Hello everybody,

I'm trying to create a (very) simple DLL by using D. Now I want export values - is there any way do this... for example:

Example:

mydll.d:
export int i;

mydll2.d:
export int i = 99;

dll.d:
// Copied from http://www.digitalmars.com/d/2.0/dll.html

test.d:
import std.stdio;
import mydll;

void main() {
   writefln(mydll.i);
}

-> The problem is (same problem for float, enum... , that I always get 0 by calling mydll.i instead of 99. I hope anyone can help me, please :)

Thanks for help in advance :)

Nrgyzer wrote:
> Hello everybody,
> 
> I'm trying to create a (very) simple DLL by using D. Now I want export values - is there any way do this... for example:
> 
> Example:
> 
> mydll.d:
> export int i;
> 
> mydll2.d:
> export int i = 99;
> 
> dll.d:
> // Copied from http://www.digitalmars.com/d/2.0/dll.html
> 
> test.d:
> import std.stdio;
> import mydll;
> 
> void main() {
>    writefln(mydll.i);
> }
> 
> -> The problem is (same problem for float, enum... , that I always get 0 by calling mydll.i instead of 99.
> I hope anyone can help me, please :)
> 
> Thanks for help in advance :)

I don't know much about dlls, but aren't you accessing mydll.i, which is 0, instead of mydll2.i, which is 99?

Ary Borenszweig Wrote:

> Nrgyzer wrote:
> > Hello everybody,
> > 
> > I'm trying to create a (very) simple DLL by using D. Now I want export values - is there any way do this... for example:
> > 
> > Example:
> > 
> > mydll.d:
> > export int i;
> > 
> > mydll2.d:
> > export int i = 99;
> > 
> > dll.d:
> > // Copied from http://www.digitalmars.com/d/2.0/dll.html
> > 
> > test.d:
> > import std.stdio;
> > import mydll;
> > 
> > void main() {
> >    writefln(mydll.i);
> > }
> > 
> > -> The problem is (same problem for float, enum... , that I always get 0 by calling mydll.i instead of 99. I hope anyone can help me, please :)
> > 
> > Thanks for help in advance :)
> 
> I don't know much about dlls, but aren't you accessing mydll.i, which is 0, instead of mydll2.i, which is 99?

By using mydll2.i instead of mydll.i I didn't need a dll because the value (in this case i) is defined in my compiled exe file (because mydll2.d will be imported by compiling). So I can simply replace the dll but this has no effect to my exe file (because i is defined in the exe)..... - I think :-D

On 04.05.2010 21:46, Nrgyzer wrote:
> Hello everybody,
>
> I'm trying to create a (very) simple DLL by using D. Now I want export values - is there any way do this...

Off the top of my head, I think it goes like this:

To export from a DLL:
export int i = 7;

To export from a DLL, with C name mangling:
export extern (C) int i = 7;


To import from a DLL:
export extern int i;

To import from a DLL with a C interface:
export extern extern (C) int i;


I'm not sure if I recall the export part correctly, it's been a while since I actuall tried this.

torhu Wrote:

> On 04.05.2010 21:46, Nrgyzer wrote:
> > Hello everybody,
> >
> > I'm trying to create a (very) simple DLL by using D. Now I want export values - is there any way do this...
> 
> Off the top of my head, I think it goes like this:
> 
> To export from a DLL:
> export int i = 7;
> 
> To export from a DLL, with C name mangling:
> export extern (C) int i = 7;
> 
> 
> To import from a DLL:
> export extern int i;
> 
> To import from a DLL with a C interface:
> export extern extern (C) int i;
> 
> 
> I'm not sure if I recall the export part correctly, it's been a while since I actuall tried this.

Thanks, but doesn't work :(

My files contain:

mydll.d:

module mydll;
export extern int i;

mydll2.d:

module mydll;
export int i = 7;

test.d:

import mydll;
import std.stdio;

void main() {
	writefln(i);
}

I can compile the dll, but when I compile test.d, I get the following error: "Error 42: Symbol Undefined _D5mydll1ii"

On 06.05.2010 16:06, Nrgyzer wrote:
> Thanks, but doesn't work :(
>
> My files contain:
>
> mydll.d:
>
> module mydll;
> export extern int i;
>
> mydll2.d:
>
> module mydll;
> export int i = 7;
>
> test.d:
>
> import mydll;
> import std.stdio;
>
> void main() {
> 	writefln(i);
> }
>
> I can compile the dll, but when I compile test.d, I get the following error: "Error 42: Symbol Undefined _D5mydll1ii"

It seems that export doesn't work for data, only functions.  If you build with -map, you'll see that i is not exported.  I got it working by using this .def file:

LIBRARY "mydll.dll"
EXETYPE NT
EXPORTS
D5mydll1ii


Then create the import lib with:
implib /s mydll.lib mydll.dll

/s adds the underscores.


If you use extern (C) the symbols will be a lot simpler to read and write, though.  Look at the .map file to see what the actual symbols are.

torhu Wrote:

> On 06.05.2010 16:06, Nrgyzer wrote:
> > Thanks, but doesn't work :(
> >
> > My files contain:
> >
> > mydll.d:
> >
> > module mydll;
> > export extern int i;
> >
> > mydll2.d:
> >
> > module mydll;
> > export int i = 7;
> >
> > test.d:
> >
> > import mydll;
> > import std.stdio;
> >
> > void main() {
> > 	writefln(i);
> > }
> >
> > I can compile the dll, but when I compile test.d, I get the following error: "Error 42: Symbol Undefined _D5mydll1ii"
> 
> It seems that export doesn't work for data, only functions.  If you build with -map, you'll see that i is not exported.  I got it working by using this .def file:
> 
> LIBRARY "mydll.dll"
> EXETYPE NT
> EXPORTS
> D5mydll1ii
> 
> 
> Then create the import lib with:
> implib /s mydll.lib mydll.dll
> 
> /s adds the underscores.
> 
> 
> If you use extern (C) the symbols will be a lot simpler to read and write, though.  Look at the .map file to see what the actual symbols are.

Thanks - works :)