ccache: Separate out into its own class

Currently, ccache is used if it is present. When building from scratch it gives
no performance improvement and creates a ton of empty directories even when its
not in use.

This change moves ccache support to a bbclass file which the user can choose to
enable. This should make builds more determinstic and make it easier/clearer
to the end user when its being used and when it is not.

(From OE-Core rev: 2acf8da4f13c175ea818b9514677b7059de1e3e2)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 5fda36b01c..48287a71ab 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -409,10 +409,9 @@ export PATH
 # Build utility info.
 ##################################################################
 
-CCACHE = "${@bb.which(d.getVar('PATH', True), 'ccache') and 'ccache '}"
+CCACHE ??= ""
 TOOLCHAIN_OPTIONS = " --sysroot=${STAGING_DIR_TARGET}"
 
-export CCACHE_DIR = "${TMPDIR}/ccache/${MULTIMACH_HOST_SYS}/${PN}"
 export CC = "${CCACHE}${HOST_PREFIX}gcc ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
 export CXX = "${CCACHE}${HOST_PREFIX}g++ ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
 export F77 = "${CCACHE}${HOST_PREFIX}g77 ${HOST_CC_ARCH}${TOOLCHAIN_OPTIONS}"
@@ -746,7 +745,7 @@ BB_CONSOLELOG ?= "${TMPDIR}/cooker.log.${DATETIME}"
 
 # Setup our default hash policy
 BB_SIGNATURE_HANDLER ?= "OEBasic"
-BB_HASHBASE_WHITELIST ?= "TMPDIR FILE PATH PWD BB_TASKHASH BBPATH DL_DIR SSTATE_DIR THISDIR FILESEXTRAPATHS FILE_DIRNAME HOME LOGNAME SHELL TERM USER FILESPATH STAGING_DIR_HOST STAGING_DIR_TARGET COREBASE PRSERV_HOST PRSERV_PORT PRSERV_DUMPDIR PRSERV_DUMPFILE PRSERV_LOCKDOWN PARALLEL_MAKE CCACHE_DIR EXTERNAL_TOOLCHAIN"
+BB_HASHBASE_WHITELIST ?= "TMPDIR FILE PATH PWD BB_TASKHASH BBPATH DL_DIR SSTATE_DIR THISDIR FILESEXTRAPATHS FILE_DIRNAME HOME LOGNAME SHELL TERM USER FILESPATH STAGING_DIR_HOST STAGING_DIR_TARGET COREBASE PRSERV_HOST PRSERV_PORT PRSERV_DUMPDIR PRSERV_DUMPFILE PRSERV_LOCKDOWN PARALLEL_MAKE CCACHE_DIR EXTERNAL_TOOLCHAIN CCACHE"
 BB_HASHCONFIG_WHITELIST ?= "${BB_HASHBASE_WHITELIST} DATE TIME SESSION_MANAGER DBUS_SESSION_BUS_ADDRESS SSH_AGENT_PID XDG_SESSION_COOKIE SSH_AUTH_SOCK XAUTHORITY"
 
 MLPREFIX ??= ""