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ce05280bfc
v8/src/objects.h
rossberg@chromium.org ce05280bfc Get rid of static module allocation, do it in code. 
Modules now have their own local scope, represented by their own context.
Module instance objects have an accessor for every export that forwards
access to the respective slot from the module's context. (Exports that are
modules themselves, however, are simple data properties.)

All modules have a _hosting_ scope/context, which (currently) is the
(innermost) enclosing global scope. To deal with recursion, nested modules
are hosted by the same scope as global ones.

For every (global or nested) module literal, the hosting context has an
internal slot that points directly to the respective module context. This
enables quick access to (statically resolved) module members by 2-dimensional
access through the hosting context. For example,

  module A {
    let x;
    module B { let y; }
  }
  module C { let z; }

allocates contexts as follows:

[header| .A | .B | .C | A | C ]  (global)
          |    |    |
          |    |    +-- [header| z ]  (module)
          |    |
          |    +------- [header| y ]  (module)
          |
          +------------ [header| x | B ]  (module)

Here, .A, .B, .C are the internal slots pointing to the hosted module
contexts, whereas A, B, C hold the actual instance objects (note that every
module context also points to the respective instance object through its
extension slot in the header).

To deal with arbitrary recursion and aliases between modules,
they are created and initialized in several stages. Each stage applies to
all modules in the hosting global scope, including nested ones.

1. Allocate: for each module _literal_, allocate the module contexts and
   respective instance object and wire them up. This happens in the
   PushModuleContext runtime function, as generated by AllocateModules
   (invoked by VisitDeclarations in the hosting scope).

2. Bind: for each module _declaration_ (i.e. literals as well as aliases),
   assign the respective instance object to respective local variables. This
   happens in VisitModuleDeclaration, and uses the instance objects created
   in the previous stage.
   For each module _literal_, this phase also constructs a module descriptor
   for the next stage. This happens in VisitModuleLiteral.

3. Populate: invoke the DeclareModules runtime function to populate each
   _instance_ object with accessors for it exports. This is generated by
   DeclareModules (invoked by VisitDeclarations in the hosting scope again),
   and uses the descriptors generated in the previous stage.

4. Initialize: execute the module bodies (and other code) in sequence. This
   happens by the separate statements generated for module bodies. To reenter
   the module scopes properly, the parser inserted ModuleStatements.

R=mstarzinger@chromium.org,svenpanne@chromium.org
BUG=

Review URL: https://codereview.chromium.org/11093074

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13033 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2012-11-22 10:25:22 +00:00

