gcc/cp/cp-objcp-common.c

   1 /* Some code common to C++ and ObjC++ front ends.
   2    Copyright (C) 2004-2018 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   gcc_checking_assert (code >= NUM_TREE_CODES);
  65   switch (code)
  66     {
  67     case PTRMEM_CST:            return sizeof (ptrmem_cst);
  68     case BASELINK:              return sizeof (tree_baselink);
  69     case TEMPLATE_PARM_INDEX:   return sizeof (template_parm_index);
  70     case DEFAULT_ARG:           return sizeof (tree_default_arg);
  71     case DEFERRED_NOEXCEPT:     return sizeof (tree_deferred_noexcept);
  72     case OVERLOAD:              return sizeof (tree_overload);
  73     case STATIC_ASSERT:         return sizeof (tree_static_assert);
  74     case TYPE_ARGUMENT_PACK:
  75     case TYPE_PACK_EXPANSION:   return sizeof (tree_type_non_common);
  76     case NONTYPE_ARGUMENT_PACK:
  77     case EXPR_PACK_EXPANSION:   return sizeof (tree_exp);
  78     case ARGUMENT_PACK_SELECT:  return sizeof (tree_argument_pack_select);
  79     case TRAIT_EXPR:            return sizeof (tree_trait_expr);
  80     case LAMBDA_EXPR:           return sizeof (tree_lambda_expr);
  81     case TEMPLATE_INFO:         return sizeof (tree_template_info);
  82     case CONSTRAINT_INFO:       return sizeof (tree_constraint_info);
  83     case USERDEF_LITERAL:       return sizeof (tree_userdef_literal);
  84     case TEMPLATE_DECL:         return sizeof (tree_template_decl);
  85     default:
  86       switch (TREE_CODE_CLASS (code))
  87         {
  88         case tcc_declaration:   return sizeof (tree_decl_non_common);
  89         case tcc_type:          return sizeof (tree_type_non_common);
  90         default: gcc_unreachable ();
  91         }
  92     }
  93   /* NOTREACHED */
  94 }
  95
  96 /* Returns true if T is a variably modified type, in the sense of C99.
  97    FN is as passed to variably_modified_p.
  98    This routine needs only check cases that cannot be handled by the
  99    language-independent logic in tree.c.  */
 100
 101 bool
 102 cp_var_mod_type_p (tree type, tree fn)
 103 {
 104   /* If TYPE is a pointer-to-member, it is variably modified if either
 105      the class or the member are variably modified.  */
 106   if (TYPE_PTRMEM_P (type))
 107     return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type), fn)
 108             || variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type),
 109                                          fn));
 110
 111   /* All other types are not variably modified.  */
 112   return false;
 113 }
 114
 115 /* This compares two types for equivalence ("compatible" in C-based languages).
 116    This routine should only return 1 if it is sure.  It should not be used
 117    in contexts where erroneously returning 0 causes problems.  */
 118
 119 int
 120 cxx_types_compatible_p (tree x, tree y)
 121 {
 122   return same_type_ignoring_top_level_qualifiers_p (x, y);
 123 }
 124
 125 static GTY((cache)) tree_cache_map *debug_type_map;
 126
 127 /* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
 128    keep TYPE.  */
 129
 130 tree
 131 cp_get_debug_type (const_tree type)
 132 {
 133   tree dtype = NULL_TREE;
 134
 135   if (TYPE_PTRMEMFUNC_P (type) && !typedef_variant_p (type))
 136     dtype = build_offset_type (TYPE_PTRMEMFUNC_OBJECT_TYPE (type),
