bytecode/GetByIdVariant.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 "GetByIdVariant.h"
  28
  29 #include "CallLinkStatus.h"
  30 #include "JSCInlines.h"
  31 #include <wtf/ListDump.h>
  32
  33 namespace JSC {
  34
  35 GetByIdVariant::GetByIdVariant(
  36     const StructureSet& structureSet, PropertyOffset offset,
  37     const IntendedStructureChain* chain, std::unique_ptr<CallLinkStatus> callLinkStatus)
  38     : m_structureSet(structureSet)
  39     , m_alternateBase(nullptr)
  40     , m_offset(offset)
  41     , m_callLinkStatus(WTF::move(callLinkStatus))
  42 {
  43     if (!structureSet.size()) {
  44         ASSERT(offset == invalidOffset);
  45         ASSERT(!chain);
  46     }
  47
  48     if (chain && chain->size()) {
  49         m_alternateBase = chain->terminalPrototype();
  50         chain->gatherChecks(m_constantChecks);
  51     }
  52 }
  53
  54 GetByIdVariant::~GetByIdVariant() { }
  55
  56 GetByIdVariant::GetByIdVariant(const GetByIdVariant& other)
  57     : GetByIdVariant()
  58 {
  59     *this = other;
  60 }
  61
  62 GetByIdVariant& GetByIdVariant::operator=(const GetByIdVariant& other)
  63 {
  64     m_structureSet = other.m_structureSet;
  65     m_constantChecks = other.m_constantChecks;
  66     m_alternateBase = other.m_alternateBase;
  67     m_offset = other.m_offset;
  68     if (other.m_callLinkStatus)
  69         m_callLinkStatus = std::make_unique<CallLinkStatus>(*other.m_callLinkStatus);
  70     else
  71         m_callLinkStatus = nullptr;
  72     return *this;
  73 }
  74
  75 StructureSet GetByIdVariant::baseStructure() const
  76 {
  77     if (!m_alternateBase)
  78         return structureSet();
  79
  80     Structure* structure = structureFor(m_constantChecks, m_alternateBase);
  81     RELEASE_ASSERT(structure);
  82     return structure;
  83 }
  84
  85 bool GetByIdVariant::attemptToMerge(const GetByIdVariant& other)
  86 {
  87     if (m_alternateBase != other.m_alternateBase)
  88         return false;
  89     if (m_offset != other.m_offset)
  90         return false;
  91     if (m_callLinkStatus || other.m_callLinkStatus)
  92         return false;
  93     if (!areCompatible(m_constantChecks, other.m_constantChecks))
  94         return false;
  95
  96     mergeInto(other.m_constantChecks, m_constantChecks);
  97     m_structureSet.merge(other.m_structureSet);
  98
  99     return true;
 100 }
 101
 102 void GetByIdVariant::dump(PrintStream& out) const
 103 {
 104     dumpInContext(out, 0);
 105 }
 106
 107 void GetByIdVariant::dumpInContext(PrintStream& out, DumpContext* context) const
 108 {
 109     if (!isSet()) {
 110         out.print("<empty>");
 111         return;
 112     }
 113
 114     out.print(
 115         "<", inContext(structureSet(), context), ", ",
 116         "[", listDumpInContext(m_constantChecks, context), "]");
 117     if (m_alternateBase)
 118         out.print(", alternateBase = ", inContext(JSValue(m_alternateBase), context));
 119     out.print(", offset = ", offset());
 120     if (m_callLinkStatus)
 121         out.print(", call = ", *m_callLinkStatus);
 122     out.print(">");
 123 }
 124
 125 } // namespace JSC
 126