Fix subgraph with custom_op (apache#15671)

src/c_api/c_api_symbolic.cc

@@ -1046,8 +1046,10 @@ int MXGenBackendSubgraph(SymbolHandle sym_handle, const char *backend_name,
   for (auto property : subgraph_prop_list) {
     nnvm::Graph g = Symbol2Graph(*s);
     property->SetAttr("graph", g);
-    g.attrs["subgraph_property"] = std::make_shared<nnvm::any>(std::move(property));
+    g.attrs["subgraph_property"] = std::make_shared<nnvm::any>(property);
     g = ApplyPass(std::move(g), "BuildSubgraph");
+    property->RemoveAttr("graph");
+    g.attrs.erase("subgraph_property");
     s->outputs = g.outputs;
   }
   *ret_sym_handle = s;

src/c_api/c_api_test.cc

@@ -50,8 +50,10 @@ int MXBuildSubgraphByOpNames(SymbolHandle sym_handle,
       g.outputs = s->outputs;
       property->SetAttr("graph", g);
       property->SetAttr("op_names", op_name_set);
-      g.attrs["subgraph_property"] = std::make_shared<nnvm::any>(std::move(property));
+      g.attrs["subgraph_property"] = std::make_shared<nnvm::any>(property);
       g = nnvm::ApplyPass(std::move(g), "BuildSubgraph");
+      property->RemoveAttr("graph");
+      g.attrs.erase("subgraph_property");
       s->outputs = g.outputs;
     }
   }

src/executor/graph_executor.cc

@@ -1688,8 +1688,10 @@ static nnvm::Symbol BuildSubgraph(const nnvm::Symbol& src, op::SubgraphPropertyP
   g = InferForwardAttrs(g, arg_shapes, arg_dtypes, arg_stypes, default_ctx, ctx_map, in_arg_ctxes,
                         aux_state_ctxes, true);
   subgraph_prop->SetAttr("graph", g);
-  g.attrs["subgraph_property"] = std::make_shared<nnvm::any>(std::move(subgraph_prop));
+  g.attrs["subgraph_property"] = std::make_shared<nnvm::any>(subgraph_prop);
   g = ApplyPass(std::move(g), "BuildSubgraph");
+  subgraph_prop->RemoveAttr("graph");
+  g.attrs.erase("subgraph_property");
   ret.outputs = g.outputs;
   return ret;
 }

src/operator/subgraph/subgraph_property.h

@@ -330,6 +330,15 @@ class SubgraphProperty {
     auto it = attrs_.find(name);
     return it != attrs_.end();
   }
+  /*!
+   * \brief Remove attr if the attr exists.
+   */
+  void RemoveAttr(const std::string& name) {
+    auto it = attrs_.find(name);
+    if (it != attrs_.end()) {
+      attrs_.erase(it);
+    }
+  }
   /*!
    * \brief Get the property type.
    */
@@ -384,6 +393,16 @@ class SubgraphBackend {
     return it != attrs_.end();
   }
 
+  /*!
+   * \brief Remove attr if the attr exists.
+   */
+  void RemoveAttr(const std::string& name) {
+    auto it = attrs_.find(name);
+    if (it != attrs_.end()) {
+      attrs_.erase(it);
+    }
+  }
+
   SubgraphPropertyPtr& RegisterSubgraphProperty(const SubgraphPropertyPtr prop) {
     prop_ptr_.push_back(prop);
     return prop_ptr_.back();

tests/python/unittest/test_subgraph.py

@@ -144,6 +144,59 @@ def make_subgraph4(stype):
                         rtol=0.001, atol=0.0001)
 
 
+def test_subgraph_with_customOp():
+    class MyAdd(mx.operator.CustomOp):
+        def forward(self, is_train, req, in_data, out_data, aux):
+            self.assign(out_data[0], req[0], in_data[0] + 1)
+
+        def backward(self, req, out_grad, in_data, out_data, in_grad, aux):
+            self.assign(in_grad[0], req[0], out_grad[0])
+
+    @mx.operator.register('MyAdd1')
+    class MyAdd1Prop(mx.operator.CustomOpProp):
+        def __init__(self):
+            super(MyAdd1Prop, self).__init__(need_top_grad=True)
+
+        def list_arguments(self):
+            return ['data']
+
+        def list_outputs(self):
+            return ['output']
+
+        def infer_shape(self, in_shape):
+            # inputs, outputs, aux
+            return [in_shape[0]], [in_shape[0]], []
+
+        def create_operator(self, ctx, shapes, dtypes):
+            return MyAdd()
+
+    @mx.operator.register('MyAdd2')
+    class MyAdd2Prop(mx.operator.CustomOpProp):
+        def __init__(self):
+            super(MyAdd2Prop, self).__init__(need_top_grad=True)
+
+        def list_arguments(self):
+            return ['data']
+
+        def list_outputs(self):
+            return ['output']
+
+        def infer_shape(self, in_shape):
+            # inputs, outputs, aux
+            return [in_shape[0]], [in_shape[0]], []
+
+        def create_operator(self, ctx, shapes, dtypes):
+            return MyAdd()
+
+    inp = mx.nd.zeros(shape=(100, 100))
+    a = mx.symbol.Variable('a')
+    b = a + 1
+    b = mx.symbol.Custom(data=a, op_type='MyAdd1')
+    c = mx.symbol.Custom(data=a, op_type='MyAdd2')
+    b.bind(mx.cpu(), {'a': inp}).forward()
+    c.bind(mx.cpu(), {'a': inp}).forward()
+    mx.nd.waitall()
+
 if __name__ == '__main__':
     import nose
     nose.runmodule()