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/*
* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 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 JSString_h
#define JSString_h
#include "CallFrame.h"
#include "CommonIdentifiers.h"
#include "Identifier.h"
#include "PropertyDescriptor.h"
#include "PropertySlot.h"
#include "Structure.h"
namespace JSC {
class JSString;
JSString* jsEmptyString(JSGlobalData*);
JSString* jsEmptyString(ExecState*);
JSString* jsString(JSGlobalData*, const UString&); // returns empty string if passed null string
JSString* jsString(ExecState*, const UString&); // returns empty string if passed null string
JSString* jsSingleCharacterString(JSGlobalData*, UChar);
JSString* jsSingleCharacterString(ExecState*, UChar);
JSString* jsSingleCharacterSubstring(ExecState*, const UString&, unsigned offset);
JSString* jsSubstring(JSGlobalData*, const UString&, unsigned offset, unsigned length);
JSString* jsSubstring(ExecState*, const UString&, unsigned offset, unsigned length);
// Non-trivial strings are two or more characters long.
// These functions are faster than just calling jsString.
JSString* jsNontrivialString(JSGlobalData*, const UString&);
JSString* jsNontrivialString(ExecState*, const UString&);
JSString* jsNontrivialString(JSGlobalData*, const char*);
JSString* jsNontrivialString(ExecState*, const char*);
// Should be used for strings that are owned by an object that will
// likely outlive the JSValue this makes, such as the parse tree or a
// DOM object that contains a UString
JSString* jsOwnedString(JSGlobalData*, const UString&);
JSString* jsOwnedString(ExecState*, const UString&);
JSString* jsStringBuilder(JSGlobalData*);
class JS_EXPORTCLASS JSString : public JSCell {
public:
friend class JIT;
friend class JSGlobalData;
friend class SpecializedThunkJIT;
friend struct ThunkHelpers;
friend JSString* jsStringBuilder(JSGlobalData*);
typedef JSCell Base;
class RopeBuilder {
public:
RopeBuilder(JSGlobalData& globalData)
: m_globalData(globalData)
, m_jsString(jsStringBuilder(&globalData))
, m_index(0)
{
}
void append(JSString* jsString)
{
if (m_index == JSString::s_maxInternalRopeLength)
expand();
m_jsString->m_fibers[m_index++].set(m_globalData, m_jsString, jsString);
m_jsString->m_length += jsString->m_length;
m_jsString->m_is8Bit = m_jsString->m_is8Bit && jsString->m_is8Bit;
}
JSString* release()
{
JSString* tmp = m_jsString;
m_jsString = 0;
return tmp;
}
unsigned length() { return m_jsString->m_length; }
private:
void expand();
JSGlobalData& m_globalData;
JSString* m_jsString;
size_t m_index;
};
private:
JSString(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
: JSCell(globalData, globalData.stringStructure.get())
, m_value(value)
{
}
JSString(JSGlobalData& globalData)
: JSCell(globalData, globalData.stringStructure.get())
{
}
void finishCreation(JSGlobalData& globalData)
{
Base::finishCreation(globalData);
m_length = 0;
m_is8Bit = true;
}
void finishCreation(JSGlobalData& globalData, size_t length)
{
ASSERT(!m_value.isNull());
Base::finishCreation(globalData);
m_length = length;
m_is8Bit = m_value.impl()->is8Bit();
}
void finishCreation(JSGlobalData& globalData, size_t length, size_t cost)
{
ASSERT(!m_value.isNull());
Base::finishCreation(globalData);
m_length = length;
m_is8Bit = m_value.impl()->is8Bit();
Heap::heap(this)->reportExtraMemoryCost(cost);
}
void finishCreation(JSGlobalData& globalData, JSString* s1, JSString* s2)
{
Base::finishCreation(globalData);
m_length = s1->length() + s2->length();
m_is8Bit = (s1->is8Bit() && s2->is8Bit());
m_fibers[0].set(globalData, this, s1);
m_fibers[1].set(globalData, this, s2);
}
void finishCreation(JSGlobalData& globalData, JSString* s1, JSString* s2, JSString* s3)
{
Base::finishCreation(globalData);
m_length = s1->length() + s2->length() + s3->length();
m_is8Bit = (s1->is8Bit() && s2->is8Bit() && s3->is8Bit());
m_fibers[0].set(globalData, this, s1);
m_fibers[1].set(globalData, this, s2);
m_fibers[2].set(globalData, this, s3);
}
static JSString* createNull(JSGlobalData& globalData)
{
JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData);
newString->finishCreation(globalData);
return newString;
}
public:
static JSString* create(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
{
ASSERT(value);
size_t length = value->length();
size_t cost = value->cost();
JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData, value);
newString->finishCreation(globalData, length, cost);
return newString;
}
static JSString* create(JSGlobalData& globalData, JSString* s1, JSString* s2)
{
JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData);
newString->finishCreation(globalData, s1, s2);
return newString;
}
static JSString* create(JSGlobalData& globalData, JSString* s1, JSString* s2, JSString* s3)
{
JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData);
newString->finishCreation(globalData, s1, s2, s3);
return newString;
}
