gcc/lto/lto-symtab.h

   1 /* LTO symbol table merging.
   2    Copyright (C) 2009-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 extern void lto_symtab_merge_decls (void);
  21 extern void lto_symtab_merge_symbols (void);
  22 extern tree lto_symtab_prevailing_decl (tree decl);
  23 extern tree lto_symtab_prevailing_virtual_decl (tree decl);
  24
  25 /* Mark DECL to be previailed by PREVAILING.
  26    Use DECL_LANG_FLAG_0 and DECL_CHAIN as special markers; those do not
  27    disturb debug_tree and diagnostics.
  28    We are safe to modify them as we wish, because the declarations disappear
  29    from the IL after the merging.  */
  30
  31 inline void
  32 lto_symtab_prevail_decl (tree prevailing, tree decl)
  33 {
  34   gcc_checking_assert (! DECL_LANG_FLAG_0 (decl));
  35   gcc_assert (TREE_PUBLIC (decl) || DECL_EXTERNAL (decl));
  36   DECL_CHAIN (decl) = prevailing;
  37   DECL_LANG_FLAG_0 (decl) = 1;
  38 }
  39
  40 /* Given the decl DECL, return the prevailing decl with the same name. */
  41
  42 inline tree
  43 lto_symtab_prevailing_decl (tree decl)
  44 {
  45   if (DECL_LANG_FLAG_0 (decl))
  46     return DECL_CHAIN (decl);
  47   else
  48     {
  49       if ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL)
  50           && DECL_VIRTUAL_P (decl)
  51           && (TREE_PUBLIC (decl) || DECL_EXTERNAL (decl))
  52           && !symtab_node::get (decl))
  53         return lto_symtab_prevailing_virtual_decl (decl);
  54       return decl;
  55     }
  56 }