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      1 /*
      2  *  Copyright (C) 1999-2000 Harri Porten (porten (at) kde.org)
      3  *  Copyright (C) 2002, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
      4  *
      5  *  This library is free software; you can redistribute it and/or
      6  *  modify it under the terms of the GNU Library General Public
      7  *  License as published by the Free Software Foundation; either
      8  *  version 2 of the License, or (at your option) any later version.
      9  *
     10  *  This library is distributed in the hope that it will be useful,
     11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13  *  Library General Public License for more details.
     14  *
     15  *  You should have received a copy of the GNU Library General Public License
     16  *  along with this library; see the file COPYING.LIB.  If not, write to
     17  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     18  *  Boston, MA 02110-1301, USA.
     19  *
     20  */
     21 
     22 #ifndef Operations_h
     23 #define Operations_h
     24 
     25 #include "ExceptionHelpers.h"
     26 #include "Interpreter.h"
     27 #include "JSImmediate.h"
     28 #include "JSNumberCell.h"
     29 #include "JSString.h"
     30 
     31 namespace JSC {
     32 
     33     NEVER_INLINE JSValue jsAddSlowCase(CallFrame*, JSValue, JSValue);
     34     JSValue jsTypeStringForValue(CallFrame*, JSValue);
     35     bool jsIsObjectType(JSValue);
     36     bool jsIsFunctionType(JSValue);
     37 
     38     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, JSString* s2)
     39     {
     40         if (!s1->length())
     41             return s2;
     42         if (!s2->length())
     43             return s1;
     44 
     45         unsigned ropeLength = s1->ropeLength() + s2->ropeLength();
     46         JSGlobalData* globalData = &exec->globalData();
     47 
     48         if (ropeLength <= JSString::s_maxInternalRopeLength)
     49             return new (globalData) JSString(globalData, ropeLength, s1, s2);
     50 
     51         unsigned index = 0;
     52         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
     53         if (UNLIKELY(!rope))
     54             return throwOutOfMemoryError(exec);
     55         rope->append(index, s1);
     56         rope->append(index, s2);
     57         ASSERT(index == ropeLength);
     58         return new (globalData) JSString(globalData, rope.release());
     59     }
     60 
     61     ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, JSString* s2)
     62     {
     63         unsigned ropeLength = 1 + s2->ropeLength();
     64         JSGlobalData* globalData = &exec->globalData();
     65 
     66         if (ropeLength <= JSString::s_maxInternalRopeLength)
     67             return new (globalData) JSString(globalData, ropeLength, u1, s2);
     68 
     69         unsigned index = 0;
     70         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
     71         if (UNLIKELY(!rope))
     72             return throwOutOfMemoryError(exec);
     73         rope->append(index, u1);
     74         rope->append(index, s2);
     75         ASSERT(index == ropeLength);
     76         return new (globalData) JSString(globalData, rope.release());
     77     }
     78 
     79     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, const UString& u2)
     80     {
     81         unsigned ropeLength = s1->ropeLength() + 1;
     82         JSGlobalData* globalData = &exec->globalData();
     83 
     84         if (ropeLength <= JSString::s_maxInternalRopeLength)
     85             return new (globalData) JSString(globalData, ropeLength, s1, u2);
     86 
     87         unsigned index = 0;
     88         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
     89         if (UNLIKELY(!rope))
     90             return throwOutOfMemoryError(exec);
     91         rope->append(index, s1);
     92         rope->append(index, u2);
     93         ASSERT(index == ropeLength);
     94         return new (globalData) JSString(globalData, rope.release());
     95     }
     96 
     97     ALWAYS_INLINE JSValue jsString(ExecState* exec, Register* strings, unsigned count)
     98     {
     99         ASSERT(count >= 3);
    100 
    101         unsigned ropeLength = 0;
    102         for (unsigned i = 0; i < count; ++i) {
    103             JSValue v = strings[i].jsValue();
    104             if (LIKELY(v.isString()))
    105                 ropeLength += asString(v)->ropeLength();
    106             else
    107                 ++ropeLength;
    108         }
    109 
    110         JSGlobalData* globalData = &exec->globalData();
    111         if (ropeLength == 3)
    112             return new (globalData) JSString(exec, strings[0].jsValue(), strings[1].jsValue(), strings[2].jsValue());
    113 
    114         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
    115         if (UNLIKELY(!rope))
    116             return throwOutOfMemoryError(exec);
    117 
    118         unsigned index = 0;
    119         for (unsigned i = 0; i < count; ++i) {
    120             JSValue v = strings[i].jsValue();
    121             if (LIKELY(v.isString()))
    122                 rope->append(index, asString(v));
    123             else
    124                 rope->append(index, v.toString(exec));
    125         }
    126 
    127         ASSERT(index == ropeLength);
    128         return new (globalData) JSString(globalData, rope.release());
    129     }
    130 
    131     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSValue thisValue, const ArgList& args)
