PATCH] PR target/65612: Multiversioning doesn't work with DSO nor PIE

[H.J. Lu]

On Tue, Mar 31, 2015 at 11:33 AM, Jack Howarth <howarth.at.gcc@gmail.com> wrote:
> On Tue, Mar 31, 2015 at 1:00 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Tue, Mar 31, 2015 at 9:39 AM, Jack Howarth <howarth.at.gcc@gmail.com> wrote:
>>> On Tue, Mar 31, 2015 at 12:14 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>>> On Tue, Mar 31, 2015 at 9:09 AM, Jack Howarth <howarth.at.gcc@gmail.com> wrote:
>>>>> H.J.,
>>>>>     Did you attach the correct version of the patch? I don't see
>>>>> anything conditional on linux.
>>>>>             Jack
>>>>
>>>> My patch will build and install libgcc_nonshared.a for all targets.  If you
>>>> don't link against it, nothing is changed.  On Linux, it is used via the
>>>> init_spec change.
>>>
>>> Isn't...
>>>
>>> diff --git a/gcc/gcc.c b/gcc/gcc.c
>>> index d956c36..3fbd549 100644
>>> --- a/gcc/gcc.c
>>> +++ b/gcc/gcc.c
>>> @@ -1566,6 +1566,7 @@ init_spec (void)
>>>         if (in_sep && *p == '-' && strncmp (p, "-lgcc", 5) == 0)
>>>           {
>>>             init_gcc_specs (&obstack,
>>> +                           "-lgcc_nonshared "
>>>                             "-lgcc_s"
>>>  #ifdef USE_LIBUNWIND_EXCEPTIONS
>>>                             " -lunwind"
>>> @@ -1591,6 +1592,7 @@ init_spec (void)
>>>             /* Ug.  We don't know shared library extensions.  Hope that
>>>                systems that use this form don't do shared libraries.  */
>>>             init_gcc_specs (&obstack,
>>> +                           "libgcc_nonshared.a%s "
>>>                             "-lgcc_s",
>>>                             "libgcc.a%s",
>>>                             "libgcc_eh.a%s"
>>>
>>> problematic for Solaris? I am unfamiliar with the Solaris spec
>>> handling but sol2.h doesn't seem to have any instances of -lgcc which
>>> might imply they use the stock compiler invocation which will now have
>>> a non-existent libgcc_nonshared static library.
>>
>> libgcc_nonshared.a is built and installed for all targets.
>>
>>>      Also, are you leaving the cpu symbols in libgcc.a on non-linux
>>> targets? If not, the linkage failure reported in
>>> https://gcc.gnu.org/ml/gcc-patches/2015-03/msg01668.html will occur,
>>> no?
>>
>> My current patch doesn't change what are in libgcc.a.  It
>> adds libgcc_nonshared.a for all targets, which contains
>> the same cpuinfo.o as in libgcc.a or a dummy .o if libgcc.a
>> doesn't have cpuinfo.o.
>
>
> I can confirm that the most current patch bootstraps on
> x86_64-apple-darwin14 and that all of the new tests show up as
> unsupported in the test suite.
>           Jack

I am re-posting this patch.  OK for trunk?

Thanks.

-- 
H.J.
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