From b09a370218c357b70b8b75f524fff3134697dbca Mon Sep 17 00:00:00 2001
From: Edward Chen <18449977+edgchen1@users.noreply.github.com>
Date: Tue, 16 Feb 2021 12:41:48 -0800
Subject: [PATCH] Address warning in data_types_internal.h (#6704)

Address "unreachable code" warning in data_types_internal.h.
---
 .../onnxruntime/core/framework/data_types_internal.h   |  7 ++++---
 onnxruntime/core/framework/tensorprotoutils.cc         | 10 ++++++----
 onnxruntime/core/session/onnxruntime_c_api.cc          |  4 ++--
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/include/onnxruntime/core/framework/data_types_internal.h b/include/onnxruntime/core/framework/data_types_internal.h
index 8e1649c552..c1ce7581d2 100644
--- a/include/onnxruntime/core/framework/data_types_internal.h
+++ b/include/onnxruntime/core/framework/data_types_internal.h
@@ -243,10 +243,11 @@ class CallableDispatchableHelper {
   }
 };
 
-// Default policy is to throw with no return type.
+// Default policy is to throw an exception.
+// Other policies may set the second result argument accordingly.
 template <class Ret>
 struct UnsupportedTypeDefaultPolicy {
-  Ret operator()(int32_t dt_type) const {
+  void operator()(int32_t dt_type, Ret& /*result*/) const {
     ORT_THROW("Unsupported data type: ", dt_type);
   }
 };
@@ -264,7 +265,7 @@ class CallableDispatchableRetHelper {
   Ret Get() {
     // No type was invoked
     if (called_ == 0) {
-      result_ = UnsupportedPolicy()(dt_type_);
+      UnsupportedPolicy()(dt_type_, result_);
     }
     return result_;
   }
diff --git a/onnxruntime/core/framework/tensorprotoutils.cc b/onnxruntime/core/framework/tensorprotoutils.cc
index 79a19983ef..015a2da9e1 100644
--- a/onnxruntime/core/framework/tensorprotoutils.cc
+++ b/onnxruntime/core/framework/tensorprotoutils.cc
@@ -909,8 +909,8 @@ static Status CopySparseData(size_t n_sparse_elements,
 }
 
 struct UnsupportedSparseDataType {
-  Status operator()(int32_t dt_type) const {
-    return ORT_MAKE_STATUS(ONNXRUNTIME, FAIL, "Unsupported sparse tensor data type of ", dt_type);
+  void operator()(int32_t dt_type, Status& status) const {
+    status = ORT_MAKE_STATUS(ONNXRUNTIME, FAIL, "Unsupported sparse tensor data type of ", dt_type);
   }
 };
 
@@ -998,7 +998,7 @@ common::Status SparseTensorProtoToDenseTensorProto(const ONNX_NAMESPACE::SparseT
 
   } else {
     // No request for std::string
-    status = UnsupportedSparseDataType()(ONNX_NAMESPACE::TensorProto_DataType_STRING);
+    UnsupportedSparseDataType()(ONNX_NAMESPACE::TensorProto_DataType_STRING, status);
   }
   return status;
 }
@@ -1056,7 +1056,9 @@ common::Status DenseTensorToSparseTensorProto(const ONNX_NAMESPACE::TensorProto&
 
   const bool is_string_data = dense_proto.data_type() == ONNX_NAMESPACE::TensorProto_DataType_STRING;
   if (is_string_data) {
-    return UnsupportedSparseDataType()(ONNX_NAMESPACE::TensorProto_DataType_STRING);
+    Status status{};
+    UnsupportedSparseDataType()(ONNX_NAMESPACE::TensorProto_DataType_STRING, status);
+    return status;
   }
 
   const auto data_type = dense_proto.data_type();
diff --git a/onnxruntime/core/session/onnxruntime_c_api.cc b/onnxruntime/core/session/onnxruntime_c_api.cc
index 3d72439a58..beb05e20db 100644
--- a/onnxruntime/core/session/onnxruntime_c_api.cc
+++ b/onnxruntime/core/session/onnxruntime_c_api.cc
@@ -1267,10 +1267,10 @@ struct CallGetValueImpl {
 
 // Return status instead of throwing if unsupported type specified
 struct UnsupportedReturnFailStatus {
-  ORT_STATUS_PTR operator()(int32_t dt_type) const {
+  void operator()(int32_t dt_type, OrtStatusPtr& status) const {
     std::string msg("Unsupported tensor element type in the input: ");
     msg.append(std::to_string(dt_type));
-    return OrtApis::CreateStatus(ORT_FAIL, msg.c_str());
+    status = OrtApis::CreateStatus(ORT_FAIL, msg.c_str());
   }
 };
 }  // namespace c_api_internal