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         JSGlobalData& globalData = exec->globalData();
  40
  41         unsigned length1 = s1->length();
  42         if (!length1)
  43             return s2;
  44         unsigned length2 = s2->length();
  45         if (!length2)
  46             return s1;
  47         if ((length1 + length2) < length1)
  48             return throwOutOfMemoryError(exec);
  49
  50         return JSRopeString::create(globalData, s1, s2);
  51     }
  52
  53     ALWAYS_INLINE JSValue jsString(ExecState* exec, const UString& u1, const UString& u2, const UString& u3)
  54     {
  55         JSGlobalData* globalData = &exec->globalData();
  56
  57         unsigned length1 = u1.length();
  58         unsigned length2 = u2.length();
  59         unsigned length3 = u3.length();
  60         if (!length1)
  61             return jsString(exec, jsString(globalData, u2), jsString(globalData, u3));
  62         if (!length2)
  63             return jsString(exec, jsString(globalData, u1), jsString(globalData, u3));
  64         if (!length3)
  65             return jsString(exec, jsString(globalData, u1), jsString(globalData, u2));
  66
  67         if ((length1 + length2) < length1)
  68             return throwOutOfMemoryError(exec);
  69         if ((length1 + length2 + length3) < length3)
  70             return throwOutOfMemoryError(exec);
  71
  72         return JSRopeString::create(exec->globalData(), jsString(globalData, u1), jsString(globalData, u2), jsString(globalData, u3));
  73     }
  74
  75     ALWAYS_INLINE JSValue jsString(ExecState* exec, Register* strings, unsigned count)
  76     {
  77         JSGlobalData* globalData = &exec->globalData();
  78         JSRopeString::RopeBuilder ropeBuilder(*globalData);
  79
  80         unsigned oldLength = 0;
  81
  82         for (unsigned i = 0; i < count; ++i) {
  83             JSValue v = strings[i].jsValue();
  84             ropeBuilder.append(v.toString(exec));
  85
  86             if (ropeBuilder.length() < oldLength) // True for overflow
  87                 return throwOutOfMemoryError(exec);
  88         }
  89
  90         return ropeBuilder.release();
  91     }
  92
  93     ALWAYS_INLINE JSValue jsStringFromArguments(ExecState* exec, JSValue thisValue)
  94     {
  95         JSGlobalData* globalData = &exec->globalData();
  96         JSRopeString::RopeBuilder ropeBuilder(*globalData);
  97         ropeBuilder.append(thisValue.toString(exec));
  98
  99         unsigned oldLength = 0;
 100
 101         for (unsigned i = 0; i < exec->argumentCount(); ++i) {
 102             JSValue v = exec->argument(i);
 103             ropeBuilder.append(v.toString(exec));
 104
 105             if (ropeBuilder.length() < oldLength) // True for overflow
 106                 return throwOutOfMemoryError(exec);
 107         }
 108
 109         return ropeBuilder.release();
 110     }
 111
 112     // ECMA 11.9.3
 113     inline bool JSValue::equal(ExecState* exec, JSValue v1, JSValue v2)
 114     {
 115         if (v1.isInt32() && v2.isInt32())
 116             return v1 == v2;
 117
 118         return equalSlowCase(exec, v1, v2);
 119     }
 120
 121     ALWAYS_INLINE bool JSValue::equalSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
 122     {
 123         do {
 124             if (v1.isNumber() && v2.isNumber())
 125                 return v1.asNumber() == v2.asNumber();
 126
 127             bool s1 = v1.isString();
 128             bool s2 = v2.isString();
 129             if (s1 && s2)
 130                 return asString(v1)->value(exec) == asString(v2)->value(exec);
 131
 132             if (v1.isUndefinedOrNull()) {
 133                 if (v2.isUndefinedOrNull())
 134                     return true;
 135                 if (!v2.isCell())
 136                     return false;
 137                 return v2.asCell()->structure()->typeInfo().masqueradesAsUndefined();
 138             }
 139
 140             if (v2.isUndefinedOrNull()) {
 141                 if (!v1.isCell())
 142                     return false;
