From: Arnaldo Carvalho de Melo Date: Thu, 12 Jun 2025 15:53:37 +0000 (-0300) Subject: tools headers: Syncronize linux/build_bug.h with the kernel sources X-Git-Tag: v6.16-rc3~15^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3417404c6f83c5d72d69ae81ded914bdc3841a49;p=thirdparty%2Fkernel%2Flinux.git tools headers: Syncronize linux/build_bug.h with the kernel sources To pick up the changes in: 243c90e917f5cfc9 ("build_bug.h: more user friendly error messages in BUILD_BUG_ON_ZERO()") This also needed to pick the __BUILD_BUG_ON_ZERO_MSG() in linux/compiler.h, that needed to be polished to avoid hitting old clang problems with _Static_assert on arrays of structs: Debian clang version 11.0.1-2~deb10u1 Debian clang version 11.0.1-2~deb10u1 $ make NO_LIBTRACEEVENT=1 ARCH= CROSS_COMPILE= EXTRA_CFLAGS= -C tools/perf O=/tmp/build/perf CC=clang btf_dump.c:895:18: error: type name does not allow storage class to be specified for (i = 0; i < ARRAY_SIZE(pads); i++) { ^ /git/perf-6.16.0-rc1/tools/include/linux/kernel.h:91:59: note: expanded from macro 'ARRAY_SIZE' #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) ^ /git/perf-6.16.0-rc1/tools/include/linux/compiler-gcc.h:26:28: note: expanded from macro '__must_be_array' #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) ^ /git/perf-6.16.0-rc1/tools/include/linux/build_bug.h:17:2: note: expanded from macro 'BUILD_BUG_ON_ZERO' __BUILD_BUG_ON_ZERO_MSG(e, ##__VA_ARGS__, #e " is true") ^ /git/perf-6.16.0-rc1/tools/include/linux/compiler.h:248:67: note: expanded from macro '__BUILD_BUG_ON_ZERO_MSG' #define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)sizeof(struct {_Static_assert(!(e), msg);})) ^ /usr/include/x86_64-linux-gnu/sys/cdefs.h:438:5: note: expanded from macro '_Static_assert' extern int (*__Static_assert_function (void)) \ ^ These also failed: toolsbuilder@five:~$ grep FAIL dm.log/summary | grep clang 1 72.87 almalinux:8 : FAIL clang version 19.1.7 ( 19.1.7-2.module_el8.10.0+3990+33d0d926) 15 73.39 centos:stream : FAIL clang version 17.0.6 (Red Hat 17.0.6-1.module_el8+767+9fa966b8) 36 87.14 opensuse:15.4 : FAIL clang version 15.0.7 37 80.08 opensuse:15.5 : FAIL clang version 15.0.7 40 72.12 oraclelinux:8 : FAIL clang version 16.0.6 (Red Hat 16.0.6-2.0.1.module+el8.9.0+90129+d3ee8717) 42 74.12 rockylinux:8 : FAIL clang version 16.0.6 (Red Hat 16.0.6-2.module+el8.9.0+1651+e10a8f6d) toolsbuilder@five:~$ This addresses this perf build warning: Warning: Kernel ABI header differences: diff -u tools/include/linux/build_bug.h include/linux/build_bug.h Cc: Adrian Hunter Cc: Ian Rogers Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Cc: Vincent Mailhol Cc: Yury Norov Link: https://lore.kernel.org/r/aEszb7SSIJB6Lp6f@x1 Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/include/linux/build_bug.h b/tools/include/linux/build_bug.h index b4898ff085ded..ab2aa97bd8ce4 100644 --- a/tools/include/linux/build_bug.h +++ b/tools/include/linux/build_bug.h @@ -4,17 +4,17 @@ #include -#ifdef __CHECKER__ -#define BUILD_BUG_ON_ZERO(e) (0) -#else /* __CHECKER__ */ /* * Force a compilation error if condition is true, but also produce a * result (of value 0 and type int), so the expression can be used * e.g. in a structure initializer (or where-ever else comma expressions * aren't permitted). + * + * Take an error message as an optional second argument. If omitted, + * default to the stringification of the tested expression. */ -#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) -#endif /* __CHECKER__ */ +#define BUILD_BUG_ON_ZERO(e, ...) \ + __BUILD_BUG_ON_ZERO_MSG(e, ##__VA_ARGS__, #e " is true") /* Force a compilation error if a constant expression is not a power of 2 */ #define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \ diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index d627e66a04a61..33411ca0cc90f 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -244,6 +244,14 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s __asm__ ("" : "=r" (var) : "0" (var)) #endif +#ifndef __BUILD_BUG_ON_ZERO_MSG +#if defined(__clang__) +#define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)(sizeof(struct { int:(-!!(e)); }))) +#else +#define __BUILD_BUG_ON_ZERO_MSG(e, msg, ...) ((int)sizeof(struct {_Static_assert(!(e), msg);})) +#endif +#endif + #endif /* __ASSEMBLY__ */ #endif /* _TOOLS_LINUX_COMPILER_H */