1 // Control various target specific ABI tweaks.  Generic version.
2 
3 // Copyright (C) 2004-2021 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
60