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