support dynamic input shape

Author: RandySheriffH

tf2onnx/onnx_opset/generator.py

@@ -39,10 +39,16 @@ def version_1(cls, ctx, node, **kwargs):
         seed = node.get_attr("seed")
         node.set_attr("seed", float(seed.f))
         if len(node.input) > 0:
-            shape = node.inputs[0].get_tensor_value()
-            ctx.remove_input(node, node.input[0])
-            node.set_attr("shape", shape)
-            ctx.set_shape(node.output[0], shape)
+            if node.inputs[0].is_const():
+                shape = node.inputs[0].get_tensor_value()
+                ctx.remove_input(node, node.input[0])
+                node.set_attr("shape", shape)
+                ctx.set_shape(node.output[0], shape)
+            else:
+                cast_node = ctx.make_node("Cast", node.input, attr={'to': onnx_pb.TensorProto.INT64})
+                const_node = ctx.make_node("ConstantOfShape", cast_node.output)
+                node.input = const_node.output
+                node.type = node.type + 'Like'
 
 
 @tf_op(["RandomNormalLike", "RandomUniformLike"])