VM support for running Kernel binaries.

runtime/vm/dil_binary.cc

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "vm/dil.h"
+
+#include "platform/signal_blocker.h"
+
+#if 0
+#define TRACE_READ_OFFSET() reader->DumpOffset(__PRETTY_FUNCTION__);
+#define TRACE_WRITE_OFFSET() writer->DumpOffset(__PRETTY_FUNCTION__);
+#else
+#define TRACE_READ_OFFSET()
+#define TRACE_WRITE_OFFSET()
+#endif
+
+namespace dart {
+
+
+class InputFile {
+ public:
+  explicit InputFile(const char* filename)
+      : filename_(filename), buffer_(NULL), size_(-1) {}
+
+  ~InputFile() { delete[] buffer_; }
+
+  bool ReadAll() {
+    size_ = FileSize();
+    if (size_ > 0) {
+      // TODO(kustermann): We could consider simply mmap()ing the file, but
+      // that might not work so easily on windows.
+      int fd = TEMP_FAILURE_RETRY(open(filename_, O_RDONLY));

[rmacnak, 2016/10/13 00:56:39]

IO belongs in the embedder, not the VM.

[Vyacheslav Egorov (Google), 2016/10/13 14:37:57]

Deleted this code.

+      if (fd < 0) return false;
+      buffer_ = new uint8_t[size_];
+      int64_t offset = 0;
+      while (offset < size_) {
+        ssize_t bytes = TEMP_FAILURE_RETRY(read(fd, buffer_, size_ - offset));
+        if (bytes < 0) FATAL("Error during reading dil file.");
+        offset += bytes;
+      }
+      TEMP_FAILURE_RETRY(close(fd));
+      return true;
+    }
+    return false;
+  }
+
+  uint8_t* buffer() { return buffer_; }
+  int64_t size() { return size_; }
+
+ private:
+  int FileSize() {
+    struct stat file_stat;
+    if (stat(filename_, &file_stat) == 0) {
+      return file_stat.st_size;
+    }
+    return -1;
+  }
+
+  const char* filename_;
+  uint8_t* buffer_;
+  int64_t size_;
+};
+
+
+class OutputFile {
+ public:
+  explicit OutputFile(const char* filename)
+      : filename_(filename), fd_(-1), offset_(0) {}
+
+  ~OutputFile() {
+    if (fd_ >= 0) {
+      Flush();
+      TEMP_FAILURE_RETRY(close(fd_));
+    }
+  }
+
+  bool Open() {
+    fd_ =
+        TEMP_FAILURE_RETRY(open(filename_, O_CREAT | O_WRONLY | O_TRUNC, 0666));
+    return fd_ >= 0;
+  }
+
+  void WriteByte(uint8_t byte) {
+    if (offset_ >= kBufferSize) {
+      Flush();
+    }
+    buffer_[offset_++] = byte;
+  }
+
+  void WriteBytes(uint8_t* buffer, int count) {
+    while (count > 0) {
+      if (offset_ >= kBufferSize) {
+        Flush();
+      }
+      int space = kBufferSize - offset_;
+      int to_write = space >= count ? count : space;
+
+      memcpy(buffer_ + offset_, buffer, to_write);  // NOLINT
+      buffer += to_write;
+      count -= to_write;
+      offset_ += to_write;
+    }
+  }
+
+  void Flush() {
+    uint8_t* buffer = buffer_;
+    int remaining = offset_;
+    while (remaining > 0) {
+      int result = TEMP_FAILURE_RETRY(write(fd_, buffer, remaining));
+      if (result <= 0) FATAL("Something went wrong when writing");
+      remaining -= result;
+      buffer += result;
+    }
+    offset_ = 0;
+  }
+
+ private:
+  static const int kBufferSize = 32 * 1024;
+
+  const char* filename_;
+  int fd_;
+  uint8_t buffer_[kBufferSize];
+  intptr_t offset_;
+};
+
+
+namespace dil {
+
+
+static const uint32_t kMagicProgramFile = 0x90ABCDEFu;
+
+
+// Keep in sync with package:dynamo/lib/binary/tag.dart
+enum Tag {
+  kNothing = 0,
+  kSomething = 1,
+
+  kNormalClass = 2,
+  kMixinClass = 3,
+
+  kField = 4,
+  kConstructor = 5,
+  kProcedure = 6,
+
+  kInvalidInitializer = 7,
+  kFieldInitializer = 8,
+  kSuperInitializer = 9,
+  kRedirectingInitializer = 10,
+  kLocalInitializer = 11,
+
+  kDirectPropertyGet = 15,
+  kDirectPropertySet = 16,
+  kDirectMethodInvocation = 17,
+  kConstStaticInvocation = 18,
+  kInvalidExpression = 19,
+  kVariableGet = 20,
+  kVariableSet = 21,
+  kPropertyGet = 22,
+  kPropertySet = 23,
+  kSuperPropertyGet = 24,
+  kSuperPropertySet = 25,
+  kStaticGet = 26,
+  kStaticSet = 27,
+  kMethodInvocation = 28,
+  kSuperMethodInvocation = 29,
+  kStaticInvocation = 30,
+  kConstructorInvocation = 31,
+  kConstConstructorInvocation = 32,
+  kNot = 33,
+  kLogicalExpression = 34,
+  kConditionalExpression = 35,
+  kStringConcatenation = 36,
+  kIsExpression = 37,
+  kAsExpression = 38,
+  kStringLiteral = 39,
+  kDoubleLiteral = 40,
+  kTrueLiteral = 41,
+  kFalseLiteral = 42,
+  kNullLiteral = 43,
+  kSymbolLiteral = 44,
+  kTypeLiteral = 45,
+  kThisExpression = 46,
+  kRethrow = 47,
+  kThrow = 48,
+  kListLiteral = 49,
+  kMapLiteral = 50,
+  kAwaitExpression = 51,
+  kFunctionExpression = 52,
+  kLet = 53,
+  kBlockExpression = 54,
+
+  kPositiveIntLiteral = 55,
+  kNegativeIntLiteral = 56,
+  kBigIntLiteral = 57,
+  kConstListLiteral = 58,
+  kConstMapLiteral = 59,
+
+  kInvalidStatement = 60,
+  kExpressionStatement = 61,
+  kBlock = 62,
+  kEmptyStatement = 63,
+  kAssertStatement = 64,
+  kLabeledStatement = 65,
+  kBreakStatement = 66,
+  kWhileStatement = 67,
+  kDoStatement = 68,
+  kForStatement = 69,
+  kForInStatement = 70,
+  kSwitchStatement = 71,
+  kContinueSwitchStatement = 72,
+  kIfStatement = 73,
+  kReturnStatement = 74,
+  kTryCatch = 75,
+  kTryFinally = 76,
+  kYieldStatement = 77,
+  kVariableDeclaration = 78,
+  kFunctionDeclaration = 79,
+  kAsyncForInStatement = 80,
+
+  kInvalidType = 90,
+  kDynamicType = 91,
+  kVoidType = 92,
+  kInterfaceType = 93,
+  kFunctionType = 94,
+  kTypeParameterType = 95,
+  kSimpleInterfaceType = 96,
+  kSimpleFunctionType = 97,
+
+  kNullReference = 99,
+  kNormalClassReference = 100,
+  kMixinClassReference = 101,
+
+  kLibraryFieldReference = 102,
+  kClassFieldReference = 103,
+  kClassConstructorReference = 104,
+  kLibraryProcedureReference = 105,
+  kClassProcedureReference = 106,
+
+  kSpecializedTagHighBit = 0x80,  // 10000000
+  kSpecializedTagMask = 0xF8,     // 11111000
+  kSpecializedPayloadMask = 0x7,  // 00000111
+
+  kSpecializedVariableGet = 128,
+  kSpecializedVariableSet = 136,
+  kSpecialIntLiteral = 144,
+};
+
+
+static const int SpecializedIntLiteralBias = 3;
+
+
+template <typename T>
+class BlockStack {
+ public:
+  BlockStack() : current_count_(0) {}
+
+  void EnterScope() {
+    variable_count_.push_back(current_count_);
+    current_count_ = 0;
+  }
+
+  void LeaveScope() {
+    variables_.resize(variables_.size() - current_count_);
+    current_count_ = variable_count_[variable_count_.size() - 1];
+    variable_count_.pop_back();
+  }
+
+  T* Lookup(int index) {
+    ASSERT(static_cast<unsigned>(index) < variables_.size());
+    return variables_[index];
+  }
+
+  void Push(T* v) {
+    variables_.push_back(v);
+    current_count_++;
+  }
+
+  void Push(List<T>* decl) {
+    for (int i = 0; i < decl->length(); i++) {
+      variables_.push_back(decl[i]);
+      current_count_++;
+    }
+  }
+
+  void Pop(T* decl) {
+    variables_.resize(variables_.size() - 1);
+    current_count_--;
+  }
+
+  void Pop(List<T>* decl) {
+    variables_.resize(variables_.size() - decl->length());
+    current_count_ -= decl->length();
+  }
+
+ private:
+  int current_count_;
+  std::vector<T*> variables_;
+  std::vector<int> variable_count_;
+};
+
+
+template <typename T>
+class BlockMap {
+ public:
+  BlockMap() : current_count_(0), stack_height_(0) {}
+
+  void EnterScope() {
+    variable_count_.push_back(current_count_);
+    current_count_ = 0;
+  }
+
+  void LeaveScope() {
+    stack_height_ -= current_count_;
+    current_count_ = variable_count_[variable_count_.size() - 1];
+    variable_count_.pop_back();
+  }
+
+  int Lookup(T* object) {
+    ASSERT(variables_.find(object) != variables_.end());
+    if (variables_.find(object) == variables_.end()) FATAL("lookup failure");
+    return variables_[object];
+  }
+
+  void Push(T* v) {
+    int index = stack_height_++;
+    variables_[v] = index;
+    current_count_++;
+  }
+
+  void Set(T* v, int index) { variables_[v] = index; }
+
+  void Push(List<T>* decl) {
+    for (int i = 0; i < decl->length(); i++) {
+      Push(decl[i]);
+    }
+  }
+
+  void Pop(T* v) {
+    current_count_--;
+    stack_height_--;
+  }
+
+ private:
+  int current_count_;
+  int stack_height_;
+  std::map<T*, int> variables_;
+  std::vector<int> variable_count_;
+};
+
+
+template <typename T>
+class VariableScope {
+ public:
+  explicit VariableScope(T* builder) : builder_(builder) {
+    builder_->variables().EnterScope();
+  }
+  ~VariableScope() { builder_->variables().LeaveScope(); }
+
+ private:
+  T* builder_;
+};
+
+
+template <typename T>
+class TypeParameterScope {
+ public:
+  explicit TypeParameterScope(T* builder) : builder_(builder) {
+    builder_->type_parameters().EnterScope();
+  }
+  ~TypeParameterScope() { builder_->type_parameters().LeaveScope(); }
+
+ private:
+  T* builder_;
+};
+
+
+template <typename T>
+class SwitchCaseScope {
+ public:
+  explicit SwitchCaseScope(T* builder) : builder_(builder) {
+    builder_->switch_cases().EnterScope();
+  }
+  ~SwitchCaseScope() { builder_->switch_cases().LeaveScope(); }
+
+ private:
+  T* builder_;
+};
+
+
+class ReaderHelper {
+ public:
+  ReaderHelper() : program_(NULL) {}
+  ~ReaderHelper() {}
+
+  Program* program() { return program_; }
+  void set_program(Program* program) { program_ = program; }
+
+  BlockStack<VariableDeclaration>& variables() { return scope_; }
+  BlockStack<TypeParameter>& type_parameters() { return type_parameters_; }
+  BlockStack<LabeledStatement>& lables() { return labels_; }
+  BlockStack<SwitchCase>& switch_cases() { return switch_cases_; }
+
+ private:
+  Program* program_;
+  BlockStack<VariableDeclaration> scope_;
+  BlockStack<TypeParameter> type_parameters_;
+  BlockStack<LabeledStatement> labels_;
+  BlockStack<SwitchCase> switch_cases_;
+};
+
+
+class Reader {
+ public:
+  Reader(const uint8_t* buffer, int64_t size)
+      : buffer_(buffer), size_(size), offset_(0) {}
+
+  uint32_t ReadUInt32() {
+    ASSERT(offset_ + 4 <= size_);
+
+    uint32_t value = (buffer_[offset_ + 0] << 24) |
+                     (buffer_[offset_ + 1] << 16) |
+                     (buffer_[offset_ + 2] << 8) | (buffer_[offset_ + 3] << 0);
+    offset_ += 4;
+    return value;
+  }
+
+  uint32_t ReadUInt() {
+    ASSERT(offset_ + 1 <= size_);
+    uint8_t byte0 = buffer_[offset_];
+    if ((byte0 & 0x80) == 0) {
+      // 0...
+      offset_++;
+      return byte0;
+    } else if ((byte0 & 0xc0) == 0x80) {
+      // 10...
+      ASSERT(offset_ + 2 <= size_);
+      uint32_t value = ((byte0 & ~0x80) << 8) | (buffer_[offset_ + 1]);
+      offset_ += 2;
+      return value;
+    } else {
+      // 11...
+      ASSERT(offset_ + 4 <= size_);
+      uint32_t value = ((byte0 & ~0xc0) << 24) | (buffer_[offset_ + 1] << 16) |
+                       (buffer_[offset_ + 2] << 8) |
+                       (buffer_[offset_ + 3] << 0);
+      offset_ += 4;
+      return value;
+    }
+  }
+
+  intptr_t ReadListLength() { return ReadUInt(); }
+
+  uint8_t ReadByte() { return buffer_[offset_++]; }
+
+  bool ReadBool() { return (ReadByte() & 1) == 1; }
+
+  word ReadFlags() { return ReadByte(); }
+
+  Tag ReadTag(uint8_t* payload = NULL) {
+    uint8_t byte = ReadByte();
+    bool has_payload = (byte & kSpecializedTagHighBit) != 0;
+    if (has_payload) {
+      if (payload != NULL) {
+        *payload = byte & kSpecializedPayloadMask;
+      }
+      return static_cast<Tag>(byte & kSpecializedTagMask);
+    } else {
+      return static_cast<Tag>(byte);
+    }
+  }
+
+  const uint8_t* Consume(int count) {
+    ASSERT(offset_ + count <= size_);
+    const uint8_t* old = buffer_ + offset_;
+    offset_ += count;
+    return old;
+  }
+
+  void EnsureEnd() {
+    if (offset_ != size_) {
+      FATAL2("Reading Dil file: Expected to be at EOF (offset: %ld, size: %ld)",
+             offset_, size_);
+    }
+  }
+
+  void DumpOffset(const char* str) {
+    fprintf(stderr, "@%ld %s\n", offset_, str);

