Expose and annotate logging functions

4 files changed, 40 insertions, 2 deletions

diff --git a/NEWS b/NEWS
index d9276887..05d7fe8a 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ serd (1.0.0) unstable;
   * Use a fixed-size reader stack
   * Simplify writer style options
   * Simplify streaming API and improve pretty printing
+  * Add logging functions to public API
 
  -- David Robillard <d@drobilla.net>  Sat, 19 Jan 2019 13:31:12 +0100
 
diff --git a/serd/serd.h b/serd/serd.h
index 9b3e35f6..ec5d9228 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -42,6 +42,12 @@
 #    define SERD_API
 #endif
 
+#if defined(__GNUC__)
+#    define SERD_LOG_FUNC(fmt, arg1) __attribute__((format(printf, fmt, arg1)))
+#else
+#    define SERD_LOG_FUNC(fmt, arg1)
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -823,6 +829,22 @@ serd_world_set_message_sink(SerdWorld*      world,
                             SerdMessageSink msg_sink,
                             void*           handle);
 
+/// Write a message to the log
+SERD_API
+SerdStatus
+serd_world_log(const SerdWorld* world, const SerdMessage* msg);
+
+/// Write a message to the log
+SERD_API
+SERD_LOG_FUNC(5, 6)
+SerdStatus
+serd_world_logf(const SerdWorld*  world,
+                SerdStatus        st,
+                SerdLogLevel      level,
+                const SerdCursor* cursor,
+                const char*       fmt,
+                ...);
+
 /**
    @}
    @name Environment
diff --git a/src/world.c b/src/world.c
index 483c46a6..7b0343cc 100644
--- a/src/world.c
+++ b/src/world.c
@@ -70,6 +70,22 @@ serd_world_log(const SerdWorld* world, const SerdMessage* msg)
 }
 
 SerdStatus
+serd_world_logf(const SerdWorld*  world,
+                SerdStatus        st,
+                SerdLogLevel      level,
+                const SerdCursor* cursor,
+                const char*       fmt,
+                ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	const SerdMessage msg = {st, level, cursor, fmt, &args};
+	serd_world_log(world, &msg);
+	va_end(args);
+	return st;
+}
+
+SerdStatus
 serd_world_errorf(const SerdWorld* world, SerdStatus st, const char* fmt, ...)
 {
 	va_list args;
diff --git a/src/world.h b/src/world.h
index f4e7ee3e..9d6dd4d2 100644
--- a/src/world.h
+++ b/src/world.h
@@ -39,8 +39,7 @@ struct SerdWorldImpl {
 
 FILE* serd_world_fopen(SerdWorld* world, const char* path, const char* mode);
 
-SerdStatus serd_world_log(const SerdWorld* world, const SerdMessage* msg);
-
+SERD_LOG_FUNC(3, 4)
 SerdStatus
 serd_world_errorf(const SerdWorld* world, SerdStatus st, const char* fmt, ...);