Alan Somers
5756980eb3
PR #2479 did this, but only in the freebsd13 and freebsd14 modules, which was incorrect. Those modules should only be used for functions that change across FreeBSD versions, and therefore need different ELF symbol versions. Functions that were newly added since FreeBSD 11 can still go in the base freebsd module. It will cause no problems for them to be there, and users will see an error at link time if they try to use such a function in an environment that is too old to support it.
libc - Raw FFI bindings to platforms' system libraries
libc provides all of the definitions necessary to easily interoperate with C
code (or "C-like" code) on each of the platforms that Rust supports. This
includes type definitions (e.g. c_int), constants (e.g. EINVAL) as well as
function headers (e.g. malloc).
This crate exports all underlying platform types, functions, and constants under
the crate root, so all items are accessible as libc::foo. The types and values
of all the exported APIs match the platform that libc is compiled for.
More detailed information about the design of this library can be found in its associated RFC.
Usage
Add the following to your Cargo.toml:
[dependencies]
libc = "0.2"
Features
-
std: by defaultlibclinks to the standard library. Disable this feature to remove this dependency and be able to uselibcin#![no_std]crates. -
extra_traits: allstructs implemented inlibcareCopyandClone. This feature derivesDebug,Eq,Hash, andPartialEq. -
const-extern-fn: Changes someextern fns intoconst extern fns. If you use Rust >= 1.62, this feature is implicitly enabled. Otherwise it requires a nightly rustc. -
deprecated:
use_stdis deprecated, and is equivalent tostd.
Rust version support
The minimum supported Rust toolchain version is currently Rust 1.13.0. (libc does not currently have any policy regarding changes to the minimum supported Rust version; such policy is a work in progress.) APIs requiring newer Rust features are only available on newer Rust toolchains:
| Feature | Version |
|---|---|
union |
1.19.0 |
const mem::size_of |
1.24.0 |
repr(align) |
1.25.0 |
extra_traits |
1.25.0 |
core::ffi::c_void |
1.30.0 |
repr(packed(N)) |
1.33.0 |
cfg(target_vendor) |
1.33.0 |
const-extern-fn |
1.62.0 |
Platform support
Platform-specific documentation (master branch).
See
ci/build.sh
for the platforms on which libc is guaranteed to build for each Rust
toolchain. The test-matrix at GitHub Actions and Cirrus CI show the
platforms in which libc tests are run.
License
This project is licensed under either of
at your option.
Contributing
We welcome all people who want to contribute. Please see the contributing instructions for more information.
Contributions in any form (issues, pull requests, etc.) to this project must adhere to Rust's Code of Conduct.
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in libc by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.