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|
// Configuration shared with both libm and libm-test
use std::env;
use std::path::PathBuf;
#[allow(dead_code)]
pub struct Config {
pub manifest_dir: PathBuf,
pub out_dir: PathBuf,
pub opt_level: String,
pub cargo_features: Vec<String>,
pub target_arch: String,
pub target_env: String,
pub target_family: Option<String>,
pub target_os: String,
pub target_string: String,
pub target_vendor: String,
pub target_features: Vec<String>,
}
impl Config {
pub fn from_env() -> Self {
let target_features = env::var("CARGO_CFG_TARGET_FEATURE")
.map(|feats| feats.split(',').map(ToOwned::to_owned).collect())
.unwrap_or_default();
let cargo_features = env::vars()
.filter_map(|(name, _value)| name.strip_prefix("CARGO_FEATURE_").map(ToOwned::to_owned))
.map(|s| s.to_lowercase().replace("_", "-"))
.collect();
Self {
manifest_dir: PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap()),
out_dir: PathBuf::from(env::var("OUT_DIR").unwrap()),
opt_level: env::var("OPT_LEVEL").unwrap(),
cargo_features,
target_arch: env::var("CARGO_CFG_TARGET_ARCH").unwrap(),
target_env: env::var("CARGO_CFG_TARGET_ENV").unwrap(),
target_family: env::var("CARGO_CFG_TARGET_FAMILY").ok(),
target_os: env::var("CARGO_CFG_TARGET_OS").unwrap(),
target_string: env::var("TARGET").unwrap(),
target_vendor: env::var("CARGO_CFG_TARGET_VENDOR").unwrap(),
target_features,
}
}
}
/// Libm gets most config options made available.
#[allow(dead_code)]
pub fn emit_libm_config(cfg: &Config) {
emit_intrinsics_cfg();
emit_arch_cfg();
emit_optimization_cfg(cfg);
emit_cfg_shorthands(cfg);
emit_cfg_env(cfg);
emit_f16_f128_cfg(cfg);
}
/// Tests don't need most feature-related config.
#[allow(dead_code)]
pub fn emit_test_config(cfg: &Config) {
emit_optimization_cfg(cfg);
emit_cfg_shorthands(cfg);
emit_cfg_env(cfg);
emit_f16_f128_cfg(cfg);
}
/// Simplify the feature logic for enabling intrinsics so code only needs to use
/// `cfg(intrinsics_enabled)`.
fn emit_intrinsics_cfg() {
println!("cargo:rustc-check-cfg=cfg(intrinsics_enabled)");
// Disabled by default; `unstable-intrinsics` enables again; `force-soft-floats` overrides
// to disable.
if cfg!(feature = "unstable-intrinsics") && !cfg!(feature = "force-soft-floats") {
println!("cargo:rustc-cfg=intrinsics_enabled");
}
}
/// Simplify the feature logic for enabling arch-specific features so code only needs to use
/// `cfg(arch_enabled)`.
fn emit_arch_cfg() {
println!("cargo:rustc-check-cfg=cfg(arch_enabled)");
// Enabled by default via the "arch" feature, `force-soft-floats` overrides to disable.
if cfg!(feature = "arch") && !cfg!(feature = "force-soft-floats") {
println!("cargo:rustc-cfg=arch_enabled");
}
}
/// Some tests are extremely slow. Emit a config option based on optimization level.
fn emit_optimization_cfg(cfg: &Config) {
println!("cargo:rustc-check-cfg=cfg(optimizations_enabled)");
if !matches!(cfg.opt_level.as_str(), "0" | "1") {
println!("cargo:rustc-cfg=optimizations_enabled");
}
}
/// Provide an alias for common longer config combinations.
fn emit_cfg_shorthands(cfg: &Config) {
println!("cargo:rustc-check-cfg=cfg(x86_no_sse)");
if cfg.target_arch == "x86" && !cfg.target_features.iter().any(|f| f == "sse") {
// Shorthand to detect i586 targets
println!("cargo:rustc-cfg=x86_no_sse");
}
}
/// Reemit config that we make use of for test logging.
fn emit_cfg_env(cfg: &Config) {
println!(
"cargo:rustc-env=CFG_CARGO_FEATURES={:?}",
cfg.cargo_features
);
println!("cargo:rustc-env=CFG_OPT_LEVEL={}", cfg.opt_level);
println!(
"cargo:rustc-env=CFG_TARGET_FEATURES={:?}",
cfg.target_features
);
}
/// Configure whether or not `f16` and `f128` support should be enabled.
fn emit_f16_f128_cfg(cfg: &Config) {
println!("cargo:rustc-check-cfg=cfg(f16_enabled)");
println!("cargo:rustc-check-cfg=cfg(f128_enabled)");
// `unstable-float` enables these features.
if !cfg!(feature = "unstable-float") {
return;
}
// Set whether or not `f16` and `f128` are supported at a basic level by LLVM. This only means
// that the backend will not crash when using these types and generates code that can be called
// without crashing (no infinite recursion). This does not mean that the platform doesn't have
// ABI or other bugs.
//
// We do this here rather than in `rust-lang/rust` because configuring via cargo features is
// not straightforward.
//
// Original source of this list:
// <https://github.com/rust-lang/compiler-builtins/pull/652#issuecomment-2266151350>
let f16_enabled = match cfg.target_arch.as_str() {
// Unsupported <https://github.com/llvm/llvm-project/issues/94434>
"arm64ec" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/50374>
"s390x" => false,
// Infinite recursion <https://github.com/llvm/llvm-project/issues/97981>
// FIXME(llvm): loongarch fixed by <https://github.com/llvm/llvm-project/pull/107791>
"csky" => false,
"hexagon" => false,
"loongarch64" => false,
"mips" | "mips64" | "mips32r6" | "mips64r6" => false,
"powerpc" | "powerpc64" => false,
"sparc" | "sparc64" => false,
"wasm32" | "wasm64" => false,
// Most everything else works as of LLVM 19
_ => true,
};
let f128_enabled = match cfg.target_arch.as_str() {
// Unsupported (libcall is not supported) <https://github.com/llvm/llvm-project/issues/121122>
"amdgpu" => false,
// Unsupported <https://github.com/llvm/llvm-project/issues/94434>
"arm64ec" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/96432>
"mips64" | "mips64r6" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/95471>
"nvptx64" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/101545>
"powerpc64" if &cfg.target_os == "aix" => false,
// Selection failure <https://github.com/llvm/llvm-project/issues/41838>
"sparc" => false,
// Most everything else works as of LLVM 19
_ => true,
};
// If the feature is set, disable these types.
let disable_both = env::var_os("CARGO_FEATURE_NO_F16_F128").is_some();
println!("cargo:rustc-check-cfg=cfg(f16_enabled)");
println!("cargo:rustc-check-cfg=cfg(f128_enabled)");
if f16_enabled && !disable_both {
println!("cargo:rustc-cfg=f16_enabled");
}
if f128_enabled && !disable_both {
println!("cargo:rustc-cfg=f128_enabled");
}
}
|
