// Copyright 2010 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #ifndef V8_OBJECTS_H_ #define V8_OBJECTS_H_ #include "builtins.h" #include "smart-pointer.h" #include "unicode-inl.h" #if V8_TARGET_ARCH_ARM #include "arm/constants-arm.h" #elif V8_TARGET_ARCH_MIPS #include "mips/constants-mips.h" #endif // // Most object types in the V8 JavaScript are described in this file. // // Inheritance hierarchy: // - MaybeObject (an object or a failure) // - Failure (immediate for marking failed operation) // - Object // - Smi (immediate small integer) // - HeapObject (superclass for everything allocated in the heap) // - JSObject // - JSArray // - JSRegExp // - JSFunction // - GlobalObject // - JSGlobalObject // - JSBuiltinsObject // - JSGlobalProxy // - JSValue // - ByteArray // - PixelArray // - ExternalArray // - ExternalByteArray // - ExternalUnsignedByteArray // - ExternalShortArray // - ExternalUnsignedShortArray // - ExternalIntArray // - ExternalUnsignedIntArray // - ExternalFloatArray // - FixedArray // - DescriptorArray // - HashTable // - Dictionary // - SymbolTable // - CompilationCacheTable // - CodeCacheHashTable // - MapCache // - Context // - JSFunctionResultCache // - SerializedScopeInfo // - String // - SeqString // - SeqAsciiString // - SeqTwoByteString // - ConsString // - ExternalString // - ExternalAsciiString // - ExternalTwoByteString // - HeapNumber // - Code // - Map // - Oddball // - Proxy // - SharedFunctionInfo // - Struct // - AccessorInfo // - AccessCheckInfo // - InterceptorInfo // - CallHandlerInfo // - TemplateInfo // - FunctionTemplateInfo // - ObjectTemplateInfo // - Script // - SignatureInfo // - TypeSwitchInfo // - DebugInfo // - BreakPointInfo // - CodeCache // // Formats of Object*: // Smi: [31 bit signed int] 0 // HeapObject: [32 bit direct pointer] (4 byte aligned) | 01 // Failure: [30 bit signed int] 11 // Ecma-262 3rd 8.6.1 enum PropertyAttributes { NONE = v8::None, READ_ONLY = v8::ReadOnly, DONT_ENUM = v8::DontEnum, DONT_DELETE = v8::DontDelete, ABSENT = 16 // Used in runtime to indicate a property is absent. // ABSENT can never be stored in or returned from a descriptor's attributes // bitfield. It is only used as a return value meaning the attributes of // a non-existent property. }; namespace v8 { namespace internal { // PropertyDetails captures type and attributes for a property. // They are used both in property dictionaries and instance descriptors. class PropertyDetails BASE_EMBEDDED { public: PropertyDetails(PropertyAttributes attributes, PropertyType type, int index = 0) { ASSERT(TypeField::is_valid(type)); ASSERT(AttributesField::is_valid(attributes)); ASSERT(IndexField::is_valid(index)); value_ = TypeField::encode(type) | AttributesField::encode(attributes) | IndexField::encode(index); ASSERT(type == this->type()); ASSERT(attributes == this->attributes()); ASSERT(index == this->index()); } // Conversion for storing details as Object*. inline PropertyDetails(Smi* smi); inline Smi* AsSmi(); PropertyType type() { return TypeField::decode(value_); } bool IsTransition() { PropertyType t = type(); ASSERT(t != INTERCEPTOR); return t == MAP_TRANSITION || t == CONSTANT_TRANSITION; } bool IsProperty() { return type() < FIRST_PHANTOM_PROPERTY_TYPE; } PropertyAttributes attributes() { return AttributesField::decode(value_); } int index() { return IndexField::decode(value_); } inline PropertyDetails AsDeleted(); static bool IsValidIndex(int index) { return IndexField::is_valid(index); } bool IsReadOnly() { return (attributes() & READ_ONLY) != 0; } bool IsDontDelete() { return (attributes() & DONT_DELETE) != 0; } bool IsDontEnum() { return (attributes() & DONT_ENUM) != 0; } bool IsDeleted() { return DeletedField::decode(value_) != 0;} // Bit fields in value_ (type, shift, size). Must be public so the // constants can be embedded in generated code. class TypeField: public BitField {}; class AttributesField: public BitField {}; class DeletedField: public BitField {}; class IndexField: public BitField {}; static const int kInitialIndex = 1; private: uint32_t value_; }; // Setter that skips the write barrier if mode is SKIP_WRITE_BARRIER. enum WriteBarrierMode { SKIP_WRITE_BARRIER, UPDATE_WRITE_BARRIER }; // PropertyNormalizationMode is used to specify whether to keep // inobject properties when normalizing properties of a JSObject. enum PropertyNormalizationMode { CLEAR_INOBJECT_PROPERTIES, KEEP_INOBJECT_PROPERTIES }; // NormalizedMapSharingMode is used to specify whether a map may be shared // by different objects with normalized properties. enum NormalizedMapSharingMode { UNIQUE_NORMALIZED_MAP, SHARED_NORMALIZED_MAP }; // Instance size sentinel for objects of variable size. static const int kVariableSizeSentinel = 0; // All Maps have a field instance_type containing a InstanceType. // It describes the type of the instances. // // As an example, a JavaScript object is a heap object and its map // instance_type is JS_OBJECT_TYPE. // // The names of the string instance types are intended to systematically // mirror their encoding in the instance_type field of the map. The default // encoding is considered TWO_BYTE. It is not mentioned in the name. ASCII // encoding is mentioned explicitly in the name. Likewise, the default // representation is considered sequential. It is not mentioned in the // name. The other representations (eg, CONS, EXTERNAL) are explicitly // mentioned. Finally, the string is either a SYMBOL_TYPE (if it is a // symbol) or a STRING_TYPE (if it is not a symbol). // // NOTE: The following things are some that depend on the string types having // instance_types that are less than those of all other types: // HeapObject::Size, HeapObject::IterateBody, the typeof operator, and // Object::IsString. // // NOTE: Everything following JS_VALUE_TYPE is considered a // JSObject for GC purposes. The first four entries here have typeof // 'object', whereas JS_FUNCTION_TYPE has typeof 'function'. #define INSTANCE_TYPE_LIST_ALL(V) \ V(SYMBOL_TYPE) \ V(ASCII_SYMBOL_TYPE) \ V(CONS_SYMBOL_TYPE) \ V(CONS_ASCII_SYMBOL_TYPE) \ V(EXTERNAL_SYMBOL_TYPE) \ V(EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE) \ V(EXTERNAL_ASCII_SYMBOL_TYPE) \ V(STRING_TYPE) \ V(ASCII_STRING_TYPE) \ V(CONS_STRING_TYPE) \ V(CONS_ASCII_STRING_TYPE) \ V(EXTERNAL_STRING_TYPE) \ V(EXTERNAL_STRING_WITH_ASCII_DATA_TYPE) \ V(EXTERNAL_ASCII_STRING_TYPE) \ V(PRIVATE_EXTERNAL_ASCII_STRING_TYPE) \ \ V(MAP_TYPE) \ V(CODE_TYPE) \ V(ODDBALL_TYPE) \ V(JS_GLOBAL_PROPERTY_CELL_TYPE) \ \ V(HEAP_NUMBER_TYPE) \ V(PROXY_TYPE) \ V(BYTE_ARRAY_TYPE) \ V(PIXEL_ARRAY_TYPE) \ /* Note: the order of these external array */ \ /* types is relied upon in */ \ /* Object::IsExternalArray(). */ \ V(EXTERNAL_BYTE_ARRAY_TYPE) \ V(EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE) \ V(EXTERNAL_SHORT_ARRAY_TYPE) \ V(EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE) \ V(EXTERNAL_INT_ARRAY_TYPE) \ V(EXTERNAL_UNSIGNED_INT_ARRAY_TYPE) \ V(EXTERNAL_FLOAT_ARRAY_TYPE) \ V(FILLER_TYPE) \ \ V(ACCESSOR_INFO_TYPE) \ V(ACCESS_CHECK_INFO_TYPE) \ V(INTERCEPTOR_INFO_TYPE) \ V(CALL_HANDLER_INFO_TYPE) \ V(FUNCTION_TEMPLATE_INFO_TYPE) \ V(OBJECT_TEMPLATE_INFO_TYPE) \ V(SIGNATURE_INFO_TYPE) \ V(TYPE_SWITCH_INFO_TYPE) \ V(SCRIPT_TYPE) \ V(CODE_CACHE_TYPE) \ \ V(FIXED_ARRAY_TYPE) \ V(SHARED_FUNCTION_INFO_TYPE) \ \ V(JS_VALUE_TYPE) \ V(JS_OBJECT_TYPE) \ V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \ V(JS_GLOBAL_OBJECT_TYPE) \ V(JS_BUILTINS_OBJECT_TYPE) \ V(JS_GLOBAL_PROXY_TYPE) \ V(JS_ARRAY_TYPE) \ V(JS_REGEXP_TYPE) \ \ V(JS_FUNCTION_TYPE) \ #ifdef ENABLE_DEBUGGER_SUPPORT #define INSTANCE_TYPE_LIST_DEBUGGER(V) \ V(DEBUG_INFO_TYPE) \ V(BREAK_POINT_INFO_TYPE) #else #define INSTANCE_TYPE_LIST_DEBUGGER(V) #endif #define INSTANCE_TYPE_LIST(V) \ INSTANCE_TYPE_LIST_ALL(V) \ INSTANCE_TYPE_LIST_DEBUGGER(V) // Since string types are not consecutive, this macro is used to // iterate over them. #define STRING_TYPE_LIST(V) \ V(SYMBOL_TYPE, \ kVariableSizeSentinel, \ symbol, \ Symbol) \ V(ASCII_SYMBOL_TYPE, \ kVariableSizeSentinel, \ ascii_symbol, \ AsciiSymbol) \ V(CONS_SYMBOL_TYPE, \ ConsString::kSize, \ cons_symbol, \ ConsSymbol) \ V(CONS_ASCII_SYMBOL_TYPE, \ ConsString::kSize, \ cons_ascii_symbol, \ ConsAsciiSymbol) \ V(EXTERNAL_SYMBOL_TYPE, \ ExternalTwoByteString::kSize, \ external_symbol, \ ExternalSymbol) \ V(EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE, \ ExternalTwoByteString::kSize, \ external_symbol_with_ascii_data, \ ExternalSymbolWithAsciiData) \ V(EXTERNAL_ASCII_SYMBOL_TYPE, \ ExternalAsciiString::kSize, \ external_ascii_symbol, \ ExternalAsciiSymbol) \ V(STRING_TYPE, \ kVariableSizeSentinel, \ string, \ String) \ V(ASCII_STRING_TYPE, \ kVariableSizeSentinel, \ ascii_string, \ AsciiString) \ V(CONS_STRING_TYPE, \ ConsString::kSize, \ cons_string, \ ConsString) \ V(CONS_ASCII_STRING_TYPE, \ ConsString::kSize, \ cons_ascii_string, \ ConsAsciiString) \ V(EXTERNAL_STRING_TYPE, \ ExternalTwoByteString::kSize, \ external_string, \ ExternalString) \ V(EXTERNAL_STRING_WITH_ASCII_DATA_TYPE, \ ExternalTwoByteString::kSize, \ external_string_with_ascii_data, \ ExternalStringWithAsciiData) \ V(EXTERNAL_ASCII_STRING_TYPE, \ ExternalAsciiString::kSize, \ external_ascii_string, \ ExternalAsciiString) // A struct is a simple object a set of object-valued fields. Including an // object type in this causes the compiler to generate most of the boilerplate // code for the class including allocation and garbage collection routines, // casts and predicates. All you need to define is the class, methods and // object verification routines. Easy, no? // // Note that for subtle reasons related to the ordering or numerical values of // type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST // manually. #define STRUCT_LIST_ALL(V) \ V(ACCESSOR_INFO, AccessorInfo, accessor_info) \ V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \ V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \ V(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \ V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \ V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \ V(SIGNATURE_INFO, SignatureInfo, signature_info) \ V(TYPE_SWITCH_INFO, TypeSwitchInfo, type_switch_info) \ V(SCRIPT, Script, script) \ V(CODE_CACHE, CodeCache, code_cache) #ifdef ENABLE_DEBUGGER_SUPPORT #define STRUCT_LIST_DEBUGGER(V) \ V(DEBUG_INFO, DebugInfo, debug_info) \ V(BREAK_POINT_INFO, BreakPointInfo, break_point_info) #else #define STRUCT_LIST_DEBUGGER(V) #endif #define STRUCT_LIST(V) \ STRUCT_LIST_ALL(V) \ STRUCT_LIST_DEBUGGER(V) // We use the full 8 bits of the instance_type field to encode heap object // instance types. The high-order bit (bit 7) is set if the object is not a // string, and cleared if it is a string. const uint32_t kIsNotStringMask = 0x80; const uint32_t kStringTag = 0x0; const uint32_t kNotStringTag = 0x80; // Bit 6 indicates that the object is a symbol (if set) or not (if cleared). // There are not enough types that the non-string types (with bit 7 set) can // have bit 6 set too. const uint32_t kIsSymbolMask = 0x40; const uint32_t kNotSymbolTag = 0x0; const uint32_t kSymbolTag = 0x40; // If bit 7 is clear then bit 2 indicates whether the string consists of // two-byte characters or one-byte characters. const uint32_t kStringEncodingMask = 0x4; const uint32_t kTwoByteStringTag = 0x0; const uint32_t kAsciiStringTag = 0x4; // If bit 7 is clear, the low-order 2 bits indicate the representation // of the string. const uint32_t kStringRepresentationMask = 0x03; enum StringRepresentationTag { kSeqStringTag = 0x0, kConsStringTag = 0x1, kExternalStringTag = 0x2 }; const uint32_t kIsConsStringMask = 0x1; // If bit 7 is clear, then bit 3 indicates whether this two-byte // string actually contains ascii data. const uint32_t kAsciiDataHintMask = 0x08; const uint32_t kAsciiDataHintTag = 0x08; // A ConsString with an empty string as the right side is a candidate // for being shortcut by the garbage collector unless it is a // symbol. It's not common to have non-flat symbols, so we do not // shortcut them thereby avoiding turning symbols into strings. See // heap.cc and mark-compact.cc. const uint32_t kShortcutTypeMask = kIsNotStringMask | kIsSymbolMask | kStringRepresentationMask; const uint32_t kShortcutTypeTag = kConsStringTag; enum InstanceType { // String types. SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kSeqStringTag, ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kSeqStringTag, CONS_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kConsStringTag, CONS_ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kConsStringTag, EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag, EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag | kAsciiDataHintTag, EXTERNAL_ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kExternalStringTag, STRING_TYPE = kTwoByteStringTag | kSeqStringTag, ASCII_STRING_TYPE = kAsciiStringTag | kSeqStringTag, CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag, CONS_ASCII_STRING_TYPE = kAsciiStringTag | kConsStringTag, EXTERNAL_STRING_TYPE = kTwoByteStringTag | kExternalStringTag, EXTERNAL_STRING_WITH_ASCII_DATA_TYPE = kTwoByteStringTag | kExternalStringTag | kAsciiDataHintTag, EXTERNAL_ASCII_STRING_TYPE = kAsciiStringTag | kExternalStringTag, PRIVATE_EXTERNAL_ASCII_STRING_TYPE = EXTERNAL_ASCII_STRING_TYPE, // Objects allocated in their own spaces (never in new space). MAP_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE CODE_TYPE, ODDBALL_TYPE, JS_GLOBAL_PROPERTY_CELL_TYPE, // "Data", objects that cannot contain non-map-word pointers to heap // objects. HEAP_NUMBER_TYPE, PROXY_TYPE, BYTE_ARRAY_TYPE, PIXEL_ARRAY_TYPE, EXTERNAL_BYTE_ARRAY_TYPE, // FIRST_EXTERNAL_ARRAY_TYPE EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE, EXTERNAL_SHORT_ARRAY_TYPE, EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE, EXTERNAL_INT_ARRAY_TYPE, EXTERNAL_UNSIGNED_INT_ARRAY_TYPE, EXTERNAL_FLOAT_ARRAY_TYPE, // LAST_EXTERNAL_ARRAY_TYPE FILLER_TYPE, // LAST_DATA_TYPE // Structs. ACCESSOR_INFO_TYPE, ACCESS_CHECK_INFO_TYPE, INTERCEPTOR_INFO_TYPE, CALL_HANDLER_INFO_TYPE, FUNCTION_TEMPLATE_INFO_TYPE, OBJECT_TEMPLATE_INFO_TYPE, SIGNATURE_INFO_TYPE, TYPE_SWITCH_INFO_TYPE, SCRIPT_TYPE, CODE_CACHE_TYPE, // The following two instance types are only used when ENABLE_DEBUGGER_SUPPORT // is defined. However as include/v8.h contain some of the instance type // constants always having them avoids them getting different numbers // depending on whether ENABLE_DEBUGGER_SUPPORT is defined or not. DEBUG_INFO_TYPE, BREAK_POINT_INFO_TYPE, FIXED_ARRAY_TYPE, SHARED_FUNCTION_INFO_TYPE, JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE JS_OBJECT_TYPE, JS_CONTEXT_EXTENSION_OBJECT_TYPE, JS_GLOBAL_OBJECT_TYPE, JS_BUILTINS_OBJECT_TYPE, JS_GLOBAL_PROXY_TYPE, JS_ARRAY_TYPE, JS_REGEXP_TYPE, // LAST_JS_OBJECT_TYPE JS_FUNCTION_TYPE, // Pseudo-types FIRST_TYPE = 0x0, LAST_TYPE = JS_FUNCTION_TYPE, INVALID_TYPE = FIRST_TYPE - 1, FIRST_NONSTRING_TYPE = MAP_TYPE, // Boundaries for testing for an external array. FIRST_EXTERNAL_ARRAY_TYPE = EXTERNAL_BYTE_ARRAY_TYPE, LAST_EXTERNAL_ARRAY_TYPE = EXTERNAL_FLOAT_ARRAY_TYPE, // Boundary for promotion to old data space/old pointer space. LAST_DATA_TYPE = FILLER_TYPE, // Boundaries for testing the type is a JavaScript "object". Note that // function objects are not counted as objects, even though they are // implemented as such; only values whose typeof is "object" are included. FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE, LAST_JS_OBJECT_TYPE = JS_REGEXP_TYPE }; STATIC_CHECK(JS_OBJECT_TYPE == Internals::kJSObjectType); STATIC_CHECK(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType); STATIC_CHECK(PROXY_TYPE == Internals::kProxyType); enum CompareResult { LESS = -1, EQUAL = 0, GREATER = 1, NOT_EQUAL = GREATER }; #define DECL_BOOLEAN_ACCESSORS(name) \ inline bool name(); \ inline void set_##name(bool value); \ #define DECL_ACCESSORS(name, type) \ inline type* name(); \ inline void set_##name(type* value, \ WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \ class StringStream; class ObjectVisitor; struct ValueInfo : public Malloced { ValueInfo() : type(FIRST_TYPE), ptr(NULL), str(NULL), number(0) { } InstanceType type; Object* ptr; const char* str; double number; }; // A template-ized version of the IsXXX functions. template static inline bool Is(Object* obj); class MaybeObject BASE_EMBEDDED { public: inline bool IsFailure(); inline bool IsRetryAfterGC(); inline bool IsOutOfMemory(); inline bool IsException(); INLINE(bool IsTheHole()); inline bool ToObject(Object** obj) { if (IsFailure()) return false; *obj = reinterpret_cast(this); return true; } inline Object* ToObjectUnchecked() { ASSERT(!IsFailure()); return reinterpret_cast(this); } inline Object* ToObjectChecked() { CHECK(!IsFailure()); return reinterpret_cast(this); } #ifdef DEBUG // Prints this object with details. void Print(); void PrintLn(); // Verifies the object. void Verify(); #endif }; // Object is the abstract superclass for all classes in the // object hierarchy. // Object does not use any virtual functions to avoid the // allocation of the C++ vtable. // Since Smi and Failure are subclasses of Object no // data members can be present in Object. class Object : public MaybeObject { public: // Type testing. inline bool IsSmi(); inline bool IsHeapObject(); inline bool IsHeapNumber(); inline bool IsString(); inline bool IsSymbol(); // See objects-inl.h for more details inline bool IsSeqString(); inline bool IsExternalString(); inline bool IsExternalTwoByteString(); inline bool IsExternalAsciiString(); inline bool IsSeqTwoByteString(); inline bool IsSeqAsciiString(); inline bool IsConsString(); inline bool IsNumber(); inline bool IsByteArray(); inline bool IsPixelArray(); inline bool IsExternalArray(); inline bool IsExternalByteArray(); inline bool IsExternalUnsignedByteArray(); inline bool IsExternalShortArray(); inline bool IsExternalUnsignedShortArray(); inline bool IsExternalIntArray(); inline bool IsExternalUnsignedIntArray(); inline bool IsExternalFloatArray(); inline bool IsJSObject(); inline bool IsJSContextExtensionObject(); inline bool IsMap(); inline bool IsFixedArray(); inline bool IsDescriptorArray(); inline bool IsContext(); inline bool IsCatchContext(); inline bool IsGlobalContext(); inline bool IsJSFunction(); inline bool IsCode(); inline bool IsOddball(); inline bool IsSharedFunctionInfo(); inline bool IsJSValue(); inline bool IsStringWrapper(); inline bool IsProxy(); inline bool IsBoolean(); inline bool IsJSArray(); inline bool IsJSRegExp(); inline bool IsHashTable(); inline bool IsDictionary(); inline bool IsSymbolTable(); inline bool IsJSFunctionResultCache(); inline bool IsNormalizedMapCache(); inline bool IsCompilationCacheTable(); inline bool IsCodeCacheHashTable(); inline bool IsMapCache(); inline bool IsPrimitive(); inline bool IsGlobalObject(); inline bool IsJSGlobalObject(); inline bool IsJSBuiltinsObject(); inline bool IsJSGlobalProxy(); inline bool IsUndetectableObject(); inline bool IsAccessCheckNeeded(); inline bool IsJSGlobalPropertyCell(); // Returns true if this object is an instance of the specified // function template. inline bool IsInstanceOf(FunctionTemplateInfo* type); inline bool IsStruct(); #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) inline bool Is##Name(); STRUCT_LIST(DECLARE_STRUCT_PREDICATE) #undef DECLARE_STRUCT_PREDICATE // Oddball testing. INLINE(bool IsUndefined()); INLINE(bool IsNull()); INLINE(bool IsTrue()); INLINE(bool IsFalse()); // Extract the number. inline double Number(); inline bool HasSpecificClassOf(String* name); MUST_USE_RESULT MaybeObject* ToObject(); // ECMA-262 9.9. Object* ToBoolean(); // ECMA-262 9.2. // Convert to a JSObject if needed. // global_context is used when creating wrapper object. MUST_USE_RESULT MaybeObject* ToObject(Context* global_context); // Converts this to a Smi if possible. // Failure is returned otherwise. MUST_USE_RESULT inline MaybeObject* ToSmi(); void Lookup(String* name, LookupResult* result); // Property access. MUST_USE_RESULT inline MaybeObject* GetProperty(String* key); MUST_USE_RESULT inline MaybeObject* GetProperty( String* key, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetPropertyWithReceiver( Object* receiver, String* key, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetProperty(Object* receiver, LookupResult* result, String* key, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetPropertyWithCallback(Object* receiver, Object* structure, String* name, Object* holder); MUST_USE_RESULT MaybeObject* GetPropertyWithDefinedGetter(Object* receiver, JSFunction* getter); inline MaybeObject* GetElement(uint32_t index); // For use when we know that no exception can be thrown. inline Object* GetElementNoExceptionThrown(uint32_t index); MaybeObject* GetElementWithReceiver(Object* receiver, uint32_t index); // Return the object's prototype (might be Heap::null_value()). Object* GetPrototype(); // Tries to convert an object to an array index. Returns true and sets // the output parameter if it succeeds. inline bool ToArrayIndex(uint32_t* index); // Returns true if this is a JSValue containing a string and the index is // < the length of the string. Used to implement [] on strings. inline bool IsStringObjectWithCharacterAt(uint32_t index); #ifdef DEBUG // Verify a pointer is a valid object pointer. static void VerifyPointer(Object* p); #endif // Prints this object without details. void ShortPrint(); // Prints this object without details to a message accumulator. void ShortPrint(StringStream* accumulator); // Casting: This cast is only needed to satisfy macros in objects-inl.h. static Object* cast(Object* value) { return value; } // Layout description. static const int kHeaderSize = 0; // Object does not take up any space. private: DISALLOW_IMPLICIT_CONSTRUCTORS(Object); }; // Smi represents integer Numbers that can be stored in 31 bits. // Smis are immediate which means they are NOT allocated in the heap. // The this pointer has the following format: [31 bit signed int] 0 // For long smis it has the following format: // [32 bit signed int] [31 bits zero padding] 0 // Smi stands for small integer. class Smi: public Object { public: // Returns the integer value. inline int value(); // Convert a value to a Smi object. static inline Smi* FromInt(int value); static inline Smi* FromIntptr(intptr_t value); // Returns whether value can be represented in a Smi. static inline bool IsValid(intptr_t value); // Casting. static inline Smi* cast(Object* object); // Dispatched behavior. void SmiPrint(); void SmiPrint(StringStream* accumulator); #ifdef DEBUG void SmiVerify(); #endif static const int kMinValue = (-1 << (kSmiValueSize - 1)); static const int kMaxValue = -(kMinValue + 1); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Smi); }; // Failure is used for reporting out of memory situations and // propagating exceptions through the runtime system. Failure objects // are transient and cannot occur as part of the object graph. // // Failures are a single word, encoded as follows: // +-------------------------+---+--+--+ // |.........unused..........