[or-cvs] Have GCC catch errors in format strings

[Nick Mathewson]

Update of /home/or/cvsroot/src/common
In directory moria.mit.edu:/tmp/cvs-serv17063/src/common

Modified Files:
	log.h 
Log Message:
Have GCC catch errors in format strings

Index: log.h
===================================================================
RCS file: /home/or/cvsroot/src/common/log.h,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -d -r1.8 -r1.9
--- log.h	17 Jun 2003 21:36:44 -0000	1.8
+++ log.h	17 Jun 2003 22:14:44 -0000	1.9
@@ -9,11 +9,20 @@
 
 #include <syslog.h>
 
+/* magic to make GCC check for proper format strings. */ 
+#ifdef __GNUC__
+#define CHECK_PRINTF(formatIdx, firstArg) \
+   __attribute__ ((format (printf, formatIdx, firstArg)))
+#else
+#define CHECK_PRINTF(formatIdx, firstArg) 
+#endif 
+
 /* Outputs a message to stdout and also logs the same message using syslog. */
-void log(int severity, const char *format, ...);
+void log(int severity, const char *format, ...) CHECK_PRINTF(2,3);
 
 #ifdef __GNUC__
-void _log_fn(int severity, const char *funcname, const char *format, ...);
+void _log_fn(int severity, const char *funcname, const char *format, ...)
+     CHECK_PRINTF(3,4);
 #define log_fn(severity, args...) \
   _log_fn(severity, __PRETTY_FUNCTION__, args)
 #else