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digitalmars.D.learn - Linking C library (.dll) to D on windows

reply "Roman" <shamyan.roman gmail.com> writes:
Stuff:
1. There are C code module.c and module.h
2. MinGW
3. DMD 2.066.1
4. Window 8.1

module.c:

#include "module.h"
int add(int a, int b) {return a + b;}

module.h:

int add(int,int);

I want to use function "add" from D

so i call


 cc -shared module.c -o module.dll


Then D code

main.d:

import std.stdio;

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

void main()
{
	writefln("From C Dll %d",add(2,3));
}


So how i should compile with dmd, to get this work?


 dmd main.d -L=module.dll


prints:
OPTLINK (R) for Win32  Release 8.00.15
Copyright (C) Digital Mars 1989-2013  All rights reserved.
http://www.digitalmars.com/ctg/optlink.html
OPTLINK : Error 8: Illegal Filename
main,,nul,user32+kernel32/noi=module.dll;

                               ^
--- errorlevel 1

I've tried to found smthing here 
http://wiki.dlang.org/Compiling_and_linking_with_DMD_on_Windows
but dll tutorial is missing

So does DMD available to link dll files?
Jan 25 2015
parent reply Mike Parker <aldacron gmail.com> writes:
On 1/26/2015 5:45 AM, Roman wrote:

 Stuff:
 1. There are C code module.c and module.h
 2. MinGW
 3. DMD 2.066.1
 4. Window 8.1

 module.c:

 #include "module.h"
 int add(int a, int b) {return a + b;}

 module.h:

 int add(int,int);

 I want to use function "add" from D

 so i call


 cc -shared module.c -o module.dll


 Then D code

 main.d:

 import std.stdio;

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

 void main()
 {
      writefln("From C Dll %d",add(2,3));
 }


 So how i should compile with dmd, to get this work?


 dmd main.d -L=module.dll


 prints:
 OPTLINK (R) for Win32  Release 8.00.15
 Copyright (C) Digital Mars 1989-2013  All rights reserved.
 http://www.digitalmars.com/ctg/optlink.html
 OPTLINK : Error 8: Illegal Filename
 main,,nul,user32+kernel32/noi=module.dll;

                                ^
 --- errorlevel 1

 I've tried to found smthing here
 http://wiki.dlang.org/Compiling_and_linking_with_DMD_on_Windows
 but dll tutorial is missing

 So does DMD available to link dll files?



ecosystem. AFAIK, MinGW is the only toolchain that supports that. By 
default, DMD uses the OPTLINK linker for 32-bit apps and uses the MS 
linker for 64-bit, neither of which have the ability to link directly 
with dlls. You need an import library.


whereas MinGW and the MS compiler output COFF. So you have three options 
for linking with 32-bit DMD:

* Compile with the Digital Mars C/C++ compiler (DMC) and generate an 
import library along with the dll.
* Compile with another compiler and run implib (part of the free Basic 
Utilities Package from Digital Mars, downloadable from [1]) on the dll 
to generate an import library in OMF format.
* Load the DLL dynamically, then you don't need an import library.

extern( C ) alias addptr = int function(int, int);
addptr add;

auto handle = LoadLibrary( "MyLib.dll" );
add = cast( addptr )GetProcAddress( handle, "add" );

Alternatively, you could compile as 64-bit, generate an import library 
with the DLL when you compile it with MinGW, and link directly with the 
import lib (the next version of DMD will support COFF for 32-bit). 
However, I have had trouble attempting to link static MinGW libraries 
with 64-bit DMD. Some have worked, some haven't. An import library is 
not the same and I assume it would work, but I've never tried.

Then again, since 64-bit DMD requires the MS toolchain to be installed, 
another option is to forego MinGW and use the MS compiler instead.
Jan 25 2015
next sibling parent Mike Parker <aldacron gmail.com> writes:
On 1/26/2015 11:18 AM, Mike Parker wrote:


 * Compile with another compiler and run implib (part of the free Basic
 Utilities Package from Digital Mars, downloadable from [1]) on the dll
 to generate an import library in OMF format.


[1] http://www.digitalmars.com/download/freecompiler.html
Jan 25 2015
prev sibling parent "Roman" <shamyan.roman gmail.com> writes:
On Monday, 26 January 2015 at 02:18:05 UTC, Mike Parker wrote:

 On 1/26/2015 5:45 AM, Roman wrote:

 Stuff:
 1. There are C code module.c and module.h
 2. MinGW
 3. DMD 2.066.1
 4. Window 8.1

 module.c:

 #include "module.h"
 int add(int a, int b) {return a + b;}

 module.h:

 int add(int,int);

 I want to use function "add" from D

 so i call


 cc -shared module.c -o module.dll


 Then D code

 main.d:

 import std.stdio;

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

 void main()
 {
     writefln("From C Dll %d",add(2,3));
 }


 So how i should compile with dmd, to get this work?


 dmd main.d -L=module.dll


 prints:
 OPTLINK (R) for Win32  Release 8.00.15
 Copyright (C) Digital Mars 1989-2013  All rights reserved.
 http://www.digitalmars.com/ctg/optlink.html
 OPTLINK : Error 8: Illegal Filename
 main,,nul,user32+kernel32/noi=module.dll;

                               ^
 --- errorlevel 1

 I've tried to found smthing here
 http://wiki.dlang.org/Compiling_and_linking_with_DMD_on_Windows
 but dll tutorial is missing

 So does DMD available to link dll files?



 Windows ecosystem. AFAIK, MinGW is the only toolchain that 
 supports that. By default, DMD uses the OPTLINK linker for 
 32-bit apps and uses the MS linker for 64-bit, neither of which 
 have the ability to link directly with dlls. You need an import 
 library.


 files, whereas MinGW and the MS compiler output COFF. So you 
 have three options for linking with 32-bit DMD:

 * Compile with the Digital Mars C/C++ compiler (DMC) and 
 generate an import library along with the dll.
 * Compile with another compiler and run implib (part of the 
 free Basic Utilities Package from Digital Mars, downloadable 
 from [1]) on the dll to generate an import library in OMF 
 format.
 * Load the DLL dynamically, then you don't need an import 
 library.

 extern( C ) alias addptr = int function(int, int);
 addptr add;

 auto handle = LoadLibrary( "MyLib.dll" );
 add = cast( addptr )GetProcAddress( handle, "add" );

 Alternatively, you could compile as 64-bit, generate an import 
 library with the DLL when you compile it with MinGW, and link 
 directly with the import lib (the next version of DMD will 
 support COFF for 32-bit). However, I have had trouble 
 attempting to link static MinGW libraries with 64-bit DMD. Some 
 have worked, some haven't. An import library is not the same 
 and I assume it would work, but I've never tried.

 Then again, since 64-bit DMD requires the MS toolchain to be 
 installed, another option is to forego MinGW and use the MS 
 compiler instead.


Many thanks Mike,

I've tried second option with MinGW generated dll

 implib /s module.lib module.dll



 dmd main.d module.lib



 main.exe


it prints:
 From C Dll 5

So it works !

P.S. I don't know why MinGW generated dll works, and I guess, 
that in more complicated dll, this can fail
Jan 26 2015