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digitalmars.D.learn - Windows DLLs with D

reply "Buk" <dprog.20.browseruk xoxy.net> writes:
Hi all,

I've read http://dlang.org/dll.html, and frankly there seems to 
be a lot of boilerplate & rote process to build a DLL.

I realise that many of the do nothing functions /can/ be used to 
do a lot more; and these may be required for some purposes. But, 
for a simple DLL of functions, that can be built in C as simply 
as:

C:\test\demo>type mydll.c
int __declspec(dllexport) add( int a, int b ) {
     return a + b;
}

C:\test\demo>cl /MT /LD mydll.c
mydll.c
/out:mydll.dll
/dll
/implib:mydll.lib
mydll.obj
    Creating library mydll.lib and object mydll.exp

C:\test\demo>dumpbin /exports mydll.dll
Dump of file mydll.dll
File Type: DLL
   Section contains the following exports for mydll.dll
            1 ordinal base
            1 number of functions
            1 number of names

     ordinal hint RVA      name

           1    0 00001000 add

Is there any similar mechanism for these 'simple' cases for D?

If not, shouldn't it be possible to create an ?interface? file 
that takes care of the boilerplate? (If so, does anyone have one 
they can share?)

Thanks, Buk.
Sep 14 2013
next sibling parent reply "Buk" <dprog.20.browseruk xoxy.net> writes:
On Saturday, 14 September 2013 at 16:46:06 UTC, Buk wrote:

 Hi all,

 I've read http://dlang.org/dll.html, and frankly there seems to 
 be a lot of boilerplate & rote process to build a DLL.

 I realise that many of the do nothing functions /can/ be used 
 to do a lot more; and these may be required for some purposes. 
 But, for a simple DLL of functions, that can be built in C as 
 simply as:

 C:\test\demo>type mydll.c
 int __declspec(dllexport) add( int a, int b ) {
     return a + b;
 }

 C:\test\demo>cl /MT /LD mydll.c
 mydll.c
 /out:mydll.dll
 /dll
 /implib:mydll.lib
 mydll.obj
    Creating library mydll.lib and object mydll.exp

 C:\test\demo>dumpbin /exports mydll.dll
 Dump of file mydll.dll
 File Type: DLL
   Section contains the following exports for mydll.dll
            1 ordinal base
            1 number of functions
            1 number of names

     ordinal hint RVA      name

           1    0 00001000 add

 Is there any similar mechanism for these 'simple' cases for D?

 If not, shouldn't it be possible to create an ?interface? file 
 that takes care of the boilerplate? (If so, does anyone have 
 one they can share?)

 Thanks, Buk.


Thanks for the help guys.
Sep 17 2013
parent "Dicebot" <public dicebot.lv> writes:
On Tuesday, 17 September 2013 at 16:05:13 UTC, Buk wrote:

 Thanks for the help guys.


Sorry for the silence. It has just happened that your question 
touches relatively under-explored area of the language and thus 
finding someone with actual experience on topic is hard. I don't 
even know if we have any official DLL support on Windows (other 
than workarounds presented on page you have linked), to be honest.

Hope this topic will attract some Windows users eventually :)
Sep 17 2013
prev sibling parent Rainer Schuetze <r.sagitario gmx.de> writes:
On 14.09.2013 18:46, Buk wrote:

 Hi all,

 I've read http://dlang.org/dll.html, and frankly there seems to be a lot
 of boilerplate & rote process to build a DLL.

 I realise that many of the do nothing functions /can/ be used to do a
 lot more; and these may be required for some purposes. But, for a simple
 DLL of functions, that can be built in C as simply as:

 C:\test\demo>type mydll.c
 int __declspec(dllexport) add( int a, int b ) {
      return a + b;
 }

 C:\test\demo>cl /MT /LD mydll.c
 mydll.c
 /out:mydll.dll
 /dll
 /implib:mydll.lib
 mydll.obj
     Creating library mydll.lib and object mydll.exp

 C:\test\demo>dumpbin /exports mydll.dll
 Dump of file mydll.dll
 File Type: DLL
    Section contains the following exports for mydll.dll
             1 ordinal base
             1 number of functions
             1 number of names

      ordinal hint RVA      name

            1    0 00001000 add

 Is there any similar mechanism for these 'simple' cases for D?

 If not, shouldn't it be possible to create an ?interface? file that
 takes care of the boilerplate? (If so, does anyone have one they can
 share?)

 Thanks, Buk.


Actually the code snippet for DllMain on that page is the needed 
boilerplate code if you don't need any tweaking of the defaults. If you 
add code in mydll.d like:

export extern(C) add(int a, int b) {
	return a + b;
}

and build this with: dmd -ofmydll.dll -d mydll.d dllmain.d

you get a dll with the export:


dumpbin /exports mydll.dll


Dump of file mydll.dll

File Type: DLL

   Section contains the following exports for mydll.dll

     00000000 characteristics
            0 time date stamp Thu Jan 01 01:00:00 1970
         0.00 version
            1 ordinal base
            1 number of functions
            1 number of names

     ordinal hint RVA      name

           1    0 00003010 _add

[The -d in the command line has nothing to do with building DLLs, but is 
needed because the DllMain snippet causes a deprecation message.]

If you are looking for something as described in the "D code calling D 
code in DLLs" section, I'd have to issue a warning: this does not really 
work sensibly yet, but it is being worked on.
Sep 17 2013