1 files changed, 62 insertions, 0 deletions
diff --git a/trace.h b/trace.h
index b4800e746..7a5ba2e61 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 */