Re: user32: Call the EnumChildWindows callback using a wrapper.

[Sebastian Lackner]

On 08.12.2015 09:53, Dmitry Timoshkov wrote:
> +extern LRESULT WNDENUMPROC_wrapper( WNDENUMPROC proc, HWND hwnd, LPARAM lparam );
> +__ASM_GLOBAL_FUNC( WNDENUMPROC_wrapper,
> +                   "pushl %ebp\n\t"
> +                   __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
> +                   __ASM_CFI(".cfi_rel_offset %ebp,0\n\t")
> +                   "movl %esp,%ebp\n\t"
> +                   __ASM_CFI(".cfi_def_cfa_register %ebp\n\t")
> +                   "pushl %edi\n\t"
> +                   __ASM_CFI(".cfi_rel_offset %edi,-4\n\t")
> +                   "pushl %esi\n\t"
> +                   __ASM_CFI(".cfi_rel_offset %esi,-8\n\t")
> +                   "pushl %ebx\n\t"
> +                   __ASM_CFI(".cfi_rel_offset %ebx,-12\n\t")
> +                   "pushl 16(%ebp)\n\t"
> +                   "pushl 12(%ebp)\n\t"
> +                   "movl 8(%ebp),%eax\n\t"
> +                   "call *%eax\n\t"

There is no need to safe edi/esi/ebx when the purpose is just to be compatible with cdecl
calling conventions. Also, you should try to keep the stack aligned, like most other
assembler wrappers do. Does it also work with something like:
http://source.winehq.org/git/wine.git/blob/HEAD:/dlls/dinput/dinput_main.c#l... ?

Regards,
Sebastian

user32: Call the EnumChildWindows callback using a wrapper.

[Dmitry Timoshkov]

Sebastian Lackner <sebastian(a)fds-team.de> wrote:
> > +extern LRESULT WNDENUMPROC_wrapper( WNDENUMPROC proc, HWND hwnd, LPARAM lparam );
> > +__ASM_GLOBAL_FUNC( WNDENUMPROC_wrapper,
> > +                   "pushl %ebp\n\t"
> > +                   __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
> > +                   __ASM_CFI(".cfi_rel_offset %ebp,0\n\t")
> > +                   "movl %esp,%ebp\n\t"
> > +                   __ASM_CFI(".cfi_def_cfa_register %ebp\n\t")
> > +                   "pushl %edi\n\t"
> > +                   __ASM_CFI(".cfi_rel_offset %edi,-4\n\t")
> > +                   "pushl %esi\n\t"
> > +                   __ASM_CFI(".cfi_rel_offset %esi,-8\n\t")
> > +                   "pushl %ebx\n\t"
> > +                   __ASM_CFI(".cfi_rel_offset %ebx,-12\n\t")
> > +                   "pushl 16(%ebp)\n\t"
> > +                   "pushl 12(%ebp)\n\t"
> > +                   "movl 8(%ebp),%eax\n\t"
> > +                   "call *%eax\n\t"
>
> There is no need to safe edi/esi/ebx when the purpose is just to be compatible with cdecl
> calling conventions. Also, you should try to keep the stack aligned, like most other
> assembler wrappers do.

I just copied the wrapper code from hook.c and adapted number of parameters,
winproc.c uses a similar wrapper.
> Does it also work with something like:
> http://source.winehq.org/git/wine.git/blob/HEAD:/dlls/dinput/dinput_main.c#l... ?

I was never able to reproduce the problem myself under Linux, just guessed what
happened from the backtrace and the suggested patch worked under MacOSX, so I
won't be able to test, but yes, this wrapper looks a lot simpler.

-- 
Dmitry.