diff --git a/paddle/gserver/gradientmachines/RecurrentGradientMachine.cpp b/paddle/gserver/gradientmachines/RecurrentGradientMachine.cpp
index a9a9f4f903..2ab964b8fc 100644
--- a/paddle/gserver/gradientmachines/RecurrentGradientMachine.cpp
+++ b/paddle/gserver/gradientmachines/RecurrentGradientMachine.cpp
@@ -155,7 +155,8 @@ protected:
 public:
   explicit BootBiasLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     if (!Layer::init(layerMap, parameterMap)) return false;
 
     if (biasParameter_) {
@@ -174,7 +175,7 @@ public:
     }
   }
 
-  virtual void forward(PassType passType) {
+  void forward(PassType passType) override {
     if (biases_) {
       MatrixPtr outV = getOutputValue();
       outV->addBias(*(biases_->getW()), 1);
@@ -182,7 +183,7 @@ public:
     }
   }
 
-  virtual void backward(const UpdateCallback& callback) {
+  void backward(const UpdateCallback& callback) override {
     if (biases_) {
       backwardActivation();
       biases_->getWGrad()->collectBias(*getOutputGrad(), 1);
diff --git a/paddle/gserver/layers/AddtoLayer.h b/paddle/gserver/layers/AddtoLayer.h
index 53d3f99cdd..4e98c174b4 100644
--- a/paddle/gserver/layers/AddtoLayer.h
+++ b/paddle/gserver/layers/AddtoLayer.h
@@ -44,19 +44,20 @@ public:
   /**
    * Intialization of AddtoLayer.
    */
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   /**
    * Forward propagation.
    * @note There is no weight matrix for each input,
    *       because it just a simple add operation.
    */
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
   /**
    * Backward propagation.
    */
-  void backward(const UpdateCallback& callback = nullptr);
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/AgentLayer.h b/paddle/gserver/layers/AgentLayer.h
index 41683ad671..b6dac7ae6f 100644
--- a/paddle/gserver/layers/AgentLayer.h
+++ b/paddle/gserver/layers/AgentLayer.h
@@ -35,7 +35,8 @@ public:
 
   ~AgentLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   // if *numSamples* set,
   // real layer output will only use first *numSamples* rows
@@ -44,8 +45,8 @@ public:
     numSamples_ = numSamples;
   }
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr) {}
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override {}
 };
 
 /**
@@ -56,8 +57,8 @@ public:
   explicit SequenceAgentLayer(const LayerConfig& config) : AgentLayer(config) {}
   ~SequenceAgentLayer() {}
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr) {}
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override {}
 };
 
 /**
@@ -78,7 +79,8 @@ public:
 
   virtual ~GatherAgentLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   // call before addRealLayer
   void copyIdAndSequenceInfo(const Argument& input,
@@ -88,8 +90,8 @@ public:
   // add one real layer, can call many times
   void addRealLayer(LayerPtr layer) { realLayers_.push_back(layer); }
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 };
 
 /**
@@ -133,7 +135,8 @@ public:
 
   virtual ~ScatterAgentLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   /**
    * @brief set real layer in generation
@@ -182,8 +185,8 @@ public:
     numSequences_ = numSequences;
   }
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 };
 
 /**
diff --git a/paddle/gserver/layers/AverageLayer.h b/paddle/gserver/layers/AverageLayer.h
index b3c4ecec8b..621e1d7bb1 100644
--- a/paddle/gserver/layers/AverageLayer.h
+++ b/paddle/gserver/layers/AverageLayer.h
@@ -38,12 +38,11 @@ public:
   explicit AverageLayer(const LayerConfig& config)
       : SequencePoolLayer(config) {}
 
-  ~AverageLayer() {}
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 protected:
   MatrixPtr outMtx_;
diff --git a/paddle/gserver/layers/BatchNormBaseLayer.h b/paddle/gserver/layers/BatchNormBaseLayer.h
index 75bda95de1..230bafc31d 100644
--- a/paddle/gserver/layers/BatchNormBaseLayer.h
+++ b/paddle/gserver/layers/BatchNormBaseLayer.h
@@ -52,7 +52,8 @@ public:
    */
   static Layer* create(const LayerConfig& config);
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   /**
    * @brief Calculate feature map size. Some input uses frameHeight and
diff --git a/paddle/gserver/layers/BatchNormalizationLayer.h b/paddle/gserver/layers/BatchNormalizationLayer.h
index 195acbbfc5..f6115801fc 100644
--- a/paddle/gserver/layers/BatchNormalizationLayer.h
+++ b/paddle/gserver/layers/BatchNormalizationLayer.h
@@ -33,9 +33,10 @@ public:
 
   ~BatchNormalizationLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 protected:
   /// Epsilon value used in the batch normalization formula.
@@ -58,7 +59,7 @@ protected:
   /// to batch, channels* imagePixels.
   void shrinkMat(const MatrixPtr& in, MatrixPtr& out);
 
-  void onPassEnd() { firstTest_ = true; }
+  void onPassEnd() override { firstTest_ = true; }
 
   MatrixPtr tmpMat_, tmpGrad_;
   MatrixPtr expandedIn_, expandedOut_;
diff --git a/paddle/gserver/layers/BilinearInterpLayer.h b/paddle/gserver/layers/BilinearInterpLayer.h
index 4ff4b0ea79..27c269f278 100644
--- a/paddle/gserver/layers/BilinearInterpLayer.h
+++ b/paddle/gserver/layers/BilinearInterpLayer.h
@@ -38,9 +38,10 @@ public:
   virtual ~BilinearInterpLayer() {}
 
   size_t getSize();
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/BlockExpandLayer.h b/paddle/gserver/layers/BlockExpandLayer.h
index cc96fdd03f..8f347400e6 100644
--- a/paddle/gserver/layers/BlockExpandLayer.h
+++ b/paddle/gserver/layers/BlockExpandLayer.h
@@ -58,10 +58,11 @@ public:
 
