Re: [PATCH 2/2] Remove the CIRCLEQ API
On Sun, 11 Oct 2020, Kamil Rytarowski wrote: It was marked deprecated in NetBSD 7 and already removed from FreeBSD in 2000 and OpenBSD in 2015. --- share/man/man3/queue.3 | 10 +++ sys/sys/queue.h| 196 - 2 files changed, 10 insertions(+), 196 deletions(-) diff --git a/share/man/man3/queue.3 b/share/man/man3/queue.3 index 4293090986d4..359c772e5439 100644 --- a/share/man/man3/queue.3 +++ b/share/man/man3/queue.3 @@ -1091,3 +1091,13 @@ and .Nm STAILQ functions first appeared in .Fx 2.1.5 . +.Pp +The +.Nm CIRCLEQ +functions first appeared in +.Bx 4.4 +and were deprecated in +.Nx 7 +and removed in +.Nx 10 +due to the pointer aliasing violations. Please reword this slightly. Instead of and and use , , and . diff --git a/sys/sys/queue.h b/sys/sys/queue.h index 5764c7a98a53..ec686364126b 100644 --- a/sys/sys/queue.h +++ b/sys/sys/queue.h @@ -69,14 +69,6 @@ * after an existing element, at the head of the list, or at the end of * the list. A tail queue may be traversed in either direction. * - * A circle queue is headed by a pair of pointers, one to the head of the - * list and the other to the tail of the list. The elements are doubly - * linked so that an arbitrary element can be removed without a need to - * traverse the list. New elements can be added to the list before or after - * an existing element, at the head of the list, or at the end of the list. - * A circle queue may be traversed in either direction, but has a more - * complex end of list detection. - * * For details on the use of these macros, see the queue(3) manual page. */ @@ -663,192 +655,4 @@ struct { \ ((struct type *)(void *)\ ((char *)((head)->stqh_last) - offsetof(struct type, field - -#ifndef _KERNEL -/* - * Circular queue definitions. Do not use. We still keep the macros - * for compatibility but because of pointer aliasing issues their use - * is discouraged! - */ - -/* - * __launder_type(): We use this ugly hack to work around the compiler - * noticing that two types may not alias each other and elide tests in code. - * We hit this in the CIRCLEQ macros when comparing 'struct name *' and - * 'struct type *' (see CIRCLEQ_HEAD()). Modern compilers (such as GCC - * 4.8) declare these comparisons as always false, causing the code to - * not run as designed. - * - * This hack is only to be used for comparisons and thus can be fully const. - * Do not use for assignment. - * - * If we ever choose to change the ABI of the CIRCLEQ macros, we could fix - * this by changing the head/tail sentinal values, but see the note above - * this one. - */ -static __inline const void * __launder_type(const void *); -static __inline const void * -__launder_type(const void *__x) -{ - __asm __volatile("" : "+r" (__x)); - return __x; -} - -#if defined(QUEUEDEBUG) -#define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) \ - if ((head)->cqh_first != CIRCLEQ_ENDC(head) && \ - (head)->cqh_first->field.cqe_prev != CIRCLEQ_ENDC(head)) \ - QUEUEDEBUG_ABORT("CIRCLEQ head forw %p %s:%d", (head),\ - __FILE__, __LINE__); \ - if ((head)->cqh_last != CIRCLEQ_ENDC(head) &&\ - (head)->cqh_last->field.cqe_next != CIRCLEQ_ENDC(head)) \ - QUEUEDEBUG_ABORT("CIRCLEQ head back %p %s:%d", (head),\ - __FILE__, __LINE__); -#define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) \ - if ((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) { \ - if ((head)->cqh_last != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm last %p %s:%d", \ - (elm), __FILE__, __LINE__); \ - } else {\ - if ((elm)->field.cqe_next->field.cqe_prev != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm forw %p %s:%d", \ - (elm), __FILE__, __LINE__); \ - } \ - if ((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) { \ - if ((head)->cqh_first != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm first %p %s:%d",\ - (elm), __FILE__, __LINE__); \ - } else {\ - if ((elm)->field.cqe_prev->field.cqe_next != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm prev %p %s:%d", \ - (elm), __FILE__, __LINE__); \ - }
