darling-JavaScriptCore/dfg/DFGNullAbstractState.h
2017-08-12 09:48:01 -07:00

63 lines
2.2 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
#if ENABLE(DFG_JIT)
namespace JSC { namespace DFG {
class Edge;
struct AbstractValue;
struct Node;
// Use this as a stub for things that can optionally take some kind of abstract state but you wish
// to not pass any abstract state. This works if the templatized code also does a check (using the
// operator bool) to see if the state is valid.
class NullAbstractState {
WTF_MAKE_FAST_ALLOCATED;
public:
NullAbstractState() { }
explicit operator bool() const { return false; }
AbstractValue& forNode(Node*)
{
RELEASE_ASSERT_NOT_REACHED();
return *bitwise_cast<AbstractValue*>(static_cast<intptr_t>(0x1234));
}
AbstractValue& forNode(Edge)
{
return forNode(nullptr);
}
// It's valid to add more stub methods here as needed.
};
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)