[rmacnak, 2016/10/13 00:56:39]

OS::PrintErr("@%" Pd64 %s\n", ...)

[Vyacheslav Egorov (Google), 2016/10/13 14:37:57]

Done.

+  }
+
+  template <typename T, typename RT>
+  T* ReadOptional() {
+    Tag tag = ReadTag();
+    if (tag == kNothing) {
+      return NULL;
+    }
+    ASSERT(tag == kSomething);
+    return RT::ReadFrom(this);
+  }
+
+  template <typename T>
+  T* ReadOptional() {
+    return ReadOptional<T, T>();
+  }
+
+  ReaderHelper* helper() { return &builder_; }
+
+ private:
+  const uint8_t* buffer_;
+  int64_t size_;
+  int64_t offset_;
+  ReaderHelper builder_;
+};
+
+
+class WriterHelper {
+ public:
+  void SetProgram(Program* program) {
+    program_ = program;
+    for (int i = 0; i < program->libraries().length(); i++) {
+      Library* lib = program->libraries()[i];
+      libraries_.Set(lib, i);
+
+      for (int j = 0; j < lib->classes().length(); j++) {
+        Class* klass = lib->classes()[j];
+        classes_.Set(klass, j);
+
+        for (int k = 0; k < klass->fields().length(); k++) {
+          Field* field = klass->fields()[k];
+          fields_.Set(field, k);
+        }
+        for (int k = 0; k < klass->constructors().length(); k++) {
+          Constructor* constructor = klass->constructors()[k];
+          constructors_.Set(constructor, k);
+        }
+        for (int k = 0; k < klass->procedures().length(); k++) {
+          Procedure* procedure = klass->procedures()[k];
+          procedures_.Set(procedure, k);
+        }
+      }
+
+      for (int k = 0; k < lib->fields().length(); k++) {
+        Field* field = lib->fields()[k];
+        fields_.Set(field, k);
+      }
+
+      for (int k = 0; k < lib->procedures().length(); k++) {
+        Procedure* procedure = lib->procedures()[k];
+        procedures_.Set(procedure, k);
+      }
+    }
+  }
+
+  Program* program() { return program_; }
+
+  BlockMap<String>& strings() { return strings_; }
+  BlockMap<Library>& libraries() { return libraries_; }
+  BlockMap<Class>& classes() { return classes_; }
+  BlockMap<Field>& fields() { return fields_; }
+  BlockMap<Procedure>& procedures() { return procedures_; }
+  BlockMap<Constructor>& constructors() { return constructors_; }
+
+  BlockMap<VariableDeclaration>& variables() { return scope_; }
+  BlockMap<TypeParameter>& type_parameters() { return type_parameters_; }
+  BlockMap<LabeledStatement>& lables() { return labels_; }
+  BlockMap<SwitchCase>& switch_cases() { return switch_cases_; }
+
+ private:
+  Program* program_;
+
+  BlockMap<String> strings_;
+  BlockMap<Library> libraries_;
+  BlockMap<Class> classes_;
+  BlockMap<Field> fields_;
+  BlockMap<Procedure> procedures_;
+  BlockMap<Constructor> constructors_;
+
+  BlockMap<VariableDeclaration> scope_;
+  BlockMap<TypeParameter> type_parameters_;
+  BlockMap<LabeledStatement> labels_;
+  BlockMap<SwitchCase> switch_cases_;
+};
+
+
+class Writer {
+ public:
+  explicit Writer(OutputFile* file) : out_(file), offset_(0) {}
+
+  void WriteUInt32(uint32_t value) {
+    uint8_t buffer[4] = {
+        static_cast<uint8_t>((value >> 24) & 0xff),
+        static_cast<uint8_t>((value >> 16) & 0xff),
+        static_cast<uint8_t>((value >> 8) & 0xff),
+        static_cast<uint8_t>((value >> 0) & 0xff),
+    };
+    WriteBytes(buffer, 4);
+  }
+
+  void WriteUInt(uint32_t value) {
+    if (value < 0x80) {
+      // 0...
+      WriteByte(static_cast<uint8_t>(value));
+    } else if (value < 0x4000) {
+      // 10...
+      WriteByte(static_cast<uint8_t>(((value >> 8) & 0x3f) | 0x80));
+      WriteByte(static_cast<uint8_t>(value & 0xff));
+    } else {
+      // 11...
+      // Ensure the highest 2 bits is not used for anything (we use it to for
+      // encoding).
+      ASSERT(static_cast<uint8_t>((value >> 24) & 0xc0) == 0);
+      uint8_t buffer[4] = {
+          static_cast<uint8_t>(((value >> 24) & 0x7f) | 0xc0),
+          static_cast<uint8_t>((value >> 16) & 0xff),
+          static_cast<uint8_t>((value >> 8) & 0xff),
+          static_cast<uint8_t>((value >> 0) & 0xff),
+      };
+      WriteBytes(buffer, 4);
+    }
+  }
+
+  void WriteListLength(intptr_t value) { return WriteUInt(value); }
+
+  void WriteByte(uint8_t value) {
+    out_->WriteByte(value);
+    offset_++;
+  }
+
+  void WriteBool(bool value) { WriteByte(value ? 1 : 0); }
+
+  void WriteFlags(uint8_t value) { WriteByte(value); }
+
+  void WriteTag(Tag tag) { WriteByte(static_cast<uint8_t>(tag)); }
+
+  void WriteTag(Tag tag, uint8_t payload) {
+    ASSERT((payload & ~kSpecializedPayloadMask) == 0);
+    WriteByte(kSpecializedTagHighBit | static_cast<uint8_t>(tag) | payload);
+  }
+
+  void WriteBytes(uint8_t* bytes, int length) {
+    out_->WriteBytes(bytes, length);
+    offset_ += length;
+  }
+
+  template <typename T>
+  void WriteOptional(T* object) {
+    if (object == NULL) {
+      WriteTag(kNothing);
+    } else {
+      WriteTag(kSomething);
+      object->WriteTo(this);
+    }
+  }
+
+  template <typename T, typename WT>
+  void WriteOptionalStatic(T* object) {
+    if (object == NULL) {
+      WriteTag(kNothing);
+    } else {
+      WriteTag(kSomething);
+      WT::WriteTo(this, object);
+    }
+  }
+
+  template <typename T>
+  void WriteOptionalStatic(T* object) {
+    return WriteOptionalStatic<T, T>(object);
+  }
+
+  void DumpOffset(const char* str) {
+    fprintf(stderr, "@%ld %s\n", offset_, str);

[rmacnak, 2016/10/13 00:56:39]

OS::PrintErr

[Vyacheslav Egorov (Google), 2016/10/13 14:37:58]

Done.

