tree.c

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  list_hash_table[hashcode % TYPE_HASH_SIZE] = h;
}

/* Given TYPE, and HASHCODE its hash code, return the canonical
   object for an identical list if one already exists.
   Otherwise, return TYPE, and record it as the canonical object
   if it is a permanent object.

   To use this function, first create a list of the sort you want.
   Then compute its hash code from the fields of the list that
   make it different from other similar lists.
   Then call this function and use the value.
   This function frees the list you pass in if it is a duplicate.  */

/* Set to 1 to debug without canonicalization.  Never set by program.  */
static int debug_no_list_hash = 0;

tree
list_hash_canon (hashcode, list)
     int hashcode;
     tree list;
{
  tree t1;

  if (debug_no_list_hash)
    return list;

  t1 = list_hash_lookup (hashcode, list);
  if (t1 != 0)
    {
      obstack_free (&class_obstack, list);
      return t1;
    }

  /* If this is a new list, record it for later reuse.  */
  list_hash_add (hashcode, list);

  return list;
}

tree
hash_tree_cons (via_public, via_virtual, via_protected, purpose, value, chain)
     int via_public, via_virtual, via_protected;
     tree purpose, value, chain;
{
  struct obstack *ambient_obstack = current_obstack;
  tree t;
  int hashcode;

  current_obstack = &class_obstack;
  t = tree_cons (purpose, value, chain);
  TREE_VIA_PUBLIC (t) = via_public;
  TREE_VIA_PROTECTED (t) = via_protected;
  TREE_VIA_VIRTUAL (t) = via_virtual;
  hashcode = list_hash (t);
  t = list_hash_canon (hashcode, t);
  current_obstack = ambient_obstack;
  return t;
}

/* Constructor for hashed lists.  */
tree
hash_tree_chain (value, chain)
     tree value, chain;
{
  struct obstack *ambient_obstack = current_obstack;
  tree t;
  int hashcode;

  current_obstack = &class_obstack;
  t = tree_cons (NULL_TREE, value, chain);
  hashcode = list_hash (t);
  t = list_hash_canon (hashcode, t);
  current_obstack = ambient_obstack;
  return t;
}

/* Similar, but used for concatenating two lists.  */
tree
hash_chainon (list1, list2)
     tree list1, list2;
{
  if (list2 == 0)
    return list1;
  if (list1 == 0)
    return list2;
  if (TREE_CHAIN (list1) == NULL_TREE)
    return hash_tree_chain (TREE_VALUE (list1), list2);
  return hash_tree_chain (TREE_VALUE (list1),
			  hash_chainon (TREE_CHAIN (list1), list2));
}

static tree
get_identifier_list (value)
     tree value;
{
  tree list = IDENTIFIER_AS_LIST (value);
  if (list != NULL_TREE
      && (TREE_CODE (list) != TREE_LIST
	  || TREE_VALUE (list) != value))
    list = NULL_TREE;
  else if (IDENTIFIER_HAS_TYPE_VALUE (value)
	   && TREE_CODE (IDENTIFIER_TYPE_VALUE (value)) == RECORD_TYPE
	   && IDENTIFIER_TYPE_VALUE (value)
	      == TYPE_MAIN_VARIANT (IDENTIFIER_TYPE_VALUE (value)))
    {
      tree type = IDENTIFIER_TYPE_VALUE (value);

      if (TYPE_PTRMEMFUNC_P (type))
	list = NULL_TREE;
      else if (type == current_class_type)
	/* Don't mess up the constructor name.  */
	list = tree_cons (NULL_TREE, value, NULL_TREE);
      else
	{
	  register tree id;
	  /* This will return the correct thing for regular types,
	     nested types, and templates.  Yay! */
	  if (TYPE_NESTED_NAME (type))
	    id = TYPE_NESTED_NAME (type);
	  else
	    id = TYPE_IDENTIFIER (type);

	  if (CLASSTYPE_ID_AS_LIST (type) == NULL_TREE)
	    CLASSTYPE_ID_AS_LIST (type)
	      = perm_tree_cons (NULL_TREE, id, NULL_TREE);
	  list = CLASSTYPE_ID_AS_LIST (type);
	}
    }
  return list;
}

tree
get_decl_list (value)
     tree value;
{
  tree list = NULL_TREE;

  if (TREE_CODE (value) == IDENTIFIER_NODE)
    list = get_identifier_list (value);
  else if (TREE_CODE (value) == RECORD_TYPE
	   && TYPE_LANG_SPECIFIC (value))
    list = CLASSTYPE_AS_LIST (value);

  if (list != NULL_TREE)
    {
      my_friendly_assert (TREE_CHAIN (list) == NULL_TREE, 301);
      return list;
    }

  return build_decl_list (NULL_TREE, value);
}

/* Look in the type hash table for a type isomorphic to
   `build_tree_list (NULL_TREE, VALUE)'.
   If one is found, return it.  Otherwise return 0.  */

tree
list_hash_lookup_or_cons (value)
     tree value;
{
  register int hashcode = TYPE_HASH (value);
  register struct list_hash *h;
  struct obstack *ambient_obstack;
  tree list = NULL_TREE;

