fix incorrect usages of std::move and other compile errors

paddle/fluid/distributed/test/ctr_accessor_test.cc

@@ -61,7 +61,7 @@ TableAccessorParameter gen_param() {
   naive_param->add_weight_bounds(-10.0);
   naive_param->add_weight_bounds(10.0);
 
-  return std::move(param);
+  return param;
 }
 
 TEST(downpour_feature_value_accessor_test, test_shrink) {

paddle/fluid/framework/ir/fusion_group/code_generator_tester.cc

@@ -420,11 +420,7 @@ std::unique_ptr<paddle::framework::ir::Graph> BuildGraph(bool backward,
       n->Var()->SetDataType(proto_dtype);
     }
   }
-#ifdef __clang__
   return graph;
-#else
-  return std::move(graph);
-#endif
 }
 
 std::unordered_set<paddle::framework::ir::Node*> DistilGradNodes(

paddle/fluid/framework/ir/fusion_group/fusion_group_pass_tester.cc

@@ -63,11 +63,7 @@ std::unique_ptr<Graph> BuildElementwiseListGraph(bool backward = false) {
       n->Var()->SetDataType(proto::VarType::FP32);
     }
   }
-#ifdef __clang__
   return graph;
-#else
-  return std::move(graph);
-#endif
 }
 
 std::unique_ptr<Graph> BuildElementwiseTreeGraph(bool backward = false) {
@@ -125,11 +121,7 @@ std::unique_ptr<Graph> BuildElementwiseTreeGraph(bool backward = false) {
       n->Var()->SetDataType(proto::VarType::FP32);
     }
   }
-#ifdef __clang__
   return graph;
-#else
-  return std::move(graph);
-#endif
 }
 
 int TestMain(std::unique_ptr<Graph> graph, std::string prefix) {

paddle/fluid/framework/new_executor/interpretercore_util.cc

@@ -740,7 +740,7 @@ std::map<int, std::list<int>> get_downstream_map(
   VLOG(6) << "downstream count: " << downstream_map_count();
   VLOG(6) << "downstream_map: " << std::endl << downstream_map_to_str();
 
-  return std::move(downstream);
+  return downstream;
 }
 
 std::map<int, std::list<int>> build_op_downstream_map(
@@ -994,7 +994,7 @@ std::map<int, std::list<int>> build_op_downstream_map(
               std::ostream_iterator<int>(oss, " "));
     VLOG(10) << oss.str();
   }
-  return std::move(get_downstream_map(op2dependences, op_happens_before));
+  return get_downstream_map(op2dependences, op_happens_before);
 }
 
 }  // namespace interpreter

paddle/fluid/framework/var_desc.h

@@ -74,6 +74,12 @@ class VarDesc {
       : desc_(other.desc_),
         attrs_(other.attrs_),
         original_id_(other.original_id_) {}
+  VarDesc &operator=(const VarDesc &other) {
+    desc_ = other.desc_;
+    attrs_ = other.attrs_;
+    original_id_ = other.original_id_;
+    return *this;
+  }
 
   proto::VarDesc *Proto() { return &desc_; }
 

paddle/fluid/inference/utils/table_printer.cc

@@ -53,7 +53,7 @@ std::string TablePrinter::PrintTable() {
 
   AddRowDivider(ss);
 
-  return std::move(ss.str());
+  return ss.str();
 }
 
 TablePrinter::TablePrinter(const std::vector<std::string>& header) {

paddle/fluid/platform/profiler.cc

@@ -612,7 +612,7 @@ static std::map<uint64_t, ThreadEvents> DockHostEventRecorderHostPart() {
   auto host_evt_sec = HostEventRecorder::GetInstance().GatherEvents();
   EmulateEventPushAndPop(host_evt_sec, &thr_events);
   EmulateCPURecordsAdd(host_evt_sec);
-  return std::move(thr_events);
+  return thr_events;
 }
 
 static void DockHostEventRecorderDevicePart(

paddle/phi/api/lib/api_gen_utils.cc

@@ -41,7 +41,7 @@ std::unique_ptr<std::vector<phi::DenseTensor>> TensorToDenseTensor(
         *std::dynamic_pointer_cast<phi::DenseTensor>(t.impl()));
   }
 
-  return std::move(pt_tensors);
+  return pt_tensors;
 }
 
 std::shared_ptr<phi::SelectedRows> TensorToSelectedRows(const Tensor& tensor) {

paddle/phi/api/lib/data_transform.cc

@@ -253,7 +253,7 @@ std::unique_ptr<std::vector<phi::DenseTensor>> PrepareData(
     }
   }
 
-  return std::move(pt_tensors);
+  return pt_tensors;
 }
 
 }  // namespace experimental

paddle/phi/core/compat/arg_map_context.h

@@ -58,6 +58,11 @@ struct KernelSignature {
 
   // TODO(chenweihang): add assign constructor to solve windows compile
   // problem, remove it later
+  KernelSignature(const KernelSignature& other)
+      : name(other.name),
+        input_names(other.input_names),
+        attr_names(other.attr_names),
+        output_names(other.output_names) {}
   KernelSignature& operator=(const KernelSignature& other) {
     name = other.name;
     input_names = other.input_names;

paddle/phi/core/utils/type_registry.h

@@ -50,7 +50,8 @@ template <typename BaseT>
 TypeInfo<BaseT> TypeRegistry<BaseT>::RegisterType(const std::string& type) {
   std::lock_guard<std::mutex> guard(mutex_);
   assert(name_to_id_.find(type) == name_to_id_.end());
-  assert(names_.size() < std::numeric_limits<int8_t>::max());
+  assert(names_.size() < static_cast<decltype(names_.size())>(
+                             std::numeric_limits<int8_t>::max()));
   int8_t id = static_cast<int8_t>(names_.size());
   names_.emplace_back(type);
   name_to_id_[type] = id;

paddle/utils/array_ref.h

@@ -96,10 +96,21 @@ class ArrayRef {
   template <size_t N>
   /*implicit*/ constexpr ArrayRef(const T (&Arr)[N]) : Data(Arr), Length(N) {}
 
-  /// Construct an ArrayRef from a std::initializer_list.
+/// Construct an ArrayRef from a std::initializer_list.
+#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ >= 9
+// Disable gcc's warning in this constructor as it generates an enormous
+// amount
+// of messages. Anyone using ArrayRef should already be aware of the fact that
+// it does not do lifetime extension.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-list-lifetime"
+#endif
   /*implicit*/ ArrayRef(const std::initializer_list<T> &Vec)
       : Data(Vec.begin() == Vec.end() ? (T *)nullptr : Vec.begin()),
         Length(Vec.size()) {}
+#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ >= 9
+#pragma GCC diagnostic pop
+#endif
 
   /// Construct an ArrayRef<const T*> from ArrayRef<T*>. This uses SFINAE to
   /// ensure that only ArrayRefs of pointers can be converted.