// Copyright 2006-2008 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 "code-stubs.h" #include "smart-pointer.h" #include "unicode-inl.h" // // All object types in the V8 JavaScript are described in this file. // // Inheritance hierarchy: // - Object // - Smi (immediate small integer) // - Failure (immediate for marking failed operation) // - HeapObject (superclass for everything allocated in the heap) // - JSObject // - JSArray // - JSRegExp // - JSFunction // - GlobalObject // - JSGlobalObject // - JSBuiltinsObject // - JSGlobalProxy // - JSValue // - Script // - Array // - ByteArray // - FixedArray // - DescriptorArray // - HashTable // - Dictionary // - SymbolTable // - CompilationCacheTable // - MapCache // - LookupCache // - Context // - GlobalContext // - String // - SeqString // - SeqAsciiString // - SeqTwoByteString // - ConsString // - SlicedString // - ExternalString // - ExternalAsciiString // - ExternalTwoByteString // - HeapNumber // - Code // - Map // - Oddball // - Proxy // - SharedFunctionInfo // - Struct // - AccessorInfo // - AccessCheckInfo // - InterceptorInfo // - CallHandlerInfo // - FunctionTemplateInfo // - ObjectTemplateInfo // - SignatureInfo // - TypeSwitchInfo // - DebugInfo // - BreakPointInfo // // 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_); } 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; } // 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 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 }; // 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 length // (SHORT, MEDIUM, or LONG) is always mentioned. 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, SLICED, 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(V) \ V(SHORT_SYMBOL_TYPE) \ V(MEDIUM_SYMBOL_TYPE) \ V(LONG_SYMBOL_TYPE) \ V(SHORT_ASCII_SYMBOL_TYPE) \ V(MEDIUM_ASCII_SYMBOL_TYPE) \ V(LONG_ASCII_SYMBOL_TYPE) \ V(SHORT_CONS_SYMBOL_TYPE) \ V(MEDIUM_CONS_SYMBOL_TYPE) \ V(LONG_CONS_SYMBOL_TYPE) \ V(SHORT_CONS_ASCII_SYMBOL_TYPE) \ V(MEDIUM_CONS_ASCII_SYMBOL_TYPE) \ V(LONG_CONS_ASCII_SYMBOL_TYPE) \ V(SHORT_SLICED_SYMBOL_TYPE) \ V(MEDIUM_SLICED_SYMBOL_TYPE) \ V(LONG_SLICED_SYMBOL_TYPE) \ V(SHORT_SLICED_ASCII_SYMBOL_TYPE) \ V(MEDIUM_SLICED_ASCII_SYMBOL_TYPE) \ V(LONG_SLICED_ASCII_SYMBOL_TYPE) \ V(SHORT_EXTERNAL_SYMBOL_TYPE) \ V(MEDIUM_EXTERNAL_SYMBOL_TYPE) \ V(LONG_EXTERNAL_SYMBOL_TYPE) \ V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE) \ V(MEDIUM_EXTERNAL_ASCII_SYMBOL_TYPE) \ V(LONG_EXTERNAL_ASCII_SYMBOL_TYPE) \ V(SHORT_STRING_TYPE) \ V(MEDIUM_STRING_TYPE) \ V(LONG_STRING_TYPE) \ V(SHORT_ASCII_STRING_TYPE) \ V(MEDIUM_ASCII_STRING_TYPE) \ V(LONG_ASCII_STRING_TYPE) \ V(SHORT_CONS_STRING_TYPE) \ V(MEDIUM_CONS_STRING_TYPE) \ V(LONG_CONS_STRING_TYPE) \ V(SHORT_CONS_ASCII_STRING_TYPE) \ V(MEDIUM_CONS_ASCII_STRING_TYPE) \ V(LONG_CONS_ASCII_STRING_TYPE) \ V(SHORT_SLICED_STRING_TYPE) \ V(MEDIUM_SLICED_STRING_TYPE) \ V(LONG_SLICED_STRING_TYPE) \ V(SHORT_SLICED_ASCII_STRING_TYPE) \ V(MEDIUM_SLICED_ASCII_STRING_TYPE) \ V(LONG_SLICED_ASCII_STRING_TYPE) \ V(SHORT_EXTERNAL_STRING_TYPE) \ V(MEDIUM_EXTERNAL_STRING_TYPE) \ V(LONG_EXTERNAL_STRING_TYPE) \ V(SHORT_EXTERNAL_ASCII_STRING_TYPE) \ V(MEDIUM_EXTERNAL_ASCII_STRING_TYPE) \ V(LONG_EXTERNAL_ASCII_STRING_TYPE) \ V(LONG_PRIVATE_EXTERNAL_ASCII_STRING_TYPE) \ \ V(MAP_TYPE) \ V(HEAP_NUMBER_TYPE) \ V(FIXED_ARRAY_TYPE) \ V(CODE_TYPE) \ V(ODDBALL_TYPE) \ V(PROXY_TYPE) \ V(BYTE_ARRAY_TYPE) \ V(FILLER_TYPE) \ \ V(ACCESSOR_INFO_TYPE) \ V(ACCESS_CHECK_INFO_TYPE) \ V(INTERCEPTOR_INFO_TYPE) \ V(SHARED_FUNCTION_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(DEBUG_INFO_TYPE) \ V(BREAK_POINT_INFO_TYPE) \ V(SCRIPT_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) \ // Since string types are not consecutive, this macro is used to // iterate over them. #define STRING_TYPE_LIST(V) \ V(SHORT_SYMBOL_TYPE, SeqTwoByteString::kHeaderSize, short_symbol) \ V(MEDIUM_SYMBOL_TYPE, SeqTwoByteString::kHeaderSize, medium_symbol) \ V(LONG_SYMBOL_TYPE, SeqTwoByteString::kHeaderSize, long_symbol) \ V(SHORT_ASCII_SYMBOL_TYPE, SeqAsciiString::kHeaderSize, short_ascii_symbol) \ V(MEDIUM_ASCII_SYMBOL_TYPE, SeqAsciiString::kHeaderSize, medium_ascii_symbol)\ V(LONG_ASCII_SYMBOL_TYPE, SeqAsciiString::kHeaderSize, long_ascii_symbol) \ V(SHORT_CONS_SYMBOL_TYPE, ConsString::kSize, short_cons_symbol) \ V(MEDIUM_CONS_SYMBOL_TYPE, ConsString::kSize, medium_cons_symbol) \ V(LONG_CONS_SYMBOL_TYPE, ConsString::kSize, long_cons_symbol) \ V(SHORT_CONS_ASCII_SYMBOL_TYPE, ConsString::kSize, short_cons_ascii_symbol) \ V(MEDIUM_CONS_ASCII_SYMBOL_TYPE, ConsString::kSize, medium_cons_ascii_symbol)\ V(LONG_CONS_ASCII_SYMBOL_TYPE, ConsString::kSize, long_cons_ascii_symbol) \ V(SHORT_SLICED_SYMBOL_TYPE, SlicedString::kSize, short_sliced_symbol) \ V(MEDIUM_SLICED_SYMBOL_TYPE, SlicedString::kSize, medium_sliced_symbol) \ V(LONG_SLICED_SYMBOL_TYPE, SlicedString::kSize, long_sliced_symbol) \ V(SHORT_SLICED_ASCII_SYMBOL_TYPE, \ SlicedString::kSize, \ short_sliced_ascii_symbol) \ V(MEDIUM_SLICED_ASCII_SYMBOL_TYPE, \ SlicedString::kSize, \ medium_sliced_ascii_symbol) \ V(LONG_SLICED_ASCII_SYMBOL_TYPE, \ SlicedString::kSize, \ long_sliced_ascii_symbol) \ V(SHORT_EXTERNAL_SYMBOL_TYPE, \ ExternalTwoByteString::kSize, \ short_external_symbol) \ V(MEDIUM_EXTERNAL_SYMBOL_TYPE, \ ExternalTwoByteString::kSize, \ medium_external_symbol) \ V(LONG_EXTERNAL_SYMBOL_TYPE, \ ExternalTwoByteString::kSize, \ long_external_symbol) \ V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE, \ ExternalAsciiString::kSize, \ short_external_ascii_symbol) \ V(MEDIUM_EXTERNAL_ASCII_SYMBOL_TYPE, \ ExternalAsciiString::kSize, \ medium_external_ascii_symbol) \ V(LONG_EXTERNAL_ASCII_SYMBOL_TYPE, \ ExternalAsciiString::kSize, \ long_external_ascii_symbol) \ V(SHORT_STRING_TYPE, SeqTwoByteString::kHeaderSize, short_string) \ V(MEDIUM_STRING_TYPE, SeqTwoByteString::kHeaderSize, medium_string) \ V(LONG_STRING_TYPE, SeqTwoByteString::kHeaderSize, long_string) \ V(SHORT_ASCII_STRING_TYPE, SeqAsciiString::kHeaderSize, short_ascii_string) \ V(MEDIUM_ASCII_STRING_TYPE, SeqAsciiString::kHeaderSize, medium_ascii_string)\ V(LONG_ASCII_STRING_TYPE, SeqAsciiString::kHeaderSize, long_ascii_string) \ V(SHORT_CONS_STRING_TYPE, ConsString::kSize, short_cons_string) \ V(MEDIUM_CONS_STRING_TYPE, ConsString::kSize, medium_cons_string) \ V(LONG_CONS_STRING_TYPE, ConsString::kSize, long_cons_string) \ V(SHORT_CONS_ASCII_STRING_TYPE, ConsString::kSize, short_cons_ascii_string) \ V(MEDIUM_CONS_ASCII_STRING_TYPE, ConsString::kSize, medium_cons_ascii_string)\ V(LONG_CONS_ASCII_STRING_TYPE, ConsString::kSize, long_cons_ascii_string) \ V(SHORT_SLICED_STRING_TYPE, SlicedString::kSize, short_sliced_string) \ V(MEDIUM_SLICED_STRING_TYPE, SlicedString::kSize, medium_sliced_string) \ V(LONG_SLICED_STRING_TYPE, SlicedString::kSize, long_sliced_string) \ V(SHORT_SLICED_ASCII_STRING_TYPE, \ SlicedString::kSize, \ short_sliced_ascii_string) \ V(MEDIUM_SLICED_ASCII_STRING_TYPE, \ SlicedString::kSize, \ medium_sliced_ascii_string) \ V(LONG_SLICED_ASCII_STRING_TYPE, \ SlicedString::kSize, \ long_sliced_ascii_string) \ V(SHORT_EXTERNAL_STRING_TYPE, \ ExternalTwoByteString::kSize, \ short_external_string) \ V(MEDIUM_EXTERNAL_STRING_TYPE, \ ExternalTwoByteString::kSize, \ medium_external_string) \ V(LONG_EXTERNAL_STRING_TYPE, \ ExternalTwoByteString::kSize, \ long_external_string) \ V(SHORT_EXTERNAL_ASCII_STRING_TYPE, \ ExternalAsciiString::kSize, \ short_external_ascii_string) \ V(MEDIUM_EXTERNAL_ASCII_STRING_TYPE, \ ExternalAsciiString::kSize, \ medium_external_ascii_string) \ V(LONG_EXTERNAL_ASCII_STRING_TYPE, \ ExternalAsciiString::kSize, \ long_external_ascii_string) // 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) #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; // If bit 7 is clear, bit 5 indicates that the string is a symbol (if set) or // not (if cleared). const uint32_t kIsSymbolMask = 0x20; const uint32_t kNotSymbolTag = 0x0; const uint32_t kSymbolTag = 0x20; // If bit 7 is clear, bits 3 and 4 are the string's size (short, medium or // long). These values are very special in that they are also used to shift // the length field to get the length, removing the hash value. This avoids // using if or switch when getting the length of a string. const uint32_t kStringSizeMask = 0x18; const uint32_t kShortStringTag = 0x18; const uint32_t kMediumStringTag = 0x10; const uint32_t kLongStringTag = 0x00; // 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, kSlicedStringTag = 0x2, kExternalStringTag = 0x3 }; // 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 { SHORT_SYMBOL_TYPE = kShortStringTag | kSymbolTag | kSeqStringTag, MEDIUM_SYMBOL_TYPE = kMediumStringTag | kSymbolTag | kSeqStringTag, LONG_SYMBOL_TYPE = kLongStringTag | kSymbolTag | kSeqStringTag, SHORT_ASCII_SYMBOL_TYPE = kShortStringTag | kAsciiStringTag | kSymbolTag | kSeqStringTag, MEDIUM_ASCII_SYMBOL_TYPE = kMediumStringTag | kAsciiStringTag | kSymbolTag | kSeqStringTag, LONG_ASCII_SYMBOL_TYPE = kLongStringTag | kAsciiStringTag | kSymbolTag | kSeqStringTag, SHORT_CONS_SYMBOL_TYPE = kShortStringTag | kSymbolTag | kConsStringTag, MEDIUM_CONS_SYMBOL_TYPE = kMediumStringTag | kSymbolTag | kConsStringTag, LONG_CONS_SYMBOL_TYPE = kLongStringTag | kSymbolTag | kConsStringTag, SHORT_CONS_ASCII_SYMBOL_TYPE = kShortStringTag | kAsciiStringTag | kSymbolTag | kConsStringTag, MEDIUM_CONS_ASCII_SYMBOL_TYPE = kMediumStringTag | kAsciiStringTag | kSymbolTag | kConsStringTag, LONG_CONS_ASCII_SYMBOL_TYPE = kLongStringTag | kAsciiStringTag | kSymbolTag | kConsStringTag, SHORT_SLICED_SYMBOL_TYPE = kShortStringTag | kSymbolTag | kSlicedStringTag, MEDIUM_SLICED_SYMBOL_TYPE = kMediumStringTag | kSymbolTag | kSlicedStringTag, LONG_SLICED_SYMBOL_TYPE = kLongStringTag | kSymbolTag | kSlicedStringTag, SHORT_SLICED_ASCII_SYMBOL_TYPE = kShortStringTag | kAsciiStringTag | kSymbolTag | kSlicedStringTag, MEDIUM_SLICED_ASCII_SYMBOL_TYPE = kMediumStringTag | kAsciiStringTag | kSymbolTag | kSlicedStringTag, LONG_SLICED_ASCII_SYMBOL_TYPE = kLongStringTag | kAsciiStringTag | kSymbolTag | kSlicedStringTag, SHORT_EXTERNAL_SYMBOL_TYPE = kShortStringTag | kSymbolTag | kExternalStringTag, MEDIUM_EXTERNAL_SYMBOL_TYPE = kMediumStringTag | kSymbolTag | kExternalStringTag, LONG_EXTERNAL_SYMBOL_TYPE = kLongStringTag | kSymbolTag | kExternalStringTag, SHORT_EXTERNAL_ASCII_SYMBOL_TYPE = kShortStringTag | kAsciiStringTag | kSymbolTag | kExternalStringTag, MEDIUM_EXTERNAL_ASCII_SYMBOL_TYPE = kMediumStringTag | kAsciiStringTag | kSymbolTag | kExternalStringTag, LONG_EXTERNAL_ASCII_SYMBOL_TYPE = kLongStringTag | kAsciiStringTag | kSymbolTag | kExternalStringTag, SHORT_STRING_TYPE = kShortStringTag | kSeqStringTag, MEDIUM_STRING_TYPE = kMediumStringTag | kSeqStringTag, LONG_STRING_TYPE = kLongStringTag | kSeqStringTag, SHORT_ASCII_STRING_TYPE = kShortStringTag | kAsciiStringTag | kSeqStringTag, MEDIUM_ASCII_STRING_TYPE = kMediumStringTag | kAsciiStringTag | kSeqStringTag, LONG_ASCII_STRING_TYPE = kLongStringTag | kAsciiStringTag | kSeqStringTag, SHORT_CONS_STRING_TYPE = kShortStringTag | kConsStringTag, MEDIUM_CONS_STRING_TYPE = kMediumStringTag | kConsStringTag, LONG_CONS_STRING_TYPE = kLongStringTag | kConsStringTag, SHORT_CONS_ASCII_STRING_TYPE = kShortStringTag | kAsciiStringTag | kConsStringTag, MEDIUM_CONS_ASCII_STRING_TYPE = kMediumStringTag | kAsciiStringTag | kConsStringTag, LONG_CONS_ASCII_STRING_TYPE = kLongStringTag | kAsciiStringTag | kConsStringTag, SHORT_SLICED_STRING_TYPE = kShortStringTag | kSlicedStringTag, MEDIUM_SLICED_STRING_TYPE = kMediumStringTag | kSlicedStringTag, LONG_SLICED_STRING_TYPE = kLongStringTag | kSlicedStringTag, SHORT_SLICED_ASCII_STRING_TYPE = kShortStringTag | kAsciiStringTag | kSlicedStringTag, MEDIUM_SLICED_ASCII_STRING_TYPE = kMediumStringTag | kAsciiStringTag | kSlicedStringTag, LONG_SLICED_ASCII_STRING_TYPE = kLongStringTag | kAsciiStringTag | kSlicedStringTag, SHORT_EXTERNAL_STRING_TYPE = kShortStringTag | kExternalStringTag, MEDIUM_EXTERNAL_STRING_TYPE = kMediumStringTag | kExternalStringTag, LONG_EXTERNAL_STRING_TYPE = kLongStringTag | kExternalStringTag, SHORT_EXTERNAL_ASCII_STRING_TYPE = kShortStringTag | kAsciiStringTag | kExternalStringTag, MEDIUM_EXTERNAL_ASCII_STRING_TYPE = kMediumStringTag | kAsciiStringTag | kExternalStringTag, LONG_EXTERNAL_ASCII_STRING_TYPE = kLongStringTag | kAsciiStringTag | kExternalStringTag, LONG_PRIVATE_EXTERNAL_ASCII_STRING_TYPE = LONG_EXTERNAL_ASCII_STRING_TYPE, MAP_TYPE = kNotStringTag, HEAP_NUMBER_TYPE, FIXED_ARRAY_TYPE, CODE_TYPE, ODDBALL_TYPE, PROXY_TYPE, BYTE_ARRAY_TYPE, FILLER_TYPE, SMI_TYPE, ACCESSOR_INFO_TYPE, ACCESS_CHECK_INFO_TYPE, INTERCEPTOR_INFO_TYPE, SHARED_FUNCTION_INFO_TYPE, CALL_HANDLER_INFO_TYPE, FUNCTION_TEMPLATE_INFO_TYPE, OBJECT_TEMPLATE_INFO_TYPE, SIGNATURE_INFO_TYPE, TYPE_SWITCH_INFO_TYPE, DEBUG_INFO_TYPE, BREAK_POINT_INFO_TYPE, SCRIPT_TYPE, JS_VALUE_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, JS_FUNCTION_TYPE, // Pseudo-types FIRST_NONSTRING_TYPE = MAP_TYPE, FIRST_TYPE = 0x0, INVALID_TYPE = FIRST_TYPE - 1, LAST_TYPE = JS_FUNCTION_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 }; 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); // 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 BASE_EMBEDDED { public: // Type testing. inline bool IsSmi(); inline bool IsHeapObject(); inline bool IsHeapNumber(); inline bool IsString(); inline bool IsSymbol(); inline bool IsSeqString(); inline bool IsSlicedString(); inline bool IsExternalString(); inline bool IsConsString(); inline bool IsExternalTwoByteString(); inline bool IsExternalAsciiString(); inline bool IsSeqTwoByteString(); inline bool IsSeqAsciiString(); inline bool IsNumber(); inline bool IsByteArray(); inline bool IsFailure(); inline bool IsRetryAfterGC(); inline bool IsOutOfMemoryFailure(); inline bool IsException(); 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 IsCompilationCacheTable(); inline bool IsMapCache(); inline bool IsLookupCache(); inline bool IsPrimitive(); inline bool IsGlobalObject(); inline bool IsJSGlobalObject(); inline bool IsJSBuiltinsObject(); inline bool IsJSGlobalProxy(); inline bool IsUndetectableObject(); inline bool IsAccessCheckNeeded(); // Returns true if this object is an instance of the specified // function template. 