diff --git a/paddle/fluid/distributed/auto_parallel/dist_attr.cc b/paddle/fluid/distributed/auto_parallel/dist_attr.cc
index 805641cf01837..26d438c23349d 100644
--- a/paddle/fluid/distributed/auto_parallel/dist_attr.cc
+++ b/paddle/fluid/distributed/auto_parallel/dist_attr.cc
@@ -23,9 +23,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/var_desc.h"
 #include "paddle/phi/core/distributed/auto_parallel/proto_helper.h"
 
-namespace paddle {
-namespace distributed {
-namespace auto_parallel {
+namespace paddle::distributed::auto_parallel {
 
 using phi::distributed::auto_parallel::str_join;
 
@@ -487,6 +485,4 @@ bool operator==(const OperatorDistAttr& lhs, const OperatorDistAttr& rhs) {
   return true;
 }
 
-}  // namespace auto_parallel
-}  // namespace distributed
-}  // namespace paddle
+}  // namespace paddle::distributed::auto_parallel
diff --git a/paddle/fluid/distributed/fleet_executor/dist_model.cc b/paddle/fluid/distributed/fleet_executor/dist_model.cc
index 4c19069b33705..ee7540d05d5ef 100644
--- a/paddle/fluid/distributed/fleet_executor/dist_model.cc
+++ b/paddle/fluid/distributed/fleet_executor/dist_model.cc
@@ -28,8 +28,7 @@
 #include "paddle/fluid/framework/scope.h"
 #include "paddle/fluid/framework/tensor.h"
 
-namespace paddle {
-namespace distributed {
+namespace paddle::distributed {
 
 namespace {
 bool IsPersistable(const framework::VarDesc *var) {
@@ -705,5 +704,4 @@ bool DistModel::Run(const std::vector<DistModelTensor> &input_data,
   return true;
 }
 
-}  // namespace distributed
-}  // namespace paddle
+}  // namespace paddle::distributed
diff --git a/paddle/fluid/distributed/ps/service/brpc_ps_client.cc b/paddle/fluid/distributed/ps/service/brpc_ps_client.cc
index 2d72a08a13f30..67ad3b729b9f3 100644
--- a/paddle/fluid/distributed/ps/service/brpc_ps_client.cc
+++ b/paddle/fluid/distributed/ps/service/brpc_ps_client.cc
@@ -24,15 +24,12 @@
 
 static const int max_port = 65535;
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 class Scope;
 class Variable;
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework
 
-namespace paddle {
-namespace distributed {
+namespace paddle::distributed {
 
 PD_DEFINE_int32(pserver_push_dense_merge_limit,
                 12,
@@ -2066,5 +2063,4 @@ void BrpcPsClient::PushDenseRawGradient(std::shared_ptr<DenseAsyncTask> &task,
   }
 }
 
-}  // namespace distributed
-}  // namespace paddle
+}  // namespace paddle::distributed
diff --git a/paddle/fluid/framework/details/multi_devices_helper.cc b/paddle/fluid/framework/details/multi_devices_helper.cc
index d2379c2c49a19..097bc0dd59127 100644
--- a/paddle/fluid/framework/details/multi_devices_helper.cc
+++ b/paddle/fluid/framework/details/multi_devices_helper.cc
@@ -18,9 +18,7 @@
 #include "paddle/fluid/framework/details/share_tensor_buffer_op_handle.h"
 #include "paddle/fluid/framework/ir/graph_helper.h"
 
-namespace paddle {
-namespace framework {
-namespace details {
+namespace paddle::framework::details {
 
 static constexpr size_t kUndefinedDevIdx = -1UL;
 
@@ -300,6 +298,4 @@ bool HasKeepLastReadOp(const ir::Graph &graph) {
   return HasDropLastReadOpImpl(graph, false);
 }
 
