decl.c

GCC编译器源代码

  /* Resume the variable caches.  */
  decls = current_binding_level->names;

  /* Restore the meanings of the local variables of this level.  */

  for (link = decls; link; link = TREE_CHAIN (link))
    {
      /* If it doesn't have a name, there is nothing left to do with it.  */
      if (DECL_NAME (link) == NULL_TREE)
	continue;

      IDENTIFIER_LOCAL_VALUE (DECL_NAME (link)) = link;

      /* If this is a TYPE_DECL, push it into the type value slot.  */
      if (TREE_CODE (link) == TYPE_DECL)
	SET_IDENTIFIER_TYPE_VALUE (DECL_NAME (link), TREE_TYPE (link));
    }
}

/* Delete the node BLOCK from the current binding level.
   This is used for the block inside a stmt expr ({...})
   so that the block can be reinserted where appropriate.  */

void
delete_block (block)
     tree block;
{
  tree t;
  if (current_binding_level->blocks == block)
    current_binding_level->blocks = TREE_CHAIN (block);
  for (t = current_binding_level->blocks; t;)
    {
      if (TREE_CHAIN (t) == block)
	TREE_CHAIN (t) = TREE_CHAIN (block);
      else
	t = TREE_CHAIN (t);
    }
  TREE_CHAIN (block) = NULL_TREE;
  /* Clear TREE_USED which is always set by poplevel.
     The flag is set again if insert_block is called.  */
  TREE_USED (block) = 0;
}

/* Insert BLOCK at the end of the list of subblocks of the
   current binding level.  This is used when a BIND_EXPR is expanded,
   to handle the BLOCK node inside the BIND_EXPR.  */

void
insert_block (block)
     tree block;
{
  TREE_USED (block) = 1;
  current_binding_level->blocks
    = chainon (current_binding_level->blocks, block);
}

/* Add BLOCK to the current list of blocks for this binding contour.  */

void
add_block_current_level (block)
     tree block;
{
  current_binding_level->blocks
    = chainon (current_binding_level->blocks, block);
}

/* Set the BLOCK node for the innermost scope
   (the one we are currently in).  */

void
set_block (block)
    register tree block;
{
  current_binding_level->this_block = block;
}

/* Do a pushlevel for class declarations.  */

void
pushlevel_class ()
{
  register struct binding_level *newlevel;

  /* Reuse or create a struct for this binding level.  */
#if defined(DEBUG_CP_BINDING_LEVELS)
  if (0)
#else /* !defined(DEBUG_CP_BINDING_LEVELS) */
  if (free_binding_level)
#endif /* !defined(DEBUG_CP_BINDING_LEVELS) */
    {
      newlevel = free_binding_level;
      free_binding_level = free_binding_level->level_chain;
    }
  else
    {
      newlevel = make_binding_level ();
    }

#if defined(DEBUG_CP_BINDING_LEVELS)
  is_class_level = 1;
#endif /* defined(DEBUG_CP_BINDING_LEVELS) */

  push_binding_level (newlevel, 0, 0);

  decl_stack = push_decl_level (decl_stack, &decl_obstack);
  class_binding_level = current_binding_level;
  class_binding_level->parm_flag = 2;
  /* We have just pushed into a new binding level.  Now, fake out the rest
     of the compiler.  Set the `current_binding_level' back to point to
     the most closely containing non-class binding level.  */
  do
    {
      current_binding_level = current_binding_level->level_chain;
    }
  while (current_binding_level->parm_flag == 2);
}

/* ...and a poplevel for class declarations.  FORCE is used to force
   clearing out of CLASS_VALUEs after a class definition.  */

tree
poplevel_class (force)
     int force;
{
  register struct binding_level *level = class_binding_level;
  tree block = NULL_TREE;
  tree shadowed;

  my_friendly_assert (level != 0, 354);
  
  decl_stack = pop_stack_level (decl_stack);
  for (shadowed = level->shadowed; shadowed; shadowed = TREE_CHAIN (shadowed))
    IDENTIFIER_LOCAL_VALUE (TREE_PURPOSE (shadowed)) = TREE_VALUE (shadowed);
  /* 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 || force)
    for (shadowed = level->class_shadowed;
	 shadowed;
	 shadowed = TREE_CHAIN (shadowed))
      IDENTIFIER_CLASS_VALUE (TREE_PURPOSE (shadowed)) = TREE_VALUE (shadowed);
  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))
    IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (shadowed)) = TREE_VALUE (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);

  if (class_binding_level->parm_flag != 2)
    class_binding_level = (struct binding_level *)0;

