add documentation for obstack_printf

[r27719]

diff --git a/include/libfirm/adt/obstack.h b/include/libfirm/adt/obstack.h
index 6ce2d8d..220eeb3 100644 (file)
--- a/include/libfirm/adt/obstack.h
+++ b/include/libfirm/adt/obstack.h
@@ -501,9 +501,13 @@ __extension__                                                              \
 
 #endif /* not __GNUC__ or not __STDC__ */
 
-int obstack_vprintf(struct obstack *obst, const char *fmt, va_list ap);
+
+/** prints formated string (printf-style format) to an obstack.
+ * This is done by "growing" the obstack with the obstack_*grow*
+ * functions. Note: Does NOT append a null-byte. */
 int obstack_printf(struct obstack *obst, const char *fmt, ...);
+int obstack_vprintf(struct obstack *obst, const char *fmt, va_list ap);
 
 #include "../end.h"
 
-#endif /* obstack.h */
+#endif