fasta: Cache relativizeUri(fileUri) on LibraryBuilder and ClassBuilder (or rather it's base class)

pkg/front_end/lib/src/fasta/builder/type_declaration_builder.dart

Index: pkg/front_end/lib/src/fasta/builder/type_declaration_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/builder/type_declaration_builder.dart b/pkg/front_end/lib/src/fasta/builder/type_declaration_builder.dart
index bb3ceb2c87cc15ffa1adcdb05481000a043f5159..3ea0d8dec94b79325dd62d6a0691187d4df3775b 100644
--- a/pkg/front_end/lib/src/fasta/builder/type_declaration_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/type_declaration_builder.dart
@@ -10,6 +10,9 @@ import 'builder.dart' show
     ModifierBuilder,
     TypeBuilder;
 
+import '../util/relativize.dart' show
+    relativizeUri;
+
 abstract class TypeDeclarationBuilder<T extends TypeBuilder, R>
     extends ModifierBuilder {
   final List<MetadataBuilder> metadata;
@@ -20,8 +23,16 @@ abstract class TypeDeclarationBuilder<T extends TypeBuilder, R>
 
   Builder parent;
 
-  TypeDeclarationBuilder(this.metadata, this.modifiers, this.name,
-      Builder parent, int charOffset, [Uri fileUri])
+  final Uri fileUri;
+  final String relativeFileUri;
+
+  TypeDeclarationBuilder(List<MetadataBuilder> metadata, int modifiers,
+      String name, Builder parent, int charOffset, [Uri fileUri])
+    : this._internal(metadata, modifiers, name, parent, charOffset, fileUri,
+        fileUri != null ? relativizeUri(fileUri) : parent?.relativeFileUri);
+
+  TypeDeclarationBuilder._internal(this.metadata, this.modifiers, this.name,
+      Builder parent, int charOffset, this.fileUri, this.relativeFileUri)

[ahe, 2017/02/21 14:15:22]

I think you can get away with one constructor here as well.

[kustermann, 2017/02/22 14:40:28]

Done - though now I have one subexpression evaluated twice. Don't think I can
avoid that with one constructor.

       : parent = parent, super(parent, charOffset, fileUri ?? parent?.fileUri);
 
   bool get isTypeDeclaration => true;