| /* |
| * Copyright (C) 1999-2002 Harri Porten (porten@kde.org) |
| * Copyright (C) 2001 Peter Kelly (pmk@post.com) |
| * Copyright (C) 2004-2019 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. |
| * |
| */ |
| |
| #include "config.h" |
| #include "JSString.h" |
| |
| #include "JSGlobalObject.h" |
| #include "JSGlobalObjectFunctions.h" |
| #include "JSObject.h" |
| #include "JSCInlines.h" |
| #include "StringObject.h" |
| #include "StringPrototype.h" |
| #include "StrongInlines.h" |
| |
| namespace JSC { |
| |
| const ClassInfo JSString::s_info = { "string", nullptr, nullptr, nullptr, CREATE_METHOD_TABLE(JSString) }; |
| |
| Structure* JSString::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue proto) |
| { |
| return Structure::create(vm, globalObject, proto, TypeInfo(StringType, StructureFlags), info()); |
| } |
| |
| JSString* JSString::createEmptyString(VM& vm) |
| { |
| JSString* newString = new (NotNull, allocateCell<JSString>(vm.heap)) JSString(vm, *StringImpl::empty()); |
| newString->finishCreation(vm); |
| return newString; |
| } |
| |
| template<> |
| void JSRopeString::RopeBuilder<RecordOverflow>::expand() |
| { |
| RELEASE_ASSERT(!this->hasOverflowed()); |
| ASSERT(m_strings.size() == JSRopeString::s_maxInternalRopeLength); |
| static_assert(3 == JSRopeString::s_maxInternalRopeLength, ""); |
| ASSERT(m_length); |
| ASSERT(asString(m_strings.at(0))->length()); |
| ASSERT(asString(m_strings.at(1))->length()); |
| ASSERT(asString(m_strings.at(2))->length()); |
| |
| JSString* string = JSRopeString::create(m_vm, asString(m_strings.at(0)), asString(m_strings.at(1)), asString(m_strings.at(2))); |
| ASSERT(string->length() == m_length); |
| m_strings.clear(); |
| m_strings.append(string); |
| } |
| |
| void JSString::destroy(JSCell* cell) |
| { |
| static_cast<JSString*>(cell)->JSString::~JSString(); |
| } |
| |
| void JSString::dumpToStream(const JSCell* cell, PrintStream& out) |
| { |
| VM& vm = cell->vm(); |
| const JSString* thisObject = jsCast<const JSString*>(cell); |
| out.printf("<%p, %s, [%u], ", thisObject, thisObject->className(vm), thisObject->length()); |
| uintptr_t pointer = thisObject->m_fiber; |
| if (pointer & isRopeInPointer) { |
| if (pointer & JSRopeString::isSubstringInPointer) |
| out.printf("[substring]"); |
| else |
| out.printf("[rope]"); |
| } else { |
| if (WTF::StringImpl* ourImpl = bitwise_cast<StringImpl*>(pointer)) { |
| if (ourImpl->is8Bit()) |
| out.printf("[8 %p]", ourImpl->characters8()); |
| else |
| out.printf("[16 %p]", ourImpl->characters16()); |
| } |
| } |
| out.printf(">"); |
| } |
| |
| bool JSString::equalSlowCase(ExecState* exec, JSString* other) const |
| { |
| VM& vm = exec->vm(); |
| auto scope = DECLARE_THROW_SCOPE(vm); |
| String str1 = value(exec); |
| RETURN_IF_EXCEPTION(scope, false); |
| String str2 = other->value(exec); |
| RETURN_IF_EXCEPTION(scope, false); |
| return WTF::equal(*str1.impl(), *str2.impl()); |
| } |
| |
| size_t JSString::estimatedSize(JSCell* cell, VM& vm) |
| { |
| JSString* thisObject = asString(cell); |
| uintptr_t pointer = thisObject->m_fiber; |
| if (pointer & isRopeInPointer) |
| return Base::estimatedSize(cell, vm); |
| return Base::estimatedSize(cell, vm) + bitwise_cast<StringImpl*>(pointer)->costDuringGC(); |
| } |
| |
| void JSString::visitChildren(JSCell* cell, SlotVisitor& visitor) |
| { |
| JSString* thisObject = asString(cell); |
| ASSERT_GC_OBJECT_INHERITS(thisObject, info()); |
