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 USERDEF_LITERAL:       return sizeof (struct tree_userdef_literal);
 104
 105     case TEMPLATE_DECL:         return sizeof (struct tree_template_decl);
 106
 107     default:
 108       if (TREE_CODE_CLASS (code) == tcc_declaration)
 109         return sizeof (struct tree_decl_non_common);
 110       gcc_unreachable ();
 111     }
 112   /* NOTREACHED */
 113 }
 114
 115 /* Returns true if T is a variably modified type, in the sense of C99.
 116    FN is as passed to variably_modified_p.
 117    This routine needs only check cases that cannot be handled by the
 118    language-independent logic in tree.c.  */
 119
 120 bool
 121 cp_var_mod_type_p (tree type, tree fn)
 122 {
 123   /* If TYPE is a pointer-to-member, it is variably modified if either
 124      the class or the member are variably modified.  */
 125   if (TYPE_PTRMEM_P (type))
 126     return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type), fn)
 127             || variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type),
 128                                          fn));
 129
 130   /* All other types are not variably modified.  */
 131   return false;
 132 }
 133
 134 /* This compares two types for equivalence ("compatible" in C-based languages).
 135    This routine should only return 1 if it is sure.  It should not be used
 136    in contexts where erroneously returning 0 causes problems.  */
 137
 138 int
 139 cxx_types_compatible_p (tree x, tree y)
 140 {
 141   return same_type_ignoring_top_level_qualifiers_p (x, y);
 142 }
 143
 144 /* Return true if DECL is explicit member function.  */
 145
 146 bool
 147 cp_function_decl_explicit_p (tree decl)
 148 {
 149   return (decl
 150           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 151           && DECL_NONCONVERTING_P (decl));
 152 }
 153
 154 /* Return true if DECL is deleted special member function.  */
 155
 156 bool
 157 cp_function_decl_deleted_p (tree decl)
 158 {
 159   return (decl
 160           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 161           && DECL_DELETED_FN (decl));
 162 }
 163
 164 /* Stubs to keep c-opts.c happy.  */
 165 void
 166 push_file_scope (void)
 167 {
 168 }
 169
 170 void
 171 pop_file_scope (void)
 172 {
 173 }
 174
 175 /* c-pragma.c needs to query whether a decl has extern "C" linkage.  */
 176 bool
 177 has_c_linkage (const_tree decl)
 178 {
 179   return DECL_EXTERN_C_P (decl);
 180 }
 181
 182 static GTY ((cache))
 183      hash_table<tree_decl_map_cache_hasher> *shadowed_var_for_decl;
 184
 185 /* Lookup a shadowed var for FROM, and return it if we find one.  */
 186
 187 tree
 188 decl_shadowed_for_var_lookup (tree from)
 189 {
 190   struct tree_decl_map *h, in;
 191   in.base.from = from;
 192
 193   h = shadowed_var_for_decl->find_with_hash (&in, DECL_UID (from));
 194   if (h)
 195     return h->to;
 196   return NULL_TREE;
 197 }
 198
 199 /* Insert a mapping FROM->TO in the shadowed var hashtable.  */
 200
 201 void
 202 decl_shadowed_for_var_insert (tree from, tree to)
 203 {
 204   struct tree_decl_map *h;
 205
 206   h = ggc_alloc<tree_decl_map> ();
 207   h->base.from = from;
 208   h->to = to;
 209   *shadowed_var_for_decl->find_slot_with_hash (h, DECL_UID (from), INSERT) = h;
 210 }
 211
 212 void
 213 init_shadowed_var_for_decl (void)
 214 {
 215   shadowed_var_for_decl
