lockable: fix __COUNTER__ macro to be referenced properly

- __COUNTER__ doesn't work with ## concat
- replaced ## with glue() macro so __COUNTER__ is evaluated

Fixes: 3284c3ddc4

Signed-off-by: Daniel Brodsky <dnbrdsky@gmail.com>
Message-id: 20200404042108.389635-2-dnbrdsky@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

include/qemu/lockable.h

@@ -152,7 +152,7 @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC(QemuLockable, qemu_lockable_auto_unlock)
  *   }
  */
 #define WITH_QEMU_LOCK_GUARD(x) \
-    WITH_QEMU_LOCK_GUARD_((x), qemu_lockable_auto##__COUNTER__)
+    WITH_QEMU_LOCK_GUARD_((x), glue(qemu_lockable_auto, __COUNTER__))
 
 /**
  * QEMU_LOCK_GUARD - Lock an object until the end of the scope
@@ -169,8 +169,9 @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC(QemuLockable, qemu_lockable_auto_unlock)
  *       return; <-- mutex is automatically unlocked
  *   }
  */
-#define QEMU_LOCK_GUARD(x) \
-    g_autoptr(QemuLockable) qemu_lockable_auto##__COUNTER__ = \
+#define QEMU_LOCK_GUARD(x)                                       \
+    g_autoptr(QemuLockable)                                      \
+    glue(qemu_lockable_auto, __COUNTER__) G_GNUC_UNUSED =        \
             qemu_lockable_auto_lock(QEMU_MAKE_LOCKABLE((x)))
 
 #endif

include/qemu/rcu.h

@@ -170,7 +170,7 @@ static inline void rcu_read_auto_unlock(RCUReadAuto *r)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(RCUReadAuto, rcu_read_auto_unlock)
 
 #define WITH_RCU_READ_LOCK_GUARD() \
-    WITH_RCU_READ_LOCK_GUARD_(_rcu_read_auto##__COUNTER__)
+    WITH_RCU_READ_LOCK_GUARD_(glue(_rcu_read_auto, __COUNTER__))
 
 #define WITH_RCU_READ_LOCK_GUARD_(var) \
     for (g_autoptr(RCUReadAuto) var = rcu_read_auto_lock(); \