Re: [Dev-C++] linking error 'undefined reference'

[Gregor P. <pe...@in...>]

Hi Luigi,

thanks for your elaborated answer.


> For example I use: #include "my_class.hpp" and #include <iostream>; so 
> that if
> I have to take some program to another system, I'll copy the file 
> "my_class.hpp" too, instead I won't copy "iostream", because I know that 
> the target system has its own copy of that file.

Normally I do it the same way. Command is a class which is needed in 
different projects und itself it is work in progress. So instead of 
changing, copying and asking myself if I put it everywhere where it is 
needed I decided to put it in a private lib-dir and add this to the 
automaticly by dev-c++ searched paths.


> In light of the above, the function "yy_flex_alloc(unsigned int)" is 
> somehow missing. Since the file lex.yy.c is already in the project, 
> probably you forgot to write the definition of the function 
> "yy_flex_alloc", so there is only a declaration of the function, 
> probably in the header file "lex.yy.h" (that is: the linker only has a 
> prototype).

flex does generate the declerations but not in a seperate file which 
should be no problem as far as I understood your example.

By the way thanks for that. That's it what's missing in all the 
tutorials, they all end up with '... and then compile it to a running 
executable'. But as I am learning right now it is a long way from 
source-code over finding/including the right header files over getting 
compiled object-code to a well linked program.

> Let me know if what I said did help.

It did :-)

For now it looks like I trapped into a bug of mingw and flex, see:
http://www.cygwin.com/ml/cygwin/1999-12/msg00382.html

I (still) try to switch from mingw to cygwin gcc which unfortunately 
isn't done by clicking an dev-c++ option. :-(

So if someone is experienced in this case I would appreciate for some tips.

	Gregor	(pe...@in...)