| Base::visitChildren(thisObject, visitor); |
| |
| uintptr_t pointer = thisObject->m_fiber; |
| if (pointer & isRopeInPointer) { |
| if (pointer & JSRopeString::isSubstringInPointer) { |
| visitor.appendUnbarriered(static_cast<JSRopeString*>(thisObject)->fiber1()); |
| return; |
| } |
| for (unsigned index = 0; index < JSRopeString::s_maxInternalRopeLength; ++index) { |
| JSString* fiber = nullptr; |
| switch (index) { |
| case 0: |
| fiber = bitwise_cast<JSString*>(pointer & JSRopeString::stringMask); |
| break; |
| case 1: |
| fiber = static_cast<JSRopeString*>(thisObject)->fiber1(); |
| break; |
| case 2: |
| fiber = static_cast<JSRopeString*>(thisObject)->fiber2(); |
| break; |
| default: |
| ASSERT_NOT_REACHED(); |
| return; |
| } |
| if (!fiber) |
| break; |
| visitor.appendUnbarriered(fiber); |
| } |
| return; |
| } |
| if (StringImpl* impl = bitwise_cast<StringImpl*>(pointer)) |
| visitor.reportExtraMemoryVisited(impl->costDuringGC()); |
| } |
| |
| static constexpr unsigned maxLengthForOnStackResolve = 2048; |
| |
| void JSRopeString::resolveRopeInternal8(LChar* buffer) const |
| { |
| if (isSubstring()) { |
| StringImpl::copyCharacters(buffer, substringBase()->valueInternal().characters8() + substringOffset(), length()); |
| return; |
| } |
| |
| resolveRopeInternal8NoSubstring(buffer); |
| } |
| |
| void JSRopeString::resolveRopeInternal8NoSubstring(LChar* buffer) const |
| { |
| for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { |
| if (fiber(i)->isRope()) { |
| resolveRopeSlowCase8(buffer); |
| return; |
| } |
| } |
| |
| LChar* position = buffer; |
| for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { |
| const StringImpl& fiberString = *fiber(i)->valueInternal().impl(); |
| unsigned length = fiberString.length(); |
| StringImpl::copyCharacters(position, fiberString.characters8(), length); |
| position += length; |
| } |
| ASSERT((buffer + length()) == position); |
| } |
| |
| void JSRopeString::resolveRopeInternal16(UChar* buffer) const |
| { |
| if (isSubstring()) { |
| StringImpl::copyCharacters( |
| buffer, substringBase()->valueInternal().characters16() + substringOffset(), length()); |
| return; |
| } |
| |
| resolveRopeInternal16NoSubstring(buffer); |
| } |
| |
| void JSRopeString::resolveRopeInternal16NoSubstring(UChar* buffer) const |
| { |
| for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { |
| if (fiber(i)->isRope()) { |
| resolveRopeSlowCase(buffer); |
| return; |
| } |
| } |
| |
| UChar* position = buffer; |
| for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { |
| const StringImpl& fiberString = *fiber(i)->valueInternal().impl(); |
| unsigned length = fiberString.length(); |
| if (fiberString.is8Bit()) |
| StringImpl::copyCharacters(position, fiberString.characters8(), length); |
| else |
| StringImpl::copyCharacters(position, fiberString.characters16(), length); |
| position += length; |
| } |
| ASSERT((buffer + length()) == position); |
| } |
| |
| AtomString JSRopeString::resolveRopeToAtomString(ExecState* exec) const |
| { |
| VM& vm = exec->vm(); |
| auto scope = DECLARE_THROW_SCOPE(vm); |
| |
| if (length() > maxLengthForOnStackResolve) { |
| scope.release(); |
| return resolveRopeWithFunction(exec, [&] (Ref<StringImpl>&& newImpl) { |
| return AtomStringImpl::add(newImpl.ptr()); |
| }); |
| } |
| |
| if (is8Bit()) { |
| LChar buffer[maxLengthForOnStackResolve]; |
| resolveRopeInternal8(buffer); |