   ~BlockExpandLayer() {}
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/CRFDecodingLayer.h b/paddle/gserver/layers/CRFDecodingLayer.h
index 1fd444ad10..3cbcac6cf6 100644
--- a/paddle/gserver/layers/CRFDecodingLayer.h
+++ b/paddle/gserver/layers/CRFDecodingLayer.h
@@ -32,9 +32,10 @@ namespace paddle {
 class CRFDecodingLayer : public CRFLayer {
 public:
   explicit CRFDecodingLayer(const LayerConfig& config) : CRFLayer(config) {}
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 
 protected:
   std::unique_ptr<LinearChainCRF> crf_;
diff --git a/paddle/gserver/layers/CRFLayer.h b/paddle/gserver/layers/CRFLayer.h
index d21b32b68c..de36a85083 100644
--- a/paddle/gserver/layers/CRFLayer.h
+++ b/paddle/gserver/layers/CRFLayer.h
@@ -29,9 +29,10 @@ namespace paddle {
 class CRFLayer : public Layer {
 public:
   explicit CRFLayer(const LayerConfig& config) : Layer(config) {}
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 
 protected:
   size_t numClasses_;
diff --git a/paddle/gserver/layers/CTCLayer.h b/paddle/gserver/layers/CTCLayer.h
index 70d429bad6..f7a515f312 100644
--- a/paddle/gserver/layers/CTCLayer.h
+++ b/paddle/gserver/layers/CTCLayer.h
@@ -22,10 +22,11 @@ namespace paddle {
 class CTCLayer : public Layer {
 public:
   explicit CTCLayer(const LayerConfig& config) : Layer(config) {}
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  virtual void forward(PassType passType);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
   void forwardImp(const Argument& softmaxSeqs, const Argument& labelSeqs);
-  virtual void backward(const UpdateCallback& callback);
+  void backward(const UpdateCallback& callback) override;
   void backwardImp(const UpdateCallback& callback,
                    const Argument& softmaxSeqs,
                    const Argument& labelSeqs);
diff --git a/paddle/gserver/layers/ConcatenateLayer.cpp b/paddle/gserver/layers/ConcatenateLayer.cpp
index d19adace7d..c5fc4cf4f8 100644
--- a/paddle/gserver/layers/ConcatenateLayer.cpp
+++ b/paddle/gserver/layers/ConcatenateLayer.cpp
@@ -28,10 +28,11 @@ public:
 
   ~ConcatenateLayer() {}
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(concat, ConcatenateLayer);
@@ -101,10 +102,11 @@ public:
 
   ~ConcatenateLayer2() {}
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 protected:
   std::vector<std::unique_ptr<Projection>> projections_;
diff --git a/paddle/gserver/layers/ConvBaseLayer.h b/paddle/gserver/layers/ConvBaseLayer.h
index aedf4100e3..e9d15d94f8 100644
--- a/paddle/gserver/layers/ConvBaseLayer.h
+++ b/paddle/gserver/layers/ConvBaseLayer.h
@@ -80,7 +80,8 @@ protected:
 public:
   explicit ConvBaseLayer(const LayerConfig& config) : Layer(config) {}
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   /**
    * imgSizeH_ and imgSizeW_ will be set according to the previous input layers
diff --git a/paddle/gserver/layers/ConvShiftLayer.cpp b/paddle/gserver/layers/ConvShiftLayer.cpp
index 9bfb1ab7a4..002be41569 100644
--- a/paddle/gserver/layers/ConvShiftLayer.cpp
+++ b/paddle/gserver/layers/ConvShiftLayer.cpp
@@ -47,10 +47,11 @@ public:
 
   ~ConvShiftLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(conv_shift, ConvShiftLayer);
diff --git a/paddle/gserver/layers/ConvexCombinationLayer.cpp b/paddle/gserver/layers/ConvexCombinationLayer.cpp
index ed57f2af3c..32eb3bf604 100644
--- a/paddle/gserver/layers/ConvexCombinationLayer.cpp
+++ b/paddle/gserver/layers/ConvexCombinationLayer.cpp
@@ -49,10 +49,11 @@ public:
 
   ~ConvexCombinationLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(convex_comb, ConvexCombinationLayer);
diff --git a/paddle/gserver/layers/CosSimLayer.h b/paddle/gserver/layers/CosSimLayer.h
index 5dcc5d8a5b..6554962609 100644
--- a/paddle/gserver/layers/CosSimLayer.h
+++ b/paddle/gserver/layers/CosSimLayer.h
@@ -38,10 +38,11 @@ public:
 
   ~CosSimLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/CosSimVecMatLayer.cpp b/paddle/gserver/layers/CosSimVecMatLayer.cpp
index ad490b0b8c..5f652319e5 100644
--- a/paddle/gserver/layers/CosSimVecMatLayer.cpp
+++ b/paddle/gserver/layers/CosSimVecMatLayer.cpp
@@ -46,10 +46,11 @@ public:
 
   ~CosSimVecMatLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(cos_vm, CosSimVecMatLayer);
diff --git a/paddle/gserver/layers/CostLayer.cpp b/paddle/gserver/layers/CostLayer.cpp
index 7e9519f6b3..998b8d7d30 100644
--- a/paddle/gserver/layers/CostLayer.cpp
+++ b/paddle/gserver/layers/CostLayer.cpp
@@ -367,8 +367,6 @@ void LambdaCost::backward(const UpdateCallback& callback) {
   getInputGrad(0)->add(*marginGrad_);
 }
 
-void LambdaCost::onPassEnd() {}
-
 void LambdaCost::calcGrad(const real* outputScore,
                           const real* score,
                           real* gradData,
@@ -611,14 +609,15 @@ class SumCostLayer : public Layer {
 public:
   explicit SumCostLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     bool ret = Layer::init(layerMap, parameterMap);
     if (!ret) return ret;
     CHECK_EQ(inputLayers_.size(), 1UL);
     return true;
   }
 
-  virtual void forward(PassType passType) {
+  void forward(PassType passType) override {
     Layer::forward(passType);
     const MatrixPtr& input = getInputValue(0);
 
@@ -629,7 +628,7 @@ public:
     output_.value->sumRows(*input, /* scaleSum= */ 1, /* scaleDest= */ 0);
   }
 
-  virtual void backward(const UpdateCallback& callback = nullptr) {
+  void backward(const UpdateCallback& callback = nullptr) override {
     getInputGrad(0)->add((real)1);
   }
 };
diff --git a/paddle/gserver/layers/CostLayer.h b/paddle/gserver/layers/CostLayer.h
index 7f73bdb3f7..b3045e0b31 100644
--- a/paddle/gserver/layers/CostLayer.h
+++ b/paddle/gserver/layers/CostLayer.h
@@ -32,15 +32,16 @@ class CostLayer : public Layer {
 public:
   explicit CostLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   LayerPtr getOutputLayer() { return inputLayers_[0]; }
 
   LayerPtr getLabelLayer() { return inputLayers_[1]; }
 
-  virtual void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void backward(const UpdateCallback& callback = nullptr) override;
 
   virtual void forwardImp(Matrix& outputValue,
                           Argument& label,
@@ -68,11 +69,14 @@ public:
   explicit MultiClassCrossEntropy(const LayerConfig& config)
       : CostLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forwardImp(Matrix& output, Argument& label, Matrix& cost);
+  void forwardImp(Matrix& output, Argument& label, Matrix& cost) override;
 
-  void backwardImp(Matrix& outputValue, Argument& label, Matrix& outputGrad);
+  void backwardImp(Matrix& outputValue,
+                   Argument& label,
+                   Matrix& outputGrad) override;
 };
 
