Commit Graph

75864 Commits (28911f7dcad1ccc6ac4f6939036de76bb4f4c09b)

Author SHA1 Message Date
Patrick Steinhardt 0ed1512141 meson: detect missing tests at configure time
It is quite easy for the list of integration tests to go out-of-sync
without anybody noticing. Introduce a new configure-time check that
verifies that all tests are wired up properly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-13 06:48:46 -08:00
Patrick Steinhardt c081e7340f t/unit-tests: rename clar-based unit tests to have a common prefix
All of the code files for unit tests using the self-grown unit testing
framework have a "t-" prefix to their name. This makes it easy to
identify them and use globbing in our Makefile and in other places. On
the other hand though, our clar-based unit tests have no prefix at all
and thus cannot easily be discerned from other files in the unit test
directory.

Introduce a new "u-" prefix for clar-based unit tests. This prefix will
be used in a subsequent commit to easily identify such tests.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-13 06:48:46 -08:00
Patrick Steinhardt 23eeee08d6 Makefile: drop -DSUPPRESS_ANNOTATED_LEAKS
The -DSUPPRESS_ANNOTATED_LEAKS preprocessor directive was used to enable
our `UNLEAK()` macro in the past, which marks memory as still-reachable
so that the leak sanitizer does not complain. Starting with 52c7dbd036
(git-compat-util: drop now-unused `UNLEAK()` macro, 2024-11-20) this
macro has been removed, and thus the preprocessor directive is not
required anymore, either.

Drop it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-13 06:48:45 -08:00
Patrick Steinhardt 714c134dd6 ci/lib: support custom output directories when creating test artifacts
Update `create_failed_test_artifacts ()` so that it can handle arbitrary
test output directories. This fixes creation of these artifacts for
macOS on GitLab CI, which uses a separate output directory already. This
will also be used by our out-of-tree builds with Meson.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-13 06:48:45 -08:00
Avi Halachmi (:avih) d77c3e35bb gitk: support auto-copy comit ID to primary clipboard
Auto-select ("Copy commit ID to X11 selection") is useful when a
selection cliboard exists, but otherwise generally meaningless, for
instance on Windows.

Add a similar pref and behavior which copies the commit ID to the
primary clipboard - for platforms without a selection clipboard, but
which can also be useful additionally on platforms with selection.

Note that while autoselect is enabled by default, autocopy isn't.

That's because the selection clipboard is typically dispensable, while
the primary clipboard can be considered a more precious resource,
which we don't want to (clear and) overwrite by default.

Signed-off-by: Avi Halachmi (:avih) <avihpit@yahoo.com>
2024-12-13 01:37:08 +02:00
Avi Halachmi (:avih) 92d911a531 gitk: prefs dialog: refine Auto-select UI
Tl;DR: change Auto-select text, move the length input to a new line.

The Auto-select preference auto-selects [part of] the commit ID text
at the respective widget on startup, and when the current commit at
the graph changes.

Its real premise, however, is to populate the selection clipboard
with the commit ID. Consider, for instance, how meaningless it is on
platforms without a selection clipboard - like Windows or macOS (on
Windows the selection is not even visible with the default Tk theme,
because it's only visible in focused widgets - which the commit ID
widget is not during normal application of this selection).

So rename the Auto-select label to "Copy commit ID to X11 selection",
to reflect better the ultimate outcome of its application

Note that there exists other, non-X11 platforms with a selection
clipboard, like Wayland, and if a native Tk client exists on such
platforms, then the description will not be accurate, but hopefully
it's not too misleading either.

Additionally, move the length input widget to a new line, because:
- This length applies to both Auto-select and "Copy commit reference"
  context menu item, so it's not exclusive to the selection length.
- The next commit will add support for primary clipboard as well,
  where this length will also be used.

Also, move the "Hide remotes" item above these selection prefs, to
keep the selection prefs semi-grouped before the spacing of the
following title "Diff display options".

Signed-off-by: Avi Halachmi (:avih) <avihpit@yahoo.com>
2024-12-13 01:27:11 +02:00
Avi Halachmi (:avih) 66496dabd4 gitk: UI text: change "SHA1 ID" to "Commit ID"
SHA1 might not stay forever, and plans to use SHA256 already exist,
so use the official name for it - "Commit ID".

Only visible UI texts are modified to reduce the noise when using
git-blame, while comments and variable names still contain SHA1/sha1.

Signed-off-by: Avi Halachmi (:avih) <avihpit@yahoo.com>
2024-12-13 01:17:05 +02:00
Toon Claes dd1072dfa8 bundle: remove unneeded code
The changes in commit c06793a4ed (allow git-bundle to create bottomless
bundle, 2007-08-08) ensure annotated tags are properly preserved when
creating a bundle using a revision range operation.

