runtime/vm/compiler/frontend/bytecode_reader.h - sdk - Git at Google

 // Copyright (c) 2018, 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.

 #ifndef RUNTIME_VM_COMPILER_FRONTEND_BYTECODE_READER_H_
 #define RUNTIME_VM_COMPILER_FRONTEND_BYTECODE_READER_H_

 #include "vm/compiler/frontend/kernel_translation_helper.h"
 #include "vm/constants_kbc.h"
 #include "vm/object.h"

 #if !defined(DART_PRECOMPILED_RUNTIME)

 namespace dart {
 namespace kernel {

 class BytecodeComponentData;

 // Helper class which provides access to bytecode metadata.
 class BytecodeMetadataHelper : public MetadataHelper {
  public:
   static const char* tag() { return "vm.bytecode"; }

   explicit BytecodeMetadataHelper(KernelReaderHelper* helper,
                                   ActiveClass* active_class);

   bool HasBytecode(intptr_t node_offset);

   void ReadMetadata(const Function& function);

   void ParseBytecodeFunction(ParsedFunction* parsed_function);
   void ParseBytecodeImplicitClosureFunction(ParsedFunction* parsed_function);

   // Reads members associated with given [node_offset] and fills in [cls].
   // Discards fields if [discard_fields] is true.
   // Returns true if class members are loaded.
   bool ReadMembers(intptr_t node_offset, const Class& cls, bool discard_fields);

   // Read annotation at given offset.
   RawObject* ReadAnnotation(intptr_t annotation_offset);

   RawLibrary* GetMainLibrary();

   RawArray* GetBytecodeComponent();
   RawArray* ReadBytecodeComponent();

  private:
   ActiveClass* const active_class_;

   DISALLOW_COPY_AND_ASSIGN(BytecodeMetadataHelper);
 };

 // Helper class for reading bytecode.
 class BytecodeReaderHelper : public ValueObject {
  public:
   explicit BytecodeReaderHelper(KernelReaderHelper* helper,
                                 ActiveClass* active_class,
                                 BytecodeComponentData* bytecode_component);

   void ReadCode(const Function& function, intptr_t code_offset);

   void ReadMembers(const Class& cls,
                    intptr_t members_offset,
                    bool discard_fields);

   void ReadFieldDeclarations(const Class& cls, bool discard_fields);
   void ReadFunctionDeclarations(const Class& cls);

   void ParseBytecodeFunction(ParsedFunction* parsed_function,
                              const Function& function);

   RawLibrary* ReadMain();

   RawArray* ReadBytecodeComponent(intptr_t md_offset);

   // Fills in [is_covariant] and [is_generic_covariant_impl] vectors
   // according to covariance attributes of [function] parameters.
   //
   // [function] should be declared in bytecode.
   // [is_covariant] and [is_generic_covariant_impl] should contain bitvectors
   // of function.NumParameters() length.
   void ReadParameterCovariance(const Function& function,
                                BitVector* is_covariant,
                                BitVector* is_generic_covariant_impl);

   // Read bytecode PackedObject.
   RawObject* ReadObject();

  private:
   // These constants should match corresponding constants in class ObjectHandle
   // (pkg/vm/lib/bytecode/object_table.dart).
   static const int kReferenceBit = 1 << 0;
   static const int kIndexShift = 1;
   static const int kKindShift = 1;
   static const int kKindMask = 0x0f;
   static const int kFlagBit0 = 1 << 5;
   static const int kFlagBit1 = 1 << 6;
   static const int kFlagBit2 = 1 << 7;
   static const int kFlagBit3 = 1 << 8;
   static const int kFlagsMask = (kFlagBit0 | kFlagBit1 | kFlagBit2 | kFlagBit3);

