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 <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Karsten Blees 2014-07-12 02:05:03 +02:00 коммит произвёл Junio C Hamano
Родитель 66f66c596f
Коммит e05bed960d
3 изменённых файлов: 126 добавлений и 12 удалений

Просмотреть файл

@ -704,6 +704,10 @@ void git_qsort(void *base, size_t nmemb, size_t size,
#endif
#endif
#if defined(__GNUC__) || (_MSC_VER >= 1400)
#define HAVE_VARIADIC_MACROS 1
#endif
/*
* Preserves errno, prints a message, but gives no warning for ENOENT.
* Always returns the return value of unlink(2).

72
trace.c
Просмотреть файл

@ -85,7 +85,8 @@ void trace_disable(struct trace_key *key)
static const char err_msg[] = "Could not trace into fd given by "
"GIT_TRACE environment variable";
static int prepare_trace_line(struct trace_key *key, struct strbuf *buf)
static int prepare_trace_line(const char *file, int line,
struct trace_key *key, struct strbuf *buf)
{
static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
struct timeval tv;
@ -108,6 +109,14 @@ static int prepare_trace_line(struct trace_key *key, struct strbuf *buf)
strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
tm.tm_sec, (long) tv.tv_usec);
#ifdef HAVE_VARIADIC_MACROS
/* print file:line */
strbuf_addf(buf, "%s:%d ", file, line);
/* align trace output (column 40 catches most files names in git) */
while (buf->len < 40)
strbuf_addch(buf, ' ');
#endif
return 1;
}
@ -121,49 +130,52 @@ static void print_trace_line(struct trace_key *key, struct strbuf *buf)
strbuf_release(buf);
}
static void trace_vprintf(struct trace_key *key, const char *format, va_list ap)
static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
const char *format, va_list ap)
{
struct strbuf buf = STRBUF_INIT;
if (!prepare_trace_line(key, &buf))
if (!prepare_trace_line(file, line, key, &buf))
return;
strbuf_vaddf(&buf, format, ap);
print_trace_line(key, &buf);
}
void trace_argv_printf(const char **argv, const char *format, ...)
static void trace_argv_vprintf_fl(const char *file, int line,
const char **argv, const char *format,
va_list ap)
{
struct strbuf buf = STRBUF_INIT;
va_list ap;
if (!prepare_trace_line(NULL, &buf))
if (!prepare_trace_line(file, line, NULL, &buf))
return;
va_start(ap, format);
strbuf_vaddf(&buf, format, ap);
va_end(ap);
sq_quote_argv(&buf, argv, 0);
print_trace_line(NULL, &buf);
}
void trace_strbuf(struct trace_key *key, const struct strbuf *data)
void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
const struct strbuf *data)
{
struct strbuf buf = STRBUF_INIT;
if (!prepare_trace_line(key, &buf))
if (!prepare_trace_line(file, line, key, &buf))
return;
strbuf_addbuf(&buf, data);
print_trace_line(key, &buf);
}
#ifndef HAVE_VARIADIC_MACROS
void trace_printf(const char *format, ...)
{
va_list ap;
va_start(ap, format);
trace_vprintf(NULL, format, ap);
trace_vprintf_fl(NULL, 0, NULL, format, ap);
va_end(ap);
}
@ -171,10 +183,46 @@ void trace_printf_key(struct trace_key *key, const char *format, ...)
{
va_list ap;
va_start(ap, format);
trace_vprintf(key, format, ap);
trace_vprintf_fl(NULL, 0, key, format, ap);
va_end(ap);
}
void trace_argv_printf(const char **argv, const char *format, ...)
{
va_list ap;
va_start(ap, format);
trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
va_end(ap);
}
void trace_strbuf(const char *key, const struct strbuf *data)
{
trace_strbuf_fl(NULL, 0, key, data);
}
#else
void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
const char *format, ...)
{
va_list ap;
va_start(ap, format);
trace_vprintf_fl(file, line, key, format, ap);
va_end(ap);
}
void trace_argv_printf_fl(const char *file, int line, const char **argv,
const char *format, ...)
{
va_list ap;
va_start(ap, format);
trace_argv_vprintf_fl(file, line, argv, format, ap);
va_end(ap);
}
#endif /* HAVE_VARIADIC_MACROS */
static const char *quote_crnl(const char *path)
{
static char new_path[PATH_MAX];

62
trace.h
Просмотреть файл

@ -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 */