CallFrame* CallFrame::trueCallerFrame()
{
// this -> The callee; this is either an inlined callee in which case it already has
// a pointer to the true caller. Otherwise it contains current PC in the machine
// caller.
//
// machineCaller -> The caller according to the machine, which may be zero or
// more frames above the true caller due to inlining.
// Am I an inline call frame? If so, we're done.
if (isInlineCallFrame())
return callerFrame();
// I am a machine call frame, so the question is: is my caller a machine call frame
// that has inlines or a machine call frame that doesn't?
CallFrame* machineCaller = callerFrame()->removeHostCallFrameFlag();
if (!machineCaller)
return 0;
ASSERT(!machineCaller->isInlineCallFrame());
// Figure out how we want to get the current code location.
if (hasHostCallFrameFlag() || returnAddressIsInCtiTrampoline(returnPC()))
return machineCaller->trueCallFrameFromVMCode();
return machineCaller->trueCallFrame(returnPC());
}
CallFrame* CallFrame::trueCallerFrameSlow()
{
// this -> The callee; this is either an inlined callee in which case it already has
// a pointer to the true caller. Otherwise it contains current PC in the machine
// caller.
//
// machineCaller -> The caller according to the machine, which may be zero or
// more frames above the true caller due to inlining.
//
// trueCaller -> The real caller.
// Am I an inline call frame? If so, we're done.
if (isInlineCallFrame())
return callerFrame();
// I am a machine call frame, so the question is: is my caller a machine call frame
// that has inlines or a machine call frame that doesn't?
CallFrame* machineCaller = callerFrame()->removeHostCallFrameFlag();
if (!machineCaller)
return 0;
ASSERT(!machineCaller->isInlineCallFrame());
if (!machineCaller->codeBlock() || !machineCaller->codeBlock()->hasCodeOrigins())
return machineCaller; // No inlining, so machineCaller == trueCaller
// Figure out where the caller frame would have gone relative to the machine
// caller, and rematerialize it. Do so for the entire inline stack.
CodeOrigin codeOrigin = machineCaller->codeBlock()->codeOriginForReturn(returnPC());
for (InlineCallFrame* inlineCallFrame = codeOrigin.inlineCallFrame; inlineCallFrame;) {
InlineCallFrame* nextInlineCallFrame = inlineCallFrame = inlineCallFrame->caller.inlineCallFrame;
CallFrame* inlinedCaller = machineCaller + inlineCallFrame->stackOffset;
JSObject* callee = machineCaller->registers()[inlineCallFrame->calleeVR].function();
JSCell* calleeAsFunctionCell = getJSFunction(callee);
ASSERT(calleeAsFunctionCell);
JSFunction* calleeAsFunction = asFunction(calleeAsFunctionCell);
// Fill in the inlinedCaller
inlinedCaller->setCodeBlock(machineCaller->codeBlock());
inlinedCaller->setScopeChain(calleeAsFunction->scope());
if (nextInlineCallFrame)
inlinedCaller->setCallerFrame(machineCaller + nextInlineCallFrame->stackOffset);
else
inlinedCaller->setCallerFrame(machineCaller);
inlinedCaller->setInlineCallFrame(inlineCallFrame);
inlinedCaller->setArgumentCountIncludingThis(inlineCallFrame->numArgumentsIncludingThis);
inlinedCaller->setCallee(callee);
inlineCallFrame = nextInlineCallFrame;
}
return machineCaller + codeOrigin.inlineCallFrame->stackOffset;
}