Fix cpplint for print_op (#10070)

* Fix print op cpplint errors

* Remove commented code

paddle/fluid/operators/print_op.cc

@@ -23,15 +23,15 @@ namespace operators {
 
 #define CLOG std::cout
 
-const std::string kForward = "FORWARD";
-const std::string kBackward = "BACKWARD";
-const std::string kBoth = "BOTH";
+const char kForward[] = "FORWARD";
+const char kBackward[] = "BACKWARD";
+const char kBoth[] = "BOTH";
 
 struct Formater {
   std::string message;
   std::string name;
   std::vector<int> dims;
-  std::type_index dtype{typeid(char)};
+  std::type_index dtype{typeid(const char)};
   framework::LoD lod;
   int summarize;
   void* data{nullptr};
@@ -62,7 +62,7 @@ struct Formater {
     }
   }
   void PrintDtype() {
-    if (dtype.hash_code() != typeid(char).hash_code()) {
+    if (dtype.hash_code() != typeid(const char).hash_code()) {
       CLOG << "\tdtype: " << dtype.name() << std::endl;
     }
   }
@@ -83,15 +83,15 @@ struct Formater {
   void PrintData(size_t size) {
     PADDLE_ENFORCE_NOT_NULL(data);
     // print float
-    if (dtype.hash_code() == typeid(float).hash_code()) {
+    if (dtype.hash_code() == typeid(const float).hash_code()) {
       Display<float>(size);
-    } else if (dtype.hash_code() == typeid(double).hash_code()) {
+    } else if (dtype.hash_code() == typeid(const double).hash_code()) {
       Display<double>(size);
-    } else if (dtype.hash_code() == typeid(int).hash_code()) {
+    } else if (dtype.hash_code() == typeid(const int).hash_code()) {
       Display<int>(size);
-    } else if (dtype.hash_code() == typeid(int64_t).hash_code()) {
+    } else if (dtype.hash_code() == typeid(const int64_t).hash_code()) {
       Display<int64_t>(size);
-    } else if (dtype.hash_code() == typeid(bool).hash_code()) {
+    } else if (dtype.hash_code() == typeid(const bool).hash_code()) {
       Display<bool>(size);
     } else {
       CLOG << "\tdata: unprintable type: " << dtype.name() << std::endl;
@@ -100,7 +100,7 @@ struct Formater {
 
   template <typename T>
   void Display(size_t size) {
-    auto* d = (T*)data;
+    auto* d = reinterpret_cast<T*>(data);
     CLOG << "\tdata: ";
     if (summarize != -1) {
       summarize = std::min(size, (size_t)summarize);
@@ -135,7 +135,7 @@ class TensorPrintOp : public framework::OperatorBase {
   void RunImpl(const framework::Scope& scope,
                const platform::Place& place) const override {
     const framework::Variable* in_var_ptr = nullptr;
-    std::string phase = kForward;
+    std::string phase(kForward);
     std::string printed_var_name = "";
 
     auto& inputs = Inputs();
@@ -146,7 +146,7 @@ class TensorPrintOp : public framework::OperatorBase {
                !Inputs("In@GRAD").empty()) {
       in_var_ptr = scope.FindVar(Input("In@GRAD"));
       printed_var_name = Inputs("In@GRAD").front();
-      phase = kBackward;
+      phase = std::string(kBackward);
     } else {
       PADDLE_THROW("Unknown phase, should be forward or backward.");
     }
@@ -163,7 +163,7 @@ class TensorPrintOp : public framework::OperatorBase {
     out_tensor.set_lod(in_tensor.lod());
 
     std::string print_phase = Attr<std::string>("print_phase");
-    if (print_phase != phase && print_phase != kBoth) {
+    if (print_phase != phase && print_phase != std::string(kBoth)) {
       return;
     }
 
@@ -199,7 +199,7 @@ class TensorPrintOp : public framework::OperatorBase {
       formater.lod = printed_tensor.lod();
     }
     formater.summarize = Attr<int>("summarize");
-    formater.data = (void*)printed_tensor.data<void>();
+    formater.data = reinterpret_cast<void*>(printed_tensor.data<void>());
     formater(printed_tensor.numel());
   }
 
@@ -223,8 +223,9 @@ class PrintOpProtoAndCheckMaker : public framework::OpProtoAndCheckerMaker {
         "print_phase",
         "(string, default 'BOTH') Which phase to display including 'FORWARD' "
         "'BACKWARD' and 'BOTH'.")
-        .SetDefault(kBoth)
-        .InEnum({kForward, kBackward, kBoth});
+        .SetDefault(std::string(kBoth))
+        .InEnum({std::string(kForward), std::string(kBackward),
+                 std::string(kBoth)});
     AddOutput("Out", "Output tensor with same data as input tensor.");
     AddComment(R"DOC(
 Creates a print op that will print when a tensor is accessed.