Merge pull request #4396 from reyoung/feature/make_python_catch_enforce_not_met

Make PyBind support C++ exception

paddle/pybind/CMakeLists.txt

 if(WITH_PYTHON)
   cc_library(paddle_pybind SHARED
-    SRCS pybind.cc protobuf.cc
+    SRCS pybind.cc exception.cc protobuf.cc
     DEPS pybind python backward
     ${GLOB_OP_LIB})
 endif(WITH_PYTHON)

paddle/pybind/exception.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
+#include "paddle/pybind/exception.h"
+
+namespace paddle {
+namespace pybind {
+
+void BindException(pybind11::module& m) {
+  static pybind11::exception<platform::EnforceNotMet> exc(m, "EnforceNotMet");
+  pybind11::register_exception_translator([](std::exception_ptr p) {
+    try {
+      if (p) std::rethrow_exception(p);
+    } catch (const platform::EnforceNotMet& e) {
+      exc(e.what());
+    }
+  });
+
+  m.def("__unittest_throw_exception__", [] { PADDLE_THROW("test exception"); });
+}
+
+}  // namespace pybind
+}  // namespace paddle

paddle/pybind/exception.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
+#pragma once
+#include "paddle/platform/enforce.h"
+#include "pybind11/pybind11.h"
+namespace paddle {
+namespace pybind {
+
+extern void BindException(pybind11::module& m);
+}  // namespace pybind
+}  // namespace paddle

paddle/pybind/pybind.cc

@@ -21,6 +21,7 @@ limitations under the License. */
 #include "paddle/operators/recurrent_op.h"
 #include "paddle/platform/enforce.h"
 #include "paddle/platform/place.h"
+#include "paddle/pybind/exception.h"
 #include "paddle/pybind/pybind.h"
 #include "paddle/pybind/tensor_py.h"
 #include "paddle/string/to_string.h"
@@ -47,6 +48,8 @@ PYBIND11_PLUGIN(core) {
   // not cause namespace pollution.
   using namespace paddle::framework;  // NOLINT
 
+  BindException(m);
+
   py::class_<Tensor>(m, "Tensor", py::buffer_protocol())
       .def_buffer(
           [](Tensor &self) -> py::buffer_info { return CastToPyBuffer(self); })

python/paddle/v2/framework/tests/test_exception.py

+import paddle.v2.framework.core as core
+import unittest
+
+
+class TestException(unittest.TestCase):
+    def test_exception(self):
+        ex = None
+        try:
+            core.__unittest_throw_exception__()
+        except core.EnforceNotMet as ex:
+            self.assertIn("test exception", ex.message)
+
+        self.assertIsNotNone(ex)
+
+
+if __name__ == "__main__":
+    unittest.main()