| error.rs |
|
1414 |
| lib.rs |
A Rust library for build scripts to automatically configure code based on
compiler support. Code snippets are dynamically tested to see if the `rustc`
will accept them, rather than hard-coding specific version support.
## Usage
Add this to your `Cargo.toml`:
```toml
[build-dependencies]
autocfg = "1"
```
Then use it in your `build.rs` script to detect compiler features. For
example, to test for 128-bit integer support, it might look like:
```rust
extern crate autocfg;
fn main() {
# // Normally, cargo will set `OUT_DIR` for build scripts.
# std::env::set_var("OUT_DIR", "target");
let ac = autocfg::new();
ac.emit_has_type("i128");
// (optional) We don't need to rerun for anything external.
autocfg::rerun_path("build.rs");
}
```
If the type test succeeds, this will write a `cargo:rustc-cfg=has_i128` line
for Cargo, which translates to Rust arguments `--cfg has_i128`. Then in the
rest of your Rust code, you can add `#[cfg(has_i128)]` conditions on code that
should only be used when the compiler supports it.
## Caution
Many of the probing methods of `AutoCfg` document the particular template they
use, **subject to change**. The inputs are not validated to make sure they are
semantically correct for their expected use, so it's _possible_ to escape and
inject something unintended. However, such abuse is unsupported and will not
be considered when making changes to the templates. |
15484 |
| tests.rs |
|
5038 |
| version.rs |
|
2092 |