short-description: Built-in options to configure project properties ...
Meson provides two kinds of options: build options provided by the build files and built-in options that are either universal options, base options, compiler options.
A list of these options can be found by running meson --help. All these can be set by passing to meson (aka meson setup) in any of these ways: --option=value, --option value, -Doption=value, or by setting them inside default_options of project() in your meson.build.
For legacy reasons --warnlevel is the cli argument for the warning_level option.
They can also be edited after setup using meson configure.
Installation options are all relative to the prefix, except:
/usr: sysconfdir defaults to /etc, localstatedir defaults to /var, and sharedstatedir defaults to /var/lib/usr/local: localstatedir defaults to /var/local, and sharedstatedir defaults to /var/local/lib| Option | Default value | Description |
|---|---|---|
| prefix | see below | Installation prefix |
| bindir | bin | Executable directory |
| datadir | share | Data file directory |
| includedir | include | Header file directory |
| infodir | share/info | Info page directory |
| libdir | see below | Library directory |
| libexecdir | libexec | Library executable directory |
| localedir | share/locale | Locale data directory |
| localstatedir | var | Localstate data directory |
| mandir | share/man | Manual page directory |
| sbindir | sbin | System executable directory |
| sharedstatedir | com | Architecture-independent data directory |
| sysconfdir | etc | Sysconf data directory |
prefix defaults to C:/ on Windows, and /usr/local/ otherwise. You should always override this value.
libdir is automatically detected based on your platform, it should be correct when doing “native” (build machine == host machine) compilation. For cross compiles meson will try to guess the correct libdir, but it may not be accurate, especially on Linux where different distributions have different defaults. Using a cross file, particularly the paths section may be necessary.
Options that are labled “per machine” in the table are set per machine. Prefixing the option with build. just affects the build machine configuration, while unprefixed just affects the host machine configuration, respectively. Using the option as-is with no prefix affects all machines. For example:
build.pkg_config_path controls the paths pkg-config will search for just native: true dependencies (build machine).
pkg_config_path controls the paths pkg-config will search for just native: false dependencies (host machine).
| Option | Default value | Description | Is per machine |
|---|---|---|---|
| auto_features {enabled, disabled, auto} | auto | Override value of all ‘auto’ features | no |
| backend {ninja, vs, vs2010, vs2015, vs2017, xcode} | ninja | Backend to use | no |
| buildtype {plain, debug, debugoptimized, release, minsize, custom} | debug | Build type to use | no |
| debug | true | Debug | no |
| default_library {shared, static, both} | shared | Default library type | no |
| errorlogs | true | Whether to print the logs from failing tests. | no |
| install_umask {preserve, 0000-0777} | 022 | Default umask to apply on permissions of installed files | no |
| layout {mirror,flat} | mirror | Build directory layout | no |
| optimization {0, g, 1, 2, 3, s} | 0 | Optimization level | no |
| pkg_config_path {OS separated path} | '' | Additional paths for pkg-config to search before builtin paths | yes |
| cmake_prefix_path | [] | Additional prefixes for cmake to search before builtin paths | yes |
| stdsplit | true | Split stdout and stderr in test logs | no |
| strip | false | Strip targets on install | no |
| unity {on, off, subprojects} | off | Unity build | no |
| warning_level {0, 1, 2, 3} | 1 | Set the warning level. From 0 = none to 3 = highest | no |
| werror | false | Treat warnings as errors | no |
| wrap_mode {default, nofallback, nodownload, forcefallback} | default | Wrap mode to use | no |
These are set in the same way as universal options, but cannot be shown in the output of meson --help because they depend on both the current platform and the compiler that will be selected. The only way to see them is to setup a builddir and then run meson configure on it with no options.
The following options are available. Note that they may not be available on all platforms or with all compilers:
| Option | Default value | Possible values | Description |
|---|---|---|---|
| b_asneeded | true | true, false | Use -Wl,--as-needed when linking |
| b_bitcode | false | true, false | Embed Apple bitcode, see below |
| b_colorout | always | auto, always, never | Use colored output |
| b_coverage | false | true, false | Enable coverage tracking |
| b_lundef | true | true, false | Don't allow undefined symbols when linking |
| b_lto | false | true, false | Use link time optimization |
| b_ndebug | false | true, false, if-release | Disable asserts |
| b_pch | true | true, false | Use precompiled headers |
| b_pgo | off | off, generate, use | Use profile guided optimization |
| b_sanitize | none | see below | Code sanitizer to use |
| b_staticpic | true | true, false | Build static libraries as position independent |
| b_pie | false | true, false | Build position-independent executables (since 0.49.0) |
| b_vscrt | from_buildtype | none, md, mdd, mt, mtd, from_buildtype | VS runtime library to use (since 0.48.0) |
The value of b_sanitize can be one of: none, address, thread, undefined, memory, address,undefined.
b_bitcode will pass -fembed-bitcode while compiling and will pass -Wl,-bitcode_bundle while linking. These options are incompatible with b_asneeded, so that option will be silently disabled.
Shared modules will not have bitcode embedded because -Wl,-bitcode_bundle is incompatible with both -bundle and -Wl,-undefined,dynamic_lookup which are necessary for shared modules to work.
Same caveats as base options above.
The following options are available. Note that both the options themselves and the possible values they can take will depend on the target platform or compiler being used:
| Option | Default value | Possible values | Description |
|---|---|---|---|
| c_args | free-form comma-separated list | C compile arguments to use | |
| c_link_args | free-form comma-separated list | C link arguments to use | |
| c_std | none | none, c89, c99, c11, c17, c18, gnu89, gnu99, gnu11, gnu17, gnu18 | C language standard to use |
| c_winlibs | see below | free-form comma-separated list | Standard Windows libs to link against |
| cpp_args | free-form comma-separated list | C++ compile arguments to use | |
| cpp_link_args | free-form comma-separated list | C++ link arguments to use | |
| cpp_std | none | none, c++98, c++03, c++11, c++14, c++17, c++1z, gnu++03, gnu++11, gnu++14, gnu++17, gnu++1z, vc++14, vc++17, vc++latest | C++ language standard to use |
| cpp_debugstl | false | true, false | C++ STL debug mode |
| cpp_eh | default | none, default, a, s, sc | C++ exception handling type |
| cpp_winlibs | see below | free-form comma-separated list | Standard Windows libs to link against |
The default values of c_winlibs and cpp_winlibs are in compiler-specific argument forms, but the libraries are: kernel32, user32, gdi32, winspool, shell32, ole32, oleaut32, uuid, comdlg32, advapi32.
c_args, cpp_args, c_link_args, and cpp_link_args only affect native builds, when cross compiling they will not be applied to binaries or libraries targeting the host system, only those being run on the build system.
When using MSVC, cpp_eh=none will result in no exception flags being passed, while the cpp_eh=[value] will result in /EH[value]. Since 0.51.0 cpp_eh=default will result in /EHsc on MSVC. When using gcc-style compilers, nothing is passed (allowing exceptions to work), while cpp_eh=none passes -fno-exceptions.