]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/sys/queue.h
xnu-7195.81.3.tar.gz
[apple/xnu.git] / bsd / sys / queue.h
index aa26d76368174d0d426a2557c05d710e2dee4780..46b382ed77f9ac928e464b1c64c87f7aecd1064e 100644 (file)
@@ -2,7 +2,7 @@
  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -22,7 +22,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*-
  */
 
 #ifndef _SYS_QUEUE_H_
-#define        _SYS_QUEUE_H_
+#define _SYS_QUEUE_H_
 
 #ifdef KERNEL_PRIVATE
 #include <kern/debug.h> /* panic function call */
-#include <sys/cdefs.h> /* __improbable in kernelspace */
+#include <sys/cdefs.h>  /* __improbable in kernelspace */
 #else
 #ifndef __improbable
-#define __improbable(x) (x)            /* noop in userspace */
+#define __improbable(x) (x)             /* noop in userspace */
 #endif /* __improbable */
 #endif /* KERNEL_PRIVATE */
 
@@ -158,29 +158,29 @@ struct qm_trace {
        int prevline;
 };
 
-#define        TRACEBUF        struct qm_trace trace;
-#define        TRASHIT(x)      do {(x) = (void *)-1;} while (0)
+#define TRACEBUF        struct qm_trace trace;
+#define TRASHIT(x)      do {(x) = (void *)-1;} while (0)
 
-#define        QMD_TRACE_HEAD(head) do {                                       \
-       (head)->trace.prevline = (head)->trace.lastline;                \
-       (head)->trace.prevfile = (head)->trace.lastfile;                \
-       (head)->trace.lastline = __LINE__;                              \
-       (head)->trace.lastfile = __FILE__;                              \
+#define QMD_TRACE_HEAD(head) do {                                       \
+       (head)->trace.prevline = (head)->trace.lastline;                \
+       (head)->trace.prevfile = (head)->trace.lastfile;                \
+       (head)->trace.lastline = __LINE__;                              \
+       (head)->trace.lastfile = __FILE__;                              \
 } while (0)
 
-#define        QMD_TRACE_ELEM(elem) do {                                       \
-       (elem)->trace.prevline = (elem)->trace.lastline;                \
-       (elem)->trace.prevfile = (elem)->trace.lastfile;                \
-       (elem)->trace.lastline = __LINE__;                              \
-       (elem)->trace.lastfile = __FILE__;                              \
+#define QMD_TRACE_ELEM(elem) do {                                       \
+       (elem)->trace.prevline = (elem)->trace.lastline;                \
+       (elem)->trace.prevfile = (elem)->trace.lastfile;                \
+       (elem)->trace.lastline = __LINE__;                              \
+       (elem)->trace.lastfile = __FILE__;                              \
 } while (0)
 
 #else
-#define        QMD_TRACE_ELEM(elem)
-#define        QMD_TRACE_HEAD(head)
-#define        TRACEBUF
-#define        TRASHIT(x)
-#endif /* QUEUE_MACRO_DEBUG */
+#define QMD_TRACE_ELEM(elem)
+#define QMD_TRACE_HEAD(head)
+#define TRACEBUF
+#define TRASHIT(x)
+#endif  /* QUEUE_MACRO_DEBUG */
 
 /*
  * Horrible macros to enable use of code that was meant to be C-specific
@@ -197,248 +197,296 @@ struct qm_trace {
  *   prepend "struct" to "type" and will cause C++ to blow up.
  */
 #if defined(__clang__) && defined(__cplusplus)
-#define __MISMATCH_TAGS_PUSH                                           \
-       _Pragma("clang diagnostic push")                                \
+#define __MISMATCH_TAGS_PUSH                                            \
+       _Pragma("clang diagnostic push")                                \
        _Pragma("clang diagnostic ignored \"-Wmismatched-tags\"")
-#define __MISMATCH_TAGS_POP                                            \
+#define __MISMATCH_TAGS_POP                                             \
        _Pragma("clang diagnostic pop")
 #else
 #define __MISMATCH_TAGS_PUSH
 #define __MISMATCH_TAGS_POP
 #endif
 
+/*!
+ * Ensures that these macros can safely be used in structs when compiling with
+ * clang. The macros do not allow for nullability attributes to be specified due
+ * to how they are expanded. For example:
+ *
+ *     SLIST_HEAD(, foo _Nullable) bar;
+ *
+ * expands to
+ *
+ *     struct {
+ *         struct foo _Nullable *slh_first;
+ *     }
+ *
+ * which is not valid because the nullability specifier has to apply to the
+ * pointer. So just ignore nullability completeness in all the places where this
+ * is an issue.
+ */
+#if defined(__clang__)
+#define __NULLABILITY_COMPLETENESS_PUSH \
+       _Pragma("clang diagnostic push") \
+       _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"")
+#define __NULLABILITY_COMPLETENESS_POP \
+       _Pragma("clang diagnostic pop")
+#else
+#define __NULLABILITY_COMPLETENESS_PUSH
+#define __NULLABILITY_COMPLETENESS_POP
+#endif
+
 /*
  * Singly-linked List declarations.
  */
-#define        SLIST_HEAD(name, type)                                          \
-__MISMATCH_TAGS_PUSH                                                   \
-struct name {                                                          \
-       struct type *slh_first; /* first element */                     \
-}                                                                      \
+#define SLIST_HEAD(name, type)                                          \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct name {                                                           \
+       struct type *slh_first; /* first element */                     \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
-#define        SLIST_HEAD_INITIALIZER(head)                                    \
+#define SLIST_HEAD_INITIALIZER(head)                                    \
        { NULL }
 
-#define        SLIST_ENTRY(type)                                               \
-__MISMATCH_TAGS_PUSH                                                   \
-struct {                                                               \
-       struct type *sle_next;  /* next element */                      \
-}                                                                      \
+#define SLIST_ENTRY(type)                                               \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct {                                                                \
+       struct type *sle_next;  /* next element */                      \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
 /*
  * Singly-linked List functions.
  */
-#define        SLIST_EMPTY(head)       ((head)->slh_first == NULL)
+#define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
 
-#define        SLIST_FIRST(head)       ((head)->slh_first)
+#define SLIST_FIRST(head)       ((head)->slh_first)
 
-#define        SLIST_FOREACH(var, head, field)                                 \
-       for ((var) = SLIST_FIRST((head));                               \
-           (var);                                                      \
+#define SLIST_FOREACH(var, head, field)                                 \
+       for ((var) = SLIST_FIRST((head));                               \
+           (var);                                                      \
            (var) = SLIST_NEXT((var), field))
 
-#define        SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
-       for ((var) = SLIST_FIRST((head));                               \
-           (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
+#define SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
+       for ((var) = SLIST_FIRST((head));                               \
+           (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
            (var) = (tvar))
 
-#define        SLIST_FOREACH_PREVPTR(var, varp, head, field)                   \
-       for ((varp) = &SLIST_FIRST((head));                             \
-           ((var) = *(varp)) != NULL;                                  \
+#define SLIST_FOREACH_PREVPTR(var, varp, head, field)                   \
+       for ((varp) = &SLIST_FIRST((head));                             \
+           ((var) = *(varp)) != NULL;                                  \
            (varp) = &SLIST_NEXT((var), field))
 
