decl.c

gcc-2.95.3 Linux下最常用的C编译器

  
  decl_stack = pop_stack_level (decl_stack);
  /* If we're leaving a toplevel class, don't bother to do the setting
     of IDENTIFIER_CLASS_VALUE to NULL_TREE, since first of all this slot
     shouldn't even be used when current_class_type isn't set, and second,
     if we don't touch it here, we're able to use the cache effect if the
     next time we're entering a class scope, it is the same class.  */
  if (current_class_depth != 1)
    {
      struct binding_level* b;

      /* Clear out our IDENTIFIER_CLASS_VALUEs.  */
      for (shadowed = level->class_shadowed;
	   shadowed;
	   shadowed = TREE_CHAIN (shadowed))
	IDENTIFIER_CLASS_VALUE (TREE_PURPOSE (shadowed)) = NULL_TREE;
	
      /* Find the next enclosing class, and recreate
	 IDENTIFIER_CLASS_VALUEs appropriate for that class.  */
      b = level->level_chain;
      while (b && b->parm_flag != 2)
	b = b->level_chain;

      if (b)
	for (shadowed = b->class_shadowed; 
	     shadowed; 
	     shadowed = TREE_CHAIN (shadowed))
	  {
	    tree t;

	    t = IDENTIFIER_BINDING (TREE_PURPOSE (shadowed));
	    while (t && BINDING_LEVEL (t) != b)
	      t = TREE_CHAIN (t);
      
	    if (t)
	      IDENTIFIER_CLASS_VALUE (TREE_PURPOSE (shadowed)) 
		= BINDING_VALUE (t);
	  }
    }
  else
    /* Remember to save what IDENTIFIER's were bound in this scope so we
       can recover from cache misses.  */
    {
      previous_class_type = current_class_type;
      previous_class_values = class_binding_level->class_shadowed;
    }
  for (shadowed = level->type_shadowed;
       shadowed;
       shadowed = TREE_CHAIN (shadowed))
    SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (shadowed), TREE_VALUE (shadowed));

  /* Remove the bindings for all of the class-level declarations.  */
  for (shadowed = level->class_shadowed; 
       shadowed; 
       shadowed = TREE_CHAIN (shadowed))
    pop_binding (TREE_PURPOSE (shadowed), TREE_TYPE (shadowed));

  GNU_xref_end_scope ((HOST_WIDE_INT) class_binding_level,
		      (HOST_WIDE_INT) class_binding_level->level_chain,
		      class_binding_level->parm_flag,
		      class_binding_level->keep);

  /* Now, pop out of the binding level which we created up in the
     `pushlevel_class' routine.  */
#if defined(DEBUG_CP_BINDING_LEVELS)
  is_class_level = 1;
#endif /* defined(DEBUG_CP_BINDING_LEVELS) */

  pop_binding_level ();

  return NULL_TREE;
}

/* We are entering the scope of a class.  Clear IDENTIFIER_CLASS_VALUE
   for any names in enclosing classes.  */

void
clear_identifier_class_values ()
{
  tree t;

  if (!class_binding_level)
    return;

  for (t = class_binding_level->class_shadowed;
       t;
       t = TREE_CHAIN (t))
    IDENTIFIER_CLASS_VALUE (TREE_PURPOSE (t)) = NULL_TREE;
}

/* Returns non-zero if T is a virtual function table.  */

int
vtable_decl_p (t, data)
     tree t;
     void *data ATTRIBUTE_UNUSED;
{
  return (TREE_CODE (t) == VAR_DECL && DECL_VIRTUAL_P (t));
}

/* Returns non-zero if T is a TYPE_DECL for a type with virtual
   functions.  */

int
vtype_decl_p (t, data)
     tree t;
     void *data ATTRIBUTE_UNUSED;
{
  return (TREE_CODE (t) == TYPE_DECL
	  && TREE_TYPE (t) != error_mark_node
	  && TYPE_LANG_SPECIFIC (TREE_TYPE (t))
	  && CLASSTYPE_VSIZE (TREE_TYPE (t)));
}

/* Returns non-zero if T is a signature table.  */

int 
sigtable_decl_p (t, data)
     tree t;
     void *data ATTRIBUTE_UNUSED;
{
  return (TREE_CODE (t) == VAR_DECL
	  && TREE_TYPE (t) != error_mark_node
	  && IS_SIGNATURE (TREE_TYPE (t)));
}