| convertToNonRope(AtomStringImpl::add(buffer, length())); |
| } else { |
| UChar buffer[maxLengthForOnStackResolve]; |
| resolveRopeInternal16(buffer); |
| convertToNonRope(AtomStringImpl::add(buffer, length())); |
| } |
| |
| // If we resolved a string that didn't previously exist, notify the heap that we've grown. |
| if (valueInternal().impl()->hasOneRef()) |
| vm.heap.reportExtraMemoryAllocated(valueInternal().impl()->cost()); |
| return valueInternal(); |
| } |
| |
| inline void JSRopeString::convertToNonRope(String&& string) const |
| { |
| // Concurrent compiler threads can access String held by JSString. So we always emit |
| // store-store barrier here to ensure concurrent compiler threads see initialized String. |
| ASSERT(JSString::isRope()); |
| WTF::storeStoreFence(); |
| new (&uninitializedValueInternal()) String(WTFMove(string)); |
| static_assert(sizeof(String) == sizeof(RefPtr<StringImpl>), "JSString's String initialization must be done in one pointer move."); |
| // We do not clear the trailing fibers and length information (fiber1 and fiber2) because we could be reading the length concurrently. |
| ASSERT(!JSString::isRope()); |
| } |
| |
| RefPtr<AtomStringImpl> JSRopeString::resolveRopeToExistingAtomString(ExecState* exec) const |
| { |
| VM& vm = exec->vm(); |
| auto scope = DECLARE_THROW_SCOPE(vm); |
| |
| if (length() > maxLengthForOnStackResolve) { |
| RefPtr<AtomStringImpl> existingAtomString; |
| resolveRopeWithFunction(exec, [&] (Ref<StringImpl>&& newImpl) -> Ref<StringImpl> { |
| existingAtomString = AtomStringImpl::lookUp(newImpl.ptr()); |
| if (existingAtomString) |
| return makeRef(*existingAtomString); |
| return WTFMove(newImpl); |
| }); |
| RETURN_IF_EXCEPTION(scope, nullptr); |
| return existingAtomString; |
| } |
| |
| if (is8Bit()) { |
| LChar buffer[maxLengthForOnStackResolve]; |
| resolveRopeInternal8(buffer); |
| if (RefPtr<AtomStringImpl> existingAtomString = AtomStringImpl::lookUp(buffer, length())) { |
| convertToNonRope(*existingAtomString); |
| return existingAtomString; |
| } |
| } else { |
| UChar buffer[maxLengthForOnStackResolve]; |
| resolveRopeInternal16(buffer); |
| if (RefPtr<AtomStringImpl> existingAtomString = AtomStringImpl::lookUp(buffer, length())) { |
| convertToNonRope(*existingAtomString); |
| return existingAtomString; |
| } |
| } |
| |
| return nullptr; |
| } |
| |
| template<typename Function> |
| const String& JSRopeString::resolveRopeWithFunction(ExecState* nullOrExecForOOM, Function&& function) const |
| { |
| ASSERT(isRope()); |
| |
| VM& vm = this->vm(); |
| if (isSubstring()) { |
| ASSERT(!substringBase()->isRope()); |
| auto newImpl = substringBase()->valueInternal().substringSharingImpl(substringOffset(), length()); |
| convertToNonRope(function(newImpl.releaseImpl().releaseNonNull())); |
| return valueInternal(); |
| } |
| |
| if (is8Bit()) { |
| LChar* buffer; |
| auto newImpl = StringImpl::tryCreateUninitialized(length(), buffer); |
| if (!newImpl) { |
| outOfMemory(nullOrExecForOOM); |
| return nullString(); |
| } |
| vm.heap.reportExtraMemoryAllocated(newImpl->cost()); |
| |
| resolveRopeInternal8NoSubstring(buffer); |
| convertToNonRope(function(newImpl.releaseNonNull())); |
| return valueInternal(); |
| } |
| |
| UChar* buffer; |
| auto newImpl = StringImpl::tryCreateUninitialized(length(), buffer); |
| if (!newImpl) { |
| outOfMemory(nullOrExecForOOM); |
| return nullString(); |
| } |
