[Buildroot] [PATCH 08/13] Store BR2_DEFCONFIG in .config, and use it to update the original input

[Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>]

From: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

defconfig file after updating the configuration.

Also use $(PROJECT_DIR) by default.

As a side-effect of this change, the *config options have been moved out
of the BR2_HAVE_DOT_CONFIG condition.  Also, the defconfig and savedefconfig
targets do need to include .config now, which makes them slightly slower.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
---
 Config.in |   13 +++++++++++++
 Makefile  |   22 +++++++++++++---------
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/Config.in b/Config.in
index 8cefcc6..4111409 100644
--- a/Config.in
+++ b/Config.in
@@ -29,6 +29,19 @@ config BR2_PROJECT_DIR
 	  This option is used to set defaults for many other configuration
 	  variables.  Each one of those can still be overridden individually.
 
+config BR2_DEFCONFIG_FROM_ENV
+	string
+	option env="BR2_DEFCONFIG"
+
+config BR2_DEFCONFIG
+	string "Location to save buildroot config"
+	default "$(PROJECT_DIR)/buildroot.config" if BR2_PROJECT_DIR != ""
+	default BR2_DEFCONFIG_FROM_ENV if BR2_DEFCONFIG_FROM_ENV != ""
+	default "defconfig"
+	help
+	  When running 'make savedefconfig', the defconfig file will be saved
+	  in this location.
+
 menu "Build options"
 
 menu "Commands"
diff --git a/Makefile b/Makefile
index d6136ed..cbaa0c4 100644
--- a/Makefile
+++ b/Makefile
@@ -56,7 +56,7 @@ DATE:=$(shell date +%Y%m%d)
 export BR2_VERSION_FULL:=$(BR2_VERSION)$(shell $(TOPDIR)/support/scripts/setlocalversion)
 
 noconfig_targets:=menuconfig nconfig gconfig xconfig config oldconfig randconfig \
-	defconfig %_defconfig savedefconfig allyesconfig allnoconfig silentoldconfig release \
+	%_defconfig allyesconfig allnoconfig silentoldconfig release \
 	randpackageconfig allyespackageconfig allnopackageconfig \
 	source-check print-version
 
@@ -97,6 +97,7 @@ ifeq ($(filter $(noconfig_targets),$(MAKECMDGOALS)),)
 endif
 
 PROJECT_DIR = $(realpath $(call qstrip,$(BR2_PROJECT_DIR)))
+DEFCONFIG = $(call qstrip,$(BR2_DEFCONFIG))
 
 # To put more focus on warnings, be less verbose as default
 # Use 'make V=1' to see the full commands
@@ -545,6 +546,8 @@ else # ifeq ($(BR2_HAVE_DOT_CONFIG),y)
 
 all: menuconfig
 
+endif # ifeq ($(BR2_HAVE_DOT_CONFIG),y)
+
 # configuration
 # ---------------------------------------------------------------------------
 
@@ -560,6 +563,7 @@ COMMON_CONFIG_ENV = \
 	KCONFIG_AUTOHEADER=$(BUILD_DIR)/buildroot-config/autoconf.h \
 	KCONFIG_TRISTATE=$(BUILD_DIR)/buildroot-config/tristate.config \
 	BR2_PROJECT_DIR=$(PROJECT_DIR) \
+	BR2_DEFCONFIG=$(DEFCONFIG) \
 	BUILDROOT_CONFIG=$(CONFIG_DIR)/.config
 
 xconfig: $(BUILD_DIR)/buildroot-config/qconf outputmakefile
@@ -626,24 +630,24 @@ silentoldconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
 	@mkdir -p $(BUILD_DIR)/buildroot-config
 	$(COMMON_CONFIG_ENV) $< --silentoldconfig $(CONFIG_CONFIG_IN)
 
-defconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
-	@mkdir -p $(BUILD_DIR)/buildroot-config
-	@$(COMMON_CONFIG_ENV) $< --defconfig$(if $(BR2_DEFCONFIG),=$(BR2_DEFCONFIG)) $(CONFIG_CONFIG_IN)
-
 %_defconfig: $(BUILD_DIR)/buildroot-config/conf $(TOPDIR)/configs/%_defconfig outputmakefile
 	@mkdir -p $(BUILD_DIR)/buildroot-config
 	@$(COMMON_CONFIG_ENV) $< --defconfig=$(TOPDIR)/configs/$@ $(CONFIG_CONFIG_IN)
 
+defconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
+	@mkdir -p $(BUILD_DIR)/buildroot-config
+	@$(COMMON_CONFIG_ENV) $< --defconfig$(if $(DEFCONFIG),=$(DEFCONFIG)) $(CONFIG_CONFIG_IN)
+
 savedefconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
 	@mkdir -p $(BUILD_DIR)/buildroot-config
-	@$(COMMON_CONFIG_ENV) $< --savedefconfig=$(CONFIG_DIR)/defconfig $(CONFIG_CONFIG_IN)
+	@$(COMMON_CONFIG_ENV) $< \
+		--savedefconfig=$(if $(DEFCONFIG),$(DEFCONFIG),$(CONFIG_DIR)/defconfig) \
+		$(CONFIG_CONFIG_IN)
 
 # check if download URLs are outdated
 source-check:
 	$(MAKE) DL_MODE=SOURCE_CHECK $(EXTRAMAKEARGS) source
 
-endif # ifeq ($(BR2_HAVE_DOT_CONFIG),y)
-
 #############################################################
 #
 # Cleanup and misc junk
@@ -757,5 +761,5 @@ print-version:
 
 include docs/manual/manual.mk
 
-.PHONY: $(noconfig_targets)
+.PHONY: $(noconfig_targets) defconfig savedefconfig