New features

Gettext targets are ignored if gettext is not installed

Previously the i18n module has errored out when gettext tools are not installed on the system. Starting with this version they will become no-ops instead. This makes it easier to build projects on minimal environments (such as when bootstrapping) that do not have translation tools installed.

Support taking environment values from a dictionary

environment() now accepts a dictionary as first argument. If provided, each key/value pair is added into the environment_object as if set() method was called for each of them.

On the various functions that take an env: keyword argument, you may now give a dictionary.

alias_target

runtarget alias_target(target_name, dep1, ...)

This function creates a new top-level target. Like all top-level targets, this integrates with the selected backend. For instance, with Ninja you can run it as ninja target_name. This is a dummy target that does not execute any command, but ensures that all dependencies are built. Dependencies can be any build target (e.g. return value of executable(), custom_target(), etc)

Enhancements to the pkg_config_path argument

Setting sys_root in the [properties] section of your cross file will now set PKG_CONFIG_SYSROOT_DIR automatically for host system dependencies when cross compiling.

The meson test program now accepts an additional "--gdb-path" argument to specify the GDB binary

meson test --gdb testname invokes GDB with the specific test case. However, sometimes GDB is not in the path or a GDB replacement is wanted. Therefore, a --gdb-path argument was added to specify which binary is executed (per default gdb):

$ meson test --gdb --gdb-path /my/special/location/for/gdb testname
$ meson test --gdb --gdb-path cgdb testname

Better support for illumos and Solaris

illumos (and hopefully Solaris) support has been dramatically improved, and one can reasonably expect projects to compile.

Splitting of Compiler.get_function_attribute('visibility')

On macOS there is no protected visibility, which results in the visbility check always failing. 0.52.0 introduces two changes to improve this situation:

  1. the "visibility" check no longer includes "protected"
  2. a new set of "split" checks are introduced which check for a single attribute instead of all attributes.

These new attributes are:

  • visibility:default
  • visibility:hidden
  • visibility:internal
  • visibility:protected

Clang-tidy target

If clang-tidy is installed and the project's source root contains a .clang-tidy (or _clang-tidy) file, Meson will automatically define a clang-tidy target that runs Clang-Tidy on all source files.

If you have defined your own clang-tidy target, Meson will not generate its own target.

Add blocks dependency

Add dependency('blocks') to use the Clang blocks extension.

Meson's builtin b_lundef is now supported on macOS

This has always been possible, but there are some addtional restrictions on macOS (mainly do to Apple only features). With the linker internal re-architecture this has become possible

Compiler and dynamic linker representation split

0.52.0 inclues a massive refactor of the representaitons of compilers to tease apart the representations of compilers and dynamic linkers (ld). This fixes a number of compiler/linker combinations. In particular this fixes use GCC and vanilla clang on macOS.

Add depth option to wrap-git

To allow shallow cloning, an option depth has been added to wrap-git. This applies recursively to submodules when clone-recursive is set to true.

Note that the git server may have to be configured to support shallow cloning not only for branches but also for tags.

Enhancements to the source_set module

SourceSet objects now provide the all_dependencies() method, that complement the existing all_sources() method.

added --only test(s) option to run_project_tests.py

Individual tests or a list of tests from run_project_tests.py can be selected like:

python run_project_tests.py --only fortran

python run_project_tests.py --only fortran python3

This assists Meson development by only running the tests for the portion of Meson being worked on during local development.

Experimental Webassembly support via Emscripten

Meson now supports compiling code to Webassembly using the Emscripten compiler. As with most things regarding Webassembly, this support is subject to change.

Version check in find_program()

A new version keyword argument has been added to find_program to specify the required version. See dependency() for argument format. The version of the program is determined by running program_name --version command. If stdout is empty it fallbacks to stderr. If the output contains more text than simply a version number, only the first occurence of numbers separated by dots is kept. If the output is more complicated than that, the version checking will have to be done manually using run_command().

Added vs_module_defs to shared_module()

Like shared_library(), shared_module() now accepts vs_module_defs argument for controlling symbol exports, etc.

Improved support for static libraries

Static libraries had numerous shortcomings in the past, especially when using uninstalled static libraries. This release brings many internal changes in the way they are handled, including:

  • link_whole: of static libraries. In the example below, lib2 used to miss symbols from lib1 and was unusable.
lib1 = static_library(sources)
lib2 = static_library(other_sources, link_whole : lib1, install : true)
  • link_with: of a static library with an uninstalled static library. In the example below, lib2 now implicitly promote link_with: to link_whole: because the installed lib2 would oterhwise be unusable.
lib1 = static_library(sources, install : false)
lib2 = static_library(sources, link_with : lib1, install : true)
  • pkg-config generator do not include uninstalled static libraries. In the example below, the generated .pc file used to be unusable because it contained Libs.private: -llib1 and lib1.a is not installed. lib1 is now ommitted from the .pc file because the link_with: has been promoted to link_whole: (see above) and thus lib1 is not needed to use lib2.
lib1 = static_library(sources, install : false)
lib2 = both_libraries(sources, link_with : lib1, install : true)
pkg.generate(lib2)

Many projects have been using extract_all_objects() to work around those issues, and hopefully those hacks could now be removed. Since this is a pretty large change, please double check if your static libraries behave correctly, and report any regression.

Enhancements to the kconfig module

kconfig.load() may now accept a configure_file() as input file.

Added include_type kwarg to dependency

The dependency() function now has a include_type kwarg. It can take the values 'preserve', 'system' and 'non-system'. If it is set to 'system', all include directories of the dependency are marked as system dependencies.

The default value of include_type is 'preserve'.

Additionally, it is also possible to check and change the include_type state of an existing dependency object with the new include_type() and as_system() methods.

Enhancements to configure_file()

input: now accepts multiple input file names for command:-configured file.

depfile: keyword argument is now accepted. The dependency file can list all the additional files the configure target depends on.

Projects args can be set separately for build and host machines (potentially breaking change)

Simplify native flag behavior in add_global_arguments, add_global_link_arguments, add_project_arguments and add_project_link_arguments. The rules are now very simple:

  • native: true affects native: true targets

  • native: false affects native: false targets

  • No native flag is the same as native: false

This further simplifies behavior to match the "build vs host" decision done in last release with c_args vs build_c_args. The underlying motivation in both cases is to execute the same commands whether the overall build is native or cross.

Allow checking if a variable is a disabler

Added the function is_disabler(var). Returns true if a variable is a disabler and false otherwise.

gtkdoc-check support

gnome.gtkdoc() now has a check keyword argument. If true runs it will run gtkdoc-check when running unit tests. Note that this has the downside of rebuilding the doc for each build, which is often very slow. It usually should be enabled only in CI.

gnome.gtkdoc() returns target object

gnome.gtkdoc() now returns a target object that can be passed as dependency to other targets using generated doc files (e.g. in content_files of another doc).

Dist is now a top level command

Previously creating a source archive could only be done with ninja dist. Starting with this release Meson provides a top level dist that can be invoked directly. It also has a command line option to determine which kinds of archives to create:

meson dist --formats=xztar,zip

The results of the search are