Remove support for shared configuration cache

The configuration cache shared between packages, while being in
principle a nice idea to speed-up the configuration of packages by
avoiding repetitive identical checks, turned out to be unreliable due
to the subtle differences between similar but not identical checks in
different packages. After spending some time trying to fix those, we
concluded that supporting the shared configuration cache is definitely
too hard and too unreliable, and that we'd better get rid of it
altogether.

This patch therefore removes the shared configuration cache
infrastructure and usage.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

CHANGES

@@ -16,6 +16,9 @@
 	Download handling reworked and support for git/svn downloads
 	added.
 
+	Removed experimental shared config.cache support, as it is
+	too unreliable.
+
 	A convenience Makefile wrapper is created when using
 	out-of-tree building, similar to how it is done for the kernel.
 

Config.in

@@ -256,20 +256,6 @@ config BR2_HAVE_DEVFILES
 	  Install headers and static libraries in the
 	  target filesystem
 
-menu "Advanced"
-
-config BR2_CONFIG_CACHE
-	bool "Use a central configure cache file (EXPERIMENTAL)"
-	help
-	  Notice: This is experimental and known to break with certain
-	  package combinations.
-
-	  This determines if a central config cache is used by
-	  packages, reducing the configure time for packages as each
-	  one caches its findings.
-
-endmenu
-
 endmenu
 
 source "toolchain/Config.in"

Makefile

@@ -447,15 +447,6 @@ external-deps:
 show-targets:
 	@echo $(TARGETS)
 
-ifeq ($(BR2_CONFIG_CACHE),y)
-# drop configure caches if configuration is changed
-$(BUILD_DIR)/tgt-config.cache $(BUILD_DIR)/host-config.cache: $(CONFIG_DIR)/.config
-	rm -f $@
-	touch $@
-
-$(BASE_TARGETS): | $(BUILD_DIR)/tgt-config.cache $(BUILD_DIR)/host-config.cache
-endif
-
 else # ifeq ($(BR2_HAVE_DOT_CONFIG),y)
 
 all: menuconfig

configs/arm_nptl_toolchain_defconfig

@@ -155,7 +155,6 @@ BR2_OPTIMIZE_2=y
 #
 # Advanced
 #
-# BR2_CONFIG_CACHE is not set
 
 #
 # Toolchain

configs/arm_toolchain_defconfig

@@ -160,7 +160,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91rm9200df_defconfig

@@ -165,7 +165,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9260dfc"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91rm9200df_ext_bare_defconfig

@@ -160,7 +160,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91rm9200df-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91rm9200df_ext_defconfig

@@ -171,7 +171,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91rm9200df-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9260dfc_defconfig

@@ -178,7 +178,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9260dfc-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9260dfc_ext_bare_defconfig

@@ -160,7 +160,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9260dfc-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9260dfc_ext_defconfig

@@ -179,7 +179,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9260dfc-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9261ek_defconfig

@@ -181,7 +181,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9261ek-NAND"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9261ek_ext_bare_defconfig

@@ -163,7 +163,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9261ek-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9261ek_ext_defconfig

@@ -182,7 +182,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9261ek-NAND"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9263ek_defconfig

@@ -179,7 +179,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9263ek-NAND"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9263ek_ext_bare_defconfig

@@ -162,7 +162,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9263ek-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9263ek_ext_defconfig

@@ -181,7 +181,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9263ek-NAND"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9g20dfc_defconfig

@@ -179,7 +179,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam92g20ek-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9g20dfc_ext_bare_defconfig

@@ -160,7 +160,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9g20dfc-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/at91sam9g20dfc_ext_defconfig

@@ -179,7 +179,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="at91sam9g20dfc-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/atngw100-base_defconfig

@@ -112,7 +112,6 @@ BR2_TOPDIR_PREFIX=""
 BR2_TOPDIR_SUFFIX=""
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/atngw100_defconfig

@@ -108,7 +108,6 @@ BR2_OPTIMIZE_S=y
 #
 # Advanced
 #
-# BR2_CONFIG_CACHE is not set
 
 #
 # Toolchain

configs/atstk1005_defconfig

@@ -111,7 +111,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/atstk100x_defconfig

@@ -111,7 +111,6 @@ BR2_TOPDIR_PREFIX=""
 BR2_TOPDIR_SUFFIX=""
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/i386_defconfig

@@ -113,7 +113,6 @@ BR2_TOPDIR_PREFIX=""
 BR2_TOPDIR_SUFFIX=""
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/i686_defconfig

