gcc/cp/typeck.c

/* Build expressions with type checking for C++ compiler.
   Copyright (C) 1987, 88, 89, 92-97, 1998 Free Software Foundation, Inc.
   Hacked by Michael Tiemann (tiemann@cygnus.com)

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */


/* This file is part of the C++ front end.
   It contains routines to build C++ expressions given their operands,
   including computing the types of the result, C and C++ specific error
   checks, and some optimization.

   There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
   and to process initializations in declarations (since they work
   like a strange sort of assignment).  */

#include "config.h"
#include "system.h"
#include "tree.h"
#include "rtl.h"
#include "cp-tree.h"
#include "flags.h"
#include "output.h"
#include "expr.h"
#include "toplev.h"

extern void compiler_error ();

static tree convert_for_assignment PROTO((tree, tree, char*, tree,
					  int));
static tree pointer_int_sum PROTO((enum tree_code, tree, tree));
static tree rationalize_conditional_expr PROTO((enum tree_code, tree));
static int comp_target_parms PROTO((tree, tree, int));
static int comp_ptr_ttypes_real PROTO((tree, tree, int));
static int comp_ptr_ttypes_const PROTO((tree, tree));
static int comp_ptr_ttypes_reinterpret PROTO((tree, tree));
static int comp_array_types PROTO((int (*) (tree, tree, int), tree,
				   tree, int));
static tree build_ptrmemfunc1 PROTO((tree, tree, tree, tree, tree));
static tree common_base_type PROTO((tree, tree));
#if 0
static tree convert_sequence PROTO((tree, tree));
#endif
static tree lookup_anon_field PROTO((tree, tree));
static tree pointer_diff PROTO((tree, tree, tree));
static tree qualify_type PROTO((tree, tree));
static tree get_delta_difference PROTO((tree, tree, int));

/* Return the target type of TYPE, which meas return T for:
   T*, T&, T[], T (...), and otherwise, just T.  */

tree
target_type (type)
     tree type;
{
  if (TREE_CODE (type) == REFERENCE_TYPE)
    type = TREE_TYPE (type);
  while (TREE_CODE (type) == POINTER_TYPE
	 || TREE_CODE (type) == ARRAY_TYPE
	 || TREE_CODE (type) == FUNCTION_TYPE
	 || TREE_CODE (type) == METHOD_TYPE
	 || TREE_CODE (type) == OFFSET_TYPE)
    type = TREE_TYPE (type);
  return type;
}

/* Do `exp = require_complete_type (exp);' to make sure exp
   does not have an incomplete type.  (That includes void types.)  */

tree
require_complete_type (value)
     tree value;
{
  tree type;

  if (processing_template_decl)
    return value;

  if (TREE_CODE (value) == OVERLOAD)
    type = unknown_type_node;
  else
    type = TREE_TYPE (value);

  /* First, detect a valid value with a complete type.  */
  if (TYPE_SIZE (type) != 0
      && type != void_type_node
      && ! (TYPE_LANG_SPECIFIC (type)
	    && (IS_SIGNATURE_POINTER (type) || IS_SIGNATURE_REFERENCE (type))
	    && TYPE_SIZE (SIGNATURE_TYPE (type)) == 0))
    return value;

  /* If we see X::Y, we build an OFFSET_TYPE which has
     not been laid out.  Try to avoid an error by interpreting
     it as this->X::Y, if reasonable.  */
  if (TREE_CODE (value) == OFFSET_REF
      && current_class_ref != 0
      && TREE_OPERAND (value, 0) == current_class_ref)
    {
      tree base, member = TREE_OPERAND (value, 1);
      tree basetype = TYPE_OFFSET_BASETYPE (type);
      my_friendly_assert (TREE_CODE (member) == FIELD_DECL, 305);
      base = convert_pointer_to (basetype, current_class_ptr);
      value = build (COMPONENT_REF, TREE_TYPE (member),
		     build_indirect_ref (base, NULL_PTR), member);
      return require_complete_type (value);
    }

  if (TYPE_SIZE (complete_type (type)))
    return value;
  else
    {
      incomplete_type_error (value, type);
      return error_mark_node;
    }
}

/* Try to complete TYPE, if it is incomplete.  For example, if TYPE is
   a template instantiation, do the instantiation.  Returns TYPE,
   whether or not it could be completed, unless something goes
   horribly wrong, in which case the error_mark_node is returned.  */

tree
complete_type (type)
     tree type;
{
  if (type == NULL_TREE)
    /* Rather than crash, we return something sure to cause an error
       at some point.  */
    return error_mark_node;

  if (type == error_mark_node || TYPE_SIZE (type) != NULL_TREE)
    ;
  else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
    {
      tree t = complete_type (TREE_TYPE (type));
      if (TYPE_SIZE (t) != NULL_TREE && ! processing_template_decl)
	layout_type (type);
      TYPE_NEEDS_CONSTRUCTING (type)
	= TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
      TYPE_NEEDS_DESTRUCTOR (type)
	= TYPE_NEEDS_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
    }
  else if (IS_AGGR_TYPE (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
    instantiate_class_template (TYPE_MAIN_VARIANT (type));

  return type;
}

/* Like complete_type, but issue an error if the TYPE cannot be
   completed.  Returns NULL_TREE if the type cannot be made 
   complete.  */

tree
complete_type_or_else (type)
     tree type;
{
  type = complete_type (type);
  if (type != error_mark_node && !TYPE_SIZE (type))
    {
      incomplete_type_error (NULL_TREE, type);
      return NULL_TREE;
    }
  else
    return type;
}

/* Return truthvalue of whether type of EXP is instantiated.  */

int
type_unknown_p (exp)
     tree exp;
{
  return (TREE_CODE (exp) == OVERLOAD
          || TREE_CODE (exp) == TREE_LIST
	  || TREE_TYPE (exp) == unknown_type_node
	  || (TREE_CODE (TREE_TYPE (exp)) == OFFSET_TYPE
	      && TREE_TYPE (TREE_TYPE (exp)) == unknown_type_node));
}

/* Return truthvalue of whether T is function (or pfn) type.  */

int
fntype_p (t)
     tree t;
{
  return (TREE_CODE (t) == FUNCTION_TYPE || TREE_CODE (t) == METHOD_TYPE
	  || (TREE_CODE (t) == POINTER_TYPE
	      && (TREE_CODE (TREE_TYPE (t)) == FUNCTION_TYPE
		  || TREE_CODE (TREE_TYPE (t)) == METHOD_TYPE)));
}

/* Do `exp = require_instantiated_type (type, exp);' to make sure EXP
   does not have an uninstantiated type.
   TYPE is type to instantiate with, if uninstantiated.  */

tree
require_instantiated_type (type, exp, errval)
     tree type, exp, errval;
{
  if (TREE_TYPE (exp) == NULL_TREE)
    {
      error ("argument list may not have an initializer list");
      return errval;
    }

  if (TREE_CODE (exp) == OVERLOAD
      || TREE_TYPE (exp) == unknown_type_node
      || (TREE_CODE (TREE_TYPE (exp)) == OFFSET_TYPE
	  && TREE_TYPE (TREE_TYPE (exp)) == unknown_type_node))
    {
      exp = instantiate_type (type, exp, 1);
      if (TREE_TYPE (exp) == error_mark_node)
	return errval;
    }
  return exp;
}

/* Return a variant of TYPE which has all the type qualifiers of LIKE
   as well as those of TYPE.  */

static tree
qualify_type (type, like)
     tree type, like;
{
  int constflag = TYPE_READONLY (type) || TYPE_READONLY (like);
  int volflag = TYPE_VOLATILE (type) || TYPE_VOLATILE (like);
  /* @@ Must do member pointers here.  */
  return cp_build_type_variant (type, constflag, volflag);
}

/* Return the common type of two parameter lists.
   We assume that comptypes has already been done and returned 1;
   if that isn't so, this may crash.

   As an optimization, free the space we allocate if the parameter
   lists are already common.  */

tree
commonparms (p1, p2)
     tree p1, p2;
{
  tree oldargs = p1, newargs, n;
  int i, len;
  int any_change = 0;
  char *first_obj = (char *) oballoc (0);

  len = list_length (p1);
  newargs = tree_last (p1);

  if (newargs == void_list_node)
    i = 1;
  else
    {
      i = 0;
      newargs = 0;
    }

  for (; i < len; i++)
    newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);

  n = newargs;

  for (i = 0; p1;
       p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
    {
      if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
	{
	  TREE_PURPOSE (n) = TREE_PURPOSE (p1);
	  any_change = 1;
	}
      else if (! TREE_PURPOSE (p1))
	{
	  if (TREE_PURPOSE (p2))
	    {
	      TREE_PURPOSE (n) = TREE_PURPOSE (p2);
	      any_change = 1;
	    }
	}
      else
	{
	  if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
	    any_change = 1;
	  TREE_PURPOSE (n) = TREE_PURPOSE (p2);
	}
      if (TREE_VALUE (p1) != TREE_VALUE (p2))
	{
	  any_change = 1;
	  TREE_VALUE (n) = common_type (TREE_VALUE (p1), TREE_VALUE (p2));
	}
      else
	TREE_VALUE (n) = TREE_VALUE (p1);
    }
  if (! any_change)
    {
      obfree (first_obj);
      return oldargs;
    }

  return newargs;
}

/* Given a type, perhaps copied for a typedef,
   find the "original" version of it.  */
tree
original_type (t)
     tree t;
{
  while (TYPE_NAME (t) != NULL_TREE)
    {
      tree x = TYPE_NAME (t);
      if (TREE_CODE (x) != TYPE_DECL)
	break;
      x = DECL_ORIGINAL_TYPE (x);
      if (x == NULL_TREE)
	break;
      t = x;
    }
  return t;
}

/* Return the common type of two types.
   We assume that comptypes has already been done and returned 1;
   if that isn't so, this may crash.

   This is the type for the result of most arithmetic operations
   if the operands have the given two types.

   We do not deal with enumeral types here because they have already been
   converted to integer types.  */

tree
common_type (t1, t2)
     tree t1, t2;
{
  register enum tree_code code1;
  register enum tree_code code2;
  tree attributes;

  /* Save time if the two types are the same.  */
  if (t1 == t2)
    return t1;
  t1 = original_type (t1);
  t2 = original_type (t2);
  if (t1 == t2)
    return t1;

  /* If one type is nonsense, use the other.  */
  if (t1 == error_mark_node)
    return t2;
  if (t2 == error_mark_node)
    return t1;

  /* Merge the attributes.  */
  attributes = merge_machine_type_attributes (t1, t2);

  { register tree a1, a2;
    a1 = TYPE_ATTRIBUTES (t1);
    a2 = TYPE_ATTRIBUTES (t2);

    /* Either one unset?  Take the set one.  */

    if (!(attributes = a1))
       attributes = a2;

    /* One that completely contains the other?  Take it.  */

    else if (a2 && !attribute_list_contained (a1, a2))
      {
	if (attribute_list_contained (a2, a1))
	  attributes = a2;
	else
	  {
	    /* Pick the longest list, and hang on the other list.  */
	    /* ??? For the moment we punt on the issue of attrs with args.  */
	
	    if (list_length (a1) < list_length (a2))
	      attributes = a2, a2 = a1;

	    for (; a2; a2 = TREE_CHAIN (a2))
	      if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
				    attributes) == NULL_TREE)
		{
		  a1 = copy_node (a2);
		  TREE_CHAIN (a1) = attributes;
		  attributes = a1;
		}
	  }
      }
  }

  /* Treat an enum type as the unsigned integer type of the same width.  */

  if (TREE_CODE (t1) == ENUMERAL_TYPE)
    t1 = type_for_size (TYPE_PRECISION (t1), 1);
  if (TREE_CODE (t2) == ENUMERAL_TYPE)
    t2 = type_for_size (TYPE_PRECISION (t2), 1);

  if (TYPE_PTRMEMFUNC_P (t1))
    t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
  if (TYPE_PTRMEMFUNC_P (t2))
    t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);

  code1 = TREE_CODE (t1);
  code2 = TREE_CODE (t2);

