Hi,
Ævar Arnfjörð Bjarmason wrote:
> Change a comment added in e208f9cc757 (make error()'s constant return
> value more visible, 2012-12-15) to note that the code doesn't only
> depend on variadic macros, which have been a hard dependency since
> 765dc168882 (git-compat-util: always enable variadic macros,
> 2021-01-28), but also on GCC's handling of __VA_ARGS__. The commit
> message for e208f9cc757 made this clear, but the comment it added did
> not.
>
> See also e05bed960d3 (trace: add 'file:line' to all trace output,
> 2014-07-12) for another comment about GNUC's handling of __VA_ARGS__.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
> ---
> git-compat-util.h | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
Oh, subtle. In fact, I believe 9798f7e5f9 (Use __VA_ARGS__ for all of
error's arguments, 2013-02-08) got rid of the gcc-ism, so we could do
the following instead.
(See section 6.10.3.10 for a description of
#define f(...) g(__VA_ARGS__)
in the C99 standard.)
Thanks,
Jonathan
-- >8 --
Subject: error: use macro-based static analysis aid on non-gcc, too
In the rest of Git, we check HAVE_VARIADIC_MACROS (which is
unconditionally defined to true as a way to discover platforms that do
not support it) to guard code that requires variadic macro support.
This variadic macro is a bit older, so it uses a __GNUC__ check
instead. Switch to use of HAVE_VARIADIC_MACROS here as well, so more
compilers can get the benefit of knowing at compile time that error()
always returns -1.
Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
---
git-compat-util.h | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/git-compat-util.h b/git-compat-util.h
index a508dbe5a3..ca22b11760 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -483,14 +483,19 @@ void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
#include <openssl/x509v3.h>
#endif /* NO_OPENSSL */
+/*
+ * This is always defined as a first step towards making the use of variadic
+ * macros unconditional. If it causes compilation problems on your platform,
+ * please report it to the Git mailing list at git@xxxxxxxxxxxxxxx.
+ */
+#define HAVE_VARIADIC_MACROS 1
+
/*
* Let callers be aware of the constant return value; this can help
- * gcc with -Wuninitialized analysis. We restrict this trick to gcc, though,
- * because some compilers may not support variadic macros. Since we're only
- * trying to help gcc, anyway, it's OK; other compilers will fall back to
- * using the function as usual.
+ * gcc with -Wuninitialized analysis. Compilers without support for variadic
+ * macros will fall back to using the function as usual.
*/
-#if defined(__GNUC__)
+#ifdef HAVE_VARIADIC_MACROS
static inline int const_error(void)
{
return -1;
@@ -1192,13 +1197,6 @@ static inline int regexec_buf(const regex_t *preg, const char *buf, size_t size,
#endif
#endif
-/*
- * This is always defined as a first step towards making the use of variadic
- * macros unconditional. If it causes compilation problems on your platform,
- * please report it to the Git mailing list at git@xxxxxxxxxxxxxxx.
- */
-#define HAVE_VARIADIC_MACROS 1
-
/* usage.c: only to be used for testing BUG() implementation (see test-tool) */
extern int BUG_exit_code;
--
2.31.1.818.g46aad6cb9e
