libvisual-devel

[Libvisual-devel] Making DLLs using mingw

[Dennis S. <sy...@yo...>]

Heya reading the mingw docs, I keep across this:

http://mingw.sourceforge.net/docs.shtml


Here's an example. Cut and paste the following into a file named
dllfct.h: 

   #ifdef BUILD_DLL
   // the dll exports
   #define EXPORT __declspec(dllexport)
   #else
   // the exe imports
   #define EXPORT __declspec(dllimport)
   #endif

   // function to be imported/exported
   EXPORT void tstfunc (void);
               

Cut and paste the following into a file named dllfct.c: 

   #include <stdio.h>
   #include "dllfct.h"

   EXPORT void tstfunc (void)
   {
      printf ("Hello\n");
   }
               




This makes me nearly sick :), is there a way to get around this ?, because
this would be a complete disaster within libvisual :)

Re: [Libvisual-devel] Making DLLs using mingw

[Duilio J. P. <dp...@fc...>]

Why this will be a disaster? EXPORT is defined by mingw? 
If it is not, you just must define EXPORT to the corresponding thing
when building on mingw, or define to empty when not.


Bye,
Duilio.

> Heya reading the mingw docs, I keep across this:
> 
> http://mingw.sourceforge.net/docs.shtml
> 
> 
> Here's an example. Cut and paste the following into a file named
> dllfct.h: 
> 
>    #ifdef BUILD_DLL
>    // the dll exports
>    #define EXPORT __declspec(dllexport)
>    #else
>    // the exe imports
>    #define EXPORT __declspec(dllimport)
>    #endif
> 
>    // function to be imported/exported
>    EXPORT void tstfunc (void);
>                
> 
> Cut and paste the following into a file named dllfct.c: 
> 
>    #include <stdio.h>
>    #include "dllfct.h"
> 
>    EXPORT void tstfunc (void)
>    {
>       printf ("Hello\n");
>    }
>                
> 
> 
> 
> 
> This makes me nearly sick :), is there a way to get around this ?, because
> this would be a complete disaster within libvisual :)

Re: [Libvisual-devel] Making DLLs using mingw

[Dennis S. <sy...@yo...>]

On Mon, 2005-02-14 at 17:27 -0500, Duilio J. Protti wrote:
> Why this will be a disaster? EXPORT is defined by mingw? 
> If it is not, you just must define EXPORT to the corresponding thing
> when building on mingw, or define to empty when not.

And put it in front of every symbol you export, IE every >EVERY< 
function.

so we get:

EXPORT VisActor *visual_actor_new (char *name);

and this for every call.

Or do I get something wrongly ?

Re: [Libvisual-devel] Making DLLs using mingw

[Vitaly V. B. <vit...@uk...>]

On Mon, 14 Feb 2005 21:41:24 +0100
Dennis Smit <sy...@yo...> wrote:

> And put it in front of every symbol you export, IE every >EVERY< 
> function.
Well, it is a common practice...

I believe it not a mandatory. I've built dll library and a import
library. Looks like every thing's fine.

[vitalyb@vb .libs]$ i386-pc-mingw32-objdump -x libvisual-0.dll
.....
[Ordinal/Name Pointer] Table
        [   0] __lv_initialized
        [   1] __lv_paramcontainer
        [   2] __lv_plugins
        [   3] __lv_plugins_actor
        [   4] __lv_plugins_input
        [   5] __lv_plugins_morph
        [   6] __lv_plugins_transform
        [   7] __lv_plugpath_cnt
        [   8] __lv_plugpaths
        [   9] __lv_progname
        [  10] __lv_userinterface
        [  11] _lv_blit_overlay_alpha32_mmx
        [  12] _lv_log
        [  13] _lv_scale_bilinear_32_mmx
        [  14] visual_actor_get_list
        [  15] visual_actor_get_next_by_name
        [  16] visual_actor_get_next_by_name_gl
....
        [ 371] visual_video_set_palette
        [ 372] visual_video_set_pitch
        [ 373] win32_sig_handler_sse@4
....

Every non-static symbol was exported. As by default is.