  /* If one type is complex, form the common type of the non-complex
     components, then make that complex.  Use T1 or T2 if it is the
     required type.  */
  if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
    {
      tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
      tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
      tree subtype = common_type (subtype1, subtype2);

      if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
	return build_type_attribute_variant (t1, attributes);
      else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
	return build_type_attribute_variant (t2, attributes);
      else
	return build_type_attribute_variant (build_complex_type (subtype),
					     attributes);
    }

  switch (code1)
    {
    case INTEGER_TYPE:
    case REAL_TYPE:
      /* If only one is real, use it as the result.  */

      if (code1 == REAL_TYPE && code2 != REAL_TYPE)
	return build_type_attribute_variant (t1, attributes);

      if (code2 == REAL_TYPE && code1 != REAL_TYPE)
        return build_type_attribute_variant (t2, attributes);

      /* Both real or both integers; use the one with greater precision.  */

      if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
	return build_type_attribute_variant (t1, attributes);
      else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
        return build_type_attribute_variant (t2, attributes);

      /* Same precision.  Prefer longs to ints even when same size.  */
  
      if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
	  || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
        return build_type_attribute_variant (long_unsigned_type_node,
					     attributes);

      if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
	  || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
	{
	  /* But preserve unsignedness from the other type,
	     since long cannot hold all the values of an unsigned int.  */
	  if (TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
	     t1 = long_unsigned_type_node;
	  else
	     t1 = long_integer_type_node;
	  return build_type_attribute_variant (t1, attributes);
	}

      if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
	  || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
	return build_type_attribute_variant (long_double_type_node,
					     attributes);	  

      /* Otherwise prefer the unsigned one.  */

      if (TREE_UNSIGNED (t1))
	return build_type_attribute_variant (t1, attributes);
      else
	return build_type_attribute_variant (t2, attributes);

    case POINTER_TYPE:
    case REFERENCE_TYPE:
      /* For two pointers, do this recursively on the target type,
	 and combine the qualifiers of the two types' targets.  */
      /* This code was turned off; I don't know why.
 	 But ANSI C++ specifies doing this with the qualifiers.
 	 So I turned it on again.  */
      {
	tree tt1 = TYPE_MAIN_VARIANT (TREE_TYPE (t1));
	tree tt2 = TYPE_MAIN_VARIANT (TREE_TYPE (t2));
	int constp
	  = TYPE_READONLY (TREE_TYPE (t1)) || TYPE_READONLY (TREE_TYPE (t2));
	int volatilep
	  = TYPE_VOLATILE (TREE_TYPE (t1)) || TYPE_VOLATILE (TREE_TYPE (t2));
	tree target;

	if (tt1 == tt2)
	  target = tt1;
	else if (tt1 == void_type_node || tt2 == void_type_node)
	  target = void_type_node;
	else if (tt1 == unknown_type_node)
	  target = tt2;
	else if (tt2 == unknown_type_node)
	  target = tt1;
	else
	  target = common_type (tt1, tt2);

	target = cp_build_type_variant (target, constp, volatilep);
	if (code1 == POINTER_TYPE)
	  t1 = build_pointer_type (target);
	else
	  t1 = build_reference_type (target);
	t1 = build_type_attribute_variant (t1, attributes);

	if (TREE_CODE (target) == METHOD_TYPE)
	  t1 = build_ptrmemfunc_type (t1);

	return t1;
      }

    case ARRAY_TYPE:
      {
	tree elt = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
	/* Save space: see if the result is identical to one of the args.  */
	if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
	  return build_type_attribute_variant (t1, attributes);
	if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
	  return build_type_attribute_variant (t2, attributes);
	/* Merge the element types, and have a size if either arg has one.  */
	t1 = build_cplus_array_type
	  (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
	return build_type_attribute_variant (t1, attributes);
      }

    case FUNCTION_TYPE:
      /* Function types: prefer the one that specified arg types.
	 If both do, merge the arg types.  Also merge the return types.  */
      {
	tree valtype = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
	tree p1 = TYPE_ARG_TYPES (t1);
	tree p2 = TYPE_ARG_TYPES (t2);
	tree rval, raises;

	/* Save space: see if the result is identical to one of the args.  */
	if (valtype == TREE_TYPE (t1) && ! p2)
	  return build_type_attribute_variant (t1, attributes);
	if (valtype == TREE_TYPE (t2) && ! p1)
	  return build_type_attribute_variant (t2, attributes);

	/* Simple way if one arg fails to specify argument types.  */
	if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
	  {
	    rval = build_function_type (valtype, p2);
	    if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
	      rval = build_exception_variant (rval, raises);
	    return build_type_attribute_variant (rval, attributes);
	  }
	raises = TYPE_RAISES_EXCEPTIONS (t1);
	if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
	  {
	    rval = build_function_type (valtype, p1);
	    if (raises)
	      rval = build_exception_variant (rval, raises);
	    return build_type_attribute_variant (rval, attributes);
	  }

	rval = build_function_type (valtype, commonparms (p1, p2));
	rval = build_exception_variant (rval, raises);
	return build_type_attribute_variant (rval, attributes);
      }

    case RECORD_TYPE:
    case UNION_TYPE:
      t1 = TYPE_MAIN_VARIANT (t1);
      t2 = TYPE_MAIN_VARIANT (t2);

      if (DERIVED_FROM_P (t1, t2) && binfo_or_else (t1, t2))
	return build_type_attribute_variant (t1, attributes);
      else if (binfo_or_else (t2, t1))
	return build_type_attribute_variant (t2, attributes);
      else
	compiler_error ("common_type called with uncommon aggregate types");

    case METHOD_TYPE:
      if (TREE_CODE (TREE_TYPE (t1)) == TREE_CODE (TREE_TYPE (t2)))
	{
	  /* Get this value the long way, since TYPE_METHOD_BASETYPE
	     is just the main variant of this.  */
	  tree basetype;
	  tree raises, t3;

	  tree b1 = TYPE_OFFSET_BASETYPE (t1);
	  tree b2 = TYPE_OFFSET_BASETYPE (t2);

	  if (comptypes (b1, b2, 1)
	      || (DERIVED_FROM_P (b1, b2) && binfo_or_else (b1, b2)))
	    basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
	  else
	    {
	      if (binfo_or_else (b2, b1) == NULL_TREE)
		compiler_error ("common_type called with uncommon method types");
	      basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t1)));
	    }

	  raises = TYPE_RAISES_EXCEPTIONS (t1);

	  /* If this was a member function type, get back to the
	     original type of type member function (i.e., without
	     the class instance variable up front.  */
	  t1 = build_function_type (TREE_TYPE (t1),
				    TREE_CHAIN (TYPE_ARG_TYPES (t1)));
	  t2 = build_function_type (TREE_TYPE (t2),
				    TREE_CHAIN (TYPE_ARG_TYPES (t2)));
	  t3 = common_type (t1, t2);
	  t3 = build_cplus_method_type (basetype, TREE_TYPE (t3),
					TYPE_ARG_TYPES (t3));
	  t1 = build_exception_variant (t3, raises);
	}
      else
        compiler_error ("common_type called with uncommon method types");

      return build_type_attribute_variant (t1, attributes);

    case OFFSET_TYPE:
      if (TREE_TYPE (t1) == TREE_TYPE (t2))
	{
	  tree b1 = TYPE_OFFSET_BASETYPE (t1);
	  tree b2 = TYPE_OFFSET_BASETYPE (t2);

	  if (comptypes (b1, b2, 1)
	      || (DERIVED_FROM_P (b1, b2) && binfo_or_else (b1, b2)))
	    return build_type_attribute_variant (t2, attributes);
	  else if (binfo_or_else (b2, b1))
	    return build_type_attribute_variant (t1, attributes);
	}
      compiler_error ("common_type called with uncommon member types");

    default:
      return build_type_attribute_variant (t1, attributes);
    }
}

/* Return 1 if TYPE1 and TYPE2 raise the same exceptions.  */

int
compexcepttypes (t1, t2)
     tree t1, t2;
{
  return TYPE_RAISES_EXCEPTIONS (t1) == TYPE_RAISES_EXCEPTIONS (t2);
}

static int
comp_array_types (cmp, t1, t2, strict)
     register int (*cmp) PROTO((tree, tree, int));
     tree t1, t2;
     int strict;
{
  tree d1 = TYPE_DOMAIN (t1);
  tree d2 = TYPE_DOMAIN (t2);

  /* Target types must match incl. qualifiers.  */
  if (!(TREE_TYPE (t1) == TREE_TYPE (t2)
	|| (*cmp) (TREE_TYPE (t1), TREE_TYPE (t2), strict)))
    return 0;

  /* Sizes must match unless one is missing or variable.  */
  if (d1 == 0 || d2 == 0 || d1 == d2
      || TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
      || TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
      || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST
      || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST)
    return 1;

  return ((TREE_INT_CST_LOW (TYPE_MIN_VALUE (d1))
	   == TREE_INT_CST_LOW (TYPE_MIN_VALUE (d2)))
	  && (TREE_INT_CST_HIGH (TYPE_MIN_VALUE (d1))
	      == TREE_INT_CST_HIGH (TYPE_MIN_VALUE (d2)))
	  && (TREE_INT_CST_LOW (TYPE_MAX_VALUE (d1))
	      == TREE_INT_CST_LOW (TYPE_MAX_VALUE (d2)))
	  && (TREE_INT_CST_HIGH (TYPE_MAX_VALUE (d1))
	      == TREE_INT_CST_HIGH (TYPE_MAX_VALUE (d2))));
}

/* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
   or various other operations.  This is what ANSI C++ speaks of as
   "being the same".

   For C++: argument STRICT says we should be strict about this
   comparison:

	2 : strict, except that if one type is a reference and
	    the other is not, compare the target type of the
	    reference to the type that's not a reference (ARM, p308).
	    This is used for checking for invalid overloading.
	1 : strict (compared according to ANSI C)
	    This is used for checking whether two function decls match.
	0 : <= (compared according to C++)
	-1: <= or >= (relaxed)

   Otherwise, pointers involving base classes and derived classes can
   be mixed as valid: i.e. a pointer to a derived class may be converted
   to a pointer to one of its base classes, as per C++. A pointer to
   a derived class may be passed as a parameter to a function expecting a
   pointer to a base classes. These allowances do not commute. In this
   case, TYPE1 is assumed to be the base class, and TYPE2 is assumed to
   be the derived class.  */

int
comptypes (type1, type2, strict)
     tree type1, type2;
     int strict;
{
  register tree t1 = type1;
  register tree t2 = type2;
  int attrval, val;

  /* Suppress errors caused by previously reported errors */

  if (t1 == t2)
    return 1;

  /* This should never happen.  */
  my_friendly_assert (t1 != error_mark_node, 307);

  if (t2 == error_mark_node)
    return 0;

  if (strict < 0)
    {
      /* Treat an enum type as the unsigned integer type of the same width.  */

      if (TREE_CODE (t1) == ENUMERAL_TYPE)
	t1 = type_for_size (TYPE_PRECISION (t1), 1);
      if (TREE_CODE (t2) == ENUMERAL_TYPE)
	t2 = type_for_size (TYPE_PRECISION (t2), 1);

      if (t1 == t2)
	return 1;
    }

  if (TYPE_PTRMEMFUNC_P (t1))
    t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
  if (TYPE_PTRMEMFUNC_P (t2))
    t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);

  /* Different classes of types can't be compatible.  */

  if (TREE_CODE (t1) != TREE_CODE (t2))
    {
      if (strict == 2
	  && ((TREE_CODE (t1) == REFERENCE_TYPE)
	      ^ (TREE_CODE (t2) == REFERENCE_TYPE)))
	{
	  if (TREE_CODE (t1) == REFERENCE_TYPE)
	    return comptypes (TREE_TYPE (t1), t2, 1);
	  return comptypes (t1, TREE_TYPE (t2), 1);
	}

      return 0;
    }
  if (strict > 1)
    strict = 1;

  /* Qualifiers must match.  */

  if (TYPE_READONLY (t1) != TYPE_READONLY (t2))
    return 0;
  if (TYPE_VOLATILE (t1) != TYPE_VOLATILE (t2))
    return 0;
  if (strict > 0 && TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
    return 0;

  /* Allow for two different type nodes which have essentially the same
     definition.  Note that we already checked for equality of the type
     qualifiers (just above).  */

  if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
    return 1;

  /* ??? COMP_TYPE_ATTRIBUTES is currently useless for variables as each
     attribute is its own main variant (`val' will remain 0).  */
#ifndef COMP_TYPE_ATTRIBUTES
#define COMP_TYPE_ATTRIBUTES(t1,t2)	1
#endif

  /* 1 if no need for warning yet, 2 if warning cause has been seen.  */
  if (! (attrval = COMP_TYPE_ATTRIBUTES (t1, t2)))
     return 0;

