[Qemu-devel] [PATCH] Makefile: avoid defconfig annoyance

["Michael S. Tsirkin" <mst@redhat.com>]

This will be the last time you get
'config-devices.mak out of date' warning.

We have a config-devices.mak feature, which
makes it possile for distros to disable devices
they do not want. However, this is annoyng
for development where you just want
to use the default most of the time.

We want to distinguish between user overriding
config manually and just updating from git.
Do this, by sticking include directive in the generated files,
and avoiding error if the generated file only has such include
directives.

This patch is also careful to:
- not print warning while defconfig target is run
- tell user what will happen if make defconfig is run
  instead of just telling her what to do
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 Makefile |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index a662d96..469ce43 100644
--- a/Makefile
+++ b/Makefile
@@ -39,18 +39,21 @@ SUBDIR_MAKEFLAGS=$(if $(V),,--no-print-directory)
 SUBDIR_DEVICES_MAK=$(patsubst %, %/config-devices.mak, $(TARGET_DIRS))
 
 config-all-devices.mak: $(SUBDIR_DEVICES_MAK)
-	$(call quiet-command,cat $(SUBDIR_DEVICES_MAK) | grep =y | sort -u > $@,"  GEN   $@")
+	$(call quiet-command,cat $(SUBDIR_DEVICES_MAK) | \
+		grep -e =y -e ^-include | sort -u > $@,"  GEN   $@")
 
 %/config-devices.mak: default-configs/%.mak
-	$(call quiet-command,cat $< > $@.tmp, "  GEN   $@")
-	@if test -f $@ ; then \
+	$(call quiet-command,echo '-include $<'> $@.tmp, "  GEN   $@")
+	@if test -z "${QEMU_MAKE_DEFCONFIG}" -a -f $@ && \
+            grep -v '^-?include' $@ ; then \
 	  echo "WARNING: $@ out of date." ;\
-	  echo "Run \"make defconfig\" to regenerate." ; \
+	  echo "Update it or run \"make defconfig\" to remove it." ; \
 	  rm $@.tmp ; \
 	 else \
 	  mv $@.tmp $@ ; \
 	 fi
 
+defconfig: QEMU_MAKE_DEFCONFIG=yes
 defconfig:
 	rm -f config-all-devices.mak $(SUBDIR_DEVICES_MAK)
 
-- 
1.6.6.rc1.43.gf55cc