From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 8955046D66 for ; Tue, 19 Aug 2025 13:26:29 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 833BD40144; Tue, 19 Aug 2025 13:26:29 +0200 (CEST) Received: from dpdk.org (dpdk.org [92.243.24.197]) by mails.dpdk.org (Postfix) with ESMTP id C8CB740144 for ; Tue, 19 Aug 2025 13:26:28 +0200 (CEST) Received: by dpdk.org (Postfix, from userid 65534) id 1C649123FC6; Tue, 19 Aug 2025 13:24:10 +0200 (CEST) Subject: |WARNING| pw156001 [PATCH v3 2/2] virtio: simplify use of pragmas In-Reply-To: <20250819112521.1608207-2-bruce.richardson@intel.com> References: <20250819112521.1608207-2-bruce.richardson@intel.com> To: test-report@dpdk.org From: checkpatch@dpdk.org Cc: Bruce Richardson Message-Id: <20250819112410.1C649123FC6@dpdk.org> Date: Tue, 19 Aug 2025 13:24:10 +0200 (CEST) X-BeenThere: test-report@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: automatic DPDK test reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: test-report-bounces@dpdk.org Test-Label: checkpatch Test-Status: WARNING http://dpdk.org/patch/156001 _coding style issues_ CHECK:CAMELCASE: Avoid CamelCase: <_Pragma> #120: FILE: drivers/net/virtio/virtio_rxtx_packed.h:74: +#define virtio_for_each_try_unroll(iter, val, size) _Pragma("GCC unroll 4") \ ERROR:COMPLEX_MACRO: Macros with complex values should be enclosed in parentheses #120: FILE: drivers/net/virtio/virtio_rxtx_packed.h:74: +#define virtio_for_each_try_unroll(iter, val, size) _Pragma("GCC unroll 4") \ for (iter = val; iter < size; iter++) BUT SEE: do {} while (0) advice is over-stated in a few situations: The more obvious case is macros, like MODULE_PARM_DESC, invoked at file-scope, where C disallows code (it must be in functions). See $exceptions if you have one to add by name. More troublesome is declarative macros used at top of new scope, like DECLARE_PER_CPU. These might just compile with a do-while-0 wrapper, but would be incorrect. Most of these are handled by detecting struct,union,etc declaration primitives in $exceptions. Theres also macros called inside an if (block), which "return" an expression. These cannot do-while, and need a ({}) wrapper. Enjoy this qualification while we work to improve our heuristics. CHECK:MACRO_ARG_REUSE: Macro argument reuse 'iter' - possible side-effects? #120: FILE: drivers/net/virtio/virtio_rxtx_packed.h:74: +#define virtio_for_each_try_unroll(iter, val, size) _Pragma("GCC unroll 4") \ for (iter = val; iter < size; iter++) CHECK:MACRO_ARG_PRECEDENCE: Macro argument 'size' may be better as '(size)' to avoid precedence issues #120: FILE: drivers/net/virtio/virtio_rxtx_packed.h:74: +#define virtio_for_each_try_unroll(iter, val, size) _Pragma("GCC unroll 4") \ for (iter = val; iter < size; iter++) CHECK:MACRO_ARG_REUSE: Macro argument reuse 'iter' - possible side-effects? #123: FILE: drivers/net/virtio/virtio_rxtx_packed.h:77: +#define virtio_for_each_try_unroll(iter, val, num) \ + for (iter = val; iter < num; iter++) CHECK:MACRO_ARG_PRECEDENCE: Macro argument 'num' may be better as '(num)' to avoid precedence issues #123: FILE: drivers/net/virtio/virtio_rxtx_packed.h:77: +#define virtio_for_each_try_unroll(iter, val, num) \ + for (iter = val; iter < num; iter++) ERROR:COMPLEX_MACRO: Macros with complex values should be enclosed in parentheses #165: FILE: lib/vhost/vhost.h:76: +#define vhost_for_each_try_unroll(iter, val, size) _Pragma("GCC unroll 4") \ + for (iter = val; iter < size; iter++) BUT SEE: do {} while (0) advice is over-stated in a few situations: The more obvious case is macros, like MODULE_PARM_DESC, invoked at file-scope, where C disallows code (it must be in functions). See $exceptions if you have one to add by name. More troublesome is declarative macros used at top of new scope, like DECLARE_PER_CPU. These might just compile with a do-while-0 wrapper, but would be incorrect. Most of these are handled by detecting struct,union,etc declaration primitives in $exceptions. Theres also macros called inside an if (block), which "return" an expression. These cannot do-while, and need a ({}) wrapper. Enjoy this qualification while we work to improve our heuristics. total: 2 errors, 0 warnings, 69 lines checked