Factor out resolvedRelativePath

Author: David Ungar

Sources/SwiftDriver/Driver/OutputFileMap.swift

@@ -246,10 +246,3 @@ extension String {
     return self + "." + ext
   }
 }
-
-extension VirtualPath {
-  fileprivate func resolvedRelativePath(base: AbsolutePath) -> VirtualPath {
-    guard case let .relative(relPath) = self else { return self }
-    return .absolute(.init(base, relPath))
-  }
-}

Sources/SwiftDriver/Incremental Compilation/BuildRecordInfo.swift

@@ -96,7 +96,9 @@ import SwiftOptions
       diagnosticEngine.emit(.warning_incremental_requires_build_record_entry)
       return nil
     }
-    return partialBuildRecordPath.resolveRelativePath(workingDirectory)
+    return workingDirectory
+      .map(partialBuildRecordPath.resolvedRelativePath(base:))
+      ?? partialBuildRecordPath
   }
 
   /// Write out the build record.
@@ -178,12 +180,3 @@ import SwiftOptions
     }
   }
 }
-
-extension VirtualPath {
-  fileprivate func resolveRelativePath(_ workingDirectory: AbsolutePath?) -> VirtualPath {
-    switch (workingDirectory, self) {
-    case let (wd?, .relative(relPath)): return .absolute(.init(wd, relPath))
-    default: return self
-    }
-  }
-}

Sources/SwiftDriver/Utilities/VirtualPath.swift

@@ -346,6 +346,14 @@ extension VirtualPath {
   }
 }
 
+extension VirtualPath {
+  /// Resolve a relative path into an absolute one, if possible.
+  public func resolvedRelativePath(base: AbsolutePath) -> VirtualPath {
+    guard case let .relative(relPath) = self else { return self }
+    return .absolute(.init(base, relPath))
+  }
+}
+
 private extension String {
   func withoutExt(_ ext: String?) -> String {
     if let ext = ext {