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authorMike Crowe <mac@mcrowe.com>2017-03-15 12:29:16 +0000
committerRichard Purdie <richard.purdie@linuxfoundation.org>2017-03-17 16:52:44 +0000
commitfb7a5cdcff19bb44a25a51e20de0440c1ebcc057 (patch)
parent2815f819c1a620949213fa952557c03f7d594ed6 (diff)
ccache: Disable CCACHE_HASHDIR by default
As of ccache-3.3, ccache tries to ensure that the paths in the debug information are always correct. It does this by including the current directory in the hash if debug output is enabled. It includes support for detecting remapping via a single -fdebug-prefix-map argument uses the remapped directory in the hash instead. The DEBUG_PREFIX_MAP in bitbake.conf remaps the source directory, target sysroot and native sysroot separately which results in multiple -fdebug-prefix-map arguments. Although ccache passes all these arguments through to the compiler, it only enables the special behaviour described above if the last one matches the current directory. (See https://github.com/ccache/ccache/issues/163 ) Even if ccache did correctly honour each of the remapping arguments, the hashes would still be different every time ${PV} or ${PR} change because the default DEBUG_PREFIX_MAP contains maps to paths including them. So it seems that for ccache to be of any use with this configuration, CCACHE_NOHASHDIR needs to be set. Signed-off-by: Mike Crowe <mac@mcrowe.com> Helped-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
1 files changed, 6 insertions, 0 deletions
diff --git a/meta/classes/ccache.bbclass b/meta/classes/ccache.bbclass
index 76c8828..9713fea 100644
--- a/meta/classes/ccache.bbclass
+++ b/meta/classes/ccache.bbclass
@@ -2,6 +2,12 @@ CCACHE = "${@bb.utils.which(d.getVar('PATH'), 'ccache') and 'ccache '}"
export CCACHE_DIR ?= "${TMPDIR}/ccache/${MULTIMACH_HOST_SYS}/${PN}"
CCACHE_DISABLE[unexport] = "1"
+# We need to stop ccache considering the current directory or the
+# debug-prefix-map target directory to be significant when calculating
+# its hash. Without this the cache would be invalidated every time
+# ${PV} or ${PR} change.
+export CCACHE_NOHASHDIR ?= "1"
DEPENDS_append_class-target = " ccache-native"
DEPENDS[vardepvalueexclude] = " ccache-native"