From: Junio C Hamano Date: Mon, 04 May 2026 01:41:16 GMT Subject: Re: [PATCH] compat/posix.h: enable UNUSED warning messages for Clang Message-ID: In-Reply-To: Junio C Hamano writes: >> I am not familiar with git's minimum compiler version but this patch >> drops support for Clang < 2.9 from 2011. > > Does this "drop support" because you force _all_ versions of Clang > to use the "deprecated" attribute, even though you _know_ some older > versions do not understand it? Don't these versions identify > themselves so that you can do > > #if defined(__clang__) && CLANG_VERSION >= 2.9 > > I do not know if the userbase of GCC and Clang upgrade with a > similar cadence, or we seem to say that we care about GCC 4.5 > (2010), so giving a similar version detection for Clang and exclude > ones older than 2.9 sounds more appropriate. IOW, something like this, perhaps? compat/posix.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git c/compat/posix.h w/compat/posix.h index faaae1b655..0dd0637fc9 100644 --- c/compat/posix.h +++ w/compat/posix.h @@ -22,6 +22,17 @@ #define GIT_GNUC_PREREQ(maj, min) 0 #endif +/* + * Similar for clang + */ +#if defined(__clang__) && defined(__clang_minor__) && defined(__clang_major__) +# define GIT_CLANG_PREREQ(maj, min) \ + ((__clang_major__ > (maj)) || \ + (__clang_major__ == (maj) && (__clang_minor__ >= (min)))) +#else +# define GIT_CLANG_PREREQ(maj, min) 0 +#endif + /* * UNUSED marks a function parameter that is always unused. It also * can be used to annotate a function, a variable, or a type that is @@ -35,7 +46,7 @@ * When a parameter may be used or unused, depending on conditional * compilation, consider using MAYBE_UNUSED instead. */ -#if GIT_GNUC_PREREQ(4, 5) +#if GIT_GNUC_PREREQ(4, 5) || GIT_CLANG_PREREQ(2, 9) #define UNUSED __attribute__((unused)) \ __attribute__((deprecated ("parameter declared as UNUSED"))) #elif defined(__GNUC__)