-}  // namespace details
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::details
diff --git a/paddle/fluid/framework/dist_multi_trainer.cc b/paddle/fluid/framework/dist_multi_trainer.cc
index 119b6e569cef3..2e4def46d0e61 100644
--- a/paddle/fluid/framework/dist_multi_trainer.cc
+++ b/paddle/fluid/framework/dist_multi_trainer.cc
@@ -22,8 +22,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/device_worker_factory.h"
 #include "paddle/fluid/framework/trainer.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 
 void DistMultiTrainer::Initialize(const TrainerDesc &trainer_desc,
                                   Dataset *dataset) {
@@ -232,5 +231,4 @@ void DistMultiTrainer::MergeToRootScope(phi::DenseTensor *root_tensor,
     root_data[i] += data[i];
   }
 }
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework
diff --git a/paddle/fluid/framework/ir/conv_elementwise_add_fuse_pass.cc b/paddle/fluid/framework/ir/conv_elementwise_add_fuse_pass.cc
index 4a0dd02db0f24..f002d88aa58a1 100644
--- a/paddle/fluid/framework/ir/conv_elementwise_add_fuse_pass.cc
+++ b/paddle/fluid/framework/ir/conv_elementwise_add_fuse_pass.cc
@@ -19,9 +19,7 @@
 #include "paddle/fluid/platform/device/gpu/gpu_info.h"
 #endif
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 #define GET_IR_NODE(node__) GET_IR_NODE_FROM_SUBGRAPH(node__, node__, pattern);
 #define GET_NODES                    \
@@ -171,9 +169,7 @@ void ConvElementwiseAddFusePass::ApplyImpl(ir::Graph* graph) const {
   AddStatis(found_conv_eltwise_count);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(conv_elementwise_add_fuse_pass,
               paddle::framework::ir::ConvElementwiseAddFusePass);
diff --git a/paddle/fluid/framework/ir/dense_multihead_matmul_to_sparse_pass_tester.cc b/paddle/fluid/framework/ir/dense_multihead_matmul_to_sparse_pass_tester.cc
index 98f55003b266b..23247ae6114ac 100644
--- a/paddle/fluid/framework/ir/dense_multihead_matmul_to_sparse_pass_tester.cc
+++ b/paddle/fluid/framework/ir/dense_multihead_matmul_to_sparse_pass_tester.cc
@@ -16,9 +16,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/ir/pass_tester_helper.h"
 #include "paddle/fluid/framework/op_version_registry.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 void AddVarToScope(Scope* param_scope,
                    const std::string& name,
@@ -147,9 +145,7 @@ TEST(DenseMultiHeadMatmulToSparsePass, basic) {
                         num_fused_nodes_after));
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 USE_PASS(multihead_matmul_fuse_pass);
 USE_PASS(multihead_matmul_fuse_pass_v2);
diff --git a/paddle/fluid/framework/ir/embedding_eltwise_layernorm_fuse_pass_tester.cc b/paddle/fluid/framework/ir/embedding_eltwise_layernorm_fuse_pass_tester.cc
index 7ac5b1690ea1c..be2ec2284fb13 100644
--- a/paddle/fluid/framework/ir/embedding_eltwise_layernorm_fuse_pass_tester.cc
+++ b/paddle/fluid/framework/ir/embedding_eltwise_layernorm_fuse_pass_tester.cc
@@ -18,9 +18,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/ir/pass_tester_helper.h"
 #include "paddle/fluid/framework/op_version_registry.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 TEST(EmbeddingElewiseLayernormFusePass, basic) {
   // inputs                           operator            output
@@ -100,8 +98,6 @@ TEST(EmbeddingElewiseLayernormFusePass, pass_op_version_check) {
           .IsPassCompatible("embedding_eltwise_layernorm_fuse_pass"));
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 USE_PASS(embedding_eltwise_layernorm_fuse_pass);
diff --git a/paddle/fluid/framework/ir/fuse_bn_act_pass.cc b/paddle/fluid/framework/ir/fuse_bn_act_pass.cc
index 048b33a649f94..7e6c6d145de87 100644
--- a/paddle/fluid/framework/ir/fuse_bn_act_pass.cc
+++ b/paddle/fluid/framework/ir/fuse_bn_act_pass.cc
@@ -19,19 +19,13 @@
 #include "paddle/fluid/framework/operator.h"
 #include "paddle/fluid/platform/enforce.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 class Node;
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 #include "paddle/fluid/platform/device/gpu/gpu_dnn.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 void FuseBatchNormActPass::ApplyImpl(ir::Graph *graph) const {
 #if defined(PADDLE_WITH_CUDA) || defined(PADDLE_WITH_HIP)
@@ -351,8 +345,6 @@ std::vector<Node *> FuseBatchNormActPass::ReplaceNode(
   return new_list;
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(fuse_bn_act_pass, paddle::framework::ir::FuseBatchNormActPass);
diff --git a/paddle/fluid/framework/ir/graph_pattern_detector_tester.cc b/paddle/fluid/framework/ir/graph_pattern_detector_tester.cc
index c775677c51688..640b2bb361afa 100644
--- a/paddle/fluid/framework/ir/graph_pattern_detector_tester.cc
+++ b/paddle/fluid/framework/ir/graph_pattern_detector_tester.cc
@@ -16,9 +16,7 @@
 
 #include "paddle/fluid/framework/ir/graph_pattern_detector.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 class Node;
 
@@ -207,6 +205,4 @@ TEST(GraphPatternDetector, IntermediateCheck) {
   ASSERT_EQ(count, 1);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
diff --git a/paddle/fluid/framework/ir/layernorm_shift_partition_fuse_pass.cc b/paddle/fluid/framework/ir/layernorm_shift_partition_fuse_pass.cc
index dbe990f636372..d613b01271b80 100644
--- a/paddle/fluid/framework/ir/layernorm_shift_partition_fuse_pass.cc
+++ b/paddle/fluid/framework/ir/layernorm_shift_partition_fuse_pass.cc
@@ -23,9 +23,7 @@
 #include "paddle/fluid/framework/op_version_registry.h"
 #include "paddle/fluid/platform/enforce.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 class Node;
 
@@ -256,9 +254,7 @@ void LayerNormShiftPartitionFusePass::ApplyImpl(ir::Graph* graph) const {
   AddStatis(found_count);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(layernorm_shift_partition_fuse_pass,
               paddle::framework::ir::LayerNormShiftPartitionFusePass);
diff --git a/paddle/fluid/framework/ir/memory_optimize_pass/buffer_shared_inplace_op_pass.cc b/paddle/fluid/framework/ir/memory_optimize_pass/buffer_shared_inplace_op_pass.cc
index e89c98f15f6f8..e6ec82abf3563 100644
--- a/paddle/fluid/framework/ir/memory_optimize_pass/buffer_shared_inplace_op_pass.cc
+++ b/paddle/fluid/framework/ir/memory_optimize_pass/buffer_shared_inplace_op_pass.cc
@@ -20,9 +20,7 @@
 #include "paddle/fluid/framework/ir/pass.h"
 #include "paddle/fluid/platform/enforce.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 class Graph;
 
@@ -301,9 +299,7 @@ void BufferSharedInplaceOpPass::ApplyImpl(ProgramDesc *main_program,
   block->Flush();
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(buffer_shared_inplace_pass,
               paddle::framework::ir::BufferSharedInplaceOpPass)
diff --git a/paddle/fluid/framework/ir/memory_optimize_pass/pylayer_op_eager_deletion_pass.cc b/paddle/fluid/framework/ir/memory_optimize_pass/pylayer_op_eager_deletion_pass.cc
index 5ec567f81a44a..c8978ef0056e5 100644
--- a/paddle/fluid/framework/ir/memory_optimize_pass/pylayer_op_eager_deletion_pass.cc
+++ b/paddle/fluid/framework/ir/memory_optimize_pass/pylayer_op_eager_deletion_pass.cc
@@ -17,9 +17,7 @@
 #include "paddle/fluid/framework/ir/pass.h"
 #include "paddle/fluid/operators/controlflow/op_variant.h"
 #include "paddle/fluid/operators/controlflow/pylayer_op_helper.h"
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 using OpVariant = operators::OpVariant;
 class PyLayerOpEagerDeletionPass : public Pass {
  protected:
@@ -94,9 +92,7 @@ class PyLayerOpEagerDeletionPass : public Pass {
   }
 };
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(pylayer_op_eager_deletion_pass,
               paddle::framework::ir::PyLayerOpEagerDeletionPass);
diff --git a/paddle/fluid/framework/ir/node.cc b/paddle/fluid/framework/ir/node.cc
index 5516a2d799ad1..be1bb0865cba5 100644
--- a/paddle/fluid/framework/ir/node.cc
+++ b/paddle/fluid/framework/ir/node.cc
@@ -14,9 +14,7 @@ limitations under the License. */
 
