Remove Fasta's copy of accessors.dart.

pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart

Index: pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart b/pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart
deleted file mode 100644
index 61aa7919fa3648ffe5aa8d317194bba51512a04b..0000000000000000000000000000000000000000
--- a/pkg/front_end/lib/src/fasta/kernel/frontend_accessors.dart
+++ /dev/null
@@ -1,495 +0,0 @@
-// Copyright (c) 2016, 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.
-
-// Note: copied from package:kernel at revision 7346348.
-
-/// A library to help transform compounds and null-aware accessors into
-/// let expressions.
-library kernel.frontend.accessors;
-
-import 'package:kernel/ast.dart';
-
-import '../names.dart' show indexGetName, indexSetName;
-
-/// An [Accessor] represents a subexpression for which we can't yet build a
-/// kernel [Expression] because we don't yet know the context in which it is
-/// used.
-///
-/// Once the context is known, an [Accessor] can be converted into an
-/// [Expression] by calling a "build" method.
-///
-/// For example, when building a kernel representation for `a[x] = b`, after
-/// parsing `a[x]` but before parsing `= b`, we don't yet know whether to
-/// generate an invocation of `operator[]` or `operator[]=`, so we generate an
-/// [Accessor] object.  Later, after `= b` is parsed, [buildAssignment] will be
-/// called.
-abstract class Accessor {
-  /// Builds an [Expression] representing a read from the accessor.
-  Expression buildSimpleRead() {
-    return _finish(_makeSimpleRead());
-  }
-
-  /// Builds an [Expression] representing an assignment with the accessor on
-  /// the LHS and [value] on the RHS.
-  ///
-  /// The returned expression evaluates to the assigned value, unless
-  /// [voidContext] is true, in which case it may evaluate to anything.
-  Expression buildAssignment(Expression value, {bool voidContext: false}) {
-    return _finish(_makeSimpleWrite(value, voidContext));
-  }
-
-  /// Returns an [Expression] representing a null-aware assignment (`??=`) with
-  /// the accessor on the LHS and [value] on the RHS.
-  ///
-  /// The returned expression evaluates to the assigned value, unless
-  /// [voidContext] is true, in which case it may evaluate to anything.
-  ///
-  /// [type] is the static type of the RHS.
-  Expression buildNullAwareAssignment(Expression value, DartType type,
-      {bool voidContext: false}) {
-    if (voidContext) {
-      return _finish(new ConditionalExpression(buildIsNull(_makeRead()),
-          _makeWrite(value, false), new NullLiteral(), type));
-    }
-    var tmp = new VariableDeclaration.forValue(_makeRead());
-    return _finish(makeLet(
-        tmp,
-        new ConditionalExpression(buildIsNull(new VariableGet(tmp)),
-            _makeWrite(value, false), new VariableGet(tmp), type)));
-  }
-
-  /// Returns an [Expression] representing a compound assignment (e.g. `+=`)
-  /// with the accessor on the LHS and [value] on the RHS.
-  Expression buildCompoundAssignment(
-      Name binaryOperator, Expression value, int charOffset,
-      {bool voidContext: false, Procedure interfaceTarget}) {
-    return _finish(_makeWrite(
-        makeBinary(
-            _makeRead(), binaryOperator, interfaceTarget, value, charOffset),
-        voidContext));
-  }
-
-  /// Returns an [Expression] representing a pre-increment or pre-decrement
-  /// of the accessor.
-  Expression buildPrefixIncrement(Name binaryOperator, int charOffset,
-      {bool voidContext: false, Procedure interfaceTarget}) {
-    return buildCompoundAssignment(
-        binaryOperator, new IntLiteral(1), charOffset,
-        voidContext: voidContext, interfaceTarget: interfaceTarget);
-  }
-
-  /// Returns an [Expression] representing a post-increment or post-decrement
-  /// of the accessor.
-  Expression buildPostfixIncrement(Name binaryOperator, int charOffset,
-      {bool voidContext: false, Procedure interfaceTarget}) {
-    if (voidContext) {
-      return buildPrefixIncrement(binaryOperator, charOffset,
-          voidContext: true, interfaceTarget: interfaceTarget);
-    }
-    var value = new VariableDeclaration.forValue(_makeRead());
-    valueAccess() => new VariableGet(value);
-    var dummy = new VariableDeclaration.forValue(_makeWrite(
-        makeBinary(valueAccess(), binaryOperator, interfaceTarget,
-            new IntLiteral(1), charOffset),
-        true));
-    return _finish(makeLet(value, makeLet(dummy, valueAccess())));
-  }
-
-  Expression _makeSimpleRead() => _makeRead();
-
-  Expression _makeSimpleWrite(Expression value, bool voidContext) {
-    return _makeWrite(value, voidContext);
-  }
-
-  Expression _makeRead();
-
-  Expression _makeWrite(Expression value, bool voidContext);
-
-  Expression _finish(Expression body) => body;
-
-  /// Returns an [Expression] representing a compile-time error.
