runtime/Operations.h

   1 /*
   2  *  Copyright (C) 1999-2000 Harri Porten (porten@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 "JSString.h"
  28 #include "JSValueInlineMethods.h"
  29
  30 namespace JSC {
  31
  32     NEVER_INLINE JSValue jsAddSlowCase(CallFrame*, JSValue, JSValue);
  33     JSValue jsTypeStringForValue(CallFrame*, JSValue);
  34     bool jsIsObjectType(JSValue);
  35     bool jsIsFunctionType(JSValue);
  36
  37     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, JSString* s2)
  38     {
  39         unsigned length1 = s1->length();
  40         if (!length1)
  41             return s2;
  42         unsigned length2 = s2->length();
  43         if (!length2)
  44             return s1;
  45         if ((length1 + length2) < length1)
  46             return throwOutOfMemoryError(exec);
  47
  48         unsigned fiberCount = s1->fiberCount() + s2->fiberCount();
  49         JSGlobalData* globalData = &exec->globalData();
  50
  51         if (fiberCount <= JSString::s_maxInternalRopeLength)
  52             return new (globalData) JSString(globalData, fiberCount, s1, s2);
  53
  54         JSString::RopeBuilder ropeBuilder(fiberCount);
  55         if (UNLIKELY(ropeBuilder.isOutOfMemory()))
  56             return throwOutOfMemoryError(exec);
  57         ropeBuilder.append(s1);
  58         ropeBuilder.append(s2);
  59         return new (globalData) JSString(globalData, ropeBuilder.release());
  60     }
  61
  62     ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, JSString* s2)
  63     {
  64         unsigned length1 = u1.length();
  65         if (!length1)
  66             return s2;
  67         unsigned length2 = s2->length();
  68         if (!length2)
  69             return jsString(exec, u1);
  70         if ((length1 + length2) < length1)
  71             return throwOutOfMemoryError(exec);
  72
  73         unsigned fiberCount = 1 + s2->fiberCount();
  74         JSGlobalData* globalData = &exec->globalData();
  75
  76         if (fiberCount <= JSString::s_maxInternalRopeLength)
  77             return new (globalData) JSString(globalData, fiberCount, u1, s2);
  78
  79         JSString::RopeBuilder ropeBuilder(fiberCount);
  80         if (UNLIKELY(ropeBuilder.isOutOfMemory()))
  81             return throwOutOfMemoryError(exec);
  82         ropeBuilder.append(u1);
  83         ropeBuilder.append(s2);
  84         return new (globalData) JSString(globalData, ropeBuilder.release());
  85     }
  86
  87     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSString* s1, const UString& u2)
  88     {
  89         unsigned length1 = s1->length();
  90         if (!length1)
  91             return jsString(exec, u2);
  92         unsigned length2 = u2.length();
  93         if (!length2)
  94             return s1;
  95         if ((length1 + length2) < length1)
  96             return throwOutOfMemoryError(exec);
  97
  98         unsigned fiberCount = s1->fiberCount() + 1;
  99         JSGlobalData* globalData = &exec->globalData();
 100
 101         if (fiberCount <= JSString::s_maxInternalRopeLength)
 102             return new (globalData) JSString(globalData, fiberCount, s1, u2);
 103
 104         JSString::RopeBuilder ropeBuilder(fiberCount);
 105         if (UNLIKELY(ropeBuilder.isOutOfMemory()))
 106             return throwOutOfMemoryError(exec);
 107         ropeBuilder.append(s1);
 108         ropeBuilder.append(u2);
 109         return new (globalData) JSString(globalData, ropeBuilder.release());
 110     }
 111
 112     ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, const UString& u2)
 113     {
 114         unsigned length1 = u1.length();
 115         if (!length1)
 116             return jsString(exec, u2);
 117         unsigned length2 = u2.length();
 118         if (!length2)
 119             return jsString(exec, u1);
 120         if ((length1 + length2) < length1)
 121             return throwOutOfMemoryError(exec);
 122
 123         JSGlobalData* globalData = &exec->globalData();
 124         return new (globalData) JSString(globalData, u1, u2);
 125     }
 126
 127     ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, const UString& u2, const UString& u3)
 128     {
 129         unsigned length1 = u1.length();
 130         unsigned length2 = u2.length();
 131         unsigned length3 = u3.length();
 132         if (!length1)
 133             return jsString(exec, u2, u3);