 /**
@@ -95,11 +99,14 @@ public:
   explicit MultiClassCrossEntropyWithSelfNorm(const LayerConfig& config)
       : CostLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forwardImp(Matrix& output, Argument& label, Matrix& cost);
+  void forwardImp(Matrix& output, Argument& label, Matrix& cost) override;
 
-  void backwardImp(Matrix& outputValue, Argument& label, Matrix& outputGrad);
+  void backwardImp(Matrix& outputValue,
+                   Argument& label,
+                   Matrix& outputGrad) override;
 
 protected:
   MatrixPtr sftMaxSum_;
@@ -117,11 +124,14 @@ public:
   explicit SoftBinaryClassCrossEntropy(const LayerConfig& config)
       : CostLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forwardImp(Matrix& output, Argument& label, Matrix& cost);
+  void forwardImp(Matrix& output, Argument& label, Matrix& cost) override;
 
-  void backwardImp(Matrix& outputValue, Argument& label, Matrix& outputGrad);
+  void backwardImp(Matrix& outputValue,
+                   Argument& label,
+                   Matrix& outputGrad) override;
 
 protected:
   MatrixPtr targetPerDim_;
@@ -139,11 +149,14 @@ public:
   explicit SumOfSquaresCostLayer(const LayerConfig& config)
       : CostLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forwardImp(Matrix& output, Argument& label, Matrix& cost);
+  void forwardImp(Matrix& output, Argument& label, Matrix& cost) override;
 
-  void backwardImp(Matrix& outputValue, Argument& label, Matrix& outputGrad);
+  void backwardImp(Matrix& outputValue,
+                   Argument& label,
+                   Matrix& outputGrad) override;
 };
 
 /**
@@ -162,17 +175,18 @@ class RankingCost : public Layer {
 public:
   explicit RankingCost(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   LayerPtr getOutputLayer(size_t i) { return inputLayers_[i]; }
 
   LayerPtr getLabelLayer() { return inputLayers_[2]; }
 
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  void backward(const UpdateCallback& callback = nullptr);
+  void backward(const UpdateCallback& callback = nullptr) override;
 
-  void onPassEnd();
+  void onPassEnd() override;
 
   void forwardImp(Matrix& output, Argument& label, Matrix& cost) {
     (void)output;
@@ -214,17 +228,16 @@ class LambdaCost : public Layer {
 public:
   explicit LambdaCost(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   LayerPtr getOutputLayer() { return inputLayers_[0]; }
 
   LayerPtr getScoreLayer() { return inputLayers_[1]; }
 
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  void backward(const UpdateCallback& callback = nullptr);
-
-  void onPassEnd();
+  void backward(const UpdateCallback& callback = nullptr) override;
 
   real calcNDCG(const real* outputScore, const real* score, int size);
   void calcGrad(const real* outputScore,
@@ -256,11 +269,14 @@ public:
   explicit MultiBinaryLabelCrossEntropy(const LayerConfig& config)
       : CostLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forwardImp(Matrix& output, Argument& label, Matrix& cost);
+  void forwardImp(Matrix& output, Argument& label, Matrix& cost) override;
 
-  void backwardImp(Matrix& outputValue, Argument& label, Matrix& outputGrad);
+  void backwardImp(Matrix& outputValue,
+                   Argument& label,
+                   Matrix& outputGrad) override;
 };
 
 /**
@@ -282,13 +298,16 @@ class HuberTwoClass : public CostLayer {
 public:
   explicit HuberTwoClass(const LayerConfig& config) : CostLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forwardImp(Matrix& output, Argument& label, Matrix& cost);
+  void forwardImp(Matrix& output, Argument& label, Matrix& cost) override;
 
   void forwardImpIn(Matrix& output, Argument& label, Matrix& cost);
 
-  void backwardImp(Matrix& outputValue, Argument& label, Matrix& outputGrad);
+  void backwardImp(Matrix& outputValue,
+                   Argument& label,
+                   Matrix& outputGrad) override;
 
   void backwardImpIn(Matrix& outputValue, Argument& label, Matrix& outputGrad);
 };
diff --git a/paddle/gserver/layers/CudnnBatchNormLayer.h b/paddle/gserver/layers/CudnnBatchNormLayer.h
index b1e7d2082f..413efd4d3e 100644
--- a/paddle/gserver/layers/CudnnBatchNormLayer.h
+++ b/paddle/gserver/layers/CudnnBatchNormLayer.h
@@ -35,14 +35,15 @@ public:
 
   ~CudnnBatchNormLayer();
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
   /**
    * reshape tensor of ioDesc_.
    */
   void reshape(int batchSize);
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 protected:
   /**
diff --git a/paddle/gserver/layers/CudnnConvLayer.h b/paddle/gserver/layers/CudnnConvLayer.h
index b869c695bd..919b1efc4e 100644
--- a/paddle/gserver/layers/CudnnConvLayer.h
+++ b/paddle/gserver/layers/CudnnConvLayer.h
@@ -45,9 +45,10 @@ public:
 
   ~CudnnConvLayer();
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
   void addBiases();
   void bpropBiases();
 };
diff --git a/paddle/gserver/layers/CudnnPoolLayer.h b/paddle/gserver/layers/CudnnPoolLayer.h
index 072b2f9513..f0aa22fe3a 100644
--- a/paddle/gserver/layers/CudnnPoolLayer.h
+++ b/paddle/gserver/layers/CudnnPoolLayer.h
@@ -45,7 +45,8 @@ public:
                         hl_pooling_mode_t* mode = nullptr);
   explicit CudnnPoolLayer(const LayerConfig& config);
   ~CudnnPoolLayer();
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   /**
    * Reshape input and output tensor descriptor.
@@ -53,8 +54,8 @@ public:
    * So reshaping is needed.
    */
   void reshape(int batchSize);
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/DataLayer.h b/paddle/gserver/layers/DataLayer.h
index d3bc97bb6c..a9cf1f943c 100644
--- a/paddle/gserver/layers/DataLayer.h
+++ b/paddle/gserver/layers/DataLayer.h
@@ -33,13 +33,13 @@ public:
   /**
    * Prefetch sparse matrix/ids only.
    */
-  void prefetch() { output_ = data_; }
+  void prefetch() override { output_ = data_; }
 
   /**
    * Forward propagation. Copy data_ (value, in, grad, ids, cpuSequenceDims,
    * sequenceStartPositions, subSequenceStartPositions, strs) to output_.
    */
-  virtual void forward(PassType passType) {
+  void forward(PassType passType) override {
     Layer::forward(passType);
     copyDataToOutput(output_);
     if (FLAGS_show_layer_stat) {
@@ -50,9 +50,9 @@ public:
   /**
    * Data layer's backward propagation do nothing.
    */
-  virtual void backward(const UpdateCallback& callback) { (void)callback; }
+  void backward(const UpdateCallback& callback) override { (void)callback; }
 