-  ///
-  /// At runtime, an exception will be thrown.
-  makeInvalidRead() => new InvalidExpression();
-
-  /// Returns an [Expression] representing a compile-time error wrapping
-  /// [value].
-  ///
-  /// At runtime, [value] will be evaluated before throwing an exception.
-  makeInvalidWrite(Expression value) => wrapInvalid(value);
-}
-
-class VariableAccessor extends Accessor {
-  VariableDeclaration variable;
-  int charOffset;
-  DartType promotedType;
-
-  VariableAccessor(this.variable, [this.promotedType]);
-
-  VariableAccessor.internal(this.variable, this.charOffset, this.promotedType);
-
-  _makeRead() =>
-      new VariableGet(variable, promotedType)..fileOffset = charOffset;
-
-  _makeWrite(Expression value, bool voidContext) {
-    return variable.isFinal || variable.isConst
-        ? makeInvalidWrite(value)
-        : new VariableSet(variable, value)..fileOffset = charOffset;
-  }
-}
-
-class PropertyAccessor extends Accessor {
-  VariableDeclaration _receiverVariable;
-  Expression receiver;
-  Name name;
-  Member getter, setter;
-  int charOffset;
-
-  static Accessor make(Expression receiver, Name name, Member getter,
-      Member setter, int charOffset) {
-    if (receiver is ThisExpression) {
-      return new ThisPropertyAccessor(name, getter, setter, charOffset);
-    } else {
-      return new PropertyAccessor.internal(
-          receiver, name, getter, setter, charOffset);
-    }
-  }
-
-  PropertyAccessor.internal(
-      this.receiver, this.name, this.getter, this.setter, this.charOffset);
-
-  _makeSimpleRead() =>
-      new PropertyGet(receiver, name, getter)..fileOffset = charOffset;
-  _makeSimpleWrite(Expression value, bool voidContext) {
-    return new PropertySet(receiver, name, value, setter)
-      ..fileOffset = charOffset;
-  }
-
-  receiverAccess() {
-    _receiverVariable ??= new VariableDeclaration.forValue(receiver);
-    return new VariableGet(_receiverVariable)..fileOffset = charOffset;
-  }
-
-  _makeRead() =>
-      new PropertyGet(receiverAccess(), name, getter)..fileOffset = charOffset;
-
-  _makeWrite(Expression value, bool voidContext) {
-    return new PropertySet(receiverAccess(), name, value, setter)
-      ..fileOffset = charOffset;
-  }
-
-  _finish(Expression body) => makeLet(_receiverVariable, body);
-}
-
-/// Special case of [PropertyAccessor] to avoid creating an indirect access to
-/// 'this'.
-class ThisPropertyAccessor extends Accessor {
-  Name name;
-  Member getter, setter;
-  final int charOffset;
-
-  ThisPropertyAccessor(this.name, this.getter, this.setter, this.charOffset);
-
-  _makeRead() => new PropertyGet(new ThisExpression(), name, getter)
-    ..fileOffset = charOffset;
-
-  _makeWrite(Expression value, bool voidContext) {
-    return new PropertySet(new ThisExpression(), name, value, setter)
-      ..fileOffset = charOffset;
-  }
-}
-
-class NullAwarePropertyAccessor extends Accessor {
-  VariableDeclaration receiver;
-  Name name;
-  Member getter, setter;
-  DartType type;
-
-  NullAwarePropertyAccessor(
-      Expression receiver, this.name, this.getter, this.setter, this.type)
-      : this.receiver = makeOrReuseVariable(receiver);
-
-  receiverAccess() => new VariableGet(receiver);
-
-  _makeRead() => new PropertyGet(receiverAccess(), name, getter);
-
-  _makeWrite(Expression value, bool voidContext) {
-    return new PropertySet(receiverAccess(), name, value, setter);
-  }
-
-  _finish(Expression body) => makeLet(
-      receiver,
-      new ConditionalExpression(
-          buildIsNull(receiverAccess()), new NullLiteral(), body, type));
-}
-
-class SuperPropertyAccessor extends Accessor {
-  Name name;
-  Member getter, setter;
-  final int charOffset;
-
-  SuperPropertyAccessor(this.name, this.getter, this.setter, this.charOffset);
-
-  _makeRead() {
-    if (getter == null) return makeInvalidRead();
-    // TODO(ahe): Use [DirectPropertyGet] when possible.
