gcc/cp/cp-objcp-common.c

   1 /* Some code common to C++ and ObjC++ front ends.
   2    Copyright (C) 2004-2017 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 "cp-tree.h"
  25 #include "cp-objcp-common.h"
  26 #include "dwarf2.h"
  27
  28 /* Special routine to get the alias set for C++.  */
  29
  30 alias_set_type
  31 cxx_get_alias_set (tree t)
  32 {
  33   if (IS_FAKE_BASE_TYPE (t))
  34     /* The base variant of a type must be in the same alias set as the
  35        complete type.  */
  36     return get_alias_set (TYPE_CONTEXT (t));
  37
  38   /* Punt on PMFs until we canonicalize functions properly.  */
  39   if (TYPE_PTRMEMFUNC_P (t)
  40       || (POINTER_TYPE_P (t)
  41           && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))))
  42     return 0;
  43
  44   return c_common_get_alias_set (t);
  45 }
  46
  47 /* Called from check_global_declaration.  */
  48
  49 bool
  50 cxx_warn_unused_global_decl (const_tree decl)
  51 {
  52   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
  53     return false;
  54   if (DECL_IN_SYSTEM_HEADER (decl))
  55     return false;
  56
  57   return true;
  58 }
  59
  60 /* Langhook for tree_size: determine size of our 'x' and 'c' nodes.  */
  61 size_t
  62 cp_tree_size (enum tree_code code)
  63 {
  64   switch (code)
  65     {
  66     case PTRMEM_CST:            return sizeof (struct ptrmem_cst);
  67     case BASELINK:              return sizeof (struct tree_baselink);
  68     case TEMPLATE_PARM_INDEX:   return sizeof (template_parm_index);
  69     case DEFAULT_ARG:           return sizeof (struct tree_default_arg);
  70     case DEFERRED_NOEXCEPT:     return sizeof (struct tree_deferred_noexcept);
  71     case OVERLOAD:              return sizeof (struct tree_overload);
  72     case STATIC_ASSERT:         return sizeof (struct tree_static_assert);
  73     case TYPE_ARGUMENT_PACK:
  74     case TYPE_PACK_EXPANSION:
  75       return sizeof (struct tree_common);
  76
  77     case NONTYPE_ARGUMENT_PACK:
  78     case EXPR_PACK_EXPANSION:
  79       return sizeof (struct tree_exp);
  80
  81     case ARGUMENT_PACK_SELECT:
  82       return sizeof (struct tree_argument_pack_select);
  83
  84     case TRAIT_EXPR:
  85       return sizeof (struct tree_trait_expr);
  86
  87     case LAMBDA_EXPR:           return sizeof (struct tree_lambda_expr);
  88
  89     case TEMPLATE_INFO:         return sizeof (struct tree_template_info);
  90
  91     case CONSTRAINT_INFO:       return sizeof (struct tree_constraint_info);
  92
  93     case USERDEF_LITERAL:       return sizeof (struct tree_userdef_literal);
  94
  95     case TEMPLATE_DECL:         return sizeof (struct tree_template_decl);
  96
  97     default:
  98       if (TREE_CODE_CLASS (code) == tcc_declaration)
  99         return sizeof (struct tree_decl_non_common);
 100       gcc_unreachable ();
 101     }
 102   /* NOTREACHED */
 103 }
 104
 105 /* Returns true if T is a variably modified type, in the sense of C99.
 106    FN is as passed to variably_modified_p.
 107    This routine needs only check cases that cannot be handled by the
 108    language-independent logic in tree.c.  */
 109
 110 bool
 111 cp_var_mod_type_p (tree type, tree fn)
 112 {
 113   /* If TYPE is a pointer-to-member, it is variably modified if either
 114      the class or the member are variably modified.  */
 115   if (TYPE_PTRMEM_P (type))
 116     return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type), fn)
 117             || variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type),
 118                                          fn));
 119
 120   /* All other types are not variably modified.  */
 121   return false;
 122 }
 123
 124 /* This compares two types for equivalence ("compatible" in C-based languages).
