Fix tensor with dynamic shape problem

Set data size to zero for tensor with dynamic shape,
prevent unexpected memory allocation for tensor data.

mindspore/core/ir/tensor.cc

@@ -44,7 +44,15 @@ static TypeId TypeIdOf(const TypePtr &data_type, TypeId defaultTypeId) {
 }
 
 static size_t SizeOf(const ShapeVector &shape) {
-  return std::accumulate(shape.begin(), shape.end(), size_t(1), std::multiplies<size_t>());
+  int64_t data_size = 1;
+  for (auto dim : shape) {
+    if (dim < 0) {
+      // For dynamic shape which has negative dimensions, data size should be zero.
+      return 0;
+    }
+    data_size *= dim;
+  }
+  return static_cast<size_t>(data_size);
 }
 
 static std::string ShapeToString(const ShapeVector &shape) {

tests/ut/cpp/mindapi/mindapi_test.cc

@@ -347,6 +347,39 @@ TEST_F(TestMindApi, test_tensor_api) {
   ASSERT_EQ(tensor_type->cast<TensorTypePtr>()->element()->type_id(), kNumberTypeFloat32);
 }
 
+/// Feature: MindAPI
+/// Description: test Tensor with dynamic shape.
+/// Expectation: Tensor API work as expected.
+TEST_F(TestMindApi, test_tensor_with_dyn_shape) {
+  ShapeVector shape{1, 2, -1, -2};
+  auto tensor = MakeShared<Tensor>(kNumberTypeFloat32, shape);
+
+  ASSERT_EQ(tensor->data_type(), kNumberTypeFloat32);
+  ASSERT_EQ(tensor->shape(), shape);
+  ASSERT_EQ(tensor->DataSize(), 0);
+  ASSERT_EQ(tensor->Size(), 0);
+
+  ShapeVector shape2{2, 3};
+  tensor->set_data_type(kNumberTypeInt32);
+  tensor->set_shape(shape2);
+  ASSERT_EQ(tensor->data_type(), kNumberTypeInt32);
+  ASSERT_EQ(tensor->shape(), shape2);
+
+  ShapeVector shape3{1, -1, 3};
+  auto tensor2 = MakeShared<Tensor>(kNumberTypeFloat32, shape);
+
+  ASSERT_EQ(tensor2->data_type(), kNumberTypeFloat32);
+  ASSERT_EQ(tensor2->shape(), shape);
+  ASSERT_EQ(tensor2->DataSize(), 0);
+  ASSERT_EQ(tensor2->Size(), 0);
+
+  ShapeVector shape4{3, 4};
+  tensor2->set_data_type(kNumberTypeInt32);
+  tensor2->set_shape(shape4);
+  ASSERT_EQ(tensor2->data_type(), kNumberTypeInt32);
+  ASSERT_EQ(tensor2->shape(), shape4);
+}
+
 /// Feature: MindAPI
 /// Description: test utils API.
 /// Expectation: Tensor API work as expected.