Remove frog from the repository.

frog/var_member.dart

-// Copyright (c) 2011, 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.
-
-/** A dynamic member stub. */
-class VarMember {
-  final String name;
-  bool isGenerated = false;
-
-  VarMember(this.name);
-
-  abstract void generate(CodeWriter code);
-
-  String get body() => null;
-
-  Type get returnType() => world.varType;
-
-  Value invoke(CallingContext context, Node node, Value target, Arguments args) {
-    return new Value(returnType,
-      '${target.code}.$name(${args.getCode()})', node.span);
-  }
-}
-
-/**
- * This function generates a dynamic call stub for functions. It's part of a
- * series of steps described below. Most of the code is generated by
- * gen.dart, with some helpers in core.js
- *
- * Given a call site in Dart like:
- *   f(1, 2, capture:true);
- *
- * We compile to JS like:
- *   f.call$2$capture(1, 2, true);
- *
- * And then generate this function:
- *   Function.prototype.call$2$capture = function($0, $1, capture) {
- *     this.call$2$capture = this.$genStub(3, ['capture']);
- *     return this.call$2$capture($0, $1, capture);
- *   }
- *
- * Or for a fixed-arity function, generate this:
- *   Function.prototype.call$2 = function($0, $1) {
- *     return this.to$call$2()($0, $1);
- *   }
- *   Function.prototype.to$call$2 = function() {
- *     this.call$2 = this.$genStub(2);
- *     this.to$call$2 = function() { return this.call$2; }
- *     return this.to$call$2();
- *   }
- * We use .to$call$2 to convert to a typed function.
- *
- * For each method that can be passed as a function, such as a "get" on the
- * method or is a lambda, generate optional argument info. Given a function
- * like:
- *   class SomeType {
- *     void add(x, y, [bubbles = true, capture = false]) { ... }
- *     ... }
- *
- * The generated argument info looks like:
- *  SomeType.prototype.add.$optional = ['bubbles','capture', 'true','false'];
- */
-// TODO(jmesserly): we don't currently put $optional on lambdas.
-// Also, maybe a string encoding would perform better?
-// TODO(jmesserly): _genStub is a hole in the run-time type checker.
-// It bypasses the checks we would do at the callsite for methods.
-// Also, it won't work properly for native JS functions (those don't have
-// an accurate .length)
-class VarFunctionStub extends VarMember {
-  final Arguments args;
-
-  VarFunctionStub(String name, Arguments callArgs)
-    : super(name), args = callArgs.toCallStubArgs() {
-    // Ensure dependency is generated
-    world.functionImplType.markUsed();
-    world.gen.genMethod(world.functionImplType.getMember('_genStub'));
-  }
-
-  Value invoke(CallingContext context, Node node, Value target,
-      Arguments args) {
-    return super.invoke(context, node, target, args);
-  }
-
-  void generate(CodeWriter code) {
-    isGenerated = true;
-    if (args.hasNames) {
-      generateNamed(code);
-    } else {
-      generatePositional(code);
-    }
-  }
-
-  void generatePositional(CodeWriter w) {
-    // Positional arg functions can be converted from "var" to a fixed arity
-    // function type. So emit a to$N stub as well as the call$N stub.
-    int arity = args.length;
-    w.enterBlock('Function.prototype.to\$$name = function() {');
-    w.writeln('this.$name = this._genStub($arity);');
-    w.writeln('this.to\$$name = function() { return this.$name; };');
-    w.writeln('return this.$name;');
-    w.exitBlock('};');
-    var argsCode = args.getCode();
-    w.enterBlock('Function.prototype.$name = function(${argsCode}) {');
-    w.writeln('return this.to\$$name()($argsCode);');
-    w.exitBlock('};');
-
-    // TODO(jmesserly): HACK, we couldn't allocate temps from Value, so we
-    // needed this stub to check for null.
-    w.writeln('function to\$$name(f) { return f && f.to\$$name(); }');
-  }
-
-  void generateNamed(CodeWriter w) {
-    // Named functions use simpler stubs, because we never convert to a named
-    // stub type.