 137                                TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (type)));
 138
 139   /* We cannot simply return the debug type here because the function uses
 140      the type canonicalization hashtable, which is GC-ed, so its behavior
 141      depends on the actual collection points.  Since we are building these
 142      types on the fly for the debug info only, they would not be attached
 143      to any GC root and always be swept, so we would make the contents of
 144      the debug info depend on the collection points.  */
 145   if (dtype)
 146     {
 147       tree ktype = CONST_CAST_TREE (type);
 148       if (debug_type_map == NULL)
 149         debug_type_map = tree_cache_map::create_ggc (512);
 150       else if (tree *slot = debug_type_map->get (ktype))
 151         return *slot;
 152       debug_type_map->put (ktype, dtype);
 153     }
 154
 155   return dtype;
 156 }
 157
 158 /* Return -1 if dwarf ATTR shouldn't be added for DECL, or the attribute
 159    value otherwise.  */
 160 int
 161 cp_decl_dwarf_attribute (const_tree decl, int attr)
 162 {
 163   if (decl == NULL_TREE)
 164     return -1;
 165
 166   switch (attr)
 167     {
 168     case DW_AT_explicit:
 169       if (TREE_CODE (decl) == FUNCTION_DECL
 170           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 171           && DECL_NONCONVERTING_P (decl))
 172         return 1;
 173       break;
 174
 175     case DW_AT_deleted:
 176       if (TREE_CODE (decl) == FUNCTION_DECL
 177           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 178           && DECL_DELETED_FN (decl))
 179         return 1;
 180       break;
 181
 182     case DW_AT_defaulted:
 183       if (TREE_CODE (decl) == FUNCTION_DECL
 184           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 185           && DECL_DEFAULTED_FN (decl))
 186         {
 187           if (DECL_DEFAULTED_IN_CLASS_P (decl))
 188             return DW_DEFAULTED_in_class;
 189
 190           if (DECL_DEFAULTED_OUTSIDE_CLASS_P (decl))
 191             return DW_DEFAULTED_out_of_class;
 192         }
 193       break;
 194
 195     case DW_AT_const_expr:
 196       if (VAR_OR_FUNCTION_DECL_P (decl) && DECL_DECLARED_CONSTEXPR_P (decl))
 197         return 1;
 198       break;
 199
 200     case DW_AT_reference:
 201       if (TREE_CODE (decl) == FUNCTION_DECL
 202           && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
 203           && FUNCTION_REF_QUALIFIED (TREE_TYPE (decl))
 204           && !FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (decl)))
 205         return 1;
 206       break;
 207
 208     case DW_AT_rvalue_reference:
 209       if (TREE_CODE (decl) == FUNCTION_DECL
 210           && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
 211           && FUNCTION_REF_QUALIFIED (TREE_TYPE (decl))
 212           && FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (decl)))
 213         return 1;
 214       break;
 215
 216     case DW_AT_inline:
 217       if (VAR_P (decl) && DECL_INLINE_VAR_P (decl))
 218         {
 219           if (DECL_VAR_DECLARED_INLINE_P (decl))
 220             return DW_INL_declared_inlined;
 221           else
 222             return DW_INL_inlined;
 223         }
 224       break;
 225
 226     case DW_AT_export_symbols:
