Refactor the collection of initializer list types

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 110d9d70608650a030bc9aa81822086d5f6a87b8..3ade4be683f686366192482aff80cce29607c9a3 100644
--- a/lib/compiler/implementation/compiler.dart
+++ b/lib/compiler/implementation/compiler.dart
@@ -34,8 +34,12 @@ class WorkItem {
 
 class Backend {
   final Compiler compiler;
+  final Map<Element, Map<SourceString, HType>> fieldInitializers;

[karlklose, 2012/06/19 15:07:40]

Why not move these datastructures to the JavaScriptBackend? The HTypes are JS
specific.

+  final Map<Element, Map<SourceString, bool>> fieldIntegerSetters;
 
-  Backend(this.compiler);
+  Backend(this.compiler)
+     : fieldInitializers = new Map<Element, Map<SourceString, HType>>(),
+       fieldIntegerSetters = new Map<Element, Map<SourceString, bool>>();
 
   void enqueueAllTopLevelFunctions(LibraryElement lib, Enqueuer world) {
     lib.forEachExport((Element e) {
@@ -49,6 +53,70 @@ class Backend {
                                      Collection<LibraryElement> libraries);
   abstract void assembleProgram();
   abstract List<CompilerTask> get tasks();
+
+  void updateFieldInitializers(Type type,
+                               SourceString name,
+                               HType propagatedType) {
+    Map<SourceString, HType> fields =
+        fieldInitializers.putIfAbsent(
+            type.element, () => new Map<SourceString, HType>());
+    if (!fields.containsKey(name)) {
+      fields[name] = propagatedType;
+    } else {
+      if (fields[name] != propagatedType) fields[name] = HType.UNKNOWN;
+    }
+  }
+
+  bool couldHaveFieldSingleTypeInitializers(Type type,
+                                            SourceString name,
+                                            HType requestedType) {
+    if (type == null) return false;
+    // If there is no information on the initializer it might still be
+    // initialized to integers only.
+    if (!fieldInitializers.containsKey(type.element)) return true;
+    Map<SourceString, HType> fields = fieldInitializers[type.element];
+    HType propagatedType = fields[name];
+    if (propagatedType == null) return true;
+    return propagatedType == requestedType;
+  }
+
+  bool hasFieldSingleTypeInitializers(Type type,
+                                      SourceString name,
+                                      HType requestedType) {
+    if (type == null) return false;
+    if (!fieldInitializers.containsKey(type.element)) return false;
+    Map<SourceString, HType> fields = fieldInitializers[type.element];
+    HType propagatedType = fields[name];
+    if (propagatedType == null) return false;
+    return propagatedType == requestedType;
+  }
+
+  void updateFieldIntegerSetters(Type type, SourceString name, bool isInteger) {
+    Map<SourceString, bool> fields =
+        fieldIntegerSetters.putIfAbsent(
+            type.element, () => new Map<SourceString, bool>());
+    if (!fields.containsKey(name)) {
+      fields[name] = isInteger;
+    } else {
+      fields[name] = fields[name] && isInteger;
+    }
+  }
+
+  bool couldHaveFieldOnlyIntegerSetters(Type type, SourceString name) {
+    if (type == null) return false;
+    if (!fieldIntegerSetters.containsKey(type.element)) return true;
+    Map<SourceString, bool> fields = fieldIntegerSetters[type.element];
+    if (!fields.containsKey(name)) return false;
+    return fields[name];
+  }
+
+  bool hasFieldOnlyIntegerSetters(Type type, SourceString name) {
+    if (type == null) return false;
+    if (!fieldIntegerSetters.containsKey(type.element)) return true;
+    Map<SourceString, bool> fields = fieldIntegerSetters[type.element];
+    if (!fields.containsKey(name)) return false;
+    return fields[name];
+  }
 }
 
 class JavaScriptBackend extends Backend {