From patchwork Sat Mar 7 21:25:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 3050 Return-Path: Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 2B50E62826 for ; Sat, 7 Mar 2020 22:25:40 +0100 (CET) Received: from pendragon.bb.dnainternet.fi (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 503C95F for ; Sat, 7 Mar 2020 22:25:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1583616339; bh=17xULLXdk8vMH42M8QNCjRRyt2Lg0y7FvBTn8cBIG4Q=; h=From:To:Subject:Date:From; b=Bh5uxbgGDjE78X18WjNqkiTlF+l5EO25YHwCK7QzKf1KBIhiEOFtCsWpIQ4XqarRn +FeckY0n8Dj/dxAii7bTU2/tP67ozAsvsobn6BJ1UG2ZNTo93Tjg3XfDqvF+gPQwux Crl3TUdnPbNu/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 Subject: [libcamera-devel] [PATCH] libcamera: controls: Fix strict aliasing violation X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 07 Mar 2020 21:25:40 -0000 gcc 8.3.0 for ARM complains about strict aliasing violations: ../../src/libcamera/controls.cpp: In member function ‘void libcamera::ControlValue::release()’: ../../src/libcamera/controls.cpp:111:13: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] delete[] *reinterpret_cast(&storage_); Fix it and simplify the code at the same time. Signed-off-by: Laurent Pinchart Reviewed-by: Kieran Bingham --- include/libcamera/controls.h | 5 ++++- src/libcamera/controls.cpp | 20 ++++++++++---------- 2 files changed, 14 insertions(+), 11 deletions(-) diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h index 4767e2d3fc8c..0e111ab72bce 100644 --- a/include/libcamera/controls.h +++ b/include/libcamera/controls.h @@ -160,7 +160,10 @@ private: ControlType type_ : 8; bool isArray_ : 1; std::size_t numElements_ : 16; - uint64_t storage_; + union { + uint64_t value_; + void *storage_; + }; void release(); void set(ControlType type, bool isArray, const void *data, diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp index 94bdbdd9c388..4326174adf86 100644 --- a/src/libcamera/controls.cpp +++ b/src/libcamera/controls.cpp @@ -107,9 +107,9 @@ void ControlValue::release() { std::size_t size = numElements_ * ControlValueSize[type_]; - if (size > sizeof(storage_)) { - delete[] *reinterpret_cast(&storage_); - storage_ = 0; + if (size > sizeof(value_)) { + delete[] reinterpret_cast(storage_); + storage_ = nullptr; } } @@ -176,9 +176,9 @@ ControlValue &ControlValue::operator=(const ControlValue &other) Span ControlValue::data() const { std::size_t size = numElements_ * ControlValueSize[type_]; - const uint8_t *data = size > sizeof(storage_) - ? *reinterpret_cast(&storage_) - : reinterpret_cast(&storage_); + const uint8_t *data = size > sizeof(value_) + ? reinterpret_cast(storage_) + : reinterpret_cast(&value_); return { data, size }; } @@ -308,11 +308,11 @@ void ControlValue::set(ControlType type, bool isArray, const void *data, std::size_t size = elementSize * numElements; void *storage; - if (size > sizeof(storage_)) { - storage = reinterpret_cast(new char[size]); - *reinterpret_cast(&storage_) = storage; + if (size > sizeof(value_)) { + storage_ = reinterpret_cast(new uint8_t[size]); + storage = storage_; } else { - storage = reinterpret_cast(&storage_); + storage = reinterpret_cast(&value_); } memcpy(storage, data, size);