-  virtual void copyOutputToOtherDevice() {
+  void copyOutputToOtherDevice() override {
     for (size_t i = 0; i != outputOtherDevice_.size(); i++) {
       copyDataToOutput(outputOtherDevice_[i]);
     }
diff --git a/paddle/gserver/layers/DataNormLayer.h b/paddle/gserver/layers/DataNormLayer.h
index b3043cffd2..f0fd044e5b 100644
--- a/paddle/gserver/layers/DataNormLayer.h
+++ b/paddle/gserver/layers/DataNormLayer.h
@@ -44,10 +44,11 @@ public:
 
   ~DataNormLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 protected:
   int mode_;
diff --git a/paddle/gserver/layers/EosIdCheckLayer.cpp b/paddle/gserver/layers/EosIdCheckLayer.cpp
index fa53e2e4cf..686f1fa054 100644
--- a/paddle/gserver/layers/EosIdCheckLayer.cpp
+++ b/paddle/gserver/layers/EosIdCheckLayer.cpp
@@ -27,14 +27,14 @@ class EosIdCheckLayer : public Layer {
 public:
   explicit EosIdCheckLayer(const LayerConfig& config) : Layer(config) {}
 
-  virtual bool init(const LayerMap& layerMap,
-                    const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     bool ret = Layer::init(layerMap, parameterMap);
     CHECK_EQ(1UL, inputLayers_.size());
     return ret;
   }
 
-  virtual void forward(PassType passType) {
+  void forward(PassType passType) override {
     Layer::forward(passType);
 
     const Argument& input = getInput(0);
@@ -42,7 +42,7 @@ public:
     output_.ids->isEqualTo(*input.ids, config_.eos_id());
   }
 
-  virtual void backward(const UpdateCallback& callback) {}
+  void backward(const UpdateCallback& callback) override {}
 };
 
 REGISTER_LAYER(eos_id, EosIdCheckLayer);
diff --git a/paddle/gserver/layers/ExpandConvBaseLayer.h b/paddle/gserver/layers/ExpandConvBaseLayer.h
index 8445642217..aabcdfc392 100644
--- a/paddle/gserver/layers/ExpandConvBaseLayer.h
+++ b/paddle/gserver/layers/ExpandConvBaseLayer.h
@@ -48,7 +48,8 @@ public:
 
   ~ExpandConvBaseLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   size_t getOutputSize();
   /**
diff --git a/paddle/gserver/layers/ExpandConvLayer.h b/paddle/gserver/layers/ExpandConvLayer.h
index de81a017e1..60681690e5 100644
--- a/paddle/gserver/layers/ExpandConvLayer.h
+++ b/paddle/gserver/layers/ExpandConvLayer.h
@@ -35,10 +35,11 @@ public:
 
   ~ExpandConvLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/ExpandConvTransLayer.h b/paddle/gserver/layers/ExpandConvTransLayer.h
index 4a527d6799..00b8f24188 100644
--- a/paddle/gserver/layers/ExpandConvTransLayer.h
+++ b/paddle/gserver/layers/ExpandConvTransLayer.h
@@ -34,10 +34,11 @@ public:
 
   ~ExpandConvTransLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/ExpandLayer.h b/paddle/gserver/layers/ExpandLayer.h
index 5c63614423..c21b3350e2 100644
--- a/paddle/gserver/layers/ExpandLayer.h
+++ b/paddle/gserver/layers/ExpandLayer.h
@@ -53,10 +53,11 @@ public:
 
   ~ExpandLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/FeatureMapExpandLayer.cpp b/paddle/gserver/layers/FeatureMapExpandLayer.cpp
index 4b685812aa..b3850f543a 100644
--- a/paddle/gserver/layers/FeatureMapExpandLayer.cpp
+++ b/paddle/gserver/layers/FeatureMapExpandLayer.cpp
@@ -46,10 +46,11 @@ public:
 
   ~FeatureMapExpandLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(featmap_expand, FeatureMapExpandLayer);
diff --git a/paddle/gserver/layers/FullyConnectedLayer.h b/paddle/gserver/layers/FullyConnectedLayer.h
index ccd584585c..64e7a05012 100644
--- a/paddle/gserver/layers/FullyConnectedLayer.h
+++ b/paddle/gserver/layers/FullyConnectedLayer.h
@@ -36,13 +36,14 @@ public:
   explicit FullyConnectedLayer(const LayerConfig& config) : Layer(config) {}
   ~FullyConnectedLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   Weight& getWeight(int idx) { return *weights_[idx]; }
 
-  void prefetch();
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void prefetch() override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/GatedRecurrentLayer.h b/paddle/gserver/layers/GatedRecurrentLayer.h
index 25770ce57f..58dd760eb8 100644
--- a/paddle/gserver/layers/GatedRecurrentLayer.h
+++ b/paddle/gserver/layers/GatedRecurrentLayer.h
@@ -50,17 +50,18 @@ class GatedRecurrentLayer : public Layer, public GruCompute {
 public:
   explicit GatedRecurrentLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  void backward(const UpdateCallback& callback);
+  void backward(const UpdateCallback& callback) override;
 
-  void resetState();
+  void resetState() override;
 
-  void setState(LayerStatePtr state);
+  void setState(LayerStatePtr state) override;
 
-  LayerStatePtr getState();
+  LayerStatePtr getState() override;
 
 protected:
   void forwardSequence(int batchSize,
diff --git a/paddle/gserver/layers/GetOutputLayer.cpp b/paddle/gserver/layers/GetOutputLayer.cpp
index b77fdbb30e..4e29efd461 100644
--- a/paddle/gserver/layers/GetOutputLayer.cpp
+++ b/paddle/gserver/layers/GetOutputLayer.cpp
@@ -22,17 +22,18 @@ public:
 
   ~GetOutputLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     if (!Layer::init(layerMap, parameterMap)) return false;
     CHECK_EQ(1U, inputLayers_.size());
     CHECK_NE(inputArgument_[0], "");
     return true;
   }
 
-  void forward(PassType passType) {
+  void forward(PassType passType) override {
     output_ = getPrev(0)->getOutput(inputArgument_[0]);
   }
-  void backward(const UpdateCallback& callback = nullptr) {}
+  void backward(const UpdateCallback& callback = nullptr) override {}
 };
 
 REGISTER_LAYER(get_output, GetOutputLayer);
diff --git a/paddle/gserver/layers/GruStepLayer.cpp b/paddle/gserver/layers/GruStepLayer.cpp
index 4a1006aa94..5b5cb25f92 100644
--- a/paddle/gserver/layers/GruStepLayer.cpp
+++ b/paddle/gserver/layers/GruStepLayer.cpp
@@ -55,10 +55,11 @@ public:
 
