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, 1 insertions, 0 deletions

diff --git a/sbin/md5/Makefile b/sbin/md5/Makefile
index c3c5a9f..eabf129 100644
--- a/sbin/md5/Makefile
+++ b/sbin/md5/Makefile
@@ -13,6 +13,7 @@ MLINKS=	md5.1 rmd160.1 \
 	md5.1 sha256.1 \
 	md5.1 sha512.1
 
+NO_WMISSING_VARIABLE_DECLARATIONS=
 WFORMAT?=	1
 
 DPADD=	${LIBMD}