diff options
author | Ingo Molnar <mingo@kernel.org> | 2020-04-16 10:21:31 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2020-04-16 10:21:31 +0200 |
commit | cd0943357bc7570f081701d005318c20982178b8 (patch) | |
tree | 2e38a1cae36af49c550f356d25908a6be88d1615 /tools/include/linux/build_bug.h | |
parent | 00086336a8d96a04aa960f912287692a258f6cf5 (diff) | |
parent | e3698b23ecb8c099b4b523e7d5c8c042e93ef15d (diff) |
Merge tag 'perf-urgent-for-mingo-5.7-20200414' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
perf stat:
Jin Yao:
- Fix no metric header if --per-socket and --metric-only set
build system:
- Fix python building when built with clang, that was failing if the clang
version doesn't support -fno-semantic-interposition.
tools UAPI headers:
Arnaldo Carvalho de Melo:
- Update various copies of kernel headers, some ended up automatically
updating build-time generated tables to enable tools such as 'perf trace'
to decode syscalls and tracepoints arguments.
Now the tools/perf build is free of UAPI drift warnings.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/include/linux/build_bug.h')
-rw-r--r-- | tools/include/linux/build_bug.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/tools/include/linux/build_bug.h b/tools/include/linux/build_bug.h new file mode 100644 index 000000000000..cc7070c7439b --- /dev/null +++ b/tools/include/linux/build_bug.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_BUILD_BUG_H +#define _LINUX_BUILD_BUG_H + +#include <linux/compiler.h> + +#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). + */ +#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) +#endif /* __CHECKER__ */ + +/* Force a compilation error if a constant expression is not a power of 2 */ +#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \ + BUILD_BUG_ON(((n) & ((n) - 1)) != 0) +#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ + BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) + +/* + * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the + * expression but avoids the generation of any code, even if that expression + * has side-effects. + */ +#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) + +/** + * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied + * error message. + * @condition: the condition which the compiler should know is false. + * + * See BUILD_BUG_ON for description. + */ +#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) + +/** + * BUILD_BUG_ON - break compile if a condition is true. + * @condition: the condition which the compiler should know is false. + * + * If you have some code which relies on certain constants being equal, or + * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to + * detect if someone changes it. + */ +#define BUILD_BUG_ON(condition) \ + BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) + +/** + * BUILD_BUG - break compile if used. + * + * If you have some code that you expect the compiler to eliminate at + * build time, you should use BUILD_BUG to detect if it is + * unexpectedly used. + */ +#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") + +/** + * static_assert - check integer constant expression at build time + * + * static_assert() is a wrapper for the C11 _Static_assert, with a + * little macro magic to make the message optional (defaulting to the + * stringification of the tested expression). + * + * Contrary to BUILD_BUG_ON(), static_assert() can be used at global + * scope, but requires the expression to be an integer constant + * expression (i.e., it is not enough that __builtin_constant_p() is + * true for expr). + * + * Also note that BUILD_BUG_ON() fails the build if the condition is + * true, while static_assert() fails the build if the expression is + * false. + */ +#ifndef static_assert +#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr) +#define __static_assert(expr, msg, ...) _Static_assert(expr, msg) +#endif // static_assert + +#endif /* _LINUX_BUILD_BUG_H */ |