   ~GruStepLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(gru_step, GruStepLayer);
diff --git a/paddle/gserver/layers/HierarchicalSigmoidLayer.h b/paddle/gserver/layers/HierarchicalSigmoidLayer.h
index 70da3ac126..3f6875fb9f 100644
--- a/paddle/gserver/layers/HierarchicalSigmoidLayer.h
+++ b/paddle/gserver/layers/HierarchicalSigmoidLayer.h
@@ -61,9 +61,10 @@ class HierarchicalSigmoidLayer : public Layer {
 public:
   explicit HierarchicalSigmoidLayer(const LayerConfig& config)
       : Layer(config) {}
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 
 protected:
   /**
diff --git a/paddle/gserver/layers/InterpolationLayer.cpp b/paddle/gserver/layers/InterpolationLayer.cpp
index 44fe1fb1fe..eac7428571 100644
--- a/paddle/gserver/layers/InterpolationLayer.cpp
+++ b/paddle/gserver/layers/InterpolationLayer.cpp
@@ -43,10 +43,11 @@ public:
 
   ~InterpolationLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(interpolation, InterpolationLayer);
diff --git a/paddle/gserver/layers/LstmLayer.h b/paddle/gserver/layers/LstmLayer.h
index f49df2c412..c45a52d2e9 100644
--- a/paddle/gserver/layers/LstmLayer.h
+++ b/paddle/gserver/layers/LstmLayer.h
@@ -74,17 +74,18 @@ class LstmLayer : public Layer, public LstmCompute {
 public:
   explicit LstmLayer(const LayerConfig &config) : Layer(config) {}
 
-  bool init(const LayerMap &layerMap, const ParameterMap &parameterMap);
+  bool init(const LayerMap &layerMap,
+            const ParameterMap &parameterMap) override;
 
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  void backward(const UpdateCallback &callback);
+  void backward(const UpdateCallback &callback) override;
 
-  void resetState();
+  void resetState() override;
 
-  void setState(LayerStatePtr state);
+  void setState(LayerStatePtr state) override;
 
-  LayerStatePtr getState();
+  LayerStatePtr getState() override;
 
 protected:
   /**
diff --git a/paddle/gserver/layers/LstmStepLayer.cpp b/paddle/gserver/layers/LstmStepLayer.cpp
index 5fc6474b86..568277a90c 100644
--- a/paddle/gserver/layers/LstmStepLayer.cpp
+++ b/paddle/gserver/layers/LstmStepLayer.cpp
@@ -35,10 +35,11 @@ public:
 
   ~LstmStepLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(lstm_step, LstmStepLayer);
diff --git a/paddle/gserver/layers/MDLstmLayer.cpp b/paddle/gserver/layers/MDLstmLayer.cpp
index 88d934d782..be0f2a07d4 100644
--- a/paddle/gserver/layers/MDLstmLayer.cpp
+++ b/paddle/gserver/layers/MDLstmLayer.cpp
@@ -181,11 +181,12 @@ class MDLstmLayer : public LstmLayer {
 public:
   explicit MDLstmLayer(const LayerConfig& config) : LstmLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  void backward(const UpdateCallback& callback);
+  void backward(const UpdateCallback& callback) override;
 
 protected:
   void forwardOneSequence(int start, CoordIterator& coordIter);
diff --git a/paddle/gserver/layers/MaxIdLayer.cpp b/paddle/gserver/layers/MaxIdLayer.cpp
index 80555f3f7b..9e72b167cd 100644
--- a/paddle/gserver/layers/MaxIdLayer.cpp
+++ b/paddle/gserver/layers/MaxIdLayer.cpp
@@ -30,8 +30,8 @@ private:
 public:
   explicit MaxIdLayer(const LayerConfig& config) : Layer(config) {}
 
-  virtual bool init(const LayerMap& layerMap,
-                    const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     bool ret = Layer::init(layerMap, parameterMap);
     CHECK_EQ(1UL, inputLayers_.size());
 
@@ -40,7 +40,7 @@ public:
     return ret;
   }
 
-  virtual void forward(PassType passType) {
+  void forward(PassType passType) override {
     Layer::forward(passType);
     const Argument& input = getInput(0);
     size_t batchSize = input.getBatchSize();
@@ -54,7 +54,7 @@ public:
     input.value->rowMax(*output_.ids, *output_.in);
   }
 
-  virtual void backward(const UpdateCallback& callback) {}
+  void backward(const UpdateCallback& callback) override {}
 };
 
 REGISTER_LAYER(maxid, MaxIdLayer);
diff --git a/paddle/gserver/layers/MaxLayer.h b/paddle/gserver/layers/MaxLayer.h
index 472ee0ccca..baa58ca2d7 100644
--- a/paddle/gserver/layers/MaxLayer.h
+++ b/paddle/gserver/layers/MaxLayer.h
@@ -42,14 +42,13 @@ protected:
 public:
   explicit MaxLayer(const LayerConfig& config) : SequencePoolLayer(config) {}
 
-  ~MaxLayer() {}
-
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     return SequencePoolLayer::init(layerMap, parameterMap);
   }
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/MaxOutLayer.h b/paddle/gserver/layers/MaxOutLayer.h
index 59c2245e0d..73fd8536be 100644
--- a/paddle/gserver/layers/MaxOutLayer.h
+++ b/paddle/gserver/layers/MaxOutLayer.h
@@ -45,10 +45,11 @@ public:
   explicit MaxOutLayer(const LayerConfig& config) : Layer(config) {}
   virtual ~MaxOutLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/MixedLayer.h b/paddle/gserver/layers/MixedLayer.h
index 9655a152c7..755c9deb8b 100644
--- a/paddle/gserver/layers/MixedLayer.h
+++ b/paddle/gserver/layers/MixedLayer.h
@@ -35,21 +35,22 @@ public:
 
   ~MixedLayer() {}
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  virtual void prefetch();
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback = nullptr);
-  virtual void resetState();
+  void prefetch() override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
+  void resetState() override;
   /**
    * setState() should be called after getState().
    * Argument state consists of all projections states.
    */
-  virtual void setState(LayerStatePtr state);
+  void setState(LayerStatePtr state) override;
   /**
    * Return state which consists of all projections states.
    */
-  virtual LayerStatePtr getState();
+  LayerStatePtr getState() override;
 
 protected:
   std::vector<std::unique_ptr<Projection>> projections_;
diff --git a/paddle/gserver/layers/MultiplexLayer.cpp b/paddle/gserver/layers/MultiplexLayer.cpp
index d09720c525..297972b3cd 100644
--- a/paddle/gserver/layers/MultiplexLayer.cpp
+++ b/paddle/gserver/layers/MultiplexLayer.cpp
@@ -69,10 +69,11 @@ public:
 
   ~MultiplexLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 private:
   /**
diff --git a/paddle/gserver/layers/NCELayer.cpp b/paddle/gserver/layers/NCELayer.cpp
index 3542e739df..0bc2ef1182 100644
--- a/paddle/gserver/layers/NCELayer.cpp
+++ b/paddle/gserver/layers/NCELayer.cpp
@@ -61,7 +61,8 @@ public:
         rand_(0, config.num_classes() - 1),
         prepared_(false) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     /* Initialize the basic parent class */
     Layer::init(layerMap, parameterMap);
 