    132     {
    133         unsigned ropeLength = 0;
    134         if (LIKELY(thisValue.isString()))
    135             ropeLength += asString(thisValue)->ropeLength();
    136         else
    137             ++ropeLength;
    138         for (unsigned i = 0; i < args.size(); ++i) {
    139             JSValue v = args.at(i);
    140             if (LIKELY(v.isString()))
    141                 ropeLength += asString(v)->ropeLength();
    142             else
    143                 ++ropeLength;
    144         }
    145 
    146         RefPtr<JSString::Rope> rope = JSString::Rope::createOrNull(ropeLength);
    147         if (UNLIKELY(!rope))
    148             return throwOutOfMemoryError(exec);
    149 
    150         unsigned index = 0;
    151         if (LIKELY(thisValue.isString()))
    152             rope->append(index, asString(thisValue));
    153         else
    154             rope->append(index, thisValue.toString(exec));
    155         for (unsigned i = 0; i < args.size(); ++i) {
    156             JSValue v = args.at(i);
    157             if (LIKELY(v.isString()))
    158                 rope->append(index, asString(v));
    159             else
    160                 rope->append(index, v.toString(exec));
    161         }
    162         ASSERT(index == ropeLength);
    163 
    164         JSGlobalData* globalData = &exec->globalData();
    165         return new (globalData) JSString(globalData, rope.release());
    166     }
    167 
    168     // ECMA 11.9.3
    169     inline bool JSValue::equal(ExecState* exec, JSValue v1, JSValue v2)
    170     {
    171         if (v1.isInt32() && v2.isInt32())
    172             return v1 == v2;
    173 
    174         return equalSlowCase(exec, v1, v2);
    175     }
    176 
    177     ALWAYS_INLINE bool JSValue::equalSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
    178     {
    179         do {
    180             if (v1.isNumber() && v2.isNumber())
    181                 return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
    182 
    183             bool s1 = v1.isString();
    184             bool s2 = v2.isString();
    185             if (s1 && s2)
    186                 return asString(v1)->value(exec) == asString(v2)->value(exec);
    187 
    188             if (v1.isUndefinedOrNull()) {
    189                 if (v2.isUndefinedOrNull())
    190                     return true;
    191                 if (!v2.isCell())
    192                     return false;
    193                 return v2.asCell()->structure()->typeInfo().masqueradesAsUndefined();
    194             }
    195 
    196             if (v2.isUndefinedOrNull()) {
    197                 if (!v1.isCell())
    198                     return false;
    199                 return v1.asCell()->structure()->typeInfo().masqueradesAsUndefined();
    200             }
    201 
    202             if (v1.isObject()) {
    203                 if (v2.isObject())
    204                     return v1 == v2;
    205                 JSValue p1 = v1.toPrimitive(exec);
    206                 if (exec->hadException())
    207                     return false;
    208                 v1 = p1;
    209                 if (v1.isInt32() && v2.isInt32())
    210                     return v1 == v2;
    211                 continue;
    212             }
    213 
    214             if (v2.isObject()) {
    215                 JSValue p2 = v2.toPrimitive(exec);
    216                 if (exec->hadException())
    217                     return false;
    218                 v2 = p2;
    219                 if (v1.isInt32() && v2.isInt32())
    220                     return v1 == v2;
    221                 continue;
    222             }
    223 
    224             if (s1 || s2) {
    225                 double d1 = v1.toNumber(exec);
    226                 double d2 = v2.toNumber(exec);
    227                 return d1 == d2;
    228             }
    229 
    230             if (v1.isBoolean()) {
    231                 if (v2.isNumber())
    232                     return static_cast<double>(v1.getBoolean()) == v2.uncheckedGetNumber();
    233             } else if (v2.isBoolean()) {
    234                 if (v1.isNumber())
    235                     return v1.uncheckedGetNumber() == static_cast<double>(v2.getBoolean());
    236             }
    237 
    238             return v1 == v2;
    239         } while (true);
    240     }
    241 
    242     // ECMA 11.9.3
    243     ALWAYS_INLINE bool JSValue::strictEqualSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
    244     {
    245         ASSERT(v1.isCell() && v2.isCell());
    246 
    247         if (v1.asCell()->isString() && v2.asCell()->isString())
    248             return asString(v1)->value(exec) == asString(v2)->value(exec);
    249 
    250         return v1 == v2;
    251     }
    252 
    253     inline bool JSValue::strictEqual(ExecState* exec, JSValue v1, JSValue v2)
    254     {
    255         if (v1.isInt32() && v2.isInt32())
    256             return v1 == v2;
    257 
    258         if (v1.isNumber() && v2.isNumber())
    259             return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
    260 
    261         if (!v1.isCell() || !v2.isCell())
    262             return v1 == v2;
    263 
    264         return strictEqualSlowCaseInline(exec, v1, v2);
    265     }
    266 
    267     ALWAYS_INLINE bool jsLess(CallFrame* callFrame, JSValue v1, JSValue v2)
    268     {
    269         if (v1.isInt32() && v2.isInt32())
    270             return v1.asInt32() < v2.asInt32();
    271 
    272         double n1;
    273         double n2;
