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>
Karsten Blees committed
Jul 12, 2014 at 02:05 UTC
e05bed960d3bf3bcfd0f27ab882df3da93e118ed
3 files changed
+126
-12
git-compat-util.h
+4
@@ -704,6 +704,10 @@ void git_qsort(void *base, size_t nmemb, size_t size,
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#endif
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#endif
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+#if defined(__GNUC__) || (_MSC_VER >= 1400)
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+#define HAVE_VARIADIC_MACROS 1
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+#endif
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+
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/*
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* Preserves errno, prints a message, but gives no warning for ENOENT.
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* Always returns the return value of unlink(2).
trace.c
+60
-12
@@ -85,7 +85,8 @@ void trace_disable(struct trace_key *key)
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static const char err_msg[] = "Could not trace into fd given by "
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"GIT_TRACE environment variable";
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-static int prepare_trace_line(struct trace_key *key, struct strbuf *buf)
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+static int prepare_trace_line(const char *file, int line,
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+ struct trace_key *key, struct strbuf *buf)
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{
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static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
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struct timeval tv;
@@ -108,6 +109,14 @@ static int prepare_trace_line(struct trace_key *key, struct strbuf *buf)
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strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
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tm.tm_sec, (long) tv.tv_usec);
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+#ifdef HAVE_VARIADIC_MACROS
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+ /* print file:line */
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+ strbuf_addf(buf, "%s:%d ", file, line);
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+ /* align trace output (column 40 catches most files names in git) */
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+ while (buf->len < 40)
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+ strbuf_addch(buf, ' ');
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+#endif
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+
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return 1;
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}
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@@ -121,49 +130,52 @@ static void print_trace_line(struct trace_key *key, struct strbuf *buf)
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strbuf_release(buf);
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}
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-static void trace_vprintf(struct trace_key *key, const char *format, va_list ap)
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+static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
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+ const char *format, va_list ap)
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{
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struct strbuf buf = STRBUF_INIT;
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- if (!prepare_trace_line(key, &buf))
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+ if (!prepare_trace_line(file, line, key, &buf))
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return;
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strbuf_vaddf(&buf, format, ap);
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print_trace_line(key, &buf);
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}
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-void trace_argv_printf(const char **argv, const char *format, ...)
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+static void trace_argv_vprintf_fl(const char *file, int line,
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+ const char **argv, const char *format,
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+ va_list ap)
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{
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struct strbuf buf = STRBUF_INIT;
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- va_list ap;
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- if (!prepare_trace_line(NULL, &buf))
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+ if (!prepare_trace_line(file, line, NULL, &buf))
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return;
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- va_start(ap, format);
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strbuf_vaddf(&buf, format, ap);
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- va_end(ap);
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sq_quote_argv(&buf, argv, 0);
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print_trace_line(NULL, &buf);
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}
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-void trace_strbuf(struct trace_key *key, const struct strbuf *data)
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+void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
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+ const struct strbuf *data)
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{
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struct strbuf buf = STRBUF_INIT;
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- if (!prepare_trace_line(key, &buf))
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+ if (!prepare_trace_line(file, line, key, &buf))
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return;
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strbuf_addbuf(&buf, data);
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print_trace_line(key, &buf);
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}
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+#ifndef HAVE_VARIADIC_MACROS
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+
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void trace_printf(const char *format, ...)
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{
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va_list ap;
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va_start(ap, format);
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- trace_vprintf(NULL, format, ap);
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+ trace_vprintf_fl(NULL, 0, NULL, format, ap);
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va_end(ap);
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}
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@@ -171,10 +183,46 @@ void trace_printf_key(struct trace_key *key, const char *format, ...)
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{
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va_list ap;
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va_start(ap, format);
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- trace_vprintf(key, format, ap);
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+ trace_vprintf_fl(NULL, 0, key, format, ap);
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+ va_end(ap);
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+}
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+
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+void trace_argv_printf(const char **argv, const char *format, ...)
