Pytorch1.5 update extract method (#876)

* change trace function for pytorch 1.5 (#870)

Co-authored-by: XiaoXYe <50827462+XiaoXYe@users.noreply.github.com>

Co-authored-by: nate.river <lvyufeng2007@hotmail.com>

mmdnn/conversion/pytorch/pytorch_graph.py

@@ -10,7 +10,44 @@
 import contextlib
 from torch.jit import _unique_state_dict
 
+class scope_name_workaround(object):
+    def __init__(self):
+        self.backup = None
+
+    def __enter__(self):
+        def _tracing_name(self_, tracing_state):
+            if not tracing_state._traced_module_stack:
+                return None
+            module = tracing_state._traced_module_stack[-1]
+            for name, child in module.named_children():
+                if child is self_:
+                    return name
+            return None
+
+        def _slow_forward(self_, *input, **kwargs):
+            tracing_state = torch._C._get_tracing_state()
+            if not tracing_state or isinstance(self_.forward, torch._C.ScriptMethod):
+                return self_.forward(*input, **kwargs)
+            if not hasattr(tracing_state, '_traced_module_stack'):
+                tracing_state._traced_module_stack = []
+            name = _tracing_name(self_, tracing_state)
+            if name:
+                tracing_state.push_scope('%s[%s]' % (self_._get_name(), name))
+            else:
+                tracing_state.push_scope(self_._get_name())
+            tracing_state._traced_module_stack.append(self_)
+            try:
+                result = self_.forward(*input, **kwargs)
+            finally:
+                tracing_state.pop_scope()
+                tracing_state._traced_module_stack.pop()
+            return result
+
+        self.backup = torch.nn.Module._slow_forward
+        setattr(torch.nn.Module, '_slow_forward', _slow_forward)
 
+    def __exit__(self, type, value, tb):
+        setattr(torch.nn.Module, '_slow_forward', self.backup)
 
 class PytorchGraphNode(GraphNode):
 
@@ -71,54 +108,12 @@ def __init__(self, model):
         self.shape_dict = dict()
         self.layer_weight_map = dict()
 
-
-    @staticmethod
-    def _optimize_graph(graph, aten, export_raw_ir=False):
-        # run dce first to eliminate dead parts of the graph that might have been
-        # left behind by things like symbolic_override
-
-        torch._C._jit_pass_dce(graph)
-        torch._C._jit_pass_lint(graph)
-
-        torch._C._jit_pass_peephole(graph)
-        torch._C._jit_pass_lint(graph)
-        if not export_raw_ir:
-            graph = torch._C._jit_pass_onnx(graph, aten)
-            torch._C._jit_pass_lint(graph)
-            torch._C._jit_pass_onnx_peephole(graph)
-            torch._C._jit_pass_lint(graph)
-        torch._C._jit_pass_dce(graph)
-        torch._C._jit_pass_lint(graph)
-        graph = torch._C._jit_pass_canonicalize(graph)
-        torch._C._jit_pass_lint(graph)
-        return graph
-
-
     @staticmethod
     def get_node_id(node):
         import re
         node_id = re.search(r"[\d]+", node.__str__())
         return node_id.group(0)
 
-    @contextlib.contextmanager
-    def set_training(self, model, mode):
-        r"""
-        A context manager to temporarily set the training mode of 'model'
-        to 'mode', resetting it when we exit the with-block.  A no-op if
-        mode is None.
-        """
-        if mode is None:
-            yield
-            return
-        old_mode = model.training
-        if old_mode != mode:
-            model.train(mode)
-        try:
-            yield
-        finally:
-            if old_mode != mode:
-                model.train(old_mode)
-
 
     def build(self, shape):
         """
@@ -180,6 +175,45 @@ def node_connection(self, graph, node, node_name):
     def CreateGraphNode(self, node):
         return PytorchGraphNode040(node)
 
+    @staticmethod
+    def _optimize_graph(graph, aten, export_raw_ir=False):
+        # run dce first to eliminate dead parts of the graph that might have been
+        # left behind by things like symbolic_override
+
+        torch._C._jit_pass_dce(graph)
+        torch._C._jit_pass_lint(graph)
+
+        torch._C._jit_pass_peephole(graph)
+        torch._C._jit_pass_lint(graph)
+        if not export_raw_ir:
+            graph = torch._C._jit_pass_onnx(graph, aten)
+            torch._C._jit_pass_lint(graph)
+            torch._C._jit_pass_onnx_peephole(graph)
+            torch._C._jit_pass_lint(graph)
+        torch._C._jit_pass_dce(graph)
+        torch._C._jit_pass_lint(graph)
+        graph = torch._C._jit_pass_canonicalize(graph)
+        torch._C._jit_pass_lint(graph)
+        return graph
+
+    @contextlib.contextmanager
+    def set_training(self, model, mode):
+        r"""
+        A context manager to temporarily set the training mode of 'model'
+        to 'mode', resetting it when we exit the with-block.  A no-op if
+        mode is None.
+        """
+        if mode is None:
+            yield
+            return
+        old_mode = model.training
+        if old_mode != mode:
+            model.train(mode)
+        try:
+            yield
+        finally:
+            if old_mode != mode:
+                model.train(old_mode)
 
 class PytorchGraph151(PytorchGraph):
 
@@ -188,22 +222,21 @@ def __init__(self, model):
 
     def extractgraph(self, dummy_input):
         import re
-        import torch.onnx.utils
-        # connect name and id in nodes with weights
-        graph, params_dict, torch_out = torch.onnx.utils._model_to_graph(self.model, dummy_input, _retain_param_name=True)
+        from torch.onnx.utils import OperatorExportTypes
+        from torch.onnx.utils import _trace
+
+        self.model.eval()
+        with scope_name_workaround():
+            graph = _trace(self.model, dummy_input, OperatorExportTypes.ONNX)
         nodes = list(graph.nodes())
+
         for node in nodes:
             # print(node.__str__())
             node_id = PytorchGraph.get_node_id(node)
             node_name = 'node' + node_id
-            node_scope_str = re.findall(r'[^()!]+', node.__str__())[-2]
-            for x in node_scope_str.split(','):
-                if re.findall(r'%\S+.weight', x):
-                    node_scope = '.'.join(re.findall(r'%\S+.weight', x)[0].replace('%','',1).split('.')[:-1])
-                    self.layer_weight_map[node_name] = node_scope
-
-        graph, params_dict, torch_out = torch.onnx.utils._model_to_graph(self.model, dummy_input)
-        nodes = list(graph.nodes())
+            self.layer_weight_map[node_name] = '.'.join(
+                re.findall(r'\[([\w\d.]+)\]', node.scopeName())
+            )
         return graph, nodes
 
     def rename_nodes(self, node, node_id):