 125    This routine should only return 1 if it is sure.  It should not be used
 126    in contexts where erroneously returning 0 causes problems.  */
 127
 128 int
 129 cxx_types_compatible_p (tree x, tree y)
 130 {
 131   return same_type_ignoring_top_level_qualifiers_p (x, y);
 132 }
 133
 134 struct debug_type_hasher : ggc_cache_ptr_hash<tree_map>
 135 {
 136   static hashval_t hash (tree_map *m) { return tree_map_hash (m); }
 137   static bool equal (tree_map *a, tree_map *b) { return tree_map_eq (a, b); }
 138
 139   static int
 140   keep_cache_entry (tree_map *&e)
 141   {
 142     return ggc_marked_p (e->base.from);
 143   }
 144 };
 145
 146 static GTY((cache)) hash_table<debug_type_hasher> *debug_type_hash;
 147
 148 /* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
 149    keep TYPE.  */
 150
 151 tree
 152 cp_get_debug_type (const_tree type)
 153 {
 154   if (TYPE_PTRMEMFUNC_P (type) && !typedef_variant_p (type))
 155     {
 156       if (debug_type_hash == NULL)
 157         debug_type_hash = hash_table<debug_type_hasher>::create_ggc (512);
 158
 159       /* We cannot simply use build_offset_type here because the function uses
 160          the type canonicalization hashtable, which is GC-ed, so its behavior
 161          depends on the actual collection points.  Since we are building these
 162          types on the fly for the debug info only, they would not be attached
 163          to any GC root and always be swept, so we would make the contents of
 164          the debug info depend on the collection points.  */
 165       struct tree_map in, *h, **slot;
 166
 167       in.base.from = CONST_CAST_TREE (type);
 168       in.hash = htab_hash_pointer (type);
 169       slot = debug_type_hash->find_slot_with_hash (&in, in.hash, INSERT);
 170       if (*slot)
 171         return (*slot)->to;
 172
 173       tree t = build_offset_type (TYPE_PTRMEMFUNC_OBJECT_TYPE (type),
 174                                   TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (type)));
 175
 176       h = ggc_alloc<tree_map> ();
 177       h->base.from = CONST_CAST_TREE (type);
 178       h->hash = htab_hash_pointer (type);
 179       h->to = t;
 180       *slot = h;
 181
 182       return t;
 183     }
 184
 185   return NULL_TREE;
 186 }
 187
 188 /* Return -1 if dwarf ATTR shouldn't be added for DECL, or the attribute
 189    value otherwise.  */
 190 int
 191 cp_decl_dwarf_attribute (const_tree decl, int attr)
 192 {
 193   if (decl == NULL_TREE)
 194     return -1;
 195
 196   switch (attr)
 197     {
 198     case DW_AT_explicit:
 199       if (TREE_CODE (decl) == FUNCTION_DECL
 200           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 201           && DECL_NONCONVERTING_P (decl))
 202         return 1;
 203       break;
 204
 205     case DW_AT_deleted:
 206       if (TREE_CODE (decl) == FUNCTION_DECL
 207           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 208           && DECL_DELETED_FN (decl))
 209         return 1;
 210       break;
 211
 212     case DW_AT_defaulted:
 213       if (TREE_CODE (decl) == FUNCTION_DECL
 214           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 215           && DECL_DEFAULTED_FN (decl))
 216         {
 217           if (DECL_DEFAULTED_IN_CLASS_P (decl))
 218             return DW_DEFAULTED_in_class;
 219
 220           if (DECL_DEFAULTED_OUTSIDE_CLASS_P (decl))
 221             return DW_DEFAULTED_out_of_class;
 222         }
 223       break;
 224
 225     case DW_AT_const_expr:
 226       if (VAR_OR_FUNCTION_DECL_P (decl) && DECL_DECLARED_CONSTEXPR_P (decl))
 227         return 1;
 228       break;
 229
 230     case DW_AT_reference:
 231       if (TREE_CODE (decl) == FUNCTION_DECL
 232           && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
 233           && FUNCTION_REF_QUALIFIED (TREE_TYPE (decl))
 234           && !FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (decl)))
 235         return 1;
 236       break;
 237
 238     case DW_AT_rvalue_reference:
 239       if (TREE_CODE (decl) == FUNCTION_DECL
 240           && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
 241           && FUNCTION_REF_QUALIFIED (TREE_TYPE (decl))
 242           && FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (decl)))
 243         return 1;
 244       break;
 245
 246     case DW_AT_inline:
 247       if (VAR_P (decl) && DECL_INLINE_VAR_P (decl))
 248         {
 249           if (DECL_VAR_DECLARED_INLINE_P (decl))
 250             return DW_INL_declared_inlined;
 251           else
 252             return DW_INL_inlined;
 253         }
 254       break;
 255
 256     case DW_AT_export_symbols:
 257       if (TREE_CODE (decl) == NAMESPACE_DECL
 258           && (DECL_NAMESPACE_INLINE_P (decl)
 259               || (DECL_NAME (decl) == NULL_TREE && dwarf_version >= 5)))
 260         return 1;
 261       break;
 262
 263     default:
 264       break;
 265     }
 266
 267   return -1;
 268 }
 269
 270 /* Return -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
 271    value otherwise.  */
 272 int
 273 cp_type_dwarf_attribute (const_tree type, int attr)
 274 {
 275   if (type == NULL_TREE)
 276     return -1;
 277
 278   switch (attr)
 279     {
 280     case DW_AT_reference:
 281       if ((TREE_CODE (type) == FUNCTION_TYPE
 282            || TREE_CODE (type) == METHOD_TYPE)
 283           && FUNCTION_REF_QUALIFIED (type)
 284           && !FUNCTION_RVALUE_QUALIFIED (type))
 285         return 1;
 286       break;
 287
 288     case DW_AT_rvalue_reference:
 289       if ((TREE_CODE (type) == FUNCTION_TYPE
 290            || TREE_CODE (type) == METHOD_TYPE)
 291           && FUNCTION_REF_QUALIFIED (type)
 292           && FUNCTION_RVALUE_QUALIFIED (type))
 293         return 1;
 294       break;
 295
 296     default:
 297       break;
 298     }
 299
 300   return -1;
 301 }
 302
