[PATCH v3 5/5] dpkg-source: Build source package only once

[Jan Kiszka <jan.kiszka@siemens.com>]

From: Jan Kiszka <jan.kiszka@siemens.com>

Avoid building the source package multiple times, possibly even
inconsistently. This is achieved by delegating this task to to the base
package and installing the source package from isar-apt in the native
and compat package variants. Those derived packages will also no longer
trigger fetching, unpacking or prepare_build as everything is supposed
to be in the source package.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 meta/classes/dpkg-base.bbclass     |  4 +--
 meta/classes/dpkg-prebuilt.bbclass |  7 ++----
 meta/classes/dpkg-source.bbclass   | 40 ++++++++++++++++++++++++++++--
 meta/classes/dpkg.bbclass          |  3 ++-
 4 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/meta/classes/dpkg-base.bbclass b/meta/classes/dpkg-base.bbclass
index 93321976..789d6c74 100644
--- a/meta/classes/dpkg-base.bbclass
+++ b/meta/classes/dpkg-base.bbclass
@@ -78,7 +78,7 @@ addtask adjust_git after do_unpack before do_patch
 do_adjust_git[lockfiles] += "${DL_DIR}/git/isar.lock"
 
 inherit patch
-addtask patch after do_adjust_git before do_dpkg_build
+addtask patch after do_adjust_git
 
 SRC_APT ?= ""
 
@@ -191,7 +191,7 @@ do_prepare_build() {
     true
 }
 
-addtask prepare_build after do_patch do_transform_template before do_dpkg_build
+addtask prepare_build after do_patch do_transform_template
 # If Isar recipes depend on each other, they typically need the package
 # deployed to isar-apt
 do_local_isarapt[depends] += "isar-apt:do_cache_config"
diff --git a/meta/classes/dpkg-prebuilt.bbclass b/meta/classes/dpkg-prebuilt.bbclass
index 8135fc81..7092670b 100644
--- a/meta/classes/dpkg-prebuilt.bbclass
+++ b/meta/classes/dpkg-prebuilt.bbclass
@@ -16,11 +16,8 @@ python do_unpack:prepend() {
     d.setVar('SRC_URI', ' '.join(src_uri))
 }
 
-# break dependencies on do_patch, etc... but still support sstate caching
-deltask dpkg_build
-addtask dpkg_build after do_unpack before do_deploy_deb
-# break inherited (from dpkg-base) dependency on sbuild_chroot
-do_dpkg_build[depends] = ""
+# also breaks inherited (from dpkg-base) dependency on sbuild_chroot
+do_dpkg_build[depends] = "${PN}:do_unpack"
 do_dpkg_build() {
     true
 }
diff --git a/meta/classes/dpkg-source.bbclass b/meta/classes/dpkg-source.bbclass
index 560f536b..d6ab5aad 100644
--- a/meta/classes/dpkg-source.bbclass
+++ b/meta/classes/dpkg-source.bbclass
@@ -18,7 +18,7 @@ do_dpkg_source() {
     find ${WORKDIR} -maxdepth 1 -name "${DEBIAN_SOURCE}_*.dsc" -delete
     sh -c "cd ${WORKDIR}; dpkg-source ${DPKG_SOURCE_EXTRA_ARGS} -b ${PPS}"
 }
-addtask dpkg_source after do_prepare_build before do_dpkg_build
+addtask dpkg_source after do_prepare_build
 
 do_deploy_source[depends] += "isar-apt:do_cache_config"
 do_deploy_source[lockfiles] = "${REPO_ISAR_DIR}/isar.lock"
@@ -34,4 +34,40 @@ do_deploy_source() {
             "${DSC_FILE}"
     fi
 }
-addtask deploy_source after do_dpkg_source before do_dpkg_build
+addtask deploy_source after do_dpkg_source
+
+do_dpkg_build[depends] += "${BPN}:do_deploy_source"
+
+SCHROOT_MOUNTS = "${WORKDIR}:/work ${REPO_ISAR_DIR}/${DISTRO}:/isar-apt"
+
+do_fetch_common_source[depends] += "${SCHROOT_DEP} ${BPN}:do_deploy_source"
+do_fetch_common_source[network] = "${TASK_USE_SUDO}"
+do_fetch_common_source() {
+    schroot_create_configs
+    insert_mounts
+
+    session_id=$(schroot -q -b -c ${SBUILD_CHROOT})
+    echo "Started session: ${session_id}"
+
+    schroot_cleanup() {
+        schroot -q -f -e -c ${session_id} > /dev/null 2>&1
+        remove_mounts > /dev/null 2>&1
+        schroot_delete_configs
+    }
+    trap 'exit 1' INT HUP QUIT TERM ALRM USR1
+    trap 'schroot_cleanup' EXIT
+
+    schroot -r -c ${session_id} -d / -u root -- \
+        apt-get update -o Dir::Etc::SourceList="sources.list.d/isar-apt.list" -o Dir::Etc::SourceParts="-" -o APT::Get::List-Cleanup="0"
+    schroot -r -c ${session_id} -d / -- \
+        sh -c '
+            cd /work
+            apt-get -y --download-only --only-source -o Acquire::Source-Symlinks="false" source ${DEBIAN_SOURCE}'
+
+    schroot -e -c ${session_id}
+    remove_mounts
+    schroot_delete_configs
+}
+addtask fetch_common_source
+
+do_dpkg_build[depends] += "${@'${PN}:do_dpkg_source' if '${PN}' == '${BPN}' else '${PN}:do_fetch_common_source'}"
diff --git a/meta/classes/dpkg.bbclass b/meta/classes/dpkg.bbclass
index 804fe5a6..d92ff68c 100644
--- a/meta/classes/dpkg.bbclass
+++ b/meta/classes/dpkg.bbclass
@@ -24,9 +24,10 @@ def expand_sbuild_pt_additions(d):
             cmds += 'sbuild_export ' + var + ' "' + varval + '"\n'
     return cmds
 
-do_prepare_build:append() {
+do_get_reference_env() {
     env > ${DPKG_PREBUILD_ENV_FILE}
 }
+addtask get_reference_env before do_dpkg_build
 
 # cp -n results in nonzero exit code starting from coreutils 9.2
 # and starting from 9.3 we can use --update=none for the same behaviour
-- 
2.35.3