1293 lines
39 KiB
C
1293 lines
39 KiB
C
/* Language-level data type conversion for GNU C++.
|
||
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
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1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
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Hacked by Michael Tiemann (tiemann@cygnus.com)
|
||
|
||
This file is part of GCC.
|
||
|
||
GCC is free software; you can redistribute it and/or modify
|
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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.
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||
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||
GCC 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.
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||
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||
You should have received a copy of the GNU General Public License
|
||
along with GCC; see the file COPYING. If not, write to
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the Free Software Foundation, 51 Franklin Street, Fifth Floor,
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||
Boston, MA 02110-1301, USA. */
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||
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/* This file contains the functions for converting C++ expressions
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to different data types. The only entry point is `convert'.
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Every language front end must have a `convert' function
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but what kind of conversions it does will depend on the language. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tree.h"
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#include "flags.h"
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#include "cp-tree.h"
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#include "convert.h"
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#include "toplev.h"
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#include "decl.h"
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#include "target.h"
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static tree cp_convert_to_pointer (tree, tree, bool);
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static tree convert_to_pointer_force (tree, tree);
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static tree build_type_conversion (tree, tree);
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static tree build_up_reference (tree, tree, int, tree);
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static void warn_ref_binding (tree, tree, tree);
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/* Change of width--truncation and extension of integers or reals--
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is represented with NOP_EXPR. Proper functioning of many things
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assumes that no other conversions can be NOP_EXPRs.
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Conversion between integer and pointer is represented with CONVERT_EXPR.
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Converting integer to real uses FLOAT_EXPR
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and real to integer uses FIX_TRUNC_EXPR.
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Here is a list of all the functions that assume that widening and
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narrowing is always done with a NOP_EXPR:
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In convert.c, convert_to_integer.
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In c-typeck.c, build_binary_op_nodefault (boolean ops),
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and c_common_truthvalue_conversion.
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In expr.c: expand_expr, for operands of a MULT_EXPR.
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In fold-const.c: fold.
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In tree.c: get_narrower and get_unwidened.
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C++: in multiple-inheritance, converting between pointers may involve
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adjusting them by a delta stored within the class definition. */
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/* Subroutines of `convert'. */
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/* if converting pointer to pointer
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if dealing with classes, check for derived->base or vice versa
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else if dealing with method pointers, delegate
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else convert blindly
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else if converting class, pass off to build_type_conversion
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else try C-style pointer conversion. If FORCE is true then allow
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conversions via virtual bases (these are permitted by reinterpret_cast,
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but not static_cast). */
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static tree
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cp_convert_to_pointer (tree type, tree expr, bool force)
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{
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tree intype = TREE_TYPE (expr);
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enum tree_code form;
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tree rval;
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if (intype == error_mark_node)
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return error_mark_node;
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if (IS_AGGR_TYPE (intype))
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{
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intype = complete_type (intype);
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if (!COMPLETE_TYPE_P (intype))
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{
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error ("can't convert from incomplete type %qT to %qT",
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intype, type);
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return error_mark_node;
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}
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rval = build_type_conversion (type, expr);
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if (rval)
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{
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if (rval == error_mark_node)
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error ("conversion of %qE from %qT to %qT is ambiguous",
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expr, intype, type);
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return rval;
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}
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}
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/* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */
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if (TREE_CODE (type) == POINTER_TYPE
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&& (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
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|| VOID_TYPE_P (TREE_TYPE (type))))
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{
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if (TYPE_PTRMEMFUNC_P (intype)
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|| TREE_CODE (intype) == METHOD_TYPE)
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return convert_member_func_to_ptr (type, expr);
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if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
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return build_nop (type, expr);
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intype = TREE_TYPE (expr);
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}
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if (expr == error_mark_node)
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return error_mark_node;
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form = TREE_CODE (intype);
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if (POINTER_TYPE_P (intype))
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{
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intype = TYPE_MAIN_VARIANT (intype);
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if (TYPE_MAIN_VARIANT (type) != intype
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&& TREE_CODE (type) == POINTER_TYPE
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&& TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE
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||
&& IS_AGGR_TYPE (TREE_TYPE (type))
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&& IS_AGGR_TYPE (TREE_TYPE (intype))
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&& TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE)
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{
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enum tree_code code = PLUS_EXPR;
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tree binfo;
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tree intype_class;
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tree type_class;
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bool same_p;
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intype_class = TREE_TYPE (intype);
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type_class = TREE_TYPE (type);
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same_p = same_type_p (TYPE_MAIN_VARIANT (intype_class),
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TYPE_MAIN_VARIANT (type_class));
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binfo = NULL_TREE;
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/* Try derived to base conversion. */
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if (!same_p)
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binfo = lookup_base (intype_class, type_class, ba_check, NULL);
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if (!same_p && !binfo)
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{
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/* Try base to derived conversion. */
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binfo = lookup_base (type_class, intype_class, ba_check, NULL);
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code = MINUS_EXPR;
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}
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if (binfo == error_mark_node)
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return error_mark_node;
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if (binfo || same_p)
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{
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if (binfo)
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expr = build_base_path (code, expr, binfo, 0);
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/* Add any qualifier conversions. */
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return build_nop (type, expr);
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}
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}
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if (TYPE_PTRMEMFUNC_P (type))
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{
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error ("cannot convert %qE from type %qT to type %qT",
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expr, intype, type);
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return error_mark_node;
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}
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return build_nop (type, expr);
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}
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else if (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
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{
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tree b1;
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tree b2;
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tree binfo;
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enum tree_code code = PLUS_EXPR;
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base_kind bk;
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b1 = TYPE_PTRMEM_CLASS_TYPE (type);
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b2 = TYPE_PTRMEM_CLASS_TYPE (intype);
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binfo = lookup_base (b1, b2, ba_check, &bk);
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if (!binfo)
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{
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binfo = lookup_base (b2, b1, ba_check, &bk);
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code = MINUS_EXPR;
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}
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if (binfo == error_mark_node)
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return error_mark_node;
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if (bk == bk_via_virtual)
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{
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if (force)
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warning (0, "pointer to member cast from %qT to %qT is via"
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" virtual base", intype, type);
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else
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{
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error ("pointer to member cast from %qT to %qT is"
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" via virtual base", intype, type);
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return error_mark_node;
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}
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/* This is a reinterpret cast, whose result is unspecified.
