From: Yorhel <git@yorhel.nl>
Date: Tue, 7 May 2013 10:03:48 +0000 (+0200)
Subject: kstring: Add printf format attribute to kvsprintf() and ksprintf()
X-Git-Tag: spawn-final~24^2
X-Git-Url: http://www.kaiwu.me/postgresql/commit/static/gitweb.js?a=commitdiff_plain;h=9f49ae119cec435ac380b6a04dcfdaa7f5848ed6;p=klib.git

kstring: Add printf format attribute to kvsprintf() and ksprintf()

This allows compile-time detection of format-string related bugs.
Although the macros only check for the GCC version, clang (and perhaps
other compilers too) have these macros defined and can recognize
the formatting attributes as well.
---

diff --git a/kstring.h b/kstring.h
index ef69a6b..13a5559 100644
--- a/kstring.h
+++ b/kstring.h
@@ -35,6 +35,13 @@
 #define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
 #endif
 
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
+#define KS_ATTR_PRINTF(fmt, arg) __attribute__((__format__ (__printf__, fmt, arg)))
+#else
+#define KS_ATTR_PRINTF(fmt, arg)
+#endif
+
+
 #ifndef KSTRING_T
 #define KSTRING_T kstring_t
 typedef struct __kstring_t {
@@ -53,8 +60,8 @@ typedef struct {
 extern "C" {
 #endif
 
-	int kvsprintf(kstring_t *s, const char *fmt, va_list ap);
-	int ksprintf(kstring_t *s, const char *fmt, ...);
+	int kvsprintf(kstring_t *s, const char *fmt, va_list ap) KS_ATTR_PRINTF(2,0);
+	int ksprintf(kstring_t *s, const char *fmt, ...) KS_ATTR_PRINTF(2,3);
 	int ksplit_core(char *s, int delimiter, int *_max, int **_offsets);
 	char *kstrstr(const char *str, const char *pat, int **_prep);
 	char *kstrnstr(const char *str, const char *pat, int n, int **_prep);