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 IsTheHole()); INLINE(bool IsNull()); INLINE(bool IsTrue()); INLINE(bool IsFalse()); // Extract the number. inline double Number(); inline bool HasSpecificClassOf(String* name); Object* 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. Object* ToObject(Context* global_context); // Converts this to a Smi if possible. // Failure is returned otherwise. inline Object* ToSmi(); void Lookup(String* name, LookupResult* result); // Property access. inline Object* GetProperty(String* key); inline Object* GetProperty(String* key, PropertyAttributes* attributes); Object* GetPropertyWithReceiver(Object* receiver, String* key, PropertyAttributes* attributes); Object* GetProperty(Object* receiver, LookupResult* result, String* key, PropertyAttributes* attributes); Object* GetPropertyWithCallback(Object* receiver, Object* structure, String* name, Object* holder); Object* GetPropertyWithDefinedGetter(Object* receiver, JSFunction* getter); inline Object* GetElement(uint32_t index); Object* GetElementWithReceiver(Object* receiver, uint32_t index); // Return the object's prototype (might be Heap::null_value()). Object* GetPrototype(); // 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 // Prints this object with details. void Print(); void PrintLn(); // Verifies the object. void Verify(); // 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 // 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(int value); static inline bool IsIntptrValid(intptr_t); // Casting. static inline Smi* cast(Object* object); // Dispatched behavior. void SmiPrint(); void SmiPrint(StringStream* accumulator); #ifdef DEBUG void SmiVerify(); #endif static const int kSmiNumBits = 31; // Min and max limits for Smi values. static const int kMinValue = -(1 << (kSmiNumBits - 1)); static const int kMaxValue = (1 << (kSmiNumBits - 1)) - 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 objects graph. // // Failures are a single word, encoded as follows: // +-------------------------+---+--+--+ // |rrrrrrrrrrrrrrrrrrrrrrrrr|sss|tt|11| // +-------------------------+---+--+--+ // // 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 encoding is found in globals.h): // 000 NEW_SPACE // 001 OLD_SPACE // 010 CODE_SPACE // 011 MAP_SPACE // 100 LO_SPACE // // The remaining bits is the number of words requested by the // allocation request that failed, and is zeroed except for // RETRY_AFTER_GC failures. The 25 bits (on a 32 bit platform) gives // a representable range of 2^27 bytes (128MB). // Failure type tag info. const int kFailureTypeTagSize = 2; const int kFailureTypeTagMask = (1 << kFailureTypeTagSize) - 1; class Failure: public Object { 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; // Returns the number of bytes requested (up to the representable maximum) // for RetryAfterGC failures. inline int requested() const; inline bool IsInternalError() const; inline bool IsOutOfMemoryException() const; static Failure* RetryAfterGC(int requested_bytes, AllocationSpace space); static inline Failure* RetryAfterGC(int requested_bytes); // NEW_SPACE static inline Failure* Exception(); static inline Failure* InternalError(); static inline Failure* OutOfMemoryException(); // Casting. static inline Failure* cast(Object* object); // Dispatched behavior. void FailurePrint(); void FailurePrint(StringStream* accumulator); #ifdef DEBUG void FailureVerify(); #endif private: inline int value() const; static inline Failure* Construct(Type type, int 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(); private: // HeapObject calls the private constructor and directly reads the value. friend class HeapObject; explicit MapWord(uintptr_t value) : value_(value) {} uintptr_t value_; // 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 // 31 21 20 10 9 0 // +-----------------+------------------+-----------------+ // |forwarding offset|page offset of map|page index of map| // +-----------------+------------------+-----------------+ // 11 bits 11 bits 10 bits static const int kMapPageIndexBits = 10; static const int kMapPageOffsetBits = 11; static const int kForwardingOffsetBits = 11; static const int kMapPageIndexShift = 0; static const int kMapPageOffsetShift = kMapPageIndexShift + kMapPageIndexBits; static const int kForwardingOffsetShift = kMapPageOffsetShift + kMapPageOffsetBits; // 0x000003FF static const uint32_t kMapPageIndexMask = (1 << kMapPageOffsetShift) - 1; // 0x001FFC00 static const uint32_t kMapPageOffsetMask = ((1 << kForwardingOffsetShift) - 1) & ~kMapPageIndexMask; // 0xFFE00000 static const uint32_t kForwardingOffsetMask = ~(kMapPageIndexMask | kMapPageOffsetMask); }; // 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); // This method only applies to struct objects. Iterates over all the fields // of this struct. void IterateStructBody(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 update remembered sets, 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. inline WriteBarrierMode GetWriteBarrierMode(); // Dispatched behavior. void HeapObjectShortPrint(StringStream* accumulator); #ifdef DEBUG void HeapObjectPrint(); void HeapObjectVerify(); inline void VerifyObjectField(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; 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); // Computes the object size from the map. // Should only be used from SizeFromMap. int SlowSizeFromMap(Map* map); private: DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject); }; // 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 // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; static const int kSize = kValueOffset + kDoubleSize; 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: // [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 Dictionary* property_dictionary(); // Gets slow properties. // [elements]: The elements (properties with names that are integers). // elements is a FixedArray in the fast case, and a Dictionary in the slow // case. DECL_ACCESSORS(elements, FixedArray) // Get and set fast elements. inline void initialize_elements(); inline bool HasFastElements(); inline Dictionary* element_dictionary(); // Gets slow elements. // Collects elements starting at index 0. // Undefined values are placed after non-undefined values. // Returns the number of non-undefined values. Object* PrepareElementsForSort(uint32_t limit); // As PrepareElementsForSort, but only on objects where elements is // a dictionary, and it will stay a dictionary. Object* PrepareSlowElementsForSort(uint32_t limit); Object* SetProperty(String* key, Object* value, PropertyAttributes attributes); Object* SetProperty(LookupResult* result, String* key, Object* value, PropertyAttributes attributes); Object* SetPropertyWithFailedAccessCheck(LookupResult* result, String* name, Object* value); Object* SetPropertyWithCallback(Object* structure, String* name, Object* value, JSObject* holder); Object* SetPropertyWithDefinedSetter(JSFunction* setter, Object* value); Object* SetPropertyWithInterceptor(String* name, Object* value, PropertyAttributes attributes); Object* SetPropertyPostInterceptor(String* name, Object* value, PropertyAttributes attributes); Object* IgnoreAttributesAndSetLocalProperty(String* key, Object* value, PropertyAttributes