Move types out of the HInstructions.

lib/compiler/implementation/compiler.dart

Index: lib/compiler/implementation/compiler.dart
diff --git a/lib/compiler/implementation/compiler.dart b/lib/compiler/implementation/compiler.dart
index 9853fa87d9eb8e195969797c190b654d2c844ff9..d013b4d1365be4fac5b9f8e9f330ac53ea63a3fd 100644
--- a/lib/compiler/implementation/compiler.dart
+++ b/lib/compiler/implementation/compiler.dart
@@ -14,13 +14,21 @@ final bool REPORT_EXCESS_RESOLUTION = false;
  */
 final bool REPORT_PASS2_OPTIMIZATIONS = false;
 
+/**
+ * Contains backend-specific data that is used throughout the compilation of
+ * one work item.
+ */
+class ItemCompilationContext {
+}
+
 class WorkItem {
+  final ItemCompilationContext compilationContext;
   final Element element;
   TreeElements resolutionTree;
   bool allowSpeculativeOptimization = true;
   List<HTypeGuard> guards = const <HTypeGuard>[];
 
-  WorkItem(this.element, this.resolutionTree);
+  WorkItem(this.element, this.resolutionTree, this.compilationContext);
 
   bool isAnalyzed() => resolutionTree !== null;
 
@@ -49,6 +57,17 @@ class Backend {
                                      Collection<LibraryElement> libraries);
   abstract void assembleProgram();
   abstract List<CompilerTask> get tasks();
+
+  ItemCompilationContext createItemCompilationContext() {
+    return new ItemCompilationContext();
+  }
+}
+
+class JavaScriptItemCompilationContext extends ItemCompilationContext {
+  final HTypeMap types;
+
+  JavaScriptItemCompilationContext()
+      : types = new HTypeMap();

[ngeoffray, 2012/08/16 13:07:00]

fits in one line

[floitsch, 2012/08/16 14:10:04]

Done.

 }
 
 class JavaScriptBackend extends Backend {
@@ -204,6 +223,10 @@ class JavaScriptBackend extends Backend {
     if (!fields.containsKey(field)) return HType.CONFLICTING;
     return fields[field];
   }
+
+  JavaScriptItemCompilationContext createItemCompilationContext() {
+    return new JavaScriptItemCompilationContext();
+  }
 }
 
 class Compiler implements DiagnosticListener {
@@ -1078,7 +1101,7 @@ class Tracer {
 
   const Tracer();
 
-  void traceCompilation(String methodName) {
+  void traceCompilation(String methodName, ItemCompilationContext context) {
   }
 
   void traceGraph(String name, var graph) {