 216     = hash_table<tree_decl_map_cache_hasher>::create_ggc (512);
 217 }
 218
 219 /* Return true if stmt can fall through.  Used by block_may_fallthru
 220    default case.  */
 221
 222 bool
 223 cxx_block_may_fallthru (const_tree stmt)
 224 {
 225   switch (TREE_CODE (stmt))
 226     {
 227     case EXPR_STMT:
 228       return block_may_fallthru (EXPR_STMT_EXPR (stmt));
 229
 230     case THROW_EXPR:
 231       return false;
 232
 233     default:
 234       return true;
 235     }
 236 }
 237
 238 void
 239 cp_common_init_ts (void)
 240 {
 241   MARK_TS_DECL_NON_COMMON (USING_DECL);
 242   MARK_TS_DECL_COMMON (TEMPLATE_DECL);
 243
 244   MARK_TS_COMMON (TEMPLATE_TEMPLATE_PARM);
 245   MARK_TS_COMMON (TEMPLATE_TYPE_PARM);
 246   MARK_TS_COMMON (TEMPLATE_PARM_INDEX);
 247   MARK_TS_COMMON (OVERLOAD);
 248   MARK_TS_COMMON (TEMPLATE_INFO);
 249   MARK_TS_COMMON (TYPENAME_TYPE);
 250   MARK_TS_COMMON (TYPEOF_TYPE);
 251   MARK_TS_COMMON (UNDERLYING_TYPE);
 252   MARK_TS_COMMON (BASELINK);
 253   MARK_TS_COMMON (TYPE_PACK_EXPANSION);
 254   MARK_TS_COMMON (TYPE_ARGUMENT_PACK);
 255   MARK_TS_COMMON (DECLTYPE_TYPE);
 256   MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
 257   MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);
 258
 259   MARK_TS_TYPED (EXPR_PACK_EXPANSION);
 260   MARK_TS_TYPED (SWITCH_STMT);
 261   MARK_TS_TYPED (IF_STMT);
 262   MARK_TS_TYPED (FOR_STMT);
 263   MARK_TS_TYPED (RANGE_FOR_STMT);
 264   MARK_TS_TYPED (AGGR_INIT_EXPR);
 265   MARK_TS_TYPED (EXPR_STMT);
 266   MARK_TS_TYPED (EH_SPEC_BLOCK);
 267   MARK_TS_TYPED (CLEANUP_STMT);
 268   MARK_TS_TYPED (SCOPE_REF);
 269   MARK_TS_TYPED (CAST_EXPR);
 270   MARK_TS_TYPED (NON_DEPENDENT_EXPR);
 271   MARK_TS_TYPED (MODOP_EXPR);
 272   MARK_TS_TYPED (TRY_BLOCK);
 273   MARK_TS_TYPED (THROW_EXPR);
 274   MARK_TS_TYPED (HANDLER);
 275   MARK_TS_TYPED (REINTERPRET_CAST_EXPR);
 276   MARK_TS_TYPED (CONST_CAST_EXPR);
 277   MARK_TS_TYPED (STATIC_CAST_EXPR);
 278   MARK_TS_TYPED (DYNAMIC_CAST_EXPR);
 279   MARK_TS_TYPED (IMPLICIT_CONV_EXPR);
 280   MARK_TS_TYPED (TEMPLATE_ID_EXPR);
 281   MARK_TS_TYPED (ARROW_EXPR);
 282   MARK_TS_TYPED (SIZEOF_EXPR);
 283   MARK_TS_TYPED (ALIGNOF_EXPR);
 284   MARK_TS_TYPED (AT_ENCODE_EXPR);
 285   MARK_TS_TYPED (UNARY_PLUS_EXPR);
 286   MARK_TS_TYPED (TRAIT_EXPR);
 287   MARK_TS_TYPED (TYPE_ARGUMENT_PACK);
 288   MARK_TS_TYPED (NOEXCEPT_EXPR);
 289   MARK_TS_TYPED (NONTYPE_ARGUMENT_PACK);
 290   MARK_TS_TYPED (WHILE_STMT);
 291   MARK_TS_TYPED (NEW_EXPR);
 292   MARK_TS_TYPED (VEC_NEW_EXPR);
 293   MARK_TS_TYPED (BREAK_STMT);
 294   MARK_TS_TYPED (MEMBER_REF);
 295   MARK_TS_TYPED (DOTSTAR_EXPR);
 296   MARK_TS_TYPED (DO_STMT);
 297   MARK_TS_TYPED (DELETE_EXPR);
 298   MARK_TS_TYPED (VEC_DELETE_EXPR);
 299   MARK_TS_TYPED (CONTINUE_STMT);
 300   MARK_TS_TYPED (TAG_DEFN);
 301   MARK_TS_TYPED (PSEUDO_DTOR_EXPR);
 302   MARK_TS_TYPED (TYPEID_EXPR);
 303   MARK_TS_TYPED (MUST_NOT_THROW_EXPR);
 304   MARK_TS_TYPED (STMT_EXPR);
 305   MARK_TS_TYPED (OFFSET_REF);
 306   MARK_TS_TYPED (OFFSETOF_EXPR);
 307   MARK_TS_TYPED (PTRMEM_CST);
 308   MARK_TS_TYPED (EMPTY_CLASS_EXPR);
 309   MARK_TS_TYPED (VEC_INIT_EXPR);
 310   MARK_TS_TYPED (USING_STMT);
 311   MARK_TS_TYPED (LAMBDA_EXPR);
 312   MARK_TS_TYPED (CTOR_INITIALIZER);
 313   MARK_TS_TYPED (ARRAY_NOTATION_REF);
 314 }
 315
 316 #include "gt-cp-cp-objcp-common.h"