[PATCH 1/2] Add --with-ilp32-large-off_t

[Andreas Jaeger]

On 07/06/2012 05:02 PM, H.J. Lu wrote:
> On Fri, Jul 6, 2012 at 7:54 AM, Andreas Jaeger <aj@suse.com> wrote:
>> On 07/06/2012 04:32 PM, H.J. Lu wrote:
>>>
>>> On Fri, Jul 6, 2012 at 7:15 AM, Andreas Jaeger <aj@suse.com> wrote:
>>>>
>>>> On 07/06/2012 04:05 PM, H.J. Lu wrote:
>>>>>
>>>>>
>>>>> Hi,
>>>>>
>>>>> On x86-64, ILP32 with large off_t (64-bit) can be either -mx32 or -m32
>>>>> with "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64".  This patch adds
>>>>> a configure time option to choose which one to use for ILP32_OFFBIG.
>>>>> Any comments?
>>>>
>>>>
>>>>
>>>> I'm not sure what you're doing, this sounds really wrong to me and I
>>>> smell
>>>> an ABI breakage. So, please help me to understand the problem you're
>>>> trying
>>>> to solve.
>>>>
>>>> Could you show a short example program that has a problem and explain the
>>>> problem a bit more?
>>>>
>>>
>>> See:
>>>
>>> http://sourceware.org/ml/libc-alpha/2012-05/msg02093.html
>>
>>
>>
>> Thanks, I see the problem. We surely should not make this the default since
>> I expect slow adoption of the new ABI - and most people won't have a full
>> development environment for it but will have on for x86 (-m32).
>
> By default, nothing is changed, except for x32 glibc, which will use -mx32
> for ILP32_OFFBIG.

But you only install headers from the 64-bit library, so you need the 
configure option for the 64-bit build - correct?

>> Looking at the rather large diff together with the additional regenerated
>> file, I wonder whether we really need to make this change now or wait until
>> x32 has seen better adoption.
>
> Unless you configure glibc with --with-ilp32-large-off_t=mx32,
> there should be no changes for -m64 nor -m32.
>
>> Btw. you say Patch 1 of 2 - where's the second one?
>
> Here is the second patch:
>
> http://sourceware.org/git/?p=glibc.git;a=patch;h=4c43d953820a1e0562416d6f3a313571ecd59eda
>
> I will submit it, pending on status of the first patch.

Ah, ok. Yes, this can wait...

thanks,
Andreas
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