Opp Repl Coverage Reports

Coverage reports

Coverage reports show which lines of C++ simulation source are executed by a run. Uses the coverage build mode (binary suffix _coverage) and LLVM's llvm-profdata / llvm-cov toolchain.

Upstream reference: https://github.com/omnetpp/opp_repl/blob/main/doc/coverage.md

Python API

# Build + run + open HTML report in browser
open_coverage_report(simulation_project=inet_project,
                     working_directory_filter="examples/ethernet",
                     sim_time_limit="10s")

# Build + run, just produce the report (don't open it)
generate_coverage_report(simulation_project=inet_project,
                         working_directory_filter="examples/ethernet",
                         sim_time_limit="10s")

Filters follow the standard vocabulary (see opp-repl-filtering).

Requirements

• LLVM 10+ on PATH (llvm-profdata, llvm-cov).
• The C++ sources built with clang (gcc does not emit the profile format LLVM expects).

Typical workflow

1. Pick one representative simulation config (coverage of a large test matrix is often dominated by a few runs).
2. Run it through open_coverage_report(...).
3. Use the HTML report to find untested branches; add fingerprint/statistical tests that exercise them.

Pitfalls

• Coverage builds are about 20 % slower than release. Long runs get expensive; keep sim_time_limit modest for coverage sweeps.
• Multiple tasks per run merge their profile data. Don't mix debug and coverage runs in the same session -- the binary suffix differs and the merge confusion can hide coverage.
• Reports include ONLY the simulation project's sources by default; to include OMNeT++ core or INET add the relevant source roots in your project's build config.

See also

• opp-repl-running-simulations — selects what to cover.
• opp-repl-profiling — orthogonal (time, not coverage).