 143                 return v1.asCell()->structure()->typeInfo().masqueradesAsUndefined();
 144             }
 145
 146             if (v1.isObject()) {
 147                 if (v2.isObject())
 148                     return v1 == v2;
 149                 JSValue p1 = v1.toPrimitive(exec);
 150                 if (exec->hadException())
 151                     return false;
 152                 v1 = p1;
 153                 if (v1.isInt32() && v2.isInt32())
 154                     return v1 == v2;
 155                 continue;
 156             }
 157
 158             if (v2.isObject()) {
 159                 JSValue p2 = v2.toPrimitive(exec);
 160                 if (exec->hadException())
 161                     return false;
 162                 v2 = p2;
 163                 if (v1.isInt32() && v2.isInt32())
 164                     return v1 == v2;
 165                 continue;
 166             }
 167
 168             if (s1 || s2) {
 169                 double d1 = v1.toNumber(exec);
 170                 double d2 = v2.toNumber(exec);
 171                 return d1 == d2;
 172             }
 173
 174             if (v1.isBoolean()) {
 175                 if (v2.isNumber())
 176                     return static_cast<double>(v1.asBoolean()) == v2.asNumber();
 177             } else if (v2.isBoolean()) {
 178                 if (v1.isNumber())
 179                     return v1.asNumber() == static_cast<double>(v2.asBoolean());
 180             }
 181
 182             return v1 == v2;
 183         } while (true);
 184     }
 185
 186     // ECMA 11.9.3
 187     ALWAYS_INLINE bool JSValue::strictEqualSlowCaseInline(ExecState* exec, JSValue v1, JSValue v2)
 188     {
 189         ASSERT(v1.isCell() && v2.isCell());
 190
 191         if (v1.asCell()->isString() && v2.asCell()->isString())
 192             return asString(v1)->value(exec) == asString(v2)->value(exec);
 193
 194         return v1 == v2;
 195     }
 196
 197     inline bool JSValue::strictEqual(ExecState* exec, JSValue v1, JSValue v2)
 198     {
 199         if (v1.isInt32() && v2.isInt32())
 200             return v1 == v2;
 201
 202         if (v1.isNumber() && v2.isNumber())
 203             return v1.asNumber() == v2.asNumber();
 204
 205         if (!v1.isCell() || !v2.isCell())
 206             return v1 == v2;
 207
 208         return strictEqualSlowCaseInline(exec, v1, v2);
 209     }
 210
 211     // See ES5 11.8.1/11.8.2/11.8.5 for definition of leftFirst, this value ensures correct
 212     // evaluation ordering for argument conversions for '<' and '>'. For '<' pass the value
 213     // true, for leftFirst, for '>' pass the value false (and reverse operand order).
 214     template<bool leftFirst>
 215     ALWAYS_INLINE bool jsLess(CallFrame* callFrame, JSValue v1, JSValue v2)
 216     {
 217         if (v1.isInt32() && v2.isInt32())
 218             return v1.asInt32() < v2.asInt32();
 219
 220         if (v1.isNumber() && v2.isNumber())
 221             return v1.asNumber() < v2.asNumber();
 222
 223         if (isJSString(v1) && isJSString(v2))
 224             return asString(v1)->value(callFrame) < asString(v2)->value(callFrame);
 225
 226         double n1;
 227         double n2;
 228         JSValue p1;
 229         JSValue p2;
 230         bool wasNotString1;
 231         bool wasNotString2;
 232         if (leftFirst) {
 233             wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 234             wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 235         } else {
 236             wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 237             wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 238         }
 239
 240         if (wasNotString1 | wasNotString2)
 241             return n1 < n2;
 242         return asString(p1)->value(callFrame) < asString(p2)->value(callFrame);
 243     }
 244
 245     // See ES5 11.8.3/11.8.4/11.8.5 for definition of leftFirst, this value ensures correct
 246     // evaluation ordering for argument conversions for '<=' and '=>'. For '<=' pass the
 247     // value true, for leftFirst, for '=>' pass the value false (and reverse operand order).
