[clang-tidy] NO.40 enable performance-inefficient-string-concatenation

.clang-tidy

@@ -192,7 +192,7 @@ performance-faster-string-find,
 -performance-for-range-copy,
 -performance-implicit-conversion-in-loop,
 -performance-inefficient-algorithm,
--performance-inefficient-string-concatenation,
+performance-inefficient-string-concatenation,
 -performance-inefficient-vector-operation,
 -performance-move-const-arg,
 -performance-move-constructor-init,

paddle/fluid/framework/ir/fuse_optimizer_ops_pass/fuse_optimizer_op_pass.cc

@@ -95,8 +95,14 @@ void FuseOptimizerOpPass::ApplyImpl(ir::Graph *graph) const {
   const std::string prefix(details::kFusedVarNamePrefix);
   for (auto &var_name : aux_var_names) {
     // NOTE: the fused_var_name should be unique.
-    auto fused_var_name = prefix + "_" + fuse_op_type + "_" + var_name + "_" +
-                          aux_var_map[var_name][0];
+    std::string fused_var_name;
+    fused_var_name.append(prefix)
+        .append("_")
+        .append(fuse_op_type)
+        .append("_")
+        .append(var_name)
+        .append("_")
+        .append(aux_var_map[var_name][0]);
     VLOG(6) << var_name << ": " << fused_var_name;
     PADDLE_ENFORCE_EQ(
         fused_var_set.count(fused_var_name),

paddle/fluid/operators/string/faster_tokenizer_op.cc

@@ -157,7 +157,7 @@ void WordPieceTokenizer::Tokenize(const wstring& text,
     while (start < end) {
       std::wstring sub = text.substr(start, end - start);
       if (start > 0) {
-        sub = L"##" + sub;
+        sub.insert(0, L"##");
       }
       auto it = vocab_->find(sub);
       if (it != vocab_->end()) {

paddle/fluid/platform/profiler.cc

@@ -815,7 +815,7 @@ std::string OpName(const framework::VariableNameMap &name_map,
   for (const auto &map_item : name_map) {
     auto name_outputs = map_item.second;
     if (!name_outputs.empty()) {
-      ret = ret + name_outputs[0];
+      ret.append(name_outputs[0]);
       break;
     }
   }
@@ -906,7 +906,8 @@ static void EmulateEventPushAndPop(
           evt_stk.push(iter->second);
           std::string prefix = thr_evts[iter->second].name;
           if (!prefix_stk.empty()) {
-            prefix = prefix_stk.top() + "/" + prefix;
+            // prefix = prefix_stk.top() + "/" + prefix;
+            prefix.insert(0, "/").insert(0, prefix_stk.top());
           }
           prefix_stk.push(prefix);
         }

paddle/fluid/pybind/kernel_signature_generator.cc

@@ -56,30 +56,28 @@ int main(int argc, char **argv) {
       }
     }
     if (kernel_signature_map.Has(op_name)) {
-      kernel_signature_map_str =
-          kernel_signature_map_str + "\"" + op_kernel_pair.first + "\":{";
+      kernel_signature_map_str.append("\"")
+          .append(op_kernel_pair.first)
+          .append("\":{");
       const auto &args = kernel_signature_map.Get(op_name);
 
       kernel_signature_map_str += "\"inputs\":[";
       auto inputs_ = args.input_names;
       for (size_t i = 0; i < inputs_.size(); i++) {
-        kernel_signature_map_str =
-            kernel_signature_map_str + "\"" + inputs_[i] + "\",";
+        kernel_signature_map_str.append("\"").append(inputs_[i]).append("\",");
       }
       if (!inputs_.empty()) kernel_signature_map_str.pop_back();
 
       kernel_signature_map_str += "],\"attrs\":[";
       auto attrs_ = args.attr_names;
       for (size_t i = 0; i < attrs_.size(); i++) {
-        kernel_signature_map_str =
-            kernel_signature_map_str + "\"" + attrs_[i] + "\",";
+        kernel_signature_map_str.append("\"").append(attrs_[i]).append("\",");
       }
       if (!attrs_.empty()) kernel_signature_map_str.pop_back();
       kernel_signature_map_str += "],\"outputs\":[";
       auto outputs_ = args.output_names;
       for (size_t i = 0; i < outputs_.size(); i++) {
-        kernel_signature_map_str =
-            kernel_signature_map_str + "\"" + outputs_[i] + "\",";
+        kernel_signature_map_str.append("\"").append(outputs_[i]).append("\",");
       }
 
       if (!outputs_.empty()) kernel_signature_map_str.pop_back();

paddle/phi/backends/device_manager.cc

@@ -702,7 +702,8 @@ std::vector<std::string> ListAllLibraries(const std::string& library_dir) {
       std::string filename(ptr->d_name);
       if (std::regex_match(
               filename.begin(), filename.end(), results, express)) {
-        libraries.push_back(library_dir + '/' + filename);
+        libraries.push_back(
+            std::string(library_dir).append("/").append(filename));
         VLOG(4) << "Found lib: " << libraries.back();
       }
     }