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| author | Jeff King <peff@peff.net> | 2014-05-06 11:14:42 -0400 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2014-05-06 15:30:38 -0700 |
| commit | 87fe5df3653cf20b6bf9854bea42e4016c7d4688 (patch) | |
| tree | 305ccac4474a31bbdeb9025ed497089102972479 | |
| parent | 0bc85abb7aa9b24b093253018801a0fb43d01122 (diff) | |
| download | git-87fe5df3653cf20b6bf9854bea42e4016c7d4688.tar.gz | |
inline constant return from error() function
Commit e208f9c introduced a macro to turn error() calls
into:
(error(), -1)
to make the constant return value more visible to the
calling code (and thus let the compiler make better
decisions about the code).
This works well for code like:
return error(...);
but the "-1" is superfluous in code that just calls error()
without caring about the return value. In older versions of
gcc, that was fine, but gcc 4.9 complains with -Wunused-value.
We can work around this by encapsulating the constant return
value in a static inline function, as gcc specifically
avoids complaining about unused function returns unless the
function has been specifically marked with the
warn_unused_result attribute.
We also use the same trick for config_error_nonbool and
opterror, which learned the same error technique in a469a10.
Reported-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | cache.h | 2 | ||||
| -rw-r--r-- | git-compat-util.h | 6 | ||||
| -rw-r--r-- | parse-options.h | 2 |
3 files changed, 7 insertions, 3 deletions
@@ -1184,7 +1184,7 @@ extern int git_env_bool(const char *, int); extern int git_config_system(void); extern int config_error_nonbool(const char *); #if defined(__GNUC__) && ! defined(__clang__) -#define config_error_nonbool(s) (config_error_nonbool(s), -1) +#define config_error_nonbool(s) (config_error_nonbool(s), const_error()) #endif extern const char *get_log_output_encoding(void); extern const char *get_commit_output_encoding(void); diff --git a/git-compat-util.h b/git-compat-util.h index d493a8c67a..90b988a5c1 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -343,7 +343,11 @@ extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2))) * using the function as usual. */ #if defined(__GNUC__) && ! defined(__clang__) -#define error(...) (error(__VA_ARGS__), -1) +static inline int const_error(void) +{ + return -1; +} +#define error(...) (error(__VA_ARGS__), const_error()) #endif extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params)); diff --git a/parse-options.h b/parse-options.h index d670cb9669..1ef8da1f3e 100644 --- a/parse-options.h +++ b/parse-options.h @@ -180,7 +180,7 @@ extern NORETURN void usage_msg_opt(const char *msg, extern int optbug(const struct option *opt, const char *reason); extern int opterror(const struct option *opt, const char *reason, int flags); #if defined(__GNUC__) && ! defined(__clang__) -#define opterror(o,r,f) (opterror((o),(r),(f)), -1) +#define opterror(o,r,f) (opterror((o),(r),(f)), const_error()) #endif /*----- incremental advanced APIs -----*/ |