On Fri, Jan 28, 2022 at 2:45 PM Fangrui Song <maskray@xxxxxxxxxx> wrote: > > On 2022-01-28, Elliot Berman wrote: > >Allow additional arguments be passed to userprogs compilation. > >Reproducible clang builds need to provide a sysroot and gcc path to > >ensure same toolchain is used across hosts. KCFLAGS is not currently > >used for any user programs compilation, so add new USERCFLAGS and > >USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS. > > > >Specifically, I'm trying to force CC_CAN_LINK to consistently fail in > >an environment where a user sysroot is not specifically available. > >Currently, Clang might automatically detect GCC installation on hosts > >which have it installed to a default location in /. With addition of > >these environment variables, you can specify flags such as: > > > >$ make USERCFLAGS=--sysroot=/dev/null USERLDFLAGS=-Wl,--sysroot=/dev/null > > > >to force sysroot detection to fail. > > -Wl,--sysroot=/dev/null => --sysroot > > As I mentioned in > https://lore.kernel.org/all/20220128031549.w5a4bilxbkppagfu@xxxxxxxxxx/ > -Wl,--sysroot=/dev/null does not suppress search paths like -L/lib . In that case, Elliot, can you please test whether USERLDFLAGS is necessary to be specified AT ALL? Maybe we can drop that addition from this patch if so? -- Thanks, ~Nick Desaulniers
