Implement InstanceMirror.== in dart2js and InstanceMirror.hashCode in the VM and dart2js.

BUG=http://dartbug.com/12909
BUG=http://dartbug.com/12919
R=ahe@google.com, asiva@google.com

Review URL: https://codereview.chromium.org//23460013

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@27075 260f80e4-7a28-3924-810f-c04153c831b5

runtime/lib/mirrors.cc

@@ -751,6 +751,18 @@ DEFINE_NATIVE_ENTRY(TypeVariableMirror_upper_bound, 1) {
 }
 
 
+DEFINE_NATIVE_ENTRY(InstanceMirror_identityHash, 1) {
+  GET_NATIVE_ARGUMENT(Instance, reflectee, arguments->NativeArgAt(0));
+  ObjectStore* object_store = isolate->object_store();
+  const Class& cls = Class::Handle(isolate, object_store->object_class());
+  const Function& function =
+      Function::Handle(isolate, cls.LookupDynamicFunction(Symbols::hashCode()));
+  const Array& args = Array::Handle(isolate, Array::New(1));
+  args.SetAt(0, reflectee);
+  return DartEntry::InvokeFunction(function, args);
+}
+
+
 // Invoke the function, or noSuchMethod if it is null. Propagate any unhandled
 // exceptions. Wrap and propagate any compilation errors.
 static RawObject* ReflectivelyInvokeDynamicFunction(const Instance& receiver,

runtime/lib/mirrors_impl.dart

@@ -283,8 +283,21 @@ class _LocalInstanceMirrorImpl extends _LocalObjectMirrorImpl
            identical(_reflectee, other._reflectee);
   }
 
-  // TODO(12909): Use the reflectee's identity hash.
-  int get hashCode => _reflectee.hashCode;
+  int get hashCode {
+    // If the reflectee is a double or bignum, use the base hashCode to preserve
+    // the illusion that boxed numbers with the same value are identical. If the
+    // reflectee is a Smi, use the base hashCode because Object.hashCode does
+    // not work for non-heap objects. Otherwise, use Object.hashCode to maintain
+    // correctness even if a user-defined hashCode returns different values for
+    // successive invocations.
+    var h = _reflectee is num ? _reflectee.hashCode : _identityHash(_reflectee);
+    // Avoid hash collisions with the reflectee. This constant is in Smi range
+    // and happens to be the inner padding from RFC 2104.
+    return h ^ 0x36363636;
+  }
+
+  static _identityHash(reflectee)
+      native "InstanceMirror_identityHash";
 
   _invoke(reflectee, functionName, positionalArguments)
       native 'InstanceMirror_invoke';

runtime/vm/bootstrap_natives.h

@@ -253,6 +253,7 @@ namespace dart {
   V(Mirrors_makeLocalTypeMirror, 1)                                            \
   V(Mirrors_makeLocalMirrorSystem, 0)                                          \
   V(MirrorReference_equals, 2)                                                 \
+  V(InstanceMirror_identityHash, 1)                                            \
   V(InstanceMirror_invoke, 4)                                                  \
   V(InstanceMirror_invokeGetter, 3)                                            \
   V(InstanceMirror_invokeSetter, 4)                                            \

runtime/vm/symbols.h

@@ -284,6 +284,7 @@ class ObjectPointerVisitor;
   V(_LocalMirrorSystemImpl, "_LocalMirrorSystemImpl")                          \
   V(_LocalTypedefMirrorImpl, "_LocalTypedefMirrorImpl")                        \
   V(_LocalTypeVariableMirrorImpl, "_LocalTypeVariableMirrorImpl")              \
+  V(hashCode, "get:hashCode")                                                  \
   V(_leftShiftWithMask32, "_leftShiftWithMask32")                              \
 
 

sdk/lib/_internal/lib/js_mirrors.dart

@@ -677,6 +677,26 @@ class JsInstanceMirror extends JsObjectMirror implements InstanceMirror {
     return JSInvocationMirror.invokeFromMirror(invocation, reflectee);
   }
 
