rust/library/std/build.rs

189 lines
8.5 KiB
Rust

use std::env;
fn main() {
println!("cargo:rerun-if-changed=build.rs");
let target_arch = env::var("CARGO_CFG_TARGET_ARCH").expect("CARGO_CFG_TARGET_ARCH was not set");
let target_os = env::var("CARGO_CFG_TARGET_OS").expect("CARGO_CFG_TARGET_OS was not set");
let target_vendor =
env::var("CARGO_CFG_TARGET_VENDOR").expect("CARGO_CFG_TARGET_VENDOR was not set");
let target_env = env::var("CARGO_CFG_TARGET_ENV").expect("CARGO_CFG_TARGET_ENV was not set");
let target_abi = env::var("CARGO_CFG_TARGET_ABI").expect("CARGO_CFG_TARGET_ABI was not set");
let target_pointer_width: u32 = env::var("CARGO_CFG_TARGET_POINTER_WIDTH")
.expect("CARGO_CFG_TARGET_POINTER_WIDTH was not set")
.parse()
.unwrap();
let is_miri = env::var_os("CARGO_CFG_MIRI").is_some();
println!("cargo:rustc-check-cfg=cfg(netbsd10)");
if target_os == "netbsd" && env::var("RUSTC_STD_NETBSD10").is_ok() {
println!("cargo:rustc-cfg=netbsd10");
}
println!("cargo:rustc-check-cfg=cfg(restricted_std)");
if target_os == "linux"
|| target_os == "android"
|| target_os == "netbsd"
|| target_os == "dragonfly"
|| target_os == "openbsd"
|| target_os == "freebsd"
|| target_os == "solaris"
|| target_os == "illumos"
|| target_os == "macos"
|| target_os == "ios"
|| target_os == "tvos"
|| target_os == "watchos"
|| target_os == "visionos"
|| target_os == "windows"
|| target_os == "fuchsia"
|| (target_vendor == "fortanix" && target_env == "sgx")
|| target_os == "hermit"
|| target_os == "l4re"
|| target_os == "redox"
|| target_os == "haiku"
|| target_os == "vxworks"
|| target_arch == "wasm32"
|| target_arch == "wasm64"
|| target_os == "espidf"
|| target_os.starts_with("solid")
|| (target_vendor == "nintendo" && target_env == "newlib")
|| target_os == "vita"
|| target_os == "aix"
|| target_os == "nto"
|| target_os == "xous"
|| target_os == "hurd"
|| target_os == "uefi"
|| target_os == "teeos"
|| target_os == "zkvm"
|| target_os == "mikros"
|| target_os == "rtems"
|| target_os == "nuttx"
// See src/bootstrap/src/core/build_steps/synthetic_targets.rs
|| env::var("RUSTC_BOOTSTRAP_SYNTHETIC_TARGET").is_ok()
{
// These platforms don't have any special requirements.
} else {
// This is for Cargo's build-std support, to mark std as unstable for
// typically no_std platforms.
// This covers:
// - os=none ("bare metal" targets)
// - mipsel-sony-psp
// - nvptx64-nvidia-cuda
// - arch=avr
// - JSON targets
// - Any new targets that have not been explicitly added above.
println!("cargo:rustc-cfg=restricted_std");
}
println!("cargo:rustc-check-cfg=cfg(backtrace_in_libstd)");
println!("cargo:rustc-cfg=backtrace_in_libstd");
println!("cargo:rustc-env=STD_ENV_ARCH={}", env::var("CARGO_CFG_TARGET_ARCH").unwrap());
// Emit these on platforms that have no known ABI bugs, LLVM selection bugs, lowering bugs,
// missing symbols, or other problems, to determine when tests get run.
// If more broken platforms are found, please update the tracking issue at
// <https://github.com/rust-lang/rust/issues/116909>
//
// Some of these match arms are redundant; the goal is to separate reasons that the type is
// unreliable, even when multiple reasons might fail the same platform.
println!("cargo:rustc-check-cfg=cfg(reliable_f16)");
println!("cargo:rustc-check-cfg=cfg(reliable_f128)");
// This is a step beyond only having the types and basic functions available. Math functions
// aren't consistently available or correct.
println!("cargo:rustc-check-cfg=cfg(reliable_f16_math)");
println!("cargo:rustc-check-cfg=cfg(reliable_f128_math)");
let has_reliable_f16 = match (target_arch.as_str(), target_os.as_str()) {
// We can always enable these in Miri as that is not affected by codegen bugs.
