On 15.10.2021 18:29, Anthony PERARD wrote: > On Thu, Oct 14, 2021 at 10:51:44AM +0200, Jan Beulich wrote: >> On 24.08.2021 12:50, Anthony PERARD wrote: >>> --- a/xen/arch/arm/efi/Makefile >>> +++ b/xen/arch/arm/efi/Makefile >>> @@ -1,4 +1,10 @@ >>> CFLAGS-y += -fshort-wchar >>> +CFLAGS-y += -I$(srctree)/common/efi >> >> Perhaps another opportunity for -iquote? > > Yes. > >>> obj-y += boot.init.o pe.init.o ebmalloc.o runtime.o >>> obj-$(CONFIG_ACPI) += efi-dom0.init.o >>> + >>> +$(obj)/%.c: common/efi/%.c >>> + $(Q)cp -f $< $@ >> >> In case both trees are on the same file system, trying to hardlink first >> would seem desirable. When copying, I think you should also pass -p. > > I don't know if doing an hardlink is a good thing to do, I'm not sure of > the kind of issue this could bring. As for -p, I don't think it's a good > idea to copy the mode, ownership, and timestamps of the source file, I'd > rather have the timestamps that Make expect, e.i. "now".
Why would "now" be correct (or expected) in any way? The cloned file is no different from the original. Nevertheless I agree that -p is not ideal; it's just that the more fine grained option to preserve just the timestamp is non-standard afaik. You could try that first and fall back to -p ... Otherwise, failing hard linking and using "cp -p", I'm afraid I'd prefer symlinking despite the arguments against it that you name in the description. Might be good to have someone else's view here as well. Jan
