adding test for null function

Author: joaosaffran

llvm/lib/Target/DirectX/DXContainerGlobals.cpp

@@ -169,7 +169,7 @@ void DXContainerGlobals::addRootSignature(Module &M,
   if (FuncRs == RSA.end())
     return;
 
-  const RootSignatureDesc &RS = FuncRs->getSecond();
+  const RootSignatureDesc &RS = FuncRs->second;
   SmallString<256> Data;
   raw_svector_ostream OS(Data);
 

llvm/lib/Target/DirectX/DXILRootSignature.cpp

@@ -132,6 +132,8 @@ analyzeModule(Module &M) {
     // Function was pruned during compilation.
     const MDOperand &FunctionPointerMdNode = RSDefNode->getOperand(0);
     if (FunctionPointerMdNode == nullptr) {
+      reportError(
+          Ctx, "Function associated with Root Signature definition is null.");
       continue;
     }