Expand description
Evaluate Cargo.toml
target specifications against platform triples.
Cargo supports platform-specific dependencies. These dependencies can be specified in one of two ways:
# 1. As Rust-like `#[cfg]` syntax.
[target.'cfg(all(unix, target_arch = "x86_64"))'.dependencies]
native = { path = "native/x86_64" }
# 2. Listing out the full target triple.
[target.x86_64-pc-windows-gnu.dependencies]
winhttp = "0.4.0"
target-spec
provides the eval
API which can be used to figure out whether such a dependency
will be included on a particular platform.
use target_spec::eval;
// Evaluate Rust-like `#[cfg]` syntax.
let cfg_target = "cfg(all(unix, target_arch = \"x86_64\"))";
assert_eq!(eval(cfg_target, "x86_64-unknown-linux-gnu").unwrap(), Some(true));
assert_eq!(eval(cfg_target, "i686-unknown-linux-gnu").unwrap(), Some(false));
assert_eq!(eval(cfg_target, "x86_64-pc-windows-msvc").unwrap(), Some(false));
// Evaluate a full target-triple.
assert_eq!(eval("x86_64-unknown-linux-gnu", "x86_64-unknown-linux-gnu").unwrap(), Some(true));
assert_eq!(eval("x86_64-unknown-linux-gnu", "x86_64-pc-windows-msvc").unwrap(), Some(false));
For more advanced usage, see Platform
and TargetSpec
.
§Optional features
custom
: Adds support for custom targets viaPlatform::new_custom
.summaries
: Adds thesummaries
module to enable serialization ofPlatform
andTargetFeatures
.proptest1
: Enables support for property-based testing ofPlatform
andTargetFeatures
usingproptest
.
§Minimum supported Rust version
The minimum supported Rust version (MSRV) is:
- For target-spec 3.0.x: Rust 1.66.
- For target-spec 3.1.x: Rust 1.73.
- For target-spec 3.2.x: Rust 1.75.
Within the 3.x series, MSRV bumps will be accompanied by a minor version update.
§Related crates
To pretty-print target-spec errors, consider using the miette diagnostic library with target-spec-miette.
Re-exports§
pub use errors::Error;
Modules§
- Errors returned by
target-spec
. - summaries
summaries
Serialized versions of platform and target features.
Structs§
- A platform to evaluate target specifications against.
- A target expression, parsed from a string beginning with
cfg(
. - A plain string as contained within a
TargetSpec::PlainString
. - A single, specific target, uniquely identified by a triple.
Enums§
- A set of target features to match.
- A parsed target specification or triple string, as found in a
Cargo.toml
file.
Functions§
- Evaluates the given spec against the provided target and returns
Some(true)
on a successful match, andSome(false)
on a failing match.