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/migration/colo-failover.c b/migration/colo-failover.c
index b717edc8e2..42453481c4 100644
--- a/migration/colo-failover.c
+++ b/migration/colo-failover.c
@@ -63,7 +63,7 @@ FailoverStatus failover_set_state(FailoverStatus old_state,
 {
     FailoverStatus old;
 
-    old = atomic_cmpxchg(&failover_state, old_state, new_state);
+    old = qatomic_cmpxchg(&failover_state, old_state, new_state);
     if (old == old_state) {
         trace_colo_failover_set_state(FailoverStatus_str(new_state));
     }
@@ -72,7 +72,7 @@ FailoverStatus failover_set_state(FailoverStatus old_state,
 
 FailoverStatus failover_get_state(void)
 {
-    return atomic_read(&failover_state);
+    return qatomic_read(&failover_state);
 }
 
 void qmp_x_colo_lost_heartbeat(Error **errp)