Remove closure_conversion.dart from pkg/kernel.

pkg/kernel/lib/transformations/closure_conversion.dart

Index: pkg/kernel/lib/transformations/closure_conversion.dart
diff --git a/pkg/kernel/lib/transformations/closure_conversion.dart b/pkg/kernel/lib/transformations/closure_conversion.dart
deleted file mode 100644
index 18da0669c04c89545b677b9cf90cdf573bcdf5cd..0000000000000000000000000000000000000000
--- a/pkg/kernel/lib/transformations/closure_conversion.dart
+++ /dev/null
@@ -1,440 +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.
-
-library kernel.transformations.closure_conversion;
-
-import '../ast.dart';
-import '../core_types.dart';
-import '../visitor.dart';
-
-Program transformProgram(Program program) {
-  var captured = new CapturedVariables();
-  captured.visitProgram(program);
-
-  var convert =
-      new ClosureConverter(new CoreTypes(program), captured.variables);
-  return convert.visitProgram(program);
-}
-
-class CapturedVariables extends RecursiveVisitor {
-  FunctionNode _currentFunction;
-  final Map<VariableDeclaration, FunctionNode> _function =
-      <VariableDeclaration, FunctionNode>{};
-
-  final Set<VariableDeclaration> variables = new Set<VariableDeclaration>();
-
-  visitFunctionNode(FunctionNode node) {
-    var saved = _currentFunction;
-    _currentFunction = node;
-    node.visitChildren(this);
-    _currentFunction = saved;
-  }
-
-  visitVariableDeclaration(VariableDeclaration node) {
-    _function[node] = _currentFunction;
-    node.visitChildren(this);
-  }
-
-  visitVariableGet(VariableGet node) {
-    if (_function[node.variable] != _currentFunction) {
-      variables.add(node.variable);
-    }
-    node.visitChildren(this);
-  }
-
-  visitVariableSet(VariableSet node) {
-    if (_function[node.variable] != _currentFunction) {
-      variables.add(node.variable);
-    }
-    node.visitChildren(this);
-  }
-}
-
-abstract class Context {
-  Expression get expression;
-
-  void extend(VariableDeclaration variable, Expression value);
-
-  Expression lookup(VariableDeclaration variable);
-  Expression assign(VariableDeclaration variable, Expression value);
-
-  Context toClosureContext(VariableDeclaration parameter);
-}
-
-class NoContext extends Context {
-  final ClosureConverter converter;
-
-  NoContext(this.converter);
-
-  Expression get expression => new NullLiteral();
-
-  void extend(VariableDeclaration variable, Expression value) {
-    converter.context =
-        new LocalContext(converter, this)..extend(variable, value);
-  }
-
-
-  Expression lookup(VariableDeclaration variable) {
-    throw 'Unbound NoContext.lookup($variable)';
-  }
-
-  Expression assign(VariableDeclaration variable, Expression value) {
-    throw 'Unbound NoContext.assign($variable, ...)';
-  }
-
-  Context toClosureContext(VariableDeclaration parameter) {
-    return new ClosureContext(converter, parameter,
-                              <List<VariableDeclaration>>[]);
-  }
-}
-
-
-class LocalContext extends Context {
-  final ClosureConverter converter;
-  final Context parent;
-  final VariableDeclaration self;
-  final IntLiteral size;
-  final List<VariableDeclaration> variables = <VariableDeclaration>[];
-
-  LocalContext._internal(this.converter, this.parent, this.self, this.size);
-
-  factory LocalContext(ClosureConverter converter, Context parent) {
-    Class contextClass = converter.internalContextClass;
-    assert(contextClass.constructors.length == 1);
-    IntLiteral zero = new IntLiteral(0);
-    VariableDeclaration declaration =
-        new VariableDeclaration.forValue(
-            new ConstructorInvocation(contextClass.constructors.first,
-                                      new Arguments(<Expression>[zero])),
-            type: new InterfaceType(contextClass));
-    converter.insert(declaration);
-    converter.insert(new ExpressionStatement(
-        new PropertySet(new VariableGet(declaration),
-                        new Name('parent'),
-                        parent.expression)));
-
-    return new LocalContext._internal(converter, parent, declaration, zero);
-  }
-
-  Expression get expression => new VariableGet(self);
-
-  void extend(VariableDeclaration variable, Expression value) {
-    converter.insert(
-        new ExpressionStatement(
-            new MethodInvocation(
-                expression,
-                new Name('[]='),
-                new Arguments(
-                    <Expression>[new IntLiteral(variables.length), value]))));
-    ++size.value;
-    variables.add(variable);
-  }
-
-  Expression lookup(VariableDeclaration variable) {
-    var index = variables.indexOf(variable);
-    return index == -1
-        ? parent.lookup(variable)
-        : new MethodInvocation(
-              expression,
-              new Name('[]'),
-              new Arguments(<Expression>[new IntLiteral(index)]));
-  }
-
-  Expression assign(VariableDeclaration variable, Expression value) {
-    var index = variables.indexOf(variable);
-    return index == -1
-        ? parent.assign(variable, value)
-        : new MethodInvocation(
-              expression,
-              new Name('[]='),
-              new Arguments(<Expression>[new IntLiteral(index), value]));
-  }
-
-  Context toClosureContext(VariableDeclaration parameter) {
-    List<List<VariableDeclaration>> variabless = <List<VariableDeclaration>>[];
-    var current = this;
-    while (current != null && current is! NoContext) {
-      if (current is LocalContext) {
-        variabless.add(current.variables);
-        current = current.parent;
-      } else if (current is ClosureContext) {
-        variabless.addAll(current.variabless);
-        current = null;
-      } else if (current is LoopContext) {
-        // TODO.