_ if is_miri => true,
// Selection failure <https://github.com/llvm/llvm-project/issues/50374>
("s390x", _) => false,
// Unsupported <https://github.com/llvm/llvm-project/issues/94434>
("arm64ec", _) => false,
// MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054>
("x86_64", "windows") if target_env == "gnu" && target_abi != "llvm" => false,
// Infinite recursion <https://github.com/llvm/llvm-project/issues/97981>
("csky", _) => false,
("hexagon", _) => false,
("loongarch64", _) => false,
("mips" | "mips64" | "mips32r6" | "mips64r6", _) => false,
("powerpc" | "powerpc64", _) => false,
("sparc" | "sparc64", _) => false,
("wasm32" | "wasm64", _) => false,
// `f16` support only requires that symbols converting to and from `f32` are available. We
// provide these in `compiler-builtins`, so `f16` should be available on all platforms that
// do not have other ABI issues or LLVM crashes.
_ => true,
};
let has_reliable_f128 = match (target_arch.as_str(), target_os.as_str()) {
// We can always enable these in Miri as that is not affected by codegen bugs.
_ if is_miri => true,
// Unsupported <https://github.com/llvm/llvm-project/issues/94434>
("arm64ec", _) => false,
// Selection bug <https://github.com/llvm/llvm-project/issues/96432>
("mips64" | "mips64r6", _) => false,
// Selection bug <https://github.com/llvm/llvm-project/issues/95471>
("nvptx64", _) => false,
// ABI bugs <https://github.com/rust-lang/rust/issues/125109> et al. (full
// list at <https://github.com/rust-lang/rust/issues/116909>)
("powerpc" | "powerpc64", _) => false,
// ABI unsupported <https://github.com/llvm/llvm-project/issues/41838>
("sparc", _) => false,
// Stack alignment bug <https://github.com/llvm/llvm-project/issues/77401>. NB: tests may
// not fail if our compiler-builtins is linked.
("x86", _) => false,
// MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054>
("x86_64", "windows") if target_env == "gnu" && target_abi != "llvm" => false,
// There are no known problems on other platforms, so the only requirement is that symbols
// are available. `compiler-builtins` provides all symbols required for core `f128`
// support, so this should work for everything else.
_ => true,
};
// Configure platforms that have reliable basics but may have unreliable math.
// LLVM is currently adding missing routines, <https://github.com/llvm/llvm-project/issues/93566>
let has_reliable_f16_math = has_reliable_f16
&& match (target_arch.as_str(), target_os.as_str()) {
// FIXME: Disabled on Miri as the intrinsics are not implemented yet.
_ if is_miri => false,
// x86 has a crash for `powi`: <https://github.com/llvm/llvm-project/issues/105747>
("x86" | "x86_64", _) => false,
// Assume that working `f16` means working `f16` math for most platforms, since
// operations just go through `f32`.
_ => true,
};
let has_reliable_f128_math = has_reliable_f128
&& match (target_arch.as_str(), target_os.as_str()) {
// FIXME: Disabled on Miri as the intrinsics are not implemented yet.
_ if is_miri => false,
// LLVM lowers `fp128` math to `long double` symbols even on platforms where
// `long double` is not IEEE binary128. See
// <https://github.com/llvm/llvm-project/issues/44744>.
//
// This rules out anything that doesn't have `long double` = `binary128`; <= 32 bits
// (ld is `f64`), anything other than Linux (Windows and MacOS use `f64`), and `x86`
// (ld is 80-bit extended precision).
("x86_64", _) => false,
(_, "linux") if target_pointer_width == 64 => true,
_ => false,
};
if has_reliable_f16 {
println!("cargo:rustc-cfg=reliable_f16");
}
if has_reliable_f128 {
println!("cargo:rustc-cfg=reliable_f128");
}
if has_reliable_f16_math {
println!("cargo:rustc-cfg=reliable_f16_math");
}
if has_reliable_f128_math {
println!("cargo:rustc-cfg=reliable_f128_math");
}
}