[Bug c/65083] Can not indirectly call some C11 atomic library functions

["jsm28 at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65083

--- Comment #3 from Joseph S. Myers <jsm28 at gcc dot gnu.org> ---
Author: jsm28
Date: Wed Nov 18 22:13:44 2015
New Revision: 230578

URL: https://gcc.gnu.org/viewcvs?rev=230578&root=gcc&view=rev
Log:
Add out-of-line versions of some <stdatomic.h> functions (PR c/65083).

PR c/65083 notes that some functions in <stdatomic.h> are normal
functions, not generic functions, and so need to have out-of-line
copies that can be called when macro expansion is suppressed (unlike
the generic functions where DR#419 makes it undefined if you suppress
a macro expansion).

This patch adds such out-of-line definitions in libatomic for those
six functions, at a new LIBATOMIC_1.2 symbol version, as trivial
wrappers to the <stdatomic.h> macros, along with declarations of those
functions in <stdatomic.h>.  Tests are added that are based on the
corresponding tests for the macros, but with parentheses around the
function names to force the out-of-line functions to be used.

Bootstrapped with no regressions on x86_64-pc-linux-gnu.

gcc:
        * ginclude/stdatomic.h (atomic_thread_fence, atomic_signal_fence)
        (atomic_flag_test_and_set, atomic_flag_test_and_set_explicit)
        (atomic_flag_clear, atomic_flag_clear_explicit): Declare as
        functions before defining as macros.

gcc/testsuite:
        * gcc.dg/atomic/stdatomic-fence-2.c,
        gcc.dg/atomic/stdatomic-flag-2.c: New tests.

libatomic:
        * fence.c, flag.c: New files.
        * Makefile.am (libatomic_la_SOURCES): Add fence.c and flag.c.
        * Makefile.in: Regenerate.
        * configure.ac (libtool_VERSION): Change to 3:0:2.
        * configure: Regenerate.
        * libatomic.map (LIBATOMIC_1.2): New symbol version.

Added:
    trunk/gcc/testsuite/gcc.dg/atomic/stdatomic-fence-2.c
    trunk/gcc/testsuite/gcc.dg/atomic/stdatomic-flag-2.c
    trunk/libatomic/fence.c
    trunk/libatomic/flag.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/ginclude/stdatomic.h
    trunk/gcc/testsuite/ChangeLog
    trunk/libatomic/ChangeLog
    trunk/libatomic/Makefile.am
    trunk/libatomic/Makefile.in
    trunk/libatomic/configure
    trunk/libatomic/configure.ac
    trunk/libatomic/libatomic.map