Various caches for incremental compilation.

dart/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart

Index: dart/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart b/dart/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
index 900823debae97ed865376b6903a98f92076cd5c0..ef845d98650e4f1f1ec695d9734420c995717d26 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
@@ -6,6 +6,9 @@ part of js_backend;
 
 class NativeEmitter {
 
+  final Map<Element, ClassBuilder> cachedBuilders =
+      new HashMap<Element, ClassBuilder>.identity();

[Johnni Winther, 2014/06/19 09:22:32]

Ditto.

+
   CodeEmitterTask emitter;
   CodeBuffer nativeBuffer;
 
@@ -279,6 +282,16 @@ class NativeEmitter {
   }
 
   ClassBuilder generateNativeClass(ClassElement classElement) {
+    ClassBuilder builder;
+    if (compiler.hasIncrementalSupport) {
+      builder = cachedBuilders[classElement];
+      if (builder != null) return builder;
+      builder = new ClassBuilder(backend.namer);
+      cachedBuilders[classElement] = builder;
+    } else {
+      builder = new ClassBuilder(backend.namer);
+    }
+
     // TODO(sra): Issue #13731- this is commented out as part of custom element
     // constructor work.
     //assert(!classElement.hasBackendMembers);
@@ -294,7 +307,6 @@ class NativeEmitter {
 
     String superName = backend.namer.getNameOfClass(superclass);
 
-    ClassBuilder builder = new ClassBuilder(backend.namer);
     emitter.classEmitter.emitClassConstructor(classElement, builder);
     bool hasFields = emitter.classEmitter.emitFields(
         classElement, builder, superName, classIsNative: true);