// Copyright 2012 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 "allocation.h" #include "builtins.h" #include "list.h" #include "property-details.h" #include "smart-array-pointer.h" #include "unicode-inl.h" #if V8_TARGET_ARCH_ARM #include "arm/constants-arm.h" #elif V8_TARGET_ARCH_MIPS #include "mips/constants-mips.h" #endif #include "v8checks.h" // // Most object types in the V8 JavaScript are described in this file. // // Inheritance hierarchy: // - MaybeObject (an object or a failure) // - Failure (immediate for marking failed operation) // - Object // - Smi (immediate small integer) // - HeapObject (superclass for everything allocated in the heap) // - JSReceiver (suitable for property access) // - JSObject // - JSArray // - JSSet // - JSMap // - JSWeakMap // - JSRegExp // - JSFunction // - GlobalObject // - JSGlobalObject // - JSBuiltinsObject // - JSGlobalProxy // - JSValue // - JSDate // - JSMessageObject // - JSProxy // - JSFunctionProxy // - FixedArrayBase // - ByteArray // - FixedArray // - DescriptorArray // - HashTable // - Dictionary // - SymbolTable // - CompilationCacheTable // - CodeCacheHashTable // - MapCache // - Context // - JSFunctionResultCache // - ScopeInfo // - FixedDoubleArray // - ExternalArray // - ExternalPixelArray // - ExternalByteArray // - ExternalUnsignedByteArray // - ExternalShortArray // - ExternalUnsignedShortArray // - ExternalIntArray // - ExternalUnsignedIntArray // - ExternalFloatArray // - String // - SeqString // - SeqAsciiString // - SeqTwoByteString // - SlicedString // - ConsString // - ExternalString // - ExternalAsciiString // - ExternalTwoByteString // - HeapNumber // - Code // - Map // - Oddball // - Foreign // - SharedFunctionInfo // - Struct // - AccessorInfo // - AccessorPair // - AccessCheckInfo // - InterceptorInfo // - CallHandlerInfo // - TemplateInfo // - FunctionTemplateInfo // - ObjectTemplateInfo // - Script // - SignatureInfo // - TypeSwitchInfo // - DebugInfo // - BreakPointInfo // - CodeCache // // Formats of Object*: // Smi: [31 bit signed int] 0 // HeapObject: [32 bit direct pointer] (4 byte aligned) | 01 // Failure: [30 bit signed int] 11 namespace v8 { namespace internal { enum ElementsKind { // The "fast" kind for elements that only contain SMI values. Must be first // to make it possible to efficiently check maps for this kind. FAST_SMI_ONLY_ELEMENTS, // The "fast" kind for tagged values. Must be second to make it possible to // efficiently check maps for this and the FAST_SMI_ONLY_ELEMENTS kind // together at once. FAST_ELEMENTS, // The "fast" kind for unwrapped, non-tagged double values. FAST_DOUBLE_ELEMENTS, // The "slow" kind. DICTIONARY_ELEMENTS, NON_STRICT_ARGUMENTS_ELEMENTS, // The "fast" kind for external arrays EXTERNAL_BYTE_ELEMENTS, EXTERNAL_UNSIGNED_BYTE_ELEMENTS, EXTERNAL_SHORT_ELEMENTS, EXTERNAL_UNSIGNED_SHORT_ELEMENTS, EXTERNAL_INT_ELEMENTS, EXTERNAL_UNSIGNED_INT_ELEMENTS, EXTERNAL_FLOAT_ELEMENTS, EXTERNAL_DOUBLE_ELEMENTS, EXTERNAL_PIXEL_ELEMENTS, // Derived constants from ElementsKind FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_BYTE_ELEMENTS, LAST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS, FIRST_ELEMENTS_KIND = FAST_SMI_ONLY_ELEMENTS, LAST_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS }; enum CompareMapMode { REQUIRE_EXACT_MAP, ALLOW_ELEMENT_TRANSITION_MAPS }; enum KeyedAccessGrowMode { DO_NOT_ALLOW_JSARRAY_GROWTH, ALLOW_JSARRAY_GROWTH }; const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1; void PrintElementsKind(FILE* out, ElementsKind kind); inline bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind, ElementsKind to_kind); // Setter that skips the write barrier if mode is SKIP_WRITE_BARRIER. enum WriteBarrierMode { SKIP_WRITE_BARRIER, UPDATE_WRITE_BARRIER }; // PropertyNormalizationMode is used to specify whether to keep // inobject properties when normalizing properties of a JSObject. enum PropertyNormalizationMode { CLEAR_INOBJECT_PROPERTIES, KEEP_INOBJECT_PROPERTIES }; // NormalizedMapSharingMode is used to specify whether a map may be shared // by different objects with normalized properties. enum NormalizedMapSharingMode { UNIQUE_NORMALIZED_MAP, SHARED_NORMALIZED_MAP }; // Indicates whether a get method should implicitly create the object looked up. enum CreationFlag { ALLOW_CREATION, OMIT_CREATION }; // Instance size sentinel for objects of variable size. const int kVariableSizeSentinel = 0; // All Maps have a field instance_type containing a InstanceType. // It describes the type of the instances. // // As an example, a JavaScript object is a heap object and its map // instance_type is JS_OBJECT_TYPE. // // The names of the string instance types are intended to systematically // mirror their encoding in the instance_type field of the map. The default // encoding is considered TWO_BYTE. It is not mentioned in the name. ASCII // encoding is mentioned explicitly in the name. Likewise, the default // representation is considered sequential. It is not mentioned in the // name. The other representations (e.g. CONS, EXTERNAL) are explicitly // mentioned. Finally, the string is either a SYMBOL_TYPE (if it is a // symbol) or a STRING_TYPE (if it is not a symbol). // // NOTE: The following things are some that depend on the string types having // instance_types that are less than those of all other types: // HeapObject::Size, HeapObject::IterateBody, the typeof operator, and // Object::IsString. // // NOTE: Everything following JS_VALUE_TYPE is considered a // JSObject for GC purposes. The first four entries here have typeof // 'object', whereas JS_FUNCTION_TYPE has typeof 'function'. #define INSTANCE_TYPE_LIST_ALL(V) \ V(SYMBOL_TYPE) \ V(ASCII_SYMBOL_TYPE) \ V(CONS_SYMBOL_TYPE) \ V(CONS_ASCII_SYMBOL_TYPE) \ V(EXTERNAL_SYMBOL_TYPE) \ V(EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE) \ V(EXTERNAL_ASCII_SYMBOL_TYPE) \ V(SHORT_EXTERNAL_SYMBOL_TYPE) \ V(SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE) \ V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE) \ V(STRING_TYPE) \ V(ASCII_STRING_TYPE) \ V(CONS_STRING_TYPE) \ V(CONS_ASCII_STRING_TYPE) \ V(SLICED_STRING_TYPE) \ V(EXTERNAL_STRING_TYPE) \ V(EXTERNAL_STRING_WITH_ASCII_DATA_TYPE) \ V(EXTERNAL_ASCII_STRING_TYPE) \ V(SHORT_EXTERNAL_STRING_TYPE) \ V(SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE) \ V(SHORT_EXTERNAL_ASCII_STRING_TYPE) \ V(PRIVATE_EXTERNAL_ASCII_STRING_TYPE) \ \ V(MAP_TYPE) \ V(CODE_TYPE) \ V(ODDBALL_TYPE) \ V(JS_GLOBAL_PROPERTY_CELL_TYPE) \ \ V(HEAP_NUMBER_TYPE) \ V(FOREIGN_TYPE) \ V(BYTE_ARRAY_TYPE) \ V(FREE_SPACE_TYPE) \ /* Note: the order of these external array */ \ /* types is relied upon in */ \ /* Object::IsExternalArray(). */ \ V(EXTERNAL_BYTE_ARRAY_TYPE) \ V(EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE) \ V(EXTERNAL_SHORT_ARRAY_TYPE) \ V(EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE) \ V(EXTERNAL_INT_ARRAY_TYPE) \ V(EXTERNAL_UNSIGNED_INT_ARRAY_TYPE) \ V(EXTERNAL_FLOAT_ARRAY_TYPE) \ V(EXTERNAL_PIXEL_ARRAY_TYPE) \ V(FILLER_TYPE) \ \ V(ACCESSOR_INFO_TYPE) \ V(ACCESSOR_PAIR_TYPE) \ V(ACCESS_CHECK_INFO_TYPE) \ V(INTERCEPTOR_INFO_TYPE) \ V(CALL_HANDLER_INFO_TYPE) \ V(FUNCTION_TEMPLATE_INFO_TYPE) \ V(OBJECT_TEMPLATE_INFO_TYPE) \ V(SIGNATURE_INFO_TYPE) \ V(TYPE_SWITCH_INFO_TYPE) \ V(SCRIPT_TYPE) \ V(CODE_CACHE_TYPE) \ V(POLYMORPHIC_CODE_CACHE_TYPE) \ V(TYPE_FEEDBACK_INFO_TYPE) \ V(ALIASED_ARGUMENTS_ENTRY_TYPE) \ \ V(FIXED_ARRAY_TYPE) \ V(FIXED_DOUBLE_ARRAY_TYPE) \ V(SHARED_FUNCTION_INFO_TYPE) \ \ V(JS_MESSAGE_OBJECT_TYPE) \ \ V(JS_VALUE_TYPE) \ V(JS_DATE_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_PROXY_TYPE) \ V(JS_WEAK_MAP_TYPE) \ V(JS_REGEXP_TYPE) \ \ V(JS_FUNCTION_TYPE) \ V(JS_FUNCTION_PROXY_TYPE) \ #ifdef ENABLE_DEBUGGER_SUPPORT #define INSTANCE_TYPE_LIST_DEBUGGER(V) \ V(DEBUG_INFO_TYPE) \ V(BREAK_POINT_INFO_TYPE) #else #define INSTANCE_TYPE_LIST_DEBUGGER(V) #endif #define INSTANCE_TYPE_LIST(V) \ INSTANCE_TYPE_LIST_ALL(V) \ INSTANCE_TYPE_LIST_DEBUGGER(V) // Since string types are not consecutive, this macro is used to // iterate over them. #define STRING_TYPE_LIST(V) \ V(SYMBOL_TYPE, \ kVariableSizeSentinel, \ symbol, \ Symbol) \ V(ASCII_SYMBOL_TYPE, \ kVariableSizeSentinel, \ ascii_symbol, \ AsciiSymbol) \ V(CONS_SYMBOL_TYPE, \ ConsString::kSize, \ cons_symbol, \ ConsSymbol) \ V(CONS_ASCII_SYMBOL_TYPE, \ ConsString::kSize, \ cons_ascii_symbol, \ ConsAsciiSymbol) \ V(EXTERNAL_SYMBOL_TYPE, \ ExternalTwoByteString::kSize, \ external_symbol, \ ExternalSymbol) \ V(EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE, \ ExternalTwoByteString::kSize, \ external_symbol_with_ascii_data, \ ExternalSymbolWithAsciiData) \ V(EXTERNAL_ASCII_SYMBOL_TYPE, \ ExternalAsciiString::kSize, \ external_ascii_symbol, \ ExternalAsciiSymbol) \ V(SHORT_EXTERNAL_SYMBOL_TYPE, \ ExternalTwoByteString::kShortSize, \ short_external_symbol, \ ShortExternalSymbol) \ V(SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE, \ ExternalTwoByteString::kShortSize, \ short_external_symbol_with_ascii_data, \ ShortExternalSymbolWithAsciiData) \ V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE, \ ExternalAsciiString::kShortSize, \ short_external_ascii_symbol, \ ShortExternalAsciiSymbol) \ V(STRING_TYPE, \ kVariableSizeSentinel, \ string, \ String) \ V(ASCII_STRING_TYPE, \ kVariableSizeSentinel, \ ascii_string, \ AsciiString) \ V(CONS_STRING_TYPE, \ ConsString::kSize, \ cons_string, \ ConsString) \ V(CONS_ASCII_STRING_TYPE, \ ConsString::kSize, \ cons_ascii_string, \ ConsAsciiString) \ V(SLICED_STRING_TYPE, \ SlicedString::kSize, \ sliced_string, \ SlicedString) \ V(SLICED_ASCII_STRING_TYPE, \ SlicedString::kSize, \ sliced_ascii_string, \ SlicedAsciiString) \ V(EXTERNAL_STRING_TYPE, \ ExternalTwoByteString::kSize, \ external_string, \ ExternalString) \ V(EXTERNAL_STRING_WITH_ASCII_DATA_TYPE, \ ExternalTwoByteString::kSize, \ external_string_with_ascii_data, \ ExternalStringWithAsciiData) \ V(EXTERNAL_ASCII_STRING_TYPE, \ ExternalAsciiString::kSize, \ external_ascii_string, \ ExternalAsciiString) \ V(SHORT_EXTERNAL_STRING_TYPE, \ ExternalTwoByteString::kShortSize, \ short_external_string, \ ShortExternalString) \ V(SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE, \ ExternalTwoByteString::kShortSize, \ short_external_string_with_ascii_data, \ ShortExternalStringWithAsciiData) \ V(SHORT_EXTERNAL_ASCII_STRING_TYPE, \ ExternalAsciiString::kShortSize, \ short_external_ascii_string, \ ShortExternalAsciiString) // 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(ACCESSOR_PAIR, AccessorPair, accessor_pair) \ V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \ V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \ V(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \ V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \ V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \ V(SIGNATURE_INFO, SignatureInfo, signature_info) \ V(TYPE_SWITCH_INFO, TypeSwitchInfo, type_switch_info) \ V(SCRIPT, Script, script) \ V(CODE_CACHE, CodeCache, code_cache) \ V(POLYMORPHIC_CODE_CACHE, PolymorphicCodeCache, polymorphic_code_cache) \ V(TYPE_FEEDBACK_INFO, TypeFeedbackInfo, type_feedback_info) \ V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) #ifdef ENABLE_DEBUGGER_SUPPORT #define STRUCT_LIST_DEBUGGER(V) \ V(DEBUG_INFO, DebugInfo, debug_info) \ V(BREAK_POINT_INFO, BreakPointInfo, break_point_info) #else #define STRUCT_LIST_DEBUGGER(V) #endif #define STRUCT_LIST(V) \ STRUCT_LIST_ALL(V) \ STRUCT_LIST_DEBUGGER(V) // We use the full 8 bits of the instance_type field to encode heap object // instance types. The high-order bit (bit 7) is set if the object is not a // string, and cleared if it is a string. const uint32_t kIsNotStringMask = 0x80; const uint32_t kStringTag = 0x0; const uint32_t kNotStringTag = 0x80; // Bit 6 indicates that the object is a symbol (if set) or not (if cleared). // There are not enough types that the non-string types (with bit 7 set) can // have bit 6 set too. const uint32_t kIsSymbolMask = 0x40; const uint32_t kNotSymbolTag = 0x0; const uint32_t kSymbolTag = 0x40; // If bit 7 is clear then bit 2 indicates whether the string consists of // two-byte characters or one-byte characters. const uint32_t kStringEncodingMask = 0x4; const uint32_t kTwoByteStringTag = 0x0; const uint32_t kAsciiStringTag = 0x4; // If bit 7 is clear, the low-order 2 bits indicate the representation // of the string. const uint32_t kStringRepresentationMask = 0x03; enum StringRepresentationTag { kSeqStringTag = 0x0, kConsStringTag = 0x1, kExternalStringTag = 0x2, kSlicedStringTag = 0x3 }; const uint32_t kIsIndirectStringMask = 0x1; const uint32_t kIsIndirectStringTag = 0x1; STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); STATIC_ASSERT( (kConsStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); STATIC_ASSERT( (kSlicedStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); // Use this mask to distinguish between cons and slice only after making // sure that the string is one of the two (an indirect string). const uint32_t kSlicedNotConsMask = kSlicedStringTag & ~kConsStringTag; STATIC_ASSERT(IS_POWER_OF_TWO(kSlicedNotConsMask) && kSlicedNotConsMask != 0); // If bit 7 is clear, then bit 3 indicates whether this two-byte // string actually contains ASCII data. const uint32_t kAsciiDataHintMask = 0x08; const uint32_t kAsciiDataHintTag = 0x08; // If bit 7 is clear and string representation indicates an external string, // then bit 4 indicates whether the data pointer is cached. const uint32_t kShortExternalStringMask = 0x10; const uint32_t kShortExternalStringTag = 0x10; // A ConsString with an empty string as the right side is a candidate // for being shortcut by the garbage collector unless it is a // symbol. It's not common to have non-flat symbols, so we do not // shortcut them thereby avoiding turning symbols into strings. See // heap.cc and mark-compact.cc. const uint32_t kShortcutTypeMask = kIsNotStringMask | kIsSymbolMask | kStringRepresentationMask; const uint32_t kShortcutTypeTag = kConsStringTag; enum InstanceType { // String types. SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kSeqStringTag, ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kSeqStringTag, CONS_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kConsStringTag, CONS_ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kConsStringTag, SHORT_EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag | kShortExternalStringTag, SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag | kAsciiDataHintTag | kShortExternalStringTag, SHORT_EXTERNAL_ASCII_SYMBOL_TYPE = kAsciiStringTag | kExternalStringTag | kSymbolTag | kShortExternalStringTag, EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag, EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag | kAsciiDataHintTag, EXTERNAL_ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kExternalStringTag, STRING_TYPE = kTwoByteStringTag | kSeqStringTag, ASCII_STRING_TYPE = kAsciiStringTag | kSeqStringTag, CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag, CONS_ASCII_STRING_TYPE = kAsciiStringTag | kConsStringTag, SLICED_STRING_TYPE = kTwoByteStringTag | kSlicedStringTag, SLICED_ASCII_STRING_TYPE = kAsciiStringTag | kSlicedStringTag, SHORT_EXTERNAL_STRING_TYPE = kTwoByteStringTag | kExternalStringTag | kShortExternalStringTag, SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE = kTwoByteStringTag | kExternalStringTag | kAsciiDataHintTag | kShortExternalStringTag, SHORT_EXTERNAL_ASCII_STRING_TYPE = kAsciiStringTag | kExternalStringTag | kShortExternalStringTag, EXTERNAL_STRING_TYPE = kTwoByteStringTag | kExternalStringTag, EXTERNAL_STRING_WITH_ASCII_DATA_TYPE = kTwoByteStringTag | kExternalStringTag | kAsciiDataHintTag, // LAST_STRING_TYPE EXTERNAL_ASCII_STRING_TYPE = kAsciiStringTag | kExternalStringTag, PRIVATE_EXTERNAL_ASCII_STRING_TYPE = EXTERNAL_ASCII_STRING_TYPE, // Objects allocated in their own spaces (never in new space). MAP_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE CODE_TYPE, ODDBALL_TYPE, JS_GLOBAL_PROPERTY_CELL_TYPE, // "Data", objects that cannot contain non-map-word pointers to heap // objects. HEAP_NUMBER_TYPE, FOREIGN_TYPE, BYTE_ARRAY_TYPE, FREE_SPACE_TYPE, EXTERNAL_BYTE_ARRAY_TYPE, // FIRST_EXTERNAL_ARRAY_TYPE EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE, EXTERNAL_SHORT_ARRAY_TYPE, EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE, EXTERNAL_INT_ARRAY_TYPE, EXTERNAL_UNSIGNED_INT_ARRAY_TYPE, EXTERNAL_FLOAT_ARRAY_TYPE, EXTERNAL_DOUBLE_ARRAY_TYPE, EXTERNAL_PIXEL_ARRAY_TYPE, // LAST_EXTERNAL_ARRAY_TYPE FIXED_DOUBLE_ARRAY_TYPE, FILLER_TYPE, // LAST_DATA_TYPE // Structs. ACCESSOR_INFO_TYPE, ACCESSOR_PAIR_TYPE, ACCESS_CHECK_INFO_TYPE, INTERCEPTOR_INFO_TYPE, CALL_HANDLER_INFO_TYPE, FUNCTION_TEMPLATE_INFO_TYPE, OBJECT_TEMPLATE_INFO_TYPE, SIGNATURE_INFO_TYPE, TYPE_SWITCH_INFO_TYPE, SCRIPT_TYPE, CODE_CACHE_TYPE, POLYMORPHIC_CODE_CACHE_TYPE, TYPE_FEEDBACK_INFO_TYPE, ALIASED_ARGUMENTS_ENTRY_TYPE, // The following two instance types are only used when ENABLE_DEBUGGER_SUPPORT // is defined. However as include/v8.h contain some of the instance type // constants always having them avoids them getting different numbers // depending on whether ENABLE_DEBUGGER_SUPPORT is defined or not. DEBUG_INFO_TYPE, BREAK_POINT_INFO_TYPE, FIXED_ARRAY_TYPE, SHARED_FUNCTION_INFO_TYPE, JS_MESSAGE_OBJECT_TYPE, // All the following types are subtypes of JSReceiver, which corresponds to // objects in the JS sense. The first and the last type in this range are // the two forms of function. This organization enables using the same // compares for checking the JS_RECEIVER/SPEC_OBJECT range and the // NONCALLABLE_JS_OBJECT range. JS_FUNCTION_PROXY_TYPE, // FIRST_JS_RECEIVER_TYPE, FIRST_JS_PROXY_TYPE JS_PROXY_TYPE, // LAST_JS_PROXY_TYPE JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE JS_DATE_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_SET_TYPE, JS_MAP_TYPE, JS_WEAK_MAP_TYPE, JS_REGEXP_TYPE, JS_FUNCTION_TYPE, // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE // Pseudo-types FIRST_TYPE = 0x0, LAST_TYPE = JS_FUNCTION_TYPE, INVALID_TYPE = FIRST_TYPE - 1, FIRST_NONSTRING_TYPE = MAP_TYPE, // Boundaries for testing for an external array. FIRST_EXTERNAL_ARRAY_TYPE = EXTERNAL_BYTE_ARRAY_TYPE, LAST_EXTERNAL_ARRAY_TYPE = EXTERNAL_PIXEL_ARRAY_TYPE, // Boundary for promotion to old data space/old pointer space. LAST_DATA_TYPE = FILLER_TYPE, // Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy). // Note that there is no range for JSObject or JSProxy, since their subtypes // are not continuous in this enum! The enum ranges instead reflect the // external class names, where proxies are treated as either ordinary objects, // or functions. FIRST_JS_RECEIVER_TYPE = JS_FUNCTION_PROXY_TYPE, LAST_JS_RECEIVER_TYPE = LAST_TYPE, // Boundaries for testing the types represented as JSObject FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE, LAST_JS_OBJECT_TYPE = LAST_TYPE, // Boundaries for testing the types represented as JSProxy FIRST_JS_PROXY_TYPE = JS_FUNCTION_PROXY_TYPE, LAST_JS_PROXY_TYPE = JS_PROXY_TYPE, // Boundaries for testing whether the type is a JavaScript object. FIRST_SPEC_OBJECT_TYPE = FIRST_JS_RECEIVER_TYPE, LAST_SPEC_OBJECT_TYPE = LAST_JS_RECEIVER_TYPE, // Boundaries for testing the types for which typeof is "object". FIRST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_PROXY_TYPE, LAST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_REGEXP_TYPE, // Note that the types for which typeof is "function" are not continuous. // Define this so that we can put assertions on discrete checks. NUM_OF_CALLABLE_SPEC_OBJECT_TYPES = 2 }; const int kExternalArrayTypeCount = LAST_EXTERNAL_ARRAY_TYPE - FIRST_EXTERNAL_ARRAY_TYPE + 1; STATIC_CHECK(JS_OBJECT_TYPE == Internals::kJSObjectType); STATIC_CHECK(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType); STATIC_CHECK(FOREIGN_TYPE == Internals::kForeignType); 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 DictionaryElementsAccessor; class ElementsAccessor; class FixedArrayBase; class ObjectVisitor; class StringStream; class Failure; struct ValueInfo : public Malloced { ValueInfo() : type(FIRST_TYPE), ptr(NULL), str(NULL), number(0) { } InstanceType type; Object* ptr; const char* str; double number; }; // A template-ized version of the IsXXX functions. template static inline bool Is(Object* obj); class MaybeObject BASE_EMBEDDED { public: inline bool IsFailure(); inline bool IsRetryAfterGC(); inline bool IsOutOfMemory(); inline bool IsException(); INLINE(bool IsTheHole()); inline bool ToObject(Object** obj) { if (IsFailure()) return false; *obj = reinterpret_cast(this); return true; } inline Failure* ToFailureUnchecked() { ASSERT(IsFailure()); return reinterpret_cast(this); } inline Object* ToObjectUnchecked() { ASSERT(!IsFailure()); return reinterpret_cast(this); } inline Object* ToObjectChecked() { CHECK(!IsFailure()); return reinterpret_cast(this); } template inline bool To(T** obj) { if (IsFailure()) return false; *obj = T::cast(reinterpret_cast(this)); return true; } #ifdef OBJECT_PRINT // Prints this object with details. inline void Print() { Print(stdout); } inline void PrintLn() { PrintLn(stdout); } void Print(FILE* out); void PrintLn(FILE* out); #endif #ifdef DEBUG // Verifies the object. void Verify(); #endif }; #define OBJECT_TYPE_LIST(V) \ V(Smi) \ V(HeapObject) \ V(Number) \ #define HEAP_OBJECT_TYPE_LIST(V) \ V(HeapNumber) \ V(String) \ V(Symbol) \ V(SeqString) \ V(ExternalString) \ V(ConsString) \ V(SlicedString) \ V(ExternalTwoByteString) \ V(ExternalAsciiString) \ V(SeqTwoByteString) \ V(SeqAsciiString) \ \ V(ExternalArray) \ V(ExternalByteArray) \ V(ExternalUnsignedByteArray) \ V(ExternalShortArray) \ V(ExternalUnsignedShortArray) \ V(ExternalIntArray) \ V(ExternalUnsignedIntArray) \ V(ExternalFloatArray) \ V(ExternalDoubleArray) \ V(ExternalPixelArray) \ V(ByteArray) \ V(FreeSpace) \ V(JSReceiver) \ V(JSObject) \ V(JSContextExtensionObject) \ V(Map) \ V(DescriptorArray) \ V(DeoptimizationInputData) \ V(DeoptimizationOutputData) \ V(TypeFeedbackCells) \ V(FixedArray) \ V(FixedDoubleArray) \ V(Context) \ V(GlobalContext) \ V(ScopeInfo) \ V(JSFunction) \ V(Code) \ V(Oddball) \ V(SharedFunctionInfo) \ V(JSValue) \ V(JSDate) \ V(JSMessageObject) \ V(StringWrapper) \ V(Foreign) \ V(Boolean) \ V(JSArray) \ V(JSProxy) \ V(JSFunctionProxy) \ V(JSSet) \ V(JSMap) \ V(JSWeakMap) \ V(JSRegExp) \ V(HashTable) \ V(Dictionary) \ V(SymbolTable) \ V(JSFunctionResultCache) \ V(NormalizedMapCache) \ V(CompilationCacheTable) \ V(CodeCacheHashTable) \ V(PolymorphicCodeCacheHashTable) \ V(MapCache) \ V(Primitive) \ V(GlobalObject) \ V(JSGlobalObject) \ V(JSBuiltinsObject) \ V(JSGlobalProxy) \ V(UndetectableObject) \ V(AccessCheckNeeded) \ V(JSGlobalPropertyCell) \ class JSReceiver; // Object is the abstract superclass for all classes in the // object hierarchy. // Object does not use any virtual functions to avoid the // allocation of the C++ vtable. // Since Smi and Failure are subclasses of Object no // data members can be present in Object. class Object : public MaybeObject { public: // Type testing. bool IsObject() { return true; } #define IS_TYPE_FUNCTION_DECL(type_) inline bool Is##type_(); OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL) HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL) #undef IS_TYPE_FUNCTION_DECL inline bool IsFixedArrayBase(); // Returns true if this object is an instance of the specified // function template. inline bool IsInstanceOf(FunctionTemplateInfo* type); inline bool IsStruct(); #define DECLARE_STRUCT_PREDICATE(NAME, Name, name) inline bool Is##Name(); STRUCT_LIST(DECLARE_STRUCT_PREDICATE) #undef DECLARE_STRUCT_PREDICATE INLINE(bool IsSpecObject()); INLINE(bool IsSpecFunction()); // Oddball testing. INLINE(bool IsUndefined()); INLINE(bool IsNull()); INLINE(bool IsTheHole()); // Shadows MaybeObject's implementation. INLINE(bool IsTrue()); INLINE(bool IsFalse()); inline bool IsArgumentsMarker(); inline bool NonFailureIsHeapObject(); // Filler objects (fillers and free space objects). inline bool IsFiller(); // Extract the number. inline double Number(); inline bool IsNaN(); // Returns true if the object is of the correct type to be used as a // implementation of a JSObject's elements. inline bool HasValidElements(); inline bool HasSpecificClassOf(String* name); MUST_USE_RESULT MaybeObject* ToObject(); // ECMA-262 9.9. Object* ToBoolean(); // ECMA-262 9.2. // Convert to a JSObject if needed. // global_context is used when creating wrapper object. MUST_USE_RESULT MaybeObject* ToObject(Context* global_context); // Converts this to a Smi if possible. // Failure is returned otherwise. MUST_USE_RESULT inline MaybeObject* ToSmi(); void Lookup(String* name, LookupResult* result); // Property access. MUST_USE_RESULT inline MaybeObject* GetProperty(String* key); MUST_USE_RESULT inline MaybeObject* GetProperty( String* key, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetPropertyWithReceiver( Object* receiver, String* key, PropertyAttributes* attributes); static Handle GetProperty(Handle object, Handle receiver, LookupResult* result, Handle key, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetProperty(Object* receiver, LookupResult* result, String* key, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetPropertyWithDefinedGetter(Object* receiver, JSReceiver* getter); static Handle GetElement(Handle object, uint32_t index); MUST_USE_RESULT inline MaybeObject* GetElement(uint32_t index); // For use when we know that no exception can be thrown. inline Object* GetElementNoExceptionThrown(uint32_t index); MUST_USE_RESULT MaybeObject* GetElementWithReceiver(Object* receiver, uint32_t index); // Return the object's prototype (might be Heap::null_value()). Object* GetPrototype(); // Returns the permanent hash code associated with this object depending on // the actual object type. Might return a failure in case no hash was // created yet or GC was caused by creation. MUST_USE_RESULT MaybeObject* GetHash(CreationFlag flag); // Checks whether this object has the same value as the given one. This // function is implemented according to ES5, section 9.12 and can be used // to implement the Harmony "egal" function. bool SameValue(Object* other); // Tries to convert an object to an array index. Returns true and sets // the output parameter if it succeeds. inline bool ToArrayIndex(uint32_t* index); // Returns true if this is a JSValue containing a string and the index is // < the length of the string. Used to implement [] on strings. inline bool IsStringObjectWithCharacterAt(uint32_t index); #ifdef DEBUG // Verify a pointer is a valid object pointer. static void VerifyPointer(Object* p); #endif // Prints this object without details. inline void ShortPrint() { ShortPrint(stdout); } void ShortPrint(FILE* out); // Prints this object without details to a message accumulator. void ShortPrint(StringStream* accumulator); // Casting: This cast is only needed to satisfy macros in objects-inl.h. static Object* cast(Object* value) { return value; } // Layout description. static const int kHeaderSize = 0; // Object does not take up any space. private: DISALLOW_IMPLICIT_CONSTRUCTORS(Object); }; // Smi represents integer Numbers that can be stored in 31 bits. // Smis are immediate which means they are NOT allocated in the heap. // The this pointer has the following format: [31 bit signed int] 0 // For long smis it has the following format: // [32 bit signed int] [31 bits zero padding] 0 // Smi stands for small integer. class Smi: public Object { public: // Returns the integer value. inline int value(); // Convert a value to a Smi object. static inline Smi* FromInt(int value); static inline Smi* FromIntptr(intptr_t value); // Returns whether value can be represented in a Smi. static inline bool IsValid(intptr_t value); // Casting. static inline Smi* cast(Object* object); // Dispatched behavior. inline void SmiPrint() { SmiPrint(stdout); } void SmiPrint(FILE* out); void SmiPrint(StringStream* accumulator); #ifdef DEBUG void SmiVerify(); #endif static const int kMinValue = (static_cast(-1)) << (kSmiValueSize - 1); static const int kMaxValue = -(kMinValue + 1); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Smi); }; // Failure is used for reporting out of memory situations and // propagating exceptions through the runtime system. Failure objects // are transient and cannot occur as part of the object graph. // // Failures are a single word, encoded as follows: // +-------------------------+---+--+--+ // |.........unused..........|sss|tt|11| // +-------------------------+---+--+--+ // 7 6 4 32 10 // // // The low two bits, 0-1, are the failure tag, 11. The next two bits, // 2-3, are a failure type tag 'tt' with possible values: // 00 RETRY_AFTER_GC // 01 EXCEPTION // 10 INTERNAL_ERROR // 11 OUT_OF_MEMORY_EXCEPTION // // The next three bits, 4-6, are an allocation space tag 'sss'. The // allocation space tag is 000 for all failure types except // RETRY_AFTER_GC. For RETRY_AFTER_GC, the possible values are the // allocation spaces (the encoding is found in globals.h). // Failure type tag info. const int kFailureTypeTagSize = 2; const int kFailureTypeTagMask = (1 << kFailureTypeTagSize) - 1; class Failure: public MaybeObject { public: // RuntimeStubs assumes EXCEPTION = 1 in the compiler-generated code. enum Type { RETRY_AFTER_GC = 0, EXCEPTION = 1, // Returning this marker tells the real exception // is in Isolate::pending_exception. INTERNAL_ERROR = 2, OUT_OF_MEMORY_EXCEPTION = 3 }; inline Type type() const; // Returns the space that needs to be collected for RetryAfterGC failures. inline AllocationSpace allocation_space() const; inline bool IsInternalError() const; inline bool IsOutOfMemoryException() const; static inline Failure* RetryAfterGC(AllocationSpace space); static inline Failure* RetryAfterGC(); // NEW_SPACE static inline Failure* Exception(); static inline Failure* InternalError(); static inline Failure* OutOfMemoryException(); // Casting. static inline Failure* cast(MaybeObject* object); // Dispatched behavior. inline void FailurePrint() { FailurePrint(stdout); } void FailurePrint(FILE* out); void FailurePrint(StringStream* accumulator); #ifdef DEBUG void FailureVerify(); #endif private: inline intptr_t value() const; static inline Failure* Construct(Type type, intptr_t value = 0); DISALLOW_IMPLICIT_CONSTRUCTORS(Failure); }; // Heap objects typically have a map pointer in their first word. However, // during GC other data (e.g. 