On Tue, Nov 12, 2024 at 7:45 PM Miguel Ojeda <ojeda@xxxxxxxxxx> wrote: > > From: HONG Yifan <elsk@xxxxxxxxxx> > > These are flags to be passed when linking proc macros for the Rust > toolchain. If unset, it defaults to $(KBUILD_HOSTLDFLAGS). > > This is needed because the list of flags to link hostprogs is not > necessarily the same as the list of flags used to link libmacros.so. > When we build proc macros, we need the latter, not the former (e.g. when > using a Rust compiler binary linked to a different C library than host > programs). > > To distinguish between the two, introduce this new variable to stand > out from KBUILD_HOSTLDFLAGS used to link other host progs. > > Signed-off-by: HONG Yifan <elsk@xxxxxxxxxx> > Link: https://lore.kernel.org/r/20241017210430.2401398-2-elsk@xxxxxxxxxx > [ v3: > > - `export`ed the variable. Otherwise it would not be visible in > `rust/Makefile`. Despite the missing export, the previous version worked for us too. I'm not sure why that is. > - Removed "additional" from the documentation and commit message, > since this actually replaces the other flags, unlike other cases. > > - Added example of use case to documentation and commit message. > Thanks Alice for the details on what Google needs! > > - Instead of `HOSTLDFLAGS`, used `KBUILD_HOSTLDFLAGS` as the fallback > to preserve the previous behavior as much as possible, as discussed > with Alice/Yifan. Thus moved the variable down too (currently we > do not modify `KBUILD_HOSTLDFLAGS` elsewhere) and avoided > mentioning `HOSTLDFLAGS` directly in the documentation. > > - Fixed documentation header formatting. > > - Reworded slightly. > > - Miguel ] > Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Tested-by: Alice Ryhl <aliceryhl@xxxxxxxxxx> Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>