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|
use std::env;
//use std::ffi::OsString;
//use std::process::Command;
fn main() {
// We don't currently need to check the Version anymore...
// But leaving this in place in case we need to in the future.
/*
let rustc = env::var_os("RUSTC").unwrap_or(OsString::from("rustc"));
let output = Command::new(&rustc)
.arg("--version")
.output()
.expect("failed to check 'rustc --version'")
.stdout;
let version = String::from_utf8(output)
.expect("rustc version output should be utf-8");
*/
enable_new_features(/*&version*/);
}
fn enable_new_features(/*raw_version: &str*/) {
/*
let version = match Version::parse(raw_version) {
Ok(version) => version,
Err(err) => {
println!("cargo:warning=failed to parse `rustc --version`: {}", err);
return;
}
};
*/
enable_simd(/*version*/);
}
fn enable_simd(/*version: Version*/) {
if env::var_os("CARGO_FEATURE_STD").is_none() {
println!("cargo:warning=building for no_std disables httparse SIMD");
return;
}
if env::var_os("CARGO_CFG_MIRI").is_some() {
println!("cargo:warning=building for Miri disables httparse SIMD");
return;
}
let env_disable = "CARGO_CFG_HTTPARSE_DISABLE_SIMD";
if var_is(env_disable, "1") {
println!("cargo:warning=detected {} environment variable, disabling SIMD", env_disable);
return;
}
println!("cargo:rustc-cfg=httparse_simd");
// cfg(target_feature) isn't stable yet, but CARGO_CFG_TARGET_FEATURE has
// a list... We aren't doing anything unsafe, since the is_x86_feature_detected
// macro still checks in the actual lib, BUT!
//
// By peeking at the list here, we can change up slightly how we do feature
// detection in the lib. If our features aren't in the feature list, we
// stick with a cached runtime detection strategy.
//
// But if the features *are* in the list, we benefit from removing our cache,
// since the compiler will eliminate several branches with its internal
// cfg(target_feature) usage.
let env_runtime_only = "CARGO_CFG_HTTPARSE_DISABLE_SIMD_COMPILETIME";
if var_is(env_runtime_only, "1") {
println!("cargo:warning=detected {} environment variable, using runtime SIMD detection only", env_runtime_only);
return;
}
let feature_list = match env::var_os("CARGO_CFG_TARGET_FEATURE") {
Some(var) => match var.into_string() {
Ok(s) => s,
Err(_) => {
println!("cargo:warning=CARGO_CFG_TARGET_FEATURE was not valid utf-8");
return;
},
},
None => {
println!("cargo:warning=CARGO_CFG_TARGET_FEATURE was not set");
return
},
};
let mut saw_sse42 = false;
let mut saw_avx2 = false;
for feature in feature_list.split(',') {
let feature = feature.trim();
if !saw_sse42 && feature == "sse4.2" {
saw_sse42 = true;
println!("cargo:rustc-cfg=httparse_simd_target_feature_sse42");
}
if !saw_avx2 && feature == "avx2" {
saw_avx2 = true;
println!("cargo:rustc-cfg=httparse_simd_target_feature_avx2");
}
}
}
/*
#[derive(Debug, Clone, Copy, PartialEq, PartialOrd)]
struct Version {
major: u32,
minor: u32,
patch: u32,
}
impl Version {
fn parse(mut s: &str) -> Result<Version, String> {
if !s.starts_with("rustc ") {
return Err(format!("unrecognized version string: {}", s));
}
s = &s["rustc ".len()..];
let parts: Vec<&str> = s.split(".").collect();
if parts.len() < 3 {
return Err(format!("not enough version parts: {:?}", parts));
}
let mut num = String::new();
for c in parts[0].chars() {
if !c.is_digit(10) {
break;
}
num.push(c);
}
let major = num.parse::<u32>().map_err(|e| e.to_string())?;
num.clear();
for c in parts[1].chars() {
if !c.is_digit(10) {
break;
}
num.push(c);
}
let minor = num.parse::<u32>().map_err(|e| e.to_string())?;
num.clear();
for c in parts[2].chars() {
if !c.is_digit(10) {
break;
}
num.push(c);
}
let patch = num.parse::<u32>().map_err(|e| e.to_string())?;
Ok(Version {
major: major,
minor: minor,
patch: patch,
})
}
}
*/
fn var_is(key: &str, val: &str) -> bool {
match env::var(key) {
Ok(v) => v == val,
Err(_) => false,
}
}
|