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, i.e. 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(); static inline MapWord FromRawValue(uintptr_t value) { return MapWord(value); } inline uintptr_t ToRawValue() { return value_; } private: // HeapObject calls the private constructor and directly reads the value. friend class HeapObject; explicit MapWord(uintptr_t value) : value_(value) {} uintptr_t value_; }; // HeapObject is the superclass for all classes describing heap allocated // objects. class HeapObject: public Object { public: // [map]: Contains a map which contains the object's reflective // information. inline Map* map(); inline void set_map(Map* value); // The no-write-barrier version. This is OK if the object is white and in // new space, or if the value is an immortal immutable object, like the maps // of primitive (non-JS) objects like strings, heap numbers etc. inline void set_map_no_write_barrier(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); // The Heap the object was allocated in. Used also to access Isolate. inline Heap* GetHeap(); // Convenience method to get current isolate. This method can be // accessed only when its result is the same as // Isolate::Current(), it ASSERTs this. See also comment for GetHeap. inline Isolate* GetIsolate(); // Converts an address to a HeapObject pointer. static inline HeapObject* FromAddress(Address address); // Returns the address of this HeapObject. inline Address address(); // Iterates over pointers contained in the object (including the Map) void Iterate(ObjectVisitor* v); // Iterates over all pointers contained in the object except the // first map pointer. The object type is given in the first // parameter. This function does not access the map pointer in the // object, and so is safe to call while the map pointer is modified. void IterateBody(InstanceType type, int object_size, ObjectVisitor* v); // Returns the heap object's size in bytes inline int Size(); // Given a heap object's map pointer, returns the heap size in bytes // Useful when the map pointer field is used for other purposes. // GC internal. inline int SizeFromMap(Map* map); // Returns the field at offset in obj, as a read/write Object* reference. // Does no checking, and is safe to use during GC, while maps are invalid. // Does not invoke write barrier, so should only be assigned to // during marking GC. static inline Object** RawField(HeapObject* obj, int offset); // Casting. static inline HeapObject* cast(Object* obj); // Return the write barrier mode for this. Callers of this function // must be able to present a reference to an AssertNoAllocation // object as a sign that they are not going to use this function // from code that allocates and thus invalidates the returned write // barrier mode. inline WriteBarrierMode GetWriteBarrierMode(const AssertNoAllocation&); // Dispatched behavior. void HeapObjectShortPrint(StringStream* accumulator); #ifdef OBJECT_PRINT inline void HeapObjectPrint() { HeapObjectPrint(stdout); } void HeapObjectPrint(FILE* out); void PrintHeader(FILE* out, const char* id); #endif #ifdef DEBUG void HeapObjectVerify(); inline void VerifyObjectField(int offset); inline void VerifySmiField(int offset); // Verify a pointer is a valid HeapObject pointer that points to object // areas in the heap. static void VerifyHeapPointer(Object* p); #endif // Layout description. // First field in a heap object is map. static const int kMapOffset = Object::kHeaderSize; static const int kHeaderSize = kMapOffset + kPointerSize; STATIC_CHECK(kMapOffset == Internals::kHeapObjectMapOffset); protected: // helpers for calling an ObjectVisitor to iterate over pointers in the // half-open range [start, end) specified as integer offsets inline void IteratePointers(ObjectVisitor* v, int start, int end); // as above, for the single element at "offset" inline void IteratePointer(ObjectVisitor* v, int offset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject); }; #define SLOT_ADDR(obj, offset) \ reinterpret_cast((obj)->address() + offset) // This class describes a body of an object of a fixed size // in which all pointer fields are located in the [start_offset, end_offset) // interval. template class FixedBodyDescriptor { public: static const int kStartOffset = start_offset; static const int kEndOffset = end_offset; static const int kSize = size; static inline void IterateBody(HeapObject* obj, ObjectVisitor* v); template static inline void IterateBody(HeapObject* obj) { StaticVisitor::VisitPointers(SLOT_ADDR(obj, start_offset), SLOT_ADDR(obj, end_offset)); } }; // This class describes a body of an object of a variable size // in which all pointer fields are located in the [start_offset, object_size) // interval. template class FlexibleBodyDescriptor { public: static const int kStartOffset = start_offset; static inline void IterateBody(HeapObject* obj, int object_size, ObjectVisitor* v); template static inline void IterateBody(HeapObject* obj, int object_size) { StaticVisitor::VisitPointers(SLOT_ADDR(obj, start_offset), SLOT_ADDR(obj, object_size)); } }; #undef SLOT_ADDR // The HeapNumber class describes heap allocated numbers that cannot be // represented in a Smi (small integer) class HeapNumber: public HeapObject { public: // [value]: number value. inline double value(); inline void set_value(double value); // Casting. static inline HeapNumber* cast(Object* obj); // Dispatched behavior. Object* HeapNumberToBoolean(); inline void HeapNumberPrint() { HeapNumberPrint(stdout); } void HeapNumberPrint(FILE* out); void HeapNumberPrint(StringStream* accumulator); #ifdef DEBUG void HeapNumberVerify(); #endif inline int get_exponent(); inline int get_sign(); // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; // IEEE doubles are two 32 bit words. The first is just mantissa, the second // is a mixture of sign, exponent and mantissa. Our current platforms are all // little endian apart from non-EABI arm which is little endian with big // endian floating point word ordering! static const int kMantissaOffset = kValueOffset; static const int kExponentOffset = kValueOffset + 4; static const int kSize = kValueOffset + kDoubleSize; static const uint32_t kSignMask = 0x80000000u; static const uint32_t kExponentMask = 0x7ff00000u; static const uint32_t kMantissaMask = 0xfffffu; static const int kMantissaBits = 52; static const int kExponentBits = 11; static const int kExponentBias = 1023; static const int kExponentShift = 20; static const int kMantissaBitsInTopWord = 20; static const int kNonMantissaBitsInTopWord = 12; private: DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber); }; enum EnsureElementsMode { DONT_ALLOW_DOUBLE_ELEMENTS, ALLOW_COPIED_DOUBLE_ELEMENTS, ALLOW_CONVERTED_DOUBLE_ELEMENTS }; // Indicates whether a property should be set or (re)defined. Setting of a // property causes attributes to remain unchanged, writability to be checked // and callbacks to be called. Defining of a property causes attributes to // be updated and callbacks to be overridden. enum SetPropertyMode { SET_PROPERTY, DEFINE_PROPERTY }; // Indicator for one component of an AccessorPair. enum AccessorComponent { ACCESSOR_GETTER, ACCESSOR_SETTER }; // JSReceiver includes types on which properties can be defined, i.e., // JSObject and JSProxy. class JSReceiver: public HeapObject { public: enum DeleteMode { NORMAL_DELETION, STRICT_DELETION, FORCE_DELETION }; // Casting. static inline JSReceiver* cast(Object* obj); static Handle SetProperty(Handle object, Handle key, Handle value, PropertyAttributes attributes, StrictModeFlag strict_mode); // Can cause GC. MUST_USE_RESULT MaybeObject* SetProperty(String* key, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetProperty(LookupResult* result, String* key, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetPropertyWithDefinedSetter(JSReceiver* setter, Object* value); MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode); MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode); // Set the index'th array element. // Can cause GC, or return failure if GC is required. MUST_USE_RESULT MaybeObject* SetElement(uint32_t index, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode, bool check_prototype); // Tests for the fast common case for property enumeration. bool IsSimpleEnum(); // Returns the class name ([[Class]] property in the specification). String* class_name(); // Returns the constructor name (the name (possibly, inferred name) of the // function that was used to instantiate the object). String* constructor_name(); inline PropertyAttributes GetPropertyAttribute(String* name); PropertyAttributes GetPropertyAttributeWithReceiver(JSReceiver* receiver, String* name); PropertyAttributes GetLocalPropertyAttribute(String* name); // Can cause a GC. inline bool HasProperty(String* name); inline bool HasLocalProperty(String* name); inline bool HasElement(uint32_t index); // Return the object's prototype (might be Heap::null_value()). inline Object* GetPrototype(); // Set the object's prototype (only JSReceiver and null are allowed). MUST_USE_RESULT MaybeObject* SetPrototype(Object* value, bool skip_hidden_prototypes); // Retrieves a permanent object identity hash code. The undefined value might // be returned in case no hash was created yet and OMIT_CREATION was used. inline MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag); // 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); protected: Smi* GenerateIdentityHash(); private: PropertyAttributes GetPropertyAttribute(JSReceiver* receiver, LookupResult* result, String* name, bool continue_search); DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver); }; // 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 JSReceiver { 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 StringDictionary* property_dictionary(); // Gets slow properties. // [elements]: The elements (properties with names that are integers). // // Elements can be in two general modes: fast and slow. Each mode // corrensponds to a set of object representations of elements that // have something in common. // // In the fast mode elements is a FixedArray and so each element can // be quickly accessed. This fact is used in the generated code. The // elements array can have one of three maps in this mode: // fixed_array_map, non_strict_arguments_elements_map or // fixed_cow_array_map (for copy-on-write arrays). In the latter case // the elements array may be shared by a few objects and so before // writing to any element the array must be copied. Use // EnsureWritableFastElements in this case. // // In the slow mode the elements is either a NumberDictionary, an // ExternalArray, or a FixedArray parameter map for a (non-strict) // arguments object. DECL_ACCESSORS(elements, FixedArrayBase) inline void initialize_elements(); MUST_USE_RESULT inline MaybeObject* ResetElements(); inline ElementsKind GetElementsKind(); inline ElementsAccessor* GetElementsAccessor(); inline bool HasFastSmiOnlyElements(); inline bool HasFastElements(); // Returns if an object has either FAST_ELEMENT or FAST_SMI_ONLY_ELEMENT // elements. TODO(danno): Rename HasFastTypeElements to HasFastElements() and // HasFastElements to HasFastObjectElements. inline bool HasFastTypeElements(); inline bool HasFastDoubleElements(); inline bool HasNonStrictArgumentsElements(); inline bool HasDictionaryElements(); inline bool HasExternalPixelElements(); inline bool HasExternalArrayElements(); inline bool HasExternalByteElements(); inline bool HasExternalUnsignedByteElements(); inline bool HasExternalShortElements(); inline bool HasExternalUnsignedShortElements(); inline bool HasExternalIntElements(); inline bool HasExternalUnsignedIntElements(); inline bool HasExternalFloatElements(); inline bool HasExternalDoubleElements(); bool HasFastArgumentsElements(); bool HasDictionaryArgumentsElements(); inline SeededNumberDictionary* element_dictionary(); // Gets slow elements. inline void set_map_and_elements( Map* map, FixedArrayBase* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Requires: HasFastElements(). MUST_USE_RESULT inline MaybeObject* EnsureWritableFastElements(); // Collects elements starting at index 0. // Undefined values are placed after non-undefined values. // Returns the number of non-undefined values. MUST_USE_RESULT MaybeObject* PrepareElementsForSort(uint32_t limit); // As PrepareElementsForSort, but only on objects where elements is // a dictionary, and it will stay a dictionary. MUST_USE_RESULT MaybeObject* PrepareSlowElementsForSort(uint32_t limit); MUST_USE_RESULT MaybeObject* GetPropertyWithCallback(Object* receiver, Object* structure, String* name); // Can cause GC. MUST_USE_RESULT MaybeObject* SetPropertyForResult(LookupResult* result, String* key, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetPropertyWithFailedAccessCheck( LookupResult* result, String* name, Object* value, bool check_prototype, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetPropertyWithCallback( Object* structure, String* name, Object* value, JSObject* holder, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetPropertyWithInterceptor( String* name, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetPropertyPostInterceptor( String* name, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode); static Handle SetLocalPropertyIgnoreAttributes( Handle object, Handle key, Handle value, PropertyAttributes attributes); // Can cause GC. MUST_USE_RESULT MaybeObject* SetLocalPropertyIgnoreAttributes( String* key, Object* value, PropertyAttributes attributes); // Retrieve a value in a normalized object given a lookup result. // Handles the special representation of JS global objects. Object* GetNormalizedProperty(LookupResult* result); // Sets the property value in a normalized object given a lookup result. // Handles the special representation of JS global objects. Object* SetNormalizedProperty(LookupResult* result, Object* value); // Sets the property value in a normalized object given (key, value, details). // Handles the special representation of JS global objects. static Handle SetNormalizedProperty(Handle object, Handle key, Handle value, PropertyDetails details); MUST_USE_RESULT MaybeObject* SetNormalizedProperty(String* name, Object* value, PropertyDetails details); // Deletes the named property in a normalized object. MUST_USE_RESULT MaybeObject* DeleteNormalizedProperty(String* name, DeleteMode mode); // Retrieve interceptors. InterceptorInfo* GetNamedInterceptor(); InterceptorInfo* GetIndexedInterceptor(); // Used from JSReceiver. 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); static void DefineAccessor(Handle object, Handle name, Handle getter, Handle setter, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* DefineAccessor(String* name, Object* getter, Object* setter, PropertyAttributes attributes); Object* LookupAccessor(String* name, AccessorComponent component); MUST_USE_RESULT MaybeObject* DefineAccessor(AccessorInfo* info); // Used from Object::GetProperty(). MUST_USE_RESULT MaybeObject* GetPropertyWithFailedAccessCheck( Object* receiver, LookupResult* result, String* name, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetPropertyWithInterceptor( JSReceiver* receiver, String* name, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetPropertyPostInterceptor( JSReceiver* receiver, String* name, PropertyAttributes* attributes); MUST_USE_RESULT MaybeObject* GetLocalPropertyPostInterceptor( JSReceiver* receiver, String* name, PropertyAttributes* attributes); // Returns true if this is an instance of an api function and has // been modified since it was created. May give false positives. bool IsDirty(); // If the receiver is a JSGlobalProxy this method will return its prototype, // otherwise the result is the receiver itself. inline Object* BypassGlobalProxy(); // Accessors for hidden properties object. // // Hidden properties are not local properties of the object itself. // Instead they are stored in an auxiliary structure kept as a local // property with a special name Heap::hidden_symbol(). But if the // receiver is a JSGlobalProxy then the auxiliary object is a property // of its prototype, and if it's a detached proxy, then you can't have // hidden properties. // Sets a hidden property on this object. Returns this object if successful, // undefined if called on a detached proxy. static Handle SetHiddenProperty(Handle obj, Handle key, Handle value); // Returns a failure if a GC is required. MUST_USE_RESULT MaybeObject* SetHiddenProperty(String* key, Object* value); // Gets the value of a hidden property with the given key. Returns undefined // if the property doesn't exist (or if called on a detached proxy), // otherwise returns the value set for the key. Object* GetHiddenProperty(String* key); // Deletes a hidden property. Deleting a non-existing property is // considered successful. void DeleteHiddenProperty(String* key); // Returns true if the object has a property with the hidden symbol as name. bool HasHiddenProperties(); static int GetIdentityHash(Handle obj); MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag); MUST_USE_RESULT MaybeObject* SetIdentityHash(Object* hash, CreationFlag flag); static Handle DeleteProperty(Handle obj, Handle name); MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode); static Handle DeleteElement(Handle obj, uint32_t index); MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode); inline void ValidateSmiOnlyElements(); // Makes sure that this object can contain HeapObject as elements. MUST_USE_RESULT inline MaybeObject* EnsureCanContainHeapObjectElements(); // Makes sure that this object can contain the specified elements. MUST_USE_RESULT inline MaybeObject* EnsureCanContainElements( Object** elements, uint32_t count, EnsureElementsMode mode); MUST_USE_RESULT inline MaybeObject* EnsureCanContainElements( FixedArrayBase* elements, EnsureElementsMode mode); MUST_USE_RESULT MaybeObject* EnsureCanContainElements( Arguments* arguments, uint32_t first_arg, uint32_t arg_count, EnsureElementsMode mode); // 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(); // Returns true if the elements of JSObject contains only values that can be // represented in a FixedDoubleArray and has at least one value that can only // be represented as a double and not a Smi. bool ShouldConvertToFastDoubleElements(bool* has_smi_only_elements); // Tells whether the index'th element is present. bool HasElementWithReceiver(JSReceiver* receiver, uint32_t index); // Computes the new capacity when expanding the elements of a JSObject. static int NewElementsCapacity(int old_capacity) { // (old_capacity + 50%) + 16 return old_capacity + (old_capacity >> 1) + 16; } // Tells whether the index'th element is present and how it is stored. enum LocalElementType { // There is no element with given index. UNDEFINED_ELEMENT, // Element with given index is handled by interceptor. INTERCEPTED_ELEMENT, // Element with given index is character in string. STRING_CHARACTER_ELEMENT, // Element with given index is stored in fast backing store. FAST_ELEMENT, // Element with given index is stored in slow backing store. DICTIONARY_ELEMENT }; LocalElementType HasLocalElement(uint32_t index); bool HasElementWithInterceptor(JSReceiver* receiver, uint32_t index); MUST_USE_RESULT MaybeObject* SetFastElement(uint32_t index, Object* value, StrictModeFlag strict_mode, bool check_prototype); MUST_USE_RESULT MaybeObject* SetDictionaryElement( uint32_t index, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode, bool check_prototype, SetPropertyMode set_mode = SET_PROPERTY); MUST_USE_RESULT MaybeObject* SetFastDoubleElement( uint32_t index, Object* value, StrictModeFlag strict_mode, bool check_prototype = true); static Handle SetOwnElement(Handle object, uint32_t index, Handle value, StrictModeFlag strict_mode); // Empty handle is returned if the element cannot be set to the given value. static MUST_USE_RESULT Handle SetElement( Handle object, uint32_t index, Handle value, PropertyAttributes attr, StrictModeFlag strict_mode, SetPropertyMode set_mode = SET_PROPERTY); // A Failure object is returned if GC is needed. MUST_USE_RESULT MaybeObject* SetElement( uint32_t index, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode, bool check_prototype = true, SetPropertyMode set_mode = SET_PROPERTY); // Returns the index'th element. // The undefined object if index is out of bounds. MUST_USE_RESULT MaybeObject* GetElementWithInterceptor(Object* receiver, uint32_t index); enum SetFastElementsCapacityMode { kAllowSmiOnlyElements, kForceSmiOnlyElements, kDontAllowSmiOnlyElements }; // Replace the elements' backing store with fast elements of the given // capacity. Update the length for JSArrays. Returns the new backing // store. MUST_USE_RESULT MaybeObject* SetFastElementsCapacityAndLength( int capacity, int length, SetFastElementsCapacityMode set_capacity_mode); MUST_USE_RESULT MaybeObject* SetFastDoubleElementsCapacityAndLength( int capacity, int 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); // 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 int GetInternalFieldOffset(int index); inline Object* GetInternalField(int index); inline void SetInternalField(int index, Object* value); inline void SetInternalField(int index, Smi* value); // 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); MUST_USE_RESULT MaybeObject* SetElementWithCallbackSetterInPrototypes( uint32_t index, Object* value, bool* found, StrictModeFlag strict_mode); 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 = NONE); // Fill in details for properties into storage starting at the specified // index. void GetLocalPropertyNames(FixedArray* storage, int index); // Returns the number of properties on this object filtering out properties // with the specified attributes (ignoring interceptors). int NumberOfLocalElements(PropertyAttributes filter); // Returns the number of enumerable elements (ignoring interceptors). int NumberOfEnumElements(); // Returns the number of elements on this object filtering out elements // with the specified attributes (ignoring interceptors). int GetLocalElementKeys(FixedArray* storage, PropertyAttributes filter); // Count and fill in the enumerable elements into storage. // (storage->length() == NumberOfEnumElements()). // If storage is NULL, will count the elements without adding // them to any storage. // Returns the number of enumerable elements. int GetEnumElementKeys(FixedArray* storage); // Add a property to a fast-case object using a map transition to // new_map. MUST_USE_RESULT MaybeObject* AddFastPropertyUsingMap(Map* new_map, String* name, Object* value); // Add a constant function property to a fast-case object. // This leaves a CONSTANT_TRANSITION in the old map, and // if it is called on a second object with this map, a // normal property is added instead, with a map transition. // This avoids the creation of many maps with the same constant // function, all orphaned. MUST_USE_RESULT MaybeObject* AddConstantFunctionProperty( String* name, JSFunction* function, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* ReplaceSlowProperty( String* name, Object* value, PropertyAttributes attributes); // Returns a new map with all transitions dropped from the object's current // map and the ElementsKind set. static Handle GetElementsTransitionMap(Handle object, ElementsKind to_kind); inline MUST_USE_RESULT MaybeObject* GetElementsTransitionMap( Isolate* isolate, ElementsKind elements_kind); MUST_USE_RESULT MaybeObject* GetElementsTransitionMapSlow( ElementsKind elements_kind); static Handle TransitionElementsKind(Handle object, ElementsKind to_kind); MUST_USE_RESULT MaybeObject* TransitionElementsKind(ElementsKind to_kind); // Converts a descriptor of any other type to a real field, // backed by the properties array. Descriptors of visible // types, such as CONSTANT_FUNCTION, keep their enumeration order. // Converts the descriptor on the original object's map to a // map transition, and the the new field is on the object's new map. MUST_USE_RESULT MaybeObject* ConvertDescriptorToFieldAndMapTransition( String* name, Object* new_value, PropertyAttributes attributes); // Converts a descriptor of any other type to a real field, // backed by the properties array. Descriptors of visible // types, such as CONSTANT_FUNCTION, keep their enumeration order. MUST_USE_RESULT MaybeObject* ConvertDescriptorToField( String* name, Object* new_value, PropertyAttributes attributes); // Add a property to a fast-case object. MUST_USE_RESULT MaybeObject* AddFastProperty(String* name, Object* value, PropertyAttributes attributes); // Add a property to a slow-case object. MUST_USE_RESULT MaybeObject* AddSlowProperty(String* name, Object* value, PropertyAttributes attributes); // Add a property to an object. MUST_USE_RESULT MaybeObject* AddProperty(String* name, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode); // Convert the object to use the canonical dictionary // representation. If the object is expected to have additional properties // added this number can be indicated to have the backing store allocated to // an initial capacity for holding these properties. static void NormalizeProperties(Handle object, PropertyNormalizationMode mode, int expected_additional_properties); MUST_USE_RESULT MaybeObject* NormalizeProperties( PropertyNormalizationMode mode, int expected_additional_properties); // Convert and update the elements backing store to be a // SeededNumberDictionary dictionary. Returns the backing after conversion. static Handle NormalizeElements( Handle object); MUST_USE_RESULT MaybeObject* NormalizeElements(); static void UpdateMapCodeCache(Handle object, Handle name, Handle code); MUST_USE_RESULT MaybeObject* UpdateMapCodeCache(String* name, Code* code); // Transform slow named properties to fast variants. // Returns failure if allocation failed. static void TransformToFastProperties(Handle object, int unused_property_fields); MUST_USE_RESULT MaybeObject* TransformToFastProperties( int unused_property_fields); // Access fast-case object properties at index. inline Object* FastPropertyAt(int index); inline Object* FastPropertyAtPut(int index, Object* value); // Access to in object properties. inline int GetInObjectPropertyOffset(int index); 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. Fill the pre-allocated fields with // pre_allocated_value and the rest with filler_value. // Note: this call does not update write barrier, the caller is responsible // to ensure that |filler_value| can be collected without WB here. inline void InitializeBody(Map* map, Object* pre_allocated_value, Object* filler_value); // Check whether this object references another object bool ReferencesObject(Object* obj); // Casting. static inline JSObject* cast(Object* obj); // Disalow further properties to be added to the object. static Handle PreventExtensions(Handle object); MUST_USE_RESULT MaybeObject* PreventExtensions(); // Dispatched behavior. void JSObjectShortPrint(StringStream* accumulator); #ifdef OBJECT_PRINT inline void JSObjectPrint() { JSObjectPrint(stdout); } void JSObjectPrint(FILE* out); #endif #ifdef DEBUG void JSObjectVerify(); #endif #ifdef OBJECT_PRINT inline void PrintProperties() { PrintProperties(stdout); } void PrintProperties(FILE* out); inline void PrintElements() { PrintElements(stdout); } void PrintElements(FILE* out); #endif void PrintElementsTransition( FILE* file, ElementsKind from_kind, FixedArrayBase* from_elements, ElementsKind to_kind, FixedArrayBase* to_elements); #ifdef DEBUG // Structure for collecting spill information about JSObjects. class SpillInformation { public: void Clear(); void Print(); int number_of_objects_; int number_of_objects_with_fast_properties_; int number_of_objects_with_fast_elements_; int number_of_fast_used_fields_; int number_of_fast_unused_fields_; int number_of_slow_used_properties_; int number_of_slow_unused_properties_; int number_of_fast_used_elements_; int number_of_fast_unused_elements_; int number_of_slow_used_elements_; int number_of_slow_unused_elements_; }; void IncrementSpillStatistics(SpillInformation* info); #endif Object* SlowReverseLookup(Object* value); // Maximal number of fast properties for the JSObject. Used to // restrict the number of map transitions to avoid an explosion in // the number of maps for objects used as dictionaries. inline int MaxFastProperties(); // Maximal number of elements (numbered 0 .. kMaxElementCount - 1). // Also maximal value of JSArray's length property. static const uint32_t kMaxElementCount = 0xffffffffu; // Constants for heuristics controlling conversion of fast elements // to slow elements. // Maximal gap that can be introduced by adding an element beyond // the current elements length. static const uint32_t kMaxGap = 1024; // Maximal length of fast elements array that won't be checked for // being dense enough on expansion. static const int kMaxUncheckedFastElementsLength = 5000; // Same as above but for old arrays. This limit is more strict. We // don't want to be wasteful with long lived objects. static const int kMaxUncheckedOldFastElementsLength = 500; static const int kInitialMaxFastElementArray = 100000; static const int kMaxFastProperties = 12; static const int kMaxInstanceSize = 255 * kPointerSize; // When extending the backing storage for property values, we increase // its size by more than the 1 entry necessary, so sequentially adding fields // to the same object requires fewer allocations and copies. static const int kFieldsAdded = 3; // Layout description. static const int kPropertiesOffset = HeapObject::kHeaderSize; static const int kElementsOffset = kPropertiesOffset + kPointerSize; static const int kHeaderSize = kElementsOffset + kPointerSize; STATIC_CHECK(kHeaderSize == Internals::kJSObjectHeaderSize); class BodyDescriptor : public FlexibleBodyDescriptor { public: static inline int SizeOf(Map* map, HeapObject* object); }; private: friend class DictionaryElementsAccessor; MUST_USE_RESULT MaybeObject* GetElementWithCallback(Object* receiver, Object* structure, uint32_t index, Object* holder); MUST_USE_RESULT MaybeObject* SetElementWithCallback( Object* structure, uint32_t index, Object* value, JSObject* holder, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetElementWithInterceptor( uint32_t index, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode, bool check_prototype, SetPropertyMode set_mode); MUST_USE_RESULT MaybeObject* SetElementWithoutInterceptor( uint32_t index, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode, bool check_prototype, SetPropertyMode set_mode); // Searches the prototype chain for a callback setter and sets the property // with the setter if it finds one. The '*found' flag indicates whether // a setter was found or not. // This function can cause GC and can return a failure result with // '*found==true'. MUST_USE_RESULT MaybeObject* SetPropertyWithCallbackSetterInPrototypes( String* name, Object* value, PropertyAttributes attributes, bool* found, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* DeletePropertyPostInterceptor(String* name, DeleteMode mode); MUST_USE_RESULT MaybeObject* DeletePropertyWithInterceptor(String* name); MUST_USE_RESULT MaybeObject* DeleteElementWithInterceptor(uint32_t index); MUST_USE_RESULT MaybeObject* DeleteFastElement(uint32_t index); MUST_USE_RESULT MaybeObject* DeleteDictionaryElement(uint32_t index, DeleteMode mode); bool ReferencesObjectFromElements(FixedArray* elements, ElementsKind kind, Object* object); // Returns true if most of the elements backing storage is used. bool HasDenseElements(); // Gets the current elements capacity and the number of used elements. void GetElementsCapacityAndUsage(int* capacity, int* used); bool CanSetCallback(String* name); MUST_USE_RESULT MaybeObject* SetElementCallback( uint32_t index, Object* structure, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* SetPropertyCallback( String* name, Object* structure, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* DefineElementAccessor( uint32_t index, Object* getter, Object* setter, PropertyAttributes attributes); MUST_USE_RESULT MaybeObject* DefinePropertyAccessor( String* name, Object* getter, Object* setter, PropertyAttributes attributes); void LookupInDescriptor(String* name, LookupResult* result); // Returns the hidden properties backing store object, currently // a StringDictionary, stored on this object. // If no hidden properties object has been put on this object, // return undefined, unless create_if_absent is true, in which case // a new dictionary is created, added to this object, and returned. MUST_USE_RESULT MaybeObject* GetHiddenPropertiesDictionary( bool create_if_absent); // Updates the existing hidden properties dictionary. MUST_USE_RESULT MaybeObject* SetHiddenPropertiesDictionary( StringDictionary* dictionary); DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject); }; // Common superclass for FixedArrays that allow implementations to share // common accessors and some code paths. class FixedArrayBase: public HeapObject { public: // [length]: length of the array. inline int length(); inline void set_length(int value); inline static FixedArrayBase* cast(Object* object); // Layout description. // Length is smi tagged when it is stored. