+++ /dev/null
-/*
- * Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
- * Copyright (C) 2001 Peter Kelly (pmk@post.com)
- * Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009 Apple Inc. All rights reserved.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public License
- * along with this library; see the file COPYING.LIB. If not, write to
- * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA 02110-1301, USA.
- *
- */
-
-#ifndef JSValue_h
-#define JSValue_h
-
-#include <math.h>
-#include <stddef.h> // for size_t
-#include <stdint.h>
-#include <wtf/AlwaysInline.h>
-#include <wtf/Assertions.h>
-#include <wtf/HashMap.h>
-#include <wtf/HashTraits.h>
-#include <wtf/MathExtras.h>
-#include <wtf/StdLibExtras.h>
-
-namespace JSC {
-
- class ExecState;
- class Identifier;
- class JSCell;
- class JSGlobalData;
- class JSGlobalObject;
- class JSObject;
- class JSString;
- class PropertySlot;
- class PutPropertySlot;
- class UString;
-#if ENABLE(DFG_JIT)
- namespace DFG {
- class AssemblyHelpers;
- class JITCompiler;
- class JITCodeGenerator;
- class JSValueSource;
- class OSRExitCompiler;
- class SpeculativeJIT;
- }
-#endif
- namespace LLInt {
- class Data;
- }
-
- struct ClassInfo;
- struct Instruction;
- struct MethodTable;
-
- template <class T> class WriteBarrierBase;
-
- enum PreferredPrimitiveType { NoPreference, PreferNumber, PreferString };
-
-
-#if USE(JSVALUE32_64)
- typedef int64_t EncodedJSValue;
-#else
- typedef void* EncodedJSValue;
-#endif
-
- union EncodedValueDescriptor {
- int64_t asInt64;
-#if USE(JSVALUE32_64)
- double asDouble;
-#elif USE(JSVALUE64)
- JSCell* ptr;
-#endif
-
-#if CPU(BIG_ENDIAN)
- struct {
- int32_t tag;
- int32_t payload;
- } asBits;
-#else
- struct {
- int32_t payload;
- int32_t tag;
- } asBits;
-#endif
- };
-
- // This implements ToInt32, defined in ECMA-262 9.5.
- JS_EXPORT_PRIVATE int32_t toInt32(double);
-
- // This implements ToUInt32, defined in ECMA-262 9.6.
- inline uint32_t toUInt32(double number)
- {
- // As commented in the spec, the operation of ToInt32 and ToUint32 only differ
- // in how the result is interpreted; see NOTEs in sections 9.5 and 9.6.
- return toInt32(number);
- }
-
- class JSValue {
- friend struct EncodedJSValueHashTraits;
- friend class JIT;
- friend class JITStubs;
- friend class JITStubCall;
- friend class JSInterfaceJIT;
- friend class SpecializedThunkJIT;
-#if ENABLE(DFG_JIT)
- friend class DFG::AssemblyHelpers;
- friend class DFG::JITCompiler;
- friend class DFG::JITCodeGenerator;
- friend class DFG::JSValueSource;
- friend class DFG::OSRExitCompiler;
- friend class DFG::SpeculativeJIT;
-#endif
- friend class LLInt::Data;
-
- public:
- static EncodedJSValue encode(JSValue);
- static JSValue decode(EncodedJSValue);
-
- enum JSNullTag { JSNull };
- enum JSUndefinedTag { JSUndefined };
- enum JSTrueTag { JSTrue };
- enum JSFalseTag { JSFalse };
- enum EncodeAsDoubleTag { EncodeAsDouble };
-
- JSValue();
- JSValue(JSNullTag);
- JSValue(JSUndefinedTag);
- JSValue(JSTrueTag);
- JSValue(JSFalseTag);
- JSValue(JSCell* ptr);
- JSValue(const JSCell* ptr);
-
- // Numbers
- JSValue(EncodeAsDoubleTag, double);
- explicit JSValue(double);
- explicit JSValue(char);
- explicit JSValue(unsigned char);
- explicit JSValue(short);
- explicit JSValue(unsigned short);
- explicit JSValue(int);
- explicit JSValue(unsigned);
- explicit JSValue(long);
- explicit JSValue(unsigned long);
- explicit JSValue(long long);
- explicit JSValue(unsigned long long);
-
- operator bool() const;
- bool operator==(const JSValue& other) const;
- bool operator!=(const JSValue& other) const;
-
- bool isInt32() const;
- bool isUInt32() const;
- bool isDouble() const;
- bool isTrue() const;
- bool isFalse() const;
-
- int32_t asInt32() const;
- uint32_t asUInt32() const;
- double asDouble() const;
- bool asBoolean() const;
- double asNumber() const;
-
- // Querying the type.