@@ -113,7 +113,6 @@ BR2_TOPDIR_PREFIX=""
 BR2_TOPDIR_SUFFIX=""
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/integrator926_defconfig

@@ -110,7 +110,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

configs/integrator926_huge_defconfig

@@ -110,7 +110,6 @@ BR2_TOPDIR_SUFFIX=""
 BR2_ROOTFS_PREFIX="$(BOARD_NAME)-rootfs"
 BR2_JLEVEL=2
 # BR2_DEPRECATED is not set
-# BR2_CONFIG_CACHE is not set
 # BR2_ENABLE_DEBUG is not set
 BR2_STRIP_strip=y
 # BR2_STRIP_sstrip is not set

docs/buildroot.html

@@ -1269,13 +1269,6 @@ LIBFOO_POST_PATCH_HOOKS += LIBFOO_POST_PATCH_FIXUP
       not. Valid values are <code>YES</code> and <code>NO</code>. By
       default, the value is <code>YES</code></li>
 
-      <li><code>LIBFOO_USE_CONFIG_CACHE</code> tells whether the configure
-      script should use the central configure cache, which caches test
-      results from previous configure scripts. Usually, this variable should
-      be left to its default value. Only packages having issues with the
-      configure cache, can set this variable to the <code>NO</code> value
-      (but this is more of a work-around than a fix)</li>
-
       <li><code>LIBFOO_INSTALL_STAGING_OPT</code> contains the make options
       used to install the package to the staging directory. By default, the
       value is <code>DESTDIR=$$(STAGING_DIR) install</code>, which is

package/Makefile.autotools.in

@@ -64,7 +64,6 @@ $(2)_MAKE_ENV			?=
 $(2)_MAKE_OPT			?=
 $(2)_AUTORECONF			?= NO
 $(2)_AUTORECONF_OPT		?=
-$(2)_USE_CONFIG_CACHE           ?= $(if $(BR2_CONFIG_CACHE),YES,NO)
 $(2)_INSTALL_STAGING_OPT	?= DESTDIR=$$(STAGING_DIR) install
 $(2)_INSTALL_TARGET_OPT		?= DESTDIR=$$(TARGET_DIR)  install
 $(2)_CLEAN_OPT			?= clean
@@ -88,7 +87,6 @@ define $(2)_CONFIGURE_CMDS
 	$$(TARGET_CONFIGURE_ARGS) \
 	$$($$(PKG)_CONF_ENV) \
 	./configure \
-		$$(if $$(filter YES,$$($$(PKG)_USE_CONFIG_CACHE)),--cache-file="$(BUILD_DIR)/tgt-config.cache",) \
 		--target=$$(GNU_TARGET_NAME) \
 		--host=$$(GNU_TARGET_NAME) \
 		--build=$$(GNU_HOST_NAME) \
@@ -112,7 +110,6 @@ define $(2)_CONFIGURE_CMDS
 		LDFLAGS="$$(HOST_LDFLAGS)" \
                 $$($$(PKG)_CONF_ENV) \
 		./configure \
-		$$(if $$(filter YES,$$($$(PKG)_USE_CONFIG_CACHE)),--cache-file="$(BUILD_DIR)/host-config.cache",) \
 		--prefix="$$(HOST_DIR)/usr" \
 		--sysconfdir="$$(HOST_DIR)/etc" \
 		$$($$(PKG)_CONF_OPT) \

package/fontconfig/fontconfig.mk

@@ -7,7 +7,6 @@ FONTCONFIG_VERSION = 2.6.0
 FONTCONFIG_SOURCE = fontconfig-$(FONTCONFIG_VERSION).tar.gz
 FONTCONFIG_SITE = http://fontconfig.org/release
 FONTCONFIG_AUTORECONF = YES
-FONTCONFIG_USE_CONFIG_CACHE = NO
 FONTCONFIG_INSTALL_STAGING = YES
 FONTCONFIG_INSTALL_TARGET = YES
 # This package does not like using the target cflags for some reason.

package/gamin/gamin.mk

@@ -19,8 +19,6 @@ GAMIN_CONF_ENV = have_abstract_sockets=no
 
 ifneq ($(BR2_LARGEFILE),y)
 GAMIN_CONF_ENV += CC="$(TARGET_CC) $(TARGET_CFLAGS) -DNO_LARGEFILE_SOURCE"
-# the above doesn't work with shared config.cache
-GAMIN_USE_CONFIG_CACHE = NO
 endif
 
