gcc/cp/cp-lang.c

   1 /* Language-dependent hooks for C++.
   2    Copyright 2001 Free Software Foundation, Inc.
   3    Contributed by Alexandre Oliva  <aoliva@redhat.com>
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "tree.h"
  25 #include "cp-tree.h"
  26 #include "c-common.h"
  27 #include "toplev.h"
  28 #include "langhooks.h"
  29 #include "langhooks-def.h"
  30
  31 static HOST_WIDE_INT cxx_get_alias_set PARAMS ((tree));
  32 static bool ok_to_generate_alias_set_for_type PARAMS ((tree));
  33
  34 #undef LANG_HOOKS_NAME
  35 #define LANG_HOOKS_NAME "GNU C++"
  36 #undef LANG_HOOKS_INIT
  37 #define LANG_HOOKS_INIT cxx_init
  38 #undef LANG_HOOKS_FINISH
  39 #define LANG_HOOKS_FINISH cxx_finish
  40 #undef LANG_HOOKS_CLEAR_BINDING_STACK
  41 #define LANG_HOOKS_CLEAR_BINDING_STACK pop_everything
  42 #undef LANG_HOOKS_INIT_OPTIONS
  43 #define LANG_HOOKS_INIT_OPTIONS cxx_init_options
  44 #undef LANG_HOOKS_DECODE_OPTION
  45 #define LANG_HOOKS_DECODE_OPTION cxx_decode_option
  46 #undef LANG_HOOKS_POST_OPTIONS
  47 #define LANG_HOOKS_POST_OPTIONS cxx_post_options
  48 #undef LANG_HOOKS_GET_ALIAS_SET
  49 #define LANG_HOOKS_GET_ALIAS_SET cxx_get_alias_set
  50 #undef LANG_HOOKS_EXPAND_CONSTANT
  51 #define LANG_HOOKS_EXPAND_CONSTANT cplus_expand_constant
  52 #undef LANG_HOOKS_SAFE_FROM_P
  53 #define LANG_HOOKS_SAFE_FROM_P c_safe_from_p
  54 #undef LANG_HOOKS_PARSE_FILE
  55 #define LANG_HOOKS_PARSE_FILE c_common_parse_file
  56 #undef LANG_HOOKS_DUP_LANG_SPECIFIC_DECL
  57 #define LANG_HOOKS_DUP_LANG_SPECIFIC_DECL cxx_dup_lang_specific_decl
  58 #undef LANG_HOOKS_UNSAVE_EXPR_NOW
  59 #define LANG_HOOKS_UNSAVE_EXPR_NOW cxx_unsave_expr_now
  60 #undef LANG_HOOKS_PRINT_STATISTICS
  61 #define LANG_HOOKS_PRINT_STATISTICS cxx_print_statistics
  62 #undef LANG_HOOKS_PRINT_XNODE
  63 #define LANG_HOOKS_PRINT_XNODE cxx_print_xnode
  64 #undef LANG_HOOKS_PRINT_DECL
  65 #define LANG_HOOKS_PRINT_DECL cxx_print_decl
  66 #undef LANG_HOOKS_PRINT_TYPE
  67 #define LANG_HOOKS_PRINT_TYPE cxx_print_type
  68 #undef LANG_HOOKS_PRINT_IDENTIFIER
  69 #define LANG_HOOKS_PRINT_IDENTIFIER cxx_print_identifier
  70 #undef LANG_HOOKS_SET_YYDEBUG
  71 #define LANG_HOOKS_SET_YYDEBUG cxx_set_yydebug
  72
  73 #undef LANG_HOOKS_TREE_INLINING_WALK_SUBTREES
  74 #define LANG_HOOKS_TREE_INLINING_WALK_SUBTREES \
  75   cp_walk_subtrees
  76 #undef LANG_HOOKS_TREE_INLINING_CANNOT_INLINE_TREE_FN
  77 #define LANG_HOOKS_TREE_INLINING_CANNOT_INLINE_TREE_FN \
  78   cp_cannot_inline_tree_fn
  79 #undef LANG_HOOKS_TREE_INLINING_ADD_PENDING_FN_DECLS
  80 #define LANG_HOOKS_TREE_INLINING_ADD_PENDING_FN_DECLS \
  81   cp_add_pending_fn_decls
  82 #undef LANG_HOOKS_TREE_INLINING_TREE_CHAIN_MATTERS_P
  83 #define LANG_HOOKS_TREE_INLINING_TREE_CHAIN_MATTERS_P \
  84   cp_is_overload_p
  85 #undef LANG_HOOKS_TREE_INLINING_AUTO_VAR_IN_FN_P
  86 #define LANG_HOOKS_TREE_INLINING_AUTO_VAR_IN_FN_P \
  87   cp_auto_var_in_fn_p
  88 #undef LANG_HOOKS_TREE_INLINING_COPY_RES_DECL_FOR_INLINING
  89 #define LANG_HOOKS_TREE_INLINING_COPY_RES_DECL_FOR_INLINING \
  90   cp_copy_res_decl_for_inlining
  91 #undef LANG_HOOKS_TREE_INLINING_ANON_AGGR_TYPE_P
  92 #define LANG_HOOKS_TREE_INLINING_ANON_AGGR_TYPE_P anon_aggr_type_p
  93 #undef LANG_HOOKS_TREE_INLINING_START_INLINING
  94 #define LANG_HOOKS_TREE_INLINING_START_INLINING cp_start_inlining
  95 #undef LANG_HOOKS_TREE_INLINING_END_INLINING
  96 #define LANG_HOOKS_TREE_INLINING_END_INLINING cp_end_inlining
  97 #undef LANG_HOOKS_TREE_DUMP_DUMP_TREE_FN
  98 #define LANG_HOOKS_TREE_DUMP_DUMP_TREE_FN cp_dump_tree
  99 #undef LANG_HOOKS_TREE_DUMP_TYPE_QUALS_FN
 100 #define LANG_HOOKS_TREE_DUMP_TYPE_QUALS_FN cp_type_quals
 101
 102 /* Each front end provides its own hooks, for toplev.c.  */
 103 const struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
 104
 105 /* Check if a C++ type is safe for aliasing.