 227       if (TREE_CODE (decl) == NAMESPACE_DECL
 228           && (DECL_NAMESPACE_INLINE_P (decl)
 229               || (DECL_NAME (decl) == NULL_TREE && dwarf_version >= 5)))
 230         return 1;
 231       break;
 232
 233     default:
 234       break;
 235     }
 236
 237   return -1;
 238 }
 239
 240 /* Return -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
 241    value otherwise.  */
 242 int
 243 cp_type_dwarf_attribute (const_tree type, int attr)
 244 {
 245   if (type == NULL_TREE)
 246     return -1;
 247
 248   switch (attr)
 249     {
 250     case DW_AT_reference:
 251       if ((TREE_CODE (type) == FUNCTION_TYPE
 252            || TREE_CODE (type) == METHOD_TYPE)
 253           && FUNCTION_REF_QUALIFIED (type)
 254           && !FUNCTION_RVALUE_QUALIFIED (type))
 255         return 1;
 256       break;
 257
 258     case DW_AT_rvalue_reference:
 259       if ((TREE_CODE (type) == FUNCTION_TYPE
 260            || TREE_CODE (type) == METHOD_TYPE)
 261           && FUNCTION_REF_QUALIFIED (type)
 262           && FUNCTION_RVALUE_QUALIFIED (type))
 263         return 1;
 264       break;
 265
 266     default:
 267       break;
 268     }
 269
 270   return -1;
 271 }
 272
 273 /* Return the unit size of TYPE without reusable tail padding.  */
 274
 275 tree
 276 cp_unit_size_without_reusable_padding (tree type)
 277 {
 278   if (CLASS_TYPE_P (type))
 279     return CLASSTYPE_SIZE_UNIT (type);
 280   return TYPE_SIZE_UNIT (type);
 281 }
 282
 283 /* Stubs to keep c-opts.c happy.  */
 284 void
 285 push_file_scope (void)
 286 {
 287 }
 288
 289 void
 290 pop_file_scope (void)
 291 {
 292 }
 293
 294 /* c-pragma.c needs to query whether a decl has extern "C" linkage.  */
 295 bool
 296 has_c_linkage (const_tree decl)
 297 {
 298   return DECL_EXTERN_C_P (decl);
 299 }
 300
 301 /* Return true if stmt can fall through.  Used by block_may_fallthru
 302    default case.  */
 303
 304 bool
 305 cxx_block_may_fallthru (const_tree stmt)
 306 {
 307   switch (TREE_CODE (stmt))
 308     {
 309     case EXPR_STMT:
 310       return block_may_fallthru (EXPR_STMT_EXPR (stmt));
 311
 312     case THROW_EXPR:
 313       return false;
 314
 315     case IF_STMT:
 316       if (block_may_fallthru (THEN_CLAUSE (stmt)))
 317         return true;
 318       return block_may_fallthru (ELSE_CLAUSE (stmt));
 319
 320     case SWITCH_STMT:
 321       return (!SWITCH_STMT_ALL_CASES_P (stmt)
 322               || !SWITCH_STMT_NO_BREAK_P (stmt)
 323               || block_may_fallthru (SWITCH_STMT_BODY (stmt)));
 324
 325     default:
 326       return true;
 327     }
 328 }
 329
 330 /* Return the list of decls in the global namespace.  */
 331
 332 tree
 333 cp_get_global_decls ()
 334 {
 335   return NAMESPACE_LEVEL (global_namespace)->names;
 336 }
 337
 338 /* Push DECL into the current scope.  */
 339
 340 tree
 341 cp_pushdecl (tree decl)
 342 {
 343   return pushdecl (decl);
 344 }
 345
 346 /* Get the global value binding of NAME.  Called directly from
 347    c-common.c, not via a hook. */
 348
 349 tree
 350 identifier_global_value (tree name)
 351 {
 352   return get_global_binding (name);
 353 }
 354
 355 /* Register c++-specific dumps.  */
 356
 357 void
 358 cp_register_dumps (gcc::dump_manager *dumps)
 359 {
 360   class_dump_id = dumps->dump_register
