darling-JavaScriptCore/domjit/DOMJITHeapRange.h
2017-08-12 09:48:01 -07:00

131 lines
3.9 KiB
C++

/*
* Copyright (C) 2016 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.
*/
#pragma once
#include <wtf/MathExtras.h>
#include <wtf/PrintStream.h>
namespace JSC { namespace DOMJIT {
class HeapRange {
public:
constexpr HeapRange()
: m_begin(UINT16_MAX)
, m_end(UINT16_MAX)
{
}
HeapRange(uint16_t begin, uint16_t end)
: m_begin(begin)
, m_end(end)
{
ASSERT_WITH_MESSAGE(begin <= end, "begin <= end is the invariant of this HeapRange.");
}
enum ConstExprTag { ConstExpr };
constexpr HeapRange(ConstExprTag, uint16_t begin, uint16_t end)
: m_begin(begin)
, m_end(end)
{
}
enum RawRepresentationTag { RawRepresentation };
explicit constexpr HeapRange(RawRepresentationTag, uint32_t value)
: m_raw(value)
{
}
constexpr static HeapRange fromRaw(uint32_t value)
{
return HeapRange(RawRepresentation, value);
}
uint16_t begin() const { return m_begin; }
uint16_t end() const { return m_end; }
uint32_t rawRepresentation() { return m_raw; }
constexpr explicit operator bool() const
{
return m_begin != m_end;
}
constexpr bool operator==(const HeapRange& other) const
{
return m_begin == other.m_begin && m_end == other.m_end;
}
constexpr bool operator!=(const HeapRange& other) const
{
return !operator==(other);
}
template<uint16_t begin, uint16_t end>
static constexpr HeapRange fromConstant()
{
static_assert(begin < end || (begin == UINT16_MAX && end == UINT16_MAX), "begin < end or the both are UINT16_MAX is the invariant of this HeapRange.");
return HeapRange(ConstExpr, begin, end);
}
static constexpr HeapRange top() { return fromConstant<0, UINT16_MAX>(); }
static constexpr HeapRange none() { return fromConstant<UINT16_MAX, UINT16_MAX>(); } // Empty range.
bool isStrictSubtypeOf(const HeapRange& other) const
{
if (!*this || !other)
return false;
if (*this == other)
return false;
return other.m_begin <= m_begin && m_end <= other.m_end;
}
bool isSubtypeOf(const HeapRange& other) const
{
if (!*this || !other)
return false;
if (*this == other)
return true;
return isStrictSubtypeOf(other);
}
bool overlaps(const HeapRange& other) const
{
return WTF::rangesOverlap(m_begin, m_end, other.m_begin, other.m_end);
}
JS_EXPORT_PRIVATE void dump(PrintStream&) const;
private:
union {
struct {
uint16_t m_begin;
uint16_t m_end;
};
uint32_t m_raw;
};
};
} }