From 1eaeee20fd802d6e4b757c86cf01a85bbe7ae7f1 Mon Sep 17 00:00:00 2001
From: Vihang Mehta <vihang@pixielabs.ai>
Date: Mon, 26 Jun 2023 11:39:24 -0700
Subject: [PATCH] Collect and maintain branch coverage (#1575)

Summary: gcov doesn't collect branch coverage by default and lcov
drops branch coverage from the files if it exists.
This change ensures that we maintain and track branch coverage.

Type of change: /kind cleanup

Test Plan: Ran the coverage build and then the coverage cleanup
script. Ensured that it now maintains branch coverage.

---------

Signed-off-by: Vihang Mehta <vihang@pixielabs.ai>
---
 .bazelrc               |  1 +
 .gitignore             |  3 +++
 ci/collect_coverage.sh | 22 ++++++++++++----------
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/.bazelrc b/.bazelrc
index 1ca15d116b1..481079770c2 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -226,6 +226,7 @@ coverage --instrument_test_targets
 coverage --define PL_COVERAGE=true
 coverage --copt -DPL_COVERAGE
 coverage --test_tag_filters=-requires_root,-requires_bpf,-no_coverage,-disabled,-no_gcc
+coverage --action_env=COVERAGE_GCOV_OPTIONS=-b
 
 
 try-import %workspace%/bes.bazelrc
diff --git a/.gitignore b/.gitignore
index 00679518f01..0b5d53bd0b9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,9 @@ user.bazelrc
 # A cache directory to be use by Bazel.
 .bazel-cache
 
+# Coverage output file
+coverage.info
+
 # Arc liberate cache
 .phutil_module_cache
 
diff --git a/ci/collect_coverage.sh b/ci/collect_coverage.sh
index 151a87c57f7..ff9fead1f6c 100755
--- a/ci/collect_coverage.sh
+++ b/ci/collect_coverage.sh
@@ -138,6 +138,8 @@ check_config
 # Print config parameters.
 print_config
 
+lcov_opts=(--rc lcov_branch_coverage=1)
+
 cd $(bazel info workspace)
 
 # Get coverage from bazel targets.
@@ -147,20 +149,20 @@ bazel coverage --remote_download_outputs=all --combined_report=lcov //src/...
 cp --no-preserve=mode "$(bazel info output_path)/_coverage/_coverage_report.dat" ${COVERAGE_FILE}
 
 # Print out the summary.
-lcov --summary ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" --summary ${COVERAGE_FILE}
 
 # Remove test files from the coverage files.
-lcov -r ${COVERAGE_FILE} '**/*_test.cc' -o ${COVERAGE_FILE}
-lcov -r ${COVERAGE_FILE} '**/*_mock.cc' -o ${COVERAGE_FILE}
-lcov -r ${COVERAGE_FILE} '**/*_mock.h' -o ${COVERAGE_FILE}
-lcov -r ${COVERAGE_FILE} '**/*_test.go' -o ${COVERAGE_FILE}
-lcov -r ${COVERAGE_FILE} '**/*.gen.go' -o ${COVERAGE_FILE}
-lcov -r ${COVERAGE_FILE} '**/*-mock.tsx' -o ${COVERAGE_FILE}
-lcov -r ${COVERAGE_FILE} '**/*-mock.ts' -o ${COVERAGE_FILE}
-lcov -r ${COVERAGE_FILE} 'src/ui/src/types/generated/**' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} '**/*_test.cc' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} '**/*_mock.cc' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} '**/*_mock.h' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} '**/*_test.go' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} '**/*.gen.go' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} '**/*-mock.tsx' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} '**/*-mock.ts' -o ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" -r ${COVERAGE_FILE} 'src/ui/src/types/generated/**' -o ${COVERAGE_FILE}
 
 # Print out the final summary.
-lcov --summary ${COVERAGE_FILE}
+lcov "${lcov_opts[@]}" --summary ${COVERAGE_FILE}
 
 # Upload to codecov.io.
 if [ "${UPLOAD_TO_CODECOV}" = true ]; then