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kHeaderSize = kLengthOffset + kPointerSize; }; class FixedDoubleArray; // FixedArray describes fixed-sized arrays with element type Object*. class FixedArray: public FixedArrayBase { public: // Setter and getter for elements. inline Object* get(int index); // Setter that uses write barrier. inline void set(int index, Object* value); inline bool is_the_hole(int index); // 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); // TODO(isolates): duplicate. inline void set_undefined(Heap* heap, int index); inline void set_null(int index); // TODO(isolates): duplicate. inline void set_null(Heap* heap, int index); inline void set_the_hole(int index); // Setters with less debug checks for the GC to use. inline void set_unchecked(int index, Smi* value); inline void set_null_unchecked(Heap* heap, int index); inline void set_unchecked(Heap* heap, int index, Object* value, WriteBarrierMode mode); // Gives access to raw memory which stores the array's data. inline Object** data_start(); inline Object** GetFirstElementAddress(); inline bool ContainsOnlySmisOrHoles(); // Copy operations. MUST_USE_RESULT inline MaybeObject* Copy(); MUST_USE_RESULT MaybeObject* CopySize(int new_length); // Add the elements of a JSArray to this FixedArray. MUST_USE_RESULT MaybeObject* AddKeysFromJSArray(JSArray* array); // Compute the union of this and other. MUST_USE_RESULT MaybeObject* UnionOfKeys(FixedArray* other); // Copy a sub array from the receiver to dest. void CopyTo(int pos, FixedArray* dest, int dest_pos, int len); // Garbage collection support. static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; } // Code Generation support. static int OffsetOfElementAt(int index) { return SizeFor(index); } // Casting. static inline FixedArray* cast(Object* obj); // Maximal allowed size, in bytes, of a single FixedArray. // Prevents overflowing size computations, as well as extreme memory // consumption. static const int kMaxSize = 128 * MB * kPointerSize; // Maximally allowed length of a FixedArray. static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize; // Dispatched behavior. #ifdef OBJECT_PRINT inline void FixedArrayPrint() { FixedArrayPrint(stdout); } void FixedArrayPrint(FILE* out); #endif #ifdef DEBUG void FixedArrayVerify(); // Checks if two FixedArrays have identical contents. bool IsEqualTo(FixedArray* other); #endif // Swap two elements in a pair of arrays. If this array and the // numbers array are the same object, the elements are only swapped // once. void SwapPairs(FixedArray* numbers, int i, int j); // Sort prefix of this array and the numbers array as pairs wrt. the // numbers. If the numbers array and the this array are the same // object, the prefix of this array is sorted. void SortPairs(FixedArray* numbers, uint32_t len); class BodyDescriptor : public FlexibleBodyDescriptor { public: static inline int SizeOf(Map* map, HeapObject* object) { return SizeFor(reinterpret_cast(object)->length()); } }; protected: // Set operation on FixedArray without using write barriers. Can // only be used for storing old space objects or smis. static inline void NoWriteBarrierSet(FixedArray* array, int index, Object* value); // Set operation on FixedArray without incremental write barrier. Can // only be used if the object is guaranteed to be white (whiteness witness // is present). static inline void NoIncrementalWriteBarrierSet(FixedArray* array, int index, Object* value); private: DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray); }; // FixedDoubleArray describes fixed-sized arrays with element type double. class FixedDoubleArray: public FixedArrayBase { public: // Setter and getter for elements. inline double get_scalar(int index); inline int64_t get_representation(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, double value); inline void set_the_hole(int index); // Checking for the hole. inline bool is_the_hole(int index); // Copy operations MUST_USE_RESULT inline MaybeObject* Copy(); // Garbage collection support. inline static int SizeFor(int length) { return kHeaderSize + length * kDoubleSize; } // Code Generation support. static int OffsetOfElementAt(int index) { return SizeFor(index); } inline static bool is_the_hole_nan(double value); inline static double hole_nan_as_double(); inline static double canonical_not_the_hole_nan_as_double(); // Casting. static inline FixedDoubleArray* cast(Object* obj); // Maximal allowed size, in bytes, of a single FixedDoubleArray. // Prevents overflowing size computations, as well as extreme memory // consumption. static const int kMaxSize = 512 * MB; // Maximally allowed length of a FixedArray. static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize; // Dispatched behavior. #ifdef OBJECT_PRINT inline void FixedDoubleArrayPrint() { FixedDoubleArrayPrint(stdout); } void FixedDoubleArrayPrint(FILE* out); #endif #ifdef DEBUG void FixedDoubleArrayVerify(); #endif private: DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray); }; class IncrementalMarking; // DescriptorArrays are fixed arrays used to hold instance descriptors. // The format of the these objects is: // TODO(1399): It should be possible to make room for bit_field3 in the map // without overloading the instance descriptors field in the map // (and storing it in the DescriptorArray when the map has one). // [0]: storage for bit_field3 for Map owning this object (Smi) // [1]: point to a fixed array with (value, detail) pairs. // [2]: next enumeration index (Smi), or pointer to small fixed array: // [0]: next enumeration index (Smi) // [1]: pointer to fixed array with enum cache // [3]: first key // [length() - 1]: last key // class DescriptorArray: public FixedArray { public: // Returns true for both shared empty_descriptor_array and for smis, which the // map uses to encode additional bit fields when the descriptor array is not // yet used. inline bool IsEmpty(); // Returns the number of descriptors in the array. int number_of_descriptors() { ASSERT(length() > kFirstIndex || IsEmpty()); int len = length(); return len <= kFirstIndex ? 0 : len - 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()) { set(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); } // TODO(1399): It should be possible to make room for bit_field3 in the map // without overloading the instance descriptors field in the map // (and storing it in the DescriptorArray when the map has one). inline int bit_field3_storage(); inline void set_bit_field3_storage(int value); // Initialize or change the enum cache, // using the supplied storage for the small "bridge". void SetEnumCache(FixedArray* bridge_storage, FixedArray* new_cache, Object* new_index_cache); // Accessors for fetching instance descriptor at descriptor number. inline String* GetKey(int descriptor_number); inline Object* GetValue(int descriptor_number); inline Smi* GetDetails(int descriptor_number); inline PropertyType GetType(int descriptor_number); inline int GetFieldIndex(int descriptor_number); inline JSFunction* GetConstantFunction(int descriptor_number); inline Object* GetCallbacksObject(int descriptor_number); inline AccessorDescriptor* GetCallbacks(int descriptor_number); inline bool IsProperty(int descriptor_number); inline bool IsTransitionOnly(int descriptor_number); inline bool IsNullDescriptor(int descriptor_number); inline bool IsDontEnum(int descriptor_number); class WhitenessWitness { public: inline explicit WhitenessWitness(DescriptorArray* array); inline ~WhitenessWitness(); private: IncrementalMarking* marking_; }; // Accessor for complete descriptor. inline void Get(int descriptor_number, Descriptor* desc); inline void Set(int descriptor_number, Descriptor* desc, const WhitenessWitness&); // Transfer a complete descriptor from the src descriptor array to the dst // one, dropping map transitions in CALLBACKS. static void CopyFrom(Handle dst, int dst_index, Handle src, int src_index, const WhitenessWitness& witness); // Transfer a complete descriptor from the src descriptor array to this // descriptor array, dropping map transitions in CALLBACKS. MUST_USE_RESULT MaybeObject* CopyFrom(int dst_index, DescriptorArray* src, int src_index, const WhitenessWitness&); // Copy the descriptor array, insert a new descriptor and optionally // remove map transitions. If the descriptor is already present, it is // replaced. If a replaced descriptor is a real property (not a transition // or null), its enumeration index is kept as is. // If adding a real property, map transitions must be removed. If adding // a transition, they must not be removed. All null descriptors are removed. MUST_USE_RESULT MaybeObject* CopyInsert(Descriptor* descriptor, TransitionFlag transition_flag); // Return a copy of the array with all transitions and null descriptors // removed. Return a Failure object in case of an allocation failure. MUST_USE_RESULT MaybeObject* RemoveTransitions(); // Sort the instance descriptors by the hash codes of their keys. // Does not check for duplicates. void SortUnchecked(const WhitenessWitness&); // Sort the instance descriptors by the hash codes of their keys. // Checks the result for duplicates. void Sort(const WhitenessWitness&); // Search the instance descriptors for given name. inline int Search(String* name); // As the above, but uses DescriptorLookupCache and updates it when // necessary. inline int SearchWithCache(String* name); // Tells whether the name is present int the array. bool Contains(String* name) { return kNotFound != Search(name); } // Perform a binary search in the instance descriptors represented // by this fixed array. low and high are descriptor indices. If there // are three instance descriptors in this array it should be called // with low=0 and high=2. int BinarySearch(String* name, int low, int high); // Perform a linear search in the instance descriptors represented // by this fixed array. len is the number of descriptor indices that are // valid. Does not require the descriptors to be sorted. int LinearSearch(String* name, int len); // Allocates a DescriptorArray, but returns the singleton // empty descriptor array object if number_of_descriptors is 0. MUST_USE_RESULT static MaybeObject* Allocate(int number_of_descriptors); // Casting. static inline DescriptorArray* cast(Object* obj); // Constant for denoting key was not found. static const int kNotFound = -1; static const int kBitField3StorageIndex = 0; static const int kContentArrayIndex = 1; static const int kEnumerationIndexIndex = 2; static const int kFirstIndex = 3; // The length of the "bridge" to the enum cache. static const int kEnumCacheBridgeLength = 3; static const int kEnumCacheBridgeEnumIndex = 0; static const int kEnumCacheBridgeCacheIndex = 1; static const int kEnumCacheBridgeIndicesCacheIndex = 2; // Layout description. static const int kBitField3StorageOffset = FixedArray::kHeaderSize; static const int kContentArrayOffset = kBitField3StorageOffset + kPointerSize; 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 OBJECT_PRINT // Print all the descriptors. inline void PrintDescriptors() { PrintDescriptors(stdout); } void PrintDescriptors(FILE* out); #endif #ifdef DEBUG // 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: // An entry in a DescriptorArray, represented as an (array, index) pair. class Entry { public: inline explicit Entry(DescriptorArray* descs, int index) : descs_(descs), index_(index) { } inline PropertyType type() { return descs_->GetType(index_); } inline Object* GetCallbackObject() { return descs_->GetValue(index_); } private: DescriptorArray* descs_; int index_; }; // Conversion from descriptor number to array indices. static int ToKeyIndex(int descriptor_number) { return descriptor_number+kFirstIndex; } static int ToDetailsIndex(int descriptor_number) { return (descriptor_number << 1) + 1; } static int ToValueIndex(int descriptor_number) { return descriptor_number << 1; } bool is_null_descriptor(int descriptor_number) { return PropertyDetails(GetDetails(descriptor_number)).type() == NULL_DESCRIPTOR; } // Swap operation on FixedArray without using write barriers. static inline void NoIncrementalWriteBarrierSwap( FixedArray* array, int first, int second); // Swap descriptor first and second. inline void NoIncrementalWriteBarrierSwapDescriptors( 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 == the_hole have been deleted. // // The hash table class is parameterized with a Shape and a Key. // Shape must be a class with the following interface: // class ExampleShape { // public: // // Tells whether key matches other. // static bool IsMatch(Key key, Object* other); // // Returns the hash value for key. // static uint32_t Hash(Key key); // // Returns the hash value for object. // static uint32_t HashForObject(Key key, Object* object); // // Convert key to an object. // static inline Object* AsObject(Key key); // // The prefix size indicates number of elements in the beginning // // of the backing storage. // static const int kPrefixSize = ..; // // The Element size indicates number of elements per entry. // static const int kEntrySize = ..; // }; // The prefix size indicates an amount of memory in the // beginning of the backing storage that can be used for non-element // information by subclasses. template class BaseShape { public: static const bool UsesSeed = false; static uint32_t Hash(Key key) { return 0; } static uint32_t SeededHash(Key key, uint32_t seed) { ASSERT(UsesSeed); return Hash(key); } static uint32_t HashForObject(Key key, Object* object) { return 0; } static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) { ASSERT(UsesSeed); return HashForObject(key, object); } }; template class HashTable: public FixedArray { public: // Wrapper methods inline uint32_t Hash(Key key) { if (Shape::UsesSeed) { return Shape::SeededHash(key, GetHeap()->HashSeed()); } else { return Shape::Hash(key); } } inline uint32_t HashForObject(Key key, Object* object) { if (Shape::UsesSeed) { return Shape::SeededHashForObject(key, GetHeap()->HashSeed(), object); } else { return Shape::HashForObject(key, object); } } // Returns the number of elements in the hash table. int NumberOfElements() { return Smi::cast(get(kNumberOfElementsIndex))->value(); } // Returns the number of deleted elements in the hash table. int NumberOfDeletedElements() { return Smi::cast(get(kNumberOfDeletedElementsIndex))->value(); } // Returns the capacity of the hash table. int Capacity() { return Smi::cast(get(kCapacityIndex))->value(); } // ElementAdded should be called whenever an element is added to a // hash table. void ElementAdded() { SetNumberOfElements(NumberOfElements() + 1); } // ElementRemoved should be called whenever an element is removed from // a hash table. void ElementRemoved() { SetNumberOfElements(NumberOfElements() - 1); SetNumberOfDeletedElements(NumberOfDeletedElements() + 1); } void ElementsRemoved(int n) { SetNumberOfElements(NumberOfElements() - n); SetNumberOfDeletedElements(NumberOfDeletedElements() + n); } // Returns a new HashTable object. Might return Failure. MUST_USE_RESULT static MaybeObject* Allocate( int at_least_space_for, PretenureFlag pretenure = NOT_TENURED); // Computes the required capacity for a table holding the given // number of elements. May be more than HashTable::kMaxCapacity. static int ComputeCapacity(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. The hole and undefined are not allowed // as keys and can be used to indicate missing or deleted elements. bool IsKey(Object* k) { return !k->IsTheHole() && !k->IsUndefined(); } // Garbage collection support. void IteratePrefix(ObjectVisitor* visitor); void IterateElements(ObjectVisitor* visitor); // Casting. static inline HashTable* cast(Object* obj); // Compute the probe offset (quadratic probing). INLINE(static uint32_t GetProbeOffset(uint32_t n)) { return (n + n * n) >> 1; } static const int kNumberOfElementsIndex = 0; static const int kNumberOfDeletedElementsIndex = 1; static const int kCapacityIndex = 2; static const int kPrefixStartIndex = 3; static const int kElementsStartIndex = kPrefixStartIndex + Shape::kPrefixSize; static const int kEntrySize = Shape::kEntrySize; static const int kElementsStartOffset = kHeaderSize + kElementsStartIndex * kPointerSize; static const int kCapacityOffset = kHeaderSize + kCapacityIndex * kPointerSize; // Constant used for denoting a absent entry. static const int kNotFound = -1; // Maximal capacity of HashTable. Based on maximal length of underlying // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex // cannot overflow. static const int kMaxCapacity = (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize; // Find entry for key otherwise return kNotFound. inline int FindEntry(Key key); int FindEntry(Isolate* isolate, Key key); protected: // Find the entry at which to insert element with the given key that // has the given hash value. uint32_t FindInsertionEntry(uint32_t hash); // Returns the index for an entry (of the key) static inline int EntryToIndex(int entry) { return (entry * kEntrySize) + kElementsStartIndex; } // Update the number of elements in the hash table. void SetNumberOfElements(int nof) { set(kNumberOfElementsIndex, Smi::FromInt(nof)); } // Update the number of deleted elements in the hash table. void SetNumberOfDeletedElements(int nod) { set(kNumberOfDeletedElementsIndex, Smi::FromInt(nod)); } // Sets the capacity of the hash table. void SetCapacity(int capacity) { // To scale a computed hash code to fit within the hash table, we // use bit-wise AND with a mask, so the capacity must be positive // and non-zero. ASSERT(capacity > 0); ASSERT(capacity <= kMaxCapacity); set(kCapacityIndex, Smi::FromInt(capacity)); } // Returns probe entry. static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) { ASSERT(IsPowerOf2(size)); return (hash + GetProbeOffset(number)) & (size - 1); } static uint32_t FirstProbe(uint32_t hash, uint32_t size) { return hash & (size - 1); } static uint32_t NextProbe(uint32_t last, uint32_t number, uint32_t size) { return (last + number) & (size - 1); } // Rehashes this hash-table into the new table. MUST_USE_RESULT MaybeObject* Rehash(HashTable* new_table, Key key); // Attempt to shrink hash table after removal of key. MUST_USE_RESULT MaybeObject* Shrink(Key key); // Ensure enough space for n additional elements. MUST_USE_RESULT MaybeObject* EnsureCapacity(int n, Key key); }; // HashTableKey is an abstract superclass for virtual key behavior. class HashTableKey { public: // Returns whether the other object matches this key. virtual bool IsMatch(Object* other) = 0; // Returns the hash value for this key. virtual uint32_t Hash() = 0; // Returns the hash value for object. virtual uint32_t HashForObject(Object* key) = 0; // Returns the key object for storing into the hash table. // If allocations fails a failure object is returned. MUST_USE_RESULT virtual MaybeObject* AsObject() = 0; // Required. virtual ~HashTableKey() {} }; class SymbolTableShape : public BaseShape { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static inline MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 1; }; class SeqAsciiString; // SymbolTable. // // No special elements in the prefix and the element size is 1 // because only the symbol itself (the key) needs to be stored. class SymbolTable: public HashTable { public: // Find symbol in the symbol table. If it is not there yet, it is // added. The return value is the symbol table which might have // been enlarged. If the return value is not a failure, the symbol // pointer *s is set to the symbol found. MUST_USE_RESULT MaybeObject* LookupSymbol(Vector str, Object** s); MUST_USE_RESULT MaybeObject* LookupAsciiSymbol(Vector str, Object** s); MUST_USE_RESULT MaybeObject* LookupSubStringAsciiSymbol( Handle str, int from, int length, Object** s); MUST_USE_RESULT MaybeObject* LookupTwoByteSymbol(Vector str, Object** s); MUST_USE_RESULT MaybeObject* LookupString(String* key, Object** s); // Looks up a symbol that is equal to the given string and returns // true if it is found, assigning the symbol to the given output // parameter. bool LookupSymbolIfExists(String* str, String** symbol); bool LookupTwoCharsSymbolIfExists(uint32_t c1, uint32_t c2, String** symbol); // Casting. static inline SymbolTable* cast(Object* obj); private: MUST_USE_RESULT MaybeObject* LookupKey(HashTableKey* key, Object** s); DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolTable); }; class MapCacheShape : public BaseShape { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static inline MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 2; }; // MapCache. // // Maps keys that are a fixed array of symbols to a map. // Used for canonicalize maps for object literals. class MapCache: public HashTable { public: // Find cached value for a string key, otherwise return null. Object* Lookup(FixedArray* key); MUST_USE_RESULT MaybeObject* Put(FixedArray* key, Map* value); static inline MapCache* cast(Object* obj); private: DISALLOW_IMPLICIT_CONSTRUCTORS(MapCache); }; template class Dictionary: public HashTable { public: static inline Dictionary* cast(Object* obj) { return reinterpret_cast*>(obj); } // Returns the value at entry. Object* ValueAt(int entry) { return this->get(HashTable::EntryToIndex(entry) + 1); } // Set the value for entry. void ValueAtPut(int entry, Object* value) { this->set(HashTable::EntryToIndex(entry) + 1, value); } // Returns the property details for the property at entry. PropertyDetails DetailsAt(int entry) { ASSERT(entry >= 0); // Not found is -1, which is not caught by get(). return PropertyDetails( Smi::cast(this->get(HashTable::EntryToIndex(entry) + 2))); } // Set the details for entry. void DetailsAtPut(int entry, PropertyDetails value) { this->set(HashTable::EntryToIndex(entry) + 2, value.AsSmi()); } // Sorting support void CopyValuesTo(FixedArray* elements); // Delete a property from the dictionary. Object* DeleteProperty(int entry, JSObject::DeleteMode mode); // Attempt to shrink the dictionary after deletion of key. MUST_USE_RESULT MaybeObject* Shrink(Key key); // 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(); enum SortMode { UNSORTED, SORTED }; // Copies keys to preallocated fixed array. void CopyKeysTo(FixedArray* storage, PropertyAttributes filter, SortMode sort_mode); // Fill in details for properties into storage. void CopyKeysTo(FixedArray* storage, int index, SortMode sort_mode); // Accessors for next enumeration index. void SetNextEnumerationIndex(int index) { this->set(kNextEnumerationIndexIndex, Smi::FromInt(index)); } int NextEnumerationIndex() { return Smi::cast(FixedArray::get(kNextEnumerationIndexIndex))->value(); } // Returns a new array for dictionary usage. Might return Failure. MUST_USE_RESULT static MaybeObject* Allocate(int at_least_space_for); // Ensure enough space for n additional elements. MUST_USE_RESULT MaybeObject* EnsureCapacity(int n, Key key); #ifdef OBJECT_PRINT inline void Print() { Print(stdout); } void Print(FILE* out); #endif // Returns the key (slow). Object* SlowReverseLookup(Object* value); // Sets the entry to (key, value) pair. inline void SetEntry(int entry, Object* key, Object* value); inline void SetEntry(int entry, Object* key, Object* value, PropertyDetails details); MUST_USE_RESULT MaybeObject* Add(Key key, Object* value, PropertyDetails details); protected: // Generic at put operation. MUST_USE_RESULT MaybeObject* AtPut(Key key, Object* value); // Add entry to dictionary. MUST_USE_RESULT MaybeObject* AddEntry(Key key, Object* value, PropertyDetails details, uint32_t hash); // Generate new enumeration indices to avoid enumeration index overflow. MUST_USE_RESULT MaybeObject* GenerateNewEnumerationIndices(); static const int kMaxNumberKeyIndex = HashTable::kPrefixStartIndex; static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1; }; class StringDictionaryShape : public BaseShape { public: static inline bool IsMatch(String* key, Object* other); static inline uint32_t Hash(String* key); static inline uint32_t HashForObject(String* key, Object* object); MUST_USE_RESULT static inline MaybeObject* AsObject(String* key); static const int kPrefixSize = 2; static const int kEntrySize = 3; static const bool kIsEnumerable = true; }; class StringDictionary: public Dictionary { public: static inline StringDictionary* cast(Object* obj) { ASSERT(obj->IsDictionary()); return reinterpret_cast(obj); } // Copies enumerable keys to preallocated fixed array. void CopyEnumKeysTo(FixedArray* storage, FixedArray* sort_array); // For transforming properties of a JSObject. MUST_USE_RESULT MaybeObject* TransformPropertiesToFastFor( JSObject* obj, int unused_property_fields); // Find entry for key, otherwise return kNotFound. Optimized version of // HashTable::FindEntry. int FindEntry(String* key); bool ContainsTransition(int entry); }; class NumberDictionaryShape : public BaseShape { public: static inline bool IsMatch(uint32_t key, Object* other); MUST_USE_RESULT static inline MaybeObject* AsObject(uint32_t key); static const int kEntrySize = 3; static const bool kIsEnumerable = false; }; class SeededNumberDictionaryShape : public NumberDictionaryShape { public: static const bool UsesSeed = true; static const int kPrefixSize = 2; static inline uint32_t SeededHash(uint32_t key, uint32_t seed); static inline uint32_t SeededHashForObject(uint32_t key, uint32_t seed, Object* object); }; class UnseededNumberDictionaryShape : public NumberDictionaryShape { public: static const int kPrefixSize = 0; static inline uint32_t Hash(uint32_t key); static inline uint32_t HashForObject(uint32_t key, Object* object); }; class SeededNumberDictionary : public Dictionary { public: static SeededNumberDictionary* cast(Object* obj) { ASSERT(obj->IsDictionary()); return reinterpret_cast(obj); } // Type specific at put (default NONE attributes is used when adding). MUST_USE_RESULT MaybeObject* AtNumberPut(uint32_t key, Object* value); MUST_USE_RESULT MaybeObject* AddNumberEntry(uint32_t key, Object* value, PropertyDetails details); // Set an existing entry or add a new one if needed. // Return the updated dictionary. MUST_USE_RESULT static Handle Set( Handle dictionary, uint32_t index, Handle value, PropertyDetails details); MUST_USE_RESULT MaybeObject* Set(uint32_t key, Object* value, PropertyDetails details); void UpdateMaxNumberKey(uint32_t key); // If slow elements are required we will never go back to fast-case // for the elements kept in this dictionary. We require slow // elements if an element has been added at