Rust module

(new in 0.57.0) (Stable since 1.0.0)

The rust module provides helper to integrate rust code into Meson. The goal is to make using rust in Meson more pleasant, while still remaining mesonic, this means that it attempts to make Rust work more like Meson, rather than Meson work more like rust.

Functions

test()

rustmod.test(name, target, ...)

This function creates a new rust unittest target from an existing rust based target, which may be a library or executable. It does this by copying the sources and arguments passed to the original target and adding the --test argument to the compilation, then creates a new test target which calls that executable, using the rust test protocol.

This function takes two positional arguments, the first is the name of the test and the second is the library or executable that is the rust based target. It also takes the following keyword arguments:

  • dependencies: a list of test-only Dependencies
  • link_with: a list of additional build Targets to link with (since 1.2.0)
  • rust_args: a list of extra arguments passed to the Rust compiler (since 1.2.0)

This function also accepts all of the keyword arguments accepted by the test() function except protocol, it will set that automatically.

bindgen()

This function wraps bindgen to simplify creating rust bindings around C libraries. This has two advantages over invoking bindgen with a generator or custom_target:

  • It handles include_directories, so one doesn't have to manually convert them to -I...
  • It automatically sets up a depfile, making the results more reliable
  • It automatically handles assertions, synchronizing Rust and C/C++ to have the same behavior

It takes the following keyword arguments

  • input: a list of Files, Strings, or CustomTargets. The first element is the header bindgen will parse, additional elements are dependencies.
  • output: the name of the output rust file
  • output_inline_wrapper: the name of the optional output c file containing wrappers for static inline function. This requires bindgen-0.65 or newer (since 1.3.0).
  • include_directories: A list of include_directories or string objects, these are passed to clang as -I arguments (string since 1.0.0)
  • c_args: a list of string arguments to pass to clang untouched
  • args: a list of string arguments to pass to bindgen untouched.
  • dependencies: a list of Dependency objects to pass to the underlying clang call (since 1.0.0)
  • language: A literal string value of c or cpp. When set this will force bindgen to treat a source as the given language. Defaults to checking based on the input file extension. (since 1.4.0)
  • bindgen_version: a list of string version values. When set the found bindgen binary must conform to these constraints. (since 1.4.0) 
rust = import('unstable-rust')

inc = include_directories('..'¸ '../../foo')

generated = rust.bindgen(
    input : 'myheader.h',
    output : 'generated.rs',
    include_directories : [inc, include_directories('foo')],
    args : ['--no-rustfmt-bindings'],
    c_args : ['-DFOO=1'],
)

If the header depends on generated headers, those headers must be passed to bindgen as well to ensure proper dependency ordering, static headers do not need to be passed, as a proper depfile is generated:

h1 = custom_target(...)
h2 = custom_target(...)

r1 = rust.bindgen(
  input : [h1, h2],  # h1 includes h2,
  output : 'out.rs',
)

Since 1.1.0 Meson will synchronize assertions for Rust and C/C++ when the b_ndebug option is set (via -DNDEBUG for C/C++, and -C debug-assertions=on for Rust), and will pass -DNDEBUG as an extra argument to clang. This allows for reliable wrapping of -DNDEBUG controlled behavior with #[cfg(debug_asserions)] and or cfg!(). Before 1.1.0, assertions for Rust were never turned on by Meson.

Since 1.2.0 Additional arguments to pass to clang may be specified in a *machine file in the properties section:

[properties]
bindgen_clang_arguments = ['-target', 'x86_64-linux-gnu']

proc_macro()

rustmod.proc_macro(name, sources, ...)

Since 1.3.0

This function creates a Rust proc-macro crate, similar to:

shared_library()(name, sources,
  rust_crate_type: 'proc-macro',
  native: true)

proc-macro targets can be passed to link_with keyword argument of other Rust targets.

Only a subset of shared_library() keyword arguments are allowed:

  • rust_args
  • rust_dependency_map
  • sources
  • dependencies
  • extra_files
  • link_args
  • link_depends
  • link_with
  • override_options

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