  /* 1 if no need for warning yet, 2 if warning cause has been seen.  */
  val = 0;

  switch (TREE_CODE (t1))
    {
    case TEMPLATE_TEMPLATE_PARM:
      if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
	  || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
	return 0;
      if (! comp_template_parms (DECL_TEMPLATE_PARMS (TYPE_NAME (t1)),
				 DECL_TEMPLATE_PARMS (TYPE_NAME (t2))))
	return 0;
      if (! CLASSTYPE_TEMPLATE_INFO (t1) && ! CLASSTYPE_TEMPLATE_INFO (t2))
	return 1;
      /* Don't check inheritance.  */
      strict = 1;
      /* fall through */

    case RECORD_TYPE:
    case UNION_TYPE:
      if (CLASSTYPE_TEMPLATE_INFO (t1) && CLASSTYPE_TEMPLATE_INFO (t2)
	  && (CLASSTYPE_TI_TEMPLATE (t1) == CLASSTYPE_TI_TEMPLATE (t2)
	      || TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM))
	return comp_template_args (CLASSTYPE_TI_ARGS (t1),
				   CLASSTYPE_TI_ARGS (t2));
      if (strict <= 0)
	goto look_hard;
      return 0;

    case OFFSET_TYPE:
      val = (comptypes (build_pointer_type (TYPE_OFFSET_BASETYPE (t1)),
			build_pointer_type (TYPE_OFFSET_BASETYPE (t2)), strict)
	     && comptypes (TREE_TYPE (t1), TREE_TYPE (t2), strict));
      break;

    case METHOD_TYPE:
      if (! compexcepttypes (t1, t2))
	return 0;

      /* This case is anti-symmetrical!
	 One can pass a base member (or member function)
	 to something expecting a derived member (or member function),
	 but not vice-versa!  */

      val = (comptypes (TREE_TYPE (t1), TREE_TYPE (t2), strict)
	     && compparms (TYPE_ARG_TYPES (t1),
			   TYPE_ARG_TYPES (t2), strict));
      break;

    case POINTER_TYPE:
    case REFERENCE_TYPE:
      t1 = TREE_TYPE (t1);
      t2 = TREE_TYPE (t2);
      if (t1 == t2)
	{
	  val = 1;
	  break;
	}
      if (strict <= 0)
	{
	  if (TREE_CODE (t1) == RECORD_TYPE && TREE_CODE (t2) == RECORD_TYPE)
	    {
	      int rval;
	    look_hard:
	      rval = t1 == t2 || DERIVED_FROM_P (t1, t2);

	      if (rval)
		{
		  val = 1;
		  break;
		}
	      if (strict < 0)
		{
		  val = DERIVED_FROM_P (t2, t1);
		  break;
		}
	    }
	  return 0;
	}
      else
	val = comptypes (t1, t2, strict);
      break;

    case FUNCTION_TYPE:
      if (! compexcepttypes (t1, t2))
	return 0;

      val = ((TREE_TYPE (t1) == TREE_TYPE (t2)
	      || comptypes (TREE_TYPE (t1), TREE_TYPE (t2), strict))
	     && compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2), strict));
      break;

    case ARRAY_TYPE:
      /* Target types must match incl. qualifiers.  */
      val = comp_array_types (comptypes, t1, t2, strict);
      break;

    case TEMPLATE_TYPE_PARM:
      return TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
	&& TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2);

    case TYPENAME_TYPE:
      if (TYPE_IDENTIFIER (t1) != TYPE_IDENTIFIER (t2))
	return 0;
      return comptypes (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2), 1);

    default:
      break;
    }
  return attrval == 2 && val == 1 ? 2 : val;
}

/* Return 1 or -1 if TTL and TTR are pointers to types that are equivalent,
   ignoring their qualifiers, 0 if not. Return 1 means that TTR can be
   converted to TTL. Return -1 means that TTL can be converted to TTR but
   not vice versa.

   NPTRS is the number of pointers we can strip off and keep cool.
   This is used to permit (for aggr A, aggr B) A, B* to convert to A*,
   but to not permit B** to convert to A**.

   This should go away.  Callers should use can_convert or something
   similar instead.  (jason 17 Apr 1997)  */

int
comp_target_types (ttl, ttr, nptrs)
     tree ttl, ttr;
     int nptrs;
{
  ttl = TYPE_MAIN_VARIANT (ttl);
  ttr = TYPE_MAIN_VARIANT (ttr);
  if (ttl == ttr)
    return 1;

  if (TREE_CODE (ttr) != TREE_CODE (ttl))
    return 0;

  if (TREE_CODE (ttr) == POINTER_TYPE
      || (TREE_CODE (ttr) == REFERENCE_TYPE))
    {
      int is_ptr = TREE_CODE (ttr) == POINTER_TYPE;

      ttl = TREE_TYPE (ttl);
      ttr = TREE_TYPE (ttr);

      if (nptrs > 0 && is_ptr)
	{
	  if (TREE_CODE (ttl) == UNKNOWN_TYPE
	      || TREE_CODE (ttr) == UNKNOWN_TYPE)
	    return 1;
	  else if (TREE_CODE (ttl) == VOID_TYPE
		   && TREE_CODE (ttr) != FUNCTION_TYPE
		   && TREE_CODE (ttr) != METHOD_TYPE
		   && TREE_CODE (ttr) != OFFSET_TYPE)
	    return 1;
	  else if (TREE_CODE (ttr) == VOID_TYPE
		   && TREE_CODE (ttl) != FUNCTION_TYPE
		   && TREE_CODE (ttl) != METHOD_TYPE
		   && TREE_CODE (ttl) != OFFSET_TYPE)
	    return -1;
	  else if (TREE_CODE (ttl) == POINTER_TYPE
		   || TREE_CODE (ttl) == ARRAY_TYPE)
	    {
	      if (comp_ptr_ttypes (ttl, ttr))
		return 1;
	      else if (comp_ptr_ttypes (ttr, ttl))
		return -1;
	      return 0;
	    }
	}

      /* Const and volatile mean something different for function types,
	 so the usual checks are not appropriate.  */
      if (TREE_CODE (ttl) == FUNCTION_TYPE || TREE_CODE (ttl) == METHOD_TYPE)
	return comp_target_types (ttl, ttr, nptrs - 1);

      /* Make sure that the cv-quals change only in the same direction as
	 the target type.  */
      {
	int t;
	int c = TYPE_READONLY (ttl) - TYPE_READONLY (ttr);
	int v = TYPE_VOLATILE (ttl) - TYPE_VOLATILE (ttr);

	if ((c > 0 && v < 0) || (c < 0 && v > 0))
	  return 0;

	if (TYPE_MAIN_VARIANT (ttl) == TYPE_MAIN_VARIANT (ttr))
	  return (c + v < 0) ? -1 : 1;

	t = comp_target_types (ttl, ttr, nptrs - 1);
	if ((t == 1 && c + v >= 0) || (t == -1 && c + v <= 0))
	  return t;

	return 0;
      }
    }

  if (TREE_CODE (ttr) == ARRAY_TYPE)
    return comp_array_types (comp_target_types, ttl, ttr, 0);
  else if (TREE_CODE (ttr) == FUNCTION_TYPE || TREE_CODE (ttr) == METHOD_TYPE)
    {
      tree argsl, argsr;
      int saw_contra = 0;

      if (pedantic)
	{
	  if (comptypes (TREE_TYPE (ttl), TREE_TYPE (ttr), 1) == 0)
	    return 0;
	}
      else
	{
	  switch (comp_target_types (TREE_TYPE (ttl), TREE_TYPE (ttr), -1))
	    {
	    case 0:
	      return 0;
	    case -1:
	      saw_contra = 1;
	    }
	}

      argsl = TYPE_ARG_TYPES (ttl);
      argsr = TYPE_ARG_TYPES (ttr);

      /* Compare 'this' here, not in comp_target_parms.  */
      if (TREE_CODE (ttr) == METHOD_TYPE)
	{
	  tree tl = TYPE_METHOD_BASETYPE (ttl);
	  tree tr = TYPE_METHOD_BASETYPE (ttr);

	  if (comptypes (tr, tl, 0) == 0)
	    {
	      if (comptypes (tl, tr, 0))
		saw_contra = 1;
	      else
		return 0;
	    }

	  argsl = TREE_CHAIN (argsl);
	  argsr = TREE_CHAIN (argsr);
	}

	switch (comp_target_parms (argsl, argsr, 1))
	  {
	  case 0:
	    return 0;
	  case -1:
	    saw_contra = 1;
	  }

	return saw_contra ? -1 : 1;
    }
  /* for C++ */
  else if (TREE_CODE (ttr) == OFFSET_TYPE)
    {
      /* Contravariance: we can assign a pointer to base member to a pointer
	 to derived member.  Note difference from simple pointer case, where
	 we can pass a pointer to derived to a pointer to base.  */
      if (comptypes (TYPE_OFFSET_BASETYPE (ttr),
		     TYPE_OFFSET_BASETYPE (ttl), 0))
	return comp_target_types (TREE_TYPE (ttl), TREE_TYPE (ttr), nptrs);
      else if (comptypes (TYPE_OFFSET_BASETYPE (ttl),
			  TYPE_OFFSET_BASETYPE (ttr), 0)
	       && comp_target_types (TREE_TYPE (ttl), TREE_TYPE (ttr), nptrs))
	return -1;
    }
  else if (IS_AGGR_TYPE (ttl))
    {
      if (nptrs < 0)
	return 0;
      if (comptypes (build_pointer_type (ttl), build_pointer_type (ttr), 0))
	return 1;
      if (comptypes (build_pointer_type (ttr), build_pointer_type (ttl), 0))
	return -1;
      return 0;
    }

  return 0;
}

/* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
   more cv-qualified that TYPE1, and 0 otherwise.  */

int
comp_cv_qualification (type1, type2)
     tree type1;
     tree type2;
{
  if (TYPE_READONLY (type1) == TYPE_READONLY (type2)
      && TYPE_VOLATILE (type1) == TYPE_VOLATILE (type2))
    return 0;

  if (TYPE_READONLY (type1) >= TYPE_READONLY (type2)
      && TYPE_VOLATILE (type1) >= TYPE_VOLATILE (type2))
    return 1;

  if (TYPE_READONLY (type2) >= TYPE_READONLY (type1)
      && TYPE_VOLATILE (type2) >= TYPE_VOLATILE (type1))
    return -1;

  return 0;
}

/* Returns 1 if the cv-qualification signature of TYPE1 is a proper
   subset of the cv-qualification signature of TYPE2, and the types
   are similar.  Returns -1 if the other way 'round, and 0 otherwise.  */

int
comp_cv_qual_signature (type1, type2)
     tree type1;
     tree type2;
{
  if (comp_ptr_ttypes_real (type2, type1, -1))
    return 1;
  else if (comp_ptr_ttypes_real (type1, type2, -1))
    return -1;
  else
    return 0;
}

/* If two types share a common base type, return that basetype.
   If there is not a unique most-derived base type, this function
   returns ERROR_MARK_NODE.  */

static tree
common_base_type (tt1, tt2)
     tree tt1, tt2;
{
  tree best = NULL_TREE;
  int i;

  /* If one is a baseclass of another, that's good enough.  */
  if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
    return tt1;
  if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
    return tt2;

  /* Otherwise, try to find a unique baseclass of TT1
     that is shared by TT2, and follow that down.  */
  for (i = CLASSTYPE_N_BASECLASSES (tt1)-1; i >= 0; i--)
    {
      tree basetype = TYPE_BINFO_BASETYPE (tt1, i);
      tree trial = common_base_type (basetype, tt2);
      if (trial)
	{
	  if (trial == error_mark_node)
	    return trial;
	  if (best == NULL_TREE)
	    best = trial;
	  else if (best != trial)
	    return error_mark_node;
	}
    }

  /* Same for TT2.  */
  for (i = CLASSTYPE_N_BASECLASSES (tt2)-1; i >= 0; i--)
    {
      tree basetype = TYPE_BINFO_BASETYPE (tt2, i);
      tree trial = common_base_type (tt1, basetype);
      if (trial)
	{
	  if (trial == error_mark_node)
	    return trial;
	  if (best == NULL_TREE)
	    best = trial;
	  else if (best != trial)
	    return error_mark_node;
	}
    }
  return best;
}

/* Subroutines of `comptypes'.  */

/* Return 1 if two parameter type lists PARMS1 and PARMS2
   are equivalent in the sense that functions with those parameter types
   can have equivalent types.
   If either list is empty, we win.
   Otherwise, the two lists must be equivalent, element by element.

