Add the Clang specific -Wmissing-variable-declarations to WARNS=6.

This compiler flag enforces that that people either mark variables
static or use an external declarations for the variable, similar to how
-Wmissing-prototypes works for functions.

Due to the fact that Yacc/Lex generate code that cannot trivially be
changed to not warn because of this (lots of yy* variables), add a
NO_WMISSING_VARIABLE_DECLARATIONS that can be used to turn off this
specific compiler warning.

Announced on:	toolchain@

1 files changed, 2 insertions, 0 deletions

diff --git a/usr.bin/bzip2recover/Makefile b/usr.bin/bzip2recover/Makefile
index 7f61946c8db1..affe91bc0b07 100644
--- a/usr.bin/bzip2recover/Makefile
+++ b/usr.bin/bzip2recover/Makefile
@@ -6,4 +6,6 @@ BZ2DIR=	${.CURDIR}/../../contrib/bzip2
 PROG=	bzip2recover
 NO_MAN=
 
+NO_WMISSING_VARIABLE_DECLARATIONS=
+
 .include <bsd.prog.mk>