The Tech Help You Need

["Charles Tuckey" <charles@xxxxxxxxx>]

Problem solved. Some of the log4cxx include files are auto generated.
On the Windows platform, I was using a set of include files I had
copied over from Linux. The log4cxx.h from Linux specified a  UTF8
logchar, the proper one from Windows specifies a wchar logchar.

I was using the Windows include files to build the log4cxx shared
library, and the Linux include files to build my library. This meant
anything with a LogString had a type mismatch.

Thanks for listening.

charlie

On 12/19/06, Charles Tuckey <charles@xxxxxxxxx> wrote:
> Hi,
>
> I built the log4cxx library on WXP SP2 with no problems. But when I
> try to link a very simple dll to it I get an unresolved symbol
> problem. My problem is very similar to Sorin Popa (Nov 28 email). I
> have some ideas on what the problem might be but I am not a very
> strong C++ programmer and I have little experience on Windows as well
> so I haven't been able to solve this. Details are below. Any help, or
> gentle nudge in the right direction, would be greatly appreciated.
>
> 1) log4cxx build
> - I'm using the HEAD from Nov. 13m 2006
> - I built according to the instructions in INSTALL except:
>   - I  added unxutils to my path so I could access the 'patch' command
>   - I ran setenv.cmd from Microsoft Platform SDK for Windows Server 2003 R2 dir
> - my command line was 'ant build'
> - I ended up with a debug lib
>
> 2) my library
> - the source consists of two files: EngineAppender.h & EngineAppender.cpp
> EngineAppender.h listing:
> #include <log4cxx/appenderskeleton.h>
> #include <log4cxx/spi/loggingevent.h>
> #include <log4cxx/helpers/pool.h>
>
> class EngineAppender : public log4cxx::AppenderSkeleton {
>   protected :
>      void append(const log4cxx::spi::LoggingEventPtr& event,
>                         log4cxx::helpers::Pool& p);
>   public :
>      void close();
>      bool requiresLayout() const;
> };
>
> EngineAppender.cpp listing:
> #include "EngineAppender.h"
> #include "log4cxx/spi/loggingevent.h"
>
> void EngineAppender::append(const log4cxx::spi::LoggingEventPtr& event,
>                                             log4cxx::helpers::Pool& p) {
>         event->getLoggerName();
> }
> void EngineAppender::close() { }
> bool EngineAppender::requiresLayout() const {return 0;}
>
> - before building I ran setenv.cmd to set up my environment
> - then I ran
> #include "EngineAppender.h"
> #include "log4cxx/spi/loggingevent.h"
>
> void EngineAppender::append(const log4cxx::spi::LoggingEventPtr&
> event, log4cxx::helpers::Pool& p) {
>         event->getLoggerName();
> }
>
> void EngineAppender::close() { }
>
> bool EngineAppender::requiresLayout() const {
>         return 0;
> }
>
> - I create the library with these two commands:
> cl -DWIN32 -D_WIN32 -EHsc -Ilog4cxx/include -c EngineAppender.cpp
> link -DLL EngineAppender.obj -out:test.dll log4cxxd.lib
>
> It fails with the error:
> EngineAppender.obj : error LNK2019: unresolved external symbol "public: class st
> d::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >
> const __thiscall log4cxx::spi::LoggingEvent::getLoggerName(void)const " (?getLog
> gerName@LoggingEvent@spi@log4cxx@@QBE?BV?$basic_string@DU?$char_traits@D@std@@V?
> $allocator@D@2@@std@@XZ) referenced in function "protected: virtual void __thisc
> all EngineAppender::append(class log4cxx::helpers::ObjectPtrT<class log4cxx::spi
> ::LoggingEvent> const &,class log4cxx::helpers::Pool &)" (?append@EngineAppender
> @@MAEXABV?$ObjectPtrT@VLoggingEvent@spi@log4cxx@@@helpers@log4cxx@@AAVPool@34@@Z
> )
>
> 3) My troubleshooting
> - In the log4cxx library the mangled name for getLoggerName is:
> ?getLoggerName@LoggingEvent@spi@log4cxx@@QBE?BV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@XZ
>
> This differs from the name the linker is looking for in the
> parameterized type to basic_string. The log4cxx library has _W (wchar)
> and my linker is looking for a char type (D). (Sorin's linker was
> looking for an unsigned short, G).
>
> Even though I thought it would have no effect since I am using VC 8 I
> tried compiling with the -Zc:wchar_t option. No change.
>
> So, I'm stumped. How do I make my object file compile using
> basic_string<wchar>? I cannot find anything on goolge (that I can
> understand) that would help me solve this.
>
> Thanks for your help,
> charlie


--
Regards,
   Charlie