2 * Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
3 * Copyright (C) 2001 Peter Kelly (pmk@post.com)
4 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public License
17 * along with this library; see the file COPYING.LIB. If not, write to
18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
25 #include "CallFrame.h"
26 #include "CommonIdentifiers.h"
27 #include "Identifier.h"
28 #include "PropertyDescriptor.h"
29 #include "PropertySlot.h"
30 #include "Structure.h"
36 JSString* jsEmptyString(JSGlobalData*);
37 JSString* jsEmptyString(ExecState*);
38 JSString* jsString(JSGlobalData*, const UString&); // returns empty string if passed null string
39 JSString* jsString(ExecState*, const UString&); // returns empty string if passed null string
41 JSString* jsSingleCharacterString(JSGlobalData*, UChar);
42 JSString* jsSingleCharacterString(ExecState*, UChar);
43 JSString* jsSingleCharacterSubstring(ExecState*, const UString&, unsigned offset);
44 JSString* jsSubstring(JSGlobalData*, const UString&, unsigned offset, unsigned length);
45 JSString* jsSubstring(ExecState*, const UString&, unsigned offset, unsigned length);
47 // Non-trivial strings are two or more characters long.
48 // These functions are faster than just calling jsString.
49 JSString* jsNontrivialString(JSGlobalData*, const UString&);
50 JSString* jsNontrivialString(ExecState*, const UString&);
51 JSString* jsNontrivialString(JSGlobalData*, const char*);
52 JSString* jsNontrivialString(ExecState*, const char*);
54 // Should be used for strings that are owned by an object that will
55 // likely outlive the JSValue this makes, such as the parse tree or a
56 // DOM object that contains a UString
57 JSString* jsOwnedString(JSGlobalData*, const UString&);
58 JSString* jsOwnedString(ExecState*, const UString&);
60 JSString* jsStringBuilder(JSGlobalData*);
62 class JS_EXPORTCLASS JSString : public JSCell {
65 friend class JSGlobalData;
66 friend class SpecializedThunkJIT;
67 friend struct ThunkHelpers;
68 friend JSString* jsStringBuilder(JSGlobalData*);
74 RopeBuilder(JSGlobalData& globalData)
75 : m_globalData(globalData)
76 , m_jsString(jsStringBuilder(&globalData))
81 void append(JSString* jsString)
83 if (m_index == JSString::s_maxInternalRopeLength)
85 m_jsString->m_fibers[m_index++].set(m_globalData, m_jsString, jsString);
86 m_jsString->m_length += jsString->m_length;
87 m_jsString->m_is8Bit = m_jsString->m_is8Bit && jsString->m_is8Bit;
92 JSString* tmp = m_jsString;
97 unsigned length() { return m_jsString->m_length; }
102 JSGlobalData& m_globalData;
103 JSString* m_jsString;
108 JSString(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
109 : JSCell(globalData, globalData.stringStructure.get())
114 JSString(JSGlobalData& globalData)
115 : JSCell(globalData, globalData.stringStructure.get())
119 void finishCreation(JSGlobalData& globalData)
121 Base::finishCreation(globalData);
126 void finishCreation(JSGlobalData& globalData, size_t length)
128 ASSERT(!m_value.isNull());
129 Base::finishCreation(globalData);
131 m_is8Bit = m_value.impl()->is8Bit();
134 void finishCreation(JSGlobalData& globalData, size_t length, size_t cost)
136 ASSERT(!m_value.isNull());
137 Base::finishCreation(globalData);
139 m_is8Bit = m_value.impl()->is8Bit();
140 Heap::heap(this)->reportExtraMemoryCost(cost);
143 void finishCreation(JSGlobalData& globalData, JSString* s1, JSString* s2)
145 Base::finishCreation(globalData);
146 m_length = s1->length() + s2->length();
147 m_is8Bit = (s1->is8Bit() && s2->is8Bit());
148 m_fibers[0].set(globalData, this, s1);
149 m_fibers[1].set(globalData, this, s2);
152 void finishCreation(JSGlobalData& globalData, JSString* s1, JSString* s2, JSString* s3)
154 Base::finishCreation(globalData);
155 m_length = s1->length() + s2->length() + s3->length();
156 m_is8Bit = (s1->is8Bit() && s2->is8Bit() && s3->is8Bit());
157 m_fibers[0].set(globalData, this, s1);
158 m_fibers[1].set(globalData, this, s2);
159 m_fibers[2].set(globalData, this, s3);
162 static JSString* createNull(JSGlobalData& globalData)
164 JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData);
165 newString->finishCreation(globalData);
170 static JSString* create(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
173 size_t length = value->length();
174 size_t cost = value->cost();
175 JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData, value);
176 newString->finishCreation(globalData, length, cost);
179 static JSString* create(JSGlobalData& globalData, JSString* s1, JSString* s2)
181 JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData);
182 newString->finishCreation(globalData, s1, s2);
185 static JSString* create(JSGlobalData& globalData, JSString* s1, JSString* s2, JSString* s3)
187 JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData);
188 newString->finishCreation(globalData, s1, s2, s3);
191 static JSString* createHasOtherOwner(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