 GAMIN_DEPENDENCIES = libglib2

package/haserl/haserl.mk

@@ -11,8 +11,6 @@ HASERL_INSTALL_TARGET:=YES
 
 # force haserl 0.8.0 to use install-sh so stripping works
 HASERL_CONF_ENV = ac_cv_path_install=./install-sh
-# the above doesn't interact nicely with a shared cache, so disable for now
-HASERL_USE_CONFIG_CACHE = NO
 ifeq ($(BR2_PACKAGE_HASERL_WITH_LUA),y)
 	HASERL_CONF_OPT += --with-lua=$(STAGING_DIR) \
 		--with-lua-headers=$(STAGING_DIR)

package/libxml2/libxml2.mk

@@ -13,8 +13,6 @@ LIBXML2_LIBTOOL_PATCH = NO
 
 ifneq ($(BR2_LARGEFILE),y)
 LIBXML2_CONF_ENV = CC="$(TARGET_CC) $(TARGET_CFLAGS) -DNO_LARGEFILE_SOURCE"
-# the above doesn't work with shared config.cache
-LIBXML2_USE_CONFIG_CACHE = NO
 endif
 
 LIBXML2_CONF_OPT = --with-gnu-ld --enable-shared \

package/multimedia/alsa-lib/alsa-lib.mk

@@ -67,8 +67,6 @@ endif
 
 ALSA_LIB_CONF_ENV = CFLAGS="$(ALSA_LIB_CFLAGS)" \
 		    LDFLAGS="$(TARGET_LDFLAGS) -lm"
-# the above doesn't work with shared config.cache
-ALSA_LIB_USE_CONFIG_CACHE = NO
 
 define ALSA_LIB_UNINSTALL_TARGET_CMDS
 	-rm -f $(TARGET_DIR)/usr/lib/libasound.so*

package/ng-spice-rework/ng-spice-rework.mk

@@ -11,8 +11,6 @@ NG_SPICE_REWORK_INSTALL_STAGING = NO
 NG_SPICE_REWORK_INSTALL_TARGET = YES
 
 NG_SPICE_REWORK_CONF_OPT = CFLAGS="-I$(STAGING_DIR)/usr/include"
-# the above doesn't work with shared config.cache
-NG_SPICE_REWORK_USE_CONFIG_CACHE = NO
 
 NG_SPICE_REWORK_DEPENDENCIES = xserver_xorg-server xlib_libXaw
 

package/rpm/rpm.mk

@@ -12,8 +12,6 @@ RPM_DEPENDENCIES = zlib beecrypt neon popt
 
 RPM_CONF_ENV = CFLAGS="$(TARGET_CFLAGS) -I$(STAGING_DIR)/usr/include/beecrypt -I$(STAGING_DIR)/usr/include/neon -DHAVE_MUTEX_THREAD_ONLY" \
 		ac_cv_va_copy=yes 
-# the above doesn't work with shared config.cache
-RPM_USE_CONFIG_CACHE = NO
 
 RPM_CONF_OPT = --disable-build-versionscript --disable-rpath \
 	--without-selinux \

package/sqlite/sqlite.mk

@@ -15,8 +15,6 @@ ifneq ($(BR2_LARGEFILE),y)
 # --disable-largefile is passed, breaking the build. Work around it by
 # simply adding it to CFLAGS for configure instead
 SQLITE_CONF_ENV = CFLAGS="$(TARGET_CFLAGS) -DSQLITE_DISABLE_LFS"
-# changing CFLAGS doesn't work with config.cache
-SQLITE_USE_CONFIG_CACHE = NO
 endif
 
 SQLITE_CONF_OPT =	--enable-shared \

package/x11r7/xserver_xorg-server/xserver_xorg-server.mk

@@ -11,7 +11,6 @@ XSERVER_XORG_SERVER_MAKE = $(MAKE1) # make install fails with parallel make
 XSERVER_XORG_SERVER_AUTORECONF = NO
 XSERVER_XORG_SERVER_LIBTOOL_PATCH = NO
 XSERVER_XORG_SERVER_INSTALL_STAGING = YES
-XSERVER_XORG_SERVER_USE_CONFIG_CACHE = NO # overrides CFLAGS
 XSERVER_XORG_SERVER_INSTALL_STAGING_OPT = DESTDIR=$(STAGING_DIR) install install-data
 
 XSERVER_XORG_SERVER_DEPENDENCIES = 	\