diff --git a/CMakeLists.txt b/CMakeLists.txt
index fed9335..eb25d11 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,7 +3,10 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 project(cgproxy VERSION 0.14)
-set(CMAKE_CXX_FLAGS  "${CMAKE_CXX_FLAGS} -Wno-unused-result")
+add_compile_options(-Wall -Wextra -Wpedantic -Wno-unused-result -Wno-unused-parameter)
+
+# for clangd
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 option(with_execsnoop "enable program level proxy control feature, need bcc installed" ON)
 option(build_tools OFF)
diff --git a/src/cgproxyd.hpp b/src/cgproxyd.hpp
index 25c901f..7d81060 100644
--- a/src/cgproxyd.hpp
+++ b/src/cgproxyd.hpp
@@ -149,8 +149,7 @@ class cgproxyd {
       return MSG_ERROR;
     }
 
-    int type, status;
-    int pid, cgroup_target;
+    int type, status, pid;
     try {
       type = j.at("type").get<int>();
       switch (type) {
diff --git a/src/socket_client.cpp b/src/socket_client.cpp
index 26c25d3..94682b3 100644
--- a/src/socket_client.cpp
+++ b/src/socket_client.cpp
@@ -42,11 +42,7 @@ void send(const char *msg, int &status) {
 }
 
 void send(const string msg, int &status) {
-  int msg_len = msg.length();
-  char buff[msg_len];
-  msg.copy(buff, msg_len, 0);
-  buff[msg_len] = '\0';
-  send(buff, status);
+  send(msg.c_str(), status);
   debug("return status: %d", status);
 }
 
diff --git a/src/socket_server.cpp b/src/socket_server.cpp
index 2081d8c..84fea34 100644
--- a/src/socket_server.cpp
+++ b/src/socket_server.cpp
@@ -4,6 +4,7 @@
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <stdlib.h>  
 
 namespace fs = std::filesystem;
 
@@ -39,12 +40,13 @@ void SocketServer::socketListening(function<int(char *)> callback, promise<void>
     flag = read(cfd, &msg_len, sizeof(int));
     continue_if_error(flag, "read length");
     // read msg
-    char msg[msg_len];
+    auto msg=(char*)malloc(msg_len+1);
     flag = read(cfd, msg, msg_len * sizeof(char));
     continue_if_error(flag, "read msg");
     msg[msg_len] = '\0';
     // handle msg
     int status = callback(msg);
+    free(msg);
     // send back flag
     flag = write(cfd, &status, sizeof(int));
     continue_if_error(flag, "write back");