Re: [Qemu-devel] PO makefile rules touching source

[Stefan Weil <sw@weilnetz.de>]

Am 06.08.2015 um 13:54 schrieb Dr. David Alan Gilbert:
> Hi Stefan,
>    I don't really understand the way PO stuff is supposed to work,
> but I often get the problem that my git tree gets changed during
> an out of tree build, causing the po subdirectory to be
> dirtied.
>
> I think this is due to the rule:
>
> $(PO_PATH)/%.po: $(PO_PATH)/messages.po
>          $(call quiet-command, msgmerge -q $@ $< > $@.bak && mv $@.bak $@, "  GEN   $@")
>
> in po/Makefile.
>
> Why does that merge into $(PO_PATH)/%.po rather than %.po - i.e.
> why to the source rather than to the build directory?
>
> Dave
>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Hi Dave,

the *.po files are initially generated, then manually
enhanced by the translated texts.

Each time when there are modifications to the
related source file (for QEMU: ui/gtk.c), the *.po
files need updates, too (new or removed texts,
but most often changes of line numbers).

That's why I have sent a patch to update the
*.po files for QEMU 2.4.0. With this patch
(which is still not applied), you would not
get changes when doing a complete build
because *.po files and ui/gtk.c would match.

As long as there is the mismatch, you'll
get modified *.po files when running
"make install". I usually handle this case
by running "git diff po|patch -p1 -R"
which removes the *.po modifications.

Stefan