 303 /* Return the unit size of TYPE without reusable tail padding.  */
 304
 305 tree
 306 cp_unit_size_without_reusable_padding (tree type)
 307 {
 308   if (CLASS_TYPE_P (type))
 309     return CLASSTYPE_SIZE_UNIT (type);
 310   return TYPE_SIZE_UNIT (type);
 311 }
 312
 313 /* Stubs to keep c-opts.c happy.  */
 314 void
 315 push_file_scope (void)
 316 {
 317 }
 318
 319 void
 320 pop_file_scope (void)
 321 {
 322 }
 323
 324 /* c-pragma.c needs to query whether a decl has extern "C" linkage.  */
 325 bool
 326 has_c_linkage (const_tree decl)
 327 {
 328   return DECL_EXTERN_C_P (decl);
 329 }
 330
 331 static GTY ((cache))
 332      hash_table<tree_decl_map_cache_hasher> *shadowed_var_for_decl;
 333
 334 /* Lookup a shadowed var for FROM, and return it if we find one.  */
 335
 336 tree
 337 decl_shadowed_for_var_lookup (tree from)
 338 {
 339   struct tree_decl_map *h, in;
 340   in.base.from = from;
 341
 342   h = shadowed_var_for_decl->find_with_hash (&in, DECL_UID (from));
 343   if (h)
 344     return h->to;
 345   return NULL_TREE;
 346 }
 347
 348 /* Insert a mapping FROM->TO in the shadowed var hashtable.  */
 349
 350 void
 351 decl_shadowed_for_var_insert (tree from, tree to)
 352 {
 353   struct tree_decl_map *h;
 354
 355   h = ggc_alloc<tree_decl_map> ();
 356   h->base.from = from;
 357   h->to = to;
 358   *shadowed_var_for_decl->find_slot_with_hash (h, DECL_UID (from), INSERT) = h;
 359 }
 360
 361 void
 362 init_shadowed_var_for_decl (void)
 363 {
 364   shadowed_var_for_decl
 365     = hash_table<tree_decl_map_cache_hasher>::create_ggc (512);
 366 }
 367
 368 /* Return true if stmt can fall through.  Used by block_may_fallthru
 369    default case.  */
 370
 371 bool
 372 cxx_block_may_fallthru (const_tree stmt)
 373 {
 374   switch (TREE_CODE (stmt))
 375     {
 376     case EXPR_STMT:
 377       return block_may_fallthru (EXPR_STMT_EXPR (stmt));
 378
 379     case THROW_EXPR:
 380       return false;
 381
 382     default:
 383       return true;
 384     }
 385 }
 386
 387 /* Return the list of decls in the global namespace.  */
 388
 389 tree
 390 cp_get_global_decls ()
 391 {
 392   return NAMESPACE_LEVEL (global_namespace)->names;
 393 }
 394
 395 /* Push DECL into the current scope.  */
 396
 397 tree
 398 cp_pushdecl (tree decl)
 399 {
 400   return pushdecl (decl);
 401 }
 402
 403 /* Register c++-specific dumps.  */
 404
 405 void
 406 cp_register_dumps (gcc::dump_manager *dumps)
 407 {
 408   class_dump_id = dumps->dump_register
 409     (".class", "lang-class", "lang-class", DK_lang, OPTGROUP_NONE, false);
 410
 411   raw_dump_id = dumps->dump_register
 412     (".raw", "lang-raw", "lang-raw", DK_lang, OPTGROUP_NONE, false);
 413 }
 414
 415 void
 416 cp_common_init_ts (void)
 417 {
 418   MARK_TS_DECL_NON_COMMON (USING_DECL);
 419   MARK_TS_DECL_COMMON (TEMPLATE_DECL);
 420   MARK_TS_DECL_COMMON (WILDCARD_DECL);
 421
 422   MARK_TS_COMMON (TEMPLATE_TEMPLATE_PARM);
