From 003a0576c9717edbfc82b0c0399139b9d4ed8698 Mon Sep 17 00:00:00 2001
From: Bryan Drewery <bdrewery@FreeBSD.org>
Date: Sat, 10 Mar 2018 02:10:19 +0000
Subject: [PATCH] Skip reading depend files with -V unless looking up a depend
 variable.

This speeds up some simple -V lookups significantly.

Reported by:	bde
MFC after:	2 weeks
Sponsored by:	Dell EMC
---
 sys/conf/kern.post.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sys/conf/kern.post.mk b/sys/conf/kern.post.mk
index 7751d43c149a..ef323c3b0e8e 100644
--- a/sys/conf/kern.post.mk
+++ b/sys/conf/kern.post.mk
@@ -201,6 +201,7 @@ _meta_filemon=	1
 # since it will track dependencies itself.  OBJS_DEPEND_GUESS is still used
 # for _meta_filemon but not for _SKIP_DEPEND.
 .if !defined(NO_SKIP_DEPEND) && (make(*obj) || \
+    (!empty(.MAKEFLAGS:M-V) && empty(.MAKEFLAGS:M*DEP*)) || \
     ${.TARGETS:M*clean*} == ${.TARGETS} || \
     ${.TARGETS:M*install*} == ${.TARGETS})
 _SKIP_DEPEND=	1