* c-common.c (warn_format_security): New variable.
	(check_format_info): Warn about non-literal formats with no format
	arguments if either -Wformat-nonliteral or -Wformat-security is
	specified.
	(set_Wformat): Set warn_format_security for settings other than 1.
	* c-common.h (warn_format_security): Declare.
	* c-decl.c (c_decode_option): Decode -Wformat-security and
	-Wno-format-security.
	* invoke.texi: Document -Wformat-security.
	* toplev.c (documented_lang_options): Include -Wformat-security
	and -Wno-format-security.

cp:
	* decl2.c (lang_decode_option): Handle -Wformat-security.

testsuite:
	* format-sec-1.c: New test.

From-SVN: r38106