1 files changed, 162 insertions, 0 deletions
diff --git a/third_party/rust/target-lexicon-0.9.0/build.rs b/third_party/rust/target-lexicon-0.9.0/build.rs
new file mode 100644
index 0000000000..a0ba3b7304
--- /dev/null
+++ b/third_party/rust/target-lexicon-0.9.0/build.rs
@@ -0,0 +1,162 @@
+//! build.rs file to obtain the host information.
+
+// Allow dead code in triple.rs and targets.rs for our purposes here.
+#![allow(dead_code)]
+
+use std::env;
+use std::fs::File;
+use std::io::{self, Write};
+use std::path::PathBuf;
+use std::str::FromStr;
+
+extern crate alloc;
+
+// Include triple.rs and targets.rs so we can parse the TARGET environment variable.
+mod triple {
+    include!("src/triple.rs");
+}
+mod targets {
+    include!("src/targets.rs");
+}
+
+// Stub out `ParseError` to minimally support triple.rs and targets.rs.
+mod parse_error {
+    #[derive(Debug)]
+    pub enum ParseError {
+        UnrecognizedArchitecture(String),
+        UnrecognizedVendor(String),
+        UnrecognizedOperatingSystem(String),
+        UnrecognizedEnvironment(String),
+        UnrecognizedBinaryFormat(String),
+        UnrecognizedField(String),
+    }
+}
+
+use self::triple::Triple;
+
+fn main() {
+    let out_dir =
+        PathBuf::from(env::var("OUT_DIR").expect("The OUT_DIR environment variable must be set"));
+    let target = env::var("TARGET").expect("The TARGET environment variable must be set");
+    let triple = Triple::from_str(&target).expect(&format!("Invalid target name: '{}'", target));
+    let out = File::create(out_dir.join("host.rs")).expect("error creating host.rs");
+    write_host_rs(out, triple).expect("error writing host.rs");
+}
+
+fn write_host_rs(mut out: File, triple: Triple) -> io::Result<()> {
+    // The generated Debug implementation for the inner architecture variants
+    // doesn't print the enum name qualifier, so import them here. There
+    // shouldn't be any conflicts because these enums all share a namespace
+    // in the triple string format.
+    writeln!(out, "#[allow(unused_imports)]")?;
+    writeln!(out, "use crate::Aarch64Architecture::*;")?;
+    writeln!(out, "#[allow(unused_imports)]")?;
+    writeln!(out, "use crate::ArmArchitecture::*;")?;
+    writeln!(out)?;
+    writeln!(out, "/// The `Triple` of the current host.")?;
+    writeln!(out, "pub const HOST: Triple = Triple {{")?;
+    writeln!(
+        out,
+        "    architecture: Architecture::{:?},",
+        triple.architecture
+    )?;
+    writeln!(out, "    vendor: Vendor::{:?},", triple.vendor)?;
+    writeln!(
+        out,
+        "    operating_system: OperatingSystem::{:?},",
+        triple.operating_system
+    )?;
+    writeln!(
+        out,
+        "    environment: Environment::{:?},",
+        triple.environment
+    )?;
+    writeln!(
+        out,
+        "    binary_format: BinaryFormat::{:?},",
+        triple.binary_format
+    )?;
+    writeln!(out, "}};")?;
+    writeln!(out)?;
+
+    writeln!(out, "impl Architecture {{")?;
+    writeln!(out, "    /// Return the architecture for the current host.")?;
+    writeln!(out, "    pub const fn host() -> Self {{")?;
+    writeln!(out, "        Architecture::{:?}", triple.architecture)?;
+    writeln!(out, "    }}")?;
+    writeln!(out, "}}")?;
+    writeln!(out)?;
+
+    writeln!(out, "impl Vendor {{")?;
+    writeln!(out, "    /// Return the vendor for the current host.")?;
+    writeln!(out, "    pub const fn host() -> Self {{")?;
+    writeln!(out, "        Vendor::{:?}", triple.vendor)?;
+    writeln!(out, "    }}")?;
+    writeln!(out, "}}")?;
+    writeln!(out)?;
+
+    writeln!(out, "impl OperatingSystem {{")?;
+    writeln!(
+        out,
+        "    /// Return the operating system for the current host."
+    )?;
+    writeln!(out, "    pub const fn host() -> Self {{")?;
+    writeln!(
+        out,
+        "        OperatingSystem::{:?}",
+        triple.operating_system
+    )?;
+    writeln!(out, "    }}")?;
+    writeln!(out, "}}")?;
+    writeln!(out)?;
+
+    writeln!(out, "impl Environment {{")?;
+    writeln!(out, "    /// Return the environment for the current host.")?;
+    writeln!(out, "    pub const fn host() -> Self {{")?;
+    writeln!(out, "        Environment::{:?}", triple.environment)?;
+    writeln!(out, "    }}")?;
+    writeln!(out, "}}")?;
+    writeln!(out)?;
+
+    writeln!(out, "impl BinaryFormat {{")?;
+    writeln!(
+        out,
+        "    /// Return the binary format for the current host."
+    )?;
+    writeln!(out, "    pub const fn host() -> Self {{")?;
+    writeln!(out, "        BinaryFormat::{:?}", triple.binary_format)?;
+    writeln!(out, "    }}")?;
+    writeln!(out, "}}")?;
+    writeln!(out)?;
+
+    writeln!(out, "impl Triple {{")?;
+    writeln!(out, "    /// Return the triple for the current host.")?;
+    writeln!(out, "    pub const fn host() -> Self {{")?;
+    writeln!(out, "        Self {{")?;
+    writeln!(
+        out,
+        "            architecture: Architecture::{:?},",
+        triple.architecture
+    )?;
+    writeln!(out, "            vendor: Vendor::{:?},", triple.vendor)?;
+    writeln!(
+        out,
+        "            operating_system: OperatingSystem::{:?},",
+        triple.operating_system
+    )?;
+    writeln!(
+        out,
+        "            environment: Environment::{:?},",
+        triple.environment
+    )?;
+    writeln!(
+        out,
+        "            binary_format: BinaryFormat::{:?},",
+        triple.binary_format
+    )?;
+    writeln!(out, "        }}")?;
+    writeln!(out, "    }}")?;
+    writeln!(out, "}}")?;
+
+    Ok(())
+}