   C++: See comment above about TYPE1, TYPE2.

   STRICT is no longer used.  */

int
compparms (parms1, parms2, strict)
     tree parms1, parms2;
     int strict;
{
  register tree t1 = parms1, t2 = parms2;

  /* An unspecified parmlist matches any specified parmlist
     whose argument types don't need default promotions.  */

  while (1)
    {
      if (t1 == 0 && t2 == 0)
	return 1;
      /* If one parmlist is shorter than the other,
	 they fail to match.  */
      if (t1 == 0 || t2 == 0)
	return 0;
      if (! comptypes (TREE_VALUE (t2), TREE_VALUE (t1), 1))
	return 0;

      t1 = TREE_CHAIN (t1);
      t2 = TREE_CHAIN (t2);
    }
}

/* This really wants return whether or not parameter type lists
   would make their owning functions assignment compatible or not.

   The return value is like for comp_target_types.

   This should go away, possibly with the exception of the empty parmlist
   conversion; there are no conversions between function types in C++.
   (jason 17 Apr 1997)  */

static int
comp_target_parms (parms1, parms2, strict)
     tree parms1, parms2;
     int strict;
{
  register tree t1 = parms1, t2 = parms2;
  int warn_contravariance = 0;

  /* In C, an unspecified parmlist matches any specified parmlist
     whose argument types don't need default promotions.  This is not
     true for C++, but let's do it anyway for unfixed headers.  */

  if (t1 == 0 && t2 != 0)
    {
      cp_pedwarn ("ANSI C++ prohibits conversion from `(%#T)' to `(...)'",
		  parms2);
      return self_promoting_args_p (t2);
    }
  if (t2 == 0)
    return self_promoting_args_p (t1);

  for (; t1 || t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
    {
      tree p1, p2;

      /* If one parmlist is shorter than the other,
	 they fail to match, unless STRICT is <= 0.  */
      if (t1 == 0 || t2 == 0)
	{
	  if (strict > 0)
	    return 0;
	  if (strict < 0)
	    return 1 + warn_contravariance;
	  return ((t1 && TREE_PURPOSE (t1)) + warn_contravariance);
	}
      p1 = TREE_VALUE (t1);
      p2 = TREE_VALUE (t2);
      if (comptypes (p1, p2, 1))
	continue;

      if (pedantic)
	return 0;

      if ((TREE_CODE (p1) == POINTER_TYPE && TREE_CODE (p2) == POINTER_TYPE)
	  || (TREE_CODE (p1) == REFERENCE_TYPE
	      && TREE_CODE (p2) == REFERENCE_TYPE))
	{
	  if (strict <= 0
	      && (TYPE_MAIN_VARIANT (TREE_TYPE (p1))
		  == TYPE_MAIN_VARIANT (TREE_TYPE (p2))))
	    continue;

	  /* The following is wrong for contravariance,
	     but many programs depend on it.  */
	  if (TREE_TYPE (p1) == void_type_node)
	    continue;
	  if (TREE_TYPE (p2) == void_type_node)
	    {
	      warn_contravariance = 1;
	      continue;
	    }
	  if (IS_AGGR_TYPE (TREE_TYPE (p1)))
	    {
	      if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (p1)),
			     TYPE_MAIN_VARIANT (TREE_TYPE (p2)), 1) == 0)
		return 0;
	    }
	}
      /* Note backwards order due to contravariance.  */
      if (comp_target_types (p2, p1, 1) <= 0)
	{
	  if (comp_target_types (p1, p2, 1) > 0)
	    {
	      warn_contravariance = 1;
	      continue;
	    }
	  if (strict != 0)
	    return 0;
	}
    }
  return warn_contravariance ? -1 : 1;
}

/* Return 1 if PARMS specifies a fixed number of parameters
   and none of their types is affected by default promotions.  */

int
self_promoting_args_p (parms)
     tree parms;
{
  register tree t;
  for (t = parms; t; t = TREE_CHAIN (t))
    {
      register tree type = TREE_VALUE (t);

      if (TREE_CHAIN (t) == 0 && type != void_type_node)
	return 0;

      if (type == 0)
	return 0;

      if (TYPE_MAIN_VARIANT (type) == float_type_node)
	return 0;

      if (C_PROMOTING_INTEGER_TYPE_P (type))
	return 0;
    }
  return 1;
}

/* Return an unsigned type the same as TYPE in other respects.

   C++: must make these work for type variants as well.  */

tree
unsigned_type (type)
     tree type;
{
  tree type1 = TYPE_MAIN_VARIANT (type);
  if (type1 == signed_char_type_node || type1 == char_type_node)
    return unsigned_char_type_node;
  if (type1 == integer_type_node)
    return unsigned_type_node;
  if (type1 == short_integer_type_node)
    return short_unsigned_type_node;
  if (type1 == long_integer_type_node)
    return long_unsigned_type_node;
  if (type1 == long_long_integer_type_node)
    return long_long_unsigned_type_node;
  if (type1 == intTI_type_node)
    return unsigned_intTI_type_node;
  if (type1 == intDI_type_node)
    return unsigned_intDI_type_node;
  if (type1 == intSI_type_node)
    return unsigned_intSI_type_node;
  if (type1 == intHI_type_node)
    return unsigned_intHI_type_node;
  if (type1 == intQI_type_node)
    return unsigned_intQI_type_node;

  return signed_or_unsigned_type (1, type);
}

/* Return a signed type the same as TYPE in other respects.  */

tree
signed_type (type)
     tree type;
{
  tree type1 = TYPE_MAIN_VARIANT (type);
  if (type1 == unsigned_char_type_node || type1 == char_type_node)
    return signed_char_type_node;
  if (type1 == unsigned_type_node)
    return integer_type_node;
  if (type1 == short_unsigned_type_node)
    return short_integer_type_node;
  if (type1 == long_unsigned_type_node)
    return long_integer_type_node;
  if (type1 == long_long_unsigned_type_node)
    return long_long_integer_type_node;
  if (type1 == unsigned_intTI_type_node)
    return intTI_type_node;
  if (type1 == unsigned_intDI_type_node)
    return intDI_type_node;
  if (type1 == unsigned_intSI_type_node)
    return intSI_type_node;
  if (type1 == unsigned_intHI_type_node)
    return intHI_type_node;
  if (type1 == unsigned_intQI_type_node)
    return intQI_type_node;

  return signed_or_unsigned_type (0, type);
}

/* Return a type the same as TYPE except unsigned or
   signed according to UNSIGNEDP.  */

tree
signed_or_unsigned_type (unsignedp, type)
     int unsignedp;
     tree type;
{
  if (! INTEGRAL_TYPE_P (type)
      || TREE_UNSIGNED (type) == unsignedp)
    return type;

  if (TYPE_PRECISION (type) == TYPE_PRECISION (signed_char_type_node))
    return unsignedp ? unsigned_char_type_node : signed_char_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) 
    return unsignedp ? unsigned_type_node : integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (short_integer_type_node)) 
    return unsignedp ? short_unsigned_type_node : short_integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (long_integer_type_node)) 
    return unsignedp ? long_unsigned_type_node : long_integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (long_long_integer_type_node)) 
    return (unsignedp ? long_long_unsigned_type_node
	    : long_long_integer_type_node);
  return type;
}

/* Compute the value of the `sizeof' operator.  */

tree
c_sizeof (type)
     tree type;
{
  enum tree_code code = TREE_CODE (type);
  tree t;

  if (processing_template_decl)
    return build_min (SIZEOF_EXPR, sizetype, type);

  if (code == FUNCTION_TYPE)
    {
      if (pedantic || warn_pointer_arith)
	pedwarn ("ANSI C++ forbids taking the sizeof a function type");
      return size_int (1);
    }
  if (code == METHOD_TYPE)
    {
      if (pedantic || warn_pointer_arith)
	pedwarn ("ANSI C++ forbids taking the sizeof a method type");
      return size_int (1);
    }
  if (code == VOID_TYPE)
    {
      if (pedantic || warn_pointer_arith)
	pedwarn ("ANSI C++ forbids taking the sizeof a void type");
      return size_int (1);
    }
  if (code == ERROR_MARK)
    return size_int (1);

  /* ARM $5.3.2: ``When applied to a reference, the result is the size of the
     referenced object.'' */
  if (code == REFERENCE_TYPE)
    type = TREE_TYPE (type);

  /* We couldn't find anything in the ARM or the draft standard that says,
     one way or the other, if doing sizeof on something that doesn't have
     an object associated with it is correct or incorrect.  For example, if
     you declare `struct S { char str[16]; };', and in your program do
     a `sizeof (S::str)', should we flag that as an error or should we give
     the size of it?  Since it seems like a reasonable thing to do, we'll go
     with giving the value.  */
  if (code == OFFSET_TYPE)
    type = TREE_TYPE (type);

  /* @@ This also produces an error for a signature ref.
        In that case we should be able to do better.  */
  if (IS_SIGNATURE (type))
    {
      error ("`sizeof' applied to a signature type");
      return size_int (0);
    }

  if (TYPE_SIZE (complete_type (type)) == 0)
    {
      cp_error ("`sizeof' applied to incomplete type `%T'", type);
      return size_int (0);
    }

  /* Convert in case a char is more than one unit.  */
  t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type), 
		  size_int (TYPE_PRECISION (char_type_node)));
  t = convert (sizetype, t);
  /* size_binop does not put the constant in range, so do it now.  */
  if (TREE_CODE (t) == INTEGER_CST && force_fit_type (t, 0))
    TREE_CONSTANT_OVERFLOW (t) = TREE_OVERFLOW (t) = 1;
  return t;
}

tree
expr_sizeof (e)
     tree e;
{
  if (processing_template_decl)
    return build_min (SIZEOF_EXPR, sizetype, e);

  if (TREE_CODE (e) == COMPONENT_REF
      && DECL_BIT_FIELD (TREE_OPERAND (e, 1)))
    error ("sizeof applied to a bit-field");
  /* ANSI says arrays and functions are converted inside comma.
     But we can't really convert them in build_compound_expr
     because that would break commas in lvalues.
     So do the conversion here if operand was a comma.  */
  if (TREE_CODE (e) == COMPOUND_EXPR
      && (TREE_CODE (TREE_TYPE (e)) == ARRAY_TYPE
	  || TREE_CODE (TREE_TYPE (e)) == FUNCTION_TYPE))
    e = default_conversion (e);
  else if (TREE_CODE (e) == TREE_LIST)
    {
      tree t = TREE_VALUE (e);
      if (t != NULL_TREE
	  && ((TREE_TYPE (t)
	       && TREE_CODE (TREE_TYPE (t)) == FUNCTION_TYPE)
	      || is_overloaded_fn (t)))
	pedwarn ("ANSI C++ forbids taking the sizeof a function type");
    }
  return c_sizeof (TREE_TYPE (e));
}
  
tree
c_sizeof_nowarn (type)
     tree type;
{
  enum tree_code code = TREE_CODE (type);
  tree t;

  if (code == FUNCTION_TYPE
      || code == METHOD_TYPE
      || code == VOID_TYPE
      || code == ERROR_MARK)
    return size_int (1);
  if (code == REFERENCE_TYPE)
    type = TREE_TYPE (type);

  if (TYPE_SIZE (type) == 0)
    return size_int (0);

  /* Convert in case a char is more than one unit.  */
  t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type), 
		  size_int (TYPE_PRECISION (char_type_node)));
  t = convert (sizetype, t);
  force_fit_type (t, 0);
  return t;
}

/* Implement the __alignof keyword: Return the minimum required
   alignment of TYPE, measured in bytes.  */

tree
c_alignof (type)
     tree type;
{
  enum tree_code code = TREE_CODE (type);
  tree t;

  if (processing_template_decl)
    return build_min (ALIGNOF_EXPR, sizetype, type);

  if (code == FUNCTION_TYPE || code == METHOD_TYPE)
    return size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT);

  if (code == VOID_TYPE || code == ERROR_MARK)
    return size_int (1);

  /* C++: this is really correct!  */
  if (code == REFERENCE_TYPE)
    type = TREE_TYPE (type);

  /* @@ This also produces an error for a signature ref.
        In that case we should be able to do better.  */
  if (IS_SIGNATURE (type))
    {
      error ("`__alignof' applied to a signature type");
      return size_int (1);
    }

  t = size_int (TYPE_ALIGN (type) / BITS_PER_UNIT);
  force_fit_type (t, 0);
  return t;
}

/* Perform default promotions for C data used in expressions.
   Arrays and functions are converted to pointers;
   enumeral types or short or char, to int.
   In addition, manifest constants symbols are replaced by their values.

