1 files changed, 5 insertions, 2 deletions
diff --git a/lib/Transforms/IPO/CrossDSOCFI.cpp b/lib/Transforms/IPO/CrossDSOCFI.cpp
index ba2e60dee3bc..1b111de06157 100644
--- a/lib/Transforms/IPO/CrossDSOCFI.cpp
+++ b/lib/Transforms/IPO/CrossDSOCFI.cpp
@@ -98,8 +98,11 @@ void CrossDSOCFI::buildCFICheck(Module &M) {
   LLVMContext &Ctx = M.getContext();
   Constant *C = M.getOrInsertFunction(
       "__cfi_check", Type::getVoidTy(Ctx), Type::getInt64Ty(Ctx),
-      Type::getInt8PtrTy(Ctx), Type::getInt8PtrTy(Ctx), nullptr);
+      Type::getInt8PtrTy(Ctx), Type::getInt8PtrTy(Ctx));
   Function *F = dyn_cast<Function>(C);
+  // Take over the existing function. The frontend emits a weak stub so that the
+  // linker knows about the symbol; this pass replaces the function body.
+  F->deleteBody();
   F->setAlignment(4096);
   auto args = F->arg_begin();
   Value &CallSiteTypeId = *(args++);
@@ -117,7 +120,7 @@ void CrossDSOCFI::buildCFICheck(Module &M) {
   IRBuilder<> IRBFail(TrapBB);
   Constant *CFICheckFailFn = M.getOrInsertFunction(
       "__cfi_check_fail", Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx),
-      Type::getInt8PtrTy(Ctx), nullptr);
+      Type::getInt8PtrTy(Ctx));
   IRBFail.CreateCall(CFICheckFailFn, {&CFICheckFailData, &Addr});
   IRBFail.CreateBr(ExitBB);