Generate coverage on Mac call Tools/Script/generate-coverage-data or by hand # delete find . -name '*.gcda' -delete # build, -framework CoreFoundation might suffice as well Tools/Scripts/build-webkit GCC_GENERATE_TEST_COVERAGE_FILES=YES GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES EXTRA_LINK=" -ftest-coverage -fprofile-arcs" OTHER_CFLAGS=" -MD " OTHER_LDFLAGS=" -ftest-coverage -fprofile-arcs -framework AppKit" Tools/Scripts/run-webkit-tests Tools/Scripts/run-javascriptcore-tests GCC_GENERATE_TEST_COVERAGE_FILES=YES GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES EXTRA_LINK=" -ftest-coverage -fprofile-arcs" OTHER_CFLAGS=" -MD " OTHER_LDFLAGS=" -ftest-coverage -fprofile-arcs -framework AppKit" # Collect files Tools/CodeCoverage/run-generate-coverage-data <RUN_ID> ../coverage-results/ # Generate graph Tools/CodeCoverage/regenerate-coverage-display ../coverage-results/ ../coverage-results/html