link from a dll to another function in another dll?

[maarten van damme]

Wow, thanks for the help
The first thing I did was in the .di file adding extern(windows){ ... }
and now compiling doesn't give errors and when examining with dllexp I can
see that it exports the same functions as the real kernel32.dll :D

Now I'm going to implement all other suggested changes, thanks a lot

2011/4/30 Rainer Schuetze <r.sagitario at gmx.de>

> I'm not sure your wrapping will work with kernel32.dll, but in general here
> are a few tips:
>
> - most functions in the windows API use the __stdcall calling convention in
> C/C++, which translates to D as "extern(Windows)"
>
> - this will usually add the number of bytes passed on the stack as a "@NN"
> postfix to the function name. This postfix does not exist in kernel32.dll,
> but in the import library kernel32.lib that you find in the dmd lib folder.
> Maybe you can use the standard import library, or use the translation shown
> below.
>
> - as the exported function and the function you want to chain to have
> identical names, you have to change at least one of these and modify them in
> some build step. I'd suggest to do this in the def file:
>
> The symbols in the d-source file containing:
>
> ----
> extern(Windows) HANDLE imported_GetCurrentProcess();
>
> export extern(Windows) HANDLE internal_GetCurrentProcess()
> {
>  return imported_GetCurrentProcess();
> }
> ----
>
> can be mapped to other symbols in the def file:
>
> ----
> EXPORTS
>  GetCurrentProcess = internal_GetCurrentProcess
>
> IMPORTS
>  imported_GetCurrentProcess = kernel33.GetCurrentProcess
> ----
>
> - if you don't know the number of arguments, you should not call the
> wrapped function, as this will change the callstack. Instead, you should
> just jump to it:
>
> void internal_hread()
> {
>  asm
>  {
>    naked;
>    jmp imported_hread;
>  }
> }
>
> I haven't tried all that, though, so there might be some mistakes...
>
> Rainer
>
>
>
> Denis Koroskin wrote:
>
>> On Sat, 30 Apr 2011 13:47:53 +0400, maarten van damme <
>> maartenvd1994 at gmail.com> wrote:
>>
>>  I've changed this, I think I'm still kinda confused with lib files.
>>> They've
>>> told me you can't do something with them without a .di file
>>> So I went ahead and made a kernel33.di file. I now import it in
>>> kernel32.d
>>> and my declaration is
>>> System(C){
>>> export void * exportedfunctionblablabal(){
>>>   return exportedfunctionblablablal();
>>> }
>>> ...
>>> }
>>>
>>> The file in the directory are:
>>> kernel32.d : http://dl.dropbox.com/u/15024434/d/kernel32.d
>>> kernel33.di : http://dl.dropbox.com/u/15024434/d/kernel33.di
>>> kernel33.lib : http://dl.dropbox.com/u/15024434/d/kernel33.lib
>>> kernel33.dll : http://dl.dropbox.com/u/15024434/d/kernel33.dll
>>>
>>> I've tried to compile using dmd -d kernel32.d kernel33.di kernel33.lib
>>> but
>>> it throws errors like
>>> "Error 42: Symbol undifined _Dkernel1336_hreadfzpV"
>>> I have literally no clue why this is the case, can someone help me out or
>>> look at the files?
>>>
>>> 2011/4/27 maarten van damme <maartenvd1994 at gmail.com>
>>>
>>>  I'm afraid I've been a little unclear.
>>>> I've copied kernel32.dll from the windows dir, renamed it to
>>>> kernel33.dll
>>>> and generated a .lib from it using implib.
>>>> Then I've created a d file with a correct dllmain(stolen from examples)
>>>> and
>>>> between
>>>>
>>>> system(C){
>>>> export void * exportedfunctionfromkernel33.dll();
>>>> export void * exportedfunction2fromkernel33.dll();
>>>> ...
>>>> }
>>>>
>>>> But it looks like you can't both declare a function from another lib and
>>>> export it at the same time.
>>>>
>>>>
>> In your kernel33.di, try making it extern (C) export void* _hread(); etc.
>> You functions get D mangling otherwise.
>>
>> I'd also suggest you to start with a less complex example, e.g. export
>> only one function, make sure it works, then add the rest.
>>
>> If you think your .lib files doesn't do its job, try using .def file
>> instead. I find them extremely helpful, and they are a lot easier to
>> edit/extend.
>>
>> Hope that helps.
>>
>
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