+  operator ==(other) {
+    return other is JsInstanceMirror &&
+           identical(reflectee, other.reflectee);
+  }
+
+  int get hashCode {
+    // If the reflectee is a built-in type, use the base-level hashCode to
+    // preserve the illusion that, e.g. doubles, with the same value are
+    // identical. Otherwise, use the primitive identity hash to maintain
+    // correctness even if a user-defined hashCode returns different values for
+    // successive invocations.
+    var h = ((JS('bool', 'typeof # != "object"', reflectee)) || 
+             (reflectee == null))
+        ? reflectee.hashCode
+        : Primitives.objectHashCode(reflectee);
+    // Avoid hash collisions with the reflectee. This constant is in Smi range
+    // and happens to be the inner padding from RFC 2104.
+    return h ^ 0x36363636;
+  }
+
   String toString() => 'InstanceMirror on ${Error.safeToString(reflectee)}';
 
   // TODO(ahe): Remove this method from the API.

tests/lib/lib.status

@@ -13,7 +13,7 @@ math/random_test: Fail
 mirrors/invoke_test: Fail # Issue 11954
 mirrors/class_mirror_type_variables_test: Fail # Issue 12087
 mirrors/invoke_private_test: Fail # Issue 12164
-mirrors/equality_test: Fail # Issue 12333, 12919
+mirrors/equality_test: Fail # Issue 12333
 mirrors/function_type_mirror_test: Fail # Issue 12166
 mirrors/generics_test: Fail # Issue 12333
 mirrors/hierarchy_invariants_test: Fail # Issue 11863

tests/lib/mirrors/equality_dart2js_test.dart

@@ -0,0 +1,112 @@
+// Copyright (c) 2013, 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.
+
+library test.class_equality_test;
+
+import 'dart:mirrors';
+
+import 'package:expect/expect.dart';
+
+class A<T> {}
+class B extends A<int> {}
+
+class BadEqualityHash {
+  int count = 0;
+  bool operator ==(other) => true;
+  int get hashCode => count++;
+}
+
+checkEquality(List<Map> equivalenceClasses) {
+  for (var equivalenceClass in equivalenceClasses) {
+    equivalenceClass.forEach((name, member) {
+      equivalenceClass.forEach((otherName, otherMember) {
+        // Reflexivity, symmetry and transitivity.
+        Expect.equals(member, 
+                      otherMember,
+                      "$name == $otherName");
+        Expect.equals(member.hashCode,
+                      otherMember.hashCode,
+                      "$name.hashCode == $otherName.hashCode");
+      });
+      for (var otherEquivalenceClass in equivalenceClasses) {
+        if (otherEquivalenceClass == equivalenceClass) continue;
+        otherEquivalenceClass.forEach((otherName, otherMember) {
+          Expect.notEquals(member,
+                           otherMember,
+                           "$name != $otherName");  // Exclusion.
+          // Hash codes may or may not be equal.
+        });
+      }
+    });
+  }
+}
+
+void subroutine() {
+}
+
+main() {
+  LibraryMirror thisLibrary =
+      currentMirrorSystem()
+      .findLibrary(const Symbol('test.class_equality_test'))
+      .single;
+
+  var o1 = new Object();
+  var o2 = new Object();
+
+  var badEqualityHash1 = new BadEqualityHash();
+  var badEqualityHash2 = new BadEqualityHash();
+
+  checkEquality([
+    {'reflect(o1)' : reflect(o1),
+     'reflect(o1), again' : reflect(o1)},
+
+    {'reflect(o2)' : reflect(o2),
+     'reflect(o2), again' : reflect(o2)},
+
+    {'reflect(badEqualityHash1)' : reflect(badEqualityHash1),
+     'reflect(badEqualityHash1), again' : reflect(badEqualityHash1)},
+
+    {'reflect(badEqualityHash2)' : reflect(badEqualityHash2),
+     'reflect(badEqualityHash2), again' : reflect(badEqualityHash2)},
+
+    {'reflect(true)' : reflect(true),
+     'reflect(true), again' : reflect(true)},
+
+    {'reflect(false)' : reflect(false),
+     'reflect(false), again' : reflect(false)},
+
+    {'reflect(null)' : reflect(null),
+     'reflect(null), again' : reflect(null)},
+
+    {'reflect(3.5+4.5)' : reflect(3.5+4.5),
+     'reflect(6.5+1.5)' : reflect(6.5+1.5)},
+
+    {'reflect(3+4)' : reflect(3+4),
+     'reflect(6+1)' : reflect(6+1)},
+
+    {'reflect("foo")' : reflect("foo"),
+     'reflect("foo"), again' : reflect("foo")},
+
+    {'currentMirrorSystem().voidType' : currentMirrorSystem().voidType},
+
+    {'currentMirrorSystem().dynamicType' : currentMirrorSystem().dynamicType,
+     'thisLibrary.functions[#main].returnType' :
+          thisLibrary.functions[const Symbol('main')].returnType},
+
+    {'reflectClass(A)' : reflectClass(A),
+     'thisLibrary.classes[#A]' : thisLibrary.classes[const Symbol('A')],
+     'reflect(new A<int>()).type.originalDeclaration' :
+          reflect(new A<int>()).type.originalDeclaration},
+
+    {'reflectClass(B)' : reflectClass(B),
+     'thisLibrary.classes[#B]' : thisLibrary.classes[const Symbol('B')],
+     'reflect(new B()).type' : reflect(new B()).type},
+
+    {'thisLibrary' : thisLibrary,
+     'reflectClass(A).owner' : reflectClass(A).owner,
+     'reflectClass(B).owner' : reflectClass(B).owner,
+     'reflect(new A()).type.owner' : reflect(new A()).type.owner,
+     'reflect(new A()).type.owner' : reflect(new A()).type.owner},
+  ]);
+}