-#define        SLIST_INIT(head) do {                                           \
-       SLIST_FIRST((head)) = NULL;                                     \
+#define SLIST_INIT(head) do {                                           \
+       SLIST_FIRST((head)) = NULL;                                     \
 } while (0)
 
-#define        SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
-       SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
-       SLIST_NEXT((slistelm), field) = (elm);                          \
+#define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
+       SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
+       SLIST_NEXT((slistelm), field) = (elm);                          \
 } while (0)
 
-#define        SLIST_INSERT_HEAD(head, elm, field) do {                        \
-       SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
-       SLIST_FIRST((head)) = (elm);                                    \
+#define SLIST_INSERT_HEAD(head, elm, field) do {                        \
+       SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
+       SLIST_FIRST((head)) = (elm);                                    \
 } while (0)
 
-#define        SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
+#define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
 
-#define        SLIST_REMOVE(head, elm, type, field)                            \
-__MISMATCH_TAGS_PUSH                                                   \
-do {                                                                   \
-       if (SLIST_FIRST((head)) == (elm)) {                             \
-               SLIST_REMOVE_HEAD((head), field);                       \
-       }                                                               \
-       else {                                                          \
-               struct type *curelm = SLIST_FIRST((head));              \
-               while (SLIST_NEXT(curelm, field) != (elm))              \
-                       curelm = SLIST_NEXT(curelm, field);             \
-               SLIST_REMOVE_AFTER(curelm, field);                      \
-       }                                                               \
-       TRASHIT((elm)->field.sle_next);                                 \
-} while (0)                                                            \
+#define SLIST_REMOVE(head, elm, type, field)                            \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+do {                                                                    \
+       if (SLIST_FIRST((head)) == (elm)) {                             \
+               SLIST_REMOVE_HEAD((head), field);                       \
+       }                                                               \
+       else {                                                          \
+               struct type *curelm = SLIST_FIRST((head));              \
+               while (SLIST_NEXT(curelm, field) != (elm))              \
+                       curelm = SLIST_NEXT(curelm, field);             \
+               SLIST_REMOVE_AFTER(curelm, field);                      \
+       }                                                               \
+       TRASHIT((elm)->field.sle_next);                                 \
+} while (0)                                                             \
+__NULLABILITY_COMPLETENESS_POP                                      \
 __MISMATCH_TAGS_POP
 
-#define SLIST_REMOVE_AFTER(elm, field) do {                            \
-       SLIST_NEXT(elm, field) =                                        \
-           SLIST_NEXT(SLIST_NEXT(elm, field), field);                  \
+#define SLIST_REMOVE_AFTER(elm, field) do {                             \
+       SLIST_NEXT(elm, field) =                                        \
+           SLIST_NEXT(SLIST_NEXT(elm, field), field);                  \
 } while (0)
 
-#define        SLIST_REMOVE_HEAD(head, field) do {                             \
-       SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
+#define SLIST_REMOVE_HEAD(head, field) do {                             \
+       SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
 } while (0)
 
 /*
  * Singly-linked Tail queue declarations.
  */
-#define        STAILQ_HEAD(name, type)                                         \
-__MISMATCH_TAGS_PUSH                                                   \
-struct name {                                                          \
-       struct type *stqh_first;/* first element */                     \
-       struct type **stqh_last;/* addr of last next element */         \
-}                                                                      \
+#define STAILQ_HEAD(name, type)                                         \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct name {                                                           \
+       struct type *stqh_first;/* first element */                     \
+       struct type **stqh_last;/* addr of last next element */         \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
-#define        STAILQ_HEAD_INITIALIZER(head)                                   \
+#define STAILQ_HEAD_INITIALIZER(head)                                   \
        { NULL, &(head).stqh_first }
 
-#define        STAILQ_ENTRY(type)                                              \
-__MISMATCH_TAGS_PUSH                                                   \
-struct {                                                               \
-       struct type *stqe_next; /* next element */                      \
-}                                                                      \
+#define STAILQ_ENTRY(type)                                              \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct {                                                                \
+       struct type *stqe_next; /* next element */                      \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                         \
 __MISMATCH_TAGS_POP
 
 /*
  * Singly-linked Tail queue functions.
  */
-#define        STAILQ_CONCAT(head1, head2) do {                                \
-       if (!STAILQ_EMPTY((head2))) {                                   \
-               *(head1)->stqh_last = (head2)->stqh_first;              \
-               (head1)->stqh_last = (head2)->stqh_last;                \
-               STAILQ_INIT((head2));                                   \
-       }                                                               \
+#define STAILQ_CONCAT(head1, head2) do {                                \
+       if (!STAILQ_EMPTY((head2))) {                                   \
+               *(head1)->stqh_last = (head2)->stqh_first;              \
+               (head1)->stqh_last = (head2)->stqh_last;                \
+               STAILQ_INIT((head2));                                   \
+       }                                                               \
 } while (0)
 
-#define        STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
+#define STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
 
-#define        STAILQ_FIRST(head)      ((head)->stqh_first)
+#define STAILQ_FIRST(head)      ((head)->stqh_first)
 
-#define        STAILQ_FOREACH(var, head, field)                                \
-       for((var) = STAILQ_FIRST((head));                               \
-          (var);                                                       \
+#define STAILQ_FOREACH(var, head, field)                                \
+       for((var) = STAILQ_FIRST((head));                               \
+          (var);                                                       \
           (var) = STAILQ_NEXT((var), field))
 
 
-#define        STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
-       for ((var) = STAILQ_FIRST((head));                              \
-           (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
+#define STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
+       for ((var) = STAILQ_FIRST((head));                              \
+           (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
            (var) = (tvar))
 
-#define        STAILQ_INIT(head) do {                                          \
-       STAILQ_FIRST((head)) = NULL;                                    \
-       (head)->stqh_last = &STAILQ_FIRST((head));                      \
+#define STAILQ_INIT(head) do {                                          \
+       STAILQ_FIRST((head)) = NULL;                                    \
+       (head)->stqh_last = &STAILQ_FIRST((head));                      \
 } while (0)
 
-#define        STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
+#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
        if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
-               (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
-       STAILQ_NEXT((tqelm), field) = (elm);                            \
+               (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
+       STAILQ_NEXT((tqelm), field) = (elm);                            \
 } while (0)
 
-#define        STAILQ_INSERT_HEAD(head, elm, field) do {                       \
-       if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
-               (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
-       STAILQ_FIRST((head)) = (elm);                                   \
+#define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
+       if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
+               (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
+       STAILQ_FIRST((head)) = (elm);                                   \
 } while (0)
 
-#define        STAILQ_INSERT_TAIL(head, elm, field) do {                       \
-       STAILQ_NEXT((elm), field) = NULL;                               \
-       *(head)->stqh_last = (elm);                                     \
-       (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
+#define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
+       STAILQ_NEXT((elm), field) = NULL;                               \
+       *(head)->stqh_last = (elm);                                     \
+       (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
 } while (0)
 
