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 #include <new>                       // For placement new.
  36
  37 /* Special routine to get the alias set for C++.  */
  38
  39 alias_set_type
  40 cxx_get_alias_set (tree t)
  41 {
  42   if (IS_FAKE_BASE_TYPE (t))
  43     /* The base variant of a type must be in the same alias set as the
  44        complete type.  */
  45     return get_alias_set (TYPE_CONTEXT (t));
  46
  47   /* Punt on PMFs until we canonicalize functions properly.  */
  48   if (TYPE_PTRMEMFUNC_P (t)
  49       || (POINTER_TYPE_P (t)
  50           && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))))
  51     return 0;
  52
  53   return c_common_get_alias_set (t);
  54 }
  55
  56 /* Called from check_global_declarations.  */
  57
  58 bool
  59 cxx_warn_unused_global_decl (const_tree decl)
  60 {
  61   if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
  62     return false;
  63   if (DECL_IN_SYSTEM_HEADER (decl))
  64     return false;
  65
  66   /* Const variables take the place of #defines in C++.  */
  67   if (VAR_P (decl) && TREE_READONLY (decl))
  68     return false;
  69
  70   return true;
  71 }
  72
  73 /* Langhook for tree_size: determine size of our 'x' and 'c' nodes.  */
  74 size_t
  75 cp_tree_size (enum tree_code code)
  76 {
  77   switch (code)
  78     {
  79     case PTRMEM_CST:            return sizeof (struct ptrmem_cst);
  80     case BASELINK:              return sizeof (struct tree_baselink);
  81     case TEMPLATE_PARM_INDEX:   return sizeof (template_parm_index);
  82     case DEFAULT_ARG:           return sizeof (struct tree_default_arg);
  83     case DEFERRED_NOEXCEPT:     return sizeof (struct tree_deferred_noexcept);
  84     case OVERLOAD:              return sizeof (struct tree_overload);
  85     case STATIC_ASSERT:         return sizeof (struct tree_static_assert);
  86     case TYPE_ARGUMENT_PACK:
  87     case TYPE_PACK_EXPANSION:
  88       return sizeof (struct tree_common);
  89
  90     case NONTYPE_ARGUMENT_PACK:
  91     case EXPR_PACK_EXPANSION:
  92       return sizeof (struct tree_exp);
  93
  94     case ARGUMENT_PACK_SELECT:
  95       return sizeof (struct tree_argument_pack_select);
  96
  97     case TRAIT_EXPR:
  98       return sizeof (struct tree_trait_expr);
  99
 100     case LAMBDA_EXPR:           return sizeof (struct tree_lambda_expr);
 101
 102     case TEMPLATE_INFO:         return sizeof (struct tree_template_info);
 103
 104     case USERDEF_LITERAL:       return sizeof (struct tree_userdef_literal);
 105
 106     default:
 107       gcc_unreachable ();
 108     }
 109   /* NOTREACHED */
 110 }
 111
 112 /* Returns true if T is a variably modified type, in the sense of C99.
 113    FN is as passed to variably_modified_p.
 114    This routine needs only check cases that cannot be handled by the
 115    language-independent logic in tree.c.  */
 116
 117 bool
 118 cp_var_mod_type_p (tree type, tree fn)
 119 {
 120   /* If TYPE is a pointer-to-member, it is variably modified if either
 121      the class or the member are variably modified.  */
 122   if (TYPE_PTRMEM_P (type))
 123     return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type), fn)
 124             || variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type),
 125                                          fn));
 126
 127   /* All other types are not variably modified.  */
 128   return false;
 129 }
 130
 131 /* Construct a C++-aware pretty-printer for CONTEXT.  It is assumed
 132    that CONTEXT->printer is an already constructed basic pretty_printer.  */
 133 void
 134 cxx_initialize_diagnostics (diagnostic_context *context)
 135 {
 136   c_common_initialize_diagnostics (context);
 137
 138   pretty_printer *base = context->printer;
 139   cxx_pretty_printer *pp = XNEW (cxx_pretty_printer);
 140   context->printer = new (pp) cxx_pretty_printer ();
 141
 142   /* It is safe to free this object because it was previously XNEW()'d.  */
 143   base->~pretty_printer ();
 144   XDELETE (base);
 145 }
 146
 147 /* This compares two types for equivalence ("compatible" in C-based languages).
