[PATCH 1 of 2] libc: add disable-versioning and enable-oldest-abi to (e)glibc

[Bryan Hundven]

On Wed, Nov 10, 2010 at 4:09 PM, Yann E. MORIN
<yann.morin.1998@anciens.enib.fr> wrote:
> Bryan, All,
>
> On Wednesday 10 November 2010 19:39:00 Bryan Hundven wrote:
>> +config LIBC_DISABLE_VERSIONING
>> +    bool
>> +    prompt "Disable versioning information in library objects"
>> +    default n
>> +    help
>> +      Do not include versioning information in the library objects.
>
> Could you elaborate on why one may wish to disable symbols versionning?

Yes,

Since the box that I am building on (Debian Lenny, x86_32) is using
glibc-2.7, and when I build, say elfutils (which does not support
HOST_CC) builds i386_gendis, which in turn it runs to generate
disassembler info for libdw, it fails with:

./i386_gendis: /lib/i686/cmov/libc.so.6: version `GLIBC_2.8' not found
(required by ./i386_gendis)

One way to fix this is to append:
-Wl,-rpath,$(HOME)/x-tools/i686-nptl-linux-gnu/i686-nptl-linux-gnu/sys-root/lib
to i386_gendis_LDADD in elfutils-0.149/libcpu/Makefile.in (Yuck)

And the other way is to remove library version info from my
cross-compiler's eglibc.

I am currently working on a patch to add proper cross-compiler support
to elfutils, but this is a ways off.

I am sure that someone else has a better use-case for removing
versioning information, but this is what I got so far.

If someone knows of a better way to handle this kind of issue, I would
love to hear about it.

>> +config LIBC_OLDEST_ABI
>> +    string
>> +    prompt "Configure the oldest ABI supported [e.g. 2.2]"
>> +    default ""
>> +    help
>> +      Setting this option, for example, to 2.2 will provide ABI support
>> +      back to (e)glibc-2.2.
>> +
>> +      If this option is not set, (e)glibc will choose for you.
>> +
>
> I've split the patch in two: one to add the symbols versioning option,
> and the other to add the ABI selection.
>
> I have them pending here. Thank you!

If you would like, I can resubmit them as separate patches?

> Regards,
> Yann E. MORIN.
>
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>
>

-Bryan

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