 #include "paddle/fluid/framework/ir/node.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 // msvc15 don't support constexpr in correct way.
 // static constexpr member implies inline since CXX17 and may cause multiple
 // definition.
@@ -39,6 +37,4 @@ std::unique_ptr<Node> CreateNodeForTest(OpDesc *op_desc) {
   return std::unique_ptr<Node>(new Node(op_desc));
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
diff --git a/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass.cc b/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass.cc
index 91f878a16abd0..e501cff846551 100644
--- a/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass.cc
+++ b/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass.cc
@@ -23,9 +23,7 @@
 #include "paddle/phi/core/enforce.h"
 #include "paddle/utils/string/pretty_log.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 using string::PrettyLogDetail;
 
@@ -635,9 +633,7 @@ void CPUQuantizeSquashPass::ApplyImpl(ir::Graph* graph) const {
   QuantizeBf16Conv(graph);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(cpu_quantize_squash_pass,
               paddle::framework::ir::CPUQuantizeSquashPass);
diff --git a/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass_tester.cc b/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass_tester.cc
index fc57bdb6b52ef..3bee2cc94146f 100644
--- a/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass_tester.cc
+++ b/paddle/fluid/framework/ir/onednn/cpu_quantize_squash_pass_tester.cc
@@ -18,9 +18,7 @@
 #include "paddle/fluid/framework/naive_executor.h"
 #include "paddle/phi/common/place.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 void SetOp(ProgramDesc* prog,
            const std::string& type,
@@ -1179,8 +1177,6 @@ TEST(CpuQuantizeSquashPass, squash_all_u8_input_to_concat2) {
       BuildU8U8ConcatProgramDesc(1.2f, 1.2f), expected_operators, remove_nodes);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 USE_PASS(cpu_quantize_squash_pass);
diff --git a/paddle/fluid/framework/ir/onednn/matmul_transpose_reshape_onednn_fuse_pass.cc b/paddle/fluid/framework/ir/onednn/matmul_transpose_reshape_onednn_fuse_pass.cc
index 0b742d763bebc..85e098e7bfe0d 100644
--- a/paddle/fluid/framework/ir/onednn/matmul_transpose_reshape_onednn_fuse_pass.cc
+++ b/paddle/fluid/framework/ir/onednn/matmul_transpose_reshape_onednn_fuse_pass.cc
@@ -18,9 +18,7 @@
 #include "paddle/phi/core/enforce.h"
 #include "paddle/utils/string/pretty_log.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 using string::PrettyLogDetail;
 
@@ -202,9 +200,7 @@ MatmulTransposeReshapeMKLDNNPass::MatmulTransposeReshapeMKLDNNPass() {
       .End();
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(matmul_transpose_reshape_onednn_fuse_pass,
               paddle::framework::ir::MatmulTransposeReshapeMKLDNNPass);
diff --git a/paddle/fluid/framework/ir/onednn/quant_dequant_onednn_pass.cc b/paddle/fluid/framework/ir/onednn/quant_dequant_onednn_pass.cc
index 6ffd3963504f2..afb9585d968bb 100644
--- a/paddle/fluid/framework/ir/onednn/quant_dequant_onednn_pass.cc
+++ b/paddle/fluid/framework/ir/onednn/quant_dequant_onednn_pass.cc
@@ -20,9 +20,7 @@
 #include "paddle/fluid/framework/ir/onednn/onednn_pass_util.h"
 #include "paddle/fluid/framework/op_version_registry.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 void QuantDequantMkldnnPass::MarkSkipQuantizedOps(
     ir::Graph* graph, const std::unordered_set<std::string>& skip_ops) const {
@@ -758,9 +756,7 @@ void QuantDequantMkldnnPass::ApplyImpl(ir::Graph* graph) const {
       graph, "has_quant_info", "var_quant_scales", var_quant_scales);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 
 REGISTER_PASS(quant_dequant_onednn_pass,
               paddle::framework::ir::QuantDequantMkldnnPass);
diff --git a/paddle/fluid/framework/ir/pass.cc b/paddle/fluid/framework/ir/pass.cc
index 0b3ebd324dc7a..ac8f8be58a605 100644
--- a/paddle/fluid/framework/ir/pass.cc
+++ b/paddle/fluid/framework/ir/pass.cc
@@ -20,21 +20,17 @@ limitations under the License. */
 #include "paddle/fluid/framework/op_proto_maker.h"
 #include "paddle/fluid/framework/program_utils.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 class Scope;
-namespace ir {
+}  // namespace paddle::framework
+namespace paddle::framework::ir {
 class Graph;
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
 #ifdef PADDLE_WITH_DNNL
 #include "paddle/fluid/platform/onednn_helper.h"
 #endif
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 static const char kParamScopeAttr[] = "__param_scope__";  // NOLINT
 
@@ -299,6 +295,4 @@ PassRegistry &PassRegistry::Instance() {
   static PassRegistry g_pass_info_map;
   return g_pass_info_map;
 }
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir
diff --git a/paddle/fluid/framework/no_need_buffer_vars_inference.cc b/paddle/fluid/framework/no_need_buffer_vars_inference.cc
index 794548aa6b44b..cf40833dfdfb9 100644
--- a/paddle/fluid/framework/no_need_buffer_vars_inference.cc
+++ b/paddle/fluid/framework/no_need_buffer_vars_inference.cc
@@ -19,8 +19,7 @@
 #include "paddle/fluid/framework/operator.h"
 #include "paddle/fluid/imperative/saved_variable_wrapper_list.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 
 const Attribute &InferNoNeedBufferVarsContext::GetAttr(
     const std::string &name) const {
@@ -66,5 +65,4 @@ bool DyGraphInferNoNeedBufferVarsContext::HasOutput(
   return false;
 }
 