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// 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 "elements-kind.h"
#include "list.h"
#include "property-details.h"
#include "smart-pointers.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"
#include "zone.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
// - JSModule
// - GlobalObject
// - JSGlobalObject
// - JSBuiltinsObject
// - JSGlobalProxy
// - JSValue
// - JSDate
// - JSMessageObject
// - JSProxy
// - JSFunctionProxy
// - FixedArrayBase
// - ByteArray
// - FixedArray
// - DescriptorArray
// - HashTable
// - Dictionary
// - SymbolTable
// - CompilationCacheTable
// - CodeCacheHashTable
// - MapCache
// - Context
// - JSFunctionResultCache
// - ScopeInfo
// - TransitionArray
// - FixedDoubleArray
// - ExternalArray
// - ExternalPixelArray
// - ExternalByteArray
// - ExternalUnsignedByteArray
// - ExternalShortArray
// - ExternalUnsignedShortArray
// - ExternalIntArray
// - ExternalUnsignedIntArray
// - ExternalFloatArray
// - String
// - SeqString
// - SeqOneByteString
// - 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 CompareMapMode {
REQUIRE_EXACT_MAP,
ALLOW_ELEMENT_TRANSITION_MAPS
};
enum KeyedAccessGrowMode {
DO_NOT_ALLOW_JSARRAY_GROWTH,
ALLOW_JSARRAY_GROWTH
};
// 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
};
// Indicates whether transitions can be added to a source map or not.
enum TransitionFlag {
INSERT_TRANSITION,
OMIT_TRANSITION
};
// Indicates whether the transition is simple: the target map of the transition
// either extends the current map with a new property, or it modifies the
// property that was added last to the current map.
enum SimpleTransitionFlag {
SIMPLE_TRANSITION,
FULL_TRANSITION
};
// Indicates whether we are only interested in the descriptors of a particular
// map, or in all descriptors in the descriptor array.
enum DescriptorFlag {
ALL_DESCRIPTORS,
OWN_DESCRIPTORS
};
// The GC maintains a bit of information, the MarkingParity, which toggles
// from odd to even and back every time marking is completed. Incremental
// marking can visit an object twice during a marking phase, so algorithms that
// that piggy-back on marking can use the parity to ensure that they only
// perform an operation on an object once per marking phase: they record the
// MarkingParity when they visit an object, and only re-visit the object when it
// is marked again and the MarkingParity changes.
enum MarkingParity {
NO_MARKING_PARITY,
ODD_MARKING_PARITY,
EVEN_MARKING_PARITY
};
// Instance size sentinel for objects of variable size.
const int kVariableSizeSentinel = 0;
const int kStubMajorKeyBits = 6;
const int kStubMinorKeyBits = kBitsPerInt - kSmiTagSize - kStubMajorKeyBits;
// 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_MODULE_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 kOneByteStringTag = 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 = kOneByteStringTag | kAsciiDataHintTag | kSymbolTag |
kSeqStringTag,
CONS_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kConsStringTag,
CONS_ASCII_SYMBOL_TYPE = kOneByteStringTag | kAsciiDataHintTag | 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 = kOneByteStringTag | kAsciiDataHintTag |
kExternalStringTag | kSymbolTag |
kShortExternalStringTag,
EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag,
EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE =
kTwoByteStringTag | kSymbolTag | kExternalStringTag | kAsciiDataHintTag,
EXTERNAL_ASCII_SYMBOL_TYPE =
kOneByteStringTag | kAsciiDataHintTag | kSymbolTag | kExternalStringTag,
STRING_TYPE = kTwoByteStringTag | kSeqStringTag,
ASCII_STRING_TYPE = kOneByteStringTag | kAsciiDataHintTag | kSeqStringTag,
CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag,
CONS_ASCII_STRING_TYPE =
kOneByteStringTag | kAsciiDataHintTag | kConsStringTag,
SLICED_STRING_TYPE = kTwoByteStringTag | kSlicedStringTag,
SLICED_ASCII_STRING_TYPE =
kOneByteStringTag | kAsciiDataHintTag | kSlicedStringTag,
SHORT_EXTERNAL_STRING_TYPE =
kTwoByteStringTag | kExternalStringTag | kShortExternalStringTag,
SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE =
kTwoByteStringTag | kExternalStringTag |
kAsciiDataHintTag | kShortExternalStringTag,
SHORT_EXTERNAL_ASCII_STRING_TYPE =
kOneByteStringTag | kAsciiDataHintTag |
kExternalStringTag | kShortExternalStringTag,
EXTERNAL_STRING_TYPE = kTwoByteStringTag | kExternalStringTag,
EXTERNAL_STRING_WITH_ASCII_DATA_TYPE =
kTwoByteStringTag | kExternalStringTag | kAsciiDataHintTag,
// LAST_STRING_TYPE
EXTERNAL_ASCII_STRING_TYPE =
kOneByteStringTag | kAsciiDataHintTag | 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_MODULE_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(ODDBALL_TYPE == Internals::kOddballType);
STATIC_CHECK(FOREIGN_TYPE == Internals::kForeignType);
#define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \
V(FAST_ELEMENTS_SUB_TYPE) \
V(DICTIONARY_ELEMENTS_SUB_TYPE) \
V(FAST_PROPERTIES_SUB_TYPE) \
V(DICTIONARY_PROPERTIES_SUB_TYPE) \
V(MAP_CODE_CACHE_SUB_TYPE) \
V(SCOPE_INFO_SUB_TYPE) \
V(SYMBOL_TABLE_SUB_TYPE) \
V(DESCRIPTOR_ARRAY_SUB_TYPE) \
V(TRANSITION_ARRAY_SUB_TYPE)
enum FixedArraySubInstanceType {
#define DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE(name) name,
FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE)
#undef DEFINE_FIXED_ARRAY_SUB_INSTANCE_TYPE
LAST_FIXED_ARRAY_SUB_TYPE = TRANSITION_ARRAY_SUB_TYPE
};
enum CompareResult {
LESS = -1,
EQUAL = 0,
GREATER = 1,
NOT_EQUAL = GREATER
};
#define DECL_BOOLEAN_ACCESSORS(name) \
inline bool name(); \
inline void set_##name(bool value); \
#define DECL_ACCESSORS(name, type) \
inline type* name(); \
inline void set_##name(type* value, \
WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \
class AccessorPair;
class DictionaryElementsAccessor;
class ElementsAccessor;
class Failure;
class FixedArrayBase;
class ObjectVisitor;
class StringStream;
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 <class C> static inline bool Is(Object* obj);
#ifdef VERIFY_HEAP
#define DECLARE_VERIFIER(Name) void Name##Verify();
#else
#define DECLARE_VERIFIER(Name)
#endif
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<Object*>(this);
return true;
}
inline Failure* ToFailureUnchecked() {
ASSERT(IsFailure());
return reinterpret_cast<Failure*>(this);
}
inline Object* ToObjectUnchecked() {
ASSERT(!IsFailure());
return reinterpret_cast<Object*>(this);
}
inline Object* ToObjectChecked() {
CHECK(!IsFailure());
return reinterpret_cast<Object*>(this);
}
template<typename T>
inline bool To(T** obj) {
if (IsFailure()) return false;
*obj = T::cast(reinterpret_cast<Object*>(this));
return true;
}
template<typename T>
inline bool ToHandle(Handle<T>* obj, Isolate* isolate) {
if (IsFailure()) return false;
*obj = handle(T::cast(reinterpret_cast<Object*>(this)), isolate);
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 VERIFY_HEAP
// 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(SeqOneByteString) \
\
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(JSModule) \
V(Map) \
V(DescriptorArray) \
V(TransitionArray) \
V(DeoptimizationInputData) \
V(DeoptimizationOutputData) \
V(TypeFeedbackCells) \
V(FixedArray) \
V(FixedDoubleArray) \
V(Context) \
V(NativeContext) \
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) \
V(ObjectHashTable) \
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();
inline bool IsExternal();
// 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.
// native_context is used when creating wrapper object.
MUST_USE_RESULT MaybeObject* ToObject(Context* native_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<Object> GetProperty(Handle<Object> object, Handle<String> key);
static Handle<Object> GetProperty(Handle<Object> object,
Handle<Object> receiver,
LookupResult* result,
Handle<String> 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<Object> GetElement(Handle<Object> 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 VERIFY_HEAP
// Verify a pointer is a valid object pointer.
static void VerifyPointer(Object* p);
#endif
inline void VerifyApiCallResultType();
// 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);
DECLARE_VERIFIER(Smi)
static const int kMinValue =
(static_cast<unsigned int>(-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);
DECLARE_VERIFIER(Failure)
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
DECLARE_VERIFIER(HeapObject)
#ifdef VERIFY_HEAP
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);
};
// 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<int start_offset, int end_offset, int size>
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<typename StaticVisitor>
static inline void IterateBody(HeapObject* obj) {
StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
HeapObject::RawField(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<int start_offset>
class FlexibleBodyDescriptor {
public:
static const int kStartOffset = start_offset;
static inline void IterateBody(HeapObject* obj,
int object_size,
ObjectVisitor* v);
template<typename StaticVisitor>
static inline void IterateBody(HeapObject* obj, int object_size) {
StaticVisitor::VisitPointers(HeapObject::RawField(obj, start_offset),
HeapObject::RawField(obj, object_size));
}
};
// 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);
DECLARE_VERIFIER(HeapNumber)
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
};
// A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
// a keyed store is of the form a[expression] = foo.
enum StoreFromKeyed {
MAY_BE_STORE_FROM_KEYED,
CERTAINLY_NOT_STORE_FROM_KEYED
};
// Internal properties (e.g. the hidden properties dictionary) might
// be added even though the receiver is non-extensible.
enum ExtensibilityCheck {
PERFORM_EXTENSIBILITY_CHECK,
OMIT_EXTENSIBILITY_CHECK
};
// Casting.
static inline JSReceiver* cast(Object* obj);
static Handle<Object> SetProperty(Handle<JSReceiver> object,
Handle<String> key,
Handle<Object> value,
PropertyAttributes attributes,
StrictModeFlag strict_mode);
// Can cause GC.
MUST_USE_RESULT MaybeObject* SetProperty(
String* key,
Object* value,
PropertyAttributes attributes,
StrictModeFlag strict_mode,
StoreFromKeyed store_from_keyed = MAY_BE_STORE_FROM_KEYED);
MUST_USE_RESULT MaybeObject* SetProperty(
LookupResult* result,
String* key,
Object* value,
PropertyAttributes attributes,
StrictModeFlag strict_mode,
StoreFromKeyed store_from_keyed = MAY_BE_STORE_FROM_KEYED);
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);
inline PropertyAttributes GetElementAttribute(uint32_t index);
inline PropertyAttributes GetLocalElementAttribute(uint32_t index);
// Can cause a GC.
inline bool HasProperty(String* name);
inline bool HasLocalProperty(String* name);
inline bool HasElement(uint32_t index);
inline bool HasLocalElement(uint32_t index);
// Return the object's prototype (might be Heap::null_value()).
inline Object* GetPrototype();
// Return the constructor function (may be Heap::null_value()).
inline Object* GetConstructor();
// 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,
bool search_hidden_prototypes = false);
void Lookup(String* name, LookupResult* result);
protected:
Smi* GenerateIdentityHash();
private:
PropertyAttributes GetPropertyAttributeForResult(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();
// Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
inline bool HasFastSmiElements();
// Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
inline bool HasFastObjectElements();
// Returns true if an object has elements of FAST_ELEMENTS or
// FAST_SMI_ONLY_ELEMENTS.
inline bool HasFastSmiOrObjectElements();
