Windows parameter

[shuji]

Can someone help me with this:
I have a library which I try to import from D
//funcs.lib
//windows includes...
HWND hwnd;
int setHWND(HWND extHwnd){
hwnd = extHwnd;
return 0;
}

//main.d
pragma(lib, gdi32.lib);
import core.runtime;
import core.sys.windows.windows;
extern (C++) {
int setHWND(HWND hwnd);
}
int main(int argc, char **argv) {
//windows initializers
setHWND(hwnd);
return 0;
}

but when I try to import that function this comes:
   Error 42: Symbol Undefined ?setHWND@@YAHPAX@Z (int cdecl
setHWND(void *))
--- errorlevel 1

it seems like I cannot use HWND directly.

Re: Windows parameter

[Simen Kjaeraas]

On Sun, 30 Jun 2013 20:24:17 +0200, shuji cravs...@hotmail.com wrote:



int setHWND(HWND extHwnd){
hwnd = extHwnd;
return 0;
}

And:


extern (C++) {
int setHWND(HWND hwnd);
}



See how these are different? One of them is an extern (C++) function, the  
other is a D function.


In other words, this should work:

//funcs.lib
//windows includes...
HWND hwnd;
extern (C++) { // This line!
int setHWND(HWND extHwnd){
hwnd = extHwnd;
return 0;
}
}

//main.d
pragma(lib, gdi32.lib);
import core.runtime;
import core.sys.windows.windows;
extern (C++) {
int setHWND(HWND hwnd);
}
int main(int argc, char **argv) {
//windows initializers
setHWND(hwnd);
return 0;
}



--
Simen

Re: Windows parameter

[shuji]

this code is in a .cpp file
//funcs.lib
//windows includes...
HWND hwnd;
int setHWND(HWND extHwnd){
hwnd = extHwnd;
return 0;
}

So im trying to import from D like this. I dont think I can 
implement this line in C++

extern (C++) {}

Re: Windows parameter

[Anthony Goins]

On Sunday, 30 June 2013 at 19:03:13 UTC, shuji wrote:

this code is in a .cpp file
//funcs.lib
//windows includes...
HWND hwnd;
int setHWND(HWND extHwnd){
hwnd = extHwnd;
return 0;
}

So im trying to import from D like this. I dont think I can 
implement this line in C++

extern (C++) {}


I'm probably the most unqualified person to offer help but are 
you sure you are linking with funcs.lib (assuming setHWND is 
defined there)

Re: Windows parameter

[shuji]

On Sunday, 30 June 2013 at 20:04:12 UTC, Anthony Goins wrote:

On Sunday, 30 June 2013 at 19:03:13 UTC, shuji wrote:

this code is in a .cpp file
//funcs.lib
//windows includes...
HWND hwnd;
int setHWND(HWND extHwnd){
hwnd = extHwnd;
return 0;
}

So im trying to import from D like this. I dont think I can 
implement this line in C++

extern (C++) {}


I'm probably the most unqualified person to offer help but are 
you sure you are linking with funcs.lib (assuming setHWND is 
defined there)


yes, i have called other functions in the same file correctly.

PD I can call a function with void* as receiving paremeter:
//main.d
extern (C++) {
int setHWND(void* ehwnd);
}
//mylib.cpp
int setmyHWND(void* exthwnd){
hwnd = (HWND)exthwnd;
return 0;
}
and then cast on C++ to HWND, but I think it would be better to 
send the parameter correctly as HWND.

Re: Windows parameter

[David]

Am 30.06.2013 22:20, schrieb shuji:
 On Sunday, 30 June 2013 at 20:04:12 UTC, Anthony Goins wrote:
 On Sunday, 30 June 2013 at 19:03:13 UTC, shuji wrote:
 this code is in a .cpp file
 //funcs.lib
 //windows includes...
 HWND hwnd;
 int setHWND(HWND extHwnd){
 hwnd = extHwnd;
 return 0;
 }

 So im trying to import from D like this. I dont think I can implement
 this line in C++
 extern (C++) {}

 I'm probably the most unqualified person to offer help but are you
 sure you are linking with funcs.lib (assuming setHWND is defined there)
 
 yes, i have called other functions in the same file correctly.
 
 PD I can call a function with void* as receiving paremeter:
 //main.d
 extern (C++) {
 int setHWND(void* ehwnd);
 }
 //mylib.cpp
 int setmyHWND(void* exthwnd){
 hwnd = (HWND)exthwnd;
 return 0;
 }
 and then cast on C++ to HWND, but I think it would be better to send the
 parameter correctly as HWND.

make sure the HWND parameter is on both sides the same (it has to get
mangled correctly!). I don't know if HWND is an opaque struct, if it is,
this might get you into trouble.

--- Cut here, I looked into core.sys.windows.windows:


---
alias void *HANDLE;
alias HANDLE HWND;
---

That is the problem, on the C++-Side HWND is not of type void* hence it
gets mangled differently, you need to get DMD mangle it the same as the
C++ compiler does...

The problem is (I just looked it up) HWND is *basically* void*

All typedefs:
PVOID = void*
HANDLE = PVOID
HWND = HANDLE

So you have to emulate a typedef to get the correct mangling... Maybe
start messing arround with structs?

struct HWND;
etc.


Maybe you could also try to use the deprecated typedef in D. Neither
of these soloutions are really great. I would consider this another bug
on the extern(C++) list.