https://github.com/volks73/cargo-rustc-cfg
A Rust crate for parsing the output from the `cargo rustc --print cfg` command
https://github.com/volks73/cargo-rustc-cfg
cargo rust rust-crate rustc
Last synced: about 1 year ago
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A Rust crate for parsing the output from the `cargo rustc --print cfg` command
- Host: GitHub
- URL: https://github.com/volks73/cargo-rustc-cfg
- Owner: volks73
- License: apache-2.0
- Created: 2020-11-28T17:46:38.000Z (over 5 years ago)
- Default Branch: main
- Last Pushed: 2021-10-12T17:06:37.000Z (over 4 years ago)
- Last Synced: 2025-03-26T21:15:00.785Z (over 1 year ago)
- Topics: cargo, rust, rust-crate, rustc
- Language: Rust
- Homepage: https://docs.rs/cargo-rustc-cfg
- Size: 65.4 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE-APACHE
Awesome Lists containing this project
README
# cargo-rustc-cfg
This crate currently needs the nightly toolchain. See the [tracking issue] for
stabilization.
A Rust library (crate) that runs the `cargo rustc --print cfg` command and
parses the output. This is inspired by the [rustc-cfg] crate, which runs the
`rustc --print cfg` command and parses the output, but it does not take into
account any flags or configurations passed from [Cargo] to the [Rust compiler
(rustc)] when building a project using Cargo. For example, if the `RUSTFLAGS`
environment variable is used to add a target feature, i.e.
`RUSTFLAGS="-C target-feature=+crt-static`, then the `rustc --print cfg` command
will not list the added target feature in its output because the `RUSTFLAGS`
environment variable is managed by Cargo. However, the `cargo rustc --print cfg`
will list the added target feature in its output. This crate is useful for
developing [third-party] [Cargo custom subcommands] that need compiler
configuration information. This crate is _not_ recommended for [build scripts].
[](https://crates.io/crates/cargo-rustc-cfg)
[](https://github.com/volks73/cargo-rustc-cfg/releases)
[](https://github.com/volks73/cargo-rustc-cfg#license)
[](https://github.com/volks73/cargo-rustc-cfg/actions)
[rustc-cfg]: https://crates.io/crates/rustc-cfg
[cargo]: http://doc.crates.io
[rust compiler (rustc)]: https://doc.rust-lang.org/rustc/index.html
[third-party]: https://github.com/rust-lang/cargo/wiki/Third-party-cargo-subcommands
[cargo custom subcommands]: https://doc.rust-lang.org/1.30.0/cargo/reference/external-tools.html#custom-subcommands
[build scripts]: https://doc.rust-lang.org/cargo/reference/build-scripts.html
[tracking issue]: https://github.com/rust-lang/cargo/issues/9357
## Quick Start
**Note**, this crate currently needs the [nightly toolchain](https://github.com/rust-lang/cargo/issues/9357).
```rust
use cargo_rustc_cfg;
let host = cargo_rustc_cfg::host()?;
println("{:?}", host);
```
## Installation
Add the following to a package's manifest (Cargo.toml):
```toml
cargo-rustc-cfg = "0.3"
```
If using the [Rust 2015 Edition], then also add the following to the `lib.rs` or `main.rs` source file:
```rust
extern crate cargo_rustc_cfg;
```
[rust 2015 edition]: https://doc.rust-lang.org/stable/edition-guide/rust-2015/index.html
## Tests
Tests are run using the `cargo test` command. Currently, only [documentation
tests] are implemented because for a relatively simple, small library these
provide enough coverage. If the default toolchain is `stable` but the `nightly`
toolchain is installed, the `cargo +nightly test` command can be used without
having to switch the default toolchain.
[documentation tests]: https://doc.rust-lang.org/rustdoc/documentation-tests.html
## License
The `cargo-rustc-cfg` project is licensed under either the [MIT license] or
the [Apache 2.0 license]. See the [LICENSE-MIT] or [LICENSE-APACHE] files for
more information about licensing and copyright.
[mit license]: https://opensource.org/licenses/MIT
[apache 2.0 license]: http://www.apache.org/licenses/LICENSE-2.0
[license-mit]: https://github.com/volks73/cargo-rustc-cfg/blob/master/LICENSE-MIT
[license-apache]: https://github.com/volks73/cargo-rustc-cfg/blob/master/LICENSE-APACHE