   // Code flags, must be in sync with Code constants in
   // pkg/vm/lib/bytecode/declarations.dart.
   struct Code {
     static const int kHasExceptionsTableFlag = 1 << 0;
     static const int kHasSourcePositionsFlag = 1 << 1;
     static const int kHasNullableFieldsFlag = 1 << 2;
     static const int kHasClosuresFlag = 1 << 3;
     static const int kHasParameterFlagsFlag = 1 << 4;
     static const int kHasForwardingStubTargetFlag = 1 << 5;
     static const int kHasDefaultFunctionTypeArgsFlag = 1 << 6;
   };

   // Parameter flags, must be in sync with ParameterDeclaration constants in
   // pkg/vm/lib/bytecode/declarations.dart.
   struct Parameter {
     static const int kIsCovariantFlag = 1 << 0;
     static const int kIsGenericCovariantImplFlag = 1 << 1;
   };

   class FunctionTypeScope : public ValueObject {
    public:
     explicit FunctionTypeScope(BytecodeReaderHelper* bytecode_reader)
         : bytecode_reader_(bytecode_reader),
           saved_type_parameters_(
               bytecode_reader->function_type_type_parameters_) {}

     ~FunctionTypeScope() {
       bytecode_reader_->function_type_type_parameters_ = saved_type_parameters_;
     }

    private:
     BytecodeReaderHelper* bytecode_reader_;
     TypeArguments* const saved_type_parameters_;
   };

   class FunctionScope : public ValueObject {
    public:
     FunctionScope(BytecodeReaderHelper* bytecode_reader,
                   const Function& function,
                   const String& name,
                   const Class& cls)
         : bytecode_reader_(bytecode_reader) {
       ASSERT(bytecode_reader_->scoped_function_.IsNull());
       ASSERT(bytecode_reader_->scoped_function_name_.IsNull());
       ASSERT(bytecode_reader_->scoped_function_class_.IsNull());
       ASSERT(name.IsSymbol());
       bytecode_reader_->scoped_function_ = function.raw();
       bytecode_reader_->scoped_function_name_ = name.raw();
       bytecode_reader_->scoped_function_class_ = cls.raw();
     }

     ~FunctionScope() {
       bytecode_reader_->scoped_function_ = Function::null();
       bytecode_reader_->scoped_function_name_ = String::null();
       bytecode_reader_->scoped_function_class_ = Class::null();
     }

    private:
     BytecodeReaderHelper* bytecode_reader_;
   };

   void ReadClosureDeclaration(const Function& function, intptr_t closureIndex);
   RawType* ReadFunctionSignature(const Function& func,
                                  bool has_optional_positional_params,
                                  bool has_optional_named_params,
                                  bool has_type_params,
                                  bool has_positional_param_names);
   void ReadTypeParametersDeclaration(const Class& parameterized_class,
                                      const Function& parameterized_function);

   void ReadConstantPool(const Function& function, const ObjectPool& pool);
   RawBytecode* ReadBytecode(const ObjectPool& pool);
   void ReadExceptionsTable(const Bytecode& bytecode, bool has_exceptions_table);
   void ReadSourcePositions(const Bytecode& bytecode, bool has_source_positions);
   RawTypedData* NativeEntry(const Function& function,
                             const String& external_name);
   RawString* ConstructorName(const Class& cls, const String& name);

   RawObject* ReadObjectContents(uint32_t header);
   RawObject* ReadConstObject(intptr_t tag);
   RawString* ReadString(bool is_canonical = true);
   RawTypeArguments* ReadTypeArguments(const Class& instantiator);
   RawPatchClass* GetPatchClass(const Class& cls, const Script& script);
   void ParseForwarderFunction(ParsedFunction* parsed_function,
                               const Function& function,
                               const Function& target);

   KernelReaderHelper* const helper_;
   TranslationHelper& translation_helper_;
   ActiveClass* const active_class_;
   Zone* const zone_;
   BytecodeComponentData* const bytecode_component_;
   Array* closures_ = nullptr;
   TypeArguments* function_type_type_parameters_ = nullptr;
   PatchClass* patch_class_ = nullptr;
   Array* functions_ = nullptr;
   intptr_t function_index_ = 0;
   Function& scoped_function_;
   String& scoped_function_name_;
   Class& scoped_function_class_;

