diff options
Diffstat (limited to 'vendor/libc/build.rs')
-rw-r--r-- | vendor/libc/build.rs | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/vendor/libc/build.rs b/vendor/libc/build.rs new file mode 100644 index 0000000..ec93200 --- /dev/null +++ b/vendor/libc/build.rs @@ -0,0 +1,297 @@ +use std::env; +use std::process::Command; +use std::str; +use std::string::String; + +// List of cfgs this build script is allowed to set. The list is needed to support check-cfg, as we +// need to know all the possible cfgs that this script will set. If you need to set another cfg +// make sure to add it to this list as well. +const ALLOWED_CFGS: &'static [&'static str] = &[ + "emscripten_new_stat_abi", + "freebsd10", + "freebsd11", + "freebsd12", + "freebsd13", + "freebsd14", + "freebsd15", + "libc_align", + "libc_cfg_target_vendor", + "libc_const_extern_fn", + "libc_const_extern_fn_unstable", + "libc_const_size_of", + "libc_core_cvoid", + "libc_deny_warnings", + "libc_int128", + "libc_long_array", + "libc_non_exhaustive", + "libc_packedN", + "libc_priv_mod_use", + "libc_ptr_addr_of", + "libc_thread_local", + "libc_underscore_const_names", + "libc_union", +]; + +// Extra values to allow for check-cfg. +const CHECK_CFG_EXTRA: &'static [(&'static str, &'static [&'static str])] = &[ + ("target_os", &["switch", "aix", "ohos", "hurd"]), + ("target_env", &["illumos", "wasi", "aix", "ohos"]), + ( + "target_arch", + &["loongarch64", "mips32r6", "mips64r6", "csky"], + ), +]; + +fn main() { + // Avoid unnecessary re-building. + println!("cargo:rerun-if-changed=build.rs"); + + let (rustc_minor_ver, is_nightly) = rustc_minor_nightly(); + 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 libc_check_cfg = env::var("LIBC_CHECK_CFG").is_ok(); + + 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 std is backward compatible with FreeBSD 12. + // 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 => set_cfg("freebsd10"), + Some(11) if libc_ci => set_cfg("freebsd11"), + Some(12) if libc_ci || rustc_dep_of_std => set_cfg("freebsd12"), + Some(13) if libc_ci => set_cfg("freebsd13"), + Some(14) if libc_ci => set_cfg("freebsd14"), + Some(15) if libc_ci => set_cfg("freebsd15"), + Some(_) | None => set_cfg("freebsd11"), + } + + match emcc_version_code() { + Some(v) if (v >= 30142) => set_cfg("emscripten_new_stat_abi"), + // Non-Emscripten or version < 3.1.42. + Some(_) | None => (), + } + + // On CI: deny all warnings + if libc_ci { + set_cfg("libc_deny_warnings"); + } + + // Rust >= 1.15 supports private module use: + if rustc_minor_ver >= 15 || rustc_dep_of_std { + set_cfg("libc_priv_mod_use"); + } + + // Rust >= 1.19 supports unions: + if rustc_minor_ver >= 19 || rustc_dep_of_std { + set_cfg("libc_union"); + } + + // Rust >= 1.24 supports const mem::size_of: + if rustc_minor_ver >= 24 || rustc_dep_of_std { + set_cfg("libc_const_size_of"); + } + + // Rust >= 1.25 supports repr(align): + if rustc_minor_ver >= 25 || rustc_dep_of_std || align_cargo_feature { + set_cfg("libc_align"); + } + + // Rust >= 1.26 supports i128 and u128: + if rustc_minor_ver >= 26 || rustc_dep_of_std { + set_cfg("libc_int128"); + } + + // 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 { + set_cfg("libc_core_cvoid"); + } + + // Rust >= 1.33 supports repr(packed(N)) and cfg(target_vendor). + if rustc_minor_ver >= 33 || rustc_dep_of_std { + set_cfg("libc_packedN"); + set_cfg("libc_cfg_target_vendor"); + } + + // Rust >= 1.40 supports #[non_exhaustive]. + if rustc_minor_ver >= 40 || rustc_dep_of_std { + set_cfg("libc_non_exhaustive"); + } + + // Rust >= 1.47 supports long array: + if rustc_minor_ver >= 47 || rustc_dep_of_std { + set_cfg("libc_long_array"); + } + + if rustc_minor_ver >= 51 || rustc_dep_of_std { + set_cfg("libc_ptr_addr_of"); + } + + // Rust >= 1.37.0 allows underscores as anonymous constant names. + if rustc_minor_ver >= 37 || rustc_dep_of_std { + set_cfg("libc_underscore_const_names"); + } + + // #[thread_local] is currently unstable + if rustc_dep_of_std { + set_cfg("libc_thread_local"); + } + + // Rust >= 1.62.0 allows to use `const_extern_fn` for "Rust" and "C". + if rustc_minor_ver >= 62 { + set_cfg("libc_const_extern_fn"); + } else { + // Rust < 1.62.0 requires a crate feature and feature gate. + if const_extern_fn_cargo_feature { + if !is_nightly || rustc_minor_ver < 40 { + panic!("const-extern-fn requires a nightly compiler >= 1.40"); + } + set_cfg("libc_const_extern_fn_unstable"); + set_cfg("libc_const_extern_fn"); + } + } + + // check-cfg is a nightly cargo/rustc feature to warn when unknown cfgs are used across the + // codebase. libc can configure it if the appropriate environment variable is passed. Since + // rust-lang/rust enforces it, this is useful when using a custom libc fork there. + // + // https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg + if libc_check_cfg { + for cfg in ALLOWED_CFGS { + if rustc_minor_ver >= 75 { + println!("cargo:rustc-check-cfg=cfg({})", cfg); + } else { + println!("cargo:rustc-check-cfg=values({})", cfg); + } + } + for &(name, values) in CHECK_CFG_EXTRA { + let values = values.join("\",\""); + if rustc_minor_ver >= 75 { + println!("cargo:rustc-check-cfg=cfg({},values(\"{}\"))", name, values); + } else { + println!("cargo:rustc-check-cfg=values({},\"{}\")", name, values); + } + } + } +} + +fn rustc_minor_nightly() -> (u32, bool) { + macro_rules! otry { + ($e:expr) => { + match $e { + Some(e) => e, + None => panic!("Failed to get rustc version"), + } + }; + } + + let rustc = otry!(env::var_os("RUSTC")); + let output = Command::new(rustc) + .arg("--version") + .output() + .ok() + .expect("Failed to get rustc version"); + if !output.status.success() { + panic!( + "failed to run rustc: {}", + String::from_utf8_lossy(output.stderr.as_slice()) + ); + } + + let version = otry!(str::from_utf8(&output.stdout).ok()); + let mut pieces = version.split('.'); + + if pieces.next() != Some("rustc 1") { + panic!("Failed to get rustc version"); + } + + 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()); + + (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), + s if s.starts_with("14") => Some(14), + s if s.starts_with("15") => Some(15), + _ => None, + } +} + +fn emcc_version_code() -> Option<u64> { + let output = std::process::Command::new("emcc") + .arg("-dumpversion") + .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 version = stdout.unwrap(); + + // Some Emscripten versions come with `-git` attached, so split the + // version string also on the `-` char. + let mut pieces = version.trim().split(|c| c == '.' || c == '-'); + + let major = pieces.next().and_then(|x| x.parse().ok()).unwrap_or(0); + let minor = pieces.next().and_then(|x| x.parse().ok()).unwrap_or(0); + let patch = pieces.next().and_then(|x| x.parse().ok()).unwrap_or(0); + + Some(major * 10000 + minor * 100 + patch) +} + +fn set_cfg(cfg: &str) { + if !ALLOWED_CFGS.contains(&cfg) { + panic!("trying to set cfg {}, but it is not in ALLOWED_CFGS", cfg); + } + println!("cargo:rustc-cfg={}", cfg); +} |