-    var named = Strings.join(args.getNames(), '", "');
-    var argsCode = args.getCode();
-    w.enterBlock('Function.prototype.$name = function(${argsCode}) {');
-    w.writeln('this.$name = this._genStub(${args.length}, ["$named"]);');
-    w.writeln('return this.$name($argsCode);');
-    w.exitBlock('}');
-  }
-}
-
-class VarMethodStub extends VarMember {
-  final Member member;
-  final Arguments args;
-  final String body;
-
-  VarMethodStub(String name, this.member, this.args, this.body): super(name);
-
-  bool get isHidden() =>
-      member != null ? member.declaringType.isHiddenNativeType : false;
-
-  Type get returnType() =>
-      member != null ? member.returnType : world.varType;
-
-  Type get declaringType() =>
-      member != null ? member.declaringType : world.objectType;
-
-  void generate(CodeWriter code) {
-    isGenerated = true;
-    if (!isHidden && _useDirectCall(args)) {
-      world.gen._writePrototypePatch(declaringType, name,
-          world.gen._prototypeOf(declaringType, member.jsname), code);
-    } else {
-      String suffix = world.gen._writePrototypePatch(declaringType, name,
-          'function(${args.getCode()}) {', code, false);
-      if (!suffix.endsWith(';')) {
-        suffix += ';';
-      }
-      if (_needsExactTypeCheck()) {
-        code.enterBlock(
-          'if (Object.getPrototypeOf(this).hasOwnProperty("$name")) {');
-        code.writeln('$body;');
-        code.exitBlock('}');
-        String argsCode = args.getCode();
-        if (argsCode != '') argsCode = ', ' + argsCode;
-        code.writeln('return Object.prototype.$name.call(this$argsCode);');
-        code.exitBlock(suffix);
-      } else {
-        code.writeln('$body;');
-        code.exitBlock(suffix);
-      }
-    }
-  }
-
-  /**
-   * If we have a native method overridden by a hidden native method, we need to
-   * make sure the base one has an exact type test. Otherwise we don't need
-   * this.
-   */
-  bool _needsExactTypeCheck() {
-    if (member == null || member.declaringType.isObject) return false;
-
-    var members = member.potentialMemberSet.members;
-    return members.filter((m) => m != member
-        && m.declaringType.isHiddenNativeType).length >= 1;
-  }
-
-  bool _useDirectCall(Arguments args) {
-    // Create direct stubs when we can. We don't do this in some cases, such as
-    // types that have native subtypes (like Object), otherwise things like
-    // Object.prototype.toString$0 end up calling the toString on Object instead
-    // of on the derived type.
-    if (member is MethodMember && !member.declaringType.hasNativeSubtypes) {
-      MethodMember method = member;
-      if (method.needsArgumentConversion(args)) {
-        return false;
-      }
-
-      // If we have the right number of parameters, or all defaults would be
-      // filled in as "undefined" anyway, we can just call the method directly.
-      for (int i = args.length; i < method.parameters.length; i++) {
-        if (method.parameters[i].value.code != 'null') {
-          return false;
-        }
-      }
-      return method.namesInHomePositions(args);
-    } else {
-      return false;
-    }
-  }
-}
-
-/**
- * A special member with a mangled name that represents a dynamic call
- * (i.e. a call with multiple valid targets). We generate this if we have
- * a dynamic call that needs different implementation methods for different
- * members.
- */
-class VarMethodSet extends VarMember {
-  final String baseName;
-  final List<Member> members;
-  final Type returnType;
-  final Arguments args;
-
-  bool invoked = false;
-
-  VarMethodSet(this.baseName, String name, this.members, Arguments callArgs,
-               this.returnType)
-    : super(name), args = callArgs.toCallStubArgs() {
-  }
-
-  Value invoke(CallingContext context, Node node, Value target,
-      Arguments args) {
-    _invokeMembers(context, node);
-    return super.invoke(context, node, target, args);
-  }
-
-  /** Invokes members to ensure they're generated. */
-  _invokeMembers(CallingContext context, Node node) {
-    if (invoked) return;
-    invoked = true;
-
-    bool hasObjectType = false;
-    for (var member in members) {
-      // Invoke the member with the stub args (this gives us the method body),
-      // then create the stub method.
-      final type = member.declaringType;
-      final target = new Value(type, 'this', node.span);
-      var result = member.invoke(context, node, target, args);
-      var stub = new VarMethodStub(name, member, args, 'return ${result.code}');
-      type.varStubs[stub.name] = stub;
-      if (type.isObject) hasObjectType = true;
-    }
-
-    // Create a noSuchMethod fallback on Object if needed.
-    // Some methods, like toString and == already have a fallback on Object.
-    if (!hasObjectType) {
-      final target = new Value(world.objectType, 'this', node.span);
-      var result = target.invokeNoSuchMethod(context, baseName, node, args);
-      var stub = new VarMethodStub(name, null, args, 'return ${result.code}');
-      world.objectType.varStubs[stub.name] = stub;
-    }
-  }
-
-  // TODO(jmesserly): get rid of this as it's unused now
-  void generate(CodeWriter code) {}
-}
-
-String _getCallStubName(String name, Arguments args) {
-  // The stub name should not collide with any user declared method name since
-  // the '$'s in the stub name are always alone and world.toJsIdentifier doubles
-  // up those in a user declared method name.
-  final nameBuilder = new StringBuffer('${name}\$${args.bareCount}');
-  for (int i = args.bareCount; i < args.length; i++) {
-    var argName = args.getName(i);
-    nameBuilder.add('\$');
-    if (argName.contains('\$')) {
-      // Disambiguate "a:b:" from "a$b:".  Prefixing the length works because
-      // parameter names can't start with digits.
-      nameBuilder.add('${argName.length}');
-    }
-    nameBuilder.add(argName);
-  }
-  return nameBuilder.toString();
-}