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We choose to do nothing. */
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return build1 (NOP_EXPR, type, expr);
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}
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||
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if (TREE_CODE (expr) == PTRMEM_CST)
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expr = cplus_expand_constant (expr);
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||
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||
if (binfo && !integer_zerop (BINFO_OFFSET (binfo)))
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||
expr = size_binop (code,
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build_nop (sizetype, expr),
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BINFO_OFFSET (binfo));
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return build_nop (type, expr);
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}
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else if (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))
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return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0,
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/*c_cast_p=*/false);
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else if (TYPE_PTRMEMFUNC_P (intype))
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{
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if (!warn_pmf2ptr)
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{
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if (TREE_CODE (expr) == PTRMEM_CST)
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return cp_convert_to_pointer (type,
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PTRMEM_CST_MEMBER (expr),
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force);
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else if (TREE_CODE (expr) == OFFSET_REF)
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{
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tree object = TREE_OPERAND (expr, 0);
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return get_member_function_from_ptrfunc (&object,
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TREE_OPERAND (expr, 1));
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}
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}
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error ("cannot convert %qE from type %qT to type %qT",
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expr, intype, type);
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return error_mark_node;
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}
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if (integer_zerop (expr))
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{
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||
if (TYPE_PTRMEMFUNC_P (type))
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return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0,
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/*c_cast_p=*/false);
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||
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if (TYPE_PTRMEM_P (type))
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{
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/* A NULL pointer-to-member is represented by -1, not by
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zero. */
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expr = build_int_cst (type, -1);
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/* Fix up the representation of -1 if appropriate. */
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expr = force_fit_type (expr, 0, false, false);
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}
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else
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expr = build_int_cst (type, 0);
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return expr;
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}
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else if (TYPE_PTR_TO_MEMBER_P (type) && INTEGRAL_CODE_P (form))
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{
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error ("invalid conversion from %qT to %qT", intype, type);
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return error_mark_node;
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}
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if (INTEGRAL_CODE_P (form))
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{
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if (TYPE_PRECISION (intype) == POINTER_SIZE)
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return build1 (CONVERT_EXPR, type, expr);
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expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr);
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/* Modes may be different but sizes should be the same. There
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is supposed to be some integral type that is the same width
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as a pointer. */
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gcc_assert (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr)))
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== GET_MODE_SIZE (TYPE_MODE (type)));
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return convert_to_pointer (type, expr);
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}
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if (type_unknown_p (expr))
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return instantiate_type (type, expr, tf_warning_or_error);
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error ("cannot convert %qE from type %qT to type %qT",
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expr, intype, type);
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return error_mark_node;
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}
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||
/* Like convert, except permit conversions to take place which
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are not normally allowed due to access restrictions
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(such as conversion from sub-type to private super-type). */
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static tree
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convert_to_pointer_force (tree type, tree expr)
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||
{
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||
tree intype = TREE_TYPE (expr);
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enum tree_code form = TREE_CODE (intype);
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||
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if (form == POINTER_TYPE)
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{
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intype = TYPE_MAIN_VARIANT (intype);
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if (TYPE_MAIN_VARIANT (type) != intype
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&& TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE
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||
&& IS_AGGR_TYPE (TREE_TYPE (type))
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||
&& IS_AGGR_TYPE (TREE_TYPE (intype))
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||
&& TREE_CODE (TREE_TYPE (intype)) == RECORD_TYPE)
|
||
{
|
||
enum tree_code code = PLUS_EXPR;
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||
tree binfo;
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||
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||
binfo = lookup_base (TREE_TYPE (intype), TREE_TYPE (type),
|
||
ba_unique, NULL);
|
||
if (!binfo)
|
||
{
|
||
binfo = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
|
||
ba_unique, NULL);
|
||
code = MINUS_EXPR;
|
||
}
|
||
if (binfo == error_mark_node)
|
||
return error_mark_node;
|
||
if (binfo)
|
||
{
|
||
expr = build_base_path (code, expr, binfo, 0);
|
||
if (expr == error_mark_node)
|
||
return error_mark_node;
|
||
/* Add any qualifier conversions. */
|
||
if (!same_type_p (TREE_TYPE (TREE_TYPE (expr)),
|
||
TREE_TYPE (type)))
|
||
expr = build_nop (type, expr);
|
||
return expr;
|
||
}
|
||
}
|
||
}
|
||
|
||
return cp_convert_to_pointer (type, expr, true);
|
||
}
|
||
|
||
/* We are passing something to a function which requires a reference.
|
||
The type we are interested in is in TYPE. The initial
|
||
value we have to begin with is in ARG.
|
||
|
||
FLAGS controls how we manage access checking.
|
||
DIRECT_BIND in FLAGS controls how any temporaries are generated.
|
||
If DIRECT_BIND is set, DECL is the reference we're binding to. */
|
||
|
||
static tree
|
||
build_up_reference (tree type, tree arg, int flags, tree decl)
|
||
{
|
||
tree rval;
|
||
tree argtype = TREE_TYPE (arg);
|
||
tree target_type = TREE_TYPE (type);
|
||
|
||
gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
|
||
|
||
if ((flags & DIRECT_BIND) && ! real_lvalue_p (arg))
|
||
{
|
||
/* Create a new temporary variable. We can't just use a TARGET_EXPR
|
||
here because it needs to live as long as DECL. */
|
||
tree targ = arg;
|
||
|
||
arg = make_temporary_var_for_ref_to_temp (decl, TREE_TYPE (arg));
|
||
|
||
/* Process the initializer for the declaration. */
|
||
DECL_INITIAL (arg) = targ;
|
||
cp_finish_decl (arg, targ, /*init_const_expr_p=*/false, NULL_TREE,
|
||
LOOKUP_ONLYCONVERTING|DIRECT_BIND);
|
||
}
|
||
else if (!(flags & DIRECT_BIND) && ! lvalue_p (arg))
|
||
return get_target_expr (arg);
|
||
|
||
/* If we had a way to wrap this up, and say, if we ever needed its
|
||
address, transform all occurrences of the register, into a memory
|
||
reference we could win better. */
|
||
rval = build_unary_op (ADDR_EXPR, arg, 1);
|
||
if (rval == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
if ((flags & LOOKUP_PROTECT)
|
||
&& TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type)
|
||
&& IS_AGGR_TYPE (argtype)
|
||
&& IS_AGGR_TYPE (target_type))
|
||
{
|
||
/* We go through lookup_base for the access control. */
|
||
tree binfo = lookup_base (argtype, target_type, ba_check, NULL);
|
||
if (binfo == error_mark_node)
|
||
return error_mark_node;
|
||
if (binfo == NULL_TREE)
|
||
return error_not_base_type (target_type, argtype);
|
||
rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
|
||
}
|
||
else
|
||
rval
|
||
= convert_to_pointer_force (build_pointer_type (target_type), rval);
|
||
return build_nop (type, rval);
|
||
}
|
||
|
||
/* Subroutine of convert_to_reference. REFTYPE is the target reference type.
