MIR Parser: Report an error when a machine function doesn't have a corresponding function.

This commit reports an error when a machine function from a MIR file that contains
LLVM IR can't find a function with the same name in the loaded LLVM IR module.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10468


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239831 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MIRParser/MIRParser.cpp

@@ -173,6 +173,9 @@ bool MIRParserImpl::parseMachineFunction(yaml::Input &In, Module &M,
   Functions.insert(std::make_pair(FunctionName, std::move(MF)));
   if (NoLLVMIR)
     createDummyFunction(FunctionName, M);
+  else if (!M.getFunction(FunctionName))
+    return error(Twine("function '") + FunctionName +
+                 "' isn't defined in the provided LLVM IR");
   return false;
 }