From 560e36d5a42e04aa2871c01da6d432592151f7e8 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 23 Sep 2019 11:24:12 -0700 Subject: [PATCH] qemu/compiler.h: Add qemu_build_not_reached MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Use this as a compile-time assert that a particular code path is not reachable. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- include/qemu/compiler.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index 20780e722d..7b93c73340 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -221,4 +221,19 @@ #define QEMU_GENERIC9(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC8(x, __VA_ARGS__)) #define QEMU_GENERIC10(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC9(x, __VA_ARGS__)) +/** + * qemu_build_not_reached() + * + * The compiler, during optimization, is expected to prove that a call + * to this function cannot be reached and remove it. If the compiler + * supports QEMU_ERROR, this will be reported at compile time; otherwise + * this will be reported at link time due to the missing symbol. + */ +#ifdef __OPTIMIZE__ +extern void QEMU_NORETURN QEMU_ERROR("code path is reachable") + qemu_build_not_reached(void); +#else +#define qemu_build_not_reached() g_assert_not_reached() +#endif + #endif /* COMPILER_H */