 423   MARK_TS_COMMON (TEMPLATE_TYPE_PARM);
 424   MARK_TS_COMMON (TEMPLATE_PARM_INDEX);
 425   MARK_TS_COMMON (OVERLOAD);
 426   MARK_TS_COMMON (TEMPLATE_INFO);
 427   MARK_TS_COMMON (TYPENAME_TYPE);
 428   MARK_TS_COMMON (TYPEOF_TYPE);
 429   MARK_TS_COMMON (UNDERLYING_TYPE);
 430   MARK_TS_COMMON (BASELINK);
 431   MARK_TS_COMMON (TYPE_PACK_EXPANSION);
 432   MARK_TS_COMMON (TYPE_ARGUMENT_PACK);
 433   MARK_TS_COMMON (DECLTYPE_TYPE);
 434   MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
 435   MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);
 436
 437   MARK_TS_TYPED (EXPR_PACK_EXPANSION);
 438   MARK_TS_TYPED (SWITCH_STMT);
 439   MARK_TS_TYPED (IF_STMT);
 440   MARK_TS_TYPED (FOR_STMT);
 441   MARK_TS_TYPED (RANGE_FOR_STMT);
 442   MARK_TS_TYPED (AGGR_INIT_EXPR);
 443   MARK_TS_TYPED (EXPR_STMT);
 444   MARK_TS_TYPED (EH_SPEC_BLOCK);
 445   MARK_TS_TYPED (CLEANUP_STMT);
 446   MARK_TS_TYPED (SCOPE_REF);
 447   MARK_TS_TYPED (CAST_EXPR);
 448   MARK_TS_TYPED (NON_DEPENDENT_EXPR);
 449   MARK_TS_TYPED (MODOP_EXPR);
 450   MARK_TS_TYPED (TRY_BLOCK);
 451   MARK_TS_TYPED (THROW_EXPR);
 452   MARK_TS_TYPED (HANDLER);
 453   MARK_TS_TYPED (REINTERPRET_CAST_EXPR);
 454   MARK_TS_TYPED (CONST_CAST_EXPR);
 455   MARK_TS_TYPED (STATIC_CAST_EXPR);
 456   MARK_TS_TYPED (DYNAMIC_CAST_EXPR);
 457   MARK_TS_TYPED (IMPLICIT_CONV_EXPR);
 458   MARK_TS_TYPED (TEMPLATE_ID_EXPR);
 459   MARK_TS_TYPED (ARROW_EXPR);
 460   MARK_TS_TYPED (SIZEOF_EXPR);
 461   MARK_TS_TYPED (ALIGNOF_EXPR);
 462   MARK_TS_TYPED (AT_ENCODE_EXPR);
 463   MARK_TS_TYPED (UNARY_PLUS_EXPR);
 464   MARK_TS_TYPED (TRAIT_EXPR);
 465   MARK_TS_TYPED (TYPE_ARGUMENT_PACK);
 466   MARK_TS_TYPED (NOEXCEPT_EXPR);
 467   MARK_TS_TYPED (NONTYPE_ARGUMENT_PACK);
 468   MARK_TS_TYPED (WHILE_STMT);
 469   MARK_TS_TYPED (NEW_EXPR);
 470   MARK_TS_TYPED (VEC_NEW_EXPR);
 471   MARK_TS_TYPED (BREAK_STMT);
 472   MARK_TS_TYPED (MEMBER_REF);
 473   MARK_TS_TYPED (DOTSTAR_EXPR);
 474   MARK_TS_TYPED (DO_STMT);
 475   MARK_TS_TYPED (DELETE_EXPR);
 476   MARK_TS_TYPED (VEC_DELETE_EXPR);
 477   MARK_TS_TYPED (CONTINUE_STMT);
 478   MARK_TS_TYPED (TAG_DEFN);
 479   MARK_TS_TYPED (PSEUDO_DTOR_EXPR);
 480   MARK_TS_TYPED (TYPEID_EXPR);
 481   MARK_TS_TYPED (MUST_NOT_THROW_EXPR);
 482   MARK_TS_TYPED (STMT_EXPR);
 483   MARK_TS_TYPED (OFFSET_REF);
 484   MARK_TS_TYPED (OFFSETOF_EXPR);
 485   MARK_TS_TYPED (ADDRESSOF_EXPR);
 486   MARK_TS_TYPED (PTRMEM_CST);
 487   MARK_TS_TYPED (EMPTY_CLASS_EXPR);
 488   MARK_TS_TYPED (VEC_INIT_EXPR);
 489   MARK_TS_TYPED (USING_STMT);
 490   MARK_TS_TYPED (LAMBDA_EXPR);
 491   MARK_TS_TYPED (CTOR_INITIALIZER);
 492   MARK_TS_TYPED (ARRAY_NOTATION_REF);
 493   MARK_TS_TYPED (REQUIRES_EXPR);
 494   MARK_TS_TYPED (UNARY_LEFT_FOLD_EXPR);
 495   MARK_TS_TYPED (UNARY_RIGHT_FOLD_EXPR);
 496   MARK_TS_TYPED (BINARY_LEFT_FOLD_EXPR);
 497   MARK_TS_TYPED (BINARY_RIGHT_FOLD_EXPR);
 498 }
 499
 500 #include "gt-cp-cp-objcp-common.h"