attributes); // Sets a property that currently has lazy loading. Object* SetLazyProperty(LookupResult* result, String* name, Object* value, PropertyAttributes attributes); // Returns the class name ([[Class]] property in the specification). String* class_name(); // Retrieve interceptors. InterceptorInfo* GetNamedInterceptor(); InterceptorInfo* GetIndexedInterceptor(); inline PropertyAttributes GetPropertyAttribute(String* name); PropertyAttributes GetPropertyAttributeWithReceiver(JSObject* receiver, String* name); PropertyAttributes GetLocalPropertyAttribute(String* name); Object* DefineAccessor(String* name, bool is_getter, JSFunction* fun, PropertyAttributes attributes); Object* LookupAccessor(String* name, bool is_getter); // Used from Object::GetProperty(). Object* GetPropertyWithFailedAccessCheck(Object* receiver, LookupResult* result, String* name, PropertyAttributes* attributes); Object* GetPropertyWithInterceptor(JSObject* receiver, String* name, PropertyAttributes* attributes); Object* GetPropertyPostInterceptor(JSObject* receiver, String* name, PropertyAttributes* attributes); Object* GetLazyProperty(Object* receiver, LookupResult* result, String* name, PropertyAttributes* attributes); // Tells whether this object needs to be loaded. inline bool IsLoaded(); 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; } Object* DeleteProperty(String* name); Object* DeleteElement(uint32_t index); Object* DeleteLazyProperty(LookupResult* result, String* name); // 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(); // Return the object's hidden properties object. If the object has no hidden // properties and create_if_needed is true, then a new hidden property object // will be allocated. Otherwise the Heap::undefined_value is returned. Object* GetHiddenProperties(bool create_if_needed); // Tells whether the index'th element is present. inline bool HasElement(uint32_t index); bool HasElementWithReceiver(JSObject* receiver, uint32_t index); bool HasLocalElement(uint32_t index); bool HasElementWithInterceptor(JSObject* receiver, uint32_t index); bool HasElementPostInterceptor(JSObject* receiver, uint32_t index); Object* SetFastElement(uint32_t index, Object* value); // Set the index'th array element. // A Failure object is returned if GC is needed. Object* SetElement(uint32_t index, Object* value); // Returns the index'th element. // The undefined object if index is out of bounds. Object* GetElementWithReceiver(JSObject* receiver, uint32_t index); void SetFastElements(FixedArray* elements); Object* 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 Object* 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); Object* LookupCallbackSetterInPrototypes(uint32_t index); 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. Object* 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. Object* AddConstantFunctionProperty(String* name, JSFunction* function, PropertyAttributes attributes); Object* 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. Object* 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. Object* ConvertDescriptorToField(String* name, Object* new_value, PropertyAttributes attributes); // Add a property to a fast-case object. Object* AddFastProperty(String* name, Object* value, PropertyAttributes attributes); // Add a property to a slow-case object. Object* AddSlowProperty(String* name, Object* value, PropertyAttributes attributes); // Add a property to an object. Object* AddProperty(String* name, Object* value, PropertyAttributes attributes); // Convert the object to use the canonical dictionary // representation. Object* NormalizeProperties(PropertyNormalizationMode mode); Object* NormalizeElements(); // Transform slow named properties to fast variants. // Returns failure if allocation failed. Object* 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); // Check whether this object references another object bool ReferencesObject(Object* obj); // Casting. static inline JSObject* cast(Object* obj); // Dispatched behavior. void JSObjectIterateBody(int object_size, ObjectVisitor* v); 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); 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; Object* GetElementWithInterceptor(JSObject* receiver, uint32_t index); private: Object* SetElementWithInterceptor(uint32_t index, Object* value); Object* SetElementPostInterceptor(uint32_t index, Object* value); Object* GetElementPostInterceptor(JSObject* receiver, uint32_t index); Object* DeletePropertyPostInterceptor(String* name); Object* DeletePropertyWithInterceptor(String* name); Object* DeleteElementPostInterceptor(uint32_t index); Object* 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(); Object* DefineGetterSetter(String* name, PropertyAttributes attributes); void LookupInDescriptor(String* name, LookupResult* result); DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject); }; // Abstract super class arrays. It provides length behavior. class Array: public HeapObject { public: // [length]: length of the array. inline int length(); inline void set_length(int value); // Convert an object to an array index. // Returns true if the conversion succeeded. static inline bool IndexFromObject(Object* object, uint32_t* index); // Layout descriptor. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kHeaderSize = kLengthOffset + kIntSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Array); }; // FixedArray describes fixed sized arrays where element // type is Object*. class FixedArray: public Array { public: // 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); // Copy operations. inline Object* Copy(); Object* CopySize(int new_length); // Add the elements of a JSArray to this FixedArray. Object* AddKeysFromJSArray(JSArray* array); // Compute the union of this and other. Object* 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; } // Casting. static inline FixedArray* cast(Object* obj); // Dispatched behavior. int FixedArraySize() { return SizeFor(length()); } void FixedArrayIterateBody(ObjectVisitor* v); #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); protected: // Set operation on FixedArray without using write barriers. 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); // Accessor for complete descriptor. inline void Get(int descriptor_number, Descriptor* desc); inline void Set(int descriptor_number, Descriptor* desc); // 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. Object* 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. Object* RemoveTransitions(); // Sort the instance descriptors by the hash codes of their keys. void Sort(); // Search the instance descriptors for given name. inline int Search(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. static Object* 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 ToValueIndex(int descriptor_number) { return descriptor_number << 1; } static int ToDetailsIndex(int descriptor_number) { return( descriptor_number << 1) + 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 prefix size and with // the size, including the key size, of the elements held in the hash // table. 