1  // Control various target specific ABI tweaks.  Generic version.
       2  
       3  // Copyright (C) 2004-2023 Free Software Foundation, Inc.
       4  //
       5  // This file is part of the GNU ISO C++ Library.  This library is free
       6  // software; you can redistribute it and/or modify it under the
       7  // terms of the GNU General Public License as published by the
       8  // Free Software Foundation; either version 3, or (at your option)
       9  // any later version.
      10  
      11  // This library is distributed in the hope that it will be useful,
      12  // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14  // GNU General Public License for more details.
      15  
      16  // Under Section 7 of GPL version 3, you are granted additional
      17  // permissions described in the GCC Runtime Library Exception, version
      18  // 3.1, as published by the Free Software Foundation.
      19  
      20  // You should have received a copy of the GNU General Public License and
      21  // a copy of the GCC Runtime Library Exception along with this program;
      22  // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23  // <http://www.gnu.org/licenses/>.
      24  
      25  /** @file bits/cxxabi_tweaks.h
      26   *  This is an internal header file, included by other library headers.
      27   *  Do not attempt to use it directly. @headername{cxxabi.h}
      28   */
      29  
      30  #ifndef _CXXABI_TWEAKS_H
      31  #define _CXXABI_TWEAKS_H 1
      32  
      33  #ifdef __cplusplus
      34  namespace __cxxabiv1
      35  {
      36    extern "C"
      37    {
      38  #endif
      39  
      40    // The generic ABI uses the first byte of a 64-bit guard variable.
      41  #define _GLIBCXX_GUARD_TEST(x) (*(char *) (x) != 0)
      42  #define _GLIBCXX_GUARD_SET(x) *(char *) (x) = 1
      43  #define _GLIBCXX_GUARD_BIT __guard_test_bit (0, 1)
      44  #define _GLIBCXX_GUARD_PENDING_BIT __guard_test_bit (1, 1)
      45  #define _GLIBCXX_GUARD_WAITING_BIT __guard_test_bit (2, 1)
      46    __extension__ typedef int __guard __attribute__((mode (__DI__)));
      47  
      48    // __cxa_vec_ctor has void return type.
      49    typedef void __cxa_vec_ctor_return_type;
      50  #define _GLIBCXX_CXA_VEC_CTOR_RETURN(x) return
      51    // Constructors and destructors do not return a value.
      52    typedef void __cxa_cdtor_return_type;
      53  
      54  #ifdef __cplusplus
      55    }
      56  } // namespace __cxxabiv1
      57  #endif
      58  
      59  #endif