   DISALLOW_COPY_AND_ASSIGN(BytecodeReaderHelper);
 };

 class BytecodeComponentData : ValueObject {
  public:
   enum {
     kVersion,
     kStringsHeaderOffset,
     kStringsContentsOffset,
     kObjectsContentsOffset,
     kMainOffset,
     kMembersOffset,
     kCodesOffset,
     kSourcePositionsOffset,
     kAnnotationsOffset,
     kNumFields
   };

   explicit BytecodeComponentData(const Array& data) : data_(data) {}

   intptr_t GetVersion() const;
   intptr_t GetStringsHeaderOffset() const;
   intptr_t GetStringsContentsOffset() const;
   intptr_t GetObjectsContentsOffset() const;
   intptr_t GetMainOffset() const;
   intptr_t GetMembersOffset() const;
   intptr_t GetCodesOffset() const;
   intptr_t GetSourcePositionsOffset() const;
   intptr_t GetAnnotationsOffset() const;
   void SetObject(intptr_t index, const Object& obj) const;
   RawObject* GetObject(intptr_t index) const;

   bool IsNull() const { return data_.IsNull(); }

   static RawArray* New(Zone* zone,
                        intptr_t version,
                        intptr_t num_objects,
                        intptr_t strings_header_offset,
                        intptr_t strings_contents_offset,
                        intptr_t objects_contents_offset,
                        intptr_t main_offset,
                        intptr_t members_offset,
                        intptr_t codes_offset,
                        intptr_t source_positions_offset,
                        intptr_t annotations_offset,
                        Heap::Space space);

  private:
   const Array& data_;
 };

 class BytecodeReader : public AllStatic {
  public:
   // Reads bytecode for the given function and sets its bytecode field.
   // Returns error (if any), or null.
   static RawError* ReadFunctionBytecode(Thread* thread,
                                         const Function& function);

   // Read annotation for the given annotation field.
   static RawObject* ReadAnnotation(const Field& annotation_field);

   static void UseBytecodeVersion(intptr_t version);
 };

 class BytecodeSourcePositionsIterator : ValueObject {
  public:
   BytecodeSourcePositionsIterator(Zone* zone, const Bytecode& bytecode)
       : reader_(TypedDataBase::Handle(zone, bytecode.GetBinary(zone))),
         pairs_remaining_(0),
         pc_shifter_(
             Isolate::Current()->is_using_old_bytecode_instructions() ? 2 : 0),
         cur_bci_(0),
         cur_token_pos_(TokenPosition::kNoSource.value()) {
     if (bytecode.HasSourcePositions()) {
       reader_.set_offset(bytecode.source_positions_binary_offset());
       pairs_remaining_ = reader_.ReadUInt();
     }
   }

   bool MoveNext() {
     if (pairs_remaining_ == 0) {
       return false;
     }
     ASSERT(pairs_remaining_ > 0);
     --pairs_remaining_;
     cur_bci_ += reader_.ReadUInt() << pc_shifter_;
     cur_token_pos_ += reader_.ReadSLEB128();
     return true;
   }

   intptr_t BytecodeInstructionIndex() const { return cur_bci_; }

   uword PcOffset() const {
     return KernelBytecode::BytecodePcToOffset(BytecodeInstructionIndex(),
                                               /* is_return_address = */ true);
   }

   TokenPosition TokenPos() const { return TokenPosition(cur_token_pos_); }

  private:
   Reader reader_;
   intptr_t pairs_remaining_;
   intptr_t pc_shifter_;
   intptr_t cur_bci_;
   intptr_t cur_token_pos_;
 };

 bool IsStaticFieldGetterGeneratedAsInitializer(const Function& function,
                                                Zone* zone);

 }  // namespace kernel
 }  // namespace dart

 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
 #endif  // RUNTIME_VM_COMPILER_FRONTEND_BYTECODE_READER_H_
	// Copyright (c) 2018, 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.

