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Tsirkin" , Cornelia Huck , Paolo Bonzini , =?UTF-8?B?TWljaGFsIFByw612b3puw61r?= , qemu-devel@nongnu.org References: <20220908080749.32211-1-chenyi.qiang@intel.com> <20220908080749.32211-3-chenyi.qiang@intel.com> From: Richard Henderson In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::32f; envelope-from=richard.henderson@linaro.org; helo=mail-wm1-x32f.google.com X-Spam_score_int: -52 X-Spam_score: -5.3 X-Spam_bar: ----- X-Spam_report: (-5.3 / 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, NICE_REPLY_A=-3.142, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" On 9/8/22 10:09, Daniel P. Berrangé wrote: > 'kvm_msrs info' is variable in size, so offset of 'entries[1]' is > undefined by C99. I presume the GNU defined semantics are that the > variable length 'entries[]' field in 'info' is zero-sized, in order > to give predictable offset for 'entries[1]' in the local msr_data. Correct. I invented this gcc extension for the benefit of glibc, which wanted to append N entries to that header, in static storage no less. I still find it odd that clang warns about a gnu extension when gnu extensions are requested via -std=gnu*. r~