At the time the range notation would peel the ends to their
corresponding commit, meaning ref v2.0 would point to the v2.0^0 commit.
So the above workaround was introduced. This code looks up the ref
before it's written to the bundle, and if the ref doesn't point to the
object we expect (for tags this would be a tag object), we skip the ref
from the bundle. Instead, when the ref is a tag that's the positive end
of the range (e.g. v2.0 from the range "v1.0..v2.0"), then that ref is
written to the bundle instead.

Later, in 895c5ba3c1 (revision: do not peel tags used in range notation,
2013-09-19), the behavior of parsing ranges was changed and the problem
was fixed at the cause. But the workaround in bundle.c was not reverted.

Now it seems this workaround can cause a race condition. git-bundle(1)
uses setup_revisions() to parse the input into `struct rev_info`. Later,
in write_bundle_refs(), it uses this info to write refs to the bundle.
As mentioned at this point each ref is looked up again and checked
whether it points to the object we expect. If not, the ref is not
written to the bundle. But, when creating a bundle in a heavy traffic
repository (a repo with many references, and frequent ref updates) it's
possible a branch ref was updated between setup_revisions() and
write_bundle_refs() and thus the extra check causes the ref to be
skipped.

The workaround was originally added to deal with tags, but the code path
also gets hit by non-tag refs, causing this race condition. Because it's
no longer needed, remove it and fix the possible race condition.

Signed-off-by: Toon Claes <toon@iotcl.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-12 17:08:35 +09:00
Patrick Steinhardt c6b43f663e ci/lib: fix "CI setup" sections with GitLab CI
Whenever we source "ci/lib.sh" we wrap the directives in a separate
group so that they can easily be collapsed in the web UI. And as we
source the script multiple times during a single CI run we thus end up
with the same section name reused multiple times, as well.

This is broken on GitLab CI though, where reusing the same group name is
not supported. The consequence is that only the last of these sections
can be collapsed.

Fix this issue by including the name of the sourcing script in the
group's name.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-12 16:57:21 +09:00
Patrick Steinhardt d2ca12020f ci/lib: do not interpret escape sequences in `group ()` arguments
We use printf to set up sections with GitLab CI, which requires us to
print a bunch of escape sequences via printf. The group name is
controlled by the user and is expanded directly into the formatting
string, which may cause problems in case the argument contains escape
sequences or formatting directives.

Fix this potential issue by using formatting directives to pass variable
data.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-12 16:57:21 +09:00
Patrick Steinhardt 33b06fa603 ci/lib: remove duplicate trap to end "CI setup" group
We exlicitly trap on EXIT in order to end the "CI setup" group. This
isn't necessary though given that `begin_group ()` already sets up the
trap for us.

Remove the duplicate trap.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-12 16:57:21 +09:00
Patrick Steinhardt e1b52cf71e gitlab-ci: update macOS images to Sonoma
The macOS Ventura images we use for GitLab CI runners have been
deprecated. Update them to macOS 14, aka Sonoma.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-12 16:57:20 +09:00
Junio C Hamano 5c46677067 Merge branch 'ps/build' into ps/ci-meson
* ps/build: (24 commits)
  Introduce support for the Meson build system
  Documentation: add comparison of build systems
  t: allow overriding build dir
  t: better support for out-of-tree builds
  Documentation: extract script to generate a list of mergetools
  Documentation: teach "cmd-list.perl" about out-of-tree builds
  Documentation: allow sourcing generated includes from separate dir
  Makefile: simplify building of templates
  Makefile: write absolute program path into bin-wrappers
  Makefile: allow "bin-wrappers/" directory to exist
  Makefile: refactor generators to be PWD-independent
  Makefile: extract script to generate gitweb.js
  Makefile: extract script to generate gitweb.cgi
  Makefile: extract script to massage Python scripts
  Makefile: extract script to massage Shell scripts
  Makefile: use "generate-perl.sh" to massage Perl library
  Makefile: extract script to massage Perl scripts
  Makefile: consistently use PERL_PATH
  Makefile: generate doc versions via GIT-VERSION-GEN
  Makefile: generate "git.rc" via GIT-VERSION-GEN
  ...
2024-12-12 16:30:28 +09:00
Junio C Hamano cb656b4222 Merge branch 'cw/worktree-extension' into ps/ci-meson
* cw/worktree-extension:
  worktree: refactor `repair_worktree_after_gitdir_move()`
  worktree: add relative cli/config options to `repair` command
  worktree: add relative cli/config options to `move` command
  worktree: add relative cli/config options to `add` command
  worktree: add `write_worktree_linking_files()` function
  worktree: refactor infer_backlink return
  worktree: add `relativeWorktrees` extension
  setup: correctly reinitialize repository version
2024-12-12 16:30:12 +09:00
Junio C Hamano caacdb5dfd The fifteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-10 10:04:58 +09:00
Junio C Hamano 7041902dfa Merge branch 'ps/reftable-iterator-reuse'
Optimize reading random references out of the reftable backend by
allowing reuse of iterator objects.

