runtime/ScopedArgumentsTable.cpp

   1 /*
   2  * Copyright (C) 2015 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 "ScopedArgumentsTable.h"
  28
  29 #include "JSCInlines.h"
  30
  31 namespace JSC {
  32
  33 const ClassInfo ScopedArgumentsTable::s_info = { "ScopedArgumentsTable", 0, 0, CREATE_METHOD_TABLE(ScopedArgumentsTable) };
  34
  35 ScopedArgumentsTable::ScopedArgumentsTable(VM& vm)
  36     : Base(vm, vm.scopedArgumentsTableStructure.get())
  37     , m_length(0)
  38     , m_locked(false)
  39 {
  40 }
  41
  42 ScopedArgumentsTable::~ScopedArgumentsTable()
  43 {
  44 }
  45
  46 void ScopedArgumentsTable::destroy(JSCell* cell)
  47 {
  48     static_cast<ScopedArgumentsTable*>(cell)->ScopedArgumentsTable::~ScopedArgumentsTable();
  49 }
  50
  51 ScopedArgumentsTable* ScopedArgumentsTable::create(VM& vm)
  52 {
  53     ScopedArgumentsTable* result =
  54         new (NotNull, allocateCell<ScopedArgumentsTable>(vm.heap)) ScopedArgumentsTable(vm);
  55     result->finishCreation(vm);
  56     return result;
  57 }
  58
  59 ScopedArgumentsTable* ScopedArgumentsTable::create(VM& vm, uint32_t length)
  60 {
  61     ScopedArgumentsTable* result = create(vm);
  62     result->m_length = length;
  63     result->m_arguments = std::make_unique<ScopeOffset[]>(length);
  64     return result;
  65 }
  66
  67 ScopedArgumentsTable* ScopedArgumentsTable::clone(VM& vm)
  68 {
  69     ScopedArgumentsTable* result = create(vm, m_length);
  70     for (unsigned i = m_length; i--;)
  71         result->m_arguments[i] = m_arguments[i];
  72     return result;
  73 }
  74
  75 ScopedArgumentsTable* ScopedArgumentsTable::setLength(VM& vm, uint32_t newLength)
  76 {
  77     if (LIKELY(!m_locked)) {
  78         std::unique_ptr<ScopeOffset[]> newArguments = std::make_unique<ScopeOffset[]>(newLength);
  79         for (unsigned i = std::min(m_length, newLength); i--;)
  80             newArguments[i] = m_arguments[i];
  81         m_length = newLength;
  82         m_arguments = WTF::move(newArguments);
  83         return this;
  84     }
  85
  86     ScopedArgumentsTable* result = create(vm, newLength);
  87     for (unsigned i = std::min(m_length, newLength); i--;)
  88         result->m_arguments[i] = m_arguments[i];
  89     return result;
  90 }
  91
  92 ScopedArgumentsTable* ScopedArgumentsTable::set(VM& vm, uint32_t i, ScopeOffset value)
  93 {
  94     ScopedArgumentsTable* result;
  95     if (UNLIKELY(m_locked))
  96         result = clone(vm);
  97     else
  98         result = this;
  99     result->at(i) = value;
 100     return result;
 101 }
 102
 103 Structure* ScopedArgumentsTable::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
 104 {
 105     return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
 106 }
 107
 108 } // namespace JSC
 109