-#define        STAILQ_LAST(head, type, field)                                  \
-__MISMATCH_TAGS_PUSH                                                   \
-       (STAILQ_EMPTY((head)) ?                                         \
-               NULL :                                                  \
-               ((struct type *)(void *)                                \
-               ((char *)((head)->stqh_last) - __offsetof(struct type, field))))\
+#define STAILQ_LAST(head, type, field)                                  \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+       (STAILQ_EMPTY((head)) ?                                         \
+               NULL :                                                  \
+               ((struct type *)(void *)                                \
+               ((char *)((head)->stqh_last) - __offsetof(struct type, field))))\
+__NULLABILITY_COMPLETENESS_POP                                         \
 __MISMATCH_TAGS_POP
 
-#define        STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
-
-#define        STAILQ_REMOVE(head, elm, type, field)                           \
-__MISMATCH_TAGS_PUSH                                                   \
-do {                                                                   \
-       if (STAILQ_FIRST((head)) == (elm)) {                            \
-               STAILQ_REMOVE_HEAD((head), field);                      \
-       }                                                               \
-       else {                                                          \
-               struct type *curelm = STAILQ_FIRST((head));             \
-               while (STAILQ_NEXT(curelm, field) != (elm))             \
-                       curelm = STAILQ_NEXT(curelm, field);            \
-               STAILQ_REMOVE_AFTER(head, curelm, field);               \
-       }                                                               \
-       TRASHIT((elm)->field.stqe_next);                                \
-} while (0)                                                            \
+#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
+
+#define STAILQ_REMOVE(head, elm, type, field)                           \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+do {                                                                    \
+       if (STAILQ_FIRST((head)) == (elm)) {                            \
+               STAILQ_REMOVE_HEAD((head), field);                      \
+       }                                                               \
+       else {                                                          \
+               struct type *curelm = STAILQ_FIRST((head));             \
+               while (STAILQ_NEXT(curelm, field) != (elm))             \
+                       curelm = STAILQ_NEXT(curelm, field);            \
+               STAILQ_REMOVE_AFTER(head, curelm, field);               \
+       }                                                               \
+       TRASHIT((elm)->field.stqe_next);                                \
+} while (0)                                                             \
+__NULLABILITY_COMPLETENESS_POP                                      \
 __MISMATCH_TAGS_POP
 
-#define        STAILQ_REMOVE_HEAD(head, field) do {                            \
-       if ((STAILQ_FIRST((head)) =                                     \
-            STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
-               (head)->stqh_last = &STAILQ_FIRST((head));              \
+#define STAILQ_REMOVE_HEAD(head, field) do {                            \
+       if ((STAILQ_FIRST((head)) =                                     \
+            STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
+               (head)->stqh_last = &STAILQ_FIRST((head));              \
 } while (0)
 
 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do {                 \
        if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \
-               (head)->stqh_last = &STAILQ_FIRST((head));              \
-} while (0)
-
-#define STAILQ_REMOVE_AFTER(head, elm, field) do {                     \
-       if ((STAILQ_NEXT(elm, field) =                                  \
-            STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL)      \
-               (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
-} while (0)
-
-#define STAILQ_SWAP(head1, head2, type)                                        \
-__MISMATCH_TAGS_PUSH                                                   \
-do {                                                                   \
-       struct type *swap_first = STAILQ_FIRST(head1);                  \
-       struct type **swap_last = (head1)->stqh_last;                   \
-       STAILQ_FIRST(head1) = STAILQ_FIRST(head2);                      \
-       (head1)->stqh_last = (head2)->stqh_last;                        \
-       STAILQ_FIRST(head2) = swap_first;                               \
-       (head2)->stqh_last = swap_last;                                 \
-       if (STAILQ_EMPTY(head1))                                        \
-               (head1)->stqh_last = &STAILQ_FIRST(head1);              \
-       if (STAILQ_EMPTY(head2))                                        \
-               (head2)->stqh_last = &STAILQ_FIRST(head2);              \
-} while (0)                                                            \
+              (head)->stqh_last = &STAILQ_FIRST((head));              \
+} while (0)
+
+#define STAILQ_REMOVE_AFTER(head, elm, field) do {                      \
+       if ((STAILQ_NEXT(elm, field) =                                  \
+            STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL)      \
+               (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
+} while (0)
+
+#define STAILQ_SWAP(head1, head2, type)                                 \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+do {                                                                    \
+       struct type *swap_first = STAILQ_FIRST(head1);                  \
+       struct type **swap_last = (head1)->stqh_last;                   \
+       STAILQ_FIRST(head1) = STAILQ_FIRST(head2);                      \
+       (head1)->stqh_last = (head2)->stqh_last;                        \
+       STAILQ_FIRST(head2) = swap_first;                               \
+       (head2)->stqh_last = swap_last;                                 \
+       if (STAILQ_EMPTY(head1))                                        \
+               (head1)->stqh_last = &STAILQ_FIRST(head1);              \
+       if (STAILQ_EMPTY(head2))                                        \
+               (head2)->stqh_last = &STAILQ_FIRST(head2);              \
+} while (0)                                                             \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
 
 /*
  * List declarations.
  */
-#define        LIST_HEAD(name, type)                                           \
-__MISMATCH_TAGS_PUSH                                                   \
-struct name {                                                          \
-       struct type *lh_first;  /* first element */                     \
-}                                                                      \
+#define LIST_HEAD(name, type)                                           \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct name {                                                           \
+       struct type *lh_first;  /* first element */                     \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
-#define        LIST_HEAD_INITIALIZER(head)                                     \
+#define LIST_HEAD_INITIALIZER(head)                                     \
        { NULL }
 
-#define        LIST_ENTRY(type)                                                \
-__MISMATCH_TAGS_PUSH                                                   \
-struct {                                                               \
-       struct type *le_next;   /* next element */                      \
-       struct type **le_prev;  /* address of previous next element */  \
-}                                                                      \
+#define LIST_ENTRY(type)                                                \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct {                                                                \
+       struct type *le_next;   /* next element */                      \
+       struct type **le_prev;  /* address of previous next element */  \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
 /*
@@ -446,270 +494,297 @@ __MISMATCH_TAGS_POP
  */
 
 #ifdef KERNEL_PRIVATE
-#define        LIST_CHECK_HEAD(head, field) do {                               \
-       if (__improbable(                                               \
-             LIST_FIRST((head)) != NULL &&                             \
-             LIST_FIRST((head))->field.le_prev !=                      \
-             &LIST_FIRST((head))))                                     \
-                    panic("Bad list head %p first->prev != head", (head));     \
+#define LIST_CHECK_HEAD(head, field) do {                               \
+       if (__improbable(                                               \
+             LIST_FIRST((head)) != NULL &&                             \
+             LIST_FIRST((head))->field.le_prev !=                      \
+             &LIST_FIRST((head))))                                     \
+                    panic("Bad list head %p first->prev != head @%u",  \
+                        (head), __LINE__);                             \
 } while (0)
 
