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..46f56c5392ade2c0e7d44168a472135f5123ee49 100644
--- a/lib/compiler/implementation/compiler.dart
+++ b/lib/compiler/implementation/compiler.dart
@@ -56,6 +56,8 @@ class JavaScriptBackend extends Backend {
   SsaOptimizerTask optimizer;
   SsaCodeGeneratorTask generator;
   CodeEmitterTask emitter;
+  final Map<Element, Map<Element, HType>> fieldInitializers;
+  final Map<Element, Map<Element, bool>> fieldIntegerSetters;
 
   List<CompilerTask> get tasks() {
     return <CompilerTask>[builder, optimizer, generator, emitter];
@@ -63,6 +65,8 @@ class JavaScriptBackend extends Backend {
 
   JavaScriptBackend(Compiler compiler)
       : emitter = new CodeEmitterTask(compiler),
+        fieldInitializers = new Map<Element, Map<Element, HType>>(),
+        fieldIntegerSetters = new Map<Element, Map<Element, bool>>(),
         super(compiler) {
     builder = new SsaBuilderTask(this);
     optimizer = new SsaOptimizerTask(this);
@@ -101,6 +105,76 @@ class JavaScriptBackend extends Backend {
   void assembleProgram() {
     emitter.assembleProgram();
   }
+
+  void updateFieldInitializers(Type type,
+                               Element field,
+                               HType propagatedType) {
+    assert(field.isField());
+    Map<Element, HType> fields =
+        fieldInitializers.putIfAbsent(
+            type.element, () => new Map<Element, HType>());
+    if (!fields.containsKey(field)) {
+      fields[field] = propagatedType;
+    } else {
+      if (fields[field] != propagatedType) fields[field] = HType.UNKNOWN;

[floitsch, 2012/06/20 10:20:33]

can't you just union the types?

[Søren Gjesse, 2012/06/21 08:51:35]

Done, that should also be better.

+    }
+  }
+
+  bool couldHaveFieldSingleTypeInitializers(Type type,
+                                            Element field,
+                                            HType requestedType) {
+    assert(field.isField());
+    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<Element, HType> fields = fieldInitializers[type.element];
+    HType propagatedType = fields[field];
+    if (propagatedType == null) return true;
+    return propagatedType == requestedType;
+  }
+
+  bool hasFieldSingleTypeInitializers(Type type,
+                                      Element field,
+                                      HType requestedType) {
+    assert(field.isField());
+    if (type == null) return false;
+    if (!fieldInitializers.containsKey(type.element)) return false;
+    Map<Element, HType> fields = fieldInitializers[type.element];
+    HType propagatedType = fields[field];
+    if (propagatedType == null) return false;
+    return propagatedType == requestedType;
+  }
+
+  void updateFieldIntegerSetters(Type type, Element field, bool isInteger) {
+    assert(field.isField());
+    Map<Element, bool> fields =
+        fieldIntegerSetters.putIfAbsent(
+            type.element, () => new Map<Element, bool>());
+    if (!fields.containsKey(field)) {
+      fields[field] = isInteger;
+    } else {
+      fields[field] = fields[field] && isInteger;
+    }
+  }
+
+  bool couldHaveFieldOnlyIntegerSetters(Type type, Element field) {

[floitsch, 2012/06/20 10:20:33]

Doesn't the  field element contain the enclosing class? If yes it should be
enough to pass the field-element.

[Søren Gjesse, 2012/06/21 08:51:35]

It does. The element of the type can be a sub-class of the containing element
for the field, but that should be OK as we only use HFieldGet/Set when the field
name is unique in the class hierarchy.

+    assert(field.isField());
+    if (type == null) return false;
+    if (!fieldIntegerSetters.containsKey(type.element)) return true;
+    Map<Element, bool> fields = fieldIntegerSetters[type.element];
+    if (!fields.containsKey(field)) return false;
+    return fields[field];
+  }
+
+  bool hasFieldOnlyIntegerSetters(Type type, Element field) {

[floitsch, 2012/06/20 10:20:33]

I would remove this method. It is identical to the
couldHaveFieldOnlyIntegerSetters.
Also it is misleading. Even when returning true the field might still have
non-integer setters (if there are dynamic setters). So from this point of view
"couldHaveFieldOnly..." fills the role. I would also add a comment to couldHave
stating that it returns true if all seen (typed) setters have been integers.

[Søren Gjesse, 2012/06/21 08:51:35]

Changed the name to onlyFieldIntegerSettersSoFar (and dropped the other). Added
a comment. The name was supposed to indicate that the information is from
HFieldSet instructions only and does not include dynamic setters.

+    assert(field.isField());
+    if (type == null) return false;
+    if (!fieldIntegerSetters.containsKey(type.element)) return true;
+    Map<Element, bool> fields = fieldIntegerSetters[type.element];
+    if (!fields.containsKey(field)) return false;
+    return fields[field];
+  }
 }
 
 class Compiler implements DiagnosticListener {
@@ -549,7 +623,7 @@ class Compiler implements DiagnosticListener {
       // TODO(ahe): Add structured diagnostics to the compiler API and
       // use it to separate this from the --verbose option.
       if (phase == PHASE_RESOLVING) {
-        log('Resolved ${enqueuer.resolution.resolvedElements.length}'
+        log('Resolved ${enqueuer.resolution.resolvedElements.length} '
             'elements.');
         progress.reset();
       }