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework
diff --git a/paddle/fluid/framework/op_version_registry.cc b/paddle/fluid/framework/op_version_registry.cc
index 198394619e00d..a2edad1eb386f 100644
--- a/paddle/fluid/framework/op_version_registry.cc
+++ b/paddle/fluid/framework/op_version_registry.cc
@@ -14,9 +14,7 @@ limitations under the License. */
 
 #include "paddle/fluid/framework/op_version_registry.h"
 
-namespace paddle {
-namespace framework {
-namespace compatible {
+namespace paddle::framework::compatible {
 
 OpVersionDesc&& OpVersionDesc::NewInput(const std::string& name,
                                         const std::string& remark) {
@@ -102,6 +100,4 @@ PassVersionCheckerRegistrar& PassVersionCheckerRegistrar::GetInstance() {
 // Provide a fake registration item for pybind testing.
 #include "paddle/fluid/framework/op_version_registry.inl"
 
-}  // namespace compatible
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::compatible
diff --git a/paddle/fluid/framework/program_converter.cc b/paddle/fluid/framework/program_converter.cc
index 2645b3cf826ab..a3b094879957b 100644
--- a/paddle/fluid/framework/program_converter.cc
+++ b/paddle/fluid/framework/program_converter.cc
@@ -25,8 +25,7 @@
 #include "paddle/fluid/framework/program_desc.h"
 #include "paddle/fluid/framework/version.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 
 using paddle::experimental::ExtractPlainVector;
 using paddle::experimental::WrapAsScalars;
@@ -80,7 +79,8 @@ std::pair<bool, std::unordered_multimap<std::string, OpDesc*>> DetectLegacyOps(
   return std::make_pair(is_legacy_program, legacy_op_map);
 }
 
-namespace no_scalar {
+}  // namespace paddle::framework
+namespace paddle::framework::no_scalar {
 void ConvertSetValueOp(OpDesc* op) {
   std::vector<paddle::experimental::Scalar> values = PADDLE_GET_CONST(
       std::vector<paddle::experimental::Scalar>, op->GetAttr("values", false));
@@ -189,9 +189,9 @@ void ConvertProgram(ProgramDesc* program) {
     }
   }
 }
-}  // namespace no_scalar
+}  // namespace paddle::framework::no_scalar
 
-namespace scalar {
+namespace paddle::framework::scalar {
 void ConvertSetValueOp(OpDesc* op) {
   std::vector<paddle::experimental::Scalar> values;
 
@@ -319,6 +319,4 @@ void ConvertProgram(ProgramDesc* program) {
     }
   }
 }
-}  // namespace scalar
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::scalar
diff --git a/paddle/fluid/imperative/all_reduce.cc b/paddle/fluid/imperative/all_reduce.cc
index f86bce962e021..445f5d92ae5ab 100644
--- a/paddle/fluid/imperative/all_reduce.cc
+++ b/paddle/fluid/imperative/all_reduce.cc
@@ -34,8 +34,7 @@
 #include "paddle/fluid/platform/device_context.h"
 #include "paddle/utils/string/string_helper.h"
 
-namespace paddle {
-namespace imperative {
+namespace paddle::imperative {
 
 static const platform::Place &GetVarPlace(const framework::Variable &src) {
   if (src.IsType<phi::DenseTensor>()) {
@@ -272,7 +271,6 @@ void AllReduce(const framework::Variable &src,
   AllReduce(src, dst, strategy, 0, true);
 }
 
-}  // namespace imperative
-}  // namespace paddle
+}  // namespace paddle::imperative
 
 #endif
diff --git a/paddle/fluid/imperative/var_helper.cc b/paddle/fluid/imperative/var_helper.cc
index 9561962935ffe..7da3f352bdffc 100644
--- a/paddle/fluid/imperative/var_helper.cc
+++ b/paddle/fluid/imperative/var_helper.cc
@@ -27,8 +27,7 @@
 #include "paddle/fluid/imperative/layer.h"
 #include "paddle/fluid/platform/place.h"
 #include "paddle/phi/core/selected_rows.h"
-namespace paddle {
-namespace imperative {
+namespace paddle::imperative {
 
 /* GetVariableWrapper */
 template <>
@@ -303,5 +302,4 @@ template void SetCachedValue<VariableWrapper>(
     std::shared_ptr<VariableWrapper> var,
     const phi::KernelKey &key,
     std::shared_ptr<VariableWrapper> res);
-}  // namespace imperative
-}  // namespace paddle
+}  // namespace paddle::imperative
diff --git a/paddle/fluid/inference/analysis/passes/adjust_cudnn_workspace_size_pass.cc b/paddle/fluid/inference/analysis/passes/adjust_cudnn_workspace_size_pass.cc
index 217d52e0dad1c..e77dcfee4e2c1 100644
--- a/paddle/fluid/inference/analysis/passes/adjust_cudnn_workspace_size_pass.cc
+++ b/paddle/fluid/inference/analysis/passes/adjust_cudnn_workspace_size_pass.cc
@@ -16,9 +16,7 @@
 
 #include "paddle/fluid/inference/analysis/argument.h"
 
-namespace paddle {
-namespace inference {
-namespace analysis {
+namespace paddle::inference::analysis {
 
 void AdjustCudnnWorkSpacePass::RunImpl(Argument* argument) {
   if (!argument->use_gpu()) return;
@@ -40,6 +38,4 @@ std::string AdjustCudnnWorkSpacePass::repr() const {
   return "adjust-cudnn-work-space-pass";
 }
 