-    Expression result = new DirectPropertyGet(new ThisExpression(), getter)
-      ..fileOffset = charOffset;
-    result = new SuperPropertyGet(name, getter)..fileOffset = charOffset;
-    return result;
-  }
-
-  _makeWrite(Expression value, bool voidContext) {
-    if (setter == null) return makeInvalidWrite(value);
-    // TODO(ahe): Use [DirectPropertySet] when possible.
-    Expression result = new DirectPropertySet(
-        new ThisExpression(), setter, value)..fileOffset = charOffset;
-    result = new SuperPropertySet(name, value, setter)..fileOffset = charOffset;
-    return result;
-  }
-}
-
-class IndexAccessor extends Accessor {
-  Expression receiver;
-  Expression index;
-  VariableDeclaration receiverVariable;
-  VariableDeclaration indexVariable;
-  Procedure getter, setter;
-  int charOffset;
-
-  static Accessor make(Expression receiver, Expression index, Procedure getter,
-      Procedure setter, int charOffset) {
-    if (receiver is ThisExpression) {
-      return new ThisIndexAccessor(index, getter, setter);
-    } else {
-      return new IndexAccessor.internal(
-          receiver, index, getter, setter, charOffset);
-    }
-  }
-
-  IndexAccessor.internal(
-      this.receiver, this.index, this.getter, this.setter, this.charOffset);
-
-  _makeSimpleRead() => new MethodInvocation(
-      receiver, indexGetName, new Arguments(<Expression>[index]), getter)
-    ..fileOffset = charOffset;
-
-  _makeSimpleWrite(Expression value, bool voidContext) {
-    if (!voidContext) return _makeWriteAndReturn(value);
-    return new MethodInvocation(
-        receiver,
-        indexSetName,
-        new Arguments(<Expression>[index, value]),
-        setter)..fileOffset = charOffset;
-  }
-
-  receiverAccess() {
-    // We cannot reuse the receiver if it is a variable since it might be
-    // reassigned in the index expression.
-    receiverVariable ??= new VariableDeclaration.forValue(receiver);
-    return new VariableGet(receiverVariable)..fileOffset = charOffset;
-  }
-
-  indexAccess() {
-    indexVariable ??= new VariableDeclaration.forValue(index);
-    return new VariableGet(indexVariable)..fileOffset = charOffset;
-  }
-
-  _makeRead() {
-    return new MethodInvocation(
-        receiverAccess(),
-        indexGetName,
-        new Arguments(<Expression>[indexAccess()]),
-        getter)..fileOffset = charOffset;
-  }
-
-  _makeWrite(Expression value, bool voidContext) {
-    if (!voidContext) return _makeWriteAndReturn(value);
-    return new MethodInvocation(
-        receiverAccess(),
-        indexSetName,
-        new Arguments(<Expression>[indexAccess(), value]),
-        setter)..fileOffset = charOffset;
-  }
-
-  _makeWriteAndReturn(Expression value) {
-    // The call to []= does not return the value like direct-style assignments
-    // do.  We need to bind the value in a let.
-    var valueVariable = new VariableDeclaration.forValue(value);
-    var dummy = new VariableDeclaration.forValue(new MethodInvocation(
-        receiverAccess(),
-        indexSetName,
-        new Arguments(
-            <Expression>[indexAccess(), new VariableGet(valueVariable)]),
-        setter)..fileOffset = charOffset);
-    return makeLet(
-        valueVariable, makeLet(dummy, new VariableGet(valueVariable)));
-  }
-
-  Expression _finish(Expression body) {
-    return makeLet(receiverVariable, makeLet(indexVariable, body));
-  }
-}
-
-/// Special case of [IndexAccessor] to avoid creating an indirect access to
-/// 'this'.
