Commit Graph

10 Commits (b28fb93e51a94907eca9cc08eb1a2db51fe1ddc8)

Author SHA1 Message Date
Patrick Steinhardt 5419445b4d Documentation: wire up sanity checks for Meson
Wire up sanity checks for Meson to verify that no man pages are missing.
This check is similar to the same check we already have for our tests.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:12 -08:00
Patrick Steinhardt 7a3136e5c7 meson: install static files for HTML documentation
Now that we generate man pages, articles and user manual with Meson the
only thing that is still missing in an installation of HTML documents is
a couple of static files. Wire these up to finalize Meson's support for
generating HTML documentation.

Diffing an installation that uses our Makefile with an installation that
uses Meson only surfaces a couple of discepancies now:

  - Meson doesn't install "everyday.html" and "git-remote-helpers.html".
    These files are marked as obsolete and don't contain any useful
    information anymore: they simply point to their modern equivalents.

  - Meson doesn't install "*.txt" files when asking for HTML docs. I'm
    not sure why our Makefiles do this in the first place, and it does
    seem like the resulting installation is fully functional even
    without those files.

Other than that, both layout and file contents are the exact same.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:11 -08:00
Patrick Steinhardt bcf7edee09 meson: generate articles
While the Meson build system already knows to generate man pages and our
user manual, it does not yet generate the random assortment of articles
that we have. Plug this gap.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:11 -08:00
Patrick Steinhardt ae0b33939d meson: generate user manual
Our documentation contains a user manual that gives people a short
introduction to Git. Our Makefile knows to generate the manual into
three different formats: an HTML page, a PDF and an info page. The Meson
build instructions don't yet generate any of these.

While wiring up all these formats I hit a couple of road blocks with how
we generate our info pages. Even though I eventually resolved these, it
made me question whether anybody actually uses info pages in the first
place. Checking through a couple of downstream consumers I couldn't find
a single user of either the info pages nor of our PDF manual in Arch
Linux, Debian, Fedora, Ubuntu, FreeBSD or OpenBSDFedora. So it's rather
safe to assume that there aren't really any users out there, and thus
the added complexity does not seem worth it.

Wire up support for building the user manual in HTML format and
conciously skip over the other two formats. This is basically a form of
silent deprecation: if people out there use the other two formats they
will eventually complain about them missing in Meson, which means we can
wire them up at a later point. If they don't we can phase out these
formats eventually.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:10 -08:00
Patrick Steinhardt 0696ebe9ce meson: generate HTML pages for all man page categories
When generating HTML pages for our man pages we only generate them for
category 1 in Meson, which are the pages corresponding to our built-in
commands. I cannot tell why I added this filter though: our Makefile
installs all man pages, so a Meson-based build misses out on many of
them.

Fix this by removing the filter.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:10 -08:00
Patrick Steinhardt b88540045c meson: fix generation of merge tools
Our buildsystems generate a list of diff and merge tools that ultimately
end up in our documentation. And while Meson does wire up the logic, it
tries to use the TOOL_MODE environment variable to set up the mode. This
is wrong though: the mode is set via an argument that we have fixed to
'diff' mode by accident.

Fix this such that merge tools are properly generated.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:09 -08:00
Patrick Steinhardt 2a8bd34c55 meson: properly wire up dependencies for our docs
A couple of Meson documentation targets use `meson.current_source_dir()`
to resolve inputs. This has the downside that it does not automagically
make Meson track these inputs as a dependency. After all, string
arguments really can be anything, even if they happen to match an actual
filesystem path.

Adapt these build targets to instead use inputs.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:09 -08:00
Patrick Steinhardt d838d821c9 meson: wire up support for AsciiDoctor
While our Makefile supports both Asciidoc and AsciiDoctor, our Meson
build instructions only support the former. Wire up support for the
latter, as well.

