contrib/gcc-3.4/gcc/cp/expr.c

   1 /* Convert language-specific tree expression to rtl instructions,
   2    for GNU compiler.
   3    Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   4    2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "tm.h"
  28 #include "rtl.h"
  29 #include "tree.h"
  30 #include "flags.h"
  31 #include "expr.h"
  32 #include "cp-tree.h"
  33 #include "toplev.h"
  34 #include "except.h"
  35 #include "tm_p.h"
  36
  37 /* Hook used by output_constant to expand language-specific
  38    constants.  */
  39
  40 tree
  41 cplus_expand_constant (tree cst)
  42 {
  43   switch (TREE_CODE (cst))
  44     {
  45     case PTRMEM_CST:
  46       {
  47         tree type = TREE_TYPE (cst);
  48         tree member;
  49
  50         /* Find the member.  */
  51         member = PTRMEM_CST_MEMBER (cst);
  52
  53         if (TREE_CODE (member) == FIELD_DECL)
  54           {
  55             /* Find the offset for the field.  */
  56             cst = byte_position (member);
  57             while (!same_type_p (DECL_CONTEXT (member),
  58                                  TYPE_PTRMEM_CLASS_TYPE (type)))
  59               {
  60                 /* The MEMBER must have been nestled within an
  61                    anonymous aggregate contained in TYPE.  Find the
  62                    anonymous aggregate.  */
  63                 member = lookup_anon_field (TYPE_PTRMEM_CLASS_TYPE (type),
  64                                             DECL_CONTEXT (member));
  65                 cst = size_binop (PLUS_EXPR, cst, byte_position (member));
  66               }
  67             cst = fold (build_nop (type, cst));
  68           }
  69         else
  70           {
  71             tree delta;
  72             tree pfn;
  73
  74             expand_ptrmemfunc_cst (cst, &delta, &pfn);
  75             cst = build_ptrmemfunc1 (type, delta, pfn);
  76           }
  77       }
  78       break;
  79
  80     default:
  81       /* There's nothing to do.  */
  82       break;
  83     }
  84
  85   return cst;
  86 }
  87
  88 /* Hook used by expand_expr to expand language-specific tree codes.  */
  89
  90 rtx
  91 cxx_expand_expr (tree exp, rtx target, enum machine_mode tmode, int modifier,
  92                  rtx *alt_rtl)
  93 {
  94   tree type = TREE_TYPE (exp);
  95   enum machine_mode mode = TYPE_MODE (type);
  96   enum tree_code code = TREE_CODE (exp);
  97   rtx ret;
  98
  99   /* No sense saving up arithmetic to be done
 100      if it's all in the wrong mode to form part of an address.
 101      And force_operand won't know whether to sign-extend or zero-extend.  */
 102
 103   if (mode != Pmode && modifier == EXPAND_SUM)
 104     modifier = EXPAND_NORMAL;
 105
 106   switch (code)
 107     {
 108     case PTRMEM_CST:
 109       return expand_expr (cplus_expand_constant (exp),
 110                           target, tmode, modifier);
 111
 112     case OFFSET_REF:
 113       /* Offset refs should not make it through to here.  */
 114       abort ();
 115       return const0_rtx;
 116
 117     case THROW_EXPR:
 118       expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode, 0);
 119       return const0_rtx;
 120
 121     case MUST_NOT_THROW_EXPR:
 122       expand_eh_region_start ();
 123       ret = expand_expr (TREE_OPERAND (exp, 0), target, tmode, modifier);
 124       expand_eh_region_end_must_not_throw (build_call (terminate_node, 0));
 125       return ret;
 126
 127     case EMPTY_CLASS_EXPR:
 128       /* We don't need to generate any code for an empty class.  */
 129       return const0_rtx;
 130
 131     case BASELINK:
 132       return expand_expr (BASELINK_FUNCTIONS (exp), target, tmode,
 133                           modifier);
 134
 135     default:
 136       return c_expand_expr (exp, target, tmode, modifier, alt_rtl);
 137     }
 138   abort ();
 139   /* NOTREACHED */
 140   return NULL;
 141 }