-}  // namespace analysis
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::analysis
diff --git a/paddle/fluid/inference/tensorrt/convert/batch_norm_op.cc b/paddle/fluid/inference/tensorrt/convert/batch_norm_op.cc
index c0df0703d1fd3..b0c88649753da 100644
--- a/paddle/fluid/inference/tensorrt/convert/batch_norm_op.cc
+++ b/paddle/fluid/inference/tensorrt/convert/batch_norm_op.cc
@@ -18,9 +18,7 @@ namespace nvinfer1 {
 class IScaleLayer;  // NOLINT
 }  // namespace nvinfer1
 
-namespace paddle {
-namespace inference {
-namespace tensorrt {
+namespace paddle::inference::tensorrt {
 
 class BatchNormOpConverter : public OpConverter {
  public:
@@ -179,8 +177,6 @@ class BatchNormOpConverter : public OpConverter {
   }
 };
 
-}  // namespace tensorrt
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::tensorrt
 
 REGISTER_TRT_OP_CONVERTER(batch_norm, BatchNormOpConverter);
diff --git a/paddle/fluid/inference/tensorrt/convert/layernorm_shift_partition_op.cc b/paddle/fluid/inference/tensorrt/convert/layernorm_shift_partition_op.cc
index 4f4b09b6173a2..3d3c79e1185c8 100644
--- a/paddle/fluid/inference/tensorrt/convert/layernorm_shift_partition_op.cc
+++ b/paddle/fluid/inference/tensorrt/convert/layernorm_shift_partition_op.cc
@@ -15,9 +15,7 @@ limitations under the License. */
 #include "paddle/fluid/inference/tensorrt/plugin/layernorm_shift_partition_op.h"
 #include "paddle/fluid/inference/tensorrt/convert/op_converter.h"
 
-namespace paddle {
-namespace inference {
-namespace tensorrt {
+namespace paddle::inference::tensorrt {
 
 class LayerNormShiftPartitionOpConverter : public OpConverter {
  public:
@@ -101,9 +99,7 @@ class LayerNormShiftPartitionOpConverter : public OpConverter {
   }
 };
 
-}  // namespace tensorrt
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::tensorrt
 
 REGISTER_TRT_OP_CONVERTER(layernorm_shift_partition,
                           LayerNormShiftPartitionOpConverter);
diff --git a/paddle/fluid/inference/tensorrt/convert/slice_op.cc b/paddle/fluid/inference/tensorrt/convert/slice_op.cc
index 4dbeff4761401..564c0a441bcfb 100644
--- a/paddle/fluid/inference/tensorrt/convert/slice_op.cc
+++ b/paddle/fluid/inference/tensorrt/convert/slice_op.cc
@@ -11,9 +11,7 @@ limitations under the License. */
 
 #include "paddle/fluid/inference/tensorrt/convert/op_converter.h"
 
-namespace paddle {
-namespace inference {
-namespace tensorrt {
+namespace paddle::inference::tensorrt {
 
 class SliceOpConverter : public OpConverter {
  public:
@@ -223,8 +221,6 @@ class SliceOpConverter : public OpConverter {
   }
 };
 
-}  // namespace tensorrt
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::tensorrt
 
 REGISTER_TRT_OP_CONVERTER(slice, SliceOpConverter);
diff --git a/paddle/fluid/memory/allocation/naive_best_fit_allocator.cc b/paddle/fluid/memory/allocation/naive_best_fit_allocator.cc
index 0506e80738662..024391739ad70 100644
--- a/paddle/fluid/memory/allocation/naive_best_fit_allocator.cc
+++ b/paddle/fluid/memory/allocation/naive_best_fit_allocator.cc
@@ -43,9 +43,7 @@ COMMON_DECLARE_uint64(initial_gpu_memory_in_mb);
 COMMON_DECLARE_uint64(reallocate_gpu_memory_in_mb);
 PD_DECLARE_bool(benchmark);
 
-namespace paddle {
-namespace memory {
-namespace legacy {
+namespace paddle::memory::legacy {
 template <typename Place>
 void *Alloc(const Place &place, size_t size);
 
@@ -623,9 +621,9 @@ size_t Usage::operator()(const platform::CUDAPinnedPlace &cuda_pinned) const {
       "'CUDAPinnedPlace' is not supported in CPU only device."));
 #endif
 }
-}  // namespace legacy
+}  // namespace paddle::memory::legacy
 
-namespace allocation {
+namespace paddle::memory::allocation {
 
 phi::Allocation *NaiveBestFitAllocator::AllocateImpl(size_t size) {
   void *ptr = paddle::platform::VisitPlace(place_, legacy::AllocVisitor(size));
@@ -644,6 +642,4 @@ uint64_t NaiveBestFitAllocator::ReleaseImpl(const platform::Place &place) {
   return paddle::platform::VisitPlace(place, legacy::ReleaseVisitor());
 }
 
-}  // namespace allocation
-}  // namespace memory
-}  // namespace paddle
+}  // namespace paddle::memory::allocation
diff --git a/paddle/fluid/memory/malloc.cc b/paddle/fluid/memory/malloc.cc
index 7dae4436854ef..4c3ee5ed6fe27 100644
--- a/paddle/fluid/memory/malloc.cc
+++ b/paddle/fluid/memory/malloc.cc
@@ -18,8 +18,7 @@ limitations under the License. */
 #include "paddle/fluid/platform/place.h"
 #include "paddle/phi/core/stream.h"
 
-namespace paddle {
-namespace memory {
+namespace paddle::memory {
 
 std::shared_ptr<Allocation> AllocShared(const platform::Place& place,
                                         size_t size) {
@@ -85,5 +84,4 @@ void RecordStream(std::shared_ptr<Allocation> allocation,
                                                               stream);
 }
 #endif
-}  // namespace memory
-}  // namespace paddle
+}  // namespace paddle::memory
diff --git a/paddle/fluid/operators/collective/c_allreduce_min_op.cc b/paddle/fluid/operators/collective/c_allreduce_min_op.cc
index 10dc4b9506b2c..efc9af8aa2a2e 100644
--- a/paddle/fluid/operators/collective/c_allreduce_min_op.cc
+++ b/paddle/fluid/operators/collective/c_allreduce_min_op.cc
@@ -14,19 +14,16 @@ limitations under the License. */
 
