1 /*

     2  *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.

     3  *

     4  *  This library is free software; you can redistribute it and/or

     5  *  modify it under the terms of the GNU Library General Public

     6  *  License as published by the Free Software Foundation; either

     7  *  version 2 of the License, or (at your option) any later version.

     8  *

     9  *  This library is distributed in the hope that it will be useful,

    10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    12  *  Library General Public License for more details.

    13  *

    14  *  You should have received a copy of the GNU Library General Public License

    15  *  along with this library; see the file COPYING.LIB.  If not, write to

    16  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

    17  *  Boston, MA 02110-1301, USA.

    18  *

    19  */

    20 

    21 #include "config.h"

    22 #include "Identifier.h"

    23 

    24 #include "CallFrame.h"

    25 #include "NumericStrings.h"

    26 #include <new> // for placement new

    27 #include <string.h> // for strlen

    28 #include <wtf/Assertions.h>

    29 #include <wtf/FastMalloc.h>

    30 #include <wtf/HashSet.h>

    31 #include <wtf/WTFThreadData.h>

    32 #include <wtf/text/StringHash.h>

    33 

    34 using WTF::ThreadSpecific;

    35 

    36 namespace JSC {

    37 

    38 IdentifierTable::~IdentifierTable()

    39 {

    40     HashSet<StringImpl*>::iterator end = m_table.end();

    41     for (HashSet<StringImpl*>::iterator iter = m_table.begin(); iter != end; ++iter)

    42         (*iter)->setIsIdentifier(false);

    43 }

    44 std::pair<HashSet<StringImpl*>::iterator, bool> IdentifierTable::add(StringImpl* value)

    45 {

    46     std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add(value);

    47     (*result.first)->setIsIdentifier(true);

    48     return result;

    49 }

    50 template<typename U, typename V>

    51 std::pair<HashSet<StringImpl*>::iterator, bool> IdentifierTable::add(U value)

    52 {

    53     std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add<U, V>(value);

    54     (*result.first)->setIsIdentifier(true);

    55     return result;

    56 }

    57 

    58 IdentifierTable* createIdentifierTable()

    59 {

    60     return new IdentifierTable;

    61 }

    62 

    63 void deleteIdentifierTable(IdentifierTable* table)

    64 {

    65     delete table;

    66 }

    67 

    68 bool Identifier::equal(const UString::Rep* r, const char* s)

    69 {

    70     int length = r->length();

    71     const UChar* d = r->characters();

    72     for (int i = 0; i != length; ++i)

    73         if (d[i] != (unsigned char)s[i])

    74             return false;

    75     return s[length] == 0;

    76 }

    77 

    78 bool Identifier::equal(const UString::Rep* r, const UChar* s, unsigned length)

    79 {

    80     if (r->length() != length)

    81         return false;

    82     const UChar* d = r->characters();

    83     for (unsigned i = 0; i != length; ++i)

    84         if (d[i] != s[i])

    85             return false;

    86     return true;

    87 }

    88 

    89 struct IdentifierCStringTranslator {

    90     static unsigned hash(const char* c)

    91     {

    92         return UString::Rep::computeHash(c);

    93     }

    94 

    95     static bool equal(UString::Rep* r, const char* s)

    96     {

    97         return Identifier::equal(r, s);

    98     }

    99 

   100     static void translate(UString::Rep*& location, const char* c, unsigned hash)

   101     {

   102         size_t length = strlen(c);

   103         UChar* d;

   104         UString::Rep* r = UString::Rep::createUninitialized(length, d).releaseRef();

   105         for (size_t i = 0; i != length; i++)

   106             d[i] = static_cast<unsigned char>(c[i]); // use unsigned char to zero-extend instead of sign-extend

   107         r->setHash(hash);

   108         location = r;

   109     }

   110 };

   111 

   112 PassRefPtr<UString::Rep> Identifier::add(JSGlobalData* globalData, const char* c)

   113 {

   114     if (!c)

   115         return UString::null().rep();

   116     if (!c[0])

   117         return UString::Rep::empty();

   118     if (!c[1])

   119         return add(globalData, globalData->smallStrings.singleCharacterStringRep(static_cast<unsigned char>(c[0])));

   120 

   121     IdentifierTable& identifierTable = *globalData->identifierTable;

   122     LiteralIdentifierTable& literalIdentifierTable = identifierTable.literalTable();

   123 

   124     const LiteralIdentifierTable::iterator& iter = literalIdentifierTable.find(c);

   125     if (iter != literalIdentifierTable.end())

   126         return iter->second;

   127 

   128     pair<HashSet<UString::Rep*>::iterator, bool> addResult = identifierTable.add<const char*, IdentifierCStringTranslator>(c);

   129 

   130     // If the string is newly-translated, then we need to adopt it.

   131     // The boolean in the pair tells us if that is so.