// Returns true if an object has any of the fast elements kinds.
inline bool HasFastElements();
// Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
// ElementsKind.
inline bool HasFastDoubleElements();
// Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
// ElementsKind.
inline bool HasFastHoleyElements();
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,
StoreFromKeyed store_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,
ExtensibilityCheck extensibility_check);
static Handle<Object> SetLocalPropertyIgnoreAttributes(
Handle<JSObject> object,
Handle<String> key,
Handle<Object> value,
PropertyAttributes attributes);
// Try to follow an existing transition to a field with attributes NONE. The
// return value indicates whether the transition was successful.
static inline bool TryTransitionToField(Handle<JSObject> object,
Handle<String> key);
inline int LastAddedFieldIndex();
// Extend the receiver with a single fast property appeared first in the
// passed map. This also extends the property backing store if necessary.
static void AddFastPropertyUsingMap(Handle<JSObject> object, Handle<Map> map);
inline MUST_USE_RESULT MaybeObject* AddFastPropertyUsingMap(Map* map);
// 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<Object> SetNormalizedProperty(Handle<JSObject> object,
Handle<String> key,
Handle<Object> 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);
MUST_USE_RESULT MaybeObject* OptimizeAsPrototype();
// 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);
PropertyAttributes GetElementAttributeWithReceiver(JSReceiver* receiver,
uint32_t index,
bool continue_search);
static void DefineAccessor(Handle<JSObject> object,
Handle<String> name,
Handle<Object> getter,
Handle<Object> setter,
PropertyAttributes attributes);
// Can cause GC.
MUST_USE_RESULT MaybeObject* DefineAccessor(String* name,
Object* getter,
Object* setter,
PropertyAttributes attributes);
// Try to define a single accessor paying attention to map transitions.
// Returns a JavaScript null if this was not possible and we have to use the
// slow case. Note that we can fail due to allocations, too.
MUST_USE_RESULT MaybeObject* DefineFastAccessor(
String* name,
AccessorComponent component,
Object* accessor,
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(
Object* receiver,
String* name,
PropertyAttributes* attributes);
MUST_USE_RESULT MaybeObject* GetPropertyPostInterceptor(
Object* receiver,
String* name,
PropertyAttributes* attributes);
MUST_USE_RESULT MaybeObject* GetLocalPropertyPostInterceptor(
Object* 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<Object> SetHiddenProperty(Handle<JSObject> obj,
Handle<String> key,
Handle<Object> 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<JSObject> obj);
MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag);
MUST_USE_RESULT MaybeObject* SetIdentityHash(Smi* hash, CreationFlag flag);
static Handle<Object> DeleteProperty(Handle<JSObject> obj,
Handle<String> name);
// Can cause GC.
MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode);
static Handle<Object> DeleteElement(Handle<JSObject> obj, uint32_t index);
MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode);
inline void ValidateElements();
// 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,
uint32_t length,
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);
// 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;
}
PropertyType GetLocalPropertyType(String* name);
PropertyType GetLocalElementType(uint32_t index);
// These methods do not perform access checks!
AccessorPair* GetLocalPropertyAccessorPair(String* name);
AccessorPair* GetLocalElementAccessorPair(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<Object> SetOwnElement(Handle<JSObject> object,
uint32_t index,
Handle<Object> value,
StrictModeFlag strict_mode);
// Empty handle is returned if the element cannot be set to the given value.
static Handle<Object> SetElement(
Handle<JSObject> object,
uint32_t index,
Handle<Object> 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 SetFastElementsCapacitySmiMode {
kAllowSmiElements,
kForceSmiElements,
kDontAllowSmiElements
};
// 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,
SetFastElementsCapacitySmiMode smi_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);
MUST_USE_RESULT MaybeObject* SetElementWithCallbackSetterInPrototypes(
uint32_t index, Object* value, bool* found, StrictModeFlag strict_mode);
void LookupCallbackProperty(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,
int field_index);
// 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<Map> GetElementsTransitionMap(Handle<JSObject> 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<Object> TransitionElementsKind(Handle<JSObject> object,
ElementsKind to_kind);
MUST_USE_RESULT MaybeObject* TransitionElementsKind(ElementsKind to_kind);
// Replaces an existing transition with a transition to a map with a FIELD.
MUST_USE_RESULT MaybeObject* ConvertTransitionToMapTransition(
int transition_index,
String* name,
Object* new_value,
PropertyAttributes attributes);
// Converts a descriptor of any other type to a real field, backed by the
// properties array.
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,
StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
// 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. May cause GC.
MUST_USE_RESULT MaybeObject* AddProperty(
String* name,
Object* value,
PropertyAttributes attributes,
StrictModeFlag strict_mode,
StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED,
ExtensibilityCheck extensibility_check = PERFORM_EXTENSIBILITY_CHECK);
// 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<JSObject> 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<SeededNumberDictionary> NormalizeElements(
Handle<JSObject> object);
MUST_USE_RESULT MaybeObject* NormalizeElements();
static void UpdateMapCodeCache(Handle<JSObject> object,
Handle<String> name,
Handle<Code> 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<JSObject> 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<Object> PreventExtensions(Handle<JSObject> 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
DECLARE_VERIFIER(JSObject)
#ifdef OBJECT_PRINT
inline void PrintProperties() {
PrintProperties(stdout);
}
void PrintProperties(FILE* out);
inline void PrintElements() {
PrintElements(stdout);
}
void PrintElements(FILE* out);
inline void PrintTransitions() {
PrintTransitions(stdout);
}
void PrintTransitions(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 bool TooManyFastProperties(int properties, StoreFromKeyed store_mode);
// 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 kFastPropertiesSoftLimit = 12;
static const int kMaxFastProperties = 64;
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<kPropertiesOffset> {
public:
static inline int SizeOf(Map* map, HeapObject* object);
};
// Enqueue change record for Object.observe. May cause GC.
static void EnqueueChangeRecord(Handle<JSObject> object,
const char* type,
Handle<String> name,
Handle<Object> old_value);
// Deliver change records to observers. May cause GC.
static void DeliverChangeRecords(Isolate* isolate);
private:
friend class DictionaryElementsAccessor;
MUST_USE_RESULT MaybeObject* GetElementWithCallback(Object* receiver,
Object* structure,
uint32_t index,
Object* holder);
MUST_USE_RESULT PropertyAttributes GetElementAttributeWithInterceptor(
JSReceiver* receiver,
uint32_t index,
bool continue_search);
MUST_USE_RESULT PropertyAttributes GetElementAttributeWithoutInterceptor(
JSReceiver* receiver,
uint32_t index,
bool continue_search);
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 property 'name'. If it is found and
// has a setter, invoke it and set '*done' to true. If it is found and is
// read-only, reject and set '*done' to true. Otherwise, set '*done' to
// false. Can cause GC and can return a failure result with '*done==true'.
MUST_USE_RESULT MaybeObject* SetPropertyViaPrototypes(
String* name,
Object* value,
PropertyAttributes attributes,
StrictModeFlag strict_mode,
bool* done);
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* CreateAccessorPairFor(String* name);
MUST_USE_RESULT MaybeObject* DefinePropertyAccessor(
String* name,
Object* getter,
Object* setter,
PropertyAttributes attributes);
enum InitializeHiddenProperties {
CREATE_NEW_IF_ABSENT,
ONLY_RETURN_INLINE_VALUE
};
// If create_if_absent is true, return the hash table backing store
// for hidden properties. If there is no backing store, allocate one.
// If create_if_absent is false, return the hash table backing store
// or the inline stored identity hash, whatever is found.
MUST_USE_RESULT MaybeObject* GetHiddenPropertiesHashTable(
InitializeHiddenProperties init_option);
// Set the hidden property backing store to either a hash table or
// the inline-stored identity hash.
MUST_USE_RESULT MaybeObject* SetHiddenPropertiesHashTable(
Object* value);
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;
class IncrementalMarking;
// 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);
inline Object** GetFirstElementAddress();
inline bool ContainsOnlySmisOrHoles();
// Gives access to raw memory which stores the array's data.
inline Object** data_start();
// Copy operations.
MUST_USE_RESULT inline MaybeObject* Copy();
MUST_USE_RESULT MaybeObject* CopySize(int new_length);
// Add the elements of a JSArray to this FixedArray.
MUST_USE_RESULT MaybeObject* AddKeysFromJSArray(JSArray* array);
// Compute the union of this and other.
MUST_USE_RESULT MaybeObject* UnionOfKeys(FixedArray* other);
// Copy a sub array from the receiver to dest.
void CopyTo(int pos, FixedArray* dest, int dest_pos, int len);
// Garbage collection support.
static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; }
// Code Generation support.
static int OffsetOfElementAt(int index) { return SizeFor(index); }
// Casting.
static inline FixedArray* cast(Object* obj);
// 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
DECLARE_VERIFIER(FixedArray)
#ifdef DEBUG
// 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<kHeaderSize> {
public:
static inline int SizeOf(Map* map, HeapObject* object) {
return SizeFor(reinterpret_cast<FixedArray*>(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:
STATIC_CHECK(kHeaderSize == Internals::kFixedArrayHeaderSize);
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;
}
// Gives access to raw memory which stores the array's data.
inline double* data_start();
// 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);
static inline FixedDoubleArray* castOrEmptyFixedArray(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
DECLARE_VERIFIER(FixedDoubleArray)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
};
// DescriptorArrays are fixed arrays used to hold instance descriptors.
// The format of the these objects is:
// [0]: Number of descriptors
// [1]: Either Smi(0) if uninitialized, or a pointer to small fixed array:
// [0]: pointer to fixed array with enum cache
// [1]: either Smi(0) or pointer to fixed array with indices
// [2]: first key
// [2 + number of descriptors * kDescriptorSize]: start of slack
class DescriptorArray: public FixedArray {
public:
// WhitenessWitness is used to prove that a descriptor array is white
// (unmarked), so incremental write barriers can be skipped because the
// marking invariant cannot be broken and slots pointing into evacuation
// candidates will be discovered when the object is scanned. A witness is
// always stack-allocated right after creating an array. By allocating a
// witness, incremental marking is globally disabled. The witness is then