 134         if (!length2)
 135             return jsString(exec, u1, u3);
 136         if (!length3)
 137             return jsString(exec, u1, u2);
 138
 139         if ((length1 + length2) < length1)
 140             return throwOutOfMemoryError(exec);
 141         if ((length1 + length2 + length3) < length3)
 142             return throwOutOfMemoryError(exec);
 143
 144         JSGlobalData* globalData = &exec->globalData();
 145         return new (globalData) JSString(globalData, u1, u2, u3);
 146     }
 147
 148     ALWAYS_INLINE JSValue jsString(ExecState* exec, Register* strings, unsigned count)
 149     {
 150         ASSERT(count >= 3);
 151
 152         unsigned fiberCount = 0;
 153         for (unsigned i = 0; i < count; ++i) {
 154             JSValue v = strings[i].jsValue();
 155             if (LIKELY(v.isString()))
 156                 fiberCount += asString(v)->fiberCount();
 157             else
 158                 ++fiberCount;
 159         }
 160
 161         JSGlobalData* globalData = &exec->globalData();
 162         if (fiberCount == 3)
 163             return new (globalData) JSString(exec, strings[0].jsValue(), strings[1].jsValue(), strings[2].jsValue());
 164
 165         JSString::RopeBuilder ropeBuilder(fiberCount);
 166         if (UNLIKELY(ropeBuilder.isOutOfMemory()))
 167             return throwOutOfMemoryError(exec);
 168
 169         unsigned length = 0;
 170         bool overflow = false;
 171
 172         for (unsigned i = 0; i < count; ++i) {
 173             JSValue v = strings[i].jsValue();
 174             if (LIKELY(v.isString()))
 175                 ropeBuilder.append(asString(v));
 176             else
 177                 ropeBuilder.append(v.toString(exec));
 178
 179             unsigned newLength = ropeBuilder.length();
 180             if (newLength < length)
 181                 overflow = true;
 182             length = newLength;
 183         }
 184
 185         if (overflow)
 186             return throwOutOfMemoryError(exec);
 187
 188         return new (globalData) JSString(globalData, ropeBuilder.release());
 189     }
 190
 191     ALWAYS_INLINE JSValue jsString(ExecState* exec, JSValue thisValue)
 192     {
 193         unsigned fiberCount = 0;
 194         if (LIKELY(thisValue.isString()))
 195             fiberCount += asString(thisValue)->fiberCount();
 196         else
 197             ++fiberCount;
 198         for (unsigned i = 0; i < exec->argumentCount(); ++i) {
 199             JSValue v = exec->argument(i);
 200             if (LIKELY(v.isString()))
 201                 fiberCount += asString(v)->fiberCount();
 202             else
 203                 ++fiberCount;
 204         }
 205
 206         JSString::RopeBuilder ropeBuilder(fiberCount);
 207         if (UNLIKELY(ropeBuilder.isOutOfMemory()))
 208             return throwOutOfMemoryError(exec);
 209
 210         if (LIKELY(thisValue.isString()))
 211             ropeBuilder.append(asString(thisValue));
 212         else
 213             ropeBuilder.append(thisValue.toString(exec));
 214
 215         unsigned length = 0;
 216         bool overflow = false;
 217
 218         for (unsigned i = 0; i < exec->argumentCount(); ++i) {
 219             JSValue v = exec->argument(i);
 220             if (LIKELY(v.isString()))
 221                 ropeBuilder.append(asString(v));
 222             else
 223                 ropeBuilder.append(v.toString(exec));
 224
 225             unsigned newLength = ropeBuilder.length();
 226             if (newLength < length)
 227                 overflow = true;
 228             length = newLength;
 229         }
 230
 231         if (overflow)
 232             return throwOutOfMemoryError(exec);
 233
 234         JSGlobalData* globalData = &exec->globalData();
 235         return new (globalData) JSString(globalData, ropeBuilder.release());
 236     }
 237
 238     // ECMA 11.9.3
 239     inline bool JSValue::equal(ExecState* exec, JSValue v1, JSValue v2)
 240     {
 241         if (v1.isInt32() && v2.isInt32())
 242             return v1 == v2;
 243
 244         return equalSlowCase(exec, v1, v2);
 245     }
 246
 247     ALWAYS_INLINE bool JSValue::equalSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
 248     {
 249         do {
 250             if (v1.isNumber() && v2.isNumber())
 251                 return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
 252