+  }
+
+  WriterHelper* helper() { return &helper_; }
+
+  void Flush() { out_->Flush(); }
+
+ private:
+  OutputFile* out_;
+  WriterHelper helper_;
+  int64_t offset_;
+};
+
+
+template <typename T>
+template <typename IT>
+void List<T>::ReadFrom(Reader* reader, TreeNode* parent) {
+  TRACE_READ_OFFSET();
+  ASSERT(parent != NULL);
+  int length = reader->ReadListLength();
+  EnsureInitialized(length);
+
+  for (int i = 0; i < length_; i++) {
+    IT* object = GetOrCreate<IT>(i, parent);
+    object->ReadFrom(reader);
+  }
+}
+
+
+template <typename T>
+template <typename IT>
+void List<T>::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  int length = reader->ReadListLength();
+  EnsureInitialized(length);
+
+  for (int i = 0; i < length_; i++) {
+    GetOrCreate<IT>(i)->ReadFrom(reader);
+  }
+}
+
+
+template <typename T>
+template <typename IT>
+void List<T>::ReadFromStatic(Reader* reader) {
+  TRACE_READ_OFFSET();
+  int length = reader->ReadListLength();
+  EnsureInitialized(length);
+
+  for (int i = 0; i < length_; i++) {
+    ASSERT(array_[i] == NULL);
+    array_[i] = IT::ReadFrom(reader);
+  }
+}
+
+
+template <typename T>
+void List<T>::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+
+  // NOTE: We only support dense lists.
+  writer->WriteListLength(length_);
+  for (int i = 0; i < length_; i++) {
+    T* object = array_[i];
+    ASSERT(object != NULL);
+    object->WriteTo(writer);
+  }
+}
+
+
+template <typename T>
+template <typename IT>
+void List<T>::WriteToStatic(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+
+  // NOTE: We only support dense lists.
+  writer->WriteListLength(length_);
+  for (int i = 0; i < length_; i++) {
+    T* object = array_[i];
+    ASSERT(object != NULL);
+    IT::WriteTo(writer, object);
+  }
+}
+
+
+void TypeParameterList::ReadFrom(Reader* reader) {
+  // It is possible for the bound of the first type parameter to refer to
+  // the second type parameter. This means we need to create [TypeParameter]
+  // objects before reading the bounds.
+  int length = reader->ReadListLength();
+  EnsureInitialized(length);
+
+  // Make all [TypeParameter]s available in scope.
+  for (int i = 0; i < length; i++) {
+    TypeParameter* parameter = (*this)[i] = new TypeParameter();
+    reader->helper()->type_parameters().Push(parameter);
+  }
+
+  // Read all [TypeParameter]s and their bounds.
+  for (int i = 0; i < length; i++) {
+    (*this)[i]->ReadFrom(reader);
+  }
+}
+
+
+void TypeParameterList::WriteTo(Writer* writer) {
+  writer->WriteListLength(length());
+
+  // Make all [TypeParameter]s available in scope.
+  for (int i = 0; i < length(); i++) {
+    TypeParameter* parameter = (*this)[i];
+    writer->helper()->type_parameters().Push(parameter);
+  }
+
+  // Write all [TypeParameter]s and their bounds.
+  for (int i = 0; i < length(); i++) {
+    TypeParameter* parameter = (*this)[i];
+    parameter->WriteTo(writer);
+  }
+}
+
+
+template <typename A, typename B>
+Tuple<A, B>* Tuple<A, B>::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  A* first = A::ReadFrom(reader);
+  B* second = B::ReadFrom(reader);
+  return new Tuple<A, B>(first, second);
+}
+
+
+template <typename A, typename B>
+void Tuple<A, B>::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  first_->WriteTo(writer);
+  second_->WriteTo(writer);
+}
+
+
+template <typename B, typename S>
+class DowncastReader {
+ public:
+  static S* ReadFrom(Reader* reader) {
+    TRACE_READ_OFFSET();
+    return S::Cast(B::ReadFrom(reader));
+  }
+};
+
+
+class StringImpl {
+ public:
+  static String* ReadFrom(Reader* reader) {
+    TRACE_READ_OFFSET();
+    return String::ReadFromImpl(reader);
+  }
+
+  static void WriteTo(Writer* writer, String* string) {
+    TRACE_WRITE_OFFSET();
+    string->WriteToImpl(writer);
+  }
+};
+
+
+class VariableDeclarationImpl {
+ public:
+  static VariableDeclaration* ReadFrom(Reader* reader) {
+    TRACE_READ_OFFSET();
+    return VariableDeclaration::ReadFromImpl(reader);
+  }
+
+  static void WriteTo(Writer* writer, VariableDeclaration* d) {
+    TRACE_WRITE_OFFSET();
+    d->WriteToImpl(writer);
+  }
+};
+
+
+String* String::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return Reference::ReadStringFrom(reader);
+}
+
+
+String* String::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  uint32_t bytes = reader->ReadUInt();
+  String* string = new String(reader->Consume(bytes), bytes);
+  return string;
+}
+
+
+void String::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  Reference::WriteStringTo(writer, this);
+}
+
+
+void String::WriteToImpl(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteUInt(size_);
+  writer->WriteBytes(buffer_, size_);
+}
+
+
+void StringTable::ReadFrom(Reader* reader) {
+  strings_.ReadFromStatic<StringImpl>(reader);
+}
+
+
+void StringTable::WriteTo(Writer* writer) {
+  strings_.WriteToStatic<StringImpl>(writer);
+
+  // Build up the "String* -> index" table.
+  WriterHelper* helper = writer->helper();
+  for (int i = 0; i < strings_.length(); i++) {
+    helper->strings().Push(strings_[i]);
+  }
+}
+
+
+void LineStartingTable::ReadFrom(Reader* reader, intptr_t length) {
+  size_ = length;
+  values_ = new intptr_t*[size_];
+  for (intptr_t i = 0; i < size_; ++i) {
+    intptr_t line_count = reader->ReadUInt();
+    intptr_t* line_starts = new intptr_t[line_count + 1];
+    line_starts[0] = line_count;
+    intptr_t previous_line_start = 0;
+    for (intptr_t j = 0; j < line_count; ++j) {
+      intptr_t lineStart = reader->ReadUInt() + previous_line_start;
+      line_starts[j + 1] = lineStart;
+      previous_line_start = lineStart;
+    }
+    values_[i] = line_starts;
+  }
+}
+
+
+void LineStartingTable::WriteTo(Writer* writer) {
+  for (intptr_t i = 0; i < size_; ++i) {
+    intptr_t* line_starts = values_[i];
+    intptr_t line_count = line_starts[0];
+    writer->WriteUInt(line_count);
+
+    intptr_t previous_line_start = 0;
+    for (intptr_t j = 0; j < line_count; ++j) {
+      intptr_t line_start = line_starts[j + 1];
+      writer->WriteUInt(line_start - previous_line_start);
+      previous_line_start = line_start;
+    }
+  }
+}
+
+
+Library* Library::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  int flags = reader->ReadFlags();
+  ASSERT(flags == 0);  // external libraries not supported
+  name_ = Reference::ReadStringFrom(reader);
+  import_uri_ = Reference::ReadStringFrom(reader);
+  reader->ReadUInt();  // TODO(jensj): source_uri_index
+
+  int num_classes = reader->ReadUInt();
+  classes().EnsureInitialized(num_classes);
+  for (int i = 0; i < num_classes; i++) {
+    Tag tag = reader->ReadTag();
+    if (tag == kNormalClass) {
+      NormalClass* klass = classes().GetOrCreate<NormalClass>(i, this);
+      klass->ReadFrom(reader);
+    } else {
+      ASSERT(tag == kMixinClass);
+      MixinClass* klass = classes().GetOrCreate<MixinClass>(i, this);
+      klass->ReadFrom(reader);
+    }
+  }
+
+  fields().ReadFrom<Field>(reader, this);
+  procedures().ReadFrom<Procedure>(reader, this);
+  return this;
+}
+
+
+void Library::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  name_->WriteTo(writer);
+  import_uri_->WriteTo(writer);
+  writer->WriteUInt(0);  // TODO(jensj): source_uri_index
+
+  writer->WriteUInt(classes_.length());
+  for (int i = 0; i < classes_.length(); i++) {
+    Class* klass = classes_[i];
+    if (klass->IsNormalClass()) {
+      writer->WriteTag(kNormalClass);
+      NormalClass::Cast(klass)->WriteTo(writer);
+    } else {
+      writer->WriteTag(kMixinClass);
+      MixinClass::Cast(klass)->WriteTo(writer);
+    }
+  }
+  fields().WriteTo(writer);
+  procedures().WriteTo(writer);
+}
+
+
+Class* Class::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+
+  is_abstract_ = reader->ReadBool();
+  name_ = Reference::ReadStringFrom(reader);
+  reader->ReadUInt();  // TODO(jensj): source_uri_index
+  annotations_.ReadFromStatic<Expression>(reader);
+
+  return this;
+}
+
+
+void Class::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteBool(is_abstract_);
+  name_->WriteTo(writer);
+  writer->WriteUInt(0);  // TODO(jensj): source_uri_index
+  annotations_.WriteTo(writer);
+}
+
+
+NormalClass* NormalClass::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Class::ReadFrom(reader);
+  TypeParameterScope<ReaderHelper> scope(reader->helper());
+
+  type_parameters_.ReadFrom(reader);
+  DartType* type = reader->ReadOptional<DartType>();
+
+  super_class_ = InterfaceType::Cast(type);
+  implemented_classes_.ReadFromStatic<DowncastReader<DartType, InterfaceType> >(
+      reader);
+  fields_.ReadFrom<Field>(reader, this);
+  constructors_.ReadFrom<Constructor>(reader, this);
+  procedures_.ReadFrom<Procedure>(reader, this);
+
+  return this;
+}
+
+
+void NormalClass::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  Class::WriteTo(writer);
+  TypeParameterScope<WriterHelper> scope(writer->helper());
+
+  type_parameters().WriteTo(writer);
+  writer->WriteOptional<DartType>(super_class_);
+  implemented_classes().WriteTo(writer);
+  fields_.WriteTo(writer);
+  constructors_.WriteTo(writer);
+  procedures_.WriteTo(writer);
+}
+
+
+MixinClass* MixinClass::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  TypeParameterScope<ReaderHelper> scope(reader->helper());
+
+  Class::ReadFrom(reader);
+  type_parameters_.ReadFrom(reader);
+  first_ = InterfaceType::Cast(DartType::ReadFrom(reader));
+  second_ = InterfaceType::Cast(DartType::ReadFrom(reader));
+  implemented_classes_.ReadFromStatic<DowncastReader<DartType, InterfaceType> >(
+      reader);
+  constructors_.ReadFrom<Constructor>(reader, this);
+  return this;
+}
+
+
+void MixinClass::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  TypeParameterScope<WriterHelper> scope(writer->helper());
+
+  Class::WriteTo(writer);
+  type_parameters_.WriteTo(writer);
+  first_->WriteTo(writer);
+  second_->WriteTo(writer);
+  implemented_classes_.WriteTo(writer);
+  constructors_.WriteTo(writer);
+}
+
+
+Member* Reference::ReadMemberFrom(Reader* reader, bool allow_null) {
+  TRACE_READ_OFFSET();
+
+  Program* program = reader->helper()->program();
+  Tag tag = reader->ReadTag();
+  switch (tag) {
+    case kLibraryFieldReference: {
+      int library_idx = reader->ReadUInt();
+      int field_idx = reader->ReadUInt();
+      Library* library = program->libraries().GetOrCreate<Library>(library_idx);
+      return library->fields().GetOrCreate<Field>(field_idx, library);
+    }
+    case kLibraryProcedureReference: {
+      int library_idx = reader->ReadUInt();
+      int procedure_idx = reader->ReadUInt();
+      Library* library = program->libraries().GetOrCreate<Library>(library_idx);
+      return library->procedures().GetOrCreate<Procedure>(procedure_idx,
+                                                          library);
+    }
+    case kClassFieldReference:
+    case kClassConstructorReference:
