1 // Control various target specific ABI tweaks. ARM 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 #ifdef __ARM_EABI__ 41 // The ARM EABI uses the least significant bit of a 32-bit 42 // guard variable. 43 #define _GLIBCXX_GUARD_TEST(x) ((*(x) & 1) != 0) 44 #define _GLIBCXX_GUARD_SET(x) *(x) = 1 45 #define _GLIBCXX_GUARD_BIT 1 46 #define _GLIBCXX_GUARD_PENDING_BIT __guard_test_bit (1, 1) 47 #define _GLIBCXX_GUARD_WAITING_BIT __guard_test_bit (2, 1) 48 typedef int __guard; 49 50 #define _GLIBCXX_GUARD_TEST_AND_ACQUIRE(x) \ 51 ((__atomic_load_n(x, __ATOMIC_ACQUIRE) & 1) != 0) 52 #define _GLIBCXX_GUARD_SET_AND_RELEASE(x) \ 53 __atomic_store_n(x, 1, __ATOMIC_RELEASE) 54 55 // We also want the element size in array cookies. 56 #define _GLIBCXX_ELTSIZE_IN_COOKIE 1 57 58 // __cxa_vec_ctor should return a pointer to the array. 59 typedef void * __cxa_vec_ctor_return_type; 60 #define _GLIBCXX_CXA_VEC_CTOR_RETURN(x) return x 61 // Constructors and destructors return the "this" pointer. 62 typedef void * __cxa_cdtor_return_type; 63 64 #else // __ARM_EABI__ 65 66 // The generic ABI uses the first byte of a 64-bit guard variable. 67 #define _GLIBCXX_GUARD_TEST(x) (*(char *) (x) != 0) 68 #define _GLIBCXX_GUARD_SET(x) *(char *) (x) = 1 69 #define _GLIBCXX_GUARD_BIT __guard_test_bit (0, 1) 70 #define _GLIBCXX_GUARD_PENDING_BIT __guard_test_bit (1, 1) 71 #define _GLIBCXX_GUARD_WAITING_BIT __guard_test_bit (2, 1) 72 __extension__ typedef int __guard __attribute__((mode (__DI__))); 73 74 // __cxa_vec_ctor has void return type. 75 typedef void __cxa_vec_ctor_return_type; 76 #define _GLIBCXX_CXA_VEC_CTOR_RETURN(x) return 77 // Constructors and destructors do not return a value. 78 typedef void __cxa_cdtor_return_type; 79 80 #endif //!__ARM_EABI__ 81 82 #ifdef __cplusplus 83 } 84 } // namespace __cxxabiv1 85 #endif 86 87 #endif 88