|
||
INTYPE is the original rvalue type and DECL is an optional _DECL node
|
||
for diagnostics.
|
||
|
||
[dcl.init.ref] says that if an rvalue is used to
|
||
initialize a reference, then the reference must be to a
|
||
non-volatile const type. */
|
||
|
||
static void
|
||
warn_ref_binding (tree reftype, tree intype, tree decl)
|
||
{
|
||
tree ttl = TREE_TYPE (reftype);
|
||
|
||
if (!CP_TYPE_CONST_NON_VOLATILE_P (ttl))
|
||
{
|
||
const char *msg;
|
||
|
||
if (CP_TYPE_VOLATILE_P (ttl) && decl)
|
||
msg = "initialization of volatile reference type %q#T from"
|
||
" rvalue of type %qT";
|
||
else if (CP_TYPE_VOLATILE_P (ttl))
|
||
msg = "conversion to volatile reference type %q#T "
|
||
" from rvalue of type %qT";
|
||
else if (decl)
|
||
msg = "initialization of non-const reference type %q#T from"
|
||
" rvalue of type %qT";
|
||
else
|
||
msg = "conversion to non-const reference type %q#T from"
|
||
" rvalue of type %qT";
|
||
|
||
pedwarn (msg, reftype, intype);
|
||
}
|
||
}
|
||
|
||
/* For C++: Only need to do one-level references, but cannot
|
||
get tripped up on signed/unsigned differences.
|
||
|
||
DECL is either NULL_TREE or the _DECL node for a reference that is being
|
||
initialized. It can be error_mark_node if we don't know the _DECL but
|
||
we know it's an initialization. */
|
||
|
||
tree
|
||
convert_to_reference (tree reftype, tree expr, int convtype,
|
||
int flags, tree decl)
|
||
{
|
||
tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype));
|
||
tree intype;
|
||
tree rval = NULL_TREE;
|
||
tree rval_as_conversion = NULL_TREE;
|
||
bool can_convert_intype_to_type;
|
||
|
||
if (TREE_CODE (type) == FUNCTION_TYPE
|
||
&& TREE_TYPE (expr) == unknown_type_node)
|
||
expr = instantiate_type (type, expr,
|
||
(flags & LOOKUP_COMPLAIN)
|
||
? tf_warning_or_error : tf_none);
|
||
|
||
if (expr == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
intype = TREE_TYPE (expr);
|
||
|
||
gcc_assert (TREE_CODE (intype) != REFERENCE_TYPE);
|
||
gcc_assert (TREE_CODE (reftype) == REFERENCE_TYPE);
|
||
|
||
intype = TYPE_MAIN_VARIANT (intype);
|
||
|
||
can_convert_intype_to_type = can_convert (type, intype);
|
||
if (!can_convert_intype_to_type
|
||
&& (convtype & CONV_IMPLICIT) && IS_AGGR_TYPE (intype)
|
||
&& ! (flags & LOOKUP_NO_CONVERSION))
|
||
{
|
||
/* Look for a user-defined conversion to lvalue that we can use. */
|
||
|
||
rval_as_conversion
|
||
= build_type_conversion (reftype, expr);
|
||
|
||
if (rval_as_conversion && rval_as_conversion != error_mark_node
|
||
&& real_lvalue_p (rval_as_conversion))
|
||
{
|
||
expr = rval_as_conversion;
|
||
rval_as_conversion = NULL_TREE;
|
||
intype = type;
|
||
can_convert_intype_to_type = 1;
|
||
}
|
||
}
|
||
|
||
if (((convtype & CONV_STATIC) && can_convert (intype, type))
|
||
|| ((convtype & CONV_IMPLICIT) && can_convert_intype_to_type))
|
||
{
|
||
if (flags & LOOKUP_COMPLAIN)
|
||
{
|
||
tree ttl = TREE_TYPE (reftype);
|
||
tree ttr = lvalue_type (expr);
|
||
|
||
if (! real_lvalue_p (expr))
|
||
warn_ref_binding (reftype, intype, decl);
|
||
|
||
if (! (convtype & CONV_CONST)
|
||
&& !at_least_as_qualified_p (ttl, ttr))
|
||
pedwarn ("conversion from %qT to %qT discards qualifiers",
|
||
ttr, reftype);
|
||
}
|
||
|
||
return build_up_reference (reftype, expr, flags, decl);
|
||
}
|
||
else if ((convtype & CONV_REINTERPRET) && lvalue_p (expr))
|
||
{
|
||
/* When casting an lvalue to a reference type, just convert into
|
||
a pointer to the new type and deference it. This is allowed
|
||
by San Diego WP section 5.2.9 paragraph 12, though perhaps it
|
||
should be done directly (jason). (int &)ri ---> *(int*)&ri */
|
||
|
||
/* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they
|
||
meant. */
|
||
if (TREE_CODE (intype) == POINTER_TYPE
|
||
&& (comptypes (TREE_TYPE (intype), type,
|
||
COMPARE_BASE | COMPARE_DERIVED)))
|
||
warning (0, "casting %qT to %qT does not dereference pointer",
|
||
intype, reftype);
|
||
|
||
rval = build_unary_op (ADDR_EXPR, expr, 0);
|
||
if (rval != error_mark_node)
|
||
rval = convert_force (build_pointer_type (TREE_TYPE (reftype)),
|
||
rval, 0);
|
||
if (rval != error_mark_node)
|
||
rval = build1 (NOP_EXPR, reftype, rval);
|
||
}
|
||
else
|
||
{
|
||
rval = convert_for_initialization (NULL_TREE, type, expr, flags,
|
||
"converting", 0, 0);
|
||
if (rval == NULL_TREE || rval == error_mark_node)
|
||
return rval;
|
||