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+{
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+ va_list ap;
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+ va_start(ap, format);
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+ trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
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va_end(ap);
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}
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+void trace_strbuf(const char *key, const struct strbuf *data)
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+{
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+ trace_strbuf_fl(NULL, 0, key, data);
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+}
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+
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+#else
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+
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+void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
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+ const char *format, ...)
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+{
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+ va_list ap;
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+ va_start(ap, format);
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+ trace_vprintf_fl(file, line, key, format, ap);
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+ va_end(ap);
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+}
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+
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+void trace_argv_printf_fl(const char *file, int line, const char **argv,
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+ const char *format, ...)
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+{
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+ va_list ap;
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+ va_start(ap, format);
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+ trace_argv_vprintf_fl(file, line, argv, format, ap);
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+ va_end(ap);
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+}
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+
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+#endif /* HAVE_VARIADIC_MACROS */
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+
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+
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static const char *quote_crnl(const char *path)
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{
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static char new_path[PATH_MAX];
trace.h
+62
@@ -17,6 +17,8 @@ extern void trace_repo_setup(const char *prefix);
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extern int trace_want(struct trace_key *key);
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extern void trace_disable(struct trace_key *key);
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+#ifndef HAVE_VARIADIC_MACROS
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+
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__attribute__((format (printf, 1, 2)))
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extern void trace_printf(const char *format, ...);
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@@ -28,4 +30,64 @@ extern void trace_argv_printf(const char **argv, const char *format, ...);
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extern void trace_strbuf(struct trace_key *key, const struct strbuf *data);
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+#else
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+
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+/*
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+ * Macros to add file:line - see above for C-style declarations of how these
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+ * should be used.
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+ */
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+
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+/*
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+ * TRACE_CONTEXT may be set to __FUNCTION__ if the compiler supports it. The
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+ * default is __FILE__, as it is consistent with assert(), and static function
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+ * names are not necessarily unique.
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+ *
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+ * __FILE__ ":" __FUNCTION__ doesn't work with GNUC, as __FILE__ is supplied
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+ * by the preprocessor as a string literal, and __FUNCTION__ is filled in by
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+ * the compiler as a string constant.
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+ */
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+#ifndef TRACE_CONTEXT
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+# define TRACE_CONTEXT __FILE__
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+#endif
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+
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+/*
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+ * Note: with C99 variadic macros, __VA_ARGS__ must include the last fixed
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+ * parameter ('format' in this case). Otherwise, a call without variable
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+ * arguments will have a surplus ','. E.g.:
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+ *
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+ * #define foo(format, ...) bar(format, __VA_ARGS__)
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+ * foo("test");
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+ *
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+ * will expand to
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+ *
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+ * bar("test",);
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+ *
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+ * which is invalid (note the ',)'). With GNUC, '##__VA_ARGS__' drops the
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+ * comma, but this is non-standard.
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+ */
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+
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+#define trace_printf(...) \
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+ trace_printf_key_fl(TRACE_CONTEXT, __LINE__, NULL, __VA_ARGS__)
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+
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+#define trace_printf_key(key, ...) \
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+ trace_printf_key_fl(TRACE_CONTEXT, __LINE__, key, __VA_ARGS__)
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+
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+#define trace_argv_printf(argv, ...) \
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+ trace_argv_printf_fl(TRACE_CONTEXT, __LINE__, argv, __VA_ARGS__)
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+
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+#define trace_strbuf(key, data) \
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+ trace_strbuf_fl(TRACE_CONTEXT, __LINE__, key, data)
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+
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+/* backend functions, use non-*fl macros instead */
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+__attribute__((format (printf, 4, 5)))
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+extern void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
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+ const char *format, ...);
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+__attribute__((format (printf, 4, 5)))
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+extern void trace_argv_printf_fl(const char *file, int line, const char **argv,
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+ const char *format, ...);
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+extern void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
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+ const struct strbuf *data);
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+
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+#endif /* HAVE_VARIADIC_MACROS */
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+
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#endif /* TRACE_H */