	#ifndef RUNTIME_VM_COMPILER_FRONTEND_BYTECODE_READER_H_
	#define RUNTIME_VM_COMPILER_FRONTEND_BYTECODE_READER_H_

	#include "vm/compiler/frontend/kernel_translation_helper.h"
	#include "vm/constants_kbc.h"
	#include "vm/object.h"

	#if !defined(DART_PRECOMPILED_RUNTIME)

	namespace dart {
	namespace kernel {

	class BytecodeComponentData;

	// Helper class which provides access to bytecode metadata.
	class BytecodeMetadataHelper : public MetadataHelper {
	public:
	static const char* tag() { return "vm.bytecode"; }

	explicit BytecodeMetadataHelper(KernelReaderHelper* helper,
	ActiveClass* active_class);

	bool HasBytecode(intptr_t node_offset);

	void ReadMetadata(const Function& function);

	void ParseBytecodeFunction(ParsedFunction* parsed_function);
	void ParseBytecodeImplicitClosureFunction(ParsedFunction* parsed_function);

	// Reads members associated with given [node_offset] and fills in [cls].
	// Discards fields if [discard_fields] is true.
	// Returns true if class members are loaded.
	bool ReadMembers(intptr_t node_offset, const Class& cls, bool discard_fields);

	// Read annotation at given offset.
	RawObject* ReadAnnotation(intptr_t annotation_offset);

	RawLibrary* GetMainLibrary();

	RawArray* GetBytecodeComponent();
	RawArray* ReadBytecodeComponent();

	private:
	ActiveClass* const active_class_;

	DISALLOW_COPY_AND_ASSIGN(BytecodeMetadataHelper);
	};

	// Helper class for reading bytecode.
	class BytecodeReaderHelper : public ValueObject {
	public:
	explicit BytecodeReaderHelper(KernelReaderHelper* helper,
	ActiveClass* active_class,
	BytecodeComponentData* bytecode_component);

	void ReadCode(const Function& function, intptr_t code_offset);

	void ReadMembers(const Class& cls,
	intptr_t members_offset,
	bool discard_fields);

	void ReadFieldDeclarations(const Class& cls, bool discard_fields);
	void ReadFunctionDeclarations(const Class& cls);

	void ParseBytecodeFunction(ParsedFunction* parsed_function,
	const Function& function);

	RawLibrary* ReadMain();

	RawArray* ReadBytecodeComponent(intptr_t md_offset);

	// Fills in [is_covariant] and [is_generic_covariant_impl] vectors
	// according to covariance attributes of [function] parameters.
	//
	// [function] should be declared in bytecode.
	// [is_covariant] and [is_generic_covariant_impl] should contain bitvectors
	// of function.NumParameters() length.
	void ReadParameterCovariance(const Function& function,
	BitVector* is_covariant,
	BitVector* is_generic_covariant_impl);

	// Read bytecode PackedObject.
	RawObject* ReadObject();

	private:
	// These constants should match corresponding constants in class ObjectHandle
	// (pkg/vm/lib/bytecode/object_table.dart).
	static const int kReferenceBit = 1 << 0;
	static const int kIndexShift = 1;
	static const int kKindShift = 1;
	static const int kKindMask = 0x0f;
	static const int kFlagBit0 = 1 << 5;
	static const int kFlagBit1 = 1 << 6;
	static const int kFlagBit2 = 1 << 7;
	static const int kFlagBit3 = 1 << 8;
	static const int kFlagsMask = (kFlagBit0 \| kFlagBit1 \| kFlagBit2 \| kFlagBit3);