warn_ref_binding (reftype, intype, decl);
|
||
rval = build_up_reference (reftype, rval, flags, decl);
|
||
}
|
||
|
||
if (rval)
|
||
{
|
||
/* If we found a way to convert earlier, then use it. */
|
||
return rval;
|
||
}
|
||
|
||
if (flags & LOOKUP_COMPLAIN)
|
||
error ("cannot convert type %qT to type %qT", intype, reftype);
|
||
|
||
return error_mark_node;
|
||
}
|
||
|
||
/* We are using a reference VAL for its value. Bash that reference all the
|
||
way down to its lowest form. */
|
||
|
||
tree
|
||
convert_from_reference (tree val)
|
||
{
|
||
if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
|
||
{
|
||
tree t = canonical_type_variant (TREE_TYPE (TREE_TYPE (val)));
|
||
tree ref = build1 (INDIRECT_REF, t, val);
|
||
|
||
/* 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) = CP_TYPE_CONST_P (t);
|
||
TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
|
||
TREE_SIDE_EFFECTS (ref)
|
||
= (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val));
|
||
REFERENCE_REF_P (ref) = 1;
|
||
val = ref;
|
||
}
|
||
|
||
return val;
|
||
}
|
||
|
||
/* Really perform an lvalue-to-rvalue conversion, including copying an
|
||
argument of class type into a temporary. */
|
||
|
||
tree
|
||
force_rvalue (tree expr)
|
||
{
|
||
if (IS_AGGR_TYPE (TREE_TYPE (expr)) && TREE_CODE (expr) != TARGET_EXPR)
|
||
expr = ocp_convert (TREE_TYPE (expr), expr,
|
||
CONV_IMPLICIT|CONV_FORCE_TEMP, LOOKUP_NORMAL);
|
||
else
|
||
expr = decay_conversion (expr);
|
||
|
||
return expr;
|
||
}
|
||
|
||
/* C++ conversions, preference to static cast conversions. */
|
||
|
||
tree
|
||
cp_convert (tree type, tree expr)
|
||
{
|
||
return ocp_convert (type, expr, CONV_OLD_CONVERT, LOOKUP_NORMAL);
|
||
}
|
||
|
||
/* Conversion...
|
||
|
||
FLAGS indicates how we should behave. */
|
||
|
||
tree
|
||
ocp_convert (tree type, tree expr, int convtype, int flags)
|
||
{
|
||
tree e = expr;
|
||
enum tree_code code = TREE_CODE (type);
|
||
const char *invalid_conv_diag;
|
||
|
||
if (error_operand_p (e) || type == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
complete_type (type);
|
||
complete_type (TREE_TYPE (expr));
|
||
|
||
if ((invalid_conv_diag
|
||
= targetm.invalid_conversion (TREE_TYPE (expr), type)))
|
||
{
|
||
error (invalid_conv_diag, "");
|
||
return error_mark_node;
|
||
}
|
||
|
||
e = integral_constant_value (e);
|
||
|
||
if (IS_AGGR_TYPE (type) && (convtype & CONV_FORCE_TEMP)
|
||
/* Some internal structures (vtable_entry_type, sigtbl_ptr_type)
|
||
don't go through finish_struct, so they don't have the synthesized
|
||
constructors. So don't force a temporary. */
|
||
&& TYPE_HAS_CONSTRUCTOR (type))
|
||
/* We need a new temporary; don't take this shortcut. */;
|
||
else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (e)))
|
||
{
|
||
if (same_type_p (type, TREE_TYPE (e)))
|
||
/* The call to fold will not always remove the NOP_EXPR as
|
||
might be expected, since if one of the types is a typedef;
|
||
the comparison in fold is just equality of pointers, not a
|
||
call to comptypes. We don't call fold in this case because
|
||
that can result in infinite recursion; fold will call
|
||
convert, which will call ocp_convert, etc. */
|
||
return e;
|
||
/* For complex data types, we need to perform componentwise
|
||
conversion. */
|
||
else if (TREE_CODE (type) == COMPLEX_TYPE)
|
||
return fold_if_not_in_template (convert_to_complex (type, e));
|
||
else if (TREE_CODE (e) == TARGET_EXPR)
|
||
{
|
||
/* Don't build a NOP_EXPR of class type. Instead, change the
|
||
type of the temporary. Only allow this for cv-qual changes,
|
||
though. */
|
||
gcc_assert (same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (e)),
|
||
TYPE_MAIN_VARIANT (type)));
|
||
TREE_TYPE (e) = TREE_TYPE (TARGET_EXPR_SLOT (e)) = type;
|
||
return e;
|
||
}
|
||
else
|
||
{
|
||
/* We shouldn't be treating objects of ADDRESSABLE type as
|
||
rvalues. */
|
||
gcc_assert (!TREE_ADDRESSABLE (type));
|
||
return fold_if_not_in_template (build_nop (type, e));
|
||
}
|
||
}
|
||
|
||
if (code == VOID_TYPE && (convtype & CONV_STATIC))
|
||
{
|
||
e = convert_to_void (e, /*implicit=*/NULL);
|
||
return e;
|
||
}
|
||
|
||
if (INTEGRAL_CODE_P (code))
|
||
{
|
||
tree intype = TREE_TYPE (e);
|
||
/* enum = enum, enum = int, enum = float, (enum)pointer are all
|
||
errors. */
|
||
if (TREE_CODE (type) == ENUMERAL_TYPE
|
||
&& (((INTEGRAL_OR_ENUMERATION_TYPE_P (intype)
