Avoid hard-coded rustc when building wrappers

Author: bjorn3

build_system/build_sysroot.rs

@@ -3,7 +3,9 @@ use std::path::Path;
 use std::process::{self, Command};
 
 use super::path::{Dirs, RelPath};
-use super::rustc_info::{get_file_name, get_rustc_version, get_wrapper_file_name};
+use super::rustc_info::{
+    get_file_name, get_rustc_version, get_toolchain_name, get_wrapper_file_name,
+};
 use super::utils::{spawn_and_wait, try_hard_link, CargoProject, Compiler};
 use super::SysrootKind;
 
@@ -44,8 +46,9 @@ pub(crate) fn build_sysroot(
     for wrapper in ["rustc-clif", "rustdoc-clif", "cargo-clif"] {
         let wrapper_name = get_wrapper_file_name(wrapper, "bin");
 
-        let mut build_cargo_wrapper_cmd = Command::new("rustc");
+        let mut build_cargo_wrapper_cmd = Command::new(&bootstrap_host_compiler.rustc);
         build_cargo_wrapper_cmd
+            .env("TOOLCHAIN_NAME", get_toolchain_name())
             .arg(RelPath::SCRIPTS.to_path(dirs).join(&format!("{wrapper}.rs")))
             .arg("-o")
             .arg(DIST_DIR.to_path(dirs).join(wrapper_name))

build_system/rustc_info.rs

@@ -23,6 +23,16 @@ pub(crate) fn get_host_triple() -> String {
         .to_owned()
 }
 
+pub(crate) fn get_toolchain_name() -> String {
+    let active_toolchain = Command::new("rustup")
+        .stderr(Stdio::inherit())
+        .args(&["show", "active-toolchain"])
+        .output()
+        .unwrap()
+        .stdout;
+    String::from_utf8(active_toolchain).unwrap().trim().split_once(' ').unwrap().0.to_owned()
+}
+
 pub(crate) fn get_cargo_path() -> PathBuf {
     let cargo_path = Command::new("rustup")
         .stderr(Stdio::inherit())

scripts/cargo-clif.rs

@@ -26,7 +26,7 @@ fn main() {
     env::set_var("RUSTDOCFLAGS", env::var("RUSTDOCFLAGS").unwrap_or(String::new()) + &rustflags);
 
     // Ensure that the right toolchain is used
-    env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));
+    env::set_var("RUSTUP_TOOLCHAIN", env!("TOOLCHAIN_NAME"));
 
     let args: Vec<_> = match env::args().nth(1).as_deref() {
         Some("jit") => {

scripts/rustc-clif.rs

@@ -24,7 +24,7 @@ fn main() {
     }
 
     // Ensure that the right toolchain is used
-    env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));
+    env::set_var("RUSTUP_TOOLCHAIN", env!("TOOLCHAIN_NAME"));
 
     #[cfg(unix)]
     Command::new("rustc").args(args).exec();

scripts/rustdoc-clif.rs

@@ -24,7 +24,7 @@ fn main() {
     }
 
     // Ensure that the right toolchain is used
-    env::set_var("RUSTUP_TOOLCHAIN", env!("RUSTUP_TOOLCHAIN"));
+    env::set_var("RUSTUP_TOOLCHAIN", env!("TOOLCHAIN_NAME"));
 
     #[cfg(unix)]
     Command::new("rustdoc").args(args).exec();