Improve prep_buildtree
Since I started using meson regularly, I have put the build directory
under the source directory, which appears to be the recommended
convention. See for example
https://mesonbuild.com/Quick-guide.html#compiling-a-meson-project
Then, if I also want to create a build directory using configure/make in
parallel to that (for example, to test the makefiles, if adding new
source files), then prep_buildtree is a bit stupid about that. It
processes all directories under the top-level source directory,
including existing other build trees, and so it makes a copy of existing
build trees under the new build tree. This isn't actually harmful, but
it seems pretty stupid, and it also makes prep_buildtree slower and
slower the more build trees you have.
I have never been much of a vpath user before meson, so I don't have
much experience with it, but I suspect that it was previously the
convention to have the build tree outside of the source tree, in which
case this wouldn't have been a problem.
To fix this, I first tried to devise a way to detect whether a given
directory is a build directory. But that seemed pretty complicated.
Instead, I chose the simpler solution that we just enumerate the source
subdirectories that we know about (config, contrib, doc, src). That way
we can also remove the special handling to exclude the .git directory
and make the find command a bit simpler.
See the attached patch.
Maybe people can try this with their local workflows to make sure it
still works for them, but I don't expect any particular problems, other
than perhaps some shell or find command portability issues. Note, this
only runs if you do a vpath configure/make build, not an in-tree
configure/make build, and of course not if you use meson.
Attachments:
0001-Improve-prep_buildtree.patchtext/plain; charset=UTF-8; name=0001-Improve-prep_buildtree.patchDownload+2-7
Hi,
Thank you for working on this!
On Wed, 30 Jul 2025 at 11:07, Peter Eisentraut <peter@eisentraut.org> wrote:
To fix this, I first tried to devise a way to detect whether a given
directory is a build directory. But that seemed pretty complicated.
Instead, I chose the simpler solution that we just enumerate the source
subdirectories that we know about (config, contrib, doc, src). That way
we can also remove the special handling to exclude the .git directory
and make the find command a bit simpler.
Meson looks for ${builddir}/meson-private/coredata.dat file to
understand if the directory is a build directory [1]https://github.com/mesonbuild/meson/blob/b4d32763940ae67d1ed36952112b3d94ba9f03a7/mesonbuild/mcompile.py#L30C1-L35C82. I am just
wondering if you tried this and found it complicated or did you try
something else.
--
Regards,
Nazir Bilal Yavuz
Microsoft
On 30.07.25 10:28, Nazir Bilal Yavuz wrote:
On Wed, 30 Jul 2025 at 11:07, Peter Eisentraut <peter@eisentraut.org> wrote:
To fix this, I first tried to devise a way to detect whether a given
directory is a build directory. But that seemed pretty complicated.
Instead, I chose the simpler solution that we just enumerate the source
subdirectories that we know about (config, contrib, doc, src). That way
we can also remove the special handling to exclude the .git directory
and make the find command a bit simpler.Meson looks for ${builddir}/meson-private/coredata.dat file to
understand if the directory is a build directory [1]. I am just
wondering if you tried this and found it complicated or did you try
something else.
I tried things along this line, but it's not easy to have a shell "find"
command handle that kind of logic.
Hi,
On Wed, 30 Jul 2025 at 12:32, Peter Eisentraut <peter@eisentraut.org> wrote:
On 30.07.25 10:28, Nazir Bilal Yavuz wrote:
On Wed, 30 Jul 2025 at 11:07, Peter Eisentraut <peter@eisentraut.org> wrote:
To fix this, I first tried to devise a way to detect whether a given
directory is a build directory. But that seemed pretty complicated.
Instead, I chose the simpler solution that we just enumerate the source
subdirectories that we know about (config, contrib, doc, src). That way
we can also remove the special handling to exclude the .git directory
and make the find command a bit simpler.Meson looks for ${builddir}/meson-private/coredata.dat file to
understand if the directory is a build directory [1]. I am just
wondering if you tried this and found it complicated or did you try
something else.I tried things along this line, but it's not easy to have a shell "find"
command handle that kind of logic.
That makes sense. I noticed one difference, patched prep_buildtree
does not create a symbolic link for the top Makefile in the builddir.
--
Regards,
Nazir Bilal Yavuz
Microsoft
Peter Eisentraut <peter@eisentraut.org> writes:
On 30.07.25 10:28, Nazir Bilal Yavuz wrote:
Meson looks for ${builddir}/meson-private/coredata.dat file to
understand if the directory is a build directory [1]. I am just
wondering if you tried this and found it complicated or did you try
something else.
I tried things along this line, but it's not easy to have a shell "find"
command handle that kind of logic.
For this purpose, I think it's better for us to rely on things we
control than things Meson controls. Adding a new top-level directory
is rare enough that I don't see a problem with needing to update
prep_buildtree.
regards, tom lane
On Wed, Jul 30, 2025 at 6:35 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
For this purpose, I think it's better for us to rely on things we
control than things Meson controls. Adding a new top-level directory
is rare enough that I don't see a problem with needing to update
prep_buildtree.
+1. (This approach should also keep prep_buildtree from recursing into
my git worktrees and vpaths, so I'm excited to give it a try!)
--Jacob
On 30.07.25 12:58, Nazir Bilal Yavuz wrote:
Hi,
On Wed, 30 Jul 2025 at 12:32, Peter Eisentraut <peter@eisentraut.org> wrote:
On 30.07.25 10:28, Nazir Bilal Yavuz wrote:
On Wed, 30 Jul 2025 at 11:07, Peter Eisentraut <peter@eisentraut.org> wrote:
To fix this, I first tried to devise a way to detect whether a given
directory is a build directory. But that seemed pretty complicated.
Instead, I chose the simpler solution that we just enumerate the source
subdirectories that we know about (config, contrib, doc, src). That way
we can also remove the special handling to exclude the .git directory
and make the find command a bit simpler.Meson looks for ${builddir}/meson-private/coredata.dat file to
understand if the directory is a build directory [1]. I am just
wondering if you tried this and found it complicated or did you try
something else.I tried things along this line, but it's not easy to have a shell "find"
command handle that kind of logic.That makes sense. I noticed one difference, patched prep_buildtree
does not create a symbolic link for the top Makefile in the builddir.
Ok, here is an updated version that takes care of that, too.
Attachments:
v2-0001-Improve-prep_buildtree.patchtext/plain; charset=UTF-8; name=v2-0001-Improve-prep_buildtree.patchDownload+2-7
Hi,
On Wed, 30 Jul 2025 at 21:56, Peter Eisentraut <peter@eisentraut.org> wrote:
On 30.07.25 12:58, Nazir Bilal Yavuz wrote:
That makes sense. I noticed one difference, patched prep_buildtree
does not create a symbolic link for the top Makefile in the builddir.Ok, here is an updated version that takes care of that, too.
Thanks. v2 LGTM.
--
Regards,
Nazir Bilal Yavuz
Microsoft
On 31.07.25 09:24, Nazir Bilal Yavuz wrote:
On Wed, 30 Jul 2025 at 21:56, Peter Eisentraut <peter@eisentraut.org> wrote:
On 30.07.25 12:58, Nazir Bilal Yavuz wrote:
That makes sense. I noticed one difference, patched prep_buildtree
does not create a symbolic link for the top Makefile in the builddir.Ok, here is an updated version that takes care of that, too.
Thanks. v2 LGTM.
committed