Re: building log4cxx

On Wed, Dec 13, 2006 at 04:39:40PM -0500, Bob Rossi wrote:
> On Wed, Dec 13, 2006 at 03:13:05PM -0500, Bob Rossi wrote:
> > On Tue, Dec 12, 2006 at 03:05:39PM -0500, Bob Rossi wrote:
> > > Hi,
> > > 
> > > OK, I'm planning on using log4cxx, along with apr. Is there anything
> > > special I should consider? Can I simply have log4cxx use the libapr that
> > > I already build?
> > 
> > I got it to this point,
> > 
> > loglog.cpp: In static member function `static void 
> > log4cxx::helpers::LogLog::emit(const std::wstring&)':
> >                                                                             
> >                             
> > loglog.cpp:89: error: `wcerr' is not a member of `std'                      
> >                             
> > make[1]: *** [loglog.lo] Error 1                                            
> >                             
> > make[1]: Leaving directory `/home/bobbybrasko/log4cxx/logging-log4cxx/src'  
> >                             
> > make: *** [all-recursive] Error 1                                           
> >                             
> > 
> > This is on windows with mingw compiler, using autotools.
> 
> 
> Apparently, include/log4cxx/private/log4cxx_private.h has
>   #define LOG4CXX_HAS_STD_WCOUT 1
> and loglog.cpp does
>   #if LOG4CXX_HAS_WCHAR_T
>   void LogLog::emit(const std::wstring& msg) {
>   #if LOG4CXX_HAS_STD_WCOUT
>     std::wcerr << L"log4cxx: " << msg << std::endl;
>   #else
>     LOG4CXX_ENCODE_CHAR(encoded, msg);
>     std::cerr << "log4cxx: " << encoded << std::endl;
>   #endif
>   }
> 
> If I comment out the WCOUT macro, I get,
>   loglog.cpp: In static member function `static void 
> log4cxx::helpers::LogLog::emit(const std::wstring&)':
>                                                                               
>                           
>   loglog.cpp:91: error: no matching function for call to 
> `log4cxx::helpers::Transcoder::encode(const std::
>   basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> 
> >&, std::string&)'             
>   ../include/log4cxx/helpers/transcoder.h:63: note: candidates are: static 
> void log4cxx::helpers::Transcod
>   er::encode(const log4cxx::LogString&, std::string&)                         
>                             
>   ../include/log4cxx/helpers/transcoder.h:81: note:                 static 
> void log4cxx::helpers::Transcod
>   er::encode(const log4cxx::LogString&, std::wstring&)                        
>                             
>   make[1]: *** [loglog.lo] Error 1                                            
>                             
>   make[1]: Leaving directory `/home/bobbybrasko/log4cxx/logging-log4cxx/src'  
>                             
>   make: *** [all-recursive] Error 1                                           
>                             

It's a combination of 3 defines that are confused during the build
process. That is,
  LOG4CXX_HAS_WCHAR_T
  LOG4CXX_HAS_STD_WCOUT
  LOG4CXX_LOGCHAR_IS_UTF8
the configure script says,
  checking for wchar_t... yes
  checking logchar type... utf-8

For some reason WCOUT is true, but mingw complains about it. Does mingw
support this? The problem code is here,

#if LOG4CXX_HAS_WCHAR_T 
void LogLog::emit(const std::wstring& msg) {
#if LOG4CXX_HAS_STD_WCOUT
    std::wcerr << L"log4cxx: " << msg << std::endl;
#else
    LOG4CXX_ENCODE_CHAR(encoded, msg);
    std::cerr << "log4cxx: " << encoded << std::endl;
#endif
}
#endif

Since wcerr isn't available, I've changed LOG4CXX_HAS_WCHAR_T to not be
defined. This calls the LOG4CXX_ENCODE_CHAR macro now. However, the
encode function looks like,
    static void encode(const LogString& src, std::string& dst);
and LogString is defined as a char because of logchar type shown in the
configure above. In logstring.h,
  #if LOG4CXX_LOGCHAR_IS_UTF8
     typedef char logchar;
     typedef std::basic_string<logchar> LogString;


So, log4cxx attempts to pass a wstring into a LogString, but a LogString
is a really string. 

Please advise on how to fix this, and I'll sumbit a patch. If I've messe
up the ./configure line, please let me know.

Thanks,
Bob Rossi