 #include "paddle/fluid/operators/collective/c_allreduce_op.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 class OpDesc;
 template <typename T>
 class EmptyGradOpMaker;
-}  // namespace framework
-namespace imperative {
+}  // namespace paddle::framework
+namespace paddle::imperative {
 class OpBase;
-}  // namespace imperative
-}  // namespace paddle
+}  // namespace paddle::imperative
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 class CAllReduceMinOpMaker : public CAllReduceOpMaker {
  protected:
@@ -37,8 +34,7 @@ DECLARE_INPLACE_OP_INFERER(AllreduceMinInplaceInferer, {"X", "Out"});
 
 DEFINE_C_ALLREDUCE_CPU_KERNEL(CAllReduceMin, kRedMin)
 
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators
 
 namespace ops = paddle::operators;
 
diff --git a/paddle/fluid/platform/cpu_helper.cc b/paddle/fluid/platform/cpu_helper.cc
index 95d770f1b8006..37ca90bee793f 100644
--- a/paddle/fluid/platform/cpu_helper.cc
+++ b/paddle/fluid/platform/cpu_helper.cc
@@ -26,8 +26,7 @@ limitations under the License. */
 #include <Accelerate/Accelerate.h>
 #endif
 
-namespace paddle {
-namespace platform {
+namespace paddle::platform {
 
 void SetNumThreads(int num_threads) {
 #ifdef PADDLE_USE_OPENBLAS
@@ -57,5 +56,4 @@ void SetNumThreads(int num_threads) {
 #endif
 }
 
-}  // namespace platform
-}  // namespace paddle
+}  // namespace paddle::platform
diff --git a/paddle/fluid/platform/dynload/cuda_driver.cc b/paddle/fluid/platform/dynload/cuda_driver.cc
index c0c752cab5fc5..c9d330974ac10 100644
--- a/paddle/fluid/platform/dynload/cuda_driver.cc
+++ b/paddle/fluid/platform/dynload/cuda_driver.cc
@@ -16,9 +16,7 @@ limitations under the License. */
 
 #include "paddle/phi/backends/dynload/cuda_driver.h"
 
-namespace paddle {
-namespace platform {
-namespace dynload {
+namespace paddle::platform::dynload {
 
 #define DEFINE_WRAP(__name) DynLoad__##__name __name
 
@@ -30,6 +28,4 @@ CUDA_ROUTINE_EACH(DEFINE_WRAP);
 
 bool HasCUDADriver() { return phi::dynload::HasCUDADriver(); }
 
-}  // namespace dynload
-}  // namespace platform
-}  // namespace paddle
+}  // namespace paddle::platform::dynload
diff --git a/paddle/fluid/platform/profiler.cc b/paddle/fluid/platform/profiler.cc
index ddd0cf8a4164e..7d1cf87424014 100644
--- a/paddle/fluid/platform/profiler.cc
+++ b/paddle/fluid/platform/profiler.cc
@@ -53,8 +53,7 @@ thread_local std::shared_ptr<phi::EventList<phi::MemEvent>>
     phi::ProfilerHelper::g_mem_event_list;
 std::mutex phi::ProfilerHelper::g_all_mem_event_lists_mutex;
 #endif
-namespace paddle {
-namespace platform {
+namespace paddle::platform {
 
 MemEventRecorder MemEventRecorder::recorder;
 
@@ -961,5 +960,4 @@ static void DockHostEventRecorderDevicePart(
   EmulateCorrelation(thr_events);
 }
 
-}  // namespace platform
-}  // namespace paddle
+}  // namespace paddle::platform
diff --git a/paddle/fluid/platform/profiler/custom_device/custom_tracer.cc b/paddle/fluid/platform/profiler/custom_device/custom_tracer.cc
index 6e3966d96d4bc..8f19567e50fd7 100644
--- a/paddle/fluid/platform/profiler/custom_device/custom_tracer.cc
+++ b/paddle/fluid/platform/profiler/custom_device/custom_tracer.cc
@@ -23,8 +23,7 @@
 #include "paddle/phi/backends/device_manager.h"
 #endif
 
-namespace paddle {
-namespace platform {
+namespace paddle::platform {
 
 CustomTracer::CustomTracer(const std::string& dev_type)
     : dev_type_(dev_type), context_(nullptr) {
@@ -116,8 +115,7 @@ void CustomTracer::CollectTraceData(TraceEventCollector* collector) {
   collector_.ClearAll();
 }
 
-}  // namespace platform
-}  // namespace paddle
+}  // namespace paddle::platform
 
 #ifdef PADDLE_WITH_CUSTOM_DEVICE
 void profiler_add_runtime_trace_event(C_Profiler prof, void* event) {
diff --git a/paddle/fluid/pybind/compatible.cc b/paddle/fluid/pybind/compatible.cc
index 25bf9c7bd05c4..f2bfce6a61829 100644
--- a/paddle/fluid/pybind/compatible.cc
+++ b/paddle/fluid/pybind/compatible.cc
@@ -33,8 +33,7 @@ using paddle::framework::compatible::OpUpdateType;
 using paddle::framework::compatible::OpVersion;
 using paddle::framework::compatible::OpVersionDesc;
 
-namespace paddle {
-namespace pybind {
+namespace paddle::pybind {
 
 namespace {
 using paddle::framework::compatible::PassVersionCheckerRegistrar;
@@ -150,5 +149,4 @@ void BindCompatible(py::module *m) {
   BindOpVersion(m);
 }
 
-}  // namespace pybind
-}  // namespace paddle
+}  // namespace paddle::pybind
diff --git a/paddle/phi/backends/cpu/cpu_info.cc b/paddle/phi/backends/cpu/cpu_info.cc
index 2c78e9f706a3b..3c492aa97cd06 100644
--- a/paddle/phi/backends/cpu/cpu_info.cc
+++ b/paddle/phi/backends/cpu/cpu_info.cc
@@ -48,9 +48,7 @@ PHI_DEFINE_EXPORTED_bool(use_pinned_memory,  // NOLINT
                          true,
                          "If set, allocate cpu pinned memory.");
 
