Delete CPS IR

pkg/compiler/lib/src/js_backend/codegen/unsugar.dart

Index: pkg/compiler/lib/src/js_backend/codegen/unsugar.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/unsugar.dart b/pkg/compiler/lib/src/js_backend/codegen/unsugar.dart
deleted file mode 100644
index 02db2c45c0f4f0fa04d076ffeb84b5748f1057bb..0000000000000000000000000000000000000000
--- a/pkg/compiler/lib/src/js_backend/codegen/unsugar.dart
+++ /dev/null
@@ -1,244 +0,0 @@
-library dart2js.unsugar_cps;
-
-import '../../common/names.dart';
-import '../../constants/values.dart';
-import '../../cps_ir/cps_fragment.dart';
-import '../../cps_ir/cps_ir_nodes.dart';
-import '../../cps_ir/optimizers.dart' show Pass;
-import '../../elements/elements.dart';
-import '../../js_backend/codegen/glue.dart';
-import '../../universe/selector.dart' show Selector;
-
-class ExplicitReceiverParameterEntity implements Local {
-  String get name => 'receiver';
-  final ExecutableElement executableContext;
-  ExplicitReceiverParameterEntity(this.executableContext);
-  toString() => 'ExplicitReceiverParameterEntity($executableContext)';
-}
-
-/// Suggested name for an interceptor.
-class InterceptorEntity extends Entity {
-  Entity interceptedVariable;
-
-  InterceptorEntity(this.interceptedVariable);
-
-  String get name => interceptedVariable.name + '_';
-}
-
-/// Rewrites the initial CPS IR to make Dart semantics explicit and inserts
-/// special nodes that respect JavaScript behavior.
-///
-/// Performs the following rewrites:
-///  - Add interceptors at call sites that use interceptor calling convention.
-///  - Add explicit receiver argument for methods that are called in interceptor
-///    calling convention.
-///  - Convert two-parameter exception handlers to one-parameter ones.
-class UnsugarVisitor extends TrampolineRecursiveVisitor implements Pass {
-  Glue _glue;
-
-  FunctionDefinition function;
-
-  Parameter get receiverParameter => function.receiverParameter;
-
-  /// The interceptor of the receiver.  For some methods, this is the receiver
-  /// itself, for others, it is the interceptor parameter.
-  Parameter receiverInterceptor;
-
-  // In a catch block, rethrow implicitly throws the block's exception
-  // parameter.  This is the exception parameter when nested in a catch
-  // block and null otherwise.
-  Parameter _exceptionParameter = null;
-
-  UnsugarVisitor(this._glue);
-
-  String get passName => 'Unsugaring';
-
-  void rewrite(FunctionDefinition function) {
-    this.function = function;
-    bool inInterceptedMethod = _glue.isInterceptedMethod(function.element);
-
-    if (function.element.name == '==' &&
-        function.parameters.length == 1 &&
-        !_glue.operatorEqHandlesNullArgument(function.element)) {
-      // Insert the null check that the language semantics requires us to
-      // perform before calling operator ==.
-      insertEqNullCheck(function);
-    }
-
-    if (inInterceptedMethod) {
-      function.interceptorParameter = new Parameter(null)..parent = function;
-      // Since the receiver won't be compiled to "this", set a hint on it
-      // so the parameter gets a meaningful name.
-      function.receiverParameter.hint =
-          new ExplicitReceiverParameterEntity(function.element);
-      // If we need an interceptor for the receiver, use the receiver itself
-      // if possible, otherwise the interceptor argument.
-      receiverInterceptor = _glue.methodUsesReceiverArgument(function.element)
-          ? function.interceptorParameter
-          : receiverParameter;
-    }
-
-    visit(function);
-  }
-
-  Constant get trueConstant {
-    return new Constant(new TrueConstantValue());
-  }
-
-  Constant get falseConstant {
-    return new Constant(new FalseConstantValue());
-  }
-
-  Constant get nullConstant {
-    return new Constant(new NullConstantValue());
-  }
-
-  void insertEqNullCheck(FunctionDefinition function) {
-    // Replace
-    //
-    //     body;
-    //
-    // with
-    //
-    //     if (identical(arg, null))
-    //       return false;
-    //     else
-    //       body;
-    //
-    CpsFragment cps = new CpsFragment();
-    Primitive isNull = cps.applyBuiltin(BuiltinOperator.Identical,
-        <Primitive>[function.parameters.single, cps.makeNull()]);
-    CpsFragment trueBranch = cps.ifTruthy(isNull);
-    trueBranch.invokeContinuation(
-        function.returnContinuation, <Primitive>[trueBranch.makeFalse()]);
-    cps.insertAbove(function.body);
-  }
-
-  /// Insert a static call to [function] immediately above [node].
-  Primitive insertStaticCallAbove(
-      FunctionElement function, List<Primitive> arguments, Expression node) {
-    // TODO(johnniwinther): Come up with an implementation of SourceInformation
-    // for calls such as this one that don't appear in the original source.