static JSString* createHasOtherOwner(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
{
ASSERT(value);
size_t length = value->length();
JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData, value);
newString->finishCreation(globalData, length);
return newString;
}
virtual ~JSString();
const UString& value(ExecState* exec) const
{
if (isRope())
resolveRope(exec);
return m_value;
}
const UString& tryGetValue() const
{
if (isRope())
resolveRope(0);
return m_value;
}
unsigned length() { return m_length; }
JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
bool toBoolean(ExecState*) const;
bool getPrimitiveNumber(ExecState*, double& number, JSValue&) const;
JSObject* toObject(ExecState*, JSGlobalObject*) const;
UString toString(ExecState*) const;
double toNumber(ExecState*) const;
bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
bool getStringPropertyDescriptor(ExecState*, const Identifier& propertyName, PropertyDescriptor&);
bool canGetIndex(unsigned i) { return i < m_length; }
JSString* getIndex(ExecState*, unsigned);
JSString* getIndexSlowCase(ExecState*, unsigned);
JSValue replaceCharacter(ExecState*, UChar, const UString& replacement);
static Structure* createStructure(JSGlobalData& globalData, JSGlobalObject* globalObject, JSValue proto)
{
return Structure::create(globalData, globalObject, proto, TypeInfo(StringType, OverridesGetOwnPropertySlot), &s_info);
}
static size_t offsetOfLength() { return OBJECT_OFFSETOF(JSString, m_length); }
static size_t offsetOfValue() { return OBJECT_OFFSETOF(JSString, m_value); }
static const ClassInfo s_info;
static void visitChildren(JSCell*, SlotVisitor&);
private:
JSString(VPtrStealingHackType)
: JSCell(VPtrStealingHack)
{
}
void resolveRope(ExecState*) const;
void resolveRopeSlowCase8(LChar*) const;
void resolveRopeSlowCase(UChar*) const;
void outOfMemory(ExecState*) const;
static JSObject* toThisObject(JSCell*, ExecState*);
// Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
static bool getOwnPropertySlot(JSCell*, ExecState*, const Identifier& propertyName, PropertySlot&);
static bool getOwnPropertySlotByIndex(JSCell*, ExecState*, unsigned propertyName, PropertySlot&);
static const unsigned s_maxInternalRopeLength = 3;
// A string is represented either by a UString or a rope of fibers.
bool m_is8Bit : 1;
unsigned m_length;
mutable UString m_value;
mutable FixedArray<WriteBarrier<JSString>, s_maxInternalRopeLength> m_fibers;
bool isRope() const { return m_value.isNull(); }
bool is8Bit() const { return m_is8Bit; }
UString& string() { ASSERT(!isRope()); return m_value; }
friend JSValue jsString(ExecState*, JSString*, JSString*);
friend JSValue jsString(ExecState*, Register*, unsigned count);
friend JSValue jsStringFromArguments(ExecState*, JSValue thisValue);
friend JSString* jsSubstring(ExecState*, JSString*, unsigned offset, unsigned length);
};
JSString* asString(JSValue);
// When an object is created from a different DLL, MSVC changes vptr to a "local" one right after invoking a constructor,
// see <http://groups.google.com/group/microsoft.public.vc.language/msg/55cdcefeaf770212>.
// This breaks isJSString(), and we don't need that hack anyway, so we change vptr back to primary one.
// The below function must be called by any inline function that invokes a JSString constructor.
#if COMPILER(MSVC) && !defined(BUILDING_JavaScriptCore)
inline JSString* fixupVPtr(JSGlobalData* globalData, JSString* string) { string->setVPtr(globalData->jsStringVPtr); return string; }
#else
inline JSString* fixupVPtr(JSGlobalData*, JSString* string) { return string; }
#endif
inline JSString* asString(JSValue value)
{
ASSERT(value.asCell()->isString());
return static_cast<JSString*>(value.asCell());
}
inline JSString* jsEmptyString(JSGlobalData* globalData)
{
return globalData->smallStrings.emptyString(globalData);
}
inline JSString* jsSingleCharacterString(JSGlobalData* globalData, UChar c)
{
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
return fixupVPtr(globalData, JSString::create(*globalData, UString(&c, 1).impl()));
}
inline JSString* jsSingleCharacterSubstring(ExecState* exec, const UString& s, unsigned offset)
{
JSGlobalData* globalData = &exec->globalData();
ASSERT(offset < static_cast<unsigned>(s.length()));
UChar c = s[offset];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
return fixupVPtr(globalData, JSString::create(*globalData, StringImpl::create(s.impl(), offset, 1)));
}
inline JSString* jsNontrivialString(JSGlobalData* globalData, const char* s)
{
ASSERT(s);
ASSERT(s[0]);
ASSERT(s[1]);
return fixupVPtr(globalData, JSString::create(*globalData, UString(s).impl()));
}
inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
{
ASSERT(s.length() > 1);
return fixupVPtr(globalData, JSString::create(*globalData, s.impl()));
}
inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
{
ASSERT(canGetIndex(i));
if (isRope())
return getIndexSlowCase(exec, i);
ASSERT(i < m_value.length());