   C++: this will automatically bash references to their target type.  */

tree
decay_conversion (exp)
     tree exp;
{
  register tree type = TREE_TYPE (exp);
  register enum tree_code code = TREE_CODE (type);

  if (code == OFFSET_TYPE)
    {
      if (TREE_CODE (exp) == OFFSET_REF)
	return decay_conversion (resolve_offset_ref (exp));

      type = TREE_TYPE (type);
      code = TREE_CODE (type);

      if (type == unknown_type_node)
	{
	  cp_pedwarn ("assuming & on overloaded member function");
	  return build_unary_op (ADDR_EXPR, exp, 0);
	}
    }

  if (code == REFERENCE_TYPE)
    {
      exp = convert_from_reference (exp);
      type = TREE_TYPE (exp);
      code = TREE_CODE (type);
    }

  /* Constants can be used directly unless they're not loadable.  */
  if (TREE_CODE (exp) == CONST_DECL)
    exp = DECL_INITIAL (exp);
  /* Replace a nonvolatile const static variable with its value.  */
  else if (TREE_READONLY_DECL_P (exp))
    {
      exp = decl_constant_value (exp);
      type = TREE_TYPE (exp);
    }

  /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
     Leave such NOP_EXPRs, since RHS is being used in non-lvalue context.  */

  if (code == VOID_TYPE)
    {
      error ("void value not ignored as it ought to be");
      return error_mark_node;
    }
  if (code == FUNCTION_TYPE)
    {
      return build_unary_op (ADDR_EXPR, exp, 0);
    }
  if (code == METHOD_TYPE)
    {
      cp_pedwarn ("assuming & on `%E'", exp);
      return build_unary_op (ADDR_EXPR, exp, 0);
    }
  if (code == ARRAY_TYPE)
    {
      register tree adr;
      tree restype;
      tree ptrtype;
      int constp, volatilep;

      if (TREE_CODE (exp) == INDIRECT_REF)
	{
	  /* Stripping away the INDIRECT_REF is not the right
	     thing to do for references...  */
	  tree inner = TREE_OPERAND (exp, 0);
	  if (TREE_CODE (TREE_TYPE (inner)) == REFERENCE_TYPE)
	    {
	      inner = build1 (CONVERT_EXPR,
			      build_pointer_type (TREE_TYPE
						  (TREE_TYPE (inner))),
			      inner);
	      TREE_CONSTANT (inner) = TREE_CONSTANT (TREE_OPERAND (inner, 0));
	    }
	  return cp_convert (build_pointer_type (TREE_TYPE (type)), inner);
	}

      if (TREE_CODE (exp) == COMPOUND_EXPR)
	{
	  tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
	  return build (COMPOUND_EXPR, TREE_TYPE (op1),
			TREE_OPERAND (exp, 0), op1);
	}

      if (!lvalue_p (exp)
	  && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
	{
	  error ("invalid use of non-lvalue array");
	  return error_mark_node;
	}

      constp = volatilep = 0;
      if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'r'
	  || TREE_CODE_CLASS (TREE_CODE (exp)) == 'd')
	{
	  constp = TREE_READONLY (exp);
	  volatilep = TREE_THIS_VOLATILE (exp);
	}

      restype = TREE_TYPE (type);
      if (TYPE_READONLY (type) || TYPE_VOLATILE (type)
	  || constp || volatilep)
	restype = cp_build_type_variant (restype,
					 TYPE_READONLY (type) || constp,
					 TYPE_VOLATILE (type) || volatilep);
      ptrtype = build_pointer_type (restype);

      if (TREE_CODE (exp) == VAR_DECL)
	{
	  /* ??? This is not really quite correct
	     in that the type of the operand of ADDR_EXPR
	     is not the target type of the type of the ADDR_EXPR itself.
	     Question is, can this lossage be avoided?  */
	  adr = build1 (ADDR_EXPR, ptrtype, exp);
	  if (mark_addressable (exp) == 0)
	    return error_mark_node;
	  TREE_CONSTANT (adr) = staticp (exp);
	  TREE_SIDE_EFFECTS (adr) = 0;   /* Default would be, same as EXP.  */
	  return adr;
	}
      /* This way is better for a COMPONENT_REF since it can
	 simplify the offset for a component.  */
      adr = build_unary_op (ADDR_EXPR, exp, 1);
      return cp_convert (ptrtype, adr);
    }

  return exp;
}

tree
default_conversion (exp)
     tree exp;
{
  tree type;
  enum tree_code code;

  exp = decay_conversion (exp);

  type = TREE_TYPE (exp);
  code = TREE_CODE (type);

  if (INTEGRAL_CODE_P (code))
    {
      tree t = type_promotes_to (type);
      if (t != type)
	return cp_convert (t, exp);
    }

  return exp;
}

/* Take the address of an inline function without setting TREE_ADDRESSABLE
   or TREE_USED.  */

tree
inline_conversion (exp)
     tree exp;
{
  if (TREE_CODE (exp) == FUNCTION_DECL)
    {
      tree type = build_type_variant
	(TREE_TYPE (exp), TREE_READONLY (exp), TREE_THIS_VOLATILE (exp));
      exp = build1 (ADDR_EXPR, build_pointer_type (type), exp);
    }
  return exp;
}

tree
build_object_ref (datum, basetype, field)
     tree datum, basetype, field;
{
  tree dtype;
  if (datum == error_mark_node)
    return error_mark_node;

  dtype = TREE_TYPE (datum);
  if (TREE_CODE (dtype) == REFERENCE_TYPE)
    dtype = TREE_TYPE (dtype);
  if (! IS_AGGR_TYPE_CODE (TREE_CODE (dtype)))
    {
      cp_error ("request for member `%T::%D' in expression of non-aggregate type `%T'",
		basetype, field, dtype);
      return error_mark_node;
    }
  else if (IS_SIGNATURE (basetype))
    {
      warning ("signature name in scope resolution ignored");
      return build_component_ref (datum, field, NULL_TREE, 1);
    }
  else if (is_aggr_type (basetype, 1))
    {
      tree binfo = binfo_or_else (basetype, dtype);
      if (binfo)
	return build_x_component_ref (build_scoped_ref (datum, basetype),
				      field, binfo, 1);
    }
  return error_mark_node;
}

/* Like `build_component_ref, but uses an already found field, and converts
   from a reference.  Must compute access for current_class_ref.
   Otherwise, ok.  */

tree
build_component_ref_1 (datum, field, protect)
     tree datum, field;
     int protect;
{
  return convert_from_reference
    (build_component_ref (datum, field, NULL_TREE, protect));
}

/* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
   can, for example, use as an lvalue.  This code used to be in
   unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
   expressions, where we're dealing with aggregates.  But now it's again only
   called from unary_complex_lvalue.  The case (in particular) that led to
   this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
   get it there.  */

static tree
rationalize_conditional_expr (code, t)
     enum tree_code code;
     tree t;
{
  /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
     the first operand is always the one to be used if both operands
     are equal, so we know what conditional expression this used to be.  */
  if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
    {
      return
	build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
						    ? LE_EXPR : GE_EXPR),
						   TREE_OPERAND (t, 0),
						   TREE_OPERAND (t, 1)),
			    build_unary_op (code, TREE_OPERAND (t, 0), 0),
			    build_unary_op (code, TREE_OPERAND (t, 1), 0));
    }

  return
    build_conditional_expr (TREE_OPERAND (t, 0),
			    build_unary_op (code, TREE_OPERAND (t, 1), 0),
			    build_unary_op (code, TREE_OPERAND (t, 2), 0));
}

/* Given the TYPE of an anonymous union field inside T, return the
   FIELD_DECL for the field.  If not found return NULL_TREE.  Because
   anonymous unions can nest, we must also search all anonymous unions
   that are directly reachable.  */

static tree
lookup_anon_field (t, type)
     tree t, type;
{
  tree field;

  for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
    {
      if (TREE_STATIC (field))
	continue;
      if (TREE_CODE (field) != FIELD_DECL)
	continue;

      /* If we find it directly, return the field.  */
      if (DECL_NAME (field) == NULL_TREE
	  && type == TREE_TYPE (field))
	{
	  return field;
	}

      /* Otherwise, it could be nested, search harder.  */
      if (DECL_NAME (field) == NULL_TREE
	  && TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
	{
	  tree subfield = lookup_anon_field (TREE_TYPE (field), type);
	  if (subfield)
	    return subfield;
	}
    }
  return NULL_TREE;
}

/* Build a COMPONENT_REF for a given DATUM, and it's member COMPONENT.
   COMPONENT can be an IDENTIFIER_NODE that is the name of the member
   that we are interested in, or it can be a FIELD_DECL.  */

tree
build_component_ref (datum, component, basetype_path, protect)
     tree datum, component, basetype_path;
     int protect;
{
  register tree basetype = TREE_TYPE (datum);
  register enum tree_code code;
  register tree field = NULL;
  register tree ref;

  if (processing_template_decl)
    return build_min_nt (COMPONENT_REF, datum, component);

  /* If DATUM is a COMPOUND_EXPR or COND_EXPR, move our reference
     inside it.  */
  switch (TREE_CODE (datum))
    {
    case COMPOUND_EXPR:
      {
	tree value = build_component_ref (TREE_OPERAND (datum, 1), component,
					  basetype_path, protect);
	return build (COMPOUND_EXPR, TREE_TYPE (value),
		      TREE_OPERAND (datum, 0), value);
      }
    case COND_EXPR:
      return build_conditional_expr
	(TREE_OPERAND (datum, 0),
	 build_component_ref (TREE_OPERAND (datum, 1), component,
			      basetype_path, protect),
	 build_component_ref (TREE_OPERAND (datum, 2), component,
			      basetype_path, protect));

    case TEMPLATE_DECL:
      cp_error ("invalid use of %D", datum);
      datum = error_mark_node;
      break;

    default:
      break;
    }

  code = TREE_CODE (basetype);

  if (code == REFERENCE_TYPE)
    {
      datum = convert_from_reference (datum);
      basetype = TREE_TYPE (datum);
      code = TREE_CODE (basetype);
    }
  if (TREE_CODE (datum) == OFFSET_REF)
    {
      datum = resolve_offset_ref (datum);
      basetype = TREE_TYPE (datum);
      code = TREE_CODE (basetype);
    }

  /* First, see if there is a field or component with name COMPONENT.  */
  if (TREE_CODE (component) == TREE_LIST)
    {
      /* I could not trigger this code. MvL */
      my_friendly_abort (980326);
#ifdef DEAD
      my_friendly_assert (!(TREE_CHAIN (component) == NULL_TREE
		&& DECL_CHAIN (TREE_VALUE (component)) == NULL_TREE), 309);
#endif
      return build (COMPONENT_REF, TREE_TYPE (component), datum, component);
    }

  if (! IS_AGGR_TYPE_CODE (code))
    {
      if (code != ERROR_MARK)
	cp_error ("request for member `%D' in `%E', which is of non-aggregate type `%T'",
		  component, datum, basetype);
      return error_mark_node;
    }

  if (!complete_type_or_else (basetype))
    return error_mark_node;

  if (TREE_CODE (component) == BIT_NOT_EXPR)
    {
      if (TYPE_IDENTIFIER (basetype) != TREE_OPERAND (component, 0))
	{
	  cp_error ("destructor specifier `%T::~%T' must have matching names",
		    basetype, TREE_OPERAND (component, 0));
	  return error_mark_node;
	}
      if (! TYPE_HAS_DESTRUCTOR (basetype))
	{
	  cp_error ("type `%T' has no destructor", basetype);
	  return error_mark_node;
	}
      return TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (basetype), 1);
    }