|sss|tt|11| // +-------------------------+---+--+--+ // 7 6 4 32 10 // // // The low two bits, 0-1, are the failure tag, 11. The next two bits, // 2-3, are a failure type tag 'tt' with possible values: // 00 RETRY_AFTER_GC // 01 EXCEPTION // 10 INTERNAL_ERROR // 11 OUT_OF_MEMORY_EXCEPTION // // The next three bits, 4-6, are an allocation space tag 'sss'. The // allocation space tag is 000 for all failure types except // RETRY_AFTER_GC. For RETRY_AFTER_GC, the possible values are the // allocation spaces (the encoding is found in globals.h). // Failure type tag info. const int kFailureTypeTagSize = 2; const int kFailureTypeTagMask = (1 << kFailureTypeTagSize) - 1; class Failure: public MaybeObject { public: // RuntimeStubs assumes EXCEPTION = 1 in the compiler-generated code. enum Type { RETRY_AFTER_GC = 0, EXCEPTION = 1, // Returning this marker tells the real exception // is in Top::pending_exception. INTERNAL_ERROR = 2, OUT_OF_MEMORY_EXCEPTION = 3 }; inline Type type() const; // Returns the space that needs to be collected for RetryAfterGC failures. inline AllocationSpace allocation_space() const; inline bool IsInternalError() const; inline bool IsOutOfMemoryException() const; static inline Failure* RetryAfterGC(AllocationSpace space); static inline Failure* RetryAfterGC(); // NEW_SPACE static inline Failure* Exception(); static inline Failure* InternalError(); static inline Failure* OutOfMemoryException(); // Casting. static inline Failure* cast(MaybeObject* object); // Dispatched behavior. void FailurePrint(); void FailurePrint(StringStream* accumulator); #ifdef DEBUG void FailureVerify(); #endif private: inline intptr_t value() const; static inline Failure* Construct(Type type, intptr_t value = 0); DISALLOW_IMPLICIT_CONSTRUCTORS(Failure); }; // Heap objects typically have a map pointer in their first word. However, // during GC other data (eg, mark bits, forwarding addresses) is sometimes // encoded in the first word. The class MapWord is an abstraction of the // value in a heap object's first word. class MapWord BASE_EMBEDDED { public: // Normal state: the map word contains a map pointer. // Create a map word from a map pointer. static inline MapWord FromMap(Map* map); // View this map word as a map pointer. inline Map* ToMap(); // Scavenge collection: the map word of live objects in the from space // contains a forwarding address (a heap object pointer in the to space). // True if this map word is a forwarding address for a scavenge // collection. Only valid during a scavenge collection (specifically, // when all map words are heap object pointers, ie. not during a full GC). inline bool IsForwardingAddress(); // Create a map word from a forwarding address. static inline MapWord FromForwardingAddress(HeapObject* object); // View this map word as a forwarding address. inline HeapObject* ToForwardingAddress(); // Marking phase of full collection: the map word of live objects is // marked, and may be marked as overflowed (eg, the object is live, its // children have not been visited, and it does not fit in the marking // stack). // True if this map word's mark bit is set. inline bool IsMarked(); // Return this map word but with its mark bit set. inline void SetMark(); // Return this map word but with its mark bit cleared. inline void ClearMark(); // True if this map word's overflow bit is set. inline bool IsOverflowed(); // Return this map word but with its overflow bit set. inline void SetOverflow(); // Return this map word but with its overflow bit cleared. inline void ClearOverflow(); // Compacting phase of a full compacting collection: the map word of live // objects contains an encoding of the original map address along with the // forwarding address (represented as an offset from the first live object // in the same page as the (old) object address). // Create a map word from a map address and a forwarding address offset. static inline MapWord EncodeAddress(Address map_address, int offset); // Return the map address encoded in this map word. inline Address DecodeMapAddress(MapSpace* map_space); // Return the forwarding offset encoded in this map word. inline int DecodeOffset(); // During serialization: the map word is used to hold an encoded // address, and possibly a mark bit (set and cleared with SetMark // and ClearMark). // Create a map word from an encoded address. static inline MapWord FromEncodedAddress(Address address); inline Address ToEncodedAddress(); // Bits used by the marking phase of the garbage collector. // // The first word of a heap object is normally a map pointer. The last two // bits are tagged as '01' (kHeapObjectTag). We reuse the last two bits to // mark an object as live and/or overflowed: // last bit = 0, marked as alive // second bit = 1, overflowed // An object is only marked as overflowed when it is marked as live while // the marking stack is overflowed. static const int kMarkingBit = 0; // marking bit static const int kMarkingMask = (1 << kMarkingBit); // marking mask static const int kOverflowBit = 1; // overflow bit static const int kOverflowMask = (1 << kOverflowBit); // overflow mask // Forwarding pointers and map pointer encoding. On 32 bit all the bits are // used. // +-----------------+------------------+-----------------+ // |forwarding offset|page offset of map|page index of map| // +-----------------+------------------+-----------------+ // ^ ^ ^ // | | | // | | kMapPageIndexBits // | kMapPageOffsetBits // kForwardingOffsetBits static const int kMapPageOffsetBits = kPageSizeBits - kMapAlignmentBits; static const int kForwardingOffsetBits = kPageSizeBits - kObjectAlignmentBits; #ifdef V8_HOST_ARCH_64_BIT static const int kMapPageIndexBits = 16; #else // Use all the 32-bits to encode on a 32-bit platform. static const int kMapPageIndexBits = 32 - (kMapPageOffsetBits + kForwardingOffsetBits); #endif static const int kMapPageIndexShift = 0; static const int kMapPageOffsetShift = kMapPageIndexShift + kMapPageIndexBits; static const int kForwardingOffsetShift = kMapPageOffsetShift + kMapPageOffsetBits; // Bit masks covering the different parts the encoding. static const uintptr_t kMapPageIndexMask = (1 << kMapPageOffsetShift) - 1; static const uintptr_t kMapPageOffsetMask = ((1 << kForwardingOffsetShift) - 1) & ~kMapPageIndexMask; static const uintptr_t kForwardingOffsetMask = ~(kMapPageIndexMask | kMapPageOffsetMask); private: // HeapObject calls the private constructor and directly reads the value. friend class HeapObject; explicit MapWord(uintptr_t value) : value_(value) {} uintptr_t value_; }; // HeapObject is the superclass for all classes describing heap allocated // objects. class HeapObject: public Object { public: // [map]: Contains a map which contains the object's reflective // information. inline Map* map(); inline void set_map(Map* value); // During garbage collection, the map word of a heap object does not // necessarily contain a map pointer. inline MapWord map_word(); inline void set_map_word(MapWord map_word); // Converts an address to a HeapObject pointer. static inline HeapObject* FromAddress(Address address); // Returns the address of this HeapObject. inline Address address(); // Iterates over pointers contained in the object (including the Map) void Iterate(ObjectVisitor* v); // Iterates over all pointers contained in the object except the // first map pointer. The object type is given in the first // parameter. This function does not access the map pointer in the // object, and so is safe to call while the map pointer is modified. void IterateBody(InstanceType type, int object_size, ObjectVisitor* v); // Returns the heap object's size in bytes inline int Size(); // Given a heap object's map pointer, returns the heap size in bytes // Useful when the map pointer field is used for other purposes. // GC internal. inline int SizeFromMap(Map* map); // Support for the marking heap objects during the marking phase of GC. // True if the object is marked live. inline bool IsMarked(); // Mutate this object's map pointer to indicate that the object is live. inline void SetMark(); // Mutate this object's map pointer to remove the indication that the // object is live (ie, partially restore the map pointer). inline void ClearMark(); // True if this object is marked as overflowed. Overflowed objects have // been reached and marked during marking of the heap, but their children // have not necessarily been marked and they have not been pushed on the // marking stack. inline bool IsOverflowed(); // Mutate this object's map pointer to indicate that the object is // overflowed. inline void SetOverflow(); // Mutate this object's map pointer to remove the indication that the // object is overflowed (ie, partially restore the map pointer). inline void ClearOverflow(); // Returns the field at offset in obj, as a read/write Object* reference. // Does no checking, and is safe to use during GC, while maps are invalid. // Does not invoke write barrier, so should only be assigned to // during marking GC. static inline Object** RawField(HeapObject* obj, int offset); // Casting. static inline HeapObject* cast(Object* obj); // Return the write barrier mode for this. Callers of this function // must be able to present a reference to an AssertNoAllocation // object as a sign that they are not going to use this function // from code that allocates and thus invalidates the returned write // barrier mode. inline WriteBarrierMode GetWriteBarrierMode(const AssertNoAllocation&); // Dispatched behavior. void HeapObjectShortPrint(StringStream* accumulator); #ifdef DEBUG void HeapObjectPrint(); void HeapObjectVerify(); inline void VerifyObjectField(int offset); inline void VerifySmiField(int offset); void PrintHeader(const char* id); // Verify a pointer is a valid HeapObject pointer that points to object // areas in the heap. static void VerifyHeapPointer(Object* p); #endif // Layout description. // First field in a heap object is map. static const int kMapOffset = Object::kHeaderSize; static const int kHeaderSize = kMapOffset + kPointerSize; STATIC_CHECK(kMapOffset == Internals::kHeapObjectMapOffset); protected: // helpers for calling an ObjectVisitor to iterate over pointers in the // half-open range [start, end) specified as integer offsets inline void IteratePointers(ObjectVisitor* v, int start, int end); // as above, for the single element at "offset" inline void IteratePointer(ObjectVisitor* v, int offset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject); }; #define SLOT_ADDR(obj, offset) \ reinterpret_cast((obj)->address() + offset) // This class describes a body of an object of a fixed size // in which all pointer fields are located in the [start_offset, end_offset) // interval. template class FixedBodyDescriptor { public: static const int kStartOffset = start_offset; static const int kEndOffset = end_offset; static const int kSize = size; static inline void IterateBody(HeapObject* obj, ObjectVisitor* v); template static inline void IterateBody(HeapObject* obj) { StaticVisitor::VisitPointers(SLOT_ADDR(obj, start_offset), SLOT_ADDR(obj, end_offset)); } }; // This class describes a body of an object of a variable size // in which all pointer fields are located in the [start_offset, object_size) // interval. template class FlexibleBodyDescriptor { public: static const int kStartOffset = start_offset; static inline void IterateBody(HeapObject* obj, int object_size, ObjectVisitor* v); template static inline void IterateBody(HeapObject* obj, int object_size) { StaticVisitor::VisitPointers(SLOT_ADDR(obj, start_offset), SLOT_ADDR(obj, object_size)); } }; #undef SLOT_ADDR // The HeapNumber class describes heap allocated numbers that cannot be // represented in a Smi (small integer) class HeapNumber: public HeapObject { public: // [value]: number value. inline double value(); inline void set_value(double value); // Casting. static inline HeapNumber* cast(Object* obj); // Dispatched behavior. Object* HeapNumberToBoolean(); void HeapNumberPrint(); void HeapNumberPrint(StringStream* accumulator); #ifdef DEBUG void HeapNumberVerify(); #endif inline int get_exponent(); inline int get_sign(); // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; // IEEE doubles are two 32 bit words. The first is just mantissa, the second // is a mixture of sign, exponent and mantissa. Our current platforms are all // little endian apart from non-EABI arm which is little endian with big // endian floating point word ordering! #if !defined(V8_HOST_ARCH_ARM) || defined(USE_ARM_EABI) static const int kMantissaOffset = kValueOffset; static const int kExponentOffset = kValueOffset + 4; #else static const int kMantissaOffset = kValueOffset + 4; static const int kExponentOffset = kValueOffset; # define BIG_ENDIAN_FLOATING_POINT 1 #endif static const int kSize = kValueOffset + kDoubleSize; static const uint32_t kSignMask = 0x80000000u; static const uint32_t kExponentMask = 0x7ff00000u; static const uint32_t kMantissaMask = 0xfffffu; static const int kMantissaBits = 52; static const int kExponentBits = 11; static const int kExponentBias = 1023; static const int kExponentShift = 20; static const int kMantissaBitsInTopWord = 20; static const int kNonMantissaBitsInTopWord = 12; private: DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber); }; // The JSObject describes real heap allocated JavaScript objects with // properties. // Note that the map of JSObject changes during execution to enable inline // caching. class JSObject: public HeapObject { public: enum DeleteMode { NORMAL_DELETION, FORCE_DELETION }; enum ElementsKind { // The only "fast" kind. FAST_ELEMENTS, // All the kinds below are "slow". DICTIONARY_ELEMENTS, PIXEL_ELEMENTS, EXTERNAL_BYTE_ELEMENTS, EXTERNAL_UNSIGNED_BYTE_ELEMENTS, EXTERNAL_SHORT_ELEMENTS, EXTERNAL_UNSIGNED_SHORT_ELEMENTS, EXTERNAL_INT_ELEMENTS, EXTERNAL_UNSIGNED_INT_ELEMENTS, EXTERNAL_FLOAT_ELEMENTS }; // [properties]: Backing storage for properties. // properties is a FixedArray in the fast case and a Dictionary in the // slow case. DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties. inline void initialize_properties(); inline bool HasFastProperties(); inline StringDictionary* property_dictionary(); // Gets slow properties. // [elements]: The elements (properties with names that are integers). // // Elements can be in two general modes: fast and slow. Each mode // corrensponds to a set of object representations of elements that // have something in common. // // In the fast mode elements is a FixedArray and so each element can // be quickly accessed. This fact is used in the generated code. The // elements array can have one of the two maps in this mode: // fixed_array_map or fixed_cow_array_map (for copy-on-write // arrays). In the latter case the elements array may be shared by a // few objects and so before writing to any element the array must // be copied. Use EnsureWritableFastElements in this case. // // In the slow mode elements is either a NumberDictionary or a // PixelArray or an ExternalArray. DECL_ACCESSORS(elements, HeapObject) inline void initialize_elements(); MUST_USE_RESULT inline MaybeObject* ResetElements(); inline ElementsKind GetElementsKind(); inline bool HasFastElements(); inline bool HasDictionaryElements(); inline bool HasPixelElements(); inline bool HasExternalArrayElements(); inline bool HasExternalByteElements(); inline bool HasExternalUnsignedByteElements(); inline bool HasExternalShortElements(); inline bool HasExternalUnsignedShortElements(); inline bool HasExternalIntElements(); inline bool HasExternalUnsignedIntElements(); inline bool HasExternalFloatElements(); inline bool AllowsSetElementsLength(); inline NumberDictionary* element_dictionary(); // Gets slow elements. // Requires: this->HasFastElements(). MUST_USE_RESULT inline MaybeObject* EnsureWritableFastElements(); // Collects elements starting at index 0. // Undefined values are placed after non-undefined values. // Returns the number of non-undefined values. MUST_USE_RESULT MaybeObject* PrepareElementsForSort(uint32_t limit); // As PrepareElementsForSort, but only on objects where elements is // a dictionary, and it will stay a dictionary. MUST_USE_RESULT MaybeObject* PrepareSlowElementsForSort(uint32_t limit); MUST_USE_RESULT MaybeObject* SetProperty(String* key, Object* value, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* SetProperty(LookupResult* result, String* key, Object* value, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* SetPropertyWithFailedAccessCheck( LookupResult* result, String* name, Object* value); MUST_USE_RESULT MaybeObject* SetPropertyWithCallback(Object* structure, String* name, Object* value, JSObject* holder); MUST_USE_RESULT MaybeObject* SetPropertyWithDefinedSetter(JSFunction* setter, Object* value); MUST_USE_RESULT MaybeObject* SetPropertyWithInterceptor( String* name, Object* value, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* SetPropertyPostInterceptor( String* name, Object* value, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* IgnoreAttributesAndSetLocalProperty( String* key, Object* value, PropertyAttributes attributes); // Retrieve a value in a normalized object given a lookup result. // Handles the special representation of JS global objects. Object* GetNormalizedProperty(LookupResult* result); // Sets the property value in a normalized object given a lookup result. // Handles the special representation of JS global objects. Object* SetNormalizedProperty(LookupResult* result, Object* value); // Sets the property value in a normalized object given (key, value, details). // Handles the special representation of JS global objects. MUST_USE_RESULT MaybeObject* SetNormalizedProperty(String* name, Object* value, PropertyDetails details); // Deletes the named property in a normalized object. MUST_USE_RESULT MaybeObject* DeleteNormalizedProperty(String* name, DeleteMode mode); // Returns the class name ([[Class]] property in the specification). String* class_name(); // Returns the constructor name (the name (possibly, inferred name) of the // function that was used to instantiate the object). String* constructor_name(); // Retrieve interceptors. InterceptorInfo* GetNamedInterceptor(); InterceptorInfo* GetIndexedInterceptor(); inline PropertyAttributes GetPropertyAttribute(String* name); PropertyAttributes GetPropertyAttributeWithReceiver(JSObject* receiver, String* name); PropertyAttributes GetLocalPropertyAttribute(String* name); MUST_USE_RESULT MaybeObject* DefineAccessor(String* name, bool is_getter, JSFunction* fun, PropertyAttributes attributes); Object* LookupAccessor(String* name, bool is_getter); MUST_USE_RESULT MaybeObject* DefineAccessor(AccessorInfo* info); // Used from Object::GetProperty(). MaybeObject* GetPropertyWithFailedAccessCheck( Object* receiver, LookupResult* result, String* name, PropertyAttributes* attributes); MaybeObject* GetPropertyWithInterceptor( JSObject* receiver, String* name, PropertyAttributes* attributes); MaybeObject* GetPropertyPostInterceptor( JSObject* receiver, String* name, PropertyAttributes* attributes); MaybeObject* GetLocalPropertyPostInterceptor(JSObject* receiver, String* name, PropertyAttributes* attributes); // Returns true if this is an instance of an api function and has // been modified since it was created. May give false positives. bool IsDirty(); bool HasProperty(String* name) { return GetPropertyAttribute(name) != ABSENT; } // Can cause a GC if it hits an interceptor. bool HasLocalProperty(String* name) { return GetLocalPropertyAttribute(name) != ABSENT; } // If the receiver is a JSGlobalProxy this method will return its prototype, // otherwise the result is the receiver itself. inline Object* BypassGlobalProxy(); // Accessors for hidden properties object. // // Hidden properties are not local properties of the object itself. // Instead they are stored on an auxiliary JSObject stored as a local // property with a special name Heap::hidden_symbol(). But if the // receiver is a JSGlobalProxy then the auxiliary object is a property // of its prototype. // // Has/Get/SetHiddenPropertiesObject methods don't allow the holder to be // a JSGlobalProxy. Use BypassGlobalProxy method above to get to the real // holder. // // These accessors do not touch interceptors or accessors. inline bool HasHiddenPropertiesObject(); inline Object* GetHiddenPropertiesObject(); MUST_USE_RESULT inline MaybeObject* SetHiddenPropertiesObject( Object* hidden_obj); MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode); MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode); // Tests for the fast common case for property enumeration. bool IsSimpleEnum(); // Do we want to keep the elements in fast case when increasing the // capacity? bool ShouldConvertToSlowElements(int new_capacity); // Returns true if the backing storage for the slow-case elements of // this object takes up nearly as much space as a fast-case backing // storage would. In that case the JSObject should have fast // elements. bool ShouldConvertToFastElements(); // Return the object's prototype (might be Heap::null_value()). inline Object* GetPrototype(); // Set the object's prototype (only JSObject and null are allowed). MUST_USE_RESULT MaybeObject* SetPrototype(Object* value, bool skip_hidden_prototypes); // Tells whether the index'th element is present. inline bool HasElement(uint32_t index); bool HasElementWithReceiver(JSObject* receiver, uint32_t index); // Tells whether the index'th element is present and how it is stored. enum LocalElementType { // There is no element with given index. UNDEFINED_ELEMENT, // Element with given index is handled by interceptor. INTERCEPTED_ELEMENT, // Element with given index is character in string. STRING_CHARACTER_ELEMENT, // Element with given index is stored in fast backing store. FAST_ELEMENT, // Element with given index is stored in slow backing store. DICTIONARY_ELEMENT }; LocalElementType HasLocalElement(uint32_t index); bool HasElementWithInterceptor(JSObject* receiver, uint32_t index); bool HasElementPostInterceptor(JSObject* receiver, uint32_t