+    case kClassProcedureReference: {
+      Class* klass = Reference::ReadClassFrom(reader);
+      if (tag == kClassFieldReference) {
+        int field_idx = reader->ReadUInt();
+        return klass->fields().GetOrCreate<Field>(field_idx, klass);
+      } else if (tag == kClassConstructorReference) {
+        int constructor_idx = reader->ReadUInt();
+        return klass->constructors().GetOrCreate<Constructor>(constructor_idx,
+                                                              klass);
+      } else {
+        ASSERT(tag == kClassProcedureReference);
+        int procedure_idx = reader->ReadUInt();
+        return klass->procedures().GetOrCreate<Procedure>(procedure_idx, klass);
+      }
+    }
+    case kNullReference:
+      if (allow_null) {
+        return NULL;
+      } else {
+        FATAL("Expected a valid member reference, but got `null`");
+      }
+    default:
+      UNREACHABLE();
+      break;
+  }
+
+  UNREACHABLE();
+  return NULL;
+}
+
+
+void Reference::WriteMemberTo(Writer* writer, Member* member, bool allow_null) {
+  TRACE_WRITE_OFFSET();
+  if (member == NULL) {
+    if (allow_null) {
+      writer->WriteTag(kNullReference);
+      return;
+    } else {
+      FATAL("Expected a valid member reference but got `null`");
+    }
+  }
+  TreeNode* node = member->parent();
+
+  WriterHelper* helper = writer->helper();
+
+  if (node->IsLibrary()) {
+    Library* library = Library::Cast(node);
+    if (member->IsField()) {
+      Field* field = Field::Cast(member);
+      writer->WriteTag(kLibraryFieldReference);
+      writer->WriteUInt(helper->libraries().Lookup(library));
+      writer->WriteUInt(helper->fields().Lookup(field));
+    } else {
+      Procedure* procedure = Procedure::Cast(member);
+      writer->WriteTag(kLibraryProcedureReference);
+      writer->WriteUInt(helper->libraries().Lookup(library));
+      writer->WriteUInt(helper->procedures().Lookup(procedure));
+    }
+  } else {
+    Class* klass = Class::Cast(node);
+
+    if (member->IsField()) {
+      Field* field = Field::Cast(member);
+      writer->WriteTag(kClassFieldReference);
+      Reference::WriteClassTo(writer, klass);
+      writer->WriteUInt(helper->fields().Lookup(field));
+    } else if (member->IsConstructor()) {
+      Constructor* constructor = Constructor::Cast(member);
+      writer->WriteTag(kClassConstructorReference);
+      Reference::WriteClassTo(writer, klass);
+      writer->WriteUInt(helper->constructors().Lookup(constructor));
+    } else {
+      Procedure* procedure = Procedure::Cast(member);
+      writer->WriteTag(kClassProcedureReference);
+      Reference::WriteClassTo(writer, klass);
+      writer->WriteUInt(helper->procedures().Lookup(procedure));
+    }
+  }
+}
+
+
+Class* Reference::ReadClassFrom(Reader* reader, bool allow_null) {
+  TRACE_READ_OFFSET();
+  Program* program = reader->helper()->program();
+
+  Tag klass_member_tag = reader->ReadTag();
+  if (klass_member_tag == kNullReference) {
+    if (allow_null) {
+      return NULL;
+    } else {
+      FATAL("Expected a valid class reference but got `null`.");
+    }
+  }
+  int library_idx = reader->ReadUInt();
+  int class_idx = reader->ReadUInt();
+
+  Library* library = program->libraries().GetOrCreate<Library>(library_idx);
+  Class* klass;
+  if (klass_member_tag == kNormalClassReference) {
+    klass = library->classes().GetOrCreate<NormalClass>(class_idx, library);
+  } else {
+    ASSERT(klass_member_tag == kMixinClassReference);
+    klass = library->classes().GetOrCreate<MixinClass>(class_idx, library);
+  }
+  return klass;
+}
+
+
+void Reference::WriteClassTo(Writer* writer, Class* klass, bool allow_null) {
+  TRACE_WRITE_OFFSET();
+  if (klass == NULL) {
+    if (allow_null) {
+      writer->WriteTag(kNullReference);
+      return;
+    } else {
+      FATAL("Expected a valid class reference but got `null`.");
+    }
+  }
+  if (klass->IsNormalClass()) {
+    writer->WriteTag(kNormalClassReference);
+  } else {
+    ASSERT(klass->IsMixinClass());
+    writer->WriteTag(kMixinClassReference);
+  }
+
+  writer->WriteUInt(writer->helper()->libraries().Lookup(klass->parent()));
+  writer->WriteUInt(writer->helper()->classes().Lookup(klass));
+}
+
+
+String* Reference::ReadStringFrom(Reader* reader) {
+  int index = reader->ReadUInt();
+  return reader->helper()->program()->string_table().strings()[index];
+}
+
+
+void Reference::WriteStringTo(Writer* writer, String* string) {
+  int index = writer->helper()->strings().Lookup(string);
+  writer->WriteUInt(index);
+}
+
+
+Field* Field::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Tag tag = reader->ReadTag();
+  ASSERT(tag == kField);
+
+  // TODO(kustermann) Do we need a variable scope here?
+  reader->ReadUInt();  // TODO(jensj): offset
+  flags_ = reader->ReadFlags();
+  name_ = Name::ReadFrom(reader);
+  reader->ReadUInt();  // TODO(jensj): source_uri_index
+  annotations_.ReadFromStatic<Expression>(reader);
+  type_ = DartType::ReadFrom(reader);
+  inferred_value_ = reader->ReadOptional<InferredValue>();
+  initializer_ = reader->ReadOptional<Expression>();
+  return this;
+}
+
+
+void Field::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kField);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  writer->WriteFlags(flags_);
+  name_->WriteTo(writer);
+  writer->WriteUInt(0);  // TODO(jensj): source_uri_index
+  annotations_.WriteTo(writer);
+  type_->WriteTo(writer);
+  writer->WriteOptional<InferredValue>(inferred_value_);
+  writer->WriteOptional<Expression>(initializer_);
+}
+
+
+Constructor* Constructor::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Tag tag = reader->ReadTag();
+  ASSERT(tag == kConstructor);
+
+  VariableScope<ReaderHelper> parameters(reader->helper());
+  flags_ = reader->ReadFlags();
+  name_ = Name::ReadFrom(reader);
+  annotations_.ReadFromStatic<Expression>(reader);
+  function_ = FunctionNode::ReadFrom(reader);
+  initializers_.ReadFromStatic<Initializer>(reader);
+  return this;
+}
+
+
+void Constructor::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kConstructor);
+
+  VariableScope<WriterHelper> parameters(writer->helper());
+  writer->WriteFlags(flags_);
+  name_->WriteTo(writer);
+  annotations_.WriteTo(writer);
+  function_->WriteTo(writer);
+  initializers_.WriteTo(writer);
+}
+
+
+Procedure* Procedure::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Tag tag = reader->ReadTag();
+  ASSERT(tag == kProcedure);
+
+  VariableScope<ReaderHelper> parameters(reader->helper());
+  kind_ = static_cast<ProcedureKind>(reader->ReadByte());
+  flags_ = reader->ReadFlags();
+  name_ = Name::ReadFrom(reader);
+  reader->ReadUInt();  // TODO(jensj): source_uri_index
+  annotations_.ReadFromStatic<Expression>(reader);
+  function_ = reader->ReadOptional<FunctionNode>();
+  return this;
+}
+
+
+void Procedure::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kProcedure);
+
+  VariableScope<WriterHelper> parameters(writer->helper());
+  writer->WriteByte(kind_);
+  writer->WriteFlags(flags_);
+  name_->WriteTo(writer);
+  writer->WriteUInt(0);  // TODO(jensj): source_uri_index
+  annotations_.WriteTo(writer);
+  writer->WriteOptional<FunctionNode>(function_);
+}
+
+
+Initializer* Initializer::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Tag tag = reader->ReadTag();
+  switch (tag) {
+    case kInvalidInitializer:
+      return InvalidInitializer::ReadFromImpl(reader);
+    case kFieldInitializer:
+      return FieldInitializer::ReadFromImpl(reader);
+    case kSuperInitializer:
+      return SuperInitializer::ReadFromImpl(reader);
+    case kRedirectingInitializer:
+      return RedirectingInitializer::ReadFromImpl(reader);
+    case kLocalInitializer:
+      return LocalInitializer::ReadFromImpl(reader);
+    default:
+      UNREACHABLE();
+  }
+  return NULL;
+}
+
+
+InvalidInitializer* InvalidInitializer::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new InvalidInitializer();
+}
+
+
+void InvalidInitializer::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kInvalidInitializer);
+}
+
+
+FieldInitializer* FieldInitializer::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  FieldInitializer* initializer = new FieldInitializer();
+  initializer->field_ = Field::Cast(Reference::ReadMemberFrom(reader));
+  initializer->value_ = Expression::ReadFrom(reader);
+  return initializer;
+}
+
+
+void FieldInitializer::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kFieldInitializer);
+  Reference::WriteMemberTo(writer, field_);
+  value_->WriteTo(writer);
+}
+
+
+SuperInitializer* SuperInitializer::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  SuperInitializer* init = new SuperInitializer();
+  init->target_ = Constructor::Cast(Reference::ReadMemberFrom(reader));
+  init->arguments_ = Arguments::ReadFrom(reader);
+  return init;
+}
+
+
+void SuperInitializer::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kSuperInitializer);
+  Reference::WriteMemberTo(writer, target_);
+  arguments_->WriteTo(writer);
+}
+
+
+RedirectingInitializer* RedirectingInitializer::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  RedirectingInitializer* init = new RedirectingInitializer();
+  init->target_ = Constructor::Cast(Reference::ReadMemberFrom(reader));
+  init->arguments_ = Arguments::ReadFrom(reader);
+  return init;
+}
+
+
+void RedirectingInitializer::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kRedirectingInitializer);
+  Reference::WriteMemberTo(writer, target_);
+  arguments_->WriteTo(writer);
+}
+
+
+LocalInitializer* LocalInitializer::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  LocalInitializer* init = new LocalInitializer();
+  init->variable_ = VariableDeclaration::ReadFromImpl(reader);
+  return init;
+}
+
+
+void LocalInitializer::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kLocalInitializer);
+  variable_->WriteToImpl(writer);
+}
+
+
+Expression* Expression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  uint8_t payload = 0;
+  Tag tag = reader->ReadTag(&payload);
+  switch (tag) {
+    case kInvalidExpression:
+      return InvalidExpression::ReadFrom(reader);
+    case kVariableGet:
+      return VariableGet::ReadFrom(reader);
+    case kSpecializedVariableGet:
+      return VariableGet::ReadFrom(reader, payload);
+    case kVariableSet:
+      return VariableSet::ReadFrom(reader);
+    case kSpecializedVariableSet:
+      return VariableSet::ReadFrom(reader, payload);
+    case kPropertyGet:
+      return PropertyGet::ReadFrom(reader);
+    case kPropertySet:
+      return PropertySet::ReadFrom(reader);
+    case kDirectPropertyGet:
+      return DirectPropertyGet::ReadFrom(reader);
+    case kDirectPropertySet:
+      return DirectPropertySet::ReadFrom(reader);
+    case kStaticGet:
+      return StaticGet::ReadFrom(reader);
+    case kStaticSet:
+      return StaticSet::ReadFrom(reader);
+    case kMethodInvocation:
