lib/AST/Decl.cpp

2550   unsigned NumRequiredArgs = getNumParams();
2554   if (NumRequiredArgs > 0 &&
2555       getParamDecl(NumRequiredArgs - 1)->isParameterPack())
2556     --NumRequiredArgs;
2560   while (NumRequiredArgs > 0 &&
2561          getParamDecl(NumRequiredArgs-1)->hasDefaultArg())
2562     --NumRequiredArgs;
2566   unsigned ArgIdx = NumRequiredArgs;
2569       NumRequiredArgs = ArgIdx;
2574   return NumRequiredArgs;