runtime/vm/parser.cc

// Copyright (c) 2012, 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.

#include "vm/parser.h"

#include "lib/invocation_mirror.h"
#include "vm/bigint_operations.h"
#include "vm/class_finalizer.h"
#include "vm/compiler.h"
#include "vm/compiler_stats.h"
#include "vm/dart_api_impl.h"
#include "vm/dart_entry.h"
#include "vm/flags.h"
#include "vm/growable_array.h"
#include "vm/longjump.h"
#include "vm/native_entry.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/resolver.h"
#include "vm/scopes.h"
#include "vm/symbols.h"

namespace dart {

DEFINE_FLAG(bool, enable_asserts, false, "Enable assert statements.");
DEFINE_FLAG(bool, enable_type_checks, false, "Enable type checks.");
DEFINE_FLAG(bool, trace_parser, false, "Trace parser operations.");
DEFINE_FLAG(bool, warning_as_error, false, "Treat warnings as errors.");
DEFINE_FLAG(bool, silent_warnings, false, "Silence warnings.");

static void CheckedModeHandler(bool value) {
  FLAG_enable_asserts = value;
  FLAG_enable_type_checks = value;
}

// --enable-checked-mode and --checked both enable checked mode which is
// equivalent to setting --enable-asserts and --enable-type-checks.
DEFINE_FLAG_HANDLER(CheckedModeHandler,
                    enable_checked_mode,
                    "Enable checked mode.");

DEFINE_FLAG_HANDLER(CheckedModeHandler,
                    checked,
                    "Enable checked mode.");

#if defined(DEBUG)
class TraceParser : public ValueObject {
 public:
  TraceParser(intptr_t token_pos, const Script& script, const char* msg) {
    if (FLAG_trace_parser) {
      // Skips tracing of bootstrap libraries.
      if (script.HasSource()) {
        intptr_t line, column;
        script.GetTokenLocation(token_pos, &line, &column);
        PrintIndent();
        OS::Print("%s (line %"Pd", col %"Pd", token %"Pd")\n",
                  msg, line, column, token_pos);
      }
      indent_++;
    }
  }
  ~TraceParser() { indent_--; }
 private:
  void PrintIndent() {
    for (int i = 0; i < indent_; i++) { OS::Print(". "); }
  }
  static int indent_;
};

int TraceParser::indent_ = 0;

#define TRACE_PARSER(s) \
  TraceParser __p__(this->TokenPos(), this->script_, s)

#else  // not DEBUG
#define TRACE_PARSER(s)
#endif  // DEBUG


static RawTypeArguments* NewTypeArguments(const GrowableObjectArray& objs) {
  const TypeArguments& a =
      TypeArguments::Handle(TypeArguments::New(objs.Length()));
  AbstractType& type = AbstractType::Handle();
  for (int i = 0; i < objs.Length(); i++) {
    type ^= objs.At(i);
    a.SetTypeAt(i, type);
  }
  // Cannot canonicalize TypeArgument yet as its types may not have been
  // finalized yet.
  return a.raw();
}


static ThrowNode* GenerateRethrow(intptr_t token_pos, const Object& obj) {
  const UnhandledException& excp = UnhandledException::Cast(obj);
  Instance& exception = Instance::ZoneHandle(excp.exception());
  if (exception.IsNew()) {
    exception ^= Object::Clone(exception, Heap::kOld);
  }
  Instance& stack_trace = Instance::ZoneHandle(excp.stacktrace());
  if (stack_trace.IsNew()) {
    stack_trace ^= Object::Clone(stack_trace, Heap::kOld);
  }
  return new ThrowNode(token_pos,
                       new LiteralNode(token_pos, exception),
                       new LiteralNode(token_pos, stack_trace));
}


LocalVariable* ParsedFunction::CreateExpressionTempVar(intptr_t token_pos) {
  return new LocalVariable(token_pos,
                           Symbols::ExprTemp(),
                           Type::ZoneHandle(Type::DynamicType()));
}


LocalVariable* ParsedFunction::CreateArrayLiteralVar(intptr_t token_pos) {
  return new LocalVariable(token_pos,
                           Symbols::ArrayLiteralVar(),
                           Type::ZoneHandle(Type::ArrayType()));
}


void ParsedFunction::SetNodeSequence(SequenceNode* node_sequence) {
  ASSERT(node_sequence_ == NULL);
  ASSERT(node_sequence != NULL);
  node_sequence_ = node_sequence;
}


LocalVariable* ParsedFunction::GetSavedArgumentsDescriptorVar() const {
  const int num_parameters = function().NumParameters();
  LocalScope* scope = node_sequence()->scope();
  if (scope->num_variables() > num_parameters) {
    LocalVariable* saved_args_desc_var = scope->VariableAt(num_parameters);
    ASSERT(saved_args_desc_var != NULL);
    // The scope of the formal parameters may also contain at this position
    // an alias for the saved arguments descriptor variable of the enclosing
    // function (check its scope owner) or an internal variable such as the
    // expression temp variable or the saved entry context variable (check its
    // name).
    if ((saved_args_desc_var->owner() == scope) &&
        saved_args_desc_var->name().StartsWith(
            Symbols::SavedArgDescVarPrefix())) {
      return saved_args_desc_var;
    }
  }
  return NULL;
}


void ParsedFunction::AllocateVariables() {
  LocalScope* scope = node_sequence()->scope();
  const intptr_t num_fixed_params = function().num_fixed_parameters();
  const intptr_t num_opt_params = function().NumOptionalParameters();
  intptr_t num_params = num_fixed_params + num_opt_params;
  // Compute start indices to parameters and locals, and the number of
  // parameters to copy.
  if (num_opt_params == 0) {
    // Parameter i will be at fp[kLastParamSlotIndex + num_params - 1 - i] and
    // local variable j will be at fp[kFirstLocalSlotIndex - j].
    ASSERT(GetSavedArgumentsDescriptorVar() == NULL);
    first_parameter_index_ = kLastParamSlotIndex + num_params - 1;
    first_stack_local_index_ = kFirstLocalSlotIndex;
    num_copied_params_ = 0;
  } else {
    // Parameter i will be at fp[kFirstLocalSlotIndex - i] and local variable
    // j will be at fp[kFirstLocalSlotIndex - num_params - j].
    // The saved arguments descriptor variable must be allocated similarly to
    // a parameter, so that it gets both a frame slot and a context slot when
    // captured.
    if (GetSavedArgumentsDescriptorVar() != NULL) {
      num_params += 1;
    }
    first_parameter_index_ = kFirstLocalSlotIndex;
    first_stack_local_index_ = first_parameter_index_ - num_params;
    num_copied_params_ = num_params;
  }

  // Allocate parameters and local variables, either in the local frame or
  // in the context(s).
  LocalScope* context_owner = NULL;  // No context needed yet.
  int next_free_frame_index =
      scope->AllocateVariables(first_parameter_index_,
                               num_params,
                               first_stack_local_index_,
                               scope,
                               &context_owner);

  // If this function allocates context variables, but none of its enclosing
  // functions do, the context on entry is not linked as parent of the allocated
  // context but saved on entry and restored on exit as to prevent memory leaks.
  // Add and allocate a local variable to this purpose.
  if (context_owner != NULL) {
    const ContextScope& context_scope =
        ContextScope::Handle(function().context_scope());
    if (context_scope.IsNull() || (context_scope.num_variables() == 0)) {
      LocalVariable* context_var =
          new LocalVariable(function().token_pos(),
                            Symbols::SavedEntryContextVar(),
                            Type::ZoneHandle(Type::DynamicType()));
      context_var->set_index(next_free_frame_index--);
      scope->AddVariable(context_var);
      set_saved_entry_context_var(context_var);
    }
  }

  // Frame indices are relative to the frame pointer and are decreasing.
  ASSERT(next_free_frame_index <= first_stack_local_index_);
  num_stack_locals_ = first_stack_local_index_ - next_free_frame_index;
}


struct Parser::Block : public ZoneAllocated {
  Block(Block* outer_block, LocalScope* local_scope, SequenceNode* seq)
    : parent(outer_block), scope(local_scope), statements(seq) {
    ASSERT(scope != NULL);
    ASSERT(statements != NULL);
  }
  Block* parent;  // Enclosing block, or NULL if outermost.
  LocalScope* scope;
  SequenceNode* statements;
};


// Class which describes an inlined finally block which is used to generate
// inlined code for the finally blocks when there is an exit from a try
// block using 'return', 'break' or 'continue'.
class Parser::TryBlocks : public ZoneAllocated {
 public:
  TryBlocks(Block* try_block, TryBlocks* outer_try_block)
      : try_block_(try_block),
        inlined_finally_nodes_(),
        outer_try_block_(outer_try_block) { }

  TryBlocks* outer_try_block() const { return outer_try_block_; }
  Block* try_block() const { return try_block_; }

  void AddNodeForFinallyInlining(AstNode* node);
  AstNode* GetNodeToInlineFinally(int index) {
    if (0 <= index && index < inlined_finally_nodes_.length()) {
      return inlined_finally_nodes_[index];
    }
    return NULL;
  }

 private:
  Block* try_block_;
  GrowableArray<AstNode*> inlined_finally_nodes_;
  TryBlocks* outer_try_block_;

  DISALLOW_COPY_AND_ASSIGN(TryBlocks);
};


void Parser::TryBlocks::AddNodeForFinallyInlining(AstNode* node) {
  inlined_finally_nodes_.Add(node);
}


// For parsing a compilation unit.
Parser::Parser(const Script& script, const Library& library)
    : script_(Script::Handle(script.raw())),
      tokens_iterator_(TokenStream::Handle(script.tokens()), 0),
      token_kind_(Token::kILLEGAL),
      current_block_(NULL),
      is_top_level_(false),
      current_member_(NULL),
      allow_function_literals_(true),
      parsed_function_(NULL),
      innermost_function_(Function::Handle()),
      current_class_(Class::Handle()),
      library_(Library::Handle(library.raw())),
      try_blocks_list_(NULL) {
  ASSERT(tokens_iterator_.IsValid());
  ASSERT(!library.IsNull());
}


// For parsing a function.
Parser::Parser(const Script& script,
               ParsedFunction* parsed_function,
               intptr_t token_position)
    : script_(Script::Handle(script.raw())),
      tokens_iterator_(TokenStream::Handle(script.tokens()), token_position),
      token_kind_(Token::kILLEGAL),
      current_block_(NULL),
      is_top_level_(false),
      current_member_(NULL),
      allow_function_literals_(true),
      parsed_function_(parsed_function),
      innermost_function_(Function::Handle(parsed_function->function().raw())),
      current_class_(Class::Handle(parsed_function->function().Owner())),
      library_(Library::Handle(Class::Handle(
          parsed_function->function().origin()).library())),
      try_blocks_list_(NULL) {
  ASSERT(tokens_iterator_.IsValid());
  ASSERT(!current_function().IsNull());
  if (FLAG_enable_type_checks) {
    EnsureExpressionTemp();
  }
}


void Parser::SetScript(const Script & script, intptr_t token_pos) {
  script_ = script.raw();
  tokens_iterator_.SetStream(TokenStream::Handle(script.tokens()), token_pos);
  token_kind_ = Token::kILLEGAL;
}


bool Parser::SetAllowFunctionLiterals(bool value) {
  bool current_value = allow_function_literals_;
  allow_function_literals_ = value;
  return current_value;
}


const Function& Parser::current_function() const {
  ASSERT(parsed_function() != NULL);
  return parsed_function()->function();
}


const Function& Parser::innermost_function() const {
  return innermost_function_;
}


const Class& Parser::current_class() const {
  return current_class_;
}


void Parser::set_current_class(const Class& value) {
  current_class_ = value.raw();
}


void Parser::SetPosition(intptr_t position) {
  if (position < TokenPos() && position != 0) {
    CompilerStats::num_tokens_rewind += (TokenPos() - position);
  }
  tokens_iterator_.SetCurrentPosition(position);
  token_kind_ = Token::kILLEGAL;
}


void Parser::ParseCompilationUnit(const Library& library,
                                  const Script& script) {
  ASSERT(Isolate::Current()->long_jump_base()->IsSafeToJump());
  TimerScope timer(FLAG_compiler_stats, &CompilerStats::parser_timer);
  Parser parser(script, library);
  parser.ParseTopLevel();
}


Token::Kind Parser::CurrentToken() {
  if (token_kind_ == Token::kILLEGAL) {
    token_kind_ = tokens_iterator_.CurrentTokenKind();
    if (token_kind_ == Token::kERROR) {
      ErrorMsg(TokenPos(), "%s", CurrentLiteral()->ToCString());
    }
  }
  CompilerStats::num_token_checks++;
  return token_kind_;
}


