use ATTR_PRINTFALIKE

src/isync.h

@@ -393,13 +393,13 @@ void cram( const char *challenge, const char *user, const char *pass,
 
 extern int DFlags;
 
-void debug( const char *, ... );
-void debugn( const char *, ... );
-void info( const char *, ... );
-void infon( const char *, ... );
-void warn( const char *, ... );
-void error( const char *, ... );
-void sys_error( const char *, ... );
+void ATTR_PRINTFLIKE(1, 2) debug( const char *, ... );
+void ATTR_PRINTFLIKE(1, 2) debugn( const char *, ... );
+void ATTR_PRINTFLIKE(1, 2) info( const char *, ... );
+void ATTR_PRINTFLIKE(1, 2) infon( const char *, ... );
+void ATTR_PRINTFLIKE(1, 2) warn( const char *, ... );
+void ATTR_PRINTFLIKE(1, 2) error( const char *, ... );
+void ATTR_PRINTFLIKE(1, 2) sys_error( const char *, ... );
 void flushn( void );
 
 char *next_arg( char ** );
@@ -414,8 +414,8 @@ void *nfcalloc( size_t sz );
 void *nfrealloc( void *mem, size_t sz );
 char *nfstrdup( const char *str );
 int nfvasprintf( char **str, const char *fmt, va_list va );
-int nfasprintf( char **str, const char *fmt, ... );
-int nfsnprintf( char *buf, int blen, const char *fmt, ... );
+int ATTR_PRINTFLIKE(2, 3) nfasprintf( char **str, const char *fmt, ... );
+int ATTR_PRINTFLIKE(3, 4) nfsnprintf( char *buf, int blen, const char *fmt, ... );
 void ATTR_NORETURN oob( void );
 
 char *expand_strdup( const char *s );

src/mdconvert.c

@@ -37,8 +37,10 @@
 
 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
 # define ATTR_NORETURN __attribute__((noreturn))
+# define ATTR_PRINTFLIKE(fmt,var) __attribute__((format(printf,fmt,var)))
 #else
 # define ATTR_NORETURN
+# define ATTR_PRINTFLIKE(fmt,var)
 #endif
 
 static void ATTR_NORETURN
@@ -48,7 +50,7 @@ oob( void )
 	abort();
 }
 
-static void
+static void ATTR_PRINTFLIKE(1, 2)
 sys_error( const char *msg, ... )
 {
 	va_list va;
@@ -61,7 +63,7 @@ sys_error( const char *msg, ... )
 	perror( buf );
 }
 
-static int
+static int ATTR_PRINTFLIKE(3, 4)
 nfsnprintf( char *buf, int blen, const char *fmt, ... )
 {
 	int ret;