Apply format string attribute to printf style functions

Not strictly C99 conform, but widely supported and easy enough to NOP
for compilers which do not support it. Besides it was already used to
mark certain functions as noreturn.

1 files changed, 2 insertions, 2 deletions

diff --git a/buffer.h b/buffer.h
index 91932c6..41c2532 100644
--- a/buffer.h
+++ b/buffer.h
@@ -43,9 +43,9 @@ bool buffer_prepend(Buffer*, const void *data, size_t len);
 /* prepend NUL-terminated data */
 bool buffer_prepend0(Buffer*, const char *data);
 /* set formatted buffer content, ensures NUL termination on success */
-bool buffer_printf(Buffer*, const char *fmt, ...);
+bool buffer_printf(Buffer*, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
 /* append formatted buffer content, ensures NUL termination on success */
-bool buffer_appendf(Buffer*, const char *fmt, ...);
+bool buffer_appendf(Buffer*, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
 /* return length of a buffer without trailing NUL byte */
 size_t buffer_length0(Buffer*);
 /* return length of a buffer including possible NUL byte */