an index larger than // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called // when defining a getter or setter with a number key. inline bool requires_slow_elements(); inline void set_requires_slow_elements(); // Get the value of the max number key that has been added to this // dictionary. max_number_key can only be called if // requires_slow_elements returns false. inline uint32_t max_number_key(); // Bit masks. static const int kRequiresSlowElementsMask = 1; static const int kRequiresSlowElementsTagSize = 1; static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1; }; class UnseededNumberDictionary : public Dictionary { public: static UnseededNumberDictionary* cast(Object* obj) { ASSERT(obj->IsDictionary()); return reinterpret_cast(obj); } // Type specific at put (default NONE attributes is used when adding). MUST_USE_RESULT MaybeObject* AtNumberPut(uint32_t key, Object* value); MUST_USE_RESULT MaybeObject* AddNumberEntry(uint32_t key, Object* value); // Set an existing entry or add a new one if needed. // Return the updated dictionary. MUST_USE_RESULT static Handle Set( Handle dictionary, uint32_t index, Handle value); MUST_USE_RESULT MaybeObject* Set(uint32_t key, Object* value); }; template class ObjectHashTableShape : public BaseShape { public: static inline bool IsMatch(Object* key, Object* other); static inline uint32_t Hash(Object* key); static inline uint32_t HashForObject(Object* key, Object* object); MUST_USE_RESULT static inline MaybeObject* AsObject(Object* key); static const int kPrefixSize = 0; static const int kEntrySize = entrysize; }; // ObjectHashSet holds keys that are arbitrary objects by using the identity // hash of the key for hashing purposes. class ObjectHashSet: public HashTable, Object*> { public: static inline ObjectHashSet* cast(Object* obj) { ASSERT(obj->IsHashTable()); return reinterpret_cast(obj); } // Looks up whether the given key is part of this hash set. bool Contains(Object* key); // Adds the given key to this hash set. MUST_USE_RESULT MaybeObject* Add(Object* key); // Removes the given key from this hash set. MUST_USE_RESULT MaybeObject* Remove(Object* key); }; // ObjectHashTable maps keys that are arbitrary objects to object values by // using the identity hash of the key for hashing purposes. class ObjectHashTable: public HashTable, Object*> { public: static inline ObjectHashTable* cast(Object* obj) { ASSERT(obj->IsHashTable()); return reinterpret_cast(obj); } // Looks up the value associated with the given key. The undefined value is // returned in case the key is not present. Object* Lookup(Object* key); // Adds (or overwrites) the value associated with the given key. Mapping a // key to the undefined value causes removal of the whole entry. MUST_USE_RESULT MaybeObject* Put(Object* key, Object* value); private: friend class MarkCompactCollector; void AddEntry(int entry, Object* key, Object* value); void RemoveEntry(int entry); // Returns the index to the value of an entry. static inline int EntryToValueIndex(int entry) { return EntryToIndex(entry) + 1; } }; // JSFunctionResultCache caches results of some JSFunction invocation. // It is a fixed array with fixed structure: // [0]: factory function // [1]: finger index // [2]: current cache size // [3]: dummy field. // The rest of array are key/value pairs. class JSFunctionResultCache: public FixedArray { public: static const int kFactoryIndex = 0; static const int kFingerIndex = kFactoryIndex + 1; static const int kCacheSizeIndex = kFingerIndex + 1; static const int kDummyIndex = kCacheSizeIndex + 1; static const int kEntriesIndex = kDummyIndex + 1; static const int kEntrySize = 2; // key + value static const int kFactoryOffset = kHeaderSize; static const int kFingerOffset = kFactoryOffset + kPointerSize; static const int kCacheSizeOffset = kFingerOffset + kPointerSize; inline void MakeZeroSize(); inline void Clear(); inline int size(); inline void set_size(int size); inline int finger_index(); inline void set_finger_index(int finger_index); // Casting static inline JSFunctionResultCache* cast(Object* obj); #ifdef DEBUG void JSFunctionResultCacheVerify(); #endif }; // ScopeInfo represents information about different scopes of a source // program and the allocation of the scope's variables. Scope information // is stored in a compressed form in ScopeInfo objects and is used // at runtime (stack dumps, deoptimization, etc.). // This object provides quick access to scope info details for runtime // routines. class ScopeInfo : public FixedArray { public: static inline ScopeInfo* cast(Object* object); // Return the type of this scope. ScopeType Type(); // Does this scope call eval? bool CallsEval(); // Return the language mode of this scope. LanguageMode language_mode(); // Does this scope make a non-strict eval call? bool CallsNonStrictEval() { return CallsEval() && (language_mode() == CLASSIC_MODE); } // Return the total number of locals allocated on the stack and in the // context. This includes the parameters that are allocated in the context. int LocalCount(); // Return the number of stack slots for code. This number consists of two // parts: // 1. One stack slot per stack allocated local. // 2. One stack slot for the function name if it is stack allocated. int StackSlotCount(); // Return the number of context slots for code if a context is allocated. This // number consists of three parts: // 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS // 2. One context slot per context allocated local. // 3. One context slot for the function name if it is context allocated. // Parameters allocated in the context count as context allocated locals. If // no contexts are allocated for this scope ContextLength returns 0. int ContextLength(); // Is this scope the scope of a named function expression? bool HasFunctionName(); // Return if this has context allocated locals. bool HasHeapAllocatedLocals(); // Return if contexts are allocated for this scope. bool HasContext(); // Return the function_name if present. String* FunctionName(); // Return the name of the given parameter. String* ParameterName(int var); // Return the name of the given local. String* LocalName(int var); // Return the name of the given stack local. String* StackLocalName(int var); // Return the name of the given context local. String* ContextLocalName(int var); // Return the mode of the given context local. VariableMode ContextLocalMode(int var); // Return the initialization flag of the given context local. InitializationFlag ContextLocalInitFlag(int var); // Lookup support for serialized scope info. Returns the // the stack slot index for a given slot name if the slot is // present; otherwise returns a value < 0. The name must be a symbol // (canonicalized). int StackSlotIndex(String* name); // Lookup support for serialized scope info. Returns the // context slot index for a given slot name if the slot is present; otherwise // returns a value < 0. The name must be a symbol (canonicalized). // If the slot is present and mode != NULL, sets *mode to the corresponding // mode for that variable. int ContextSlotIndex(String* name, VariableMode* mode, InitializationFlag* init_flag); // Lookup support for serialized scope info. Returns the // parameter index for a given parameter name if the parameter is present; // otherwise returns a value < 0. The name must be a symbol (canonicalized). int ParameterIndex(String* name); // Lookup support for serialized scope info. Returns the // function context slot index if the function name is present (named // function expressions, only), otherwise returns a value < 0. The name // must be a symbol (canonicalized). int FunctionContextSlotIndex(String* name, VariableMode* mode); static Handle Create(Scope* scope); // Serializes empty scope info. static ScopeInfo* Empty(); #ifdef DEBUG void Print(); #endif // The layout of the static part of a ScopeInfo is as follows. Each entry is // numeric and occupies one array slot. // 1. A set of properties of the scope // 2. The number of parameters. This only applies to function scopes. For // non-function scopes this is 0. // 3. The number of non-parameter variables allocated on the stack. // 4. The number of non-parameter and parameter variables allocated in the // context. #define FOR_EACH_NUMERIC_FIELD(V) \ V(Flags) \ V(ParameterCount) \ V(StackLocalCount) \ V(ContextLocalCount) #define FIELD_ACCESSORS(name) \ void Set##name(int value) { \ set(k##name, Smi::FromInt(value)); \ } \ int name() { \ if (length() > 0) { \ return Smi::cast(get(k##name))->value(); \ } else { \ return 0; \ } \ } FOR_EACH_NUMERIC_FIELD(FIELD_ACCESSORS) #undef FIELD_ACCESSORS private: enum { #define DECL_INDEX(name) k##name, FOR_EACH_NUMERIC_FIELD(DECL_INDEX) #undef DECL_INDEX #undef FOR_EACH_NUMERIC_FIELD kVariablePartIndex }; // The layout of the variable part of a ScopeInfo is as follows: // 1. ParameterEntries: // This part stores the names of the parameters for function scopes. One // slot is used per parameter, so in total this part occupies // ParameterCount() slots in the array. For other scopes than function // scopes ParameterCount() is 0. // 2. StackLocalEntries: // Contains the names of local variables that are allocated on the stack, // in increasing order of the stack slot index. One slot is used per stack // local, so in total this part occupies StackLocalCount() slots in the // array. // 3. ContextLocalNameEntries: // Contains the names of local variables and parameters that are allocated // in the context. They are stored in increasing order of the context slot // index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per // context local, so in total this part occupies ContextLocalCount() slots // in the array. // 4. ContextLocalInfoEntries: // Contains the variable modes and initialization flags corresponding to // the context locals in ContextLocalNameEntries. One slot is used per // context local, so in total this part occupies ContextLocalCount() // slots in the array. // 5. FunctionNameEntryIndex: // If the scope belongs to a named function expression this part contains // information about the function variable. It always occupies two array // slots: a. The name of the function variable. // b. The context or stack slot index for the variable. int ParameterEntriesIndex(); int StackLocalEntriesIndex(); int ContextLocalNameEntriesIndex(); int ContextLocalInfoEntriesIndex(); int FunctionNameEntryIndex(); // Location of the function variable for named function expressions. enum FunctionVariableInfo { NONE, // No function name present. STACK, // Function CONTEXT, UNUSED }; // Properties of scopes. class TypeField: public BitField {}; class CallsEvalField: public BitField {}; class LanguageModeField: public BitField {}; class FunctionVariableField: public BitField {}; class FunctionVariableMode: public BitField {}; // BitFields representing the encoded information for context locals in the // ContextLocalInfoEntries part. class ContextLocalMode: public BitField {}; class ContextLocalInitFlag: public BitField {}; }; // The cache for maps used by normalized (dictionary mode) objects. // Such maps do not have property descriptors, so a typical program // needs very limited number of distinct normalized maps. class NormalizedMapCache: public FixedArray { public: static const int kEntries = 64; MUST_USE_RESULT MaybeObject* Get(JSObject* object, PropertyNormalizationMode mode); void Clear(); // Casting static inline NormalizedMapCache* cast(Object* obj); #ifdef DEBUG void NormalizedMapCacheVerify(); #endif }; // ByteArray represents fixed sized byte arrays. Used for the relocation info // that is attached to code objects. class ByteArray: public FixedArrayBase { public: inline int Size() { return RoundUp(length() + kHeaderSize, kPointerSize); } // Setter and getter. inline byte get(int index); inline void set(int index, byte value); // Treat contents as an int array. inline int get_int(int index); static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length); } // We use byte arrays for free blocks in the heap. Given a desired size in // bytes that is a multiple of the word size and big enough to hold a byte // array, this function returns the number of elements a byte array should // have. static int LengthFor(int size_in_bytes) { ASSERT(IsAligned(size_in_bytes, kPointerSize)); ASSERT(size_in_bytes >= kHeaderSize); return size_in_bytes - kHeaderSize; } // Returns data start address. inline Address GetDataStartAddress(); // Returns a pointer to the ByteArray object for a given data start address. static inline ByteArray* FromDataStartAddress(Address address); // Casting. static inline ByteArray* cast(Object* obj); // Dispatched behavior. inline int ByteArraySize() { return SizeFor(this->length()); } #ifdef OBJECT_PRINT inline void ByteArrayPrint() { ByteArrayPrint(stdout); } void ByteArrayPrint(FILE* out); #endif #ifdef DEBUG void ByteArrayVerify(); #endif // Layout description. static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); // Maximal memory consumption for a single ByteArray. static const int kMaxSize = 512 * MB; // Maximal length of a single ByteArray. static const int kMaxLength = kMaxSize - kHeaderSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray); }; // FreeSpace represents fixed sized areas of the heap that are not currently in // use. Used by the heap and GC. class FreeSpace: public HeapObject { public: // [size]: size of the free space including the header. inline int size(); inline void set_size(int value); inline int Size() { return size(); } // Casting. static inline FreeSpace* cast(Object* obj); #ifdef OBJECT_PRINT inline void FreeSpacePrint() { FreeSpacePrint(stdout); } void FreeSpacePrint(FILE* out); #endif #ifdef DEBUG void FreeSpaceVerify(); #endif // Layout description. // Size is smi tagged when it is stored. static const int kSizeOffset = HeapObject::kHeaderSize; static const int kHeaderSize = kSizeOffset + kPointerSize; static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); private: DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace); }; // An ExternalArray represents a fixed-size array of primitive values // which live outside the JavaScript heap. Its subclasses are used to // implement the CanvasArray types being defined in the WebGL // specification. As of this writing the first public draft is not yet // available, but Khronos members can access the draft at: // https://cvs.khronos.org/svn/repos/3dweb/trunk/doc/spec/WebGL-spec.html // // The semantics of these arrays differ from CanvasPixelArray. // Out-of-range values passed to the setter are converted via a C // cast, not clamping. Out-of-range indices cause exceptions to be // raised rather than being silently ignored. class ExternalArray: public FixedArrayBase { public: inline bool is_the_hole(int index) { return false; } // [external_pointer]: The pointer to the external memory area backing this // external array. DECL_ACCESSORS(external_pointer, void) // Pointer to the data store. // Casting. static inline ExternalArray* cast(Object* obj); // Maximal acceptable length for an external array. static const int kMaxLength = 0x3fffffff; // ExternalArray headers are not quadword aligned. static const int kExternalPointerOffset = POINTER_SIZE_ALIGN(FixedArrayBase::kLengthOffset + kPointerSize); static const int kHeaderSize = kExternalPointerOffset + kPointerSize; static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalArray); }; // A ExternalPixelArray represents a fixed-size byte array with special // semantics used for implementing the CanvasPixelArray object. Please see the // specification at: // http://www.whatwg.org/specs/web-apps/current-work/ // multipage/the-canvas-element.html#canvaspixelarray // In particular, write access clamps the value written to 0 or 255 if the // value written is outside this range. class ExternalPixelArray: public ExternalArray { public: inline uint8_t* external_pixel_pointer(); // Setter and getter. inline uint8_t get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, uint8_t value); // This accessor applies the correct conversion from Smi, HeapNumber and // undefined and clamps the converted value between 0 and 255. Object* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalPixelArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalPixelArrayPrint() { ExternalPixelArrayPrint(stdout); } void ExternalPixelArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalPixelArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalPixelArray); }; class ExternalByteArray: public ExternalArray { public: // Setter and getter. inline int8_t get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, int8_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalByteArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalByteArrayPrint() { ExternalByteArrayPrint(stdout); } void ExternalByteArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalByteArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalByteArray); }; class ExternalUnsignedByteArray: public ExternalArray { public: // Setter and getter. inline uint8_t get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, uint8_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalUnsignedByteArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalUnsignedByteArrayPrint() { ExternalUnsignedByteArrayPrint(stdout); } void ExternalUnsignedByteArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalUnsignedByteArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedByteArray); }; class ExternalShortArray: public ExternalArray { public: // Setter and getter. inline int16_t get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, int16_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalShortArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalShortArrayPrint() { ExternalShortArrayPrint(stdout); } void ExternalShortArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalShortArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalShortArray); }; class ExternalUnsignedShortArray: public ExternalArray { public: // Setter and getter. inline uint16_t get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, uint16_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalUnsignedShortArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalUnsignedShortArrayPrint() { ExternalUnsignedShortArrayPrint(stdout); } void ExternalUnsignedShortArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalUnsignedShortArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedShortArray); }; class ExternalIntArray: public ExternalArray { public: // Setter and getter. inline int32_t get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, int32_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalIntArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalIntArrayPrint() { ExternalIntArrayPrint(stdout); } void ExternalIntArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalIntArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalIntArray); }; class ExternalUnsignedIntArray: public ExternalArray { public: // Setter and getter. inline uint32_t get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, uint32_t value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalUnsignedIntArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalUnsignedIntArrayPrint() { ExternalUnsignedIntArrayPrint(stdout); } void ExternalUnsignedIntArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalUnsignedIntArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedIntArray); }; class ExternalFloatArray: public ExternalArray { public: // Setter and getter. inline float get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, float value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalFloatArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalFloatArrayPrint() { ExternalFloatArrayPrint(stdout); } void ExternalFloatArrayPrint(FILE* out); #endif #ifdef DEBUG void ExternalFloatArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloatArray); }; class ExternalDoubleArray: public ExternalArray { public: // Setter and getter. inline double get_scalar(int index); MUST_USE_RESULT inline MaybeObject* get(int index); inline void set(int index, double value); // This accessor applies the correct conversion from Smi, HeapNumber // and undefined. MUST_USE_RESULT MaybeObject* SetValue(uint32_t index, Object* value); // Casting. static inline ExternalDoubleArray* cast(Object* obj); #ifdef OBJECT_PRINT inline void ExternalDoubleArrayPrint() { ExternalDoubleArrayPrint(stdout); } void ExternalDoubleArrayPrint(FILE* out); #endif // OBJECT_PRINT #ifdef DEBUG void ExternalDoubleArrayVerify(); #endif // DEBUG private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalDoubleArray); }; // DeoptimizationInputData is a fixed array used to hold the deoptimization // data for code generated by the Hydrogen/Lithium compiler. It also // contains information about functions that were inlined. If N different // functions were inlined then first N elements of the literal array will // contain these functions. // // It can be empty. class DeoptimizationInputData: public FixedArray { public: // Layout description. Indices in the array. static const int kTranslationByteArrayIndex = 0; static const int kInlinedFunctionCountIndex = 1; static const int kLiteralArrayIndex = 2; static const int kOsrAstIdIndex = 3; static const int kOsrPcOffsetIndex = 4; static const int kFirstDeoptEntryIndex = 5; // Offsets of deopt entry elements relative to the start of the entry. static const int kAstIdOffset = 0; static const int kTranslationIndexOffset = 1; static const int kArgumentsStackHeightOffset = 2; static const int kPcOffset = 3; static const int kDeoptEntrySize = 4; // Simple element accessors. #define DEFINE_ELEMENT_ACCESSORS(name, type) \ type* name() { \ return type::cast(get(k##name##Index)); \ } \ void Set##name(type* value) { \ set(k##name##Index, value); \ } DEFINE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray) DEFINE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi) DEFINE_ELEMENT_ACCESSORS(LiteralArray, FixedArray) DEFINE_ELEMENT_ACCESSORS(OsrAstId, Smi) DEFINE_ELEMENT_ACCESSORS(OsrPcOffset, Smi) #undef DEFINE_ELEMENT_ACCESSORS // Accessors for elements of the ith deoptimization entry. #define DEFINE_ENTRY_ACCESSORS(name, type) \ type* name(int i) { \ return type::cast(get(IndexForEntry(i) + k##name##Offset)); \ } \ void Set##name(int i, type* value) { \ set(IndexForEntry(i) + k##name##Offset, value); \ } DEFINE_ENTRY_ACCESSORS(AstId, Smi) DEFINE_ENTRY_ACCESSORS(TranslationIndex, Smi) DEFINE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi) DEFINE_ENTRY_ACCESSORS(Pc, Smi) #undef DEFINE_ENTRY_ACCESSORS int DeoptCount() { return (length() - kFirstDeoptEntryIndex) / kDeoptEntrySize; } // Allocates a DeoptimizationInputData. MUST_USE_RESULT static MaybeObject* Allocate(int deopt_entry_count, PretenureFlag pretenure); // Casting. static inline DeoptimizationInputData* cast(Object* obj); #ifdef ENABLE_DISASSEMBLER void DeoptimizationInputDataPrint(FILE* out); #endif private: static int IndexForEntry(int i) { return kFirstDeoptEntryIndex + (i * kDeoptEntrySize); } static int LengthFor(int entry_count) { return IndexForEntry(entry_count); } }; // DeoptimizationOutputData is a fixed array used to hold the deoptimization // data for code generated by the full compiler. // The format of the these objects is // [i * 2]: Ast ID for ith deoptimization. // [i * 2 + 1]: PC and state of ith deoptimization class DeoptimizationOutputData: public FixedArray { public: int DeoptPoints() { return length() / 2; } Smi* AstId(int index) { return Smi::cast(get(index * 2)); } void SetAstId(int index, Smi* id) { set(index * 2, id); } Smi* PcAndState(int index) { return Smi::cast(get(1 + index * 2)); } void SetPcAndState(int index, Smi* offset) { set(1 + index * 2, offset); } static int LengthOfFixedArray(int deopt_points) { return deopt_points * 2; } // Allocates a DeoptimizationOutputData. MUST_USE_RESULT static MaybeObject* Allocate(int number_of_deopt_points, PretenureFlag pretenure); // Casting. static inline DeoptimizationOutputData* cast(Object* obj); #if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER) void DeoptimizationOutputDataPrint(FILE* out); #endif }; // Forward declaration. class JSGlobalPropertyCell; // TypeFeedbackCells is a fixed array used to hold the association between // cache cells and AST ids for code generated by the full compiler. // The format of the these objects is // [i * 2]: Global property cell of ith cache cell. // [i * 2 + 1]: Ast ID for ith cache cell. class TypeFeedbackCells: public FixedArray { public: int CellCount() { return length() / 2; } static int LengthOfFixedArray(int cell_count) { return cell_count * 2; } // Accessors for AST ids associated with cache values. inline Smi* AstId(int index); inline void SetAstId(int index, Smi* id); // Accessors for global property cells holding the cache values. inline JSGlobalPropertyCell* Cell(int index); inline void SetCell(int index, JSGlobalPropertyCell* cell); // The object that indicates an uninitialized cache. static inline Handle UninitializedSentinel(Isolate* isolate); // The object that indicates a megamorphic state. static inline Handle MegamorphicSentinel(Isolate* isolate); // A raw version of the uninitialized sentinel that's safe to read during // garbage collection (e.g., for patching the cache). static inline Object* RawUninitializedSentinel(Heap* heap); // Casting. static inline TypeFeedbackCells* cast(Object* obj); static const int kForInFastCaseMarker = 0; static const int kForInSlowCaseMarker = 1; }; // Forward declaration. class SafepointEntry; class TypeFeedbackInfo; // Code describes objects with on-the-fly generated machine code. class Code: public HeapObject { public: // Opaque data type for encapsulating code flags like kind, inline // cache state, and arguments count. // FLAGS_MIN_VALUE and FLAGS_MAX_VALUE are specified to ensure that // enumeration type has correct value range (see Issue 830 for more details). enum Flags { FLAGS_MIN_VALUE = kMinInt, FLAGS_MAX_VALUE = kMaxInt }; enum Kind { FUNCTION, OPTIMIZED_FUNCTION, STUB, BUILTIN, LOAD_IC, KEYED_LOAD_IC, CALL_IC, KEYED_CALL_IC, STORE_IC, KEYED_STORE_IC, UNARY_OP_IC, BINARY_OP_IC, COMPARE_IC, TO_BOOLEAN_IC, // No more than 16 kinds. The value currently encoded in four bits in // Flags. // Pseudo-kinds. REGEXP = BUILTIN, FIRST_IC_KIND = LOAD_IC, LAST_IC_KIND = TO_BOOLEAN_IC }; enum { NUMBER_OF_KINDS = LAST_IC_KIND + 1 }; typedef int ExtraICState; static const ExtraICState kNoExtraICState = 0; #ifdef ENABLE_DISASSEMBLER // Printing static const char* Kind2String(Kind kind); static const char* ICState2String(InlineCacheState state); static const char* PropertyType2String(PropertyType type); static void PrintExtraICState(FILE* out, Kind kind, ExtraICState extra); inline void Disassemble(const char* name) { Disassemble(name, stdout); } void Disassemble(const char* name, FILE* out); #endif // ENABLE_DISASSEMBLER // [instruction_size]: Size of the native instructions inline int instruction_size(); inline void set_instruction_size(int value); // [relocation_info]: Code relocation information DECL_ACCESSORS(relocation_info, ByteArray) void InvalidateRelocation(); // [handler_table]: Fixed array containing offsets of exception handlers. DECL_ACCESSORS(handler_table, FixedArray) // [deoptimization_data]: Array containing data for deopt. DECL_ACCESSORS(deoptimization_data, FixedArray) // [type_feedback_info]: Struct containing type feedback information. // Will contain either a TypeFeedbackInfo object, or undefined. DECL_ACCESSORS(type_feedback_info, Object) // [gc_metadata]: Field used to hold GC related metadata. The contents of this // field does not have to be traced during garbage collection since // it is only used by the garbage collector itself. DECL_ACCESSORS(gc_metadata, Object) // [ic_age]: Inline caching age: the value of the Heap::global_ic_age // at the moment when this object was created. inline void set_ic_age(int count); inline int ic_age(); // Unchecked accessors to be used during GC. inline ByteArray* unchecked_relocation_info(); inline FixedArray* unchecked_deoptimization_data(); inline int relocation_size(); // [flags]: Various code flags. inline Flags flags(); inline void set_flags(Flags flags); // [flags]: Access to specific code flags. inline Kind kind(); inline InlineCacheState ic_state(); // Only valid for IC stubs. inline ExtraICState extra_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; } inline bool is_keyed_call_stub() { return kind() == KEYED_CALL_IC; } inline bool is_unary_op_stub() { return kind() == UNARY_OP_IC; } inline bool is_binary_op_stub() { return kind() == BINARY_OP_IC; } inline bool is_compare_ic_stub() { return kind() == COMPARE_IC; } inline bool is_to_boolean_ic_stub() { return kind() == TO_BOOLEAN_IC; } // [major_key]: For kind STUB or BINARY_OP_IC, the major key. inline int major_key(); inline void set_major_key(int value); // For stubs, tells whether they should always exist, so that they can be // called from other stubs. inline bool is_pregenerated(); inline void set_is_pregenerated(bool value); // [optimizable]: For FUNCTION kind, tells if it is optimizable. inline bool optimizable(); inline void set_optimizable(bool value); // [has_deoptimization_support]: For FUNCTION kind, tells if it has // deoptimization support. inline bool has_deoptimization_support(); inline void set_has_deoptimization_support(bool value); // [has_debug_break_slots]: For FUNCTION kind, tells if it has // been compiled with debug break slots. inline bool has_debug_break_slots(); inline void set_has_debug_break_slots(bool value); // [compiled_with_optimizing]: For FUNCTION kind, tells if it has // been compiled with IsOptimizing set to true. inline bool is_compiled_optimizable(); inline void set_compiled_optimizable(bool value); // [has_self_optimization_header]: For FUNCTION kind, tells if it has // a self-optimization header. inline bool has_self_optimization_header(); inline void set_self_optimization_header(bool value); // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for // how long the function has been marked for OSR and therefore which // level of loop nesting we are willing to do on-stack replacement // for. inline void set_allow_osr_at_loop_nesting_level(int level); inline int allow_osr_at_loop_nesting_level(); // [profiler_ticks]: For FUNCTION kind, tells for how many profiler ticks // the code object was seen on the stack with no IC patching going on. inline int profiler_ticks(); inline void set_profiler_ticks(int ticks); // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots // reserved in the code prologue. inline unsigned stack_slots(); inline void set_stack_slots(unsigned slots); // [safepoint_table_start]: For kind OPTIMIZED_CODE, the offset in // the instruction stream where the safepoint table starts. inline unsigned safepoint_table_offset(); inline void set_safepoint_table_offset(unsigned offset); // [stack_check_table_start]: For kind FUNCTION, the offset in the // instruction stream where the stack check table starts. inline unsigned stack_check_table_offset(); inline void set_stack_check_table_offset(unsigned offset); // [check type]: For kind CALL_IC, tells how to check if the // receiver is valid for the given call. inline CheckType check_type(); inline void set_check_type(CheckType value); // [type-recording unary op type]: For kind UNARY_OP_IC. inline byte unary_op_type(); inline void set_unary_op_type(byte value); // [type-recording binary op type]: For kind BINARY_OP_IC. inline byte binary_op_type(); inline void set_binary_op_type(byte value); inline byte binary_op_result_type(); inline void set_binary_op_result_type(byte value); // [compare state]: For kind COMPARE_IC, tells what state the stub is in. inline byte compare_state(); inline void set_compare_state(byte value); // [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in. inline byte to_boolean_state(); inline void set_to_boolean_state(byte value); // [has_function_cache]: For kind STUB tells whether there is a function // cache is passed to the stub. inline bool has_function_cache(); inline void set_has_function_cache(bool flag); // Get the safepoint entry for the given pc. SafepointEntry GetSafepointEntry(Address pc); // Mark this code object as not having a stack check table. Assumes kind // is FUNCTION. void SetNoStackCheckTable(); // Find the first map in an IC stub. Map* FindFirstMap(); class ExtraICStateStrictMode: public BitField {}; class ExtraICStateKeyedAccessGrowMode: public BitField {}; // NOLINT static const int kExtraICStateGrowModeShift = 1; static inline StrictModeFlag GetStrictMode(ExtraICState extra_ic_state) { return ExtraICStateStrictMode::decode(extra_ic_state); } static inline KeyedAccessGrowMode GetKeyedAccessGrowMode( ExtraICState extra_ic_state) { return ExtraICStateKeyedAccessGrowMode::decode(extra_ic_state); } static inline ExtraICState ComputeExtraICState( KeyedAccessGrowMode grow_mode, StrictModeFlag strict_mode) { return ExtraICStateKeyedAccessGrowMode::encode(grow_mode) | ExtraICStateStrictMode::encode(strict_mode); } // Flags operations. static inline Flags ComputeFlags( Kind kind, InlineCacheState ic_state = UNINITIALIZED, ExtraICState extra_ic_state = kNoExtraICState, PropertyType type = NORMAL, int argc = -1, InlineCacheHolderFlag holder = OWN_MAP); static inline Flags ComputeMonomorphicFlags( Kind kind, PropertyType type, ExtraICState extra_ic_state = kNoExtraICState, InlineCacheHolderFlag holder = OWN_MAP, int argc = -1); static inline InlineCacheState ExtractICStateFromFlags(Flags flags); static inline PropertyType ExtractTypeFromFlags(Flags flags); static inline Kind ExtractKindFromFlags(Flags flags); static inline InlineCacheHolderFlag ExtractCacheHolderFromFlags(Flags flags); static inline ExtraICState ExtractExtraICStateFromFlags(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); // Convert an entry address into an object. static inline Object* GetObjectFromEntryAddress(Address location_of_address); // Returns the address of the first instruction. inline byte* instruction_start(); // Returns the address right after the last instruction. inline byte* instruction_end(); // Returns the size of the instructions, padding, and relocation information. inline int body_size(); // Returns the address of the first relocation info (read backwards!). inline byte* relocation_start(); // Code entry point. inline byte* entry(); // Returns true if pc is inside this object's instructions. inline bool contains(byte* pc); // Relocate the code by delta bytes. Called to signal that this code // object has been moved by delta bytes. void Relocate(intptr_t delta); // Migrate code described by desc. void CopyFrom(const CodeDesc& desc); // Returns the object size for a given body (used for allocation). static int SizeFor(int body_size) { ASSERT_SIZE_TAG_ALIGNED(body_size); return RoundUp(kHeaderSize + body_size, kCodeAlignment); } // Calculate the size of the code object to report for log events. This takes // the layout of the code object into account. int ExecutableSize() { // Check that the assumptions about the layout of the code object holds. ASSERT_EQ(static_cast(instruction_start() - address()), Code::kHeaderSize); return instruction_size() + Code::kHeaderSize; } // Locating source position. int SourcePosition(Address pc); int SourceStatementPosition(Address pc); // Casting. static inline Code* cast(Object* obj); // Dispatched behavior. int CodeSize() { return SizeFor(body_size()); } inline void CodeIterateBody(ObjectVisitor* v); template inline void CodeIterateBody(Heap* heap); #ifdef OBJECT_PRINT inline void CodePrint() { CodePrint(stdout); } void CodePrint(FILE* out); #endif #ifdef DEBUG void CodeVerify(); #endif void ClearInlineCaches(); // Max loop nesting marker used to postpose OSR. We don't take loop // nesting that is deeper than 5 levels into account. static const int kMaxLoopNestingMarker = 6; // Layout description. static const int kInstructionSizeOffset = HeapObject::kHeaderSize; static const int kRelocationInfoOffset = kInstructionSizeOffset + kIntSize; static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize; static const int kDeoptimizationDataOffset = kHandlerTableOffset + kPointerSize; static const int kTypeFeedbackInfoOffset = kDeoptimizationDataOffset + kPointerSize; static const int kGCMetadataOffset = kTypeFeedbackInfoOffset + kPointerSize; static const int kICAgeOffset = kGCMetadataOffset + kPointerSize; static const int kFlagsOffset = kICAgeOffset + kIntSize; static const int kKindSpecificFlagsOffset = kFlagsOffset + kIntSize; static const int kKindSpecificFlagsSize = 2 * kIntSize; static const int kHeaderPaddingStart = kKindSpecificFlagsOffset + kKindSpecificFlagsSize; // Add padding to align the instruction start following right after // the Code object header. static const int kHeaderSize = (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask; // Byte offsets within kKindSpecificFlagsOffset. static const int kStubMajorKeyOffset = kKindSpecificFlagsOffset; static const int kOptimizableOffset = kKindSpecificFlagsOffset; static const int kStackSlotsOffset = kKindSpecificFlagsOffset; static const int kCheckTypeOffset = kKindSpecificFlagsOffset; static const int kUnaryOpTypeOffset = kStubMajorKeyOffset + 1; static const int kBinaryOpTypeOffset = kStubMajorKeyOffset + 1; static const int kCompareStateOffset = kStubMajorKeyOffset + 1; static const int kToBooleanTypeOffset = kStubMajorKeyOffset + 1; static const int kHasFunctionCacheOffset = kStubMajorKeyOffset + 1; static const int kFullCodeFlags = kOptimizableOffset + 1; class FullCodeFlagsHasDeoptimizationSupportField: public BitField {}; // NOLINT class FullCodeFlagsHasDebugBreakSlotsField: public BitField {}; class FullCodeFlagsIsCompiledOptimizable: public BitField {}; class FullCodeFlagsHasSelfOptimizationHeader: public BitField {}; static const int kBinaryOpReturnTypeOffset = kBinaryOpTypeOffset + 1; static const int kAllowOSRAtLoopNestingLevelOffset = kFullCodeFlags + 1; static const int kProfilerTicksOffset = kAllowOSRAtLoopNestingLevelOffset + 1; static const int kSafepointTableOffsetOffset = kStackSlotsOffset + kIntSize; static const int kStackCheckTableOffsetOffset = kStackSlotsOffset + kIntSize; // Flags layout. BitField. class ICStateField: public BitField {}; class TypeField: public BitField {}; class CacheHolderField: public BitField {}; class KindField: public BitField {}; class ExtraICStateField: public BitField {}; class IsPregeneratedField: public BitField {}; // Signed field cannot be encoded using the BitField class. static const int kArgumentsCountShift = 15; static const int kArgumentsCountMask = ~((1 << kArgumentsCountShift) - 1); // This constant should be encodable in an ARM instruction. static const int kFlagsNotUsedInLookup = TypeField::kMask | CacheHolderField::kMask; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Code); }; // All heap objects have a Map that describes their structure. // A Map contains information about: // - Size information about the object // - How to iterate over an object (for garbage collection) class Map: public HeapObject { public: // Instance size. // Size in bytes or kVariableSizeSentinel if instances do not have // a fixed size. inline int instance_size(); inline void set_instance_size(int value); // Count of properties allocated in the object. inline int inobject_properties(); inline void set_inobject_properties(int value); // Count of property fields pre-allocated in the object when first allocated. inline int pre_allocated_property_fields(); inline void set_pre_allocated_property_fields(int value); // Instance type. inline InstanceType instance_type(); inline void set_instance_type(InstanceType value); // Tells how many unused property fields are available in the // instance (only used for JSObject in fast mode). inline int unused_property_fields(); inline void set_unused_property_fields(int value); // Bit field. inline byte bit_field(); inline void set_bit_field(byte value); // Bit field 2. inline byte bit_field2(); inline void set_bit_field2(byte value); // Bit field 3. // TODO(1399): It should be possible to make room for bit_field3 in the map // without overloading the instance descriptors field (and storing it in the // DescriptorArray when the map has one). inline int bit_field3(); inline void set_bit_field3(int value); // Tells whether the object in the prototype property will be used // for instances created from this function. If the prototype // property is set to a value that is not a JSObject, the prototype // property will not be used to create instances of the function. // See ECMA-262, 13.2.2. inline void set_non_instance_prototype(bool value); inline bool has_non_instance_prototype(); // Tells whether function has special prototype property. If not, prototype // property will not be created when accessed (will return undefined), // and construction from this function will not be allowed. inline void set_function_with_prototype(bool value); inline bool function_with_prototype(); // Tells whether the instance with this map should be ignored by the // __proto__ accessor. inline void set_is_hidden_prototype() { set_bit_field(bit_field() | (1 << kIsHiddenPrototype)); } inline bool is_hidden_prototype() { return ((1 << kIsHiddenPrototype) & bit_field()) != 0; } // Records and queries whether the instance has a named interceptor. inline void set_has_named_interceptor() { set_bit_field(bit_field() | (1 << kHasNamedInterceptor)); } inline bool has_named_interceptor() { return ((1 << kHasNamedInterceptor) & bit_field()) != 0; } // Records and queries whether the instance has an indexed interceptor. inline void set_has_indexed_interceptor() { set_bit_field(bit_field() | (1 << kHasIndexedInterceptor)); } inline bool has_indexed_interceptor() { return ((1 << kHasIndexedInterceptor) & bit_field()) != 0; } // Tells whether the instance is undetectable. // An undetectable object is a special class of JSObject: 'typeof' operator // returns undefined, ToBoolean returns false. Otherwise it behaves like // a normal JS object. It is useful for implementing undetectable // document.all in Firefox & Safari. // See https://bugzilla.mozilla.org/show_bug.cgi?id=248549. inline void set_is_undetectable() { set_bit_field(bit_field() | (1 << kIsUndetectable)); } inline bool is_undetectable() { return ((1 << kIsUndetectable) & bit_field()) != 0; } // Tells whether the instance has a call-as-function handler. inline void set_has_instance_call_handler() { set_bit_field(bit_field() | (1 << kHasInstanceCallHandler)); } inline bool has_instance_call_handler() { return ((1 << kHasInstanceCallHandler) & bit_field()) != 0; } inline void set_is_extensible(bool value); inline bool is_extensible(); inline void set_elements_kind(ElementsKind elements_kind) { ASSERT(elements_kind < kElementsKindCount); ASSERT(kElementsKindCount <= (1 << kElementsKindBitCount)); set_bit_field2((bit_field2() & ~kElementsKindMask) | (elements_kind << kElementsKindShift)); ASSERT(this->elements_kind() == elements_kind); } inline ElementsKind elements_kind() { return static_cast( (bit_field2() & kElementsKindMask) >> kElementsKindShift); } // Tells whether the instance has fast elements that are only Smis. inline bool has_fast_smi_only_elements() { return elements_kind() == FAST_SMI_ONLY_ELEMENTS; } // Tells whether the instance has fast elements. inline bool has_fast_elements() { return elements_kind() == FAST_ELEMENTS; } inline bool has_fast_double_elements() { return elements_kind() == FAST_DOUBLE_ELEMENTS; } inline bool has_non_strict_arguments_elements() { return elements_kind() == NON_STRICT_ARGUMENTS_ELEMENTS; } inline bool has_external_array_elements() { ElementsKind kind(elements_kind()); return kind >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND && kind <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND; } inline bool has_dictionary_elements() { return elements_kind() == DICTIONARY_ELEMENTS; } inline bool has_slow_elements_kind() { return elements_kind() == DICTIONARY_ELEMENTS || elements_kind() == NON_STRICT_ARGUMENTS_ELEMENTS; } static bool IsValidElementsTransition(ElementsKind from_kind, ElementsKind to_kind); // Tells whether the map is attached to SharedFunctionInfo // (for inobject slack tracking). inline void set_attached_to_shared_function_info(bool value); inline bool attached_to_shared_function_info(); // Tells whether the map is shared between objects that may have different // behavior. If true, the map should never be modified, instead a clone // should be created and modified. inline void set_is_shared(bool value); inline bool is_shared(); // Tells whether the instance needs security checks when accessing its // properties. inline void set_is_access_check_needed(bool access_check_needed); inline bool is_access_check_needed(); // [prototype]: implicit prototype object. DECL_ACCESSORS(prototype, Object) // [constructor]: points back to the function responsible for this map. DECL_ACCESSORS(constructor, Object) inline JSFunction* unchecked_constructor(); // Should only be called by the code that initializes map to set initial valid // value of the instance descriptor member. inline void init_instance_descriptors(); // [instance descriptors]: describes the object. DECL_ACCESSORS(instance_descriptors, DescriptorArray) // Sets the instance descriptor array for the map to be an empty descriptor // array. inline void clear_instance_descriptors(); // [stub cache]: contains stubs compiled for this map. DECL_ACCESSORS(code_cache, Object) // [prototype transitions]: cache of prototype transitions. // Prototype transition is a transition that happens // when we change object's prototype to a new one. // Cache format: // 0: finger - index of the first free cell in the cache // 1 + 2 * i: prototype // 2 + 2 * i: target map DECL_ACCESSORS(prototype_transitions, FixedArray) inline FixedArray* unchecked_prototype_transitions(); static const int kProtoTransitionHeaderSize = 1; static const int kProtoTransitionNumberOfEntriesOffset = 0; static const int kProtoTransitionElementsPerEntry = 2; static const int kProtoTransitionPrototypeOffset = 0; static const int kProtoTransitionMapOffset = 1; inline int NumberOfProtoTransitions() { FixedArray* cache = prototype_transitions(); if (cache->length() == 0) return 0; return Smi::cast(cache->get(kProtoTransitionNumberOfEntriesOffset))->value(); } inline void SetNumberOfProtoTransitions(int value) { FixedArray* cache = prototype_transitions(); ASSERT(cache->length() != 0); cache->set_unchecked(kProtoTransitionNumberOfEntriesOffset, Smi::FromInt(value)); } // Lookup in the map's instance descriptors and fill out the result // with the given holder if the name is found. The holder may be // NULL when this function is used from the compiler. void LookupInDescriptors(JSObject* holder, String* name, LookupResult* result); MUST_USE_RESULT MaybeObject* CopyDropDescriptors(); MUST_USE_RESULT MaybeObject* CopyNormalized(PropertyNormalizationMode mode, NormalizedMapSharingMode sharing); // Returns a copy of the map, with all transitions dropped from the // instance descriptors. MUST_USE_RESULT MaybeObject* CopyDropTransitions(); // Returns 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 // filtering out properties with the specified attributes. int NumberOfDescribedProperties(PropertyAttributes filter = NONE); // 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(Heap* heap); // Update code cache. static void UpdateCodeCache(Handle map, Handle name, Handle code); MUST_USE_RESULT MaybeObject* UpdateCodeCache(String* name, Code* code); // Returns the found code or undefined if absent. Object* FindInCodeCache(String* name, Code::Flags flags); // Returns the non-negative index of the code object if it is in the // cache and -1 otherwise. int IndexInCodeCache(Object* name, Code* code); // Removes a code object from the code cache at the given index. void RemoveFromCodeCache(String* name, Code* code, int index); // For every transition in this map, makes the transition's // target's prototype pointer point back to this map. // This is undone in MarkCompactCollector::ClearNonLiveTransitions(). void CreateBackPointers(); void CreateOneBackPointer(Object* transition_target); // 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(Heap* heap, Object* real_prototype); // Restore a possible back pointer in the prototype field of object. // Return true in that case and false otherwise. Set *keep_entry to // true when a live map transition has been found. bool RestoreOneBackPointer(Object* object, Object* real_prototype, bool* keep_entry); // Computes a hash value for this map, to be used in HashTables and such. int Hash(); // Compares this map to another to see if they describe equivalent objects. // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if // it had exactly zero inobject properties. // The "shared" flags of both this map and |other| are ignored. bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode); // Returns the contents of this map's descriptor array for the given string. // May return NULL. |safe_to_add_transition| is set to false and NULL // is returned if adding transitions is not allowed. Object* GetDescriptorContents(String* sentinel_name, bool* safe_to_add_transitions); // Returns the map that this map transitions to if its elements_kind // is changed to |elements_kind|, or NULL if no such map is cached yet. // |safe_to_add_transitions| is set to false if adding transitions is not // allowed. Map* LookupElementsTransitionMap(ElementsKind elements_kind, bool* safe_to_add_transition); // Adds an entry to this map's descriptor array for a transition to // |transitioned_map| when its elements_kind is changed to |elements_kind|. MUST_USE_RESULT MaybeObject* AddElementsTransition( ElementsKind elements_kind, Map* transitioned_map); // Returns the transitioned map for this map with the most generic // elements_kind that's found in |candidates|, or null handle if no match is // found at all. Handle FindTransitionedMap(MapHandleList* candidates); Map* FindTransitionedMap(MapList* candidates); // Dispatched behavior. #ifdef OBJECT_PRINT inline void MapPrint() { MapPrint(stdout); } void MapPrint(FILE* out); #endif #ifdef DEBUG void MapVerify(); void SharedMapVerify(); #endif inline int visitor_id(); inline void set_visitor_id(int visitor_id); typedef void (*TraverseCallback)(Map* map, void* data); void TraverseTransitionTree(TraverseCallback callback, void* data); static const int kMaxCachedPrototypeTransitions = 256; Object* GetPrototypeTransition(Object* prototype); MUST_USE_RESULT MaybeObject* PutPrototypeTransition(Object* prototype, Map* map); static const int kMaxPreAllocatedPropertyFields = 255; // Layout description. static const int kInstanceSizesOffset = HeapObject::kHeaderSize; static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize; static const int kPrototypeOffset = kInstanceAttributesOffset + kIntSize; static const int kConstructorOffset = kPrototypeOffset + kPointerSize; // Storage for instance descriptors is overloaded to also contain additional // map flags when unused (bit_field3). When the map has instance descriptors, // the flags are transferred to the instance descriptor array and accessed // through an extra indirection. // TODO(1399): It should be possible to make room for bit_field3 in the map // without overloading the instance descriptors field, but the map is // currently perfectly aligned to 32 bytes and extending it at all would // double its size. After the increment GC work lands, this size restriction // could be loosened and bit_field3 moved directly back in the map. static const int kInstanceDescriptorsOrBitField3Offset = kConstructorOffset + kPointerSize; static const int kCodeCacheOffset = kInstanceDescriptorsOrBitField3Offset + kPointerSize; static const int kPrototypeTransitionsOffset = kCodeCacheOffset + kPointerSize; static const int kPadStart = kPrototypeTransitionsOffset + kPointerSize; static const int kSize = MAP_POINTER_ALIGN(kPadStart); // Layout of pointer fields. Heap iteration code relies on them // being continuously allocated. static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset; static const int kPointerFieldsEndOffset = Map::kPrototypeTransitionsOffset + kPointerSize; // Byte offsets within kInstanceSizesOffset. static const int kInstanceSizeOffset = kInstanceSizesOffset + 0; static const int kInObjectPropertiesByte = 1; static const int kInObjectPropertiesOffset = kInstanceSizesOffset + kInObjectPropertiesByte; static const int kPreAllocatedPropertyFieldsByte = 2; static const int kPreAllocatedPropertyFieldsOffset = kInstanceSizesOffset + kPreAllocatedPropertyFieldsByte; static const int kVisitorIdByte = 3; static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte; // Byte offsets within kInstanceAttributesOffset attributes. static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0; static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 1; static const int kBitFieldOffset = kInstanceAttributesOffset + 2; static const int kBitField2Offset = kInstanceAttributesOffset + 3; STATIC_CHECK(kInstanceTypeOffset == Internals::kMapInstanceTypeOffset); // Bit positions for bit field. static const int kUnused = 0; // To be used for marking recently used maps. static const int kHasNonInstancePrototype = 1; static const int kIsHiddenPrototype = 2; static const int kHasNamedInterceptor = 3; static const int kHasIndexedInterceptor = 4; static const int kIsUndetectable = 5; static const int kHasInstanceCallHandler = 6; static const int kIsAccessCheckNeeded = 7; // Bit positions for bit field 2 static const int kIsExtensible = 0; static const int kFunctionWithPrototype = 1; static const int kStringWrapperSafeForDefaultValueOf = 2; static const int kAttachedToSharedFunctionInfo = 3; // No bits can be used after kElementsKindFirstBit, they are all reserved for // storing ElementKind. static const int kElementsKindShift = 4; static const int kElementsKindBitCount = 4; // Derived values from bit field 2 static const int kElementsKindMask = (-1 << kElementsKindShift) & ((1 << (kElementsKindShift + kElementsKindBitCount)) - 1); static const int8_t kMaximumBitField2FastElementValue = static_cast( (FAST_ELEMENTS + 1) << Map::kElementsKindShift) - 1; static const int8_t kMaximumBitField2FastSmiOnlyElementValue = static_cast((FAST_SMI_ONLY_ELEMENTS + 1) << Map::kElementsKindShift) - 1; // Bit positions for bit field 3 static const int kIsShared = 0; // Layout of the default cache. It holds alternating name and code objects. static const int kCodeCacheEntrySize = 2; static const int kCodeCacheEntryNameOffset = 0; static const int kCodeCacheEntryCodeOffset = 1; typedef FixedBodyDescriptor BodyDescriptor; private: String* elements_transition_sentinel_name(); 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 be // identified in the type system. class Struct: public HeapObject { public: inline void InitializeBody(int object_size); static inline Struct* cast(Object* that); }; // Script describes a script which has been added to the VM. class Script: public Struct { public: // Script types. enum Type { TYPE_NATIVE = 0, TYPE_EXTENSION = 1, TYPE_NORMAL = 2 }; // Script compilation types. enum CompilationType { COMPILATION_TYPE_HOST = 0, COMPILATION_TYPE_EVAL = 1 }; // Script compilation state. enum CompilationState { COMPILATION_STATE_INITIAL = 0, COMPILATION_STATE_COMPILED = 1 }; // [source]: the script source. DECL_ACCESSORS(source, Object) // [name]: the script name. DECL_ACCESSORS(name, Object) // [id]: the script id. DECL_ACCESSORS(id, Object) // [line_offset]: script line offset in resource from where it was extracted. DECL_ACCESSORS(line_offset, Smi) // [column_offset]: script column offset in resource from where it was // extracted. DECL_ACCESSORS(column_offset, Smi) // [data]: additional data associated with this script. DECL_ACCESSORS(data, Object) // [context_data]: context data for the context this script was compiled in. DECL_ACCESSORS(context_data, Object) // [wrapper]: the wrapper cache. DECL_ACCESSORS(wrapper, Foreign) // [type]: the script type. DECL_ACCESSORS(type, Smi) // [compilation]: how the the script was compiled. DECL_ACCESSORS(compilation_type, Smi) // [is_compiled]: determines whether the script has already been compiled. DECL_ACCESSORS(compilation_state, Smi) // [line_ends]: FixedArray of line ends positions. DECL_ACCESSORS(line_ends, Object) // [eval_from_shared]: for eval scripts the shared funcion info for the // function from which eval was called. DECL_ACCESSORS(eval_from_shared, Object) // [eval_from_instructions_offset]: the instruction offset in the code for the // function from which eval was called where eval was called. DECL_ACCESSORS(eval_from_instructions_offset, Smi) static inline Script* cast(Object* obj); // If script source is an external string, check that the underlying // resource is accessible. Otherwise, always return true. inline bool HasValidSource(); #ifdef OBJECT_PRINT inline void ScriptPrint() { ScriptPrint(stdout); } void ScriptPrint(FILE* out); #endif #ifdef DEBUG void ScriptVerify(); #endif static const int kSourceOffset = HeapObject::kHeaderSize; static const int kNameOffset = kSourceOffset + kPointerSize; static const int kLineOffsetOffset = kNameOffset + kPointerSize; static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize; static const int kDataOffset = kColumnOffsetOffset + kPointerSize; static const int kContextOffset = kDataOffset + kPointerSize; static const int kWrapperOffset = kContextOffset + kPointerSize; static const int kTypeOffset = kWrapperOffset + kPointerSize; static const int kCompilationTypeOffset = kTypeOffset + kPointerSize; static const int kCompilationStateOffset = kCompilationTypeOffset + kPointerSize; static const int kLineEndsOffset = kCompilationStateOffset + kPointerSize; static const int kIdOffset = kLineEndsOffset + kPointerSize; static const int kEvalFromSharedOffset = kIdOffset + kPointerSize; static const int kEvalFrominstructionsOffsetOffset = kEvalFromSharedOffset + kPointerSize; static const int kSize = kEvalFrominstructionsOffsetOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Script); }; // List of builtin functions we want to identify to improve code // generation. // // Each entry has a name of a global object property holding an object // optionally followed by ".prototype", a name of a builtin function // on the object (the one the id is set for), and a label. // // Installation of ids for the selected builtin functions is handled // by the bootstrapper. // // NOTE: Order is important: math functions should be at the end of // the list and MathFloor should be the first math function. #define FUNCTIONS_WITH_ID_LIST(V) \ V(Array.prototype, push, ArrayPush) \ V(Array.prototype, pop, ArrayPop) \ V(Function.prototype, apply, FunctionApply) \ V(String.prototype, charCodeAt, StringCharCodeAt) \ V(String.prototype, charAt, StringCharAt) \ V(String, fromCharCode, StringFromCharCode) \ V(Math, floor, MathFloor) \ V(Math, round, MathRound) \ V(Math, ceil, MathCeil) \ V(Math, abs, MathAbs) \ V(Math, log, MathLog) \ V(Math, sin, MathSin) \ V(Math, cos, MathCos) \ V(Math, tan, MathTan) \ V(Math, asin, MathASin) \ V(Math, acos, MathACos) \ V(Math, atan, MathATan) \ V(Math, exp, MathExp) \ V(Math, sqrt, MathSqrt) \ V(Math, pow, MathPow) \ V(Math, random, MathRandom) \ V(Math, max, MathMax) \ V(Math, min, MathMin) enum BuiltinFunctionId { #define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \ k##name, FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID) #undef DECLARE_FUNCTION_ID // Fake id for a special case of Math.pow. Note, it continues the // list of math functions. kMathPowHalf, kFirstMathFunctionId = kMathFloor }; // SharedFunctionInfo describes the JSFunction information that can be // shared by multiple instances of the function. class SharedFunctionInfo: public HeapObject { public: // [name]: Function name. DECL_ACCESSORS(name, Object) // [code]: Function code. DECL_ACCESSORS(code, Code) // [scope_info]: Scope