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 7A1264603A; Sat, 18 Jan 2025 03:46:37 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 8BCC140E15; Sat, 18 Jan 2025 03:46:26 +0100 (CET) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mails.dpdk.org (Postfix) with ESMTP id 436DE40298 for ; Sat, 18 Jan 2025 03:46:23 +0100 (CET) Received: by linux.microsoft.com (Postfix, from userid 1213) id 4595420BEBFC; Fri, 17 Jan 2025 18:46:22 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 4595420BEBFC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1737168382; bh=82VR/cb0gC9ufH+bAjhoxS7qzpVk52gXHfjqQQzD944=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CYUk6HaVfmMpKKeWnfQhcYEcUkaCHwUmkzZ9StLZMUcTS4dofHS7zlpArjISsZQjp w7OimCREvABNefda9gLgnnyfXkWUzLS1NcfLY21nheCCGDgMNeebVGUcDwAB0M9NeL dVMwHq/5t8HkhwYT/dJFvntr79My9F/Xv9agfnjY= From: Andre Muezerie To: andremue@linux.microsoft.com Cc: dev@dpdk.org, stephen@networkplumber.org, bruce.richardson@intel.com Subject: [PATCH v14 1/3] eal: add diagnostics macros to make code portable Date: Fri, 17 Jan 2025 18:46:11 -0800 Message-Id: <1737168373-25364-2-git-send-email-andremue@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1737168373-25364-1-git-send-email-andremue@linux.microsoft.com> References: <1735263196-2809-1-git-send-email-andremue@linux.microsoft.com> <1737168373-25364-1-git-send-email-andremue@linux.microsoft.com> X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org It was a common pattern to have "GCC diagnostic ignored" pragmas sprinkled over the code and only activate these pragmas for certain compilers (gcc and clang). Clang supports GCC's pragma for compatibility with existing source code, so #pragma GCC diagnostic and #pragma clang diagnostic are synonyms for Clang (https://clang.llvm.org/docs/UsersManual.html). Now that effort is being made to make the code compatible with MSVC these expressions would become more complex. It makes sense to hide this complexity behind macros. This makes maintenance easier as these macros are defined in a single place. As a plus the code becomes more readable as well. Signed-off-by: Andre Muezerie --- lib/eal/include/rte_common.h | 50 ++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/lib/eal/include/rte_common.h b/lib/eal/include/rte_common.h index 40592f71b1..26da7a7476 100644 --- a/lib/eal/include/rte_common.h +++ b/lib/eal/include/rte_common.h @@ -156,6 +156,56 @@ typedef uint16_t unaligned_uint16_t; #define RTE_DEPRECATED(x) #endif +/** + * Macros to cause the compiler to remember the state of the diagnostics as of + * each push, and restore to that point at each pop. + */ +#if !defined(__INTEL_COMPILER) && !defined(RTE_TOOLCHAIN_MSVC) +#define __rte_diagnostic_push _Pragma("GCC diagnostic push") +#define __rte_diagnostic_pop _Pragma("GCC diagnostic pop") +#else +#define __rte_diagnostic_push +#define __rte_diagnostic_pop +#endif + +/** + * Macro to disable compiler warnings about removing a type + * qualifier from the target type. + */ +#if !defined(__INTEL_COMPILER) && !defined(RTE_TOOLCHAIN_MSVC) +#define __rte_diagnostic_ignored_wcast_qual \ + _Pragma("GCC diagnostic ignored \"-Wcast-qual\"") +#else +#define __rte_diagnostic_ignored_wcast_qual +#endif + +/** + * Workaround to discard qualifiers (such as const, volatile, restrict) from a pointer, + * without the compiler emitting a warning. + * + * Once the project uses C23, the definition below can be used instead + * (-Wcast-qual will emit a warning with this new definition though) + * #define RTE_PTR_UNQUAL(X) ((typeof_unqual(*X)*)(X)) + */ +#define RTE_PTR_UNQUAL(X) ((void *)(uintptr_t)(X)) + +/** + * Workaround to discard qualifiers (such as const, volatile, restrict) from a pointer + * and cast it to a specific type, without the compiler emitting a warning. + * + * @warning + * Although this macro can be abused for casting a pointer to point to a different type, + * alignment may be incorrect when casting to point to a larger type. E.g.: + * struct s { + * uint16_t a; + * uint8_t b; + * uint8_t c; + * uint8_t d; + * } v; + * uint16_t * p = RTE_CAST_PTR(uint16_t *, &v.c); // "p" is not 16 bit aligned! + */ +#define RTE_CAST_PTR(type, ptr) ((type)(uintptr_t)(ptr)) + /** * Mark a function or variable to a weak reference. */ -- 2.47.2.vfs.0.1