Cheat sheet

This page lists the commands to invoke to achieve some common build tasks with Meson. Unless otherwise specified all the examples below assume that the build directory is created in a directory called build which is located in the source tree's root. It is also assumed that all commands are executed in that directory.

Producing a coverage report

First initialise the build directory with this command.

meson --enable-gcov ..

Then issue the following commands.

ninja
ninja test
ninja coverage-html (or coverage-xml)

The coverage report can be found in the meson-logs subdirectory.

Adding some optimization to debug builds

By default the debug build does not use any optimizations. This is the desired approach most of the time. However some projects benefit from having some minor optimizations enabled. Gcc even has a specific compiler flag -Og for this. To enable its use, just issue the following command.

mesonconf -Dcargs=-Og

This causes all subsequent builds to use this command line argument.

Using address sanitizer

Clang comes with a selection of analysis tools such as the address sanitizer. They are enabled by adding a few compiler flags (requires a relatively recent GCC or Clang).

First we set up meson.

CFLAGS='-fsanitize=address -fno-omit-frame-pointer' meson ..

This example uses only plain C. For C++ you would set the variable CXXFLAGS.

After this you just compile your code and run the test suite. Address sanitizer will abort executables which have bugs so they show up as test failures.

Using Clang static analyzer

The clang compiler comes with a static analysis tool which is invoked by compiling the application via a wrapper command. We will generate this report in a custom build directory and clean it up afterwards so no build artifacts remain lingering anywhere. This is achieved by running the following commands in the root of the source directory.

mkdir uniquedirname
cd uniquedirname
scan-build meson ..
scan-build ninja
cd ..
rm -rf uniquedirname

The static analysis report will be found in the /tmp subdirectory, though you can forward it somewhere else if you prefer.

Using profile guided optimization

Using profile guided optimization with GCC is a two phase operation. First we set up the project with profile measurements enabled and compile it.

CFLAGS='-pg -fprofile-generate' meson .. <Meson options, such as --buildtype=debugoptimized>
ninja

Then we need to run the program with some representative input. This step depends on your project.

Once that is done we change the compiler flags to use the generated information and rebuild.

mesonconf -Dcargs=-fprofile-use -Dclinkargs=-fprofile-use
ninja

After these steps the resulting binary is fully optimized.