1 files changed, 6 insertions, 1 deletions

diff --git a/contrib/llvm/lib/Target/WebAssembly/WebAssemblyFixFunctionBitcasts.cpp b/contrib/llvm/lib/Target/WebAssembly/WebAssemblyFixFunctionBitcasts.cpp
index adf904ee0269..76a2ff3f9803 100644
--- a/contrib/llvm/lib/Target/WebAssembly/WebAssemblyFixFunctionBitcasts.cpp
+++ b/contrib/llvm/lib/Target/WebAssembly/WebAssemblyFixFunctionBitcasts.cpp
@@ -84,7 +84,7 @@ static void FindUses(Value *V, Function &F,
 //  - Call with fewer arguments than needed: arguments are filled in with undef
 //  - Return value is not needed: drop it
 //  - Return value needed but not present: supply an undef
-//  
+//
 // For now, return nullptr without creating a wrapper if the wrapper cannot
 // be generated due to incompatible types.
 static Function *CreateWrapper(Function *F, FunctionType *Ty) {
@@ -148,6 +148,11 @@ bool FixFunctionBitcasts::runOnModule(Module &M) {
     if (!Ty)
       continue;
 
+    // Wasm varargs are not ABI-compatible with non-varargs. Just ignore
+    // such casts for now.
+    if (Ty->isVarArg() || F->isVarArg())
+      continue;
+
     auto Pair = Wrappers.insert(std::make_pair(std::make_pair(F, Ty), nullptr));
     if (Pair.second)
       Pair.first->second = CreateWrapper(F, Ty);