes;

/* Nonzero means warn for any global function def
   without separate previous prototype decl.  */

int warn_missing_prototypes;

/* Nonzero means warn for any global function def
   without separate previous decl.  */

int warn_missing_declarations;

/* Nonzero means warn about multiple (redundant) decls for the same single
   variable or function.  */

int warn_redundant_decls = 0;

/* Nonzero means warn about extern declarations of objects not at
   file-scope level and about *all* declarations of functions (whether
   extern or static) not at file-scope level.  Note that we exclude
   implicit function declarations.  To get warnings about those, use
   -Wimplicit.  */

int warn_nested_externs = 0;

/* Warn about *printf or *scanf format/argument anomalies. */

int warn_format;

/* Warn about a subscript that has type char.  */

int warn_char_subscripts = 0;

/* Warn if a type conversion is done that might have confusing results.  */

int warn_conversion;

/* Warn if adding () is suggested.  */

int warn_parentheses;

/* Warn if initializer is not completely bracketed.  */

int warn_missing_braces;

/* 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 1
#endif
int dollars_in_ident = DOLLARS_IN_IDENTIFIERS > 1;

/* Decode the string P as a language-specific option for C.
   Return 1 if it is recognized (and handle it);
   return 0 if not recognized.  */
   
int
c_decode_option (p)
     char *p;
{
  if (!strcmp (p, "-ftraditional") || !strcmp (p, "-traditional"))
    {
      flag_traditional = 1;
      flag_writable_strings = 1;
#if DOLLARS_IN_IDENTIFIERS > 0
      dollars_in_ident = 1;
#endif
    }
  else if (!strcmp (p, "-fallow-single-precision"))
    flag_allow_single_precision = 1;
  else if (!strcmp (p, "-fnotraditional") || !strcmp (p, "-fno-traditional"))
    {
      flag_traditional = 0;
      flag_writable_strings = 0;
      dollars_in_ident = DOLLARS_IN_IDENTIFIERS > 1;
    }
  else if (!strcmp (p, "-fdollars-in-identifiers"))
    {
#if DOLLARS_IN_IDENTIFIERS > 0
      dollars_in_ident = 1;
#endif
    }
  else if (!strcmp (p, "-fno-dollars-in-identifiers"))
    dollars_in_ident = 0;
  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, "-fsigned-bitfields")
	   || !strcmp (p, "-fno-unsigned-bitfields"))
    {
      flag_signed_bitfields = 1;
      explicit_flag_signed_bitfields = 1;
    }
  else if (!strcmp (p, "-funsigned-bitfields")
	   || !strcmp (p, "-fno-signed-bitfields"))
    {
      flag_signed_bitfields = 0;
      explicit_flag_signed_bitfields = 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, "-fshort-double"))
    flag_short_double = 1;
  else if (!strcmp (p, "-fno-short-double"))
    flag_short_double = 0;
  else if (!strcmp (p, "-fasm"))
    flag_no_asm = 0;
  else if (!strcmp (p, "-fno-asm"))
    flag_no_asm = 1;
  else if (!strcmp (p, "-fbuiltin"))
    flag_no_builtin = 0;
  else if (!strcmp (p, "-fno-builtin"))
    flag_no_builtin = 1;
  else if (!strcmp (p, "-fno-ident"))
    flag_no_ident = 1;
  else if (!strcmp (p, "-fident"))
    flag_no_ident = 0;
  else if (!strcmp (p, "-ansi"))
    flag_no_asm = 1, flag_no_nonansi_builtin = 1, dollars_in_ident = 0;
  else if (!strcmp (p, "-Wimplicit"))
    warn_implicit = 1;
  else if (!strcmp (p, "-Wno-implicit"))
    warn_implicit = 0;
  else if (!strcmp (p, "-Wwrite-strings"))
    warn_write_strings = 1;
  else if (!strcmp (p, "-Wno-write-strings"))
    warn_write_strings = 0;
  else if (!strcmp (p, "-Wcast-qual"))
    warn_cast_qual = 1;
  else if (!strcmp (p, "-Wno-cast-qual"))
    warn_cast_qual = 0;
  else if (!strcmp (p, "-Wbad-function-cast"))
    warn_bad_function_cast = 1;
  else if (!strcmp (p, "-Wno-bad-function-cast"))
    warn_bad_function_cast = 0;
  else if (!strcmp (p, "-Wpointer-arith"))
    warn_pointer_arith = 1;
  else if (!strcmp (p, "-Wno-pointer-arith"))