 248     template<bool leftFirst>
 249     ALWAYS_INLINE bool jsLessEq(CallFrame* callFrame, JSValue v1, JSValue v2)
 250     {
 251         if (v1.isInt32() && v2.isInt32())
 252             return v1.asInt32() <= v2.asInt32();
 253
 254         if (v1.isNumber() && v2.isNumber())
 255             return v1.asNumber() <= v2.asNumber();
 256
 257         if (isJSString(v1) && isJSString(v2))
 258             return !(asString(v2)->value(callFrame) < asString(v1)->value(callFrame));
 259
 260         double n1;
 261         double n2;
 262         JSValue p1;
 263         JSValue p2;
 264         bool wasNotString1;
 265         bool wasNotString2;
 266         if (leftFirst) {
 267             wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 268             wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 269         } else {
 270             wasNotString2 = v2.getPrimitiveNumber(callFrame, n2, p2);
 271             wasNotString1 = v1.getPrimitiveNumber(callFrame, n1, p1);
 272         }
 273
 274         if (wasNotString1 | wasNotString2)
 275             return n1 <= n2;
 276         return !(asString(p2)->value(callFrame) < asString(p1)->value(callFrame));
 277     }
 278
 279     // Fast-path choices here are based on frequency data from SunSpider:
 280     //    <times> Add case: <t1> <t2>
 281     //    ---------------------------
 282     //    5626160 Add case: 3 3 (of these, 3637690 are for immediate values)
 283     //    247412  Add case: 5 5
 284     //    20900   Add case: 5 6
 285     //    13962   Add case: 5 3
 286     //    4000    Add case: 3 5
 287
 288     ALWAYS_INLINE JSValue jsAdd(CallFrame* callFrame, JSValue v1, JSValue v2)
 289     {
 290         if (v1.isNumber() && v2.isNumber())
 291             return jsNumber(v1.asNumber() + v2.asNumber());
 292
 293         if (v1.isString() && !v2.isObject())
 294             return jsString(callFrame, asString(v1), v2.toString(callFrame));
 295
 296         // All other cases are pretty uncommon
 297         return jsAddSlowCase(callFrame, v1, v2);
 298     }
 299
 300     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSValue base, JSValue slotBase, const Identifier& propertyName, size_t& slotOffset)
 301     {
 302         JSCell* cell = base.asCell();
 303         size_t count = 0;
 304
 305         while (slotBase != cell) {
 306             JSValue v = cell->structure()->prototypeForLookup(callFrame);
 307
 308             // If we didn't find slotBase in base's prototype chain, then base
 309             // must be a proxy for another object.
 310
 311             if (v.isNull())
 312                 return 0;
 313
 314             cell = v.asCell();
 315
 316             // Since we're accessing a prototype in a loop, it's a good bet that it
 317             // should not be treated as a dictionary.
 318             if (cell->structure()->isDictionary()) {
 319                 asObject(cell)->flattenDictionaryObject(callFrame->globalData());
 320                 if (slotBase == cell)
 321                     slotOffset = cell->structure()->get(callFrame->globalData(), propertyName);
 322             }
 323
 324             ++count;
 325         }
 326
 327         ASSERT(count);
 328         return count;
 329     }
 330
 331     inline size_t normalizePrototypeChain(CallFrame* callFrame, JSCell* base)
 332     {
 333         size_t count = 0;
 334         while (1) {
 335             JSValue v = base->structure()->prototypeForLookup(callFrame);
 336             if (v.isNull())
 337                 return count;
 338
 339             base = v.asCell();
 340
 341             // Since we're accessing a prototype in a loop, it's a good bet that it
 342             // should not be treated as a dictionary.
 343             if (base->structure()->isDictionary())
 344                 asObject(base)->flattenDictionaryObject(callFrame->globalData());
 345
 346             ++count;
 347         }
 348     }
 349
 350     ALWAYS_INLINE JSValue resolveBase(CallFrame* callFrame, Identifier& property, ScopeChainNode* scopeChain, bool isStrictPut)
 351     {
 352         ScopeChainIterator iter = scopeChain->begin();
 353         ScopeChainIterator next = iter;
 354         ++next;
 355         ScopeChainIterator end = scopeChain->end();
 356         ASSERT(iter != end);
 357
 358         PropertySlot slot;
 359         JSObject* base;
 360         while (true) {
 361             base = iter->get();
 362             if (next == end) {
 363                 if (isStrictPut && !base->getPropertySlot(callFrame, property, slot))
 364                     return JSValue();
 365                 return base;
 366             }
 367             if (base->getPropertySlot(callFrame, property, slot))
 368                 return base;
 369
 370             iter = next;
 371             ++next;
 372         }
 373
 374         ASSERT_NOT_REACHED();
 375         return JSValue();
 376     }
 377 } // namespace JSC
 378
 379 #endif // Operations_h