https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102329
--- Comment #14 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Florian Weimer from comment #7)
> We need to suppress this warning for pthread_setspecific in glibc because it
> is incorrect there. There is currently no good way to implement that
> suppression unfortunately.
For completeness, in glibc:
commit b25b06749179d8d9a891381466e323a9dd2215f9
Author: Martin Sebor <mse...@redhat.com>
Date: Tue Apr 27 19:05:30 2021 -0600
Pass a valid pointer to pthread_setspecific to avoid GCC 11 warning.
commit a1561c3bbe8e72c6e44280d1eb5e529d2da4ecd0
Author: Martin Sebor <mse...@redhat.com>
Date: Tue Apr 27 13:01:55 2021 -0600
Add __attribute_access_none to disable GCC warnings [BZ #27714]
GCC 11 warns when a pointer to an uninitialized object is passed
to a function that takes a const-qualified argument. This is done
on the assumption that most such functions read from the object.
For the rare case of a function that doesn't, GCC 11 extends
attribute access to add a new mode called none.
POSIX pthread_setspecific() is one such rare function that takes
a const void* argument but that doesn't read from the object it
points to. To suppress the -Wmaybe-uninitialized issued by GCC
11 when the address of an uninitialized object is passed to it
(e.g., the result of malloc()), this change #defines
__attr_access_none in cdefs.h and uses the macro on the function
in sysdeps/htl/pthread.h and sysdeps/nptl/pthread.h.