- bool isEmpty() const;
- bool isFunction() const;
- bool isUndefined() const;
- bool isNull() const;
- bool isUndefinedOrNull() const;
- bool isBoolean() const;
- bool isNumber() const;
- bool isString() const;
- bool isPrimitive() const;
- bool isGetterSetter() const;
- bool isObject() const;
- bool inherits(const ClassInfo*) const;
-
- // Extracting the value.
- bool getString(ExecState* exec, UString&) const;
- UString getString(ExecState* exec) const; // null string if not a string
- JSObject* getObject() const; // 0 if not an object
-
- // Extracting integer values.
- bool getUInt32(uint32_t&) const;
-
- // Basic conversions.
- JSValue toPrimitive(ExecState*, PreferredPrimitiveType = NoPreference) const;
- bool getPrimitiveNumber(ExecState*, double& number, JSValue&);
-
- bool toBoolean(ExecState*) const;
-
- // toNumber conversion is expected to be side effect free if an exception has
- // been set in the ExecState already.
- double toNumber(ExecState*) const;
- JSString* toString(ExecState*) const;
- UString toUString(ExecState*) const;
- UString toUStringInline(ExecState*) const;
- JSObject* toObject(ExecState*) const;
- JSObject* toObject(ExecState*, JSGlobalObject*) const;
-
- // Integer conversions.
- JS_EXPORT_PRIVATE double toInteger(ExecState*) const;
- double toIntegerPreserveNaN(ExecState*) const;
- int32_t toInt32(ExecState*) const;
- uint32_t toUInt32(ExecState*) const;
-
- // Floating point conversions (this is a convenience method for webcore;
- // signle precision float is not a representation used in JS or JSC).
- float toFloat(ExecState* exec) const { return static_cast<float>(toNumber(exec)); }
-
- // Object operations, with the toObject operation included.
- JSValue get(ExecState*, const Identifier& propertyName) const;
- JSValue get(ExecState*, const Identifier& propertyName, PropertySlot&) const;
- JSValue get(ExecState*, unsigned propertyName) const;
- JSValue get(ExecState*, unsigned propertyName, PropertySlot&) const;
- void put(ExecState*, const Identifier& propertyName, JSValue, PutPropertySlot&);
- void putToPrimitive(ExecState*, const Identifier& propertyName, JSValue, PutPropertySlot&);
- void putByIndex(ExecState*, unsigned propertyName, JSValue, bool shouldThrow);
-
- JSObject* toThisObject(ExecState*) const;
-
- static bool equal(ExecState* exec, JSValue v1, JSValue v2);
- static bool equalSlowCase(ExecState* exec, JSValue v1, JSValue v2);
- static bool equalSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2);
- static bool strictEqual(ExecState* exec, JSValue v1, JSValue v2);
- static bool strictEqualSlowCase(ExecState* exec, JSValue v1, JSValue v2);
- static bool strictEqualSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2);
-
- bool isCell() const;
- JSCell* asCell() const;
- JS_EXPORT_PRIVATE bool isValidCallee();
-
- char* description();
-
- JS_EXPORT_PRIVATE JSObject* synthesizePrototype(ExecState*) const;
-
- private:
- template <class T> JSValue(WriteBarrierBase<T>);
-
- enum HashTableDeletedValueTag { HashTableDeletedValue };
- JSValue(HashTableDeletedValueTag);
-
- inline const JSValue asValue() const { return *this; }
- JS_EXPORT_PRIVATE double toNumberSlowCase(ExecState*) const;
- JS_EXPORT_PRIVATE JSString* toStringSlowCase(ExecState*) const;
- JS_EXPORT_PRIVATE UString toUStringSlowCase(ExecState*) const;
- JS_EXPORT_PRIVATE JSObject* toObjectSlowCase(ExecState*, JSGlobalObject*) const;
- JS_EXPORT_PRIVATE JSObject* toThisObjectSlowCase(ExecState*) const;
-
-#if USE(JSVALUE32_64)
- /*
- * On 32-bit platforms USE(JSVALUE32_64) should be defined, and we use a NaN-encoded
- * form for immediates.
