What is Pc Materialization?

Question

I am working with a tool called for binary instrumentation called Intel Pin. However I encountered this strange terminology while I was examining part of the examples that Pin comes with. Here is the relevant part:

VOID CallTrace(TRACE trace, INS ins)
{
    if (!KnobTraceCalls)
        return;

    if (INS_IsCall(ins) && !INS_IsDirectBranchOrCall(ins))
    {
        // Indirect call
        string s = "Call " + FormatAddress(INS_Address(ins), TRACE_Rtn(trace));
        s += " -> ";

        INS_InsertCall(ins, IPOINT_BEFORE, AFUNPTR(EmitIndirectCall), IARG_THREAD_ID,
                       IARG_PTR, new string(s), IARG_BRANCH_TARGET_ADDR,
                       IARG_G_ARG0_CALLER, IARG_G_ARG1_CALLER, IARG_END);
    }
    else if (INS_IsDirectBranchOrCall(ins))
    {
        // Is this a tail call?
        RTN sourceRtn = TRACE_Rtn(trace);
        RTN destRtn = RTN_FindByAddress(INS_DirectBranchOrCallTargetAddress(ins));

        if (INS_IsCall(ins)         // conventional call
            || sourceRtn != destRtn // tail call
        )
        {
            BOOL tailcall = !INS_IsCall(ins);

            string s = "";
            if (tailcall)
            {
                s += "Tailcall ";
            }
            else
            {
                if( INS_IsProcedureCall(ins) )
                    s += "Call ";
                else
                {
                    s += "PcMaterialization ";
                    tailcall=1;
                }

            }

            //s += INS_Mnemonic(ins) + " ";

            s += FormatAddress(INS_Address(ins), TRACE_Rtn(trace));
            s += " -> ";

            ADDRINT target = INS_DirectBranchOrCallTargetAddress(ins);

            s += FormatAddress(target, RTN_FindByAddress(target));

            INS_InsertCall(ins, IPOINT_BEFORE, AFUNPTR(EmitDirectCall),
                           IARG_THREAD_ID, IARG_PTR, new string(s), IARG_BOOL, tailcall,
                           IARG_G_ARG0_CALLER, IARG_G_ARG1_CALLER, IARG_END);
        }
    }
    else if (INS_IsRet(ins))
    {
        RTN rtn =  TRACE_Rtn(trace);

#if defined(TARGET_LINUX) && defined(TARGET_IA32)
//        if( RTN_Name(rtn) ==  "_dl_debug_state") return;
        if( RTN_Valid(rtn) && RTN_Name(rtn) ==  "_dl_runtime_resolve") return;
#endif
        string tracestring = "Return " + FormatAddress(INS_Address(ins), rtn);
        INS_InsertCall(ins, IPOINT_BEFORE, AFUNPTR(EmitReturn),
                       IARG_THREAD_ID, IARG_PTR, new string(tracestring), IARG_G_RESULT0, IARG_END);
    }
}

This method determines what actually is the instruction doing (direct call, indirect call, tail call, return and the unknown Pc Materialization).

Here is the full code.

So what does it mean at all? I tried googling - no relevant results.

Answer 1

BOOL LEVEL_CORE::INS_IsPcMaterialization ( INS ins )

Returns: true if this is a call to the next instruction, which is an idiom for materializing the instruction pointer

Check it