* ps/reftable-iterator-reuse:
  refs/reftable: reuse iterators when reading refs
  reftable/merged: drain priority queue on reseek
  reftable/stack: add mechanism to notify callers on reload
  refs/reftable: refactor reflog expiry to use reftable backend
  refs/reftable: refactor reading symbolic refs to use reftable backend
  refs/reftable: read references via `struct reftable_backend`
  refs/reftable: figure out hash via `reftable_stack`
  reftable/stack: add accessor for the hash ID
  refs/reftable: handle reloading stacks in the reftable backend
  refs/reftable: encapsulate reftable stack
2024-12-10 10:04:58 +09:00
Junio C Hamano de9278127e Merge branch 'ps/reftable-detach'
Isolates the reftable subsystem from the rest of Git's codebase by
using fewer pieces of Git's infrastructure.

* ps/reftable-detach:
  reftable/system: provide thin wrapper for lockfile subsystem
  reftable/stack: drop only use of `get_locked_file_path()`
  reftable/system: provide thin wrapper for tempfile subsystem
  reftable/stack: stop using `fsync_component()` directly
  reftable/system: stop depending on "hash.h"
  reftable: explicitly handle hash format IDs
  reftable/system: move "dir.h" to its only user
2024-12-10 10:04:56 +09:00
Junio C Hamano 35f40385e4 Merge branch 'bc/allow-upload-pack-from-other-people'
Loosen overly strict ownership check introduced in the recent past,
to keep the promise "cloning a suspicious repository is a safe
first step to inspect it".

* bc/allow-upload-pack-from-other-people:
  Allow cloning from repositories owned by another user
2024-12-10 10:04:55 +09:00
Junio C Hamano 9cd1e2e1a0 Merge branch 'pb/mergetool-errors'
End-user experience of "git mergetool" when the command errors out
has been improved.

* pb/mergetool-errors:
  git-difftool--helper.sh: exit upon initialize_merge_tool errors
  git-mergetool--lib.sh: add error message for unknown tool variant
  git-mergetool--lib.sh: add error message if 'setup_user_tool' fails
  git-mergetool--lib.sh: use TOOL_MODE when erroring about unknown tool
  completion: complete '--tool-help' in 'git mergetool'
2024-12-10 10:04:53 +09:00
Junio C Hamano bd31944dda Merge branch 'jc/doc-opt-tilde-expand'
Describe a case where an option value needs to be spelled as a
separate argument, i.e. "--opt val", not "--opt=val".

* jc/doc-opt-tilde-expand:
  doc: option value may be separate for valid reasons
2024-12-10 10:04:52 +09:00
Junio C Hamano 8afff26aa0 Merge branch 'bc/ancient-ci'
Drop support for ancient environments in various CI jobs.

* bc/ancient-ci:
  Add additional CI jobs to avoid accidental breakage
  ci: remove clause for Ubuntu 16.04
  gitlab-ci: switch from Ubuntu 16.04 to 20.04
2024-12-10 10:04:51 +09:00
Rubén Justo 14ef8c04c5 strvec: `strvec_splice()` to a statically initialized vector
We use a singleton empty array to initialize a `struct strvec`;
similar to the empty string singleton we use to initialize a `struct
strbuf`.

Note that an empty strvec instance (with zero elements) does not
necessarily need to be an instance initialized with the singleton.
Let's refer to strvec instances initialized with the singleton as
"empty-singleton" instances.

    As a side note, this is the current `strvec_pop()`:

    void strvec_pop(struct strvec *array)
    {
    	if (!array->nr)
    		return;
    	free((char *)array->v[array->nr - 1]);
    	array->v[array->nr - 1] = NULL;
    	array->nr--;
    }

    So, with `strvec_pop()` an instance can become empty but it does
    not going to be the an "empty-singleton".

This "empty-singleton" circumstance requires us to be careful when
adding elements to instances.  Specifically, when adding the first
element:  when we detach the strvec instance from the singleton and
set the internal pointer in the instance to NULL.  After this point we
apply `realloc()` on the pointer.  We do this in
`strvec_push_nodup()`, for example.

The recently introduced `strvec_splice()` API is expected to be
normally used with non-empty strvec's.  However, it can also end up
being used with "empty-singleton" strvec's:

       struct strvec arr = STRVEC_INIT;
       int a = 0, b = 0;

       ... no modification to arr, a or b ...

       const char *rep[] = { "foo" };
       strvec_splice(&arr, a, b, rep, ARRAY_SIZE(rep));

So, we'll try to add elements to an "empty-singleton" strvec instance.