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. // HashTableKey is an abstract superclass keys. class HashTableKey { public: // Returns whether the other object matches this key. virtual bool IsMatch(Object* other) = 0; typedef uint32_t (*HashFunction)(Object* obj); // Returns the hash function used for this key. virtual HashFunction GetHashFunction() = 0; // Returns the hash value for this key. virtual uint32_t Hash() = 0; // Returns the key object for storing into the dictionary. // If allocations fails a failure object is returned. virtual Object* GetObject() = 0; virtual bool IsStringKey() = 0; // Required. virtual ~HashTableKey() {} }; template class HashTable: public FixedArray { public: // Returns the number of elements in the dictionary. int NumberOfElements() { return Smi::cast(get(kNumberOfElementsIndex))->value(); } // Returns the capacity of the dictionary. int Capacity() { return Smi::cast(get(kCapacityIndex))->value(); } // ElementAdded should be called whenever an element is added to a // dictionary. void ElementAdded() { SetNumberOfElements(NumberOfElements() + 1); } // ElementRemoved should be called whenever an element is removed from // a dictionary. void ElementRemoved() { SetNumberOfElements(NumberOfElements() - 1); } void ElementsRemoved(int n) { SetNumberOfElements(NumberOfElements() - n); } // Returns a new array for dictionary usage. Might return Failure. static Object* Allocate(int at_least_space_for); // 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 kCapacityIndex = 1; static const int kPrefixStartIndex = 2; static const int kElementsStartIndex = kPrefixStartIndex + prefix_size; static const int kElementSize = element_size; static const int kElementsStartOffset = kHeaderSize + kElementsStartIndex * kPointerSize; protected: // Find entry for key otherwise return -1. int FindEntry(HashTableKey* key); // Find the entry at which to insert element with the given key that // has the given hash value. uint32_t FindInsertionEntry(Object* key, uint32_t hash); // Returns the index for an entry (of the key) static inline int EntryToIndex(int entry) { return (entry * kElementSize) + kElementsStartIndex; } // Update the number of elements in the dictionary. void SetNumberOfElements(int nof) { fast_set(this, kNumberOfElementsIndex, Smi::FromInt(nof)); } // 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); 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); } // Ensure enough space for n additional elements. Object* EnsureCapacity(int n, HashTableKey* key); }; // 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<0, 1> { 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. Object* LookupSymbol(Vector str, Object** s); Object* 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); // Casting. static inline SymbolTable* cast(Object* obj); private: Object* LookupKey(HashTableKey* key, Object** s); DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolTable); }; // MapCache. // // Maps keys that are a fixed array of symbols to a map. // Used for canonicalize maps for object literals. class MapCache: public HashTable<0, 2> { public: // Find cached value for a string key, otherwise return null. Object* Lookup(FixedArray* key); Object* Put(FixedArray* key, Map* value); static inline MapCache* cast(Object* obj); private: DISALLOW_IMPLICIT_CONSTRUCTORS(MapCache); }; // LookupCache. // // Maps a key consisting of a map and a name to an index within a // fast-case properties array. // // LookupCaches are used to avoid repeatedly searching instance // descriptors. class LookupCache: public HashTable<0, 2> { public: int Lookup(Map* map, String* name); Object* Put(Map* map, String* name, int offset); static inline LookupCache* cast(Object* obj); // Constant returned by Lookup when the key was not found. static const int kNotFound = -1; private: DISALLOW_IMPLICIT_CONSTRUCTORS(LookupCache); }; // Dictionary for keeping properties and elements in slow case. // // One element in the prefix is used for storing non-element // information about the dictionary. // // The rest of the array embeds triples of (key, value, details). // if key == undefined the triple is empty. // if key == null the triple has been deleted. // otherwise key contains the name of a property. class DictionaryBase: public HashTable<2, 3> {}; class Dictionary: public DictionaryBase { public: // Returns the value at entry. Object* ValueAt(int entry) { return get(EntryToIndex(entry)+1); } // Set the value for entry. void ValueAtPut(int entry, Object* value) { set(EntryToIndex(entry)+1, value); } // Returns the property details for the property at entry. PropertyDetails DetailsAt(int entry) { return PropertyDetails(Smi::cast(get(EntryToIndex(entry) + 2))); } // Set the details for entry. void DetailsAtPut(int entry, PropertyDetails value) { set(EntryToIndex(entry) + 2, value.AsSmi()); } // Remove all entries were key is a number and (from <= key && key < to). void RemoveNumberEntries(uint32_t from, uint32_t to); // Sorting support void CopyValuesTo(FixedArray* elements); // Casting. static inline Dictionary* cast(Object* obj); // Find entry for string key otherwise return -1. int FindStringEntry(String* key); // Find entry for number key otherwise return -1. int FindNumberEntry(uint32_t index); // Delete a property from the dictionary. Object* DeleteProperty(int entry); // Type specific at put (default NONE attributes is used when adding). Object* AtStringPut(String* key, Object* value); Object* AtNumberPut(uint32_t key, Object* value); Object* AddStringEntry(String* key, Object* value, PropertyDetails details); Object* AddNumberEntry(uint32_t key, Object* value, PropertyDetails details); // Set an existing entry or add a new one if needed. Object* SetOrAddStringEntry(String* key, Object* value, PropertyDetails details); Object* SetOrAddNumberEntry(uint32_t key, Object* value, PropertyDetails details); // 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); // Copies enumerable keys to preallocated fixed array. void CopyEnumKeysTo(FixedArray* storage, FixedArray* sort_array); // Fill in details for properties into storage. void CopyKeysTo(FixedArray* storage); // For transforming properties of a JSObject. Object* TransformPropertiesToFastFor(JSObject* obj, int unused_property_fields); // 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(); // Accessors for next enumeration index. void SetNextEnumerationIndex(int index) { fast_set(this, kNextEnumerationIndexIndex, Smi::FromInt(index)); } int NextEnumerationIndex() { return Smi::cast(get(kNextEnumerationIndexIndex))->value(); } // Returns a new array for dictionary usage. Might return Failure. static Object* Allocate(int at_least_space_for); // Ensure enough space for n additional elements. Object* EnsureCapacity(int n, HashTableKey* key); #ifdef DEBUG void Print(); #endif // Returns the key (slow). Object* SlowReverseLookup(Object* value); // Bit masks. static const int kRequiresSlowElementsMask = 1; static const int kRequiresSlowElementsTagSize = 1; static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1; void UpdateMaxNumberKey(uint32_t key); private: // Generic at put