gcc/cp/cp-objcp-common.c

   1 /* Some code common to C++ and ObjC++ front ends.
   2    Copyright (C) 2004-2014 Free Software Foundation, Inc.
   3    Contributed by Ziemowit Laski  <zlaski@apple.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "tree.h"
  26 #include "cp-tree.h"
  27 #include "c-family/c-common.h"
  28 #include "langhooks.h"
  29 #include "langhooks-def.h"
  30 #include "diagnostic.h"
  31 #include "debug.h"
  32 #include "cxx-pretty-print.h"
  33 #include "cp-objcp-common.h"
  34
  35 /* Special routine to get the alias set for C++.  */
  36
  37 alias_set_type
  38 cxx_get_alias_set (tree t)
  39 {
  40   if (IS_FAKE_BASE_TYPE (t))
  41     /* The base variant of a type must be in the same alias set as the
  42        complete type.  */
  43     return get_alias_set (TYPE_CONTEXT (t));
  44
  45   /* Punt on PMFs until we canonicalize functions properly.  */
  46   if (TYPE_PTRMEMFUNC_P (t)
  47       || (POINTER_TYPE_P (t)
  48           && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))))
  49     return 0;
  50
  51   return c_common_get_alias_set (t);
  52 }
  53
  54 /* Called from check_global_declarations.  */
  55
  56 bool
  57 cxx_warn_unused_global_decl (const_tree decl)
  58 {
  59   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
  60     return false;
  61   if (DECL_IN_SYSTEM_HEADER (decl))
  62     return false;
  63
  64   /* Const variables take the place of #defines in C++.  */
  65   if (VAR_P (decl) && TREE_READONLY (decl))
  66     return false;
  67
  68   return true;
  69 }
  70
  71 /* Langhook for tree_size: determine size of our 'x' and 'c' nodes.  */
  72 size_t
  73 cp_tree_size (enum tree_code code)
  74 {
  75   switch (code)
  76     {
  77     case PTRMEM_CST:            return sizeof (struct ptrmem_cst);
  78     case BASELINK:              return sizeof (struct tree_baselink);
  79     case TEMPLATE_PARM_INDEX:   return sizeof (template_parm_index);
  80     case DEFAULT_ARG:           return sizeof (struct tree_default_arg);
  81     case DEFERRED_NOEXCEPT:     return sizeof (struct tree_deferred_noexcept);
  82     case OVERLOAD:              return sizeof (struct tree_overload);
  83     case STATIC_ASSERT:         return sizeof (struct tree_static_assert);
  84     case TYPE_ARGUMENT_PACK:
  85     case TYPE_PACK_EXPANSION:
  86       return sizeof (struct tree_common);
  87
  88     case NONTYPE_ARGUMENT_PACK:
  89     case EXPR_PACK_EXPANSION:
  90       return sizeof (struct tree_exp);
  91
  92     case ARGUMENT_PACK_SELECT:
  93       return sizeof (struct tree_argument_pack_select);
  94
  95     case TRAIT_EXPR:
  96       return sizeof (struct tree_trait_expr);
  97
  98     case LAMBDA_EXPR:           return sizeof (struct tree_lambda_expr);
  99
 100     case TEMPLATE_INFO:         return sizeof (struct tree_template_info);
 101
 102     case USERDEF_LITERAL:       return sizeof (struct tree_userdef_literal);
 103
 104     case TEMPLATE_DECL:         return sizeof (struct tree_template_decl);
 105
 106     default:
 107       if (TREE_CODE_CLASS (code) == tcc_declaration)
 108         return sizeof (struct tree_decl_non_common);
 109       gcc_unreachable ();
 110     }
 111   /* NOTREACHED */
 112 }
 113
 114 /* Returns true if T is a variably modified type, in the sense of C99.
 115    FN is as passed to variably_modified_p.
 116    This routine needs only check cases that cannot be handled by the
 117    language-independent logic in tree.c.  */
 118
 119 bool
 120 cp_var_mod_type_p (tree type, tree fn)
 121 {
 122   /* If TYPE is a pointer-to-member, it is variably modified if either
 123      the class or the member are variably modified.  */
 124   if (TYPE_PTRMEM_P (type))
 125     return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type), fn)
 126             || variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type),
 127                                          fn));
 128
 129   /* All other types are not variably modified.  */
 130   return false;
 131 }
 132
 133 /* This compares two types for equivalence ("compatible" in C-based languages).