- *
- * The encoding makes use of unused NaN space in the IEEE754 representation. Any value
- * with the top 13 bits set represents a QNaN (with the sign bit set). QNaN values
- * can encode a 51-bit payload. Hardware produced and C-library payloads typically
- * have a payload of zero. We assume that non-zero payloads are available to encode
- * pointer and integer values. Since any 64-bit bit pattern where the top 15 bits are
- * all set represents a NaN with a non-zero payload, we can use this space in the NaN
- * ranges to encode other values (however there are also other ranges of NaN space that
- * could have been selected).
- *
- * For JSValues that do not contain a double value, the high 32 bits contain the tag
- * values listed in the enums below, which all correspond to NaN-space. In the case of
- * cell, integer and bool values the lower 32 bits (the 'payload') contain the pointer
- * integer or boolean value; in the case of all other tags the payload is 0.
- */
- enum { Int32Tag = 0xffffffff };
- enum { BooleanTag = 0xfffffffe };
- enum { NullTag = 0xfffffffd };
- enum { UndefinedTag = 0xfffffffc };
- enum { CellTag = 0xfffffffb };
- enum { EmptyValueTag = 0xfffffffa };
- enum { DeletedValueTag = 0xfffffff9 };
-
- enum { LowestTag = DeletedValueTag };
-
- uint32_t tag() const;
- int32_t payload() const;
-#elif USE(JSVALUE64)
- /*
- * On 64-bit platforms USE(JSVALUE64) should be defined, and we use a NaN-encoded
- * form for immediates.
- *
- * The encoding makes use of unused NaN space in the IEEE754 representation. Any value
- * with the top 13 bits set represents a QNaN (with the sign bit set). QNaN values
- * can encode a 51-bit payload. Hardware produced and C-library payloads typically
- * have a payload of zero. We assume that non-zero payloads are available to encode
- * pointer and integer values. Since any 64-bit bit pattern where the top 15 bits are
- * all set represents a NaN with a non-zero payload, we can use this space in the NaN
- * ranges to encode other values (however there are also other ranges of NaN space that
- * could have been selected).
- *
- * This range of NaN space is represented by 64-bit numbers begining with the 16-bit
- * hex patterns 0xFFFE and 0xFFFF - we rely on the fact that no valid double-precision
- * numbers will begin fall in these ranges.
- *
- * The top 16-bits denote the type of the encoded JSValue:
- *
- * Pointer { 0000:PPPP:PPPP:PPPP
- * / 0001:****:****:****
- * Double { ...
- * \ FFFE:****:****:****
- * Integer { FFFF:0000:IIII:IIII
- *
- * The scheme we have implemented encodes double precision values by performing a
- * 64-bit integer addition of the value 2^48 to the number. After this manipulation
- * no encoded double-precision value will begin with the pattern 0x0000 or 0xFFFF.
- * Values must be decoded by reversing this operation before subsequent floating point
- * operations my be peformed.
- *
- * 32-bit signed integers are marked with the 16-bit tag 0xFFFF.
- *
- * The tag 0x0000 denotes a pointer, or another form of tagged immediate. Boolean,
- * null and undefined values are represented by specific, invalid pointer values:
- *
- * False: 0x06
- * True: 0x07
- * Undefined: 0x0a
- * Null: 0x02
- *
- * These values have the following properties:
- * - Bit 1 (TagBitTypeOther) is set for all four values, allowing real pointers to be
- * quickly distinguished from all immediate values, including these invalid pointers.
- * - With bit 3 is masked out (TagBitUndefined) Undefined and Null share the
- * same value, allowing null & undefined to be quickly detected.
- *
- * No valid JSValue will have the bit pattern 0x0, this is used to represent array
- * holes, and as a C++ 'no value' result (e.g. JSValue() has an internal value of 0).
- */
-
- // These values are #defines since using static const integers here is a ~1% regression!
-
- // This value is 2^48, used to encode doubles such that the encoded value will begin
- // with a 16-bit pattern within the range 0x0001..0xFFFE.
