Re: [Mingw-users] Fw: A DLL problem

[Roger K. W. <ROG...@sa...>]

Virtual wrote:

> I have a little problem sharing variables from a DLL to 
> another...please see this example:
>  
> -------- FILE 1: hello.c --------
>  
> #include "dllfct.h"
>  
> int main () {
>   i = 5;
>   tstfunc();
>   i = 2;
>   tstfunc2();
>   return (0);
> }
>  
> --------- FILE 2: dllfct.h -------
>  
> #ifdef BUILD_DLL
>   #define EXPORT __declspec(dllexport)
> #else
>   #define EXPORT __declspec(dllimport)
> #endif
>  
> EXPORT int i;
> EXPORT void tstfunc (void);
>  
> --------- FILE 3: dllfct.c ----------
>  
>    #include <stdio.h>
>    #include "dllfct.h"
>  
>    EXPORT int i=0;
>  
>    EXPORT void tstfunc (void) {
>       printf ("Hello%d\n", i);
>    }
> ---------- FILE 4: dllfct2.h -----------
> EXPORT void tstfunc2 (void);
> ---------- FILE 5: dllfct2.c -----------
>  
> #include <stdio.h>
> #include "dllfct.h"
> #include "dllfct2.h"
>  
> EXPORT void tstfunc2 (void) {
>   printf("VAL IS=%d", i);
> }
>  
> ---------- COMPILED WITH: --------------
>  
> gcc -DBUILD_DLL -shared -o tst.dll  dllfct.c 
> -Wl,--output-def,tstdll.def,--out-implib,libtstdll.a
>  
> gcc -DBUILD_DLL -shared -o tst2.dll  dllfct2.c 
> -Wl,--output-def,tst2dll.def,--out-implib,libtstdll2.a
>  
> gcc -o hello.exe hello.o -L./ -ltstdll -ltstdll2
>  
> ----------- BUT ON VIDEO: ----------------
>  
> Hello5
> VAL IS=0
>  
> --------------------------------------------
>  
> how can I view the changes to i, maded by  hello.c, from tstfunc2 into 
> tst2.dll ????
>  
> Please, it's very important.
>  
>  
> P.S: 'scuse for my bad english!!!

you need two BUILD_DLL macros.  This because when you are building 
dllfct2.dll you are in fact using dllfct.dll.  Define DLLFCT_BUILD_DLL & 
DLLFCT2_BUILD_DLL & define them as appropriate

hope this helps

-- 
Roger Wells, P.E.
SAIC
221 Third St
Newport, RI 02840
401-847-4210 (voice)
401-849-1585 (fax)
ro...@mt...