@@ -146,7 +147,7 @@ public:
     prepared_ = true;
   }
 
-  void prefetch() {
+  void prefetch() override {
     prepareSamples();
     IVector::resizeOrCreate(labelIds_, samples_.size(), useGpu_);
     int* ids = labelIds_->getData();
@@ -163,7 +164,7 @@ public:
     }
   }
 
-  void forward(PassType passType) {
+  void forward(PassType passType) override {
     Layer::forward(passType);
 
     CHECK(!useGpu_) << "GPU is not supported";
@@ -199,7 +200,7 @@ public:
     forwardCost();
   }
 
-  void backward(const UpdateCallback& callback) {
+  void backward(const UpdateCallback& callback) override {
     Matrix::resizeOrCreate(sampleOut_.grad,
                            1,
                            samples_.size(),
diff --git a/paddle/gserver/layers/NormLayer.h b/paddle/gserver/layers/NormLayer.h
index 011bab8fde..e77faaa322 100644
--- a/paddle/gserver/layers/NormLayer.h
+++ b/paddle/gserver/layers/NormLayer.h
@@ -30,7 +30,8 @@ class NormLayer : public Layer {
 public:
   explicit NormLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     Layer::init(layerMap, parameterMap);
     return true;
   }
@@ -56,9 +57,10 @@ protected:
 public:
   explicit ResponseNormLayer(const LayerConfig& config) : NormLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  void forward(PassType passType) { LOG(FATAL) << "Not implemented"; }
-  void backward(const UpdateCallback& callback = nullptr) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override { LOG(FATAL) << "Not implemented"; }
+  void backward(const UpdateCallback& callback = nullptr) override {
     LOG(FATAL) << "Not implemented";
   }
 };
diff --git a/paddle/gserver/layers/NormProjectionLayer.h b/paddle/gserver/layers/NormProjectionLayer.h
index 2c0d8a3a71..2997ae8848 100644
--- a/paddle/gserver/layers/NormProjectionLayer.h
+++ b/paddle/gserver/layers/NormProjectionLayer.h
@@ -36,9 +36,10 @@ public:
 
   size_t getSize();
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 protected:
   TensorShape shape_;
diff --git a/paddle/gserver/layers/OuterProdLayer.cpp b/paddle/gserver/layers/OuterProdLayer.cpp
index b606e44365..283fdb003a 100644
--- a/paddle/gserver/layers/OuterProdLayer.cpp
+++ b/paddle/gserver/layers/OuterProdLayer.cpp
@@ -38,10 +38,11 @@ public:
 
   ~OuterProdLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(out_prod, OuterProdLayer);
diff --git a/paddle/gserver/layers/PadLayer.h b/paddle/gserver/layers/PadLayer.h
index 3e3a21a997..b2bbf28082 100644
--- a/paddle/gserver/layers/PadLayer.h
+++ b/paddle/gserver/layers/PadLayer.h
@@ -29,9 +29,10 @@ public:
 
   ~PadLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 protected:
   void setOutDims(const size_t batchSize);
diff --git a/paddle/gserver/layers/ParameterReluLayer.h b/paddle/gserver/layers/ParameterReluLayer.h
index a82497fc01..9a11b81ebf 100644
--- a/paddle/gserver/layers/ParameterReluLayer.h
+++ b/paddle/gserver/layers/ParameterReluLayer.h
@@ -56,9 +56,10 @@ public:
 
   ~ParameterReluLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 }  // namespace paddle
diff --git a/paddle/gserver/layers/PoolLayer.h b/paddle/gserver/layers/PoolLayer.h
index 318b89d7c2..d43292ad2d 100644
--- a/paddle/gserver/layers/PoolLayer.h
+++ b/paddle/gserver/layers/PoolLayer.h
@@ -46,7 +46,8 @@ public:
    */
   static Layer* create(const LayerConfig& config);
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/PoolProjectionLayer.h b/paddle/gserver/layers/PoolProjectionLayer.h
index 3dc6af2f0e..e31116de8c 100644
--- a/paddle/gserver/layers/PoolProjectionLayer.h
+++ b/paddle/gserver/layers/PoolProjectionLayer.h
@@ -40,7 +40,7 @@ public:
 
   size_t getSize();
 
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 }  // namespace paddle
diff --git a/paddle/gserver/layers/PowerLayer.cpp b/paddle/gserver/layers/PowerLayer.cpp
index 64fecab5b0..31c34b43e2 100644
--- a/paddle/gserver/layers/PowerLayer.cpp
+++ b/paddle/gserver/layers/PowerLayer.cpp
@@ -40,10 +40,11 @@ public:
 
   ~PowerLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(power, PowerLayer);
diff --git a/paddle/gserver/layers/PrintLayer.cpp b/paddle/gserver/layers/PrintLayer.cpp
index ac7f658864..85f52ad5de 100644
--- a/paddle/gserver/layers/PrintLayer.cpp
+++ b/paddle/gserver/layers/PrintLayer.cpp
@@ -19,8 +19,8 @@ namespace paddle {
 class PrintLayer : public Layer {
 public:
   explicit PrintLayer(const LayerConfig& config) : Layer(config) {}
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback) {}
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override {}
 };
 
 void PrintLayer::forward(PassType passType) {
diff --git a/paddle/gserver/layers/PriorBox.cpp b/paddle/gserver/layers/PriorBox.cpp
index 36ace7597c..bcf5e912a5 100644
--- a/paddle/gserver/layers/PriorBox.cpp
+++ b/paddle/gserver/layers/PriorBox.cpp
@@ -30,10 +30,11 @@ namespace paddle {
 class PriorBoxLayer : public Layer {
 public:
   explicit PriorBoxLayer(const LayerConfig& config) : Layer(config) {}
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback) {}
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override {}
 
 protected:
   int numPriors_;
diff --git a/paddle/gserver/layers/RecurrentLayer.cpp b/paddle/gserver/layers/RecurrentLayer.cpp
index b843fa1265..e4c2b483d2 100644
--- a/paddle/gserver/layers/RecurrentLayer.cpp
+++ b/paddle/gserver/layers/RecurrentLayer.cpp
@@ -45,17 +45,18 @@ class RecurrentLayer : public Layer {
 public:
   explicit RecurrentLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  void backward(const UpdateCallback& callback);
+  void backward(const UpdateCallback& callback) override;
 
-  void resetState();
+  void resetState() override;
 
-  void setState(LayerStatePtr state);
+  void setState(LayerStatePtr state) override;
 