 253             bool s1 = v1.isString();
 254             bool s2 = v2.isString();
 255             if (s1 && s2)
 256                 return asString(v1)->value(exec) == asString(v2)->value(exec);
 257
 258             if (v1.isUndefinedOrNull()) {
 259                 if (v2.isUndefinedOrNull())
 260                     return true;
 261                 if (!v2.isCell())
 262                     return false;
 263                 return v2.asCell()->structure()->typeInfo().masqueradesAsUndefined();
 264             }
 265
 266             if (v2.isUndefinedOrNull()) {
 267                 if (!v1.isCell())
 268                     return false;
 269                 return v1.asCell()->structure()->typeInfo().masqueradesAsUndefined();
 270             }
 271
 272             if (v1.isObject()) {
 273                 if (v2.isObject())
 274                     return v1 == v2;
 275                 JSValue p1 = v1.toPrimitive(exec);
 276                 if (exec->hadException())
 277                     return false;
 278                 v1 = p1;
 279                 if (v1.isInt32() && v2.isInt32())
 280                     return v1 == v2;
 281                 continue;
 282             }
 283
 284             if (v2.isObject()) {
 285                 JSValue p2 = v2.toPrimitive(exec);
 286                 if (exec->hadException())
 287                     return false;
 288                 v2 = p2;
 289                 if (v1.isInt32() && v2.isInt32())
 290                     return v1 == v2;
 291                 continue;
 292             }
 293
 294             if (s1 || s2) {
 295                 double d1 = v1.toNumber(exec);
 296                 double d2 = v2.toNumber(exec);
 297                 return d1 == d2;
 298             }
 299
 300             if (v1.isBoolean()) {
 301                 if (v2.isNumber())
 302                     return static_cast<double>(v1.getBoolean()) == v2.uncheckedGetNumber();
 303             } else if (v2.isBoolean()) {
 304                 if (v1.isNumber())
 305                     return v1.uncheckedGetNumber() == static_cast<double>(v2.getBoolean());
 306             }
 307
 308             return v1 == v2;
 309         } while (true);
 310     }
 311
 312     // ECMA 11.9.3
 313     ALWAYS_INLINE bool JSValue::strictEqualSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
 314     {
 315         ASSERT(v1.isCell() && v2.isCell());
 316
 317         if (v1.asCell()->isString() && v2.asCell()->isString())
 318             return asString(v1)->value(exec) == asString(v2)->value(exec);
 319
 320         return v1 == v2;
 321     }
 322
 323     inline bool JSValue::strictEqual(ExecState* exec, JSValue v1, JSValue v2)
 324     {
 325         if (v1.isInt32() && v2.isInt32())
 326             return v1 == v2;
 327
 328         if (v1.isNumber() && v2.isNumber())
 329             return v1.uncheckedGetNumber() == v2.uncheckedGetNumber();
 330
 331         if (!v1.isCell() || !v2.isCell())
 332             return v1 == v2;
 333
 334         return strictEqualSlowCaseInline(exec, v1, v2);
 335     }
 336
 337     ALWAYS_INLINE bool jsLess(CallFrame* callFrame, JSValue v1, JSValue v2)
 338     {
 339         if (v1.isInt32() && v2.isInt32())
 340             return v1.asInt32() < v2.asInt32();
 341
 342         double n1;
 343         double n2;
 344         if (v1.getNumber(n1) && v2.getNumber(n2))
 345             return n1 < n2;
 346
 347         JSGlobalData* globalData = &callFrame->globalData();
 348         if (isJSString(globalData, v1) && isJSString(globalData, v2))
 349             return asString(v1)->value(callFrame) < asString(v2)->value(callFrame);
 350
 351         JSValue p1;
 352         JSValue p2;
 353         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 354         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 355
 356         if (wasNotString1 | wasNotString2)
 357             return n1 < n2;
 358
 359         return asString(p1)->value(callFrame) < asString(p2)->value(callFrame);
 360     }
 361
 362     inline bool jsLessEq(CallFrame* callFrame, JSValue v1, JSValue v2)
 363     {
 364         if (v1.isInt32() && v2.isInt32())
 365             return v1.asInt32() <= v2.asInt32();
 366
 367         double n1;
 368         double n2;
 369         if (v1.getNumber(n1) && v2.getNumber(n2))
 370             return n1 <= n2;
 371
 372         JSGlobalData* globalData = &callFrame->globalData();
