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, 2007 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 3, 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 COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "tm.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "cp-tree.h"
  30 #include "toplev.h"
  31 #include "except.h"
  32 #include "tm_p.h"
  33
  34 /* Expand C++-specific constants.  Currently, this means PTRMEM_CST.  */
  35
  36 tree
  37 cplus_expand_constant (tree cst)
  38 {
  39   switch (TREE_CODE (cst))
  40     {
  41     case PTRMEM_CST:
  42       {
  43         tree type = TREE_TYPE (cst);
  44         tree member;
  45
  46         /* Find the member.  */
  47         member = PTRMEM_CST_MEMBER (cst);
  48
  49         if (TREE_CODE (member) == FIELD_DECL)
  50           {
  51             /* Find the offset for the field.  */
  52             cst = byte_position (member);
  53             while (!same_type_p (DECL_CONTEXT (member),
  54                                  TYPE_PTRMEM_CLASS_TYPE (type)))
  55               {
  56                 /* The MEMBER must have been nestled within an
  57                    anonymous aggregate contained in TYPE.  Find the
  58                    anonymous aggregate.  */
  59                 member = lookup_anon_field (TYPE_PTRMEM_CLASS_TYPE (type),
  60                                             DECL_CONTEXT (member));
  61                 cst = size_binop (PLUS_EXPR, cst, byte_position (member));
  62               }
  63             cst = fold (build_nop (type, cst));
  64           }
  65         else
  66           {
  67             tree delta;
  68             tree pfn;
  69
  70             expand_ptrmemfunc_cst (cst, &delta, &pfn);
  71             cst = build_ptrmemfunc1 (type, delta, pfn);
  72           }
  73       }
  74       break;
  75
  76     default:
  77       /* There's nothing to do.  */
  78       break;
  79     }
  80
  81   return cst;
  82 }
  83
  84 /* Called whenever an expression is used
  85    in a rvalue context.  */
  86
  87 tree
  88 mark_rvalue_use (tree expr)
  89 {
  90   mark_exp_read (expr);
  91   return expr;
  92 }
  93
  94 /* Called whenever an expression is used
  95    in a lvalue context.  */
  96
  97 tree
  98 mark_lvalue_use (tree expr)
  99 {
 100   mark_exp_read (expr);
 101   return expr;
 102 }
 103
 104 /* Called whenever an expression is used in a type use context.  */
 105
 106 tree
 107 mark_type_use (tree expr)
 108 {
 109   mark_exp_read (expr);
 110   return expr;
 111 }
 112
 113 /* Mark EXP as read, not just set, for set but not used -Wunused
 114    warning purposes.  */
 115
 116 void
 117 mark_exp_read (tree exp)
 118 {
 119   if (exp == NULL)
 120     return;
 121
 122   switch (TREE_CODE (exp))
 123     {
 124     case VAR_DECL:
 125     case PARM_DECL:
 126       DECL_READ_P (exp) = 1;
 127       break;
 128     case ARRAY_REF:
 129     case COMPONENT_REF:
 130     case MODIFY_EXPR:
 131     case REALPART_EXPR:
 132     case IMAGPART_EXPR:
 133     CASE_CONVERT:
 134     case ADDR_EXPR:
 135       mark_exp_read (TREE_OPERAND (exp, 0));
 136       break;
 137     case COMPOUND_EXPR:
 138       mark_exp_read (TREE_OPERAND (exp, 1));
 139       break;
 140     case COND_EXPR:
 141       if (TREE_OPERAND (exp, 1))
 142         mark_exp_read (TREE_OPERAND (exp, 1));
 143       if (TREE_OPERAND (exp, 2))
 144         mark_exp_read (TREE_OPERAND (exp, 2));
 145       break;
 146     default:
 147       break;
 148     }
 149 }
 150