  /* Look up component name in the structure type definition.  */
  if (CLASSTYPE_VFIELD (basetype)
      && DECL_NAME (CLASSTYPE_VFIELD (basetype)) == component)
    /* Special-case this because if we use normal lookups in an ambiguous
       hierarchy, the compiler will abort (because vptr lookups are
       not supposed to be ambiguous.  */
    field = CLASSTYPE_VFIELD (basetype);
  else if (TREE_CODE (component) == FIELD_DECL)
    field = component;
  else if (TREE_CODE (component) == TYPE_DECL)
    {
      cp_pedwarn ("invalid use of type decl `%#D' as expression", component);
      return component;
    }
  else
    {
      tree name = component;
      if (TREE_CODE (component) == VAR_DECL)
	name = DECL_NAME (component);
      if (basetype_path == NULL_TREE)
	basetype_path = TYPE_BINFO (basetype);
      field = lookup_field (basetype_path, name,
			    protect && !VFIELD_NAME_P (name), 0);
      if (field == error_mark_node)
	return error_mark_node;

      if (field == NULL_TREE)
	{
	  /* Not found as a data field, look for it as a method.  If found,
	     then if this is the only possible one, return it, else
	     report ambiguity error.  */
	  tree fndecls = lookup_fnfields (basetype_path, name, 1);
	  if (fndecls == error_mark_node)
	    return error_mark_node;
	  if (fndecls)
	    {
	      if (TREE_CHAIN (fndecls) == NULL_TREE
		  && TREE_CODE (TREE_VALUE (fndecls)) != OVERLOAD)
		{
		  tree access, fndecl;

		  /* Unique, so use this one now.  */
		  basetype = TREE_PURPOSE (fndecls);
		  fndecl = TREE_VALUE (fndecls);
		  access = compute_access (TREE_PURPOSE (fndecls), fndecl);
		  if (access == access_public_node)
		    {
		      if (DECL_VINDEX (fndecl)
			  && ! resolves_to_fixed_type_p (datum, 0))
			{
			  tree addr = build_unary_op (ADDR_EXPR, datum, 0);
			  tree fntype = TREE_TYPE (fndecl);

			  addr = convert_pointer_to (DECL_CONTEXT (fndecl),
						     addr);
			  datum = build_indirect_ref (addr, NULL_PTR);
			  my_friendly_assert (datum != error_mark_node, 310);
			  fndecl = build_vfn_ref (&addr, datum,
						  DECL_VINDEX (fndecl));
			  /* The type of fndecl is a function type,
			     not a pointer-to-function type, since
			     build_vfn_ref returns not the correct
			     vtable slot, but the indirection of the
			     correct vtable slot.  */
			  TREE_TYPE (fndecl) = fntype;
			}
		      else
			mark_used (fndecl);
		      return build (OFFSET_REF, TREE_TYPE (fndecl),
				    datum, fndecl);
		    }
		  if (access == access_protected_node)
		    cp_error ("member function `%D' is protected", fndecl);
		  else
		    cp_error ("member function `%D' is private", fndecl);
		  return error_mark_node;
		}
	      else
		{
		  /* Just act like build_offset_ref, since the object does
                     not matter unless we're actually calling the function.  */
		  tree t;

		  t = build_tree_list (error_mark_node, fndecls);
		  TREE_TYPE (t) = build_offset_type (basetype,
						     unknown_type_node);
		  return t;
		}
	    }

	  cp_error ("`%#T' has no member named `%D'", basetype, name);
	  return error_mark_node;
	}
      else if (TREE_TYPE (field) == error_mark_node)
	return error_mark_node;

      if (TREE_CODE (field) != FIELD_DECL)
	{
	  if (TREE_CODE (field) == TYPE_DECL)
	    cp_pedwarn ("invalid use of type decl `%#D' as expression", field);
	  else if (DECL_RTL (field) != 0)
	    mark_used (field);
	  else
	    TREE_USED (field) = 1;
	  return field;
	}
    }

  /* See if we have to do any conversions so that we pick up the field from the
     right context.  */
  if (DECL_FIELD_CONTEXT (field) != basetype)
    {
      tree context = DECL_FIELD_CONTEXT (field);
      tree base = context;
      while (!comptypes (base, basetype,1) && TYPE_NAME (base)
	     && ANON_UNION_TYPE_P (base))
	{
	  base = TYPE_CONTEXT (base);
	}

      /* Handle base classes here...  */
      if (base != basetype && TYPE_USES_COMPLEX_INHERITANCE (basetype))
	{
	  tree addr = build_unary_op (ADDR_EXPR, datum, 0);
	  if (integer_zerop (addr))
	    {
	      error ("invalid reference to NULL ptr, use ptr-to-member instead");
	      return error_mark_node;
	    }
	  if (VBASE_NAME_P (DECL_NAME (field)))
	    {
	      /* It doesn't matter which vbase pointer we grab, just
		 find one of them.  */
	      tree binfo = get_binfo (base,
				      TREE_TYPE (TREE_TYPE (addr)), 0);
	      addr = convert_pointer_to_real (binfo, addr);
	    }
	  else
	    addr = convert_pointer_to (base, addr);
	  datum = build_indirect_ref (addr, NULL_PTR);
	  my_friendly_assert (datum != error_mark_node, 311);
	}
      basetype = base;
 
      /* Handle things from anon unions here...  */
      if (TYPE_NAME (context) && ANON_UNION_TYPE_P (context))
	{
	  tree subfield = lookup_anon_field (basetype, context);
	  tree subdatum = build_component_ref (datum, subfield,
					       basetype_path, protect);
	  return build_component_ref (subdatum, field, basetype_path, protect);
	}
    }

  ref = fold (build (COMPONENT_REF, TREE_TYPE (field),
		     break_out_cleanups (datum), field));

  if (TREE_READONLY (datum) || TREE_READONLY (field))
    TREE_READONLY (ref) = 1;
  if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (field))
    TREE_THIS_VOLATILE (ref) = 1;
  if (DECL_LANG_SPECIFIC (field) && DECL_MUTABLE_P (field))
    TREE_READONLY (ref) = 0;

  return ref;
}

/* Variant of build_component_ref for use in expressions, which should
   never have REFERENCE_TYPE.  */

tree
build_x_component_ref (datum, component, basetype_path, protect)
     tree datum, component, basetype_path;
     int protect;
{
  tree t = build_component_ref (datum, component, basetype_path, protect);

  if (! processing_template_decl)
    t = convert_from_reference (t);

  return t;
}

/* Given an expression PTR for a pointer, return an expression
   for the value pointed to.
   ERRORSTRING is the name of the operator to appear in error messages.

   This function may need to overload OPERATOR_FNNAME.
   Must also handle REFERENCE_TYPEs for C++.  */

tree
build_x_indirect_ref (ptr, errorstring)
     tree ptr;
     char *errorstring;
{
  tree rval;

  if (processing_template_decl)
    return build_min_nt (INDIRECT_REF, ptr);

  rval = build_opfncall (INDIRECT_REF, LOOKUP_NORMAL, ptr, NULL_TREE,
			 NULL_TREE);
  if (rval)
    return rval;
  return build_indirect_ref (ptr, errorstring);
}

tree
build_indirect_ref (ptr, errorstring)
     tree ptr;
     char *errorstring;
{
  register tree pointer, type;

  if (ptr == error_mark_node)
    return error_mark_node;

  pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
	     ? ptr : default_conversion (ptr));
  type = TREE_TYPE (pointer);

  if (ptr == current_class_ptr)
    return current_class_ref;

  if (TREE_CODE (type) == POINTER_TYPE || TREE_CODE (type) == REFERENCE_TYPE)
    {
      if (TREE_CODE (pointer) == ADDR_EXPR
	  && !flag_volatile
	  && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (pointer, 0)))
	      == TYPE_MAIN_VARIANT (TREE_TYPE (type)))
	  && (TREE_READONLY (TREE_OPERAND (pointer, 0))
	      == TYPE_READONLY (TREE_TYPE (type)))
	  && (TREE_THIS_VOLATILE (TREE_OPERAND (pointer, 0))
	      == TYPE_VOLATILE (TREE_TYPE (type))))
	return TREE_OPERAND (pointer, 0);
      else
	{
	  tree t = TREE_TYPE (type);
	  register tree ref = build1 (INDIRECT_REF,
				      TYPE_MAIN_VARIANT (t), pointer);

	  /* We *must* set TREE_READONLY when dereferencing a pointer to const,
	     so that we get the proper error message if the result is used
	     to assign to.  Also, &* is supposed to be a no-op.  */
	  TREE_READONLY (ref) = TYPE_READONLY (t);
	  TREE_SIDE_EFFECTS (ref)
	    = (TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer)
	       || flag_volatile);
	  TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
	  return ref;
	}
    }
  /* `pointer' won't be an error_mark_node if we were given a
     pointer to member, so it's cool to check for this here.  */
  else if (TYPE_PTRMEMFUNC_P (type))
    error ("invalid use of `%s' on pointer to member function", errorstring);
  else if (TREE_CODE (type) == RECORD_TYPE
	   && (IS_SIGNATURE_POINTER (type) || IS_SIGNATURE_REFERENCE (type)))
    error ("cannot dereference signature pointer/reference");
  else if (pointer != error_mark_node)
    {
      if (errorstring)
	error ("invalid type argument of `%s'", errorstring);
      else
	error ("invalid type argument");
    }
  return error_mark_node;
}

/* This handles expressions of the form "a[i]", which denotes
   an array reference.

   This is logically equivalent in C to *(a+i), but we may do it differently.
   If A is a variable or a member, we generate a primitive ARRAY_REF.
   This avoids forcing the array out of registers, and can work on
   arrays that are not lvalues (for example, members of structures returned
   by functions).

   If INDEX is of some user-defined type, it must be converted to
   integer type.  Otherwise, to make a compatible PLUS_EXPR, it
   will inherit the type of the array, which will be some pointer type.  */

tree
build_array_ref (array, idx)
     tree array, idx;
{
  if (idx == 0)
    {
      error ("subscript missing in array reference");
      return error_mark_node;
    }

  if (TREE_TYPE (array) == error_mark_node
      || TREE_TYPE (idx) == error_mark_node)
    return error_mark_node;

  if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE
      && TREE_CODE (array) != INDIRECT_REF)
    {
      tree rval, type;

      /* Subscripting with type char is likely to lose
	 on a machine where chars are signed.
	 So warn on any machine, but optionally.
	 Don't warn for unsigned char since that type is safe.
	 Don't warn for signed char because anyone who uses that
	 must have done so deliberately.  */
      if (warn_char_subscripts
	  && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
	warning ("array subscript has type `char'");

      /* Apply default promotions *after* noticing character types.  */
      idx = default_conversion (idx);

      if (TREE_CODE (TREE_TYPE (idx)) != INTEGER_TYPE)
	{
	  error ("array subscript is not an integer");
	  return error_mark_node;
	}

      /* An array that is indexed by a non-constant
	 cannot be stored in a register; we must be able to do
	 address arithmetic on its address.
	 Likewise an array of elements of variable size.  */
      if (TREE_CODE (idx) != INTEGER_CST
	  || (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))) != 0
	      && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
		  != INTEGER_CST)))
	{
	  if (mark_addressable (array) == 0)
	    return error_mark_node;
	}
      /* An array that is indexed by a constant value which is not within
	 the array bounds cannot be stored in a register either; because we
	 would get a crash in store_bit_field/extract_bit_field when trying
	 to access a non-existent part of the register.  */
      if (TREE_CODE (idx) == INTEGER_CST
	  && TYPE_VALUES (TREE_TYPE (array))
	  && ! int_fits_type_p (idx, TYPE_VALUES (TREE_TYPE (array))))
	{
	  if (mark_addressable (array) == 0)
	    return error_mark_node;
	}

      if (pedantic && !lvalue_p (array))
	pedwarn ("ANSI C++ forbids subscripting non-lvalue array");

      /* Note in C++ it is valid to subscript a `register' array, since
	 it is valid to take the address of something with that
	 storage specification.  */
      if (extra_warnings)
	{
	  tree foo = array;
	  while (TREE_CODE (foo) == COMPONENT_REF)
	    foo = TREE_OPERAND (foo, 0);
	  if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
	    warning ("subscripting array declared `register'");
	}

      type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (array)));
      rval = build (ARRAY_REF, type, array, idx);
      /* Array ref is const/volatile if the array elements are
	 or if the array is..  */
      TREE_READONLY (rval)
	|= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
	    | TREE_READONLY (array));
      TREE_SIDE_EFFECTS (rval)
	|= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
	    | TREE_SIDE_EFFECTS (array));
      TREE_THIS_VOLATILE (rval)
	|= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
	    /* This was added by rms on 16 Nov 91.
	       It fixes  vol struct foo *a;  a->elts[1] 
	       in an inline function.
	       Hope it doesn't break something else.  */
	    | TREE_THIS_VOLATILE (array));
      return require_complete_type (fold (rval));
    }

  {
    tree ar = default_conversion (array);
    tree ind = default_conversion (idx);

    /* Put the integer in IND to simplify error checking.  */
    if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
      {
	tree temp = ar;
	ar = ind;
	ind = temp;
      }

    if (ar == error_mark_node)
      return ar;

    if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
      {
	error ("subscripted value is neither array nor pointer");
	return error_mark_node;
      }
    if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
      {
	error ("array subscript is not an integer");
	return error_mark_node;
      }

    return build_indirect_ref (build_binary_op_nodefault (PLUS_EXPR, ar,
							  ind, PLUS_EXPR),
			       "array indexing");
  }
}

/* Build a function call to function FUNCTION with parameters PARAMS.
   PARAMS is a list--a chain of TREE_LIST nodes--in which the
   TREE_VALUE of each node is a parameter-expression.  The PARAMS do
   not include any object pointer that may be required.  FUNCTION's
   data type may be a function type or a pointer-to-function.

