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/*
* Copyright (C) 2011, 2012 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.
*/
#ifndef CommonSlowPaths_h
#define CommonSlowPaths_h
#include "CodeBlock.h"
#include "CodeSpecializationKind.h"
#include "ExceptionHelpers.h"
#include "JSArray.h"
#include "NameInstance.h"
namespace JSC {
// The purpose of this namespace is to include slow paths that are shared
// between the interpreter and baseline JIT. They are written to be agnostic
// with respect to the slow-path calling convention, but they do rely on the
// JS code being executed more-or-less directly from bytecode (so the call
// frame layout is unmodified, making it potentially awkward to use these
// from any optimizing JIT, like the DFG).
namespace CommonSlowPaths {
ALWAYS_INLINE ExecState* arityCheckFor(ExecState* exec, RegisterFile* registerFile, CodeSpecializationKind kind)
{
JSFunction* callee = jsCast<JSFunction*>(exec->callee());
ASSERT(!callee->isHostFunction());
CodeBlock* newCodeBlock = &callee->jsExecutable()->generatedBytecodeFor(kind);
int argumentCountIncludingThis = exec->argumentCountIncludingThis();
// This ensures enough space for the worst case scenario of zero arguments passed by the caller.
if (!registerFile->grow(exec->registers() + newCodeBlock->numParameters() + newCodeBlock->m_numCalleeRegisters))
return 0;
ASSERT(argumentCountIncludingThis < newCodeBlock->numParameters());
// Too few arguments -- copy call frame and arguments, then fill in missing arguments with undefined.
size_t delta = newCodeBlock->numParameters() - argumentCountIncludingThis;
Register* src = exec->registers();
Register* dst = exec->registers() + delta;
int i;
int end = -ExecState::offsetFor(argumentCountIncludingThis);
for (i = -1; i >= end; --i)
dst[i] = src[i];
end -= delta;
for ( ; i >= end; --i)
dst[i] = jsUndefined();
ExecState* newExec = ExecState::create(dst);
ASSERT((void*)newExec <= registerFile->end());
return newExec;
}
ALWAYS_INLINE bool opInstanceOfSlow(ExecState* exec, JSValue value, JSValue baseVal, JSValue proto)
{
ASSERT(!value.isCell() || !baseVal.isCell() || !proto.isCell()
|| !value.isObject() || !baseVal.isObject() || !proto.isObject()
|| !asObject(baseVal)->structure()->typeInfo().implementsDefaultHasInstance());
// ECMA-262 15.3.5.3:
// Throw an exception either if baseVal is not an object, or if it does not implement 'HasInstance' (i.e. is a function).
TypeInfo typeInfo(UnspecifiedType);
if (!baseVal.isObject() || !(typeInfo = asObject(baseVal)->structure()->typeInfo()).implementsHasInstance()) {
exec->globalData().exception = createInvalidParamError(exec, "instanceof", baseVal);
return false;
}
ASSERT(typeInfo.type() != UnspecifiedType);
if (!typeInfo.overridesHasInstance() && !value.isObject())
return false;
return asObject(baseVal)->methodTable()->hasInstance(asObject(baseVal), exec, value, proto);
}
inline bool opIn(ExecState* exec, JSValue propName, JSValue baseVal)
{
if (!baseVal.isObject()) {
exec->globalData().exception = createInvalidParamError(exec, "in", baseVal);
return false;
}
JSObject* baseObj = asObject(baseVal);
uint32_t i;
if (propName.getUInt32(i))
return baseObj->hasProperty(exec, i);
if (isName(propName))
return baseObj->hasProperty(exec, jsCast<NameInstance*>(propName.asCell())->privateName());
Identifier property(exec, propName.toString(exec)->value(exec));
if (exec->globalData().exception)
return false;
return baseObj->hasProperty(exec, property);
}
ALWAYS_INLINE JSValue opResolve(ExecState* exec, Identifier& ident)
{
ScopeChainNode* scopeChain = exec->scopeChain();
ScopeChainIterator iter = scopeChain->begin();
ScopeChainIterator end = scopeChain->end();
ASSERT(iter != end);
do {
JSObject* o = iter->get();
PropertySlot slot(o);
if (o->getPropertySlot(exec, ident, slot))
return slot.getValue(exec, ident);
} while (++iter != end);
exec->globalData().exception = createUndefinedVariableError(exec, ident);
return JSValue();
}
ALWAYS_INLINE JSValue opResolveSkip(ExecState* exec, Identifier& ident, int skip)
{
ScopeChainNode* scopeChain = exec->scopeChain();
ScopeChainIterator iter = scopeChain->begin();
ScopeChainIterator end = scopeChain->end();
ASSERT(iter != end);
CodeBlock* codeBlock = exec->codeBlock();
bool checkTopLevel = codeBlock->codeType() == FunctionCode && codeBlock->needsFullScopeChain();
ASSERT(skip || !checkTopLevel);
if (checkTopLevel && skip--) {
if (exec->uncheckedR(codeBlock->activationRegister()).jsValue())
++iter;
}
while (skip--) {
++iter;
ASSERT(iter != end);
}
do {
JSObject* o = iter->get();
PropertySlot slot(o);
if (o->getPropertySlot(exec, ident, slot))
return slot.getValue(exec, ident);
} while (++iter != end);
exec->globalData().exception = createUndefinedVariableError(exec, ident);
return JSValue();
}
ALWAYS_INLINE JSValue opResolveWithBase(ExecState* exec, Identifier& ident, Register& baseSlot)
{
ScopeChainNode* scopeChain = exec->scopeChain();
ScopeChainIterator iter = scopeChain->begin();
ScopeChainIterator end = scopeChain->end();
// FIXME: add scopeDepthIsZero optimization
ASSERT(iter != end);
JSObject* base;
do {
base = iter->get();
PropertySlot slot(base);
if (base->getPropertySlot(exec, ident, slot)) {
JSValue result = slot.getValue(exec, ident);
if (exec->globalData().exception)
return JSValue();
baseSlot = JSValue(base);
return result;
}
++iter;
} while (iter != end);
exec->globalData().exception = createUndefinedVariableError(exec, ident);
return JSValue();
}
ALWAYS_INLINE JSValue opResolveWithThis(ExecState* exec, Identifier& ident, Register& baseSlot)
{
ScopeChainNode* scopeChain = exec->scopeChain();
ScopeChainIterator iter = scopeChain->begin();
ScopeChainIterator end = scopeChain->end();
// FIXME: add scopeDepthIsZero optimization
ASSERT(iter != end);
JSObject* base;
do {
base = iter->get();
++iter;
PropertySlot slot(base);
if (base->getPropertySlot(exec, ident, slot)) {
JSValue result = slot.getValue(exec, ident);
if (exec->globalData().exception)
return JSValue();
// All entries on the scope chain should be EnvironmentRecords (activations etc),
// other then 'with' object, which are directly referenced from the scope chain,
// and the global object. If we hit either an EnvironmentRecord or a global
// object at the end of the scope chain, this is undefined. If we hit a non-
// EnvironmentRecord within the scope chain, pass the base as the this value.
if (iter == end || base->structure()->typeInfo().isEnvironmentRecord())
baseSlot = jsUndefined();
else
baseSlot = JSValue(base);
return result;
}
} while (iter != end);
exec->globalData().exception = createUndefinedVariableError(exec, ident);
return JSValue();
}
} } // namespace JSC::CommonSlowPaths
#endif // CommonSlowPaths_h
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