| # Code Coverage |
| |
| ## Categories of coverage |
| |
| * executed - this line of code was hit during execution |
| * instrumented - this line of code was part of the compilation unit, but not |
| executed |
| * missing - in a source file, but not compiled. |
| * ignored - not an executable line, or a line we don't care about |
| |
| Coverage is calculated as `exe / (inst + miss)`. In general, lines that are in |
| `miss` should be ignored, but our exclusion rules are not good enough. |
| |
| ## Buildbots |
| |
| Buildbots are currently on the |
| [experimental waterfall](http://build.chromium.org/buildbot/waterfall.fyi/waterfall). |
| The coverage figures they calculate come from running some subset of the |
| chromium testing suite. |
| |
| * [Linux](http://build.chromium.org/buildbot/waterfall.fyi/builders/Linux%20Coverage%20(dbg)) |
| - uses `gcov` |
| * [Windows](http://build.chromium.org/buildbot/waterfall.fyi/builders/Win%20Coverage%20%28dbg%29) |
| * [Mac](http://build.chromium.org/buildbot/waterfall.fyi/builders/Mac%20Coverage%20%28dbg%29) |
| |
| Also, |
| |
| * [Coverage dashboard](http://build.chromium.org/buildbot/coverage/) |
| * [Example coverage summary](http://build.chromium.org/buildbot/coverage/linux-debug/49936/) |
| - the coverage is calculated at directory and file level, and the directory |
| structure is navigable via the **Subdirectories** table. |
| |
| ## Calculating coverage locally |
| |
| TODO |
| |
| ## Advanced Tips |
| |
| Sometimes a line of code should never be reached (e.g., `NOTREACHED()`). These |
| can be marked in the source with `// COV_NF_LINE`. Note that this syntax is |
| exact. |
