ci: add an ABI check job

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7875>

.gitlab-ci.yml

@@ -37,6 +37,7 @@ variables:
   INDENT_AMD64_SUFFIX: 'amd64/gst-indent'
   COMMITLINT_AMD64_SUFFIX: 'amd64/commitlint'
   WINDOWS_AMD64_SUFFIX: 'amd64/windows'
+  ABI_CHECK_AMD64_SUFFIX: 'amd64/abi-check'
 
   WINDOWS_IMAGE: "$CI_REGISTRY_IMAGE/$WINDOWS_AMD64_SUFFIX:$WINDOWS_TAG-$GST_UPSTREAM_BRANCH"
   WINDOWS_UPSTREAM_IMAGE: "$CI_REGISTRY/$FDO_UPSTREAM_REPO/$WINDOWS_AMD64_SUFFIX:$WINDOWS_TAG-$GST_UPSTREAM_BRANCH"
@@ -263,6 +264,28 @@ windows amd64 docker:
   tags:
     - gst-mac-arm
 
+.abi-check image:
+  variables:
+    CCACHE_DIR: !reference [".fedora image", "variables", CCACHE_DIR]
+    FDO_DISTRIBUTION_VERSION: !reference [".fedora image", "variables", FDO_DISTRIBUTION_VERSION]
+    FDO_REPO_SUFFIX: !reference [".fedora image", "variables", FDO_REPO_SUFFIX]
+    FDO_BASE_IMAGE: '$CI_REGISTRY_IMAGE/$FDO_REPO_SUFFIX:$FEDORA_TAG-$GST_UPSTREAM_BRANCH'
+    FDO_DISTRIBUTION_TAG: "abi-check-$ABI_CHECK_TAG-$GST_UPSTREAM_BRANCH"
+    FDO_DISTRIBUTION_PACKAGES: 'libabigail'
+    FDO_DISTRIBUTION_EXEC: 'GIT_BRANCH=$CI_COMMIT_REF_NAME GIT_URL=$CI_REPOSITORY_URL bash ci/docker/abi-check/prepare.sh'
+    ABI_CHECK_CACHE: '/abi-check-cache'
+
+abi-check docker:
+  # placeholder-job has very minimal CPU available and may overrun the job
+  # timeout if an image rebuild (which builds GStreamer) needs to be performed.
+  #tags: [ 'placeholder-job' ]
+  stage: 'preparation'
+  extends:
+    - '.abi-check image'
+    - '.fdo.container-build@fedora'
+  needs:
+    - 'fedora amd64 docker'
+
 # ---- Preparation ----- #
 #
 # gst-indent!!
@@ -701,6 +724,26 @@ build macos:
           -Dgst-plugins-good:cairo=enabled
           -Dgst-plugins-good:soup=enabled
 
+abi-check:
+  stage: 'build'
+  extends:
+    - '.abi-check image'
+    - '.fdo.suffixed-image@fedora'
+    - '.build'
+  needs:
+    - "trigger"
+    - 'abi-check docker'
+  script:
+    - $CI_PROJECT_DIR/ci/scripts/abi-check.sh build/
+  variables:
+    ABI_CHECK_DIR: 'abi-dumps'
+  artifacts:
+    expire_in: "7 days"
+    when: "always"
+    paths:
+      - 'meson-logs/'
+      - '$ABI_CHECK_DIR'
+
 # ---- Tests ----- #
 
 .test:

.gitlab-image-tags.yml

@@ -13,4 +13,6 @@ variables:
 
   LINT_TAG: '2024-02-20.0'
 
+  ABI_CHECK_TAG: '2024-11-18.0'
+
   WINDOWS_TAG: '2024-11-12.0'

ci/docker/abi-check/install-abi-check-cache.sh

@@ -0,0 +1,13 @@
+#! /bin/bash
+
+set -eux
+
+meson_args="${MESON_ARGS:-}"
+
+install_prefix=/tmp/install
+MESON_ARGS="${meson_args} --prefix ${install_prefix} --optimization=g" ./ci/scripts/build.sh build/
+ninja -C build/ install
+
+find ${install_prefix}/lib64 -type f -iname *libgst*.so.* -print0 | xargs -0 -I '{}' bash ./ci/scripts/save-abi.sh {} ${ABI_CHECK_CACHE}
+
+rm -rf $install_prefix

ci/docker/abi-check/prepare.sh

@@ -0,0 +1,5 @@
+#! /bin/bash
+
+set -eux
+
+bash ./ci/docker/abi-check/install-abi-check-cache.sh

ci/scripts/abi-check.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+set -eux
+
+builddir="$1"
+
+meson_args="${MESON_ARGS:-}"
+
+if [[ -z "$builddir" ]]; then
+  echo "Usage: build.sh <build_directory>"
+  exit 1
+fi
+
+echo ${ABI_CHECK_CACHE}
+echo ${ABI_CHECK_DIR}
+
+# nproc works on linux
+# sysctl for macos
+_jobs=$(nproc || sysctl -n hw.ncpu)
+jobs="${FDO_CI_CONCURRENT:-$_jobs}"
+
+install_prefix=/tmp/install
+MESON_ARGS="${meson_args} --prefix ${install_prefix} --optimization=g" ./ci/scripts/build.sh build/
+ninja -C $builddir install
+
+find ${install_prefix}/lib64 -type f -iname *libgst*.so.* -print0 | xargs -0 -I '{}' bash ${CI_PROJECT_DIR}/ci/scripts/save-abi.sh {} ${ABI_CHECK_DIR}
+
+fail_file=abi-compare-failure
+if ! find ${ABI_CHECK_CACHE} -type f -print0 | xargs -0 -I '{}' bash ${CI_PROJECT_DIR}/ci/scripts/compare-abi.sh {} ${CI_PROJECT_DIR}/${ABI_CHECK_DIR}/ ${fail_file}
+then
+  echo ABI comparison failed for the following modules!
+  cat ${fail_file}
+  rm -rf $install_prefix
+  exit 1;
+fi
+
+rm -rf $install_prefix

ci/scripts/compare-abi.sh

@@ -0,0 +1,24 @@
+#! /bin/bash
+
+set -eux
+
+old_abi=${1}
+output_dir=${2}
+output_fail_file=${3}
+upstream_branch=${GST_UPSTREAM_BRANCH:-}
+
+module=$(basename ${old_abi})
+
+opts="--drop-private-types"
+if [ "x$upstream_branch" = "xmain" ]
+then
+  # don't error out on added symbols
+  opts="${opts} --no-added-syms"
+fi
+
+mkdir -p ${output_dir}
+if ! abidiff ${opts} ${old_abi} ${output_dir}/${module}
+then
+  echo ${module} >> ${output_fail_file}
+  exit 1;
+fi

ci/scripts/save-abi.sh

@@ -0,0 +1,10 @@
+#! /bin/bash
+
+set -eux
+
+filename=${1}
+output_dir=${2}
+module=$(basename ${filename} | cut -f1,2 -d'.')
+
+mkdir -p ${output_dir}
+abidw -o ${output_dir}/${module}.abi --drop-private-types ${filename}