Collect the actual types for all field setters.

lib/compiler/implementation/compiler.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
 final bool REPORT_EXCESS_RESOLUTION = false;
@@ skipping 40 matching lines @@
   abstract List<CompilerTask> get tasks();
 }
 
 class JavaScriptBackend extends Backend {
   SsaBuilderTask builder;
   SsaOptimizerTask optimizer;
   SsaCodeGeneratorTask generator;
   CodeEmitterTask emitter;
   final Map<Element, Map<Element, HType>> fieldInitializers;
   final Map<Element, Map<Element, HType>> fieldConstructorSetters;
-  final Map<Element, Map<Element, bool>> fieldIntegerSetters;
+  final Map<Element, Map<Element, HType>> fieldSettersType;
 
   List<CompilerTask> get tasks() {
     return <CompilerTask>[builder, optimizer, generator, emitter];
   }
 
   JavaScriptBackend(Compiler compiler, bool generateSourceMap)
       : emitter = new CodeEmitterTask(compiler, generateSourceMap),
         fieldInitializers = new Map<Element, Map<Element, HType>>(),
         fieldConstructorSetters = new Map<Element, Map<Element, HType>>(),
-        fieldIntegerSetters = new Map<Element, Map<Element, bool>>(),
+        fieldSettersType = new Map<Element, Map<Element, HType>>(),
         super(compiler) {
     builder = new SsaBuilderTask(this);
     optimizer = new SsaOptimizerTask(this);
     generator = new SsaCodeGeneratorTask(this);
   }
 
   void enqueueHelpers(Enqueuer world) {
     enqueueAllTopLevelFunctions(compiler.jsHelperLibrary, world);
     enqueueAllTopLevelFunctions(compiler.interceptorsLibrary, world);
     for (var helper in [const SourceString('Closure'),
@@ skipping 101 matching lines @@
         return HType.UNKNOWN;
       }
     } else if (fieldInitializers.containsKey(field.enclosingElement)) {
       HType type = fieldInitializers[field.enclosingElement][field];
       return type == null ? HType.UNKNOWN : type;
     } else {
       return HType.UNKNOWN;
     }
   }
 
-  void updateFieldIntegerSetters(Element field, bool isInteger) {
+  void updateFieldSetters(Element field, HType type) {
     assert(field.isField());
     assert(field.enclosingElement.isClass());
     Map<Element, bool> fields =
-        fieldIntegerSetters.putIfAbsent(
-          field.enclosingElement, () => new Map<Element, bool>());
+        fieldSettersType.putIfAbsent(
+          field.enclosingElement, () => new Map<Element, HType>());
     if (!fields.containsKey(field)) {
-      fields[field] = isInteger;
+      fields[field] = type;
     } else {
-      fields[field] = fields[field] && isInteger;
+      fields[field] = fields[field].union(type);
     }
   }
 
   // Returns whether nothing but setters setting the field to an integer have
   // been seen during compilation so far.
-  bool onlyFieldIntegerSettersSoFar(Element field) {
+  HType fieldSettersTypeSoFar(Element field) {
     assert(field.isField());
     assert(field.enclosingElement.isClass());
-    if (!fieldIntegerSetters.containsKey(field.enclosingElement)) return true;
-    Map<Element, bool> fields = fieldIntegerSetters[field.enclosingElement];
-    if (!fields.containsKey(field)) return false;
+    if (!fieldSettersType.containsKey(field.enclosingElement)) {
+      return HType.UNKNOWN;
+    }
+    Map<Element, Htype> fields = fieldSettersType[field.enclosingElement];
+    if (!fields.containsKey(field)) return HType.UNKNOWN;
     return fields[field];
   }
 }
 
 class Compiler implements DiagnosticListener {
   final Map<String, LibraryElement> libraries;
   int nextFreeClassId = 0;
   World world;
   String assembledCode;
   Namer namer;
@@ skipping 768 matching lines @@
                      f(int beginOffset, int endOffset)) {
     final beginOffset = begin.charOffset;
     final endOffset = end.charOffset + end.slowCharCount;
 
     // [begin] and [end] might be the same for the same empty token. This
     // happens for instance when scanning '$$'.
     assert(endOffset >= beginOffset);
     return f(beginOffset, endOffset);
   }
 }