qemu/atomic.h: rename atomic_ to qatomic_

clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/util/qemu-coroutine-sleep.c b/util/qemu-coroutine-sleep.c
index 769a76e57d..8c4dac4fd7 100644
--- a/util/qemu-coroutine-sleep.c
+++ b/util/qemu-coroutine-sleep.c
@@ -28,7 +28,7 @@ struct QemuCoSleepState {
 void qemu_co_sleep_wake(QemuCoSleepState *sleep_state)
 {
     /* Write of schedule protected by barrier write in aio_co_schedule */
-    const char *scheduled = atomic_cmpxchg(&sleep_state->co->scheduled,
+    const char *scheduled = qatomic_cmpxchg(&sleep_state->co->scheduled,
                                            qemu_co_sleep_ns__scheduled, NULL);
 
     assert(scheduled == qemu_co_sleep_ns__scheduled);
@@ -54,7 +54,7 @@ void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns,
         .user_state_pointer = sleep_state,
     };
 
-    const char *scheduled = atomic_cmpxchg(&state.co->scheduled, NULL,
+    const char *scheduled = qatomic_cmpxchg(&state.co->scheduled, NULL,
                                            qemu_co_sleep_ns__scheduled);
     if (scheduled) {
         fprintf(stderr,