Add llvm_unreacheable to silence warning "not all control paths return a value" ...

diff --git a/mlir/lib/IR/SymbolTable.cpp b/mlir/lib/IR/SymbolTable.cpp
index aef7b92..9f145a2 100644 (file)
--- a/mlir/lib/IR/SymbolTable.cpp
+++ b/mlir/lib/IR/SymbolTable.cpp
@@ -385,6 +385,7 @@ raw_ostream &mlir::operator<<(raw_ostream &os,
   case SymbolTable::Visibility::Nested:
     return os << "nested";
   }
+  llvm_unreachable("Unexpected visibility");
 }
 
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