  if (TREE_CODE (value) == IDENTIFIER_NODE)
    list = get_identifier_list (value);
  else if (TREE_CODE (value) == TYPE_DECL
	   && TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE
	   && TYPE_LANG_SPECIFIC (TREE_TYPE (value)))
    list = CLASSTYPE_ID_AS_LIST (TREE_TYPE (value));
  else if (TREE_CODE (value) == RECORD_TYPE
	   && TYPE_LANG_SPECIFIC (value))
    list = CLASSTYPE_AS_LIST (value);

  if (list != NULL_TREE)
    {
      my_friendly_assert (TREE_CHAIN (list) == NULL_TREE, 302);
      return list;
    }

  if (debug_no_list_hash)
    return hash_tree_chain (value, NULL_TREE);

  for (h = list_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
    if (h->hashcode == hashcode
	&& TREE_VIA_VIRTUAL (h->list) == 0
	&& TREE_VIA_PUBLIC (h->list) == 0
	&& TREE_VIA_PROTECTED (h->list) == 0
	&& TREE_PURPOSE (h->list) == 0
	&& TREE_VALUE (h->list) == value)
      {
	my_friendly_assert (TREE_TYPE (h->list) == 0, 303);
	my_friendly_assert (TREE_CHAIN (h->list) == 0, 304);
	return h->list;
      }

  ambient_obstack = current_obstack;
  current_obstack = &class_obstack;
  list = build_tree_list (NULL_TREE, value);
  list_hash_add (hashcode, list);
  current_obstack = ambient_obstack;
  return list;
}

/* Build an association between TYPE and some parameters:

   OFFSET is the offset added to `this' to convert it to a pointer
   of type `TYPE *'

   BINFO is the base binfo to use, if we are deriving from one.  This
   is necessary, as we want specialized parent binfos from base
   classes, so that the VTABLE_NAMEs of bases are for the most derived
   type, instead of of the simple type.

   VTABLE is the virtual function table with which to initialize
   sub-objects of type TYPE.

   VIRTUALS are the virtual functions sitting in VTABLE.

   CHAIN are more associations we must retain.  */

tree
make_binfo (offset, binfo, vtable, virtuals, chain)
     tree offset, binfo;
     tree vtable, virtuals;
     tree chain;
{
  tree new_binfo = make_tree_vec (6);
  tree type;

  if (TREE_CODE (binfo) == TREE_VEC)
    type = BINFO_TYPE (binfo);
  else
    {
      type = binfo;
      binfo = TYPE_BINFO (binfo);
    }

  TREE_CHAIN (new_binfo) = chain;
  if (chain)
    TREE_USED (new_binfo) = TREE_USED (chain);

  TREE_TYPE (new_binfo) = TYPE_MAIN_VARIANT (type);
  BINFO_OFFSET (new_binfo) = offset;
  BINFO_VTABLE (new_binfo) = vtable;
  BINFO_VIRTUALS (new_binfo) = virtuals;
  BINFO_VPTR_FIELD (new_binfo) = NULL_TREE;

  if (binfo && BINFO_BASETYPES (binfo) != NULL_TREE)
    BINFO_BASETYPES (new_binfo) = copy_node (BINFO_BASETYPES (binfo));      
  return new_binfo;
}

/* Return the binfo value for ELEM in TYPE.  */

tree
binfo_value (elem, type)
     tree elem;
     tree type;
{
  if (get_base_distance (elem, type, 0, (tree *)0) == -2)
    compiler_error ("base class `%s' ambiguous in binfo_value",
		    TYPE_NAME_STRING (elem));
  if (elem == type)
    return TYPE_BINFO (type);
  if (TREE_CODE (elem) == RECORD_TYPE && TYPE_BINFO (elem) == type)
    return type;
  return get_binfo (elem, type, 0);
}

tree
reverse_path (path)
     tree path;
{
  register tree prev = 0, tmp, next;
  for (tmp = path; tmp; tmp = next)
    {
      next = BINFO_INHERITANCE_CHAIN (tmp);
      BINFO_INHERITANCE_CHAIN (tmp) = prev;
      prev = tmp;
    }
  return prev;
}

tree
virtual_member (elem, list)
     tree elem;
     tree list;
{
  tree t;
  tree rval, nval;

  for (t = list; t; t = TREE_CHAIN (t))
    if (elem == BINFO_TYPE (t))
      return t;
  rval = 0;
  for (t = list; t; t = TREE_CHAIN (t))
    {
      tree binfos = BINFO_BASETYPES (t);
      int i;

      if (binfos != NULL_TREE)
	for (i = TREE_VEC_LENGTH (binfos)-1; i >= 0; i--)
	  {
	    nval = binfo_value (elem, BINFO_TYPE (TREE_VEC_ELT (binfos, i)));
	    if (nval)
	      {
		if (rval && BINFO_OFFSET (nval) != BINFO_OFFSET (rval))
		  my_friendly_abort (104);
		rval = nval;
	      }
	  }
    }
  return rval;
}