Token::Kind Parser::LookaheadToken(int num_tokens) {
  CompilerStats::num_tokens_lookahead++;
  CompilerStats::num_token_checks++;
  return tokens_iterator_.LookaheadTokenKind(num_tokens);
}


String* Parser::CurrentLiteral() const {
  String& result = String::ZoneHandle();
  result = tokens_iterator_.CurrentLiteral();
  return &result;
}


RawDouble* Parser::CurrentDoubleLiteral() const {
  LiteralToken& token = LiteralToken::Handle();
  token ^= tokens_iterator_.CurrentToken();
  ASSERT(token.kind() == Token::kDOUBLE);
  return reinterpret_cast<RawDouble*>(token.value());
}


RawInteger* Parser::CurrentIntegerLiteral() const {
  LiteralToken& token = LiteralToken::Handle();
  token ^= tokens_iterator_.CurrentToken();
  ASSERT(token.kind() == Token::kINTEGER);
  return reinterpret_cast<RawInteger*>(token.value());
}


// A QualIdent is an optionally qualified identifier.
struct QualIdent {
  QualIdent() {
    Clear();
  }
  void Clear() {
    lib_prefix = NULL;
    ident_pos = 0;
    ident = NULL;
  }
  LibraryPrefix* lib_prefix;
  intptr_t ident_pos;
  String* ident;
};


struct ParamDesc {
  ParamDesc()
      : type(NULL),
        name_pos(0),
        name(NULL),
        default_value(NULL),
        is_final(false),
        is_field_initializer(false) { }
  const AbstractType* type;
  intptr_t name_pos;
  const String* name;
  const Object* default_value;  // NULL if not an optional parameter.
  bool is_final;
  bool is_field_initializer;
};


struct ParamList {
  ParamList() {
    Clear();
  }

  void Clear() {
    num_fixed_parameters = 0;
    num_optional_parameters = 0;
    has_optional_positional_parameters = false;
    has_optional_named_parameters = false;
    has_field_initializer = false;
    implicitly_final = false;
    skipped = false;
    this->parameters = new ZoneGrowableArray<ParamDesc>();
  }

  void AddFinalParameter(intptr_t name_pos,
                         const String* name,
                         const AbstractType* type) {
    this->num_fixed_parameters++;
    ParamDesc param;
    param.name_pos = name_pos;
    param.name = name;
    param.is_final = true;
    param.type = type;
    this->parameters->Add(param);
  }

  void AddReceiver(const Type* receiver_type) {
    ASSERT(this->parameters->is_empty());
    AddFinalParameter(receiver_type->token_pos(),
                      &Symbols::This(),
                      receiver_type);
  }

  void SetImplicitlyFinal() {
    implicitly_final = true;
  }

  int num_fixed_parameters;
  int num_optional_parameters;
  bool has_optional_positional_parameters;
  bool has_optional_named_parameters;
  bool has_field_initializer;
  bool implicitly_final;
  bool skipped;
  ZoneGrowableArray<ParamDesc>* parameters;
};


struct MemberDesc {
  MemberDesc() {
    Clear();
  }
  void Clear() {
    has_abstract = false;
    has_external = false;
    has_final = false;
    has_const = false;
    has_static = false;
    has_var = false;
    has_factory = false;
    has_operator = false;
    operator_token = Token::kILLEGAL;
    type = NULL;
    name_pos = 0;
    name = NULL;
    redirect_name = NULL;
    constructor_name = NULL;
    params.Clear();
    kind = RawFunction::kRegularFunction;
  }
  bool IsConstructor() const {
    return (kind == RawFunction::kConstructor) && !has_static;
  }
  bool IsFactory() const {
    return (kind == RawFunction::kConstructor) && has_static;
  }
  bool IsFactoryOrConstructor() const {
    return (kind == RawFunction::kConstructor);
  }
  bool IsGetter() const {
    return kind == RawFunction::kGetterFunction;
  }
  bool IsSetter() const {
    return kind == RawFunction::kSetterFunction;
  }
  bool has_abstract;
  bool has_external;
  bool has_final;
  bool has_const;
  bool has_static;
  bool has_var;
  bool has_factory;
  bool has_operator;
  Token::Kind operator_token;
  const AbstractType* type;
  intptr_t name_pos;
  String* name;
  // For constructors: NULL or name of redirected to constructor.
  String* redirect_name;
  // For constructors: NULL for unnamed constructor,
  // identifier after classname for named constructors.
  String* constructor_name;
  ParamList params;
  RawFunction::Kind kind;
};


class ClassDesc : public ValueObject {
 public:
  ClassDesc(const Class& cls,
            const String& cls_name,
            bool is_interface,
            intptr_t token_pos)
      : clazz_(cls),
        class_name_(cls_name),
        token_pos_(token_pos),
        functions_(GrowableObjectArray::Handle(GrowableObjectArray::New())),
        fields_(GrowableObjectArray::Handle(GrowableObjectArray::New())) {
  }

  // Parameter 'name' is the unmangled name, i.e. without the setter
  // name mangling.
  bool FunctionNameExists(const String& name, RawFunction::Kind kind) const {
    // First check if a function or field of same name exists.
    if ((kind != RawFunction::kSetterFunction) && FunctionExists(name)) {
      return true;
    }
    // Now check whether there is a field and whether its implicit getter
    // or setter collides with the name.
    Field* field = LookupField(name);
    if (field != NULL) {
      if (kind == RawFunction::kSetterFunction) {
        // It's ok to have an implicit getter, it does not collide with
        // this setter function.
        if (!field->is_final()) {
          return true;
        }
      } else {
        // The implicit getter of the field collides with the name.
        return true;
      }
    }

    String& accessor_name = String::Handle();
    if (kind == RawFunction::kSetterFunction) {
      // Check if a setter function of same name exists.
      accessor_name = Field::SetterName(name);
      if (FunctionExists(accessor_name)) {
        return true;
      }
    } else {
      // Check if a getter function of same name exists.
      accessor_name = Field::GetterName(name);
      if (FunctionExists(accessor_name)) {
        return true;
      }
    }
    return false;
  }

  bool FieldNameExists(const String& name, bool check_setter) const {
    // First check if a function or field of same name exists.
    if (FunctionExists(name) || FieldExists(name)) {
      return true;
    }
    // Now check if a getter/setter function of same name exists.
    String& getter_name = String::Handle(Field::GetterName(name));
    if (FunctionExists(getter_name)) {
      return true;
    }
    if (check_setter) {
      String& setter_name = String::Handle(Field::SetterName(name));
      if (FunctionExists(setter_name)) {
        return true;
      }
    }
    return false;
  }

  void AddFunction(const Function& function) {
    ASSERT(!FunctionExists(String::Handle(function.name())));
    functions_.Add(function);
  }

  const GrowableObjectArray& functions() const {
    return functions_;
  }

  void AddField(const Field& field) {
    ASSERT(!FieldExists(String::Handle(field.name())));
    fields_.Add(field);
  }

  const GrowableObjectArray& fields() const {
    return fields_;
  }

  RawClass* clazz() const {
    return clazz_.raw();
  }

  const String& class_name() const {
    return class_name_;
  }

  bool has_constructor() const {
    Function& func = Function::Handle();
    for (int i = 0; i < functions_.Length(); i++) {
      func ^= functions_.At(i);
      if (func.kind() == RawFunction::kConstructor) {
        return true;
      }
    }
    return false;
  }

  intptr_t token_pos() const {
    return token_pos_;
  }

  void AddMember(const MemberDesc& member) {
    members_.Add(member);
  }

  const GrowableArray<MemberDesc>& members() const {
    return members_;
  }

  MemberDesc* LookupMember(const String& name) const {
    for (int i = 0; i < members_.length(); i++) {
      if (name.Equals(*members_[i].name)) {
        return &members_[i];
      }
    }
    return NULL;
  }

 private:
  Field* LookupField(const String& name) const {
    String& test_name = String::Handle();
    Field& field = Field::Handle();
    for (int i = 0; i < fields_.Length(); i++) {
      field ^= fields_.At(i);
      test_name = field.name();
      if (name.Equals(test_name)) {
        return &field;
      }
    }
    return NULL;
  }

  bool FieldExists(const String& name) const {
    return LookupField(name) != NULL;
  }

  Function* LookupFunction(const String& name) const {
    String& test_name = String::Handle();
    Function& func = Function::Handle();
    for (int i = 0; i < functions_.Length(); i++) {
      func ^= functions_.At(i);
      test_name = func.name();
      if (name.Equals(test_name)) {
        return &func;
      }
    }
    return NULL;
  }

  bool FunctionExists(const String& name) const {
    return LookupFunction(name) != NULL;
  }

  const Class& clazz_;
  const String& class_name_;
  intptr_t token_pos_;   // Token index of "class" keyword.
  GrowableObjectArray& functions_;
  GrowableObjectArray& fields_;
  GrowableArray<MemberDesc> members_;
};


struct TopLevel {
  TopLevel() :
      fields(GrowableObjectArray::Handle(GrowableObjectArray::New())),
      functions(GrowableObjectArray::Handle(GrowableObjectArray::New())) { }

  GrowableObjectArray& fields;
  GrowableObjectArray& functions;
};


static bool HasReturnNode(SequenceNode* seq) {
  if (seq->length() == 0) {
    return false;
  } else if ((seq->length()) == 1 &&
             (seq->NodeAt(seq->length() - 1)->IsSequenceNode())) {
    return HasReturnNode(seq->NodeAt(seq->length() - 1)->AsSequenceNode());
  } else {
    return seq->NodeAt(seq->length() - 1)->IsReturnNode();
  }
}


void Parser::ParseFunction(ParsedFunction* parsed_function) {
  TimerScope timer(FLAG_compiler_stats, &CompilerStats::parser_timer);
  Isolate* isolate = Isolate::Current();
  ASSERT(isolate->long_jump_base()->IsSafeToJump());
  ASSERT(parsed_function != NULL);
  const Function& func = parsed_function->function();
  const Script& script = Script::Handle(isolate, func.script());
  Parser parser(script, parsed_function, func.token_pos());
  SequenceNode* node_sequence = NULL;
  Array& default_parameter_values = Array::ZoneHandle(isolate, Array::null());
  switch (func.kind()) {
    case RawFunction::kRegularFunction:
    case RawFunction::kClosureFunction:
    case RawFunction::kGetterFunction:
    case RawFunction::kSetterFunction:
    case RawFunction::kConstructor:
      // The call to a redirecting factory is redirected.
      ASSERT(!func.IsRedirectingFactory());
      node_sequence = parser.ParseFunc(func, default_parameter_values);
      break;
    case RawFunction::kImplicitGetter:
      ASSERT(!func.is_static());
      node_sequence = parser.ParseInstanceGetter(func);
      break;
    case RawFunction::kImplicitSetter:
      ASSERT(!func.is_static());
      node_sequence = parser.ParseInstanceSetter(func);
      break;
    case RawFunction::kConstImplicitGetter:
      node_sequence = parser.ParseStaticConstGetter(func);
      break;
    case RawFunction::kMethodExtractor:
      node_sequence = parser.ParseMethodExtractor(func);
      break;
    default:
      UNREACHABLE();
  }

  parsed_function->set_array_literal_var(
      ParsedFunction::CreateArrayLiteralVar(func.token_pos()));
  node_sequence->scope()->AddVariable(parsed_function->array_literal_var());

  if (!HasReturnNode(node_sequence)) {
    // Add implicit return node.
    node_sequence->Add(new ReturnNode(func.end_token_pos()));
  }
  if (parsed_function->has_expression_temp_var()) {
    node_sequence->scope()->AddVariable(parsed_function->expression_temp_var());
  }
  if (parsed_function->has_saved_current_context_var()) {
    node_sequence->scope()->AddVariable(
        parsed_function->saved_current_context_var());
  }
  parsed_function->SetNodeSequence(node_sequence);

