projects / librseq.git / blame
| Commit | Line | Data |
|---|---|---|
| 90702366 | 1 | /* SPDX-License-Identifier: MIT */ |
| f2d7b530 MJ |
2 | /* SPDX-FileCopyrightText: 2021 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> */ |
| 3 | ||
| dd76f2d6 MD |
4 | /* |
| 5 | * rseq/compiler.h | |
| 6 | * | |
| 7 | * Work-around asm goto compiler bugs. | |
| dd76f2d6 MD |
8 | */ |
| 9 | ||
| 10 | #ifndef RSEQ_COMPILER_H | |
| 11 | #define RSEQ_COMPILER_H | |
| 12 | ||
| d292e9e1 MD |
13 | #if defined __cplusplus |
| 14 | # include <type_traits> /* for std::remove_cv */ | |
| 15 | #endif | |
| 16 | ||
| dd76f2d6 MD |
17 | /* |
| 18 | * gcc prior to 4.8.2 miscompiles asm goto. | |
| 19 | * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 | |
| 20 | * | |
| 21 | * gcc prior to 8.1.0 miscompiles asm goto at O1. | |
| 22 | * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908 | |
| 23 | * | |
| 24 | * clang prior to version 13.0.1 miscompiles asm goto at O2. | |
| 25 | * https://github.com/llvm/llvm-project/issues/52735 | |
| 26 | * | |
| 27 | * Work around these issues by adding a volatile inline asm with | |
| 28 | * memory clobber in the fallthrough after the asm goto and at each | |
| 29 | * label target. Emit this for all compilers in case other similar | |
| 30 | * issues are found in the future. | |
| 31 | */ | |
| 6a5fa598 | 32 | #define rseq_after_asm_goto() __asm__ __volatile__ ("" : : : "memory") |
| dd76f2d6 | 33 | |
| eb5d1cbe MD |
34 | #if defined(__SIZEOF_LONG__) |
| 35 | #define RSEQ_BITS_PER_LONG (__SIZEOF_LONG__ * 8) | |
| 36 | #elif defined(_LP64) | |
| 37 | #define RSEQ_BITS_PER_LONG 64 | |
| 38 | #else | |
| 39 | #define RSEQ_BITS_PER_LONG 32 | |
| 40 | #endif | |
| 41 | ||
| d292e9e1 MD |
42 | #ifdef __cplusplus |
| 43 | #define rseq_unqual_scalar_typeof(x) \ | |
| 732b2f65 | 44 | __typeof__(reinterpret_cast<std::remove_cv<__typeof__(x)>::type>((__typeof__(x))0)) |
| d292e9e1 MD |
45 | #else |
| 46 | /* | |
| 47 | * Use C11 _Generic to express unqualified type from expression. This removes | |
| 48 | * volatile qualifier from expression type. | |
| 49 | */ | |
| 50 | #define rseq_unqual_scalar_typeof(x) \ | |
| 51 | __typeof__( \ | |
| 52 | _Generic((x), \ | |
| 53 | char: (char)0, \ | |
| 54 | unsigned char: (unsigned char)0, \ | |
| 55 | signed char: (signed char)0, \ | |
| 56 | unsigned short: (unsigned short)0, \ | |
| 57 | signed short: (signed short)0, \ | |
| 58 | unsigned int: (unsigned int)0, \ | |
| 59 | signed int: (signed int)0, \ | |
| 60 | unsigned long: (unsigned long)0, \ | |
| 61 | signed long: (signed long)0, \ | |
| 62 | unsigned long long: (unsigned long long)0, \ | |
| 63 | signed long long: (signed long long)0, \ | |
| 64 | default: (x) \ | |
| 65 | ) \ | |
| 66 | ) | |
| 67 | #endif | |
| 68 | ||
| dd76f2d6 | 69 | #endif /* RSEQ_COMPILER_H_ */ |