33.5. 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 it requires the
gcov and lcov programs.A typical workflow looks 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.If you don't have
lcov or prefer text output over an HTML report, you can runmake coverage
instead of
make coverage-html, which will produce .gcov output files for each source file relevant to the test. (make coverage and make coverage-html will overwrite each other's files, so mixing them might be confusing.)You can run several different tests before making the coverage report; the execution counts will accumulate. If you want to reset the execution counts between test runs, run:
make coverage-clean
You can run the
make coverage-html or make coverage command in a subdirectory if you want a coverage report for only a portion of the code tree.Use
make distclean to clean up when done.