// passed along wherever needed to statically prove that the array is known to
// be white.
class WhitenessWitness {
public:
inline explicit WhitenessWitness(FixedArray* array);
inline ~WhitenessWitness();
private:
IncrementalMarking* marking_;
};
// 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 == 0 ? 0 : Smi::cast(get(kDescriptorLengthIndex))->value();
}
int number_of_descriptors_storage() {
int len = length();
return len == 0 ? 0 : (len - kFirstIndex) / kDescriptorSize;
}
int NumberOfSlackDescriptors() {
return number_of_descriptors_storage() - number_of_descriptors();
}
inline void SetNumberOfDescriptors(int number_of_descriptors);
inline int number_of_entries() { return number_of_descriptors(); }
bool HasEnumCache() {
return !IsEmpty() && !get(kEnumCacheIndex)->IsSmi();
}
void CopyEnumCacheFrom(DescriptorArray* array) {
set(kEnumCacheIndex, array->get(kEnumCacheIndex));
}
FixedArray* GetEnumCache() {
ASSERT(HasEnumCache());
FixedArray* bridge = FixedArray::cast(get(kEnumCacheIndex));
return FixedArray::cast(bridge->get(kEnumCacheBridgeCacheIndex));
}
bool HasEnumIndicesCache() {
if (IsEmpty()) return false;
Object* object = get(kEnumCacheIndex);
if (object->IsSmi()) return false;
FixedArray* bridge = FixedArray::cast(object);
return !bridge->get(kEnumCacheBridgeIndicesCacheIndex)->IsSmi();
}
FixedArray* GetEnumIndicesCache() {
ASSERT(HasEnumIndicesCache());
FixedArray* bridge = FixedArray::cast(get(kEnumCacheIndex));
return FixedArray::cast(bridge->get(kEnumCacheBridgeIndicesCacheIndex));
}
Object** GetEnumCacheSlot() {
ASSERT(HasEnumCache());
return HeapObject::RawField(reinterpret_cast<HeapObject*>(this),
kEnumCacheOffset);
}
void ClearEnumCache();
// 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** GetKeySlot(int descriptor_number);
inline Object* GetValue(int descriptor_number);
inline Object** GetValueSlot(int descriptor_number);
inline PropertyDetails 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 String* GetSortedKey(int descriptor_number);
inline int GetSortedKeyIndex(int descriptor_number);
inline void SetSortedKey(int pointer, int descriptor_number);
// Accessor for complete descriptor.
inline void Get(int descriptor_number, Descriptor* desc);
inline void Set(int descriptor_number,
Descriptor* desc,
const WhitenessWitness&);
inline void Set(int descriptor_number, Descriptor* desc);
// Append automatically sets the enumeration index. This should only be used
// to add descriptors in bulk at the end, followed by sorting the descriptor
// array.
inline void Append(Descriptor* desc, const WhitenessWitness&);
inline void Append(Descriptor* desc);
// Transfer a complete descriptor from the src descriptor array to this
// descriptor array.
void CopyFrom(int dst_index,
DescriptorArray* src,
int src_index,
const WhitenessWitness&);
MUST_USE_RESULT MaybeObject* CopyUpTo(int enumeration_index);
// Sort the instance descriptors by the hash codes of their keys.
void Sort();
// Search the instance descriptors for given name.
INLINE(int Search(String* name, int number_of_own_descriptors));
// As the above, but uses DescriptorLookupCache and updates it when
// necessary.
INLINE(int SearchWithCache(String* name, Map* map));
// 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,
int slack = 0);
// Casting.
static inline DescriptorArray* cast(Object* obj);
// Constant for denoting key was not found.
static const int kNotFound = -1;
static const int kDescriptorLengthIndex = 0;
static const int kEnumCacheIndex = 1;
static const int kFirstIndex = 2;
// The length of the "bridge" to the enum cache.
static const int kEnumCacheBridgeLength = 2;
static const int kEnumCacheBridgeCacheIndex = 0;
static const int kEnumCacheBridgeIndicesCacheIndex = 1;
// Layout description.
static const int kDescriptorLengthOffset = FixedArray::kHeaderSize;
static const int kEnumCacheOffset = kDescriptorLengthOffset + kPointerSize;
static const int kFirstOffset = kEnumCacheOffset + kPointerSize;
// Layout description for the bridge array.
static const int kEnumCacheBridgeCacheOffset = FixedArray::kHeaderSize;
// Layout of descriptor.
static const int kDescriptorKey = 0;
static const int kDescriptorDetails = 1;
static const int kDescriptorValue = 2;
static const int kDescriptorSize = 3;
#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(int valid_descriptors = -1);
// Is the descriptor array consistent with the back pointers in targets?
bool IsConsistentWithBackPointers(Map* current_map);
// 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;
// Returns the fixed array length required to hold number_of_descriptors
// descriptors.
static int LengthFor(int number_of_descriptors) {
return ToKeyIndex(number_of_descriptors);
}
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 kFirstIndex +
(descriptor_number * kDescriptorSize) +
kDescriptorKey;
}
static int ToDetailsIndex(int descriptor_number) {
return kFirstIndex +
(descriptor_number * kDescriptorSize) +
kDescriptorDetails;
}
static int ToValueIndex(int descriptor_number) {
return kFirstIndex +
(descriptor_number * kDescriptorSize) +
kDescriptorValue;
}
// Swap first and second descriptor.
inline void SwapSortedKeys(int first, int second);
DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
};
enum SearchMode { ALL_ENTRIES, VALID_ENTRIES };
template<SearchMode search_mode, typename T>
inline int LinearSearch(T* array, String* name, int len, int valid_entries);
template<SearchMode search_mode, typename T>
inline int Search(T* array, String* name, int valid_entries = 0);
// 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<typename Key>
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<typename Shape, typename Key>
class HashTable: public FixedArray {
public:
enum MinimumCapacity {
USE_DEFAULT_MINIMUM_CAPACITY,
USE_CUSTOM_MINIMUM_CAPACITY
};
// 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,
MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY,
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);
}
inline static uint32_t FirstProbe(uint32_t hash, uint32_t size) {
return hash & (size - 1);
}
inline 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<HashTableKey*> {
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 SeqOneByteString;
// 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<SymbolTableShape, HashTableKey*> {
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<const char> str, Object** s);
MUST_USE_RESULT MaybeObject* LookupAsciiSymbol(Vector<const char> str,
Object** s);
MUST_USE_RESULT MaybeObject* LookupSubStringAsciiSymbol(
Handle<SeqOneByteString> str,
int from,
int length,
Object** s);
MUST_USE_RESULT MaybeObject* LookupTwoByteSymbol(Vector<const uc16> 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);
template <bool seq_ascii> friend class JsonParser;
DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolTable);
};
class MapCacheShape : public BaseShape<HashTableKey*> {
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<MapCacheShape, HashTableKey*> {
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 <typename Shape, typename Key>
class Dictionary: public HashTable<Shape, Key> {
public:
static inline Dictionary<Shape, Key>* cast(Object* obj) {
return reinterpret_cast<Dictionary<Shape, Key>*>(obj);
}
// Returns the value at entry.
Object* ValueAt(int entry) {
return this->get(HashTable<Shape, Key>::EntryToIndex(entry) + 1);
}
// Set the value for entry.
void ValueAtPut(int entry, Object* value) {
this->set(HashTable<Shape, Key>::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<Shape, Key>::EntryToIndex(entry) + 2)));
}
// Set the details for entry.
void DetailsAtPut(int entry, PropertyDetails value) {
this->set(HashTable<Shape, Key>::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) {
ASSERT(index != 0);
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<Shape, Key>::kPrefixStartIndex;
static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
};
class StringDictionaryShape : public BaseShape<String*> {
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<StringDictionaryShape, String*> {
public:
static inline StringDictionary* cast(Object* obj) {
ASSERT(obj->IsDictionary());
return reinterpret_cast<StringDictionary*>(obj);
}
// Copies enumerable keys to preallocated fixed array.
FixedArray* CopyEnumKeysTo(FixedArray* storage);
static void DoGenerateNewEnumerationIndices(
Handle<StringDictionary> dictionary);
// 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);
};
class NumberDictionaryShape : public BaseShape<uint32_t> {
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<SeededNumberDictionaryShape, uint32_t> {
public:
static SeededNumberDictionary* cast(Object* obj) {
ASSERT(obj->IsDictionary());
return reinterpret_cast<SeededNumberDictionary*>(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<SeededNumberDictionary> Set(
Handle<SeededNumberDictionary> dictionary,
uint32_t index,
Handle<Object> 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<UnseededNumberDictionaryShape, uint32_t> {
public:
static UnseededNumberDictionary* cast(Object* obj) {
ASSERT(obj->IsDictionary());
return reinterpret_cast<UnseededNumberDictionary*>(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<UnseededNumberDictionary> Set(
Handle<UnseededNumberDictionary> dictionary,
uint32_t index,
Handle<Object> value);
MUST_USE_RESULT MaybeObject* Set(uint32_t key, Object* value);
};
template <int entrysize>
class ObjectHashTableShape : public BaseShape<Object*> {
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<ObjectHashTableShape<1>, Object*> {
public:
static inline ObjectHashSet* cast(Object* obj) {
ASSERT(obj->IsHashTable());
return reinterpret_cast<ObjectHashSet*>(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<ObjectHashTableShape<2>, Object*> {
public:
static inline ObjectHashTable* cast(Object* obj) {
ASSERT(obj->IsHashTable());
return reinterpret_cast<ObjectHashTable*>(obj);
}
// Looks up the value associated with the given key. The hole 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 hole 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);
DECLARE_VERIFIER(JSFunctionResultCache)
};
// 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 and context-allocated (named
// function expressions, only), otherwise returns a value < 0. The name
// must be a symbol (canonicalized).
int FunctionContextSlotIndex(String* name, VariableMode* mode);
static Handle<ScopeInfo> Create(Scope* scope, Zone* zone);
// 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<ScopeType, 0, 3> {};
class CallsEvalField: public BitField<bool, 3, 1> {};
class LanguageModeField: public BitField<LanguageMode, 4, 2> {};
class FunctionVariableField: public BitField<FunctionVariableInfo, 6, 2> {};
class FunctionVariableMode: public BitField<VariableMode, 8, 3> {};
// BitFields representing the encoded information for context locals in the
// ContextLocalInfoEntries part.
class ContextLocalMode: public BitField<VariableMode, 0, 3> {};
class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {};
};
// 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);
DECLARE_VERIFIER(NormalizedMapCache)
};
// 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
DECLARE_VERIFIER(ByteArray)
// 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
DECLARE_VERIFIER(FreeSpace)
// 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
DECLARE_VERIFIER(ExternalPixelArray)
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
DECLARE_VERIFIER(ExternalByteArray)
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
DECLARE_VERIFIER(ExternalUnsignedByteArray)