-    InvokeStatic invoke = new InvokeStatic(
-        function, new Selector.fromElement(function), arguments, null);
-    new LetPrim(invoke).insertAbove(node);
-    return invoke;
-  }
-
-  @override
-  Expression traverseLetHandler(LetHandler node) {
-    assert(node.handler.parameters.length == 2);
-    Parameter previousExceptionParameter = _exceptionParameter;
-
-    // BEFORE: Handlers have two parameters, exception and stack trace.
-    // AFTER: Handlers have a single parameter, which is unwrapped to get
-    // the exception and stack trace.
-    _exceptionParameter = node.handler.parameters.first;
-    Parameter stackTraceParameter = node.handler.parameters.last;
-    Expression body = node.handler.body;
-    if (_exceptionParameter.hasAtLeastOneUse ||
-        stackTraceParameter.hasAtLeastOneUse) {
-      InvokeStatic unwrapped = insertStaticCallAbove(
-          _glue.getExceptionUnwrapper(),
-          [new Parameter(null)], // Dummy argument, see below.
-          body);
-      _exceptionParameter.replaceUsesWith(unwrapped);
-
-      // Replace the dummy with the exception parameter.  It must be set after
-      // replacing all uses of [_exceptionParameter].
-      unwrapped.argumentRefs[0].changeTo(_exceptionParameter);
-
-      if (stackTraceParameter.hasAtLeastOneUse) {
-        InvokeStatic stackTraceValue = insertStaticCallAbove(
-            _glue.getTraceFromException(), [_exceptionParameter], body);
-        stackTraceParameter.replaceUsesWith(stackTraceValue);
-      }
-    }
-
-    assert(stackTraceParameter.hasNoUses);
-    node.handler.parameters.removeLast();
-
-    visit(node.handler);
-    _exceptionParameter = previousExceptionParameter;
-
-    return node.body;
-  }
-
-  processThrow(Throw node) {
-    // The subexpression of throw is wrapped in the JavaScript output.
-    Primitive wrappedException = insertStaticCallAbove(
-        _glue.getWrapExceptionHelper(), [node.value], node);
-    node.valueRef.changeTo(wrappedException);
-  }
-
-  processRethrow(Rethrow node) {
-    // Rethrow can only appear in a catch block.  It throws that block's
-    // (wrapped) caught exception.
-    Throw replacement = new Throw(_exceptionParameter);
-    InteriorNode parent = node.parent;
-    parent.body = replacement;
-    replacement.parent = parent;
-    // The original rethrow does not have any references that we need to
-    // worry about unlinking.
-  }
-
-  bool isNullConstant(Primitive prim) {
-    return prim is Constant && prim.value.isNull;
-  }
-
-  processInvokeMethod(InvokeMethod node) {
-    Selector selector = node.selector;
-    if (!_glue.isInterceptedSelector(selector)) return;
-
-    // Some platform libraries will compare non-interceptable objects against
-    // null using the Dart == operator.  These must be translated directly.
-    if (node.selector == Selectors.equals &&
-        node.argumentRefs.length == 1 &&
-        isNullConstant(node.argument(0))) {
-      node.replaceWith(new ApplyBuiltinOperator(BuiltinOperator.Identical,
-          [node.receiver, node.argument(0)], node.sourceInformation));
-      return;
-    }
-
-    Primitive receiver = node.receiver;
-    Primitive interceptor;
-
-    if (receiver == receiverParameter && receiverInterceptor != null) {
-      // TODO(asgerf): This could be done by GVN.
-      // If the receiver is 'this', we are calling a method in
-      // the same interceptor:
-      //  Change 'receiver.foo()'  to  'this.foo(receiver)'.
-      interceptor = receiverInterceptor;
-    } else {
-      interceptor = new Interceptor(receiver, node.sourceInformation);
-      if (receiver.hint != null) {
-        interceptor.hint = new InterceptorEntity(receiver.hint);
-      }
-      new LetPrim(interceptor).insertAbove(node.parent);
-    }
-    assert(node.interceptorRef == null);
-    node.makeIntercepted(interceptor);
-  }
-
-  processInvokeMethodDirectly(InvokeMethodDirectly node) {
-    if (!_glue.isInterceptedMethod(node.target)) return;
-
-    Primitive receiver = node.receiver;
-    Primitive interceptor;
-
-    if (receiver == receiverParameter && receiverInterceptor != null) {
-      // If the receiver is 'this', we are calling a method in
-      // the same interceptor:
-      //  Change 'receiver.foo()'  to  'this.foo(receiver)'.
-      interceptor = receiverInterceptor;
-    } else {
-      interceptor = new Interceptor(receiver, node.sourceInformation);
-      if (receiver.hint != null) {
-        interceptor.hint = new InterceptorEntity(receiver.hint);
-      }
-      new LetPrim(interceptor).insertAbove(node.parent);
-    }
-    assert(node.interceptorRef == null);
-    node.makeIntercepted(interceptor);
-  }
-}