[LLVMdev] Name of the libraries + soname? 3.4.1 ?

[Tobias Grosser]

On 12/05/2014 18:01, Tom Stellard wrote:
> On Mon, May 12, 2014 at 05:49:22PM +0200, Tobias Grosser wrote:
>> On 12/05/2014 17:12, Tom Stellard wrote:
>>> On Mon, May 12, 2014 at 04:17:05PM +0200, Sylvestre Ledru wrote:
>>>> On 12/05/2014 16:13, Tom Stellard wrote:
>>>>> On Mon, May 12, 2014 at 04:05:20PM +0200, Sylvestre Ledru wrote:
>>>>>> On 12/05/2014 15:22, Tom Stellard wrote:
>>>>>>> On Mon, May 12, 2014 at 08:41:36AM +0200, Sylvestre Ledru wrote:
>>>>>>>> Hello,
>>>>>>>>
>>>>>>>> With the release of 3.4.1, the LLVM library has been renamed from
>>>>>>>> libLLVM-3.4.so to libLLVM-3.4.1.so. In parallel, the soname has been
>>>>>>>> updated to
>>>>>>>> reflect this change.
>>>>>>>>
>>>>>>>> AFAIK, we kept the ABI compatible from 3.4 to 3.4.1. So, is there any
>>>>>>>> reason for doing it?
>>>>>>>> This caused some breakages in Debian (basically, breaking some X because
>>>>>>>> of mesa could not
>>>>>>>> link against LLVM due to the new soname).
>>>>>>>> I noticed that we did the same with 3.5.
>>>>>>>>
>>>>>>>> I am not sure to understand what was wrong with the X.Y naming schema.
>>>>>>>
>>>>>>> The library was renamed, but a libLLVM-3.4.so symlink was added to point
>>>>>>> to libLLVM-3.4.1.so, so I don't think anything should break.
>>>>>> Yes but the (distro?) tools relies on the soname for linking and the
>>>>>> soname was updated.
>>>>>
>>>>> Is soname an attribute that is stored somewhere within the shared library, or does
>>>>> it refer to the name of the shared object file?
>>>> It is stored inside (and built with -Wl,-soname,libfoo.so.0)
>>>> For example, in Debian (and Ubuntu), we consider that a library in
>>>> /usr/lib/* without a soname is an error.
>>>>
>>>> Example:
>>>> $ objdump -p /usr/lib/x86_64-linux-gnu/libLLVM-3.4.so.1 |grep SONAME
>>>>    SONAME               libLLVM-3.4.so.1
>>>>
>>>
>>> Ok, this makes sense now, so it does look like a bug in in the LLVM build system.
>>> Your suggestion to swap the symlink (i.e. create a libLLVM-3.4.1.so symlink that
>>> points to libLLVM-3.4.so) seems like a good one.  I will make this change unless
>>> someone objects.
>>
>> Just to warn you. Distributors are very sensitive to release
>> binaries that change. If you already published files for LLVM 3.4.1,
>> those files should be assumed frozen. Anything that changes their
>> MD5 sum will cause problems.
>>
>
> We will not be changing the 3.4.1 release binaries.  This fix will go into 3.4.2.

Perfect! Thanks!

Tobias