Re: [Qemu-devel] [PATCH 2/2] Makefile: Derive "PKGVERSION" from "git describe" by default

[Fam Zheng <famz@redhat.com>]

On Tue, 05/31 21:05, Eric Blake wrote:
> On 05/31/2016 07:31 PM, Fam Zheng wrote:
> > Currently, if not specified in "./configure", QEMU_PKGVERSION will be
> > empty. Write a rule in Makefile to generate a value from "git describe"
> > combined with a possible git tree cleanness suffix, and write into a new
> > header.
> > 
> >     $ cat qemu-version.h
> >     #define QEMU_PKGVERSION "-v2.6.0-557-gd6550e9-unclean"
> > 
> > Include the header in .c files where the macro is referenced. It's not
> > necessary to include it in all files, otherwise each time the content of
> > the file changes, all sources have to be recompiled.
> > 
> > Signed-off-by: Fam Zheng <famz@redhat.com>
> > ---
> 
> > +qemu-version.h: FORCE
> > +	$(call quiet-command, \
> > +		(cd $(SRC_PATH); \
> 
> Can CDPATH interfere with this one?

I think SRC_PATH is either an absolute path, or is ".". Both cases are fine.

> 
> > +		echo -n '#define QEMU_PKGVERSION '; \
> 
> 'echo -n' is non-portable, use printf instead.

Will fix.

> 
> > +		if test -n "$(PKGVERSION)"; then \
> > +			echo '"$(PKGVERSION)"'; \
> > +		else \
> > +			echo -n '"-'; \
> 
> And again
> 
> > +			if ! git status &>/dev/null; then \
> > +				echo -n "no-git"; \
> 
> and again
> 
> > +			else \
> > +				git describe 2>/dev/null | tr -d '\n'; \
> > +				if ! git diff-index --quiet HEAD &>/dev/null; then \
> > +					echo -n '-unclean'; \
> 
> and again
> 
> Why -unclean instead of -dirty?

The non-native speaker can fix that.

> 
> > +				fi \
> > +			fi; \
> > +			echo '"'; \
> > +		fi) > $@.tmp)
> > +	$(call quiet-command, cmp --quiet $@ $@.tmp || mv $@.tmp $@)
> > +
> 
> 
> -- 
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
> 

Thanks,

Fam