 134    This routine should only return 1 if it is sure.  It should not be used
 135    in contexts where erroneously returning 0 causes problems.  */
 136
 137 int
 138 cxx_types_compatible_p (tree x, tree y)
 139 {
 140   return same_type_ignoring_top_level_qualifiers_p (x, y);
 141 }
 142
 143 /* Return true if DECL is explicit member function.  */
 144
 145 bool
 146 cp_function_decl_explicit_p (tree decl)
 147 {
 148   return (decl
 149           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 150           && DECL_NONCONVERTING_P (decl));
 151 }
 152
 153 /* Return true if DECL is deleted special member function.  */
 154
 155 bool
 156 cp_function_decl_deleted_p (tree decl)
 157 {
 158   return (decl
 159           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 160           && DECL_DELETED_FN (decl));
 161 }
 162
 163 /* Stubs to keep c-opts.c happy.  */
 164 void
 165 push_file_scope (void)
 166 {
 167 }
 168
 169 void
 170 pop_file_scope (void)
 171 {
 172 }
 173
 174 /* c-pragma.c needs to query whether a decl has extern "C" linkage.  */
 175 bool
 176 has_c_linkage (const_tree decl)
 177 {
 178   return DECL_EXTERN_C_P (decl);
 179 }
 180
 181 static GTY ((cache))
 182      hash_table<tree_decl_map_cache_hasher> *shadowed_var_for_decl;
 183
 184 /* Lookup a shadowed var for FROM, and return it if we find one.  */
 185
 186 tree
 187 decl_shadowed_for_var_lookup (tree from)
 188 {
 189   struct tree_decl_map *h, in;
 190   in.base.from = from;
 191
 192   h = shadowed_var_for_decl->find_with_hash (&in, DECL_UID (from));
 193   if (h)
 194     return h->to;
 195   return NULL_TREE;
 196 }
 197
 198 /* Insert a mapping FROM->TO in the shadowed var hashtable.  */
 199
 200 void
 201 decl_shadowed_for_var_insert (tree from, tree to)
 202 {
 203   struct tree_decl_map *h;
 204
 205   h = ggc_alloc<tree_decl_map> ();
 206   h->base.from = from;
 207   h->to = to;
 208   *shadowed_var_for_decl->find_slot_with_hash (h, DECL_UID (from), INSERT) = h;
 209 }
 210
 211 void
 212 init_shadowed_var_for_decl (void)
 213 {
 214   shadowed_var_for_decl
 215     = hash_table<tree_decl_map_cache_hasher>::create_ggc (512);
 216 }
 217
 218 /* Return true if stmt can fall through.  Used by block_may_fallthru
 219    default case.  */
 220
 221 bool
 222 cxx_block_may_fallthru (const_tree stmt)
 223 {
 224   switch (TREE_CODE (stmt))
 225     {
 226     case EXPR_STMT:
 227       return block_may_fallthru (EXPR_STMT_EXPR (stmt));
 228
 229     case THROW_EXPR:
 230       return false;
 231
 232     default:
 233       return true;
 234     }
 235 }
 236
 237 void
 238 cp_common_init_ts (void)
 239 {
 240   MARK_TS_DECL_NON_COMMON (USING_DECL);
 241   MARK_TS_DECL_COMMON (TEMPLATE_DECL);
 242
