libc-rs/build.rs

153 lines
5.0 KiB
Rust

use std::env;
use std::process::Command;
use std::str;
fn main() {
let (rustc_minor_ver, is_nightly) =
rustc_minor_nightly().expect("Failed to get rustc version");
let rustc_dep_of_std = env::var("CARGO_FEATURE_RUSTC_DEP_OF_STD").is_ok();
let align_cargo_feature = env::var("CARGO_FEATURE_ALIGN").is_ok();
let const_extern_fn_cargo_feature =
env::var("CARGO_FEATURE_CONST_EXTERN_FN").is_ok();
let libc_ci = env::var("LIBC_CI").is_ok();
let target = env::var("TARGET").unwrap();
if env::var("CARGO_FEATURE_USE_STD").is_ok() {
println!(
"cargo:warning=\"libc's use_std cargo feature is deprecated since libc 0.2.55; \
please consider using the `std` cargo feature instead\""
);
}
// The ABI of libc used by libstd is backward compatible with FreeBSD 10.
// The ABI of libc from crates.io is backward compatible with FreeBSD 11.
//
// On CI, we detect the actual FreeBSD version and match its ABI exactly,
// running tests to ensure that the ABI is correct.
match which_freebsd() {
Some(10) if libc_ci || rustc_dep_of_std => {
println!("cargo:rustc-cfg=freebsd10")
}
Some(11) if libc_ci => println!("cargo:rustc-cfg=freebsd11"),
Some(12) if libc_ci => println!("cargo:rustc-cfg=freebsd12"),
Some(13) if libc_ci => println!("cargo:rustc-cfg=freebsd13"),
Some(_) | None => println!("cargo:rustc-cfg=freebsd11"),
}
// On CI: deny all warnings
if libc_ci {
println!("cargo:rustc-cfg=libc_deny_warnings");
}
// Rust >= 1.15 supports private module use:
if rustc_minor_ver >= 15 || rustc_dep_of_std {
println!("cargo:rustc-cfg=libc_priv_mod_use");
}
// Rust >= 1.19 supports unions:
if rustc_minor_ver >= 19 || rustc_dep_of_std {
println!("cargo:rustc-cfg=libc_union");
}
// Rust >= 1.24 supports const mem::size_of:
if rustc_minor_ver >= 24 || rustc_dep_of_std {
println!("cargo:rustc-cfg=libc_const_size_of");
}
// Rust >= 1.25 supports repr(align):
if rustc_minor_ver >= 25 || rustc_dep_of_std || align_cargo_feature {
println!("cargo:rustc-cfg=libc_align");
}
// Rust >= 1.30 supports `core::ffi::c_void`, so libc can just re-export it.
// Otherwise, it defines an incompatible type to retaining
// backwards-compatibility.
if rustc_minor_ver >= 30 || rustc_dep_of_std {
println!("cargo:rustc-cfg=libc_core_cvoid");
}
// Rust >= 1.33 supports repr(packed(N)) and cfg(target_vendor).
if rustc_minor_ver >= 33 || rustc_dep_of_std {
println!("cargo:rustc-cfg=libc_packedN");
println!("cargo:rustc-cfg=libc_cfg_target_vendor");
}
// #[thread_local] is currently unstable
if rustc_dep_of_std {
println!("cargo:rustc-cfg=libc_thread_local");
}
if const_extern_fn_cargo_feature {
if !is_nightly || rustc_minor_ver < 40 {
panic!("const-extern-fn requires a nightly compiler >= 1.40")
}
println!("cargo:rustc-cfg=libc_const_extern_fn");
}
// For unknown reason, libiconv can't be linked by adding #[link(name = iconv)] to
// a macOS-specific struct, so we do the linking here.
if target.contains("-apple-") {
println!("cargo:rustc-link-lib=iconv");
}
}
fn rustc_minor_nightly() -> Option<(u32, bool)> {
macro_rules! otry {
($e:expr) => {
match $e {
Some(e) => e,
None => return None,
}
};
}
let rustc = otry!(env::var_os("RUSTC"));
let output = otry!(Command::new(rustc).arg("--version").output().ok());
let version = otry!(str::from_utf8(&output.stdout).ok());
let mut pieces = version.split('.');
if pieces.next() != Some("rustc 1") {
return None;
}
let minor = pieces.next();
// If `rustc` was built from a tarball, its version string
// will have neither a git hash nor a commit date
// (e.g. "rustc 1.39.0"). Treat this case as non-nightly,
// since a nightly build should either come from CI
// or a git checkout
let nightly_raw = otry!(pieces.next()).split('-').nth(1);
let nightly = nightly_raw
.map(|raw| raw.starts_with("dev") || raw.starts_with("nightly"))
.unwrap_or(false);
let minor = otry!(otry!(minor).parse().ok());
Some((minor, nightly))
}
fn which_freebsd() -> Option<i32> {
let output = std::process::Command::new("freebsd-version").output().ok();
if output.is_none() {
return None;
}
let output = output.unwrap();
if !output.status.success() {
return None;
}
let stdout = String::from_utf8(output.stdout).ok();
if stdout.is_none() {
return None;
}
let stdout = stdout.unwrap();
match &stdout {
s if s.starts_with("10") => Some(10),
s if s.starts_with("11") => Some(11),
s if s.starts_with("12") => Some(12),
s if s.starts_with("13") => Some(13),
_ => None,
}
}