From e05bed960d3bf3bcfd0f27ab882df3da93e118ed Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 12 Jul 2014 02:05:03 +0200 Subject: trace: add 'file:line' to all trace output This is useful to see where trace output came from. Add 'const char *file, int line' parameters to the printing functions and rename them to *_fl. Add trace_printf* and trace_strbuf macros resolving to the *_fl functions and let the preprocessor fill in __FILE__ and __LINE__. As the trace_printf* functions take a variable number of arguments, this requires variadic macros (i.e. '#define foo(...) foo_impl(__VA_ARGS__)'. Though part of C99, it is unclear whether older compilers support this. Thus keep the old functions and only enable variadic macros for GNUC and MSVC 2005+ (_MSC_VER 1400). This has the nice side effect that the old C-style declarations serve as documentation how the macros are to be used. Print 'file:line ' as prefix to each trace line. Align the remaining trace output at column 40 to accommodate 18 char file names + 4 digit line number (currently there are 30 *.c files of length 18 and just 11 of 19). Trace output from longer source files (e.g. builtin/receive-pack.c) will not be aligned. Signed-off-by: Karsten Blees Signed-off-by: Junio C Hamano --- trace.h | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'trace.h') diff --git a/trace.h b/trace.h index b4800e7461..7a5ba2e61c 100644 --- a/trace.h +++ b/trace.h @@ -17,6 +17,8 @@ extern void trace_repo_setup(const char *prefix); extern int trace_want(struct trace_key *key); extern void trace_disable(struct trace_key *key); +#ifndef HAVE_VARIADIC_MACROS + __attribute__((format (printf, 1, 2))) extern void trace_printf(const char *format, ...); @@ -28,4 +30,64 @@ extern void trace_argv_printf(const char **argv, const char *format, ...); extern void trace_strbuf(struct trace_key *key, const struct strbuf *data); +#else + +/* + * Macros to add file:line - see above for C-style declarations of how these + * should be used. + */ + +/* + * TRACE_CONTEXT may be set to __FUNCTION__ if the compiler supports it. The + * default is __FILE__, as it is consistent with assert(), and static function + * names are not necessarily unique. + * + * __FILE__ ":" __FUNCTION__ doesn't work with GNUC, as __FILE__ is supplied + * by the preprocessor as a string literal, and __FUNCTION__ is filled in by + * the compiler as a string constant. + */ +#ifndef TRACE_CONTEXT +# define TRACE_CONTEXT __FILE__ +#endif + +/* + * Note: with C99 variadic macros, __VA_ARGS__ must include the last fixed + * parameter ('format' in this case). Otherwise, a call without variable + * arguments will have a surplus ','. E.g.: + * + * #define foo(format, ...) bar(format, __VA_ARGS__) + * foo("test"); + * + * will expand to + * + * bar("test",); + * + * which is invalid (note the ',)'). With GNUC, '##__VA_ARGS__' drops the + * comma, but this is non-standard. + */ + +#define trace_printf(...) \ + trace_printf_key_fl(TRACE_CONTEXT, __LINE__, NULL, __VA_ARGS__) + +#define trace_printf_key(key, ...) \ + trace_printf_key_fl(TRACE_CONTEXT, __LINE__, key, __VA_ARGS__) + +#define trace_argv_printf(argv, ...) \ + trace_argv_printf_fl(TRACE_CONTEXT, __LINE__, argv, __VA_ARGS__) + +#define trace_strbuf(key, data) \ + trace_strbuf_fl(TRACE_CONTEXT, __LINE__, key, data) + +/* backend functions, use non-*fl macros instead */ +__attribute__((format (printf, 4, 5))) +extern void trace_printf_key_fl(const char *file, int line, struct trace_key *key, + const char *format, ...); +__attribute__((format (printf, 4, 5))) +extern void trace_argv_printf_fl(const char *file, int line, const char **argv, + const char *format, ...); +extern void trace_strbuf_fl(const char *file, int line, struct trace_key *key, + const struct strbuf *data); + +#endif /* HAVE_VARIADIC_MACROS */ + #endif /* TRACE_H */ -- cgit v1.2.3