kumquat-buildroot/package/ccache/ccache.mk

#############################################################
#
# ccache
#
#############################################################

CCACHE_VERSION = 3.1.7
CCACHE_SITE    = http://samba.org/ftp/ccache
CCACHE_SOURCE  = ccache-$(CCACHE_VERSION).tar.bz2

# When ccache is being built for the host, ccache is not yet
# available, so we have to use the special C compiler without the
# cache.
HOST_CCACHE_CONF_ENV = \
	CC="$(HOSTCC_NOCCACHE)"

# Force ccache to use its internal zlib. The problem is that without
# this, ccache would link against the zlib of the build system, but we
# might build and install a different version of zlib in $(O)/host
# afterwards, which ccache will pick up. This might break if there is
# a version mismatch. A solution would be to add host-zlib has a
# dependency of ccache, but it would require tuning the zlib .mk file
# to use HOSTCC_NOCCACHE as the compiler. Instead, we take the easy
# path: tell ccache to use its internal copy of zlib, so that ccache
# has zero dependency besides the C library.
HOST_CCACHE_CONF_OPT += ccache_cv_zlib_1_2_3=no

# Patch host-ccache as follows:
#  - Use BUILDROOT_CACHE_DIR instead of CCACHE_DIR, because CCACHE_DIR
#    is already used by autotargets for the ccache package.
#    BUILDROOT_CACHE_DIR is exported by Makefile based on config option
#    BR2_CCACHE_DIR.
#  - ccache shouldn't use the compiler binary mtime to detect a change in
#    the compiler, because in the context of Buildroot, that completely
#    defeats the purpose of ccache. Of course, that leaves the user
#    responsible for purging its cache when the compiler changes.
define HOST_CCACHE_PATCH_CONFIGURATION
	sed -i 's,getenv("CCACHE_DIR"),getenv("BUILDROOT_CACHE_DIR"),' $(@D)/ccache.c
	sed -i 's,getenv("CCACHE_COMPILERCHECK"),"none",' $(@D)/ccache.c
endef

HOST_CCACHE_POST_CONFIGURE_HOOKS += \
	HOST_CCACHE_PATCH_CONFIGURATION

$(eval $(autotools-package))
$(eval $(host-autotools-package))

ifeq ($(BR2_CCACHE),y)
ccache-stats: host-ccache
	$(Q)$(CCACHE) -s
endif