From fd3f2518a4fe3f9ee52d03eb519bd654c3ce4055 Mon Sep 17 00:00:00 2001
From: Christian Sigg <csigg@google.com>
Date: Thu, 3 Jun 2021 09:25:22 +0200
Subject: [PATCH] [mlir] Catch nonconvertible types in async conversion

Reviewed By: ezhulenev, ftynse

Differential Revision: https://reviews.llvm.org/D103592
---
 mlir/lib/Conversion/AsyncToLLVM/AsyncToLLVM.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mlir/lib/Conversion/AsyncToLLVM/AsyncToLLVM.cpp b/mlir/lib/Conversion/AsyncToLLVM/AsyncToLLVM.cpp
index a66f246..ff2460b 100644
--- a/mlir/lib/Conversion/AsyncToLLVM/AsyncToLLVM.cpp
+++ b/mlir/lib/Conversion/AsyncToLLVM/AsyncToLLVM.cpp
@@ -1059,7 +1059,8 @@ void mlir::populateAsyncStructuralTypeConversionsAndLegality(
     ConversionTarget &target) {
   typeConverter.addConversion([&](TokenType type) { return type; });
   typeConverter.addConversion([&](ValueType type) {
-    return ValueType::get(typeConverter.convertType(type.getValueType()));
+    Type converted = typeConverter.convertType(type.getValueType());
+    return converted ? ValueType::get(converted) : converted;
   });
 
   patterns.add<ConvertExecuteOpTypes, ConvertAwaitOpTypes, ConvertYieldOpTypes>(
-- 
2.7.4