Re: [PATCH] ide: Build fix for CONFIG_IDE_PROC_FS=n

[Elias Oltmanns <eo@nebensachen.de>]

Sergei Shtylyov <sshtylyov@ru.mvista.com> wrote:
> Hello, I have just written:
>>> Recent changes have broken compilation when CONFIG_IDE_PROC_FS is
>
>>> not set.
>>>
>>> Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
>>>   
>> [...]
>>> diff --git a/drivers/ide/ide-disk.h b/drivers/ide/ide-disk.h
>>> index f937772..5254cae 100644
>>> --- a/drivers/ide/ide-disk.h
>>> +++ b/drivers/ide/ide-disk.h
>>> @@ -23,8 +23,10 @@ ide_decl_devset(acoustic);
>>>  /* ide-disk_ioctl.c */
>>>  int ide_disk_ioctl(struct inode *, struct file *, unsigned int,
>>> unsigned long);
>>>  +#ifdef CONFIG_IDE_PROC_FS
>>>  /* ide-disk_proc.c */
>>>  extern ide_proc_entry_t ide_disk_proc[];
>>>  extern const struct ide_proc_devset ide_disk_settings[];
>>> +#endif /* CONFIG_IDE_PROC_FS */
>>>   #endif /* __IDE_DISK_H */
[...]
>>
>>   Is surrounding 'extern' declarations by #ifdef's really of any value?
>>   They shouldn't be used if CONFIG_IDE_PROC_FS=n, so no object file
>> records should be generated.
>
>   Ah, you probably mean to turn the possible link time errors if the
> do get referenced into the compile time errors...

Sorry, I don't quite understand that last sentence. But we definitely
have compile time errors here because the compiler doesn't even know of
ide_proc_entry_t when CONFIG_IDE_PROC_FS is not set. Therefore the
forward declarations appear to be syntactically incorrect, regardless
whether extern or not.

Regards,

Elias