-  LayerStatePtr getState();
+  LayerStatePtr getState() override;
 
 protected:
   /**
diff --git a/paddle/gserver/layers/RecurrentLayerGroup.cpp b/paddle/gserver/layers/RecurrentLayerGroup.cpp
index af8dd61d84..78a74ff19a 100644
--- a/paddle/gserver/layers/RecurrentLayerGroup.cpp
+++ b/paddle/gserver/layers/RecurrentLayerGroup.cpp
@@ -33,15 +33,15 @@ public:
   void initSubNetwork(NeuralNetwork* rootNetwork,
                       const ModelConfig& config,
                       const std::vector<ParameterType>& parameterTypes,
-                      bool useGpu);
+                      bool useGpu) override;
 
-  void forward(PassType passType) {
+  void forward(PassType passType) override {
     REGISTER_TIMER_INFO("RecurrentGroupFwTime", getName().c_str());
     const std::vector<Argument> inArgs;
     std::vector<Argument> outArgs;
     network_->forward(inArgs, &outArgs, passType);
   }
-  void backward(const UpdateCallback& callback) {
+  void backward(const UpdateCallback& callback) override {
     REGISTER_TIMER_INFO("RecurrentGroupBwTime", getName().c_str());
     network_->backward(nullptr);
 
@@ -53,7 +53,8 @@ public:
   /**
    * @see Layer.accessSubNetwork
    */
-  void accessSubNetwork(const std::function<void(NeuralNetwork&)>& callback) {
+  void accessSubNetwork(
+      const std::function<void(NeuralNetwork&)>& callback) override {
     callback(*network_);
   }
 
diff --git a/paddle/gserver/layers/ResizeLayer.cpp b/paddle/gserver/layers/ResizeLayer.cpp
index 7fcb3adea0..eb3b63c106 100644
--- a/paddle/gserver/layers/ResizeLayer.cpp
+++ b/paddle/gserver/layers/ResizeLayer.cpp
@@ -20,18 +20,19 @@ namespace paddle {
 /**
  * @brief A layer for resizing a minibatch matrix h*w to h'*w'
  * @note
- * origin matrix height * witdth)
+ * origin matrix height * width)
  * resize matrix: (height * width / size) * size
  */
 class ResizeLayer : public Layer {
 public:
   explicit ResizeLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  void backward(const UpdateCallback& callback);
+  void backward(const UpdateCallback& callback) override;
 };
 
 REGISTER_LAYER(resize, ResizeLayer);
diff --git a/paddle/gserver/layers/SamplingIdLayer.cpp b/paddle/gserver/layers/SamplingIdLayer.cpp
index 59ff5d41b5..2538d99bb7 100644
--- a/paddle/gserver/layers/SamplingIdLayer.cpp
+++ b/paddle/gserver/layers/SamplingIdLayer.cpp
@@ -35,8 +35,8 @@ public:
   explicit SamplingIdLayer(const LayerConfig& config)
       : Layer(config), rand1_(0, 1) {}
 
-  virtual bool init(const LayerMap& layerMap,
-                    const ParameterMap& parameterMap) {
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override {
     bool ret = Layer::init(layerMap, parameterMap);
     CHECK_EQ(1UL, inputLayers_.size());
     if (useGpu_) {
@@ -48,7 +48,7 @@ public:
     return ret;
   }
 
-  void forward(PassType passType) {
+  void forward(PassType passType) override {
     Layer::forward(passType);
     if (useGpu_) {
       for (size_t i = 0; i < inputLayers_.size(); i++) {
@@ -83,7 +83,7 @@ public:
     output_.ids->copyFrom(ids.data(), batchSize);
   }
 
-  virtual void backward(const UpdateCallback& callback) {}
+  void backward(const UpdateCallback& callback) override {}
 };
 
 REGISTER_LAYER(sampling_id, SamplingIdLayer);
diff --git a/paddle/gserver/layers/ScalingLayer.cpp b/paddle/gserver/layers/ScalingLayer.cpp
index 7f0084be6b..a38ee0857a 100644
--- a/paddle/gserver/layers/ScalingLayer.cpp
+++ b/paddle/gserver/layers/ScalingLayer.cpp
@@ -37,10 +37,11 @@ public:
 
   ~ScalingLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(scaling, ScalingLayer);
diff --git a/paddle/gserver/layers/SelectiveFullyConnectedLayer.h b/paddle/gserver/layers/SelectiveFullyConnectedLayer.h
index bdf9a4652c..99126fdba5 100644
--- a/paddle/gserver/layers/SelectiveFullyConnectedLayer.h
+++ b/paddle/gserver/layers/SelectiveFullyConnectedLayer.h
@@ -65,9 +65,10 @@ public:
       : Layer(config), selCols_(nullptr) {}
 
   ~SelectiveFullyConnectedLayer() {}
-  void prefetch();
+  void prefetch() override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   Weight& getWeight(int idx) { return *weights_[idx]; }
 
@@ -90,8 +91,8 @@ public:
   void fillSelectiveData(
       const std::shared_ptr<std::vector<std::pair<int*, size_t>>>& candidates);
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 
 private:
   /**
diff --git a/paddle/gserver/layers/SequenceConcatLayer.cpp b/paddle/gserver/layers/SequenceConcatLayer.cpp
index 069bc26e60..b4677687a6 100644
--- a/paddle/gserver/layers/SequenceConcatLayer.cpp
+++ b/paddle/gserver/layers/SequenceConcatLayer.cpp
@@ -35,10 +35,11 @@ public:
 
   ~SequenceConcatLayer() {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(seqconcat, SequenceConcatLayer);
diff --git a/paddle/gserver/layers/SequenceLastInstanceLayer.cpp b/paddle/gserver/layers/SequenceLastInstanceLayer.cpp
index 4bfce766c7..7a13cd7ad0 100644
--- a/paddle/gserver/layers/SequenceLastInstanceLayer.cpp
+++ b/paddle/gserver/layers/SequenceLastInstanceLayer.cpp
@@ -42,12 +42,11 @@ public:
   explicit SequenceLastInstanceLayer(const LayerConfig& config)
       : SequencePoolLayer(config) {}
 
-  ~SequenceLastInstanceLayer() {}
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(seqlastins, SequenceLastInstanceLayer);
diff --git a/paddle/gserver/layers/SequencePoolLayer.h b/paddle/gserver/layers/SequencePoolLayer.h
index aa9c132586..85b51ccd1d 100644
--- a/paddle/gserver/layers/SequencePoolLayer.h
+++ b/paddle/gserver/layers/SequencePoolLayer.h
@@ -46,12 +46,11 @@ protected:
 public:
   explicit SequencePoolLayer(const LayerConfig& config) : Layer(config) {}
 
-  virtual ~SequencePoolLayer() {}
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 }  // namespace paddle
diff --git a/paddle/gserver/layers/SequenceReshapeLayer.cpp b/paddle/gserver/layers/SequenceReshapeLayer.cpp
index 23924b0490..66f4915908 100644
--- a/paddle/gserver/layers/SequenceReshapeLayer.cpp
+++ b/paddle/gserver/layers/SequenceReshapeLayer.cpp
@@ -34,12 +34,11 @@ protected:
 public:
   explicit SequenceReshapeLayer(const LayerConfig& config) : Layer(config) {}
 
