## 31.5. Test Coverage Examination

The PostgreSQL source code can be compiled with coverage testing instrumentation, so that it becomes possible to examine which parts of the code are covered by the regression tests or any other test suite that is run with the code. This is currently supported when compiling with GCC and requires the `gcov` and `lcov` programs.

A typical workflow would look like this:

    ./configure --enable-coverage ... OTHER OPTIONS ...
    make
    make check # or other test suite
    make coverage-html

Then point your HTML browser to `coverage/index.html`. The `make` commands also work in subdirectories.

To reset the execution counts between test runs, run:

    make coverage-clean