Fix #12542 An error occurred (#12603 An error occurred )

* Fix #12542
  
An error occurred
 


* Remove ignore of non-virtual-dtor error

modules/dnn/CMakeLists.txt

@@ -36,7 +36,6 @@ else()
                                        -Wunused-parameter -Wunused-local-typedefs -Wsign-compare -Wsign-promo
                                        -Wundef -Wtautological-undefined-compare -Wignored-qualifiers -Wextra
                                        -Wunused-function -Wunused-const-variable -Wdeprecated-declarations
-                                       -Werror=non-virtual-dtor
   )
 endif()
 

modules/dnn/src/onnx/onnx_importer.cpp

@@ -213,7 +213,7 @@ LayerParams ONNXImporter::getLayerParams(const opencv_onnx::NodeProto& node_prot
         else if (attribute_proto.floats_size() > 0)
         {
             lp.set(attribute_name, DictValue::arrayReal(
-                (float*)attribute_proto.mutable_floats(), attribute_proto.floats_size()));
+                attribute_proto.floats().data(), attribute_proto.floats_size()));
         }
         else if (attribute_proto.ints_size() > 0)
         {

modules/dnn/src/tensorflow/tf_graph_simplifier.cpp

@@ -20,6 +20,8 @@ using ::google::protobuf::MapPair;
 class Subgraph  // Interface to match and replace TensorFlow subgraphs.
 {
 public:
+    virtual ~Subgraph() {}
+
     // Add a node to be matched in the origin graph. Specify ids of nodes that
     // are expected to be inputs. Returns id of a newly added node.
     // TODO: Replace inputs to std::vector<int> in C++11