cps-ir: Implement boolean conversion in and use it to implement '&&', '||', and '?:'.

pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart

 // Copyright (c) 2014, 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 tree_ir_builder;
 
-import '../dart2jslib.dart' as dart2js;
 import '../dart_types.dart';
 import '../elements/elements.dart';
 import '../cps_ir/cps_ir_nodes.dart' as cps_ir;
 import 'tree_ir_nodes.dart';
+import 'package:compiler/src/js_backend/codegen/unsugar.dart'
+    as js_cps_ir show Boolify;

[sigurdm, 2014/11/20 12:47:28]

package import

+import 'package:compiler/src/constants/expressions.dart';
+import 'package:compiler/src/constants/values.dart';
+import 'package:compiler/src/common.dart' as dart2js;
 
 /**
  * Builder translates from CPS-based IR to direct-style Tree.
  *
  * A call `Invoke(fun, cont, args)`, where cont is a singly-referenced
  * non-exit continuation `Cont(v, body)` is translated into a direct-style call
  * whose value is bound in the continuation body:
  *
  * `LetVal(v, Invoke(fun, args), body)`
  *
@@ skipping 444 matching lines @@
   Expression visitContinuation(cps_ir.Continuation node) {
     // Until continuations with multiple uses are supported, they are not
     // visited.
     compiler.internalError(compiler.currentElement, 'Unexpected IR node.');
     return null;
   }
 
   Expression visitIsTrue(cps_ir.IsTrue node) {
     return getVariableReference(node.value);
   }
+
+  /**
+   * Boolean conversion maps any object o into a boolean. Boolean conversion is
+   * defined by the function application
+   *   (bool v){
+   *     assert(v != null);
+   *     return identical(v, true);
+   *   }(o)
+   */
+  Expression visitBoolify(js_cps_ir.Boolify node) {
+    /// TODO(karlklose): implement the assert(v != null) check.
+    return new InvokeStatic(
+        compiler.identicalFunction,
+        identicalSelector,
+        <Expression>[visitIsTrue(node), constantTrue]);
+  }
+
+  // Helpers.
+
+  dart2js.Selector get identicalSelector {
+    return new dart2js.Selector(
+        dart2js.SelectorKind.CALL,
+        'identical',
+        null,
+        2);
+  }
+
+  /// TOOD(karlklose): cache this?
+  Constant get constantTrue {
+    ConstantExpression trueValue =
+        new PrimitiveConstantExpression(new TrueConstantValue());
+    return new Constant(trueValue);
+  }
 }