opt-dist: change build_dir field to be an actual build dir

make it configurable so users can set build.build-dir option in bootstrap.toml

src/tools/opt-dist/src/environment.rs

@@ -48,7 +48,7 @@ impl Environment {
     }
 
     pub fn build_artifacts(&self) -> Utf8PathBuf {
-        self.build_root().join("build").join(&self.host_tuple)
+        self.build_root().join(&self.host_tuple)
     }
 
     pub fn artifact_dir(&self) -> Utf8PathBuf {

src/tools/opt-dist/src/exec.rs

@@ -99,7 +99,7 @@ pub struct Bootstrap {
 
 impl Bootstrap {
     pub fn build(env: &Environment) -> Self {
-        let metrics_path = env.build_root().join("build").join("metrics.json");
+        let metrics_path = env.build_root().join("metrics.json");
         let cmd = cmd(&[
             env.python_binary(),
             env.checkout_path().join("x.py").as_str(),
@@ -119,7 +119,7 @@ impl Bootstrap {
     }
 
     pub fn dist(env: &Environment, dist_args: &[String]) -> Self {
-        let metrics_path = env.build_root().join("build").join("metrics.json");
+        let metrics_path = env.build_root().join("metrics.json");
         let args = dist_args.iter().map(|arg| arg.as_str()).collect::<Vec<_>>();
         let cmd = cmd(&args).env("RUST_BACKTRACE", "full");
         let mut cmd = add_shared_x_flags(env, cmd);

src/tools/opt-dist/src/main.rs

@@ -102,6 +102,11 @@ enum EnvironmentCmd {
         /// Will be LLVM built during the run?
         #[arg(long, default_value_t = true, action(clap::ArgAction::Set))]
         build_llvm: bool,
+
+        /// Set build artifacts dir. Relative to `checkout_dir`, should point to the directory set
+        /// in bootstrap.toml via `build.build-dir` option
+        #[arg(long, default_value = "build")]
+        build_dir: Utf8PathBuf,
     },
     /// Perform an optimized build on Linux CI, from inside Docker.
     LinuxCi {
@@ -138,6 +143,7 @@ fn create_environment(args: Args) -> anyhow::Result<(Environment, Vec<String>)>
             shared,
             run_tests,
             build_llvm,
+            build_dir,
         } => {
             let env = EnvironmentBuilder::default()
                 .host_tuple(target_triple)
@@ -145,7 +151,7 @@ fn create_environment(args: Args) -> anyhow::Result<(Environment, Vec<String>)>
                 .checkout_dir(checkout_dir.clone())
                 .host_llvm_dir(llvm_dir)
                 .artifact_dir(artifact_dir)
-                .build_dir(checkout_dir)
+                .build_dir(checkout_dir.join(build_dir))
                 .prebuilt_rustc_perf(rustc_perf_checkout_dir)
                 .shared_llvm(llvm_shared)
                 .use_bolt(use_bolt)
@@ -171,7 +177,7 @@ fn create_environment(args: Args) -> anyhow::Result<(Environment, Vec<String>)>
                 .checkout_dir(checkout_dir.clone())
                 .host_llvm_dir(Utf8PathBuf::from("/rustroot"))
                 .artifact_dir(Utf8PathBuf::from("/tmp/tmp-multistage/opt-artifacts"))
-                .build_dir(checkout_dir.join("obj"))
+                .build_dir(checkout_dir.join("obj").join("build"))
                 .shared_llvm(true)
                 // FIXME: Enable bolt for aarch64 once it's fixed upstream. Broken as of December 2024.
                 .use_bolt(!is_aarch64)
@@ -194,7 +200,7 @@ fn create_environment(args: Args) -> anyhow::Result<(Environment, Vec<String>)>
                 .checkout_dir(checkout_dir.clone())
                 .host_llvm_dir(checkout_dir.join("citools").join("clang-rust"))
                 .artifact_dir(checkout_dir.join("opt-artifacts"))
-                .build_dir(checkout_dir)
+                .build_dir(checkout_dir.join("build"))
                 .shared_llvm(false)
                 .use_bolt(false)
                 .skipped_tests(vec![])

src/tools/opt-dist/src/tests.rs

@@ -13,7 +13,7 @@ pub fn run_tests(env: &Environment) -> anyhow::Result<()> {
     // and then use that extracted rustc as a stage0 compiler.
     // Then we run a subset of tests using that compiler, to have a basic smoke test which checks
     // whether the optimization pipeline hasn't broken something.
-    let build_dir = env.build_root().join("build");
+    let build_dir = env.build_root();
     let dist_dir = build_dir.join("dist");
     let unpacked_dist_dir = build_dir.join("unpacked-dist");
     std::fs::create_dir_all(&unpacked_dist_dir)?;