[Offload] Fix Error checking

[RossBrunton]

All errors must be checked - this includes the local variable we were
using to increase the lifetime of Res. As we were not explicitly
checking it, it resulted in an abort in debug builds.

[llvmbot]

@llvm/pr-subscribers-offload

Author: Ross Brunton (RossBrunton)

Changes

All errors must be checked - this includes the local variable we were
using to increase the lifetime of Res. As we were not explicitly
checking it, it resulted in an abort in debug builds.

---

Full diff: https://github.com/llvm/llvm-project/pull/141939.diff

1 Files Affected:

• (modified) offload/liboffload/src/OffloadImpl.cpp (+9-7)

diff --git a/offload/liboffload/src/OffloadImpl.cpp b/offload/liboffload/src/OffloadImpl.cpp
index a5935a7e5b318..7b67cbba43e68 100644
--- a/offload/liboffload/src/OffloadImpl.cpp
+++ b/offload/liboffload/src/OffloadImpl.cpp
@@ -416,18 +416,20 @@ Error olMemcpy_impl(ol_queue_handle_t Queue, void *DstPtr,
 
   // If no queue is given the memcpy will be synchronous
   auto QueueImpl = Queue ? Queue->AsyncInfo : nullptr;
-  Error Res = Error::success();
 
   if (DstDevice == HostDevice()) {
-    Res = SrcDevice->Device->dataRetrieve(DstPtr, SrcPtr, Size, QueueImpl);
+    if (auto Res =
+            SrcDevice->Device->dataRetrieve(DstPtr, SrcPtr, Size, QueueImpl))
+      return Res;
   } else if (SrcDevice == HostDevice()) {
-    Res = DstDevice->Device->dataSubmit(DstPtr, SrcPtr, Size, QueueImpl);
+    if (auto Res =
+            DstDevice->Device->dataSubmit(DstPtr, SrcPtr, Size, QueueImpl))
+      return Res;
   } else {
-    Res = SrcDevice->Device->dataExchange(SrcPtr, *DstDevice->Device, DstPtr,
-                                          Size, QueueImpl);
+    if (auto Res = SrcDevice->Device->dataExchange(SrcPtr, *DstDevice->Device,
+                                                   DstPtr, Size, QueueImpl))
+      return Res;
   }
-  if (Res)
-    return Res;
 
   if (EventOut)
     *EventOut = makeEvent(Queue);