+      return MethodInvocation::ReadFrom(reader);
+    case kDirectMethodInvocation:
+      return DirectMethodInvocation::ReadFrom(reader);
+    case kStaticInvocation:
+      return StaticInvocation::ReadFrom(reader, false);
+    case kConstStaticInvocation:
+      return StaticInvocation::ReadFrom(reader, true);
+    case kConstructorInvocation:
+      return ConstructorInvocation::ReadFrom(reader, false);
+    case kConstConstructorInvocation:
+      return ConstructorInvocation::ReadFrom(reader, true);
+    case kNot:
+      return Not::ReadFrom(reader);
+    case kLogicalExpression:
+      return LogicalExpression::ReadFrom(reader);
+    case kConditionalExpression:
+      return ConditionalExpression::ReadFrom(reader);
+    case kStringConcatenation:
+      return StringConcatenation::ReadFrom(reader);
+    case kIsExpression:
+      return IsExpression::ReadFrom(reader);
+    case kAsExpression:
+      return AsExpression::ReadFrom(reader);
+    case kSymbolLiteral:
+      return SymbolLiteral::ReadFrom(reader);
+    case kTypeLiteral:
+      return TypeLiteral::ReadFrom(reader);
+    case kThisExpression:
+      return ThisExpression::ReadFrom(reader);
+    case kRethrow:
+      return Rethrow::ReadFrom(reader);
+    case kThrow:
+      return Throw::ReadFrom(reader);
+    case kListLiteral:
+      return ListLiteral::ReadFrom(reader, false);
+    case kConstListLiteral:
+      return ListLiteral::ReadFrom(reader, true);
+    case kMapLiteral:
+      return MapLiteral::ReadFrom(reader, false);
+    case kConstMapLiteral:
+      return MapLiteral::ReadFrom(reader, true);
+    case kAwaitExpression:
+      return AwaitExpression::ReadFrom(reader);
+    case kFunctionExpression:
+      return FunctionExpression::ReadFrom(reader);
+    case kLet:
+      return Let::ReadFrom(reader);
+    case kBlockExpression:
+      return BlockExpression::ReadFrom(reader);
+    case kBigIntLiteral:
+      return BigintLiteral::ReadFrom(reader);
+    case kStringLiteral:
+      return StringLiteral::ReadFrom(reader);
+    case kSpecialIntLiteral:
+      return IntLiteral::ReadFrom(reader, payload);
+    case kNegativeIntLiteral:
+      return IntLiteral::ReadFrom(reader, true);
+    case kPositiveIntLiteral:
+      return IntLiteral::ReadFrom(reader, false);
+    case kDoubleLiteral:
+      return DoubleLiteral::ReadFrom(reader);
+    case kTrueLiteral:
+      return BoolLiteral::ReadFrom(reader, true);
+    case kFalseLiteral:
+      return BoolLiteral::ReadFrom(reader, false);
+    case kNullLiteral:
+      return NullLiteral::ReadFrom(reader);
+    default:
+      UNREACHABLE();
+  }
+  return NULL;
+}
+
+
+InvalidExpression* InvalidExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new InvalidExpression();
+}
+
+
+void InvalidExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kInvalidExpression);
+}
+
+
+VariableGet* VariableGet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableGet* get = new VariableGet();
+  get->variable_ = reader->helper()->variables().Lookup(reader->ReadUInt());
+  reader->ReadOptional<DartType>();  // Unused promoted type.
+  return get;
+}
+
+
+VariableGet* VariableGet::ReadFrom(Reader* reader, uint8_t payload) {
+  TRACE_READ_OFFSET();
+  VariableGet* get = new VariableGet();
+  get->variable_ = reader->helper()->variables().Lookup(payload);
+  return get;
+}
+
+
+void VariableGet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  int index = writer->helper()->variables().Lookup(variable_);
+  if ((index & kSpecializedPayloadMask) == index) {
+    writer->WriteTag(kSpecializedVariableGet, static_cast<uint8_t>(index));
+  } else {
+    writer->WriteTag(kVariableGet);
+    writer->WriteUInt(index);
+    writer->WriteOptional<DartType>(NULL);
+  }
+}
+
+
+VariableSet* VariableSet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableSet* set = new VariableSet();
+  set->variable_ = reader->helper()->variables().Lookup(reader->ReadUInt());
+  set->expression_ = Expression::ReadFrom(reader);
+  return set;
+}
+
+
+VariableSet* VariableSet::ReadFrom(Reader* reader, uint8_t payload) {
+  TRACE_READ_OFFSET();
+  VariableSet* set = new VariableSet();
+  set->variable_ = reader->helper()->variables().Lookup(payload);
+  set->expression_ = Expression::ReadFrom(reader);
+  return set;
+}
+
+
+void VariableSet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  int index = writer->helper()->variables().Lookup(variable_);
+  if ((index & kSpecializedPayloadMask) == index) {
+    writer->WriteTag(kSpecializedVariableSet, static_cast<uint8_t>(index));
+  } else {
+    writer->WriteTag(kVariableSet);
+    writer->WriteUInt(index);
+  }
+  expression_->WriteTo(writer);
+}
+
+
+PropertyGet* PropertyGet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  PropertyGet* get = new PropertyGet();
+  reader->ReadUInt();  // TODO(jensj): offset
+  get->receiver_ = Expression::ReadFrom(reader);
+  get->name_ = Name::ReadFrom(reader);
+  get->interfaceTarget_ = Reference::ReadMemberFrom(reader, true);
+  return get;
+}
+
+
+void PropertyGet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kPropertyGet);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  receiver_->WriteTo(writer);
+  name_->WriteTo(writer);
+  Reference::WriteMemberTo(writer, interfaceTarget_, true);
+}
+
+
+PropertySet* PropertySet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  PropertySet* set = new PropertySet();
+  reader->ReadUInt();  // TODO(jensj): offset
+  set->receiver_ = Expression::ReadFrom(reader);
+  set->name_ = Name::ReadFrom(reader);
+  set->value_ = Expression::ReadFrom(reader);
+  set->interfaceTarget_ = Reference::ReadMemberFrom(reader, true);
+  return set;
+}
+
+
+void PropertySet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kPropertySet);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  receiver_->WriteTo(writer);
+  name_->WriteTo(writer);
+  value_->WriteTo(writer);
+  Reference::WriteMemberTo(writer, interfaceTarget_, true);
+}
+
+
+DirectPropertyGet* DirectPropertyGet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  DirectPropertyGet* get = new DirectPropertyGet();
+  get->receiver_ = Expression::ReadFrom(reader);
+  get->target_ = Reference::ReadMemberFrom(reader);
+  return get;
+}
+
+
+void DirectPropertyGet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kDirectPropertyGet);
+  receiver_->WriteTo(writer);
+  Reference::WriteMemberTo(writer, target_);
+}
+
+
+DirectPropertySet* DirectPropertySet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  DirectPropertySet* set = new DirectPropertySet();
+  set->receiver_ = Expression::ReadFrom(reader);
+  set->target_ = Reference::ReadMemberFrom(reader);
+  set->value_ = Expression::ReadFrom(reader);
+  return set;
+}
+
+
+void DirectPropertySet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kDirectPropertySet);
+  receiver_->WriteTo(writer);
+  Reference::WriteMemberTo(writer, target_);
+  value_->WriteTo(writer);
+}
+
+
+StaticGet* StaticGet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  StaticGet* get = new StaticGet();
+  reader->ReadUInt();  // TODO(jensj): offset
+  get->target_ = Reference::ReadMemberFrom(reader);
+  return get;
+}
+
+
+void StaticGet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kStaticGet);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  Reference::WriteMemberTo(writer, target_);
+}
+
+
+StaticSet* StaticSet::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  StaticSet* set = new StaticSet();
+  set->target_ = Reference::ReadMemberFrom(reader);
+  set->expression_ = Expression::ReadFrom(reader);
+  return set;
+}
+
+
+void StaticSet::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kStaticSet);
+  Reference::WriteMemberTo(writer, target_);
+  expression_->WriteTo(writer);
+}
+
+
+Arguments* Arguments::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Arguments* arguments = new Arguments();
+  arguments->types().ReadFromStatic<DartType>(reader);
+  arguments->positional().ReadFromStatic<Expression>(reader);
+  arguments->named().ReadFromStatic<NamedExpression>(reader);
+  return arguments;
+}
+
+
+void Arguments::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  types().WriteTo(writer);
+  positional().WriteTo(writer);
+  named().WriteTo(writer);
+}
+
+
+NamedExpression* NamedExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  String* name = Reference::ReadStringFrom(reader);
+  Expression* expression = Expression::ReadFrom(reader);
+  return new NamedExpression(name, expression);
+}
+
+
+void NamedExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  name_->WriteTo(writer);
+  expression_->WriteTo(writer);
+}
+
+
+MethodInvocation* MethodInvocation::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  MethodInvocation* invocation = new MethodInvocation();
+  reader->ReadUInt();  // TODO(jensj): offset
+  invocation->receiver_ = Expression::ReadFrom(reader);
+  invocation->name_ = Name::ReadFrom(reader);
+  invocation->arguments_ = Arguments::ReadFrom(reader);
+  invocation->interfaceTarget_ = Reference::ReadMemberFrom(reader, true);
+  return invocation;
+}
+
+
+void MethodInvocation::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kMethodInvocation);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  receiver_->WriteTo(writer);
+  name_->WriteTo(writer);
+  arguments_->WriteTo(writer);
+  Reference::WriteMemberTo(writer, interfaceTarget_, true);
+}
+
+
+DirectMethodInvocation* DirectMethodInvocation::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  DirectMethodInvocation* invocation = new DirectMethodInvocation();
+  invocation->receiver_ = Expression::ReadFrom(reader);
+  invocation->target_ = Procedure::Cast(Reference::ReadMemberFrom(reader));
+  invocation->arguments_ = Arguments::ReadFrom(reader);
+  return invocation;
+}
+
+
+void DirectMethodInvocation::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kDirectMethodInvocation);
+  receiver_->WriteTo(writer);
+  Reference::WriteMemberTo(writer, target_);
+  arguments_->WriteTo(writer);
+}
+
+
+StaticInvocation* StaticInvocation::ReadFrom(Reader* reader, bool is_const) {
+  TRACE_READ_OFFSET();
+
+  reader->ReadUInt();  // TODO(jensj): offset
+  Member* member = Reference::ReadMemberFrom(reader);
+  Arguments* args = Arguments::ReadFrom(reader);
+
+  return new StaticInvocation(Procedure::Cast(member), args, is_const);
+}
+
+
+void StaticInvocation::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(is_const_ ? kConstStaticInvocation : kStaticInvocation);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  Reference::WriteMemberTo(writer, procedure_);
+  arguments_->WriteTo(writer);
+}
+
+
+ConstructorInvocation* ConstructorInvocation::ReadFrom(Reader* reader,
+                                                       bool is_const) {
+  TRACE_READ_OFFSET();
+  ConstructorInvocation* invocation = new ConstructorInvocation();
+  invocation->is_const_ = is_const;