 373         if (isJSString(globalData, v1) && isJSString(globalData, v2))
 374             return !(asString(v2)->value(callFrame) < asString(v1)->value(callFrame));
 375
 376         JSValue p1;
 377         JSValue p2;
 378         bool wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 379         bool wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 380
 381         if (wasNotString1 | wasNotString2)
 382             return n1 <= n2;
 383
 384         return !(asString(p2)->value(callFrame) < asString(p1)->value(callFrame));
 385     }
 386
 387     // Fast-path choices here are based on frequency data from SunSpider:
 388     //    <times> Add case: <t1> <t2>
 389     //    ---------------------------
 390     //    5626160 Add case: 3 3 (of these, 3637690 are for immediate values)
 391     //    247412  Add case: 5 5
 392     //    20900   Add case: 5 6
 393     //    13962   Add case: 5 3
 394     //    4000    Add case: 3 5
 395
 396     ALWAYS_INLINE JSValue jsAdd(CallFrame* callFrame, JSValue v1, JSValue v2)
 397     {
 398         double left = 0.0, right;
 399         if (v1.getNumber(left) && v2.getNumber(right))
 400             return jsNumber(left + right);
 401
 402         if (v1.isString()) {
 403             return v2.isString()
 404                 ? jsString(callFrame, asString(v1), asString(v2))
 405                 : jsString(callFrame, asString(v1), v2.toPrimitiveString(callFrame));
 406         }
 407
 408         // All other cases are pretty uncommon
 409         return jsAddSlowCase(callFrame, v1, v2);
 410     }
 411
 412     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, size_t& slotOffset)
 413     {
 414         JSCell* cell = base.asCell();
 415         size_t count = 0;
 416
 417         while (slotBase != cell) {
 418             JSValue v = cell->structure()->prototypeForLookup(callFrame);
 419
 420             // If we didn't find slotBase in base's prototype chain, then base
 421             // must be a proxy for another object.
 422
 423             if (v.isNull())
 424                 return 0;
 425
 426             cell = v.asCell();
 427
 428             // Since we're accessing a prototype in a loop, it's a good bet that it
 429             // should not be treated as a dictionary.
 430             if (cell->structure()->isDictionary()) {
 431                 asObject(cell)->flattenDictionaryObject(callFrame->globalData());
 432                 if (slotBase == cell)
 433                     slotOffset = cell->structure()->get(callFrame->globalData(), propertyName);
 434             }
 435
 436             ++count;
 437         }
 438
 439         ASSERT(count);
 440         return count;
 441     }
 442
 443     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSCell* base)
 444     {
 445         size_t count = 0;
 446         while (1) {
 447             JSValue v = base->structure()->prototypeForLookup(callFrame);
 448             if (v.isNull())
 449                 return count;
 450
 451             base = v.asCell();
 452
 453             // Since we're accessing a prototype in a loop, it's a good bet that it
 454             // should not be treated as a dictionary.
 455             if (base->structure()->isDictionary())
 456                 asObject(base)->flattenDictionaryObject(callFrame->globalData());
 457
 458             ++count;
 459         }
 460     }
 461
 462     ALWAYS_INLINE JSValue resolveBase(CallFrame* callFrame, Identifier& property, ScopeChainNode* scopeChain, bool isStrictPut)
 463     {
 464         ScopeChainIterator iter = scopeChain->begin();
 465         ScopeChainIterator next = iter;
 466         ++next;
 467         ScopeChainIterator end = scopeChain->end();
 468         ASSERT(iter != end);
 469
 470         PropertySlot slot;
 471         JSObject* base;
 472         while (true) {
 473             base = iter->get();
 474             if (next == end) {
 475                 if (isStrictPut && !base->getPropertySlot(callFrame, property, slot))
 476                     return JSValue();
 477                 return base;
 478             }
 479             if (base->getPropertySlot(callFrame, property, slot))
 480                 return base;
 481
 482             iter = next;
 483             ++next;
 484         }
 485
 486         ASSERT_NOT_REACHED();
 487         return JSValue();
 488     }
 489 } // namespace JSC
 490
 491 #endif // Operations_h