| --- | |
| short-description: Auto-detection of features like ccache and code coverage | |
| ... | |
| # Feature autodetection | |
| Meson is designed for high productivity. It tries to do as many things | |
| automatically as it possibly can. | |
| Ccache | |
| -- | |
| [Ccache](https://ccache.dev/) is a cache system designed to make | |
| compiling faster. When you run Meson for the first time for a given | |
| project, it checks if Ccache is installed. If it is, Meson will use it | |
| automatically. | |
| If you do not wish to use Ccache for some reason, just specify your | |
| compiler with environment variables `CC` and/or `CXX` when first | |
| running Meson (remember that once specified the compiler cannot be | |
| changed). Meson will then use the specified compiler without Ccache. | |
| [sccache](https://github.com/mozilla/sccache) is auto-detected the | |
| same way, and is preferred over Ccache when both are installed. | |
| [BuildCache](https://gitlab.com/bits-n-bites/buildcache) is | |
| auto-detected as well, after Ccache and sccache. | |
| [kache](https://github.com/kunobi-ninja/kache) is also supported, but | |
| is never added automatically: it must be invoked with a compiler | |
| subcommand (`kache cc`, `kache c++`, ...), so Meson cannot safely | |
| prepend it to an arbitrary compiler. To use it, put it in front of | |
| the compiler yourself, e.g. `CC="kache cc"`. | |
| Coverage | |
| -- | |
| When doing a code coverage build, Meson will check for existence of | |
| the binaries `gcovr`, `lcov` and `genhtml`. If version 3.3 or higher | |
| of the first is found, targets called *coverage-text*, *coverage-xml* | |
| and *coverage-html* are generated. If version 4.2 or higher of the | |
| first is found, targets *coverage-text*, *coverage-xml*, *coverage-sonarqube* | |
| and *coverage-html* are generated. Alternatively, if the latter two | |
| are found, only the target *coverage-html* is generated. Coverage | |
| reports can then be produced simply by calling e.g. `meson compile | |
| coverage-xml`. As a convenience, a high-level *coverage* target is | |
| also generated which will produce all 3 coverage report types, if | |
| possible. | |
| Note that generating any of the coverage reports described above | |
| requires the tests (i.e. `meson test`) to finish running so the | |
| information about the functions that are called in the tests can be | |
| gathered for the report. |