	// Code flags, must be in sync with Code constants in
	// pkg/vm/lib/bytecode/declarations.dart.
	struct Code {
	static const int kHasExceptionsTableFlag = 1 << 0;
	static const int kHasSourcePositionsFlag = 1 << 1;
	static const int kHasNullableFieldsFlag = 1 << 2;
	static const int kHasClosuresFlag = 1 << 3;
	static const int kHasParameterFlagsFlag = 1 << 4;
	static const int kHasForwardingStubTargetFlag = 1 << 5;
	static const int kHasDefaultFunctionTypeArgsFlag = 1 << 6;
	};

	// Parameter flags, must be in sync with ParameterDeclaration constants in
	// pkg/vm/lib/bytecode/declarations.dart.
	struct Parameter {
	static const int kIsCovariantFlag = 1 << 0;
	static const int kIsGenericCovariantImplFlag = 1 << 1;
	};

	class FunctionTypeScope : public ValueObject {
	public:
	explicit FunctionTypeScope(BytecodeReaderHelper* bytecode_reader)
	: bytecode_reader_(bytecode_reader),
	saved_type_parameters_(
	bytecode_reader->function_type_type_parameters_) {}

	~FunctionTypeScope() {
	bytecode_reader_->function_type_type_parameters_ = saved_type_parameters_;
	}

	private:
	BytecodeReaderHelper* bytecode_reader_;
	TypeArguments* const saved_type_parameters_;
	};

	class FunctionScope : public ValueObject {
	public:
	FunctionScope(BytecodeReaderHelper* bytecode_reader,
	const Function& function,
	const String& name,
	const Class& cls)
	: bytecode_reader_(bytecode_reader) {
	ASSERT(bytecode_reader_->scoped_function_.IsNull());
	ASSERT(bytecode_reader_->scoped_function_name_.IsNull());
	ASSERT(bytecode_reader_->scoped_function_class_.IsNull());
	ASSERT(name.IsSymbol());
	bytecode_reader_->scoped_function_ = function.raw();
	bytecode_reader_->scoped_function_name_ = name.raw();
	bytecode_reader_->scoped_function_class_ = cls.raw();
	}

	~FunctionScope() {
	bytecode_reader_->scoped_function_ = Function::null();
	bytecode_reader_->scoped_function_name_ = String::null();
	bytecode_reader_->scoped_function_class_ = Class::null();
	}

	private:
	BytecodeReaderHelper* bytecode_reader_;
	};

	void ReadClosureDeclaration(const Function& function, intptr_t closureIndex);
	RawType* ReadFunctionSignature(const Function& func,
	bool has_optional_positional_params,
	bool has_optional_named_params,
	bool has_type_params,
	bool has_positional_param_names);
	void ReadTypeParametersDeclaration(const Class& parameterized_class,
	const Function& parameterized_function);

	void ReadConstantPool(const Function& function, const ObjectPool& pool);
	RawBytecode* ReadBytecode(const ObjectPool& pool);
	void ReadExceptionsTable(const Bytecode& bytecode, bool has_exceptions_table);
	void ReadSourcePositions(const Bytecode& bytecode, bool has_source_positions);
	RawTypedData* NativeEntry(const Function& function,
	const String& external_name);
	RawString* ConstructorName(const Class& cls, const String& name);

	RawObject* ReadObjectContents(uint32_t header);
	RawObject* ReadConstObject(intptr_t tag);
	RawString* ReadString(bool is_canonical = true);
	RawTypeArguments* ReadTypeArguments(const Class& instantiator);
	RawPatchClass* GetPatchClass(const Class& cls, const Script& script);
	void ParseForwarderFunction(ParsedFunction* parsed_function,
	const Function& function,
	const Function& target);

	KernelReaderHelper* const helper_;
	TranslationHelper& translation_helper_;
	ActiveClass* const active_class_;
	Zone* const zone_;
	BytecodeComponentData* const bytecode_component_;
	Array* closures_ = nullptr;
	TypeArguments* function_type_type_parameters_ = nullptr;
	PatchClass* patch_class_ = nullptr;
	Array* functions_ = nullptr;
	intptr_t function_index_ = 0;
	Function& scoped_function_;
	String& scoped_function_name_;
	Class& scoped_function_class_;