-#define        LIST_CHECK_NEXT(elm, field) do {                                \
-       if (__improbable(                                               \
-             LIST_NEXT((elm), field) != NULL &&                        \
-             LIST_NEXT((elm), field)->field.le_prev !=                 \
-             &((elm)->field.le_next)))                                 \
-                    panic("Bad link elm %p next->prev != elm", (elm)); \
+#define LIST_CHECK_NEXT(elm, field) do {                                \
+       if (__improbable(                                               \
+             LIST_NEXT((elm), field) != NULL &&                        \
+             LIST_NEXT((elm), field)->field.le_prev !=                 \
+             &((elm)->field.le_next)))                                 \
+                    panic("Bad link elm %p next->prev != elm @%u",     \
+                        (elm), __LINE__);                              \
 } while (0)
 
-#define        LIST_CHECK_PREV(elm, field) do {                                \
-       if (__improbable(*(elm)->field.le_prev != (elm)))               \
-               panic("Bad link elm %p prev->next != elm", (elm));      \
+#define LIST_CHECK_PREV(elm, field) do {                                \
+       if (__improbable(*(elm)->field.le_prev != (elm)))               \
+               panic("Bad link elm %p prev->next != elm @%u",          \
+                   (elm), __LINE__);                                   \
 } while (0)
 #else
-#define        LIST_CHECK_HEAD(head, field)
-#define        LIST_CHECK_NEXT(elm, field)
-#define        LIST_CHECK_PREV(elm, field)
+#define LIST_CHECK_HEAD(head, field)
+#define LIST_CHECK_NEXT(elm, field)
+#define LIST_CHECK_PREV(elm, field)
 #endif /* KERNEL_PRIVATE */
 
-#define        LIST_EMPTY(head)        ((head)->lh_first == NULL)
+#define LIST_EMPTY(head)        ((head)->lh_first == NULL)
 
-#define        LIST_FIRST(head)        ((head)->lh_first)
+#define LIST_FIRST(head)        ((head)->lh_first)
 
-#define        LIST_FOREACH(var, head, field)                                  \
-       for ((var) = LIST_FIRST((head));                                \
-           (var);                                                      \
+#define LIST_FOREACH(var, head, field)                                  \
+       for ((var) = LIST_FIRST((head));                                \
+           (var);                                                      \
            (var) = LIST_NEXT((var), field))
 
-#define        LIST_FOREACH_SAFE(var, head, field, tvar)                       \
-       for ((var) = LIST_FIRST((head));                                \
-           (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
+#define LIST_FOREACH_SAFE(var, head, field, tvar)                       \
+       for ((var) = LIST_FIRST((head));                                \
+           (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
            (var) = (tvar))
 
-#define        LIST_INIT(head) do {                                            \
-       LIST_FIRST((head)) = NULL;                                      \
+#define LIST_INIT(head) do {                                            \
+       LIST_FIRST((head)) = NULL;                                      \
 } while (0)
 
-#define        LIST_INSERT_AFTER(listelm, elm, field) do {                     \
-       LIST_CHECK_NEXT(listelm, field);                                \
+#define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
+       LIST_CHECK_NEXT(listelm, field);                                \
        if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
-               LIST_NEXT((listelm), field)->field.le_prev =            \
-                   &LIST_NEXT((elm), field);                           \
-       LIST_NEXT((listelm), field) = (elm);                            \
-       (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
-} while (0)
-
-#define        LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
-       LIST_CHECK_PREV(listelm, field);                                \
-       (elm)->field.le_prev = (listelm)->field.le_prev;                \
-       LIST_NEXT((elm), field) = (listelm);                            \
-       *(listelm)->field.le_prev = (elm);                              \
-       (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
-} while (0)
-
-#define        LIST_INSERT_HEAD(head, elm, field) do {                         \
-       LIST_CHECK_HEAD((head), field);                         \
-       if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
-               LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
-       LIST_FIRST((head)) = (elm);                                     \
-       (elm)->field.le_prev = &LIST_FIRST((head));                     \
-} while (0)
-
-#define        LIST_NEXT(elm, field)   ((elm)->field.le_next)
-
-#define        LIST_REMOVE(elm, field) do {                                    \
-       LIST_CHECK_NEXT(elm, field);                            \
-       LIST_CHECK_PREV(elm, field);                            \
-       if (LIST_NEXT((elm), field) != NULL)                            \
-               LIST_NEXT((elm), field)->field.le_prev =                \
-                   (elm)->field.le_prev;                               \
-       *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
-       TRASHIT((elm)->field.le_next);                                  \
-       TRASHIT((elm)->field.le_prev);                                  \
-} while (0)
-
-#define LIST_SWAP(head1, head2, type, field)                           \
-__MISMATCH_TAGS_PUSH                                                   \
-do {                                                                   \
-       struct type *swap_tmp = LIST_FIRST((head1));                    \
-       LIST_FIRST((head1)) = LIST_FIRST((head2));                      \
-       LIST_FIRST((head2)) = swap_tmp;                                 \
-       if ((swap_tmp = LIST_FIRST((head1))) != NULL)                   \
-               swap_tmp->field.le_prev = &LIST_FIRST((head1));         \
-       if ((swap_tmp = LIST_FIRST((head2))) != NULL)                   \
-               swap_tmp->field.le_prev = &LIST_FIRST((head2));         \
-} while (0)                                                            \
+               LIST_NEXT((listelm), field)->field.le_prev =            \
+                   &LIST_NEXT((elm), field);                           \
+       LIST_NEXT((listelm), field) = (elm);                            \
+       (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
+} while (0)
+
+#define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
+       LIST_CHECK_PREV(listelm, field);                                \
+       (elm)->field.le_prev = (listelm)->field.le_prev;                \
+       LIST_NEXT((elm), field) = (listelm);                            \
+       *(listelm)->field.le_prev = (elm);                              \
+       (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
+} while (0)
+
+#define LIST_INSERT_HEAD(head, elm, field) do {                         \
+       LIST_CHECK_HEAD((head), field);                         \
+       if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
+               LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
+       LIST_FIRST((head)) = (elm);                                     \
+       (elm)->field.le_prev = &LIST_FIRST((head));                     \
+} while (0)
+
+#define LIST_NEXT(elm, field)   ((elm)->field.le_next)
+
+#define LIST_REMOVE(elm, field) do {                                    \
+       LIST_CHECK_NEXT(elm, field);                            \
+       LIST_CHECK_PREV(elm, field);                            \
+       if (LIST_NEXT((elm), field) != NULL)                            \
+               LIST_NEXT((elm), field)->field.le_prev =                \
+                   (elm)->field.le_prev;                               \
+       *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
+       TRASHIT((elm)->field.le_next);                                  \
+       TRASHIT((elm)->field.le_prev);                                  \
+} while (0)
+
+#define LIST_SWAP(head1, head2, type, field)                            \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+do {                                                                    \
+       struct type *swap_tmp = LIST_FIRST((head1));                    \
+       LIST_FIRST((head1)) = LIST_FIRST((head2));                      \
+       LIST_FIRST((head2)) = swap_tmp;                                 \
+       if ((swap_tmp = LIST_FIRST((head1))) != NULL)                   \
+               swap_tmp->field.le_prev = &LIST_FIRST((head1));         \
+       if ((swap_tmp = LIST_FIRST((head2))) != NULL)                   \
+               swap_tmp->field.le_prev = &LIST_FIRST((head2));         \
+} while (0)                                                             \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
 /*
  * Tail queue declarations.
  */
-#define        TAILQ_HEAD(name, type)                                          \
-__MISMATCH_TAGS_PUSH                                                   \
-struct name {                                                          \
-       struct type *tqh_first; /* first element */                     \
-       struct type **tqh_last; /* addr of last next element */         \
-       TRACEBUF                                                        \
-}                                                                      \
+#define TAILQ_HEAD(name, type)                                          \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct name {                                                           \
+       struct type *tqh_first; /* first element */                     \
+       struct type **tqh_last; /* addr of last next element */         \
+       TRACEBUF                                                        \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
-#define        TAILQ_HEAD_INITIALIZER(head)                                    \
+#define TAILQ_HEAD_INITIALIZER(head)                                    \
        { NULL, &(head).tqh_first }
 
