Source/JavaScriptCore/wasm/WasmFormat.cpp

/*
 * Copyright (C) 2016-2017 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"

#include "WasmFormat.h"

#if ENABLE(WEBASSEMBLY)

#include "WasmMemory.h"
#include <wtf/CheckedArithmetic.h>
#include <wtf/FastMalloc.h>

namespace JSC { namespace Wasm {

Segment* Segment::create(I32InitExpr offset, uint32_t sizeInBytes)
{
    Checked<uint32_t, RecordOverflow> totalBytesChecked = sizeInBytes;
    totalBytesChecked += sizeof(Segment);
    uint32_t totalBytes;
    if (totalBytesChecked.safeGet(totalBytes) == CheckedState::DidOverflow)
        return nullptr;
    auto allocated = tryFastCalloc(totalBytes, 1);
    Segment* segment;
    if (!allocated.getValue(segment))
        return nullptr;
    segment->offset = offset;
    segment->sizeInBytes = sizeInBytes;
    return segment;
}

void Segment::destroy(Segment *segment)
{
    fastFree(segment);
}

Segment::Ptr Segment::adoptPtr(Segment* segment)
{
    return Ptr(segment, &Segment::destroy);
}

String makeString(const Name& characters)
{
    String result = String::fromUTF8(characters);
    ASSERT(result);
    return result;
}

} } // namespace JSC::Wasm

#endif // ENABLE(WEBASSEMBLY)