Em Mon, 17 May 2021 23:13:45 +0100
Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx> escreveu:
> Ah, yes I should have been clearer there - but they don't do 'anything'
> except the bare minimum for both:
>
> ----------
> kbingham@Q:/opt/projects/media/v4l-utils$ cat make-autoconf.sh
> #!/bin/sh
>
> export CCACHE_DISABLE=true
>
> rm -rf build-autoconf
> mkdir -p build-autoconf
> cd build-autoconf
> ../configure
This is not the bare minimum. It is just the opposite: the way we
intentionally implemented configure.ac is to auto-detect as much as possible
what tools are supported and to build the maximum number of features as
possible.
See, when one calls:
$ ./configure
It will display at the end the optional features that were enabled
that we found important enough to report:
compile time options summary
============================
Host OS : linux-gnu
X11 : yes
GL : yes
glu : yes
libelf : yes
libjpeg : yes
libudev : yes
pthread : yes
QT version : v5.4 with QtGL
ALSA support : yes
SDL support : yes
build dynamic libs : yes
build static libs : yes
gconv : no
dynamic libv4l : yes
v4l_plugins : yes
v4l_wrappers : yes
libdvbv5 : yes
dvbv5-daemon : yes
v4lutils : yes
qv4l2 : yes
qvidcap : yes
v4l2-ctl uses libv4l : yes
v4l2-ctl-32 : no
v4l2-compliance : yes
v4l2-compliance uses libv4l: yes
v4l2-compliance-32 : no
BPF IR Decoders: : no
a bare minimum setting would print most (if not all) above features
as "no".
See, we never treated internationalization or documentation as
features. So, it won't display anything about that. It will just
build docs and .po files by default, if the needed tools and
libraries are present at the building system.
Yet, autotools have some options that could disable building them.
./configure --help is your friend[1], if you want a bare minimum
build.
[1] You can see most of the options that can be enabled/disabled with:
./configure --help|grep -E '(enable|disable|with)'
The command would be similar to:
./configure --disable-nls --disable-libdvbv5 --disable-dyn-libv4l --disable-v4l-utils --disable-v4l2-compliance-libv4l --disable-v4l2-ctl-libv4l --disable-qv4l2 --disable-qvidcap --disable-bpf --without-jpeg --without-libudev --disable-gconv --disable-doxygen-doc --disable-doxygen-dot --disable-doxygen-html --disable-doxygen-ps --disable-doxygen-pdf
here, after running the above, building with autoconf was very fast.
$ make clean
$ time CCACHE_DISABLE=true make -j8
real 0m4,594s
user 0m14,050s
sys 0m1,613s
> meson build-meson
> ninja -C build-meson
I would be expecting that the above would do the same, but
it sounds it is lacking a lot of things...
> >> du -sh build-autoconf build-meson/
> >> 129M build-autoconf
> >> 69M build-meson/
as otherwise the difference won't be so huge.
See, you're comparing very different things, as autotools is clearly
doing a lot more than meson. If they were building the same thing, I
would expect a difference at the order of tens of KB at most, due to
temporary/cache files, build logs and, in the case of autotools, m4
files. Neither of those are huge.
Assuming that both builds used the same compilers, a difference at
the order of (tens of) MB can only be explained if Meson build
was very incomplete, and/or the output files don't carry the same
debug info.
Thanks,
Mauro