  // The instantiator may be required at run time for generic type checks or
  // allocation of generic types.
  if (parser.IsInstantiatorRequired()) {
    // In the case of a local function, only set the instantiator if the
    // receiver (or type arguments parameter of a factory) was captured.
    LocalVariable* instantiator = NULL;
    const bool kTestOnly = true;
    if (parser.current_function().IsInFactoryScope()) {
      instantiator = parser.LookupTypeArgumentsParameter(node_sequence->scope(),
                                                         kTestOnly);
    } else {
      instantiator = parser.LookupReceiver(node_sequence->scope(), kTestOnly);
    }
    if (!parser.current_function().IsLocalFunction() ||
        ((instantiator != NULL) && instantiator->is_captured())) {
      parsed_function->set_instantiator(
          new LoadLocalNode(node_sequence->token_pos(), instantiator));
    }
  }

  parsed_function->set_default_parameter_values(default_parameter_values);
}


// TODO(regis): Since a const variable is implicitly final,
// rename ParseStaticConstGetter to ParseStaticFinalGetter and
// rename kConstImplicitGetter to kImplicitFinalGetter.
SequenceNode* Parser::ParseStaticConstGetter(const Function& func) {
  TRACE_PARSER("ParseStaticConstGetter");
  ParamList params;
  ASSERT(func.num_fixed_parameters() == 0);  // static.
  ASSERT(!func.HasOptionalParameters());
  ASSERT(AbstractType::Handle(func.result_type()).IsResolved());

  // Build local scope for function and populate with the formal parameters.
  OpenFunctionBlock(func);
  AddFormalParamsToScope(&params, current_block_->scope);

  intptr_t ident_pos = TokenPos();
  const String& field_name = *ExpectIdentifier("field name expected");
  const Class& field_class = Class::Handle(func.Owner());
  const Field& field =
      Field::ZoneHandle(field_class.LookupStaticField(field_name));

  // Static const fields must have an initializer.
  ExpectToken(Token::kASSIGN);

  // We don't want to use ParseConstExpr() here because we don't want
  // the constant folding code to create, compile and execute a code
  // fragment to evaluate the expression. Instead, we just make sure
  // the static const field initializer is a constant expression and
  // leave the evaluation to the getter function.
  const intptr_t expr_pos = TokenPos();
  AstNode* expr = ParseExpr(kAllowConst, kConsumeCascades);

  if (field.is_const()) {
    // This getter will only be called once at compile time.
    if (expr->EvalConstExpr() == NULL) {
      ErrorMsg(expr_pos, "initializer must be a compile-time constant");
    }
    ReturnNode* return_node = new ReturnNode(ident_pos, expr);
    current_block_->statements->Add(return_node);
  } else {
    // This getter may be called each time the static field is accessed.
    // The following generated code lazily initializes the field:
    // if (field.value === transition_sentinel) {
    //   field.value = null;
    //   throw("circular dependency in field initialization");
    // }
    // if (field.value === sentinel) {
    //   field.value = transition_sentinel;
    //   field.value = expr;
    // }
    // return field.value;  // Type check is executed here in checked mode.

    // Generate code checking for circular dependency in field initialization.
    AstNode* compare_circular = new ComparisonNode(
        ident_pos,
        Token::kEQ_STRICT,
        new LoadStaticFieldNode(ident_pos, field),
        new LiteralNode(ident_pos, Object::transition_sentinel()));
    // Set field to null prior to throwing exception, so that subsequent
    // accesses to the field do not throw again, since initializers should only
    // be executed once.
    SequenceNode* report_circular = new SequenceNode(ident_pos, NULL);
    report_circular->Add(
        new StoreStaticFieldNode(
            ident_pos,
            field,
            new LiteralNode(ident_pos, Instance::ZoneHandle())));
    // TODO(regis): Exception to throw is not specified by spec.
    const String& circular_error = String::ZoneHandle(
        Symbols::New("circular dependency in field initialization"));
    report_circular->Add(
        new ThrowNode(ident_pos,
                      new LiteralNode(ident_pos, circular_error),
                      NULL));
    AstNode* circular_check =
        new IfNode(ident_pos, compare_circular, report_circular, NULL);
    current_block_->statements->Add(circular_check);

    // Generate code checking for uninitialized field.
    AstNode* compare_uninitialized = new ComparisonNode(
        ident_pos,
        Token::kEQ_STRICT,
        new LoadStaticFieldNode(ident_pos, field),
        new LiteralNode(ident_pos, Object::sentinel()));
    SequenceNode* initialize_field = new SequenceNode(ident_pos, NULL);
    initialize_field->Add(
        new StoreStaticFieldNode(
            ident_pos,
            field,
            new LiteralNode(ident_pos, Object::transition_sentinel())));
    // TODO(hausner): If evaluation of the field value throws an exception,
    // we leave the field value as 'transition_sentinel', which is wrong.
    // A second reference to the field later throws a circular dependency
    // exception. The field should instead be set to null after an exception.
    initialize_field->Add(new StoreStaticFieldNode(ident_pos, field, expr));
    AstNode* uninitialized_check =
        new IfNode(ident_pos, compare_uninitialized, initialize_field, NULL);
    current_block_->statements->Add(uninitialized_check);

    // Generate code returning the field value.
    ReturnNode* return_node =
        new ReturnNode(ident_pos,
                       new LoadStaticFieldNode(ident_pos, field));
    current_block_->statements->Add(return_node);
  }
  return CloseBlock();
}


// Create AstNodes for an implicit instance getter method:
//   LoadLocalNode 0 ('this');
//   LoadInstanceFieldNode (field_name);
//   ReturnNode (field's value);
SequenceNode* Parser::ParseInstanceGetter(const Function& func) {
  TRACE_PARSER("ParseInstanceGetter");
  ParamList params;
  // func.token_pos() points to the name of the field.
  intptr_t ident_pos = func.token_pos();
  ASSERT(current_class().raw() == func.Owner());
  params.AddReceiver(ReceiverType(ident_pos));
  ASSERT(func.num_fixed_parameters() == 1);  // receiver.
  ASSERT(!func.HasOptionalParameters());
  ASSERT(AbstractType::Handle(func.result_type()).IsResolved());

  // Build local scope for function and populate with the formal parameters.
  OpenFunctionBlock(func);
  AddFormalParamsToScope(&params, current_block_->scope);

  // Receiver is local 0.
  LocalVariable* receiver = current_block_->scope->VariableAt(0);
  LoadLocalNode* load_receiver = new LoadLocalNode(ident_pos, receiver);
  ASSERT(IsIdentifier());
  const String& field_name = *CurrentLiteral();
  const Class& field_class = Class::Handle(func.Owner());
  const Field& field =
      Field::ZoneHandle(field_class.LookupInstanceField(field_name));

  LoadInstanceFieldNode* load_field =
      new LoadInstanceFieldNode(ident_pos, load_receiver, field);

  ReturnNode* return_node = new ReturnNode(ident_pos, load_field);
  current_block_->statements->Add(return_node);
  return CloseBlock();
}


// Create AstNodes for an implicit instance setter method:
//   LoadLocalNode 0 ('this')
//   LoadLocalNode 1 ('value')
//   SetInstanceField (field_name);
//   ReturnNode (void);
SequenceNode* Parser::ParseInstanceSetter(const Function& func) {
  TRACE_PARSER("ParseInstanceSetter");
  // func.token_pos() points to the name of the field.
  intptr_t ident_pos = func.token_pos();
  const String& field_name = *CurrentLiteral();
  const Class& field_class = Class::ZoneHandle(func.Owner());
  const Field& field =
      Field::ZoneHandle(field_class.LookupInstanceField(field_name));
  const AbstractType& field_type = AbstractType::ZoneHandle(field.type());

  ParamList params;
  ASSERT(current_class().raw() == func.Owner());
  params.AddReceiver(ReceiverType(ident_pos));
  params.AddFinalParameter(ident_pos,
                           &Symbols::Value(),
                           &field_type);
  ASSERT(func.num_fixed_parameters() == 2);  // receiver, value.
  ASSERT(!func.HasOptionalParameters());
  ASSERT(AbstractType::Handle(func.result_type()).IsVoidType());

  // Build local scope for function and populate with the formal parameters.
  OpenFunctionBlock(func);
  AddFormalParamsToScope(&params, current_block_->scope);

  LoadLocalNode* receiver =
      new LoadLocalNode(ident_pos, current_block_->scope->VariableAt(0));
  LoadLocalNode* value =
      new LoadLocalNode(ident_pos, current_block_->scope->VariableAt(1));

  EnsureExpressionTemp();
  StoreInstanceFieldNode* store_field =
      new StoreInstanceFieldNode(ident_pos, receiver, field, value);
  current_block_->statements->Add(store_field);
  current_block_->statements->Add(new ReturnNode(ident_pos));
  return CloseBlock();
}


SequenceNode* Parser::ParseMethodExtractor(const Function& func) {
  TRACE_PARSER("ParseMethodExtractor");
  ParamList params;

  const intptr_t ident_pos = func.token_pos();
  ASSERT(func.token_pos() == 0);
  ASSERT(current_class().raw() == func.Owner());
  params.AddReceiver(ReceiverType(ident_pos));
  ASSERT(func.num_fixed_parameters() == 1);  // Receiver.
  ASSERT(!func.HasOptionalParameters());

  // Build local scope for function and populate with the formal parameters.
  OpenFunctionBlock(func);
  AddFormalParamsToScope(&params, current_block_->scope);

  // Receiver is local 0.
  LocalVariable* receiver = current_block_->scope->VariableAt(0);
  LoadLocalNode* load_receiver = new LoadLocalNode(ident_pos, receiver);

  ClosureNode* closure = new ClosureNode(
      ident_pos,
      Function::ZoneHandle(func.extracted_method_closure()),
      load_receiver,
      NULL);

  ReturnNode* return_node = new ReturnNode(ident_pos, closure);
  current_block_->statements->Add(return_node);
  return CloseBlock();
}


void Parser::SkipBlock() {
  ASSERT(CurrentToken() == Token::kLBRACE);
  GrowableArray<Token::Kind> token_stack(8);
  const intptr_t block_start_pos = TokenPos();
  bool is_match = true;
  bool unexpected_token_found = false;
  Token::Kind token;
  intptr_t token_pos;
  do {
    token = CurrentToken();
    token_pos = TokenPos();
    switch (token) {
      case Token::kLBRACE:
      case Token::kLPAREN:
      case Token::kLBRACK:
        token_stack.Add(token);
        break;
      case Token::kRBRACE:
        is_match = token_stack.RemoveLast() == Token::kLBRACE;
        break;
      case Token::kRPAREN:
        is_match = token_stack.RemoveLast() == Token::kLPAREN;
        break;
      case Token::kRBRACK:
        is_match = token_stack.RemoveLast() == Token::kLBRACK;
        break;
      case Token::kEOS:
        unexpected_token_found = true;
        break;
      default:
        // nothing.
        break;
    }
    ConsumeToken();
  } while (!token_stack.is_empty() && is_match && !unexpected_token_found);
  if (!is_match) {
    ErrorMsg(token_pos, "unbalanced '%s'", Token::Str(token));
  } else if (unexpected_token_found) {
    ErrorMsg(block_start_pos, "unterminated block");
  }
}


void Parser::ParseFormalParameter(bool allow_explicit_default_value,
                                  ParamList* params) {
  TRACE_PARSER("ParseFormalParameter");
  ParamDesc parameter;
  bool var_seen = false;
  bool this_seen = false;

  SkipMetadata();
  if (CurrentToken() == Token::kFINAL) {
    ConsumeToken();
    parameter.is_final = true;
  } else if (CurrentToken() == Token::kVAR) {
    ConsumeToken();
    var_seen = true;
    // The parameter type is the 'dynamic' type.
    parameter.type = &Type::ZoneHandle(Type::DynamicType());
  }
  if (CurrentToken() == Token::kTHIS) {
    ConsumeToken();
    ExpectToken(Token::kPERIOD);
    this_seen = true;
    parameter.is_field_initializer = true;
  }
  if (params->implicitly_final) {
    parameter.is_final = true;
  }
  if ((parameter.type == NULL) && (CurrentToken() == Token::kVOID)) {
    ConsumeToken();
    // This must later be changed to a closure type if we recognize
    // a closure/function type parameter. We check this at the end
    // of ParseFormalParameter.
    parameter.type = &Type::ZoneHandle(Type::VoidType());
  }
  if (parameter.type == NULL) {
    // At this point, we must see an identifier for the type or the
    // function parameter.
    if (!IsIdentifier()) {
      ErrorMsg("parameter name or type expected");
    }
    // We have not seen a parameter type yet, so we check if the next
    // identifier could represent a type before parsing it.
    Token::Kind follower = LookaheadToken(1);
    // We have an identifier followed by a 'follower' token.
    // We either parse a type or assume that no type is specified.
    if ((follower == Token::kLT) ||  // Parameterized type.
        (follower == Token::kPERIOD) ||  // Qualified class name of type.
        Token::IsIdentifier(follower) ||  // Parameter name following a type.
        (follower == Token::kTHIS)) {  // Field parameter following a type.
      // The types of formal parameters are never ignored, even in unchecked
      // mode, because they are part of the function type of closurized
      // functions appearing in type tests with typedefs.
      parameter.type = &AbstractType::ZoneHandle(
          ParseType(is_top_level_ ? ClassFinalizer::kTryResolve :
                                    ClassFinalizer::kCanonicalize));
    } else {
      parameter.type = &Type::ZoneHandle(Type::DynamicType());
    }
  }
  if (!this_seen && (CurrentToken() == Token::kTHIS)) {
    ConsumeToken();
    ExpectToken(Token::kPERIOD);
    this_seen = true;
    parameter.is_field_initializer = true;
  }

