{"id":3050,"url":"https://patchwork.libcamera.org/api/patches/3050/?format=json","web_url":"https://patchwork.libcamera.org/patch/3050/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","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/people/2/?format=json","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/series/713/?format=json","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":"","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 ;\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 ;\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 ","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":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","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(&storage_);\n\nFix it and simplify the code at the same time.\n\nSigned-off-by: Laurent Pinchart \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(&storage_);\n-\t\tstorage_ = 0;\n+\tif (size > sizeof(value_)) {\n+\t\tdelete[] reinterpret_cast(storage_);\n+\t\tstorage_ = nullptr;\n \t}\n }\n \n@@ -176,9 +176,9 @@ ControlValue &ControlValue::operator=(const ControlValue &other)\n Span 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(&storage_)\n-\t\t\t : reinterpret_cast(&storage_);\n+\tconst uint8_t *data = size > sizeof(value_)\n+\t\t\t ? reinterpret_cast(storage_)\n+\t\t\t : reinterpret_cast(&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(new char[size]);\n-\t\t*reinterpret_cast(&storage_) = storage;\n+\tif (size > sizeof(value_)) {\n+\t\tstorage_ = reinterpret_cast(new uint8_t[size]);\n+\t\tstorage = storage_;\n \t} else {\n-\t\tstorage = reinterpret_cast(&storage_);\n+\t\tstorage = reinterpret_cast(&value_);\n \t}\n \n \tmemcpy(storage, data, size);\n","prefixes":["libcamera-devel"]}