[igt-dev] [PATCH 0/9] Add support to collecr code coverage data

[Mauro Carvalho Chehab]

From: Mauro Carvalho Chehab <mchehab at kernel.org>

The gcc compiler has a feature that allows collecting code coverage
in runtime, which is already supported by the Linux Kernel, as described
on its documentation:

	https://01.org/linuxgraphics/gfx-docs/drm/dev-tools/gcov.html

Add support for it at the igt_runner and scripts/run-tests.sh.

With such support, once a Kernel is compiled with:

	./scripts/config -e DEBUG_FS -e GCOV_KERNEL

And GCOV is enabled by one or more drivers, like doing:

	for i in $(find drivers/gpu/drm/ -name Makefile); do sed '1 a GCOV_PROFILE := y' -i $i; done

One can use igt_runner and/or run-tests.sh to collect the code coverage.

The way the implementation works is that the igt_runner has internally
the logic which reset the gcov usage counters. The code capture itself
is done via an external script.

There are two versions of such script:

- scripts/code_cov_capture.sh:

  Assumes that the Kernel was built at the same machine, and uses
  the lcov tool to generate GCC-independent code coverage data,
  in the form of *.info files;

- scripts/code_cov_gather_on_test.py:

  Generates a gzipped tarbal with the code coverage counters in
  binary format. Such kind of output should then be parsed at
  the same machine where the Kernel as built, as its content is not
  ony dependent on the Kernel source, but also on the Kernel output
  objects.

Either way, both igt_runner and scripts/run-tests.sh could be used
to generate the code coverage results.

So, in order to get the code coverage results, storing results per each
IGT test, one should run either:

	./scripts/run-tests.sh -T my_tests.testlist -k ~/linux \
		-c scripts/code_cov_gather_on_test.py -P

or:

	sudo ./build/runner/igt_runner -o --test-list my_tests.testlist \
		--coverage-per-test \
		--collect-script scripts/code_cov_gather_on_test.py \
		build/tests results

Once the data is captured, it is possible to generate HTML reports
using scripts/code_cov_gen_report.sh:

	scripts/code_cov_gen_report.sh -r results/code_cov/i915_selftest_live.info -k ~/linux -o cov_results -i -f

Mauro Carvalho Chehab (8):
  runner: check if it has root permissions
  runner: Add support for code coverage
  scripts/code_cov_gather*/sh: add help scripts for code coverage
  scripts/code_cov_gather_on_build.sh: Improve the script
  scripts/code_cov_capture.sh: add a script to use lcov on build+test
    machine
  scripts/code_cov_gen_report.sh: add a script to generate code coverage
    reports
  scripts/run-tests.sh: add code coverage support
  docs: add documentation for code coverage

Tomi Sarvela (1):
  scripts:code_cov_gather_on_test: use a faster script

 docs/code_coverage.md               | 293 ++++++++++++++++++++++++++++
 runner/executor.c                   | 200 ++++++++++++++++++-
 runner/resume.c                     |   4 +-
 runner/runner_tests.c               |  30 +++
 runner/settings.c                   |  87 ++++++++-
 runner/settings.h                   |   8 +
 scripts/code_cov_capture.sh         |  25 +++
 scripts/code_cov_gather_on_build.sh |  39 ++++
 scripts/code_cov_gather_on_test.py  |  91 +++++++++
 scripts/code_cov_gen_report.sh      | 170 ++++++++++++++++
 scripts/run-tests.sh                |  52 ++++-
 11 files changed, 979 insertions(+), 20 deletions(-)
 create mode 100644 docs/code_coverage.md
 create mode 100755 scripts/code_cov_capture.sh
 create mode 100755 scripts/code_cov_gather_on_build.sh
 create mode 100755 scripts/code_cov_gather_on_test.py
 create mode 100755 scripts/code_cov_gen_report.sh

-- 
2.35.1