  // At this point, we must see an identifier for the parameter name.
  parameter.name_pos = TokenPos();
  parameter.name = ExpectIdentifier("parameter name expected");
  if (parameter.is_field_initializer) {
    params->has_field_initializer = true;
  }

  // Check for duplicate formal parameters.
  const intptr_t num_existing_parameters =
      params->num_fixed_parameters + params->num_optional_parameters;
  for (intptr_t i = 0; i < num_existing_parameters; i++) {
    ParamDesc& existing_parameter = (*params->parameters)[i];
    if (existing_parameter.name->Equals(*parameter.name)) {
      ErrorMsg(parameter.name_pos, "duplicate formal parameter '%s'",
               parameter.name->ToCString());
    }
  }

  if (CurrentToken() == Token::kLPAREN) {
    // This parameter is probably a closure. If we saw the keyword 'var'
    // or 'final', a closure is not legal here and we ignore the
    // opening parens.
    if (!var_seen && !parameter.is_final) {
      // The parsed parameter type is actually the function result type.
      const AbstractType& result_type =
          AbstractType::Handle(parameter.type->raw());

      // Finish parsing the function type parameter.
      ParamList func_params;

      // Add implicit closure object parameter.
      func_params.AddFinalParameter(
          TokenPos(),
          &Symbols::ClosureParameter(),
          &Type::ZoneHandle(Type::DynamicType()));

      const bool no_explicit_default_values = false;
      ParseFormalParameterList(no_explicit_default_values, &func_params);

      // The field 'is_static' has no meaning for signature functions.
      const Function& signature_function = Function::Handle(
          Function::New(*parameter.name,
                        RawFunction::kSignatureFunction,
                        /* is_static = */ false,
                        /* is_const = */ false,
                        /* is_abstract = */ false,
                        /* is_external = */ false,
                        current_class(),
                        parameter.name_pos));
      signature_function.set_result_type(result_type);
      AddFormalParamsToFunction(&func_params, signature_function);
      const String& signature = String::Handle(signature_function.Signature());
      // Lookup the signature class, i.e. the class whose name is the signature.
      // We only lookup in the current library, but not in its imports, and only
      // create a new canonical signature class if it does not exist yet.
      Class& signature_class = Class::ZoneHandle(
          library_.LookupLocalClass(signature));
      if (signature_class.IsNull()) {
        signature_class = Class::NewSignatureClass(signature,
                                                   signature_function,
                                                   script_,
                                                   parameter.name_pos);
        // Record the function signature class in the current library, unless
        // we are currently skipping a formal parameter list, in which case
        // the signature class could remain unfinalized.
        if (!params->skipped) {
          library_.AddClass(signature_class);
        }
      } else {
        signature_function.set_signature_class(signature_class);
      }
      ASSERT(signature_function.signature_class() == signature_class.raw());
      Type& signature_type = Type::ZoneHandle(signature_class.SignatureType());
      if (!is_top_level_ && !signature_type.IsFinalized()) {
        signature_type ^= ClassFinalizer::FinalizeType(
            signature_class, signature_type, ClassFinalizer::kCanonicalize);
      }
      // The type of the parameter is now the signature type.
      parameter.type = &signature_type;
    }
  }

  if ((CurrentToken() == Token::kASSIGN) || (CurrentToken() == Token::kCOLON)) {
    if ((!params->has_optional_positional_parameters &&
         !params->has_optional_named_parameters) ||
        !allow_explicit_default_value) {
      ErrorMsg("parameter must not specify a default value");
    }
    if (params->has_optional_positional_parameters) {
      ExpectToken(Token::kASSIGN);
    } else {
      ExpectToken(Token::kCOLON);
    }
    params->num_optional_parameters++;
    if (is_top_level_) {
      // Skip default value parsing.
      SkipExpr();
    } else {
      const Object& const_value = ParseConstExpr()->literal();
      parameter.default_value = &const_value;
    }
  } else {
    if (params->has_optional_positional_parameters ||
        params->has_optional_named_parameters) {
      // Implicit default value is null.
      params->num_optional_parameters++;
      parameter.default_value = &Object::ZoneHandle();
    } else {
      params->num_fixed_parameters++;
      ASSERT(params->num_optional_parameters == 0);
    }
  }
  if (parameter.type->IsVoidType()) {
    ErrorMsg("parameter '%s' may not be 'void'", parameter.name->ToCString());
  }
  params->parameters->Add(parameter);
}


// Parses a sequence of normal or optional formal parameters.
void Parser::ParseFormalParameters(bool allow_explicit_default_values,
                                   ParamList* params) {
  TRACE_PARSER("ParseFormalParameters");
  do {
    ConsumeToken();
    if (!params->has_optional_positional_parameters &&
        !params->has_optional_named_parameters &&
        (CurrentToken() == Token::kLBRACK)) {
      // End of normal parameters, start of optional positional parameters.
      params->has_optional_positional_parameters = true;
      return;
    }
    if (!params->has_optional_positional_parameters &&
        !params->has_optional_named_parameters &&
        (CurrentToken() == Token::kLBRACE)) {
      // End of normal parameters, start of optional named parameters.
      params->has_optional_named_parameters = true;
      return;
    }
    ParseFormalParameter(allow_explicit_default_values, params);
  } while (CurrentToken() == Token::kCOMMA);
}


void Parser::ParseFormalParameterList(bool allow_explicit_default_values,
                                      ParamList* params) {
  TRACE_PARSER("ParseFormalParameterList");
  ASSERT(CurrentToken() == Token::kLPAREN);

  if (LookaheadToken(1) != Token::kRPAREN) {
    // Parse fixed parameters.
    ParseFormalParameters(allow_explicit_default_values, params);
    if (params->has_optional_positional_parameters ||
        params->has_optional_named_parameters) {
      // Parse optional parameters.
      ParseFormalParameters(allow_explicit_default_values, params);
      if (params->has_optional_positional_parameters) {
        if (CurrentToken() != Token::kRBRACK) {
          ErrorMsg("',' or ']' expected");
        }
      } else {
        if (CurrentToken() != Token::kRBRACE) {
          ErrorMsg("',' or '}' expected");
        }
      }
      ConsumeToken();  // ']' or '}'.
    }
    if ((CurrentToken() != Token::kRPAREN) &&
        !params->has_optional_positional_parameters &&
        !params->has_optional_named_parameters) {
      ErrorMsg("',' or ')' expected");
    }
  } else {
    ConsumeToken();
  }
  ExpectToken(Token::kRPAREN);
}


String& Parser::ParseNativeDeclaration() {
  TRACE_PARSER("ParseNativeDeclaration");
  ASSERT(IsLiteral("native"));
  ConsumeToken();
  if (CurrentToken() != Token::kSTRING) {
    ErrorMsg("string literal expected");
  }
  String& native_name = *CurrentLiteral();
  ConsumeToken();
  ExpectSemicolon();
  return native_name;
}


// Resolve and return the dynamic function of the given name in the superclass.
// If it is not found, and resolve_getter is true, try to resolve a getter of
// the same name. If it is still not found, return noSuchMethod and
// set is_no_such_method to true..
RawFunction* Parser::GetSuperFunction(intptr_t token_pos,
                                      const String& name,
                                      ArgumentListNode* arguments,
                                      bool resolve_getter,
                                      bool* is_no_such_method) {
  const Class& super_class = Class::Handle(current_class().SuperClass());
  if (super_class.IsNull()) {
    ErrorMsg(token_pos, "class '%s' does not have a superclass",
             String::Handle(current_class().Name()).ToCString());
  }
  Function& super_func = Function::Handle(
      Resolver::ResolveDynamicAnyArgs(super_class, name));
  if (!super_func.IsNull() &&
      !super_func.AreValidArguments(arguments->length(),
                                    arguments->names(),
                                    NULL)) {
    super_func = Function::null();
  } else if (super_func.IsNull() && resolve_getter) {
    const String& getter_name = String::ZoneHandle(Field::GetterName(name));
    super_func = Resolver::ResolveDynamicAnyArgs(super_class, getter_name);
    ASSERT(super_func.IsNull() ||
           (super_func.kind() != RawFunction::kConstImplicitGetter));
  }
  if (super_func.IsNull()) {
    super_func =
        Resolver::ResolveDynamicAnyArgs(super_class, Symbols::NoSuchMethod());
    ASSERT(!super_func.IsNull());
    *is_no_such_method = true;
  } else {
    *is_no_such_method = false;
  }
  return super_func.raw();
}


// Lookup class in the core lib which also contains various VM
// helper methods and classes. Allow look up of private classes.
static RawClass* LookupCoreClass(const String& class_name) {
  const Library& core_lib = Library::Handle(Library::CoreLibrary());
  String& name = String::Handle(class_name.raw());
  if (class_name.CharAt(0) == Scanner::kPrivateIdentifierStart) {
    // Private identifiers are mangled on a per script basis.
    name = String::Concat(name, String::Handle(core_lib.private_key()));
    name = Symbols::New(name);
  }
  return core_lib.LookupClass(name);
}


static const String& PrivateCoreLibName(const String& str) {
  const Library& core_lib = Library::Handle(Library::CoreLibrary());
  const String& private_name = String::ZoneHandle(core_lib.PrivateName(str));
  return private_name;
}


LocalVariable* Parser::BuildArrayTempLocal(intptr_t token_pos) {
  char name[64];
  OS::SNPrint(name, 64, ":arrlit%"Pd, token_pos);
  LocalVariable* temp =
      new LocalVariable(token_pos,
                        String::ZoneHandle(Symbols::New(name)),
                        Type::ZoneHandle(Type::ArrayType()));
  current_block_->scope->AddVariable(temp);
  return temp;
}


StaticCallNode* Parser::BuildInvocationMirrorAllocation(
    intptr_t call_pos,
    const String& function_name,
    const ArgumentListNode& function_args) {
  const intptr_t args_pos = function_args.token_pos();
  // Build arguments to the call to the static
  // InvocationMirror._allocateInvocationMirror method.
  ArgumentListNode* arguments = new ArgumentListNode(args_pos);
  // The first argument is the original function name.
  arguments->Add(new LiteralNode(args_pos, function_name));
  // The second argument is the arguments descriptor of the original function.
  const Array& args_descriptor =
      Array::ZoneHandle(ArgumentsDescriptor::New(function_args.length(),
                                                 function_args.names()));
  arguments->Add(new LiteralNode(args_pos, args_descriptor));
  // The third argument is an array containing the original function arguments,
  // including the receiver.
  ArrayNode* args_array = new ArrayNode(
      args_pos, Type::ZoneHandle(Type::ArrayType()),
      *BuildArrayTempLocal(call_pos));
  for (intptr_t i = 0; i < function_args.length(); i++) {
    args_array->AddElement(function_args.NodeAt(i));
  }
  arguments->Add(args_array);
  // Lookup the static InvocationMirror._allocateInvocationMirror method.
  const Class& mirror_class =
      Class::Handle(LookupCoreClass(Symbols::InvocationMirror()));
  ASSERT(!mirror_class.IsNull());
  const Function& allocation_function = Function::ZoneHandle(
      mirror_class.LookupStaticFunction(
          PrivateCoreLibName(Symbols::AllocateInvocationMirror())));
  ASSERT(!allocation_function.IsNull());
  return new StaticCallNode(call_pos, allocation_function, arguments);
}


ArgumentListNode* Parser::BuildNoSuchMethodArguments(
    intptr_t call_pos,
    const String& function_name,
    const ArgumentListNode& function_args) {
  ASSERT(function_args.length() >= 1);  // The receiver is the first argument.
  const intptr_t args_pos = function_args.token_pos();
  ArgumentListNode* arguments = new ArgumentListNode(args_pos);
  arguments->Add(function_args.NodeAt(0));
  // The second argument is the invocation mirror.
  arguments->Add(BuildInvocationMirrorAllocation(
      call_pos, function_name, function_args));
  return arguments;
}


AstNode* Parser::ParseSuperCall(const String& function_name) {
  TRACE_PARSER("ParseSuperCall");
  ASSERT(CurrentToken() == Token::kLPAREN);
  const intptr_t supercall_pos = TokenPos();

