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/hw/display/qxl.c b/hw/display/qxl.c
index 1187134..431c107 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -1908,7 +1908,7 @@ static void qxl_send_events(PCIQXLDevice *d, uint32_t events)
     /*
      * Older versions of Spice forgot to define the QXLRam struct
      * with the '__aligned__(4)' attribute. clang 7 and newer will
-     * thus warn that atomic_fetch_or(&d->ram->int_pending, ...)
+     * thus warn that qatomic_fetch_or(&d->ram->int_pending, ...)
      * might be a misaligned atomic access, and will generate an
      * out-of-line call for it, which results in a link error since
      * we don't currently link against libatomic.
@@ -1928,7 +1928,7 @@ static void qxl_send_events(PCIQXLDevice *d, uint32_t events)
 #define ALIGNED_UINT32_PTR(P) ((uint32_t *)P)
 #endif
 
-    old_pending = atomic_fetch_or(ALIGNED_UINT32_PTR(&d->ram->int_pending),
+    old_pending = qatomic_fetch_or(ALIGNED_UINT32_PTR(&d->ram->int_pending),
                                   le_events);
     if ((old_pending & le_events) == le_events) {
         return;