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GET /api/1.1/patches/3050/?format=api
{ "id": 3050, "url": "https://patchwork.libcamera.org/api/1.1/patches/3050/?format=api", "web_url": "https://patchwork.libcamera.org/patch/3050/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20200307212530.28053-3-laurent.pinchart@ideasonboard.com>", "date": "2020-03-07T21:25:30", "name": "[libcamera-devel] libcamera: controls: Fix strict aliasing violation", "commit_ref": "4de31ccc9ef47e7b16330d226d071d5d006faa6d", "pull_url": null, "state": "accepted", "archived": false, "hash": "a5048a837cf8af4d20f2b9e2c83ab18da29963ea", "submitter": { "id": 2, "url": "https://patchwork.libcamera.org/api/1.1/people/2/?format=api", "name": "Laurent Pinchart", "email": "laurent.pinchart@ideasonboard.com" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/3050/mbox/", "series": [ { "id": 713, "url": "https://patchwork.libcamera.org/api/1.1/series/713/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=713", "date": "2020-03-07T21:25:30", "name": "[libcamera-devel] libcamera: controls: Fix strict aliasing violation", "version": 1, "mbox": "https://patchwork.libcamera.org/series/713/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/3050/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/3050/checks/", "tags": {}, "headers": { "Return-Path": "<laurent.pinchart@ideasonboard.com>", "Received": [ "from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 2B50E62826\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tSat, 7 Mar 2020 22:25:40 +0100 (CET)", "from pendragon.bb.dnainternet.fi (81-175-216-236.bb.dnainternet.fi\n\t[81.175.216.236])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 503C95F\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tSat, 7 Mar 2020 22:25:39 +0100 (CET)" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1583616339;\n\tbh=17xULLXdk8vMH42M8QNCjRRyt2Lg0y7FvBTn8cBIG4Q=;\n\th=From:To:Subject:Date:From;\n\tb=Bh5uxbgGDjE78X18WjNqkiTlF+l5EO25YHwCK7QzKf1KBIhiEOFtCsWpIQ4XqarRn\n\t+FeckY0n8Dj/dxAii7bTU2/tP67ozAsvsobn6BJ1UG2ZNTo93Tjg3XfDqvF+gPQwux\n\tCrl3TUdnPbNu/iNWTrHuKm/FCQzyjqqpWvzOgt2M=", "From": "Laurent Pinchart <laurent.pinchart@ideasonboard.com>", "To": "libcamera-devel@lists.libcamera.org", "Date": "Sat, 7 Mar 2020 23:25:30 +0200", "Message-Id": "<20200307212530.28053-3-laurent.pinchart@ideasonboard.com>", "X-Mailer": "git-send-email 2.24.1", "MIME-Version": "1.0", "Content-Type": "text/plain; charset=UTF-8", "Content-Transfer-Encoding": "8bit", "Subject": "[libcamera-devel] [PATCH] libcamera: controls: Fix strict aliasing\n\tviolation", "X-BeenThere": "libcamera-devel@lists.libcamera.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "X-List-Received-Date": "Sat, 07 Mar 2020 21:25:40 -0000" }, "content": "gcc 8.3.0 for ARM complains about strict aliasing violations:\n\n../../src/libcamera/controls.cpp: In member function ‘void libcamera::ControlValue::release()’:\n../../src/libcamera/controls.cpp:111:13: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]\n delete[] *reinterpret_cast<char **>(&storage_);\n\nFix it and simplify the code at the same time.\n\nSigned-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>\n---\n include/libcamera/controls.h | 5 ++++-\n src/libcamera/controls.cpp | 20 ++++++++++----------\n 2 files changed, 14 insertions(+), 11 deletions(-)", "diff": "diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h\nindex 4767e2d3fc8c..0e111ab72bce 100644\n--- a/include/libcamera/controls.h\n+++ b/include/libcamera/controls.h\n@@ -160,7 +160,10 @@ private:\n \tControlType type_ : 8;\n \tbool isArray_ : 1;\n \tstd::size_t numElements_ : 16;\n-\tuint64_t storage_;\n+\tunion {\n+\t\tuint64_t value_;\n+\t\tvoid *storage_;\n+\t};\n \n \tvoid release();\n \tvoid set(ControlType type, bool isArray, const void *data,\ndiff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp\nindex 94bdbdd9c388..4326174adf86 100644\n--- a/src/libcamera/controls.cpp\n+++ b/src/libcamera/controls.cpp\n@@ -107,9 +107,9 @@ void ControlValue::release()\n {\n \tstd::size_t size = numElements_ * ControlValueSize[type_];\n \n-\tif (size > sizeof(storage_)) {\n-\t\tdelete[] *reinterpret_cast<char **>(&storage_);\n-\t\tstorage_ = 0;\n+\tif (size > sizeof(value_)) {\n+\t\tdelete[] reinterpret_cast<uint8_t *>(storage_);\n+\t\tstorage_ = nullptr;\n \t}\n }\n \n@@ -176,9 +176,9 @@ ControlValue &ControlValue::operator=(const ControlValue &other)\n Span<const uint8_t> ControlValue::data() const\n {\n \tstd::size_t size = numElements_ * ControlValueSize[type_];\n-\tconst uint8_t *data = size > sizeof(storage_)\n-\t\t\t ? *reinterpret_cast<const uint8_t * const *>(&storage_)\n-\t\t\t : reinterpret_cast<const uint8_t *>(&storage_);\n+\tconst uint8_t *data = size > sizeof(value_)\n+\t\t\t ? reinterpret_cast<const uint8_t *>(storage_)\n+\t\t\t : reinterpret_cast<const uint8_t *>(&value_);\n \treturn { data, size };\n }\n \n@@ -308,11 +308,11 @@ void ControlValue::set(ControlType type, bool isArray, const void *data,\n \tstd::size_t size = elementSize * numElements;\n \tvoid *storage;\n \n-\tif (size > sizeof(storage_)) {\n-\t\tstorage = reinterpret_cast<void *>(new char[size]);\n-\t\t*reinterpret_cast<void **>(&storage_) = storage;\n+\tif (size > sizeof(value_)) {\n+\t\tstorage_ = reinterpret_cast<void *>(new uint8_t[size]);\n+\t\tstorage = storage_;\n \t} else {\n-\t\tstorage = reinterpret_cast<void *>(&storage_);\n+\t\tstorage = reinterpret_cast<void *>(&value_);\n \t}\n \n \tmemcpy(storage, data, size);\n", "prefixes": [ "libcamera-devel" ] }