37 lines
1.1 KiB
C
37 lines
1.1 KiB
C
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/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
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/*
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* rseq/compiler.h
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*
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* Work-around asm goto compiler bugs.
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*
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* (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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*/
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#ifndef RSEQ_COMPILER_H
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#define RSEQ_COMPILER_H
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/*
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* gcc prior to 4.8.2 miscompiles asm goto.
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* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
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*
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* gcc prior to 8.1.0 miscompiles asm goto at O1.
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* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908
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*
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* clang prior to version 13.0.1 miscompiles asm goto at O2.
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* https://github.com/llvm/llvm-project/issues/52735
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*
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* Work around these issues by adding a volatile inline asm with
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* memory clobber in the fallthrough after the asm goto and at each
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* label target. Emit this for all compilers in case other similar
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* issues are found in the future.
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*/
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#define rseq_after_asm_goto() asm volatile ("" : : : "memory")
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/* Combine two tokens. */
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#define RSEQ__COMBINE_TOKENS(_tokena, _tokenb) \
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_tokena##_tokenb
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#define RSEQ_COMBINE_TOKENS(_tokena, _tokenb) \
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RSEQ__COMBINE_TOKENS(_tokena, _tokenb)
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#endif /* RSEQ_COMPILER_H_ */
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