+  reader->ReadUInt();  // TODO(jensj): offset
+  invocation->target_ = Constructor::Cast(Reference::ReadMemberFrom(reader));
+  invocation->arguments_ = Arguments::ReadFrom(reader);
+  return invocation;
+}
+
+
+void ConstructorInvocation::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(is_const_ ? kConstConstructorInvocation
+                             : kConstructorInvocation);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  Reference::WriteMemberTo(writer, target_);
+  arguments_->WriteTo(writer);
+}
+
+
+Not* Not::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Not* n = new Not();
+  n->expression_ = Expression::ReadFrom(reader);
+  return n;
+}
+
+
+void Not::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kNot);
+  expression_->WriteTo(writer);
+}
+
+
+LogicalExpression* LogicalExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  LogicalExpression* expr = new LogicalExpression();
+  expr->left_ = Expression::ReadFrom(reader);
+  expr->operator_ = static_cast<Operator>(reader->ReadByte());
+  expr->right_ = Expression::ReadFrom(reader);
+  return expr;
+}
+
+
+void LogicalExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kLogicalExpression);
+  left_->WriteTo(writer);
+  writer->WriteByte(operator_);
+  right_->WriteTo(writer);
+}
+
+
+ConditionalExpression* ConditionalExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  ConditionalExpression* expr = new ConditionalExpression();
+  expr->condition_ = Expression::ReadFrom(reader);
+  expr->then_ = Expression::ReadFrom(reader);
+  expr->otherwise_ = Expression::ReadFrom(reader);
+  reader->ReadOptional<DartType>();  // Unused static type.
+  return expr;
+}
+
+
+void ConditionalExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kConditionalExpression);
+  condition_->WriteTo(writer);
+  then_->WriteTo(writer);
+  otherwise_->WriteTo(writer);
+  writer->WriteOptional<DartType>(NULL);  // Unused static type.
+}
+
+
+StringConcatenation* StringConcatenation::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  StringConcatenation* concat = new StringConcatenation();
+  concat->expressions_.ReadFromStatic<Expression>(reader);
+  return concat;
+}
+
+
+void StringConcatenation::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kStringConcatenation);
+  expressions_.WriteTo(writer);
+}
+
+
+IsExpression* IsExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  IsExpression* expr = new IsExpression();
+  expr->operand_ = Expression::ReadFrom(reader);
+  expr->type_ = DartType::ReadFrom(reader);
+  return expr;
+}
+
+
+void IsExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kIsExpression);
+  operand_->WriteTo(writer);
+  type_->WriteTo(writer);
+}
+
+
+AsExpression* AsExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  AsExpression* expr = new AsExpression();
+  expr->operand_ = Expression::ReadFrom(reader);
+  expr->type_ = DartType::ReadFrom(reader);
+  return expr;
+}
+
+
+void AsExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kAsExpression);
+  operand_->WriteTo(writer);
+  type_->WriteTo(writer);
+}
+
+
+StringLiteral* StringLiteral::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new StringLiteral(Reference::ReadStringFrom(reader));
+}
+
+
+void StringLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kStringLiteral);
+  value_->WriteTo(writer);
+}
+
+
+BigintLiteral* BigintLiteral::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new BigintLiteral(Reference::ReadStringFrom(reader));
+}
+
+
+void BigintLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kBigIntLiteral);
+  value_->WriteTo(writer);
+}
+
+
+IntLiteral* IntLiteral::ReadFrom(Reader* reader, bool is_negative) {
+  TRACE_READ_OFFSET();
+  IntLiteral* literal = new IntLiteral();
+  literal->value_ = is_negative ? -static_cast<int64_t>(reader->ReadUInt())
+                                : reader->ReadUInt();
+  return literal;
+}
+
+
+IntLiteral* IntLiteral::ReadFrom(Reader* reader, uint8_t payload) {
+  TRACE_READ_OFFSET();
+  IntLiteral* literal = new IntLiteral();
+  literal->value_ = static_cast<int32_t>(payload) - SpecializedIntLiteralBias;
+  return literal;
+}
+
+
+void IntLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  int64_t payload = value_ + SpecializedIntLiteralBias;
+  if ((payload & kSpecializedPayloadMask) == payload) {
+    writer->WriteTag(kSpecialIntLiteral, static_cast<uint8_t>(payload));
+  } else {
+    writer->WriteTag(value_ < 0 ? kNegativeIntLiteral : kPositiveIntLiteral);
+    writer->WriteUInt(static_cast<uint32_t>(value_ < 0 ? -value_ : value_));
+  }
+}
+
+
+DoubleLiteral* DoubleLiteral::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  DoubleLiteral* literal = new DoubleLiteral();
+  literal->value_ = Reference::ReadStringFrom(reader);
+  return literal;
+}
+
+
+void DoubleLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kDoubleLiteral);
+  value_->WriteTo(writer);
+}
+
+
+BoolLiteral* BoolLiteral::ReadFrom(Reader* reader, bool value) {
+  TRACE_READ_OFFSET();
+  BoolLiteral* lit = new BoolLiteral();
+  lit->value_ = value;
+  return lit;
+}
+
+
+void BoolLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(value_ ? kTrueLiteral : kFalseLiteral);
+}
+
+
+NullLiteral* NullLiteral::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new NullLiteral();
+}
+
+
+void NullLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kNullLiteral);
+}
+
+
+SymbolLiteral* SymbolLiteral::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  SymbolLiteral* lit = new SymbolLiteral();
+  lit->value_ = Reference::ReadStringFrom(reader);
+  return lit;
+}
+
+
+void SymbolLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kSymbolLiteral);
+  value_->WriteTo(writer);
+}
+
+
+TypeLiteral* TypeLiteral::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  TypeLiteral* literal = new TypeLiteral();
+  literal->type_ = DartType::ReadFrom(reader);
+  return literal;
+}
+
+
+void TypeLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kTypeLiteral);
+  type_->WriteTo(writer);
+}
+
+
+ThisExpression* ThisExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new ThisExpression();
+}
+
+
+void ThisExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kThisExpression);
+}
+
+
+Rethrow* Rethrow::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new Rethrow();
+}
+
+
+void Rethrow::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kRethrow);
+}
+
+
+Throw* Throw::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Throw* t = new Throw();
+  reader->ReadUInt();  // TODO(jensj): offset
+  t->expression_ = Expression::ReadFrom(reader);
+  return t;
+}
+
+
+void Throw::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kThrow);
+  writer->WriteUInt(0);  // TODO(jensj): offset
+  expression_->WriteTo(writer);
+}
+
+
+ListLiteral* ListLiteral::ReadFrom(Reader* reader, bool is_const) {
+  TRACE_READ_OFFSET();
+  ListLiteral* literal = new ListLiteral();
+  literal->is_const_ = is_const;
+  literal->type_ = DartType::ReadFrom(reader);
+  literal->expressions_.ReadFromStatic<Expression>(reader);
+  return literal;
+}
+
+
+void ListLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(is_const_ ? kConstListLiteral : kListLiteral);
+  type_->WriteTo(writer);
+  expressions_.WriteTo(writer);
+}
+
+
+MapLiteral* MapLiteral::ReadFrom(Reader* reader, bool is_const) {
+  TRACE_READ_OFFSET();
+  MapLiteral* literal = new MapLiteral();
+  literal->is_const_ = is_const;
+  literal->key_type_ = DartType::ReadFrom(reader);
+  literal->value_type_ = DartType::ReadFrom(reader);
+  literal->entries_.ReadFromStatic<MapEntry>(reader);
+  return literal;
+}
+
+
+void MapLiteral::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(is_const_ ? kConstMapLiteral : kMapLiteral);
+  key_type_->WriteTo(writer);
+  value_type_->WriteTo(writer);
+  entries_.WriteTo(writer);
+}
+
+
+MapEntry* MapEntry::ReadFrom(Reader* reader) {
+  MapEntry* entry = new MapEntry();
+  entry->key_ = Expression::ReadFrom(reader);
+  entry->value_ = Expression::ReadFrom(reader);
+  return entry;
+}
+
+
+void MapEntry::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  key_->WriteTo(writer);
+  value_->WriteTo(writer);
+}
+
+
+AwaitExpression* AwaitExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  AwaitExpression* await = new AwaitExpression();
+  await->operand_ = Expression::ReadFrom(reader);
+  return await;
+}
+
+
+void AwaitExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kAwaitExpression);
+  operand_->WriteTo(writer);
+}
+
+
+FunctionExpression* FunctionExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableScope<ReaderHelper> parameters(reader->helper());
+  FunctionExpression* expr = new FunctionExpression();
+  expr->function_ = FunctionNode::ReadFrom(reader);
+  return expr;
+}
+
+
+void FunctionExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  VariableScope<WriterHelper> parameters(writer->helper());
+  writer->WriteTag(kFunctionExpression);
+  function_->WriteTo(writer);
+}
+
+
+Let* Let::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableScope<ReaderHelper> vars(reader->helper());
+  Let* let = new Let();
+  let->variable_ = VariableDeclaration::ReadFromImpl(reader);
+  let->body_ = Expression::ReadFrom(reader);
+  return let;
+}
+
+
+void Let::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  VariableScope<WriterHelper> vars(writer->helper());
+  writer->WriteTag(kLet);
+  variable_->WriteToImpl(writer);
+  body_->WriteTo(writer);
+}
+
+
+BlockExpression* BlockExpression::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  BlockExpression* be = new BlockExpression();
+  be->body_ = Block::ReadFromImpl(reader);
+  be->value_ = Expression::ReadFrom(reader);
+  return be;
+}
+
+
+void BlockExpression::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kBlockExpression);
+  body_->WriteToImpl(writer);
+  value_->WriteTo(writer);
+}
+
+
+Statement* Statement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Tag tag = reader->ReadTag();
+  switch (tag) {
+    case kInvalidStatement:
+      return InvalidStatement::ReadFrom(reader);
+    case kExpressionStatement:
+      return ExpressionStatement::ReadFrom(reader);
+    case kBlock:
+      return Block::ReadFromImpl(reader);
+    case kEmptyStatement:
+      return EmptyStatement::ReadFrom(reader);
+    case kAssertStatement:
+      return AssertStatement::ReadFrom(reader);
+    case kLabeledStatement:
+      return LabeledStatement::ReadFrom(reader);
+    case kBreakStatement:
+      return BreakStatement::ReadFrom(reader);
+    case kWhileStatement:
+      return WhileStatement::ReadFrom(reader);
+    case kDoStatement:
+      return DoStatement::ReadFrom(reader);
+    case kForStatement:
+      return ForStatement::ReadFrom(reader);
+    case kForInStatement:
+      return ForInStatement::ReadFrom(reader, false);
+    case kAsyncForInStatement:
+      return ForInStatement::ReadFrom(reader, true);
+    case kSwitchStatement:
+      return SwitchStatement::ReadFrom(reader);
+    case kContinueSwitchStatement:
+      return ContinueSwitchStatement::ReadFrom(reader);
+    case kIfStatement:
+      return IfStatement::ReadFrom(reader);
+    case kReturnStatement:
+      return ReturnStatement::ReadFrom(reader);
+    case kTryCatch:
+      return TryCatch::ReadFrom(reader);
+    case kTryFinally:
+      return TryFinally::ReadFrom(reader);
+    case kYieldStatement:
+      return YieldStatement::ReadFrom(reader);
+    case kVariableDeclaration:
+      return VariableDeclaration::ReadFromImpl(reader);
+    case kFunctionDeclaration:
+      return FunctionDeclaration::ReadFrom(reader);
+    default:
+      UNREACHABLE();
+  }
+  return NULL;
+}
+
+
+InvalidStatement* InvalidStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new InvalidStatement();
+}
+
+
+void InvalidStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kInvalidStatement);
+}
+
+
+ExpressionStatement* ExpressionStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new ExpressionStatement(Expression::ReadFrom(reader));
+}
+
+
+void ExpressionStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kExpressionStatement);
+  expression_->WriteTo(writer);
+}
+
+
+Block* Block::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableScope<ReaderHelper> vars(reader->helper());
+  Block* block = new Block();
+  block->statements().ReadFromStatic<Statement>(reader);
+  return block;
+}
+
+
+void Block::WriteTo(Writer* writer) {
+  writer->WriteTag(kBlock);
+  WriteToImpl(writer);
+}
+
+
+void Block::WriteToImpl(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  VariableScope<WriterHelper> vars(writer->helper());
+  statements_.WriteTo(writer);
+}
+
+
+EmptyStatement* EmptyStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new EmptyStatement();
+}
+
+
+void EmptyStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kEmptyStatement);
+}
+
+
+AssertStatement* AssertStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  AssertStatement* stmt = new AssertStatement();
+  stmt->condition_ = Expression::ReadFrom(reader);
+  stmt->message_ = reader->ReadOptional<Expression>();
+  return stmt;
+}
+
+
+void AssertStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kAssertStatement);
+  condition_->WriteTo(writer);
+  writer->WriteOptional<Expression>(message_);
+}
+
+
+LabeledStatement* LabeledStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  LabeledStatement* stmt = new LabeledStatement();
+  reader->helper()->lables().Push(stmt);
+  stmt->body_ = Statement::ReadFrom(reader);
+  reader->helper()->lables().Pop(stmt);
+  return stmt;
+}
+
+
+void LabeledStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kLabeledStatement);
+  writer->helper()->lables().Push(this);
+  body_->WriteTo(writer);
+  writer->helper()->lables().Pop(this);
+}
+
+
+BreakStatement* BreakStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  BreakStatement* stmt = new BreakStatement();
+  stmt->target_ = reader->helper()->lables().Lookup(reader->ReadUInt());
+  return stmt;
+}
+
+
+void BreakStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kBreakStatement);
+  writer->WriteUInt(writer->helper()->lables().Lookup(target_));
+}
+
+
+WhileStatement* WhileStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  WhileStatement* stmt = new WhileStatement();
+  stmt->condition_ = Expression::ReadFrom(reader);
+  stmt->body_ = Statement::ReadFrom(reader);
+  return stmt;
+}
+
+
+void WhileStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kWhileStatement);
+  condition_->WriteTo(writer);
+  body_->WriteTo(writer);
+}
+
+
+DoStatement* DoStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  DoStatement* dostmt = new DoStatement();
+  dostmt->body_ = Statement::ReadFrom(reader);
+  dostmt->condition_ = Expression::ReadFrom(reader);
+  return dostmt;
+}
+
+
+void DoStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kDoStatement);
+  body_->WriteTo(writer);
+  condition_->WriteTo(writer);
+}
+
+
+ForStatement* ForStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableScope<ReaderHelper> vars(reader->helper());
+  ForStatement* forstmt = new ForStatement();
+  forstmt->variables_.ReadFromStatic<VariableDeclarationImpl>(reader);
+  forstmt->condition_ = reader->ReadOptional<Expression>();
+  forstmt->updates_.ReadFromStatic<Expression>(reader);
+  forstmt->body_ = Statement::ReadFrom(reader);
+  return forstmt;
+}
+
+
+void ForStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kForStatement);
+  VariableScope<WriterHelper> vars(writer->helper());
+  variables_.WriteToStatic<VariableDeclarationImpl>(writer);
+  writer->WriteOptional<Expression>(condition_);
+  updates_.WriteTo(writer);
+  body_->WriteTo(writer);
+}
+
+
+ForInStatement* ForInStatement::ReadFrom(Reader* reader, bool is_async) {
+  TRACE_READ_OFFSET();
+  VariableScope<ReaderHelper> vars(reader->helper());
+  ForInStatement* forinstmt = new ForInStatement();
+  forinstmt->is_async_ = is_async;
+  forinstmt->variable_ = VariableDeclaration::ReadFromImpl(reader);
+  forinstmt->iterable_ = Expression::ReadFrom(reader);
+  forinstmt->body_ = Statement::ReadFrom(reader);
+  return forinstmt;
+}
+
+
+void ForInStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(is_async_ ? kAsyncForInStatement : kForInStatement);
+  VariableScope<WriterHelper> vars(writer->helper());
+  variable_->WriteToImpl(writer);
+  iterable_->WriteTo(writer);
+  body_->WriteTo(writer);
+}
+
+
+SwitchStatement* SwitchStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  SwitchCaseScope<ReaderHelper> scope(reader->helper());
+  SwitchStatement* stmt = new SwitchStatement();
+  stmt->condition_ = Expression::ReadFrom(reader);
+  // We need to explicitly create empty [SwitchCase]s first in order to add them
+  // to the [SwitchCaseScope]. This is necessary since a [Statement] in a switch
+  // case can refer to one defined later on.
+  int count = reader->ReadUInt();
+  for (int i = 0; i < count; i++) {
+    SwitchCase* sc = stmt->cases_.GetOrCreate<SwitchCase>(i);
+    reader->helper()->switch_cases().Push(sc);
+  }
+  for (int i = 0; i < count; i++) {
+    SwitchCase* sc = stmt->cases_[i];
+    sc->ReadFrom(reader);
+  }
+  return stmt;
+}
+
+
+void SwitchStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  SwitchCaseScope<WriterHelper> scope(writer->helper());
+  writer->WriteTag(kSwitchStatement);
+  condition_->WriteTo(writer);
+  for (int i = 0; i < cases_.length(); i++) {
+    writer->helper()->switch_cases().Push(cases_[i]);
+  }
+  cases_.WriteTo(writer);
+}
+
+
+SwitchCase* SwitchCase::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  expressions_.ReadFromStatic<Expression>(reader);
+  is_default_ = reader->ReadBool();
+  body_ = Statement::ReadFrom(reader);
+  return this;
+}
+
+
+void SwitchCase::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  expressions_.WriteTo(writer);
+  writer->WriteBool(is_default_);
+  body_->WriteTo(writer);
+}
+
+
+ContinueSwitchStatement* ContinueSwitchStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  ContinueSwitchStatement* stmt = new ContinueSwitchStatement();
+  stmt->target_ = reader->helper()->switch_cases().Lookup(reader->ReadUInt());
+  return stmt;
+}
+
+
+void ContinueSwitchStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kContinueSwitchStatement);
+  writer->WriteUInt(writer->helper()->switch_cases().Lookup(target_));
+}
+
+
+IfStatement* IfStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  IfStatement* ifstmt = new IfStatement();
+  ifstmt->condition_ = Expression::ReadFrom(reader);
+  ifstmt->then_ = Statement::ReadFrom(reader);
+  ifstmt->otherwise_ = Statement::ReadFrom(reader);
+  return ifstmt;
+}
+
+
+void IfStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kIfStatement);
+  condition_->WriteTo(writer);
+  then_->WriteTo(writer);
+  otherwise_->WriteTo(writer);
+}
+
+
+ReturnStatement* ReturnStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  ReturnStatement* ret = new ReturnStatement();
+  ret->expression_ = reader->ReadOptional<Expression>();
+  return ret;
+}
+
+
+void ReturnStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kReturnStatement);
+  writer->WriteOptional<Expression>(expression_);
+}
+
+
+TryCatch* TryCatch::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  TryCatch* tc = new TryCatch();
+  tc->body_ = Statement::ReadFrom(reader);
+  tc->catches_.ReadFromStatic<Catch>(reader);
+  return tc;
+}
+
+
+void TryCatch::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kTryCatch);
+  body_->WriteTo(writer);
+  catches_.WriteTo(writer);
+}
+
+
+Catch* Catch::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableScope<ReaderHelper> vars(reader->helper());
+  Catch* c = new Catch();
+  c->guard_ = DartType::ReadFrom(reader);
+  c->exception_ =
+      reader->ReadOptional<VariableDeclaration, VariableDeclarationImpl>();
+  c->stack_trace_ =
+      reader->ReadOptional<VariableDeclaration, VariableDeclarationImpl>();
+  c->body_ = Statement::ReadFrom(reader);
+  return c;
+}
+
+
+void Catch::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  VariableScope<WriterHelper> vars(writer->helper());
+  guard_->WriteTo(writer);
+  writer->WriteOptionalStatic<VariableDeclaration, VariableDeclarationImpl>(
+      exception_);
+  writer->WriteOptionalStatic<VariableDeclaration, VariableDeclarationImpl>(
+      stack_trace_);
+  body_->WriteTo(writer);
+}
+
+
+TryFinally* TryFinally::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  TryFinally* tf = new TryFinally();
+  tf->body_ = Statement::ReadFrom(reader);
+  tf->finalizer_ = Statement::ReadFrom(reader);
+  return tf;
+}
+
+
+void TryFinally::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kTryFinally);
+  body_->WriteTo(writer);
+  finalizer_->WriteTo(writer);
+}
+
+
+YieldStatement* YieldStatement::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  YieldStatement* stmt = new YieldStatement();
+  stmt->flags_ = reader->ReadByte();
+  stmt->expression_ = Expression::ReadFrom(reader);
+  return stmt;
+}
+
+
+void YieldStatement::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kYieldStatement);
+  writer->WriteByte(flags_);
+  expression_->WriteTo(writer);
+}
+
+
+VariableDeclaration* VariableDeclaration::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Tag tag = reader->ReadTag();
+  ASSERT(tag == kVariableDeclaration);
+  return VariableDeclaration::ReadFromImpl(reader);
+}
+
+
+VariableDeclaration* VariableDeclaration::ReadFromImpl(Reader* reader) {
+  TRACE_READ_OFFSET();
+  VariableDeclaration* decl = new VariableDeclaration();
+  decl->flags_ = reader->ReadFlags();
+  decl->name_ = Reference::ReadStringFrom(reader);
+  decl->type_ = DartType::ReadFrom(reader);
+  decl->inferred_value_ = reader->ReadOptional<InferredValue>();
+  decl->initializer_ = reader->ReadOptional<Expression>();
+  reader->helper()->variables().Push(decl);
+  return decl;
