From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Thu, 2 Nov 2023 08:40:21 +0000 (+0100)
Subject: dnsdist: Fix Coverity CID 1523748: Performance inefficiencies in dolog.hh
X-Git-Tag: rec-5.0.0-beta1~12^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7e01b698ef441ff4961f8703246f2f7274b8ae7d;p=thirdparty%2Fpdns.git

dnsdist: Fix Coverity CID 1523748: Performance inefficiencies in dolog.hh

Coverity reports:
```
Performance inefficiencies (COPY_INSTEAD_OF_MOVE): "args" is
passed-by-value as parameter to "dolog" when it could be moved instead.
```
This PR implements perfect forwarding for the variadic template parameters
of DNSdist's logging methods to address it, even though the performance of
these functions should not matter much.
---

diff --git a/pdns/dolog.hh b/pdns/dolog.hh
index a28777ab81..b94edb2507 100644
--- a/pdns/dolog.hh
+++ b/pdns/dolog.hh
@@ -58,7 +58,7 @@ inline void dolog(std::ostream& os, const char*s)
 }
 
 template<typename T, typename... Args>
-void dolog(std::ostream& os, const char* s, T value, Args... args)
+void dolog(std::ostream& os, const char* s, T value, Args&&... args)
 {
   while (*s) {
     if (*s == '%') {
@@ -68,7 +68,7 @@ void dolog(std::ostream& os, const char* s, T value, Args... args)
       else {
 	os << value;
 	s += 2;
-	dolog(os, s, args...);
+	dolog(os, s, std::forward<Args>(args)...);
 	return;
       }
     }
@@ -91,10 +91,10 @@ inline void setSyslogFacility(int facility)
 }
 
 template<typename... Args>
-void genlog(std::ostream& stream, int level, bool doSyslog, const char* s, Args... args)
+void genlog(std::ostream& stream, int level, bool doSyslog, const char* s, Args&&... args)
 {
   std::ostringstream str;
-  dolog(str, s, args...);
+  dolog(str, s, std::forward<Args>(args)...);
 
   auto output = str.str();
 
@@ -120,15 +120,15 @@ void genlog(std::ostream& stream, int level, bool doSyslog, const char* s, Args.
 }
 
 template<typename... Args>
-void verboselog(const char* s, Args... args)
+void verboselog(const char* s, Args&&... args)
 {
 #ifdef DNSDIST
   if (g_verboseStream) {
-    genlog(*g_verboseStream, LOG_DEBUG, false, s, args...);
+    genlog(*g_verboseStream, LOG_DEBUG, false, s, std::forward<Args>(args)...);
   }
   else {
 #endif /* DNSDIST */
-    genlog(std::cout, LOG_DEBUG, g_syslog, s, args...);
+    genlog(std::cout, LOG_DEBUG, g_syslog, s, std::forward<Args>(args)...);
 #ifdef DNSDIST
   }
 #endif /* DNSDIST */
@@ -137,21 +137,21 @@ void verboselog(const char* s, Args... args)
 #define vinfolog if (g_verbose) verboselog
 
 template<typename... Args>
-void infolog(const char* s, Args... args)
+void infolog(const char* s, Args&&... args)
 {
-  genlog(std::cout, LOG_INFO, g_syslog, s, args...);
+  genlog(std::cout, LOG_INFO, g_syslog, s, std::forward<Args>(args)...);
 }
 
 template<typename... Args>
-void warnlog(const char* s, Args... args)
+void warnlog(const char* s, Args&&... args)
 {
-  genlog(std::cout, LOG_WARNING, g_syslog, s, args...);
+  genlog(std::cout, LOG_WARNING, g_syslog, s, std::forward<Args>(args)...);
 }
 
 template<typename... Args>
-void errlog(const char* s, Args... args)
+void errlog(const char* s, Args&&... args)
 {
-  genlog(std::cout, LOG_ERR, g_syslog, s, args...);
+  genlog(std::cout, LOG_ERR, g_syslog, s, std::forward<Args>(args)...);
 }
 
 #else // RECURSOR
@@ -169,7 +169,7 @@ inline void dolog(const char* s)
 }
 
 template<typename T, typename... Args>
-void dolog(Logger::Urgency u, const char* s, T value, Args... args)
+void dolog(Logger::Urgency u, const char* s, T value, Args&&... args)
 {
   g_log << u;
   while (*s) {
@@ -180,7 +180,7 @@ void dolog(Logger::Urgency u, const char* s, T value, Args... args)
       else {
 	g_log << value;
 	s += 2;
-	dolog(s, args...);
+	dolog(s, std::forward<Args>(args)...);
 	return;
       }
     }
@@ -191,21 +191,21 @@ void dolog(Logger::Urgency u, const char* s, T value, Args... args)
 #define vinfolog if(g_verbose)infolog
 
 template<typename... Args>
-void infolog(const char* s, Args... args)
+void infolog(const char* s, Args&&... args)
 {
-  dolog(Logger::Info, s, args...);
+  dolog(Logger::Info, s, std::forward<Args>(args)...);
 }
 
 template<typename... Args>
-void warnlog(const char* s, Args... args)
+void warnlog(const char* s, Args&&... args)
 {
-  dolog(Logger::Warning, s, args...);
+  dolog(Logger::Warning, s, std::forward<Args>(args)...);
 }
 
 template<typename... Args>
-void errlog(const char* s, Args... args)
+void errlog(const char* s, Args&&... args)
 {
-  dolog(Logger::Error, s, args...);
+  dolog(Logger::Error, s, std::forward<Args>(args)...);
 }
 
 #endif