0999158088e0fb3715eb27703c8c4f7123d77144
galt
  Mon Sep 21 16:51:20 2015 -0700
added GNU-C attributes to function declarations in src/inc, src/hg/inc, and some CGIs so that the compiler can catch errors where the parameter list given by the user does not match their format string. These var-args functions are like printf.

diff --git src/hg/inc/jsHelper.h src/hg/inc/jsHelper.h
index bc8ca76..5c99cff 100644
--- src/hg/inc/jsHelper.h
+++ src/hg/inc/jsHelper.h
@@ -143,21 +143,24 @@
  * With support for varying font size */
 
 void jsEndCollapsibleSection();
 /* End the collapsible <TR id=...>. */
 
 void jsReloadOnBackButton(struct cart *cart);
 /* Add some javascript to detect that the back button (or reload) has been pressed,
  * and to resubmit in that case to redraw the page with the latest cart contents. */
 
 // --- Genome browser specific json stuff - see also inc/json.h for more generic stuff 
 
 void jsonPrint(struct jsonElement *json, char *name, int indentLevel);
 // print out a jsonElement and children using hPrintf, and for indentLevel >=0
 // bracketing with comments.  See also jsonPrintToFile.
 
-void jsonErrPrintf(struct dyString *ds, char *format, ...);
+void jsonErrPrintf(struct dyString *ds, char *format, ...)
 //  Printf a json error to a dyString for communicating with ajax code; format is:
 //  {"error": error message here}
-
+#if defined(__GNUC__)
+__attribute__((format(printf, 2, 3)))
+#endif
+;
 
 #endif /* JSHELPER_H */