// After Bullseye instrumentation (conceptual) probe_1 = 0; // Counter for the decision if (temperature > 100 && pressure < 50) probe_1++; // Counts entry of the true branch activate_alarm();
of 100% would be achieved if a single test calls validate_user(25, true, false) . All lines execute. But have you tested all logical possibilities? bullseye code coverage
bool validate_user(int age, bool has_license, bool is_insured) is_insured)) return true; return false; // After Bullseye instrumentation (conceptual) probe_1 = 0;
| Tool | Best For | Bullseye Advantage | | :--- | :--- | :--- | | | Rapid iteration, open-source | Bullseye has decision coverage, LLVM only line/function | | Codecov / Coveralls | SaaS dashboards, PR comments | Bullseye works air-gapped (offline) for classified work | | SonarQube | Multi-language, quality gates | Bullseye’s merge engine is vastly superior for embedded | | Parasoft C/C++test | Full SDLC compliance | Bullseye is lighter-weight and cheaper | Bullseye has notable constraints:
set(CMAKE_C_COMPILER "covc" CACHE STRING "") set(CMAKE_CXX_COMPILER "covc" CACHE STRING "") set(CMAKE_CXX_COMPILER_LAUNCHER "" CACHE STRING "") set(CMAKE_C_COMPILER_ARG1 "--compiler" CACHE STRING "") set(CMAKE_CXX_COMPILER_ARG1 "--compiler" CACHE STRING "") export PATH=/usr/local/bullseye/bin:$PATH covselect --add --on # Turn on coverage measurement cmake -DCMAKE_TOOLCHAIN_FILE=bullseye-toolchain.cmake .. covbuild cmake --build . --parallel Step 3: Run Tests & Capture Data cov01 -1 # Reset counters to zero ./bin/my_unit_tests covrun ./bin/integration_tests Step 4: Merge & Report covmerge -a *.cov # Merge all .cov files into one covhtml --title "Sprint 23 Coverage" -o coverage_html coverage.cov Step 5: Set a Quality Gate In your CI script, fail the build if decision coverage drops below 80%:
cov01 -1 # Instrument source make # Build covrun ./run_tests # Execute covhtml -o coverage_report *.cov # Generate HTML Automotive (ISO 26262 ASIL-D) In autonomous driving software, a single untested branch in a lane-keeping algorithm could cause a fatality. Bullseye is used to achieve Modified Condition/Decision Coverage (MC/DC) , which is required for ASIL-D. Bullseye’s reports can be directly submitted to certification auditors. Medical Devices (FDA Class III) The FDA requires objective evidence of test completeness. Bullseye’s ability to exclude TESTMARGIN regions (e.g., "this error handler is only for cosmic ray bit flips") and merge coverage from 10,000 hours of simulation is unmatched. Legacy Code Refactoring When taking over a million-line C++ codebase with 0% tests, Bullseye helps prioritize. Run a smoke test, generate a report, and refactor the red (uncovered) and yellow (partial) functions first. This risk-based testing approach saves months of effort. 6. Limitations and Critical Considerations No tool is perfect. Bullseye has notable constraints: