src/tools/rustfmt/tests/target/cfg_if/lib.rs

   1 //! Run-time feature detection for the Rust standard library.
   2 //!
   3 //! To detect whether a feature is enabled in the system running the binary
   4 //! use one of the appropriate macro for the target:
   5 //!
   6 //! * `x86` and `x86_64`: [`is_x86_feature_detected`]
   7 //! * `arm`: [`is_arm_feature_detected`]
   8 //! * `aarch64`: [`is_aarch64_feature_detected`]
   9 //! * `mips`: [`is_mips_feature_detected`]
  10 //! * `mips64`: [`is_mips64_feature_detected`]
  11 //! * `powerpc`: [`is_powerpc_feature_detected`]
  12 //! * `powerpc64`: [`is_powerpc64_feature_detected`]
  13
  14 #![unstable(feature = "stdsimd", issue = "27731")]
  15 #![feature(const_fn, staged_api, stdsimd, doc_cfg, allow_internal_unstable)]
  16 #![allow(clippy::shadow_reuse)]
  17 #![deny(clippy::missing_inline_in_public_items)]
  18 #![cfg_attr(target_os = "linux", feature(linkage))]
  19 #![cfg_attr(all(target_os = "freebsd", target_arch = "aarch64"), feature(asm))]
  20 #![cfg_attr(stdsimd_strict, deny(warnings))]
  21 #![cfg_attr(test, allow(unused_imports))]
  22 #![no_std]
  23
  24 #[macro_use]
  25 extern crate cfg_if;
  26
  27 cfg_if! {
  28     if #[cfg(feature = "std_detect_file_io")] {
  29         #[cfg_attr(test, macro_use(println))]
  30         extern crate std;
  31
  32         #[allow(unused_imports)]
  33         use std::{arch, fs, io, mem, sync};
  34     } else {
  35         #[cfg(test)]
  36         #[macro_use(println)]
  37         extern crate std;
  38
  39         #[allow(unused_imports)]
  40         use core::{arch, mem, sync};
  41     }
  42 }
  43
  44 #[cfg(feature = "std_detect_dlsym_getauxval")]
  45 extern crate libc;
  46
  47 #[doc(hidden)]
  48 #[unstable(feature = "stdsimd", issue = "27731")]
  49 pub mod detect;