operation. Object* AtPut(HashTableKey* key, Object* value); Object* Add(HashTableKey* key, Object* value, PropertyDetails details); // Add entry to dictionary. void AddEntry(Object* key, Object* value, PropertyDetails details, uint32_t hash); // Sets the entry to (key, value) pair. inline void SetEntry(int entry, Object* key, Object* value, PropertyDetails details); // Generate new enumeration indices to avoid enumeration index overflow. Object* GenerateNewEnumerationIndices(); static const int kMaxNumberKeyIndex = kPrefixStartIndex; static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1; DISALLOW_IMPLICIT_CONSTRUCTORS(Dictionary); }; // 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 Array { public: // 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 kHeaderSize + OBJECT_SIZE_ALIGN(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. int ByteArraySize() { return SizeFor(length()); } #ifdef DEBUG void ByteArrayPrint(); void ByteArrayVerify(); #endif private: DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray); }; // 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. enum Flags { }; enum Kind { FUNCTION, STUB, BUILTIN, LOAD_IC, KEYED_LOAD_IC, CALL_IC, STORE_IC, KEYED_STORE_IC, // No more than eight kinds. The value currently encoded in three bits in // Flags. // Pseudo-kinds. REGEXP = BUILTIN, FIRST_IC_KIND = LOAD_IC, LAST_IC_KIND = KEYED_STORE_IC }; enum { NUMBER_OF_KINDS = KEYED_STORE_IC + 1 }; // A state indicates that inline cache in this Code object contains // objects or relative instruction addresses. enum ICTargetState { IC_TARGET_IS_ADDRESS, IC_TARGET_IS_OBJECT }; #ifdef ENABLE_DISASSEMBLER // Printing static const char* Kind2String(Kind kind); static const char* ICState2String(InlineCacheState state); 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_size]: Size of relocation information. inline int relocation_size(); inline void set_relocation_size(int value); // [sinfo_size]: Size of scope information. inline int sinfo_size(); inline void set_sinfo_size(int value); // [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 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; } // [ic_flag]: State of inline cache targets. The flag is set to the // object variant in ConvertICTargetsFromAddressToObject, and set to // the address variant in ConvertICTargetsFromObjectToAddress. inline ICTargetState ic_flag(); inline void set_ic_flag(ICTargetState value); // [major_key]: For kind STUB, the major key. inline CodeStub::Major major_key(); inline void set_major_key(CodeStub::Major major); // Flags operations. static inline Flags ComputeFlags(Kind kind, InlineCacheState ic_state = UNINITIALIZED, PropertyType type = NORMAL, int argc = -1); static inline Flags ComputeMonomorphicFlags(Kind kind, PropertyType type, int argc = -1); static inline Kind ExtractKindFromFlags(Flags flags); static inline InlineCacheState ExtractICStateFromFlags(Flags flags); static inline PropertyType ExtractTypeFromFlags(Flags flags); static inline int ExtractArgumentsCountFromFlags(Flags flags); static inline Flags RemoveTypeFromFlags(Flags flags); // Convert a target address into a code object. static inline Code* GetCodeFromTargetAddress(Address address); // Returns the address of the first instruction. inline byte* instruction_start(); // 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); // Returns the address of the scope information. inline byte* sinfo_start(); // Convert inline cache target from address to code object before GC. void ConvertICTargetsFromAddressToObject(); // Convert inline cache target from code object to address after GC void ConvertICTargetsFromObjectToAddress(); // Relocate the code by delta bytes. Called to signal that this code // object has been moved by delta bytes. void Relocate(int delta); // Migrate code described by desc. void CopyFrom(const CodeDesc& desc); // Returns the object size for a given body and sinfo size (Used for // allocation). static int SizeFor(int body_size, int sinfo_size) { ASSERT_SIZE_TAG_ALIGNED(body_size); ASSERT_SIZE_TAG_ALIGNED(sinfo_size); return RoundUp(kHeaderSize + body_size + sinfo_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(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(), sinfo_size()); } void CodeIterateBody(ObjectVisitor* v); #ifdef DEBUG void CodePrint(); void CodeVerify(); #endif // Layout description. static const int kInstructionSizeOffset = HeapObject::kHeaderSize; static const int kRelocationSizeOffset = kInstructionSizeOffset + kIntSize; static const int kSInfoSizeOffset = kRelocationSizeOffset + kIntSize; static const int kFlagsOffset = kSInfoSizeOffset + kIntSize; static const int kKindSpecificFlagsOffset = kFlagsOffset + kIntSize; // Add filler objects to align the instruction start following right after // the Code object header. static const int kFiller6Offset = kKindSpecificFlagsOffset + kIntSize; static const int kFiller7Offset = kFiller6Offset + kIntSize; static const int kHeaderSize = kFiller7Offset + kIntSize; // Code entry points are aligned to 32 bytes. static const int kCodeAlignment = 32; // Byte offsets within kKindSpecificFlagsOffset. static const int kICFlagOffset = kKindSpecificFlagsOffset + 0; static const int kStubMajorKeyOffset = kKindSpecificFlagsOffset + 1; // Flags layout. static const int kFlagsICStateShift = 0; static const int kFlagsKindShift = 3; static const int kFlagsTypeShift = 6; static const int kFlagsArgumentsCountShift = 9; static const int kFlagsICStateMask = 0x00000007; // 000000111 static const int kFlagsKindMask = 0x00000038; // 000111000 static const int kFlagsTypeMask = 0x000001C0; // 111000000 static const int kFlagsArgumentsCountMask = 0xFFFFFE00; 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. 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); // 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 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; } // Tells 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; } // Tells whether the instance has a named 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; } inline void set_needs_loading(bool value) { if (value) { set_bit_field2(bit_field2() | (1 << kNeedsLoading)); } else { set_bit_field2(bit_field2() & ~(1 << kNeedsLoading)); } } // Does this object or function require a lazily loaded script to be // run before being used? inline bool needs_loading() { return ((1 << kNeedsLoading) & bit_field2()) != 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; } // 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) // [instance descriptors]: describes the object. DECL_ACCESSORS(instance_descriptors, DescriptorArray) // [stub cache]: contains stubs compiled for this map. DECL_ACCESSORS(code_cache, FixedArray) // Returns a copy of the map. Object* CopyDropDescriptors(); // Returns a copy of the map, with all transitions dropped from the // instance descriptors. Object* CopyDropTransitions(); // 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. Object* 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(Code* code); // Removes a code object from the code cache at the given index. void RemoveFromCodeCache(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. void