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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/rustix/build.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | vendor/rustix/build.rs | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/vendor/rustix/build.rs b/vendor/rustix/build.rs new file mode 100644 index 000000000..f6fa64579 --- /dev/null +++ b/vendor/rustix/build.rs @@ -0,0 +1,192 @@ +#[cfg(feature = "cc")] +use cc::Build; +use std::env::var; +use std::io::Write; + +/// The directory for out-of-line ("outline") libraries. +const OUTLINE_PATH: &str = "src/imp/linux_raw/arch/outline"; + +fn main() { + // Don't rerun this on changes other than build.rs, as we only depend on + // the rustc version. + println!("cargo:rerun-if-changed=build.rs"); + + use_feature_or_nothing("rustc_attrs"); + + // Features only used in no-std configurations. + #[cfg(not(feature = "std"))] + { + use_feature_or_nothing("const_raw_ptr_deref"); + use_feature_or_nothing("core_ffi_c"); + use_feature_or_nothing("core_c_str"); + use_feature_or_nothing("alloc_c_string"); + } + + // Gather target information. + let arch = var("CARGO_CFG_TARGET_ARCH").unwrap(); + let asm_name = format!("{}/{}.s", OUTLINE_PATH, arch); + let asm_name_present = std::fs::metadata(&asm_name).is_ok(); + let os_name = var("CARGO_CFG_TARGET_OS").unwrap(); + let pointer_width = var("CARGO_CFG_TARGET_POINTER_WIDTH").unwrap(); + let endian = var("CARGO_CFG_TARGET_ENDIAN").unwrap(); + + // Check for special target variants. + let is_x32 = arch == "x86_64" && pointer_width == "32"; + let is_arm64_ilp32 = arch == "aarch64" && pointer_width == "32"; + let is_powerpc64be = arch == "powerpc64" && endian == "big"; + let is_mipseb = arch == "mips" && endian == "big"; + let is_mips64eb = arch == "mips64" && endian == "big"; + let is_unsupported_abi = is_x32 || is_arm64_ilp32 || is_powerpc64be || is_mipseb || is_mips64eb; + + // Check for `--features=use-libc`. This allows crate users to enable the + // libc backend. + let feature_use_libc = var("CARGO_FEATURE_USE_LIBC").is_ok(); + + // Check for `--features=rustc-dep-of-std`. This is used when rustix is + // being used to build std, in which case `can_compile` doesn't work + // because `core` isn't available yet, but also, we can assume we have a + // recent compiler. + let feature_rustc_dep_of_std = var("CARGO_FEATURE_RUSTC_DEP_OF_STD").is_ok(); + + // Check for `RUSTFLAGS=--cfg=rustix_use_libc`. This allows end users to + // enable the libc backend even if rustix is depended on transitively. + let cfg_use_libc = var("CARGO_CFG_RUSTIX_USE_LIBC").is_ok(); + + // Check for eg. `RUSTFLAGS=--cfg=rustix_use_experimental_asm`. This is a + // rustc flag rather than a cargo feature flag because it's experimental + // and not something we want accidentally enabled via `--all-features`. + let rustix_use_experimental_asm = var("CARGO_CFG_RUSTIX_USE_EXPERIMENTAL_ASM").is_ok(); + + // Miri doesn't support inline asm, and has builtin support for recognizing + // libc FFI calls, so if we're running under miri, use the libc backend. + let miri = var("CARGO_CFG_MIRI").is_ok(); + + // If the libc backend is requested, or if we're not on a platform for + // which we have linux_raw support, use the libc backend. + // + // For now Android uses the libc backend; in theory it could use the + // linux_raw backend, but to do that we'll need to figure out how to + // install the toolchain for it. + if feature_use_libc + || cfg_use_libc + || os_name != "linux" + || !asm_name_present + || is_unsupported_abi + || miri + { + // Use the libc backend. + use_feature("libc"); + } else { + // Use the linux_raw backend. + use_feature("linux_raw"); + use_feature_or_nothing("core_intrinsics"); + + // Use inline asm if we have it, or outline asm otherwise. On PowerPC + // and MIPS, Rust's inline asm is considered experimental, so only use + // it if `--cfg=rustix_use_experimental_asm` is given. + if (feature_rustc_dep_of_std || can_compile("use std::arch::asm;")) + && (arch != "x86" || has_feature("naked_functions")) + && ((arch != "powerpc64" && arch != "mips" && arch != "mips64") + || rustix_use_experimental_asm) + { + use_feature("asm"); + if arch == "x86" { + use_feature("naked_functions"); + } + if rustix_use_experimental_asm { + use_feature("asm_experimental_arch"); + } + } else { + link_in_librustix_outline(&arch, &asm_name); + } + } + + println!("cargo:rerun-if-env-changed=CARGO_CFG_RUSTIX_USE_EXPERIMENTAL_ASM"); +} + +/// Link in the desired version of librustix_outline_{arch}.a, containing the +/// outline assembly code for making syscalls. +fn link_in_librustix_outline(arch: &str, asm_name: &str) { + let name = format!("rustix_outline_{}", arch); + let profile = var("PROFILE").unwrap(); + let to = format!("{}/{}/lib{}.a", OUTLINE_PATH, profile, name); + println!("cargo:rerun-if-changed={}", to); + + // If "cc" is not enabled, use a pre-built library. + #[cfg(not(feature = "cc"))] + { + let _ = asm_name; + println!("cargo:rustc-link-search={}/{}", OUTLINE_PATH, profile); + println!("cargo:rustc-link-lib=static={}", name); + } + + // If "cc" is enabled, build the library from source, update the pre-built + // version, and assert that the pre-built version is checked in. + #[cfg(feature = "cc")] + { + let out_dir = var("OUT_DIR").unwrap(); + Build::new().file(&asm_name).compile(&name); + println!("cargo:rerun-if-changed={}", asm_name); + if std::fs::metadata(".git").is_ok() { + let from = format!("{}/lib{}.a", out_dir, name); + let prev_metadata = std::fs::metadata(&to); + std::fs::copy(&from, &to).unwrap(); + assert!( + prev_metadata.is_ok(), + "{} didn't previously exist; please inspect the new file and `git add` it", + to + ); + assert!( + std::process::Command::new("git") + .arg("diff") + .arg("--quiet") + .arg(&to) + .status() + .unwrap() + .success(), + "{} changed; please inspect the change and `git commit` it", + to + ); + } + } +} + +fn use_feature_or_nothing(feature: &str) { + if has_feature(feature) { + use_feature(feature); + } +} + +fn use_feature(feature: &str) { + println!("cargo:rustc-cfg={}", feature); +} + +/// Test whether the rustc at `var("RUSTC")` supports the given feature. +fn has_feature(feature: &str) -> bool { + can_compile(&format!( + "#![allow(stable_features)]\n#![feature({})]", + feature + )) +} + +/// Test whether the rustc at `var("RUSTC")` can compile the given code. +fn can_compile(code: &str) -> bool { + use std::process::Stdio; + let out_dir = var("OUT_DIR").unwrap(); + let rustc = var("RUSTC").unwrap(); + + let mut child = std::process::Command::new(rustc) + .arg("--crate-type=rlib") // Don't require `main`. + .arg("--emit=metadata") // Do as little as possible but still parse. + .arg("--out-dir") + .arg(out_dir) // Put the output somewhere inconsequential. + .arg("-") // Read from stdin. + .stdin(Stdio::piped()) // Stdin is a pipe. + .stderr(Stdio::null()) + .spawn() + .unwrap(); + + writeln!(child.stdin.take().unwrap(), "{}", code).unwrap(); + + child.wait().unwrap().success() +} |