/* Walk all the namespaces contained NAMESPACE, including NAMESPACE
   itself, calling F for each.  The DATA is passed to F as well.  */

static int
walk_namespaces_r (namespace, f, data)
     tree namespace;
     walk_namespaces_fn f;
     void *data;
{
  tree current;
  int result = 0;

  result |= (*f) (namespace, data);

  for (current = NAMESPACE_LEVEL (namespace)->names;
       current;
       current = TREE_CHAIN (current))
    {
      if (TREE_CODE (current) != NAMESPACE_DECL
	  || DECL_NAMESPACE_ALIAS (current))
	continue;
      if (!DECL_LANG_SPECIFIC (current))
	{
	  /* Hmm. std. */
	  my_friendly_assert (current == std_node, 393);
	  continue;
	}

      /* We found a namespace.  */
      result |= walk_namespaces_r (current, f, data);
    }

  return result;
}

/* Walk all the namespaces, calling F for each.  The DATA is passed to
   F as well.  */

int
walk_namespaces (f, data)
     walk_namespaces_fn f;
     void *data;
{
  return walk_namespaces_r (global_namespace, f, data);
}

struct walk_globals_data {
  walk_globals_pred p;
  walk_globals_fn f;
  void *data;
};

/* Walk the global declarations in NAMESPACE.  Whenever one is found
   for which P returns non-zero, call F with its address.  If any call
   to F returns a non-zero value, return a non-zero value.  */

static int 
walk_globals_r (namespace, data)
     tree namespace;
     void *data;
{
  struct walk_globals_data* wgd = (struct walk_globals_data *) data;
  walk_globals_pred p = wgd->p;
  walk_globals_fn f = wgd->f;
  void *d = wgd->data;
  tree *t;
  int result = 0;

  t = &NAMESPACE_LEVEL (namespace)->names;

  while (*t)
    {
      tree glbl = *t;

      if ((*p) (glbl, d))
	result |= (*f) (t, d);

      /* If F changed *T, then *T still points at the next item to
	 examine.  */
      if (*t == glbl)
	t = &TREE_CHAIN (*t);
    }

  return result;
}

/* Walk the global declarations.  Whenever one is found for which P
   returns non-zero, call F with its address.  If any call to F
   returns a non-zero value, return a non-zero value.  */

int
walk_globals (p, f, data)
     walk_globals_pred p;
     walk_globals_fn f;
     void *data;
{
  struct walk_globals_data wgd;
  wgd.p = p;
  wgd.f = f;
  wgd.data = data;

  return walk_namespaces (walk_globals_r, &wgd);
}

/* Call wrapup_globals_declarations for the globals in NAMESPACE.  If
   DATA is non-NULL, this is the last time we will call
   wrapup_global_declarations for this NAMESPACE.  */

int
wrapup_globals_for_namespace (namespace, data)
     tree namespace;
     void *data;
{
  tree globals = NAMESPACE_LEVEL (namespace)->names;
  int len = list_length (globals);
  tree *vec = (tree *) alloca (sizeof (tree) * len);
  int i;
  int result;
  tree decl;
  int last_time = (data != 0);

  if (last_time && namespace == global_namespace)
    /* Let compile_file handle the global namespace.  */
    return 0;

  /* Process the decls in reverse order--earliest first.
     Put them into VEC from back to front, then take out from front.  */
  
  for (i = 0, decl = globals; i < len; i++, decl = TREE_CHAIN (decl))
    vec[len - i - 1] = decl;
  
  if (last_time)
    {
      check_global_declarations (vec, len);
      return 0;
    }

  /* Temporarily mark vtables as external.  That prevents
     wrapup_global_declarations from writing them out; we must process
     them ourselves in finish_vtable_vardecl.  */
  for (i = 0; i < len; ++i)
    if (vtable_decl_p (vec[i], /*data=*/0) && !DECL_EXTERNAL (vec[i]))
      {
	DECL_NOT_REALLY_EXTERN (vec[i]) = 1;
	DECL_EXTERNAL (vec[i]) = 1;
      }

  /* Write out any globals that need to be output.  */
  result = wrapup_global_declarations (vec, len);

  /* Undo the hack to DECL_EXTERNAL above.  */
  for (i = 0; i < len; ++i)
    if (vtable_decl_p (vec[i], /*data=*/0)
	&& DECL_NOT_REALLY_EXTERN (vec[i]))
      {
	DECL_NOT_REALLY_EXTERN (vec[i]) = 0;
	DECL_EXTERNAL (vec[i]) = 0;
      }

  return result;
}


/* For debugging.  */
static int no_print_functions = 0;
static int no_print_builtins = 0;

