Re: [PATCH] virhostcpu: Fix build with clang and newest kernel headers

On Tue, Aug 23, 2022 at 04:15:54PM +0200, Peter Krempa wrote: > The most recent environment e.g. present in our Fedora Rawhide builds > fail to build the tree with clang with the following error: > > ../src/util/virhostcpu.c:1291:25: error: field 'header' with variable sized type 'struct kvm_msrs' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct kvm_msrs header; > ^ > > The problem seems to be that clang doesn't like the new way the > 'entries' field in struct kvm_msrs is declared. > > To work around the issue we can simply allocate the variable dynamically > and use the 'entries' member as it was intended to to access the > members. We explicitly only support GCC and CLang, and intentionally rely on many GNU extensions to C. CLang is trying to be helpful to people who need fully portable C code, but we don't care about that. So why not just turn off the warning by adding -Wno-gnu-variable-sized-style-not-at-end better than making our code less understandable IMHO