Suppress annoying "conditional expression is constant" win32 warning

include/fc/exception/exception.hpp

@@ -298,21 +298,26 @@ namespace fc
  *  @brief Checks a condition and throws an assert_exception if the test is FALSE
  */
 #define FC_ASSERT( TEST, ... ) \
-   FC_EXPAND_MACRO( \
+  FC_EXPAND_MACRO( \
-      do { if( !(TEST) ) { FC_THROW_EXCEPTION( fc::assert_exception, #TEST ": "  __VA_ARGS__ ); } } while(0) \
+    FC_MULTILINE_MACRO_BEGIN \
-   )
+      if( !(TEST) ) \
+        FC_THROW_EXCEPTION( fc::assert_exception, #TEST ": "  __VA_ARGS__ ); \
+    FC_MULTILINE_MACRO_END \
+  )
 
 #define FC_CAPTURE_AND_THROW( EXCEPTION_TYPE, ... ) \
-   do { throw EXCEPTION_TYPE( FC_LOG_MESSAGE( error, "", FC_FORMAT_ARG_PARAMS(__VA_ARGS__) ) ); } while(0)
+  FC_MULTILINE_MACRO_BEGIN \
+    throw EXCEPTION_TYPE( FC_LOG_MESSAGE( error, "", FC_FORMAT_ARG_PARAMS(__VA_ARGS__) ) ); \
+  FC_MULTILINE_MACRO_END
 
 //#define FC_THROW( FORMAT, ... ) 
 // FC_INDIRECT_EXPAND workas around a bug in Visual C++ variadic macro processing that prevents it
 // from separating __VA_ARGS__ into separate tokens
 #define FC_INDIRECT_EXPAND(MACRO, ARGS) MACRO ARGS
 #define FC_THROW(  ... ) \
-   do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   throw fc::exception( FC_INDIRECT_EXPAND(FC_LOG_MESSAGE, ( error, __VA_ARGS__ )) );  \
+    throw fc::exception( FC_INDIRECT_EXPAND(FC_LOG_MESSAGE, ( error, __VA_ARGS__ )) );  \
-   } while(0)
+  FC_MULTILINE_MACRO_END
 
 #define FC_EXCEPTION( EXCEPTION_TYPE, FORMAT, ... ) \
     EXCEPTION_TYPE( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) )  
@@ -322,9 +327,9 @@ namespace fc
  *  @param format - a const char* string with "${keys}"
  */
 #define FC_THROW_EXCEPTION( EXCEPTION, FORMAT, ... ) \
-   do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   throw EXCEPTION( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
+    throw EXCEPTION( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
-   } while(0)
+  FC_MULTILINE_MACRO_END
 
 
 /**
@@ -332,10 +337,10 @@ namespace fc
  *  @brief Appends a log_message to the exception ER and rethrows it.
  */
 #define FC_RETHROW_EXCEPTION( ER, LOG_LEVEL, FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-     ER.append_log( FC_LOG_MESSAGE( LOG_LEVEL, FORMAT, __VA_ARGS__ ) ); \
+    ER.append_log( FC_LOG_MESSAGE( LOG_LEVEL, FORMAT, __VA_ARGS__ ) ); \
-     throw;\
+    throw; \
-  } while(0)
+  FC_MULTILINE_MACRO_END
 
 #define FC_LOG_AND_RETHROW( )  \
    catch( fc::exception& er ) { \

include/fc/log/logger.hpp

@@ -61,74 +61,77 @@ namespace fc
 #define DEFAULT_LOGGER
 #endif
 
-   
+// suppress warning "conditional expression is constant" in the while(0) for visual c++
+// http://cnicholson.net/2009/03/stupid-c-tricks-dowhile0-and-c4127/
+#define FC_MULTILINE_MACRO_BEGIN do {
+#ifdef _MSC_VER
+# define FC_MULTILINE_MACRO_END \
+    __pragma(warning(push)) \
+    __pragma(warning(disable:4127)) \
+    } while (0) \
+    __pragma(warning(pop))
+#else
+# define FC_MULTILINE_MACRO_END  } while (0)
+#endif
+
 #define fc_dlog( LOGGER, FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (LOGGER).is_enabled( fc::log_level::debug ) ) { \
+   if( (LOGGER).is_enabled( fc::log_level::debug ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( debug, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 #define fc_ilog( LOGGER, FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (LOGGER).is_enabled( fc::log_level::info ) ) { \
+   if( (LOGGER).is_enabled( fc::log_level::info ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( info, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 #define fc_wlog( LOGGER, FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (LOGGER).is_enabled( fc::log_level::warn ) ) { \
+   if( (LOGGER).is_enabled( fc::log_level::warn ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( warn, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 #define fc_elog( LOGGER, FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (LOGGER).is_enabled( fc::log_level::error ) ) { \
+   if( (LOGGER).is_enabled( fc::log_level::error ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 #define dlog( FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::debug ) ) { \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::debug ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( debug, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 /**
  * Sends the log message to a special 'user' log stream designed for messages that
  * the end user may like to see.
  */
 #define ulog( FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (fc::logger::get("user")).is_enabled( fc::log_level::debug ) ) { \
+   if( (fc::logger::get("user")).is_enabled( fc::log_level::debug ) ) \
       (fc::logger::get("user")).log( FC_LOG_MESSAGE( debug, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 
 #define ilog( FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::info ) ) { \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::info ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( info, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 #define wlog( FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::warn ) ) { \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::warn ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( warn, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 #define elog( FORMAT, ... ) \
-  do { \
+  FC_MULTILINE_MACRO_BEGIN \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::error ) ) { \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::error ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
-   } \
+  FC_MULTILINE_MACRO_END
-  } while (0)
 
 #include <boost/preprocessor/seq/for_each.hpp>
 #include <boost/preprocessor/seq/enum.hpp>
@@ -164,13 +167,13 @@ namespace fc
 // a slowdown.
 #ifdef FC_DISABLE_LOGGING
 # undef ulog
-# define ulog(...) do {} while(0)
+# define ulog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef elog
-# define elog(...) do {} while(0)
+# define elog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef wlog
-# define wlog(...) do {} while(0)
+# define wlog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef ilog
-# define ilog(...) do {} while(0)
+# define ilog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef dlog
-# define dlog(...) do {} while(0)
+# define dlog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 #endif