Add Clang support for -Wall -Wextra -Werror; fix -Wunused-parameter warnings when not using OpenSSL (#175)

Author: engineerjames

CMakeLists.txt

@@ -46,7 +46,7 @@ else(BUILD_TRANTOR_SHARED)
   add_library(${PROJECT_NAME} STATIC)
 endif(BUILD_TRANTOR_SHARED)
 
-if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Windows" AND CMAKE_CXX_COMPILER_ID MATCHES GNU)
+if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "Windows" AND CMAKE_CXX_COMPILER_ID MATCHES Clang|GNU)
     target_compile_options(${PROJECT_NAME} PRIVATE -Wall -Wextra -Werror)
 endif()
 

trantor/net/TcpClient.cc

@@ -221,6 +221,13 @@ void TcpClient::enableSSL(
     }
 
 #else
+    // When not using OpenSSL, using `void` here will
+    // work around the unused parameter warnings without overhead.
+    (void)useOldTLS;
+    (void)validateCert;
+    (void)hostname;
+    (void)sslConfCmds;
+
     LOG_FATAL << "OpenSSL is not found in your system!";
     abort();
 #endif

trantor/net/TcpClient.h

@@ -228,8 +228,13 @@ class TRANTOR_EXPORT TcpClient : NonCopyable
     mutable std::mutex mutex_;
     TcpConnectionPtr connection_;  // @GuardedBy mutex_
     std::shared_ptr<SSLContext> sslCtxPtr_;
-    bool validateCert_{false};
     std::string SSLHostName_;
+
+// This member variable is only needed when using OpenSSL, so
+// we can safely remove it when not using OpenSSL.
+#ifdef USE_OPENSSL
+    bool validateCert_{false};
+#endif
 #ifndef _WIN32
     class IgnoreSigPipe
     {

trantor/net/TcpServer.cc

@@ -195,6 +195,13 @@ void TcpServer::enableSSL(
     /* Create a new OpenSSL context */
     sslCtxPtr_ = newSSLServerContext(certPath, keyPath, useOldTLS, sslConfCmds);
 #else
+    // When not using OpenSSL, using `void` here will
+    // work around the unused parameter warnings without overhead.
+    (void)certPath;
+    (void)keyPath;
+    (void)useOldTLS;
+    (void)sslConfCmds;
+
     LOG_FATAL << "OpenSSL is not found in your system!";
     abort();
 #endif

trantor/net/inner/TcpConnectionImpl.cc

@@ -352,10 +352,10 @@ std::shared_ptr<SSLContext> newSSLServerContext(
 namespace trantor
 {
 std::shared_ptr<SSLContext> newSSLServerContext(
-    const std::string &certPath,
-    const std::string &keyPath,
-    bool useOldTLS,
-    const std::vector<std::pair<std::string, std::string>> &sslConfCmds)
+    const std::string &,
+    const std::string &,
+    bool,
+    const std::vector<std::pair<std::string, std::string>> &)
 {
     LOG_FATAL << "OpenSSL is not found in your system!";
     abort();
@@ -470,6 +470,11 @@ void TcpConnectionImpl::startServerEncryption(
     std::function<void()> callback)
 {
 #ifndef USE_OPENSSL
+    // When not using OpenSSL, using `void` here will
+    // work around the unused parameter warnings without overhead.
+    (void)ctx;
+    (void)callback;
+
     LOG_FATAL << "OpenSSL is not found in your system!";
     abort();
 #else
@@ -496,6 +501,14 @@ void TcpConnectionImpl::startClientEncryption(
     const std::vector<std::pair<std::string, std::string>> &sslConfCmds)
 {
 #ifndef USE_OPENSSL
+    // When not using OpenSSL, using `void` here will
+    // work around the unused parameter warnings without overhead.
+    (void)callback;
+    (void)useOldTLS;
+    (void)validateCert;
+    (void)hostname;
+    (void)sslConfCmds;
+
     LOG_FATAL << "OpenSSL is not found in your system!";
     abort();
 #else