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[216.180.64.156]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7fbcc22ca48sm5862141a12.51.2024.11.25.08.48.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 Nov 2024 08:48:09 -0800 (PST) Message-ID: Date: Mon, 25 Nov 2024 08:48:09 -0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Supporting clang on windows Content-Language: en-US To: Thomas Huth , Paolo Bonzini , =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= Cc: "qemu-devel@nongnu.org" , =?UTF-8?Q?Alex_Benn=C3=A9e?= , Richard Henderson , Peter Maydell References: <66c346de-7e20-4831-b3eb-1cda83240af9@linaro.org> <05108195-009e-4d06-bc79-065b1e3432ed@redhat.com> From: Pierrick Bouvier In-Reply-To: <05108195-009e-4d06-bc79-065b1e3432ed@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::533; envelope-from=pierrick.bouvier@linaro.org; helo=mail-pg1-x533.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Thanks everyone for your valuable feedback on this, and taking time to give more rationale about the previous position you had. On 11/25/24 03:19, Thomas Huth wrote: > > So fine for me if we allow compiling with Clang on Windows now, but we > should make sure to avoid that those problems are sneaking in again. So > Pierrick, please provide a patch to docs/devel/style.rst to say that we > disallow bitfields in packed structs in future contributions. Then I think > it's ok to remove the gcc_struct from QEMU_PACKED. (Just my 2 cents, of course) > > Thomas > I just compared windows binaries with/without gcc_struct, and as Thomas found for qemu linux binaries using pahole, there is no difference with or without gcc_struct, so the attribute is unused now. In case you want to check that by yourself, I uploaded binaries and dwarf info on this repo: https://github.com/pbo-linaro/qemu_packed_structs (gcc_attribute has gcc_struct binaries, gcc_no_attribute_no_option has binaries without it). Before sending the a series removing gcc_struct and editing the documentation, do we all agree here it's the right move forward? If yes, should we apply this to 9.2 release? Thanks, Pierrick