| // 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"); |
| } |
| } |