index); MUST_USE_RESULT MaybeObject* SetFastElement(uint32_t index, Object* value); // Set the index'th array element. // A Failure object is returned if GC is needed. MUST_USE_RESULT MaybeObject* SetElement(uint32_t index, Object* value); // Returns the index'th element. // The undefined object if index is out of bounds. MaybeObject* GetElementWithReceiver(JSObject* receiver, uint32_t index); MaybeObject* GetElementWithInterceptor(JSObject* receiver, uint32_t index); MUST_USE_RESULT MaybeObject* SetFastElementsCapacityAndLength(int capacity, int length); MUST_USE_RESULT MaybeObject* SetSlowElements(Object* length); // Lookup interceptors are used for handling properties controlled by host // objects. inline bool HasNamedInterceptor(); inline bool HasIndexedInterceptor(); // Support functions for v8 api (needed for correct interceptor behavior). bool HasRealNamedProperty(String* key); bool HasRealElementProperty(uint32_t index); bool HasRealNamedCallbackProperty(String* key); // Initializes the array to a certain length MUST_USE_RESULT MaybeObject* SetElementsLength(Object* length); // Get the header size for a JSObject. Used to compute the index of // internal fields as well as the number of internal fields. inline int GetHeaderSize(); inline int GetInternalFieldCount(); inline Object* GetInternalField(int index); inline void SetInternalField(int index, Object* value); // Lookup a property. If found, the result is valid and has // detailed information. void LocalLookup(String* name, LookupResult* result); void Lookup(String* name, LookupResult* result); // The following lookup functions skip interceptors. void LocalLookupRealNamedProperty(String* name, LookupResult* result); void LookupRealNamedProperty(String* name, LookupResult* result); void LookupRealNamedPropertyInPrototypes(String* name, LookupResult* result); void LookupCallbackSetterInPrototypes(String* name, LookupResult* result); bool SetElementWithCallbackSetterInPrototypes(uint32_t index, Object* value); void LookupCallback(String* name, LookupResult* result); // Returns the number of properties on this object filtering out properties // with the specified attributes (ignoring interceptors). int NumberOfLocalProperties(PropertyAttributes filter); // Returns the number of enumerable properties (ignoring interceptors). int NumberOfEnumProperties(); // Fill in details for properties into storage starting at the specified // index. void GetLocalPropertyNames(FixedArray* storage, int index); // Returns the number of properties on this object filtering out properties // with the specified attributes (ignoring interceptors). int NumberOfLocalElements(PropertyAttributes filter); // Returns the number of enumerable elements (ignoring interceptors). int NumberOfEnumElements(); // Returns the number of elements on this object filtering out elements // with the specified attributes (ignoring interceptors). int GetLocalElementKeys(FixedArray* storage, PropertyAttributes filter); // Count and fill in the enumerable elements into storage. // (storage->length() == NumberOfEnumElements()). // If storage is NULL, will count the elements without adding // them to any storage. // Returns the number of enumerable elements. int GetEnumElementKeys(FixedArray* storage); // Add a property to a fast-case object using a map transition to // new_map. MUST_USE_RESULT MaybeObject* AddFastPropertyUsingMap(Map* new_map, String* name, Object* value); // Add a constant function property to a fast-case object. // This leaves a CONSTANT_TRANSITION in the old map, and // if it is called on a second object with this map, a // normal property is added instead, with a map transition. // This avoids the creation of many maps with the same constant // function, all orphaned. MUST_USE_RESULT MaybeObject* AddConstantFunctionProperty( String* name, JSFunction* function, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* ReplaceSlowProperty( String* name, Object* value, PropertyAttributes attributes); // Converts a descriptor of any other type to a real field, // backed by the properties array. Descriptors of visible // types, such as CONSTANT_FUNCTION, keep their enumeration order. // Converts the descriptor on the original object's map to a // map transition, and the the new field is on the object's new map. MUST_USE_RESULT MaybeObject* ConvertDescriptorToFieldAndMapTransition( String* name, Object* new_value, PropertyAttributes attributes); // Converts a descriptor of any other type to a real field, // backed by the properties array. Descriptors of visible // types, such as CONSTANT_FUNCTION, keep their enumeration order. MUST_USE_RESULT MaybeObject* ConvertDescriptorToField( String* name, Object* new_value, PropertyAttributes attributes); // Add a property to a fast-case object. MUST_USE_RESULT MaybeObject* AddFastProperty(String* name, Object* value, PropertyAttributes attributes); // Add a property to a slow-case object. MUST_USE_RESULT MaybeObject* AddSlowProperty(String* name, Object* value, PropertyAttributes attributes); // Add a property to an object. MUST_USE_RESULT MaybeObject* AddProperty(String* name, Object* value, PropertyAttributes attributes); // Convert the object to use the canonical dictionary // representation. If the object is expected to have additional properties // added this number can be indicated to have the backing store allocated to // an initial capacity for holding these properties. MUST_USE_RESULT MaybeObject* NormalizeProperties( PropertyNormalizationMode mode, int expected_additional_properties); MUST_USE_RESULT MaybeObject* NormalizeElements(); MUST_USE_RESULT MaybeObject* UpdateMapCodeCache(String* name, Code* code); // Transform slow named properties to fast variants. // Returns failure if allocation failed. MUST_USE_RESULT MaybeObject* TransformToFastProperties( int unused_property_fields); // Access fast-case object properties at index. inline Object* FastPropertyAt(int index); inline Object* FastPropertyAtPut(int index, Object* value); // Access to in object properties. inline Object* InObjectPropertyAt(int index); inline Object* InObjectPropertyAtPut(int index, Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // initializes the body after properties slot, properties slot is // initialized by set_properties // Note: this call does not update write barrier, it is caller's // reponsibility to ensure that *v* can be collected without WB here. inline void InitializeBody(int object_size, Object* value); // Check whether this object references another object bool ReferencesObject(Object* obj); // Casting. static inline JSObject* cast(Object* obj); // Disalow further properties to be added to the object. MUST_USE_RESULT MaybeObject* PreventExtensions(); // Dispatched behavior. void JSObjectShortPrint(StringStream* accumulator); #ifdef DEBUG void JSObjectPrint(); void JSObjectVerify(); void PrintProperties(); void PrintElements(); // Structure for collecting spill information about JSObjects. class SpillInformation { public: void Clear(); void Print(); int number_of_objects_; int number_of_objects_with_fast_properties_; int number_of_objects_with_fast_elements_; int number_of_fast_used_fields_; int number_of_fast_unused_fields_; int number_of_slow_used_properties_; int number_of_slow_unused_properties_; int number_of_fast_used_elements_; int number_of_fast_unused_elements_; int number_of_slow_used_elements_; int number_of_slow_unused_elements_; }; void IncrementSpillStatistics(SpillInformation* info); #endif Object* SlowReverseLookup(Object* value); // Maximal number of fast properties for the JSObject. Used to // restrict the number of map transitions to avoid an explosion in // the number of maps for objects used as dictionaries. inline int MaxFastProperties(); // Maximal number of elements (numbered 0 .. kMaxElementCount - 1). // Also maximal value of JSArray's length property. static const uint32_t kMaxElementCount = 0xffffffffu; static const uint32_t kMaxGap = 1024; static const int kMaxFastElementsLength = 5000; static const int kInitialMaxFastElementArray = 100000; static const int kMaxFastProperties = 8; static const int kMaxInstanceSize = 255 * kPointerSize; // When extending the backing storage for property values, we increase // its size by more than the 1 entry necessary, so sequentially adding fields // to the same object requires fewer allocations and copies. static const int kFieldsAdded = 3; // Layout description. static const int kPropertiesOffset = HeapObject::kHeaderSize; static const int kElementsOffset = kPropertiesOffset + kPointerSize; static const int kHeaderSize = kElementsOffset + kPointerSize; STATIC_CHECK(kHeaderSize == Internals::kJSObjectHeaderSize); class BodyDescriptor : public FlexibleBodyDescriptor { public: static inline int SizeOf(Map* map, HeapObject* object); }; private: MUST_USE_RESULT MaybeObject* GetElementWithCallback(Object* receiver, Object* structure, uint32_t index, Object* holder); MaybeObject* SetElementWithCallback(Object* structure, uint32_t index, Object* value, JSObject* holder); MUST_USE_RESULT MaybeObject* SetElementWithInterceptor(uint32_t index, Object* value); MUST_USE_RESULT MaybeObject* SetElementWithoutInterceptor(uint32_t index, Object* value); MaybeObject* GetElementPostInterceptor(JSObject* receiver, uint32_t index); MUST_USE_RESULT MaybeObject* DeletePropertyPostInterceptor(String* name, DeleteMode mode); MUST_USE_RESULT MaybeObject* DeletePropertyWithInterceptor(String* name); MUST_USE_RESULT MaybeObject* DeleteElementPostInterceptor(uint32_t index, DeleteMode mode); MUST_USE_RESULT MaybeObject* DeleteElementWithInterceptor(uint32_t index); PropertyAttributes GetPropertyAttributePostInterceptor(JSObject* receiver, String* name, bool continue_search); PropertyAttributes GetPropertyAttributeWithInterceptor(JSObject* receiver, String* name, bool continue_search); PropertyAttributes GetPropertyAttributeWithFailedAccessCheck( Object* receiver, LookupResult* result, String* name, bool continue_search); PropertyAttributes GetPropertyAttribute(JSObject* receiver, LookupResult* result, String* name, bool continue_search); // Returns true if most of the elements backing storage is used. bool HasDenseElements(); bool CanSetCallback(String* name); MUST_USE_RESULT MaybeObject* SetElementCallback( uint32_t index, Object* structure, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* SetPropertyCallback( String* name, Object* structure, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* DefineGetterSetter( String* name, PropertyAttributes attributes); void LookupInDescriptor(String* name, LookupResult* result); DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject); }; // FixedArray describes fixed-sized arrays with element type Object*. class FixedArray: public HeapObject { public: // [length]: length of the array. inline int length(); inline void set_length(int value); // Setter and getter for elements. inline Object* get(int index); // Setter that uses write barrier. inline void set(int index, Object* value); // Setter that doesn't need write barrier). inline void set(int index, Smi* value); // Setter with explicit barrier mode. inline void set(int index, Object* value, WriteBarrierMode mode); // Setters for frequently used oddballs located in old space. inline void set_undefined(int index); inline void set_null(int index); inline void set_the_hole(int index); // Setters with less debug checks for the GC to use. inline void set_unchecked(int index, Smi* value); inline void set_null_unchecked(int index); inline void set_unchecked(int index, Object* value, WriteBarrierMode mode); // Gives access to raw memory which stores the array's data. inline Object** data_start(); // Copy operations. MUST_USE_RESULT inline MaybeObject* Copy(); MUST_USE_RESULT MaybeObject* CopySize(int new_length); // Add the elements of a JSArray to this FixedArray. MUST_USE_RESULT MaybeObject* AddKeysFromJSArray(JSArray* array); // Compute the union of this and other. MUST_USE_RESULT MaybeObject* UnionOfKeys(FixedArray* other); // Copy a sub array from the receiver to dest. void CopyTo(int pos, FixedArray* dest, int dest_pos, int len); // Garbage collection support. static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; } // Code Generation support. static int OffsetOfElementAt(int index) { return SizeFor(index); } // Casting. static inline FixedArray* cast(Object* obj); // Layout description. // Length is smi tagged when it is stored. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kHeaderSize = kLengthOffset + kPointerSize; // Maximal allowed size, in bytes, of a single FixedArray. // Prevents overflowing size computations, as well as extreme memory // consumption. static const int kMaxSize = 512 * MB; // Maximally allowed length of a FixedArray. static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize; // Dispatched behavior. #ifdef DEBUG void FixedArrayPrint(); void FixedArrayVerify(); // Checks if two FixedArrays have identical contents. bool IsEqualTo(FixedArray* other); #endif // Swap two elements in a pair of arrays. If this array and the // numbers array are the same object, the elements are only swapped // once. void SwapPairs(FixedArray* numbers, int i, int j); // Sort prefix of this array and the numbers array as pairs wrt. the // numbers. If the numbers array and the this array are the same // object, the prefix of this array is sorted. void SortPairs(FixedArray* numbers, uint32_t len); class BodyDescriptor : public FlexibleBodyDescriptor { public: static inline int SizeOf(Map* map, HeapObject* object) { return SizeFor(reinterpret_cast(object)->length()); } }; protected: // Set operation on FixedArray without using write barriers. Can // only be used for storing old space objects or smis. static inline void fast_set(FixedArray* array, int index, Object* value); private: DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray); }; // DescriptorArrays are fixed arrays used to hold instance descriptors. // The format of the these objects is: // [0]: point to a fixed array with (value, detail) pairs. // [1]: next enumeration index (Smi), or pointer to small fixed array: // [0]: next enumeration index (Smi) // [1]: pointer to fixed array with enum cache // [2]: first key // [length() - 1]: last key // class DescriptorArray: public FixedArray { public: // Is this the singleton empty_descriptor_array? inline bool IsEmpty(); // Returns the number of descriptors in the array. int number_of_descriptors() { return IsEmpty() ? 0 : length() - kFirstIndex; } int NextEnumerationIndex() { if (IsEmpty()) return PropertyDetails::kInitialIndex; Object* obj = get(kEnumerationIndexIndex); if (obj->IsSmi()) { return Smi::cast(obj)->value(); } else { Object* index = FixedArray::cast(obj)->get(kEnumCacheBridgeEnumIndex); return Smi::cast(index)->value(); } } // Set next enumeration index and flush any enum cache. void SetNextEnumerationIndex(int value) { if (!IsEmpty()) { fast_set(this, kEnumerationIndexIndex, Smi::FromInt(value)); } } bool HasEnumCache() { return !IsEmpty() && !get(kEnumerationIndexIndex)->IsSmi(); } Object* GetEnumCache() { ASSERT(HasEnumCache()); FixedArray* bridge = FixedArray::cast(get(kEnumerationIndexIndex)); return bridge->get(kEnumCacheBridgeCacheIndex); } // Initialize or change the enum cache, // using the supplied storage for the small "bridge". void SetEnumCache(FixedArray* bridge_storage, FixedArray* new_cache); // Accessors for fetching instance descriptor at descriptor number. inline String* GetKey(int descriptor_number); inline Object* GetValue(int descriptor_number); inline Smi* GetDetails(int descriptor_number); inline PropertyType GetType(int descriptor_number); inline int GetFieldIndex(int descriptor_number); inline JSFunction* GetConstantFunction(int descriptor_number); inline Object* GetCallbacksObject(int descriptor_number); inline AccessorDescriptor* GetCallbacks(int descriptor_number); inline bool IsProperty(int descriptor_number); inline bool IsTransition(int descriptor_number); inline bool IsNullDescriptor(int descriptor_number); inline bool IsDontEnum(int descriptor_number); // Accessor for complete descriptor. inline void Get(int descriptor_number, Descriptor* desc); inline void Set(int descriptor_number, Descriptor* desc); // Transfer complete descriptor from another descriptor array to // this one. inline void CopyFrom(int index, DescriptorArray* src, int src_index); // Copy the descriptor array, insert a new descriptor and optionally // remove map transitions. If the descriptor is already present, it is // replaced. If a replaced descriptor is a real property (not a transition // or null), its enumeration index is kept as is. // If adding a real property, map transitions must be removed. If adding // a transition, they must not be removed. All null descriptors are removed. MUST_USE_RESULT MaybeObject* CopyInsert(Descriptor* descriptor, TransitionFlag transition_flag); // Remove all transitions. Return a copy of the array with all transitions // removed, or a Failure object if the new array could not be allocated. MUST_USE_RESULT MaybeObject* RemoveTransitions(); // Sort the instance descriptors by the hash codes of their keys. // Does not check for duplicates. void SortUnchecked(); // Sort the instance descriptors by the hash codes of their keys. // Checks the result for duplicates. void Sort(); // Search the instance descriptors for given name. inline int Search(String* name); // As the above, but uses DescriptorLookupCache and updates it when // necessary. inline int SearchWithCache(String* name); // Tells whether the name is present int the array. bool Contains(String* name) { return kNotFound != Search(name); } // Perform a binary search in the instance descriptors represented // by this fixed array. low and high are descriptor indices. If there // are three instance descriptors in this array it should be called // with low=0 and high=2. int BinarySearch(String* name, int low, int high); // Perform a linear search in the instance descriptors represented // by this fixed array. len is the number of descriptor indices that are // valid. Does not require the descriptors to be sorted. int LinearSearch(String* name, int len); // Allocates a DescriptorArray, but returns the singleton // empty descriptor array object if number_of_descriptors is 0. MUST_USE_RESULT static MaybeObject* Allocate(int number_of_descriptors); // Casting. static inline DescriptorArray* cast(Object* obj); // Constant for denoting key was not found. static const int kNotFound = -1; static const int kContentArrayIndex = 0; static const int kEnumerationIndexIndex = 1; static const int kFirstIndex = 2; // The length of the "bridge" to the enum cache. static const int kEnumCacheBridgeLength = 2; static const int kEnumCacheBridgeEnumIndex = 0; static const int kEnumCacheBridgeCacheIndex = 1; // Layout description. static const int kContentArrayOffset = FixedArray::kHeaderSize; static const int kEnumerationIndexOffset = kContentArrayOffset + kPointerSize; static const int kFirstOffset = kEnumerationIndexOffset + kPointerSize; // Layout description for the bridge array. static const int kEnumCacheBridgeEnumOffset = FixedArray::kHeaderSize; static const int kEnumCacheBridgeCacheOffset = kEnumCacheBridgeEnumOffset + kPointerSize; #ifdef DEBUG // Print all the descriptors. void PrintDescriptors(); // Is the descriptor array sorted and without duplicates? bool IsSortedNoDuplicates(); // Are two DescriptorArrays equal? bool IsEqualTo(DescriptorArray* other); #endif // The maximum number of descriptors we want in a descriptor array (should // fit in a page). static const int kMaxNumberOfDescriptors = 1024 + 512; private: // Conversion from descriptor number to array indices. static int ToKeyIndex(int descriptor_number) { return descriptor_number+kFirstIndex; } static int ToDetailsIndex(int descriptor_number) { return (descriptor_number << 1) + 1; } static int ToValueIndex(int descriptor_number) { return descriptor_number << 1; } bool is_null_descriptor(int descriptor_number) { return PropertyDetails(GetDetails(descriptor_number)).type() == NULL_DESCRIPTOR; } // Swap operation on FixedArray without using write barriers. static inline void fast_swap(FixedArray* array, int first, int second); // Swap descriptor first and second. inline void Swap(int first, int second); FixedArray* GetContentArray() { return FixedArray::cast(get(kContentArrayIndex)); } DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray); }; // HashTable is a subclass of FixedArray that implements a hash table // that uses open addressing and quadratic probing. // // In order for the quadratic probing to work, elements that have not // yet been used and elements that have been deleted are // distinguished. Probing continues when deleted elements are // encountered and stops when unused elements are encountered. // // - Elements with key == undefined have not been used yet. // - Elements with key == null have been deleted. // // The hash table class is parameterized with a Shape and a Key. // Shape must be a class with the following interface: // class ExampleShape { // public: // // Tells whether key matches other. // static bool IsMatch(Key key, Object* other); // // Returns the hash value for key. // static uint32_t Hash(Key key); // // Returns the hash value for object. // static uint32_t HashForObject(Key key, Object* object); // // Convert key to an object. // static inline Object* AsObject(Key key); // // The prefix size indicates number of elements in the beginning // // of the backing storage. // static const int kPrefixSize = ..; // // The Element size indicates number of elements per entry. // static const int kEntrySize = ..; // }; // The prefix size indicates an amount of memory in the // beginning of the backing storage that can be used for non-element // information by subclasses. template class HashTable: public FixedArray { public: // Returns the number of elements in the hash table. int NumberOfElements() { return Smi::cast(get(kNumberOfElementsIndex))->value(); } // Returns the number of deleted elements in the hash table. int NumberOfDeletedElements() { return Smi::cast(get(kNumberOfDeletedElementsIndex))->value(); } // Returns the capacity of the hash table. int Capacity() { return Smi::cast(get(kCapacityIndex))->value(); } // ElementAdded should be called whenever an element is added to a // hash table. void ElementAdded() { SetNumberOfElements(NumberOfElements() + 1); } // ElementRemoved should be called whenever an element is removed from // a hash table. void