| vm.heap.reportExtraMemoryAllocated(newImpl->cost()); |
| |
| resolveRopeInternal16NoSubstring(buffer); |
| convertToNonRope(function(newImpl.releaseNonNull())); |
| return valueInternal(); |
| } |
| |
| const String& JSRopeString::resolveRope(ExecState* nullOrExecForOOM) const |
| { |
| return resolveRopeWithFunction(nullOrExecForOOM, [] (Ref<StringImpl>&& newImpl) { |
| return WTFMove(newImpl); |
| }); |
| } |
| |
| // Overview: These functions convert a JSString from holding a string in rope form |
| // down to a simple String representation. It does so by building up the string |
| // backwards, since we want to avoid recursion, we expect that the tree structure |
| // representing the rope is likely imbalanced with more nodes down the left side |
| // (since appending to the string is likely more common) - and as such resolving |
| // in this fashion should minimize work queue size. (If we built the queue forwards |
| // we would likely have to place all of the constituent StringImpls into the |
| // Vector before performing any concatenation, but by working backwards we likely |
| // only fill the queue with the number of substrings at any given level in a |
| // rope-of-ropes.) |
| void JSRopeString::resolveRopeSlowCase8(LChar* buffer) const |
| { |
| LChar* position = buffer + length(); // We will be working backwards over the rope. |
| Vector<JSString*, 32, UnsafeVectorOverflow> workQueue; // Putting strings into a Vector is only OK because there are no GC points in this method. |
| |
| for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) |
| workQueue.append(fiber(i)); |
| |
| while (!workQueue.isEmpty()) { |
| JSString* currentFiber = workQueue.last(); |
| workQueue.removeLast(); |
| |
| const LChar* characters; |
| |
| if (currentFiber->isRope()) { |
| JSRopeString* currentFiberAsRope = static_cast<JSRopeString*>(currentFiber); |
| if (!currentFiberAsRope->isSubstring()) { |
| for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->fiber(i); ++i) |
| workQueue.append(currentFiberAsRope->fiber(i)); |
| continue; |
| } |
| ASSERT(!currentFiberAsRope->substringBase()->isRope()); |
| characters = |
| currentFiberAsRope->substringBase()->valueInternal().characters8() + |
| currentFiberAsRope->substringOffset(); |
| } else |
| characters = currentFiber->valueInternal().characters8(); |
| |
| unsigned length = currentFiber->length(); |
| position -= length; |
| StringImpl::copyCharacters(position, characters, length); |
| } |
| |
| ASSERT(buffer == position); |
| } |
| |
| void JSRopeString::resolveRopeSlowCase(UChar* buffer) const |
| { |
| UChar* position = buffer + length(); // We will be working backwards over the rope. |
| Vector<JSString*, 32, UnsafeVectorOverflow> workQueue; // These strings are kept alive by the parent rope, so using a Vector is OK. |
| |
| for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) |
| workQueue.append(fiber(i)); |
| |
| while (!workQueue.isEmpty()) { |
| JSString* currentFiber = workQueue.last(); |
| workQueue.removeLast(); |
| |
| if (currentFiber->isRope()) { |
| JSRopeString* currentFiberAsRope = static_cast<JSRopeString*>(currentFiber); |
| if (currentFiberAsRope->isSubstring()) { |
| ASSERT(!currentFiberAsRope->substringBase()->isRope()); |
| StringImpl* string = static_cast<StringImpl*>( |
| currentFiberAsRope->substringBase()->valueInternal().impl()); |
| unsigned offset = currentFiberAsRope->substringOffset(); |