void
print_binding_level (lvl)
     struct binding_level *lvl;
{
  tree t;
  int i = 0, len;
  fprintf (stderr, " blocks=");
  fprintf (stderr, HOST_PTR_PRINTF, lvl->blocks);
  fprintf (stderr, " n_incomplete=%d parm_flag=%d keep=%d",
	   list_length (lvl->incomplete), lvl->parm_flag, lvl->keep);
  if (lvl->tag_transparent)
    fprintf (stderr, " tag-transparent");
  if (lvl->more_cleanups_ok)
    fprintf (stderr, " more-cleanups-ok");
  if (lvl->have_cleanups)
    fprintf (stderr, " have-cleanups");
  fprintf (stderr, "\n");
  if (lvl->names)
    {
      fprintf (stderr, " names:\t");
      /* We can probably fit 3 names to a line?  */
      for (t = lvl->names; t; t = TREE_CHAIN (t))
	{
	  if (no_print_functions && (TREE_CODE (t) == FUNCTION_DECL)) 
	    continue;
	  if (no_print_builtins
	      && (TREE_CODE (t) == TYPE_DECL)
	      && (!strcmp (DECL_SOURCE_FILE (t),"<built-in>")))
	    continue;

	  /* Function decls tend to have longer names.  */
	  if (TREE_CODE (t) == FUNCTION_DECL)
	    len = 3;
	  else
	    len = 2;
	  i += len;
	  if (i > 6)
	    {
	      fprintf (stderr, "\n\t");
	      i = len;
	    }
	  print_node_brief (stderr, "", t, 0);
	  if (t == error_mark_node)
	    break;
	}
      if (i)
        fprintf (stderr, "\n");
    }
  if (lvl->tags)
    {
      fprintf (stderr, " tags:\t");
      i = 0;
      for (t = lvl->tags; t; t = TREE_CHAIN (t))
	{
	  if (TREE_PURPOSE (t) == NULL_TREE)
	    len = 3;
	  else if (TREE_PURPOSE (t) == TYPE_IDENTIFIER (TREE_VALUE (t)))
	    len = 2;
	  else
	    len = 4;
	  i += len;
	  if (i > 5)
	    {
	      fprintf (stderr, "\n\t");
	      i = len;
	    }
	  if (TREE_PURPOSE (t) == NULL_TREE)
	    {
	      print_node_brief (stderr, "<unnamed-typedef", TREE_VALUE (t), 0);
	      fprintf (stderr, ">");
	    }
	  else if (TREE_PURPOSE (t) == TYPE_IDENTIFIER (TREE_VALUE (t)))
	    print_node_brief (stderr, "", TREE_VALUE (t), 0);
	  else
	    {
	      print_node_brief (stderr, "<typedef", TREE_PURPOSE (t), 0);
	      print_node_brief (stderr, "", TREE_VALUE (t), 0);
	      fprintf (stderr, ">");
	    }
	}
      if (i)
	fprintf (stderr, "\n");
    }
  if (lvl->class_shadowed)
    {
      fprintf (stderr, " class-shadowed:");
      for (t = lvl->class_shadowed; t; t = TREE_CHAIN (t))
	{
	  fprintf (stderr, " %s ", IDENTIFIER_POINTER (TREE_PURPOSE (t)));
	}
      fprintf (stderr, "\n");
    }
  if (lvl->type_shadowed)
    {
      fprintf (stderr, " type-shadowed:");
      for (t = lvl->type_shadowed; t; t = TREE_CHAIN (t))
        {
	  fprintf (stderr, " %s ", IDENTIFIER_POINTER (TREE_PURPOSE (t)));
        }
      fprintf (stderr, "\n");
    }
}

void
print_other_binding_stack (stack)
     struct binding_level *stack;
{
  struct binding_level *level;
  for (level = stack; level != global_binding_level; level = level->level_chain)
    {
      fprintf (stderr, "binding level ");
      fprintf (stderr, HOST_PTR_PRINTF, level);
      fprintf (stderr, "\n");
      print_binding_level (level);
    }
}

void
print_binding_stack ()
{
  struct binding_level *b;
  fprintf (stderr, "current_binding_level=");
  fprintf (stderr, HOST_PTR_PRINTF, current_binding_level);
  fprintf (stderr, "\nclass_binding_level=");
  fprintf (stderr, HOST_PTR_PRINTF, class_binding_level);
  fprintf (stderr, "\nglobal_binding_level=");
  fprintf (stderr, HOST_PTR_PRINTF, global_binding_level);
  fprintf (stderr, "\n");
  if (class_binding_level)
    {
      for (b = class_binding_level; b; b = b->level_chain)
	if (b == current_binding_level)
	  break;
      if (b)
	b = class_binding_level;
      else
	b = current_binding_level;
    }
  else
    b = current_binding_level;
  print_other_binding_stack (b);
  fprintf (stderr, "global:\n");
  print_binding_level (global_binding_level);
}

/* Namespace binding access rou