ElementRemoved() { SetNumberOfElements(NumberOfElements() - 1); SetNumberOfDeletedElements(NumberOfDeletedElements() + 1); } void ElementsRemoved(int n) { SetNumberOfElements(NumberOfElements() - n); SetNumberOfDeletedElements(NumberOfDeletedElements() + n); } // Returns a new HashTable object. Might return Failure. MUST_USE_RESULT static MaybeObject* Allocate( int at_least_space_for, PretenureFlag pretenure = NOT_TENURED); // Returns the key at entry. Object* KeyAt(int entry) { return get(EntryToIndex(entry)); } // Tells whether k is a real key. Null and undefined are not allowed // as keys and can be used to indicate missing or deleted elements. bool IsKey(Object* k) { return !k->IsNull() && !k->IsUndefined(); } // Garbage collection support. void IteratePrefix(ObjectVisitor* visitor); void IterateElements(ObjectVisitor* visitor); // Casting. static inline HashTable* cast(Object* obj); // Compute the probe offset (quadratic probing). INLINE(static uint32_t GetProbeOffset(uint32_t n)) { return (n + n * n) >> 1; } static const int kNumberOfElementsIndex = 0; static const int kNumberOfDeletedElementsIndex = 1; static const int kCapacityIndex = 2; static const int kPrefixStartIndex = 3; static const int kElementsStartIndex = kPrefixStartIndex + Shape::kPrefixSize; static const int kEntrySize = Shape::kEntrySize; static const int kElementsStartOffset = kHeaderSize + kElementsStartIndex * kPointerSize; static const int kCapacityOffset = kHeaderSize + kCapacityIndex * kPointerSize; // Constant used for denoting a absent entry. static const int kNotFound = -1; // Maximal capacity of HashTable. Based on maximal length of underlying // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex // cannot overflow. static const int kMaxCapacity = (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize; // Find entry for key otherwise return kNotFound. int FindEntry(Key key); protected: // Find the entry at which to insert element with the given key that // has the given hash value. uint32_t FindInsertionEntry(uint32_t hash); // Returns the index for an entry (of the key) static inline int EntryToIndex(int entry) { return (entry * kEntrySize) + kElementsStartIndex; } // Update the number of elements in the hash table. void SetNumberOfElements(int nof) { fast_set(this, kNumberOfElementsIndex, Smi::FromInt(nof)); } // Update the number of deleted elements in the hash table. void SetNumberOfDeletedElements(int nod) { fast_set(this, kNumberOfDeletedElementsIndex, Smi::FromInt(nod)); } // Sets the capacity of the hash table. void SetCapacity(int capacity) { // To scale a computed hash code to fit within the hash table, we // use bit-wise AND with a mask, so the capacity must be positive // and non-zero. ASSERT(capacity > 0); ASSERT(capacity <= kMaxCapacity); fast_set(this, kCapacityIndex, Smi::FromInt(capacity)); } // Returns probe entry. static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) { ASSERT(IsPowerOf2(size)); return (hash + GetProbeOffset(number)) & (size - 1); } static uint32_t FirstProbe(uint32_t hash, uint32_t size) { return hash & (size - 1); } static uint32_t NextProbe(uint32_t last, uint32_t number, uint32_t size) { return (last + number) & (size - 1); } // Ensure enough space for n additional elements. MUST_USE_RESULT MaybeObject* EnsureCapacity(int n, Key key); }; // HashTableKey is an abstract superclass for virtual key behavior. class HashTableKey { public: // Returns whether the other object matches this key. virtual bool IsMatch(Object* other) = 0; // Returns the hash value for this key. virtual uint32_t Hash() = 0; // Returns the hash value for object. virtual uint32_t HashForObject(Object* key) = 0; // Returns the key object for storing into the hash table. // If allocations fails a failure object is returned. MUST_USE_RESULT virtual MaybeObject* AsObject() = 0; // Required. virtual ~HashTableKey() {} }; class SymbolTableShape { public: static bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static uint32_t Hash(HashTableKey* key) { return key->Hash(); } static uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 1; }; // SymbolTable. // // No special elements in the prefix and the element size is 1 // because only the symbol itself (the key) needs to be stored. class SymbolTable: public HashTable { public: // Find symbol in the symbol table. If it is not there yet, it is // added. The return value is the symbol table which might have // been enlarged. If the return value is not a failure, the symbol // pointer *s is set to the symbol found. MUST_USE_RESULT MaybeObject* LookupSymbol(Vector str, Object** s); MUST_USE_RESULT MaybeObject* LookupString(String* key, Object** s); // Looks up a symbol that is equal to the given string and returns // true if it is found, assigning the symbol to the given output // parameter. bool LookupSymbolIfExists(String* str, String** symbol); bool LookupTwoCharsSymbolIfExists(uint32_t c1, uint32_t c2, String** symbol); // Casting. static inline SymbolTable* cast(Object* obj); private: MUST_USE_RESULT MaybeObject* LookupKey(HashTableKey* key, Object** s); DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolTable); }; class MapCacheShape { public: static bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static uint32_t Hash(HashTableKey* key) { return key->Hash(); } static uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 2; }; // MapCache. // // Maps keys that are a fixed array of symbols to a map. // Used for canonicalize maps for object literals. class MapCache: public HashTable { public: // Find cached value for a string key, otherwise return null. Object* Lookup(FixedArray* key); MUST_USE_RESULT MaybeObject* Put(FixedArray* key, Map* value); static inline MapCache* cast(Object* obj); private: DISALLOW_IMPLICIT_CONSTRUCTORS(MapCache); }; template class Dictionary: public HashTable { public: static inline Dictionary* cast(Object* obj) { return reinterpret_cast*>(obj); } // Returns the value at entry. Object* ValueAt(int entry) { return this->get(HashTable::EntryToIndex(entry)+1); } // Set the value for entry. void ValueAtPut(int entry, Object* value) { // Check that this value can actually be written. PropertyDetails details = DetailsAt(entry); // If a value has not been initilized we allow writing to it even if // it is read only (a declared const that has not been initialized). if (details.IsReadOnly() && !ValueAt(entry)->IsTheHole()) return; this->set(HashTable::EntryToIndex(entry)+1, value); } // Returns the property details for the property at entry. PropertyDetails DetailsAt(int entry) { ASSERT(entry >= 0); // Not found is -1, which is not caught by get(). return PropertyDetails( Smi::cast(this->get(HashTable::EntryToIndex(entry) + 2))); } // Set the details for entry. void DetailsAtPut(int entry, PropertyDetails value) { this->set(HashTable::EntryToIndex(entry) + 2, value.AsSmi()); } // Sorting support void CopyValuesTo(FixedArray* elements); // Delete a property from the dictionary. Object* DeleteProperty(int entry, JSObject::DeleteMode mode); // Returns the number of elements in the dictionary filtering out properties // with the specified attributes. int NumberOfElementsFilterAttributes(PropertyAttributes filter); // Returns the number of enumerable elements in the dictionary. int NumberOfEnumElements(); // Copies keys to preallocated fixed array. void CopyKeysTo(FixedArray* storage, PropertyAttributes filter); // Fill in details for properties into storage. void CopyKeysTo(FixedArray* storage); // Accessors for next enumeration index. void SetNextEnumerationIndex(int index) { this->fast_set(this, kNextEnumerationIndexIndex, Smi::FromInt(index)); } int NextEnumerationIndex() { return Smi::cast(FixedArray::get(kNextEnumerationIndexIndex))->value(); } // Returns a new array for dictionary usage. Might return Failure. MUST_USE_RESULT static MaybeObject* Allocate(int at_least_space_for); // Ensure enough space for n additional elements. MUST_USE_RESULT MaybeObject* EnsureCapacity(int n, Key key); #ifdef DEBUG void Print(); #endif // Returns the key (slow). Object* SlowReverseLookup(Object* value); // Sets the entry to (key, value) pair. inline void SetEntry(int entry, Object* key, Object* value, PropertyDetails details); MUST_USE_RESULT MaybeObject* Add(Key key, Object* value, PropertyDetails details); protected: // Generic at put operation. MUST_USE_RESULT MaybeObject* AtPut(Key key, Object* value); // Add entry to dictionary. MUST_USE_RESULT MaybeObject* AddEntry(Key key, Object* value, PropertyDetails details, uint32_t hash); // Generate new enumeration indices to avoid enumeration index overflow. MUST_USE_RESULT MaybeObject* GenerateNewEnumerationIndices(); static const int kMaxNumberKeyIndex = HashTable::kPrefixStartIndex; static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1; }; class StringDictionaryShape { public: static inline bool IsMatch(String* key, Object* other); static inline uint32_t Hash(String* key); static inline uint32_t HashForObject(String* key, Object* object); MUST_USE_RESULT static inline MaybeObject* AsObject(String* key); static const int kPrefixSize = 2; static const int kEntrySize = 3; static const bool kIsEnumerable = true; }; class StringDictionary: public Dictionary { public: static inline StringDictionary* cast(Object* obj) { ASSERT(obj->IsDictionary()); return reinterpret_cast(obj); } // Copies enumerable keys to preallocated fixed array. void CopyEnumKeysTo(FixedArray* storage, FixedArray* sort_array); // For transforming properties of a JSObject. MUST_USE_RESULT MaybeObject* TransformPropertiesToFastFor( JSObject* obj, int unused_property_fields); // Find entry for key otherwise return kNotFound. Optimzed version of // HashTable::FindEntry. int FindEntry(String* key); }; class NumberDictionaryShape { public: static inline bool IsMatch(uint32_t key, Object* other); static inline uint32_t Hash(uint32_t key); static inline uint32_t HashForObject(uint32_t key, Object* object); MUST_USE_RESULT static inline MaybeObject* AsObject(uint32_t key); static const int kPrefixSize = 2; static const int kEntrySize = 3; static const bool kIsEnumerable = false; }; class NumberDictionary: public Dictionary { public: static NumberDictionary* cast(Object* obj) { ASSERT(obj->IsDictionary()); return reinterpret_cast(obj); } // Type specific at put (default NONE attributes is used when adding). MUST_USE_RESULT MaybeObject* AtNumberPut(uint32_t key, Object* value); MUST_USE_RESULT MaybeObject* AddNumberEntry(uint32_t key, Object* value, PropertyDetails details); // Set an existing entry or add a new one if needed. MUST_USE_RESULT MaybeObject* Set(uint32_t key, Object* value, PropertyDetails details); void UpdateMaxNumberKey(uint32_t key); // If slow elements are required we will never go back to fast-case // for the elements kept in this dictionary. We require slow // elements if an element has been added at an index larger than // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called // when defining a getter or setter with a number key. inline bool requires_slow_elements(); inline void set_requires_slow_elements(); // Get the value of the max number key that has been added to this // dictionary. max_number_key can only be called if // requires_slow_elements returns false. inline uint32_t max_number_key(); // Remove all entries were key is a number and (from <= key && key < to). void RemoveNumberEntries(uint32_t from, uint32_t to); // Bit masks. static const int kRequiresSlowElementsMask = 1; static const int kRequiresSlowElementsTagSize = 1; static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1; }; // JSFunctionResultCache caches results of some JSFunction invocation. // It is a fixed array with fixed structure: // [0]: factory function // [1]: finger index // [2]: current cache size // [3]: dummy field. // The rest of array are key/value pairs. class JSFunctionResultCache: public FixedArray { public: static const int kFactoryIndex = 0; static const int kFingerIndex = kFactoryIndex + 1; static const int kCacheSizeIndex = kFingerIndex + 1; static const int kDummyIndex = kCacheSizeIndex + 1; static const int kEntriesIndex = kDummyIndex + 1; static const int kEntrySize = 2; // key + value static const int kFactoryOffset = kHeaderSize; static const int kFingerOffset = kFactoryOffset + kPointerSize; static const int kCacheSizeOffset = kFingerOffset + kPointerSize; inline void MakeZeroSize(); inline void Clear(); // Casting static inline JSFunctionResultCache* cast(Object* obj); #ifdef DEBUG void JSFunctionResultCacheVerify(); #endif }; // The cache for maps used by normalized (dictionary mode) objects. // Such maps do not have property descriptors, so a typical program // needs very limited number of distinct normalized maps. class NormalizedMapCache: public FixedArray { public: static const int kEntries = 64; MUST_USE_RESULT MaybeObject* Get(JSObject* object, PropertyNormalizationMode mode); void Clear(); // Casting static inline NormalizedMapCache* cast(Object* obj); #ifdef DEBUG void NormalizedMapCacheVerify(); #endif private: static int Hash(Map* fast); static bool CheckHit(Map* slow, Map* fast, PropertyNormalizationMode mode); }; // ByteArray represents fixed sized byte arrays. Used by the outside world, // such as PCRE, and also by the memory allocator and garbage collector to // fill in free blocks in the heap. class ByteArray: public HeapObject { public: // [length]: length of the array. inline int length(); inline void set_length(int value); // Setter and getter. inline byte get(int index); inline void set(int index, byte value); // Treat contents as an int array. inline int get_int(int index); static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length); } // We use byte arrays for free blocks in the heap. Given a desired size in // bytes that is a multiple of the word size and big enough to hold a byte // array, this function returns the number of elements a byte array should // have. static int LengthFor(int size_in_bytes) { ASSERT(IsAligned(size_in_bytes, kPointerSize)); ASSERT(size_in_bytes >= kHeaderSize); return size_in_bytes - kHeaderSize; } // Returns data start address. inline Address GetDataStartAddress(); // Returns a pointer to the ByteArray object for a given data start address. static inline ByteArray* FromDataStartAddress(Address address); // Casting. static inline ByteArray* cast(Object* obj); // Dispatched behavior. inline int ByteArraySize() { return SizeFor(this->length()); } #ifdef DEBUG void ByteArrayPrint(); void ByteArrayVerify(); #endif // Layout description. // Length is smi tagged when it is stored. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kHeaderSize = kLengthOffset + kPointerSize; static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); // Maximal memory consumption for a single ByteArray. static const int kMaxSize = 512 * MB; // Maximal length of a single ByteArray. static const int kMaxLength = kMaxSize - kHeaderSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray); }; // A PixelArray represents a fixed-size byte array with special semantics // used for implementing the CanvasPixelArray object. Please see the // specification at: // http://www.whatwg.org/specs/web-apps/current-work/ // multipage/the-canvas-element.html#canvaspixelarray // In particular, write access clamps the value written to 0 or 255 if the // value written is outside this range. class PixelArray: public HeapObject { public: // [length]: length of the array. inline int length(); inline void set_length(int value); // [external_pointer]: The pointer to the external memory area backing this // pixel array. DECL_ACCESSORS(external_pointer, uint8_t) // Pointer to the data store. // Setter and getter. inline uint8_t get(int index); inline void set(int index, uint8_t value); // This accessor applies the correct conversion from Smi, HeapNumber and // undefined and clamps the converted value between 0 and 255. Object* SetValue(uint32_t index, Object* value); // Casting. static inline PixelArray* cast(Object* obj); #ifdef DEBUG void PixelArrayPrint(); void PixelArrayVerify(); #endif // DEBUG // Maximal acceptable length for a pixel array. static const int kMaxLength = 0x3fffffff; // PixelArray headers are not quadword aligned. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kExternalPointerOffset = POINTER_SIZE_ALIGN(kLengthOffset + kIntSize); static const int kHeaderSize = kExternalPointerOffset + kPointerSize; static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); private: DISALLOW_IMPLICIT_CONSTRUCTORS(PixelArray); }; // An ExternalArray represents a fixed-size array of primitive values // which live outside the JavaScript heap. Its subclasses are used to // implement the CanvasArray types being defined in the WebGL // specification. As of this writing the first public draft is not yet // available, but Khronos members can access the draft at: // https://cvs.khronos.org/svn/repos/3dweb/trunk/doc/spec/WebGL-spec.html // // The semantics of these arrays differ from CanvasPixelArray. // Out-of-range values passed to the setter are converted via a C // cast, not clamping. Out-of-range indices cause exceptions to be // raised rather than being silently ignored. class ExternalArray: public HeapObject { public: // [length]: length of the array. inline int length(); inline void set_length(int value); // [external_pointer]: The pointer to the external memory area backing this // external array. DECL_ACCESSORS(external_pointer, void) // Pointer to the data store. // Casting. static inline ExternalArray* cast(Object* obj); // Maximal acceptable length for an external array. static const int kMaxLength = 0x3fffffff; // ExternalArray headers are not quadword aligned. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kExternalPointerOffset = POINTER_SIZE_ALIGN(kLengthOffset + kIntSize); static const int kHeaderSize = kExternalPointerOffset + kPointerSize; static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalArray); }; class ExternalByteArray: public ExternalArray { public: // Setter and getter. inline int8_t get(int index); inline void set(int index, int8_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalByteArray* cast(Object* obj); #ifdef DEBUG void ExternalByteArrayPrint(); void ExternalByteArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalByteArray); }; class ExternalUnsignedByteArray: public ExternalArray { public: // Setter and getter. inline uint8_t get(int index); inline void set(int index, uint8_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalUnsignedByteArray* cast(Object* obj); #ifdef DEBUG void ExternalUnsignedByteArrayPrint(); void ExternalUnsignedByteArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedByteArray); }; class ExternalShortArray: public ExternalArray { public: // Setter and getter. inline int16_t get(int index); inline void set(int index, int16_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalShortArray* cast(Object* obj); #ifdef DEBUG void ExternalShortArrayPrint(); void ExternalShortArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalShortArray); }; class ExternalUnsignedShortArray: public ExternalArray { public: // Setter and getter. inline uint16_t get(int index); inline void set(int index, uint16_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalUnsignedShortArray* cast(Object* obj); #ifdef DEBUG void ExternalUnsignedShortArrayPrint(); void ExternalUnsignedShortArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedShortArray); }; class ExternalIntArray: public ExternalArray { public: // Setter and getter. inline int32_t get(int index); inline void set(int index, int32_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalIntArray* cast(Object* obj); #ifdef DEBUG void ExternalIntArrayPrint(); void ExternalIntArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalIntArray); }; class ExternalUnsignedIntArray: public ExternalArray { public: // Setter and getter. inline uint32_t get(int index); inline void set(int index, uint32_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalUnsignedIntArray* cast(Object* obj); #ifdef DEBUG void ExternalUnsignedIntArrayPrint(); void ExternalUnsignedIntArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedIntArray); }; class ExternalFloatArray: public ExternalArray { public: // Setter and getter. inline float get(int index); inline void set(int index, float value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalFloatArray* cast(Object* obj); #ifdef DEBUG void ExternalFloatArrayPrint(); void ExternalFloatArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloatArray); }; // Code describes objects with on-the-fly generated machine code. class Code: public HeapObject { public: // Opaque data type for encapsulating code flags like kind, inline // cache state, and arguments count. // FLAGS_MIN_VALUE and FLAGS_MAX_VALUE are specified to ensure that // enumeration type has correct value range (see Issue 830 for more details). enum Flags { FLAGS_MIN_VALUE = kMinInt, FLAGS_MAX_VALUE = kMaxInt }; enum Kind { FUNCTION, STUB, BUILTIN, LOAD_IC, KEYED_LOAD_IC, CALL_IC, KEYED_CALL_IC, STORE_IC, KEYED_STORE_IC, BINARY_OP_IC, // No more than 16 kinds. The value currently encoded in four bits in // Flags. // Pseudo-kinds. REGEXP = BUILTIN, FIRST_IC_KIND = LOAD_IC, LAST_IC_KIND = BINARY_OP_IC }; enum { NUMBER_OF_KINDS = LAST_IC_KIND + 1 }; #ifdef ENABLE_DISASSEMBLER // Printing static const char* Kind2String(Kind kind); static const char* ICState2String(InlineCacheState state); static const char* PropertyType2String(PropertyType type); void Disassemble(const char* name); #endif // ENABLE_DISASSEMBLER // [instruction_size]: Size of the native instructions inline int instruction_size(); inline void set_instruction_size(int value); // [relocation_info]: Code relocation information DECL_ACCESSORS(relocation_info, ByteArray) // Unchecked accessor to be used during GC. inline ByteArray* unchecked_relocation_info(); inline int relocation_size(); // [flags]: Various code flags. inline Flags flags(); inline void set_flags(Flags flags); // [flags]: Access to specific code flags. inline Kind kind(); inline InlineCacheState ic_state(); // Only valid for IC stubs. inline InLoopFlag ic_in_loop(); // Only valid for IC stubs. inline PropertyType type(); // Only valid for monomorphic IC stubs. inline int arguments_count(); // Only valid for call IC stubs. // Testers for IC stub kinds. inline bool is_inline_cache_stub(); inline bool is_load_stub() { return kind() == LOAD_IC; } inline bool is_keyed_load_stub() { return kind() == KEYED_LOAD_IC; } inline bool is_store_stub() { return kind() == STORE_IC; } inline