| unsigned length = currentFiberAsRope->length(); |
| position -= length; |
| if (string->is8Bit()) |
| StringImpl::copyCharacters(position, string->characters8() + offset, length); |
| else |
| StringImpl::copyCharacters(position, string->characters16() + offset, length); |
| continue; |
| } |
| for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->fiber(i); ++i) |
| workQueue.append(currentFiberAsRope->fiber(i)); |
| continue; |
| } |
| |
| StringImpl* string = static_cast<StringImpl*>(currentFiber->valueInternal().impl()); |
| unsigned length = string->length(); |
| position -= length; |
| if (string->is8Bit()) |
| StringImpl::copyCharacters(position, string->characters8(), length); |
| else |
| StringImpl::copyCharacters(position, string->characters16(), length); |
| } |
| |
| ASSERT(buffer == position); |
| } |
| |
| void JSRopeString::outOfMemory(ExecState* nullOrExecForOOM) const |
| { |
| ASSERT(isRope()); |
| if (nullOrExecForOOM) { |
| VM& vm = nullOrExecForOOM->vm(); |
| auto scope = DECLARE_THROW_SCOPE(vm); |
| throwOutOfMemoryError(nullOrExecForOOM, scope); |
| } |
| } |
| |
| JSValue JSString::toPrimitive(ExecState*, PreferredPrimitiveType) const |
| { |
| return const_cast<JSString*>(this); |
| } |
| |
| bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result) const |
| { |
| VM& vm = exec->vm(); |
| auto scope = DECLARE_THROW_SCOPE(vm); |
| StringView view = unsafeView(exec); |
| RETURN_IF_EXCEPTION(scope, false); |
| result = this; |
| number = jsToNumber(view); |
| return false; |
| } |
| |
| double JSString::toNumber(ExecState* exec) const |
| { |
| VM& vm = exec->vm(); |
| auto scope = DECLARE_THROW_SCOPE(vm); |
| StringView view = unsafeView(exec); |
| RETURN_IF_EXCEPTION(scope, 0); |
| return jsToNumber(view); |
| } |
| |
| inline StringObject* StringObject::create(VM& vm, JSGlobalObject* globalObject, JSString* string) |
| { |
| StringObject* object = new (NotNull, allocateCell<StringObject>(vm.heap)) StringObject(vm, globalObject->stringObjectStructure()); |
| object->finishCreation(vm, string); |
| return object; |
| } |
| |
| JSObject* JSString::toObject(ExecState* exec, JSGlobalObject* globalObject) const |
| { |
| return StringObject::create(exec->vm(), globalObject, const_cast<JSString*>(this)); |
| } |
| |
| JSValue JSString::toThis(JSCell* cell, ExecState* exec, ECMAMode ecmaMode) |
| { |
| if (ecmaMode == StrictMode) |
| return cell; |
| return StringObject::create(exec->vm(), exec->lexicalGlobalObject(), asString(cell)); |
| } |
| |
| bool JSString::getStringPropertyDescriptor(ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor) |
| { |
| VM& vm = exec->vm(); |
| if (propertyName == vm.propertyNames->length) { |
| descriptor.setDescriptor(jsNumber(length()), PropertyAttribute::DontEnum | PropertyAttribute::DontDelete | PropertyAttribute::ReadOnly); |
| return true; |
| } |
| |
| Optional<uint32_t> index = parseIndex(propertyName); |
| if (index && index.value() < length()) { |
| descriptor.setDescriptor(getIndex(exec, index.value()), PropertyAttribute::DontDelete | PropertyAttribute::ReadOnly); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| JSString* jsStringWithCacheSlowCase(VM& vm, StringImpl& stringImpl) |
| { |
| if (JSString* string = vm.stringCache.get(&stringImpl)) |
| return string; |
| |
| JSString* string = jsString(vm, String(stringImpl)); |
| vm.lastCachedString.set(vm, string); |
| return string; |
| } |
| |
| } // namespace JSC |
