[PATCH v3 1/3] meta: Support for ccache for custom packages

[Uladzimir Bely <ubely@ilbers.de>]

Add `USE_CCACHE = "1"` to local.conf to globally activate
the ccache functionality for dpkg-based recipes.
Add `USE_CCACHE = "0"` to the recipe to disable ccache for it
even if globaly enabled.

Signed-off-by: Uladzimir Bely <ubely@ilbers.de>
---
 meta-isar/conf/local.conf.sample                  | 5 +++++
 meta/classes/buildchroot.bbclass                  | 9 +++++++++
 meta/classes/dpkg.bbclass                         | 2 +-
 meta/conf/bitbake.conf                            | 5 +++++
 meta/recipes-devtools/buildchroot/buildchroot.inc | 1 +
 meta/recipes-devtools/buildchroot/files/build.sh  | 5 +++++
 meta/recipes-devtools/buildchroot/files/common.sh | 1 +
 7 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/meta-isar/conf/local.conf.sample b/meta-isar/conf/local.conf.sample
index 1ab640d0..42a69aed 100644
--- a/meta-isar/conf/local.conf.sample
+++ b/meta-isar/conf/local.conf.sample
@@ -227,3 +227,8 @@ USER_isar[flags] += "clear-text-password"
 
 # Uncomment the below line to debug WIC.
 # WIC_CREATE_EXTRA_ARGS += "-D"
+
+# Uncomment this to use ccache for custom packages
+#USE_CCACHE = "1"
+# Uncomment and set own top level ccache directory to share between builds
+#CCACHE_TOP_DIR ?= "${TMPDIR}/ccache"
diff --git a/meta/classes/buildchroot.bbclass b/meta/classes/buildchroot.bbclass
index e9eb9afa..dd8f4206 100644
--- a/meta/classes/buildchroot.bbclass
+++ b/meta/classes/buildchroot.bbclass
@@ -24,6 +24,10 @@ python __anonymous() {
 MOUNT_LOCKFILE = "${BUILDCHROOT_DIR}.lock"
 
 buildchroot_do_mounts() {
+    if [ "${USE_CCACHE}" = "1" ]; then
+        mkdir -p ${CCACHE_DIR}
+    fi
+
     sudo -s <<'EOSUDO'
         ( flock 9
         set -e
@@ -32,6 +36,11 @@ buildchroot_do_mounts() {
             mount --bind '${REPO_ISAR_DIR}/${DISTRO}' '${BUILDCHROOT_DIR}/isar-apt'
         mountpoint -q '${BUILDCHROOT_DIR}/downloads' ||
             mount --bind '${DL_DIR}' '${BUILDCHROOT_DIR}/downloads'
+        if [ "${USE_CCACHE}" = "1" ]; then
+            mkdir -p '${BUILDCHROOT_DIR}/ccache'
+            mountpoint -q '${BUILDCHROOT_DIR}/ccache' ||
+                mount --bind '${CCACHE_DIR}' '${BUILDCHROOT_DIR}/ccache'
+        fi
         mountpoint -q '${BUILDCHROOT_DIR}/dev' ||
             mount --rbind /dev '${BUILDCHROOT_DIR}/dev'
         mount --make-rslave '${BUILDCHROOT_DIR}/dev'
diff --git a/meta/classes/dpkg.bbclass b/meta/classes/dpkg.bbclass
index 4e7c2f77..86b47c28 100644
--- a/meta/classes/dpkg.bbclass
+++ b/meta/classes/dpkg.bbclass
@@ -33,5 +33,5 @@ dpkg_runbuild() {
     E="${@ isar_export_proxies(d)}"
     export PARALLEL_MAKE="${PARALLEL_MAKE}"
     sudo -E chroot --userspec=$( id -u ):$( id -g ) ${BUILDCHROOT_DIR} \
-         /isar/build.sh ${PP}/${PPS} ${PACKAGE_ARCH}
+         /isar/build.sh ${PP}/${PPS} ${PACKAGE_ARCH} ${USE_CCACHE}
 }
diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 7f5901d7..dce467b2 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -115,6 +115,11 @@ BBINCLUDELOGS ??= "yes"
 # Add event handlers for bitbake
 INHERIT += "isar-events"
 
+# Default values for ccache
+USE_CCACHE ??= "0"
+CCACHE_TOP_DIR ?= "${TMPDIR}/ccache"
+CCACHE_DIR ?= "${CCACHE_TOP_DIR}/${DISTRO}-${DISTRO_ARCH}"
+
 include conf/local.conf
 include conf/multiconfig/${BB_CURRENT_MC}.conf
 include conf/machine/${MACHINE}.conf
diff --git a/meta/recipes-devtools/buildchroot/buildchroot.inc b/meta/recipes-devtools/buildchroot/buildchroot.inc
index 31524a11..726c7bbd 100644
--- a/meta/recipes-devtools/buildchroot/buildchroot.inc
+++ b/meta/recipes-devtools/buildchroot/buildchroot.inc
@@ -32,6 +32,7 @@ BUILDCHROOT_PREINSTALL_COMMON = " \
     make \
     debhelper \
     autotools-dev \
+    ccache \
     dpkg \
     locales \
     docbook-to-man \
diff --git a/meta/recipes-devtools/buildchroot/files/build.sh b/meta/recipes-devtools/buildchroot/files/build.sh
index 101581db..8e6507c6 100644
--- a/meta/recipes-devtools/buildchroot/files/build.sh
+++ b/meta/recipes-devtools/buildchroot/files/build.sh
@@ -14,4 +14,9 @@ for i in configure aclocal.m4 Makefile.am Makefile.in; do
     fi
 done
 
+if [ "$use_ccache" == "1" ]; then
+    export CCACHE_DIR=/ccache
+    export PATH=/usr/lib/ccache:$PATH
+fi
+
 ${GBP_PREFIX}dpkg-buildpackage -a$target_arch -d --source-option=-I
diff --git a/meta/recipes-devtools/buildchroot/files/common.sh b/meta/recipes-devtools/buildchroot/files/common.sh
index 0063a38e..7085f443 100644
--- a/meta/recipes-devtools/buildchroot/files/common.sh
+++ b/meta/recipes-devtools/buildchroot/files/common.sh
@@ -17,6 +17,7 @@ fi
 
 # Create human-readable names
 target_arch=$2
+use_ccache=$3
 
 set_arch="--host-arch $target_arch"
 
-- 
2.20.1