  // 'this' parameter is the first argument to super call.
  ArgumentListNode* arguments = new ArgumentListNode(supercall_pos);
  AstNode* receiver = LoadReceiver(supercall_pos);
  arguments->Add(receiver);
  ParseActualParameters(arguments, kAllowConst);

  const bool kResolveGetter = true;
  bool is_no_such_method = false;
  const Function& super_function = Function::ZoneHandle(
      GetSuperFunction(supercall_pos,
                       function_name,
                       arguments,
                       kResolveGetter,
                       &is_no_such_method));
  if (super_function.IsGetterFunction() ||
      super_function.IsImplicitGetterFunction()) {
    const Class& super_class = Class::ZoneHandle(current_class().SuperClass());
    AstNode* closure = new StaticGetterNode(supercall_pos,
                                            LoadReceiver(supercall_pos),
                                            /* is_super_getter */ true,
                                            super_class,
                                            function_name);
    EnsureSavedCurrentContext();
    // 'this' is not passed as parameter to the closure.
    ArgumentListNode* closure_arguments = new ArgumentListNode(supercall_pos);
    for (int i = 1; i < arguments->length(); i++) {
      closure_arguments->Add(arguments->NodeAt(i));
    }
    return new ClosureCallNode(supercall_pos, closure, closure_arguments);
  }
  if (is_no_such_method) {
    arguments = BuildNoSuchMethodArguments(
        supercall_pos, function_name, *arguments);
  }
  return new StaticCallNode(supercall_pos, super_function, arguments);
}


// Simple test if a node is side effect free.
static bool IsSimpleLocalOrLiteralNode(AstNode* node) {
  if (node->IsLiteralNode()) {
    return true;
  }
  if (node->IsLoadLocalNode() && !node->AsLoadLocalNode()->HasPseudo()) {
    return true;
  }
  return false;
}


AstNode* Parser::BuildUnarySuperOperator(Token::Kind op, PrimaryNode* super) {
  ASSERT(super->IsSuper());
  AstNode* super_op = NULL;
  const intptr_t super_pos = super->token_pos();
  if ((op == Token::kNEGATE) ||
      (op == Token::kBIT_NOT)) {
    // Resolve the operator function in the superclass.
    const String& operator_function_name =
        String::ZoneHandle(Symbols::New(Token::Str(op)));
    ArgumentListNode* op_arguments = new ArgumentListNode(super_pos);
    AstNode* receiver = LoadReceiver(super_pos);
    op_arguments->Add(receiver);
    const bool kResolveGetter = false;
    bool is_no_such_method = false;
    const Function& super_operator = Function::ZoneHandle(
        GetSuperFunction(super_pos,
                         operator_function_name,
                         op_arguments,
                         kResolveGetter,
                         &is_no_such_method));
    if (is_no_such_method) {
      op_arguments = BuildNoSuchMethodArguments(
          super_pos, operator_function_name, *op_arguments);
    }
    super_op = new StaticCallNode(super_pos, super_operator, op_arguments);
  } else {
    ErrorMsg(super_pos, "illegal super operator call");
  }
  return super_op;
}


AstNode* Parser::ParseSuperOperator() {
  TRACE_PARSER("ParseSuperOperator");
  AstNode* super_op = NULL;
  const intptr_t operator_pos = TokenPos();

  if (CurrentToken() == Token::kLBRACK) {
    ConsumeToken();
    AstNode* index_expr = ParseExpr(kAllowConst, kConsumeCascades);
    ExpectToken(Token::kRBRACK);
    AstNode* receiver = LoadReceiver(operator_pos);
    const Class& super_class = Class::ZoneHandle(current_class().SuperClass());
    ASSERT(!super_class.IsNull());
    super_op =
        new LoadIndexedNode(operator_pos, receiver, index_expr, super_class);
  } else if (Token::CanBeOverloaded(CurrentToken()) ||
             (CurrentToken() == Token::kNE)) {
    Token::Kind op = CurrentToken();
    ConsumeToken();

    bool negate_result = false;
    if (op == Token::kNE) {
      op = Token::kEQ;
      negate_result = true;
    }

    ASSERT(Token::Precedence(op) >= Token::Precedence(Token::kBIT_OR));
    AstNode* other_operand = ParseBinaryExpr(Token::Precedence(op) + 1);

    ArgumentListNode* op_arguments = new ArgumentListNode(operator_pos);
    AstNode* receiver = LoadReceiver(operator_pos);
    op_arguments->Add(receiver);
    op_arguments->Add(other_operand);

    // Resolve the operator function in the superclass.
    const String& operator_function_name =
        String::ZoneHandle(Symbols::New(Token::Str(op)));
    const bool kResolveGetter = false;
    bool is_no_such_method = false;
    const Function& super_operator = Function::ZoneHandle(
        GetSuperFunction(operator_pos,
                         operator_function_name,
                         op_arguments,
                         kResolveGetter,
                         &is_no_such_method));
    if (is_no_such_method) {
      op_arguments = BuildNoSuchMethodArguments(
          operator_pos, operator_function_name, *op_arguments);
    }
    super_op = new StaticCallNode(operator_pos, super_operator, op_arguments);
    if (negate_result) {
      super_op = new UnaryOpNode(operator_pos, Token::kNOT, super_op);
    }
  }
  return super_op;
}


AstNode* Parser::CreateImplicitClosureNode(const Function& func,
                                           intptr_t token_pos,
                                           AstNode* receiver) {
  Function& implicit_closure_function =
      Function::ZoneHandle(func.ImplicitClosureFunction());
  if (receiver != NULL) {
    // If we create an implicit instance closure from inside a closure of a
    // parameterized class, make sure that the receiver is captured as
    // instantiator.
    if (current_block_->scope->function_level() > 0) {
      const Class& signature_class = Class::Handle(
          implicit_closure_function.signature_class());
      if (signature_class.NumTypeParameters() > 0) {
        CaptureInstantiator();
      }
    }
  }
  return new ClosureNode(token_pos, implicit_closure_function, receiver, NULL);
}


AstNode* Parser::ParseSuperFieldAccess(const String& field_name) {
  TRACE_PARSER("ParseSuperFieldAccess");
  const intptr_t field_pos = TokenPos();
  const Class& super_class = Class::ZoneHandle(current_class().SuperClass());
  if (super_class.IsNull()) {
    ErrorMsg("class '%s' does not have a superclass",
             String::Handle(current_class().Name()).ToCString());
  }
  AstNode* implicit_argument = LoadReceiver(field_pos);

  const String& getter_name =
      String::ZoneHandle(Field::GetterName(field_name));
  const Function& super_getter = Function::ZoneHandle(
      Resolver::ResolveDynamicAnyArgs(super_class, getter_name));
  if (super_getter.IsNull()) {
    const String& setter_name =
        String::ZoneHandle(Field::SetterName(field_name));
    const Function& super_setter = Function::ZoneHandle(
        Resolver::ResolveDynamicAnyArgs(super_class, setter_name));
    if (!super_setter.IsNull()) {
      return new StaticGetterNode(
          field_pos, implicit_argument, true, super_class, field_name);
    }
  }
  if (super_getter.IsNull()) {
    // Check if this is an access to an implicit closure using 'super'.
    // If a function exists of the specified field_name then try
    // accessing it as a getter, at runtime we will handle this by
    // creating an implicit closure of the function and returning it.
    const Function& super_function = Function::ZoneHandle(
        Resolver::ResolveDynamicAnyArgs(super_class, field_name));
    if (!super_function.IsNull()) {
      // In case CreateAssignmentNode is called later on this
      // CreateImplicitClosureNode, it will be replaced by a StaticSetterNode.
      return CreateImplicitClosureNode(super_function,
                                       field_pos,
                                       implicit_argument);
    }
    // No function or field exists of the specified field_name.
    // Emit a StaticGetterNode anyway, so that noSuchMethod gets called.
  }
  return new StaticGetterNode(
      field_pos, implicit_argument, true, super_class, field_name);
}


void Parser::GenerateSuperConstructorCall(const Class& cls,
                                          LocalVariable* receiver) {
  const intptr_t supercall_pos = TokenPos();
  const Class& super_class = Class::Handle(cls.SuperClass());
  // Omit the implicit super() if there is no super class (i.e.
  // we're not compiling class Object), or if the super class is an
  // artificially generated "wrapper class" that has no constructor.
  if (super_class.IsNull() ||
      (super_class.num_native_fields() > 0 &&
       Class::Handle(super_class.SuperClass()).IsObjectClass())) {
    return;
  }
  String& ctor_name = String::Handle(super_class.Name());
  ctor_name = String::Concat(ctor_name, Symbols::Dot());
  ArgumentListNode* arguments = new ArgumentListNode(supercall_pos);
  // Implicit 'this' parameter is the first argument.
  AstNode* implicit_argument = new LoadLocalNode(supercall_pos, receiver);
  arguments->Add(implicit_argument);
  // Implicit construction phase parameter is second argument.
  AstNode* phase_parameter =
      new LiteralNode(supercall_pos,
                      Smi::ZoneHandle(Smi::New(Function::kCtorPhaseAll)));
  arguments->Add(phase_parameter);
  const Function& super_ctor = Function::ZoneHandle(
      super_class.LookupConstructor(ctor_name));
  if (super_ctor.IsNull()) {
      ErrorMsg(supercall_pos,
               "unresolved implicit call to super constructor '%s()'",
               String::Handle(super_class.Name()).ToCString());
  }
  String& error_message = String::Handle();
  if (!super_ctor.AreValidArguments(arguments->length(),
                                    arguments->names(),
                                    &error_message)) {
    ErrorMsg(supercall_pos,
             "invalid arguments passed to super constructor '%s()': %s",
             String::Handle(super_class.Name()).ToCString(),
             error_message.ToCString());
  }
  current_block_->statements->Add(
      new StaticCallNode(supercall_pos, super_ctor, arguments));
}


AstNode* Parser::ParseSuperInitializer(const Class& cls,
                                       LocalVariable* receiver) {
  TRACE_PARSER("ParseSuperInitializer");
  ASSERT(CurrentToken() == Token::kSUPER);
  const intptr_t supercall_pos = TokenPos();
  ConsumeToken();
  const Class& super_class = Class::Handle(cls.SuperClass());
  ASSERT(!super_class.IsNull());
  String& ctor_name = String::Handle(super_class.Name());
  ctor_name = String::Concat(ctor_name, Symbols::Dot());
  if (CurrentToken() == Token::kPERIOD) {
    ConsumeToken();
    ctor_name = String::Concat(ctor_name,
                               *ExpectIdentifier("constructor name expected"));
  }
  if (CurrentToken() != Token::kLPAREN) {
    ErrorMsg("parameter list expected");
  }

  ArgumentListNode* arguments = new ArgumentListNode(supercall_pos);
  // 'this' parameter is the first argument to super class constructor.
  AstNode* implicit_argument = new LoadLocalNode(supercall_pos, receiver);
  arguments->Add(implicit_argument);
  // Second implicit parameter is the construction phase. We optimistically
  // assume that we can execute both the super initializer and the super
  // constructor body. We may later change this to only execute the
  // super initializer.
  AstNode* phase_parameter =
      new LiteralNode(supercall_pos,
                      Smi::ZoneHandle(Smi::New(Function::kCtorPhaseAll)));
  arguments->Add(phase_parameter);
  // 'this' parameter must not be accessible to the other super call arguments.
  receiver->set_invisible(true);
  ParseActualParameters(arguments, kAllowConst);
  receiver->set_invisible(false);

  // Resolve the constructor.
  const Function& super_ctor = Function::ZoneHandle(
      super_class.LookupConstructor(ctor_name));
  if (super_ctor.IsNull()) {
    ErrorMsg(supercall_pos,
             "super class constructor '%s' not found",
             ctor_name.ToCString());
  }
  String& error_message = String::Handle();
  if (!super_ctor.AreValidArguments(arguments->length(),
                                    arguments->names(),
                                    &error_message)) {
    ErrorMsg(supercall_pos,
             "invalid arguments passed to super class constructor '%s': %s",
             ctor_name.ToCString(),
             error_message.ToCString());
  }
  return new StaticCallNode(supercall_pos, super_ctor, arguments);
}


