[Local] Add dbg location on unreachable inst in changeToUnreachable

As show in https://bugs.llvm.org/show_bug.cgi?id=37960
it would be desirable to have debug location in the unreachable
instruction.

Also adds a unti test for this function.

Differential Revision: https://reviews.llvm.org/D50340

llvm-svn: 339173

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index d5c54ccc82c..7e607f17fc0 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1930,7 +1930,8 @@ unsigned llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap,
     CallInst *CallTrap = CallInst::Create(TrapFn, "", I);
     CallTrap->setDebugLoc(I->getDebugLoc());
   }
-  new UnreachableInst(I->getContext(), I);
+  auto *UI = new UnreachableInst(I->getContext(), I);
+  UI->setDebugLoc(I->getDebugLoc());
 
   // All instructions after this are dead.
   unsigned NumInstrsRemoved = 0;