194 size_t length = value->length();
195 JSString* newString = new (allocateCell<JSString>(globalData.heap)) JSString(globalData, value);
196 newString->finishCreation(globalData, length);
202 const UString& value(ExecState* exec) const
208 const UString& tryGetValue() const
214 unsigned length() { return m_length; }
216 JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
217 bool toBoolean(ExecState*) const;
218 bool getPrimitiveNumber(ExecState*, double& number, JSValue&) const;
219 JSObject* toObject(ExecState*, JSGlobalObject*) const;
220 UString toString(ExecState*) const;
221 double toNumber(ExecState*) const;
223 bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
224 bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
225 bool getStringPropertyDescriptor(ExecState*, const Identifier& propertyName, PropertyDescriptor&);
227 bool canGetIndex(unsigned i) { return i < m_length; }
228 JSString* getIndex(ExecState*, unsigned);
229 JSString* getIndexSlowCase(ExecState*, unsigned);
231 JSValue replaceCharacter(ExecState*, UChar, const UString& replacement);
233 static Structure* createStructure(JSGlobalData& globalData, JSGlobalObject* globalObject, JSValue proto)
235 return Structure::create(globalData, globalObject, proto, TypeInfo(StringType, OverridesGetOwnPropertySlot), &s_info);
238 static size_t offsetOfLength() { return OBJECT_OFFSETOF(JSString, m_length); }
239 static size_t offsetOfValue() { return OBJECT_OFFSETOF(JSString, m_value); }
241 static const ClassInfo s_info;
243 static void visitChildren(JSCell*, SlotVisitor&);
246 JSString(VPtrStealingHackType)
247 : JSCell(VPtrStealingHack)
251 void resolveRope(ExecState*) const;
252 void resolveRopeSlowCase8(LChar*) const;
253 void resolveRopeSlowCase(UChar*) const;
254 void outOfMemory(ExecState*) const;
256 static JSObject* toThisObject(JSCell*, ExecState*);
258 // Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
259 static bool getOwnPropertySlot(JSCell*, ExecState*, const Identifier& propertyName, PropertySlot&);
260 static bool getOwnPropertySlotByIndex(JSCell*, ExecState*, unsigned propertyName, PropertySlot&);
262 static const unsigned s_maxInternalRopeLength = 3;
264 // A string is represented either by a UString or a rope of fibers.
267 mutable UString m_value;
268 mutable FixedArray<WriteBarrier<JSString>, s_maxInternalRopeLength> m_fibers;
270 bool isRope() const { return m_value.isNull(); }
271 bool is8Bit() const { return m_is8Bit; }
272 UString& string() { ASSERT(!isRope()); return m_value; }
274 friend JSValue jsString(ExecState*, JSString*, JSString*);
275 friend JSValue jsString(ExecState*, Register*, unsigned count);
276 friend JSValue jsStringFromArguments(ExecState*, JSValue thisValue);
277 friend JSString* jsSubstring(ExecState*, JSString*, unsigned offset, unsigned length);
280 JSString* asString(JSValue);
282 // When an object is created from a different DLL, MSVC changes vptr to a "local" one right after invoking a constructor,
283 // see <http://groups.google.com/group/microsoft.public.vc.language/msg/55cdcefeaf770212>.
284 // This breaks isJSString(), and we don't need that hack anyway, so we change vptr back to primary one.
285 // The below function must be called by any inline function that invokes a JSString constructor.
286 #if COMPILER(MSVC) && !defined(BUILDING_JavaScriptCore)
287 inline JSString* fixupVPtr(JSGlobalData* globalData, JSString* string) { string->setVPtr(globalData->jsStringVPtr); return string; }
289 inline JSString* fixupVPtr(JSGlobalData*, JSString* string) { return string; }
292 inline JSString* asString(JSValue value)
294 ASSERT(value.asCell()->isString());
295 return static_cast<JSString*>(value.asCell());
298 inline JSString* jsEmptyString(JSGlobalData* globalData)
300 return globalData->smallStrings.emptyString(globalData);
303 inline JSString* jsSingleCharacterString(JSGlobalData* globalData, UChar c)
305 if (c <= maxSingleCharacterString)
306 return globalData->smallStrings.singleCharacterString(globalData, c);
307 return fixupVPtr(globalData, JSString::create(*globalData, UString(&c, 1).impl()));
310 inline JSString* jsSingleCharacterSubstring(ExecState* exec, const UString& s, unsigned offset)
312 JSGlobalData* globalData = &exec->globalData();
313 ASSERT(offset < static_cast<unsigned>(s.length()));
315 if (c <= maxSingleCharacterString)
316 return globalData->smallStrings.singleCharacterString(globalData, c);
317 return fixupVPtr(globalData, JSString::create(*globalData, StringImpl::create(s.impl(), offset, 1)));
320 inline JSString* jsNontrivialString(JSGlobalData* globalData, const char* s)
325 return fixupVPtr(globalData, JSString::create(*globalData, UString(s).impl()));
328 inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
330 ASSERT(s.length() > 1);
331 return fixupVPtr(globalData, JSString::create(*globalData, s.impl()));