============ test.c
int main()
{
    return visual_actor_get_list();
}
============ 

[vitalyb@vb .libs]$ i386-pc-mingw32-gcc test.c -L. -lvisual.dll
[vitalyb@vb .libs]$ i386-pc-mingw32-objdump -x a.exe
....
The Import Tables (interpreted .idata section contents)
 vma:            Hint    Time      Forward  DLL       First
                 Table   Stamp     Chain    Name      Thunk
 00004000       00004054 00000000 00000000 000041bc 000040a0

        DLL Name: libvisual-0.dll
        vma:  Hint/Ord Member-Name Bound-To
        40e8       14  visual_actor_get_list
....

So, with GNU tools EXPORT stuff is not necessary.

But with non-GNU tools you need these at least within the headers,
for successful compilation, I think. Import library can be built
from .def (hm, I don't remember exactly) file.

-- 
Vitaly
GPG Key ID: F95A23B9

Re: [Libvisual-devel] Making DLLs using mingw

[Duilio J. P. <dp...@fc...>]

> I think. Import library can be built
> from .def (hm, I don't remember exactly) file.

You are right, using 'autogen' tool.

Re: [Libvisual-devel] Making DLLs using mingw

[Dennis S. <sy...@yo...>]

Heya, the win32.dll is building here under windows, I am now
diving into the win32 sdk docs to fill up the out defined parts
(#if defined(VISUAL_OS_WIN32)) is what I mean :)

This is while using the mingw environment btw.

I think it would be quite fun to support winamp in the
near future! :). We would have a cross operation system
audio visualisation platform! how is that :)

Cheers,
Dennis


On Mon, 2005-02-14 at 23:14 +0200, Vitaly V. Bursov wrote:
> On Mon, 14 Feb 2005 21:41:24 +0100
> Dennis Smit <sy...@yo...> wrote:
> 
> > And put it in front of every symbol you export, IE every >EVERY< 
> > function.
> Well, it is a common practice...
> 
> I believe it not a mandatory. I've built dll library and a import
> library. Looks like every thing's fine.
> 
> [vitalyb@vb .libs]$ i386-pc-mingw32-objdump -x libvisual-0.dll
> .....
> [Ordinal/Name Pointer] Table
>         [   0] __lv_initialized
>         [   1] __lv_paramcontainer
>         [   2] __lv_plugins
>         [   3] __lv_plugins_actor
>         [   4] __lv_plugins_input
>         [   5] __lv_plugins_morph
>         [   6] __lv_plugins_transform
>         [   7] __lv_plugpath_cnt
>         [   8] __lv_plugpaths
>         [   9] __lv_progname
>         [  10] __lv_userinterface
>         [  11] _lv_blit_overlay_alpha32_mmx
>         [  12] _lv_log
>         [  13] _lv_scale_bilinear_32_mmx
>         [  14] visual_actor_get_list
>         [  15] visual_actor_get_next_by_name
>         [  16] visual_actor_get_next_by_name_gl
> ....
>         [ 371] visual_video_set_palette
>         [ 372] visual_video_set_pitch
>         [ 373] win32_sig_handler_sse@4
> ....
> 
> Every non-static symbol was exported. As by default is.
> 
> ============ test.c
> int main()
> {
>     return visual_actor_get_list();
> }
> ============ 
> 
> [vitalyb@vb .libs]$ i386-pc-mingw32-gcc test.c -L. -lvisual.dll
> [vitalyb@vb .libs]$ i386-pc-mingw32-objdump -x a.exe
> ....
> The Import Tables (interpreted .idata section contents)
>  vma:            Hint    Time      Forward  DLL       First
>                  Table   Stamp     Chain    Name      Thunk
>  00004000       00004054 00000000 00000000 000041bc 000040a0
> 
>         DLL Name: libvisual-0.dll
>         vma:  Hint/Ord Member-Name Bound-To
>         40e8       14  visual_actor_get_list
> ....
> 
> So, with GNU tools EXPORT stuff is not necessary.
> 
> But with non-GNU tools you need these at least within the headers,
> for successful compilation, I think. Import library can be built
> from .def (hm, I don't remember exactly) file.
>