RE: [Dev-C++] Newbie linking errors: 'undefined reference'

[Ioannis V. <no...@ya...>]

> -----Original Message-----
> From: dev...@li... 
> [mailto:dev...@li...] On Behalf 
> Of Devin Carless
> Sent: Saturday, February 09, 2002 9:47 PM
> To: dev...@li...
> Subject: [Dev-C++] Newbie linking errors: 'undefined reference'
> 
> 
> 
>   Generally, I like to lurk and listen a bit before I post, 
> but this time I'm really at wit's end.
> 
>   My project, a simple game based on the old Lost Worlds 
> booklets,  keeps generating undefined reference errors in the 
> linking stage.  They look like this:
> 
> d:/devin/projects/lostworlds/womanqsprototype.o(.data$_vt$11Wo
> manQSBook+0x5c
> ):womanqsprototy: undefined reference to 
> `BaseBook::Lookup(unsigned short, unsigned short) const'
> 
>   The compiler had no problems with just such a function, but 
> the linker does.  (I'm using Dev-C++ 4 with MinGW 2.95.2, 
> with the -v -H flags for the linker.)  I don't know what 
> 'undefined reference' means, and nowhere on the Net (that 


Generally "undefined reference" means there is no definition for such
thing. In your case 

BaseBook::Lookup(unsigned short, unsigned short) const


Probably it has to do with the graphics library you use.


> Google can find) is there a document that tells me, either.
>   Sometimes I can temporarily make them go away with cosmetic 
> changes to the code: moving a function definition from the 
> .cpp to the .h, moving a function declaration in the .h, 
> etc., seems to work for individual errors.  But whenever I 
> add a new module they come back again, twice as plentiful.
> 
>   I thought it might be STL and vectors, but changing my 
> container implementation to use arrays didn't help.  So it's 
> not, as I thought, STL's fault.  It might be a link order 


No relation to STL.


> problem, so I used the Make Makefile function and tried to do 
> things from the command line.  However, I can't get make to 
> work with the
> Dev-C++'s makefiles: it gives me errors like '**18: Multiple
> targets.'  And Dev-C++'s Project Options only asks for
> -additional- arguments to pass to the linker.
>   So I'm really getting demoralized.  This problem has held 
> me up for three days now.  I'd very much appreciate some assistance.
> 
>   It has been suggested I provide a code fragment, but since 
> the errors seem to be independent of legality of the code, 
> and only crop up when the projects gets big, I don't see how 
> it would help. However, I will provide such a thing if asked, 
> though I really have no idea what could be relevant to the problem.
> 
> --Devin Carless

Either there is no such thing in the library you use or if the construct
is yours you have not provided a definition.



Ioannis
 
* Ioannis Vranos
* Programming pages: http://www.noicys.d2g.com
* Alternative URL: http://run.to/noicys