-#define        TAILQ_ENTRY(type)                                               \
-__MISMATCH_TAGS_PUSH                                                   \
-struct {                                                               \
-       struct type *tqe_next;  /* next element */                      \
-       struct type **tqe_prev; /* address of previous next element */  \
-       TRACEBUF                                                        \
-}                                                                      \
+#define TAILQ_ENTRY(type)                                               \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct {                                                                \
+       struct type *tqe_next;  /* next element */                      \
+       struct type **tqe_prev; /* address of previous next element */  \
+       TRACEBUF                                                        \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
 /*
  * Tail queue functions.
  */
 #ifdef KERNEL_PRIVATE
-#define TAILQ_CHECK_HEAD(head, field) do {                             \
-       if (__improbable(                                               \
-             TAILQ_FIRST((head)) != NULL &&                            \
-             TAILQ_FIRST((head))->field.tqe_prev !=                    \
-             &TAILQ_FIRST((head))))                                    \
-                    panic("Bad tailq head %p first->prev != head", (head));    \
-} while (0)
-
-#define TAILQ_CHECK_NEXT(elm, field) do {                              \
-       if (__improbable(                                               \
-             TAILQ_NEXT((elm), field) != NULL &&                       \
-             TAILQ_NEXT((elm), field)->field.tqe_prev !=               \
-             &((elm)->field.tqe_next)))                                \
-                    panic("Bad tailq elm %p next->prev != elm", (elm));        \
+#define TAILQ_CHECK_HEAD(head, field) do {                              \
+       if (__improbable(                                                \
+             TAILQ_FIRST((head)) != NULL &&                            \
+             TAILQ_FIRST((head))->field.tqe_prev !=                    \
+             &TAILQ_FIRST((head))))                                    \
+                    panic("Bad tailq head %p first->prev != head @%u", \
+                        (head), __LINE__);                             \
+} while (0)
+
+#define TAILQ_CHECK_NEXT(elm, field) do {                               \
+       if (__improbable(                                                \
+             TAILQ_NEXT((elm), field) != NULL &&                       \
+             TAILQ_NEXT((elm), field)->field.tqe_prev !=               \
+             &((elm)->field.tqe_next)))                                \
+                    panic("Bad tailq elm %p next->prev != elm @%u",    \
+                        (elm), __LINE__);                              \
 } while(0)
 
-#define        TAILQ_CHECK_PREV(elm, field) do {                               \
-       if (__improbable(*(elm)->field.tqe_prev != (elm)))              \
-             panic("Bad tailq elm %p prev->next != elm", (elm));       \
+#define TAILQ_CHECK_PREV(elm, field) do {                               \
+       if (__improbable(*(elm)->field.tqe_prev != (elm)))               \
+             panic("Bad tailq elm %p prev->next != elm @%u",           \
+                 (elm), __LINE__);                                     \
 } while(0)
 #else
-#define        TAILQ_CHECK_HEAD(head, field)
-#define        TAILQ_CHECK_NEXT(elm, field)
-#define        TAILQ_CHECK_PREV(elm, field)
+#define TAILQ_CHECK_HEAD(head, field)
+#define TAILQ_CHECK_NEXT(elm, field)
+#define TAILQ_CHECK_PREV(elm, field)
 #endif /* KERNEL_PRIVATE */
 
-#define        TAILQ_CONCAT(head1, head2, field) do {                          \
-       if (!TAILQ_EMPTY(head2)) {                                      \
-               *(head1)->tqh_last = (head2)->tqh_first;                \
-               (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
-               (head1)->tqh_last = (head2)->tqh_last;                  \
-               TAILQ_INIT((head2));                                    \
-               QMD_TRACE_HEAD(head1);                                  \
-               QMD_TRACE_HEAD(head2);                                  \
-       }                                                               \
+#define TAILQ_CONCAT(head1, head2, field) do {                          \
+       if (!TAILQ_EMPTY(head2)) {                                      \
+               *(head1)->tqh_last = (head2)->tqh_first;                \
+               (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
+               (head1)->tqh_last = (head2)->tqh_last;                  \
+               TAILQ_INIT((head2));                                    \
+               QMD_TRACE_HEAD(head1);                                  \
+               QMD_TRACE_HEAD(head2);                                  \
+       }                                                               \
 } while (0)
 
-#define        TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
+#define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
 
-#define        TAILQ_FIRST(head)       ((head)->tqh_first)
+#define TAILQ_FIRST(head)       ((head)->tqh_first)
 
-#define        TAILQ_FOREACH(var, head, field)                                 \
-       for ((var) = TAILQ_FIRST((head));                               \
-           (var);                                                      \
+#define TAILQ_FOREACH(var, head, field)                                 \
+       for ((var) = TAILQ_FIRST((head));                               \
+           (var);                                                      \
            (var) = TAILQ_NEXT((var), field))
 
-#define        TAILQ_FOREACH_SAFE(var, head, field, tvar)                      \
-       for ((var) = TAILQ_FIRST((head));                               \
-           (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
+#define TAILQ_FOREACH_SAFE(var, head, field, tvar)                      \
+       for ((var) = TAILQ_FIRST((head));                               \
+           (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
            (var) = (tvar))
 
-#define        TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
-       for ((var) = TAILQ_LAST((head), headname);                      \
-           (var);                                                      \
+#define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
+       for ((var) = TAILQ_LAST((head), headname);                      \
+           (var);                                                      \
            (var) = TAILQ_PREV((var), headname, field))
 
-#define        TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
-       for ((var) = TAILQ_LAST((head), headname);                      \
-           (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
+#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
+       for ((var) = TAILQ_LAST((head), headname);                      \
+           (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
            (var) = (tvar))
 
