coverage tool support

.bazelrc

@@ -4,4 +4,22 @@ build --copt="-Wall"
 build --copt="-Werror"
 build:windows --copt=/wd4716
 
+# Coverage options
+coverage --config=coverage
+coverage --build_tests_only
+build:coverage --action_env=BAZEL_USE_LLVM_NATIVE_COVERAGE=1
+build:coverage --action_env=GCOV=llvm-profdata
+build:coverage --combined_report=lcov
+build:coverage --experimental_use_llvm_covmap
+build:coverage --experimental_generate_llvm_lcov
+build:coverage --collect_code_coverage
+build:coverage --instrumentation_filter="//source[/:],//cpp2sky[/:]"
+build:coverage --coverage_support=@cpp2sky//bazel/coverage:coverage_support
+build:coverage --test_env=CC_CODE_COVERAGE_SCRIPT=external/cpp2sky/bazel/coverage/collect_cc_coverage.sh
+build:coverage --strategy=TestRunner=local
+build:coverage --strategy=CoverageReport=local
+build:coverage --experimental_use_llvm_covmap
+build:coverage --collect_code_coverage
+build:coverage --test_tag_filters=-nocoverage
+
 try-import %workspace%/user.bazelrc

.bazelversion

@@ -1 +1 @@
-3.7.2
+4.0.0

.gitignore

@@ -44,4 +44,6 @@ user.bazelrc
 .vscode/
 
 .clangd/
-compile_commands.json
+compile_commands.json
+
+coverage_report

bazel/coverage/BUILD

@@ -0,0 +1,6 @@
+licenses(["notice"])  # Apache 2
+
+filegroup(
+    name = "coverage_support",
+    srcs = ["collect_cc_coverage.sh"],
+)