bool is_keyed_store_stub() { return kind() == KEYED_STORE_IC; } inline bool is_call_stub() { return kind() == CALL_IC; } inline bool is_keyed_call_stub() { return kind() == KEYED_CALL_IC; } // [major_key]: For kind STUB or BINARY_OP_IC, the major key. inline int major_key(); inline void set_major_key(int major); // Flags operations. static inline Flags ComputeFlags(Kind kind, InLoopFlag in_loop = NOT_IN_LOOP, InlineCacheState ic_state = UNINITIALIZED, PropertyType type = NORMAL, int argc = -1, InlineCacheHolderFlag holder = OWN_MAP); static inline Flags ComputeMonomorphicFlags( Kind kind, PropertyType type, InlineCacheHolderFlag holder = OWN_MAP, InLoopFlag in_loop = NOT_IN_LOOP, int argc = -1); static inline Kind ExtractKindFromFlags(Flags flags); static inline InlineCacheState ExtractICStateFromFlags(Flags flags); static inline InLoopFlag ExtractICInLoopFromFlags(Flags flags); static inline PropertyType ExtractTypeFromFlags(Flags flags); static inline int ExtractArgumentsCountFromFlags(Flags flags); static inline InlineCacheHolderFlag ExtractCacheHolderFromFlags(Flags flags); static inline Flags RemoveTypeFromFlags(Flags flags); // Convert a target address into a code object. static inline Code* GetCodeFromTargetAddress(Address address); // Convert an entry address into an object. static inline Object* GetObjectFromEntryAddress(Address location_of_address); // Returns the address of the first instruction. inline byte* instruction_start(); // Returns the address right after the last instruction. inline byte* instruction_end(); // Returns the size of the instructions, padding, and relocation information. inline int body_size(); // Returns the address of the first relocation info (read backwards!). inline byte* relocation_start(); // Code entry point. inline byte* entry(); // Returns true if pc is inside this object's instructions. inline bool contains(byte* pc); // Relocate the code by delta bytes. Called to signal that this code // object has been moved by delta bytes. void Relocate(intptr_t delta); // Migrate code described by desc. void CopyFrom(const CodeDesc& desc); // Returns the object size for a given body (used for allocation). static int SizeFor(int body_size) { ASSERT_SIZE_TAG_ALIGNED(body_size); return RoundUp(kHeaderSize + body_size, kCodeAlignment); } // Calculate the size of the code object to report for log events. This takes // the layout of the code object into account. int ExecutableSize() { // Check that the assumptions about the layout of the code object holds. ASSERT_EQ(static_cast(instruction_start() - address()), Code::kHeaderSize); return instruction_size() + Code::kHeaderSize; } // Locating source position. int SourcePosition(Address pc); int SourceStatementPosition(Address pc); // Casting. static inline Code* cast(Object* obj); // Dispatched behavior. int CodeSize() { return SizeFor(body_size()); } inline void CodeIterateBody(ObjectVisitor* v); template inline void CodeIterateBody(); #ifdef DEBUG void CodePrint(); void CodeVerify(); #endif // Layout description. static const int kInstructionSizeOffset = HeapObject::kHeaderSize; static const int kRelocationInfoOffset = kInstructionSizeOffset + kIntSize; static const int kFlagsOffset = kRelocationInfoOffset + kPointerSize; static const int kKindSpecificFlagsOffset = kFlagsOffset + kIntSize; // Add padding to align the instruction start following right after // the Code object header. static const int kHeaderSize = CODE_POINTER_ALIGN(kKindSpecificFlagsOffset + kIntSize); // Byte offsets within kKindSpecificFlagsOffset. static const int kStubMajorKeyOffset = kKindSpecificFlagsOffset + 1; // Flags layout. static const int kFlagsICStateShift = 0; static const int kFlagsICInLoopShift = 3; static const int kFlagsTypeShift = 4; static const int kFlagsKindShift = 7; static const int kFlagsICHolderShift = 11; static const int kFlagsArgumentsCountShift = 12; static const int kFlagsICStateMask = 0x00000007; // 00000000111 static const int kFlagsICInLoopMask = 0x00000008; // 00000001000 static const int kFlagsTypeMask = 0x00000070; // 00001110000 static const int kFlagsKindMask = 0x00000780; // 11110000000 static const int kFlagsCacheInPrototypeMapMask = 0x00000800; static const int kFlagsArgumentsCountMask = 0xFFFFF000; static const int kFlagsNotUsedInLookup = (kFlagsICInLoopMask | kFlagsTypeMask | kFlagsCacheInPrototypeMapMask); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Code); }; // All heap objects have a Map that describes their structure. // A Map contains information about: // - Size information about the object // - How to iterate over an object (for garbage collection) class Map: public HeapObject { public: // Instance size. // Size in bytes or kVariableSizeSentinel if instances do not have // a fixed size. inline int instance_size(); inline void set_instance_size(int value); // Count of properties allocated in the object. inline int inobject_properties(); inline void set_inobject_properties(int value); // Count of property fields pre-allocated in the object when first allocated. inline int pre_allocated_property_fields(); inline void set_pre_allocated_property_fields(int value); // Instance type. inline InstanceType instance_type(); inline void set_instance_type(InstanceType value); // Tells how many unused property fields are available in the // instance (only used for JSObject in fast mode). inline int unused_property_fields(); inline void set_unused_property_fields(int value); // Bit field. inline byte bit_field(); inline void set_bit_field(byte value); // Bit field 2. inline byte bit_field2(); inline void set_bit_field2(byte value); // Tells whether the object in the prototype property will be used // for instances created from this function. If the prototype // property is set to a value that is not a JSObject, the prototype // property will not be used to create instances of the function. // See ECMA-262, 13.2.2. inline void set_non_instance_prototype(bool value); inline bool has_non_instance_prototype(); // Tells whether function has special prototype property. If not, prototype // property will not be created when accessed (will return undefined), // and construction from this function will not be allowed. inline void set_function_with_prototype(bool value); inline bool function_with_prototype(); // Tells whether the instance with this map should be ignored by the // __proto__ accessor. inline void set_is_hidden_prototype() { set_bit_field(bit_field() | (1 << kIsHiddenPrototype)); } inline bool is_hidden_prototype() { return ((1 << kIsHiddenPrototype) & bit_field()) != 0; } // Records and queries whether the instance has a named interceptor. inline void set_has_named_interceptor() { set_bit_field(bit_field() | (1 << kHasNamedInterceptor)); } inline bool has_named_interceptor() { return ((1 << kHasNamedInterceptor) & bit_field()) != 0; } // Records and queries whether the instance has an indexed interceptor. inline void set_has_indexed_interceptor() { set_bit_field(bit_field() | (1 << kHasIndexedInterceptor)); } inline bool has_indexed_interceptor() { return ((1 << kHasIndexedInterceptor) & bit_field()) != 0; } // Tells whether the instance is undetectable. // An undetectable object is a special class of JSObject: 'typeof' operator // returns undefined, ToBoolean returns false. Otherwise it behaves like // a normal JS object. It is useful for implementing undetectable // document.all in Firefox & Safari. // See https://bugzilla.mozilla.org/show_bug.cgi?id=248549. inline void set_is_undetectable() { set_bit_field(bit_field() | (1 << kIsUndetectable)); } inline bool is_undetectable() { return ((1 << kIsUndetectable) & bit_field()) != 0; } // Tells whether the instance has a call-as-function handler. inline void set_has_instance_call_handler() { set_bit_field(bit_field() | (1 << kHasInstanceCallHandler)); } inline bool has_instance_call_handler() { return ((1 << kHasInstanceCallHandler) & bit_field()) != 0; } inline void set_is_extensible(bool value); inline bool is_extensible(); // Tells whether the instance has fast elements. // Equivalent to instance->GetElementsKind() == FAST_ELEMENTS. inline void set_has_fast_elements(bool value) { if (value) { set_bit_field2(bit_field2() | (1 << kHasFastElements)); } else { set_bit_field2(bit_field2() & ~(1 << kHasFastElements)); } } inline bool has_fast_elements() { return ((1 << kHasFastElements) & bit_field2()) != 0; } // Tells whether the map is attached to SharedFunctionInfo // (for inobject slack tracking). inline void set_attached_to_shared_function_info(bool value); inline bool attached_to_shared_function_info(); // Tells whether the map is shared between objects that may have different // behavior. If true, the map should never be modified, instead a clone // should be created and modified. inline void set_is_shared(bool value); inline bool is_shared(); // Tells whether the instance needs security checks when accessing its // properties. inline void set_is_access_check_needed(bool access_check_needed); inline bool is_access_check_needed(); // [prototype]: implicit prototype object. DECL_ACCESSORS(prototype, Object) // [constructor]: points back to the function responsible for this map. DECL_ACCESSORS(constructor, Object) inline JSFunction* unchecked_constructor(); // [instance descriptors]: describes the object. DECL_ACCESSORS(instance_descriptors, DescriptorArray) // [stub cache]: contains stubs compiled for this map. DECL_ACCESSORS(code_cache, Object) MUST_USE_RESULT MaybeObject* CopyDropDescriptors(); MUST_USE_RESULT MaybeObject* CopyNormalized(PropertyNormalizationMode mode, NormalizedMapSharingMode sharing); // Returns a copy of the map, with all transitions dropped from the // instance descriptors. MUST_USE_RESULT MaybeObject* CopyDropTransitions(); // Returns this map if it has the fast elements bit set, otherwise // returns a copy of the map, with all transitions dropped from the // descriptors and the fast elements bit set. MUST_USE_RESULT inline MaybeObject* GetFastElementsMap(); // Returns this map if it has the fast elements bit cleared, // otherwise returns a copy of the map, with all transitions dropped // from the descriptors and the fast elements bit cleared. MUST_USE_RESULT inline MaybeObject* GetSlowElementsMap(); // Returns the property index for name (only valid for FAST MODE). int PropertyIndexFor(String* name); // Returns the next free property index (only valid for FAST MODE). int NextFreePropertyIndex(); // Returns the number of properties described in instance_descriptors. int NumberOfDescribedProperties(); // Casting. static inline Map* cast(Object* obj); // Locate an accessor in the instance descriptor. AccessorDescriptor* FindAccessor(String* name); // Code cache operations. // Clears the code cache. inline void ClearCodeCache(); // Update code cache. MUST_USE_RESULT MaybeObject* UpdateCodeCache(String* name, Code* code); // Returns the found code or undefined if absent. Object* FindInCodeCache(String* name, Code::Flags flags); // Returns the non-negative index of the code object if it is in the // cache and -1 otherwise. int IndexInCodeCache(Object* name, Code* code); // Removes a code object from the code cache at the given index. void RemoveFromCodeCache(String* name, Code* code, int index); // For every transition in this map, makes the transition's // target's prototype pointer point back to this map. // This is undone in MarkCompactCollector::ClearNonLiveTransitions(). void CreateBackPointers(); // Set all map transitions from this map to dead maps to null. // Also, restore the original prototype on the targets of these // transitions, so that we do not process this map again while // following back pointers. void ClearNonLiveTransitions(Object* real_prototype); // Dispatched behavior. #ifdef DEBUG void MapPrint(); void MapVerify(); void SharedMapVerify(); #endif inline int visitor_id(); inline void set_visitor_id(int visitor_id); typedef void (*TraverseCallback)(Map* map, void* data); void TraverseTransitionTree(TraverseCallback callback, void* data); static const int kMaxPreAllocatedPropertyFields = 255; // Layout description. static const int kInstanceSizesOffset = HeapObject::kHeaderSize; static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize; static const int kPrototypeOffset = kInstanceAttributesOffset + kIntSize; static const int kConstructorOffset = kPrototypeOffset + kPointerSize; static const int kInstanceDescriptorsOffset = kConstructorOffset + kPointerSize; static const int kCodeCacheOffset = kInstanceDescriptorsOffset + kPointerSize; static const int kPadStart = kCodeCacheOffset + kPointerSize; static const int kSize = MAP_POINTER_ALIGN(kPadStart); // Layout of pointer fields. Heap iteration code relies on them // being continiously allocated. static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset; static const int kPointerFieldsEndOffset = Map::kCodeCacheOffset + kPointerSize; // Byte offsets within kInstanceSizesOffset. static const int kInstanceSizeOffset = kInstanceSizesOffset + 0; static const int kInObjectPropertiesByte = 1; static const int kInObjectPropertiesOffset = kInstanceSizesOffset + kInObjectPropertiesByte; static const int kPreAllocatedPropertyFieldsByte = 2; static const int kPreAllocatedPropertyFieldsOffset = kInstanceSizesOffset + kPreAllocatedPropertyFieldsByte; static const int kVisitorIdByte = 3; static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte; // Byte offsets within kInstanceAttributesOffset attributes. static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0; static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 1; static const int kBitFieldOffset = kInstanceAttributesOffset + 2; static const int kBitField2Offset = kInstanceAttributesOffset + 3; STATIC_CHECK(kInstanceTypeOffset == Internals::kMapInstanceTypeOffset); // Bit positions for bit field. static const int kUnused = 0; // To be used for marking recently used maps. static const int kHasNonInstancePrototype = 1; static const int kIsHiddenPrototype = 2; static const int kHasNamedInterceptor = 3; static const int kHasIndexedInterceptor = 4; static const int kIsUndetectable = 5; static const int kHasInstanceCallHandler = 6; static const int kIsAccessCheckNeeded = 7; // Bit positions for bit field 2 static const int kIsExtensible = 0; static const int kFunctionWithPrototype = 1; static const int kHasFastElements = 2; static const int kStringWrapperSafeForDefaultValueOf = 3; static const int kAttachedToSharedFunctionInfo = 4; static const int kIsShared = 5; // Layout of the default cache. It holds alternating name and code objects. static const int kCodeCacheEntrySize = 2; static const int kCodeCacheEntryNameOffset = 0; static const int kCodeCacheEntryCodeOffset = 1; typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Map); }; // An abstract superclass, a marker class really, for simple structure classes. // It doesn't carry much functionality but allows struct classes to me // identified in the type system. class Struct: public HeapObject { public: inline void InitializeBody(int object_size); static inline Struct* cast(Object* that); }; // Script describes a script which has been added to the VM. class Script: public Struct { public: // Script types. enum Type { TYPE_NATIVE = 0, TYPE_EXTENSION = 1, TYPE_NORMAL = 2 }; // Script compilation types. enum CompilationType { COMPILATION_TYPE_HOST = 0, COMPILATION_TYPE_EVAL = 1 }; // [source]: the script source. DECL_ACCESSORS(source, Object) // [name]: the script name. DECL_ACCESSORS(name, Object) // [id]: the script id. DECL_ACCESSORS(id, Object) // [line_offset]: script line offset in resource from where it was extracted. DECL_ACCESSORS(line_offset, Smi) // [column_offset]: script column offset in resource from where it was // extracted. DECL_ACCESSORS(column_offset, Smi) // [data]: additional data associated with this script. DECL_ACCESSORS(data, Object) // [context_data]: context data for the context this script was compiled in. DECL_ACCESSORS(context_data, Object) // [wrapper]: the wrapper cache. DECL_ACCESSORS(wrapper, Proxy) // [type]: the script type. DECL_ACCESSORS(type, Smi) // [compilation]: how the the script was compiled. DECL_ACCESSORS(compilation_type, Smi) // [line_ends]: FixedArray of line ends positions. DECL_ACCESSORS(line_ends, Object) // [eval_from_shared]: for eval scripts the shared funcion info for the // function from which eval was called. DECL_ACCESSORS(eval_from_shared, Object) // [eval_from_instructions_offset]: the instruction offset in the code for the // function from which eval was called where eval was called. DECL_ACCESSORS(eval_from_instructions_offset, Smi) static inline Script* cast(Object* obj); // If script source is an external string, check that the underlying // resource is accessible. Otherwise, always return true. inline bool HasValidSource(); #ifdef DEBUG void ScriptPrint(); void ScriptVerify(); #endif static const int kSourceOffset = HeapObject::kHeaderSize; static const int kNameOffset = kSourceOffset + kPointerSize; static const int kLineOffsetOffset = kNameOffset + kPointerSize; static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize; static const int kDataOffset = kColumnOffsetOffset + kPointerSize; static const int kContextOffset = kDataOffset + kPointerSize; static const int kWrapperOffset = kContextOffset + kPointerSize; static const int kTypeOffset = kWrapperOffset + kPointerSize; static const int kCompilationTypeOffset = kTypeOffset + kPointerSize; static const int kLineEndsOffset = kCompilationTypeOffset + kPointerSize; static const int kIdOffset = kLineEndsOffset + kPointerSize; static const int kEvalFromSharedOffset = kIdOffset + kPointerSize; static const int kEvalFrominstructionsOffsetOffset = kEvalFromSharedOffset + kPointerSize; static const int kSize = kEvalFrominstructionsOffsetOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Script); }; // SharedFunctionInfo describes the JSFunction information that can be // shared by multiple instances of the function. class SharedFunctionInfo: public HeapObject { public: // [name]: Function name. DECL_ACCESSORS(name, Object) // [code]: Function code. DECL_ACCESSORS(code, Code) // [scope_info]: Scope info. DECL_ACCESSORS(scope_info, SerializedScopeInfo) // [construct stub]: Code stub for constructing instances of this function. DECL_ACCESSORS(construct_stub, Code) inline Code* unchecked_code(); // Returns if this function has been compiled to native code yet. inline bool is_compiled(); // [length]: The function length - usually the number of declared parameters. // Use up to 2^30 parameters. inline int length(); inline void set_length(int value); // [formal parameter count]: The declared number of parameters. inline int formal_parameter_count(); inline void set_formal_parameter_count(int value); // Set the formal parameter count so the function code will be // called without using argument adaptor frames. inline void DontAdaptArguments(); // [expected_nof_properties]: Expected number of properties for the function. inline int expected_nof_properties(); inline void set_expected_nof_properties(int value); // Inobject slack tracking is the way to reclaim unused inobject space. // // The instance size is initially determined by adding some slack to // expected_nof_properties (to allow for a few extra properties added // after the constructor). There is no guarantee that the extra space // will not be wasted. // // Here is the algorithm to reclaim the unused inobject space: // - Detect the first constructor call for this SharedFunctionInfo. // When it happens enter the "in progress" state: remember the // constructor's initial_map and install a special construct stub that // counts constructor calls. // - While the tracking is in progress create objects filled with // one_pointer_filler_map instead of undefined_value. This way they can be // resized quickly and safely. // - Once enough (kGenerousAllocationCount) objects have been created // compute the 'slack' (traverse the map transition tree starting from the // initial_map and find the lowest value of unused_property_fields). // - Traverse the transition tree again and decrease the instance size // of every map. Existing objects will resize automatically (they are // filled with one_pointer_filler_map). All further allocations will // use the adjusted instance size. // - Decrease expected_nof_properties so that an allocations made from // another context will use the adjusted instance size too. // - Exit "in progress" state by clearing the reference to the initial_map // and setting the regular construct stub (generic or inline). // // The above is the main event sequence. Some special cases are possible // while the tracking is in progress: // // - GC occurs. // Check if the initial_map is referenced by any live objects (except this // SharedFunctionInfo). If it is, continue tracking as usual. // If it is not, clear the reference and reset the tracking state. The // tracking will be initiated again on the next constructor call. // // - The constructor is called from another context. // Immediately complete the tracking, perform all the necessary changes // to maps. This is necessary because there is no efficient way to track // multiple initial_maps. // Proceed to create an object in the current context (with the adjusted // size). // // - A different constructor function sharing the same SharedFunctionInfo is // called in the same context. This could be another closure in the same // context, or the first function could have been disposed. // This is handled the same way as the previous case. // // Important: inobject slack tracking is not attempted during the snapshot // creation. static const int kGenerousAllocationCount = 8; // [construction_count]: Counter for constructor calls made during // the tracking phase. inline int construction_count(); inline void set_construction_count(int value); // [initial_map]: initial map of the first function called as a constructor. // Saved for the duration of the tracking phase. // This is a weak link (GC resets it to undefined_value if no other live // object reference this map). DECL_ACCESSORS(initial_map, Object) // True if the initial_map is not undefined and the countdown stub is // installed. inline bool IsInobjectSlackTrackingInProgress(); // Starts the tracking. // Stores the initial map and installs the countdown stub. // IsInobjectSlackTrackingInProgress is normally true after this call, // except when tracking have not been started (e.g. the map has no unused // properties or the snapshot is being built). void