tests/lib/mirrors/equality_test.dart

@@ -11,6 +11,12 @@ import 'package:expect/expect.dart';
 class A<T> {}
 class B extends A<int> {}
 
+class BadEqualityHash {
+  int count = 0;
+  bool operator ==(other) => true;
+  int get hashCode => count++;
+}
+
 checkEquality(List<Map> equivalenceClasses) {
   for (var equivalenceClass in equivalenceClasses) {
     equivalenceClass.forEach((name, member) {
@@ -45,8 +51,11 @@ main() {
       .findLibrary(const Symbol('test.class_equality_test'))
       .single;
 
-  Object o1 = new Object();
-  Object o2 = new Object();
+  var o1 = new Object();
+  var o2 = new Object();
+
+  var badEqualityHash1 = new BadEqualityHash();
+  var badEqualityHash2 = new BadEqualityHash();
 
   checkEquality([
     {'reflect(o1)' : reflect(o1),
@@ -55,9 +64,30 @@ main() {
     {'reflect(o2)' : reflect(o2),
      'reflect(o2), again' : reflect(o2)},
 
+    {'reflect(badEqualityHash1)' : reflect(badEqualityHash1),
+     'reflect(badEqualityHash1), again' : reflect(badEqualityHash1)},
+
+    {'reflect(badEqualityHash2)' : reflect(badEqualityHash2),
+     'reflect(badEqualityHash2), again' : reflect(badEqualityHash2)},
+
+    {'reflect(true)' : reflect(true),
+     'reflect(true), again' : reflect(true)},
+
+    {'reflect(false)' : reflect(false),
+     'reflect(false), again' : reflect(false)},
+
+    {'reflect(null)' : reflect(null),
+     'reflect(null), again' : reflect(null)},
+
+    {'reflect(3.5+4.5)' : reflect(3.5+4.5),
+     'reflect(6.5+1.5)' : reflect(6.5+1.5)},
+
     {'reflect(3+4)' : reflect(3+4),
      'reflect(6+1)' : reflect(6+1)},
 
+    {'reflect("foo")' : reflect("foo"),
+     'reflect("foo"), again' : reflect("foo")},
+
     {'currentMirrorSystem().voidType' : currentMirrorSystem().voidType,
      'thisLibrary.functions[#subroutine].returnType' :
           thisLibrary.functions[const Symbol('subroutine')].returnType},