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
DECLARE_VERIFIER(ExternalShortArray)
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
DECLARE_VERIFIER(ExternalUnsignedShortArray)
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
DECLARE_VERIFIER(ExternalIntArray)
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
DECLARE_VERIFIER(ExternalUnsignedIntArray)
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
DECLARE_VERIFIER(ExternalFloatArray)
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
DECLARE_VERIFIER(ExternalDoubleArray)
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 kAstIdRawOffset = 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(AstIdRaw, Smi)
DEFINE_ENTRY_ACCESSORS(TranslationIndex, Smi)
DEFINE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi)
DEFINE_ENTRY_ACCESSORS(Pc, Smi)
#undef DEFINE_ENTRY_ACCESSORS
BailoutId AstId(int i) {
return BailoutId(AstIdRaw(i)->value());
}
void SetAstId(int i, BailoutId value) {
SetAstIdRaw(i, Smi::FromInt(value.ToInt()));
}
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; }
BailoutId AstId(int index) {
return BailoutId(Smi::cast(get(index * 2))->value());
}
void SetAstId(int index, BailoutId id) {
set(index * 2, Smi::FromInt(id.ToInt()));
}
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 TypeFeedbackId AstId(int index);
inline void SetAstId(int index, TypeFeedbackId 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<Object> UninitializedSentinel(Isolate* isolate);
// The object that indicates a megamorphic state.
static inline Handle<Object> 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
};
#define CODE_KIND_LIST(V) \
V(FUNCTION) \
V(OPTIMIZED_FUNCTION) \
V(STUB) \
V(BUILTIN) \
V(LOAD_IC) \
V(KEYED_LOAD_IC) \
V(CALL_IC) \
V(KEYED_CALL_IC) \
V(STORE_IC) \
V(KEYED_STORE_IC) \
V(UNARY_OP_IC) \
V(BINARY_OP_IC) \
V(COMPARE_IC) \
V(TO_BOOLEAN_IC)
enum Kind {
#define DEFINE_CODE_KIND_ENUM(name) name,
CODE_KIND_LIST(DEFINE_CODE_KIND_ENUM)
#undef DEFINE_CODE_KIND_ENUM
// Pseudo-kinds.
LAST_CODE_KIND = TO_BOOLEAN_IC,
REGEXP = BUILTIN,
FIRST_IC_KIND = LOAD_IC,
LAST_IC_KIND = TO_BOOLEAN_IC
};
// No more than 16 kinds. The value is currently encoded in four bits in
// Flags.
STATIC_ASSERT(LAST_CODE_KIND < 16);
// Types of stubs.
enum StubType {
NORMAL,
FIELD,
CONSTANT_FUNCTION,
CALLBACKS,
INTERCEPTOR,
MAP_TRANSITION,
NONEXISTENT
};
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* StubType2String(StubType 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.
// STUBs can use this slot to store arbitrary information as a Smi.
// Will contain either a TypeFeedbackInfo object, or undefined, or a Smi.
DECL_ACCESSORS(type_feedback_info, Object)
inline void InitializeTypeFeedbackInfoNoWriteBarrier(Object* value);
inline int stub_info();
inline void set_stub_info(int info);
// [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 StubType 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);
// [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);
// [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);
bool allowed_in_shared_map_code_cache();
// 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<StrictModeFlag, 0, 1> {};
class ExtraICStateKeyedAccessGrowMode:
public BitField<KeyedAccessGrowMode, 1, 1> {}; // 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,
StubType type = NORMAL,
int argc = -1,
InlineCacheHolderFlag holder = OWN_MAP);
static inline Flags ComputeMonomorphicFlags(
Kind kind,
StubType type,
ExtraICState extra_ic_state = kNoExtraICState,
InlineCacheHolderFlag holder = OWN_MAP,
int argc = -1);
static inline InlineCacheState ExtractICStateFromFlags(Flags flags);
static inline StubType 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<int>(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<typename StaticVisitor>
inline void CodeIterateBody(Heap* heap);
#ifdef OBJECT_PRINT
inline void CodePrint() {
CodePrint(stdout);
}
void CodePrint(FILE* out);
#endif
DECLARE_VERIFIER(Code)
void ClearInlineCaches();
void ClearTypeFeedbackCells(Heap* heap);
#define DECLARE_CODE_AGE_ENUM(X) k##X##CodeAge,
enum Age {
kNoAge = 0,
CODE_AGE_LIST(DECLARE_CODE_AGE_ENUM)
kAfterLastCodeAge,
kLastCodeAge = kAfterLastCodeAge - 1,
kCodeAgeCount = kAfterLastCodeAge - 1
};
#undef DECLARE_CODE_AGE_ENUM
// Code aging
static void MakeCodeAgeSequenceYoung(byte* sequence);
void MakeYoung();
void MakeOlder(MarkingParity);
static bool IsYoungSequence(byte* sequence);
bool IsOld();
// 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 kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
static const int kKindSpecificFlags2Offset =
kKindSpecificFlags1Offset + kIntSize;
static const int kHeaderPaddingStart = kKindSpecificFlags2Offset + kIntSize;
// Add padding to align the instruction start following right after
// the Code object header.
static const int kHeaderSize =
(kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
// Byte offsets within kKindSpecificFlags1Offset.
static const int kOptimizableOffset = kKindSpecificFlags1Offset;
static const int kCheckTypeOffset = kKindSpecificFlags1Offset;
static const int kFullCodeFlags = kOptimizableOffset + 1;
class FullCodeFlagsHasDeoptimizationSupportField:
public BitField<bool, 0, 1> {}; // NOLINT
class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {};
class FullCodeFlagsIsCompiledOptimizable: public BitField<bool, 2, 1> {};
static const int kAllowOSRAtLoopNestingLevelOffset = kFullCodeFlags + 1;
static const int kProfilerTicksOffset = kAllowOSRAtLoopNestingLevelOffset + 1;
// Flags layout. BitField<type, shift, size>.
class ICStateField: public BitField<InlineCacheState, 0, 3> {};
class TypeField: public BitField<StubType, 3, 3> {};
class CacheHolderField: public BitField<InlineCacheHolderFlag, 6, 1> {};
class KindField: public BitField<Kind, 7, 4> {};
class ExtraICStateField: public BitField<ExtraICState, 11, 2> {};
class IsPregeneratedField: public BitField<bool, 13, 1> {};
// KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION)
static const int kStackSlotsFirstBit = 0;
static const int kStackSlotsBitCount = 24;
static const int kUnaryOpTypeFirstBit =
kStackSlotsFirstBit + kStackSlotsBitCount;
static const int kUnaryOpTypeBitCount = 3;
static const int kToBooleanStateFirstBit =
kStackSlotsFirstBit + kStackSlotsBitCount;
static const int kToBooleanStateBitCount = 8;
static const int kHasFunctionCacheFirstBit =
kStackSlotsFirstBit + kStackSlotsBitCount;
static const int kHasFunctionCacheBitCount = 1;
STATIC_ASSERT(kStackSlotsFirstBit + kStackSlotsBitCount <= 32);
STATIC_ASSERT(kUnaryOpTypeFirstBit + kUnaryOpTypeBitCount <= 32);
STATIC_ASSERT(kToBooleanStateFirstBit + kToBooleanStateBitCount <= 32);
STATIC_ASSERT(kHasFunctionCacheFirstBit + kHasFunctionCacheBitCount <= 32);
class StackSlotsField: public BitField<int,
kStackSlotsFirstBit, kStackSlotsBitCount> {}; // NOLINT
class UnaryOpTypeField: public BitField<int,
kUnaryOpTypeFirstBit, kUnaryOpTypeBitCount> {}; // NOLINT
class ToBooleanStateField: public BitField<int,
kToBooleanStateFirstBit, kToBooleanStateBitCount> {}; // NOLINT
class HasFunctionCacheField: public BitField<bool,
kHasFunctionCacheFirstBit, kHasFunctionCacheBitCount> {}; // NOLINT
// KindSpecificFlags2 layout (STUB and OPTIMIZED_FUNCTION)
static const int kStubMajorKeyFirstBit = 0;
static const int kSafepointTableOffsetFirstBit =
kStubMajorKeyFirstBit + kStubMajorKeyBits;
static const int kSafepointTableOffsetBitCount = 26;
STATIC_ASSERT(kStubMajorKeyFirstBit + kStubMajorKeyBits <= 32);
STATIC_ASSERT(kSafepointTableOffsetFirstBit +
kSafepointTableOffsetBitCount <= 32);
class SafepointTableOffsetField: public BitField<int,
kSafepointTableOffsetFirstBit,
kSafepointTableOffsetBitCount> {}; // NOLINT
class StubMajorKeyField: public BitField<int,
kStubMajorKeyFirstBit, kStubMajorKeyBits> {}; // NOLINT
// KindSpecificFlags2 layout (FUNCTION)
class StackCheckTableOffsetField: public BitField<int, 0, 31> {};
// Signed field cannot be encoded using the BitField class.
static const int kArgumentsCountShift = 14;
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:
friend class RelocIterator;
// Code aging
byte* FindCodeAgeSequence();
static void GetCodeAgeAndParity(Code* code, Age* age,
MarkingParity* parity);
static void GetCodeAgeAndParity(byte* sequence, Age* age,
MarkingParity* parity);
static Code* GetCodeAgeStub(Age age, MarkingParity parity);
// Code aging -- platform-specific
byte* FindPlatformCodeAgeSequence();
static void PatchPlatformCodeAge(byte* sequence, Age age,
MarkingParity parity);
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.
inline int bit_field3();
inline void set_bit_field3(int value);
class EnumLengthBits: public BitField<int, 0, 11> {};
class NumberOfOwnDescriptorsBits: public BitField<int, 11, 11> {};
class IsShared: public BitField<bool, 22, 1> {};
class FunctionWithPrototype: public BitField<bool, 23, 1> {};
class DictionaryMap: public BitField<bool, 24, 1> {};
class OwnsDescriptors: public BitField<bool, 25, 1> {};
class IsObserved: public BitField<bool, 26, 1> {};
// 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<ElementsKind>(
(bit_field2() & kElementsKindMask) >> kElementsKindShift);
}
// Tells whether the instance has fast elements that are only Smis.
inline bool has_fast_smi_elements() {
return IsFastSmiElementsKind(elements_kind());
}
// Tells whether the instance has fast elements.
inline bool has_fast_object_elements() {
return IsFastObjectElementsKind(elements_kind());
}
inline bool has_fast_smi_or_object_elements() {
return IsFastSmiOrObjectElementsKind(elements_kind());
}
inline bool has_fast_double_elements() {
return IsFastDoubleElementsKind(elements_kind());
}
inline bool has_non_strict_arguments_elements() {
return elements_kind() == NON_STRICT_ARGUMENTS_ELEMENTS;
}
inline bool has_external_array_elements() {
return IsExternalArrayElementsKind(elements_kind());
}
inline bool has_dictionary_elements() {
return IsDictionaryElementsKind(elements_kind());
}
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);
inline bool HasTransitionArray();
inline bool HasElementsTransition();
inline Map* elements_transition_map();
MUST_USE_RESULT inline MaybeObject* set_elements_transition_map(
Map* transitioned_map);
inline void SetTransition(int transition_index, Map* target);
inline Map* GetTransition(int transition_index);
MUST_USE_RESULT inline MaybeObject* AddTransition(String* key,
Map* target,
SimpleTransitionFlag flag);
DECL_ACCESSORS(transitions, TransitionArray)
inline void ClearTransitions(Heap* heap,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// 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 map is used for JSObjects in dictionary mode (ie
// normalized objects, ie objects for which HasFastProperties returns false).
// A map can never be used for both dictionary mode and fast mode JSObjects.
// False by default and for HeapObjects that are not JSObjects.
inline void set_dictionary_map(bool value);
inline bool is_dictionary_map();
// Tells whether the instance needs security checks when accessing its
// properties.
inline void set_is_access_check_needed(bool access_check_needed);
inline bool is_access_check_needed();
// [prototype]: implicit prototype object.
DECL_ACCESSORS(prototype, Object)
// [constructor]: points back to the function responsible for this map.
DECL_ACCESSORS(constructor, Object)
inline JSFunction* unchecked_constructor();
// [instance descriptors]: describes the object.
DECL_ACCESSORS(instance_descriptors, DescriptorArray)
inline void InitializeDescriptors(DescriptorArray* descriptors);
// [stub cache]: contains stubs compiled for this map.
