From 2a07e5163347f771ae97e8d0533648d6bda8c346 Mon Sep 17 00:00:00 2001
From: Valentin Clement <clementval@gmail.com>
Date: Mon, 4 Nov 2024 09:59:05 -0800
Subject: [PATCH] [flang][cuda] Crash if mode is not recognized

---
 flang/runtime/CUDA/memory.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/flang/runtime/CUDA/memory.cpp b/flang/runtime/CUDA/memory.cpp
index daf1db684a3d2..5aa7ac5c3cccd 100644
--- a/flang/runtime/CUDA/memory.cpp
+++ b/flang/runtime/CUDA/memory.cpp
@@ -111,7 +111,6 @@ void RTDEF(CUFDataTransferPtrDesc)(void *addr, Descriptor *desc,
 
 void RTDECL(CUFDataTransferDescDesc)(Descriptor *dstDesc, Descriptor *srcDesc,
     unsigned mode, const char *sourceFile, int sourceLine) {
-  Terminator terminator{sourceFile, sourceLine};
   MemmoveFct memmoveFct;
   if (mode == kHostToDevice) {
     memmoveFct = &MemmoveHostToDevice;
@@ -119,6 +118,9 @@ void RTDECL(CUFDataTransferDescDesc)(Descriptor *dstDesc, Descriptor *srcDesc,
     memmoveFct = &MemmoveDeviceToHost;
   } else if (mode == kDeviceToDevice) {
     memmoveFct = &MemmoveDeviceToDevice;
+  } else {
+    Terminator terminator{sourceFile, sourceLine};
+    terminator.Crash("host to host copy not supported");
   }
   Fortran::runtime::Assign(
       *dstDesc, *srcDesc, terminator, MaybeReallocate, memmoveFct);