bazel/coverage/collect_cc_coverage.sh

@@ -0,0 +1,208 @@
+#!/bin/bash -x
+# This is fork from https://raw.githubusercontent.com/bazelbuild/bazel/master/tools/test/collect_cc_coverage.sh
+
+# Copyright 2016 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This script collects code coverage data for C++ sources, after the tests
+# were executed.
+#
+# Bazel C++ code coverage collection support is poor and limited. There is
+# an ongoing effort to improve this (tracking issue #1118).
+#
+# Bazel uses the lcov tool for gathering coverage data. There is also
+# an experimental support for clang llvm coverage, which uses the .profraw
+# data files to compute the coverage report.
+#
+# This script assumes the following environment variables are set:
+# - COVERAGE_DIR            Directory containing metadata files needed for
+#                           coverage collection (e.g. gcda files, profraw).
+# - COVERAGE_MANIFEST       Location of the instrumented file manifest.
+# - COVERAGE_GCOV_PATH      Location of gcov. This is set by the TestRunner.
+# - COVERAGE_GCOV_OPTIONS   Additional options to pass to gcov.
+# - ROOT                    Location from where the code coverage collection
+#                           was invoked.
+#
+# The script looks in $COVERAGE_DIR for the C++ metadata coverage files (either
+# gcda or profraw) and uses either lcov or gcov to get the coverage data.
+# The coverage data is placed in $COVERAGE_OUTPUT_FILE.
+
+# Checks if clang llvm coverage should be used instead of lcov.
+function uses_llvm() {
+  if stat "${COVERAGE_DIR}"/*.profraw >/dev/null 2>&1; then
+    return 0
+  fi
+  return 1
+}
+
+# Returns 0 if gcov must be used, 1 otherwise.
+function uses_gcov() {
+  [[ "$GCOV_COVERAGE" -eq "1"  ]] && return 0
+  return 1
+}
+
+function init_gcov() {
+  # Symlink the gcov tool such with a link called gcov. Clang comes with a tool
+  # called llvm-cov, which behaves like gcov if symlinked in this way (otherwise
+  # we would need to invoke it with "llvm-cov gcov").
+  # For more details see https://llvm.org/docs/CommandGuide/llvm-cov.html.
+  GCOV="${COVERAGE_DIR}/gcov"
+  if [ ! -f "${COVERAGE_GCOV_PATH}" ]; then
+    echo "GCov does not exist at the given path: '${COVERAGE_GCOV_PATH}'"
+    exit 1
+  fi
+  # When using a tool from a toolchain COVERAGE_GCOV_PATH will be a relative
+  # path. To make it work on different working directories it's required to
+  # convert the path to an absolute one.
+  COVERAGE_GCOV_PATH_ABS="$(cd "${COVERAGE_GCOV_PATH%/*}" && pwd)/${COVERAGE_GCOV_PATH##*/}"
+  ln -s "${COVERAGE_GCOV_PATH_ABS}" "${GCOV}"
+}
+
+# Computes code coverage data using the clang generated metadata found under
+# $COVERAGE_DIR.
+# Writes the collected coverage into the given output file.
+function llvm_coverage_lcov() {
+  local output_file="${1}"; shift
+  export LLVM_PROFILE_FILE="${COVERAGE_DIR}/%h-%p-%m.profraw"
+  "${COVERAGE_GCOV_PATH}" merge -output "${output_file}.data" \
+      "${COVERAGE_DIR}"/*.profraw
+
+  local object_param=""
+  while read -r line; do
+    if [[ ${line: -24} == "runtime_objects_list.txt" ]]; then
+      while read -r line_runtime_object; do
+          if [[ ${line_runtime_object} == *"absl"* ]]; then
+            continue
+          fi
+          object_param+=" -object ${RUNFILES_DIR}/${TEST_WORKSPACE}/${line_runtime_object}"
+      done < "${line}"
+    fi
+  done < "${COVERAGE_MANIFEST}"
+
+  "${LLVM_COV}" export -instr-profile "${output_file}.data" -format=lcov \
+      -ignore-filename-regex='.*external/.+' \
+      -ignore-filename-regex='/tmp/.+' \
+      ${object_param} | sed 's#/proc/self/cwd/##' > "${output_file}"
+}
+
+function llvm_coverage_profdata() {
+  local output_file="${1}"; shift
+  export LLVM_PROFILE_FILE="${COVERAGE_DIR}/%h-%p-%m.profraw"
+  "${COVERAGE_GCOV_PATH}" merge -output "${output_file}" \
+      "${COVERAGE_DIR}"/*.profraw
+}
+
+# Generates a code coverage report in gcov intermediate text format by invoking
+# gcov and using the profile data (.gcda) and notes (.gcno) files.
+#
+# The profile data files are expected to be found under $COVERAGE_DIR.
+# The notes file are expected to be found under $ROOT.
+#
+# - output_file     The location of the file where the generated code coverage
+#                   report is written.
+function gcov_coverage() {
+  local output_file="${1}"; shift
+
+  # We'll save the standard output of each the gcov command in this log.
+  local gcov_log="$output_file.gcov.log"
+
+  # Copy .gcno files next to their corresponding .gcda files in $COVERAGE_DIR
+  # because gcov expects them to be in the same directory.
+  while read -r line; do
+    if [[ ${line: -4} == "gcno" ]]; then
+      gcno_path=${line}
+      local gcda="${COVERAGE_DIR}/$(dirname ${gcno_path})/$(basename ${gcno_path} .gcno).gcda"
+      # If the gcda file was not found we skip generating coverage from the gcno
+      # file.
+      if [[ -f "$gcda" ]]; then
+          # gcov expects both gcno and gcda files to be in the same directory.
+          # We overcome this by copying the gcno to $COVERAGE_DIR where the gcda
+          # files are expected to be.
+          if [ ! -f "${COVERAGE_DIR}/${gcno_path}" ]; then
+              mkdir -p "${COVERAGE_DIR}/$(dirname ${gcno_path})"
+              cp "$ROOT/${gcno_path}" "${COVERAGE_DIR}/${gcno_path}"
+          fi
+          # Invoke gcov to generate a code coverage report with the flags:
+          # -i              Output gcov file in an intermediate text format.
+          #                 The output is a single .gcov file per .gcda file.
+          #                 No source code is required.
+          # -o directory    The directory containing the .gcno and
+          #                 .gcda data files.
+          # "${gcda"}       The input file name. gcov is looking for data files
+          #                 named after the input filename without its extension.
+          # gcov produces files called <source file name>.gcov in the current
+          # directory. These contain the coverage information of the source file
+          # they correspond to. One .gcov file is produced for each source
+          # (or header) file containing code which was compiled to produce the
+          # .gcda files.
+          # Don't generate branch coverage (-b) because of a gcov issue that
+          # segfaults when both -i and -b are used (see
+          # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84879).
+          "${GCOV}" -i $COVERAGE_GCOV_OPTIONS -o "$(dirname ${gcda})" "${gcda}"
+
+          # Extract gcov's version: the output of `gcov --version` contains the
+          # version as a set of major-minor-patch numbers, of which we extract
+          # the major version.
+          gcov_major_version=$("${GCOV}" --version | sed -n -E -e 's/^.*\s([0-9]+)\.[0-9]+\.[0-9]+\s?.*$/\1/p')
+
+          # Check the gcov version so we can process the data correctly
+          if [[ $gcov_major_version -ge 9 ]]; then
+              # gcov 9 or higher use a JSON based format for their coverage reports.
+              # The output is generated into multiple files: "$(basename ${gcda}).gcov.json.gz"
+              # Concatenating JSON documents does not yield a valid document, so they are moved individually
+              mv -- *.gcov.json.gz "$(dirname "$output_file")"
+          else
+              # Append all .gcov files in the current directory to the output file.
+              cat -- *.gcov >> "$output_file"
+              # Delete the .gcov files.
+              rm -- *.gcov
+          fi
+      fi
+    fi
+  done < "${COVERAGE_MANIFEST}"
+}
+
+function main() {
+  init_gcov
+
+  # If llvm code coverage is used, we output the raw code coverage report in
+  # the $COVERAGE_OUTPUT_FILE. This report will not be converted to any other
+  # format by LcovMerger.
+  # TODO(#5881): Convert profdata reports to lcov.
+  if uses_llvm; then
+    if [[ "${GENERATE_LLVM_LCOV}" == "1" ]]; then
+        BAZEL_CC_COVERAGE_TOOL="LLVM_LCOV"
+    else
+        BAZEL_CC_COVERAGE_TOOL="PROFDATA"
+    fi
+  fi
+
+  # When using either gcov or lcov, have an output file specific to the test
+  # and format used. For lcov we generate a ".dat" output file and for gcov
+  # a ".gcov" output file. It is important that these files are generated under
+  # COVERAGE_DIR.
+  # When this script is invoked by tools/test/collect_coverage.sh either of
+  # these two coverage reports will be picked up by LcovMerger and their
+  # content will be converted and/or merged with other reports to an lcov
+  # format, generating the final code coverage report.
+  case "$BAZEL_CC_COVERAGE_TOOL" in
+        ("GCOV") gcov_coverage "$COVERAGE_DIR/_cc_coverage.gcov" ;;
+        ("PROFDATA") llvm_coverage_profdata "$COVERAGE_DIR/_cc_coverage.profdata" ;;
+        ("LLVM_LCOV") llvm_coverage_lcov "$COVERAGE_DIR/_cc_coverage.dat" ;;
+        (*) echo "Coverage tool $BAZEL_CC_COVERAGE_TOOL not supported" \
+            && exit 1
+  esac
+}
+
+main

