Make it possible to attach opaque string metadata to StepMetadata

Author: Kobzol

src/bootstrap/src/core/builder/mod.rs

@@ -146,6 +146,8 @@ pub struct StepMetadata {
     target: TargetSelection,
     built_by: Option<Compiler>,
     stage: Option<u32>,
+    /// Additional opaque string printed in the metadata
+    metadata: Option<String>,
 }
 
 impl StepMetadata {
@@ -170,7 +172,7 @@ impl StepMetadata {
     }
 
     fn new(name: &'static str, target: TargetSelection, kind: Kind) -> Self {
-        Self { name, kind, target, built_by: None, stage: None }
+        Self { name, kind, target, built_by: None, stage: None, metadata: None }
     }
 
     pub fn built_by(mut self, compiler: Compiler) -> Self {
@@ -183,6 +185,11 @@ impl StepMetadata {
         self
     }
 
+    pub fn with_metadata(mut self, metadata: String) -> Self {
+        self.metadata = Some(metadata);
+        self
+    }
+
     pub fn get_stage(&self) -> Option<u32> {
         self.stage.or(self
             .built_by

src/bootstrap/src/core/builder/tests.rs

@@ -1587,7 +1587,7 @@ impl ExecutedSteps {
 }
 
 fn fuzzy_metadata_eq(executed: &StepMetadata, to_match: &StepMetadata) -> bool {
-    let StepMetadata { name, kind, target, built_by: _, stage: _ } = executed;
+    let StepMetadata { name, kind, target, built_by: _, stage: _, metadata } = executed;
     *name == to_match.name && *kind == to_match.kind && *target == to_match.target
 }
 
@@ -1648,6 +1648,9 @@ fn render_metadata(metadata: &StepMetadata) -> String {
     }
     let stage = metadata.get_stage().map(|stage| format!("{stage} ")).unwrap_or_default();
     write!(record, "{} {stage}<{}>", metadata.name, normalize_target(metadata.target));
+    if let Some(metadata) = &metadata.metadata {
+        write!(record, " {metadata}");
+    }
     record
 }