bytecode/ComplexGetStatus.cpp

   1 /*
   2  * Copyright (C) 2014 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "ComplexGetStatus.h"
  28
  29 #include "JSCInlines.h"
  30
  31 namespace JSC {
  32
  33 ComplexGetStatus ComplexGetStatus::computeFor(
  34     CodeBlock* profiledBlock, Structure* headStructure, StructureChain* chain,
  35     unsigned chainCount, UniquedStringImpl* uid)
  36 {
  37     // FIXME: We should assert that we never see a structure that
  38     // hasImpureGetOwnPropertySlot() but for which we don't
  39     // newImpurePropertyFiresWatchpoints(). We're not at a point where we can do
  40     // that, yet.
  41     // https://bugs.webkit.org/show_bug.cgi?id=131810
  42
  43     if (headStructure->takesSlowPathInDFGForImpureProperty())
  44         return takesSlowPath();
  45
  46     ComplexGetStatus result;
  47     result.m_kind = Inlineable;
  48
  49     if (chain && chainCount) {
  50         result.m_chain = adoptRef(new IntendedStructureChain(
  51             profiledBlock, headStructure, chain, chainCount));
  52
  53         if (!result.m_chain->isStillValid())
  54             return skip();
  55
  56         if (headStructure->takesSlowPathInDFGForImpureProperty()
  57             || result.m_chain->takesSlowPathInDFGForImpureProperty())
  58             return takesSlowPath();
  59
  60         JSObject* currentObject = result.m_chain->terminalPrototype();
  61         Structure* currentStructure = result.m_chain->last();
  62
  63         ASSERT_UNUSED(currentObject, currentObject);
  64
  65         result.m_offset = currentStructure->getConcurrently(uid, result.m_attributes);
  66     } else {
  67         result.m_offset = headStructure->getConcurrently(uid, result.m_attributes);
  68     }
  69
  70     if (!isValidOffset(result.m_offset))
  71         return takesSlowPath();
  72
  73     return result;
  74 }
  75
  76 } // namespace JSC
  77
  78