| #![warn(rust_2018_idioms, single_use_lifetimes)] |
| |
| use autocfg::AutoCfg; |
| use std::env; |
| |
| include!("no_atomic_cas.rs"); |
| |
| // The rustc-cfg listed below are considered public API, but it is *unstable* |
| // and outside of the normal semver guarantees: |
| // |
| // - `futures_no_atomic_cas` |
| // Assume the target does *not* support atomic CAS operations. |
| // This is usually detected automatically by the build script, but you may |
| // need to enable it manually when building for custom targets or using |
| // non-cargo build systems that don't run the build script. |
| // |
| // With the exceptions mentioned above, the rustc-cfg strings below are |
| // *not* public API. Please let us know by opening a GitHub issue if your build |
| // environment requires some way to enable these cfgs other than by executing |
| // our build script. |
| fn main() { |
| let target = match env::var("TARGET") { |
| Ok(target) => target, |
| Err(e) => { |
| println!( |
| "cargo:warning={}: unable to get TARGET environment variable: {}", |
| env!("CARGO_PKG_NAME"), |
| e |
| ); |
| return; |
| } |
| }; |
| |
| // Note that this is `no_*`, not `has_*`. This allows treating |
| // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't |
| // run. This is needed for compatibility with non-cargo build systems that |
| // don't run the build script. |
| if NO_ATOMIC_CAS_TARGETS.contains(&&*target) { |
| println!("cargo:rustc-cfg=futures_no_atomic_cas"); |
| } |
| |
| let cfg = match AutoCfg::new() { |
| Ok(cfg) => cfg, |
| Err(e) => { |
| println!( |
| "cargo:warning={}: unable to determine rustc version: {}", |
| env!("CARGO_PKG_NAME"), |
| e |
| ); |
| return; |
| } |
| }; |
| |
| // Function like procedural macros in expressions patterns statements stabilized in Rust 1.45: |
| // https://blog.rust-lang.org/2020/07/16/Rust-1.45.0.html#stabilizing-function-like-procedural-macros-in-expressions-patterns-and-statements |
| if cfg.probe_rustc_version(1, 45) { |
| println!("cargo:rustc-cfg=fn_like_proc_macro"); |
| } |
| |
| println!("cargo:rerun-if-changed=no_atomic_cas.rs"); |
| } |