 148    This routine should only return 1 if it is sure.  It should not be used
 149    in contexts where erroneously returning 0 causes problems.  */
 150
 151 int
 152 cxx_types_compatible_p (tree x, tree y)
 153 {
 154   return same_type_ignoring_top_level_qualifiers_p (x, y);
 155 }
 156
 157 /* Return true if DECL is explicit member function.  */
 158
 159 bool
 160 cp_function_decl_explicit_p (tree decl)
 161 {
 162   return (decl
 163           && FUNCTION_FIRST_USER_PARMTYPE (decl) != void_list_node
 164           && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
 165           && DECL_NONCONVERTING_P (decl));
 166 }
 167
 168 /* Stubs to keep c-opts.c happy.  */
 169 void
 170 push_file_scope (void)
 171 {
 172 }
 173
 174 void
 175 pop_file_scope (void)
 176 {
 177 }
 178
 179 /* c-pragma.c needs to query whether a decl has extern "C" linkage.  */
 180 bool
 181 has_c_linkage (const_tree decl)
 182 {
 183   return DECL_EXTERN_C_P (decl);
 184 }
 185
 186 static GTY ((if_marked ("tree_decl_map_marked_p"), param_is (struct tree_decl_map)))
 187      htab_t shadowed_var_for_decl;
 188
 189 /* Lookup a shadowed var for FROM, and return it if we find one.  */
 190
 191 tree
 192 decl_shadowed_for_var_lookup (tree from)
 193 {
 194   struct tree_decl_map *h, in;
 195   in.base.from = from;
 196
 197   h = (struct tree_decl_map *)
 198       htab_find_with_hash (shadowed_var_for_decl, &in, DECL_UID (from));
 199   if (h)
 200     return h->to;
 201   return NULL_TREE;
 202 }
 203
 204 /* Insert a mapping FROM->TO in the shadowed var hashtable.  */
 205
 206 void
 207 decl_shadowed_for_var_insert (tree from, tree to)
 208 {
 209   struct tree_decl_map *h;
 210   void **loc;
 211
 212   h = ggc_alloc_tree_decl_map ();
 213   h->base.from = from;
 214   h->to = to;
 215   loc = htab_find_slot_with_hash (shadowed_var_for_decl, h, DECL_UID (from),
 216                                   INSERT);
 217   *(struct tree_decl_map **) loc = h;
 218 }
 219
 220 void
 221 init_shadowed_var_for_decl (void)
 222 {
 223   shadowed_var_for_decl = htab_create_ggc (512, tree_decl_map_hash,
 224                                            tree_decl_map_eq, 0);
 225 }
 226
 227 /* Return true if stmt can fall through.  Used by block_may_fallthru
 228    default case.  */
 229
 230 bool
 231 cxx_block_may_fallthru (const_tree stmt)
 232 {
 233   switch (TREE_CODE (stmt))
 234     {
 235     case EXPR_STMT:
 236       return block_may_fallthru (EXPR_STMT_EXPR (stmt));
 237
 238     case THROW_EXPR:
 239       return false;
 240
 241     default:
 242       return true;
 243     }
 244 }
 245
 246 void
 247 cp_common_init_ts (void)
 248 {
 249   MARK_TS_DECL_NON_COMMON (NAMESPACE_DECL);
 250   MARK_TS_DECL_NON_COMMON (USING_DECL);
