CI: Include coverage data of code which isn't executed by the test suite.

See comment in !151. Using the "--initial" option of lcov we collect
the coverage of all compiled files and merge them later into the final
report. This way we can see which files are built but never executed
by the test suite.

Because the --initial switch also collects files in the ccache directory
we have to point it to the build directory instead, which in turn breaks
--no-external. Instead of using --no-external in the collection step,
filter out any files not in the source tree in the final coverage job
through a path filter.

.gitlab-ci.yml

@@ -21,9 +21,10 @@ fedora-x86_64:
   script:
     - meson --buildtype debug --werror -Dsystemtap=true -Ddtrace=true -Dfam=true _build .
     - ninja -C _build
-    - meson test -C _build --timeout-multiplier ${MESON_TEST_TIMEOUT_MULTIPLIER}
     - mkdir -p _coverage
-    - lcov --rc lcov_branch_coverage=1 --directory . --capture --no-external --output-file "_coverage/${CI_JOB_NAME}.lcov"
+    - lcov --rc lcov_branch_coverage=1 --directory _build --capture --initial --output-file "_coverage/${CI_JOB_NAME}-baseline.lcov"
+    - meson test -C _build --timeout-multiplier ${MESON_TEST_TIMEOUT_MULTIPLIER}
+    - lcov --rc lcov_branch_coverage=1 --directory _build --capture --output-file "_coverage/${CI_JOB_NAME}.lcov"
   artifacts:
     name: "glib-${CI_JOB_NAME}-${CI_COMMIT_REF_NAME}"
     when: always

.gitlab-ci/coverage-docker.sh

@@ -5,9 +5,11 @@ set -e
 # Fixup Windows paths
 python3 ./.gitlab-ci/fixup-cov-paths.py _coverage/*.lcov
 
-# Remove coverage from generated code in the build directory
 for path in _coverage/*.lcov; do
+    # Remove coverage from generated code in the build directory
     lcov --rc lcov_branch_coverage=1 -r "${path}" '*/_build/*' -o "$(pwd)/${path}"
+    # Remove any coverage from system files
+    lcov --rc lcov_branch_coverage=1 -e "${path}" "$(pwd)/*" -o "$(pwd)/${path}"
 done
 
 genhtml \

.gitlab-ci/test-msys2.sh

@@ -23,29 +23,38 @@ pacman --noconfirm -S --needed \
     mingw-w64-$MSYS2_ARCH-toolchain \
     mingw-w64-$MSYS2_ARCH-zlib
 
+curl -O -J -L "https://github.com/linux-test-project/lcov/releases/download/v1.13/lcov-1.13.tar.gz"
+echo "44972c878482cc06a05fe78eaa3645cbfcbad6634615c3309858b207965d8a23  lcov-1.13.tar.gz" | sha256sum -c
+tar -xzf lcov-1.13.tar.gz
+LCOV="$(pwd)/lcov-1.13/bin/lcov"
+
+mkdir -p _coverage
 mkdir -p _ccache
 export CCACHE_BASEDIR="$(pwd)"
 export CCACHE_DIR="${CCACHE_BASEDIR}/_ccache"
 pip3 install --upgrade --user meson
 export PATH="$HOME/.local/bin:$PATH"
 export CFLAGS="-coverage -ftest-coverage -fprofile-arcs"
+DIR="$(pwd)"
 
 meson --werror --buildtype debug _build
 cd _build
 ninja
 
+"${LCOV}" \
+    --quiet \
+    --rc lcov_branch_coverage=1 \
+    --directory "${DIR}/_build" \
+    --capture \
+    --initial \
+    --output-file "${DIR}/_coverage/${CI_JOB_NAME}-baseline.lcov"
+
 # FIXME: fix the test suite
 meson test --timeout-multiplier ${MESON_TEST_TIMEOUT_MULTIPLIER} || true
 
-cd ..
-curl -O -J -L "https://github.com/linux-test-project/lcov/releases/download/v1.13/lcov-1.13.tar.gz"
-echo "44972c878482cc06a05fe78eaa3645cbfcbad6634615c3309858b207965d8a23  lcov-1.13.tar.gz" | sha256sum -c
-tar -xvzf lcov-1.13.tar.gz
-
-mkdir -p _coverage
-./lcov-1.13/bin/lcov \
+"${LCOV}" \
+    --quiet \
     --rc lcov_branch_coverage=1 \
-    --directory . \
+    --directory "${DIR}/_build" \
     --capture \
-    --no-external \
-    --output-file "_coverage/${CI_JOB_NAME}.lcov"
+    --output-file "${DIR}/_coverage/${CI_JOB_NAME}.lcov"