gcc/cp/cp-objcp-common.c

   1 /* Some code common to C++ and ObjC++ front ends.
   2    Copyright (C) 2004-2015 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 "alias.h"
  26 #include "tree.h"
  27 #include "cp-tree.h"
  28 #include "c-family/c-common.h"
  29 #include "langhooks.h"
  30 #include "langhooks-def.h"
  31 #include "diagnostic.h"
  32 #include "debug.h"
  33 #include "cxx-pretty-print.h"
  34 #include "cp-objcp-common.h"
  35
  36 /* Special routine to get the alias set for C++.  */
  37
  38 alias_set_type
  39 cxx_get_alias_set (tree t)
  40 {
  41   if (IS_FAKE_BASE_TYPE (t))
  42     /* The base variant of a type must be in the same alias set as the
  43        complete type.  */
  44     return get_alias_set (TYPE_CONTEXT (t));
  45
  46   /* Punt on PMFs until we canonicalize functions properly.  */
  47   if (TYPE_PTRMEMFUNC_P (t)
  48       || (POINTER_TYPE_P (t)
  49           && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))))
  50     return 0;
  51
  52   return c_common_get_alias_set (t);
  53 }
  54
  55 /* Called from check_global_declaration.  */
  56
  57 bool
  58 cxx_warn_unused_global_decl (const_tree decl)
  59 {
  60   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
  61     return false;
  62   if (DECL_IN_SYSTEM_HEADER (decl))
  63     return false;
  64
  65   /* Const variables take the place of #defines in C++.  */
  66   if (VAR_P (decl) && TREE_READONLY (decl))
  67     return false;
  68
  69   return true;
  70 }
  71
  72 /* Langhook for tree_size: determine size of our 'x' and 'c' nodes.  */
  73 size_t
  74 cp_tree_size (enum tree_code code)
  75 {
  76   switch (code)
  77     {
  78     case PTRMEM_CST:            return sizeof (struct ptrmem_cst);
  79     case BASELINK:              return sizeof (struct tree_baselink);
  80     case TEMPLATE_PARM_INDEX:   return sizeof (template_parm_index);
  81     case DEFAULT_ARG:           return sizeof (struct tree_default_arg);
  82     case DEFERRED_NOEXCEPT:     return sizeof (struct tree_deferred_noexcept);
  83     case OVERLOAD:              return sizeof (struct tree_overload);
  84     case STATIC_ASSERT:         return sizeof (struct tree_static_assert);
  85     case TYPE_ARGUMENT_PACK:
  86     case TYPE_PACK_EXPANSION:
  87       return sizeof (struct tree_common);
  88
  89     case NONTYPE_ARGUMENT_PACK:
  90     case EXPR_PACK_EXPANSION:
  91       return sizeof (struct tree_exp);
  92
  93     case ARGUMENT_PACK_SELECT:
  94       return sizeof (struct tree_argument_pack_select);
  95
  96     case TRAIT_EXPR:
  97       return sizeof (struct tree_trait_expr);
  98
  99     case LAMBDA_EXPR:           return sizeof (struct tree_lambda_expr);
 100
 101     case TEMPLATE_INFO:         return sizeof (struct tree_template_info);
 102
 103     case CONSTRAINT_INFO:       return sizeof (struct tree_constraint_info);
 104
 105     case USERDEF_LITERAL:       return sizeof (struct tree_userdef_literal);
 106
 107     case TEMPLATE_DECL:         return sizeof (struct tree_template_decl);
 108
 109     default:
 110       if (TREE_CODE_CLASS (code) == tcc_declaration)
 111         return sizeof (struct tree_decl_non_common);
 112       gcc_unreachable ();
 113     }
 114   /* NOTREACHED */
 115 }
 116
 117 /* Returns true if T is a variably modified type, in the sense of C99.
 118    FN is as passed to variably_modified_p.
 119    This routine needs only check cases that cannot be handled by the
 120    language-independent logic in tree.c.  */
 121
 122 bool
 123 cp_var_mod_type_p (tree type, tree fn)
 124 {
 125   /* If TYPE is a pointer-to-member, it is variably modified if either
 126      the class or the member are variably modified.  */
 127   if (TYPE_PTRMEM_P (type))
 128     return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type), fn)
 129             || variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type),
 130                                          fn));
 131
 132   /* All other types are not variably modified.  */
 133   return false;
 134 }
 135
 136 /* This compares two types for equivalence ("compatible" in C-based languages).