coverage.sh

@@ -0,0 +1,75 @@
+#!/bin/bash
+
+set -e
+#set -x
+
+[[ -z "${SRCDIR}" ]] && SRCDIR="${PWD}"
+
+OUTPUT_DIR="./coverage_report/"
+DATA_DIR="${SRCDIR}/bazel-testlogs/"
+PROJECT=`basename "${SRCDIR}"`
+
+# This is the target that will be run to generate coverage data. It can be overridden by consumer
+# projects that want to run coverage on a different/combined target.
+# Command-line arguments take precedence over ${COVERAGE_TARGET}.
+if [[ $# -gt 0 ]]; then
+  COVERAGE_TARGETS=$*
+elif [[ -n "${COVERAGE_TARGET}" ]]; then
+  COVERAGE_TARGETS=${COVERAGE_TARGET}
+else
+  COVERAGE_TARGETS=//test/...
+fi
+
+
+echo "Starting gen_coverage.sh..."
+echo "    PWD=$(pwd)"
+echo "    OUTPUT_DIR=${OUTPUT_DIR}"
+echo "    DATA_DIR=${DATA_DIR}"
+echo "    TARGETS=${COVERAGE_TARGETS}"
+
+function gen_coverage_data() {
+    echo "Generating coverage data..."
+    bazel coverage "$1" --test_output=errors
+}
+
+function purge_files() {
+    local src_files="$1"
+    local purge_files="$2"
+
+    for file in ${src_files}
+    do
+        if [ -s "${file}" ] ; then
+            mv "${file}" "${file}".bak
+            lcov --remove "${file}".bak "${purge_files}" -o "${file}"
+            chmod 777 "${file}"
+        fi
+    done
+}
+
+function gen_report() {
+    echo "Generating report..."
+
+    local output_directory="$1"
+
+    # The location where coverage.dat files were stored
+    path="${DATA_DIR}"
+
+    datfiles=$(find ${path} -name "coverage.dat")
+
+    purge_files ${datfiles} "pb.h pb.cc"
+
+    find ${path} -name "coverage.dat" -size 0 -delete
+
+    datfiles=$(find ${path} -name "coverage.dat")
+
+    # add --branch-coverage to show branch coverage
+    genhtml --title ${PROJECT} --ignore-errors "source" ${datfiles} -o "${OUTPUT_DIR}"
+    tar -zcf ${PROJECT}_coverage.tar.gz ${OUTPUT_DIR}
+    mv ${PROJECT}_coverage.tar.gz ${OUTPUT_DIR}
+
+    echo "HTML coverage report is in ${OUTPUT_DIR}/index.html"
+    echo "All coverage report files are in ${OUTPUT_DIR}/${PROJECT}_coverage.tar.gz"
+}
+
+gen_coverage_data ${COVERAGE_TARGETS}
+gen_report ${OUTPUT_DIR}