void
debug_binfo (elem)
     tree elem;
{
  unsigned HOST_WIDE_INT n;
  tree virtuals;

  fprintf (stderr, "type \"%s\"; offset = %d\n",
	   TYPE_NAME_STRING (BINFO_TYPE (elem)),
	   TREE_INT_CST_LOW (BINFO_OFFSET (elem)));
  fprintf (stderr, "vtable type:\n");
  debug_tree (BINFO_TYPE (elem));
  if (BINFO_VTABLE (elem))
    fprintf (stderr, "vtable decl \"%s\"\n", IDENTIFIER_POINTER (DECL_NAME (BINFO_VTABLE (elem))));
  else
    fprintf (stderr, "no vtable decl yet\n");
  fprintf (stderr, "virtuals:\n");
  virtuals = BINFO_VIRTUALS (elem);

  n = skip_rtti_stuff (&virtuals);

  while (virtuals)
    {
      tree fndecl = TREE_OPERAND (FNADDR_FROM_VTABLE_ENTRY (TREE_VALUE (virtuals)), 0);
      fprintf (stderr, "%s [%d =? %d]\n",
	       IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl)),
	       n, TREE_INT_CST_LOW (DECL_VINDEX (fndecl)));
      ++n;
      virtuals = TREE_CHAIN (virtuals);
    }
}

/* Return the length of a chain of nodes chained through DECL_CHAIN.
   We expect a null pointer to mark the end of the chain.
   This is the Lisp primitive `length'.  */

int
decl_list_length (t)
     tree t;
{
  register tree tail;
  register int len = 0;

  my_friendly_assert (TREE_CODE (t) == FUNCTION_DECL
		      || TREE_CODE (t) == TEMPLATE_DECL, 300);
  for (tail = t; tail; tail = DECL_CHAIN (tail))
    len++;

  return len;
}

int
count_functions (t)
     tree t;
{
  if (TREE_CODE (t) == FUNCTION_DECL)
    return 1;
  else if (TREE_CODE (t) == TREE_LIST)
    return decl_list_length (TREE_VALUE (t));

  my_friendly_abort (359);
  return 0;
}

/* Like value_member, but for DECL_CHAINs.  */
tree
decl_value_member (elem, list)
     tree elem, list;
{
  while (list)
    {
      if (elem == list)
	return list;
      list = DECL_CHAIN (list);
    }
  return NULL_TREE;
}

int
is_overloaded_fn (x)
     tree x;
{
  if (TREE_CODE (x) == FUNCTION_DECL)
    return 1;

  if (TREE_CODE (x) == TREE_LIST
      && (TREE_CODE (TREE_VALUE (x)) == FUNCTION_DECL
	  || TREE_CODE (TREE_VALUE (x)) == TEMPLATE_DECL))
    return 1;

  return 0;
}

int
really_overloaded_fn (x)
     tree x;
{     
  if (TREE_CODE (x) == TREE_LIST
      && (TREE_CODE (TREE_VALUE (x)) == FUNCTION_DECL
	  || TREE_CODE (TREE_VALUE (x)) == TEMPLATE_DECL))
    return 1;

  return 0;
}

tree
get_first_fn (from)
     tree from;
{
  if (TREE_CODE (from) == FUNCTION_DECL)
    return from;

  my_friendly_assert (TREE_CODE (from) == TREE_LIST, 9);
  
  return TREE_VALUE (from);
}

tree
fnaddr_from_vtable_entry (entry)
     tree entry;
{
  if (flag_vtable_thunks)
    {
      tree func = entry;
      if (TREE_CODE (func) == ADDR_EXPR)
	func = TREE_OPERAND (func, 0);
      if (TREE_CODE (func) == THUNK_DECL)
	return DECL_INITIAL (func);
      else
	return entry;
    }
  else
    return TREE_VALUE (TREE_CHAIN (TREE_CHAIN (CONSTRUCTOR_ELTS (entry))));
}

void
set_fnaddr_from_vtable_entry (entry, value)
     tree entry, value;
{
  if (flag_vtable_thunks)
    abort ();
  else
  TREE_VALUE (TREE_CHAIN (TREE_CHAIN (CONSTRUCTOR_ELTS (entry)))) = value;
}

tree
function_arg_chain (t)
     tree t;
{
  return TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (t)));
}

int
promotes_to_aggr_type (t, code)
     tree t;
     enum tree_code code;
{
  if (TREE_CODE (t) == code)
    t = TREE_TYPE (t);
  return IS_AGGR_TYPE (t);
}

int
is_aggr_type_2 (t1, t2)
     tree t1, t2;
{
  if (TREE_CODE (t1) != TREE_CODE (t2))
    return 0;
  return IS_AGGR_TYPE (t1) && IS_AGGR_TYPE (t2);
}

/* Give message using types TYPE1 and TYPE2 as arguments.
   PFN is the function which will print the message;
   S is the format string for PFN to use.  */
void
message_2_types (pfn, s, type1, type2)
     void (*pfn) ();
     char *s;
     tree type1, type2;
{
  tree name1 = TYPE_NAME (type1);