 137    This routine should only return 1 if it is sure.  It should not be used
 138    in contexts where erroneously returning 0 causes problems.  */
 139
 140 int
 141 cxx_types_compatible_p (tree x, tree y)
 142 {
 143   return same_type_ignoring_top_level_qualifiers_p (x, y);
 144 }
 145
 146 /* Return true if DECL is explicit member function.  */
 147
 148 bool
 149 cp_function_decl_explicit_p (tree decl)
 150 {
 151   return (decl
 152           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 153           && DECL_NONCONVERTING_P (decl));
 154 }
 155
 156 /* Return true if DECL is deleted special member function.  */
 157
 158 bool
 159 cp_function_decl_deleted_p (tree decl)
 160 {
 161   return (decl
 162           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 163           && DECL_DELETED_FN (decl));
 164 }
 165
 166 /* Stubs to keep c-opts.c happy.  */
 167 void
 168 push_file_scope (void)
 169 {
 170 }
 171
 172 void
 173 pop_file_scope (void)
 174 {
 175 }
 176
 177 /* c-pragma.c needs to query whether a decl has extern "C" linkage.  */
 178 bool
 179 has_c_linkage (const_tree decl)
 180 {
 181   return DECL_EXTERN_C_P (decl);
 182 }
 183
 184 static GTY ((cache))
 185      hash_table<tree_decl_map_cache_hasher> *shadowed_var_for_decl;
 186
 187 /* Lookup a shadowed var for FROM, and return it if we find one.  */
 188
 189 tree
 190 decl_shadowed_for_var_lookup (tree from)
 191 {
 192   struct tree_decl_map *h, in;
 193   in.base.from = from;
 194
 195   h = shadowed_var_for_decl->find_with_hash (&in, DECL_UID (from));
 196   if (h)
 197     return h->to;
 198   return NULL_TREE;
 199 }
 200
 201 /* Insert a mapping FROM->TO in the shadowed var hashtable.  */
 202
 203 void
 204 decl_shadowed_for_var_insert (tree from, tree to)
 205 {
 206   struct tree_decl_map *h;
 207
 208   h = ggc_alloc<tree_decl_map> ();
 209   h->base.from = from;
 210   h->to = to;
 211   *shadowed_var_for_decl->find_slot_with_hash (h, DECL_UID (from), INSERT) = h;
 212 }
 213
 214 void
 215 init_shadowed_var_for_decl (void)
 216 {
 217   shadowed_var_for_decl
 218     = hash_table<tree_decl_map_cache_hasher>::create_ggc (512);
 219 }
 220
 221 /* Return true if stmt can fall through.  Used by block_may_fallthru
 222    default case.  */
 223
 224 bool
 225 cxx_block_may_fallthru (const_tree stmt)
 226 {
 227   switch (TREE_CODE (stmt))
 228     {
 229     case EXPR_STMT:
 230       return block_may_fallthru (EXPR_STMT_EXPR (stmt));
 231
 232     case THROW_EXPR:
 233       return false;
 234
 235     default:
 236       return true;
 237     }
 238 }
 239
 240 void
 241 cp_common_init_ts (void)
 242 {
 243   MARK_TS_DECL_NON_COMMON (USING_DECL);
 244   MARK_TS_DECL_COMMON (TEMPLATE_DECL);
 245   MARK_TS_DECL_COMMON (WILDCARD_DECL);
