[PATCH v6 1/6] eal: provide rte stdatomics optional atomics API

[David Marchand]

On Fri, Sep 29, 2023 at 10:54 AM Morten Brørup <mb at smartsharesystems.com> wrote:
> In my opinion, our move to C11 thus makes RTE_BUILD_BUG_ON obsolete.

That's my thought too.

>
> We should mark RTE_BUILD_BUG_ON as deprecated, and disallow RTE_BUILD_BUG_ON in new code. Perhaps checkpatches could catch this?

For a clear deprecation of a part of DPDK API, I don't see a need to
add something in checkpatch.
Putting a RTE_DEPRECATED in RTE_BUILD_BUG_ON directly triggers a build
warning (caught by CI since we run with Werror).


diff --git a/lib/eal/include/rte_common.h b/lib/eal/include/rte_common.h
index 771c70f2c8..40542629c1 100644
--- a/lib/eal/include/rte_common.h
+++ b/lib/eal/include/rte_common.h
@@ -495,7 +495,7 @@ rte_is_aligned(const void * const __rte_restrict
ptr, const unsigned int align)
 /**
  * Triggers an error at compilation time if the condition is true.
  */
-#define RTE_BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
+#define RTE_BUILD_BUG_ON(condition) RTE_DEPRECATED(RTE_BUILD_BUG_ON)
((void)sizeof(char[1 - 2*!!(condition)]))

 /*********** Cache line related macros ********/



$ ninja -C build-mini
...
[18/333] Compiling C object lib/librte_eal.a.p/eal_common_eal_common_trace.c.o
../lib/eal/common/eal_common_trace.c: In function ‘eal_trace_init’:
../lib/eal/common/eal_common_trace.c:44:20: warning:
"RTE_BUILD_BUG_ON" is deprecated
   44 |         RTE_BUILD_BUG_ON((offsetof(struct __rte_trace_header,
mem) % 8) != 0);
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[38/333] Compiling C object lib/librte_eal.a.p/eal_common_malloc_heap.c.o
../lib/eal/common/malloc_heap.c: In function ‘malloc_heap_destroy’:
../lib/eal/common/malloc_heap.c:1398:20: warning: "RTE_BUILD_BUG_ON"
is deprecated
 1398 |         RTE_BUILD_BUG_ON(offsetof(struct malloc_heap, lock) != 0);
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[50/333] Compiling C object lib/librte_eal.a.p/eal_unix_rte_thread.c.o
../lib/eal/unix/rte_thread.c: In function ‘rte_thread_self’:
../lib/eal/unix/rte_thread.c:239:20: warning: "RTE_BUILD_BUG_ON" is deprecated
  239 |         RTE_BUILD_BUG_ON(sizeof(pthread_t) > sizeof(uintptr_t));
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


-- 
David Marchand