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 | |
| 809f5ee3 MD |
34 | /* Combine two tokens. */ |
| 35 | #define RSEQ__COMBINE_TOKENS(_tokena, _tokenb) \ | |
| 36 | _tokena##_tokenb | |
| 37 | #define RSEQ_COMBINE_TOKENS(_tokena, _tokenb) \ | |
| 38 | RSEQ__COMBINE_TOKENS(_tokena, _tokenb) | |
| 39 | ||
| eb5d1cbe MD |
40 | #if defined(__SIZEOF_LONG__) |
| 41 | #define RSEQ_BITS_PER_LONG (__SIZEOF_LONG__ * 8) | |
| 42 | #elif defined(_LP64) | |
| 43 | #define RSEQ_BITS_PER_LONG 64 | |
| 44 | #else | |
| 45 | #define RSEQ_BITS_PER_LONG 32 | |
| 46 | #endif | |
| 47 | ||
| d292e9e1 MD |
48 | #ifdef __cplusplus |
| 49 | #define rseq_unqual_scalar_typeof(x) \ | |
| 96d67c89 | 50 | std::remove_cv<std::remove_reference<decltype(x)>::type>::type |
| d292e9e1 | 51 | #else |
| a95cabb3 MD |
52 | #define rseq_scalar_type_to_expr(type) \ |
| 53 | unsigned type: (unsigned type)0, \ | |
| 54 | signed type: (signed type)0 | |
| 55 | ||
| d292e9e1 MD |
56 | /* |
| 57 | * Use C11 _Generic to express unqualified type from expression. This removes | |
| 58 | * volatile qualifier from expression type. | |
| 59 | */ | |
| 60 | #define rseq_unqual_scalar_typeof(x) \ | |
| 61 | __typeof__( \ | |
| 62 | _Generic((x), \ | |
| 63 | char: (char)0, \ | |
| a95cabb3 MD |
64 | rseq_scalar_type_to_expr(char), \ |
| 65 | rseq_scalar_type_to_expr(short), \ | |
| 66 | rseq_scalar_type_to_expr(int), \ | |
| 67 | rseq_scalar_type_to_expr(long), \ | |
| 68 | rseq_scalar_type_to_expr(long long), \ | |
| d292e9e1 MD |
69 | default: (x) \ |
| 70 | ) \ | |
| 71 | ) | |
| 72 | #endif | |
| 73 | ||
| dd76f2d6 | 74 | #endif /* RSEQ_COMPILER_H_ */ |