[PATCH] Revert "headers: avoid bareword attributes" for clang

[Eric Blake <eblake@redhat.com>]

This reverts most of commit 979d467ff6e39ee5c52cf1aac7a6c9c63058141c.

We cannot avoid some bareword attributes until clang is fixed to
properly support __-decorated attributes; see this bug:
https://bugs.llvm.org/show_bug.cgi?id=34319

The macros in question expand to the empty string under gcc, so
only compilation under clang is affected, and since clang has the
bug, the obvious solution is to roll back the changes, and document
the issue.

Signed-off-by: Eric Blake <eblake@redhat.com>
---

I'm pushing this as a result of Sebastian's investigations.

 newlib/libc/include/sys/cdefs.h | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 9e58ee980..8ce14b68e 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -681,42 +681,44 @@
 #endif

 /* Structure implements a lock. */
-#define	__lockable		__lock_annotate(__lockable__)
+/* FIXME: Use __lockable__, etc. to avoid colliding with user namespace macros,
+ * once clang is fixed: https://bugs.llvm.org/show_bug.cgi?id=34319 */
+#define	__lockable		__lock_annotate(lockable)

 /* Function acquires an exclusive or shared lock. */
 #define	__locks_exclusive(...) \
-	__lock_annotate(__exclusive_lock_function__(__VA_ARGS__))
+	__lock_annotate(exclusive_lock_function(__VA_ARGS__))
 #define	__locks_shared(...) \
-	__lock_annotate(__shared_lock_function__(__VA_ARGS__))
+	__lock_annotate(shared_lock_function(__VA_ARGS__))

 /* Function attempts to acquire an exclusive or shared lock. */
 #define	__trylocks_exclusive(...) \
-	__lock_annotate(__exclusive_trylock_function__(__VA_ARGS__))
+	__lock_annotate(exclusive_trylock_function(__VA_ARGS__))
 #define	__trylocks_shared(...) \
-	__lock_annotate(__shared_trylock_function__(__VA_ARGS__))
+	__lock_annotate(shared_trylock_function(__VA_ARGS__))

 /* Function releases a lock. */
-#define	__unlocks(...)		__lock_annotate(__unlock_function__(__VA_ARGS__))
+#define	__unlocks(...)		__lock_annotate(unlock_function(__VA_ARGS__))

 /* Function asserts that an exclusive or shared lock is held. */
 #define	__asserts_exclusive(...) \
-	__lock_annotate(__assert_exclusive_lock__(__VA_ARGS__))
+	__lock_annotate(assert_exclusive_lock(__VA_ARGS__))
 #define	__asserts_shared(...) \
-	__lock_annotate(__assert_shared_lock__(__VA_ARGS__))
+	__lock_annotate(assert_shared_lock(__VA_ARGS__))

 /* Function requires that an exclusive or shared lock is or is not held. */
 #define	__requires_exclusive(...) \
-	__lock_annotate(__exclusive_locks_required__(__VA_ARGS__))
+	__lock_annotate(exclusive_locks_required(__VA_ARGS__))
 #define	__requires_shared(...) \
-	__lock_annotate(__shared_locks_required__(__VA_ARGS__))
+	__lock_annotate(shared_locks_required(__VA_ARGS__))
 #define	__requires_unlocked(...) \
-	__lock_annotate(__locks_excluded__(__VA_ARGS__))
+	__lock_annotate(locks_excluded(__VA_ARGS__))

 /* Function should not be analyzed. */
-#define	__no_lock_analysis	__lock_annotate(__no_thread_safety_analysis__)
+#define	__no_lock_analysis	__lock_annotate(no_thread_safety_analysis)

 /* Guard variables and structure members by lock. */
-#define	__guarded_by(x)		__lock_annotate(__guarded_by__(x))
-#define	__pt_guarded_by(x)	__lock_annotate(__pt_guarded_by__(x))
+#define	__guarded_by(x)		__lock_annotate(guarded_by(x))
+#define	__pt_guarded_by(x)	__lock_annotate(pt_guarded_by(x))

 #endif /* !_SYS_CDEFS_H_ */
-- 
2.13.5