From: Jeff King Date: Fri, 8 Jul 2016 09:12:42 +0000 (-0400) Subject: write_file: add format attribute X-Git-Tag: v2.10.0-rc0~102^2~2 X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/e04d08a4b3373972717c805ae8e788219b873b2a?ds=inline;hp=--cc write_file: add format attribute This gives us compile-time checking of our format strings, which is a good thing. I had also hoped it would help with confusing write_file() and write_file_buf(), since the former's "..." can make it match the signature of the latter. But given that the buffer for write_file_buf() is generally not a string literal, the compiler won't complain unless -Wformat-nonliteral is on, and that creates a ton of false positives elsewhere in the code base. While we're there, let's also give the function a docstring, which it never had. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- e04d08a4b3373972717c805ae8e788219b873b2a diff --git a/cache.h b/cache.h index 206d594370..b2d24da73f 100644 --- a/cache.h +++ b/cache.h @@ -1740,6 +1740,14 @@ static inline ssize_t write_str_in_full(int fd, const char *str) */ extern void write_file_buf(const char *path, const char *buf, size_t len); +/** + * Like write_file_buf(), but format the contents into a buffer first. + * Additionally, write_file() will append a newline if one is not already + * present, making it convenient to write text files: + * + * write_file(path, "counter: %d", ctr); + */ +__attribute__((format (printf, 2, 3))) extern void write_file(const char *path, const char *fmt, ...); /* pager.c */