Trouble with DLL address

[dnewbie]

I have a DLL which exports a function GetFunction. GetFunction 
returns a pointer to RealFunction. Now I want to run RealFunction 
from my D program, but for some reason I get the wrong address. 
Here is the code.


 dll64.c -
#define WIN32_LEAN_AND_MEAN
#include windows.h

int __stdcall RealFunction(int a)
{
return a + 1;
}

typedef int (__stdcall *FuncPtr)(int);

FuncPtr __stdcall GetFunction()
{
return RealFunction;
}

 mydll64.def 
LIBRARY mydll64.dll
EXPORTS
GetFunction
-

build with MSVC64:
cl -c dll64.c -Fomydll64.obj
link /DLL /OUT:mydll64.dll mydll64.obj /DEF:mydll64.def

And this is the D program.

 testdll64d.d 
// dmd -m64 -c testdll64d.d -oftestdll64d.obj
// link /OUT:testdll64d.exe testdll64d.obj

import core.runtime;
import std.c.windows.windows;
import std.stdio;

alias extern(Windows) int function(int) FuncPtr;

int main(string[] args)
{
HMODULE dll  = LoadLibraryA(mydll64.DLL);
FARPROC getFunction  = GetProcAddress(dll, GetFunction);
FuncPtr realFunction = cast(FuncPtr) getFunction();

writefln(dll address:  %08x, dll);
writefln(GetFunction address:  %08x, getFunction);
writefln(RealFunction address: %08x, realFunction);
writefln(RealFunction result:  %d,   realFunction(7));//-- 
CRASH


return 0;
}
--

Output:
dll address:  18000
GetFunction address:  180001020
RealFunction address: 80001000
CRASH

BTW, this works:
FuncPtr realFunction = cast(FuncPtr) (getFunction()  
0x | cast(size_t) dll);

Re: Trouble with DLL address

[dennis luehring]

Just ignore my post - too early in the morning :(

Am 14.01.2013 10:19, schrieb dennis luehring:

http://dlang.org/type.html

int = signed 32 bits

but don't you need long in D

Am 14.01.2013 10:13, schrieb dnewbie:

I have a DLL which exports a function GetFunction. GetFunction
returns a pointer to RealFunction. Now I want to run RealFunction
from my D program, but for some reason I get the wrong address.
Here is the code.

 dll64.c -
#define WIN32_LEAN_AND_MEAN
#include windows.h

int __stdcall RealFunction(int a)
{
  return a + 1;
}

typedef int (__stdcall *FuncPtr)(int);

FuncPtr __stdcall GetFunction()
{
  return RealFunction;
}

 mydll64.def 
LIBRARY mydll64.dll
EXPORTS
GetFunction
-

build with MSVC64:
cl -c dll64.c -Fomydll64.obj
link /DLL /OUT:mydll64.dll mydll64.obj /DEF:mydll64.def

And this is the D program.

 testdll64d.d 
// dmd -m64 -c testdll64d.d -oftestdll64d.obj
// link /OUT:testdll64d.exe testdll64d.obj

import core.runtime;
import std.c.windows.windows;
import std.stdio;

alias extern(Windows) int function(int) FuncPtr;

int main(string[] args)
{
  HMODULE dll  = LoadLibraryA(mydll64.DLL);
  FARPROC getFunction  = GetProcAddress(dll, GetFunction);
  FuncPtr realFunction = cast(FuncPtr) getFunction();

  writefln(dll address:  %08x, dll);
  writefln(GetFunction address:  %08x, getFunction);
  writefln(RealFunction address: %08x, realFunction);
  writefln(RealFunction result:  %d,   realFunction(7));//--
CRASH

  return 0;
}
--

Output:
dll address:  18000
GetFunction address:  180001020
RealFunction address: 80001000
CRASH

BTW, this works:
FuncPtr realFunction = cast(FuncPtr) (getFunction() 
0x | cast(size_t) dll);

Re: Trouble with DLL address

[dennis luehring]

http://dlang.org/type.html

int = signed 32 bits

but don't you need long in D

Am 14.01.2013 10:13, schrieb dnewbie:

I have a DLL which exports a function GetFunction. GetFunction
returns a pointer to RealFunction. Now I want to run RealFunction
from my D program, but for some reason I get the wrong address.
Here is the code.

 dll64.c -
#define WIN32_LEAN_AND_MEAN
#include windows.h

int __stdcall RealFunction(int a)
{
  return a + 1;
}

typedef int (__stdcall *FuncPtr)(int);

FuncPtr __stdcall GetFunction()
{
  return RealFunction;
}

 mydll64.def 
LIBRARY mydll64.dll
EXPORTS
GetFunction
-

build with MSVC64:
cl -c dll64.c -Fomydll64.obj
link /DLL /OUT:mydll64.dll mydll64.obj /DEF:mydll64.def

And this is the D program.

 testdll64d.d 
// dmd -m64 -c testdll64d.d -oftestdll64d.obj
// link /OUT:testdll64d.exe testdll64d.obj

import core.runtime;
import std.c.windows.windows;
import std.stdio;

alias extern(Windows) int function(int) FuncPtr;

int main(string[] args)
{
  HMODULE dll  = LoadLibraryA(mydll64.DLL);
  FARPROC getFunction  = GetProcAddress(dll, GetFunction);
  FuncPtr realFunction = cast(FuncPtr) getFunction();

  writefln(dll address:  %08x, dll);
  writefln(GetFunction address:  %08x, getFunction);
  writefln(RealFunction address: %08x, realFunction);
  writefln(RealFunction result:  %d,   realFunction(7));//--
CRASH

  return 0;
}
--

Output:
dll address:  18000
GetFunction address:  180001020
RealFunction address: 80001000
CRASH

BTW, this works:
FuncPtr realFunction = cast(FuncPtr) (getFunction() 
0x | cast(size_t) dll);

Re: Trouble with DLL address

[Andrej Mitrovic]

On 1/14/13, dnewbie r...@myopera.com wrote:
  FuncPtr realFunction = cast(FuncPtr) getFunction();

Make that:

FuncPtr realFunction = cast(FuncPtr) getFunction;

Don't call the FARPROC, just cast it.

Re: Trouble with DLL address

[dnewbie]

The problem is FARPROC. Thank you everybody.

Solution:
import core.runtime;
import std.c.windows.windows;
import std.stdio;

alias extern(Windows) int function(int) FuncPtr;
alias extern(Windows) FuncPtr function() GetFuncPtr;

int main(string[] args)
{
HMODULE dll= LoadLibraryA(mydll64.DLL);
	GetFuncPtr getFunction = cast(GetFuncPtr) GetProcAddress(dll, 
GetFunction);	

FuncPtr realFunction   = cast(FuncPtr) getFunction();

writefln(dll address:  %08x, dll);
writefln(GetFunction address:  %08x, getFunction);
writefln(RealFunction address: %08x, realFunction);
writefln(RealFunction result:  %d,   realFunction(7));

return 0;   
}