[PATCH 2/2] Remove the CIRCLEQ API
It was marked deprecated in NetBSD 7 and already removed from FreeBSD in 2000 and OpenBSD in 2015. --- share/man/man3/queue.3 | 10 +++ sys/sys/queue.h| 196 - 2 files changed, 10 insertions(+), 196 deletions(-) diff --git a/share/man/man3/queue.3 b/share/man/man3/queue.3 index 4293090986d4..359c772e5439 100644 --- a/share/man/man3/queue.3 +++ b/share/man/man3/queue.3 @@ -1091,3 +1091,13 @@ and .Nm STAILQ functions first appeared in .Fx 2.1.5 . +.Pp +The +.Nm CIRCLEQ +functions first appeared in +.Bx 4.4 +and were deprecated in +.Nx 7 +and removed in +.Nx 10 +due to the pointer aliasing violations. diff --git a/sys/sys/queue.h b/sys/sys/queue.h index 5764c7a98a53..ec686364126b 100644 --- a/sys/sys/queue.h +++ b/sys/sys/queue.h @@ -69,14 +69,6 @@ * after an existing element, at the head of the list, or at the end of * the list. A tail queue may be traversed in either direction. * - * A circle queue is headed by a pair of pointers, one to the head of the - * list and the other to the tail of the list. The elements are doubly - * linked so that an arbitrary element can be removed without a need to - * traverse the list. New elements can be added to the list before or after - * an existing element, at the head of the list, or at the end of the list. - * A circle queue may be traversed in either direction, but has a more - * complex end of list detection. - * * For details on the use of these macros, see the queue(3) manual page. */ @@ -663,192 +655,4 @@ struct { \ ((struct type *)(void *)\ ((char *)((head)->stqh_last) - offsetof(struct type, field - -#ifndef _KERNEL -/* - * Circular queue definitions. Do not use. We still keep the macros - * for compatibility but because of pointer aliasing issues their use - * is discouraged! - */ - -/* - * __launder_type(): We use this ugly hack to work around the compiler - * noticing that two types may not alias each other and elide tests in code. - * We hit this in the CIRCLEQ macros when comparing 'struct name *' and - * 'struct type *' (see CIRCLEQ_HEAD()). Modern compilers (such as GCC - * 4.8) declare these comparisons as always false, causing the code to - * not run as designed. - * - * This hack is only to be used for comparisons and thus can be fully const. - * Do not use for assignment. - * - * If we ever choose to change the ABI of the CIRCLEQ macros, we could fix - * this by changing the head/tail sentinal values, but see the note above - * this one. - */ -static __inline const void * __launder_type(const void *); -static __inline const void * -__launder_type(const void *__x) -{ - __asm __volatile("" : "+r" (__x)); - return __x; -} - -#if defined(QUEUEDEBUG) -#define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) \ - if ((head)->cqh_first != CIRCLEQ_ENDC(head) && \ - (head)->cqh_first->field.cqe_prev != CIRCLEQ_ENDC(head))\ - QUEUEDEBUG_ABORT("CIRCLEQ head forw %p %s:%d", (head), \ - __FILE__, __LINE__); \ - if ((head)->cqh_last != CIRCLEQ_ENDC(head) && \ - (head)->cqh_last->field.cqe_next != CIRCLEQ_ENDC(head)) \ - QUEUEDEBUG_ABORT("CIRCLEQ head back %p %s:%d", (head), \ - __FILE__, __LINE__); -#define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) \ - if ((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) { \ - if ((head)->cqh_last != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm last %p %s:%d", \ - (elm), __FILE__, __LINE__); \ - } else {\ - if ((elm)->field.cqe_next->field.cqe_prev != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm forw %p %s:%d", \ - (elm), __FILE__, __LINE__); \ - } \ - if ((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) { \ - if ((head)->cqh_first != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm first %p %s:%d", \ - (elm), __FILE__, __LINE__); \ - } else {\ - if ((elm)->field.cqe_prev->field.cqe_next != (elm)) \ - QUEUEDEBUG_ABORT("CIRCLEQ elm prev %p %s:%d", \ - (elm), __FILE__, __LINE__); \ - } -#define QUEUEDEBUG_CIRCLEQ_POSTREMOVE(elm, field) \ - (elm)->field.cqe_next = (void *)1L; \ -