 361     (".class", "lang-class", "lang-class", DK_lang, OPTGROUP_NONE, false);
 362
 363   raw_dump_id = dumps->dump_register
 364     (".raw", "lang-raw", "lang-raw", DK_lang, OPTGROUP_NONE, false);
 365 }
 366
 367 void
 368 cp_common_init_ts (void)
 369 {
 370   MARK_TS_DECL_NON_COMMON (USING_DECL);
 371   MARK_TS_DECL_COMMON (TEMPLATE_DECL);
 372   MARK_TS_DECL_COMMON (WILDCARD_DECL);
 373
 374   MARK_TS_COMMON (TEMPLATE_TEMPLATE_PARM);
 375   MARK_TS_COMMON (TEMPLATE_TYPE_PARM);
 376   MARK_TS_COMMON (TEMPLATE_PARM_INDEX);
 377   MARK_TS_COMMON (OVERLOAD);
 378   MARK_TS_COMMON (TEMPLATE_INFO);
 379   MARK_TS_COMMON (TYPENAME_TYPE);
 380   MARK_TS_COMMON (TYPEOF_TYPE);
 381   MARK_TS_COMMON (UNDERLYING_TYPE);
 382   MARK_TS_COMMON (BASELINK);
 383   MARK_TS_COMMON (TYPE_PACK_EXPANSION);
 384   MARK_TS_COMMON (TYPE_ARGUMENT_PACK);
 385   MARK_TS_COMMON (DECLTYPE_TYPE);
 386   MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
 387   MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);
 388
 389   MARK_TS_TYPED (EXPR_PACK_EXPANSION);
 390   MARK_TS_TYPED (SWITCH_STMT);
 391   MARK_TS_TYPED (IF_STMT);
 392   MARK_TS_TYPED (FOR_STMT);
 393   MARK_TS_TYPED (RANGE_FOR_STMT);
 394   MARK_TS_TYPED (AGGR_INIT_EXPR);
 395   MARK_TS_TYPED (EXPR_STMT);
 396   MARK_TS_TYPED (EH_SPEC_BLOCK);
 397   MARK_TS_TYPED (CLEANUP_STMT);
 398   MARK_TS_TYPED (SCOPE_REF);
 399   MARK_TS_TYPED (CAST_EXPR);
 400   MARK_TS_TYPED (NON_DEPENDENT_EXPR);
 401   MARK_TS_TYPED (MODOP_EXPR);
 402   MARK_TS_TYPED (TRY_BLOCK);
 403   MARK_TS_TYPED (THROW_EXPR);
 404   MARK_TS_TYPED (HANDLER);
 405   MARK_TS_TYPED (REINTERPRET_CAST_EXPR);
 406   MARK_TS_TYPED (CONST_CAST_EXPR);
 407   MARK_TS_TYPED (STATIC_CAST_EXPR);
 408   MARK_TS_TYPED (DYNAMIC_CAST_EXPR);
 409   MARK_TS_TYPED (IMPLICIT_CONV_EXPR);
 410   MARK_TS_TYPED (TEMPLATE_ID_EXPR);
 411   MARK_TS_TYPED (ARROW_EXPR);
 412   MARK_TS_TYPED (SIZEOF_EXPR);
 413   MARK_TS_TYPED (ALIGNOF_EXPR);
 414   MARK_TS_TYPED (AT_ENCODE_EXPR);
 415   MARK_TS_TYPED (UNARY_PLUS_EXPR);
 416   MARK_TS_TYPED (TRAIT_EXPR);
 417   MARK_TS_TYPED (TYPE_ARGUMENT_PACK);
 418   MARK_TS_TYPED (NOEXCEPT_EXPR);
 419   MARK_TS_TYPED (NONTYPE_ARGUMENT_PACK);
 420   MARK_TS_TYPED (WHILE_STMT);
 421   MARK_TS_TYPED (NEW_EXPR);
 422   MARK_TS_TYPED (VEC_NEW_EXPR);
 423   MARK_TS_TYPED (BREAK_STMT);
 424   MARK_TS_TYPED (MEMBER_REF);
 425   MARK_TS_TYPED (DOTSTAR_EXPR);
 426   MARK_TS_TYPED (DO_STMT);
 427   MARK_TS_TYPED (DELETE_EXPR);
 428   MARK_TS_TYPED (VEC_DELETE_EXPR);
 429   MARK_TS_TYPED (CONTINUE_STMT);
 430   MARK_TS_TYPED (TAG_DEFN);
 431   MARK_TS_TYPED (PSEUDO_DTOR_EXPR);
 432   MARK_TS_TYPED (TYPEID_EXPR);
 433   MARK_TS_TYPED (MUST_NOT_THROW_EXPR);
 434   MARK_TS_TYPED (STMT_EXPR);
 435   MARK_TS_TYPED (OFFSET_REF);
 436   MARK_TS_TYPED (OFFSETOF_EXPR);
 437   MARK_TS_TYPED (ADDRESSOF_EXPR);
 438   MARK_TS_TYPED (PTRMEM_CST);
 439   MARK_TS_TYPED (EMPTY_CLASS_EXPR);
 440   MARK_TS_TYPED (VEC_INIT_EXPR);
 441   MARK_TS_TYPED (USING_STMT);
 442   MARK_TS_TYPED (LAMBDA_EXPR);
 443   MARK_TS_TYPED (CTOR_INITIALIZER);
 444   MARK_TS_TYPED (REQUIRES_EXPR);
 445   MARK_TS_TYPED (UNARY_LEFT_FOLD_EXPR);
 446   MARK_TS_TYPED (UNARY_RIGHT_FOLD_EXPR);
 447   MARK_TS_TYPED (BINARY_LEFT_FOLD_EXPR);
 448   MARK_TS_TYPED (BINARY_RIGHT_FOLD_EXPR);
 449 }
 450
 451 #include "gt-cp-cp-objcp-common.h"