|
||
|| TREE_CODE (intype) == REAL_TYPE)
|
||
&& ! (convtype & CONV_STATIC))
|
||
|| TREE_CODE (intype) == POINTER_TYPE))
|
||
{
|
||
if (flags & LOOKUP_COMPLAIN)
|
||
pedwarn ("conversion from %q#T to %q#T", intype, type);
|
||
|
||
if (flag_pedantic_errors)
|
||
return error_mark_node;
|
||
}
|
||
if (IS_AGGR_TYPE (intype))
|
||
{
|
||
tree rval;
|
||
rval = build_type_conversion (type, e);
|
||
if (rval)
|
||
return rval;
|
||
if (flags & LOOKUP_COMPLAIN)
|
||
error ("%q#T used where a %qT was expected", intype, type);
|
||
return error_mark_node;
|
||
}
|
||
if (code == BOOLEAN_TYPE)
|
||
return cp_truthvalue_conversion (e);
|
||
|
||
return fold_if_not_in_template (convert_to_integer (type, e));
|
||
}
|
||
if (POINTER_TYPE_P (type) || TYPE_PTR_TO_MEMBER_P (type))
|
||
return fold_if_not_in_template (cp_convert_to_pointer (type, e, false));
|
||
if (code == VECTOR_TYPE)
|
||
{
|
||
tree in_vtype = TREE_TYPE (e);
|
||
if (IS_AGGR_TYPE (in_vtype))
|
||
{
|
||
tree ret_val;
|
||
ret_val = build_type_conversion (type, e);
|
||
if (ret_val)
|
||
return ret_val;
|
||
if (flags & LOOKUP_COMPLAIN)
|
||
error ("%q#T used where a %qT was expected", in_vtype, type);
|
||
return error_mark_node;
|
||
}
|
||
return fold_if_not_in_template (convert_to_vector (type, e));
|
||
}
|
||
if (code == REAL_TYPE || code == COMPLEX_TYPE)
|
||
{
|
||
if (IS_AGGR_TYPE (TREE_TYPE (e)))
|
||
{
|
||
tree rval;
|
||
rval = build_type_conversion (type, e);
|
||
if (rval)
|
||
return rval;
|
||
else
|
||
if (flags & LOOKUP_COMPLAIN)
|
||
error ("%q#T used where a floating point value was expected",
|
||
TREE_TYPE (e));
|
||
}
|
||
if (code == REAL_TYPE)
|
||
return fold_if_not_in_template (convert_to_real (type, e));
|
||
else if (code == COMPLEX_TYPE)
|
||
return fold_if_not_in_template (convert_to_complex (type, e));
|
||
}
|
||
|
||
/* New C++ semantics: since assignment is now based on
|
||
memberwise copying, if the rhs type is derived from the
|
||
lhs type, then we may still do a conversion. */
|
||
if (IS_AGGR_TYPE_CODE (code))
|
||
{
|
||
tree dtype = TREE_TYPE (e);
|
||
tree ctor = NULL_TREE;
|
||
|
||
dtype = TYPE_MAIN_VARIANT (dtype);
|
||
|
||
/* Conversion between aggregate types. New C++ semantics allow
|
||
objects of derived type to be cast to objects of base type.
|
||
Old semantics only allowed this between pointers.
|
||
|
||
There may be some ambiguity between using a constructor
|
||
vs. using a type conversion operator when both apply. */
|
||
|
||
ctor = e;
|
||
|
||
if (abstract_virtuals_error (NULL_TREE, type))
|
||
return error_mark_node;
|
||
|
||
if ((flags & LOOKUP_ONLYCONVERTING)
|
||
&& ! (IS_AGGR_TYPE (dtype) && DERIVED_FROM_P (type, dtype)))
|
||
/* For copy-initialization, first we create a temp of the proper type
|
||
with a user-defined conversion sequence, then we direct-initialize
|
||
the target with the temp (see [dcl.init]). */
|
||
ctor = build_user_type_conversion (type, ctor, flags);
|
||
else
|
||
ctor = build_special_member_call (NULL_TREE,
|
||
complete_ctor_identifier,
|
||
build_tree_list (NULL_TREE, ctor),
|
||
type, flags);
|
||
if (ctor)
|
||
return build_cplus_new (type, ctor);
|
||
}
|
||
|
||
if (flags & LOOKUP_COMPLAIN)
|
||
error ("conversion from %qT to non-scalar type %qT requested",
|
||
TREE_TYPE (expr), type);
|
||
return error_mark_node;
|
||
}
|
||
|
||
/* When an expression is used in a void context, its value is discarded and
|
||
no lvalue-rvalue and similar conversions happen [expr.static.cast/4,
|
||
stmt.expr/1, expr.comma/1]. This permits dereferencing an incomplete type
|
||
in a void context. The C++ standard does not define what an `access' to an
|
||
object is, but there is reason to believe that it is the lvalue to rvalue
|
||
conversion -- if it were not, `*&*p = 1' would violate [expr]/4 in that it
|
||
accesses `*p' not to calculate the value to be stored. But, dcl.type.cv/8
|
||
indicates that volatile semantics should be the same between C and C++
|
||
where ever possible. C leaves it implementation defined as to what
|
||
constitutes an access to a volatile. So, we interpret `*vp' as a read of
|
||
the volatile object `vp' points to, unless that is an incomplete type. For
|
||
volatile references we do not do this interpretation, because that would
|
||
make it impossible to ignore the reference return value from functions. We
|
||
issue warnings in the confusing cases.
