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digitalmars.D.learn - Mixing D and C - Windows

reply "DNewbie" <run3 myopera.com> writes:
C program loads D dll
or
D program loads C dll
Is it possible?

-- 
  
  D
Dec 31 2011
next sibling parent reply "Jakob Ovrum" <jakobovrum gmail.com> writes:
On Saturday, 31 December 2011 at 19:05:44 UTC, DNewbie wrote:

 C program loads D dll
 or
 D program loads C dll
 Is it possible?


Both are possible.

Here's how to create a DLL in D, usable from C:

http://dlang.org/dll.html

As for loading C symbols in a DLL from a D program, you must link 
against an import library of the DLL, and create an interface 
module (similar to a header file) with the C declarations. For 
example, if this is your C DLL:

-----------
#include <stdio.h>

__declspec(dllexport) void sayHello(const char* name)
{
    printf("hello, %s!", name);
}
-----------

Then your D interface module should look like this:
-----------
extern(C) void sayHello(const char* name);

-----------

The import library must be in the OMF format. The easiest way to 
get such an import library is to use the `impllib` tool which can 
be downloaded from here:

http://ftp.digitalmars.com/bup.zip
Dec 31 2011
parent Exec <dragon-x gmx.de> writes:
Jakob Ovrum Wrote:

 As for loading C symbols in a DLL from a D program, you must link 
 against an import library of the DLL, and create an interface 
 module (similar to a header file) with the C declarations.


Alternatively, you can load the DLL via the Windows API.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms684175%28v=vs.85%29.aspx
Dec 31 2011
prev sibling next sibling parent reply "DNewbie" <run3 myopera.com> writes:
Thank you both.

I've created a D DLL [http://dlang.org/dll.html], then I've loaded it from a C
program [compiled with dmc].
However, I'd want to be able to call it from a C program compiled with MSVC,
and I got a link error - unresolved external symbol [link testdll.obj
/implib:mydll.lib /out:testdll-msvc.exe]. The LoadLibrary works with both
DMC/MSVC, but it isn't 'handy'.?.



On Sat, Dec 31, 2011, at 07:20 PM, Exec wrote:

 Jakob Ovrum Wrote:

 As for loading C symbols in a DLL from a D program, you must link 
 against an import library of the DLL, and create an interface 
 module (similar to a header file) with the C declarations.


 Alternatively, you can load the DLL via the Windows API.
 http://msdn.microsoft.com/en-us/library/windows/desktop/ms684175%28v=vs.85%29.aspx
 



-- 
  
  D
Jan 02 2012
parent reply Mike Parker <aldacron gmail.com> writes:
On 1/3/2012 10:02 AM, DNewbie wrote:

 Thank you both.

 I've created a D DLL [http://dlang.org/dll.html], then I've loaded it from a C
program [compiled with dmc].
 However, I'd want to be able to call it from a C program compiled with MSVC,
and I got a link error - unresolved external symbol [link testdll.obj
/implib:mydll.lib /out:testdll-msvc.exe]. The LoadLibrary works with both
DMC/MSVC, but it isn't 'handy'.?.


That's because the object file formats used by DMC and MSVC are 
different. DMC outputs OMF, MSCV uses COFF. If you download objconv[1], 
you can use it to convert between the two formats. Something like

objconv -fcoff -nu mydll.lib mydll_mscv.lib

should do the trick.

[1] http://www.agner.org/optimize/objconv.zip
Jan 02 2012
next sibling parent Mike Parker <aldacron gmail.com> writes:
On 1/3/2012 12:43 PM, Mike Parker wrote:

 On 1/3/2012 10:02 AM, DNewbie wrote:

 Thank you both.

 I've created a D DLL [http://dlang.org/dll.html], then I've loaded it
 from a C program [compiled with dmc].
 However, I'd want to be able to call it from a C program compiled with
 MSVC, and I got a link error - unresolved external symbol [link
 testdll.obj /implib:mydll.lib /out:testdll-msvc.exe]. The LoadLibrary
 works with both DMC/MSVC, but it isn't 'handy'.?.


 That's because the object file formats used by DMC and MSVC are
 different. DMC outputs OMF, MSCV uses COFF. If you download objconv[1],
 you can use it to convert between the two formats. Something like

 objconv -fcoff -nu mydll.lib mydll_mscv.lib

 should do the trick.

 [1] http://www.agner.org/optimize/objconv.zip


Or did you do that already? I just realized that would likely give a 
corrupt file error, not an unresolved symbol.
Jan 02 2012
prev sibling parent Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
Maybe I'm wrong, but IIRC objconv won't work on import libs.

But there are other ways to do it: http://support.microsoft.com/kb/131313
Jan 02 2012
prev sibling parent "DNewbie" <run3 myopera.com> writes:
Resolved.
Thanks everyone.


On Tue, Jan 3, 2012, at 04:49 AM, Andrej Mitrovic wrote:

 Maybe I'm wrong, but IIRC objconv won't work on import libs.
 
 But there are other ways to do it: http://support.microsoft.com/kb/131313
 



-- 
  
  D
Jan 02 2012