improved error handling of zero count

Author: oleksandr-pavlyk

dpctl-capi/source/dpctl_sycl_device_interface.cpp

@@ -578,7 +578,12 @@ DPCTLDevice_CreateSubDevicesEqually(__dpctl_keep const DPCTLSyclDeviceRef DRef,
                                     size_t count)
 {
     vector_class<DPCTLSyclDeviceRef> *Devices = nullptr;
-    if (DRef && count) {
+    if (DRef) {
+        if (count == 0) {
+            std::cerr << "Can not create sub-devices with zero compute units"
+                      << '\n';
+            return nullptr;
+        }
         auto D = unwrap(DRef);
         try {
             auto subDevices = D->create_sub_devices<
@@ -611,10 +616,15 @@ DPCTLDevice_CreateSubDevicesByCounts(__dpctl_keep const DPCTLSyclDeviceRef DRef,
                                      size_t ncounts)
 {
     vector_class<DPCTLSyclDeviceRef> *Devices = nullptr;
-    std::vector<size_t> vcounts;
+    std::vector<size_t> vcounts(ncounts);
     vcounts.assign(counts, counts + ncounts);
     size_t min_elem = *std::min_element(vcounts.begin(), vcounts.end());
-    if (DRef && min_elem) {
+    if (min_elem == 0) {
+        std::cerr << "Can not create sub-devices with zero compute units"
+                  << '\n';
+        return nullptr;
+    }
+    if (DRef) {
         auto D = unwrap(DRef);
         vector_class<std::remove_pointer<decltype(D)>::type> subDevices;
         try {