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