-namespace phi {
-namespace backends {
-namespace cpu {
+namespace phi::backends::cpu {
 
 size_t CpuTotalPhysicalMemory() {
 #ifdef __APPLE__
@@ -199,6 +197,4 @@ bool MayIUse(const cpu_isa_t cpu_isa) {
 }
 #endif
 
-}  // namespace cpu
-}  // namespace backends
-}  // namespace phi
+}  // namespace phi::backends::cpu
diff --git a/paddle/phi/backends/dynload/mklml.cc b/paddle/phi/backends/dynload/mklml.cc
index e5b490e519d12..79479a89046c3 100644
--- a/paddle/phi/backends/dynload/mklml.cc
+++ b/paddle/phi/backends/dynload/mklml.cc
@@ -14,8 +14,7 @@ limitations under the License. */
 
 #include "paddle/phi/backends/dynload/mklml.h"
 
-namespace phi {
-namespace dynload {
+namespace phi::dynload {
 
 std::once_flag mklml_dso_flag;
 void* mklml_dso_handle = nullptr;
@@ -29,5 +28,4 @@ DEFINE_WRAP(mkl_scsrmm);
 DEFINE_WRAP(mkl_dcsrmm);
 #endif
 
-}  // namespace dynload
-}  // namespace phi
+}  // namespace phi::dynload
diff --git a/paddle/phi/core/distributed/auto_parallel/reshard/s_to_s_reshard_function.cc b/paddle/phi/core/distributed/auto_parallel/reshard/s_to_s_reshard_function.cc
index f4b05c8c13064..4e93f74912bad 100644
--- a/paddle/phi/core/distributed/auto_parallel/reshard/s_to_s_reshard_function.cc
+++ b/paddle/phi/core/distributed/auto_parallel/reshard/s_to_s_reshard_function.cc
@@ -25,8 +25,7 @@
 #include "paddle/phi/kernels/reshape_kernel.h"
 #include "paddle/phi/kernels/transpose_kernel.h"
 
-namespace phi {
-namespace distributed {
+namespace phi::distributed {
 
 bool SToSReshardFunction::IsSuitable(const DistTensor& in,
                                      const TensorDistAttr& out_dist_attr) {
@@ -191,5 +190,4 @@ void SToSReshardFunctionCrossMesh::Eval(DeviceContext* dev_ctx,
   }
 }
 
-}  // namespace distributed
-}  // namespace phi
+}  // namespace phi::distributed
diff --git a/paddle/phi/core/distributed/store/socket.cpp b/paddle/phi/core/distributed/store/socket.cpp
index 8b260e9da202b..2a8dd1da914ec 100644
--- a/paddle/phi/core/distributed/store/socket.cpp
+++ b/paddle/phi/core/distributed/store/socket.cpp
@@ -24,8 +24,7 @@
 #include <cerrno>
 #include <cstdio>
 
-namespace phi {
-namespace distributed {
+namespace phi::distributed {
 
 #ifdef _WIN32
 static int _get_sockname_of_win(int sock, char* out, int out_len) {
@@ -76,5 +75,4 @@ std::string GetSockName(int fd) {
   return std::string(out.data());
 }
 
-}  // namespace distributed
-}  // namespace phi
+}  // namespace phi::distributed
diff --git a/paddle/phi/infermeta/spmd_rules/fused_rope.cc b/paddle/phi/infermeta/spmd_rules/fused_rope.cc
index 1db67a896bab7..f3aa720d61ece 100644
--- a/paddle/phi/infermeta/spmd_rules/fused_rope.cc
+++ b/paddle/phi/infermeta/spmd_rules/fused_rope.cc
@@ -21,8 +21,7 @@ limitations under the License. */
 #include "paddle/phi/core/distributed/auto_parallel/utils.h"
 #include "paddle/phi/infermeta/spmd_rules/utils.h"
 
-namespace phi {
-namespace distributed {
+namespace phi::distributed {
 
 using auto_parallel::str_join;
 const int kNumHeadsDimIndex = 2;
@@ -571,5 +570,4 @@ SpmdInfo FusedRopeGradInferSpmd(const DistMetaTensor& sin,
   return {dist_attrs, spmd_info.second};
 }
 
-}  // namespace distributed
-}  // namespace phi
+}  // namespace phi::distributed
diff --git a/paddle/phi/kernels/funcs/jit/gen/act.cc b/paddle/phi/kernels/funcs/jit/gen/act.cc
index e1877c46c81b0..cd240028aec3c 100644
--- a/paddle/phi/kernels/funcs/jit/gen/act.cc
+++ b/paddle/phi/kernels/funcs/jit/gen/act.cc
@@ -18,9 +18,7 @@
 #include "paddle/phi/backends/cpu/cpu_info.h"
 #include "paddle/phi/kernels/funcs/jit/registry.h"
 
-namespace phi {
-namespace jit {
-namespace gen {
+namespace phi::jit::gen {
 
 const float ALIGN32_BEG exp_float_consts[] ALIGN32_END = {  // NOLINT
     REPEAT_8TIMES(1.f),
@@ -149,9 +147,7 @@ size_t VTanhCreator::CodeSize(const int& d) const {
 
 #undef DECLARE_ACT_CREATOR
 
-}  // namespace gen
-}  // namespace jit
-}  // namespace phi
+}  // namespace phi::jit::gen
 
 namespace gen = phi::jit::gen;
 
diff --git a/paddle/phi/kernels/funcs/jit/helper.cc b/paddle/phi/kernels/funcs/jit/helper.cc
index 5ab391678bd90..58f9a245ab190 100644
--- a/paddle/phi/kernels/funcs/jit/helper.cc
+++ b/paddle/phi/kernels/funcs/jit/helper.cc
@@ -18,8 +18,7 @@
 