   132     RefPtr<UString::Rep> addedString = addResult.second ? adoptRef(*addResult.first) : *addResult.first;

   133 

   134     literalIdentifierTable.add(c, addedString.get());

   135 

   136     return addedString.release();

   137 }

   138 

   139 PassRefPtr<UString::Rep> Identifier::add(ExecState* exec, const char* c)

   140 {

   141     return add(&exec->globalData(), c);

   142 }

   143 

   144 struct UCharBuffer {

   145     const UChar* s;

   146     unsigned int length;

   147 };

   148 

   149 struct IdentifierUCharBufferTranslator {

   150     static unsigned hash(const UCharBuffer& buf)

   151     {

   152         return UString::Rep::computeHash(buf.s, buf.length);

   153     }

   154 

   155     static bool equal(UString::Rep* str, const UCharBuffer& buf)

   156     {

   157         return Identifier::equal(str, buf.s, buf.length);

   158     }

   159 

   160     static void translate(UString::Rep*& location, const UCharBuffer& buf, unsigned hash)

   161     {

   162         UChar* d;

   163         UString::Rep* r = UString::Rep::createUninitialized(buf.length, d).releaseRef();

   164         for (unsigned i = 0; i != buf.length; i++)

   165             d[i] = buf.s[i];

   166         r->setHash(hash);

   167         location = r; 

   168     }

   169 };

   170 

   171 PassRefPtr<UString::Rep> Identifier::add(JSGlobalData* globalData, const UChar* s, int length)

   172 {

   173     if (length == 1) {

   174         UChar c = s[0];

   175         if (c <= 0xFF)

   176             return add(globalData, globalData->smallStrings.singleCharacterStringRep(c));

   177     }

   178     if (!length)

   179         return UString::Rep::empty();

   180     UCharBuffer buf = {s, length}; 

   181     pair<HashSet<UString::Rep*>::iterator, bool> addResult = globalData->identifierTable->add<UCharBuffer, IdentifierUCharBufferTranslator>(buf);

   182 

   183     // If the string is newly-translated, then we need to adopt it.

   184     // The boolean in the pair tells us if that is so.

   185     return addResult.second ? adoptRef(*addResult.first) : *addResult.first;

   186 }

   187 

   188 PassRefPtr<UString::Rep> Identifier::add(ExecState* exec, const UChar* s, int length)

   189 {

   190     return add(&exec->globalData(), s, length);

   191 }

   192 

   193 PassRefPtr<UString::Rep> Identifier::addSlowCase(JSGlobalData* globalData, UString::Rep* r)

   194 {

   195     ASSERT(!r->isIdentifier());

   196     // The empty & null strings are static singletons, and static strings are handled

   197     // in ::add() in the header, so we should never get here with a zero length string.

   198     ASSERT(r->length());

   199 

   200     if (r->length() == 1) {

   201         UChar c = r->characters()[0];

   202         if (c <= 0xFF)

   203             r = globalData->smallStrings.singleCharacterStringRep(c);

   204             if (r->isIdentifier())

   205                 return r;

   206     }

   207 

   208     return *globalData->identifierTable->add(r).first;

   209 }

   210 

   211 PassRefPtr<UString::Rep> Identifier::addSlowCase(ExecState* exec, UString::Rep* r)

   212 {

   213     return addSlowCase(&exec->globalData(), r);

   214 }

   215 

   216 Identifier Identifier::from(ExecState* exec, unsigned value)

   217 {

   218     return Identifier(exec, exec->globalData().numericStrings.add(value));

   219 }

   220 

   221 Identifier Identifier::from(ExecState* exec, int value)

   222 {

   223     return Identifier(exec, exec->globalData().numericStrings.add(value));

   224 }

   225 

   226 Identifier Identifier::from(ExecState* exec, double value)

   227 {

   228     return Identifier(exec, exec->globalData().numericStrings.add(value));

   229 }

   230 

   231 Identifier Identifier::from(JSGlobalData* globalData, unsigned value)

   232 {

   233     return Identifier(globalData, globalData->numericStrings.add(value));

   234 }

   235 

   236 Identifier Identifier::from(JSGlobalData* globalData, int value)

   237 {

   238     return Identifier(globalData, globalData->numericStrings.add(value));

   239 }

   240 

   241 Identifier Identifier::from(JSGlobalData* globalData, double value)

   242 {

   243     return Identifier(globalData, globalData->numericStrings.add(value));

   244 }

   245 

   246 #ifndef NDEBUG

   247 

   248 void Identifier::checkCurrentIdentifierTable(JSGlobalData* globalData)

   249 {

   250     // Check the identifier table accessible through the threadspecific matches the

   251     // globalData's identifier table.

   252     ASSERT_UNUSED(globalData, globalData->identifierTable == wtfThreadData().currentIdentifierTable());

   253 }

   254 

   255 void Identifier::checkCurrentIdentifierTable(ExecState* exec)

   256 {

   257     checkCurrentIdentifierTable(&exec->globalData());

   258 }

   259 

   260 #else

   261 

   262 // These only exists so that our exports are the same for debug and release builds.

   263 // This would be an ASSERT_NOT_REACHED(), but we're in NDEBUG only code here!

   264 void Identifier::checkCurrentIdentifierTable(JSGlobalData*) { CRASH(); }

   265 void Identifier::checkCurrentIdentifierTable(ExecState*) { CRASH(); }

   266 

   267 #endif

   268 

   269 } // namespace JSC