-  ~SequenceReshapeLayer() {}
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(seqreshape, SequenceReshapeLayer);
diff --git a/paddle/gserver/layers/SlopeInterceptLayer.cpp b/paddle/gserver/layers/SlopeInterceptLayer.cpp
index b678f414b6..faf98744a7 100644
--- a/paddle/gserver/layers/SlopeInterceptLayer.cpp
+++ b/paddle/gserver/layers/SlopeInterceptLayer.cpp
@@ -39,12 +39,11 @@ class SlopeInterceptLayer : public Layer {
 public:
   explicit SlopeInterceptLayer(const LayerConfig& config) : Layer(config) {}
 
-  ~SlopeInterceptLayer() {}
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(slope_intercept, SlopeInterceptLayer);
diff --git a/paddle/gserver/layers/SpatialPyramidPoolLayer.h b/paddle/gserver/layers/SpatialPyramidPoolLayer.h
index 32e88cf141..7d3cb80443 100644
--- a/paddle/gserver/layers/SpatialPyramidPoolLayer.h
+++ b/paddle/gserver/layers/SpatialPyramidPoolLayer.h
@@ -43,9 +43,8 @@ protected:
 public:
   explicit SpatialPyramidPoolLayer(const LayerConfig& config) : Layer(config) {}
 
-  ~SpatialPyramidPoolLayer() {}
-
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   ProjectionConfig getConfig(size_t sizeX_,
                              size_t sizeY_,
@@ -54,7 +53,7 @@ public:
                              std::string& poolType_);
   size_t getSize();
 
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 }  // namespace paddle
diff --git a/paddle/gserver/layers/SubSequenceLayer.cpp b/paddle/gserver/layers/SubSequenceLayer.cpp
index c52fbee262..19b7ad1869 100644
--- a/paddle/gserver/layers/SubSequenceLayer.cpp
+++ b/paddle/gserver/layers/SubSequenceLayer.cpp
@@ -35,12 +35,11 @@ protected:
 public:
   explicit SubSequenceLayer(const LayerConfig& config) : Layer(config) {}
 
-  ~SubSequenceLayer() {}
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(subseq, SubSequenceLayer);
diff --git a/paddle/gserver/layers/SumToOneNormLayer.cpp b/paddle/gserver/layers/SumToOneNormLayer.cpp
index aa99b49380..00f8519550 100644
--- a/paddle/gserver/layers/SumToOneNormLayer.cpp
+++ b/paddle/gserver/layers/SumToOneNormLayer.cpp
@@ -41,12 +41,11 @@ protected:
 public:
   explicit SumToOneNormLayer(const LayerConfig& config) : Layer(config) {}
 
-  ~SumToOneNormLayer() {}
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 
 REGISTER_LAYER(sum_to_one_norm, SumToOneNormLayer);
diff --git a/paddle/gserver/layers/TensorLayer.h b/paddle/gserver/layers/TensorLayer.h
index ac38ffb620..43992f692d 100644
--- a/paddle/gserver/layers/TensorLayer.h
+++ b/paddle/gserver/layers/TensorLayer.h
@@ -44,13 +44,12 @@ protected:
 public:
   explicit TensorLayer(const LayerConfig& config) : Layer(config) {}
 
-  ~TensorLayer() {}
-
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   Weight& getWeight(int idx) { return *weights_[idx]; }
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 }  // namespace paddle
diff --git a/paddle/gserver/layers/TransLayer.h b/paddle/gserver/layers/TransLayer.h
index 1d5a370b34..be10bb74f6 100644
--- a/paddle/gserver/layers/TransLayer.h
+++ b/paddle/gserver/layers/TransLayer.h
@@ -32,9 +32,10 @@ class TransLayer : public Layer {
 public:
   explicit TransLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void forward(PassType passType);
-  void backward(const UpdateCallback& callback = nullptr);
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback = nullptr) override;
 };
 }  // namespace paddle
diff --git a/paddle/gserver/layers/ValidationLayer.h b/paddle/gserver/layers/ValidationLayer.h
index 4c1de7b3b7..c8b2634a13 100644
--- a/paddle/gserver/layers/ValidationLayer.h
+++ b/paddle/gserver/layers/ValidationLayer.h
@@ -26,7 +26,8 @@ class ValidationLayer : public Layer {
 public:
   explicit ValidationLayer(const LayerConfig& config) : Layer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
   LayerPtr getOutputLayer() { return inputLayers_[0]; }
 
@@ -37,13 +38,13 @@ public:
     return inputLayers_[2];
   }
 
-  virtual void forward(PassType passType);
+  void forward(PassType passType) override;
 
-  virtual void backward(const UpdateCallback& callback = nullptr);
+  void backward(const UpdateCallback& callback = nullptr) override;
 
   virtual void validationImp(MatrixPtr outputValue, IVectorPtr label) = 0;
 
-  virtual void onPassEnd() = 0;
+  void onPassEnd() override = 0;
 };
 
 /*
@@ -57,11 +58,12 @@ public:
         cpuLabel_(nullptr),
         cpuWeight_(nullptr) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void validationImp(MatrixPtr outputValue, IVectorPtr label);
+  void validationImp(MatrixPtr outputValue, IVectorPtr label) override;
 
-  void onPassEnd();
+  void onPassEnd() override;
 
   struct PredictionResult {
     PredictionResult(real __out, int __label) : out(__out), label(__label) {}
@@ -86,11 +88,12 @@ public:
   explicit PnpairValidation(const LayerConfig& config)
       : ValidationLayer(config) {}
 
-  bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
 
-  void validationImp(MatrixPtr outputValue, IVectorPtr label);
+  void validationImp(MatrixPtr outputValue, IVectorPtr label) override;
 
-  void onPassEnd();
+  void onPassEnd() override;
 
 private:
   bool passBegin_;
diff --git a/paddle/gserver/layers/WarpCTCLayer.h b/paddle/gserver/layers/WarpCTCLayer.h
index 3d9ae9249a..7e8d7379d2 100644
--- a/paddle/gserver/layers/WarpCTCLayer.h
+++ b/paddle/gserver/layers/WarpCTCLayer.h
@@ -30,9 +30,10 @@ public:
   explicit WarpCTCLayer(const LayerConfig& config) : Layer(config) {}
   ~WarpCTCLayer() {}
 
-  virtual bool init(const LayerMap& layerMap, const ParameterMap& parameterMap);
-  virtual void forward(PassType passType);
-  virtual void backward(const UpdateCallback& callback);
+  bool init(const LayerMap& layerMap,
+            const ParameterMap& parameterMap) override;
+  void forward(PassType passType) override;
+  void backward(const UpdateCallback& callback) override;
 
 protected:
   /**