Re: Warnings in kern/dl.c

[Bean]

On Fri, Jul 18, 2008 at 2:18 PM, Bean <address@hidden> wrote:
> On Fri, Jul 18, 2008 at 1:38 PM, Pavel Roskin <address@hidden> wrote:
>> Hello, Bean!
>>
>> I think this change from the x86_64 EFI patch should be reverted:
>>
>>        * kern/dl.c (GRUB_CPU_SIZEOF_VOID_P): Changed to
>>         GRUB_TARGET_SIZEOF_VOID_P.
>>
>> It causes warnings when compiling grub-emu on x64_64 for i386:
>>
>> kern/dl.c: In function 'grub_dl_resolve_symbols':
>> kern/dl.c:357: warning: cast from pointer to integer of different size
>> kern/dl.c:368: warning: cast from pointer to integer of different size
>> kern/dl.c:370: warning: cast to pointer from integer of different size
>> kern/dl.c:376: warning: cast from pointer to integer of different size
>> kern/dl.c:378: warning: cast to pointer from integer of different size
>> kern/dl.c:382: warning: cast to pointer from integer of different size
>> kern/dl.c:384: warning: cast to pointer from integer of different size
>> kern/dl.c:389: warning: cast from pointer to integer of different size
>>
>> I'm really close to eliminating all warnings, and such additions are not
>> making me happy.
>>
>> The warnings could be suppressed somehow, but I don't think it's the right
>> thing to do.  64-bit grub-emu cannot load 32-bit modules (and vice versa).
>>  64-bit grub-emu could load 64-bit modules in principle, although we don't
>> compile them.   We could compile special grub-emu modules, but I would not
>> spend any serious effort on it.
>>
>> Anyway, I would prefer that we compile support for loading 64-bit modules
>> and possibly catch some useful warnings relevant to 64-bit platforms (even
>> if our target is 32-bit).  It's better than to "implement"
>> cross-architecture loading of modules that would not work anyway by filling
>> the code with casts.  It's better than to tolerate several warnings.  Either
>> increases the risk that a real warning would be missed.
>
> Hi,
>
> This is used for cross complication. For example, when we compile
> x86_64-efi in i386, the host system is i386, but target system is
> 64-bit. I have been compiling the efi image using this method, there
> is no problem.
>
> As for grub-emu, does it matter if we can't load external modules ?
> The import module are all static linked. Besides, some of the modules
> depend on real mode component, so we can't load them anyway.

Hi,

BTW, there is another way to solve this. For grub-emu, we define
GRUB_TARGET_SIZEOF_VOID_P the same as GRUB_CPU_SIZEOF_VOID_P, doesn't
that fix the problem ?

-- 
Bean