- #define DoubleEncodeOffset 0x1000000000000ll
- // If all bits in the mask are set, this indicates an integer number,
- // if any but not all are set this value is a double precision number.
- #define TagTypeNumber 0xffff000000000000ll
-
- // All non-numeric (bool, null, undefined) immediates have bit 2 set.
- #define TagBitTypeOther 0x2ll
- #define TagBitBool 0x4ll
- #define TagBitUndefined 0x8ll
- // Combined integer value for non-numeric immediates.
- #define ValueFalse (TagBitTypeOther | TagBitBool | false)
- #define ValueTrue (TagBitTypeOther | TagBitBool | true)
- #define ValueUndefined (TagBitTypeOther | TagBitUndefined)
- #define ValueNull (TagBitTypeOther)
-
- // TagMask is used to check for all types of immediate values (either number or 'other').
- #define TagMask (TagTypeNumber | TagBitTypeOther)
-
- // These special values are never visible to JavaScript code; Empty is used to represent
- // Array holes, and for uninitialized JSValues. Deleted is used in hash table code.
- // These values would map to cell types in the JSValue encoding, but not valid GC cell
- // pointer should have either of these values (Empty is null, deleted is at an invalid
- // alignment for a GC cell, and in the zero page).
- #define ValueEmpty 0x0ll
- #define ValueDeleted 0x4ll
-#endif
-
- EncodedValueDescriptor u;
- };
-
-#if USE(JSVALUE32_64)
- typedef IntHash<EncodedJSValue> EncodedJSValueHash;
-
- struct EncodedJSValueHashTraits : HashTraits<EncodedJSValue> {
- static const bool emptyValueIsZero = false;
- static EncodedJSValue emptyValue() { return JSValue::encode(JSValue()); }
- static void constructDeletedValue(EncodedJSValue& slot) { slot = JSValue::encode(JSValue(JSValue::HashTableDeletedValue)); }
- static bool isDeletedValue(EncodedJSValue value) { return value == JSValue::encode(JSValue(JSValue::HashTableDeletedValue)); }
- };
-#else
- typedef PtrHash<EncodedJSValue> EncodedJSValueHash;
-
- struct EncodedJSValueHashTraits : HashTraits<EncodedJSValue> {
- static void constructDeletedValue(EncodedJSValue& slot) { slot = JSValue::encode(JSValue(JSValue::HashTableDeletedValue)); }
- static bool isDeletedValue(EncodedJSValue value) { return value == JSValue::encode(JSValue(JSValue::HashTableDeletedValue)); }
- };
-#endif
-
- typedef HashMap<EncodedJSValue, unsigned, EncodedJSValueHash, EncodedJSValueHashTraits> JSValueMap;
-
- // Stand-alone helper functions.
- inline JSValue jsNull()
- {
- return JSValue(JSValue::JSNull);
- }
-
- inline JSValue jsUndefined()
- {
- return JSValue(JSValue::JSUndefined);
- }
-
- inline JSValue jsBoolean(bool b)
- {
- return b ? JSValue(JSValue::JSTrue) : JSValue(JSValue::JSFalse);
- }
-
- ALWAYS_INLINE JSValue jsDoubleNumber(double d)
- {
- ASSERT(JSValue(JSValue::EncodeAsDouble, d).isNumber());
- return JSValue(JSValue::EncodeAsDouble, d);
- }
-
- ALWAYS_INLINE JSValue jsNumber(double d)
- {
- ASSERT(JSValue(d).isNumber());
- return JSValue(d);
- }
-
- ALWAYS_INLINE JSValue jsNumber(char i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(unsigned char i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(short i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(unsigned short i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(int i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(unsigned i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(long i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(unsigned long i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(long long i)
- {
- return JSValue(i);
- }
-
- ALWAYS_INLINE JSValue jsNumber(unsigned long long i)
- {
- return JSValue(i);
- }
-
- inline bool operator==(const JSValue a, const JSCell* b) { return a == JSValue(b); }
- inline bool operator==(const JSCell* a, const JSValue b) { return JSValue(a) == b; }
-
- inline bool operator!=(const JSValue a, const JSCell* b) { return a != JSValue(b); }
- inline bool operator!=(const JSCell* a, const JSValue b) { return JSValue(a) != b; }
-
-} // namespace JSC
-
-#endif // JSValue_h
projects / apple / javascriptcore.git / blobdiff