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@xxxxxxx>
---
git-compat-util.h | 4 ++++
trace.c | 72 +++++++++++++++++++++++++++++++++++++++++++++----------
trace.h | 54 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 118 insertions(+), 12 deletions(-)
diff --git a/git-compat-util.h b/git-compat-util.h
index b6f03b3..4dd065d 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -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).
diff --git a/trace.c b/trace.c
index e8ce619..f013958 100644
--- a/trace.c
+++ b/trace.c
@@ -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];
diff --git a/trace.h b/trace.h
index 0c98da2..c3ca47c 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 +30,56 @@ 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.
+ */
+#define TRACE_CONTEXT __FILE__
+
+/*
+ * 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 */
--
2.0.0.406.ge74f8ff
--
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