AstNode* Parser::ParseInitializer(const Class& cls,
                                  LocalVariable* receiver,
                                  GrowableArray<Field*>* initialized_fields) {
  TRACE_PARSER("ParseInitializer");
  const intptr_t field_pos = TokenPos();
  if (CurrentToken() == Token::kTHIS) {
    ConsumeToken();
    ExpectToken(Token::kPERIOD);
  }
  const String& field_name = *ExpectIdentifier("field name expected");
  ExpectToken(Token::kASSIGN);

  const bool saved_mode = SetAllowFunctionLiterals(false);
  // "this" must not be accessible in initializer expressions.
  receiver->set_invisible(true);
  AstNode* init_expr = ParseConditionalExpr();
  if (CurrentToken() == Token::kCASCADE) {
    init_expr = ParseCascades(init_expr);
  }
  receiver->set_invisible(false);
  SetAllowFunctionLiterals(saved_mode);
  Field& field = Field::ZoneHandle(cls.LookupInstanceField(field_name));
  if (field.IsNull()) {
    ErrorMsg(field_pos, "unresolved reference to instance field '%s'",
             field_name.ToCString());
  }
  CheckDuplicateFieldInit(field_pos, initialized_fields, &field);
  AstNode* instance = new LoadLocalNode(field_pos, receiver);
  EnsureExpressionTemp();
  return new StoreInstanceFieldNode(field_pos, instance, field, init_expr);
}


void Parser::CheckConstFieldsInitialized(const Class& cls) {
  const Array& fields = Array::Handle(cls.fields());
  Field& field = Field::Handle();
  SequenceNode* initializers = current_block_->statements;
  for (int field_num = 0; field_num < fields.Length(); field_num++) {
    field ^= fields.At(field_num);
    if (field.is_static()) {
      continue;
    }

    bool found = false;
    for (int i = 0; i < initializers->length(); i++) {
      found = false;
      if (initializers->NodeAt(i)->IsStoreInstanceFieldNode()) {
        StoreInstanceFieldNode* initializer =
            initializers->NodeAt(i)->AsStoreInstanceFieldNode();
        if (initializer->field().raw() == field.raw()) {
          found = true;
          break;
        }
      }
    }

    if (found) continue;

    if (field.is_final()) {
      ErrorMsg("final field '%s' not initialized",
               String::Handle(field.name()).ToCString());
    } else {
      field.UpdateCid(kNullCid);
    }
  }
}


AstNode* Parser::ParseExternalInitializedField(const Field& field) {
  // Only use this function if the initialized field originates
  // from a different class. We need to save and restore current
  // class, library, and token stream (script).
  ASSERT(current_class().raw() != field.origin());
  const Class& saved_class = Class::Handle(current_class().raw());
  const Library& saved_library = Library::Handle(library().raw());
  const Script& saved_script = Script::Handle(script().raw());
  const intptr_t saved_token_pos = TokenPos();

  set_current_class(Class::Handle(field.origin()));
  set_library(Library::Handle(current_class().library()));
  SetScript(Script::Handle(current_class().script()), field.token_pos());

  ASSERT(IsIdentifier());
  ConsumeToken();
  ExpectToken(Token::kASSIGN);
  AstNode* init_expr = NULL;
  if (field.is_const()) {
    init_expr = ParseConstExpr();
  } else {
    init_expr = ParseExpr(kAllowConst, kConsumeCascades);
    if (init_expr->EvalConstExpr() != NULL) {
      init_expr =
          new LiteralNode(field.token_pos(), EvaluateConstExpr(init_expr));
    }
  }
  set_current_class(saved_class);
  set_library(saved_library);
  SetScript(saved_script, saved_token_pos);
  return init_expr;
}


void Parser::ParseInitializedInstanceFields(const Class& cls,
                 LocalVariable* receiver,
                 GrowableArray<Field*>* initialized_fields) {
  TRACE_PARSER("ParseInitializedInstanceFields");
  const Array& fields = Array::Handle(cls.fields());
  Field& f = Field::Handle();
  const intptr_t saved_pos = TokenPos();
  for (int i = 0; i < fields.Length(); i++) {
    f ^= fields.At(i);
    if (!f.is_static() && f.has_initializer()) {
      Field& field = Field::ZoneHandle();
      field ^= fields.At(i);
      if (field.is_final()) {
        // Final fields with initializer expression may not be initialized
        // again by constructors. Remember that this field is already
        // initialized.
        initialized_fields->Add(&field);
      }
      AstNode* init_expr = NULL;
      if (current_class().raw() != field.origin()) {
        init_expr = ParseExternalInitializedField(field);
      } else {
        SetPosition(field.token_pos());
        ASSERT(IsIdentifier());
        ConsumeToken();
        ExpectToken(Token::kASSIGN);
        if (field.is_const()) {
          init_expr = ParseConstExpr();
        } else {
          init_expr = ParseExpr(kAllowConst, kConsumeCascades);
          if (init_expr->EvalConstExpr() != NULL) {
            init_expr = new LiteralNode(field.token_pos(),
                                        EvaluateConstExpr(init_expr));
          }
        }
      }
      ASSERT(init_expr != NULL);
      AstNode* instance = new LoadLocalNode(field.token_pos(), receiver);
      EnsureExpressionTemp();
      AstNode* field_init =
          new StoreInstanceFieldNode(field.token_pos(),
                                     instance,
                                     field,
                                     init_expr);
      current_block_->statements->Add(field_init);
    }
  }
  SetPosition(saved_pos);
}


void Parser::CheckDuplicateFieldInit(intptr_t init_pos,
                                    GrowableArray<Field*>* initialized_fields,
                                    Field* field) {
  ASSERT(!field->is_static());
  for (int i = 0; i < initialized_fields->length(); i++) {
    Field* initialized_field = (*initialized_fields)[i];
    if (initialized_field->raw() == field->raw()) {
      ErrorMsg(init_pos,
               "duplicate initialization for field %s",
               String::Handle(field->name()).ToCString());
    }
  }
  initialized_fields->Add(field);
}


void Parser::ParseInitializers(const Class& cls,
                               LocalVariable* receiver,
                               GrowableArray<Field*>* initialized_fields) {
  TRACE_PARSER("ParseInitializers");
  bool super_init_seen = false;
  if (CurrentToken() == Token::kCOLON) {
    if ((LookaheadToken(1) == Token::kTHIS) &&
        ((LookaheadToken(2) == Token::kLPAREN) ||
        ((LookaheadToken(2) == Token::kPERIOD) &&
            (LookaheadToken(4) == Token::kLPAREN)))) {
      // Either we see this(...) or this.xxx(...) which is a
      // redirected constructor. We don't need to check whether
      // const fields are initialized. The other constructor will
      // guarantee that.
      ConsumeToken();  // Colon.
      ParseConstructorRedirection(cls, receiver);
      return;
    }
    do {
      ConsumeToken();  // Colon or comma.
      AstNode* init_statement;
      if (CurrentToken() == Token::kSUPER) {
        if (super_init_seen) {
          ErrorMsg("duplicate call to super constructor");
        }
        init_statement = ParseSuperInitializer(cls, receiver);
        super_init_seen = true;
      } else {
        init_statement = ParseInitializer(cls, receiver, initialized_fields);
      }
      current_block_->statements->Add(init_statement);
    } while (CurrentToken() == Token::kCOMMA);
  }
  if (!super_init_seen) {
    // Generate implicit super() if we haven't seen an explicit super call
    // or constructor redirection.
    GenerateSuperConstructorCall(cls, receiver);
  }
  CheckConstFieldsInitialized(cls);
}


void Parser::ParseConstructorRedirection(const Class& cls,
                                         LocalVariable* receiver) {
  TRACE_PARSER("ParseConstructorRedirection");
  ASSERT(CurrentToken() == Token::kTHIS);
  const intptr_t call_pos = TokenPos();
  ConsumeToken();
  String& ctor_name = String::Handle(cls.Name());

  ctor_name = String::Concat(ctor_name, Symbols::Dot());
  if (CurrentToken() == Token::kPERIOD) {
    ConsumeToken();
    ctor_name = String::Concat(ctor_name,
                               *ExpectIdentifier("constructor name expected"));
  }
  if (CurrentToken() != Token::kLPAREN) {
    ErrorMsg("parameter list expected");
  }

  ArgumentListNode* arguments = new ArgumentListNode(call_pos);
  // 'this' parameter is the first argument to constructor.
  AstNode* implicit_argument = new LoadLocalNode(call_pos, receiver);
  arguments->Add(implicit_argument);
  // Construction phase parameter is second argument.
  LocalVariable* phase_param = LookupPhaseParameter();
  ASSERT(phase_param != NULL);
  AstNode* phase_argument = new LoadLocalNode(call_pos, phase_param);
  arguments->Add(phase_argument);
  receiver->set_invisible(true);
  ParseActualParameters(arguments, kAllowConst);
  receiver->set_invisible(false);
  // Resolve the constructor.
  const Function& redirect_ctor = Function::ZoneHandle(
      cls.LookupConstructor(ctor_name));
  if (redirect_ctor.IsNull()) {
    ErrorMsg(call_pos, "constructor '%s' not found", ctor_name.ToCString());
  }
  String& error_message = String::Handle();
  if (!redirect_ctor.AreValidArguments(arguments->length(),
                                       arguments->names(),
                                       &error_message)) {
    ErrorMsg(call_pos,
             "invalid arguments passed to constructor '%s': %s",
             ctor_name.ToCString(),
             error_message.ToCString());
  }
  current_block_->statements->Add(
      new StaticCallNode(call_pos, redirect_ctor, arguments));
}


SequenceNode* Parser::MakeImplicitConstructor(const Function& func) {
  ASSERT(func.IsConstructor());
  const intptr_t ctor_pos = TokenPos();
  OpenFunctionBlock(func);
  const Class& cls = Class::Handle(func.Owner());
  LocalVariable* receiver = new LocalVariable(
      ctor_pos,
      Symbols::This(),
      Type::ZoneHandle(Type::DynamicType()));
  current_block_->scope->AddVariable(receiver);

  LocalVariable* phase_parameter = new LocalVariable(
       ctor_pos,
       Symbols::PhaseParameter(),
       Type::ZoneHandle(Type::SmiType()));
  current_block_->scope->AddVariable(phase_parameter);

  // Parse expressions of instance fields that have an explicit
  // initializer expression.
  // The receiver must not be visible to field initializer expressions.
  receiver->set_invisible(true);
  GrowableArray<Field*> initialized_fields;
  ParseInitializedInstanceFields(cls, receiver, &initialized_fields);
  receiver->set_invisible(false);

  GenerateSuperConstructorCall(cls, receiver);
  CheckConstFieldsInitialized(cls);

  // Empty constructor body.
  SequenceNode* statements = CloseBlock();
  return statements;
}


// Helper function to make the first num_variables variables in the
// given scope visible/invisible.
static void SetInvisible(LocalScope* scope, int num_variables, bool invisible) {
  ASSERT(num_variables <= scope->num_variables());
  for (int i = 0; i < num_variables; i++) {
    scope->VariableAt(i)->set_invisible(invisible);
  }
}


// Parser is at the opening parenthesis of the formal parameter declaration
// of function. Parse the formal parameters, initializers and code.
SequenceNode* Parser::ParseConstructor(const Function& func,
                                       Array& default_parameter_values) {
  TRACE_PARSER("ParseConstructor");
  ASSERT(func.IsConstructor());
  ASSERT(!func.IsFactory());
  ASSERT(!func.is_static());
  ASSERT(!func.IsLocalFunction());
  const Class& cls = Class::Handle(func.Owner());
  ASSERT(!cls.IsNull());

  if (func.IsImplicitConstructor()) {
    // Special case: implicit constructor.
    // The parser adds an implicit default constructor when a class
    // does not have any explicit constructor or factory (see
    // Parser::AddImplicitConstructor).
    // There is no source text to parse. We just build the
    // sequence node by hand.
    return MakeImplicitConstructor(func);
  }

  OpenFunctionBlock(func);
  ParamList params;
  const bool allow_explicit_default_values = true;
  ASSERT(CurrentToken() == Token::kLPAREN);

  // Add implicit receiver parameter which is passed the allocated
  // but uninitialized instance to construct.
  ASSERT(current_class().raw() == func.Owner());
  params.AddReceiver(ReceiverType(TokenPos()));

  // Add implicit parameter for construction phase.
  params.AddFinalParameter(
      TokenPos(),
      &Symbols::PhaseParameter(),
      &Type::ZoneHandle(Type::SmiType()));

  if (func.is_const()) {
    params.SetImplicitlyFinal();
  }
  ParseFormalParameterList(allow_explicit_default_values, &params);

  SetupDefaultsForOptionalParams(&params, default_parameter_values);
  ASSERT(AbstractType::Handle(func.result_type()).IsResolved());
  ASSERT(func.NumParameters() == params.parameters->length());

  // Now populate function scope with the formal parameters.
  AddFormalParamsToScope(&params, current_block_->scope);