 #include "paddle/phi/core/enforce.h"
 
-namespace phi {
-namespace jit {
+namespace phi::jit {
 
 std::map<size_t, std::shared_ptr<void>>& GetFuncCacheMap() {
   static thread_local std::map<size_t, std::shared_ptr<void>> g_func_cache_map;
@@ -149,5 +148,4 @@ typename std::enable_if<!std::is_same<T, float>::value>::type pack_weights(
       "Only supports pack weights with float type."));
 }
 
-}  // namespace jit
-}  // namespace phi
+}  // namespace phi::jit
diff --git a/paddle/phi/kernels/selected_rows/uniform_kernel.cc b/paddle/phi/kernels/selected_rows/uniform_kernel.cc
index 0af5d8788c71f..4b6ea429782b2 100644
--- a/paddle/phi/kernels/selected_rows/uniform_kernel.cc
+++ b/paddle/phi/kernels/selected_rows/uniform_kernel.cc
@@ -20,8 +20,7 @@ limitations under the License. */
 #include "paddle/phi/core/kernel_registry.h"
 #include "paddle/phi/kernels/uniform_kernel.h"
 
-namespace phi {
-namespace sr {
+namespace phi::sr {
 
 template <typename T, typename Context>
 void UniformRawKernel(const Context& dev_ctx,
@@ -58,8 +57,7 @@ void UniformKernel(const Context& dev_ctx,
       dev_ctx, shape, dtype, min, max, seed, out->mutable_value());
 }
 
-}  // namespace sr
-}  // namespace phi
+}  // namespace phi::sr
 
 PD_REGISTER_KERNEL(uniform_raw_sr,
                    CPU,
diff --git a/paddle/phi/kernels/sparse/cpu/conv_kernel.cc b/paddle/phi/kernels/sparse/cpu/conv_kernel.cc
index 52695d8b4a3ff..2534b04dba743 100644
--- a/paddle/phi/kernels/sparse/cpu/conv_kernel.cc
+++ b/paddle/phi/kernels/sparse/cpu/conv_kernel.cc
@@ -19,8 +19,7 @@ limitations under the License. */
 #include "paddle/phi/kernels/funcs/blas/blas.h"
 #include "paddle/phi/kernels/sparse/cpu/conv.h"
 
-namespace phi {
-namespace sparse {
+namespace phi::sparse {
 
 /**
  * x: (N, D, H, W, C)
@@ -206,8 +205,7 @@ void Conv3dCooKernel(const Context& dev_ctx,
                                                                counter);
                                }));
 }
-}  // namespace sparse
-}  // namespace phi
+}  // namespace phi::sparse
 
 PD_REGISTER_KERNEL(
     conv3d_coo, CPU, ALL_LAYOUT, phi::sparse::Conv3dCooKernel, float, double) {
diff --git a/paddle/phi/kernels/sparse/cpu/sum_grad_kernel.cc b/paddle/phi/kernels/sparse/cpu/sum_grad_kernel.cc
index 177b89be10a86..f82756edd081b 100644
--- a/paddle/phi/kernels/sparse/cpu/sum_grad_kernel.cc
+++ b/paddle/phi/kernels/sparse/cpu/sum_grad_kernel.cc
@@ -22,8 +22,7 @@
 #include "paddle/phi/kernels/sparse/empty_kernel.h"
 #include "paddle/phi/kernels/sparse/impl/unary_grad_kernel_impl.h"
 
-namespace phi {
-namespace sparse {
+namespace phi::sparse {
 
 template <typename T, typename IntT, typename Context>
 void SumCooGradCPUKernel(const Context& dev_ctx,
@@ -194,8 +193,7 @@ void SumCooGradKernel(const Context& dev_ctx,
       }));
 }
 
-}  // namespace sparse
-}  // namespace phi
+}  // namespace phi::sparse
 
 PD_REGISTER_KERNEL(sum_coo_grad,
                    CPU,
diff --git a/paddle/phi/kernels/sparse/cpu/unary_kernel.cc b/paddle/phi/kernels/sparse/cpu/unary_kernel.cc
index 4e4394af45a01..50aba3051778c 100644
--- a/paddle/phi/kernels/sparse/cpu/unary_kernel.cc
+++ b/paddle/phi/kernels/sparse/cpu/unary_kernel.cc
@@ -21,8 +21,7 @@
 #include "paddle/phi/kernels/sparse/impl/unary_grad_kernel_impl.h"
 #include "paddle/phi/kernels/sparse/impl/unary_kernel_impl.h"
 
-namespace phi {
-namespace sparse {
+namespace phi::sparse {
 
 template <typename T, typename Context>
 void DivScalarCooKernel(const Context& dev_ctx,
@@ -56,8 +55,7 @@ void DivScalarCsrKernel(const Context& dev_ctx,
       dev, eigen_out, eigen_x, static_cast<T>(scalar));
 }
 
-}  // namespace sparse
-}  // namespace phi
+}  // namespace phi::sparse
 
 #define PD_REGISTER_SPARSE_UNARY_CPU_KERNEL(name, prefix)          \
   PD_REGISTER_KERNEL(name##_coo,                                   \
diff --git a/paddle/pir/src/core/utils.cc b/paddle/pir/src/core/utils.cc
index c95c7c814743d..984e626172bf9 100644
--- a/paddle/pir/src/core/utils.cc
+++ b/paddle/pir/src/core/utils.cc
@@ -14,8 +14,7 @@
 
 #include "paddle/pir/include/core/utils.h"
 
-namespace pir {
-namespace detail {
+namespace pir::detail {
 
 std::size_t hash_combine(std::size_t lhs, std::size_t rhs) {
   lhs ^= rhs + 0x9e3779b9 + (lhs << 6) + (lhs >> 2);
@@ -66,5 +65,4 @@ void PrintHeader(const std::string &header, std::ostream &os) {
   os << "===" << std::string(line_len, '-') << "===\n";
 }
 
-}  // namespace detail
-}  // namespace pir
+}  // namespace pir::detail