remove stage-specific artifacts when --stage is used

Signed-off-by: ozkanonur <work@onurozkan.dev>

src/bootstrap/clean.rs

@@ -26,10 +26,15 @@ fn make_run(run: RunConfig<'_>) {
     }
 
     fn run(self, builder: &Builder<'_>) -> Self::Output {
-        let Subcommand::Clean { all, .. } = builder.config.cmd else {
+        let Subcommand::Clean { all, stage } = builder.config.cmd else {
             unreachable!("wrong subcommand?")
         };
-        clean_default(builder.build, all)
+
+        if all && stage.is_some() {
+            panic!("--all and --stage can't be used at the same time for `x clean`");
+        }
+
+        clean(builder.build, all, stage)
     }
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -86,16 +91,52 @@ fn run(self, builder: &Builder<'_>) -> Self::Output {
     Std, Mode::Std, "sysroot";
 }
 
-fn clean_default(build: &Build, all: bool) {
+fn clean(build: &Build, all: bool, stage: Option<u32>) {
     if build.config.dry_run() {
         return;
     }
 
     rm_rf("tmp".as_ref());
 
+    // Clean the entire build directory
     if all {
         rm_rf(&build.out);
-    } else {
+        return;
+    }
+
+    // Clean the target stage artifacts
+    if let Some(stage) = stage {
+        clean_specific_stage(build, stage);
+        return;
+    }
+
+    // Follow the default behaviour
+    clean_default(build);
+}
+
+fn clean_specific_stage(build: &Build, stage: u32) {
+    for host in &build.hosts {
+        let entries = match build.out.join(host.triple).read_dir() {
+            Ok(iter) => iter,
+            Err(_) => continue,
+        };
+
+        for entry in entries {
+            let entry = t!(entry);
+            let stage_prefix = format!("stage{}", stage);
+
+            // if current entry is not related with the target stage, continue
+            if !entry.file_name().to_str().unwrap_or("").contains(&stage_prefix) {
+                continue;
+            }
+
+            let path = t!(entry.path().canonicalize());
+            rm_rf(&path);
+        }
+    }
+}
+
+fn clean_default(build: &Build) {
     rm_rf(&build.out.join("tmp"));
     rm_rf(&build.out.join("dist"));
     rm_rf(&build.out.join("bootstrap"));
@@ -116,7 +157,6 @@ fn clean_default(build: &Build, all: bool) {
             rm_rf(&path);
         }
     }
-    }
 }
 
 fn rm_rf(path: &Path) {