support code coverage in unit tests

[pabigot]

Coverage of standard tests can be done with a command like:

sanitycheck --platform native_posix_64 -C -T tests/lib/onoff/

This doesn't seem to work for unit tests:

tirzah[93]$ sanitycheck --platform native_posix_64 -C -T tests/unit/timeutil/
Renaming output directory to /mnt/devel/zp/zephyr/sanity-out.8
INFO    - JOBS: 32
INFO    - Building initial testcase list...
INFO    - 0 test configurations selected, 0 configurations discarded due to filters.
INFO    - Adding tasks to the queue...

INFO    - 0 of 0 tests passed (0.00%), 0 failed, 0 skipped with 0 warnings in 0.31 seconds
INFO    - In total 0 test cases were executed on 0 out of total 289 platforms (0.00%)
INFO    - 0 tests executed on platforms, 0 tests were only built.
INFO    - Generating coverage files...
geninfo: WARNING: no .gcda files found in /mnt/devel/zp/zephyr/sanity-out - skipping!
lcov: ERROR: no valid records found in tracefile /mnt/devel/zp/zephyr/sanity-out/coverage.info
lcov: ERROR: no valid records found in tracefile /mnt/devel/zp/zephyr/sanity-out/coverage.info
lcov: ERROR: no valid records found in tracefile /mnt/devel/zp/zephyr/sanity-out/coverage.info
lcov: ERROR: no valid records found in tracefile /mnt/devel/zp/zephyr/sanity-out/coverage.info
genhtml: ERROR: no valid records found in tracefile /mnt/devel/zp/zephyr/sanity-out/coverage.info
tirzah[94]$

It'd be nice to have coverage for these tests.

[pabigot]

Not sure who should take this.

[nashif]

sanitycheck -p unit_testing -T tests/unit/crc --coverage

[nashif]

unit tests are not run with native_posix, they are built as host binaries, you need to use special board 'unit_testing' for this.

[pabigot]

OK, confirmed that this works. Seems like this should be documented somewhere, probably in coverage.rst. Do you want to do that @nashif or should I do it?

[nashif]

Do you want to do that @nashif or should I do it?

be my guest.