-        current = current.parent;
-      }
-    }
-    return new ClosureContext(converter, parameter, variabless);
-  }
-}
-
-class LoopContext {
-  final ClosureConverter converter;
-  final Context parent;
-
-  LoopContext(this.converter, this.parent);
-
-  void extend(VariableDeclaration variable, Expression value) {
-    converter.context =
-        new LocalContext(converter, parent)..extend(variable, value);
-  }
-}
-
-class ClosureContext extends Context {
-  final ClosureConverter converter;
-  final VariableDeclaration self;
-  final List<List<VariableDeclaration>> variabless;
-
-  ClosureContext(this.converter, this.self, this.variabless);
-
-  Expression get expression => new VariableGet(self);
-
-  void extend(VariableDeclaration variable, Expression value) {
-    converter.context =
-        new LocalContext(converter, this)..extend(variable, value);
-  }
-
-  Expression lookup(VariableDeclaration variable) {
-    var context = expression;
-    for (var variables in variabless) {
-      var index = variables.indexOf(variable);
-      if (index != -1) {
-        return new MethodInvocation(
-            context,
-            new Name('[]'),
-            new Arguments(<Expression>[new IntLiteral(index)]));
-      }
-      context = new PropertyGet(context, new Name('parent'));
-    }
-    throw 'Unbound ClosureContext.lookup($variable)';
-  }
-
-  Expression assign(VariableDeclaration variable, Expression value) {
-    var context = expression;
-    for (var variables in variabless) {
-      var index = variables.indexOf(variable);
-      if (index != -1) {
-        return new MethodInvocation(
-            context,
-            new Name('[]='),
-            new Arguments(<Expression>[new IntLiteral(index), value]));
-      }
-      context = new PropertyGet(context, new Name('parent'));
-    }
-    throw 'Unbound ClosureContext.lookup($variable)';
-  }
-
-  Context toClosureContext(VariableDeclaration parameter) {
-    return new ClosureContext(converter, parameter, variabless);
-  }
-}
-
-class ClosureConverter extends Transformer {
-  final CoreTypes coreTypes;
-  Class internalContextClass;
-  final Set<VariableDeclaration> captured;
-
-  Block _currentBlock;
-  int _insertionIndex = 0;
-
-  Context context;
-
-  ClosureConverter(this.coreTypes, this.captured) {
-    internalContextClass = coreTypes.getCoreClass('dart:_internal', 'Context');
-  }
-
-  void insert(Statement statement) {
-    _currentBlock.statements.insert(_insertionIndex++, statement);
-    statement.parent = _currentBlock;
-  }
-
-  TreeNode visitConstructor(Constructor node) {
-    return node;
-  }
-
-  TreeNode visitFunctionDeclaration(FunctionDeclaration node) {
-    if (captured.contains(node.variable)) {
-      context.extend(node.variable,
-                     new FunctionExpression(node.function));
-    }
-
-    Block savedBlock = _currentBlock;
-    int savedIndex = _insertionIndex;
-    Context savedContext = context;
-
-    Statement body = node.function.body;
-    assert(body != null);
-
-    if (body is Block) {
-      _currentBlock = body;
-    } else {
-      _currentBlock = new Block(<Statement>[body]);
-      node.function.body = body.parent = _currentBlock;
-    }
-    _insertionIndex = 0;
-
-    // TODO: This is really the closure, not the context.
-    VariableDeclaration parameter =
-        new VariableDeclaration(null,
-            type: internalContextClass.rawType,
-            isFinal: true);
-    node.function.positionalParameters.insert(0, parameter);
-    parameter.parent = node.function;
-    ++node.function.requiredParameterCount;
-    context = context.toClosureContext(parameter);
-
-    // Don't visit the children, because that included a variable declaration.
