1 files changed, 7 insertions, 0 deletions
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 2015e3b821d..7025314c691 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3419,6 +3419,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       Args.AddLastArg(CmdArgs, options::OPT_flto, options::OPT_flto_EQ);
   }
 
+  if (const Arg *A = Args.getLastArg(options::OPT_fthinlto_index_EQ)) {
+    if (!types::isLLVMIR(Input.getType()))
+      D.Diag(diag::err_drv_argument_only_allowed_with) << A->getAsString(Args)
+                                                       << "-x ir";
+    Args.AddLastArg(CmdArgs, options::OPT_fthinlto_index_EQ);
+  }
+
   // We normally speed up the clang process a bit by skipping destructors at
   // exit, but when we're generating diagnostics we can rely on some of the
   // cleanup.