DECL_ACCESSORS(code_cache, Object)
// [back pointer]: points back to the parent map from which a transition
// leads to this map. The field overlaps with prototype transitions and the
// back pointer will be moved into the prototype transitions array if
// required.
inline Object* GetBackPointer();
inline void SetBackPointer(Object* value,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
inline void init_back_pointer(Object* undefined);
// [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: back pointer that overlaps with prototype transitions field.
// 2 + 2 * i: prototype
// 3 + 2 * i: target map
inline FixedArray* GetPrototypeTransitions();
MUST_USE_RESULT inline MaybeObject* SetPrototypeTransitions(
FixedArray* prototype_transitions);
inline bool HasPrototypeTransitions();
inline HeapObject* UncheckedPrototypeTransitions();
inline TransitionArray* unchecked_transition_array();
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 = GetPrototypeTransitions();
if (cache->length() == 0) return 0;
return
Smi::cast(cache->get(kProtoTransitionNumberOfEntriesOffset))->value();
}
inline void SetNumberOfProtoTransitions(int value) {
FixedArray* cache = GetPrototypeTransitions();
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.
inline void LookupDescriptor(JSObject* holder,
String* name,
LookupResult* result);
inline void LookupTransition(JSObject* holder,
String* name,
LookupResult* result);
// The size of transition arrays are limited so they do not end up in large
// object space. Otherwise ClearNonLiveTransitions would leak memory while
// applying in-place right trimming.
inline bool CanHaveMoreTransitions();
int LastAdded() {
int number_of_own_descriptors = NumberOfOwnDescriptors();
ASSERT(number_of_own_descriptors > 0);
return number_of_own_descriptors - 1;
}
int NumberOfOwnDescriptors() {
return NumberOfOwnDescriptorsBits::decode(bit_field3());
}
void SetNumberOfOwnDescriptors(int number) {
ASSERT(number <= instance_descriptors()->number_of_descriptors());
set_bit_field3(NumberOfOwnDescriptorsBits::update(bit_field3(), number));
}
inline JSGlobalPropertyCell* RetrieveDescriptorsPointer();
int EnumLength() {
return EnumLengthBits::decode(bit_field3());
}
void SetEnumLength(int length) {
if (length != kInvalidEnumCache) {
ASSERT(length >= 0);
ASSERT(length == 0 || instance_descriptors()->HasEnumCache());
ASSERT(length <= NumberOfOwnDescriptors());
}
set_bit_field3(EnumLengthBits::update(bit_field3(), length));
}
inline bool owns_descriptors();
inline void set_owns_descriptors(bool is_shared);
inline bool is_observed();
inline void set_is_observed(bool is_observed);
MUST_USE_RESULT MaybeObject* RawCopy(int instance_size);
MUST_USE_RESULT MaybeObject* CopyWithPreallocatedFieldDescriptors();
MUST_USE_RESULT MaybeObject* CopyDropDescriptors();
MUST_USE_RESULT MaybeObject* CopyReplaceDescriptors(
DescriptorArray* descriptors,
String* name,
TransitionFlag flag,
int descriptor_index);
MUST_USE_RESULT MaybeObject* ShareDescriptor(DescriptorArray* descriptors,
Descriptor* descriptor);
MUST_USE_RESULT MaybeObject* CopyAddDescriptor(Descriptor* descriptor,
TransitionFlag flag);
MUST_USE_RESULT MaybeObject* CopyInsertDescriptor(Descriptor* descriptor,
TransitionFlag flag);
MUST_USE_RESULT MaybeObject* CopyReplaceDescriptor(
DescriptorArray* descriptors,
Descriptor* descriptor,
int index,
TransitionFlag flag);
MUST_USE_RESULT MaybeObject* CopyAsElementsKind(ElementsKind kind,
TransitionFlag flag);
MUST_USE_RESULT MaybeObject* CopyNormalized(PropertyNormalizationMode mode,
NormalizedMapSharingMode sharing);
inline void AppendDescriptor(Descriptor* desc,
const DescriptorArray::WhitenessWitness&);
// Returns a copy of the map, with all transitions dropped from the
// instance descriptors.
MUST_USE_RESULT MaybeObject* Copy();
// 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(DescriptorFlag which = OWN_DESCRIPTORS,
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> map,
Handle<String> name,
Handle<Code> code);
MUST_USE_RESULT MaybeObject* UpdateCodeCache(String* name, Code* code);
// Extend the descriptor array of the map with the list of descriptors.
// In case of duplicates, the latest descriptor is used.
static void AppendCallbackDescriptors(Handle<Map> map,
Handle<Object> descriptors);
static void EnsureDescriptorSlack(Handle<Map> map, int slack);
// 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);
// Set all map transitions from this map to dead maps to null. Also clear
// back pointers in transition targets so that we do not process this map
// again while following back pointers.
void ClearNonLiveTransitions(Heap* heap);
// 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 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);
// 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<Map> FindTransitionedMap(MapHandleList* candidates);
Map* FindTransitionedMap(MapList* candidates);
// Zaps the contents of backing data structures. Note that the
// heap verifier (i.e. VerifyMarkingVisitor) relies on zapping of objects
// holding weak references when incremental marking is used, because it also
// iterates over objects that are otherwise unreachable.
// In general we only want to call these functions in release mode when
// heap verification is turned on.
void ZapPrototypeTransitions();
void ZapTransitions();
// Dispatched behavior.
#ifdef OBJECT_PRINT
inline void MapPrint() {
MapPrint(stdout);
}
void MapPrint(FILE* out);
#endif
DECLARE_VERIFIER(Map)
#ifdef VERIFY_HEAP
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);
// When you set the prototype of an object using the __proto__ accessor you
// need a new map for the object (the prototype is stored in the map). In
// order not to multiply maps unnecessarily we store these as transitions in
// the original map. That way we can transition to the same map if the same
// prototype is set, rather than creating a new map every time. The
// transitions are in the form of a map where the keys are prototype objects
// and the values are the maps the are transitioned to.
static const int kMaxCachedPrototypeTransitions = 256;
Map* GetPrototypeTransition(Object* prototype);
MUST_USE_RESULT MaybeObject* PutPrototypeTransition(Object* prototype,
Map* map);
static const int kMaxPreAllocatedPropertyFields = 255;
// Constant for denoting that the enum cache is not yet initialized.
static const int kInvalidEnumCache = EnumLengthBits::kMax;
// 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 the transition array is overloaded to directly contain a back
// pointer if unused. When the map has transitions, the back pointer is
// transferred to the transition array and accessed through an extra
// indirection.
static const int kTransitionsOrBackPointerOffset =
kConstructorOffset + kPointerSize;
static const int kDescriptorsOffset =
kTransitionsOrBackPointerOffset + kPointerSize;
static const int kCodeCacheOffset =
kDescriptorsOffset + kPointerSize;
static const int kBitField3Offset = kCodeCacheOffset + kPointerSize;
static const int kSize = kBitField3Offset + kPointerSize;
// Layout of pointer fields. Heap iteration code relies on them
// being continuously allocated.
static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
static const int kPointerFieldsEndOffset = kBitField3Offset + 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 kStringWrapperSafeForDefaultValueOf = 1;
static const int kAttachedToSharedFunctionInfo = 2;
// No bits can be used after kElementsKindFirstBit, they are all reserved for
// storing ElementKind.
static const int kElementsKindShift = 3;
static const int kElementsKindBitCount = 5;
// Derived values from bit field 2
static const int kElementsKindMask = (-1 << kElementsKindShift) &
((1 << (kElementsKindShift + kElementsKindBitCount)) - 1);
static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
(FAST_ELEMENTS + 1) << Map::kElementsKindShift) - 1;
static const int8_t kMaximumBitField2FastSmiElementValue =
static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
Map::kElementsKindShift) - 1;
static const int8_t kMaximumBitField2FastHoleyElementValue =
static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
Map::kElementsKindShift) - 1;
static const int8_t kMaximumBitField2FastHoleySmiElementValue =
static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
Map::kElementsKindShift) - 1;
typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
kPointerFieldsEndOffset,
kSize> BodyDescriptor;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
};
// An abstract superclass, a marker class really, for simple structure classes.
// It doesn't carry much functionality but allows struct classes to 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
DECLARE_VERIFIER(Script)
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)
// [optimized_code_map]: Map from native context to optimized code
// and a shared literals array or Smi 0 if none.
DECL_ACCESSORS(optimized_code_map, Object)
// Returns index i of the entry with the specified context. At position
// i - 1 is the context, position i the code, and i + 1 the literals array.
// Returns -1 when no matching entry is found.
int SearchOptimizedCodeMap(Context* native_context);
// Installs optimized code from the code map on the given closure. The
// index has to be consistent with a search result as defined above.
void InstallFromOptimizedCodeMap(JSFunction* function, int index);
// Clear optimized code map.
void ClearOptimizedCodeMap();
// Add a new entry to the optimized code map.
static void AddToOptimizedCodeMap(Handle<SharedFunctionInfo> shared,
Handle<Context> native_context,
Handle<Code> code,
Handle<FixedArray> literals);
static const int kEntryLength = 3;
// [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();
// Invoked before pointers in SharedFunctionInfo are being marked.
// Also clears the optimized code map.
inline void BeforeVisitingPointers();
// 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 stress_deopt_counter();
inline void set_stress_deopt_counter(int counter);
inline int profiler_ticks();
// 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 if this function can be lazy compiled without a context.
// This is used to determine if we can force compilation without reaching
// the function through program execution but through other means (e.g. heap
// iteration by the debugger).
DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation_without_context)
// 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 that code for this function cannot be cached.
DECL_BOOLEAN_ACCESSORS(dont_cache)
// 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(const char* reason);
// 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(BailoutId 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<Object> GetSourceCode();
// Number of times the function was optimized.
inline int opt_count();
inline void set_opt_count(int opt_count);
// Number of times the function was deoptimized.
inline void set_deopt_count(int value);
inline int deopt_count();
inline void increment_deopt_count();
// Number of time we tried to re-enable optimization after it
// was disabled due to high number of deoptimizations.
inline void set_opt_reenable_tries(int value);
inline int opt_reenable_tries();
inline void TryReenableOptimization();
// Stores deopt_count, opt_reenable_tries and ic_age as bit-fields.
inline void set_counters(int value);
inline int counters();
// 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
DECLARE_VERIFIER(SharedFunctionInfo)
void ResetForNewContext(int new_ic_age);
