[PATCH v3 20/20] sbuild: add ccache support

[Uladzimir Bely <ubely@ilbers.de>]

This adds ccache support for custom packages in the same manner
as it was done previously for buildchroot-based build, by using
USE_CCACHE variable in local.conf or per-recipe.

Signed-off-by: Uladzimir Bely <ubely@ilbers.de>
---
 meta/classes/dpkg.bbclass                     |  4 ++++
 meta/classes/sbuild.bbclass                   | 22 +++++++++++++++++++
 .../sbuild-chroot/sbuild-chroot.inc           |  1 +
 3 files changed, 27 insertions(+)

diff --git a/meta/classes/dpkg.bbclass b/meta/classes/dpkg.bbclass
index 85bb1300..e68605ef 100644
--- a/meta/classes/dpkg.bbclass
+++ b/meta/classes/dpkg.bbclass
@@ -27,6 +27,10 @@ dpkg_runbuild() {
             echo '$apt_keep_downloaded_packages = 1;' >> ${SCHROOT_USER_HOME}/.sbuildrc
     ) 9>"${TMPDIR}/sbuildrc.lock"
 
+    if [ ${USE_CCACHE} -eq 1 ]; then
+        schroot_configure_ccache
+    fi
+
     sbuild -A -n -c ${SBUILD_CHROOT} --extra-repository="${ISAR_APT_REPO}" \
         --host=${PACKAGE_ARCH} --build=${SBUILD_HOST_ARCH} \
         --starting-build-commands="runuser -u ${SCHROOT_USER} -- sh -c \"${SBUILD_PREBUILD:-:}\"" \
diff --git a/meta/classes/sbuild.bbclass b/meta/classes/sbuild.bbclass
index 0df8cb90..54ae8550 100644
--- a/meta/classes/sbuild.bbclass
+++ b/meta/classes/sbuild.bbclass
@@ -160,3 +160,25 @@ schroot_run() {
     remove_mounts
     schroot_delete_configs
 }
+
+schroot_configure_ccache() {
+    sudo -s <<'EOSUDO'
+        set -e
+
+        sbuild_fstab="${SBUILD_CONF_DIR}/fstab"
+
+        install --group=sbuild --mode=2775 -d ${CCACHE_DIR}
+        fstab_ccachedir="${CCACHE_DIR} /ccache none rw,bind 0 0"
+        grep -qxF "${fstab_ccachedir}" ${sbuild_fstab} || echo "${fstab_ccachedir}" >> ${sbuild_fstab}
+
+        cat << END > ${CCACHE_DIR}/sbuild-setup
+#!/bin/sh
+export CCACHE_DIR=/ccache
+export PATH="/usr/lib/ccache:\$PATH"
+exec "\$@"
+END
+        chmod a+rx ${CCACHE_DIR}/sbuild-setup
+
+        echo "command-prefix=/ccache/sbuild-setup" >> "${SCHROOT_CONF_FILE}"
+EOSUDO
+}
diff --git a/meta/recipes-devtools/sbuild-chroot/sbuild-chroot.inc b/meta/recipes-devtools/sbuild-chroot/sbuild-chroot.inc
index 7b41d11d..4688da1d 100644
--- a/meta/recipes-devtools/sbuild-chroot/sbuild-chroot.inc
+++ b/meta/recipes-devtools/sbuild-chroot/sbuild-chroot.inc
@@ -14,6 +14,7 @@ SBUILD_CHROOT_PREINSTALL_COMMON = " \
     fakeroot \
     build-essential \
     debhelper \
+    ccache \
     devscripts \
     equivs \
 "
-- 
2.20.1