re PR c++/17212 (-W(no)format-zero-length does not work with C++)

/gcc
2011-10-14  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/17212
	* c-family/c.opt ([Wformat-zero-length]): Add C++ and Objective-C++.
	* doc/invoke.texi: Update.

/testsuite
2011-10-14  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/17212
	* g++.dg/warn/format6.C: New.
	* obj-c++.dg/warn6.mm: Likewise.

From-SVN: r179963

gcc/c-family/c.opt

@@ -396,7 +396,7 @@ C ObjC C++ ObjC++ Var(warn_format_y2k) Warning
 Warn about strftime formats yielding 2-digit years
 
 Wformat-zero-length
-C ObjC Var(warn_format_zero_length) Warning
+C ObjC C++ ObjC++ Var(warn_format_zero_length) Warning
 Warn about zero-length formats
 
 Wformat=

gcc/doc/invoke.texi

@@ -3190,7 +3190,7 @@ in the case of @code{scanf} formats, this option will suppress the
 warning if the unused arguments are all pointers, since the Single
 Unix Specification says that such unused arguments are allowed.
 
-@item -Wno-format-zero-length @r{(C and Objective-C only)}
+@item -Wno-format-zero-length @r{(C, C++, Objective-C and Objective-C++ only)}
 @opindex Wno-format-zero-length
 @opindex Wformat-zero-length
 If @option{-Wformat} is specified, do not warn about zero-length formats.

gcc/testsuite/g++.dg/warn/format6.C

+// PR c++/17212
+// { dg-options "-Wformat -Wno-format-zero-length" }
+
+void f()
+{
+  __builtin_printf("");
+}

gcc/testsuite/obj-c++.dg/warn6.mm

+// PR c++/17212
+// { dg-options "-Wformat -Wno-format-zero-length" }
+
+void f()
+{
+  __builtin_printf("");
+}