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, 2010 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 "tm_p.h"
  32
  33 /* Expand C++-specific constants.  Currently, this means PTRMEM_CST.  */
  34
  35 tree
  36 cplus_expand_constant (tree cst)
  37 {
  38   switch (TREE_CODE (cst))
  39     {
  40     case PTRMEM_CST:
  41       {
  42         tree type = TREE_TYPE (cst);
  43         tree member;
  44
  45         /* Find the member.  */
  46         member = PTRMEM_CST_MEMBER (cst);
  47
  48         if (TREE_CODE (member) == FIELD_DECL)
  49           {
  50             /* Find the offset for the field.  */
  51             cst = byte_position (member);
  52             while (!same_type_p (DECL_CONTEXT (member),
  53                                  TYPE_PTRMEM_CLASS_TYPE (type)))
  54               {
  55                 /* The MEMBER must have been nestled within an
  56                    anonymous aggregate contained in TYPE.  Find the
  57                    anonymous aggregate.  */
  58                 member = lookup_anon_field (TYPE_PTRMEM_CLASS_TYPE (type),
  59                                             DECL_CONTEXT (member));
  60                 cst = size_binop (PLUS_EXPR, cst, byte_position (member));
  61               }
  62             cst = fold (build_nop (type, cst));
  63           }
  64         else
  65           {
  66             tree delta;
  67             tree pfn;
  68
  69             expand_ptrmemfunc_cst (cst, &delta, &pfn);
  70             cst = build_ptrmemfunc1 (type, delta, pfn);
  71           }
  72       }
  73       break;
  74
  75     default:
  76       /* There's nothing to do.  */
  77       break;
  78     }
  79
  80   return cst;
  81 }
  82
  83 /* Called whenever an expression is used
  84    in a rvalue context.  */
  85
  86 tree
  87 mark_rvalue_use (tree expr)
  88 {
  89   mark_exp_read (expr);
  90   return expr;
  91 }
  92
  93 /* Called whenever an expression is used
  94    in a lvalue context.  */
  95
  96 tree
  97 mark_lvalue_use (tree expr)
  98 {
  99   mark_exp_read (expr);
 100   return expr;
 101 }
 102
 103 /* Called whenever an expression is used in a type use context.  */
 104
 105 tree
 106 mark_type_use (tree expr)
 107 {
 108   mark_exp_read (expr);
 109   return expr;
 110 }
 111
 112 /* Mark EXP as read, not just set, for set but not used -Wunused
 113    warning purposes.  */
 114
 115 void
 116 mark_exp_read (tree exp)
 117 {
 118   if (exp == NULL)
 119     return;
 120
 121   switch (TREE_CODE (exp))
 122     {
 123     case VAR_DECL:
 124     case PARM_DECL:
 125       DECL_READ_P (exp) = 1;
 126       break;
 127     case ARRAY_REF:
 128     case COMPONENT_REF:
 129     case MODIFY_EXPR:
 130     case REALPART_EXPR:
 131     case IMAGPART_EXPR:
 132     CASE_CONVERT:
 133     case ADDR_EXPR:
 134     case INDIRECT_REF:
 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