return jsSingleCharacterSubstring(exec, m_value, i);
}
inline JSString* jsString(JSGlobalData* globalData, const UString& s)
{
int size = s.length();
if (!size)
return globalData->smallStrings.emptyString(globalData);
if (size == 1) {
UChar c = s[0];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
return fixupVPtr(globalData, JSString::create(*globalData, s.impl()));
}
inline JSString* jsSubstring(ExecState* exec, JSString* s, unsigned offset, unsigned length)
{
ASSERT(offset <= static_cast<unsigned>(s->length()));
ASSERT(length <= static_cast<unsigned>(s->length()));
ASSERT(offset + length <= static_cast<unsigned>(s->length()));
JSGlobalData* globalData = &exec->globalData();
if (!length)
return globalData->smallStrings.emptyString(globalData);
return jsSubstring(globalData, s->value(exec), offset, length);
}
inline JSString* jsSubstring8(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
{
ASSERT(offset <= static_cast<unsigned>(s.length()));
ASSERT(length <= static_cast<unsigned>(s.length()));
ASSERT(offset + length <= static_cast<unsigned>(s.length()));
if (!length)
return globalData->smallStrings.emptyString(globalData);
if (length == 1) {
UChar c = s[offset];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
return fixupVPtr(globalData, JSString::createHasOtherOwner(*globalData, StringImpl::create8(s.impl(), offset, length)));
}
inline JSString* jsSubstring(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
{
ASSERT(offset <= static_cast<unsigned>(s.length()));
ASSERT(length <= static_cast<unsigned>(s.length()));
ASSERT(offset + length <= static_cast<unsigned>(s.length()));
if (!length)
return globalData->smallStrings.emptyString(globalData);
if (length == 1) {
UChar c = s[offset];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
return fixupVPtr(globalData, JSString::createHasOtherOwner(*globalData, StringImpl::create(s.impl(), offset, length)));
}
inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
{
int size = s.length();
if (!size)
return globalData->smallStrings.emptyString(globalData);
if (size == 1) {
UChar c = s[0];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
return fixupVPtr(globalData, JSString::createHasOtherOwner(*globalData, s.impl()));
}
inline JSString* jsStringBuilder(JSGlobalData* globalData)
{
return fixupVPtr(globalData, JSString::createNull(*globalData));
}
inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->globalData()); }
inline JSString* jsString(ExecState* exec, const UString& s) { return jsString(&exec->globalData(), s); }
inline JSString* jsSingleCharacterString(ExecState* exec, UChar c) { return jsSingleCharacterString(&exec->globalData(), c); }
inline JSString* jsSubstring8(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring8(&exec->globalData(), s, offset, length); }
inline JSString* jsSubstring(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring(&exec->globalData(), s, offset, length); }
inline JSString* jsNontrivialString(ExecState* exec, const UString& s) { return jsNontrivialString(&exec->globalData(), s); }
inline JSString* jsNontrivialString(ExecState* exec, const char* s) { return jsNontrivialString(&exec->globalData(), s); }
inline JSString* jsOwnedString(ExecState* exec, const UString& s) { return jsOwnedString(&exec->globalData(), s); }
ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
if (propertyName == exec->propertyNames().length) {
slot.setValue(jsNumber(m_length));
return true;
}
bool isStrictUInt32;
unsigned i = propertyName.toUInt32(isStrictUInt32);
if (isStrictUInt32 && i < m_length) {
slot.setValue(getIndex(exec, i));
return true;
}
return false;
}
ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
{
if (propertyName < m_length) {
slot.setValue(getIndex(exec, propertyName));
return true;
}
return false;
}
inline bool isJSString(JSGlobalData* globalData, JSValue v) { return v.isCell() && v.asCell()->vptr() == globalData->jsStringVPtr; }
inline bool JSCell::toBoolean(ExecState* exec) const
{
if (isString())
return static_cast<const JSString*>(this)->toBoolean(exec);
return !structure()->typeInfo().masqueradesAsUndefined();
}
// --- JSValue inlines ----------------------------
inline bool JSValue::toBoolean(ExecState* exec) const
{
if (isInt32())
return asInt32();
if (isDouble())
return asDouble() > 0.0 || asDouble() < 0.0; // false for NaN
if (isCell())
return asCell()->toBoolean(exec);
return isTrue(); // false, null, and undefined all convert to false.
}
inline UString JSValue::toString(ExecState* exec) const
{
if (isString())
return static_cast<JSString*>(asCell())->value(exec);
if (isInt32())
return exec->globalData().numericStrings.add(asInt32());
if (isDouble())
return exec->globalData().numericStrings.add(asDouble());
if (isTrue())
return "true";
if (isFalse())
return "false";
if (isNull())
return "null";
if (isUndefined())
return "undefined";
ASSERT(isCell());
return asCell()->toString(exec);
}
} // namespace JSC
#endif // JSString_h