Re: Allocating memory in D shared library when accessed from C++

2011-12-20 Thread Martin Drasar 

Dne 20.12.2011 2:22, Andrej Mitrovic napsal(a):

test.cpp: http://www.ideone.com/uh7vN
DLibrary.d: http://www.ideone.com/fOLN8

$ g++ test.cpp
$ dmd -ofDLibrary.dll DLibrary.d
$ a.exe
$ 9


Hi, Andrej,

you are right, this works. Problem is going to be either in VisualD or 
cv2pdb.


For those who are interested:
The version produced by VisualD simply does not work and crashes. 
Hovewer, if you just execute dmd command that VisualD uses and then 
manually call cv2pdb, everything works fine and you can hapilly debug in 
Visual Studio.


Library compiled by VisualD:

DLibrary.dll | size: 936 082B
DLibrary.pdb | size: 248 832B

Library compiled by using VisualD commandline parameters:
-
$ dmd dllmain.d -g -debug -X -XfDLibrary.json -deps=DLibrary.dep 
-of..\Debug\DLibrary.dll -map DLibrary.map


Results after calling cv2pdb on the DLibrary.dll

DLibrary.dll | size: 935 570B
DLibrary.pdb | size: 248 832B

Manual execution of that two commands produces library that works and is 
debugable and also, by some strange coincidence, 112 bytes smaller.


Funny... if you have any ideas, do not hesitate to share ;-)

Regards,
Martin

Re: Allocating memory in D shared library when accessed from C++

2011-12-20 Thread Andrej Mitrovic 
I'd say make a small test-case and file it to visuald's bugtracker.

Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Martin Drasar 

Hello everyone,

I would like to ask you about linking D shared objects (.dll and .so) 
from a C++ program.


Say I have this C++ loader:


typedef int (*MagicFunction) ();

HMODULE handle = LoadLibraryA(DLibrary.dll);
if (handle)
{
  MagicFunction fn = (MagicFunction) GetProcAddress(handle, _magicFunction);
  std::coutfn()std::endl;
}


and this D library:


class Something {}

export extern (C) int magicNumber()
{
  Something desc = new Something();
  return 9;
}

extern (Windows)
BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
{
final switch (ulReason)
{
case DLL_PROCESS_ATTACH:
g_hInst = hInstance;
dll_process_attach( hInstance, true );
break;

case DLL_PROCESS_DETACH:
dll_process_detach( hInstance, true );
break;

case DLL_THREAD_ATTACH:
dll_thread_attach( true, true );
break;

case DLL_THREAD_DETACH:
dll_thread_detach( true, true );
break;
}
return true;
}


then whenever the code reaches the call:

Something desc = new Something();

I get 'Access violation reading location 0x...'

I thought that the GC is angry with me, so I have tried to use malloc, 
but to no avail. Error is the same...


Can you please give me a hint what I am doing wrong? Also I am curious 
why is the first name of exported function underscored and all the 
others are not.


Thanks for your time.

Martin

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Andrej Mitrovic 
Check if GetProcAddress returns null? It seems to me you're looking
for _magicFunction but defining magicNumber, two different names.

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Simon 

On 19/12/2011 18:01, Andrej Mitrovic wrote:

Check if GetProcAddress returns null? It seems to me you're looking
for _magicFunction but defining magicNumber, two different names.


that's be it. can't remember the rules for whether it will have a 
leading underscore, but you can always use dependency walker to find out:


http://dependencywalker.com/

--
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Martin Drašar 

Dne 19.12.2011 19:39, Simon napsal(a):

On 19/12/2011 18:01, Andrej Mitrovic wrote:

Check if GetProcAddress returns null? It seems to me you're looking
for _magicFunction but defining magicNumber, two different names.


that's be it. can't remember the rules for whether it will have a
leading underscore, but you can always use dependency walker to find out:

http://dependencywalker.com/



Hi guys,

thanks for your response... but it is not the problem. I must have made 
a mistake writing this down.


It actualy returns a procedure address and the procedure is called. It 
lands inside export extern (C) int magicNumber() and crashes when 
attempting to allocate memory for Something.


I have used dependency walker, that is why I asked why only the first 
function is exported with underscore and the others are not.


Martin

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Trass3r 
It actualy returns a procedure address and the procedure is called. It  
lands inside export extern (C) int magicNumber() and crashes when  
attempting to allocate memory for Something.


Did you properly initialize druntime?

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Martin Drašar 

Dne 19.12.2011 23:09, Trass3r napsal(a):

It actualy returns a procedure address and the procedure is called. It
lands inside export extern (C) int magicNumber() and crashes when
attempting to allocate memory for Something.


Did you properly initialize druntime?


As I am just starting with D, the most precise answer I can give you is: 
I don't know... how do I tell? Or in another way - the code for D 
library is almost complete except for imports. The rest was done for me 
by Visual D.


Martin

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Trass3r 

Am 19.12.2011, 23:13 Uhr, schrieb Martin Drašar dra...@ics.muni.cz:


Dne 19.12.2011 23:09, Trass3r napsal(a):

It actualy returns a procedure address and the procedure is called. It
lands inside export extern (C) int magicNumber() and crashes when
attempting to allocate memory for Something.


Did you properly initialize druntime?


As I am just starting with D, the most precise answer I can give you is:  
I don't know... how do I tell? Or in another way - the code for D  
library is almost complete except for imports. The rest was done for me  
by Visual D.


It's explained there: http://www.dlang.org/dll.html

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Martin Drašar 

Dne 20.12.2011 0:02, Trass3r napsal(a):

Am 19.12.2011, 23:13 Uhr, schrieb Martin Drašar dra...@ics.muni.cz:


Dne 19.12.2011 23:09, Trass3r napsal(a):

It actualy returns a procedure address and the procedure is called. It
lands inside export extern (C) int magicNumber() and crashes when
attempting to allocate memory for Something.


Did you properly initialize druntime?


As I am just starting with D, the most precise answer I can give you
is: I don't know... how do I tell? Or in another way - the code for D
library is almost complete except for imports. The rest was done for
me by Visual D.


It's explained there: http://www.dlang.org/dll.html



Well as far as I can tell, the runtime is initialized with call to 
Runtime.initialize(). This call is executed inside dll_process_attach here:



extern (Windows)
BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
{
final switch (ulReason)
{
case DLL_PROCESS_ATTACH:
g_hInst = hInstance;
dll_process_attach( hInstance, true );
break;


so I would say that the runtime is properly initialized.

Martin

Re: Allocating memory in D shared library when accessed from C++

2011-12-19 Thread Andrej Mitrovic 
test.cpp: http://www.ideone.com/uh7vN
DLibrary.d: http://www.ideone.com/fOLN8

$ g++ test.cpp
$ dmd -ofDLibrary.dll DLibrary.d
$ a.exe
$ 9