info. DECL_ACCESSORS(scope_info, ScopeInfo) // [construct stub]: Code stub for constructing instances of this function. DECL_ACCESSORS(construct_stub, Code) inline Code* unchecked_code(); // Returns if this function has been compiled to native code yet. inline bool is_compiled(); // [length]: The function length - usually the number of declared parameters. // Use up to 2^30 parameters. inline int length(); inline void set_length(int value); // [formal parameter count]: The declared number of parameters. inline int formal_parameter_count(); inline void set_formal_parameter_count(int value); // Set the formal parameter count so the function code will be // called without using argument adaptor frames. inline void DontAdaptArguments(); // [expected_nof_properties]: Expected number of properties for the function. inline int expected_nof_properties(); inline void set_expected_nof_properties(int value); // Inobject slack tracking is the way to reclaim unused inobject space. // // The instance size is initially determined by adding some slack to // expected_nof_properties (to allow for a few extra properties added // after the constructor). There is no guarantee that the extra space // will not be wasted. // // Here is the algorithm to reclaim the unused inobject space: // - Detect the first constructor call for this SharedFunctionInfo. // When it happens enter the "in progress" state: remember the // constructor's initial_map and install a special construct stub that // counts constructor calls. // - While the tracking is in progress create objects filled with // one_pointer_filler_map instead of undefined_value. This way they can be // resized quickly and safely. // - Once enough (kGenerousAllocationCount) objects have been created // compute the 'slack' (traverse the map transition tree starting from the // initial_map and find the lowest value of unused_property_fields). // - Traverse the transition tree again and decrease the instance size // of every map. Existing objects will resize automatically (they are // filled with one_pointer_filler_map). All further allocations will // use the adjusted instance size. // - Decrease expected_nof_properties so that an allocations made from // another context will use the adjusted instance size too. // - Exit "in progress" state by clearing the reference to the initial_map // and setting the regular construct stub (generic or inline). // // The above is the main event sequence. Some special cases are possible // while the tracking is in progress: // // - GC occurs. // Check if the initial_map is referenced by any live objects (except this // SharedFunctionInfo). If it is, continue tracking as usual. // If it is not, clear the reference and reset the tracking state. The // tracking will be initiated again on the next constructor call. // // - The constructor is called from another context. // Immediately complete the tracking, perform all the necessary changes // to maps. This is necessary because there is no efficient way to track // multiple initial_maps. // Proceed to create an object in the current context (with the adjusted // size). // // - A different constructor function sharing the same SharedFunctionInfo is // called in the same context. This could be another closure in the same // context, or the first function could have been disposed. // This is handled the same way as the previous case. // // Important: inobject slack tracking is not attempted during the snapshot // creation. static const int kGenerousAllocationCount = 8; // [construction_count]: Counter for constructor calls made during // the tracking phase. inline int construction_count(); inline void set_construction_count(int value); // [initial_map]: initial map of the first function called as a constructor. // Saved for the duration of the tracking phase. // This is a weak link (GC resets it to undefined_value if no other live // object reference this map). DECL_ACCESSORS(initial_map, Object) // True if the initial_map is not undefined and the countdown stub is // installed. inline bool IsInobjectSlackTrackingInProgress(); // Starts the tracking. // Stores the initial map and installs the countdown stub. // IsInobjectSlackTrackingInProgress is normally true after this call, // except when tracking have not been started (e.g. the map has no unused // properties or the snapshot is being built). void StartInobjectSlackTracking(Map* map); // Completes the tracking. // IsInobjectSlackTrackingInProgress is false after this call. void CompleteInobjectSlackTracking(); // Clears the initial_map before the GC marking phase to ensure the reference // is weak. IsInobjectSlackTrackingInProgress is false after this call. void DetachInitialMap(); // Restores the link to the initial map after the GC marking phase. // IsInobjectSlackTrackingInProgress is true after this call. void AttachInitialMap(Map* map); // False if there are definitely no live objects created from this function. // True if live objects _may_ exist (existence not guaranteed). // May go back from true to false after GC. DECL_BOOLEAN_ACCESSORS(live_objects_may_exist) // [instance class name]: class name for instances. DECL_ACCESSORS(instance_class_name, Object) // [function data]: This field holds some additional data for function. // Currently it either has FunctionTemplateInfo to make benefit the API // or Smi identifying a builtin function. // In the long run we don't want all functions to have this field but // we can fix that when we have a better model for storing hidden data // on objects. DECL_ACCESSORS(function_data, Object) inline bool IsApiFunction(); inline FunctionTemplateInfo* get_api_func_data(); inline bool HasBuiltinFunctionId(); inline BuiltinFunctionId builtin_function_id(); // [script info]: Script from which the function originates. DECL_ACCESSORS(script, Object) // [num_literals]: Number of literals used by this function. inline int num_literals(); inline void set_num_literals(int value); // [start_position_and_type]: Field used to store both the source code // position, whether or not the function is a function expression, // and whether or not the function is a toplevel function. The two // least significants bit indicates whether the function is an // expression and the rest contains the source code position. inline int start_position_and_type(); inline void set_start_position_and_type(int value); // [debug info]: Debug information. DECL_ACCESSORS(debug_info, Object) // [inferred name]: Name inferred from variable or property // assignment of this function. Used to facilitate debugging and // profiling of JavaScript code written in OO style, where almost // all functions are anonymous but are assigned to object // properties. DECL_ACCESSORS(inferred_name, String) // The function's name if it is non-empty, otherwise the inferred name. String* DebugName(); // Position of the 'function' token in the script source. inline int function_token_position(); inline void set_function_token_position(int function_token_position); // Position of this function in the script source. inline int start_position(); inline void set_start_position(int start_position); // End position of this function in the script source. inline int end_position(); inline void set_end_position(int end_position); // Is this function a function expression in the source code. DECL_BOOLEAN_ACCESSORS(is_expression) // Is this function a top-level function (scripts, evals). DECL_BOOLEAN_ACCESSORS(is_toplevel) // Bit field containing various information collected by the compiler to // drive optimization. inline int compiler_hints(); inline void set_compiler_hints(int value); inline int ast_node_count(); inline void set_ast_node_count(int count); // A counter used to determine when to stress the deoptimizer with a // deopt. inline int deopt_counter(); inline void set_deopt_counter(int counter); // Inline cache age is used to infer whether the function survived a context // disposal or not. In the former case we reset the opt_count. inline int ic_age(); inline void set_ic_age(int age); // Add information on assignments of the form this.x = ...; void SetThisPropertyAssignmentsInfo( bool has_only_simple_this_property_assignments, FixedArray* this_property_assignments); // Clear information on assignments of the form this.x = ...; void ClearThisPropertyAssignmentsInfo(); // Indicate that this function only consists of assignments of the form // this.x = y; where y is either a constant or refers to an argument. inline bool has_only_simple_this_property_assignments(); // Indicates if this function can be lazy compiled. // This is used to determine if we can safely flush code from a function // when doing GC if we expect that the function will no longer be used. DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation) // Indicates how many full GCs this function has survived with assigned // code object. Used to determine when it is relatively safe to flush // this code object and replace it with lazy compilation stub. // Age is reset when GC notices that the code object is referenced // from the stack or compilation cache. inline int code_age(); inline void set_code_age(int age); // Indicates whether optimizations have been disabled for this // shared function info. If a function is repeatedly optimized or if // we cannot optimize the function we disable optimization to avoid // spending time attempting to optimize it again. DECL_BOOLEAN_ACCESSORS(optimization_disabled) // Indicates the language mode of the function's code as defined by the // current harmony drafts for the next ES language standard. Possible // values are: // 1. CLASSIC_MODE - Unrestricted syntax and semantics, same as in ES5. // 2. STRICT_MODE - Restricted syntax and semantics, same as in ES5. // 3. EXTENDED_MODE - Only available under the harmony flag, not part of ES5. inline LanguageMode language_mode(); inline void set_language_mode(LanguageMode language_mode); // Indicates whether the language mode of this function is CLASSIC_MODE. inline bool is_classic_mode(); // Indicates whether the language mode of this function is EXTENDED_MODE. inline bool is_extended_mode(); // False if the function definitely does not allocate an arguments object. DECL_BOOLEAN_ACCESSORS(uses_arguments) // True if the function has any duplicated parameter names. DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters) // Indicates whether the function is a native function. // These needs special treatment in .call and .apply since // null passed as the receiver should not be translated to the // global object. DECL_BOOLEAN_ACCESSORS(native) // Indicates that the function was created by the Function function. // Though it's anonymous, toString should treat it as if it had the name // "anonymous". We don't set the name itself so that the system does not // see a binding for it. DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous) // Indicates whether the function is a bound function created using // the bind function. DECL_BOOLEAN_ACCESSORS(bound) // Indicates that the function is anonymous (the name field can be set // through the API, which does not change this flag). DECL_BOOLEAN_ACCESSORS(is_anonymous) // Is this a function or top-level/eval code. DECL_BOOLEAN_ACCESSORS(is_function) // Indicates that the function cannot be optimized. DECL_BOOLEAN_ACCESSORS(dont_optimize) // Indicates that the function cannot be inlined. DECL_BOOLEAN_ACCESSORS(dont_inline) // Indicates whether or not the code in the shared function support // deoptimization. inline bool has_deoptimization_support(); // Enable deoptimization support through recompiled code. void EnableDeoptimizationSupport(Code* recompiled); // Disable (further) attempted optimization of all functions sharing this // shared function info. void DisableOptimization(); // Lookup the bailout ID and ASSERT that it exists in the non-optimized // code, returns whether it asserted (i.e., always true if assertions are // disabled). bool VerifyBailoutId(int id); // Check whether a inlined constructor can be generated with the given // prototype. bool CanGenerateInlineConstructor(Object* prototype); // Prevents further attempts to generate inline constructors. // To be called if generation failed for any reason. void ForbidInlineConstructor(); // For functions which only contains this property assignments this provides // access to the names for the properties assigned. DECL_ACCESSORS(this_property_assignments, Object) inline int this_property_assignments_count(); inline void set_this_property_assignments_count(int value); String* GetThisPropertyAssignmentName(int index); bool IsThisPropertyAssignmentArgument(int index); int GetThisPropertyAssignmentArgument(int index); Object* GetThisPropertyAssignmentConstant(int index); // [source code]: Source code for the function. bool HasSourceCode(); Handle GetSourceCode(); inline int opt_count(); inline void set_opt_count(int opt_count); // Source size of this function. int SourceSize(); // Calculate the instance size. int CalculateInstanceSize(); // Calculate the number of in-object properties. int CalculateInObjectProperties(); // Dispatched behavior. // Set max_length to -1 for unlimited length. void SourceCodePrint(StringStream* accumulator, int max_length); #ifdef OBJECT_PRINT inline void SharedFunctionInfoPrint() { SharedFunctionInfoPrint(stdout); } void SharedFunctionInfoPrint(FILE* out); #endif #ifdef DEBUG void SharedFunctionInfoVerify(); #endif void ResetForNewContext(int new_ic_age); // Helpers to compile the shared code. Returns true on success, false on // failure (e.g., stack overflow during compilation). static bool EnsureCompiled(Handle shared, ClearExceptionFlag flag); static bool CompileLazy(Handle shared, ClearExceptionFlag flag); void SharedFunctionInfoIterateBody(ObjectVisitor* v); // Casting. static inline SharedFunctionInfo* cast(Object* obj); // Constants. static const int kDontAdaptArgumentsSentinel = -1; // Layout description. // Pointer fields. static const int kNameOffset = HeapObject::kHeaderSize; static const int kCodeOffset = kNameOffset + kPointerSize; static const int kScopeInfoOffset = kCodeOffset + kPointerSize; static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize; static const int kInstanceClassNameOffset = kConstructStubOffset + kPointerSize; static const int kFunctionDataOffset = kInstanceClassNameOffset + kPointerSize; static const int kScriptOffset = kFunctionDataOffset + kPointerSize; static const int kDebugInfoOffset = kScriptOffset + kPointerSize; static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize; static const int kInitialMapOffset = kInferredNameOffset + kPointerSize; static const int kThisPropertyAssignmentsOffset = kInitialMapOffset + kPointerSize; // ic_age is a Smi field. It could be grouped with another Smi field into a // PSEUDO_SMI_ACCESSORS pair (on x64), if one becomes available. static const int kICAgeOffset = kThisPropertyAssignmentsOffset + kPointerSize; #if V8_HOST_ARCH_32_BIT // Smi fields. static const int kLengthOffset = kICAgeOffset + kPointerSize; static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize; static const int kExpectedNofPropertiesOffset = kFormalParameterCountOffset + kPointerSize; static const int kNumLiteralsOffset = kExpectedNofPropertiesOffset + kPointerSize; static const int kStartPositionAndTypeOffset = kNumLiteralsOffset + kPointerSize; static const int kEndPositionOffset = kStartPositionAndTypeOffset + kPointerSize; static const int kFunctionTokenPositionOffset = kEndPositionOffset + kPointerSize; static const int kCompilerHintsOffset = kFunctionTokenPositionOffset + kPointerSize; static const int kThisPropertyAssignmentsCountOffset = kCompilerHintsOffset + kPointerSize; static const int kOptCountOffset = kThisPropertyAssignmentsCountOffset + kPointerSize; static const int kAstNodeCountOffset = kOptCountOffset + kPointerSize; static const int kDeoptCounterOffset = kAstNodeCountOffset + kPointerSize; // Total size. static const int kSize = kDeoptCounterOffset + kPointerSize; #else // The only reason to use smi fields instead of int fields // is to allow iteration without maps decoding during // garbage collections. // To avoid wasting space on 64-bit architectures we use // the following trick: we group integer fields into pairs // First integer in each pair is shifted left by 1. // By doing this we guarantee that LSB of each kPointerSize aligned // word is not set and thus this word cannot be treated as pointer // to HeapObject during old space traversal. static const int kLengthOffset = kICAgeOffset + kPointerSize; static const int kFormalParameterCountOffset = kLengthOffset + kIntSize; static const int kExpectedNofPropertiesOffset = kFormalParameterCountOffset + kIntSize; static const int kNumLiteralsOffset = kExpectedNofPropertiesOffset + kIntSize; static const int kEndPositionOffset = kNumLiteralsOffset + kIntSize; static const int kStartPositionAndTypeOffset = kEndPositionOffset + kIntSize; static const int kFunctionTokenPositionOffset = kStartPositionAndTypeOffset + kIntSize; static const int kCompilerHintsOffset = kFunctionTokenPositionOffset + kIntSize; static const int kThisPropertyAssignmentsCountOffset = kCompilerHintsOffset + kIntSize; static const int kOptCountOffset = kThisPropertyAssignmentsCountOffset + kIntSize; static const int kAstNodeCountOffset = kOptCountOffset + kIntSize; static const int kDeoptCounterOffset = kAstNodeCountOffset + kIntSize; // Total size. static const int kSize = kDeoptCounterOffset + kIntSize; #endif // The construction counter for inobject slack tracking is stored in the // most significant byte of compiler_hints which is otherwise unused. // Its offset depends on the endian-ness of the architecture. #if __BYTE_ORDER == __LITTLE_ENDIAN static const int kConstructionCountOffset = kCompilerHintsOffset + 3; #elif __BYTE_ORDER == __BIG_ENDIAN static const int kConstructionCountOffset = kCompilerHintsOffset + 0; #else #error Unknown byte ordering #endif static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize); typedef FixedBodyDescriptor BodyDescriptor; // Bit positions in start_position_and_type. // The source code start position is in the 30 most significant bits of // the start_position_and_type field. static const int kIsExpressionBit = 0; static const int kIsTopLevelBit = 1; static const int kStartPositionShift = 2; static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1); // Bit positions in compiler_hints. static const int kCodeAgeSize = 3; static const int kCodeAgeMask = (1 << kCodeAgeSize) - 1; enum CompilerHints { kHasOnlySimpleThisPropertyAssignments, kAllowLazyCompilation, kLiveObjectsMayExist, kCodeAgeShift, kOptimizationDisabled = kCodeAgeShift + kCodeAgeSize, kStrictModeFunction, kExtendedModeFunction, kUsesArguments, kHasDuplicateParameters, kNative, kBoundFunction, kIsAnonymous, kNameShouldPrintAsAnonymous, kIsFunction, kDontOptimize, kDontInline, kCompilerHintsCount // Pseudo entry }; private: #if V8_HOST_ARCH_32_BIT // On 32 bit platforms, compiler hints is a smi. static const int kCompilerHintsSmiTagSize = kSmiTagSize; static const int kCompilerHintsSize = kPointerSize; #else // On 64 bit platforms, compiler hints is not a smi, see comment above. static const int kCompilerHintsSmiTagSize = 0; static const int kCompilerHintsSize = kIntSize; #endif STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <= SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte); public: // Constants for optimizing codegen for strict mode function and // native tests. // Allows to use byte-width instructions. static const int kStrictModeBitWithinByte = (kStrictModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte; static const int kExtendedModeBitWithinByte = (kExtendedModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte; static const int kNativeBitWithinByte = (kNative + kCompilerHintsSmiTagSize) % kBitsPerByte; #if __BYTE_ORDER == __LITTLE_ENDIAN static const int kStrictModeByteOffset = kCompilerHintsOffset + (kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte; static const int kExtendedModeByteOffset = kCompilerHintsOffset + (kExtendedModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte; static const int kNativeByteOffset = kCompilerHintsOffset + (kNative + kCompilerHintsSmiTagSize) / kBitsPerByte; #elif __BYTE_ORDER == __BIG_ENDIAN static const int kStrictModeByteOffset = kCompilerHintsOffset + (kCompilerHintsSize - 1) - ((kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte); static const int kExtendedModeByteOffset = kCompilerHintsOffset + (kCompilerHintsSize - 1) - ((kExtendedModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte); static const int kNativeByteOffset = kCompilerHintsOffset + (kCompilerHintsSize - 1) - ((kNative + kCompilerHintsSmiTagSize) / kBitsPerByte); #else #error Unknown byte ordering #endif private: 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]: The information about the function that // can be shared by instances. DECL_ACCESSORS(shared, SharedFunctionInfo) inline SharedFunctionInfo* unchecked_shared(); // [context]: The context for this function. inline Context* context(); inline Object* unchecked_context(); inline void set_context(Object* context); // [code]: The generated code object for this function. Executed // when the function is invoked, e.g. foo() or new foo(). See // [[Call]] and [[Construct]] description in ECMA-262, section // 8.6.2, page 27. inline Code* code(); inline void set_code(Code* code); inline void ReplaceCode(Code* code); inline Code* unchecked_code(); // Tells whether this function is builtin. inline bool IsBuiltin(); // Tells whether or not the function needs arguments adaption. inline bool NeedsArgumentsAdaption(); // Tells whether or not this function has been optimized. inline bool IsOptimized(); // Tells whether or not this function can be optimized. inline bool IsOptimizable(); // Mark this function for lazy recompilation. The function will be // recompiled the next time it is executed. void MarkForLazyRecompilation(); // Helpers to compile this function. Returns true on success, false on // failure (e.g., stack overflow during compilation). static bool CompileLazy(Handle function, ClearExceptionFlag flag); static bool CompileOptimized(Handle function, int osr_ast_id, ClearExceptionFlag flag); // Tells whether or not the function is already marked for lazy // recompilation. inline bool IsMarkedForLazyRecompilation(); // Check whether or not this function is inlineable. bool IsInlineable(); // [literals_or_bindings]: Fixed array holding either // the materialized literals or the bindings of a bound function. // // 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. // // On bound functions, the array is a (copy-on-write) fixed-array containing // the function that was bound, bound this-value and any bound // arguments. Bound functions never contain literals. DECL_ACCESSORS(literals_or_bindings, FixedArray) inline FixedArray* literals(); inline void set_literals(FixedArray* literals); inline FixedArray* function_bindings(); inline void set_function_bindings(FixedArray* bindings); // The initial map for an object created by this constructor. inline Map* initial_map(); inline void set_initial_map(Map* value); MUST_USE_RESULT inline MaybeObject* set_initial_map_and_cache_transitions( 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(); MUST_USE_RESULT MaybeObject* SetInstancePrototype(Object* value); MUST_USE_RESULT MaybeObject* SetPrototype(Object* value); // After prototype is removed, it will not be created when accessed, and // [[Construct]] from this function will not be allowed. Object* RemovePrototype(); inline bool should_have_prototype(); // Accessor for this function's initial map's [[class]] // property. This is primarily used by ECMA native functions. This // method sets the class_name field of this function's initial map // to a given value. It creates an initial map if this function does // not have one. Note that this method does not copy the initial map // if it has one already, but simply replaces it with the new value. // Instances created afterwards will have a map whose [[class]] is // set to 'value', but there is no guarantees on instances created // before. Object* SetInstanceClassName(String* name); // Returns if this function has been compiled to native code yet. inline bool is_compiled(); // [next_function_link]: Field for linking functions. This list is treated as // a weak list by the GC. DECL_ACCESSORS(next_function_link, Object) // Prints the name of the function using PrintF. inline void PrintName() { PrintName(stdout); } void PrintName(FILE* out); // Casting. static inline JSFunction* cast(Object* obj); // Iterates the objects, including code objects indirectly referenced // through pointers to the first instruction in the code object. void JSFunctionIterateBody(int object_size, ObjectVisitor* v); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSFunctionPrint() { JSFunctionPrint(stdout); } void JSFunctionPrint(FILE* out); #endif #ifdef DEBUG 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. The last property (from kNonWeakFieldsEndOffset to // kSize) is weak and has special handling during garbage collection. static const int kCodeEntryOffset = JSObject::kHeaderSize; static const int kPrototypeOrInitialMapOffset = kCodeEntryOffset + kPointerSize; static const int kSharedFunctionInfoOffset = kPrototypeOrInitialMapOffset + kPointerSize; static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize; static const int kLiteralsOffset = kContextOffset + kPointerSize; static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize; static const int kNextFunctionLinkOffset = kNonWeakFieldsEndOffset; static const int kSize = kNextFunctionLinkOffset + kPointerSize; // Layout of the literals array. static const int kLiteralsPrefixSize = 1; static const int kLiteralGlobalContextIndex = 0; // Layout of the bound-function binding array. static const int kBoundFunctionIndex = 0; static const int kBoundThisIndex = 1; static const int kBoundArgumentsStartIndex = 2; 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 global 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 OBJECT_PRINT inline void JSGlobalProxyPrint() { JSGlobalProxyPrint(stdout); } void JSGlobalProxyPrint(FILE* out); #endif #ifdef DEBUG void JSGlobalProxyVerify(); #endif // Layout description. static const int kContextOffset = JSObject::kHeaderSize; static const int kSize = kContextOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy); }; // Forward declaration. class JSBuiltinsObject; // Common super class for JavaScript global objects and the special // builtins global objects. class GlobalObject: public JSObject { public: // [builtins]: the object holding the runtime routines written in JS. DECL_ACCESSORS(builtins, JSBuiltinsObject) // [global context]: the global context corresponding to this global object. DECL_ACCESSORS(global_context, Context) // [global receiver]: the global receiver object of the context DECL_ACCESSORS(global_receiver, JSObject) // Retrieve the property cell used to store a property. JSGlobalPropertyCell* GetPropertyCell(LookupResult* result); // This is like GetProperty, but is used when you know the lookup won't fail // by throwing an exception. This is for the debug and builtins global // objects, where it is known which properties can be expected to be present // on the object. Object* GetPropertyNoExceptionThrown(String* key) { Object* answer = GetProperty(key)->ToObjectUnchecked(); return answer; } // Ensure that the global object has a cell for the given property name. static Handle EnsurePropertyCell( Handle global, Handle name); // TODO(kmillikin): This function can be eliminated once the stub cache is // full handlified (and the static helper can be written directly). MUST_USE_RESULT MaybeObject* EnsurePropertyCell(String* name); // Casting. static inline GlobalObject* cast(Object* obj); // Layout description. static const int kBuiltinsOffset = JSObject::kHeaderSize; static const int kGlobalContextOffset = kBuiltinsOffset + kPointerSize; static const int kGlobalReceiverOffset = kGlobalContextOffset + kPointerSize; static const int kHeaderSize = kGlobalReceiverOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject); }; // JavaScript global object. class JSGlobalObject: public GlobalObject { public: // Casting. static inline JSGlobalObject* cast(Object* obj); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSGlobalObjectPrint() { JSGlobalObjectPrint(stdout); } void JSGlobalObjectPrint(FILE* out); #endif #ifdef DEBUG void JSGlobalObjectVerify(); #endif // Layout description. static const int kSize = GlobalObject::kHeaderSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject); }; // Builtins global object which holds the runtime routines written in // JavaScript. class JSBuiltinsObject: public GlobalObject { public: // Accessors for the runtime routines written in JavaScript. inline Object* javascript_builtin(Builtins::JavaScript id); inline void set_javascript_builtin(Builtins::JavaScript id, Object* value); // Accessors for code of the runtime routines written in JavaScript. inline Code* javascript_builtin_code(Builtins::JavaScript id); inline void set_javascript_builtin_code(Builtins::JavaScript id, Code* value); // Casting. static inline JSBuiltinsObject* cast(Object* obj); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSBuiltinsObjectPrint() { JSBuiltinsObjectPrint(stdout); } void JSBuiltinsObjectPrint(FILE* out); #endif #ifdef DEBUG void JSBuiltinsObjectVerify(); #endif // Layout description. The size of the builtins object includes // room for two pointers per runtime routine written in javascript // (function and code object). static const int kJSBuiltinsCount = Builtins::id_count; static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize; static const int kJSBuiltinsCodeOffset = GlobalObject::kHeaderSize + (kJSBuiltinsCount * kPointerSize); static const int kSize = kJSBuiltinsCodeOffset + (kJSBuiltinsCount * kPointerSize); static int OffsetOfFunctionWithId(Builtins::JavaScript