   For C++: If FUNCTION's data type is a TREE_LIST, then the tree list
   is the list of possible methods that FUNCTION could conceivably
   be.  If the list of methods comes from a class, then it will be
   a list of lists (where each element is associated with the class
   that produced it), otherwise it will be a simple list (for
   functions overloaded in global scope).

   In the first case, TREE_VALUE (function) is the head of one of those
   lists, and TREE_PURPOSE is the name of the function.

   In the second case, TREE_PURPOSE (function) is the function's
   name directly.

   DECL is the class instance variable, usually CURRENT_CLASS_REF.

   When calling a TEMPLATE_DECL, we don't require a complete return
   type.  */

tree
build_x_function_call (function, params, decl)
     tree function, params, decl;
{
  tree type;
  tree template_id = NULL_TREE;
  int is_method;

  if (function == error_mark_node)
    return error_mark_node;

  if (processing_template_decl)
    return build_min_nt (CALL_EXPR, function, params, NULL_TREE);

  /* Save explicit template arguments if found */
  if (TREE_CODE (function) == TEMPLATE_ID_EXPR)
    {
      template_id = function;
      function = TREE_OPERAND (function, 0);
    }

  type = TREE_TYPE (function);

  if (TREE_CODE (type) == OFFSET_TYPE
      && TREE_TYPE (type) == unknown_type_node
      && TREE_CODE (function) == TREE_LIST
      && TREE_CHAIN (function) == NULL_TREE)
    {
      /* Undo (Foo:bar)()...  */
      type = TYPE_OFFSET_BASETYPE (type);
      function = TREE_VALUE (function);
      my_friendly_assert (TREE_CODE (function) == TREE_LIST, 999);
      my_friendly_assert (TREE_CHAIN (function) == NULL_TREE, 999);
      function = TREE_VALUE (function);
      if (TREE_CODE (function) == OVERLOAD)
	function = OVL_FUNCTION (function);
      my_friendly_assert (TREE_CODE (function) == FUNCTION_DECL, 999);
      function = DECL_NAME (function);
      return build_method_call (decl, function, params,
				TYPE_BINFO (type), LOOKUP_NORMAL);
    }
    
  is_method = ((TREE_CODE (function) == TREE_LIST
		&& current_class_type != NULL_TREE
		&& (IDENTIFIER_CLASS_VALUE (TREE_PURPOSE (function))
		    == function))
	       || TREE_CODE (function) == IDENTIFIER_NODE
	       || TREE_CODE (type) == METHOD_TYPE
	       || TYPE_PTRMEMFUNC_P (type));

  if ((TREE_CODE (function) == FUNCTION_DECL
       && DECL_STATIC_FUNCTION_P (function))
      || (TREE_CODE (function) == TEMPLATE_DECL
	  && DECL_STATIC_FUNCTION_P (DECL_RESULT (function))))
    return build_member_call
      (DECL_CONTEXT (function), DECL_NAME (function), params);

  /* A friend template.  Make it look like a toplevel declaration.  */
  if (! is_method && TREE_CODE (function) == TEMPLATE_DECL)
    function = scratch_ovl_cons (function, NULL_TREE);

  /* Handle methods, friends, and overloaded functions, respectively.  */
  if (is_method)
    {
      tree basetype = NULL_TREE;

      if (TREE_CODE (function) == FUNCTION_DECL
	  || DECL_FUNCTION_TEMPLATE_P (function))
	{
	  basetype = DECL_CLASS_CONTEXT (function);

	  if (DECL_NAME (function))
	    function = DECL_NAME (function);
	  else
	    function = TYPE_IDENTIFIER (DECL_CLASS_CONTEXT (function));
	}
      else if (TREE_CODE (function) == TREE_LIST)
	{
	  my_friendly_assert (TREE_CODE (TREE_VALUE (function))
			      == FUNCTION_DECL, 312);
	  basetype = DECL_CLASS_CONTEXT (TREE_VALUE (function));
	  function = TREE_PURPOSE (function);
	}
      else if (TREE_CODE (function) != IDENTIFIER_NODE)
	{
	  if (TREE_CODE (function) == OFFSET_REF)
	    {
	      if (TREE_OPERAND (function, 0))
		decl = TREE_OPERAND (function, 0);
	    }
	  /* Call via a pointer to member function.  */
	  if (decl == NULL_TREE)
	    {
	      error ("pointer to member function called, but not in class scope");
	      return error_mark_node;
	    }
	  /* What other type of POINTER_TYPE could this be? */
	  if (TREE_CODE (TREE_TYPE (function)) != POINTER_TYPE
	      && ! TYPE_PTRMEMFUNC_P (TREE_TYPE (function))
	      && TREE_CODE (function) != OFFSET_REF)
	    function = build (OFFSET_REF, TREE_TYPE (type), NULL_TREE,
			      function);
	  goto do_x_function;
	}

      /* this is an abbreviated method call.
         must go through here in case it is a virtual function.
	 @@ Perhaps this could be optimized.  */

      if (basetype && (! current_class_type
		       || ! DERIVED_FROM_P (basetype, current_class_type)))
	return build_member_call (basetype, function, params);

      if (decl == NULL_TREE)
	{
	  if (current_class_type == NULL_TREE)
	    {
	      error ("object missing in call to method `%s'",
		     IDENTIFIER_POINTER (function));
	      return error_mark_node;
	    }
	  /* Yow: call from a static member function.  */
	  decl = build1 (NOP_EXPR, build_pointer_type (current_class_type),
			 error_mark_node);
	  decl = build_indirect_ref (decl, NULL_PTR);
	}

      /* Put back explicit template arguments, if any.  */
      if (template_id)
        function = template_id;
      return build_method_call (decl, function, params,
				NULL_TREE, LOOKUP_NORMAL);
    }
  else if (TREE_CODE (function) == COMPONENT_REF
	   && type == unknown_type_node)
    {
      /* Should we undo what was done in build_component_ref? */
      if (TREE_CODE (TREE_PURPOSE (TREE_OPERAND (function, 1))) == TREE_VEC)
	/* Get the name that build_component_ref hid.  */
	function = DECL_NAME (TREE_VALUE (TREE_OPERAND (function, 1)));
      else
	function = TREE_PURPOSE (TREE_OPERAND (function, 1));
      return build_method_call (decl, function, params,
				NULL_TREE, LOOKUP_NORMAL);
    }
  else if (really_overloaded_fn (function))
    {
      if (OVL_FUNCTION (function) == NULL_TREE)
	{
	  cp_error ("function `%D' declared overloaded, but no definitions appear with which to resolve it?!?",
		    TREE_PURPOSE (function));
	  return error_mark_node;
	}
      else
	{
	  /* Put back explicit template arguments, if any.  */
	  if (template_id)
	    function = template_id;
	  return build_new_function_call (function, params);
	}
    }
  else
    /* Remove a potential OVERLOAD around it */
    function = OVL_CURRENT (function);

 do_x_function:
  if (TREE_CODE (function) == OFFSET_REF)
    {
      /* If the component is a data element (or a virtual function), we play
	 games here to make things work.  */
      tree decl_addr;

      if (TREE_OPERAND (function, 0))
	decl = TREE_OPERAND (function, 0);
      else
	decl = current_class_ref;

      decl_addr = build_unary_op (ADDR_EXPR, decl, 0);

      /* Sigh.  OFFSET_REFs are being used for too many things.
	 They're being used both for -> and ->*, and we want to resolve
	 the -> cases here, but leave the ->*.  We could use
	 resolve_offset_ref for those, too, but it would call
         get_member_function_from_ptrfunc and decl_addr wouldn't get
         updated properly.  Nasty.  */
      if (TREE_CODE (TREE_OPERAND (function, 1)) == FIELD_DECL)
	function = resolve_offset_ref (function);
      else
	function = TREE_OPERAND (function, 1);

      function = get_member_function_from_ptrfunc (&decl_addr, function);
      params = expr_tree_cons (NULL_TREE, decl_addr, params);
      return build_function_call (function, params);
    }

  type = TREE_TYPE (function);
  if (type != error_mark_node)
    {
      if (TREE_CODE (type) == REFERENCE_TYPE)
	type = TREE_TYPE (type);

      if (IS_AGGR_TYPE (type))
	return build_opfncall (CALL_EXPR, LOOKUP_NORMAL, function, params, NULL_TREE);
    }

  if (is_method)
    {
      tree fntype = TREE_TYPE (function);
      tree ctypeptr = NULL_TREE;

      /* Explicitly named method?  */
      if (TREE_CODE (function) == FUNCTION_DECL)
	ctypeptr = build_pointer_type (DECL_CLASS_CONTEXT (function));
      /* Expression with ptr-to-method type?  It could either be a plain
	 usage, or it might be a case where the ptr-to-method is being
	 passed in as an argument.  */
      else if (TYPE_PTRMEMFUNC_P (fntype))
	{
	  tree rec = TYPE_METHOD_BASETYPE (TREE_TYPE
					   (TYPE_PTRMEMFUNC_FN_TYPE (fntype)));
	  ctypeptr = build_pointer_type (rec);
	}
      /* Unexpected node type?  */
      else
	my_friendly_abort (116);
      if (decl == NULL_TREE)
	{
	  if (current_function_decl
	      && DECL_STATIC_FUNCTION_P (current_function_decl))
	    error ("invalid call to member function needing `this' in static member function scope");
	  else
	    error ("pointer to member function called, but not in class scope");
	  return error_mark_node;
	}
      if (TREE_CODE (TREE_TYPE (decl)) != POINTER_TYPE
	  && ! TYPE_PTRMEMFUNC_P (TREE_TYPE (decl)))
	{
	  decl = build_unary_op (ADDR_EXPR, decl, 0);
	  decl = convert_pointer_to (TREE_TYPE (ctypeptr), decl);
	}
      else
	decl = build_c_cast (ctypeptr, decl);
      params = expr_tree_cons (NULL_TREE, decl, params);
    }

  return build_function_call (function, params);
}

/* Resolve a pointer to member function.  INSTANCE is the object
   instance to use, if the member points to a virtual member.  */

tree
get_member_function_from_ptrfunc (instance_ptrptr, function)
     tree *instance_ptrptr;
     tree function;
{
  if (TREE_CODE (function) == OFFSET_REF)
    {
      function = TREE_OPERAND (function, 1);
    }

  if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
    {
      tree fntype, idx, e1, delta, delta2, e2, e3, aref, vtbl;
      tree instance;

      tree instance_ptr = *instance_ptrptr;

      if (TREE_SIDE_EFFECTS (instance_ptr))
	instance_ptr = save_expr (instance_ptr);

      if (TREE_SIDE_EFFECTS (function))
	function = save_expr (function);

      fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));

      /* Promoting idx before saving it improves performance on RISC
	 targets.  Without promoting, the first compare used
	 load-with-sign-extend, while the second used normal load then
	 shift to sign-extend.  An optimizer flaw, perhaps, but it's easier
	 to make this change.  */
      idx = save_expr (default_conversion
		       (build_component_ref (function,
					     index_identifier,
					     NULL_TREE, 0)));
      e1 = build_binary_op (GT_EXPR, idx, integer_zero_node, 1);
      delta = cp_convert (ptrdiff_type_node,
			  build_component_ref (function, delta_identifier,
					       NULL_TREE, 0));
      delta2 = DELTA2_FROM_PTRMEMFUNC (function);