  // Initialize instance fields that have an explicit initializer expression.
  // The formal parameter names must not be visible to the instance
  // field initializer expressions, yet the parameters must be added to
  // the scope so the expressions use the correct offsets for 'this' when
  // storing values. We make the formal parameters temporarily invisible
  // while parsing the instance field initializer expressions.
  SetInvisible(current_block_->scope, params.parameters->length(), true);
  GrowableArray<Field*> initialized_fields;
  LocalVariable* receiver = current_block_->scope->VariableAt(0);
  OpenBlock();
  ParseInitializedInstanceFields(cls, receiver, &initialized_fields);
  // Make the parameters (which are in the outer scope) visible again.
  SetInvisible(current_block_->scope->parent(),
               params.parameters->length(), false);

  // Turn formal field parameters into field initializers or report error
  // if the function is not a constructor.
  if (params.has_field_initializer) {
    for (int i = 0; i < params.parameters->length(); i++) {
      ParamDesc& param = (*params.parameters)[i];
      if (param.is_field_initializer) {
        const String& field_name = *param.name;
        Field& field = Field::ZoneHandle(cls.LookupInstanceField(field_name));
        if (field.IsNull()) {
          ErrorMsg(param.name_pos,
                   "unresolved reference to instance field '%s'",
                   field_name.ToCString());
        }
        CheckDuplicateFieldInit(param.name_pos, &initialized_fields, &field);
        AstNode* instance = new LoadLocalNode(param.name_pos, receiver);
        LocalVariable* p =
            current_block_->scope->LookupVariable(*param.name, false);
        ASSERT(p != NULL);
        // Initializing formals cannot be used in the explicit initializer
        // list, nor can they be used in the constructor body.
        // Thus, make the parameter invisible.
        p->set_invisible(true);
        AstNode* value = new LoadLocalNode(param.name_pos, p);
        EnsureExpressionTemp();
        AstNode* initializer = new StoreInstanceFieldNode(
            param.name_pos, instance, field, value);
        current_block_->statements->Add(initializer);
      }
    }
  }

  // Now parse the explicit initializer list or constructor redirection.
  ParseInitializers(cls, receiver, &initialized_fields);

  SequenceNode* init_statements = CloseBlock();
  if (init_statements->length() > 0) {
    // Generate guard around the initializer code.
    LocalVariable* phase_param = LookupPhaseParameter();
    AstNode* phase_value = new LoadLocalNode(TokenPos(), phase_param);
    AstNode* phase_check = new BinaryOpNode(
        TokenPos(), Token::kBIT_AND, phase_value,
        new LiteralNode(TokenPos(),
                        Smi::ZoneHandle(Smi::New(Function::kCtorPhaseInit))));
    AstNode* comparison =
        new ComparisonNode(TokenPos(), Token::kNE_STRICT,
                           phase_check,
                           new LiteralNode(TokenPos(),
                                           Smi::ZoneHandle(Smi::New(0))));
    AstNode* guarded_init_statements =
        new IfNode(TokenPos(), comparison, init_statements, NULL);
    current_block_->statements->Add(guarded_init_statements);
  }

  // Parsing of initializers done. Now we parse the constructor body
  // and add the implicit super call to the super constructor's body
  // if necessary.
  StaticCallNode* super_call = NULL;
  // Look for the super initializer call in the sequence of initializer
  // statements. If it exists and is not the last initializer statement,
  // we need to create an implicit super call to the super constructor's
  // body.
  // Thus, iterate over all but the last initializer to see whether
  // it's a super constructor call.
  for (int i = 0; i < init_statements->length() - 1; i++) {
    if (init_statements->NodeAt(i)->IsStaticCallNode()) {
      StaticCallNode* static_call =
      init_statements->NodeAt(i)->AsStaticCallNode();
      if (static_call->function().IsConstructor()) {
        super_call = static_call;
        break;
      }
    }
  }
  if (super_call != NULL) {
    // Generate an implicit call to the super constructor's body.
    // We need to patch the super _initializer_ call so that it
    // saves the evaluated actual arguments in temporary variables.
    // The temporary variables are necessary so that the argument
    // expressions are not evaluated twice.
    ArgumentListNode* ctor_args = super_call->arguments();
    // The super initializer call has at least 2 arguments: the
    // implicit receiver, and the hidden construction phase.
    ASSERT(ctor_args->length() >= 2);
    for (int i = 2; i < ctor_args->length(); i++) {
      AstNode* arg = ctor_args->NodeAt(i);
      if (!IsSimpleLocalOrLiteralNode(arg)) {
        LocalVariable* temp =
            CreateTempConstVariable(arg->token_pos(), "sca");
        AstNode* save_temp = new StoreLocalNode(arg->token_pos(), temp, arg);
        ctor_args->SetNodeAt(i, save_temp);
      }
    }
  }
  OpenBlock();  // Block to collect constructor body nodes.

  // Insert the implicit super call to the super constructor body.
  if (super_call != NULL) {
    ArgumentListNode* initializer_args = super_call->arguments();
    const Function& super_ctor = super_call->function();
    // Patch the initializer call so it only executes the super initializer.
    initializer_args->SetNodeAt(1,
        new LiteralNode(TokenPos(),
                        Smi::ZoneHandle(Smi::New(Function::kCtorPhaseInit))));

    ArgumentListNode* super_call_args = new ArgumentListNode(TokenPos());
    // First argument is the receiver.
    super_call_args->Add(new LoadLocalNode(TokenPos(), receiver));
    // Second argument is the construction phase argument.
    AstNode* phase_parameter =
        new LiteralNode(TokenPos(),
                        Smi::ZoneHandle(Smi::New(Function::kCtorPhaseBody)));
    super_call_args->Add(phase_parameter);
    super_call_args->set_names(initializer_args->names());
    for (int i = 2; i < initializer_args->length(); i++) {
      AstNode* arg = initializer_args->NodeAt(i);
      if (arg->IsLiteralNode()) {
        LiteralNode* lit = arg->AsLiteralNode();
        super_call_args->Add(new LiteralNode(TokenPos(), lit->literal()));
      } else {
        ASSERT(arg->IsLoadLocalNode() || arg->IsStoreLocalNode());
        if (arg->IsLoadLocalNode()) {
          const LocalVariable& temp = arg->AsLoadLocalNode()->local();
          super_call_args->Add(new LoadLocalNode(TokenPos(), &temp));
        } else if (arg->IsStoreLocalNode()) {
          const LocalVariable& temp = arg->AsStoreLocalNode()->local();
          super_call_args->Add(new LoadLocalNode(TokenPos(), &temp));
        }
      }
    }
    ASSERT(super_ctor.AreValidArguments(super_call_args->length(),
                                        super_call_args->names(),
                                        NULL));
    current_block_->statements->Add(
        new StaticCallNode(TokenPos(), super_ctor, super_call_args));
  }

  if (CurrentToken() == Token::kLBRACE) {
    ConsumeToken();
    ParseStatementSequence();
    ExpectToken(Token::kRBRACE);
  } else if (CurrentToken() == Token::kARROW) {
    ErrorMsg("constructors may not return a value");
  } else if (IsLiteral("native")) {
    ErrorMsg("native constructors not supported");
  } else if (CurrentToken() == Token::kSEMICOLON) {
    // Some constructors have no function body.
    ConsumeToken();
  } else {
    UnexpectedToken();
  }

  SequenceNode* ctor_block = CloseBlock();
  if (ctor_block->length() > 0) {
    // Generate guard around the constructor body code.
    LocalVariable* phase_param = LookupPhaseParameter();
    AstNode* phase_value = new LoadLocalNode(TokenPos(), phase_param);
    AstNode* phase_check =
        new BinaryOpNode(TokenPos(), Token::kBIT_AND,
            phase_value,
            new LiteralNode(TokenPos(),
                Smi::ZoneHandle(Smi::New(Function::kCtorPhaseBody))));
    AstNode* comparison =
       new ComparisonNode(TokenPos(), Token::kNE_STRICT,
                         phase_check,
                         new LiteralNode(TokenPos(),
                                         Smi::ZoneHandle(Smi::New(0))));
    AstNode* guarded_block_statements =
        new IfNode(TokenPos(), comparison, ctor_block, NULL);
    current_block_->statements->Add(guarded_block_statements);
  }

  SequenceNode* statements = CloseBlock();
  return statements;
}


// Parser is at the opening parenthesis of the formal parameter
// declaration of the function or constructor.
// Parse the formal parameters and code.
SequenceNode* Parser::ParseFunc(const Function& func,
                                Array& default_parameter_values) {
  TRACE_PARSER("ParseFunc");
  Function& saved_innermost_function =
      Function::Handle(innermost_function().raw());
  innermost_function_ = func.raw();

  // Check to ensure we don't have classes with native fields in libraries
  // which do not have a native resolver. This check is delayed until the class
  // is actually used. Invocation of a function in the class is the first point
  // of use. Access of const static fields in the class do not trigger an error.
  if (current_class().num_native_fields() != 0) {
    const Library& lib = Library::Handle(current_class().library());
    if (lib.native_entry_resolver() == NULL) {
      const String& cls_name = String::Handle(current_class().Name());
      const String& lib_name = String::Handle(lib.url());
      ErrorMsg(current_class().token_pos(),
               "class '%s' is trying to extend a native fields class, "
               "but library '%s' has no native resolvers",
               cls_name.ToCString(), lib_name.ToCString());
    }
  }

  if (func.IsConstructor()) {
    SequenceNode* statements = ParseConstructor(func, default_parameter_values);
    innermost_function_ = saved_innermost_function.raw();
    return statements;
  }

  ASSERT(!func.IsConstructor());
  OpenFunctionBlock(func);  // Build local scope for function.

  ParamList params;
  // An instance closure function may capture and access the receiver, but via
  // the context and not via the first formal parameter.
  if (func.IsClosureFunction()) {
    // The first parameter of a closure function is the closure object.
    ASSERT(!func.is_const());  // Closure functions cannot be const.
    params.AddFinalParameter(
        TokenPos(),
        &Symbols::ClosureParameter(),
        &Type::ZoneHandle(Type::DynamicType()));
  } else if (!func.is_static()) {
    // Static functions do not have a receiver.
    ASSERT(current_class().raw() == func.Owner());
    params.AddReceiver(ReceiverType(TokenPos()));
  } else if (func.IsFactory()) {
    // The first parameter of a factory is the AbstractTypeArguments vector of
    // the type of the instance to be allocated.
    params.AddFinalParameter(
        TokenPos(),
        &Symbols::TypeArgumentsParameter(),
        &Type::ZoneHandle(Type::DynamicType()));
  }
  ASSERT((CurrentToken() == Token::kLPAREN) || func.IsGetterFunction());
  const bool allow_explicit_default_values = true;
  if (!func.IsGetterFunction()) {
    ParseFormalParameterList(allow_explicit_default_values, &params);
  } else {
    // TODO(hausner): Remove this once we no longer support the old
    // getter syntax with explicit empty parameter list.
    if (CurrentToken() == Token::kLPAREN) {
      ConsumeToken();
      ExpectToken(Token::kRPAREN);
    }
  }

  // The number of parameters and their type are not yet set in local functions,
  // since they are not 'top-level' parsed.
  if (func.IsLocalFunction()) {
    AddFormalParamsToFunction(&params, func);
  }
  SetupDefaultsForOptionalParams(&params, default_parameter_values);
  ASSERT(AbstractType::Handle(func.result_type()).IsResolved());
  ASSERT(func.NumParameters() == params.parameters->length());

  // Check whether the function has any field initializer formal parameters,
  // which are not allowed in non-constructor functions.
  if (params.has_field_initializer) {
    for (int i = 0; i < params.parameters->length(); i++) {
      ParamDesc& param = (*params.parameters)[i];
      if (param.is_field_initializer) {
        ErrorMsg(param.name_pos,
                 "field initializer only allowed in constructors");
      }
    }
  }
  // Populate function scope with the formal parameters.
  AddFormalParamsToScope(&params, current_block_->scope);

  if (FLAG_enable_type_checks &&
      (current_block_->scope->function_level() > 0)) {
    // We are parsing, but not compiling, a local function.
    // The instantiator may be required at run time for generic type checks.
    if (IsInstantiatorRequired()) {
      // Make sure that the receiver of the enclosing instance function
      // (or implicit first parameter of an enclosing factory) is marked as
      // captured if type checks are enabled, because they may access it to
      // instantiate types.
      CaptureInstantiator();
    }
  }