id) { return kJSBuiltinsOffset + id * kPointerSize; } static int OffsetOfCodeWithId(Builtins::JavaScript id) { return kJSBuiltinsCodeOffset + id * kPointerSize; } private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSBuiltinsObject); }; // Representation for JS Wrapper objects, String, Number, Boolean, 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 OBJECT_PRINT inline void JSValuePrint() { JSValuePrint(stdout); } void JSValuePrint(FILE* out); #endif #ifdef DEBUG void JSValueVerify(); #endif // Layout description. static const int kValueOffset = JSObject::kHeaderSize; static const int kSize = kValueOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue); }; class DateCache; // Representation for JS date objects. class JSDate: public JSObject { public: // If one component is NaN, all of them are, indicating a NaN time value. // [value]: the time value. DECL_ACCESSORS(value, Object) // [year]: caches year. Either undefined, smi, or NaN. DECL_ACCESSORS(year, Object) // [month]: caches month. Either undefined, smi, or NaN. DECL_ACCESSORS(month, Object) // [day]: caches day. Either undefined, smi, or NaN. DECL_ACCESSORS(day, Object) // [weekday]: caches day of week. Either undefined, smi, or NaN. DECL_ACCESSORS(weekday, Object) // [hour]: caches hours. Either undefined, smi, or NaN. DECL_ACCESSORS(hour, Object) // [min]: caches minutes. Either undefined, smi, or NaN. DECL_ACCESSORS(min, Object) // [sec]: caches seconds. Either undefined, smi, or NaN. DECL_ACCESSORS(sec, Object) // [cache stamp]: sample of the date cache stamp at the // moment when local fields were cached. DECL_ACCESSORS(cache_stamp, Object) // Casting. static inline JSDate* cast(Object* obj); // Returns the date field with the specified index. // See FieldIndex for the list of date fields. static MaybeObject* GetField(Object* date, Smi* index); void SetValue(Object* value, bool is_value_nan); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSDatePrint() { JSDatePrint(stdout); } void JSDatePrint(FILE* out); #endif #ifdef DEBUG void JSDateVerify(); #endif // The order is important. It must be kept in sync with date macros // in macros.py. enum FieldIndex { kDateValue, kYear, kMonth, kDay, kWeekday, kHour, kMinute, kSecond, kFirstUncachedField, kMillisecond = kFirstUncachedField, kDays, kTimeInDay, kFirstUTCField, kYearUTC = kFirstUTCField, kMonthUTC, kDayUTC, kWeekdayUTC, kHourUTC, kMinuteUTC, kSecondUTC, kMillisecondUTC, kDaysUTC, kTimeInDayUTC, kTimezoneOffset }; // Layout description. static const int kValueOffset = JSObject::kHeaderSize; static const int kYearOffset = kValueOffset + kPointerSize; static const int kMonthOffset = kYearOffset + kPointerSize; static const int kDayOffset = kMonthOffset + kPointerSize; static const int kWeekdayOffset = kDayOffset + kPointerSize; static const int kHourOffset = kWeekdayOffset + kPointerSize; static const int kMinOffset = kHourOffset + kPointerSize; static const int kSecOffset = kMinOffset + kPointerSize; static const int kCacheStampOffset = kSecOffset + kPointerSize; static const int kSize = kCacheStampOffset + kPointerSize; private: inline Object* DoGetField(FieldIndex index); Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache); // Computes and caches the cacheable fields of the date. inline void SetLocalFields(int64_t local_time_ms, DateCache* date_cache); DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate); }; // Representation of message objects used for error reporting through // the API. The messages are formatted in JavaScript so this object is // a real JavaScript object. The information used for formatting the // error messages are not directly accessible from JavaScript to // prevent leaking information to user code called during error // formatting. class JSMessageObject: public JSObject { public: // [type]: the type of error message. DECL_ACCESSORS(type, String) // [arguments]: the arguments for formatting the error message. DECL_ACCESSORS(arguments, JSArray) // [script]: the script from which the error message originated. DECL_ACCESSORS(script, Object) // [stack_trace]: the stack trace for this error message. DECL_ACCESSORS(stack_trace, Object) // [stack_frames]: an array of stack frames for this error object. DECL_ACCESSORS(stack_frames, Object) // [start_position]: the start position in the script for the error message. inline int start_position(); inline void set_start_position(int value); // [end_position]: the end position in the script for the error message. inline int end_position(); inline void set_end_position(int value); // Casting. static inline JSMessageObject* cast(Object* obj); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSMessageObjectPrint() { JSMessageObjectPrint(stdout); } void JSMessageObjectPrint(FILE* out); #endif #ifdef DEBUG void JSMessageObjectVerify(); #endif // Layout description. static const int kTypeOffset = JSObject::kHeaderSize; static const int kArgumentsOffset = kTypeOffset + kPointerSize; static const int kScriptOffset = kArgumentsOffset + kPointerSize; static const int kStackTraceOffset = kScriptOffset + kPointerSize; static const int kStackFramesOffset = kStackTraceOffset + kPointerSize; static const int kStartPositionOffset = kStackFramesOffset + kPointerSize; static const int kEndPositionOffset = kStartPositionOffset + kPointerSize; static const int kSize = kEndPositionOffset + kPointerSize; typedef FixedBodyDescriptor BodyDescriptor; }; // 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), or a smi // used for tracking the last usage (used for code flushing). // - a reference to code for UC16 inputs (bytecode or compiled), or a smi // used for tracking the last usage (used for code flushing).. // - 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); // Used during GC when flushing code or setting age. inline Object* DataAtUnchecked(int index); inline void SetDataAtUnchecked(int index, Object* value, Heap* heap); inline Type TypeTagUnchecked(); static int code_index(bool is_ascii) { if (is_ascii) { return kIrregexpASCIICodeIndex; } else { return kIrregexpUC16CodeIndex; } } static int saved_code_index(bool is_ascii) { if (is_ascii) { return kIrregexpASCIICodeSavedIndex; } else { return kIrregexpUC16CodeSavedIndex; } } static inline JSRegExp* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void JSRegExpVerify(); #endif static const int kDataOffset = JSObject::kHeaderSize; static const int kSize = kDataOffset + kPointerSize; // Indices in the data array. static const int kTagIndex = 0; static const int kSourceIndex = kTagIndex + 1; static const int kFlagsIndex = kSourceIndex + 1; static const int kDataIndex = kFlagsIndex + 1; // The data fields are used in different ways depending on the // value of the tag. // Atom regexps (literal strings). static const int kAtomPatternIndex = kDataIndex; static const int kAtomDataSize = kAtomPatternIndex + 1; // Irregexp compiled code or bytecode for ASCII. If compilation // fails, this fields hold an exception object that should be // thrown if the regexp is used again. static const int kIrregexpASCIICodeIndex = kDataIndex; // Irregexp compiled code or bytecode for UC16. If compilation // fails, this fields hold an exception object that should be // thrown if the regexp is used again. static const int kIrregexpUC16CodeIndex = kDataIndex + 1; // Saved instance of Irregexp compiled code or bytecode for ASCII that // is a potential candidate for flushing. static const int kIrregexpASCIICodeSavedIndex = kDataIndex + 2; // Saved instance of Irregexp compiled code or bytecode for UC16 that is // a potential candidate for flushing. static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3; // 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 + 4; // Number of captures in the compiled regexp. static const int kIrregexpCaptureCountIndex = kDataIndex + 5; static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1; // Offsets directly into the data fixed array. static const int kDataTagOffset = FixedArray::kHeaderSize + kTagIndex * kPointerSize; static const int kDataAsciiCodeOffset = FixedArray::kHeaderSize + kIrregexpASCIICodeIndex * kPointerSize; static const int kDataUC16CodeOffset = FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize; static const int kIrregexpCaptureCountOffset = FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize; // In-object fields. static const int kSourceFieldIndex = 0; static const int kGlobalFieldIndex = 1; static const int kIgnoreCaseFieldIndex = 2; static const int kMultilineFieldIndex = 3; static const int kLastIndexFieldIndex = 4; static const int kInObjectFieldCount = 5; // The uninitialized value for a regexp code object. static const int kUninitializedValue = -1; // The compilation error value for the regexp code object. The real error // object is in the saved code field. static const int kCompilationErrorValue = -2; // When we store the sweep generation at which we moved the code from the // code index to the saved code index we mask it of to be in the [0:255] // range. static const int kCodeAgeMask = 0xff; }; class CompilationCacheShape : public BaseShape { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 2; }; class CompilationCacheTable: public HashTable { public: // Find cached value for a string key, otherwise return null. Object* Lookup(String* src); Object* LookupEval(String* src, Context* context, LanguageMode language_mode, int scope_position); Object* LookupRegExp(String* source, JSRegExp::Flags flags); MUST_USE_RESULT MaybeObject* Put(String* src, Object* value); MUST_USE_RESULT MaybeObject* PutEval(String* src, Context* context, SharedFunctionInfo* value, int scope_position); MUST_USE_RESULT MaybeObject* PutRegExp(String* src, JSRegExp::Flags flags, FixedArray* value); // Remove given value from cache. void Remove(Object* value); static inline CompilationCacheTable* cast(Object* obj); private: DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable); }; class CodeCache: public Struct { public: DECL_ACCESSORS(default_cache, FixedArray) DECL_ACCESSORS(normal_type_cache, Object) // Add the code object to the cache. MUST_USE_RESULT MaybeObject* Update(String* name, Code* code); // Lookup code object in the cache. Returns code object if found and undefined // if not. Object* Lookup(String* name, Code::Flags flags); // Get the internal index of a code object in the cache. Returns -1 if the // code object is not in that cache. This index can be used to later call // RemoveByIndex. The cache cannot be modified between a call to GetIndex and // RemoveByIndex. int GetIndex(Object* name, Code* code); // Remove an object from the cache with the provided internal index. void RemoveByIndex(Object* name, Code* code, int index); static inline CodeCache* cast(Object* obj); #ifdef OBJECT_PRINT inline void CodeCachePrint() { CodeCachePrint(stdout); } void CodeCachePrint(FILE* out); #endif #ifdef DEBUG void CodeCacheVerify(); #endif static const int kDefaultCacheOffset = HeapObject::kHeaderSize; static const int kNormalTypeCacheOffset = kDefaultCacheOffset + kPointerSize; static const int kSize = kNormalTypeCacheOffset + kPointerSize; private: MUST_USE_RESULT MaybeObject* UpdateDefaultCache(String* name, Code* code); MUST_USE_RESULT MaybeObject* UpdateNormalTypeCache(String* name, Code* code); Object* LookupDefaultCache(String* name, Code::Flags flags); Object* LookupNormalTypeCache(String* name, Code::Flags flags); // Code cache layout of the default cache. Elements are alternating name and // code objects for non normal load/store/call IC's. static const int kCodeCacheEntrySize = 2; static const int kCodeCacheEntryNameOffset = 0; static const int kCodeCacheEntryCodeOffset = 1; DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache); }; class CodeCacheHashTableShape : public BaseShape { public: static inline bool IsMatch(HashTableKey* key, Object* value) { return key->IsMatch(value); } static inline uint32_t Hash(HashTableKey* key) { return key->Hash(); } static inline uint32_t HashForObject(HashTableKey* key, Object* object) { return key->HashForObject(object); } MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { return key->AsObject(); } static const int kPrefixSize = 0; static const int kEntrySize = 2; }; class CodeCacheHashTable: public HashTable { public: Object* Lookup(String* name, Code::Flags flags); MUST_USE_RESULT MaybeObject* Put(String* name, Code* code); int GetIndex(String* name, Code::Flags flags); void RemoveByIndex(int index); static inline CodeCacheHashTable* cast(Object* obj); // Initial size of the fixed array backing the hash table. static const int kInitialSize = 64; private: DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable); }; class PolymorphicCodeCache: public Struct { public: DECL_ACCESSORS(cache, Object) static void Update(Handle cache, MapHandleList* maps, Code::Flags flags, Handle code); MUST_USE_RESULT MaybeObject* Update(MapHandleList* maps, Code::Flags flags, Code* code); // Returns an undefined value if the entry is not found. Handle Lookup(MapHandleList* maps, Code::Flags flags); static inline PolymorphicCodeCache* cast(Object* obj); #ifdef OBJECT_PRINT inline void PolymorphicCodeCachePrint() { PolymorphicCodeCachePrint(stdout); } void PolymorphicCodeCachePrint(FILE* out); #endif #ifdef DEBUG void PolymorphicCodeCacheVerify(); #endif static const int kCacheOffset = HeapObject::kHeaderSize; static const int kSize = kCacheOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache); }; class PolymorphicCodeCacheHashTable : public HashTable { public: Object* Lookup(MapHandleList* maps, int code_kind); MUST_USE_RESULT MaybeObject* Put(MapHandleList* maps, int code_kind, Code* code); static inline PolymorphicCodeCacheHashTable* cast(Object* obj); static const int kInitialSize = 64; private: DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable); }; class TypeFeedbackInfo: public Struct { public: inline int ic_total_count(); inline void set_ic_total_count(int count); inline int ic_with_type_info_count(); inline void set_ic_with_type_info_count(int count); DECL_ACCESSORS(type_feedback_cells, TypeFeedbackCells) static inline TypeFeedbackInfo* cast(Object* obj); #ifdef OBJECT_PRINT inline void TypeFeedbackInfoPrint() { TypeFeedbackInfoPrint(stdout); } void TypeFeedbackInfoPrint(FILE* out); #endif #ifdef DEBUG void TypeFeedbackInfoVerify(); #endif static const int kIcTotalCountOffset = HeapObject::kHeaderSize; static const int kIcWithTypeinfoCountOffset = kIcTotalCountOffset + kPointerSize; static const int kTypeFeedbackCellsOffset = kIcWithTypeinfoCountOffset + kPointerSize; static const int kSize = kTypeFeedbackCellsOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackInfo); }; // Representation of a slow alias as part of a non-strict arguments objects. // For fast aliases (if HasNonStrictArgumentsElements()): // - the parameter map contains an index into the context // - all attributes of the element have default values // For slow aliases (if HasDictionaryArgumentsElements()): // - the parameter map contains no fast alias mapping (i.e. the hole) // - this struct (in the slow backing store) contains an index into the context // - all attributes are available as part if the property details class AliasedArgumentsEntry: public Struct { public: inline int aliased_context_slot(); inline void set_aliased_context_slot(int count); static inline AliasedArgumentsEntry* cast(Object* obj); #ifdef OBJECT_PRINT inline void AliasedArgumentsEntryPrint() { AliasedArgumentsEntryPrint(stdout); } void AliasedArgumentsEntryPrint(FILE* out); #endif #ifdef DEBUG void AliasedArgumentsEntryVerify(); #endif static const int kAliasedContextSlot = HeapObject::kHeaderSize; static const int kSize = kAliasedContextSlot + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(AliasedArgumentsEntry); }; enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS}; enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL}; class StringHasher { public: explicit inline StringHasher(int length, uint32_t seed); // 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(uint32_t 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(uint32_t c); // Add a character above 0xffff as a surrogate pair. These can get into // the hasher through the routines that take a UTF-8 string and make a symbol. void AddSurrogatePair(uc32 c); void AddSurrogatePairNoIndex(uc32 c); // Returns the value to store in the hash field of a string with // the given length and contents. uint32_t GetHashField(); // Returns true if the characters seen so far make up a legal array // index. bool is_array_index() { return is_array_index_; } bool is_valid() { return is_valid_; } void invalidate() { is_valid_ = false; } // Calculated hash value for a string consisting of 1 to // String::kMaxArrayIndexSize digits with no leading zeros (except "0"). // value is represented decimal value. static uint32_t MakeArrayIndexHash(uint32_t value, int length); // No string is allowed to have a hash of zero. That value is reserved // for internal properties. If the hash calculation yields zero then we // use 27 instead. static const int kZeroHash = 27; private: uint32_t array_index() { ASSERT(is_array_index()); return array_index_; } inline uint32_t GetHash(); int length_; uint32_t raw_running_hash_; uint32_t array_index_; bool is_array_index_; bool is_first_char_; bool is_valid_; friend class TwoCharHashTableKey; }; // Calculates string hash. template inline uint32_t HashSequentialString(const schar* chars, int length, uint32_t seed); // 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 IsIndirect(); inline bool IsExternalAscii(); inline bool IsExternalTwoByte(); inline bool IsSequentialAscii(); inline bool IsSequentialTwoByte(); inline bool IsSymbol(); inline StringRepresentationTag representation_tag(); inline uint32_t encoding_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: // Representation of the flat content of a String. // A non-flat string doesn't have flat content. // A flat string has content that's encoded as a sequence of either // ASCII chars or two-byte UC16. // Returned by String::GetFlatContent(). class FlatContent { public: // Returns true if the string is flat and this structure contains content. bool IsFlat() { return state_ != NON_FLAT; } // Returns true if the structure contains ASCII content. bool IsAscii() { return state_ == ASCII; } // Returns true if the structure contains two-byte content. bool IsTwoByte() { return state_ == TWO_BYTE; } // Return the ASCII content of the string. Only use if IsAscii() returns // true. Vector ToAsciiVector() { ASSERT_EQ(ASCII, state_); return Vector::cast(buffer_); } // Return the two-byte content of the string. Only use if IsTwoByte() // returns true. Vector ToUC16Vector() { ASSERT_EQ(TWO_BYTE, state_); return Vector::cast(buffer_); } private: enum State { NON_FLAT, ASCII, TWO_BYTE }; // Constructors only used by String::GetFlatContent(). explicit FlatContent(Vector chars) : buffer_(Vector::cast(chars)), state_(ASCII) { } explicit FlatContent(Vector chars) : buffer_(Vector::cast(chars)), state_(TWO_BYTE) { } FlatContent() : buffer_(), state_(NON_FLAT) { } Vector buffer_; State state_; friend class String; }; // Get and set the length of the string. inline int length(); inline void set_length(int value); // Get and set the hash field of the string. inline uint32_t hash_field(); inline void set_hash_field(uint32_t value); // Returns whether this string has only ASCII chars, i.e. all of them can // be ASCII encoded. This might be the case even if the string is // two-byte. Such strings may appear when the embedder prefers // two-byte external representations even for ASCII data. inline bool IsAsciiRepresentation(); inline bool IsTwoByteRepresentation(); // Cons and slices have an encoding flag that may not represent the actual // encoding of the underlying string. This is taken into account here. // Requires: this->IsFlat() inline bool IsAsciiRepresentationUnderneath(); inline bool IsTwoByteRepresentationUnderneath(); // NOTE: this should be considered only a hint. False negatives are // possible. inline bool HasOnlyAsciiChars(); // Get and set individual two byte chars in the string. inline void Set(int index, uint16_t value); // Get individual two byte char in the string. Repeated calls // to this method are not efficient unless the string is flat. inline uint16_t Get(int index); // Try to flatten the string. Checks first inline to see if it is // necessary. Does nothing if the string is not a cons string. // Flattening allocates a sequential string with the same data as // the given string and mutates the cons string to a degenerate // form, where the first component is the new sequential string and // the second component is the empty string. If allocation fails, // this function returns a failure. If flattening succeeds, this // function returns the sequential string that is now the first // component of the cons string. // // Degenerate cons strings are handled specially by the garbage // collector (see IsShortcutCandidate). // // Use FlattenString from Handles.cc to flatten even in case an // allocation failure happens. inline MaybeObject* TryFlatten(PretenureFlag pretenure = NOT_TENURED); // Convenience function. Has exactly the same behavior as // TryFlatten(), except in the case of failure returns the original // string. inline String* TryFlattenGetString(PretenureFlag pretenure = NOT_TENURED); // Tries to return the content of a flat string as a structure holding either // a flat vector of char or of uc16. // If the string isn't flat, and therefore doesn't have flat content, the // returned structure will report so, and can't provide a vector of either // kind. FlatContent GetFlatContent(); // Returns the parent of a sliced string or first part of a flat cons string. // Requires: StringShape(this).IsIndirect() && this->IsFlat() inline String* GetUnderlying(); // Mark the string as an undetectable object. It only applies to // ASCII and two byte string types. bool MarkAsUndetectable(); // Return a substring. MUST_USE_RESULT MaybeObject* SubString(int from, int to, PretenureFlag pretenure = NOT_TENURED); // String equality operations. inline bool Equals(String* other); bool IsEqualTo(Vector str); bool IsAsciiEqualTo(Vector str); bool IsTwoByteEqualTo(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. SmartArrayPointer ToCString(AllowNullsFlag allow_nulls, RobustnessFlag robustness_flag, int offset, int length, int* length_output = 0); SmartArrayPointer ToCString( AllowNullsFlag allow_nulls = DISALLOW_NULLS, RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL, int* length_output = 0); // 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. SmartArrayPointer ToWideCString( RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL); // Tells whether the hash code has been computed. inline bool HasHashCode(); // Returns a hash value used for the property table inline uint32_t Hash(); static uint32_t ComputeHashField(unibrow::CharacterStream* buffer, int length, uint32_t seed); 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 OBJECT_PRINT inline void StringPrint() { StringPrint(stdout); } void StringPrint(FILE* out); char* ToAsciiArray(); #endif #ifdef DEBUG void StringVerify(); #endif inline bool IsFlat(); // Layout description. static const int kLengthOffset = HeapObject::kHeaderSize; static const int kHashFieldOffset = kLengthOffset + kPointerSize; static const int kSize = kHashFieldOffset + kPointerSize; // Maximum number of characters to consider when trying to convert a string // value into an array index. static const int kMaxArrayIndexSize = 10; // Max ASCII char code. static const int kMaxAsciiCharCode = unibrow::Utf8::kMaxOneByteChar; static const unsigned kMaxAsciiCharCodeU = unibrow::Utf8::kMaxOneByteChar; static const int kMaxUtf16CodeUnit = 0xffff; // Mask constant for checking if a string has a computed hash code // and if it is an array index. The least significant bit indicates // whether a hash code has been computed. If the hash code has been // computed the 2nd bit tells whether the string can be used as an // array index. static const int kHashNotComputedMask = 1; static const int kIsNotArrayIndexMask = 1 << 1; static const int kNofHashBitFields = 2; // Shift constant retrieving hash code from hash field. static const int kHashShift = kNofHashBitFields; // Only these bits are relevant in the hash, since the top two are shifted // out. static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift; // Array index strings this short can keep their index in the hash // field. static const int kMaxCachedArrayIndexLength = 7; // For strings which are array indexes the hash value has the string length // mixed into the hash, mainly to avoid a hash value of zero which would be // the case for the string '0'. 24 bits are used for the array index value. static const int kArrayIndexValueBits = 24; static const int kArrayIndexLengthBits = kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields; STATIC_CHECK((kArrayIndexLengthBits > 0)); STATIC_CHECK(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits)); static const int kArrayIndexHashLengthShift = kArrayIndexValueBits + kNofHashBitFields; static const int kArrayIndexHashMask = (1 << kArrayIndexHashLengthShift) - 1; static const int kArrayIndexValueMask = ((1 << kArrayIndexValueBits) - 1) << kHashShift; // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we // could use a mask to test if the length of string is less than or equal to // kMaxCachedArrayIndexLength. STATIC_CHECK(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1)); static const int kContainsCachedArrayIndexMask = (~kMaxCachedArrayIndexLength << kArrayIndexHashLengthShift) | kIsNotArrayIndexMask; // Value of empty hash field indicating that the hash is not computed. static const int kEmptyHashField = kIsNotArrayIndexMask | kHashNotComputedMask; // Value of hash field containing computed hash equal to zero. static const int kZeroHash = kIsNotArrayIndexMask; // Maximal string length. static const int kMaxLength = (1 << (32 - 2)) - 1; // Max length for computing hash. For strings longer than this limit the // string length is used as the hash value. static const int kMaxHashCalcLength = 16383; // Limit for truncation in short printing. static const int kMaxShortPrintLength = 1024; // Support for regular expressions. const uc16* GetTwoByteData(); const uc16* GetTwoByteData(unsigned start); // Support for StringInputBuffer static const unibrow::byte* ReadBlock(String* input, unibrow::byte* util_buffer, unsigned capacity, unsigned* remaining, unsigned* offset); static const unibrow::byte* ReadBlock(String** input, unibrow::byte* util_buffer, unsigned capacity, unsigned* remaining, unsigned* offset); // Helper function for flattening strings. template static void WriteToFlat(String* source, sinkchar* sink, int from, int to); static inline bool IsAscii(const char* chars, int length) { const char* limit = chars + length; #ifdef V8_HOST_CAN_READ_UNALIGNED ASSERT(kMaxAsciiCharCode == 0x7F); const uintptr_t non_ascii_mask = kUintptrAllBitsSet / 0xFF * 0x80; while (chars <= limit - sizeof(uintptr_t)) { if (*reinterpret_cast(chars) & non_ascii_mask) { return false; } chars += sizeof(uintptr_t); } #endif while (chars < limit) { if (static_cast(*chars) > kMaxAsciiCharCodeU) return false; ++chars; } return true; } static inline bool IsAscii(const uc16* chars, int length) { const uc16* limit = chars + length; while (chars < limit) { if (*chars > kMaxAsciiCharCodeU) return false; ++chars; } return true; } protected: class ReadBlockBuffer { public: ReadBlockBuffer(unibrow::byte* util_buffer_, unsigned cursor_, unsigned capacity_, unsigned remaining_) : util_buffer(util_buffer_), cursor(cursor_), capacity(capacity_), remaining(remaining_) { } unibrow::byte* util_buffer; unsigned cursor; unsigned capacity; unsigned remaining; }; static inline const unibrow::byte* ReadBlock(String* input, ReadBlockBuffer* buffer, unsigned* offset, unsigned max_chars); static void ReadBlockIntoBuffer(String* input, ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned max_chars); private: // Try to flatten the top level ConsString that is hiding behind this // string. This is a no-op unless the string is a ConsString. Flatten // mutates the ConsString and might return a failure. MUST_USE_RESULT MaybeObject* SlowTryFlatten(PretenureFlag pretenure); static inline bool IsHashFieldComputed(uint32_t field); // Slow case of String::Equals. This implementation works on any strings // but it is most efficient on strings that are almost flat. bool SlowEquals(String* other); // Slow case of AsArrayIndex. bool SlowAsArrayIndex(uint32_t* index); // Compute and set the hash code. uint32_t ComputeAndSetHash(); DISALLOW_IMPLICIT_CONSTRUCTORS(String); }; // The SeqString abstract class captures sequential string values. class SeqString: public String { public: // Casting. static inline SeqString* cast(Object* obj); // Layout description. static const int kHeaderSize = String::kSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString); }; // The AsciiString class captures sequential ASCII string objects. // Each character in the AsciiString is an ASCII character. class SeqAsciiString: public SeqString { public: static const bool kHasAsciiEncoding = true; // Dispatched behavior. inline uint16_t SeqAsciiStringGet(int index); inline void SeqAsciiStringSet(int index, uint16_t value); // Get the address of the characters in this string. inline Address GetCharsAddress(); inline char* GetChars(); // Casting static inline SeqAsciiString* cast(Object* obj); // Garbage collection support. This method is called by the // garbage collector to compute the actual size of an AsciiString // instance. inline int SeqAsciiStringSize(InstanceType instance_type); // Computes the size for an AsciiString instance of a given length. static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize); } // Maximal memory usage for a single sequential ASCII string. static const int kMaxSize = 512 * MB - 1; // Maximal length of a single sequential ASCII