From bb585a784e9ad69207315d694e7dad2c422f6baa Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 3 Apr 2013 17:53:21 +0200
Subject: [PATCH] build: enable using $(CONFIG_FOO) on the rhs of config files

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Makefile | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 80344d9..0b6e6a1 100644
--- a/Makefile
+++ b/Makefile
@@ -76,7 +76,10 @@ config-all-devices.mak:
 	$(call quiet-command,echo '# no devices' > $@,"  GEN   $@")
 else
 config-all-devices.mak: $(SUBDIR_DEVICES_MAK)
-	$(call quiet-command,cat $(SUBDIR_DEVICES_MAK) | grep =y | sort -u > $@,"  GEN   $@")
+	$(call quiet-command, sed -n \
+             's|^\([^=]*\)=\(.*\)$$|\1:=$$(findstring y,$$(\1)\2)|p' \
+             $(SUBDIR_DEVICES_MAK) | sort -u > $@, \
+             "  GEN   $@")
 endif
 
 -include $(SUBDIR_DEVICES_MAK_DEP)
-- 
2.7.4