|
||
|
||
IMPLICIT is tells us the context of an implicit void conversion. */
|
||
|
||
tree
|
||
convert_to_void (tree expr, const char *implicit)
|
||
{
|
||
if (expr == error_mark_node
|
||
|| TREE_TYPE (expr) == error_mark_node)
|
||
return error_mark_node;
|
||
if (!TREE_TYPE (expr))
|
||
return expr;
|
||
if (invalid_nonstatic_memfn_p (expr))
|
||
return error_mark_node;
|
||
if (TREE_CODE (expr) == PSEUDO_DTOR_EXPR)
|
||
{
|
||
error ("pseudo-destructor is not called");
|
||
return error_mark_node;
|
||
}
|
||
if (VOID_TYPE_P (TREE_TYPE (expr)))
|
||
return expr;
|
||
switch (TREE_CODE (expr))
|
||
{
|
||
case COND_EXPR:
|
||
{
|
||
/* The two parts of a cond expr might be separate lvalues. */
|
||
tree op1 = TREE_OPERAND (expr,1);
|
||
tree op2 = TREE_OPERAND (expr,2);
|
||
tree new_op1 = convert_to_void
|
||
(op1, (implicit && !TREE_SIDE_EFFECTS (op2)
|
||
? "second operand of conditional" : NULL));
|
||
tree new_op2 = convert_to_void
|
||
(op2, (implicit && !TREE_SIDE_EFFECTS (op1)
|
||
? "third operand of conditional" : NULL));
|
||
|
||
expr = build3 (COND_EXPR, TREE_TYPE (new_op1),
|
||
TREE_OPERAND (expr, 0), new_op1, new_op2);
|
||
break;
|
||
}
|
||
|
||
case COMPOUND_EXPR:
|
||
{
|
||
/* The second part of a compound expr contains the value. */
|
||
tree op1 = TREE_OPERAND (expr,1);
|
||
tree new_op1 = convert_to_void
|
||
(op1, (implicit && !TREE_NO_WARNING (expr)
|
||
? "right-hand operand of comma" : NULL));
|
||
|
||
if (new_op1 != op1)
|
||
{
|
||
tree t = build2 (COMPOUND_EXPR, TREE_TYPE (new_op1),
|
||
TREE_OPERAND (expr, 0), new_op1);
|
||
expr = t;
|
||
}
|
||
|
||
break;
|
||
}
|
||
|
||
case NON_LVALUE_EXPR:
|
||
case NOP_EXPR:
|
||
/* These have already decayed to rvalue. */
|
||
break;
|
||
|
||
case CALL_EXPR: /* We have a special meaning for volatile void fn(). */
|
||
break;
|
||
|
||
case INDIRECT_REF:
|
||
{
|
||
tree type = TREE_TYPE (expr);
|
||
int is_reference = TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0)))
|
||
== REFERENCE_TYPE;
|
||
int is_volatile = TYPE_VOLATILE (type);
|
||
int is_complete = COMPLETE_TYPE_P (complete_type (type));
|
||
|
||
/* Can't load the value if we don't know the type. */
|
||
if (is_volatile && !is_complete)
|
||
warning (0, "object of incomplete type %qT will not be accessed in %s",
|
||
type, implicit ? implicit : "void context");
|
||
/* Don't load the value if this is an implicit dereference, or if
|
||
the type needs to be handled by ctors/dtors. */
|
||
else if (is_volatile && (is_reference || TREE_ADDRESSABLE (type)))
|
||
warning (0, "object of type %qT will not be accessed in %s",
|
||
TREE_TYPE (TREE_OPERAND (expr, 0)),
|
||
implicit ? implicit : "void context");
|
||
if (is_reference || !is_volatile || !is_complete || TREE_ADDRESSABLE (type))
|
||
expr = TREE_OPERAND (expr, 0);
|
||
|
||
break;
|
||
}
|
||
|
||
case VAR_DECL:
|
||
{
|
||
/* External variables might be incomplete. */
|
||
tree type = TREE_TYPE (expr);
|
||
int is_complete = COMPLETE_TYPE_P (complete_type (type));
|
||
|
||
if (TYPE_VOLATILE (type) && !is_complete)
|
||
warning (0, "object %qE of incomplete type %qT will not be accessed in %s",
|
||
expr, type, implicit ? implicit : "void context");
|
||
break;
|
||
}
|
||
|
||
case TARGET_EXPR:
|
||
/* Don't bother with the temporary object returned from a function if
|
||
we don't use it and don't need to destroy it. We'll still
|
||
allocate space for it in expand_call or declare_return_variable,
|
||
but we don't need to track it through all the tree phases. */
|
||
if (TARGET_EXPR_IMPLICIT_P (expr)
|
||
&& TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (expr)))
|
||
{
|
||
tree init = TARGET_EXPR_INITIAL (expr);
|
||
if (TREE_CODE (init) == AGGR_INIT_EXPR
|
||
&& !AGGR_INIT_VIA_CTOR_P (init))
|
||
{
|
||
tree fn = TREE_OPERAND (init, 0);
|
||
expr = build3 (CALL_EXPR, TREE_TYPE (TREE_TYPE (TREE_TYPE (fn))),
|
||
fn, TREE_OPERAND (init, 1), NULL_TREE);
|
||
}
|
||
}
|
||
break;
|
||
|
||
default:;
|
||
}
|
||
{
|
||
tree probe = expr;
|
||
|
||
if (TREE_CODE (probe) == ADDR_EXPR)
|
||
probe = TREE_OPERAND (expr, 0);
|
||
if (type_unknown_p (probe))
|
||
{
|
||
/* [over.over] enumerates the places where we can take the address
|
||
of an overloaded function, and this is not one of them. */
|
||
pedwarn ("%s cannot resolve address of overloaded function",
|
||
implicit ? implicit : "void cast");
|
||
expr = void_zero_node;
|
||
}
|
||
else if (implicit && probe == expr && is_overloaded_fn (probe))
|
||
{
|
||
/* Only warn when there is no &. */
|
||
warning (OPT_Waddress, "%s is a reference, not call, to function %qE",
|
||
implicit, expr);
|
||
if (TREE_CODE (expr) == COMPONENT_REF)
|
||
expr = TREE_OPERAND (expr, 0);
|
||
}
|
||
}
|
||
|
||
if (expr != error_mark_node && !VOID_TYPE_P (TREE_TYPE (expr)))
|
||
{
|
||
if (implicit
|
||
&& warn_unused_value
|
||
&& !TREE_NO_WARNING (expr)
|
||
&& !processing_template_decl)
|
||
{
|
||
/* The middle end does not warn about expressions that have
|
||
been explicitly cast to void, so we must do so here. */
|
||
if (!TREE_SIDE_EFFECTS (expr))
|
||
warning (OPT_Wunused_value, "%s has no effect", implicit);
|
||
else
|
||
{
|
||
tree e;
|
||
enum tree_code code;
|
||
enum tree_code_class class;
|
||
|
||
e = expr;
|
||
/* We might like to warn about (say) "(int) f()", as the
|
||
cast has no effect, but the compiler itself will
|
||
generate implicit conversions under some
|
||
circumstances. (For example a block copy will be
|
||
turned into a call to "__builtin_memcpy", with a
|
||
conversion of the return value to an appropriate
|
||
type.) So, to avoid false positives, we strip
|
||
conversions. Do not use STRIP_NOPs because it will
|
||
not strip conversions to "void", as that is not a
|
||
mode-preserving conversion. */
|
||
while (TREE_CODE (e) == NOP_EXPR)
|
||
e = TREE_OPERAND (e, 0);
|
||
|
||
code = TREE_CODE (e);
|
||
class = TREE_CODE_CLASS (code);
|
||
if (class == tcc_comparison
|
||
|| class == tcc_unary
|
||
|| (class == tcc_binary
|
||
&& !(code == MODIFY_EXPR
|
||
|| code == INIT_EXPR
|
||
|| code == PREDECREMENT_EXPR
|
||
|| code == PREINCREMENT_EXPR
|
||
|| code == POSTDECREMENT_EXPR
|
||
|| code == POSTINCREMENT_EXPR)))
|
||
warning (OPT_Wunused_value, "value computed is not used");
|
||
}
|
||
}
|
||
expr = build1 (CONVERT_EXPR, void_type_node, expr);
|
||
}
|
||
if (! TREE_SIDE_EFFECTS (expr))
|
||
expr = void_zero_node;
|
||
return expr;
|
||
}
|
||
|
||
/* Create an expression whose value is that of EXPR,
|
||
converted to type TYPE. The TREE_TYPE of the value
|
||
is always TYPE. This function implements all reasonable
|
||
conversions; callers should filter out those that are
|
||
not permitted by the language being compiled.
