Пример #1
0
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;
}
Пример #2
0
CallFrame* CallFrame::trueCallFrame(AbstractPC pc)
{
    // Am I an inline call frame? If so, we're done.
    if (isInlineCallFrame())
        return this;
    
    // If I don't have a code block, then I'm not DFG code, so I'm the true call frame.
    CodeBlock* machineCodeBlock = codeBlock();
    if (!machineCodeBlock)
        return this;
    
    // If the code block does not have any code origins, then there was no inlining, so
    // I'm done.
    if (!machineCodeBlock->hasCodeOrigins())
        return this;
    
    // At this point the PC must be due either to the DFG, or it must be unset.
    ASSERT(pc.hasJITReturnAddress() || !pc);
    
    // Try to determine the CodeOrigin. If we don't have a pc set then the only way
    // that this makes sense is if the CodeOrigin index was set in the call frame.
    // FIXME: Note that you will see "Not currently in inlined code" comments below.
    // Currently, we do not record code origins for code that is not inlined, because
    // the only thing that we use code origins for is determining the inline stack.
    // But in the future, we'll want to use this same functionality (having a code
    // origin mapping for any calls out of JIT code) to determine the PC at any point
    // in the stack even if not in inlined code. When that happens, the code below
    // will have to change the way it detects the presence of inlining: it will always
    // get a code origin, but sometimes, that code origin will not have an inline call
    // frame. In that case, this method should bail and return this.
    CodeOrigin codeOrigin;
    if (pc.isSet()) {
        ReturnAddressPtr currentReturnPC = pc.jitReturnAddress();
        
        bool hasCodeOrigin = machineCodeBlock->codeOriginForReturn(currentReturnPC, codeOrigin);
        ASSERT_UNUSED(hasCodeOrigin, hasCodeOrigin);
    } else {
        unsigned index = codeOriginIndexForDFG();
        codeOrigin = machineCodeBlock->codeOrigin(index);
    }

    if (!codeOrigin.inlineCallFrame)
        return this; // Not currently in inlined code.
    
    for (InlineCallFrame* inlineCallFrame = codeOrigin.inlineCallFrame; inlineCallFrame;) {
        InlineCallFrame* nextInlineCallFrame = inlineCallFrame->caller.inlineCallFrame;
        
        CallFrame* inlinedCaller = this + inlineCallFrame->stackOffset;
        
        JSFunction* calleeAsFunction = inlineCallFrame->callee.get();
        
        // Fill in the inlinedCaller
        inlinedCaller->setCodeBlock(machineCodeBlock);
        
        inlinedCaller->setScopeChain(calleeAsFunction->scope());
        if (nextInlineCallFrame)
            inlinedCaller->setCallerFrame(this + nextInlineCallFrame->stackOffset);
        else
            inlinedCaller->setCallerFrame(this);
        
        inlinedCaller->setInlineCallFrame(inlineCallFrame);
        inlinedCaller->setArgumentCountIncludingThis(inlineCallFrame->arguments.size());
        inlinedCaller->setCallee(calleeAsFunction);
        
        inlineCallFrame = nextInlineCallFrame;
    }
    
    return this + codeOrigin.inlineCallFrame->stackOffset;
}