 106    Return TRUE if T safe for aliasing FALSE otherwise.  */
 107
 108 static bool
 109 ok_to_generate_alias_set_for_type (t)
 110      tree t;
 111 {
 112   if (TYPE_PTRMEMFUNC_P (t))
 113     return true;
 114   if (AGGREGATE_TYPE_P (t))
 115     {
 116       if ((TREE_CODE (t) == RECORD_TYPE) || (TREE_CODE (t) == UNION_TYPE))
 117         {
 118           tree fields;
 119           /* PODs are safe.  */
 120           if (! CLASSTYPE_NON_POD_P(t))
 121             return true;
 122           /* Classes with virtual baseclasses are not.  */
 123           if (TYPE_USES_VIRTUAL_BASECLASSES (t))
 124             return false;
 125           /* Recursively check the base classes.  */
 126           if (TYPE_BINFO (t) != NULL && TYPE_BINFO_BASETYPES (t) != NULL)
 127             {
 128               int i;
 129               for (i = 0; i < TREE_VEC_LENGTH (TYPE_BINFO_BASETYPES (t)); i++)
 130                 {
 131                   tree binfo = TREE_VEC_ELT (TYPE_BINFO_BASETYPES (t), i);
 132                   if (!ok_to_generate_alias_set_for_type (BINFO_TYPE (binfo)))
 133                     return false;
 134                 }
 135             }
 136           /* Check all the fields.  */
 137           for (fields = TYPE_FIELDS (t); fields; fields = TREE_CHAIN (fields))
 138             {
 139               if (TREE_CODE (fields) != FIELD_DECL)
 140                 continue;
 141               if (! ok_to_generate_alias_set_for_type (TREE_TYPE (fields)))
 142                 return false;
 143             }
 144           return true;
 145         }
 146       else if (TREE_CODE (t) == ARRAY_TYPE)
 147         return ok_to_generate_alias_set_for_type (TREE_TYPE (t));
 148       else
 149         /* This should never happen, we dealt with all the aggregate
 150            types that can appear in C++ above.  */
 151         abort ();
 152     }
 153   else
 154     return true;
 155 }
 156
 157 /* Tree code classes. */
 158
 159 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
 160
 161 const char tree_code_type[] = {
 162 #include "tree.def"
 163   'x',
 164 #include "c-common.def"
 165   'x',
 166 #include "cp-tree.def"
 167 };
 168 #undef DEFTREECODE
 169
 170 /* Table indexed by tree code giving number of expression
 171    operands beyond the fixed part of the node structure.
 172    Not used for types or decls.  */
 173
 174 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
 175
 176 const unsigned char tree_code_length[] = {
 177 #include "tree.def"
 178   0,
 179 #include "c-common.def"
 180   0,
 181 #include "cp-tree.def"
 182 };
 183 #undef DEFTREECODE
 184
 185 /* Names of tree components.
 186    Used for printing out the tree and error messages.  */
 187 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
 188
 189 const char *const tree_code_name[] = {
 190 #include "tree.def"
 191   "@@dummy",
 192 #include "c-common.def"
 193   "@@dummy",
 194 #include "cp-tree.def"
 195 };
 196 #undef DEFTREECODE
 197
 198 /* Special routine to get the alias set for C++.  */
 199
 200 static HOST_WIDE_INT
 201 cxx_get_alias_set (t)
 202      tree t;
 203 {
 204   /* It's not yet safe to use alias sets for classes in C++.  */
 205   if (!ok_to_generate_alias_set_for_type(t))
 206     return 0;
 207
 208   return c_common_get_alias_set (t);
 209 }