string. // Q.v. String::kMaxLength which is the maximal size of concatenated strings. static const int kMaxLength = (kMaxSize - kHeaderSize); // Support for StringInputBuffer. inline void SeqAsciiStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset, unsigned chars); inline const unibrow::byte* SeqAsciiStringReadBlock(unsigned* remaining, unsigned* offset, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqAsciiString); }; // The TwoByteString class captures sequential unicode string objects. // Each character in the TwoByteString is a two-byte uint16_t. class SeqTwoByteString: public SeqString { public: static const bool kHasAsciiEncoding = false; // Dispatched behavior. inline uint16_t SeqTwoByteStringGet(int index); inline void SeqTwoByteStringSet(int index, uint16_t value); // Get the address of the characters in this string. inline Address GetCharsAddress(); inline uc16* GetChars(); // For regexp code. const uint16_t* SeqTwoByteStringGetData(unsigned start); // Casting static inline SeqTwoByteString* cast(Object* obj); // Garbage collection support. This method is called by the // garbage collector to compute the actual size of a TwoByteString // instance. inline int SeqTwoByteStringSize(InstanceType instance_type); // Computes the size for a TwoByteString instance of a given length. static int SizeFor(int length) { return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize); } // Maximal memory usage for a single sequential two-byte string. static const int kMaxSize = 512 * MB - 1; // Maximal length of a single sequential two-byte string. // Q.v. String::kMaxLength which is the maximal size of concatenated strings. static const int kMaxLength = (kMaxSize - kHeaderSize) / sizeof(uint16_t); // Support for StringInputBuffer. inline void SeqTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString); }; // The ConsString class describes string values built by using the // addition operator on strings. A ConsString is a pair where the // first and second components are pointers to other string values. // One or both components of a ConsString can be pointers to other // ConsStrings, creating a binary tree of ConsStrings where the leaves // are non-ConsString string values. The string value represented by // a ConsString can be obtained by concatenating the leaf string // values in a left-to-right depth-first traversal of the tree. class ConsString: public String { public: // First string of the cons cell. inline String* first(); // Doesn't check that the result is a string, even in debug mode. This is // useful during GC where the mark bits confuse the checks. inline Object* unchecked_first(); inline void set_first(String* first, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Second string of the cons cell. inline String* second(); // Doesn't check that the result is a string, even in debug mode. This is // useful during GC where the mark bits confuse the checks. inline Object* unchecked_second(); inline void set_second(String* second, WriteBarrierMode mode = UPDATE_WRITE_BARRIER); // Dispatched behavior. uint16_t ConsStringGet(int index); // Casting. static inline ConsString* cast(Object* obj); // Layout description. static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize); static const int kSecondOffset = kFirstOffset + kPointerSize; static const int kSize = kSecondOffset + kPointerSize; // Support for StringInputBuffer. inline const unibrow::byte* ConsStringReadBlock(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); inline void ConsStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); // Minimum length for a cons string. static const int kMinLength = 13; typedef FixedBodyDescriptor BodyDescriptor; #ifdef DEBUG void ConsStringVerify(); #endif private: DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString); }; // The Sliced String class describes strings that are substrings of another // sequential string. The motivation is to save time and memory when creating // a substring. A Sliced String is described as a pointer to the parent, // the offset from the start of the parent string and the length. Using // a Sliced String therefore requires unpacking of the parent string and // adding the offset to the start address. A substring of a Sliced String // are not nested since the double indirection is simplified when creating // such a substring. // Currently missing features are: // - handling externalized parent strings // - external strings as parent // - truncating sliced string to enable otherwise unneeded parent to be GC'ed. class SlicedString: public String { public: inline String* parent(); inline void set_parent(String* parent); inline int offset(); inline void set_offset(int offset); // Dispatched behavior. uint16_t SlicedStringGet(int index); // Casting. static inline SlicedString* cast(Object* obj); // Layout description. static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize); static const int kOffsetOffset = kParentOffset + kPointerSize; static const int kSize = kOffsetOffset + kPointerSize; // 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); // Minimum length for a sliced string. static const int kMinLength = 13; typedef FixedBodyDescriptor BodyDescriptor; #ifdef DEBUG void SlicedStringVerify(); #endif 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 = POINTER_SIZE_ALIGN(String::kSize); static const int kShortSize = kResourceOffset + kPointerSize; static const int kResourceDataOffset = kResourceOffset + kPointerSize; static const int kSize = kResourceDataOffset + kPointerSize; // Return whether external string is short (data pointer is not cached). inline bool is_short(); STATIC_CHECK(kResourceOffset == Internals::kStringResourceOffset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString); }; // The ExternalAsciiString class is an external string backed by an // ASCII string. class ExternalAsciiString: public ExternalString { public: static const bool kHasAsciiEncoding = true; typedef v8::String::ExternalAsciiStringResource Resource; // The underlying resource. inline const Resource* resource(); inline void set_resource(const Resource* buffer); // Update the pointer cache to the external character array. // The cached pointer is always valid, as the external character array does = // not move during lifetime. Deserialization is the only exception, after // which the pointer cache has to be refreshed. inline void update_data_cache(); inline const char* GetChars(); // Dispatched behavior. inline uint16_t ExternalAsciiStringGet(int index); // Casting. static inline ExternalAsciiString* cast(Object* obj); // Garbage collection support. inline void ExternalAsciiStringIterateBody(ObjectVisitor* v); template inline void ExternalAsciiStringIterateBody(); // Support for StringInputBuffer. const unibrow::byte* ExternalAsciiStringReadBlock(unsigned* remaining, unsigned* offset, unsigned chars); inline void ExternalAsciiStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalAsciiString); }; // The ExternalTwoByteString class is an external string backed by a UTF-16 // encoded string. class ExternalTwoByteString: public ExternalString { public: static const bool kHasAsciiEncoding = false; typedef v8::String::ExternalStringResource Resource; // The underlying string resource. inline const Resource* resource(); inline void set_resource(const Resource* buffer); // Update the pointer cache to the external character array. // The cached pointer is always valid, as the external character array does = // not move during lifetime. Deserialization is the only exception, after // which the pointer cache has to be refreshed. inline void update_data_cache(); inline const uint16_t* GetChars(); // Dispatched behavior. inline uint16_t ExternalTwoByteStringGet(int index); // For regexp code. inline const uint16_t* ExternalTwoByteStringGetData(unsigned start); // Casting. static inline ExternalTwoByteString* cast(Object* obj); // Garbage collection support. inline void ExternalTwoByteStringIterateBody(ObjectVisitor* v); template inline void ExternalTwoByteStringIterateBody(); // Support for StringInputBuffer. void ExternalTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, unsigned* offset_ptr, unsigned chars); private: DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString); }; // Utility superclass for stack-allocated objects that must be updated // on gc. It provides two ways for the gc to update instances, either // iterating or updating after gc. class Relocatable BASE_EMBEDDED { public: explicit inline Relocatable(Isolate* isolate); inline virtual ~Relocatable(); virtual void IterateInstance(ObjectVisitor* v) { } virtual void PostGarbageCollection() { } static void PostGarbageCollectionProcessing(); static int ArchiveSpacePerThread(); static char* ArchiveState(Isolate* isolate, char* to); static char* RestoreState(Isolate* isolate, char* from); static void Iterate(ObjectVisitor* v); static void Iterate(ObjectVisitor* v, Relocatable* top); static char* Iterate(ObjectVisitor* v, char* t); private: Isolate* isolate_; Relocatable* prev_; }; // A flat string reader provides random access to the contents of a // string independent of the character width of the string. The handle // must be valid as long as the reader is being used. class FlatStringReader : public Relocatable { public: FlatStringReader(Isolate* isolate, Handle str); FlatStringReader(Isolate* isolate, Vector input); void PostGarbageCollection(); inline uc32 Get(int index); int length() { return length_; } private: String** str_; bool is_ascii_; int length_; const void* start_; }; // Note that StringInputBuffers are not valid across a GC! To fix this // it would have to store a String Handle instead of a String* and // AsciiStringReadBlock would have to be modified to use memcpy. // // StringInputBuffer is able to traverse any string regardless of how // deeply nested a sequence of ConsStrings it is made of. However, // performance will be better if deep strings are flattened before they // are traversed. Since flattening requires memory allocation this is // not always desirable, however (esp. in debugging situations). class StringInputBuffer: public unibrow::InputBuffer { public: virtual void Seek(unsigned pos); inline StringInputBuffer(): unibrow::InputBuffer() {} explicit inline StringInputBuffer(String* backing): unibrow::InputBuffer(backing) {} }; class SafeStringInputBuffer : public unibrow::InputBuffer { public: virtual void Seek(unsigned pos); inline SafeStringInputBuffer() : unibrow::InputBuffer() {} explicit 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) inline byte kind(); inline void set_kind(byte kind); // Casting. static inline Oddball* cast(Object* obj); // Dispatched behavior. #ifdef DEBUG void OddballVerify(); #endif // Initialize the fields. MUST_USE_RESULT MaybeObject* Initialize(const char* to_string, Object* to_number, byte kind); // Layout description. static const int kToStringOffset = HeapObject::kHeaderSize; static const int kToNumberOffset = kToStringOffset + kPointerSize; static const int kKindOffset = kToNumberOffset + kPointerSize; static const int kSize = kKindOffset + kPointerSize; static const byte kFalse = 0; static const byte kTrue = 1; static const byte kNotBooleanMask = ~1; static const byte kTheHole = 2; static const byte kNull = 3; static const byte kArgumentMarker = 4; static const byte kUndefined = 5; static const byte kOther = 6; typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball); }; class JSGlobalPropertyCell: public HeapObject { public: // [value]: value of the global property. DECL_ACCESSORS(value, Object) // Casting. static inline JSGlobalPropertyCell* cast(Object* obj); #ifdef DEBUG void JSGlobalPropertyCellVerify(); #endif #ifdef OBJECT_PRINT inline void JSGlobalPropertyCellPrint() { JSGlobalPropertyCellPrint(stdout); } void JSGlobalPropertyCellPrint(FILE* out); #endif // Layout description. static const int kValueOffset = HeapObject::kHeaderSize; static const int kSize = kValueOffset + kPointerSize; typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalPropertyCell); }; // The JSProxy describes EcmaScript Harmony proxies class JSProxy: public JSReceiver { public: // [handler]: The handler property. DECL_ACCESSORS(handler, Object) // [hash]: The hash code property (undefined if not initialized yet). DECL_ACCESSORS(hash, Object) // Casting. static inline JSProxy* cast(Object* obj); bool HasPropertyWithHandler(String* name); bool HasElementWithHandler(uint32_t index); MUST_USE_RESULT MaybeObject* GetPropertyWithHandler( Object* receiver, String* name); MUST_USE_RESULT MaybeObject* GetElementWithHandler( Object* receiver, uint32_t index); MUST_USE_RESULT MaybeObject* SetPropertyWithHandler( String* name, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode); MUST_USE_RESULT MaybeObject* SetElementWithHandler( uint32_t index, Object* value, StrictModeFlag strict_mode); // If the handler defines an accessor property, invoke its setter // (or throw if only a getter exists) and set *found to true. Otherwise false. MUST_USE_RESULT MaybeObject* SetPropertyWithHandlerIfDefiningSetter( String* name, Object* value, PropertyAttributes attributes, StrictModeFlag strict_mode, bool* found); MUST_USE_RESULT MaybeObject* DeletePropertyWithHandler( String* name, DeleteMode mode); MUST_USE_RESULT MaybeObject* DeleteElementWithHandler( uint32_t index, DeleteMode mode); MUST_USE_RESULT PropertyAttributes GetPropertyAttributeWithHandler( JSReceiver* receiver, String* name); MUST_USE_RESULT PropertyAttributes GetElementAttributeWithHandler( JSReceiver* receiver, uint32_t index); MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag); // Turn this into an (empty) JSObject. void Fix(); // Initializes the body after the handler slot. inline void InitializeBody(int object_size, Object* value); // Invoke a trap by name. If the trap does not exist on this's handler, // but derived_trap is non-NULL, invoke that instead. May cause GC. Handle CallTrap(const char* name, Handle derived_trap, int argc, Handle args[]); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSProxyPrint() { JSProxyPrint(stdout); } void JSProxyPrint(FILE* out); #endif #ifdef DEBUG void JSProxyVerify(); #endif // Layout description. We add padding so that a proxy has the same // size as a virgin JSObject. This is essential for becoming a JSObject // upon freeze. static const int kHandlerOffset = HeapObject::kHeaderSize; static const int kHashOffset = kHandlerOffset + kPointerSize; static const int kPaddingOffset = kHashOffset + kPointerSize; static const int kSize = JSObject::kHeaderSize; static const int kHeaderSize = kPaddingOffset; static const int kPaddingSize = kSize - kPaddingOffset; STATIC_CHECK(kPaddingSize >= 0); typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy); }; class JSFunctionProxy: public JSProxy { public: // [call_trap]: The call trap. DECL_ACCESSORS(call_trap, Object) // [construct_trap]: The construct trap. DECL_ACCESSORS(construct_trap, Object) // Casting. static inline JSFunctionProxy* cast(Object* obj); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSFunctionProxyPrint() { JSFunctionProxyPrint(stdout); } void JSFunctionProxyPrint(FILE* out); #endif #ifdef DEBUG void JSFunctionProxyVerify(); #endif // Layout description. static const int kCallTrapOffset = JSProxy::kPaddingOffset; static const int kConstructTrapOffset = kCallTrapOffset + kPointerSize; static const int kPaddingOffset = kConstructTrapOffset + kPointerSize; static const int kSize = JSFunction::kSize; static const int kPaddingSize = kSize - kPaddingOffset; STATIC_CHECK(kPaddingSize >= 0); typedef FixedBodyDescriptor BodyDescriptor; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunctionProxy); }; // The JSSet describes EcmaScript Harmony sets class JSSet: public JSObject { public: // [set]: the backing hash set containing keys. DECL_ACCESSORS(table, Object) // Casting. static inline JSSet* cast(Object* obj); #ifdef OBJECT_PRINT inline void JSSetPrint() { JSSetPrint(stdout); } void JSSetPrint(FILE* out); #endif #ifdef DEBUG void JSSetVerify(); #endif static const int kTableOffset = JSObject::kHeaderSize; static const int kSize = kTableOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet); }; // The JSMap describes EcmaScript Harmony maps class JSMap: public JSObject { public: // [table]: the backing hash table mapping keys to values. DECL_ACCESSORS(table, Object) // Casting. static inline JSMap* cast(Object* obj); #ifdef OBJECT_PRINT inline void JSMapPrint() { JSMapPrint(stdout); } void JSMapPrint(FILE* out); #endif #ifdef DEBUG void JSMapVerify(); #endif static const int kTableOffset = JSObject::kHeaderSize; static const int kSize = kTableOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap); }; // The JSWeakMap describes EcmaScript Harmony weak maps class JSWeakMap: public JSObject { public: // [table]: the backing hash table mapping keys to values. DECL_ACCESSORS(table, Object) // [next]: linked list of encountered weak maps during GC. DECL_ACCESSORS(next, Object) // Casting. static inline JSWeakMap* cast(Object* obj); #ifdef OBJECT_PRINT inline void JSWeakMapPrint() { JSWeakMapPrint(stdout); } void JSWeakMapPrint(FILE* out); #endif #ifdef DEBUG void JSWeakMapVerify(); #endif static const int kTableOffset = JSObject::kHeaderSize; static const int kNextOffset = kTableOffset + kPointerSize; static const int kSize = kNextOffset + kPointerSize; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap); }; // Foreign 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 Foreign: public HeapObject { public: // [address]: field containing the address. inline Address foreign_address(); inline void set_foreign_address(Address value); // Casting. static inline Foreign* cast(Object* obj); // Dispatched behavior. inline void ForeignIterateBody(ObjectVisitor* v); template inline void ForeignIterateBody(); #ifdef OBJECT_PRINT inline void ForeignPrint() { ForeignPrint(stdout); } void ForeignPrint(FILE* out); #endif #ifdef DEBUG void ForeignVerify(); #endif // Layout description. static const int kForeignAddressOffset = HeapObject::kHeaderSize; static const int kSize = kForeignAddressOffset + kPointerSize; STATIC_CHECK(kForeignAddressOffset == Internals::kForeignAddressOffset); private: DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign); }; // The JSArray describes JavaScript Arrays // Such an array can be in one of two modes: // - fast, backing storage is a FixedArray and length <= elements.length(); // Please note: push and pop can be used to grow and shrink the array. // - slow, backing storage is a HashTable with numbers as keys. class JSArray: public JSObject { public: // [length]: The length property. DECL_ACCESSORS(length, Object) // Overload the length setter to skip write barrier when the length // is set to a smi. This matches the set function on FixedArray. inline void set_length(Smi* length); MUST_USE_RESULT MaybeObject* JSArrayUpdateLengthFromIndex(uint32_t index, Object* value); // Initialize the array with the given capacity. The function may // fail due to out-of-memory situations, but only if the requested // capacity is non-zero. MUST_USE_RESULT MaybeObject* Initialize(int capacity); // Initializes the array to a certain length. inline bool AllowsSetElementsLength(); MUST_USE_RESULT MaybeObject* SetElementsLength(Object* length); // Set the content of the array to the content of storage. MUST_USE_RESULT inline MaybeObject* SetContent(FixedArrayBase* storage); // Casting. static inline JSArray* cast(Object* obj); // Uses handles. Ensures that the fixed array backing the JSArray has at // least the stated size. inline void EnsureSize(int minimum_size_of_backing_fixed_array); // Dispatched behavior. #ifdef OBJECT_PRINT inline void JSArrayPrint() { JSArrayPrint(stdout); } void JSArrayPrint(FILE* out); #endif #ifdef DEBUG void JSArrayVerify(); #endif // Number of element slots to pre-allocate for an empty array. static const int kPreallocatedArrayElements = 4; // Layout description. static const int kLengthOffset = JSObject::kHeaderSize; static const int kSize = kLengthOffset + kPointerSize; private: // Expand the fixed array backing of a fast-case JSArray to at least // the requested size. void Expand(int minimum_size_of_backing_fixed_array); DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray); }; // JSRegExpResult is just a JSArray with a specific initial map. // This initial map adds in-object properties for "index" and "input" // properties, as assigned by RegExp.prototype.exec, which allows // faster creation of RegExp exec results. // This class just holds constants used when creating the result. // After creation the result must be treated as a JSArray in all regards. class JSRegExpResult: public JSArray { public: // Offsets of object fields. static const int kIndexOffset = JSArray::kSize; static const int kInputOffset = kIndexOffset + kPointerSize; static const int kSize = kInputOffset + kPointerSize; // Indices of in-object properties. static const int kIndexIndex = 0; static const int kInputIndex = 1; private: DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult); }; // An accessor must have a getter, but can have no setter. // // When setting a property, V8 searches accessors in prototypes. // If an accessor was found and it does not have a setter, // the request is ignored. // // If the accessor in the prototype has the READ_ONLY property attribute, then // a new value is added to the local object when the property is set. // This shadows the accessor in the prototype. class AccessorInfo: public Struct { public: DECL_ACCESSORS(getter, Object) DECL_ACCESSORS(setter, Object) DECL_ACCESSORS(data, Object) DECL_ACCESSORS(name, Object) DECL_ACCESSORS(flag, Smi) 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 OBJECT_PRINT inline void AccessorInfoPrint() { AccessorInfoPrint(stdout); } void AccessorInfoPrint(FILE* out); #endif #ifdef DEBUG 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); }; // Support for JavaScript accessors: A pair of a getter and a setter. Each // accessor can either be // * a pointer to a JavaScript function or proxy: a real accessor // * undefined: considered an accessor by the spec, too, strangely enough // * the hole: an accessor which has not been set // * a pointer to a map: a transition used to ensure map sharing class AccessorPair: public Struct { public: DECL_ACCESSORS(getter, Object) DECL_ACCESSORS(setter, Object) static inline AccessorPair* cast(Object* obj); MUST_USE_RESULT MaybeObject* CopyWithoutTransitions(); // Note: Returns undefined instead in case of a hole. Object* GetComponent(AccessorComponent component); // Set both components, skipping arguments which are a JavaScript null. void SetComponents(Object* getter, Object* setter) { if (!getter->IsNull()) set_getter(getter); if (!setter->IsNull()) set_setter(setter); } bool ContainsAccessor() { return IsJSAccessor(getter()) || IsJSAccessor(setter()); } #ifdef OBJECT_PRINT void AccessorPairPrint(FILE* out = stdout); #endif #ifdef DEBUG void AccessorPairVerify(); #endif static const int kGetterOffset = HeapObject::kHeaderSize; static const int kSetterOffset = kGetterOffset + kPointerSize; static const int kSize = kSetterOffset + kPointerSize; private: // Strangely enough, in addition to functions and harmony proxies, the spec // requires us to consider undefined as a kind of accessor, too: // var obj = {}; // Object.defineProperty(obj, "foo", {get: undefined}); // assertTrue("foo" in obj); bool IsJSAccessor(Object* obj) { return obj->IsSpecFunction() || obj->IsUndefined(); } DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair); }; 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 OBJECT_PRINT inline void AccessCheckInfoPrint() { AccessCheckInfoPrint(stdout); } void AccessCheckInfoPrint(FILE* out); #endif #ifdef DEBUG 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 OBJECT_PRINT inline void InterceptorInfoPrint() { InterceptorInfoPrint(stdout); } void InterceptorInfoPrint(FILE* out); #endif #ifdef DEBUG 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 OBJECT_PRINT inline void CallHandlerInfoPrint() { CallHandlerInfoPrint(stdout); } void CallHandlerInfoPrint(FILE* out); #endif #ifdef DEBUG 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; private: 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) DECL_BOOLEAN_ACCESSORS(read_only_prototype) static inline FunctionTemplateInfo* cast(Object* obj); #ifdef OBJECT_PRINT inline void FunctionTemplateInfoPrint() { FunctionTemplateInfoPrint(stdout); } void FunctionTemplateInfoPrint(FILE* out); #endif #ifdef DEBUG 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; static const int kReadOnlyPrototypeBit = 3; 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 OBJECT_PRINT inline void ObjectTemplateInfoPrint() { ObjectTemplateInfoPrint(stdout); } void ObjectTemplateInfoPrint(FILE* out); #endif #ifdef DEBUG void ObjectTemplateInfoVerify(); #endif static const int kConstructorOffset = TemplateInfo::kHeaderSize; static const int kInternalFieldCountOffset = kConstructorOffset + kPointerSize; static const int kSize = kInternalFieldCountOffset + kPointerSize; }; class SignatureInfo: public Struct { public: DECL_ACCESSORS(receiver, Object) DECL_ACCESSORS(args, Object) static inline SignatureInfo* cast(Object* obj); #ifdef OBJECT_PRINT inline void SignatureInfoPrint() { SignatureInfoPrint(stdout); } void SignatureInfoPrint(FILE* out); #endif #ifdef DEBUG 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 OBJECT_PRINT inline void TypeSwitchInfoPrint() { TypeSwitchInfoPrint(stdout); } void TypeSwitchInfoPrint(FILE* out); #endif #ifdef DEBUG 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 OBJECT_PRINT inline void DebugInfoPrint() { DebugInfoPrint(stdout); } void DebugInfoPrint(FILE* out); #endif #ifdef DEBUG 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 OBJECT_PRINT inline void BreakPointInfoPrint() { BreakPointInfoPrint(stdout); } void BreakPointInfoPrint(FILE* out); #endif #ifdef DEBUG 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 #define VISITOR_SYNCHRONIZATION_TAGS_LIST(V) \ V(kSymbolTable, "symbol_table", "(Symbols)") \ V(kExternalStringsTable, "external_strings_table", "(External strings)") \ V(kStrongRootList, "strong_root_list", "(Strong roots)") \ V(kSymbol, "symbol", "(Symbol)") \ V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \ V(kTop, "top", "(Isolate)") \ V(kRelocatable, "relocatable", "(Relocatable)") \ V(kDebug, "debug", "(Debugger)") \ V(kCompilationCache, "compilationcache", "(Compilation cache)") \ V(kHandleScope, "handlescope", "(Handle scope)") \ V(kBuiltins, "builtins", "(Builtins)") \ V(kGlobalHandles, "globalhandles", "(Global handles)") \ V(kThreadManager, "threadmanager", "(Thread manager)") \ V(kExtensions, "Extensions", "(Extensions)") class VisitorSynchronization : public AllStatic { public: #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item, enum SyncTag { VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_ENUM) kNumberOfSyncTags }; #undef DECLARE_ENUM static const char* const kTags[kNumberOfSyncTags]; static const char* const kTagNames[kNumberOfSyncTags]; }; // Abstract base class for visiting, and optionally modifying, the // pointers contained in Objects. Used in GC and serialization/deserialization. class ObjectVisitor BASE_EMBEDDED { public: virtual ~ObjectVisitor() {} // Visits a contiguous arrays of pointers in the half-open range // [start, end). Any or all of the values may be modified on return. virtual void VisitPointers(Object** start, Object** end) = 0; // To allow lazy clearing of inline caches the visitor has // a rich interface for iterating over Code objects.. // Visits a code target in the instruction stream. virtual void VisitCodeTarget(RelocInfo* rinfo); // Visits a code entry in a JS function. virtual void VisitCodeEntry(Address entry_address); // Visits a global property cell reference in the instruction stream. virtual void VisitGlobalPropertyCell(RelocInfo* rinfo); // Visits a runtime entry in the instruction stream. virtual void VisitRuntimeEntry(RelocInfo* rinfo) {} // Visits the resource of an ASCII or two-byte string. virtual void VisitExternalAsciiString( v8::String::ExternalAsciiStringResource** resource) {} virtual void VisitExternalTwoByteString( v8::String::ExternalStringResource** resource) {} // Visits a debug call target in the instruction stream. virtual void VisitDebugTarget(RelocInfo* rinfo); // Handy shorthand for visiting a single pointer. virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); } // Visit pointer embedded into a code object. virtual void VisitEmbeddedPointer(RelocInfo* rinfo); virtual void VisitSharedFunctionInfo(SharedFunctionInfo* shared) {} // 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) {} virtual void VisitExternalReference(RelocInfo* rinfo); inline void VisitExternalReference(Address* p) { VisitExternalReferences(p, p + 1); } // Visits a handle that has an embedder-assigned class ID. virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {} // Intended for serialization/deserialization checking: insert, or // check for the presence of, a tag at this position in the stream. // Also used for marking up GC roots in heap snapshots. virtual void Synchronize(VisitorSynchronization::SyncTag tag) {} }; class StructBodyDescriptor : public FlexibleBodyDescriptor { public: static inline int SizeOf(Map* map, HeapObject* object) { return map->instance_size(); } }; // BooleanBit is a helper class for setting and getting a bit in an // integer or Smi. class BooleanBit : public AllStatic { public: static inline bool get(Smi* smi, int bit_position) { return get(smi->value(), bit_position); } static inline bool get(int value, int bit_position) { return (value & (1 << bit_position)) != 0; } static inline Smi* set(Smi* smi, int bit_position, bool v) { return Smi::FromInt(set(smi->value(), bit_position, v)); } static inline int set(int value, int bit_position, bool v) { if (v) { value |= (1 << bit_position); } else { value &= ~(1 << bit_position); } return value; } }; } } // namespace v8::internal #endif // V8_OBJECTS_H_