The patch adds a couple of ignores and three Makefile targets for gcov and lcov reports. lcov [1] is a project that can create html reports from gcov output for C files.

make coverage-report first cleans up the source tree, then recompiles Python with gcov, runs the unit test and finally creates a HTML report.

I have a sample output on my box. Do we have a server where I can host about 55 MB?

[1] http://ltp.sourceforge.net/coverage/lcov.php

The new patch removes 3rd party components like expat and libffi. lcov doesn't support complex matches so I had to remove each library on its own.

I have moved the static pages to bitbucket:

  http://tiran.bitbucket.org/python-lcov/

How much slower is the execution of Python under the coverage? And can you run it with regrtest's -j (I assume not, but I thought I would ask)?

I'm asking because this would be interesting to try and tie into devinabox, but having to run two multi-hour testing runs might be a bit much to ask of sprint leaders.

I'm using the PSF's virtual machine for Coverity Scan to run the lcov tests. A full configure (without pydebug), build, test and analyze cycle takes about 25 to 30 minutes. I'm not sure if gcov supports multiple processes.

Maybe we can set up a service that builds C and Py coverage reports once a day? The service could push the reports to a public web site and offer rsync pulls over ssh for developers.

My long term hope is something exactly like that. I'm about to rewrite the instructions for handling coverage.py to use a venv for devinabox, but it's definitely something that can be entirely automated for a daily report.

And I should part of the reason I would love a daily report is it currently takes a couple of hours to run a full coverage report and that's without branch coverage.

Yeah, it's horrible slow. We need something like https://bitbucket.org/ned/coveragepy/src/2c5fb3a8b81cc56d8ad57dd1bd83ef7740f0d65d/coverage/tracer.c?at=default in the core. I already talked to Ned about contributing the module.

It's actually slower even with tracer.c. You actually can't use the full coverage script without using the tracer extension module.

New changeset 85ec2b5bfcd2 by Christian Heimes in branch 'default':
Issue #18481: Add C coverage reporting with gcov and lcov. A new make target
http://hg.python.org/cpython/rev/85ec2b5bfcd2

New changeset 116b05b98bea by Christian Heimes in branch 'default':
Issue #18481: document new C coverage make targets
http://hg.python.org/devguide/rev/116b05b98bea

I have add two new make targets and documented the new stuff in our devguide. I'm going to run and upload the report every now and then.