Meson is a modern build system that has seen a rise in adoption and some
version of it is available in almost every platform supported.
Compared to automake, meson has the following advantages:
* Meson provides a significant boost to the build and configuration time
by better exploiting parallelism.
* Meson is subjectively considered to be better in readability.
These merits alone justify experimenting with meson as a way of
improving development time and ergonomics. However, there are some
compromises to ensure the transition goes relatively smooth:
* The system tests currently rely on various files within the source
directory. Changing this requirement is a non-trivial task that can't
be currently justified. Currently the last compiled build directory
writes into the source tree which is in turn used by pytest.
* The minimum version supported has been fixed at 0.61. Increasing this
value will require choosing a baseline of distributions that can
package with meson. On the contrary, there will likely be an attempt
to decrease this value to ensure almost universal support for building
BIND 9 with meson.
The lock-file configuration (both from configuration file and -X
argument to named) has better alternatives nowadays. Modern process
supervisor should be used to ensure that a single named process is
running on a given configuration.
Alternatively, it's possible to wrap the named with flock(1).
All changes in this commit were automated using the command:
shfmt -w -i 2 -ci -bn . $(find . -name "*.sh.in")
By default, only *.sh and files without extension are checked, so
*.sh.in files have to be added additionally. (See mvdan/sh#944)
The script will start the named process configured as both an
authoritative and recursive server for each pairwise ./configure
configuration. The test is considered successful if the named process
runs until the 5-second timeout is triggered, and there is no named.lock
file present, indicating that named did not crash on shutdown.
This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
Removing stderr from the pict tool serves no purpose and drops valuable
information, we might use when debugging failed pairwise CI job, such
as:
Input Error: A parameter names must be unique
The --enable-option-checking=fatal option prevents ./configure from
proceeding when an unknown option is used in the ./configure step in CI.
This change will avoid adding unsupported ./configure options or options
with typo or typo in pairwise testing "# [pairwise: ...]" marker.
The size of the log generated by each GitLab CI job is limited to 4 MB
by default. While this limit is configurable, it makes little sense to
print build logs to standard output if they are being captured to files
anyway. Limit use of "tee" in util/pairwise-testing.sh to printing the
combination of configure switches used for a given build. This way the
job should never exceed the default 4 MB log size limit, yet it will
still indicate its progress in a concise way.
Pairwise testing is a test case generation technique based on the
observation that most faults are caused by interactions of at most two
factors. For BIND, its configure options can be thought of as such
factors.
Process BIND configure options into a model that is subsequently
processed by the PICT tool in order to find an effective test vector.
That test vector is then used for configuring and building BIND using
various combinations of configure options.
