decl.c

gcc-2.95.3 Linux下最常用的C编译器

/* These are irrelevant for Chill, but are referenced from from c-typeck.c. */
int warn_format;
int warn_traditional;
int warn_bad_function_cast;

/* Identifiers that hold VAR_LENGTH and VAR_DATA.  */
tree var_length_id, var_data_id;

tree case_else_node;

/* For each binding contour we allocate a scope 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.
 */

/* To communicate between pass 1 and 2, we maintain a list of "scopes".
   Each scope corrresponds to a nested source scope/block that contain 
   that can contain declarations.  The TREE_VALUE of the scope points
   to the list of declarations declared in that scope.
   The TREE_PURPOSE of the scope points to the surrounding scope.
   (We may need to handle nested modules later.  FIXME)
   The TREE_CHAIN field contains a list of scope as they are seen
   in chronological order.  (Reverse order during first pass,
   but it is reverse before pass 2.) */

struct scope
{
  /* The enclosing scope. */
  struct scope *enclosing;
  
  /* The next scope, in chronlogical order. */
  struct scope *next;
  
  /* A chain of DECLs constructed using save_decl during pass 1. */
  tree remembered_decls;
  
  /* A chain of _DECL nodes for all variables, constants, functions,
     and typedef types belong to this scope. */
  tree decls;
  
  /* List of declarations that have been granted into this scope. */
  tree granted_decls;

  /* List of implied (weak) names. */
  tree weak_decls;
  
  /* 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 BLOCK nodes for all the levels
     that were entered and exited one level down.  */
  tree blocks;
  
  /* The BLOCK node for this level, if one has been preallocated.
     If 0, the BLOCK is allocated (if needed) when the level is popped.  */
  tree this_block;
  
  /* The binding level which this one is contained in (inherits from).  */
  struct scope *level_chain;
  
  /* Nonzero for a level that corresponds to a module. */
  char module_flag;
  
  /* Zero means called from backend code. */
  char two_pass;
  
  /* The modules that are directly enclosed by this scope
     are chained together. */
  struct scope* first_child_module;
  struct scope** tail_child_module;
  struct scope* next_sibling_module;
};

/* The outermost binding level, for pre-defined (builtin) names. */

static struct scope builtin_scope = {
  NULL, NULL, NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE,
  NULL_TREE, NULL_TREE, NULL, 0, 0, NULL, NULL, NULL};

struct scope *global_scope;

/* The binding level currently in effect.  */

static struct scope *current_scope = &builtin_scope;

/* The most recently seen scope. */
struct scope *last_scope = &builtin_scope;

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

static struct scope clear_scope = {
  NULL, NULL, NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE,
  NULL_TREE, NULL_TREE, NULL, 0, 0, NULL, NULL, NULL};

/* Chain of decls accessible through IDENTIFIER_OUTER_VALUE.
   Decls with the same DECL_NAME are adjacent in the chain. */

static tree outer_decls = NULL_TREE;

/* 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 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 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 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 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;

/* Define the special tree codes that we use.  */

/* Table indexed by tree code giving a string containing a character
   classifying the tree code.  Possibilities are
   t, d, s, c, r, <, 1 and 2.  See ch-tree.def for details.  */

#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
  
  char chill_tree_code_type[] = {
    'x',
#include "ch-tree.def"
  };
#undef DEFTREECODE

/* Table indexed by tree code giving number of expression
   operands beyond the fixed part of the node structure.
   Not used for types or decls.  */

#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
  
int chill_tree_code_length[] = {
    0,
#include "ch-tree.def"
  };
#undef DEFTREECODE


/* Names of tree components.
   Used for printing out the tree and error messages.  */
#define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
  
char *chill_tree_code_name[] = {
    "@@dummy",
#include "ch-tree.def"
  };
#undef DEFTREECODE

/* 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 > 1;

/* An identifier that is used internally to indicate
   an "ALL" prefix for granting or seizing.
   We use "*" rather than the external name "ALL", partly for convenience,
   and partly to avoid case senstivity problems. */

tree ALL_POSTFIX;

void
allocate_lang_decl (t)
     tree t ATTRIBUTE_UNUSED;
{
  /* Nothing needed */
}

void
copy_lang_decl (node)
     tree node ATTRIBUTE_UNUSED;
{
  /* Nothing needed */
}

tree
build_lang_decl (code, name, type)
     enum chill_tree_code code;
     tree name;
     tree type;
{
  return build_decl (code, name, type);
}

/* Decode the string P as a language-specific option for C.
   Return the number of strings consumed for a valid option.
   Return 0 for an invalid option.  */

int
c_decode_option (argc, argv)
     int argc ATTRIBUTE_UNUSED;
     char **argv;
{
  char *p = argv[0];
  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, "-fnotraditional") || !strcmp (p, "-fno-traditional"))
    {
      flag_traditional = 0;
      flag_writable_strings = 0;
      dollars_in_ident = DOLLARS_IN_IDENTIFIERS > 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, "-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, "-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, "-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, "-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, "-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"))
    {
      extra_warnings = 1;
      /* 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_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;
{
  indent_to (file, indent + 3);
  fputs ("nesting_level ", file);
  fprintf (file, HOST_WIDE_INT_PRINT_DEC, DECL_NESTING_LEVEL (node));