MapIterateBody(ObjectVisitor* v); #ifdef DEBUG void MapPrint(); void MapVerify(); #endif // 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 kSize = kCodeCacheOffset + kIntSize; // Byte offsets within kInstanceSizesOffset. static const int kInstanceSizeOffset = kInstanceSizesOffset + 0; static const int kInObjectPropertiesOffset = kInstanceSizesOffset + 1; // The bytes at positions 2 and 3 are not in use at the moment. // 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; // 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 but field 2 static const int kNeedsLoading = 0; 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 types. enum ScriptType { SCRIPT_TYPE_NATIVE, SCRIPT_TYPE_EXTENSION, SCRIPT_TYPE_NORMAL }; // Script describes a script which has been added to the VM. class Script: public Struct { public: // [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) // [line_ends]: array of line ends positions DECL_ACCESSORS(line_ends, Object) static inline Script* cast(Object* obj); #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 kLineEndsOffset = kTypeOffset + kPointerSize; static const int kIdOffset = kLineEndsOffset + kPointerSize; static const int kSize = kIdOffset + 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) // 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); // [instance class name]: class name for instances. DECL_ACCESSORS(instance_class_name, Object) // [function data]: This field has been added for make benefit the API. // 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) // [script info]: Script from which the function originates. DECL_ACCESSORS(script, Object) // [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) // 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. Used for accessing the // caller of functions. Top-level functions (scripts, evals) are // returned as null; see JSFunction::GetCallerAccessor(...). inline bool is_toplevel(); inline void set_is_toplevel(bool value); // [source code]: Source code for the function. bool HasSourceCode(); Object* GetSourceCode(); // Dispatched behavior. void SharedFunctionInfoIterateBody(ObjectVisitor* v); // 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. static const int kNameOffset = HeapObject::kHeaderSize; static const int kCodeOffset = kNameOffset + kPointerSize; static const int kLengthOffset = kCodeOffset + kPointerSize; static const int kFormalParameterCountOffset = kLengthOffset + kIntSize; static const int kExpectedNofPropertiesOffset = kFormalParameterCountOffset + kIntSize; static const int kInstanceClassNameOffset = kExpectedNofPropertiesOffset + kIntSize; static const int kExternalReferenceDataOffset = kInstanceClassNameOffset + kPointerSize; static const int kScriptOffset = kExternalReferenceDataOffset + kPointerSize; static const int kStartPositionAndTypeOffset = kScriptOffset + kPointerSize; static const int kEndPositionOffset = kStartPositionAndTypeOffset + kIntSize; static const int kFunctionTokenPositionOffset = kEndPositionOffset + kIntSize; static const int kDebugInfoOffset = kFunctionTokenPositionOffset + kIntSize; static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize; static const int kSize = kInferredNameOffset + kPointerSize; private: // Bit positions in length_and_flg. // The least significant bit is used as the flag. static const int kFlagBit = 0; static const int kLengthShift = 1; static const int kLengthMask = ~((1 << kLengthShift) - 1); // 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); 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) // [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); // Tells whether this function is a context-independent boilerplate // function. inline bool IsBoilerplate(); // [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); Object* SetPrototype(Object* value); // 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); // 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 kPrototypeOrInitialMapOffset = JSObject::kHeaderSize; 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) // 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); // 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 one pointer per runtime routine written in javascript. static const int kJSBuiltinsCount = Builtins::id_count; static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize; static const int kSize = kJSBuiltinsOffset + (kJSBuiltinsCount * 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 inline JSRegExp* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void JSRegExpVerify(); #endif static const int kDataOffset = JSObject::kHeaderSize; static const int kSize = kDataOffset + kIntSize; // 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. static const int kIrregexpASCIICodeIndex = kDataIndex; // Irregexp compiled code or bytecode for UC16. 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; }; class CompilationCacheTable: public HashTable<0, 2> { 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); Object* Put(String* src, Object* value); Object* PutEval(String* src, Context* context, Object* value); Object* PutRegExp(String* src, JSRegExp::Flags flags, FixedArray* value); static inline CompilationCacheTable* cast(Object* obj); private: DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable); }; 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; } 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_; }; // 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 IsSliced(); 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 uninterpreted length field of the string. Notice // that the length field is also used to cache the hash value of // strings. In order to get or set the actual length of the string // use the length() and set_length methods. inline uint32_t length_field(); inline void set_length_field(uint32_t value); inline bool IsAsciiRepresentation(); inline bool IsTwoByteRepresentation(); // 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 top level ConsString that is hiding behind this // string. This is a no-op unless the string is a ConsString or a // SlicedString. Flatten mutates the ConsString and might return a // failure. Object* TryFlatten(); // Try to flatten the string. Checks first inline to see if it is necessary. // Do not handle allocation failures. After calling TryFlattenIfNotFlat, the // string could still be a ConsString, in which case a failure is returned. // Use FlattenString from Handles.cc to be sure to flatten. inline Object* TryFlattenIfNotFlat(); Vector ToAsciiVector(); Vector ToUC16Vector(); // Mark the string as an undetectable object. It only applies to // ascii and two byte string types. bool MarkAsUndetectable(); // Slice the string and return a substring. Object* Slice(int from, int to); // 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 ComputeLengthAndHashField(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 kSize = kLengthOffset + kIntSize; // Limits on sizes of different types of strings. static const int kMaxShortStringSize = 63; static const int kMaxMediumStringSize = 16383; 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 or sliced 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 kHashComputedMask = 1; static const int kIsArrayIndexMask = 1 << 1; static const int kNofLengthBitFields = 2; // Array index strings this short can keep their index in the hash // field. static const int kMaxCachedArrayIndexLength = 7; // Shift constants for retriving length and hash code from // length/hash field. static const int kHashShift = kNofLengthBitFields; static const int kShortLengthShift = kHashShift + kShortStringTag; static const int kMediumLengthShift = kHashShift + kMediumStringTag; static const int kLongLengthShift = kHashShift + kLongStringTag; // 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; }; // NOTE: If you call StringInputBuffer routines on strings that are // too deeply nested trees of cons and slice strings, then this // routine will overflow the stack. Strings that are merely deeply // nested trees of cons strings do not have a problem apart from // performance. 