[PATCH v3 2/2] compat/posix.h: simplify GIT_GNUC_PREREQ() comparison
- From
- Dominik Loidolt <dominik.loidolt@univie.ac.at>
- Date
- Jun 8, 2026, 12:44 UTC
- Message-ID
- <20260608124419.38905-2-dominik.loidolt@univie.ac.at>
- In-Reply-To
- <20260608124419.38905-1-dominik.loidolt@univie.ac.at>
Replace the glibc-style bit-shift version comparison with an explicit major/minor comparison. This is easier to read and is consistent with the format already used by GIT_CLANG_PREREQ() and many BSD <sys/cdefs.h> headers.
This has no runtime impact, as the macro is evaluated at compile time. It is also more future-proof, as it no longer assumes that GCC version components stay below 65536.
Signed-off-by: Dominik Loidolt <dominik.loidolt@univie.ac.at> --- compat/posix.h | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/compat/posix.h b/compat/posix.h index ffdfd91c7b..deefc43f28 100644 --- a/compat/posix.h +++ b/compat/posix.h @@ -4,22 +4,24 @@ #define _FILE_OFFSET_BITS 64 /* - * Derived from Linux "Features Test Macro" header - * Convenience macros to test the versions of gcc (or - * a compatible compiler). + * Convenience macros to test the versions of GCC (or a compatible compiler). * Use them like this: * #if GIT_GNUC_PREREQ (2,8) - * ... code requiring gcc 2.8 or later ... + * ... code requiring GCC 2.8 or later ... * #endif * + * Note that Clang and other compilers define __GNUC__ for compatibility; use + * GIT_CLANG_PREREQ() to check for specific Clang versions. + * * This macro of course is not part of POSIX, but we need it for the UNUSED * macro which is used by some of our POSIX compatibility wrappers. -*/ + */ #if defined(__GNUC__) && defined(__GNUC_MINOR__) # define GIT_GNUC_PREREQ(maj, min) \ - ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) + ((__GNUC__ > (maj)) || \ + (__GNUC__ == (maj) && __GNUC_MINOR__ >= (min))) #else - #define GIT_GNUC_PREREQ(maj, min) 0 +# define GIT_GNUC_PREREQ(maj, min) 0 #endif /* Similar for Clang. */
-- 2.54.0