Our Makefile always favors Asciidoc, but Meson will automatically figure
out which of both to use based on whether they are installed or not. To
keep compatibility with our Makefile it favors Asciidoc over Asciidoctor
in case both are available.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:09 -08:00
Patrick Steinhardt 1bc815c3d0 meson: add options to override build information
We inject various different kinds of build information into build
artifacts, like the version string or the commit from which Git was
built. Add options to let users explicitly override this information
with Meson.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 12:36:46 -08:00
Patrick Steinhardt 904339edbd Introduce support for the Meson build system
Introduce support for the Meson build system, a "modern" meta build
system that supports many different platforms, including Linux, macOS,
Windows and BSDs. Meson supports different backends, including Ninja,
Xcode and Microsoft Visual Studio. Several common IDEs provide an
integration with it.

The biggest contender compared to Meson is probably CMake as outlined in
our "Documentation/technical/build-systems.txt" file. Based on my own
personal experience from working with both build systems extensively I
strongly favor Meson over CMake. In my opinion, it feels significantly
easier to use with a syntax that feels more like a "real" programming
language. The second big reason is that Meson supports Rust natively,
which may prove to be important given that the project may pick up Rust
as another language eventually.

Using Meson is rather straight-forward. An example:

    ```
    # Meson uses out-of-tree builds. You can set up multiple build
    # directories, how you name them is completely up to you.
    $ mkdir build
    $ cd build
    $ meson setup .. -Dprefix=/tmp/git-installation

    # Build the project. This also provides several other targets like
    e.g. `install` or `test`.
    $ ninja

    # Meson has been wired up to support execution of our test suites.
    # Both our unit tests and our integration tests are supported.
    # Running `meson test` without any arguments will execute all tests,
    # but the syntax supports globbing to select only some tests.
    $ meson test 't-*'
    # Execute single test interactively to allow for debugging.
    $ meson test 't0000-*' --interactive --test-args=-ix
    ```

The build instructions have been successfully tested on the following
systems, tests are passing:

  - Apple macOS 10.15.

  - FreeBSD 14.1.

  - NixOS 24.11.

  - OpenBSD 7.6.

  - Ubuntu 24.04.

  - Windows 10 with Cygwin.

  - Windows 10 with MinGW64, except for t9700, which is also broken with
    our Makefile.

  - Windows 10 with Visual Studio 2022 toolchain, using the Native Tools
    Command Prompt with `meson setup --vsenv`. Tests pass, except for
    t9700.

  - Windows 10 with Visual Studio 2022 solution, using the Native Tools
    Command Prompt with `meson setup --backend vs2022`. Tests pass,
    except for t9700.

  - Windows 10 with VS Code, using the Meson plug-in.

It is expected that there will still be rough edges in the current
version. If this patch lands the expectation is that it will coexist
with our other build systems for a while. Like this, distributions can
slowly migrate over to Meson and report any findings they have to us
such that we can continue to iterate. A potential cutoff date for other
build systems may be Git 3.0.

Some notes:

  - The installed distribution is structured somewhat differently than
    how it used to be the case. All of our binaries are installed into
    `$libexec/git-core`, while all binaries part of `$bindir` are now
    symbolic links pointing to the former. This rule is consistent in
    itself and thus easier to reason about.

  - We do not install dashed binaries into `$libexec/git-core` anymore,
    so there won't e.g. be a symlink for git-add(1). These are not
    required by modern Git and there isn't really much of a use case for
    those anymore. By not installing those symlinks we thus start the
    deprecation of this layout.

  - We're targeting Meson 1.3.0, which has been released relatively
    recently November 2023. The only feature we use from that version is
    `fs.relative_to()`, which we could replace if necessary. If so, we
    could start to target Meson 1.0.0 and newer, released in December
    2022.

  - The whole build instructions count around 3300 lines, half of which
    is listing all of our code and test files. Our Makefiles are around
    5000 lines, autoconf adds another 1300 lines. CMake in comparison
    has only 1200 linescode, but it avoids listing individual files and
    does not wire up auto-configuration as extensively as the Meson
    instructions do.

  - We bundle a set of subproject wrappers for curl, expat, openssl,
    pcre2 and zlib. This allows developers to build Git without these
    dependencies preinstalled, and Meson will fetch and build them
    automatically. This is especially helpful on Windows.

Helped-by: Eli Schwartz <eschwartz@gentoo.org>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:14 +09:00