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digitalmars.D.learn - Export values (enum, int, char[]...) for DLL

reply Nrgyzer <nrgyzer gmail.com> writes:
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 :)
May 04 2010
next sibling parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
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?
May 05 2010
parent Nrgyzer <nrgyzer gmail.com> writes:
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
May 05 2010
prev sibling parent reply torhu <no spam.invalid> writes:
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.
May 05 2010
parent reply Nrgyzer <nrgyzer gmail.com> writes:
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"
May 06 2010
parent reply torhu <no spam.invalid> writes:
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.
May 06 2010
parent Nrgyzer <nrgyzer gmail.com> writes:
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 :)
May 07 2010