-class ThisIndexAccessor extends Accessor {
-  Expression index;
-  VariableDeclaration indexVariable;
-  Procedure getter, setter;
-
-  ThisIndexAccessor(this.index, this.getter, this.setter);
-
-  _makeSimpleRead() {
-    return new MethodInvocation(new ThisExpression(), indexGetName,
-        new Arguments(<Expression>[index]), getter);
-  }
-
-  _makeSimpleWrite(Expression value, bool voidContext) {
-    if (!voidContext) return _makeWriteAndReturn(value);
-    return new MethodInvocation(new ThisExpression(), indexSetName,
-        new Arguments(<Expression>[index, value]), setter);
-  }
-
-  indexAccess() {
-    indexVariable ??= new VariableDeclaration.forValue(index);
-    return new VariableGet(indexVariable);
-  }
-
-  _makeRead() => new MethodInvocation(new ThisExpression(), indexGetName,
-      new Arguments(<Expression>[indexAccess()]), getter);
-
-  _makeWrite(Expression value, bool voidContext) {
-    if (!voidContext) return _makeWriteAndReturn(value);
-    return new MethodInvocation(new ThisExpression(), indexSetName,
-        new Arguments(<Expression>[indexAccess(), value]), setter);
-  }
-
-  _makeWriteAndReturn(Expression value) {
-    var valueVariable = new VariableDeclaration.forValue(value);
-    var dummy = new VariableDeclaration.forValue(new MethodInvocation(
-        new ThisExpression(),
-        indexSetName,
-        new Arguments(
-            <Expression>[indexAccess(), new VariableGet(valueVariable)]),
-        setter));
-    return makeLet(
-        valueVariable, makeLet(dummy, new VariableGet(valueVariable)));
-  }
-
-  Expression _finish(Expression body) => makeLet(indexVariable, body);
-}
-
-class SuperIndexAccessor extends Accessor {
-  Expression index;
-  VariableDeclaration indexVariable;
-  Member getter, setter;
-
-  SuperIndexAccessor(this.index, this.getter, this.setter);
-
-  indexAccess() {
-    indexVariable ??= new VariableDeclaration.forValue(index);
-    return new VariableGet(indexVariable);
-  }
-
-  _makeSimpleRead() => new SuperMethodInvocation(
-      indexGetName, new Arguments(<Expression>[index]), getter);
-
-  _makeSimpleWrite(Expression value, bool voidContext) {
-    if (!voidContext) return _makeWriteAndReturn(value);
-    return new SuperMethodInvocation(
-        indexSetName, new Arguments(<Expression>[index, value]), setter);
-  }
-
-  _makeRead() {
-    return new SuperMethodInvocation(
-        indexGetName, new Arguments(<Expression>[indexAccess()]), getter);
-  }
-
-  _makeWrite(Expression value, bool voidContext) {
-    if (!voidContext) return _makeWriteAndReturn(value);
-    return new SuperMethodInvocation(indexSetName,
-        new Arguments(<Expression>[indexAccess(), value]), setter);
-  }
-
-  _makeWriteAndReturn(Expression value) {
-    var valueVariable = new VariableDeclaration.forValue(value);
-    var dummy = new VariableDeclaration.forValue(new SuperMethodInvocation(
-        indexSetName,
-        new Arguments(
-            <Expression>[indexAccess(), new VariableGet(valueVariable)]),
-        setter));
-    return makeLet(
-        valueVariable, makeLet(dummy, new VariableGet(valueVariable)));
-  }
-
-  Expression _finish(Expression body) {
-    return makeLet(indexVariable, body);
-  }
-}
-
-class StaticAccessor extends Accessor {
-  Member readTarget;
-  Member writeTarget;
-  int charOffset;
-
-  StaticAccessor(this.readTarget, this.writeTarget, this.charOffset);
-
-  _makeRead() =>
-      readTarget == null ? makeInvalidRead() : new StaticGet(readTarget)
-        ..fileOffset = charOffset;
-
-  _makeWrite(Expression value, bool voidContext) {
-    return writeTarget == null
-        ? makeInvalidWrite(value)
-        : new StaticSet(writeTarget, value)..fileOffset = charOffset;
-  }
-}
-
-class ReadOnlyAccessor extends Accessor {
-  Expression expression;
-  VariableDeclaration value;
-
-  ReadOnlyAccessor(this.expression);
-
-  _makeSimpleRead() => expression;
-
-  _makeRead() {
-    value ??= new VariableDeclaration.forValue(expression);
-    return new VariableGet(value);
-  }
-
-  _makeWrite(Expression value, bool voidContext) => makeInvalidWrite(value);
-
-  Expression _finish(Expression body) => makeLet(value, body);
-}
-
-Expression makeLet(VariableDeclaration variable, Expression body) {
-  if (variable == null) return body;
-  return new Let(variable, body);
-}
-
-Expression makeBinary(Expression left, Name operator, Procedure interfaceTarget,
-    Expression right, int charOffset) {
-  return new MethodInvocation(
-      left, operator, new Arguments(<Expression>[right]), interfaceTarget)
-    ..fileOffset = charOffset;
-}
-
-final Name _equalOperator = new Name('==');
-
-Expression buildIsNull(Expression value) {
-  return makeBinary(
-      value, _equalOperator, null, new NullLiteral(), TreeNode.noOffset);
-}
-
-VariableDeclaration makeOrReuseVariable(Expression value) {
-  // TODO: Devise a way to remember if a variable declaration was reused
-  // or is fresh (hence needs a let binding).
-  return new VariableDeclaration.forValue(value);
-}
-
-Expression wrapInvalid(Expression e) {
-  return new Let(new VariableDeclaration.forValue(e), new InvalidExpression());
-}