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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 next 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
prev sibling parent reply Nrgyzer <nrgyzer gmail.com> writes:
Nrgyzer Wrote:


 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 :)


Hello,

dmd now exports all values successfully. But when I try to export a class, I
get the following errors:

"Error 42: Symbol Undefined _D5mydll1t7__ClassZ
Error 42: Symbol Undefined _D5mydll1t5_ctorMFZC11mydll1t"

Source of mydll.d is:

export class t {
	
	export this();
	
}

Source of mydll2.d is:

import std.stdio: writefln;

export class t {

	export this() {
		writefln("hello world!");
	}
}

Source of test.d:

pragma(lib, "mydll.lib");
import mydll;

void main() {
	
	t myTest = new t();
	
}

When I export D5mydll1t7__ClassZ in my def-File, I can compile it but when I
try to create a new instance of t, I get an access violation :(.
May 13 2010
parent torhu <no spam.invalid> writes:
On 13.05.2010 18:23, Nrgyzer wrote:

 Nrgyzer Wrote:
 dmd now exports all values successfully. But when I try to export a class, I
get the following errors:

 "Error 42: Symbol Undefined _D5mydll1t7__ClassZ
 Error 42: Symbol Undefined _D5mydll1t5_ctorMFZC11mydll1t"

 Source of mydll.d is:

 export class t {
 	
 	export this();
 	
 }

 Source of mydll2.d is:

 import std.stdio: writefln;

 export class t {

 	export this() {
 		writefln("hello world!");
 	}
 }

 Source of test.d:

 pragma(lib, "mydll.lib");
 import mydll;

 void main() {
 	
 	t myTest = new t();
 	
 }

 When I export D5mydll1t7__ClassZ in my def-File, I can compile it but when I
try to create a new instance of t, I get an access violation :(.


Never tried exporting a class, but there's some info on this page:

http://prowiki.org/wiki4d/wiki.cgi?BestPractices/DLL
May 13 2010