From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f68.google.com (mail-wm0-f68.google.com [74.125.82.68]) by dpdk.org (Postfix) with ESMTP id A17EA20F for ; Mon, 21 Nov 2016 17:57:05 +0100 (CET) Received: by mail-wm0-f68.google.com with SMTP id u144so543999wmu.0 for ; Mon, 21 Nov 2016 08:57:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id; bh=T+rKJB7dzdFzk0/b3hpq3AO6pmHz3NP5abxSAH4N4w0=; b=PzsGFMHVD9yTnQoknJtQ1WmdvNfdASiULEVPLjTgb5ziPeampxrqzcn0XXelGuAiGI wk68/TOJOCNxL20HlrmecVsL3H4WYsCHmRSW7s9pXgIo/rYUrEk3HCd/KEB1MeWQ/7Zz 3aFFFSk5fP1YGMajDsTCBWhcDT7SOgxhnX4jrLOSKWGD7wrozovSXizSvuvXGI78WIHE VJF+80rV9ojE0ORNpedXxVkyarOnshhd5y6fR4Ndrp7VBf/pAfRe/GTXGgibwHBuq6PK 2MvDHqmneSWWyxyha/zJzH/ttsUJIKu0Qnj489Gyb0HbjlZB+PnOHnuhCJg8NLS6loVK B3+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id; bh=T+rKJB7dzdFzk0/b3hpq3AO6pmHz3NP5abxSAH4N4w0=; b=T9iOMT6O+YtHkMLiYCA+b3/cizrCVAlP1lRH5jo7NVPksIhDgmvtiN+ajLhU338lx5 qvIXPSU6xKQCh4E8nxZLqhszn59Ml3g4cbcGu2zX6zn0nnz/CkpJzwrsB7DcCd2rcAGm WERzb6vL5TMTkMUzSefIUnBlGwkDqSjaZM17o7LWJV31YeRDPD7dTiyXISUu4NqyLZLz Kh5Iln5y+fVtmxeUwGjbEJ9z0qm0yh588ptz0pqs9pbs1ar+KOS64PytfoajgGhUMVDd oHZKQQ2o6/Zf/VY3ymDswx4O5wyOpk+BXKlUeMZxzJUynyJXq6iP+MrK/Gz9LGFS7sZd z0/Q== X-Gm-Message-State: AKaTC00GVtIS3vJy8GDXh+/HC3ubpXxiobVLIUxiNl/i0nTmZzbhIw12pNHh50FwjH4BxA== X-Received: by 10.28.126.146 with SMTP id z140mr18035634wmc.84.1479747425249; Mon, 21 Nov 2016 08:57:05 -0800 (PST) Received: from weierstrass.local.net ([91.200.110.70]) by smtp.gmail.com with ESMTPSA id v202sm20536051wmv.8.2016.11.21.08.57.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 Nov 2016 08:57:04 -0800 (PST) Sender: Jan Blunck From: Jan Blunck To: dev@dpdk.org Cc: shreyansh.jain@nxp.com, david.marchand@6wind.com, Jan Viktorin Date: Mon, 21 Nov 2016 17:55:15 +0100 Message-Id: <1479747322-5774-1-git-send-email-jblunck@infradead.org> X-Mailer: git-send-email 2.7.4 Subject: [dpdk-dev] [PATCH v2 1/8] eal: define container_of macro X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Nov 2016 16:57:05 -0000 This macro is based on Jan Viktorin's original patch but also checks the type of the passed pointer against the type of the member. Signed-off-by: Jan Viktorin Signed-off-by: Shreyansh Jain [jblunck@infradead.org: add type checking and __extension__] Signed-off-by: Jan Blunck --- lib/librte_eal/common/include/rte_common.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h index db5ac91..8dda3e2 100644 --- a/lib/librte_eal/common/include/rte_common.h +++ b/lib/librte_eal/common/include/rte_common.h @@ -331,6 +331,26 @@ rte_bsf32(uint32_t v) #define offsetof(TYPE, MEMBER) __builtin_offsetof (TYPE, MEMBER) #endif +/** + * Return pointer to the wrapping struct instance. + * + * Example: + * + * struct wrapper { + * ... + * struct child c; + * ... + * }; + * + * struct child *x = obtain(...); + * struct wrapper *w = container_of(x, struct wrapper, c); + */ +#ifndef container_of +#define container_of(ptr, type, member) __extension__ ({ \ + typeof(((type *)0)->member) *_ptr = (ptr); \ + (type *)(((char *)_ptr) - offsetof(type, member)); }) +#endif + #define _RTE_STR(x) #x /** Take a macro value and get a string version of it */ #define RTE_STR(x) _RTE_STR(x) -- 2.7.4