1 files changed, 5 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index cc277eea9f4..0679ec02c98 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -582,8 +582,11 @@ bool MIRParserImpl::initializeJumpTableInfo(
       Blocks.push_back(MBB);
     }
     unsigned Index = JTI->createJumpTableIndex(Blocks);
-    // TODO: Report an error when the same jump table slot ID is redefined.
-    PFS.JumpTableSlots.insert(std::make_pair(Entry.ID, Index));
+    if (!PFS.JumpTableSlots.insert(std::make_pair(Entry.ID.Value, Index))
+             .second)
+      return error(Entry.ID.SourceRange.Start,
+                   Twine("redefinition of jump table entry '%jump-table.") +
+                       Twine(Entry.ID.Value) + "'");
   }
   return false;
 }