|
||
|
||
Most of this routine is from build_reinterpret_cast.
|
||
|
||
The backend cannot call cp_convert (what was convert) because
|
||
conversions to/from basetypes may involve memory references
|
||
(vbases) and adding or subtracting small values (multiple
|
||
inheritance), but it calls convert from the constant folding code
|
||
on subtrees of already built trees after it has ripped them apart.
|
||
|
||
Also, if we ever support range variables, we'll probably also have to
|
||
do a little bit more work. */
|
||
|
||
tree
|
||
convert (tree type, tree expr)
|
||
{
|
||
tree intype;
|
||
|
||
if (type == error_mark_node || expr == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
intype = TREE_TYPE (expr);
|
||
|
||
if (POINTER_TYPE_P (type) && POINTER_TYPE_P (intype))
|
||
return fold_if_not_in_template (build_nop (type, expr));
|
||
|
||
return ocp_convert (type, expr, CONV_OLD_CONVERT,
|
||
LOOKUP_NORMAL|LOOKUP_NO_CONVERSION);
|
||
}
|
||
|
||
/* Like cp_convert, except permit conversions to take place which
|
||
are not normally allowed due to access restrictions
|
||
(such as conversion from sub-type to private super-type). */
|
||
|
||
tree
|
||
convert_force (tree type, tree expr, int convtype)
|
||
{
|
||
tree e = expr;
|
||
enum tree_code code = TREE_CODE (type);
|
||
|
||
if (code == REFERENCE_TYPE)
|
||
return (fold_if_not_in_template
|
||
(convert_to_reference (type, e, CONV_C_CAST, LOOKUP_COMPLAIN,
|
||
NULL_TREE)));
|
||
|
||
if (code == POINTER_TYPE)
|
||
return fold_if_not_in_template (convert_to_pointer_force (type, e));
|
||
|
||
/* From typeck.c convert_for_assignment */
|
||
if (((TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE && TREE_CODE (e) == ADDR_EXPR
|
||
&& TREE_CODE (TREE_TYPE (e)) == POINTER_TYPE
|
||
&& TREE_CODE (TREE_TYPE (TREE_TYPE (e))) == METHOD_TYPE)
|
||
|| integer_zerop (e)
|
||
|| TYPE_PTRMEMFUNC_P (TREE_TYPE (e)))
|
||
&& TYPE_PTRMEMFUNC_P (type))
|
||
/* compatible pointer to member functions. */
|
||
return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), e, 1,
|
||
/*c_cast_p=*/1);
|
||
|
||
return ocp_convert (type, e, CONV_C_CAST|convtype, LOOKUP_NORMAL);
|
||
}
|
||
|
||
/* Convert an aggregate EXPR to type XTYPE. If a conversion
|
||
exists, return the attempted conversion. This may
|
||
return ERROR_MARK_NODE if the conversion is not
|
||
allowed (references private members, etc).
|
||
If no conversion exists, NULL_TREE is returned.
|
||
|
||
FIXME: Ambiguity checking is wrong. Should choose one by the implicit
|
||
object parameter, or by the second standard conversion sequence if
|
||
that doesn't do it. This will probably wait for an overloading rewrite.
|
||
(jason 8/9/95) */
|
||
|
||
static tree
|
||
build_type_conversion (tree xtype, tree expr)
|
||
{
|
||
/* C++: check to see if we can convert this aggregate type
|
||
into the required type. */
|
||
return build_user_type_conversion (xtype, expr, LOOKUP_NORMAL);
|
||
}
|
||
|
||
/* Convert the given EXPR to one of a group of types suitable for use in an
|
||
expression. DESIRES is a combination of various WANT_* flags (q.v.)