// Helper to compile the shared code. Returns true on success, false on
// failure (e.g., stack overflow during compilation). This is only used by
// the debugger, it is not possible to compile without a context otherwise.
static bool CompileLazy(Handle<SharedFunctionInfo> shared,
ClearExceptionFlag flag);
// 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 kOptimizedCodeMapOffset = kCodeOffset + kPointerSize;
static const int kScopeInfoOffset = kOptimizedCodeMapOffset + 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;
// ast_node_count 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 kAstNodeCountOffset =
kThisPropertyAssignmentsOffset + kPointerSize;
#if V8_HOST_ARCH_32_BIT
// Smi fields.
static const int kLengthOffset =
kAstNodeCountOffset + 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 kCountersOffset = kOptCountOffset + kPointerSize;
static const int kStressDeoptCounterOffset = kCountersOffset + kPointerSize;
// Total size.
static const int kSize = kStressDeoptCounterOffset + 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 =
kAstNodeCountOffset + 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 kCountersOffset = kOptCountOffset + kIntSize;
static const int kStressDeoptCounterOffset = kCountersOffset + kIntSize;
// Total size.
static const int kSize = kStressDeoptCounterOffset + 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<kNameOffset,
kThisPropertyAssignmentsOffset + kPointerSize,
kSize> 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,
kAllowLazyCompilationWithoutContext,
kLiveObjectsMayExist,
kCodeAgeShift,
kOptimizationDisabled = kCodeAgeShift + kCodeAgeSize,
kStrictModeFunction,
kExtendedModeFunction,
kUsesArguments,
kHasDuplicateParameters,
kNative,
kBoundFunction,
kIsAnonymous,
kNameShouldPrintAsAnonymous,
kIsFunction,
kDontOptimize,
kDontInline,
kDontCache,
kCompilerHintsCount // Pseudo entry
};
class DeoptCountBits: public BitField<int, 0, 4> {};
class OptReenableTriesBits: public BitField<int, 4, 18> {};
class ICAgeBits: public BitField<int, 22, 8> {};
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);
};
// Representation for module instance objects.
class JSModule: public JSObject {
public:
// [context]: the context holding the module's locals, or undefined if none.
DECL_ACCESSORS(context, Object)
// [scope_info]: Scope info.
DECL_ACCESSORS(scope_info, ScopeInfo)
// Casting.
static inline JSModule* cast(Object* obj);
// Dispatched behavior.
#ifdef OBJECT_PRINT
inline void JSModulePrint() {
JSModulePrint(stdout);
}
void JSModulePrint(FILE* out);
#endif
DECLARE_VERIFIER(JSModule)
// Layout description.
static const int kContextOffset = JSObject::kHeaderSize;
static const int kScopeInfoOffset = kContextOffset + kPointerSize;
static const int kSize = kScopeInfoOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSModule);
};
// 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();
void MarkForParallelRecompilation();
// Helpers to compile this function. Returns true on success, false on
// failure (e.g., stack overflow during compilation).
static bool EnsureCompiled(Handle<JSFunction> function,
ClearExceptionFlag flag);
static bool CompileLazy(Handle<JSFunction> function,
ClearExceptionFlag flag);
static bool CompileOptimized(Handle<JSFunction> function,
BailoutId osr_ast_id,
ClearExceptionFlag flag);
// Tells whether or not the function is already marked for lazy
// recompilation.
inline bool IsMarkedForLazyRecompilation();
inline bool IsMarkedForParallelRecompilation();
// Tells whether or not the function is on the parallel
// recompilation queue.
inline bool IsInRecompileQueue();
// 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);
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.
void 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.
void 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
DECLARE_VERIFIER(JSFunction)
// Returns the number of allocated literals.
inline int NumberOfLiterals();
// Retrieve the native context from a function's literal array.
static Context* NativeContextFromLiterals(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 kLiteralNativeContextIndex = 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:
// [native_context]: the owner native context of this global proxy object.
// It is null value if this object is not used by any context.
DECL_ACCESSORS(native_context, Object)
// Casting.
static inline JSGlobalProxy* cast(Object* obj);
// Dispatched behavior.
#ifdef OBJECT_PRINT
inline void JSGlobalProxyPrint() {
JSGlobalProxyPrint(stdout);
}
void JSGlobalProxyPrint(FILE* out);
#endif
DECLARE_VERIFIER(JSGlobalProxy)
// Layout description.
static const int kNativeContextOffset = JSObject::kHeaderSize;
static const int kSize = kNativeContextOffset + 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)
// [native context]: the natives corresponding to this global object.
DECL_ACCESSORS(native_context, Context)
// [global context]: the most recent (i.e. innermost) global context.
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<JSGlobalPropertyCell> EnsurePropertyCell(
Handle<GlobalObject> global,
Handle<String> name);
// TODO(kmillikin): This function can be eliminated once the stub cache is
// fully 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 kNativeContextOffset = kBuiltinsOffset + kPointerSize;
static const int kGlobalContextOffset = kNativeContextOffset + 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
DECLARE_VERIFIER(JSGlobalObject)
// 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
DECLARE_VERIFIER(JSBuiltinsObject)
// 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
DECLARE_VERIFIER(JSValue)
// 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 Object* 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
DECLARE_VERIFIER(JSDate)
// 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
DECLARE_VERIFIER(JSMessageObject)
// 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<HeapObject::kMapOffset,
kStackFramesOffset + kPointerSize,
kSize> 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.
DECLARE_VERIFIER(JSRegExp)
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<HashTableKey*> {
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<CompilationCacheShape,
HashTableKey*> {
public:
// Find cached value for a string key, otherwise return null.
Object* Lookup(String* src, Context* context);
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,
Context* context,
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
DECLARE_VERIFIER(CodeCache)
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<HashTableKey*> {
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<CodeCacheHashTableShape,
HashTableKey*> {
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<PolymorphicCodeCache> cache,
MapHandleList* maps,
Code::Flags flags,
Handle<Code> code);
MUST_USE_RESULT MaybeObject* Update(MapHandleList* maps,
Code::Flags flags,
Code* code);
// Returns an undefined value if the entry is not found.
Handle<Object> 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
DECLARE_VERIFIER(PolymorphicCodeCache)
static const int kCacheOffset = HeapObject::kHeaderSize;
static const int kSize = kCacheOffset + kPointerSize;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache);
};
class PolymorphicCodeCacheHashTable
: public HashTable<CodeCacheHashTableShape, HashTableKey*> {
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 change_ic_with_type_info_count(int count);
inline void initialize_storage();
inline void change_own_type_change_checksum();
inline int own_type_change_checksum();
inline void set_inlined_type_change_checksum(int checksum);
inline bool matches_inlined_type_change_checksum(int checksum);
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
DECLARE_VERIFIER(TypeFeedbackInfo)
static const int kStorage1Offset = HeapObject::kHeaderSize;
static const int kStorage2Offset = kStorage1Offset + kPointerSize;
static const int kTypeFeedbackCellsOffset = kStorage2Offset + kPointerSize;
static const int kSize = kTypeFeedbackCellsOffset + kPointerSize;
private:
static const int kTypeChangeChecksumBits = 7;
class ICTotalCountField: public BitField<int, 0,
kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
class OwnTypeChangeChecksum: public BitField<int,
kSmiValueSize - kTypeChangeChecksumBits,
kTypeChangeChecksumBits> {}; // NOLINT
class ICsWithTypeInfoCountField: public BitField<int, 0,
kSmiValueSize - kTypeChangeChecksumBits> {}; // NOLINT
class InlinedTypeChangeChecksum: public BitField<int,
kSmiValueSize - kTypeChangeChecksumBits,
kTypeChangeChecksumBits> {}; // NOLINT
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
DECLARE_VERIFIER(AliasedArgumentsEntry)
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_; }
// 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();
// Reusable parts of the hashing algorithm.
INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint32_t c));
INLINE(static uint32_t GetHashCore(uint32_t running_hash));
int length_;
uint32_t raw_running_hash_;
uint32_t array_index_;
bool is_array_index_;
bool is_first_char_;
friend class TwoCharHashTableKey;
template <bool seq_ascii> friend class JsonParser;
};
class IncrementalAsciiStringHasher {
public:
explicit inline IncrementalAsciiStringHasher(uint32_t seed, char first_char);
inline void AddCharacter(uc32 c);
inline uint32_t GetHash();
private:
int length_;
uint32_t raw_running_hash_;
uint32_t array_index_;
bool is_array_index_;
char first_char_;
};
// Calculates string hash.
template <typename schar>
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<const char> ToAsciiVector() {
ASSERT_EQ(ASCII, state_);
return Vector<const char>::cast(buffer_);
}
// Return the two-byte content of the string. Only use if IsTwoByte()
// returns true.
Vector<const uc16> ToUC16Vector() {
ASSERT_EQ(TWO_BYTE, state_);
return Vector<const uc16>::cast(buffer_);
}
private:
enum State { NON_FLAT, ASCII, TWO_BYTE };
// Constructors only used by String::GetFlatContent().
explicit FlatContent(Vector<const char> chars)
: buffer_(Vector<const byte>::cast(chars)),
state_(ASCII) { }
explicit FlatContent(Vector<const uc16> chars)
: buffer_(Vector<const byte>::cast(chars)),
state_(TWO_BYTE) { }
FlatContent() : buffer_(), state_(NON_FLAT) { }
Vector<const byte> 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 IsOneByteRepresentation();
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 IsOneByteRepresentationUnderneath();
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<const char> str);
bool IsAsciiEqualTo(Vector<const char> str);
bool IsTwoByteEqualTo(Vector<const uc16> 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<char> ToCString(AllowNullsFlag allow_nulls,
RobustnessFlag robustness_flag,
int offset,
int length,
int* length_output = 0);
SmartArrayPointer<char> 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<uc16> 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
DECLARE_VERIFIER(String)
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 kEmptyStringHash = 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 <typename sinkchar>
static void WriteToFlat(String* source,
sinkchar* sink,
int from,
int to);
// The return value may point to the first aligned word containing the
// first non-ascii character, rather than directly to the non-ascii character.
// If the return value is >= the passed length, the entire string was ASCII.
static inline int NonAsciiStart(const char* chars, int length) {
const char* start = chars;
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 + sizeof(uintptr_t) <= limit) {
if (*reinterpret_cast<const uintptr_t*>(chars) & non_ascii_mask) {
