Replace MSG_TEST() macro for static inline msg_test()

Using a static inline function instead of a macro has the advantages that
(1) 'flags' is not evaluated twice and (2) coverity will stop complaining
that 'Macro compares unsigned to 0 (NO_EFFECT)' each time we use flags
with loglevel 0 (e.g. M_FATAL or M_WARN).

This has a performance impact when compiler optimizations are fully
disabled ('-O0'), but should otherwise be as fast as using a macro.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1459088296-5046-1-git-send-email-steffan@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/11368
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit bbde0a766c69f573746461415c6f5cd289272fff)

diff --git a/src/openvpn/error.c b/src/openvpn/error.c
index b47a9e5f03da58fdf3f7d980ac88e69dc750c889..6ccdeae0004597237dacb21351f35f4e854d24ae 100644 (file)
--- a/src/openvpn/error.c
+++ b/src/openvpn/error.c
@@ -217,7 +217,7 @@ void x_msg_va (const unsigned int flags, const char *format, va_list arglist)
 
 #ifndef HAVE_VARARG_MACROS
   /* the macro has checked this otherwise */
-  if (!MSG_TEST (flags))
+  if (!msg_test (flags))
     return;
 #endif
 

diff --git a/src/openvpn/error.h b/src/openvpn/error.h
index 52ef0bd008023673521d1516f1975e9474b97480..4024e5e50c456bd732ad91c6ab57bd5b84c222b5 100644 (file)
--- a/src/openvpn/error.h
+++ b/src/openvpn/error.h
@@ -135,26 +135,31 @@ extern int x_msg_line_num;
  * msg() as a macro for optimization win.
  */
 
-bool dont_mute (unsigned int flags); /* check muting filter */
+/** Check muting filter */
+bool dont_mute (unsigned int flags);
 
-#define MSG_TEST(flags) (unlikely((((unsigned int)flags) & M_DEBUG_LEVEL) <= x_debug_level) && dont_mute (flags))
+/** Return true if flags represent an enabled, not muted log level */
+static inline bool msg_test (unsigned int flags)
+{
+  return ((flags & M_DEBUG_LEVEL) <= x_debug_level) && dont_mute (flags);
+}
 
 /* Macro to ensure (and teach static analysis tools) we exit on fatal errors */
 #define EXIT_FATAL(flags) do { if ((flags) & M_FATAL) _exit(1); } while (false)
 
 #if defined(HAVE_CPP_VARARG_MACRO_ISO) && !defined(__LCLINT__)
 # define HAVE_VARARG_MACROS
-# define msg(flags, ...) do { if (MSG_TEST(flags)) x_msg((flags), __VA_ARGS__); EXIT_FATAL(flags); } while (false)
+# define msg(flags, ...) do { if (msg_test(flags)) x_msg((flags), __VA_ARGS__); EXIT_FATAL(flags); } while (false)
 # ifdef ENABLE_DEBUG
-#  define dmsg(flags, ...) do { if (MSG_TEST(flags)) x_msg((flags), __VA_ARGS__); EXIT_FATAL(flags); } while (false)
+#  define dmsg(flags, ...) do { if (msg_test(flags)) x_msg((flags), __VA_ARGS__); EXIT_FATAL(flags); } while (false)
 # else
 #  define dmsg(flags, ...)
 # endif
 #elif defined(HAVE_CPP_VARARG_MACRO_GCC) && !defined(__LCLINT__)
 # define HAVE_VARARG_MACROS
-# define msg(flags, args...) do { if (MSG_TEST(flags)) x_msg((flags), args); EXIT_FATAL(flags); } while (false)
+# define msg(flags, args...) do { if (msg_test(flags)) x_msg((flags), args); EXIT_FATAL(flags); } while (false)
 # ifdef ENABLE_DEBUG
-#  define dmsg(flags, args...) do { if (MSG_TEST(flags)) x_msg((flags), args); EXIT_FATAL(flags); } while (false)
+#  define dmsg(flags, args...) do { if (msg_test(flags)) x_msg((flags), args); EXIT_FATAL(flags); } while (false)
 # else
 #  define dmsg(flags, args...)
 # endif

diff --git a/src/openvpn/plugin.c b/src/openvpn/plugin.c
index 54c5b52d69a5661e19351f52cb3251f225e37bf6..4e5e6ce14a748995e51f3d1b0b9a828271351c56 100644 (file)
--- a/src/openvpn/plugin.c
+++ b/src/openvpn/plugin.c
@@ -316,7 +316,7 @@ plugin_vlog (openvpn_plugin_log_flags_t flags, const char *name, const char *for
   if (flags & PLOG_NOMUTE)
     msg_flags |= M_NOMUTE;
 
-  if (MSG_TEST (msg_flags))
+  if (msg_test (msg_flags))
     {
       struct gc_arena gc;
       char* msg_fmt;