|
||
which indicates which types are suitable. If COMPLAIN is true, complain
|
||
about ambiguity; otherwise, the caller will deal with it. */
|
||
|
||
tree
|
||
build_expr_type_conversion (int desires, tree expr, bool complain)
|
||
{
|
||
tree basetype = TREE_TYPE (expr);
|
||
tree conv = NULL_TREE;
|
||
tree winner = NULL_TREE;
|
||
|
||
if (expr == null_node
|
||
&& (desires & WANT_INT)
|
||
&& !(desires & WANT_NULL))
|
||
warning (OPT_Wconversion, "converting NULL to non-pointer type");
|
||
|
||
basetype = TREE_TYPE (expr);
|
||
|
||
if (basetype == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
if (! IS_AGGR_TYPE (basetype))
|
||
switch (TREE_CODE (basetype))
|
||
{
|
||
case INTEGER_TYPE:
|
||
if ((desires & WANT_NULL) && null_ptr_cst_p (expr))
|
||
return expr;
|
||
/* else fall through... */
|
||
|
||
case BOOLEAN_TYPE:
|
||
return (desires & WANT_INT) ? expr : NULL_TREE;
|
||
case ENUMERAL_TYPE:
|
||
return (desires & WANT_ENUM) ? expr : NULL_TREE;
|
||
case REAL_TYPE:
|
||
return (desires & WANT_FLOAT) ? expr : NULL_TREE;
|
||
case POINTER_TYPE:
|
||
return (desires & WANT_POINTER) ? expr : NULL_TREE;
|
||
|
||
case FUNCTION_TYPE:
|
||
case ARRAY_TYPE:
|
||
return (desires & WANT_POINTER) ? decay_conversion (expr)
|
||
: NULL_TREE;
|
||
|
||
case VECTOR_TYPE:
|
||
if ((desires & WANT_VECTOR) == 0)
|
||
return NULL_TREE;
|
||
switch (TREE_CODE (TREE_TYPE (basetype)))
|
||
{
|
||
case INTEGER_TYPE:
|
||
case BOOLEAN_TYPE:
|
||
return (desires & WANT_INT) ? expr : NULL_TREE;
|
||
case ENUMERAL_TYPE:
|
||
return (desires & WANT_ENUM) ? expr : NULL_TREE;
|
||
case REAL_TYPE:
|
||
return (desires & WANT_FLOAT) ? expr : NULL_TREE;
|
||
default:
|
||
return NULL_TREE;
|
||
}
|
||
|
||
default:
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* The code for conversions from class type is currently only used for
|
||
delete expressions. Other expressions are handled by build_new_op. */
|
||
if (!complete_type_or_else (basetype, expr))
|
||
return error_mark_node;
|
||
if (!TYPE_HAS_CONVERSION (basetype))
|
||
return NULL_TREE;
|
||
|
||
for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv))
|
||
{
|
||
int win = 0;
|
||
tree candidate;
|
||
tree cand = TREE_VALUE (conv);
|
||
|
||
if (winner && winner == cand)
|
||
continue;
|
||
|
||
candidate = non_reference (TREE_TYPE (TREE_TYPE (cand)));
|
||
|
||
switch (TREE_CODE (candidate))
|
||
{
|
||
case BOOLEAN_TYPE:
|
||
case INTEGER_TYPE:
|
||
win = (desires & WANT_INT); break;
|
||
case ENUMERAL_TYPE:
|
||
win = (desires & WANT_ENUM); break;
|
||
case REAL_TYPE:
|
||
win = (desires & WANT_FLOAT); break;
|
||
case POINTER_TYPE:
|
||
win = (desires & WANT_POINTER); break;
|
||
|
||
case VECTOR_TYPE:
|
||
if ((desires & WANT_VECTOR) == 0)
|
||
break;
|
||
switch (TREE_CODE (TREE_TYPE (candidate)))
|
||
{
|
||
case BOOLEAN_TYPE:
|
||
case INTEGER_TYPE:
|
||
win = (desires & WANT_INT); break;
|
||
case ENUMERAL_TYPE:
|
||
win = (desires & WANT_ENUM); break;
|
||
case REAL_TYPE:
|
||
win = (desires & WANT_FLOAT); break;
|
||
default:
|
||
break;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
if (win)
|
||
{
|
||
if (winner)
|
||
{
|
||
if (complain)
|
||
{
|
||
error ("ambiguous default type conversion from %qT",
|
||
basetype);
|
||
error (" candidate conversions include %qD and %qD",
|
||
winner, cand);
|
||
}
|
||
return error_mark_node;
|
||
}
|
||
else
|
||
winner = cand;
|
||
}
|
||
}
|
||
|
||
if (winner)
|
||
{
|
||
tree type = non_reference (TREE_TYPE (TREE_TYPE (winner)));
|
||
return build_user_type_conversion (type, expr, LOOKUP_NORMAL);
|
||
}
|
||
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* Implements integral promotion (4.1) and float->double promotion. */
|
||
|
||
tree
|
||
type_promotes_to (tree type)
|
||
{
|
||
if (type == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
type = TYPE_MAIN_VARIANT (type);
|
||
|
||
/* bool always promotes to int (not unsigned), even if it's the same
|
||
size. */
|
||
if (type == boolean_type_node)
|
||
type = integer_type_node;
|
||
|
||
/* Normally convert enums to int, but convert wide enums to something
|
||
wider. */
|
||
else if (TREE_CODE (type) == ENUMERAL_TYPE
|
||
|| type == wchar_type_node)
|
||
{
|
||
int precision = MAX (TYPE_PRECISION (type),
|
||
TYPE_PRECISION (integer_type_node));
|
||
tree totype = c_common_type_for_size (precision, 0);
|
||
if (TYPE_UNSIGNED (type)
|
||
&& ! int_fits_type_p (TYPE_MAX_VALUE (type), totype))
|
||
type = c_common_type_for_size (precision, 1);
|
||
else
|
||
type = totype;
|
||
}
|
||
else if (c_promoting_integer_type_p (type))
|
||
{
|
||
/* Retain unsignedness if really not getting bigger. */
|
||
if (TYPE_UNSIGNED (type)
|
||
&& TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
|
||
type = unsigned_type_node;
|
||
else
|
||
type = integer_type_node;
|
||
}
|
||
else if (type == float_type_node)
|
||
type = double_type_node;
|
||
|
||
return type;
|
||
}
|
||
|
||
/* The routines below this point are carefully written to conform to
|
||
the standard. They use the same terminology, and follow the rules
|
||
closely. Although they are used only in pt.c at the moment, they
|
||
should presumably be used everywhere in the future. */
|
||
|
||
/* Attempt to perform qualification conversions on EXPR to convert it
|
||
to TYPE. Return the resulting expression, or error_mark_node if
|
||
the conversion was impossible. */
|
||
|
||
tree
|
||
perform_qualification_conversions (tree type, tree expr)
|
||
{
|
||
tree expr_type;
|
||
|
||
expr_type = TREE_TYPE (expr);
|
||
|
||
if (same_type_p (type, expr_type))
|
||
return expr;
|
||
else if (TYPE_PTR_P (type) && TYPE_PTR_P (expr_type)
|
||
&& comp_ptr_ttypes (TREE_TYPE (type), TREE_TYPE (expr_type)))
|
||
return build_nop (type, expr);
|
||
else if (TYPE_PTR_TO_MEMBER_P (type)
|
||
&& TYPE_PTR_TO_MEMBER_P (expr_type)
|
||
&& same_type_p (TYPE_PTRMEM_CLASS_TYPE (type),
|
||
TYPE_PTRMEM_CLASS_TYPE (expr_type))
|
||
&& comp_ptr_ttypes (TYPE_PTRMEM_POINTED_TO_TYPE (type),
|
||
TYPE_PTRMEM_POINTED_TO_TYPE (expr_type)))
|
||
return build_nop (type, expr);
|
||
else
|
||
return error_mark_node;
|
||
}
|