On Tue, 12 Jan 2021, Paul Ramsey wrote:
On Jan 11, 2021, at 1:09 AM, Roger Bivand <roger.biv...@nhh.no> wrote:
Cmake proponents: apart from the reservations raised by packagers, why for me
does rm -rf _build not lead to
mkdir _build && cd _build && cmake .. && make
taking the same time when repeated compare to the first time through? What else
do I need to delete to distclean the previous build? Is what I am seeing from
searching correct, that cmake squirrels stuff away and does not offer any
distclean to zero the build completely?
How can one be sure that stale stuff is not hanging around when using cmake ..
in an empty _build in the local git repo
All build changes/output are confined to the build directory. You can put it in
_build in the source dir. Or you can be even more isolated (this is what I do)
and put it literally to the side of the source dir. I have
$CODE/geos-git
$CODE/geos-git-build
in my working area.
You can prove it to yourself:
wget http://download.osgeo.org/geos/geos-3.9.0.tar.bz2
tar xvfj geos-3.9.0.tar.bz2
du -sk > ../before_sz.txt
# 23368
find . > ../before.txt
mkdir _build
cmake ..
time make
# 674.13s
rm -rf _build
du -sk > ../after_sz.txt
# 23368
find . > ../after.txt
diff ../before ../after
cat ../before_sz.txt ../after_sz.txt
wget http://download.osgeo.org/geos/geos-3.9.0.tar.bz2
tar xvfj geos-3.9.0.tar.bz2
du -sk > ../before_sz.txt
find . > ../before.txt
mkdir _build
cd _build
cmake ../geos-3.9.0
time make
# real 10m28.376s
# user 8m35.684s
# sys 0m51.954s
cd ..
rm -rf _build
du -sk > ../after_sz.txt
find . > ../after.txt
diff ../before.txt ../after.txt
cat ../before_sz.txt ../after_sz.txt
# 28640 .
# 28640 .
mkdir _build
cd _build
cmake ../geos-3.9.0
time make
# real 0m12.127s
# user 0m8.169s
# sys 0m3.701s
rm -rf _build
(log out and reboot system)
mkdir _build
cd _build
cmake ../geos-3.9.0
time make
# real 0m12.358s
# user 0m8.308s
# sys 0m3.393s
The ouput objects are being cached somewhere, and survive a reboot. They
are not in the Gnome wastebasket either (rm doesn't put them there).
Roger
Nothing is added to the source dir. The file list is identical before
and after. If you're building out-of-tree, the equivalent of 'make
distclean' is 'rm -rf $BUILDDIR`
P.
--
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; e-mail: roger.biv...@nhh.no
https://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
_______________________________________________
geos-devel mailing list
geos-devel@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/geos-devel