 243   MARK_TS_COMMON (TEMPLATE_TEMPLATE_PARM);
 244   MARK_TS_COMMON (TEMPLATE_TYPE_PARM);
 245   MARK_TS_COMMON (TEMPLATE_PARM_INDEX);
 246   MARK_TS_COMMON (OVERLOAD);
 247   MARK_TS_COMMON (TEMPLATE_INFO);
 248   MARK_TS_COMMON (TYPENAME_TYPE);
 249   MARK_TS_COMMON (TYPEOF_TYPE);
 250   MARK_TS_COMMON (UNDERLYING_TYPE);
 251   MARK_TS_COMMON (BASELINK);
 252   MARK_TS_COMMON (TYPE_PACK_EXPANSION);
 253   MARK_TS_COMMON (TYPE_ARGUMENT_PACK);
 254   MARK_TS_COMMON (DECLTYPE_TYPE);
 255   MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
 256   MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);
 257
 258   MARK_TS_TYPED (EXPR_PACK_EXPANSION);
 259   MARK_TS_TYPED (SWITCH_STMT);
 260   MARK_TS_TYPED (IF_STMT);
 261   MARK_TS_TYPED (FOR_STMT);
 262   MARK_TS_TYPED (RANGE_FOR_STMT);
 263   MARK_TS_TYPED (AGGR_INIT_EXPR);
 264   MARK_TS_TYPED (EXPR_STMT);
 265   MARK_TS_TYPED (EH_SPEC_BLOCK);
 266   MARK_TS_TYPED (CLEANUP_STMT);
 267   MARK_TS_TYPED (SCOPE_REF);
 268   MARK_TS_TYPED (CAST_EXPR);
 269   MARK_TS_TYPED (NON_DEPENDENT_EXPR);
 270   MARK_TS_TYPED (MODOP_EXPR);
 271   MARK_TS_TYPED (TRY_BLOCK);
 272   MARK_TS_TYPED (THROW_EXPR);
 273   MARK_TS_TYPED (HANDLER);
 274   MARK_TS_TYPED (REINTERPRET_CAST_EXPR);
 275   MARK_TS_TYPED (CONST_CAST_EXPR);
 276   MARK_TS_TYPED (STATIC_CAST_EXPR);
 277   MARK_TS_TYPED (DYNAMIC_CAST_EXPR);
 278   MARK_TS_TYPED (IMPLICIT_CONV_EXPR);
 279   MARK_TS_TYPED (TEMPLATE_ID_EXPR);
 280   MARK_TS_TYPED (ARROW_EXPR);
 281   MARK_TS_TYPED (SIZEOF_EXPR);
 282   MARK_TS_TYPED (ALIGNOF_EXPR);
 283   MARK_TS_TYPED (AT_ENCODE_EXPR);
 284   MARK_TS_TYPED (UNARY_PLUS_EXPR);
 285   MARK_TS_TYPED (TRAIT_EXPR);
 286   MARK_TS_TYPED (TYPE_ARGUMENT_PACK);
 287   MARK_TS_TYPED (NOEXCEPT_EXPR);
 288   MARK_TS_TYPED (NONTYPE_ARGUMENT_PACK);
 289   MARK_TS_TYPED (WHILE_STMT);
 290   MARK_TS_TYPED (NEW_EXPR);
 291   MARK_TS_TYPED (VEC_NEW_EXPR);
 292   MARK_TS_TYPED (BREAK_STMT);
 293   MARK_TS_TYPED (MEMBER_REF);
 294   MARK_TS_TYPED (DOTSTAR_EXPR);
 295   MARK_TS_TYPED (DO_STMT);
 296   MARK_TS_TYPED (DELETE_EXPR);
 297   MARK_TS_TYPED (VEC_DELETE_EXPR);
 298   MARK_TS_TYPED (CONTINUE_STMT);
 299   MARK_TS_TYPED (TAG_DEFN);
 300   MARK_TS_TYPED (PSEUDO_DTOR_EXPR);
 301   MARK_TS_TYPED (TYPEID_EXPR);
 302   MARK_TS_TYPED (MUST_NOT_THROW_EXPR);
 303   MARK_TS_TYPED (STMT_EXPR);
 304   MARK_TS_TYPED (OFFSET_REF);
 305   MARK_TS_TYPED (OFFSETOF_EXPR);
 306   MARK_TS_TYPED (PTRMEM_CST);
 307   MARK_TS_TYPED (EMPTY_CLASS_EXPR);
 308   MARK_TS_TYPED (VEC_INIT_EXPR);
 309   MARK_TS_TYPED (USING_STMT);
 310   MARK_TS_TYPED (LAMBDA_EXPR);
 311   MARK_TS_TYPED (CTOR_INITIALIZER);
 312   MARK_TS_TYPED (ARRAY_NOTATION_REF);
 313 }
 314
 315 #include "gt-cp-cp-objcp-common.h"