Even though many of those scripts are very simple, it is easier to include
the header than to try to say whether each of those files is trivial enough
not to require one.
vcs_tag() is slow. When the version-tag meson option is set,
we can use configure_file() directly to speed up incremental
builds.
Before (with version-tag set to v247):
```
‣ Running build script...
[1/418] Generating version.h with a custom command
real 0m0.521s
user 0m0.229s
sys 0m0.067s
```
After (with version-tag set to v247):
```
‣ Running build script...
ninja: no work to do.
real 0m0.094s
user 0m0.048s
sys 0m0.022s
```
As in 2a5fcfae02
and in 3e67e5c992
using /usr/bin/env allows bash to be looked up in PATH
rather than being hard-coded.
As with the previous changes the same arguments apply
- distributions have scripts to rewrite shebangs on installation and
they know what locations to rely on.
- For tests/compilation we should rather rely on the user to have setup
there PATH correctly.
In particular this makes testing from git easier on NixOS where do not provide
/bin/bash to improve compose-ability.
When build from release tarball and where there is parent .git dir,
this situtaion will get wrong version info. (build with buildroot)
The systemd running show wrong version in dmesg log:
systemd[1]: systemd 2019.02-1086-gf5f17c4 running in system mode.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Shoule be:
systemd[1]: systemd 241 running in system mode. (-PAM -AUDIT -SEL
^^^^^^^^^^^
We had all kinds of indentation: 2 sp, 3 sp, 4 sp, 8 sp, and mixed.
4 sp was the most common, in particular the majority of scripts under test/
used that. Let's standarize on 4 sp, because many commandlines are long and
there's a lot of nesting, and with 8sp indentation less stuff fits. 4 sp
also seems to be the default indentation, so this will make it less likely
that people will mess up if they don't load the editor config. (I think people
often use vi, and vi has no support to load project-wide configuration
automatically. We distribute a .vimrc file, but it is not loaded by default,
and even the instructions in it seem to discourage its use for security
reasons.)
Also remove the few vim config lines that were left. We should either have them
on all files, or none.
Also remove some strange stuff like '#!/bin/env bash', yikes.
This will be useful when building distro packages, because we can set the
version string to the rpm/dpkg/whatever version string, and getter reports
from end users.
$ build/systemctl --version
systemd 239-3555-g6178cbb5b5
+PAM +AUDIT +SELINUX +IMA -APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN +PCRE2 default-hierarchy=hybrid
$ git tag v240 -m 'v240'
$ ninja -C build
ninja: Entering directory `build'
[76/76] Linking target fuzz-unit-file.
$ build/systemctl --version
systemd 240
+PAM +AUDIT +SELINUX +IMA -APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN +PCRE2 default-hierarchy=hybrid
This is very useful during development, because a precise version string is
embedded in the build product and displayed during boot, so we don't have to
guess answers for questions like "did I just boot the latest version or the one
from before?".
This change creates an overhead for "noop" builds. On my laptop, 'ninja -C
build' that does nothing goes from 0.1 to 0.5 s. It would be nice to avoid
this, but I think that <1 s is still acceptable.
Fixes#7183.
PACKAGE_VERSION is renamed to GIT_VERSION, to make it obvious that this is the
more dynamically changing version string.
Why save to a file? It would be easy to generate the version tag using
run_command(), but we want to go through a file so that stuff gets rebuilt when
this file changes. If we just defined an variable in meson, ninja wouldn't know
it needs to rebuild things.