 246
 247   MARK_TS_COMMON (TEMPLATE_TEMPLATE_PARM);
 248   MARK_TS_COMMON (TEMPLATE_TYPE_PARM);
 249   MARK_TS_COMMON (TEMPLATE_PARM_INDEX);
 250   MARK_TS_COMMON (OVERLOAD);
 251   MARK_TS_COMMON (TEMPLATE_INFO);
 252   MARK_TS_COMMON (TYPENAME_TYPE);
 253   MARK_TS_COMMON (TYPEOF_TYPE);
 254   MARK_TS_COMMON (UNDERLYING_TYPE);
 255   MARK_TS_COMMON (BASELINK);
 256   MARK_TS_COMMON (TYPE_PACK_EXPANSION);
 257   MARK_TS_COMMON (TYPE_ARGUMENT_PACK);
 258   MARK_TS_COMMON (DECLTYPE_TYPE);
 259   MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
 260   MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);
 261
 262   MARK_TS_TYPED (EXPR_PACK_EXPANSION);
 263   MARK_TS_TYPED (SWITCH_STMT);
 264   MARK_TS_TYPED (IF_STMT);
 265   MARK_TS_TYPED (FOR_STMT);
 266   MARK_TS_TYPED (RANGE_FOR_STMT);
 267   MARK_TS_TYPED (AGGR_INIT_EXPR);
 268   MARK_TS_TYPED (EXPR_STMT);
 269   MARK_TS_TYPED (EH_SPEC_BLOCK);
 270   MARK_TS_TYPED (CLEANUP_STMT);
 271   MARK_TS_TYPED (SCOPE_REF);
 272   MARK_TS_TYPED (CAST_EXPR);
 273   MARK_TS_TYPED (NON_DEPENDENT_EXPR);
 274   MARK_TS_TYPED (MODOP_EXPR);
 275   MARK_TS_TYPED (TRY_BLOCK);
 276   MARK_TS_TYPED (THROW_EXPR);
 277   MARK_TS_TYPED (HANDLER);
 278   MARK_TS_TYPED (REINTERPRET_CAST_EXPR);
 279   MARK_TS_TYPED (CONST_CAST_EXPR);
 280   MARK_TS_TYPED (STATIC_CAST_EXPR);
 281   MARK_TS_TYPED (DYNAMIC_CAST_EXPR);
 282   MARK_TS_TYPED (IMPLICIT_CONV_EXPR);
 283   MARK_TS_TYPED (TEMPLATE_ID_EXPR);
 284   MARK_TS_TYPED (ARROW_EXPR);
 285   MARK_TS_TYPED (SIZEOF_EXPR);
 286   MARK_TS_TYPED (ALIGNOF_EXPR);
 287   MARK_TS_TYPED (AT_ENCODE_EXPR);
 288   MARK_TS_TYPED (UNARY_PLUS_EXPR);
 289   MARK_TS_TYPED (TRAIT_EXPR);
 290   MARK_TS_TYPED (TYPE_ARGUMENT_PACK);
 291   MARK_TS_TYPED (NOEXCEPT_EXPR);
 292   MARK_TS_TYPED (NONTYPE_ARGUMENT_PACK);
 293   MARK_TS_TYPED (WHILE_STMT);
 294   MARK_TS_TYPED (NEW_EXPR);
 295   MARK_TS_TYPED (VEC_NEW_EXPR);
 296   MARK_TS_TYPED (BREAK_STMT);
 297   MARK_TS_TYPED (MEMBER_REF);
 298   MARK_TS_TYPED (DOTSTAR_EXPR);
 299   MARK_TS_TYPED (DO_STMT);
 300   MARK_TS_TYPED (DELETE_EXPR);
 301   MARK_TS_TYPED (VEC_DELETE_EXPR);
 302   MARK_TS_TYPED (CONTINUE_STMT);
 303   MARK_TS_TYPED (TAG_DEFN);
 304   MARK_TS_TYPED (PSEUDO_DTOR_EXPR);
 305   MARK_TS_TYPED (TYPEID_EXPR);
 306   MARK_TS_TYPED (MUST_NOT_THROW_EXPR);
 307   MARK_TS_TYPED (STMT_EXPR);
 308   MARK_TS_TYPED (OFFSET_REF);
 309   MARK_TS_TYPED (OFFSETOF_EXPR);
 310   MARK_TS_TYPED (PTRMEM_CST);
 311   MARK_TS_TYPED (EMPTY_CLASS_EXPR);
 312   MARK_TS_TYPED (VEC_INIT_EXPR);
 313   MARK_TS_TYPED (USING_STMT);
 314   MARK_TS_TYPED (LAMBDA_EXPR);
 315   MARK_TS_TYPED (CTOR_INITIALIZER);
 316   MARK_TS_TYPED (ARRAY_NOTATION_REF);
 317   MARK_TS_TYPED (REQUIRES_EXPR);
 318 }
 319
 320 #include "gt-cp-cp-objcp-common.h"