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Diffstat (limited to 'Source/JavaScriptCore/runtime/Identifier.cpp')
| -rw-r--r-- | Source/JavaScriptCore/runtime/Identifier.cpp | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/runtime/Identifier.cpp b/Source/JavaScriptCore/runtime/Identifier.cpp new file mode 100644 index 000000000..0d233e355 --- /dev/null +++ b/Source/JavaScriptCore/runtime/Identifier.cpp @@ -0,0 +1,288 @@ +/* + * 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. + * + */ + +#include "config.h" +#include "Identifier.h" + +#include "CallFrame.h" +#include "JSObject.h" +#include "NumericStrings.h" +#include "ScopeChain.h" +#include <new> // for placement new +#include <string.h> // for strlen +#include <wtf/Assertions.h> +#include <wtf/FastMalloc.h> +#include <wtf/HashSet.h> +#include <wtf/text/StringHash.h> + +using WTF::ThreadSpecific; + +namespace JSC { + +IdentifierTable::~IdentifierTable() +{ + HashSet<StringImpl*>::iterator end = m_table.end(); + for (HashSet<StringImpl*>::iterator iter = m_table.begin(); iter != end; ++iter) + (*iter)->setIsIdentifier(false); +} + +std::pair<HashSet<StringImpl*>::iterator, bool> IdentifierTable::add(StringImpl* value) +{ + std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add(value); + (*result.first)->setIsIdentifier(true); + return result; +} + +IdentifierTable* createIdentifierTable() +{ + return new IdentifierTable; +} + +void deleteIdentifierTable(IdentifierTable* table) +{ + delete table; +} + +struct IdentifierCStringTranslator { + static unsigned hash(const LChar* c) + { + return StringHasher::computeHash<LChar>(c); + } + + static bool equal(StringImpl* r, const LChar* s) + { + return Identifier::equal(r, s); + } + + static void translate(StringImpl*& location, const LChar* c, unsigned hash) + { + size_t length = strlen(reinterpret_cast<const char*>(c)); + LChar* d; + StringImpl* r = StringImpl::createUninitialized(length, d).leakRef(); + for (size_t i = 0; i != length; i++) + d[i] = c[i]; + r->setHash(hash); + location = r; + } +}; + +struct IdentifierLCharFromUCharTranslator { + static unsigned hash(const CharBuffer<UChar>& buf) + { + return StringHasher::computeHash<UChar>(buf.s, buf.length); + } + + static bool equal(StringImpl* str, const CharBuffer<UChar>& buf) + { + return Identifier::equal(str, buf.s, buf.length); + } + + static void translate(StringImpl*& location, const CharBuffer<UChar>& buf, unsigned hash) + { + LChar* d; + StringImpl* r = StringImpl::createUninitialized(buf.length, d).leakRef(); + for (unsigned i = 0; i != buf.length; i++) { + UChar c = buf.s[i]; + ASSERT(c <= 0xff); + d[i] = c; + } + r->setHash(hash); + location = r; + } +}; + +PassRefPtr<StringImpl> Identifier::add(JSGlobalData* globalData, const char* c) +{ + if (!c) + return 0; + if (!c[0]) + return StringImpl::empty(); + if (!c[1]) + return add(globalData, globalData->smallStrings.singleCharacterStringRep(c[0])); + + IdentifierTable& identifierTable = *globalData->identifierTable; + LiteralIdentifierTable& literalIdentifierTable = identifierTable.literalTable(); + + const LiteralIdentifierTable::iterator& iter = literalIdentifierTable.find(c); + if (iter != literalIdentifierTable.end()) + return iter->second; + + pair<HashSet<StringImpl*>::iterator, bool> addResult = identifierTable.add<const LChar*, IdentifierCStringTranslator>(reinterpret_cast<const LChar*>(c)); + + // If the string is newly-translated, then we need to adopt it. + // The boolean in the pair tells us if that is so. + RefPtr<StringImpl> addedString = addResult.second ? adoptRef(*addResult.first) : *addResult.first; + + literalIdentifierTable.add(c, addedString.get()); + + return addedString.release(); +} + +PassRefPtr<StringImpl> Identifier::add(ExecState* exec, const char* c) +{ + return add(&exec->globalData(), c); +} + +PassRefPtr<StringImpl> Identifier::add8(JSGlobalData* globalData, const UChar* s, int length) +{ + if (length == 1) { + UChar c = s[0]; + ASSERT(c <= 0xff); + if (canUseSingleCharacterString(c)) + return add(globalData, globalData->smallStrings.singleCharacterStringRep(c)); + } + + if (!length) + return StringImpl::empty(); + CharBuffer<UChar> buf = {s, length}; + pair<HashSet<StringImpl*>::iterator, bool> addResult = globalData->identifierTable->add<CharBuffer<UChar>, IdentifierLCharFromUCharTranslator >(buf); + + // If the string is newly-translated, then we need to adopt it. + // The boolean in the pair tells us if that is so. + return addResult.second ? adoptRef(*addResult.first) : *addResult.first; +} + +template <typename CharType> +ALWAYS_INLINE uint32_t Identifier::toUInt32FromCharacters(const CharType* characters, unsigned length, bool& ok) +{ + // Get the first character, turning it into a digit. + uint32_t value = characters[0] - '0'; + if (value > 9) + return 0; + + // Check for leading zeros. If the first characher is 0, then the + // length of the string must be one - e.g. "042" is not equal to "42". + if (!value && length > 1) + return 0; + + while (--length) { + // Multiply value by 10, checking for overflow out of 32 bits. + if (value > 0xFFFFFFFFU / 10) + return 0; + value *= 10; + + // Get the next character, turning it into a digit. + uint32_t newValue = *(++characters) - '0'; + if (newValue > 9) + return 0; + + // Add in the old value, checking for overflow out of 32 bits. + newValue += value; + if (newValue < value) + return 0; + value = newValue; + } + + ok = true; + return value; +} + +uint32_t Identifier::toUInt32(const UString& string, bool& ok) +{ + ok = false; + + unsigned length = string.length(); + + // An empty string is not a number. + if (!length) + return 0; + + if (string.is8Bit()) + return toUInt32FromCharacters(string.characters8(), length, ok); + return toUInt32FromCharacters(string.characters16(), length, ok); +} + +PassRefPtr<StringImpl> Identifier::addSlowCase(JSGlobalData* globalData, StringImpl* r) +{ + ASSERT(!r->isIdentifier()); + // The empty & null strings are static singletons, and static strings are handled + // in ::add() in the header, so we should never get here with a zero length string. + ASSERT(r->length()); + + if (r->length() == 1) { + UChar c = (*r)[0]; + if (c <= maxSingleCharacterString) + r = globalData->smallStrings.singleCharacterStringRep(c); + if (r->isIdentifier()) + return r; + } + + return *globalData->identifierTable->add(r).first; +} + +PassRefPtr<StringImpl> Identifier::addSlowCase(ExecState* exec, StringImpl* r) +{ + return addSlowCase(&exec->globalData(), r); +} + +Identifier Identifier::from(ExecState* exec, unsigned value) +{ + return Identifier(exec, exec->globalData().numericStrings.add(value)); +} + +Identifier Identifier::from(ExecState* exec, int value) +{ + return Identifier(exec, exec->globalData().numericStrings.add(value)); +} + +Identifier Identifier::from(ExecState* exec, double value) +{ + return Identifier(exec, exec->globalData().numericStrings.add(value)); +} + +Identifier Identifier::from(JSGlobalData* globalData, unsigned value) +{ + return Identifier(globalData, globalData->numericStrings.add(value)); +} + +Identifier Identifier::from(JSGlobalData* globalData, int value) +{ + return Identifier(globalData, globalData->numericStrings.add(value)); +} + +Identifier Identifier::from(JSGlobalData* globalData, double value) +{ + return Identifier(globalData, globalData->numericStrings.add(value)); +} + +#ifndef NDEBUG + +void Identifier::checkCurrentIdentifierTable(JSGlobalData* globalData) +{ + // Check the identifier table accessible through the threadspecific matches the + // globalData's identifier table. + ASSERT_UNUSED(globalData, globalData->identifierTable == wtfThreadData().currentIdentifierTable()); +} + +void Identifier::checkCurrentIdentifierTable(ExecState* exec) +{ + checkCurrentIdentifierTable(&exec->globalData()); +} + +#else + +// These only exists so that our exports are the same for debug and release builds. +// This would be an ASSERT_NOT_REACHED(), but we're in NDEBUG only code here! +NO_RETURN_DUE_TO_CRASH void Identifier::checkCurrentIdentifierTable(JSGlobalData*) { CRASH(); } +NO_RETURN_DUE_TO_CRASH void Identifier::checkCurrentIdentifierTable(ExecState*) { CRASH(); } + +#endif + +} // namespace JSC |