Re: Kconfig entry defined multiple times

[gwr <gwr@free.fr>]

On 08/22/2012 10:45 AM, gwr wrote:
>
> On 08/22/2012 10:05 AM, gwr wrote:
>> Hello,
>>
>> I am working on kernel 2.6.32.38, and I see :
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> arch/x86/Kconfig, 202 :
>> =============
>>
>> config USE_GENERIC_SMP_HELPERS
>>     def_bool y
>>     depends on SMP
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> arch/Kconfig, 112 :
>> ===========
>>
>> config USE_GENERIC_SMP_HELPERS
>>     bool
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Although we have this in Kconfig documentation,
>> ================================================
>> A config option can be defined multiple times with the same name, but 
>> every
>> definition can have only a single input prompt and the type must not 
>> conflict.
>> ================================================
>>
>> here,
>>   - the first definition is a child of "Linux Kernel Configuration 
>> for x86" MainMenu ( arch/x86/Kconfig, 1 )
>>   - the second definition is a child of "General setup" Menu ( 
>> init/Kconfig, 24 )
>>
>> So the hierarchy is different ; Can someone give explanations on this ?
>>
>> Thx
>> -- 
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>
> I forgot the second half on my message :
>
> - I am trying to build a linux kernel configurator that do not need to 
> reparse
>   all the kernel Kconfig input at each entry modification
>
> - the problem :
>
>   -- if I keep the 2 entries as separates objects, I cant choose 
> between the 2 at
>     expression evaluation time,because the second definition has no 
> dependancy.
>
>   -- the second definition has no dependancy => it suggest that the
>     2 entries have to be joined into a single entry. But at which 
> place in the hierarchy ?
>
> ( note  : a "make gconfig" ends up with 2 different 
> USE_GENERIC_SMP_HELPERS entries in the tree )
>
>
>
> Now consider the X86_EXTENDED_PLATFORM entry :
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> arch/x86/Kconfig,312 :
> =============
>
> if X86_32
> config X86_EXTENDED_PLATFORM
>     bool "Support for extended (non-PC) x86 platforms"
>     default y
>     ---help---
> ( ...help text 1... )
> endif
>
> if X86_64
> config X86_EXTENDED_PLATFORM
>     bool "Support for extended (non-PC) x86 platforms"
>     default y
>     ---help---
> ( ...help text 2... )
> endif
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> the dependancies are mutually exclusive.
>
>
>
>
> So in fact, the real question I ask is : could not be Kconfig grammar 
> simplified, by adding some restricting rules ?
>
> Thx
>
Simplification could be NOT ALLOWING multiple entries with the same 
name, I counted
only 14 "entries with duplicate name" in my 2.6.32.38 kernel, among many 
thousands entries.

Example : X86_EXTENDED_PLATFORM could easily redeclared simply by 
allowing dependancies to help texts.

Thx