	DISALLOW_COPY_AND_ASSIGN(BytecodeReaderHelper);
	};

	class BytecodeComponentData : ValueObject {
	public:
	enum {
	kVersion,
	kStringsHeaderOffset,
	kStringsContentsOffset,
	kObjectsContentsOffset,
	kMainOffset,
	kMembersOffset,
	kCodesOffset,
	kSourcePositionsOffset,
	kAnnotationsOffset,
	kNumFields
	};

	explicit BytecodeComponentData(const Array& data) : data_(data) {}

	intptr_t GetVersion() const;
	intptr_t GetStringsHeaderOffset() const;
	intptr_t GetStringsContentsOffset() const;
	intptr_t GetObjectsContentsOffset() const;
	intptr_t GetMainOffset() const;
	intptr_t GetMembersOffset() const;
	intptr_t GetCodesOffset() const;
	intptr_t GetSourcePositionsOffset() const;
	intptr_t GetAnnotationsOffset() const;
	void SetObject(intptr_t index, const Object& obj) const;
	RawObject* GetObject(intptr_t index) const;

	bool IsNull() const { return data_.IsNull(); }

	static RawArray* New(Zone* zone,
	intptr_t version,
	intptr_t num_objects,
	intptr_t strings_header_offset,
	intptr_t strings_contents_offset,
	intptr_t objects_contents_offset,
	intptr_t main_offset,
	intptr_t members_offset,
	intptr_t codes_offset,
	intptr_t source_positions_offset,
	intptr_t annotations_offset,
	Heap::Space space);

	private:
	const Array& data_;
	};

	class BytecodeReader : public AllStatic {
	public:
	// Reads bytecode for the given function and sets its bytecode field.
	// Returns error (if any), or null.
	static RawError* ReadFunctionBytecode(Thread* thread,
	const Function& function);

	// Read annotation for the given annotation field.
	static RawObject* ReadAnnotation(const Field& annotation_field);

	static void UseBytecodeVersion(intptr_t version);
	};

	class BytecodeSourcePositionsIterator : ValueObject {
	public:
	BytecodeSourcePositionsIterator(Zone* zone, const Bytecode& bytecode)
	: reader_(TypedDataBase::Handle(zone, bytecode.GetBinary(zone))),
	pairs_remaining_(0),
	pc_shifter_(
	Isolate::Current()->is_using_old_bytecode_instructions() ? 2 : 0),
	cur_bci_(0),
	cur_token_pos_(TokenPosition::kNoSource.value()) {
	if (bytecode.HasSourcePositions()) {
	reader_.set_offset(bytecode.source_positions_binary_offset());
	pairs_remaining_ = reader_.ReadUInt();
	}
	}

	bool MoveNext() {
	if (pairs_remaining_ == 0) {
	return false;
	}
	ASSERT(pairs_remaining_ > 0);
	--pairs_remaining_;
	cur_bci_ += reader_.ReadUInt() << pc_shifter_;
	cur_token_pos_ += reader_.ReadSLEB128();
	return true;
	}

	intptr_t BytecodeInstructionIndex() const { return cur_bci_; }

	uword PcOffset() const {
	return KernelBytecode::BytecodePcToOffset(BytecodeInstructionIndex(),
	/* is_return_address = */ true);
	}

	TokenPosition TokenPos() const { return TokenPosition(cur_token_pos_); }

	private:
	Reader reader_;
	intptr_t pairs_remaining_;
	intptr_t pc_shifter_;
	intptr_t cur_bci_;
	intptr_t cur_token_pos_;
	};

	bool IsStaticFieldGetterGeneratedAsInitializer(const Function& function,
	Zone* zone);

	} // namespace kernel
	} // namespace dart

	#endif // !defined(DART_PRECOMPILED_RUNTIME)
	#endif // RUNTIME_VM_COMPILER_FRONTEND_BYTECODE_READER_H_