+}
+
+
+void VariableDeclaration::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kVariableDeclaration);
+  WriteToImpl(writer);
+}
+
+
+void VariableDeclaration::WriteToImpl(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteFlags(flags_);
+  name_->WriteTo(writer);
+  type_->WriteTo(writer);
+  writer->WriteOptional<InferredValue>(inferred_value_);
+  writer->WriteOptional<Expression>(initializer_);
+  writer->helper()->variables().Push(this);
+}
+
+
+FunctionDeclaration* FunctionDeclaration::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  FunctionDeclaration* decl = new FunctionDeclaration();
+  decl->variable_ = VariableDeclaration::ReadFromImpl(reader);
+  VariableScope<ReaderHelper> parameters(reader->helper());
+  decl->function_ = FunctionNode::ReadFrom(reader);
+  return decl;
+}
+
+
+void FunctionDeclaration::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kFunctionDeclaration);
+  variable_->WriteToImpl(writer);
+  VariableScope<WriterHelper> parameters(writer->helper());
+  function_->WriteTo(writer);
+}
+
+
+Name* Name::ReadFrom(Reader* reader) {
+  String* string = Reference::ReadStringFrom(reader);
+  if (string->size() >= 1 && string->buffer()[0] == '_') {
+    int lib_index = reader->ReadUInt();
+    Library* library =
+        reader->helper()->program()->libraries().GetOrCreate<Library>(
+            lib_index);
+    return new Name(string, library);
+  } else {
+    return new Name(string, NULL);
+  }
+}
+
+
+void Name::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  string_->WriteTo(writer);
+  Library* library = library_;
+  bool is_private = library != NULL;
+  if (is_private) {
+    writer->WriteUInt(writer->helper()->libraries().Lookup(library_));
+  }
+}
+
+
+InferredValue* InferredValue::ReadFrom(Reader* reader) {
+  InferredValue* type = new InferredValue();
+  type->klass_ = Reference::ReadClassFrom(reader, true);
+  type->kind_ = static_cast<BaseClassKind>(reader->ReadByte());
+  type->value_bits_ = reader->ReadByte();
+  return type;
+}
+
+
+void InferredValue::WriteTo(Writer* writer) {
+  Reference::WriteClassTo(writer, klass_, true);
+  writer->WriteByte(static_cast<uint8_t>(kind_));
+  writer->WriteByte(value_bits_);
+}
+
+
+DartType* DartType::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Tag tag = reader->ReadTag();
+  switch (tag) {
+    case kInvalidType:
+      return InvalidType::ReadFrom(reader);
+    case kDynamicType:
+      return DynamicType::ReadFrom(reader);
+    case kVoidType:
+      return VoidType::ReadFrom(reader);
+    case kInterfaceType:
+      return InterfaceType::ReadFrom(reader);
+    case kSimpleInterfaceType:
+      return InterfaceType::ReadFrom(reader, true);
+    case kFunctionType:
+      return FunctionType::ReadFrom(reader);
+    case kSimpleFunctionType:
+      return FunctionType::ReadFrom(reader, true);
+    case kTypeParameterType:
+      return TypeParameterType::ReadFrom(reader);
+    default:
+      UNREACHABLE();
+  }
+  UNREACHABLE();
+  return NULL;
+}
+
+
+InvalidType* InvalidType::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new InvalidType();
+}
+
+
+void InvalidType::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kInvalidType);
+}
+
+
+DynamicType* DynamicType::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new DynamicType();
+}
+
+
+void DynamicType::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kDynamicType);
+}
+
+
+VoidType* VoidType::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  return new VoidType();
+}
+
+
+void VoidType::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kVoidType);
+}
+
+
+InterfaceType* InterfaceType::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  Class* klass = Reference::ReadClassFrom(reader);
+  InterfaceType* type = new InterfaceType(klass);
+  type->type_arguments().ReadFromStatic<DartType>(reader);
+  return type;
+}
+
+
+InterfaceType* InterfaceType::ReadFrom(Reader* reader,
+                                       bool _without_type_arguments_) {
+  TRACE_READ_OFFSET();
+  Class* klass = Reference::ReadClassFrom(reader);
+  InterfaceType* type = new InterfaceType(klass);
+  ASSERT(_without_type_arguments_);
+  return type;
+}
+
+
+void InterfaceType::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  if (type_arguments_.length() == 0) {
+    writer->WriteTag(kSimpleInterfaceType);
+    Reference::WriteClassTo(writer, klass_);
+  } else {
+    writer->WriteTag(kInterfaceType);
+    Reference::WriteClassTo(writer, klass_);
+    type_arguments_.WriteTo(writer);
+  }
+}
+
+
+FunctionType* FunctionType::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  FunctionType* type = new FunctionType();
+  TypeParameterScope<ReaderHelper> scope(reader->helper());
+  type->type_parameters().ReadFrom(reader);
+  type->required_parameter_count_ = reader->ReadUInt();
+  type->positional_parameters().ReadFromStatic<DartType>(reader);
+  type->named_parameters().ReadFromStatic<Tuple<String, DartType> >(reader);
+  type->return_type_ = DartType::ReadFrom(reader);
+  return type;
+}
+
+
+FunctionType* FunctionType::ReadFrom(Reader* reader, bool _is_simple_) {
+  TRACE_READ_OFFSET();
+  FunctionType* type = new FunctionType();
+  ASSERT(_is_simple_);
+  type->positional_parameters().ReadFromStatic<DartType>(reader);
+  type->required_parameter_count_ = type->positional_parameters().length();
+  type->return_type_ = DartType::ReadFrom(reader);
+  return type;
+}
+
+
+void FunctionType::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+
+  bool is_simple =
+      positional_parameters_.length() == required_parameter_count_ &&
+      type_parameters_.length() == 0 && named_parameters_.length() == 0;
+  if (is_simple) {
+    writer->WriteTag(kSimpleFunctionType);
+    positional_parameters_.WriteTo(writer);
+    return_type_->WriteTo(writer);
+  } else {
+    TypeParameterScope<WriterHelper> scope(writer->helper());
+    writer->WriteTag(kFunctionType);
+    type_parameters_.WriteTo(writer);
+    writer->WriteUInt(required_parameter_count_);
+    positional_parameters_.WriteTo(writer);
+    named_parameters_.WriteTo(writer);
+    return_type_->WriteTo(writer);
+  }
+}
+
+
+TypeParameterType* TypeParameterType::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  TypeParameterType* type = new TypeParameterType();
+  type->parameter_ =
+      reader->helper()->type_parameters().Lookup(reader->ReadUInt());
+  return type;
+}
+
+
+void TypeParameterType::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  writer->WriteTag(kTypeParameterType);
+  writer->WriteUInt(writer->helper()->type_parameters().Lookup(parameter_));
+}
+
+
+Program* Program::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  uint32_t magic = reader->ReadUInt32();
+  if (magic != kMagicProgramFile) FATAL("Invalid magic identifier");
+
+  Program* program = new Program();
+  reader->helper()->set_program(program);
+
+  program->string_table_.ReadFrom(reader);
+  StringTable dummy1;
+  dummy1.ReadFrom(reader);  // TODO(jensj): source_uri_table
+  LineStartingTable dummy2;
+  // TODO(jensj) line_starting_table
+  dummy2.ReadFrom(reader, dummy1.strings_.length());
+
+  int libraries = reader->ReadUInt();
+  program->libraries().EnsureInitialized(libraries);
+  for (int i = 0; i < libraries; i++) {
+    program->libraries().GetOrCreate<Library>(i)->ReadFrom(reader);
+  }
+
+  program->main_method_ = Procedure::Cast(Reference::ReadMemberFrom(reader));
+
+  return program;
+}
+
+
+void Program::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+
+  writer->helper()->SetProgram(this);
+
+  writer->WriteUInt32(kMagicProgramFile);
+
+  // TODO(kustermann): We should really change the format so we don't need to
+  // loop over the whole program to GC all strings and build the table. Let's
+  // just do the table at the end!
+  //
+  // NOTE: Currently we don't GC strings and we require that all referenced
+  // strings in nodes are present in [string_table_].
+  string_table_.WriteTo(writer);
+  StringTable dummy1;
+  dummy1.WriteTo(writer);  // TODO(jensj): source_uri_table
+  LineStartingTable dummy2;
+  dummy2.WriteTo(writer);  // TODO(jensj) line_starting_table
+
+  libraries_.WriteTo(writer);
+  Reference::WriteMemberTo(writer, main_method_);
+}
+
+
+FunctionNode* FunctionNode::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  TypeParameterScope<ReaderHelper> scope(reader->helper());
+
+  FunctionNode* function = new FunctionNode();
+  function->async_marker_ =
+      static_cast<FunctionNode::AsyncMarker>(reader->ReadByte());
+  function->type_parameters().ReadFrom(reader);
+  function->required_parameter_count_ = reader->ReadUInt();
+  function->positional_parameters().ReadFromStatic<VariableDeclarationImpl>(
+      reader);
+  function->named_parameters().ReadFromStatic<VariableDeclarationImpl>(reader);
+  function->return_type_ = DartType::ReadFrom(reader);
+  function->inferred_return_value_ = reader->ReadOptional<InferredValue>();
+
+  VariableScope<ReaderHelper> vars(reader->helper());
+  function->body_ = reader->ReadOptional<Statement>();
+  return function;
+}
+
+
+void FunctionNode::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  TypeParameterScope<WriterHelper> scope(writer->helper());
+
+  writer->WriteByte(static_cast<uint8_t>(async_marker_));
+  type_parameters().WriteTo(writer);
+  writer->WriteUInt(required_parameter_count());
+  positional_parameters().WriteToStatic<VariableDeclarationImpl>(writer);
+  named_parameters().WriteToStatic<VariableDeclarationImpl>(writer);
+  return_type_->WriteTo(writer);
+  writer->WriteOptional<InferredValue>(inferred_return_value_);
+
+  VariableScope<WriterHelper> vars(writer->helper());
+  writer->WriteOptional<Statement>(body_);
+}
+
+
+TypeParameter* TypeParameter::ReadFrom(Reader* reader) {
+  TRACE_READ_OFFSET();
+  name_ = Reference::ReadStringFrom(reader);
+  bound_ = DartType::ReadFrom(reader);
+  return this;
+}
+
+
+void TypeParameter::WriteTo(Writer* writer) {
+  TRACE_WRITE_OFFSET();
+  name_->WriteTo(writer);
+  bound_->WriteTo(writer);
+}
+
+
+}  // namespace dil
+
+dil::Program* ReadPrecompiledDil(const char* filename) {
+  if (filename != NULL) {
+    InputFile file(filename);
+    if (file.ReadAll()) {
+      dil::Reader reader(file.buffer(), file.size());
+      return dil::Program::ReadFrom(&reader);
+    }
+  }
+  return NULL;
+}
+
+
+dil::Program* ReadPrecompiledDilFromBuffer(const uint8_t* buffer,
+                                           intptr_t buffer_length) {
+  dil::Reader reader(buffer, buffer_length);
+  return dil::Program::ReadFrom(&reader);
+}
+
+
+bool WritePrecompiledDil(const char* filename, dil::Program* program) {
+  ASSERT(filename != NULL);
+
+  {
+    OutputFile file(filename);
+    if (!file.Open()) return false;
+
+    dil::Writer writer(&file);
+    program->WriteTo(&writer);
+    return true;
+  }
+  return false;
+}
+
+
+}  // namespace dart