      /* Convert down to the right base, before using the instance.  */
      instance
	= convert_pointer_to_real (TYPE_METHOD_BASETYPE (TREE_TYPE (fntype)),
				   instance_ptr);
      if (instance == error_mark_node && instance_ptr != error_mark_node)
	return instance;

      vtbl = convert_pointer_to (ptr_type_node, instance);
      vtbl
	= build (PLUS_EXPR,
		 build_pointer_type (build_pointer_type (vtable_entry_type)),
		 vtbl, cp_convert (ptrdiff_type_node, delta2));
      vtbl = build_indirect_ref (vtbl, NULL_PTR);
      aref = build_array_ref (vtbl, build_binary_op (MINUS_EXPR,
						     idx,
						     integer_one_node, 1));
      if (! flag_vtable_thunks)
	{
	  aref = save_expr (aref);

	  delta = build_binary_op
	    (PLUS_EXPR,
	     build_conditional_expr (e1, build_component_ref (aref,
							      delta_identifier,
							      NULL_TREE, 0),
				     integer_zero_node),
	     delta, 1);
	}

      *instance_ptrptr = build (PLUS_EXPR, TREE_TYPE (instance_ptr),
				instance_ptr, delta);
      if (flag_vtable_thunks)
	e2 = aref;
      else
	e2 = build_component_ref (aref, pfn_identifier, NULL_TREE, 0);

      e3 = PFN_FROM_PTRMEMFUNC (function);
      TREE_TYPE (e2) = TREE_TYPE (e3);
      e1 = build_conditional_expr (e1, e2, e3);

      if (instance_ptr == error_mark_node
	  && TREE_CODE (e1) != ADDR_EXPR
	  && TREE_CODE (TREE_OPERAND (e1, 0)) != FUNCTION_DECL)
	cp_error ("object missing in `%E'", function);

      function = e1;

      /* Make sure this doesn't get evaluated first inside one of the
         branches of the COND_EXPR.  */
      if (TREE_CODE (instance_ptr) == SAVE_EXPR)
	function = build (COMPOUND_EXPR, TREE_TYPE (function),
			  instance_ptr, function);
    }
  return function;
}

tree
build_function_call_real (function, params, require_complete, flags)
     tree function, params;
     int require_complete, flags;
{
  register tree fntype, fndecl;
  register tree value_type;
  register tree coerced_params;
  tree name = NULL_TREE, assembler_name = NULL_TREE;
  int is_method;

  /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
     Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context.  */
  if (TREE_CODE (function) == NOP_EXPR
      && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
    function = TREE_OPERAND (function, 0);

  if (TREE_CODE (function) == FUNCTION_DECL)
    {
      name = DECL_NAME (function);
      assembler_name = DECL_ASSEMBLER_NAME (function);

      GNU_xref_call (current_function_decl,
		     IDENTIFIER_POINTER (name ? name
					 : TYPE_IDENTIFIER (DECL_CLASS_CONTEXT
							    (function))));
      mark_used (function);
      fndecl = function;

      /* Convert anything with function type to a pointer-to-function.  */
      if (pedantic && DECL_MAIN_P (function))
	pedwarn ("ANSI C++ forbids calling `main' from within program");

      /* Differs from default_conversion by not setting TREE_ADDRESSABLE
	 (because calling an inline function does not mean the function
	 needs to be separately compiled).  */

      if (DECL_INLINE (function))
	function = inline_conversion (function);
      else
	function = build_addr_func (function);
    }
  else
    {
      fndecl = NULL_TREE;

      function = build_addr_func (function);
    }

  if (function == error_mark_node)
    return error_mark_node;

  fntype = TREE_TYPE (function);

  if (TYPE_PTRMEMFUNC_P (fntype))
    {
      cp_error ("must use .* or ->* to call pointer-to-member function in `%E (...)'",
		function);
      return error_mark_node;
    }

  is_method = (TREE_CODE (fntype) == POINTER_TYPE
	       && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);

  if (!((TREE_CODE (fntype) == POINTER_TYPE
	 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
	|| is_method
	|| TREE_CODE (function) == TEMPLATE_ID_EXPR))
    {
      cp_error ("`%E' cannot be used as a function", function);
      return error_mark_node;
    }

  /* fntype now gets the type of function pointed to.  */
  fntype = TREE_TYPE (fntype);

  /* Convert the parameters to the types declared in the
     function prototype, or apply default promotions.  */

  if (flags & LOOKUP_COMPLAIN)
    coerced_params = convert_arguments (NULL_TREE, TYPE_ARG_TYPES (fntype),
					params, fndecl, LOOKUP_NORMAL);
  else
    coerced_params = convert_arguments (NULL_TREE, TYPE_ARG_TYPES (fntype),
					params, fndecl, 0);

  if (coerced_params == error_mark_node)
    {
      if (flags & LOOKUP_SPECULATIVELY)
	return NULL_TREE;
      else
	return error_mark_node;
    }

  /* Check for errors in format strings.  */

  if (warn_format && (name || assembler_name))
    check_function_format (name, assembler_name, coerced_params);

  /* Recognize certain built-in functions so we can make tree-codes
     other than CALL_EXPR.  We do this when it enables fold-const.c
     to do something useful.  */

  if (TREE_CODE (function) == ADDR_EXPR
      && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL
      && DECL_BUILT_IN (TREE_OPERAND (function, 0)))
    switch (DECL_FUNCTION_CODE (TREE_OPERAND (function, 0)))
      {
      case BUILT_IN_ABS:
      case BUILT_IN_LABS:
      case BUILT_IN_FABS:
	if (coerced_params == 0)
	  return integer_zero_node;
	return build_unary_op (ABS_EXPR, TREE_VALUE (coerced_params), 0);

      default:
	break;
      }

  /* C++ */
  value_type = TREE_TYPE (fntype) ? TREE_TYPE (fntype) : void_type_node;
  {
    register tree result
      = build_call (function, value_type, coerced_params);

    if (require_complete)
      {
	if (value_type == void_type_node)
	  return result;
	result = require_complete_type (result);
      }
    if (IS_AGGR_TYPE (value_type))
      result = build_cplus_new (value_type, result);
    return convert_from_reference (result);
  }
}

tree
build_function_call (function, params)
     tree function, params;
{
  return build_function_call_real (function, params, 1, LOOKUP_NORMAL);
}

/* Convert the actual parameter expressions in the list VALUES
   to the types in the list TYPELIST.
   If parmdecls is exhausted, or when an element has NULL as its type,
   perform the default conversions.

   RETURN_LOC is the location of the return value, if known, NULL_TREE
   otherwise.  This is useful in the case where we can avoid creating
   a temporary variable in the case where we can initialize the return
   value directly.  If we are not eliding constructors, then we set this
   to NULL_TREE to avoid this avoidance.

   NAME is an IDENTIFIER_NODE or 0.  It is used only for error messages.

   This is also where warnings about wrong number of args are generated.
   
   Return a list of expressions for the parameters as converted.

   Both VALUES and the returned value are chains of TREE_LIST nodes
   with the elements of the list in the TREE_VALUE slots of those nodes.

   In C++, unspecified trailing parameters can be filled in with their
   default arguments, if such were specified.  Do so here.  */

tree
convert_arguments (return_loc, typelist, values, fndecl, flags)
     tree return_loc, typelist, values, fndecl;
     int flags;
{
  register tree typetail, valtail;
  register tree result = NULL_TREE;
  char *called_thing = 0;
  int i = 0;

  if (! flag_elide_constructors)
    return_loc = 0;

  /* Argument passing is always copy-initialization.  */
  flags |= LOOKUP_ONLYCONVERTING;

  if (fndecl)
    {
      if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
	{
	  if (DECL_NAME (fndecl) == NULL_TREE
	      || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
	    called_thing = "constructor";
	  else
	    called_thing = "member function";
	}
      else
	called_thing = "function";
    }

  for (valtail = values, typetail = typelist;
       valtail;
       valtail = TREE_CHAIN (valtail), i++)
    {
      register tree type = typetail ? TREE_VALUE (typetail) : 0;
      register tree val = TREE_VALUE (valtail);

      if (val == error_mark_node)
	return error_mark_node;

      if (type == void_type_node)
	{
	  if (fndecl)
	    {
	      cp_error_at ("too many arguments to %s `%+D'", called_thing,
			   fndecl);
	      error ("at this point in file");
	    }
	  else
	    error ("too many arguments to function");
	  /* In case anybody wants to know if this argument
	     list is valid.  */
	  if (result)
	    TREE_TYPE (tree_last (result)) = error_mark_node;
	  break;
	}

      /* The tree type of the parameter being passed may not yet be
	 known.  In this case, its type is TYPE_UNKNOWN, and will
	 be instantiated by the type given by TYPE.  If TYPE
	 is also NULL, the tree type of VAL is ERROR_MARK_NODE.  */
      if (type && type_unknown_p (val))
	val = require_instantiated_type (type, val, integer_zero_node);
      else if (type_unknown_p (val))
	{
	  /* Strip the `&' from an overloaded FUNCTION_DECL.  */
	  if (TREE_CODE (val) == ADDR_EXPR)
	    val = TREE_OPERAND (val, 0);
	  if (really_overloaded_fn (val))
	    cp_error ("insufficient type information to resolve address of overloaded function `%D'",
		      DECL_NAME (get_first_fn (val)));
	  else
	    error ("insufficient type information in parameter list");
	  val = integer_zero_node;
	}
      else if (TREE_CODE (val) == OFFSET_REF
	    && TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
	{
	  /* This is unclean.  Should be handled elsewhere.  */
	  val = build_unary_op (ADDR_EXPR, val, 0);
	}
      else if (TREE_CODE (val) == OFFSET_REF)
	val = resolve_offset_ref (val);

      /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
	 Strip such NOP_EXPRs, since VAL is used in non-lvalue context.  */
      if (TREE_CODE (val) == NOP_EXPR
	  && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
	  && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
	val = TREE_OPERAND (val, 0);

      if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
	{
	  if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
	      || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
	      || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
	    val = default_conversion (val);

	  val = require_complete_type (val);
	}

      if (val == error_mark_node)
	return error_mark_node;

      if (type != 0)
	{
	  /* Formal parm type is specified by a function prototype.  */
	  tree parmval;

	  if (TYPE_SIZE (complete_type (type)) == 0)
	    {
	      error ("parameter type of called function is incomplete");
	      parmval = val;
	    }
	  else
	    {
	      parmval = convert_for_initialization
		(return_loc, type, val, flags,
		 "argument passing", fndecl, i);
#ifdef PROMOTE_PROTOTYPES
	      if ((TREE_CODE (type) == INTEGER_TYPE
		   || TREE_CODE (type) == ENUMERAL_TYPE)
		  && (TYPE_PRECISION (type)
		      < TYPE_PRECISION (integer_type_node)))
		parmval = default_conversion (parmval);
#endif
	    }

	  if (parmval == error_mark_node)
	    return error_mark_node;

	  result = expr_tree_cons (NULL_TREE, parmval, result);
	}
      else
	{
	  if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
	    val = convert_from_reference (val);

	  result = expr_tree_cons (NULL_TREE,
				   convert_arg_to_ellipsis (val),
				   result);
	}

      if (typetail)
	typetail = TREE_CHAIN (typetail);
    }

  if (typetail != 0 && typetail != void_list_node)
    {
      /* See if there are default arguments that can be used */
      if (TREE_PURPOSE (typetail))
	{
	  for (; typetail != void_list_node; ++i)
	    {
	      tree type = TREE_VALUE (typetail);
	      tree val = TREE_PURPOSE (typetail);
	      tree parmval = convert_default_arg (type, val);

	      if (parmval == error_mark_node)
		return error_mark_node;

	      result = expr_tree_cons (0, parmval, result);
	      typetail = TREE_CHAIN (typetail);
	      /* ends with `...'.  */
	      if (typetail == NULL_TREE)
		break;
	    }
	}
      else
	{
	  if (fndecl)
	    {
	      char *buf = (char *)alloca (32 + strlen (called_thing));
	      sprintf (buf, "too few arguments to %s `%%#D'", called_thing);
	      cp_error_at (buf, fndecl);
	      error ("at this point in file");
	    }
	  else
	    error ("too few arguments to function");
	  return error_mark_list;
	}
    }

  return nreverse (result);
}

/* Build a binary-operation expression, after performing default
   conversions on the operands.  CODE is the kind of expression to build.  */

tree
build_x_binary_op (code, arg1, arg2)
     enum tree_code code;
     tree arg1, arg2;