-#define        TAILQ_INIT(head) do {                                           \
-       TAILQ_FIRST((head)) = NULL;                                     \
-       (head)->tqh_last = &TAILQ_FIRST((head));                        \
-       QMD_TRACE_HEAD(head);                                           \
+#if XNU_KERNEL_PRIVATE
+/*
+ * Can be used when the initialized HEAD was just bzeroed
+ * Works around deficiencies in clang analysis of initialization patterns.
+ * See: <rdar://problem/47939050>
+ */
+#define TAILQ_INIT_AFTER_BZERO(head) do {                               \
+       (head)->tqh_last = &TAILQ_FIRST((head));                        \
+} while (0)
+#endif /* XNU_KERNEL_PRIVATE */
+
+#define TAILQ_INIT(head) do {                                           \
+       TAILQ_FIRST((head)) = NULL;                                     \
+       (head)->tqh_last = &TAILQ_FIRST((head));                        \
+       QMD_TRACE_HEAD(head);                                           \
 } while (0)
 
 
-#define        TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
-        TAILQ_CHECK_NEXT(listelm, field);                              \
+#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
+       TAILQ_CHECK_NEXT(listelm, field);                               \
        if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
-               TAILQ_NEXT((elm), field)->field.tqe_prev =              \
-                   &TAILQ_NEXT((elm), field);                          \
-       else {                                                          \
-               (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
-               QMD_TRACE_HEAD(head);                                   \
-       }                                                               \
-       TAILQ_NEXT((listelm), field) = (elm);                           \
-       (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
-       QMD_TRACE_ELEM(&(elm)->field);                                  \
-       QMD_TRACE_ELEM(&listelm->field);                                \
-} while (0)
-
-#define        TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
-        TAILQ_CHECK_PREV(listelm, field);                              \
-       (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
-       TAILQ_NEXT((elm), field) = (listelm);                           \
-       *(listelm)->field.tqe_prev = (elm);                             \
-       (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
-       QMD_TRACE_ELEM(&(elm)->field);                                  \
-       QMD_TRACE_ELEM(&listelm->field);                                \
-} while (0)
-
-#define        TAILQ_INSERT_HEAD(head, elm, field) do {                        \
-        TAILQ_CHECK_HEAD(head, field);                                 \
-       if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
-               TAILQ_FIRST((head))->field.tqe_prev =                   \
-                   &TAILQ_NEXT((elm), field);                          \
-       else                                                            \
-               (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
-       TAILQ_FIRST((head)) = (elm);                                    \
-       (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
-       QMD_TRACE_HEAD(head);                                           \
-       QMD_TRACE_ELEM(&(elm)->field);                                  \
-} while (0)
-
-#define        TAILQ_INSERT_TAIL(head, elm, field) do {                        \
-       TAILQ_NEXT((elm), field) = NULL;                                \
-       (elm)->field.tqe_prev = (head)->tqh_last;                       \
-       *(head)->tqh_last = (elm);                                      \
-       (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
-       QMD_TRACE_HEAD(head);                                           \
-       QMD_TRACE_ELEM(&(elm)->field);                                  \
-} while (0)
-
-#define        TAILQ_LAST(head, headname)                                      \
-__MISMATCH_TAGS_PUSH                                                   \
-       (*(((struct headname *)((head)->tqh_last))->tqh_last))          \
+               TAILQ_NEXT((elm), field)->field.tqe_prev =              \
+                   &TAILQ_NEXT((elm), field);                          \
+       else {                                                          \
+               (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
+               QMD_TRACE_HEAD(head);                                   \
+       }                                                               \
+       TAILQ_NEXT((listelm), field) = (elm);                           \
+       (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
+       QMD_TRACE_ELEM(&(elm)->field);                                  \
+       QMD_TRACE_ELEM(&listelm->field);                                \
+} while (0)
+
+#define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
+       TAILQ_CHECK_PREV(listelm, field);                               \
+       (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
+       TAILQ_NEXT((elm), field) = (listelm);                           \
+       *(listelm)->field.tqe_prev = (elm);                             \
+       (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
+       QMD_TRACE_ELEM(&(elm)->field);                                  \
+       QMD_TRACE_ELEM(&listelm->field);                                \
+} while (0)
+
+#define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
+       TAILQ_CHECK_HEAD(head, field);                                  \
+       if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
+               TAILQ_FIRST((head))->field.tqe_prev =                   \
+                   &TAILQ_NEXT((elm), field);                          \
+       else                                                            \
+               (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
+       TAILQ_FIRST((head)) = (elm);                                    \
+       (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
+       QMD_TRACE_HEAD(head);                                           \
+       QMD_TRACE_ELEM(&(elm)->field);                                  \
+} while (0)
+
+#define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
+       TAILQ_NEXT((elm), field) = NULL;                                \
+       (elm)->field.tqe_prev = (head)->tqh_last;                       \
+       *(head)->tqh_last = (elm);                                      \
+       (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
+       QMD_TRACE_HEAD(head);                                           \
+       QMD_TRACE_ELEM(&(elm)->field);                                  \
+} while (0)
+
+#define TAILQ_LAST(head, headname)                                      \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+       (*(((struct headname *)((head)->tqh_last))->tqh_last))          \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
-#define        TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
+#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
 
-#define        TAILQ_PREV(elm, headname, field)                                \
-__MISMATCH_TAGS_PUSH                                                   \
-       (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))     \
+#define TAILQ_PREV(elm, headname, field)                                \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+       (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))     \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
-#define        TAILQ_REMOVE(head, elm, field) do {                             \
-        TAILQ_CHECK_NEXT(elm, field);                                  \
-        TAILQ_CHECK_PREV(elm, field);                                  \
-       if ((TAILQ_NEXT((elm), field)) != NULL)                         \
-               TAILQ_NEXT((elm), field)->field.tqe_prev =              \
-                   (elm)->field.tqe_prev;                              \
-       else {                                                          \
-               (head)->tqh_last = (elm)->field.tqe_prev;               \
-               QMD_TRACE_HEAD(head);                                   \
-       }                                                               \
-       *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
-       TRASHIT((elm)->field.tqe_next);                                 \
-       TRASHIT((elm)->field.tqe_prev);                                 \
-       QMD_TRACE_ELEM(&(elm)->field);                                  \
+#define TAILQ_REMOVE(head, elm, field) do {                             \
+       TAILQ_CHECK_NEXT(elm, field);                                   \
+       TAILQ_CHECK_PREV(elm, field);                                   \
+       if ((TAILQ_NEXT((elm), field)) != NULL)                         \
+               TAILQ_NEXT((elm), field)->field.tqe_prev =              \
+                   (elm)->field.tqe_prev;                              \
+       else {                                                          \
+               (head)->tqh_last = (elm)->field.tqe_prev;               \
+               QMD_TRACE_HEAD(head);                                   \
+       }                                                               \
+       *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
+       TRASHIT((elm)->field.tqe_next);                                 \
+       TRASHIT((elm)->field.tqe_prev);                                 \
+       QMD_TRACE_ELEM(&(elm)->field);                                  \
 } while (0)
 