    274         if (v1.getNumber(n1) && v2.getNumber(n2))
    275             return n1 < n2;
    276 
    277         JSGlobalData* globalData = &callFrame->globalData();
    278         if (isJSString(globalData, v1) && isJSString(globalData, v2))
    279             return asString(v1)->value(callFrame) < asString(v2)->value(callFrame);
    280 
    281         JSValue p1;
    282         JSValue p2;
    283         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
    284         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
    285 
    286         if (wasNotString1 | wasNotString2)
    287             return n1 < n2;
    288 
    289         return asString(p1)->value(callFrame) < asString(p2)->value(callFrame);
    290     }
    291 
    292     inline bool jsLessEq(CallFrame* callFrame, JSValue v1, JSValue v2)
    293     {
    294         if (v1.isInt32() && v2.isInt32())
    295             return v1.asInt32() <= v2.asInt32();
    296 
    297         double n1;
    298         double n2;
    299         if (v1.getNumber(n1) && v2.getNumber(n2))
    300             return n1 <= n2;
    301 
    302         JSGlobalData* globalData = &callFrame->globalData();
    303         if (isJSString(globalData, v1) && isJSString(globalData, v2))
    304             return !(asString(v2)->value(callFrame) < asString(v1)->value(callFrame));
    305 
    306         JSValue p1;
    307         JSValue p2;
    308         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
    309         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
    310 
    311         if (wasNotString1 | wasNotString2)
    312             return n1 <= n2;
    313 
    314         return !(asString(p2)->value(callFrame) < asString(p1)->value(callFrame));
    315     }
    316 
    317     // Fast-path choices here are based on frequency data from SunSpider:
    318     //    <times> Add case: <t1> <t2>
    319     //    ---------------------------
    320     //    5626160 Add case: 3 3 (of these, 3637690 are for immediate values)
    321     //    247412  Add case: 5 5
    322     //    20900   Add case: 5 6
    323     //    13962   Add case: 5 3
    324     //    4000    Add case: 3 5
    325 
    326     ALWAYS_INLINE JSValue jsAdd(CallFrame* callFrame, JSValue v1, JSValue v2)
    327     {
    328         double left = 0.0, right;
    329         if (v1.getNumber(left) && v2.getNumber(right))
    330             return jsNumber(callFrame, left + right);
    331 
    332         if (v1.isString()) {
    333             return v2.isString()
    334                 ? jsString(callFrame, asString(v1), asString(v2))
    335                 : jsString(callFrame, asString(v1), v2.toPrimitiveString(callFrame));
    336         }
    337 
    338         // All other cases are pretty uncommon
    339         return jsAddSlowCase(callFrame, v1, v2);
    340     }
    341 
    342     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, size_t& slotOffset)
    343     {
    344         JSCell* cell = asCell(base);
    345         size_t count = 0;
    346 
    347         while (slotBase != cell) {
    348             JSValue v = cell->structure()->prototypeForLookup(callFrame);
    349 
    350             // If we didn't find slotBase in base's prototype chain, then base
    351             // must be a proxy for another object.
    352 
    353             if (v.isNull())
    354                 return 0;
    355 
    356             cell = asCell(v);
    357 
    358             // Since we're accessing a prototype in a loop, it's a good bet that it
    359             // should not be treated as a dictionary.
    360             if (cell->structure()->isDictionary()) {
    361                 asObject(cell)->flattenDictionaryObject();
    362                 if (slotBase == cell)
    363                     slotOffset = cell->structure()->get(propertyName);
    364             }
    365 
    366             ++count;
    367         }
    368 
    369         ASSERT(count);
    370         return count;
    371     }
    372 
    373     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSCell* base)
    374     {
    375         size_t count = 0;
    376         while (1) {
    377             JSValue v = base->structure()->prototypeForLookup(callFrame);
    378             if (v.isNull())
    379                 return count;
    380 
    381             base = asCell(v);
    382 
    383             // Since we're accessing a prototype in a loop, it's a good bet that it
    384             // should not be treated as a dictionary.
    385             if (base->structure()->isDictionary())
    386                 asObject(base)->flattenDictionaryObject();
    387 
    388             ++count;
    389         }
    390     }
    391 
    392     ALWAYS_INLINE JSValue resolveBase(CallFrame* callFrame, Identifier& property, ScopeChainNode* scopeChain)
    393     {
    394         ScopeChainIterator iter = scopeChain->begin();
    395         ScopeChainIterator next = iter;
    396         ++next;
    397         ScopeChainIterator end = scopeChain->end();
    398         ASSERT(iter != end);
    399 
    400         PropertySlot slot;
    401         JSObject* base;
    402         while (true) {
    403             base = *iter;
    404             if (next == end || base->getPropertySlot(callFrame, property, slot))
    405                 return base;
    406 
    407             iter = next;
    408             ++next;
    409         }
    410 
    411         ASSERT_NOT_REACHED();
    412         return JSValue();
    413     }
    414 } // namespace JSC
    415 
    416 #endif // Operations_h
    417