  OpenBlock();  // Open a nested scope for the outermost function block.
  if (CurrentToken() == Token::kLBRACE) {
    ConsumeToken();
    ParseStatementSequence();
    ExpectToken(Token::kRBRACE);
  } else if (CurrentToken() == Token::kARROW) {
    ConsumeToken();
    const intptr_t expr_pos = TokenPos();
    AstNode* expr = ParseExpr(kAllowConst, kConsumeCascades);
    ASSERT(expr != NULL);
    current_block_->statements->Add(new ReturnNode(expr_pos, expr));
  } else if (IsLiteral("native")) {
    ParseNativeFunctionBlock(&params, func);
  } else if (func.is_external()) {
    // Body of an external method contains a single throw.
    const String& function_name = String::ZoneHandle(func.name());
    // TODO(regis): For an instance function, pass the receiver to
    // NoSuchMethodError.
    current_block_->statements->Add(
        ThrowNoSuchMethodError(TokenPos(),
                               current_class(),
                               function_name,
                               func.is_static() ?
                                   InvocationMirror::kStatic :
                                   InvocationMirror::kDynamic,
                               InvocationMirror::kMethod));
  } else {
    UnexpectedToken();
  }
  SequenceNode* body = CloseBlock();
  current_block_->statements->Add(body);
  innermost_function_ = saved_innermost_function.raw();
  return CloseBlock();
}


void Parser::SkipIf(Token::Kind token) {
  if (CurrentToken() == token) {
    ConsumeToken();
  }
}


// Skips tokens up to matching closing parenthesis.
void Parser::SkipToMatchingParenthesis() {
  ASSERT(CurrentToken() == Token::kLPAREN);
  int level = 0;
  do {
    if (CurrentToken() == Token::kLPAREN) {
      level++;
    } else if (CurrentToken() == Token::kRPAREN) {
      level--;
    }
    ConsumeToken();
  } while ((level > 0) && (CurrentToken() != Token::kEOS));
}


void Parser::SkipInitializers() {
  ASSERT(CurrentToken() == Token::kCOLON);
  do {
    ConsumeToken();  // Colon or comma.
    if (CurrentToken() == Token::kSUPER) {
      ConsumeToken();
      if (CurrentToken() == Token::kPERIOD) {
        ConsumeToken();
        ExpectIdentifier("identifier expected");
      }
      if (CurrentToken() != Token::kLPAREN) {
        ErrorMsg("'(' expected");
      }
      SkipToMatchingParenthesis();
    } else {
      SkipIf(Token::kTHIS);
      SkipIf(Token::kPERIOD);
      ExpectIdentifier("identifier expected");
      ExpectToken(Token::kASSIGN);
      SetAllowFunctionLiterals(false);
      SkipExpr();
      SetAllowFunctionLiterals(true);
    }
  } while (CurrentToken() == Token::kCOMMA);
}


void Parser::ParseQualIdent(QualIdent* qual_ident) {
  TRACE_PARSER("ParseQualIdent");
  ASSERT(IsIdentifier());
  ASSERT(!current_class().IsNull());
  qual_ident->ident_pos = TokenPos();
  qual_ident->ident = CurrentLiteral();
  qual_ident->lib_prefix = NULL;
  ConsumeToken();
  if (CurrentToken() == Token::kPERIOD) {
    // An identifier cannot be resolved in a local scope when top level parsing.
    if (is_top_level_ ||
        !ResolveIdentInLocalScope(qual_ident->ident_pos,
                                  *(qual_ident->ident),
                                  NULL)) {
      LibraryPrefix& lib_prefix = LibraryPrefix::ZoneHandle();
      lib_prefix = current_class().LookupLibraryPrefix(*(qual_ident->ident));
      if (!lib_prefix.IsNull()) {
        // We have a library prefix qualified identifier, unless the prefix is
        // shadowed by a type parameter in scope.
        if (current_class().IsNull() ||
            (current_class().LookupTypeParameter(*(qual_ident->ident),
                                                 TokenPos()) ==
             TypeParameter::null())) {
          ConsumeToken();  // Consume the kPERIOD token.
          qual_ident->lib_prefix = &lib_prefix;
          qual_ident->ident_pos = TokenPos();
          qual_ident->ident =
              ExpectIdentifier("identifier expected after '.'");
        }
      }
    }
  }
}


void Parser::ParseMethodOrConstructor(ClassDesc* members, MemberDesc* method) {
  TRACE_PARSER("ParseMethodOrConstructor");
  ASSERT(CurrentToken() == Token::kLPAREN || method->IsGetter());
  intptr_t method_pos = this->TokenPos();
  ASSERT(method->type != NULL);
  ASSERT(method->name_pos > 0);
  ASSERT(current_member_ == method);

  if (method->has_var) {
    ErrorMsg(method->name_pos, "keyword var not allowed for methods");
  }
  if (method->has_final) {
    ErrorMsg(method->name_pos, "'final' not allowed for methods");
  }
  if (method->has_abstract && method->has_static) {
    ErrorMsg(method->name_pos,
             "static method '%s' cannot be abstract",
             method->name->ToCString());
  }
  if (method->has_const && !method->IsFactoryOrConstructor()) {
    ErrorMsg(method->name_pos, "'const' not allowed for methods");
  }
  if (method->has_abstract && method->IsFactoryOrConstructor()) {
    ErrorMsg(method->name_pos, "constructor cannot be abstract");
  }
  if (method->has_const && method->IsConstructor()) {
    Class& cls = Class::Handle(library_.LookupClass(members->class_name()));
    cls.set_is_const();
  }

  // Parse the formal parameters.
  const bool are_implicitly_final = method->has_const;
  const bool allow_explicit_default_values = true;
  const intptr_t formal_param_pos = TokenPos();
  method->params.Clear();
  // Static functions do not have a receiver.
  // The first parameter of a factory is the AbstractTypeArguments vector of
  // the type of the instance to be allocated.
  if (!method->has_static || method->IsConstructor()) {
    method->params.AddReceiver(ReceiverType(formal_param_pos));
  } else if (method->IsFactory()) {
    method->params.AddFinalParameter(
        formal_param_pos,
        &Symbols::TypeArgumentsParameter(),
        &Type::ZoneHandle(Type::DynamicType()));
  }
  // Constructors have an implicit parameter for the construction phase.
  if (method->IsConstructor()) {
    method->params.AddFinalParameter(
        TokenPos(),
        &Symbols::PhaseParameter(),
        &Type::ZoneHandle(Type::SmiType()));
  }
  if (are_implicitly_final) {
    method->params.SetImplicitlyFinal();
  }
  if (!method->IsGetter()) {
    ParseFormalParameterList(allow_explicit_default_values, &method->params);
  }

  // Now that we know the parameter list, we can distinguish between the
  // unary and binary operator -.
  if (method->has_operator) {
    if ((method->operator_token == Token::kSUB) &&
       (method->params.num_fixed_parameters == 1)) {
      // Patch up name for unary operator - so it does not clash with the
      // name for binary operator -.
      method->operator_token = Token::kNEGATE;
      *method->name = Symbols::New(Token::Str(Token::kNEGATE));
    }
    CheckOperatorArity(*method);
  }

  if (members->FunctionNameExists(*method->name, method->kind)) {
    ErrorMsg(method->name_pos,
             "field or method '%s' already defined", method->name->ToCString());
  }

  // Mangle the name for getter and setter functions and check function
  // arity.
  if (method->IsGetter() || method->IsSetter()) {
    int expected_num_parameters = 0;
    if (method->IsGetter()) {
      expected_num_parameters = (method->has_static) ? 0 : 1;
      method->name = &String::ZoneHandle(Field::GetterSymbol(*method->name));
    } else {
      ASSERT(method->IsSetter());
      expected_num_parameters = (method->has_static) ? 1 : 2;
      method->name = &String::ZoneHandle(Field::SetterSymbol(*method->name));
    }
    if ((method->params.num_fixed_parameters != expected_num_parameters) ||
        (method->params.num_optional_parameters != 0)) {
      ErrorMsg(method->name_pos, "illegal %s parameters",
               method->IsGetter() ? "getter" : "setter");
    }
  }

  // Parse redirecting factory constructor.
  Type& redirection_type = Type::Handle();
  String& redirection_identifier = String::Handle();
  if (method->IsFactory() && (CurrentToken() == Token::kASSIGN)) {
    ConsumeToken();
    const intptr_t type_pos = TokenPos();
    const AbstractType& type = AbstractType::Handle(
        ParseType(ClassFinalizer::kTryResolve));
    if (!type.IsMalformed() &&
        (type.IsTypeParameter() || type.IsDynamicType())) {
      // Replace the type with a malformed type and compile a throw when called.
      redirection_type = ClassFinalizer::NewFinalizedMalformedType(
          Error::Handle(),  // No previous error.
          current_class(),
          type_pos,
          ClassFinalizer::kTryResolve,  // No compile-time error.
          "factory '%s' may not redirect to %s'%s'",
          method->name->ToCString(),
          type.IsTypeParameter() ? "type parameter " : "",
          type.IsTypeParameter() ?
              String::Handle(type.UserVisibleName()).ToCString() : "dynamic");
    } else {
      redirection_type ^= type.raw();
    }
    if (CurrentToken() == Token::kPERIOD) {
      // Named constructor or factory.
      ConsumeToken();
      redirection_identifier = ExpectIdentifier("identifier expected")->raw();
    }
  } else if (CurrentToken() == Token::kCOLON) {
    // Parse initializers.
    if (!method->IsConstructor()) {
      ErrorMsg("initializers only allowed on constructors");
    }
    if ((LookaheadToken(1) == Token::kTHIS) &&
        ((LookaheadToken(2) == Token::kLPAREN) ||
         LookaheadToken(4) == Token::kLPAREN)) {
      // Redirected constructor: either this(...) or this.xxx(...).
      if (method->params.has_field_initializer) {
        // Constructors that redirect to another constructor must not
        // initialize any fields using field initializer parameters.
        ErrorMsg(formal_param_pos, "Redirecting constructor "
                 "may not use field initializer parameters");
      }
      ConsumeToken();  // Colon.
      ExpectToken(Token::kTHIS);
      String& redir_name = String::ZoneHandle(
          String::Concat(members->class_name(), Symbols::Dot()));
      if (CurrentToken() == Token::kPERIOD) {
        ConsumeToken();
        redir_name = String::Concat(redir_name,
            *ExpectIdentifier("constructor name expected"));
      }
      method->redirect_name = &redir_name;
      if (CurrentToken() != Token::kLPAREN) {
        ErrorMsg("'(' expected");
      }
      SkipToMatchingParenthesis();
    } else {
      SkipInitializers();
    }
  }

  // Only constructors can redirect to another method.
  ASSERT((method->redirect_name == NULL) || method->IsConstructor());

  intptr_t method_end_pos = method_pos;
  if ((CurrentToken() == Token::kLBRACE) ||
      (CurrentToken() == Token::kARROW)) {
    if (method->has_abstract) {
      ErrorMsg(method->name_pos,
               "abstract method '%s' may not have a function body",
               method->name->ToCString());
    } else if (method->has_external) {
      ErrorMsg(method->name_pos,
               "external method '%s' may not have a function body",
               method->name->ToCString());
    } else if (method->IsFactoryOrConstructor() && method->has_const) {
      ErrorMsg(method->name_pos,
               "const constructor or factory '%s' may not have a function body",
               method->name->ToCString());
    }
    if (method->redirect_name != NULL) {
      ErrorMsg(method->name_pos,
               "Constructor with redirection may not have a function body");
    }
    if (CurrentToken() == Token::kLBRACE) {
      SkipBlock();
    } else {
      ConsumeToken();
      SkipExpr();
      ExpectSemicolon();
    }
    method_end_pos = TokenPos() - 1;
  } else if (IsLiteral("native")) {
    if (method->has_abstract) {
      ErrorMsg(method->name_pos,
               "abstract method '%s' may not have a function body",
               method->name->ToCString());
    } else if (method->IsFactoryOrConstructor() && method->has_const) {
      ErrorMsg(method->name_pos,
               "const constructor or factory '%s' may not be native",
               method->name->ToCString());
    }
    if (method->redirect_name != NULL) {
      ErrorMsg(method->name_pos,
               "Constructor with redirection may not have a function body");
    }
    ParseNativeDeclaration();
  } else {
    // We haven't found a method body. Issue error if one is required.
    const bool must_have_body =
        method->has_static &&
        !method->has_external &&
        redirection_type.IsNull();
    if (must_have_body) {
      ErrorMsg(method->name_pos,
               "function body expected for method '%s'",
               method->name->ToCString());
    }

    if (CurrentToken() == Token::kSEMICOLON) {
      ConsumeToken();
      if (!method->has_static &&
          !method->has_external &&
          !method->IsConstructor()) {
          // Methods, getters and setters without a body are
          // implicitly abstract.
        method->has_abstract = true;