StartInobjectSlackTracking(Map* map); // Completes the tracking. // IsInobjectSlackTrackingInProgress is false after this call. void CompleteInobjectSlackTracking(); // Clears the initial_map before the GC marking phase to ensure the reference // is weak. IsInobjectSlackTrackingInProgress is false after this call. void DetachInitialMap(); // Restores the link to the initial map after the GC marking phase. // IsInobjectSlackTrackingInProgress is true after this call. void AttachInitialMap(Map* map); // False if there are definitely no live objects created from this function. // True if live objects _may_ exist (existence not guaranteed). // May go back from true to false after GC. inline bool live_objects_may_exist(); inline void set_live_objects_may_exist(bool value); // [instance class name]: class name for instances. DECL_ACCESSORS(instance_class_name, Object) // [function data]: This field holds some additional data for function. // Currently it either has FunctionTemplateInfo to make benefit the API // or Smi identifying a custom call generator. // In the long run we don't want all functions to have this field but // we can fix that when we have a better model for storing hidden data // on objects. DECL_ACCESSORS(function_data, Object) inline bool IsApiFunction(); inline FunctionTemplateInfo* get_api_func_data(); inline bool HasCustomCallGenerator(); inline int custom_call_generator_id(); // [script info]: Script from which the function originates. DECL_ACCESSORS(script, Object) // [num_literals]: Number of literals used by this function. inline int num_literals(); inline void set_num_literals(int value); // [start_position_and_type]: Field used to store both the source code // position, whether or not the function is a function expression, // and whether or not the function is a toplevel function. The two // least significants bit indicates whether the function is an // expression and the rest contains the source code position. inline int start_position_and_type(); inline void set_start_position_and_type(int value); // [debug info]: Debug information. DECL_ACCESSORS(debug_info, Object) // [inferred name]: Name inferred from variable or property // assignment of this function. Used to facilitate debugging and // profiling of JavaScript code written in OO style, where almost // all functions are anonymous but are assigned to object // properties. DECL_ACCESSORS(inferred_name, String) // The function's name if it is non-empty, otherwise the inferred name. String* DebugName(); // Position of the 'function' token in the script source. inline int function_token_position(); inline void set_function_token_position(int function_token_position); // Position of this function in the script source. inline int start_position(); inline void set_start_position(int start_position); // End position of this function in the script source. inline int end_position(); inline void set_end_position(int end_position); // Is this function a function expression in the source code. inline bool is_expression(); inline void set_is_expression(bool value); // Is this function a top-level function (scripts, evals). inline bool is_toplevel(); inline void set_is_toplevel(bool value); // Bit field containing various information collected by the compiler to // drive optimization. inline int compiler_hints(); inline void set_compiler_hints(int value); // Add information on assignments of the form this.x = ...; void SetThisPropertyAssignmentsInfo( bool has_only_simple_this_property_assignments, FixedArray* this_property_assignments); // Clear information on assignments of the form this.x = ...; void ClearThisPropertyAssignmentsInfo(); // Indicate that this function only consists of assignments of the form // this.x = y; where y is either a constant or refers to an argument. inline bool has_only_simple_this_property_assignments(); inline bool try_full_codegen(); inline void set_try_full_codegen(bool flag); // Indicates if this function can be lazy compiled. // This is used to determine if we can safely flush code from a function // when doing GC if we expect that the function will no longer be used. inline bool allows_lazy_compilation(); inline void set_allows_lazy_compilation(bool flag); // Indicates how many full GCs this function has survived with assigned // code object. Used to determine when it is relatively safe to flush // this code object and replace it with lazy compilation stub. // Age is reset when GC notices that the code object is referenced // from the stack or compilation cache. inline int code_age(); inline void set_code_age(int age); // Check whether a inlined constructor can be generated with the given // prototype. bool CanGenerateInlineConstructor(Object* prototype); // Prevents further attempts to generate inline constructors. // To be called if generation failed for any reason. void ForbidInlineConstructor(); // For functions which only contains this property assignments this provides // access to the names for the properties assigned. DECL_ACCESSORS(this_property_assignments, Object) inline int this_property_assignments_count(); inline void set_this_property_assignments_count(int value); String* GetThisPropertyAssignmentName(int index); bool IsThisPropertyAssignmentArgument(int index); int GetThisPropertyAssignmentArgument(int index); Object* GetThisPropertyAssignmentConstant(int index); // [source code]: Source code for the function. bool HasSourceCode(); Object* GetSourceCode(); // Calculate the instance size. int CalculateInstanceSize(); // Calculate the number of in-object properties. int CalculateInObjectProperties(); // Dispatched behavior. // Set max_length to -1 for unlimited length. void SourceCodePrint(StringStream* accumulator, int max_length); #ifdef DEBUG void SharedFunctionInfoPrint(); void SharedFunctionInfoVerify(); #endif // Casting. static inline SharedFunctionInfo* cast(Object* obj); // Constants. static const int kDontAdaptArgumentsSentinel = -1; // Layout description. // Pointer fields. static const int kNameOffset = HeapObject::kHeaderSize; static const int kCodeOffset = kNameOffset + kPointerSize; static const int kScopeInfoOffset = kCodeOffset + kPointerSize; static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize; static const int kInstanceClassNameOffset = kConstructStubOffset + kPointerSize; static const int kFunctionDataOffset = kInstanceClassNameOffset + kPointerSize; static const int kScriptOffset = kFunctionDataOffset + kPointerSize; static const int kDebugInfoOffset = kScriptOffset + kPointerSize; static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize; static const int kInitialMapOffset = kInferredNameOffset + kPointerSize; static const int kThisPropertyAssignmentsOffset = kInitialMapOffset + kPointerSize; #if V8_HOST_ARCH_32_BIT // Smi fields. static const int kLengthOffset = kThisPropertyAssignmentsOffset + kPointerSize; static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize; static const int kExpectedNofPropertiesOffset = kFormalParameterCountOffset + kPointerSize; static const int kNumLiteralsOffset = kExpectedNofPropertiesOffset + kPointerSize; static const int kStartPositionAndTypeOffset = kNumLiteralsOffset + kPointerSize; static const int kEndPositionOffset = kStartPositionAndTypeOffset + kPointerSize; static const int kFunctionTokenPositionOffset = kEndPositionOffset + kPointerSize; static const int kCompilerHintsOffset = kFunctionTokenPositionOffset + kPointerSize; static const int kThisPropertyAssignmentsCountOffset = kCompilerHintsOffset + kPointerSize; // Total size. static const int kSize = kThisPropertyAssignmentsCountOffset + kPointerSize; #else // The only reason to use smi fields instead of int fields // is to allow iteration without maps decoding during // garbage collections. // To avoid wasting space on 64-bit architectures we use // the following trick: we group integer fields into pairs // First integer in each pair is shifted left by 1. // By doing this we guarantee that LSB of each kPointerSize aligned // word is not set and thus this word cannot be treated as pointer // to HeapObject during old space traversal. static const int kLengthOffset = kThisPropertyAssignmentsOffset + kPointerSize; static const int kFormalParameterCountOffset = kLengthOffset + kIntSize; static const int kExpectedNofPropertiesOffset = kFormalParameterCountOffset + kIntSize; static const int kNumLiteralsOffset = kExpectedNofPropertiesOffset + kIntSize; static const int kEndPositionOffset = kNumLiteralsOffset + kIntSize; static const int kStartPositionAndTypeOffset = kEndPositionOffset + kIntSize; static const int kFunctionTokenPositionOffset = kStartPositionAndTypeOffset + kIntSize; static const int kCompilerHintsOffset = kFunctionTokenPositionOffset + kIntSize; static const int kThisPropertyAssignmentsCountOffset = kCompilerHintsOffset + kIntSize; // Total size. static const int kSize = kThisPropertyAssignmentsCountOffset + kIntSize; #endif // The construction counter for inobject slack tracking is stored in the // most significant byte of compiler_hints which is otherwise unused. // Its offset depends on the endian-ness of the architecture. #if __BYTE_ORDER == __LITTLE_ENDIAN static const int kConstructionCountOffset = kCompilerHintsOffset + 3; #elif __BYTE_ORDER == __BIG_ENDIAN static const int kConstructionCountOffset = kCompilerHintsOffset + 0; #else #error Unknown byte ordering #endif static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize); typedef FixedBodyDescriptor BodyDescriptor; private: // Bit positions in start_position_and_type. // The source code start position is in the 30 most significant bits of // the start_position_and_type field. static const int kIsExpressionBit = 0; static const int kIsTopLevelBit = 1; static const int kStartPositionShift = 2; static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1); // Bit positions in compiler_hints. static const int kHasOnlySimpleThisPropertyAssignments = 0; static const int kTryFullCodegen = 1; static const int kAllowLazyCompilation = 2; static const int kLiveObjectsMayExist = 3; static const int kCodeAgeShift = 4; static const int kCodeAgeMask = 7; DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo); }; // JSFunction describes JavaScript functions. class JSFunction: public JSObject { public: // [prototype_or_initial_map]: DECL_ACCESSORS(prototype_or_initial_map, Object) // [shared_function_info]: The information about the function that // can be shared by instances. DECL_ACCESSORS(shared, SharedFunctionInfo) inline SharedFunctionInfo* unchecked_shared(); // [context]: The context for this function. inline Context* context(); inline Object* unchecked_context(); inline void set_context(Object* context); // [code]: The generated code object for this function. Executed // when the function is invoked, e.g. foo() or new foo(). See // [[Call]] and [[Construct]] description in ECMA-262, section // 8.6.2, page 27. inline Code* code(); inline void set_code(Code* value); inline Code* unchecked_code(); // Tells whether this function is builtin. inline bool IsBuiltin(); // [literals]: Fixed array holding the materialized literals. // // If the function contains object, regexp or array literals, the // literals array prefix contains the object, regexp, and array // function to be used when creating these literals. This is // necessary so that we do not dynamically lookup the object, regexp // or array functions. Performing a dynamic lookup, we might end up // using the functions from a new context that we should not have // access to. DECL_ACCESSORS(literals, FixedArray) // The initial map for an object created by this constructor. inline Map* initial_map(); inline void set_initial_map(Map* value); inline bool has_initial_map(); // Get and set the prototype property on a JSFunction. If the // function has an initial map the prototype is set on the initial // map. Otherwise, the prototype is put in the initial map field // until an initial map is needed. inline bool has_prototype(); inline bool has_instance_prototype(); inline Object* prototype(); inline Object* instance_prototype(); Object* SetInstancePrototype(Object* value); MUST_USE_RESULT MaybeObject* SetPrototype(Object* value); // After prototype is removed, it will not be created when accessed, and // [[Construct]] from this function will not be allowed. Object* RemovePrototype(); inline bool should_have_prototype(); // Accessor for this function's initial map's [[class]] // property. This is primarily used by ECMA native functions. This // method sets the class_name field of this function's initial map // to a given value. It creates an initial map if this function does // not have one. Note that this method does not copy the initial map // if it has one already, but simply replaces it with the new value. // Instances created afterwards will have a map whose [[class]] is // set to 'value', but there is no guarantees on instances created // before. Object* SetInstanceClassName(String* name); // Returns if this function has been compiled to native code yet. inline bool is_compiled(); // Casting. static inline JSFunction* cast(Object* obj); // Iterates the objects, including code objects indirectly referenced // through pointers to the first instruction in the code object. void JSFunctionIterateBody(int object_size, ObjectVisitor* v); // Dispatched behavior. #ifdef DEBUG void JSFunctionPrint(); void JSFunctionVerify(); #endif // Returns the number of allocated literals. inline int NumberOfLiterals(); // Retrieve the global context from a function's literal array. static Context* GlobalContextFromLiterals(FixedArray* literals); // Layout descriptors. static const int kCodeEntryOffset = JSObject::kHeaderSize; static const int kPrototypeOrInitialMapOffset = kCodeEntryOffset + kPointerSize; static const int kSharedFunctionInfoOffset = kPrototypeOrInitialMapOffset + kPointerSize; static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize; static const int kLiteralsOffset = kContextOffset + kPointerSize; static const int kSize = kLiteralsOffset + kPointerSize; // Layout of the literals array. static const int kLiteralsPrefixSize = 1; static const int kLiteralGlobalContextIndex = 0; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction); }; // JSGlobalProxy's prototype must be a JSGlobalObject or null, // and the prototype is hidden. JSGlobalProxy always delegates // property accesses to its prototype if the prototype is not null. // // A JSGlobalProxy can be reinitialized which will preserve its identity. // // Accessing a JSGlobalProxy requires security check. class JSGlobalProxy : public JSObject { public: // [context]: the owner global context of this proxy object. // It is null value if this object is not used by any context. DECL_ACCESSORS(context, Object) // Casting. static inline JSGlobalProxy* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void JSGlobalProxyPrint(); void JSGlobalProxyVerify(); #endif // Layout description. static const int kContextOffset = JSObject::kHeaderSize; static const int kSize = kContextOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy); }; // Forward declaration. class JSBuiltinsObject; // Common super class for JavaScript global objects and the special // builtins global objects. class GlobalObject: public JSObject { public: // [builtins]: the object holding the runtime routines written in JS. DECL_ACCESSORS(builtins, JSBuiltinsObject) // [global context]: the global context corresponding to this global object. DECL_ACCESSORS(global_context, Context) // [global receiver]: the global receiver object of the context DECL_ACCESSORS(global_receiver, JSObject) // Retrieve the property cell used to store a property. Object* GetPropertyCell(LookupResult* result); // This is like GetProperty, but is used when you know the lookup won't fail // by throwing an exception. This is for the debug and builtins global // objects, where it is known which properties can be expected to be present // on the object. Object* GetPropertyNoExceptionThrown(String* key) { Object* answer = GetProperty(key)->ToObjectUnchecked(); return answer; } // Ensure that the global object has a cell for the given property name. MUST_USE_RESULT MaybeObject* EnsurePropertyCell(String* name); // Casting. static inline GlobalObject* cast(Object* obj); // Layout description. static const int kBuiltinsOffset = JSObject::kHeaderSize; static const int kGlobalContextOffset = kBuiltinsOffset + kPointerSize; static const int kGlobalReceiverOffset = kGlobalContextOffset + kPointerSize; static const int kHeaderSize = kGlobalReceiverOffset + kPointerSize; private: friend class AGCCVersionRequiresThisClassToHaveAFriendSoHereItIs; DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject); }; // JavaScript global object. class JSGlobalObject: public GlobalObject { public: // Casting. static inline JSGlobalObject* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void JSGlobalObjectPrint(); void JSGlobalObjectVerify(); #endif // Layout description. static const int kSize = GlobalObject::kHeaderSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject); }; // Builtins global object which holds the runtime routines written in // JavaScript. class JSBuiltinsObject: public GlobalObject { public: // Accessors for the runtime routines written in JavaScript. inline Object* javascript_builtin(Builtins::JavaScript id); inline void set_javascript_builtin(Builtins::JavaScript id, Object* value); // Accessors for code of the runtime routines written in JavaScript. inline Code* javascript_builtin_code(Builtins::JavaScript id); inline void set_javascript_builtin_code(Builtins::JavaScript id, Code* value); // Casting. static inline JSBuiltinsObject* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void JSBuiltinsObjectPrint(); void JSBuiltinsObjectVerify(); #endif // Layout description. The size of the builtins object includes // room for two pointers per runtime routine written in javascript // (function and code object). static const int kJSBuiltinsCount = Builtins::id_count; static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize; static const int kJSBuiltinsCodeOffset = GlobalObject::kHeaderSize + (kJSBuiltinsCount * kPointerSize); static const int kSize = kJSBuiltinsCodeOffset + (kJSBuiltinsCount * kPointerSize); static int OffsetOfFunctionWithId(Builtins::JavaScript id) { return kJSBuiltinsOffset + id * kPointerSize; } static int OffsetOfCodeWithId(Builtins::JavaScript id) { return kJSBuiltinsCodeOffset + id * kPointerSize; } private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSBuiltinsObject); }; // Representation for JS Wrapper objects, String, Number, Boolean, Date, etc. class JSValue: public JSObject { public: // [value]: the object being wrapped. DECL_ACCESSORS(value, Object) // Casting. static inline JSValue* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void JSValuePrint(); void JSValueVerify(); #endif // Layout description. static const int kValueOffset = JSObject::kHeaderSize; static const int kSize = kValueOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue); }; // Regular expressions // The regular expression holds a single reference to a FixedArray in // the kDataOffset field. // The FixedArray contains the following data: // - tag : type of regexp implementation (not compiled yet, atom or irregexp) // - reference to the original source string // - reference to the original flag string // If it is an atom regexp // - a reference to a literal string to search for // If it is an irregexp regexp: // - a reference to code for ASCII inputs (bytecode or compiled). // - a reference to code for UC16 inputs (bytecode or compiled). // - max number of registers used by irregexp implementations. // - number of capture registers (output values) of the regexp. class JSRegExp: public JSObject { public: // Meaning of Type: // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet. // ATOM: A simple string to match against using an indexOf operation. // IRREGEXP: Compiled with Irregexp. // IRREGEXP_NATIVE: Compiled to native code with Irregexp. enum Type { NOT_COMPILED, ATOM, IRREGEXP }; enum Flag { NONE = 0, GLOBAL = 1, IGNORE_CASE = 2, MULTILINE = 4 }; class Flags { public: explicit Flags(uint32_t value) : value_(value) { } bool is_global() { return (value_ & GLOBAL) != 0; } bool is_ignore_case() { return (value_ & IGNORE_CASE) != 0; } bool is_multiline() { return (value_ & MULTILINE) != 0; } uint32_t value() { return value_; } private: uint32_t value_; }; DECL_ACCESSORS(data, Object) inline Type TypeTag(); inline int CaptureCount(); inline Flags GetFlags(); inline String* Pattern(); inline Object* DataAt(int index); // Set implementation data after the object has been prepared. inline void SetDataAt(int index, Object* value); static int code_index(bool is_ascii) { if (is_ascii) { return kIrregexpASCIICodeIndex; } else { return kIrregexpUC16CodeIndex; } } static inline JSRegExp* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void JSRegExpVerify(); #endif static const int kDataOffset = JSObject::kHeaderSize; static const int kSize = kDataOffset + kPointerSize; // Indices in the data array. static const int kTagIndex = 0; static const int kSourceIndex = kTagIndex + 1; static const int kFlagsIndex = kSourceIndex + 1; static const int kDataIndex = kFlagsIndex + 1; // The data fields are used in different ways depending on the // value of the tag. // Atom regexps (literal strings). static const int kAtomPatternIndex = kDataIndex; static const int kAtomDataSize = kAtomPatternIndex + 1; // Irregexp compiled code or bytecode for ASCII. If compilation // fails, this fields hold an exception object that should be // thrown if the regexp is used again. static const int kIrregexpASCIICodeIndex = kDataIndex; // Irregexp compiled code or bytecode for UC16. If compilation // fails, this fields hold an exception object that should be // thrown if the regexp is used again. static const int kIrregexpUC16CodeIndex = kDataIndex + 1; // Maximal number of registers used by either ASCII or UC16. // Only used to check that there is enough stack space static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 2; // Number of captures in the compiled regexp. static const int kIrregexpCaptureCountIndex = kDataIndex + 3; static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1; // Offsets directly into the data fixed array. static const int kDataTagOffset = FixedArray::kHeaderSize + kTagIndex * kPointerSize; static const int kDataAsciiCodeOffset = FixedArray::kHeaderSize + kIrregexpASCIICodeIndex * kPointerSize; static const int kDataUC16CodeOffset = FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize; static const int kIrregexpCaptureCountOffset = FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize; // In-object fields. static const int kSourceFieldIndex = 0; static const int kGlobalFieldIndex = 1; static const int kIgnoreCaseFieldIndex = 2; static const int kMultilineFieldIndex = 3; static const int kLastIndexFieldIndex = 4; static const int kInObjectFieldCount = 5; }; class CompilationCacheShape { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 2; }; class CompilationCacheTable: public HashTable { public: // Find cached value for a string key, otherwise return null. Object* Lookup(String* src); Object* LookupEval(String* src, Context* context); Object* LookupRegExp(String* source, JSRegExp::Flags flags); MaybeObject* Put(String* src, Object* value); MaybeObject* PutEval(String* src, Context* context, Object* value); MaybeObject* PutRegExp(String* src, JSRegExp::Flags flags, FixedArray* value); static inline CompilationCacheTable* cast(Object* obj); private: DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable); }; class CodeCache: public Struct { public: DECL_ACCESSORS(default_cache, FixedArray) DECL_ACCESSORS(normal_type_cache, Object) // Add the code object to the cache. MUST_USE_RESULT MaybeObject* Update(String* name, Code* code); // Lookup code object in the cache. Returns code object if found and undefined // if not. Object* Lookup(String* name, Code::Flags flags); // Get the internal index of a code object in the cache. Returns -1 if the // code object is not in that cache. This index can be used to later call // RemoveByIndex. The cache cannot be modified between a call to GetIndex and // RemoveByIndex. int GetIndex(Object* name, Code* code); // Remove an object from the cache with the provided internal index. void RemoveByIndex(Object* name, Code* code, int index); static inline CodeCache* cast(Object* obj); #ifdef DEBUG void CodeCachePrint(); void CodeCacheVerify(); #endif static const int kDefaultCacheOffset = HeapObject::kHeaderSize; static const int kNormalTypeCacheOffset = kDefaultCacheOffset + kPointerSize; static const int kSize = kNormalTypeCacheOffset + kPointerSize; private: MUST_USE_RESULT MaybeObject* UpdateDefaultCache(String* name, Code* code); MUST_USE_RESULT MaybeObject* UpdateNormalTypeCache(String* name, Code* code); Object* LookupDefaultCache(String* name, Code::Flags flags); Object* LookupNormalTypeCache(String* name, Code::Flags flags); // Code cache layout of the default cache. Elements are alternating name and // code objects for non normal load/store/call IC's. static const int kCodeCacheEntrySize = 2; static const int kCodeCacheEntryNameOffset = 0; static const int kCodeCacheEntryCodeOffset = 1; DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache); }; class CodeCacheHashTableShape { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 2; }; class CodeCacheHashTable: public HashTable { public: Object* Lookup(String* name, Code::Flags flags); MUST_USE_RESULT MaybeObject* Put(String* name, Code* code); int GetIndex(String* name, Code::Flags flags); void RemoveByIndex(int index); static inline CodeCacheHashTable* cast(Object* obj); // Initial size of the fixed array backing the hash table. static const int kInitialSize = 64; private: DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable); }; enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS}; enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL}; class StringHasher { public: inline StringHasher(int length); // Returns true if the hash of this string can be computed without // looking at the contents. inline bool has_trivial_hash(); // Add a character to the hash and update the array index calculation. inline void AddCharacter(uc32 c); // Adds a character to the hash but does not update the array index // calculation. This can only be called when it has been verified // that the input is not an array index. inline void AddCharacterNoIndex(uc32 c); // Returns the value to store in the hash field of a string with // the given length and contents. uint32_t GetHashField(); // Returns true if the characters seen so far make up a legal array // index. bool is_array_index() { return is_array_index_; } bool is_valid() { return is_valid_; } void invalidate() { is_valid_ = false; } // Calculated hash value for a string consisting of 1 to // String::kMaxArrayIndexSize digits with no leading zeros (except "0"). // value is represented decimal value. static uint32_t MakeArrayIndexHash(uint32_t value, int length); private: uint32_t array_index() { ASSERT(is_array_index()); return array_index_; } inline uint32_t GetHash(); int length_; uint32_t raw_running_hash_; uint32_t array_index_; bool is_array_index_; bool is_first_char_; bool is_valid_; friend class TwoCharHashTableKey; }; // The characteristics of a string are stored in its map. Retrieving these // few bits of information is moderately expensive, involving two memory // loads where the second is dependent on the first. To improve efficiency // the shape of the string is given its own class so that it can be retrieved // once and used for several string operations. A StringShape is small enough // to be passed by value and is immutable, but be aware that flattening a // string can potentially alter its shape. Also be aware that a GC caused by // something else can alter the shape of a string due to ConsString // shortcutting. Keeping these restrictions in mind has proven to be error- // prone and so we no longer put StringShapes in variables unless there is a // concrete performance benefit at that particular point in the code. class StringShape BASE_EMBEDDED { public: inline explicit StringShape(String* s); inline explicit StringShape(Map* s); inline explicit StringShape(InstanceType t); inline bool IsSequential(); inline bool IsExternal(); inline bool IsCons(); inline bool IsExternalAscii(); inline bool IsExternalTwoByte(); inline bool IsSequentialAscii(); inline bool IsSequentialTwoByte(); inline bool IsSymbol(); inline StringRepresentationTag representation_tag(); inline uint32_t full_representation_tag(); inline uint32_t size_tag(); #ifdef DEBUG inline uint32_t type() { return type_; } inline void invalidate() { valid_ = false; } inline bool valid() { return valid_; } #else inline void invalidate() { } #endif private: uint32_t type_; #ifdef DEBUG inline void set_valid() { valid_ = true; } bool valid_; #else inline void set_valid() { } #endif }; // The String abstract class captures JavaScript string values: // // Ecma-262: // 4.3.16 String Value // A string value is a member of the type String and is a finite // ordered sequence of zero or more 16-bit unsigned integer values. // // All string values have a length field. class String: public HeapObject { public: // Get and set the length of the string. inline int length(); inline void set_length(int value); // Get and set the hash field of the string. inline uint32_t hash_field(); inline void set_hash_field(uint32_t value); inline bool IsAsciiRepresentation(); inline bool IsTwoByteRepresentation(); // Returns whether this string has ascii chars, i.e. all of them can // be ascii encoded. This might be the case even if the string is // two-byte. Such strings may appear when the embedder prefers // two-byte external representations even for ascii data. // // NOTE: this should be considered only a hint. False negatives are // possible. inline bool HasOnlyAsciiChars(); // Get and set individual two byte chars in the string. inline void Set(int index, uint16_t value); // Get individual two byte char in the string. Repeated calls // to this method are not efficient unless the string is flat. inline uint16_t Get(int index); // Try to flatten the string. Checks first inline to see if it is // necessary. Does nothing if the string is not a cons string. // Flattening allocates a sequential string with the same data as // the given string and mutates the cons string to a degenerate // form, where the first component is the new sequential string and // the second component is the empty string. If allocation fails, // this function returns a failure. If flattening succeeds, this // function returns the sequential string that is now the first // component of the cons string. // // Degenerate cons strings are handled specially by the garbage // collector (see IsShortcutCandidate). // // Use FlattenString from Handles.cc to flatten even in case an // allocation failure happens. inline MaybeObject* TryFlatten(PretenureFlag pretenure = NOT_TENURED); // Convenience function. Has exactly the same behavior as // TryFlatten(), except in the case of failure returns the original // string. inline String* TryFlattenGetString(PretenureFlag pretenure = NOT_TENURED); Vector ToAsciiVector(); Vector ToUC16Vector(); // Mark the string as an undetectable object. It only applies to // ascii and two byte string types. bool MarkAsUndetectable(); // Return a substring. MUST_USE_RESULT MaybeObject* SubString(int from, int to, PretenureFlag pretenure = NOT_TENURED); // String equality operations. inline bool Equals(String* other); bool IsEqualTo(Vector str); // Return a UTF8 representation of the string. The string is null // terminated but may optionally contain nulls. Length is returned // in length_output if length_output is not a null pointer The string // should be nearly flat, otherwise the performance of this method may // be very slow (quadratic in the length). Setting robustness_flag to // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it // handles unexpected data without causing assert failures and it does not // do any heap allocations. This is useful when printing stack traces. SmartPointer ToCString(AllowNullsFlag allow_nulls, RobustnessFlag robustness_flag, int offset, int length, int* length_output = 0); SmartPointer ToCString( AllowNullsFlag allow_nulls = DISALLOW_NULLS, RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL, int* length_output = 0); int Utf8Length(); // Return a 16 bit Unicode representation of the string. // The string should be nearly flat, otherwise the performance of // of this method may be very bad. Setting robustness_flag to // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it // handles unexpected data without causing assert failures and it does not // do any heap allocations. This is useful when printing stack traces. SmartPointer ToWideCString( RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL); // Tells whether the hash code has been computed. inline bool HasHashCode(); // Returns a hash value used for the property table inline uint32_t Hash(); static uint32_t ComputeHashField(unibrow::CharacterStream* buffer, int length); static bool ComputeArrayIndex(unibrow::CharacterStream* buffer, uint32_t* index, int length); // Externalization. bool MakeExternal(v8::String::ExternalStringResource* resource); bool MakeExternal(v8::String::ExternalAsciiStringResource* resource); // Conversion. inline bool AsArrayIndex(uint32_t* index); // Casting. static inline String* cast(Object* obj); void PrintOn(FILE* out); // For use during stack traces. Performs rudimentary sanity check. bool LooksValid(); // Dispatched behavior. void StringShortPrint(StringStream* accumulator); #ifdef DEBUG void StringPrint(); void StringVerify(); #endif inline bool IsFlat(); // Layout description. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kHashFieldOffset = kLengthOffset + kPointerSize; static const int kSize = kHashFieldOffset + kPointerSize; // Maximum number of characters to consider when trying to convert a string // value into an array index. static const int kMaxArrayIndexSize = 10; // Max ascii char code. static const int kMaxAsciiCharCode = unibrow::Utf8::kMaxOneByteChar; static const unsigned kMaxAsciiCharCodeU = unibrow::Utf8::kMaxOneByteChar; static const int kMaxUC16CharCode = 0xffff; // Minimum length for a cons string. static const int kMinNonFlatLength = 13; // Mask constant for checking if a string has a computed hash code // and if it is an array index. The least significant bit indicates // whether a hash code has been computed. If the hash code has been // computed the 2nd bit tells whether the string can be used as an // array index. static const int kHashNotComputedMask = 1; static const int kIsNotArrayIndexMask = 1 << 1; static const int kNofHashBitFields = 2; // Shift constant retrieving hash code from hash field. static const int kHashShift = kNofHashBitFields; // Array index strings this short can keep their index in the hash // field. static const int kMaxCachedArrayIndexLength = 7; // For strings which are array indexes the hash value has the string length // mixed into the hash, mainly to avoid a hash value of zero which would be // the case for the string '0'. 24 bits are used for the array index value. static const int kArrayIndexValueBits = 24; static const int kArrayIndexLengthBits = kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields; STATIC_CHECK((kArrayIndexLengthBits > 0)); STATIC_CHECK(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits)); static const int kArrayIndexHashLengthShift = kArrayIndexValueBits + kNofHashBitFields; static const int kArrayIndexHashMask = (1 << kArrayIndexHashLengthShift) - 1; static const int kArrayIndexValueMask = ((1 << kArrayIndexValueBits) - 1) << kHashShift; // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we // could use a mask to test if the length of string is less than or equal to // kMaxCachedArrayIndexLength. STATIC_CHECK(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1)); static const int kContainsCachedArrayIndexMask = (~kMaxCachedArrayIndexLength << kArrayIndexHashLengthShift) | kIsNotArrayIndexMask; // Value of empty hash field indicating that the hash is not computed. static const int kEmptyHashField = kIsNotArrayIndexMask | kHashNotComputedMask; // Value of hash field containing computed hash equal to zero. static const int kZeroHash = kIsNotArrayIndexMask; // Maximal string length. static const int kMaxLength = (1 << (32 - 2)) - 1; // Max length for computing hash. For strings longer than this limit the // string length is used as the hash value. static const int kMaxHashCalcLength = 16383; // Limit for truncation in short printing. static const int kMaxShortPrintLength = 1024; // Support for regular expressions. const uc16* GetTwoByteData(); const uc16* GetTwoByteData(unsigned start); // Support for StringInputBuffer static const unibrow::byte* ReadBlock(String* input, unibrow::byte* util_buffer, unsigned capacity, unsigned* remaining, unsigned* offset); static const unibrow::byte* ReadBlock(String** input, unibrow::byte* util_buffer, unsigned capacity, unsigned* remaining, unsigned* offset); // Helper function for flattening strings. template static void WriteToFlat(String* source, sinkchar* sink, int from, int to); protected: class ReadBlockBuffer { public: ReadBlockBuffer(unibrow::byte* util_buffer_, unsigned cursor_, unsigned capacity_, unsigned remaining_) : util_buffer(util_buffer_), cursor(cursor_), capacity(capacity_), remaining(remaining_) { } unibrow::byte* util_buffer; unsigned cursor; unsigned capacity; unsigned remaining; }; static inline const unibrow::byte* ReadBlock(String* input, ReadBlockBuffer* buffer, unsigned* offset, unsigned max_chars); static void ReadBlockIntoBuffer(String* input, ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned max_chars); private: // Try to flatten the top level ConsString that is hiding behind this // string. This is a no-op unless the string is a ConsString. Flatten // mutates the ConsString and might return a failure. MUST_USE_RESULT MaybeObject* SlowTryFlatten(PretenureFlag pretenure); static inline bool IsHashFieldComputed(uint32_t field); // Slow case of String::Equals. This implementation works on any strings // but it is most efficient on strings that are almost flat. bool SlowEquals(String* other); // Slow case of AsArrayIndex. bool SlowAsArrayIndex(uint32_t* index); // Compute and set the hash code. uint32_t ComputeAndSetHash(); DISALLOW_IMPLICIT_CONSTRUCTORS(String); }; // The SeqString abstract class captures sequential string values. class SeqString: public String { public: // Casting. static inline SeqString* cast(Object* obj); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString); }; // The AsciiString class captures sequential ascii string objects. // Each character in the AsciiString is an ascii character. class SeqAsciiString: public SeqString { public: static const bool kHasAsciiEncoding = true; // Dispatched behavior. inline uint16_t SeqAsciiStringGet(int index); inline void SeqAsciiStringSet(int index, uint16_t value); // Get the address of the characters in this string. inline Address GetCharsAddress(); inline char* GetChars(); // Casting static inline SeqAsciiString* cast(Object* obj); // Garbage collection support. This method is called by the // garbage collector to compute the actual size of an AsciiString // instance. inline int SeqAsciiStringSize(InstanceType instance_type); // Computes the size for an AsciiString instance of a given length. static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize); } // Layout description. static const int kHeaderSize = String::kSize; static const int kAlignedSize = POINTER_SIZE_ALIGN(kHeaderSize); // Maximal memory usage for a single sequential ASCII string. static const int kMaxSize = 512 * MB; // Maximal length of a single sequential ASCII string. // Q.v. String::kMaxLength which is the maximal size of concatenated strings. static const int kMaxLength = (kMaxSize - kHeaderSize); // Support for StringInputBuffer. inline void SeqAsciiStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset, unsigned chars); inline const unibrow::byte* SeqAsciiStringReadBlock(unsigned* remaining, unsigned* offset, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqAsciiString); }; // The TwoByteString class captures sequential unicode string objects. // Each character in the TwoByteString is a two-byte uint16_t. class SeqTwoByteString: public SeqString { public: static const bool kHasAsciiEncoding = false; // Dispatched behavior. inline uint16_t SeqTwoByteStringGet(int index); inline void SeqTwoByteStringSet(int index, uint16_t value); // Get the address of the characters in this string. inline Address GetCharsAddress(); inline uc16* GetChars(); // For regexp code. const uint16_t* SeqTwoByteStringGetData(unsigned start); // Casting static inline SeqTwoByteString* cast(Object* obj); // Garbage collection support. This method is called by the // garbage collector to compute the actual size of a TwoByteString // instance. inline int SeqTwoByteStringSize(InstanceType instance_type); // Computes the size for a TwoByteString instance of a given length. static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize); } // Layout description. static const int kHeaderSize = String::kSize; static const int kAlignedSize = POINTER_SIZE_ALIGN(kHeaderSize); // Maximal memory usage for a single sequential two-byte string. static const int kMaxSize = 512 * MB; // Maximal length of a single sequential two-byte string. // Q.v. String::kMaxLength which is the maximal size of concatenated strings. static const int kMaxLength = (kMaxSize - kHeaderSize) / sizeof(uint16_t); // Support for StringInputBuffer. inline void SeqTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString); }; // The ConsString class describes string values built by using the // addition operator on strings. A ConsString is a pair where the // first and second components are pointers to other string values. // One or both components of a ConsString can be pointers to other // ConsStrings, creating a binary tree of ConsStrings where the leaves // are non-ConsString string values. The string value represented by // a ConsString can be obtained by concatenating the leaf string // values in a left-to-right depth-first traversal of the tree. class ConsString: public String { public: // First string of the cons cell. inline String* first(); // Doesn't check that the result is a string, even in debug mode. This is // useful during GC where the mark bits confuse the checks. inline Object* unchecked_first(); inline void set_first(String* first, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Second string of the cons cell. inline String* second(); // Doesn't check that the result is a string, even in debug mode. This is // useful during GC where the mark bits confuse the checks. inline Object* unchecked_second(); inline void set_second(String* second, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Dispatched behavior. uint16_t ConsStringGet(int index); // Casting. static inline ConsString* cast(Object* obj); // Layout description. static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize); static const int kSecondOffset = kFirstOffset + kPointerSize; static const int kSize = kSecondOffset + kPointerSize; // Support for StringInputBuffer. inline const unibrow::byte* ConsStringReadBlock(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); inline void ConsStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); // Minimum length for a cons string. static const int kMinLength = 13; typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString); }; // The ExternalString class describes string values that are backed by // a string resource that lies outside the V8 heap. ExternalStrings // consist of the length field common to all strings, a pointer to the // external resource. It is important to ensure (externally) that the // resource is not deallocated while the ExternalString is live in the // V8 heap. // // The API expects that all ExternalStrings are created through the // API. Therefore, ExternalStrings should not be used internally. class ExternalString: public String { public: // Casting static inline ExternalString* cast(Object* obj); // Layout description. static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize); static const int kSize = kResourceOffset + kPointerSize; STATIC_CHECK(kResourceOffset == Internals::kStringResourceOffset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString); }; // The ExternalAsciiString class is an external string backed by an // ASCII string. class ExternalAsciiString: public ExternalString { public: static const bool kHasAsciiEncoding = true; typedef v8::String::ExternalAsciiStringResource Resource; // The underlying resource. inline Resource* resource(); inline void set_resource(Resource* buffer); // Dispatched behavior. uint16_t ExternalAsciiStringGet(int index); // Casting. static inline