 251   MARK_TS_DECL_NON_COMMON (TEMPLATE_DECL);
 252
 253   MARK_TS_COMMON (TEMPLATE_TEMPLATE_PARM);
 254   MARK_TS_COMMON (TEMPLATE_TYPE_PARM);
 255   MARK_TS_COMMON (TEMPLATE_PARM_INDEX);
 256   MARK_TS_COMMON (OVERLOAD);
 257   MARK_TS_COMMON (TEMPLATE_INFO);
 258   MARK_TS_COMMON (TYPENAME_TYPE);
 259   MARK_TS_COMMON (TYPEOF_TYPE);
 260   MARK_TS_COMMON (UNDERLYING_TYPE);
 261   MARK_TS_COMMON (BASELINK);
 262   MARK_TS_COMMON (TYPE_PACK_EXPANSION);
 263   MARK_TS_COMMON (TYPE_ARGUMENT_PACK);
 264   MARK_TS_COMMON (DECLTYPE_TYPE);
 265   MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
 266   MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);
 267
 268   MARK_TS_TYPED (EXPR_PACK_EXPANSION);
 269   MARK_TS_TYPED (SWITCH_STMT);
 270   MARK_TS_TYPED (IF_STMT);
 271   MARK_TS_TYPED (FOR_STMT);
 272   MARK_TS_TYPED (RANGE_FOR_STMT);
 273   MARK_TS_TYPED (AGGR_INIT_EXPR);
 274   MARK_TS_TYPED (EXPR_STMT);
 275   MARK_TS_TYPED (EH_SPEC_BLOCK);
 276   MARK_TS_TYPED (CLEANUP_STMT);
 277   MARK_TS_TYPED (SCOPE_REF);
 278   MARK_TS_TYPED (CAST_EXPR);
 279   MARK_TS_TYPED (NON_DEPENDENT_EXPR);
 280   MARK_TS_TYPED (MODOP_EXPR);
 281   MARK_TS_TYPED (TRY_BLOCK);
 282   MARK_TS_TYPED (THROW_EXPR);
 283   MARK_TS_TYPED (HANDLER);
 284   MARK_TS_TYPED (REINTERPRET_CAST_EXPR);
 285   MARK_TS_TYPED (CONST_CAST_EXPR);
 286   MARK_TS_TYPED (STATIC_CAST_EXPR);
 287   MARK_TS_TYPED (DYNAMIC_CAST_EXPR);
 288   MARK_TS_TYPED (IMPLICIT_CONV_EXPR);
 289   MARK_TS_TYPED (TEMPLATE_ID_EXPR);
 290   MARK_TS_TYPED (ARROW_EXPR);
 291   MARK_TS_TYPED (SIZEOF_EXPR);
 292   MARK_TS_TYPED (ALIGNOF_EXPR);
 293   MARK_TS_TYPED (AT_ENCODE_EXPR);
 294   MARK_TS_TYPED (UNARY_PLUS_EXPR);
 295   MARK_TS_TYPED (TRAIT_EXPR);
 296   MARK_TS_TYPED (TYPE_ARGUMENT_PACK);
 297   MARK_TS_TYPED (NOEXCEPT_EXPR);
 298   MARK_TS_TYPED (NONTYPE_ARGUMENT_PACK);
 299   MARK_TS_TYPED (WHILE_STMT);
 300   MARK_TS_TYPED (NEW_EXPR);
 301   MARK_TS_TYPED (VEC_NEW_EXPR);
 302   MARK_TS_TYPED (BREAK_STMT);
 303   MARK_TS_TYPED (MEMBER_REF);
 304   MARK_TS_TYPED (DOTSTAR_EXPR);
 305   MARK_TS_TYPED (DO_STMT);
 306   MARK_TS_TYPED (DELETE_EXPR);
 307   MARK_TS_TYPED (VEC_DELETE_EXPR);
 308   MARK_TS_TYPED (CONTINUE_STMT);
 309   MARK_TS_TYPED (TAG_DEFN);
 310   MARK_TS_TYPED (PSEUDO_DTOR_EXPR);
 311   MARK_TS_TYPED (TYPEID_EXPR);
 312   MARK_TS_TYPED (MUST_NOT_THROW_EXPR);
 313   MARK_TS_TYPED (STMT_EXPR);
 314   MARK_TS_TYPED (OFFSET_REF);
 315   MARK_TS_TYPED (OFFSETOF_EXPR);
 316   MARK_TS_TYPED (PTRMEM_CST);
 317   MARK_TS_TYPED (EMPTY_CLASS_EXPR);
 318   MARK_TS_TYPED (VEC_INIT_EXPR);
 319   MARK_TS_TYPED (USING_STMT);
 320   MARK_TS_TYPED (LAMBDA_EXPR);
 321   MARK_TS_TYPED (CTOR_INITIALIZER);
 322   MARK_TS_TYPED (ARRAY_NOTATION_REF);
 323 }
 324
 325 #include "gt-cp-cp-objcp-common.h"