-Wformat-sign-mismatch?

[Dan Kegel]

Joseph S. Myers wrote:
> On Mon, 10 Feb 2003, Dan Kegel wrote:
> 
> 
>>Thanks very much.  I did read the manual, but it didn't
>>hint that -pedantic would turn on this kind of -Wformat check.
>>Would it be appropriate to spell this out more clearly?  e.g.
> 
> 
> It already says "if -pedantic is used with -Wformat, warnings will be
> given about format features not in the selected standard version".  This
> includes various pointer type mismatches that the C standard doesn't
> permit for variadic functions, but which most implementations (and the
> Single Unix Specification) permit, as well as the obvious cases such as
> additional format specifiers.

As you point out in the above paragraph, this is not obvious.
The paragraph you just wrote, if added to the manual, would clarify this.
e.g.

--- invoke.texi.old     Mon Feb 10 13:21:32 2003
+++ invoke.texi Mon Feb 10 13:46:51 2003
@@ -2025,6 +2025,9 @@
  in the selected standard version (but not for @code{strfmon} formats,
  since those are not in any version of the C standard).  @xref{C Dialect
  Options,,Options Controlling C Dialect}.
+It will also warn about various pointer type mismatches that the C standard
+doesn't permit for variadic functions, but which most implementations (and the
+Single Unix Specification) permit.

  Since @option{-Wformat} also checks for null format arguments for
  several functions, @option{-Wformat} also implies @option{-Wnonnull}.