ExternalAsciiString* cast(Object* obj); // Garbage collection support. inline void ExternalAsciiStringIterateBody(ObjectVisitor* v); template inline void ExternalAsciiStringIterateBody(); // Support for StringInputBuffer. const unibrow::byte* ExternalAsciiStringReadBlock(unsigned* remaining, unsigned* offset, unsigned chars); inline void ExternalAsciiStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalAsciiString); }; // The ExternalTwoByteString class is an external string backed by a UTF-16 // encoded string. class ExternalTwoByteString: public ExternalString { public: static const bool kHasAsciiEncoding = false; typedef v8::String::ExternalStringResource Resource; // The underlying string resource. inline Resource* resource(); inline void set_resource(Resource* buffer); // Dispatched behavior. uint16_t ExternalTwoByteStringGet(int index); // For regexp code. const uint16_t* ExternalTwoByteStringGetData(unsigned start); // Casting. static inline ExternalTwoByteString* cast(Object* obj); // Garbage collection support. inline void ExternalTwoByteStringIterateBody(ObjectVisitor* v); template inline void ExternalTwoByteStringIterateBody(); // Support for StringInputBuffer. void ExternalTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString); }; // Utility superclass for stack-allocated objects that must be updated // on gc. It provides two ways for the gc to update instances, either // iterating or updating after gc. class Relocatable BASE_EMBEDDED { public: inline Relocatable() : prev_(top_) { top_ = this; } virtual ~Relocatable() { ASSERT_EQ(top_, this); top_ = prev_; } virtual void IterateInstance(ObjectVisitor* v) { } virtual void PostGarbageCollection() { } static void PostGarbageCollectionProcessing(); static int ArchiveSpacePerThread(); static char* ArchiveState(char* to); static char* RestoreState(char* from); static void Iterate(ObjectVisitor* v); static void Iterate(ObjectVisitor* v, Relocatable* top); static char* Iterate(ObjectVisitor* v, char* t); private: static Relocatable* top_; Relocatable* prev_; }; // A flat string reader provides random access to the contents of a // string independent of the character width of the string. The handle // must be valid as long as the reader is being used. class FlatStringReader : public Relocatable { public: explicit FlatStringReader(Handle str); explicit FlatStringReader(Vector input); void PostGarbageCollection(); inline uc32 Get(int index); int length() { return length_; } private: String** str_; bool is_ascii_; int length_; const void* start_; }; // Note that StringInputBuffers are not valid across a GC! To fix this // it would have to store a String Handle instead of a String* and // AsciiStringReadBlock would have to be modified to use memcpy. // // StringInputBuffer is able to traverse any string regardless of how // deeply nested a sequence of ConsStrings it is made of. However, // performance will be better if deep strings are flattened before they // are traversed. Since flattening requires memory allocation this is // not always desirable, however (esp. in debugging situations). class StringInputBuffer: public unibrow::InputBuffer { public: virtual void Seek(unsigned pos); inline StringInputBuffer(): unibrow::InputBuffer() {} inline StringInputBuffer(String* backing): unibrow::InputBuffer(backing) {} }; class SafeStringInputBuffer : public unibrow::InputBuffer { public: virtual void Seek(unsigned pos); inline SafeStringInputBuffer() : unibrow::InputBuffer() {} inline SafeStringInputBuffer(String** backing) : unibrow::InputBuffer(backing) {} }; template class VectorIterator { public: VectorIterator(T* d, int l) : data_(Vector(d, l)), index_(0) { } explicit VectorIterator(Vector data) : data_(data), index_(0) { } T GetNext() { return data_[index_++]; } bool has_more() { return index_ < data_.length(); } private: Vector data_; int index_; }; // The Oddball describes objects null, undefined, true, and false. class Oddball: public HeapObject { public: // [to_string]: Cached to_string computed at startup. DECL_ACCESSORS(to_string, String) // [to_number]: Cached to_number computed at startup. DECL_ACCESSORS(to_number, Object) // Casting. static inline Oddball* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void OddballVerify(); #endif // Initialize the fields. MUST_USE_RESULT MaybeObject* Initialize(const char* to_string, Object* to_number); // Layout description. static const int kToStringOffset = HeapObject::kHeaderSize; static const int kToNumberOffset = kToStringOffset + kPointerSize; static const int kSize = kToNumberOffset + kPointerSize; typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball); }; class JSGlobalPropertyCell: public HeapObject { public: // [value]: value of the global property. DECL_ACCESSORS(value, Object) // Casting. static inline JSGlobalPropertyCell* cast(Object* obj); #ifdef DEBUG void JSGlobalPropertyCellVerify(); void JSGlobalPropertyCellPrint(); #endif // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; static const int kSize = kValueOffset + kPointerSize; typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalPropertyCell); }; // Proxy describes objects pointing from JavaScript to C structures. // Since they cannot contain references to JS HeapObjects they can be // placed in old_data_space. class Proxy: public HeapObject { public: // [proxy]: field containing the address. inline Address proxy(); inline void set_proxy(Address value); // Casting. static inline Proxy* cast(Object* obj); // Dispatched behavior. inline void ProxyIterateBody(ObjectVisitor* v); template inline void ProxyIterateBody(); #ifdef DEBUG void ProxyPrint(); void ProxyVerify(); #endif // Layout description. static const int kProxyOffset = HeapObject::kHeaderSize; static const int kSize = kProxyOffset + kPointerSize; STATIC_CHECK(kProxyOffset == Internals::kProxyProxyOffset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Proxy); }; // The JSArray describes JavaScript Arrays // Such an array can be in one of two modes: // - fast, backing storage is a FixedArray and length <= elements.length(); // Please note: push and pop can be used to grow and shrink the array. // - slow, backing storage is a HashTable with numbers as keys. class JSArray: public JSObject { public: // [length]: The length property. DECL_ACCESSORS(length, Object) // Overload the length setter to skip write barrier when the length // is set to a smi. This matches the set function on FixedArray. inline void set_length(Smi* length); MUST_USE_RESULT MaybeObject* JSArrayUpdateLengthFromIndex(uint32_t index, Object* value); // Initialize the array with the given capacity. The function may // fail due to out-of-memory situations, but only if the requested // capacity is non-zero. MUST_USE_RESULT MaybeObject* Initialize(int capacity); // Set the content of the array to the content of storage. inline void SetContent(FixedArray* storage); // Casting. static inline JSArray* cast(Object* obj); // Uses handles. Ensures that the fixed array backing the JSArray has at // least the stated size. inline void EnsureSize(int minimum_size_of_backing_fixed_array); // Dispatched behavior. #ifdef DEBUG void JSArrayPrint(); void JSArrayVerify(); #endif // Number of element slots to pre-allocate for an empty array. static const int kPreallocatedArrayElements = 4; // Layout description. static const int kLengthOffset = JSObject::kHeaderSize; static const int kSize = kLengthOffset + kPointerSize; private: // Expand the fixed array backing of a fast-case JSArray to at least // the requested size. void Expand(int minimum_size_of_backing_fixed_array); DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray); }; // JSRegExpResult is just a JSArray with a specific initial map. // This initial map adds in-object properties for "index" and "input" // properties, as assigned by RegExp.prototype.exec, which allows // faster creation of RegExp exec results. // This class just holds constants used when creating the result. // After creation the result must be treated as a JSArray in all regards. class JSRegExpResult: public JSArray { public: // Offsets of object fields. static const int kIndexOffset = JSArray::kSize; static const int kInputOffset = kIndexOffset + kPointerSize; static const int kSize = kInputOffset + kPointerSize; // Indices of in-object properties. static const int kIndexIndex = 0; static const int kInputIndex = 1; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult); }; // An accessor must have a getter, but can have no setter. // // When setting a property, V8 searches accessors in prototypes. // If an accessor was found and it does not have a setter, // the request is ignored. // // If the accessor in the prototype has the READ_ONLY property attribute, then // a new value is added to the local object when the property is set. // This shadows the accessor in the prototype. class AccessorInfo: public Struct { public: DECL_ACCESSORS(getter, Object) DECL_ACCESSORS(setter, Object) DECL_ACCESSORS(data, Object) DECL_ACCESSORS(name, Object) DECL_ACCESSORS(flag, Smi) DECL_ACCESSORS(load_stub_cache, Object) inline bool all_can_read(); inline void set_all_can_read(bool value); inline bool all_can_write(); inline void set_all_can_write(bool value); inline bool prohibits_overwriting(); inline void set_prohibits_overwriting(bool value); inline PropertyAttributes property_attributes(); inline void set_property_attributes(PropertyAttributes attributes); static inline AccessorInfo* cast(Object* obj); #ifdef DEBUG void AccessorInfoPrint(); void AccessorInfoVerify(); #endif static const int kGetterOffset = HeapObject::kHeaderSize; static const int kSetterOffset = kGetterOffset + kPointerSize; static const int kDataOffset = kSetterOffset + kPointerSize; static const int kNameOffset = kDataOffset + kPointerSize; static const int kFlagOffset = kNameOffset + kPointerSize; static const int kLoadStubCacheOffset = kFlagOffset + kPointerSize; static const int kSize = kLoadStubCacheOffset + kPointerSize; private: // Bit positions in flag. static const int kAllCanReadBit = 0; static const int kAllCanWriteBit = 1; static const int kProhibitsOverwritingBit = 2; class AttributesField: public BitField {}; DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo); }; class AccessCheckInfo: public Struct { public: DECL_ACCESSORS(named_callback, Object) DECL_ACCESSORS(indexed_callback, Object) DECL_ACCESSORS(data, Object) static inline AccessCheckInfo* cast(Object* obj); #ifdef DEBUG void AccessCheckInfoPrint(); void AccessCheckInfoVerify(); #endif static const int kNamedCallbackOffset = HeapObject::kHeaderSize; static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize; static const int kDataOffset = kIndexedCallbackOffset + kPointerSize; static const int kSize = kDataOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo); }; class InterceptorInfo: public Struct { public: DECL_ACCESSORS(getter, Object) DECL_ACCESSORS(setter, Object) DECL_ACCESSORS(query, Object) DECL_ACCESSORS(deleter, Object) DECL_ACCESSORS(enumerator, Object) DECL_ACCESSORS(data, Object) static inline InterceptorInfo* cast(Object* obj); #ifdef DEBUG void InterceptorInfoPrint(); void InterceptorInfoVerify(); #endif static const int kGetterOffset = HeapObject::kHeaderSize; static const int kSetterOffset = kGetterOffset + kPointerSize; static const int kQueryOffset = kSetterOffset + kPointerSize; static const int kDeleterOffset = kQueryOffset + kPointerSize; static const int kEnumeratorOffset = kDeleterOffset + kPointerSize; static const int kDataOffset = kEnumeratorOffset + kPointerSize; static const int kSize = kDataOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo); }; class CallHandlerInfo: public Struct { public: DECL_ACCESSORS(callback, Object) DECL_ACCESSORS(data, Object) static inline CallHandlerInfo* cast(Object* obj); #ifdef DEBUG void CallHandlerInfoPrint(); void CallHandlerInfoVerify(); #endif static const int kCallbackOffset = HeapObject::kHeaderSize; static const int kDataOffset = kCallbackOffset + kPointerSize; static const int kSize = kDataOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo); }; class TemplateInfo: public Struct { public: DECL_ACCESSORS(tag, Object) DECL_ACCESSORS(property_list, Object) #ifdef DEBUG void TemplateInfoVerify(); #endif static const int kTagOffset = HeapObject::kHeaderSize; static const int kPropertyListOffset = kTagOffset + kPointerSize; static const int kHeaderSize = kPropertyListOffset + kPointerSize; protected: friend class AGCCVersionRequiresThisClassToHaveAFriendSoHereItIs; DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo); }; class FunctionTemplateInfo: public TemplateInfo { public: DECL_ACCESSORS(serial_number, Object) DECL_ACCESSORS(call_code, Object) DECL_ACCESSORS(property_accessors, Object) DECL_ACCESSORS(prototype_template, Object) DECL_ACCESSORS(parent_template, Object) DECL_ACCESSORS(named_property_handler, Object) DECL_ACCESSORS(indexed_property_handler, Object) DECL_ACCESSORS(instance_template, Object) DECL_ACCESSORS(class_name, Object) DECL_ACCESSORS(signature, Object) DECL_ACCESSORS(instance_call_handler, Object) DECL_ACCESSORS(access_check_info, Object) DECL_ACCESSORS(flag, Smi) // Following properties use flag bits. DECL_BOOLEAN_ACCESSORS(hidden_prototype) DECL_BOOLEAN_ACCESSORS(undetectable) // If the bit is set, object instances created by this function // requires access check. DECL_BOOLEAN_ACCESSORS(needs_access_check) static inline FunctionTemplateInfo* cast(Object* obj); #ifdef DEBUG void FunctionTemplateInfoPrint(); void FunctionTemplateInfoVerify(); #endif static const int kSerialNumberOffset = TemplateInfo::kHeaderSize; static const int kCallCodeOffset = kSerialNumberOffset + kPointerSize; static const int kPropertyAccessorsOffset = kCallCodeOffset + kPointerSize; static const int kPrototypeTemplateOffset = kPropertyAccessorsOffset + kPointerSize; static const int kParentTemplateOffset = kPrototypeTemplateOffset + kPointerSize; static const int kNamedPropertyHandlerOffset = kParentTemplateOffset + kPointerSize; static const int kIndexedPropertyHandlerOffset = kNamedPropertyHandlerOffset + kPointerSize; static const int kInstanceTemplateOffset = kIndexedPropertyHandlerOffset + kPointerSize; static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize; static const int kSignatureOffset = kClassNameOffset + kPointerSize; static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize; static const int kAccessCheckInfoOffset = kInstanceCallHandlerOffset + kPointerSize; static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize; static const int kSize = kFlagOffset + kPointerSize; private: // Bit position in the flag, from least significant bit position. static const int kHiddenPrototypeBit = 0; static const int kUndetectableBit = 1; static const int kNeedsAccessCheckBit = 2; DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo); }; class ObjectTemplateInfo: public TemplateInfo { public: DECL_ACCESSORS(constructor, Object) DECL_ACCESSORS(internal_field_count, Object) static inline ObjectTemplateInfo* cast(Object* obj); #ifdef DEBUG void ObjectTemplateInfoPrint(); void ObjectTemplateInfoVerify(); #endif static const int kConstructorOffset = TemplateInfo::kHeaderSize; static const int kInternalFieldCountOffset = kConstructorOffset + kPointerSize; static const int kSize = kInternalFieldCountOffset + kPointerSize; }; class SignatureInfo: public Struct { public: DECL_ACCESSORS(receiver, Object) DECL_ACCESSORS(args, Object) static inline SignatureInfo* cast(Object* obj); #ifdef DEBUG void SignatureInfoPrint(); void SignatureInfoVerify(); #endif static const int kReceiverOffset = Struct::kHeaderSize; static const int kArgsOffset = kReceiverOffset + kPointerSize; static const int kSize = kArgsOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(SignatureInfo); }; class TypeSwitchInfo: public Struct { public: DECL_ACCESSORS(types, Object) static inline TypeSwitchInfo* cast(Object* obj); #ifdef DEBUG void TypeSwitchInfoPrint(); void TypeSwitchInfoVerify(); #endif static const int kTypesOffset = Struct::kHeaderSize; static const int kSize = kTypesOffset + kPointerSize; }; #ifdef ENABLE_DEBUGGER_SUPPORT // The DebugInfo class holds additional information for a function being // debugged. class DebugInfo: public Struct { public: // The shared function info for the source being debugged. DECL_ACCESSORS(shared, SharedFunctionInfo) // Code object for the original code. DECL_ACCESSORS(original_code, Code) // Code object for the patched code. This code object is the code object // currently active for the function. DECL_ACCESSORS(code, Code) // Fixed array holding status information for each active break point. DECL_ACCESSORS(break_points, FixedArray) // Check if there is a break point at a code position. bool HasBreakPoint(int code_position); // Get the break point info object for a code position. Object* GetBreakPointInfo(int code_position); // Clear a break point. static void ClearBreakPoint(Handle debug_info, int code_position, Handle break_point_object); // Set a break point. static void SetBreakPoint(Handle debug_info, int code_position, int source_position, int statement_position, Handle break_point_object); // Get the break point objects for a code position. Object* GetBreakPointObjects(int code_position); // Find the break point info holding this break point object. static Object* FindBreakPointInfo(Handle debug_info, Handle break_point_object); // Get the number of break points for this function. int GetBreakPointCount(); static inline DebugInfo* cast(Object* obj); #ifdef DEBUG void DebugInfoPrint(); void DebugInfoVerify(); #endif static const int kSharedFunctionInfoIndex = Struct::kHeaderSize; static const int kOriginalCodeIndex = kSharedFunctionInfoIndex + kPointerSize; static const int kPatchedCodeIndex = kOriginalCodeIndex + kPointerSize; static const int kActiveBreakPointsCountIndex = kPatchedCodeIndex + kPointerSize; static const int kBreakPointsStateIndex = kActiveBreakPointsCountIndex + kPointerSize; static const int kSize = kBreakPointsStateIndex + kPointerSize; private: static const int kNoBreakPointInfo = -1; // Lookup the index in the break_points array for a code position. int GetBreakPointInfoIndex(int code_position); DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo); }; // The BreakPointInfo class holds information for break points set in a // function. The DebugInfo object holds a BreakPointInfo object for each code // position with one or more break points. class BreakPointInfo: public Struct { public: // The position in the code for the break point. DECL_ACCESSORS(code_position, Smi) // The position in the source for the break position. DECL_ACCESSORS(source_position, Smi) // The position in the source for the last statement before this break // position. DECL_ACCESSORS(statement_position, Smi) // List of related JavaScript break points. DECL_ACCESSORS(break_point_objects, Object) // Removes a break point. static void ClearBreakPoint(Handle info, Handle break_point_object); // Set a break point. static void SetBreakPoint(Handle info, Handle break_point_object); // Check if break point info has this break point object. static bool HasBreakPointObject(Handle info, Handle break_point_object); // Get the number of break points for this code position. int GetBreakPointCount(); static inline BreakPointInfo* cast(Object* obj); #ifdef DEBUG void BreakPointInfoPrint(); void BreakPointInfoVerify(); #endif static const int kCodePositionIndex = Struct::kHeaderSize; static const int kSourcePositionIndex = kCodePositionIndex + kPointerSize; static const int kStatementPositionIndex = kSourcePositionIndex + kPointerSize; static const int kBreakPointObjectsIndex = kStatementPositionIndex + kPointerSize; static const int kSize = kBreakPointObjectsIndex + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo); }; #endif // ENABLE_DEBUGGER_SUPPORT #undef DECL_BOOLEAN_ACCESSORS #undef DECL_ACCESSORS // Abstract base class for visiting, and optionally modifying, the // pointers contained in Objects. Used in GC and serialization/deserialization. class ObjectVisitor BASE_EMBEDDED { public: virtual ~ObjectVisitor() {} // Visits a contiguous arrays of pointers in the half-open range // [start, end). Any or all of the values may be modified on return. virtual void VisitPointers(Object** start, Object** end) = 0; // To allow lazy clearing of inline caches the visitor has // a rich interface for iterating over Code objects.. // Visits a code target in the instruction stream. virtual void VisitCodeTarget(RelocInfo* rinfo); // Visits a code entry in a JS function. virtual void VisitCodeEntry(Address entry_address); // Visits a runtime entry in the instruction stream. virtual void VisitRuntimeEntry(RelocInfo* rinfo) {} // Visits the resource of an ASCII or two-byte string. virtual void VisitExternalAsciiString( v8::String::ExternalAsciiStringResource** resource) {} virtual void VisitExternalTwoByteString( v8::String::ExternalStringResource** resource) {} // Visits a debug call target in the instruction stream. virtual void VisitDebugTarget(RelocInfo* rinfo); // Handy shorthand for visiting a single pointer. virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); } // Visits a contiguous arrays of external references (references to the C++ // heap) in the half-open range [start, end). Any or all of the values // may be modified on return. virtual void VisitExternalReferences(Address* start, Address* end) {} inline void VisitExternalReference(Address* p) { VisitExternalReferences(p, p + 1); } #ifdef DEBUG // Intended for serialization/deserialization checking: insert, or // check for the presence of, a tag at this position in the stream. virtual void Synchronize(const char* tag) {} #else inline void Synchronize(const char* tag) {} #endif }; class StructBodyDescriptor : public FlexibleBodyDescriptor { public: static inline int SizeOf(Map* map, HeapObject* object) { return map->instance_size(); } }; // BooleanBit is a helper class for setting and getting a bit in an // integer or Smi. class BooleanBit : public AllStatic { public: static inline bool get(Smi* smi, int bit_position) { return get(smi->value(), bit_position); } static inline bool get(int value, int bit_position) { return (value & (1 << bit_position)) != 0; } static inline Smi* set(Smi* smi, int bit_position, bool v) { return Smi::FromInt(set(smi->value(), bit_position, v)); } static inline int set(int value, int bit_position, bool v) { if (v) { value |= (1 << bit_position); } else { value &= ~(1 << bit_position); } return value; } }; } } // namespace v8::internal #endif // V8_OBJECTS_H_