334 inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
336 ASSERT(canGetIndex(i));
338 return getIndexSlowCase(exec, i);
339 ASSERT(i < m_value.length());
340 return jsSingleCharacterSubstring(exec, m_value, i);
343 inline JSString* jsString(JSGlobalData* globalData, const UString& s)
345 int size = s.length();
347 return globalData->smallStrings.emptyString(globalData);
350 if (c <= maxSingleCharacterString)
351 return globalData->smallStrings.singleCharacterString(globalData, c);
353 return fixupVPtr(globalData, JSString::create(*globalData, s.impl()));
356 inline JSString* jsSubstring(ExecState* exec, JSString* s, unsigned offset, unsigned length)
358 ASSERT(offset <= static_cast<unsigned>(s->length()));
359 ASSERT(length <= static_cast<unsigned>(s->length()));
360 ASSERT(offset + length <= static_cast<unsigned>(s->length()));
361 JSGlobalData* globalData = &exec->globalData();
363 return globalData->smallStrings.emptyString(globalData);
364 return jsSubstring(globalData, s->value(exec), offset, length);
367 inline JSString* jsSubstring8(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
369 ASSERT(offset <= static_cast<unsigned>(s.length()));
370 ASSERT(length <= static_cast<unsigned>(s.length()));
371 ASSERT(offset + length <= static_cast<unsigned>(s.length()));
373 return globalData->smallStrings.emptyString(globalData);
376 if (c <= maxSingleCharacterString)
377 return globalData->smallStrings.singleCharacterString(globalData, c);
379 return fixupVPtr(globalData, JSString::createHasOtherOwner(*globalData, StringImpl::create8(s.impl(), offset, length)));
382 inline JSString* jsSubstring(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
384 ASSERT(offset <= static_cast<unsigned>(s.length()));
385 ASSERT(length <= static_cast<unsigned>(s.length()));
386 ASSERT(offset + length <= static_cast<unsigned>(s.length()));
388 return globalData->smallStrings.emptyString(globalData);
391 if (c <= maxSingleCharacterString)
392 return globalData->smallStrings.singleCharacterString(globalData, c);
394 return fixupVPtr(globalData, JSString::createHasOtherOwner(*globalData, StringImpl::create(s.impl(), offset, length)));
397 inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
399 int size = s.length();
401 return globalData->smallStrings.emptyString(globalData);
404 if (c <= maxSingleCharacterString)
405 return globalData->smallStrings.singleCharacterString(globalData, c);
407 return fixupVPtr(globalData, JSString::createHasOtherOwner(*globalData, s.impl()));
410 inline JSString* jsStringBuilder(JSGlobalData* globalData)
412 return fixupVPtr(globalData, JSString::createNull(*globalData));
415 inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->globalData()); }
416 inline JSString* jsString(ExecState* exec, const UString& s) { return jsString(&exec->globalData(), s); }
417 inline JSString* jsSingleCharacterString(ExecState* exec, UChar c) { return jsSingleCharacterString(&exec->globalData(), c); }
418 inline JSString* jsSubstring8(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring8(&exec->globalData(), s, offset, length); }
419 inline JSString* jsSubstring(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring(&exec->globalData(), s, offset, length); }
420 inline JSString* jsNontrivialString(ExecState* exec, const UString& s) { return jsNontrivialString(&exec->globalData(), s); }
421 inline JSString* jsNontrivialString(ExecState* exec, const char* s) { return jsNontrivialString(&exec->globalData(), s); }
422 inline JSString* jsOwnedString(ExecState* exec, const UString& s) { return jsOwnedString(&exec->globalData(), s); }
424 ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
426 if (propertyName == exec->propertyNames().length) {
427 slot.setValue(jsNumber(m_length));
432 unsigned i = propertyName.toUInt32(isStrictUInt32);
433 if (isStrictUInt32 && i < m_length) {
434 slot.setValue(getIndex(exec, i));
441 ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
443 if (propertyName < m_length) {
444 slot.setValue(getIndex(exec, propertyName));
451 inline bool isJSString(JSGlobalData* globalData, JSValue v) { return v.isCell() && v.asCell()->vptr() == globalData->jsStringVPtr; }
453 inline bool JSCell::toBoolean(ExecState* exec) const
456 return static_cast<const JSString*>(this)->toBoolean(exec);
457 return !structure()->typeInfo().masqueradesAsUndefined();
460 // --- JSValue inlines ----------------------------
462 inline bool JSValue::toBoolean(ExecState* exec) const
467 return asDouble() > 0.0 || asDouble() < 0.0; // false for NaN
469 return asCell()->toBoolean(exec);
470 return isTrue(); // false, null, and undefined all convert to false.
473 inline UString JSValue::toString(ExecState* exec) const
476 return static_cast<JSString*>(asCell())->value(exec);
478 return exec->globalData().numericStrings.add(asInt32());
480 return exec->globalData().numericStrings.add(asDouble());
490 return asCell()->toString(exec);