-    node.function = node.function.accept(this);
-
-    _currentBlock = savedBlock;
-    _insertionIndex = savedIndex;
-    context = savedContext;
-
-    return captured.contains(node.variable) ? null : node;
-  }
-
-  TreeNode visitFunctionExpression(FunctionExpression node) {
-    Block savedBlock = _currentBlock;
-    int savedIndex = _insertionIndex;
-    Context savedContext = context;
-
-    Statement body = node.function.body;
-    assert(body != null);
-
-    if (body is Block) {
-      _currentBlock = body;
-    } else {
-      _currentBlock = new Block(<Statement>[body]);
-      node.function.body = body.parent = _currentBlock;
-    }
-    _insertionIndex = 0;
-
-    // TODO: This is really the closure, not the context.
-    VariableDeclaration parameter =
-        new VariableDeclaration(null,
-            type: internalContextClass.rawType,
-            isFinal: true);
-    node.function.positionalParameters.insert(0, parameter);
-    parameter.parent = node.function;
-    ++node.function.requiredParameterCount;
-    context = context.toClosureContext(parameter);
-
-    node.transformChildren(this);
-
-    _currentBlock = savedBlock;
-    _insertionIndex = savedIndex;
-    context = savedContext;
-
-    return node;
-  }
-
-  TreeNode visitProcedure(Procedure node) {
-    assert(_currentBlock == null);
-    assert(_insertionIndex == 0);
-    assert(context == null);
-
-    Statement body = node.function.body;
-    if (body == null) return node;
-
-    // Ensure that the body is a block which becomes the current block.
-    if (body is Block) {
-      _currentBlock = body;
-    } else {
-      _currentBlock = new Block(<Statement>[body]);
-      node.function.body = body.parent = _currentBlock;
-    }
-    _insertionIndex = 0;
-
-    // Start with no context.  This happens after setting up _currentBlock
-    // so statements can be emitted into _currentBlock if necessary.
-    context = new NoContext(this);
-
-    node.transformChildren(this);
-
-    _currentBlock = null;
-    _insertionIndex = 0;
-    context = null;
-    return node;
-  }
-
-  TreeNode visitLocalInitializer(LocalInitializer node) {
-    assert(!captured.contains(node.variable));
-    node.transformChildren(this);
-    return node;
-  }
-
-  TreeNode visitFunctionNode(FunctionNode node) {
-    transformList(node.typeParameters, this, node);
-
-    void extend(VariableDeclaration parameter) {
-      context.extend(parameter, new VariableGet(parameter));
-    }
-    // TODO: Can parameters contain initializers (e.g., for optional ones) that
-    // need to be closure converted?
-    node.positionalParameters.where(captured.contains).forEach(extend);
-    node.namedParameters.where(captured.contains).forEach(extend);
-
-    assert(node.body != null);
-    node.body = node.body.accept(this);
-    node.body.parent = node;
-    return node;
-  }
-
-  TreeNode visitBlock(Block node) {
-    Block savedBlock;
-    int savedIndex;
-    if (_currentBlock != node) {
-      savedBlock = _currentBlock;
-      savedIndex = _insertionIndex;
-      _currentBlock = node;
-      _insertionIndex = 0;
-    }
-
-    while (_insertionIndex < _currentBlock.statements.length) {
-      assert(_currentBlock == node);
-
-      var original = _currentBlock.statements[_insertionIndex];
-      var transformed = original.accept(this);
-      assert(_currentBlock.statements[_insertionIndex] == original);
-      if (transformed == null) {
-        _currentBlock.statements.removeAt(_insertionIndex);
-      } else {
-        _currentBlock.statements[_insertionIndex++] = transformed;
-        transformed.parent = _currentBlock;
-      }
-    }
-
-    if (savedBlock != null) {
-      _currentBlock = savedBlock;
-      _insertionIndex = savedIndex;
-    }
-    return node;
-  }
-
-  TreeNode visitVariableDeclaration(VariableDeclaration node) {
-    node.transformChildren(this);
-
-    if (!captured.contains(node)) return node;
-    context.extend(node, node.initializer ?? new NullLiteral());
-
-    // TODO(ahe): Return null here when the parent has been correctly
-    // rewritten. So far, only for-in is known to use this return value.
-    return new VariableDeclaration(null, initializer: new InvalidExpression());
-  }
-
-  TreeNode visitVariableGet(VariableGet node) {
-    return captured.contains(node.variable)
-        ? context.lookup(node.variable)
-        : node;
-  }
-
-  TreeNode visitVariableSet(VariableSet node) {
-    node.transformChildren(this);
-
-    return captured.contains(node.variable)
-        ? context.assign(node.variable, node.value)
-        : node;
-  }
-}