 /*
@@ -717,6 +792,7 @@ __MISMATCH_TAGS_POP
  */
 #define TAILQ_SWAP(head1, head2, type, field)                           \
 __MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
 do {                                                                    \
        struct type *swap_first = (head1)->tqh_first;                   \
        struct type **swap_last = (head1)->tqh_last;                    \
@@ -725,139 +801,147 @@ do {                                                                    \
        (head2)->tqh_first = swap_first;                                \
        (head2)->tqh_last = swap_last;                                  \
        if ((swap_first = (head1)->tqh_first) != NULL)                  \
-               swap_first->field.tqe_prev = &(head1)->tqh_first;       \
+               swap_first->field.tqe_prev = &(head1)->tqh_first;       \
        else                                                            \
-               (head1)->tqh_last = &(head1)->tqh_first;                \
+               (head1)->tqh_last = &(head1)->tqh_first;                \
        if ((swap_first = (head2)->tqh_first) != NULL)                  \
-               swap_first->field.tqe_prev = &(head2)->tqh_first;       \
+               swap_first->field.tqe_prev = &(head2)->tqh_first;       \
        else                                                            \
-               (head2)->tqh_last = &(head2)->tqh_first;                \
+               (head2)->tqh_last = &(head2)->tqh_first;                \
 } while (0)                                                             \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
 /*
  * Circular queue definitions.
  */
-#define CIRCLEQ_HEAD(name, type)                                       \
-__MISMATCH_TAGS_PUSH                                                   \
-struct name {                                                          \
-       struct type *cqh_first;         /* first element */             \
-       struct type *cqh_last;          /* last element */              \
-}                                                                      \
+#define CIRCLEQ_HEAD(name, type)                                        \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct name {                                                           \
+       struct type *cqh_first;         /* first element */             \
+       struct type *cqh_last;          /* last element */              \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                          \
 __MISMATCH_TAGS_POP
 
-#define CIRCLEQ_ENTRY(type)                                            \
-__MISMATCH_TAGS_PUSH                                                   \
-struct {                                                               \
-       struct type *cqe_next;          /* next element */              \
-       struct type *cqe_prev;          /* previous element */          \
-}                                                                      \
+#define CIRCLEQ_ENTRY(type)                                             \
+__MISMATCH_TAGS_PUSH                                                    \
+__NULLABILITY_COMPLETENESS_PUSH                                         \
+struct {                                                                \
+       struct type *cqe_next;          /* next element */              \
+       struct type *cqe_prev;          /* previous element */          \
+}                                                                       \
+__NULLABILITY_COMPLETENESS_POP                                         \
 __MISMATCH_TAGS_POP
 
 /*
  * Circular queue functions.
  */
 #ifdef KERNEL_PRIVATE
-#define        CIRCLEQ_CHECK_HEAD(head, field) do {                            \
-       if (__improbable(                                               \
-             CIRCLEQ_FIRST((head)) != ((void*)(head)) &&               \
+#define CIRCLEQ_CHECK_HEAD(head, field) do {                            \
+       if (__improbable(                                                \
+             CIRCLEQ_FIRST((head)) != ((void*)(head)) &&               \
              CIRCLEQ_FIRST((head))->field.cqe_prev != ((void*)(head))))\
-                    panic("Bad circleq head %p first->prev != head", (head));  \
+                    panic("Bad circleq head %p first->prev != head @%u", \
+                        (head), __LINE__);                             \
 } while(0)
-#define        CIRCLEQ_CHECK_NEXT(head, elm, field) do {                       \
-       if (__improbable(                                               \
-             CIRCLEQ_NEXT((elm), field) != ((void*)(head)) &&          \
-             CIRCLEQ_NEXT((elm), field)->field.cqe_prev != (elm)))     \
-                    panic("Bad circleq elm %p next->prev != elm", (elm));      \
+#define CIRCLEQ_CHECK_NEXT(head, elm, field) do {                       \
+       if (__improbable(                                                \
+             CIRCLEQ_NEXT((elm), field) != ((void*)(head)) &&          \
+             CIRCLEQ_NEXT((elm), field)->field.cqe_prev != (elm)))     \
+                    panic("Bad circleq elm %p next->prev != elm @%u",  \
+                        (elm), __LINE__);                              \
 } while(0)
-#define        CIRCLEQ_CHECK_PREV(head, elm, field) do {                       \
-       if (__improbable(                                               \
-             CIRCLEQ_PREV((elm), field) != ((void*)(head)) &&          \
-             CIRCLEQ_PREV((elm), field)->field.cqe_next != (elm)))     \
-                    panic("Bad circleq elm %p prev->next != elm", (elm));      \
+#define CIRCLEQ_CHECK_PREV(head, elm, field) do {                       \
+       if (__improbable(                                                \
+             CIRCLEQ_PREV((elm), field) != ((void*)(head)) &&          \
+             CIRCLEQ_PREV((elm), field)->field.cqe_next != (elm)))     \
+                    panic("Bad circleq elm %p prev->next != elm @%u",  \
+                        (elm), __LINE__);                              \
 } while(0)
 #else
-#define        CIRCLEQ_CHECK_HEAD(head, field)
-#define        CIRCLEQ_CHECK_NEXT(head, elm, field)
-#define        CIRCLEQ_CHECK_PREV(head, elm, field)
+#define CIRCLEQ_CHECK_HEAD(head, field)
+#define CIRCLEQ_CHECK_NEXT(head, elm, field)
+#define CIRCLEQ_CHECK_PREV(head, elm, field)
 #endif /* KERNEL_PRIVATE */
 
 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head))
 
 #define CIRCLEQ_FIRST(head) ((head)->cqh_first)
 
-#define CIRCLEQ_FOREACH(var, head, field)                              \
-       for((var) = (head)->cqh_first;                                  \
-           (var) != (void *)(head);                                    \
+#define CIRCLEQ_FOREACH(var, head, field)                               \
+       for((var) = (head)->cqh_first;                                  \
+           (var) != (void *)(head);                                    \
            (var) = (var)->field.cqe_next)
 
