summaryrefslogtreecommitdiffstats
path: root/vendor/rustix/build.rs
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /vendor/rustix/build.rs
parentInitial commit. (diff)
downloadrustc-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 'vendor/rustix/build.rs')
-rw-r--r--vendor/rustix/build.rs192
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()
+}