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/block.c b/block.c
index 11ab55f80b..f72a2e26e8 100644
--- a/block.c
+++ b/block.c
@@ -1694,7 +1694,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
     }
 
     /* bdrv_new() and bdrv_close() make it so */
-    assert(atomic_read(&bs->copy_on_read) == 0);
+    assert(qatomic_read(&bs->copy_on_read) == 0);
 
     if (bs->open_flags & BDRV_O_COPY_ON_READ) {
         if (!bs->read_only) {
@@ -4436,7 +4436,7 @@ static void bdrv_close(BlockDriverState *bs)
     bs->file = NULL;
     g_free(bs->opaque);
     bs->opaque = NULL;
-    atomic_set(&bs->copy_on_read, 0);
+    qatomic_set(&bs->copy_on_read, 0);
     bs->backing_file[0] = '\0';
     bs->backing_format[0] = '\0';
     bs->total_sectors = 0;