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/*
* 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 "ThrowScope.h"
#include "Exception.h"
#include "JSCInlines.h"
#include "VM.h"
namespace JSC {
#if ENABLE(EXCEPTION_SCOPE_VERIFICATION)
ThrowScope::ThrowScope(VM& vm, ExceptionEventLocation location)
: ExceptionScope(vm, location)
{
m_vm.verifyExceptionCheckNeedIsSatisfied(m_recursionDepth, m_location);
}
ThrowScope::~ThrowScope()
{
RELEASE_ASSERT(m_vm.m_topExceptionScope);
if (!m_isReleased)
m_vm.verifyExceptionCheckNeedIsSatisfied(m_recursionDepth, m_location);
else {
// If we released the scope, that means we're letting our callers do the
// exception check. However, because our caller may be a LLInt or JIT
// function (which always checks for exceptions but won't clear the
// m_needExceptionCheck bit), we should clear m_needExceptionCheck here
// and let code below decide if we need to simulate a re-throw.
m_vm.m_needExceptionCheck = false;
}
bool willBeHandleByLLIntOrJIT = false;
void* previousScope = m_previousScope;
void* topEntryFrame = m_vm.topEntryFrame;
// If the topEntryFrame was pushed on the stack after the previousScope was instantiated,
// then this throwScope will be returning to LLINT or JIT code that always do an exception
// check. In that case, skip the simulated throw because the LLInt and JIT will be
// checking for the exception their own way instead of calling ThrowScope::exception().
if (topEntryFrame && previousScope > topEntryFrame)
willBeHandleByLLIntOrJIT = true;
if (!willBeHandleByLLIntOrJIT)
simulateThrow();
}
void ThrowScope::throwException(ExecState* exec, Exception* exception)
{
if (m_vm.exception() && m_vm.exception() != exception)
m_vm.verifyExceptionCheckNeedIsSatisfied(m_recursionDepth, m_location);
m_vm.throwException(exec, exception);
}
JSValue ThrowScope::throwException(ExecState* exec, JSValue error)
{
if (!error.isCell() || !jsDynamicCast<Exception*>(m_vm, error.asCell()))
m_vm.verifyExceptionCheckNeedIsSatisfied(m_recursionDepth, m_location);
return m_vm.throwException(exec, error);
}
JSObject* ThrowScope::throwException(ExecState* exec, JSObject* obj)
{
if (!jsDynamicCast<Exception*>(m_vm, obj))
m_vm.verifyExceptionCheckNeedIsSatisfied(m_recursionDepth, m_location);
return m_vm.throwException(exec, obj);
}
void ThrowScope::simulateThrow()
{
RELEASE_ASSERT(m_vm.m_topExceptionScope);
m_vm.m_simulatedThrowPointLocation = m_location;
m_vm.m_simulatedThrowPointRecursionDepth = m_recursionDepth;
m_vm.m_needExceptionCheck = true;
if (UNLIKELY(Options::dumpSimulatedThrows()))
m_vm.m_nativeStackTraceOfLastSimulatedThrow = StackTrace::captureStackTrace(Options::unexpectedExceptionStackTraceLimit());
}
#endif // ENABLE(EXCEPTION_SCOPE_VERIFICATION)
} // namespace JSC