  /* Now, pop out of the 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 block;
}

/* 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->shadowed)
    {
      fprintf (stderr, " shadowed:");
      for (t = lvl->shadowed; t; t = TREE_CHAIN (t))
	{
	  fprintf (stderr, " %s ", IDENTIFIER_POINTER (TREE_PURPOSE (t)));
	}
      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);
}

extern char * first_global_object_name;

/* Get a unique name for each call to this routine for unnamed namespaces.
   Mostly copied from get_file_function_name.  */

static tree
get_unique_name ()
{
  static int temp_name_counter = 0;
  char *buf;
  register char *p;

  if (first_global_object_name)
    p = first_global_object_name;
  else if (main_input_filename)
    p = main_input_filename;
  else
    p = input_filename;

#define UNNAMED_NAMESPACE_FORMAT "__%s_%d"

  buf = (char *) alloca (sizeof (UNNAMED_NAMESPACE_FORMAT) + strlen (p));

  sprintf (buf, UNNAMED_NAMESPACE_FORMAT, p, temp_name_counter++);

  /* Don't need to pull weird characters out of global names.  */
  if (p != first_global_object_name)
    {
      for (p = buf+11; *p; p++)
	if (! ((*p >= '0' && *p <= '9')
#ifndef NO_DOLLAR_IN_LABEL	/* this for `$'; unlikely, but... -- kr */
	       || *p == '$'
#endif
#ifndef NO_DOT_IN_LABEL		/* this for `.'; unlikely, but...  */
	       || *p == '.'
#endif
	       || (*p >= 'A' && *p <= 'Z')
	       || (*p >= 'a' && *p <= 'z')))
	  *p = '_';
    }

  return get_identifier (buf);
}

/* Push into the scope of the NAME namespace.  If NAME is NULL_TREE, then we
   select a name that is unique to this compilation unit.  */

void
push_namespace (name)
     tree name;
{
#if 1
  static int warned;
  if (! warned)
    sorry ("namespace");
  
  warned = 1;
#else
  extern tree current_namespace;
  tree old_id = get_namespace_id ();
  char *buf;
  tree d;

  if (! name)
    {
      /* Create a truly ugly name! */
      name = get_unique_name ();
    }

  d = build_lang_decl (NAMESPACE_DECL, name, void_type_node);

  /* Mark them as external, so redeclaration_error_message doesn't think
     they are duplicates.  */

  DECL_EXTERNAL (d) = 1;
  d = pushdecl (d);

  if (NAMESPACE_LEVEL (d) == 0)
    {
      /* This is new for this compilation unit.  */
      pushlevel (0);
      declare_namespace_level ();
      NAMESPACE_LEVEL (d) = current_binding_level;
    }
  else
    resume_level (NAMESPACE_LEVEL (d));

  /* This code is just is bit old now...  */ 
  current_namespace = tree_cons (NULL_TREE, name, current_namespace);
  buf = (char *) alloca (4 + (old_id ? IDENTIFIER_LENGTH (old_id) : 0)
			 + IDENTIFIER_LENGTH (name));
  sprintf (buf, "%s%s", old_id ? IDENTIFIER_POINTER (old_id) : "",
	   IDENTIFIER_POINTER (name));
  TREE_PURPOSE (current_namespace) = get_identifier (buf);
#endif
}

/* Pop from the scope of the current namespace.  */

void
pop_namespace ()
{
#if 0
  extern tree current_namespace;
  tree decls, link;
  current_namespace = TREE_CHAIN (current_namespace);

  /* Just in case we get out of sync.  */
  if (! namespace_bindings_p ())
    poplevel (0, 0, 0);

  decls = current_binding_level->names;

  /* Clear out the meanings of the local variables of this level.  */

  for (link = decls; link; link = TREE_CHAIN (link))