Re: btrfs-progs-v4.12: cross compiling

[David Sterba <dsterba@suse.cz>]

On Tue, Aug 15, 2017 at 02:44:07PM +0200, Hallo32 wrote:
> Am 15.08.2017 um 01:39 schrieb Qu Wenruo:
> > On 2017年08月15日 02:57, Goffredo Baroncelli wrote:
> >> On 08/14/2017 05:10 PM, David Sterba wrote:
> >>> On Mon, Aug 14, 2017 at 10:14:42PM +0800, Qu Wenruo wrote:
> >> [...]
> >>> mktables.c is synced from kernel sources, taking updates from there is
> >>> easier than porting any changes to the proposed scripted 
> >>> implementation.
> >>>
> >>> The workflow is simple:
> >>> - copy kernel mktables.c changes to btrfs-progs mktables.c
> >>
> >> How the kernel deals with this kind of problem ?
> >> Looking at the source of btrfs Makefile, it is more simple to replace
> >>
> >>    mktables: kernel-lib/mktables.c
> >>          @echo "    [CC]     $@"
> >>          $(Q)$(CC) $(CFLAGS) $< -o $@
> >>
> >> with
> >>
> >>
> >>    mktables: kernel-lib/mktables.c
> >>          @echo "    [HOSTCC] $@"
> >>          $(Q)$(HOSTCC) $(CFLAGS) $< -o $@
> >>
> >> where HOSTCC is defined as
> >>
> >> HOSTCC=gcc
> >>
> >>
> >> (may be the same applied also to CFLAGS <-> HOSTCFLAGS ?)
> >
> > If using HOSTCC then I'm fine with it.
> 
> CFLAGS needs also be replaced by something like HOSTCFLAGS, because if 
> you use something like mips/architecture specific CFLAGS, they may be 
> not applicably on the host system.

Good point. Without a regular/automated cross-compilation build testing
I think we could break it quite easily. I'm going to keep the
pregenerated file in git.