    warn_pointer_arith = 0;
  else if (!strcmp (p, "-Wstrict-prototypes"))
    warn_strict_prototypes = 1;
  else if (!strcmp (p, "-Wno-strict-prototypes"))
    warn_strict_prototypes = 0;
  else if (!strcmp (p, "-Wmissing-prototypes"))
    warn_missing_prototypes = 1;
  else if (!strcmp (p, "-Wno-missing-prototypes"))
    warn_missing_prototypes = 0;
  else if (!strcmp (p, "-Wmissing-declarations"))
    warn_missing_declarations = 1;
  else if (!strcmp (p, "-Wno-missing-declarations"))
    warn_missing_declarations = 0;
  else if (!strcmp (p, "-Wredundant-decls"))
    warn_redundant_decls = 1;
  else if (!strcmp (p, "-Wno-redundant-decls"))
    warn_redundant_decls = 0;
  else if (!strcmp (p, "-Wnested-externs"))
    warn_nested_externs = 1;
  else if (!strcmp (p, "-Wno-nested-externs"))
    warn_nested_externs = 0;
  else if (!strcmp (p, "-Wtraditional"))
    warn_traditional = 1;
  else if (!strcmp (p, "-Wno-traditional"))
    warn_traditional = 0;
  else if (!strcmp (p, "-Wformat"))
    warn_format = 1;
  else if (!strcmp (p, "-Wno-format"))
    warn_format = 0;
  else if (!strcmp (p, "-Wchar-subscripts"))
    warn_char_subscripts = 1;
  else if (!strcmp (p, "-Wno-char-subscripts"))
    warn_char_subscripts = 0;
  else if (!strcmp (p, "-Wconversion"))
    warn_conversion = 1;
  else if (!strcmp (p, "-Wno-conversion"))
    warn_conversion = 0;
  else if (!strcmp (p, "-Wparentheses"))
    warn_parentheses = 1;
  else if (!strcmp (p, "-Wno-parentheses"))
    warn_parentheses = 0;
  else if (!strcmp (p, "-Wreturn-type"))
    warn_return_type = 1;
  else if (!strcmp (p, "-Wno-return-type"))
    warn_return_type = 0;
  else if (!strcmp (p, "-Wcomment"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wno-comment"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wcomments"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wno-comments"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wtrigraphs"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wno-trigraphs"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wimport"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wno-import"))
    ; /* cpp handles this one.  */
  else if (!strcmp (p, "-Wmissing-braces"))
    warn_missing_braces = 1;
  else if (!strcmp (p, "-Wno-missing-braces"))
    warn_missing_braces = 0;
  else if (!strcmp (p, "-Wall"))
    {
      /* We save the value of warn_uninitialized, since if they put
	 -Wuninitialized on the command line, we need to generate a
	 warning about not using it without also specifying -O.  */
      if (warn_uninitialized != 1)
	warn_uninitialized = 2;
      warn_implicit = 1;
      warn_return_type = 1;
      warn_unused = 1;
      warn_switch = 1;
      warn_format = 1;
      warn_char_subscripts = 1;
      warn_parentheses = 1;
      warn_missing_braces = 1;
    }
  else
    return 0;

  return 1;
}

/* Hooks for print_node.  */

void
print_lang_decl (file, node, indent)
     FILE *file;
     tree node;
     int indent;
{
}

void
print_lang_type (file, node, indent)
     FILE *file;
     tree node;
     int indent;
{
}

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);
  print_node (file, "limbo value", IDENTIFIER_LIMBO_VALUE (node), indent + 4);
}

/* Hook called at end of compilation to assume 1 elt
   for a top-level array decl that wasn't complete before.  */
   
void
finish_incomplete_decl (decl)
     tree decl;
{
  if (TREE_CODE (decl) == VAR_DECL && TREE_TYPE (decl) != error_mark_node)
    {
      tree type = TREE_TYPE (decl);
      if (TREE_CODE (type) == ARRAY_TYPE
	  && TYPE_DOMAIN (type) == 0
	  && TREE_CODE (decl) != TYPE_DECL)
	{
	  complete_array_type (type, NULL_TREE, 1);

	  layout_decl (decl, 0);
	}
    }
}

/* 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 BLOCK made.  */

int
kept_level_p ()