return static_cast<int>(chars - start);
}
chars += sizeof(uintptr_t);
}
#endif
while (chars < limit) {
if (static_cast<uint8_t>(*chars) > kMaxAsciiCharCodeU) {
return static_cast<int>(chars - start);
}
++chars;
}
return static_cast<int>(chars - start);
}
static inline bool IsAscii(const char* chars, int length) {
return NonAsciiStart(chars, length) >= length;
}
static inline int NonAsciiStart(const uc16* chars, int length) {
const uc16* limit = chars + length;
const uc16* start = chars;
while (chars < limit) {
if (*chars > kMaxAsciiCharCodeU) return static_cast<int>(chars - start);
++chars;
}
return static_cast<int>(chars - start);
}
static inline bool IsAscii(const uc16* chars, int length) {
return NonAsciiStart(chars, length) >= length;
}
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 SeqOneByteString: public SeqString {
public:
static const bool kHasAsciiEncoding = true;
// Dispatched behavior.
inline uint16_t SeqOneByteStringGet(int index);
inline void SeqOneByteStringSet(int index, uint16_t value);
// Get the address of the characters in this string.
inline Address GetCharsAddress();
inline char* GetChars();
// Casting
static inline SeqOneByteString* 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 SeqOneByteStringSize(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 SeqOneByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer,
unsigned* offset,
unsigned chars);
inline const unibrow::byte* SeqOneByteStringReadBlock(unsigned* remaining,
unsigned* offset,
unsigned chars);
DECLARE_VERIFIER(SeqOneByteString)
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString);
};
// 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<kFirstOffset, kSecondOffset + kPointerSize, kSize>
BodyDescriptor;
DECLARE_VERIFIER(ConsString)
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,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
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<kParentOffset,
kOffsetOffset + kPointerSize, kSize>
BodyDescriptor;
DECLARE_VERIFIER(SlicedString)
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<typename StaticVisitor>
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<typename StaticVisitor>
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<String> str);
FlatStringReader(Isolate* isolate, Vector<const char> 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<String, String*, 1024> {
public:
virtual void Seek(unsigned pos);
inline StringInputBuffer(): unibrow::InputBuffer<String, String*, 1024>() {}
explicit inline StringInputBuffer(String* backing):
unibrow::InputBuffer<String, String*, 1024>(backing) {}
};
class SafeStringInputBuffer
: public unibrow::InputBuffer<String, String**, 256> {
public:
virtual void Seek(unsigned pos);
inline SafeStringInputBuffer()
: unibrow::InputBuffer<String, String**, 256>() {}
explicit inline SafeStringInputBuffer(String** backing)
: unibrow::InputBuffer<String, String**, 256>(backing) {}
};
template <typename T>
class VectorIterator {
public:
VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { }
explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { }
T GetNext() { return data_[index_++]; }
bool has_more() { return index_ < data_.length(); }
private:
Vector<const T> 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.
DECLARE_VERIFIER(Oddball)
// 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<kToStringOffset,
kToNumberOffset + kPointerSize,
kSize> BodyDescriptor;
STATIC_CHECK(kKindOffset == Internals::kOddballKindOffset);
STATIC_CHECK(kNull == Internals::kNullOddballKind);
STATIC_CHECK(kUndefined == Internals::kUndefinedOddballKind);
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);
static inline JSGlobalPropertyCell* FromValueAddress(Address value) {
return cast(FromAddress(value - kValueOffset));
}
inline Address ValueAddress() {
return address() + kValueOffset;
}
DECLARE_VERIFIER(JSGlobalPropertyCell)
#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<kValueOffset,
kValueOffset + kPointerSize,
kSize> 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(
JSReceiver* receiver,
String* name,
Object* value,
PropertyAttributes attributes,
StrictModeFlag strict_mode);
MUST_USE_RESULT MaybeObject* SetElementWithHandler(
JSReceiver* receiver,
uint32_t index,
Object* value,
StrictModeFlag strict_mode);
// If the handler defines an accessor property with a setter, invoke it.
// If it defines an accessor property without a setter, or a data property
// that is read-only, throw. In all these cases set '*done' to true,
// otherwise set it to false.
MUST_USE_RESULT MaybeObject* SetPropertyViaPrototypesWithHandler(
JSReceiver* receiver,
String* name,
Object* value,
PropertyAttributes attributes,
StrictModeFlag strict_mode,
bool* done);
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<Object> CallTrap(const char* name,
Handle<Object> derived_trap,
int argc,
Handle<Object> args[]);
// Dispatched behavior.
#ifdef OBJECT_PRINT
inline void JSProxyPrint() {
JSProxyPrint(stdout);
}
void JSProxyPrint(FILE* out);
#endif
DECLARE_VERIFIER(JSProxy)
// 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<kHandlerOffset,
kPaddingOffset,
kSize> 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
DECLARE_VERIFIER(JSFunctionProxy)
// 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<kHandlerOffset,
kConstructTrapOffset + kPointerSize,
kSize> 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
DECLARE_VERIFIER(JSSet)
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
DECLARE_VERIFIER(JSMap)
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
DECLARE_VERIFIER(JSWeakMap)
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<typename StaticVisitor>
inline void ForeignIterateBody();
#ifdef OBJECT_PRINT
inline void ForeignPrint() {
ForeignPrint(stdout);
}
void ForeignPrint(FILE* out);
#endif
DECLARE_VERIFIER(Foreign)
// Layout description.
static const int kForeignAddressOffset = HeapObject::kHeaderSize;
static const int kSize = kForeignAddressOffset + kPointerSize;
STATIC_CHECK(kForeignAddressOffset == Internals::kForeignAddressOffset);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
};
class PropertyIndex;
// 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();
// Can cause GC.
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
DECLARE_VERIFIER(JSArray)
// 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;
static inline PropertyIndex ArrayLengthIndex();
STATIC_ASSERT(kLengthOffset % kPointerSize == 0);
private:
// Expand the fixed array backing of a fast-case JSArray to at least
// the requested size.
void Expand(int minimum_size_of_backing_fixed_array);
DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray);
};
// JSRegExpResult is just a JSArray with a specific initial map.
// This initial map adds in-object properties for "index" and "input"
// properties, as assigned by RegExp.prototype.exec, which allows
// faster creation of RegExp exec results.
// This class just holds constants used when creating the result.
// After creation the result must be treated as a JSArray in all regards.
class JSRegExpResult: public JSArray {
public:
// Offsets of object fields.
static const int kIndexOffset = JSArray::kSize;
static const int kInputOffset = kIndexOffset + kPointerSize;
static const int kSize = kInputOffset + kPointerSize;
// Indices of in-object properties.
static const int kIndexIndex = 0;
static const int kInputIndex = 1;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult);
};
// An accessor must have a getter, but can have no setter.
//
// When setting a property, V8 searches accessors in prototypes.
// If an accessor was found and it does not have a setter,
// the request is ignored.
//
// If the accessor in the prototype has the READ_ONLY property attribute, then
// a new value is added to the local object when the property is set.
// This shadows the accessor in the prototype.
class AccessorInfo: public Struct {
public:
DECL_ACCESSORS(getter, Object)
DECL_ACCESSORS(setter, Object)
DECL_ACCESSORS(data, Object)
DECL_ACCESSORS(name, Object)
DECL_ACCESSORS(flag, Smi)
DECL_ACCESSORS(expected_receiver_type, Object)
inline bool all_can_read();
inline void set_all_can_read(bool value);
inline bool all_can_write();
inline void set_all_can_write(bool value);
inline bool prohibits_overwriting();
inline void set_prohibits_overwriting(bool value);
inline PropertyAttributes property_attributes();
inline void set_property_attributes(PropertyAttributes attributes);
// Checks whether the given receiver is compatible with this accessor.
inline bool IsCompatibleReceiver(Object* receiver);
static inline AccessorInfo* cast(Object* obj);
#ifdef OBJECT_PRINT
inline void AccessorInfoPrint() {
AccessorInfoPrint(stdout);
}
void AccessorInfoPrint(FILE* out);
#endif
DECLARE_VERIFIER(AccessorInfo)
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 kExpectedReceiverTypeOffset = kFlagOffset + kPointerSize;
static const int kSize = kExpectedReceiverTypeOffset + 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<PropertyAttributes, 3, 3> {};
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* Copy();
Object* get(AccessorComponent component) {
return component == ACCESSOR_GETTER ? getter() : setter();
}
void set(AccessorComponent component, Object* value) {
if (component == ACCESSOR_GETTER) {
set_getter(value);
} else {
set_setter(value);
}
}
// 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
DECLARE_VERIFIER(AccessorPair)
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
DECLARE_VERIFIER(AccessCheckInfo)
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
DECLARE_VERIFIER(InterceptorInfo)
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
DECLARE_VERIFIER(CallHandlerInfo)
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)
DECLARE_VERIFIER(TemplateInfo)
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
DECLARE_VERIFIER(FunctionTemplateInfo)
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
DECLARE_VERIFIER(ObjectTemplateInfo)
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
DECLARE_VERIFIER(SignatureInfo)
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
DECLARE_VERIFIER(TypeSwitchInfo)
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<DebugInfo> debug_info,
int code_position,
Handle<Object> break_point_object);
// Set a break point.
static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_position,
int source_position, int statement_position,
Handle<Object> 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<DebugInfo> debug_info,
Handle<Object> 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
DECLARE_VERIFIER(DebugInfo)
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<BreakPointInfo> info,
Handle<Object> break_point_object);
// Set a break point.
static void SetBreakPoint(Handle<BreakPointInfo> info,
Handle<Object> break_point_object);
// Check if break point info has this break point object.
static bool HasBreakPointObject(Handle<BreakPointInfo> info,
Handle<Object> 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
DECLARE_VERIFIER(BreakPointInfo)
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
#undef DECLARE_VERIFIER
#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);
// Visits the byte sequence in a function's prologue that contains information
// about the code's age.
virtual void VisitCodeAgeSequence(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);
// 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<HeapObject::kHeaderSize> {
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_
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