Ohhh arise extern wizards! Want silencePlayers in bzflag.cxx

[michaelh20]

am trying to access the SilenceList silencePlayer in playing.cxx *in* dumpResources() which is part of bzflag.cxx so I can dump the list into the resources database (more or less).


I have done this numberous ways, all of which result in an undefined symbol link error (VC++)

My current iteration has nothing in bzflag.cxx,
moved BZF_DEFINE_ALIST(SilenceList, BzfString);
into playing.h (which is included into bzflag.cxx, right?),
Then I added the following to playing,h
class SilenceList; //?
extern SilenceList silencePlayers; //?

Then I have static SilenceList silencePlayers; in playing.cxx....


I think this would made SilenceList global in all the files, which is not needed. And I would think all I would need would be to define the list class in playing.h and extern SilenceList silencePlayers in bzflag.cxx, and then I should be able to use SilenceList in bzflag.cxx and have it be the one from playing.cxx...

But.. this -------> undefined symbol error in linking which is driving me wonkers. Am I missing something about how the files are put together? Does being a macro do something here?

Tried using extern SilenceList * silencePlayers --> did NOT work

[michaelh20]

Ok... so I can make a function SilenceList getSilenceList(); and declare it extern in the other file and it works. But.. I can't actually get the variable itself.






O.. k.....

[purple_cow]

I suggest you make these changes to the latest CVS. AList has all been replaced with std::vector, so it should make things easier.

[michaelh20]

Drat....

already almost done

[badger]

Then I added the following to playing,h
class SilenceList; //?
extern SilenceList silencePlayers; //?

Then I have static SilenceList silencePlayers; in playing.cxx....

you know the purpose of `static' at file scope is to hide a symbol from the linker. no amount of `extern' is going to change that. did you try removing `static' from the line in playing.cxx?

p.s. i'm guessing that your getSlienceList() function was visible because you didn't declare it static. i.e. you did

Code: Select all

  SilenceList& getSilenceList();

not

Code: Select all

  static SilenceList& getSilenceList();

it's the missing static not the extern in another file that makes it work.