-#define        CIRCLEQ_INIT(head) do {                                         \
-       (head)->cqh_first = (void *)(head);                             \
-       (head)->cqh_last = (void *)(head);                              \
-} while (0)
-
-#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do {           \
-        CIRCLEQ_CHECK_NEXT(head, listelm, field);                      \
-       (elm)->field.cqe_next = (listelm)->field.cqe_next;              \
-       (elm)->field.cqe_prev = (listelm);                              \
-       if ((listelm)->field.cqe_next == (void *)(head))                \
-               (head)->cqh_last = (elm);                               \
-       else                                                            \
-               (listelm)->field.cqe_next->field.cqe_prev = (elm);      \
-       (listelm)->field.cqe_next = (elm);                              \
-} while (0)
-
-#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do {          \
-        CIRCLEQ_CHECK_PREV(head, listelm, field);                      \
-       (elm)->field.cqe_next = (listelm);                              \
-       (elm)->field.cqe_prev = (listelm)->field.cqe_prev;              \
-       if ((listelm)->field.cqe_prev == (void *)(head))                \
-               (head)->cqh_first = (elm);                              \
-       else                                                            \
-               (listelm)->field.cqe_prev->field.cqe_next = (elm);      \
-       (listelm)->field.cqe_prev = (elm);                              \
-} while (0)
-
-#define CIRCLEQ_INSERT_HEAD(head, elm, field) do {                     \
-        CIRCLEQ_CHECK_HEAD(head, field);                               \
-       (elm)->field.cqe_next = (head)->cqh_first;                      \
-       (elm)->field.cqe_prev = (void *)(head);                         \
-       if ((head)->cqh_last == (void *)(head))                         \
-               (head)->cqh_last = (elm);                               \
-       else                                                            \
-               (head)->cqh_first->field.cqe_prev = (elm);              \
-       (head)->cqh_first = (elm);                                      \
-} while (0)
-
-#define CIRCLEQ_INSERT_TAIL(head, elm, field) do {                     \
-       (elm)->field.cqe_next = (void *)(head);                         \
-       (elm)->field.cqe_prev = (head)->cqh_last;                       \
-       if ((head)->cqh_first == (void *)(head))                        \
-               (head)->cqh_first = (elm);                              \
-       else                                                            \
-               (head)->cqh_last->field.cqe_next = (elm);               \
-       (head)->cqh_last = (elm);                                       \
+#define CIRCLEQ_INIT(head) do {                                         \
+       (head)->cqh_first = (void *)(head);                             \
+       (head)->cqh_last = (void *)(head);                              \
+} while (0)
+
+#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
+       CIRCLEQ_CHECK_NEXT(head, listelm, field);                       \
+       (elm)->field.cqe_next = (listelm)->field.cqe_next;              \
+       (elm)->field.cqe_prev = (listelm);                              \
+       if ((listelm)->field.cqe_next == (void *)(head))                \
+               (head)->cqh_last = (elm);                               \
+       else                                                            \
+               (listelm)->field.cqe_next->field.cqe_prev = (elm);      \
+       (listelm)->field.cqe_next = (elm);                              \
+} while (0)
+
+#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do {           \
+       CIRCLEQ_CHECK_PREV(head, listelm, field);                       \
+       (elm)->field.cqe_next = (listelm);                              \
+       (elm)->field.cqe_prev = (listelm)->field.cqe_prev;              \
+       if ((listelm)->field.cqe_prev == (void *)(head))                \
+               (head)->cqh_first = (elm);                              \
+       else                                                            \
+               (listelm)->field.cqe_prev->field.cqe_next = (elm);      \
+       (listelm)->field.cqe_prev = (elm);                              \
+} while (0)
+
+#define CIRCLEQ_INSERT_HEAD(head, elm, field) do {                      \
+       CIRCLEQ_CHECK_HEAD(head, field);                                \
+       (elm)->field.cqe_next = (head)->cqh_first;                      \
+       (elm)->field.cqe_prev = (void *)(head);                         \
+       if ((head)->cqh_last == (void *)(head))                         \
+               (head)->cqh_last = (elm);                               \
+       else                                                            \
+               (head)->cqh_first->field.cqe_prev = (elm);              \
+       (head)->cqh_first = (elm);                                      \
+} while (0)
+
+#define CIRCLEQ_INSERT_TAIL(head, elm, field) do {                      \
+       (elm)->field.cqe_next = (void *)(head);                         \
+       (elm)->field.cqe_prev = (head)->cqh_last;                       \
+       if ((head)->cqh_first == (void *)(head))                        \
+               (head)->cqh_first = (elm);                              \
+       else                                                            \
+               (head)->cqh_last->field.cqe_next = (elm);               \
+       (head)->cqh_last = (elm);                                       \
 } while (0)
 
 #define CIRCLEQ_LAST(head) ((head)->cqh_last)
 
-#define CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next)
+#define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next)
 
-#define CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev)
+#define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev)
 
-#define        CIRCLEQ_REMOVE(head, elm, field) do {                           \
-        CIRCLEQ_CHECK_NEXT(head, elm, field);                          \
-        CIRCLEQ_CHECK_PREV(head, elm, field);                          \
-       if ((elm)->field.cqe_next == (void *)(head))                    \
-               (head)->cqh_last = (elm)->field.cqe_prev;               \
-       else                                                            \
-               (elm)->field.cqe_next->field.cqe_prev =                 \
-                   (elm)->field.cqe_prev;                              \
-       if ((elm)->field.cqe_prev == (void *)(head))                    \
-               (head)->cqh_first = (elm)->field.cqe_next;              \
-       else                                                            \
-               (elm)->field.cqe_prev->field.cqe_next =                 \
-                   (elm)->field.cqe_next;                              \
+#define CIRCLEQ_REMOVE(head, elm, field) do {                           \
+       CIRCLEQ_CHECK_NEXT(head, elm, field);                           \
+       CIRCLEQ_CHECK_PREV(head, elm, field);                           \
+       if ((elm)->field.cqe_next == (void *)(head))                    \
+               (head)->cqh_last = (elm)->field.cqe_prev;               \
+       else                                                            \
+               (elm)->field.cqe_next->field.cqe_prev =                 \
+                   (elm)->field.cqe_prev;                              \
+       if ((elm)->field.cqe_prev == (void *)(head))                    \
+               (head)->cqh_first = (elm)->field.cqe_next;              \
+       else                                                            \
+               (elm)->field.cqe_prev->field.cqe_next =                 \
+                   (elm)->field.cqe_next;                              \
 } while (0)
 
 #ifdef _KERNEL
@@ -879,21 +963,21 @@ struct quehead {
 static __inline void
 chkquenext(void *a)
 {
-       struct quehead *element = (struct quehead *)a;
-       if (__improbable(element->qh_link != NULL &&
-                           element->qh_link->qh_rlink != element)) {
-             panic("Bad que elm %p next->prev != elm", a);
-       }
+       struct quehead *element = (struct quehead *)a;
+       if (__improbable(element->qh_link != NULL &&
+           element->qh_link->qh_rlink != element)) {
+               panic("Bad que elm %p next->prev != elm", a);
+       }
 }
 
 static __inline void
 chkqueprev(void *a)
 {
-       struct quehead *element = (struct quehead *)a;
-       if (__improbable(element->qh_rlink != NULL &&
-                           element->qh_rlink->qh_link != element)) {
-             panic("Bad que elm %p prev->next != elm", a);
-       }
+       struct quehead *element = (struct quehead *)a;
+       if (__improbable(element->qh_rlink != NULL &&
+           element->qh_rlink->qh_link != element)) {
+               panic("Bad que elm %p prev->next != elm", a);
+       }
 }
 #else /* !KERNEL_PRIVATE */
 #define chkquenext(a)
@@ -904,7 +988,7 @@ static __inline void
 insque(void *a, void *b)
 {
        struct quehead *element = (struct quehead *)a,
-                *head = (struct quehead *)b;
+           *head = (struct quehead *)b;
        chkquenext(head);
 
        element->qh_link = head->qh_link;
@@ -927,8 +1011,8 @@ remque(void *a)
 
 #else /* !__GNUC__ */
 
-void   insque(void *a, void *b);
-void   remque(void *a);
+void    insque(void *a, void *b);
+void    remque(void *a);
 
 #endif /* __GNUC__ */