[committed] libstdc++: Fix call to __glibcxx_rwlock_init (PR 93244)

[Jonathan Wakely]

On 06/03/20 12:04 +0000, Jonathan Wakely wrote:
>When the target doesn't define PTHREAD_RWLOCK_INITIALIZER we use a
>wrapper around pthread_wrlock_init, but the wrapper only takes one
>argument and we try to call it with two.
>
>This went unnnoticed on most targets because they do define the
>PTHREAD_RWLOCK_INITIALIZER macro, but it causes a bootstrap failure on
>darwin8.
>
>	PR libstdc++/93244
>	* include/std/shared_mutex [!PTHREAD_RWLOCK_INITIALIZER]
>	(__shared_mutex_pthread::__shared_mutex_pthread()): Remove incorrect
>	second argument to __glibcxx_rwlock_init.
>	* testsuite/30_threads/shared_timed_mutex/94069.cc: New test.
>
>Tested powerpc64le-linux, committed to master.
>
>This also needs to be backported to gcc-9 but I'll let the release
>managers decide whether that's before or after the upcoming 9.3
>release.
>
>

>commit b0815713a32c5cc062bd41fa75dac4d4408215fb
>Author: Jonathan Wakely <jwakely@redhat.com>
>Date:   Fri Mar 6 12:03:17 2020 +0000
>
>    libstdc++: Fix call to __glibcxx_rwlock_init (PR 93244)
>
>    When the target doesn't define PTHREAD_RWLOCK_INITIALIZER we use a
>    wrapper around pthread_wrlock_init, but the wrapper only takes one
>    argument and we try to call it with two.
>
>    This went unnnoticed on most targets because they do define the
>    PTHREAD_RWLOCK_INITIALIZER macro, but it causes a bootstrap failure on
>    darwin8.
>
>            PR libstdc++/93244

Oops, the correct PR number is 94069. Fixed in the ChangeLog now.