coreutils/DEVELOPER_INSTRUCTIONS.md

Code Coverage Report Generation

Code coverage report can be generated using grcov.

Using Nightly Rust

To generate gcov-based coverage report

$ export CARGO_INCREMENTAL=0
$ export RUSTFLAGS="-Zprofile -Ccodegen-units=1 -Copt-level=0 -Clink-dead-code -Coverflow-checks=off -Zpanic_abort_tests -Cpanic=abort"
$ export RUSTDOCFLAGS="-Cpanic=abort"
$ cargo build <options...> # e.g., --features feat_os_unix
$ cargo test <options...> # e.g., --features feat_os_unix test_pathchk
$ grcov . -s . --binary-path ./target/debug/ -t html --branch --ignore-not-existing --ignore build.rs --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?\#\[derive\()" -o ./target/debug/coverage/
$ # open target/debug/coverage/index.html in browser

if changes are not reflected in the report then run cargo clean and run the above commands.

Using Stable Rust

If you are using stable version of Rust that doesn't enable code coverage instrumentation by default then add -Z-Zinstrument-coverage flag to RUSTFLAGS env variable specified above.