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: // 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); // Dispatched behaviour. // For regexp code. uint16_t* SeqStringGetTwoByteAddress(); 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: // 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 kHeaderSize + OBJECT_SIZE_ALIGN(length * kCharSize); } // Layout description. static const int kHeaderSize = String::kSize; // 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: // 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 kHeaderSize + OBJECT_SIZE_ALIGN(length * kShortSize); } // Layout description. static const int kHeaderSize = String::kSize; // 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); // Garbage collection support. This method is called during garbage // collection to iterate through the heap pointers in the body of // the ConsString. void ConsStringIterateBody(ObjectVisitor* v); // Layout description. static const int kFirstOffset = 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; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString); }; // The SlicedString class describes string values that are slices of // some other string. SlicedStrings consist of a reference to an // underlying heap-allocated string value, a start index, and the // length field common to all strings. class SlicedString: public String { public: // The underlying string buffer. inline String* buffer(); inline void set_buffer(String* buffer); // The start index of the slice. inline int start(); inline void set_start(int start); // Dispatched behavior. uint16_t SlicedStringGet(int index); // Casting. static inline SlicedString* cast(Object* obj); // Garbage collection support. void SlicedStringIterateBody(ObjectVisitor* v); // Layout description static const int kBufferOffset = String::kSize; static const int kStartOffset = kBufferOffset + kPointerSize; static const int kSize = kStartOffset + kIntSize; // Support for StringInputBuffer. inline const unibrow::byte* SlicedStringReadBlock(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); inline void SlicedStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString); }; // 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 = String::kSize; static const int kSize = kResourceOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString); }; // The ExternalAsciiString class is an external string backed by an // ASCII string. class ExternalAsciiString: public ExternalString { public: 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); // Support for StringInputBuffer. const unibrow::byte* ExternalAsciiStringReadBlock(unsigned* remaining, unsigned* offset, unsigned chars); inline void ExternalAsciiStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset, unsigned chars); // Identify the map for the external string/symbol with a particular length. static inline Map* StringMap(int length); static inline Map* SymbolMap(int length); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalAsciiString); }; // The ExternalTwoByteString class is an external string backed by a UTF-16 // encoded string. class ExternalTwoByteString: public ExternalString { public: 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); // Support for StringInputBuffer. void ExternalTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); // Identify the map for the external string/symbol with a particular length. static inline Map* StringMap(int length); static inline Map* SymbolMap(int length); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString); }; // 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 BASE_EMBEDDED { public: explicit FlatStringReader(Handle str); explicit FlatStringReader(Vector input); ~FlatStringReader(); void RefreshState(); inline uc32 Get(int index); int length() { return length_; } static void PostGarbageCollectionProcessing(); private: String** str_; bool is_ascii_; int length_; const void* start_; FlatStringReader* prev_; static FlatStringReader* top_; }; // 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. void OddballIterateBody(ObjectVisitor* v); #ifdef DEBUG void OddballVerify(); #endif // Initialize the fields. Object* 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; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball); }; // 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); #ifdef DEBUG void ProxyPrint(); void ProxyVerify(); #endif // Layout description. static const int kProxyOffset = HeapObject::kHeaderSize; static const int kSize = kProxyOffset + kPointerSize; 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) Object* 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. Object* 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. void EnsureSize(int minimum_size_of_backing_fixed_array); // Dispatched behavior. #ifdef DEBUG void JSArrayPrint(); void JSArrayVerify(); #endif // Layout description. static const int kLengthOffset = JSObject::kHeaderSize; static const int kSize = kLengthOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray); }; // 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. // // To allow shadow an accessor property, the accessor can // have READ_ONLY property attribute so that a new value // is added to the local object to shadow the accessor // in prototypes. 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) 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 kSize = kFlagOffset + 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 + kHeaderSize; }; 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.. // Called prior to visiting the body of a Code object. virtual void BeginCodeIteration(Code* code); // Visits a code target in the instruction stream. virtual void VisitCodeTarget(RelocInfo* rinfo); // Visits a runtime entry in the instruction stream. virtual void VisitRuntimeEntry(RelocInfo* rinfo) {} // Visits a debug call target in the instruction stream. virtual void VisitDebugTarget(RelocInfo* rinfo); // Called after completing visiting the body of a Code object. virtual void EndCodeIteration(Code* code) {} // 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) {} #endif }; // 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_