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|
// Configuration shared with both libm and libm-test
use std::path::PathBuf;
use std::process::{Command, Stdio};
use std::{env, str};
#[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_triple: 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>,
pub reliable_f128: bool,
pub reliable_f16: bool,
}
impl Config {
pub fn from_env() -> Self {
let target_triple = env::var("TARGET").unwrap();
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();
// Query rustc for options that Cargo does not provide env for. The bootstrap hack is used
// to get consistent output regardless of channel (`f16`/`f128` config options are hidden
// on stable otherwise).
let mut cmd = Command::new(env::var("RUSTC").unwrap());
cmd.args(["--print=cfg", "--target", &target_triple])
.env("RUSTC_BOOTSTRAP", "1")
.stderr(Stdio::inherit());
let out = cmd
.output()
.unwrap_or_else(|e| panic!("failed to run `{cmd:?}`: {e}"));
let rustc_cfg = str::from_utf8(&out.stdout).unwrap();
// If we couldn't query `rustc` (e.g. a custom JSON target was used), make the safe
// choice and leave `f16` and `f128` disabled.
let rustc_output_ok = out.status.success();
let reliable_f128 =
rustc_output_ok && rustc_cfg.lines().any(|l| l == "target_has_reliable_f128");
let reliable_f16 =
rustc_output_ok && rustc_cfg.lines().any(|l| l == "target_has_reliable_f16");
Self {
target_triple,
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,
reliable_f128,
reliable_f16,
}
}
}
/// 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;
}
/* See the compiler-builtins configure file for info about the meaning of these options */
// If the feature is set, disable both of these types.
let no_f16_f128 = cfg.cargo_features.iter().any(|s| s == "no-f16-f128");
println!("cargo:rustc-check-cfg=cfg(f16_enabled)");
if cfg.reliable_f16 && !no_f16_f128 {
println!("cargo:rustc-cfg=f16_enabled");
}
println!("cargo:rustc-check-cfg=cfg(f128_enabled)");
if cfg.reliable_f128 && !no_f16_f128 {
println!("cargo:rustc-cfg=f128_enabled");
}
}
|