Avoid misapplying `realloc()` to the singleton in `strvec_splice()` by
adding a special case for strvec's initialized with the singleton.

Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-10 09:07:47 +09:00
Jonathan Tan 1a14c857db index-pack --promisor: also check commits' trees
Commit c08589efdc (index-pack: repack local links into promisor packs,
2024-11-01) seems to contain an oversight in that the tree of a commit
is not checked. Teach git to check these trees.

The fix slows down a fetch from a certain repo at $DAYJOB from 2m2.127s
to 2m45.052s, but in order to make the fetch correct, it seems worth it.

In order to test this, we could create server and client repos as
follows...

 C   S
  \ /
   O

(O and C are commits both on the client and server. S is a commit
only on the server. C and S have the same tree but different commit
messages. The diff between O and C is non-zero.)

...and then, from the client, fetch S from the server.

In theory, the client declares "have C" and the server can use this
information to exclude S's tree (since it knows that the client has C's
tree, which is the same as S's tree). However, it is also possible for
the server to compute that it needs to send S and not O, and proceed
from there; therefore the objects of C are not considered at all when
determining what to send in the packfile. In order to prevent a test of
client functionality from having such a dependence on server behavior, I
have not included such a test.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-10 08:53:59 +09:00
Jonathan Tan 36198026d8 index-pack --promisor: don't check blobs
As a follow-up to the parent of this commit, it was found that not
checking for the existence of blobs linked from trees sped up the fetch
from 24m47.815s to 2m2.127s. Teach Git to do that.

The tradeoff of not checking blobs is documented in a code comment.

(Blobs may also be linked from tag objects, but it is impossible to know
the type of an object linked from a tag object without looking it up in
the object database, so the code for that is untouched.)

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-10 08:53:59 +09:00
Jonathan Tan 911d14203c index-pack --promisor: dedup before checking links
Commit c08589efdc (index-pack: repack local links into promisor packs,
2024-11-01) fixed a bug with what was believed to be a negligible
decrease in performance [1] [2]. But at $DAYJOB, with at least one repo,
it was found that the decrease in performance was very significant.

Looking at the patch, whenever we parse an object in the packfile to
be indexed, we check the targets of all its outgoing links for its
existence. However, this could be optimized by first collecting all such
targets into an oidset (thus deduplicating them) before checking. Teach
Git to do that.

On a certain fetch from the aforementioned repo, this improved
performance from approximately 7 hours to 24m47.815s. This number will
be further reduced in a subsequent patch.

[1] https://lore.kernel.org/git/CAG1j3zGiNMbri8rZNaF0w+yP+6OdMz0T8+8_Wgd1R_p1HzVasg@mail.gmail.com/
[2] https://lore.kernel.org/git/20241105212849.3759572-1-jonathantanmy@google.com/

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-10 08:53:59 +09:00
Alejandro Barreto 8525e92886 Document HOME environment variable
Git documentation refers to $HOME and $XDG_CONFIG_HOME often, but does
not specify how or where these values come from on Windows where neither
is set by default. The new documentation reflects the behavior of
setup_windows_environment() in compat/mingw.c.

Signed-off-by: Alejandro Barreto <alejandro.barreto@ni.com>
Signed-off-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-10 08:47:55 +09:00
Johannes Sixt 0668f0470d Merge branch 'yk/console-encoding'
* yk/console-encoding:
  git-gui: use system encoding to show console output

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
2024-12-09 21:19:33 +01:00
Christoph Sommer 904b36b815 gitk: add text wrapping preferences
Add a new preference "wrapdefault" which allows enabling char/word wrap.
Impacts all text in the ctext widget for which no other preference exists.

Also make the (existing) preference "wrapcomment" configurable graphically.
Its setting impacts only the "comment" part of the ctext widget.

Signed-off-by: Christoph Sommer <sommer@cms-labs.org>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
2024-12-09 20:58:02 +01:00
Christoph Sommer b2490ae42f gitk: make headings of preferences bold
Make preference groups like "Diff display options" stand out more.

Signed-off-by: Christoph Sommer <sommer@cms-labs.org>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
2024-12-09 20:58:02 +01:00
Yuri Konotopov e5b5eca3f2
git-gui: use system encoding to show console output
This change makes non-ascii console output (eg server messages in the
`git push` command output) properly render in the git gui windows.

Fixes: https://github.com/prati0100/git-gui/issues/68

Signed-off-by: Yuri Konotopov <ykonotopov@gnome.org>
2024-12-08 22:14:45 +04:00
Patrick Steinhardt 0ff919e87a object-name: fix reversed ordering with ":/<text>" revisions
Recently it was reported [1] that "look for the youngest commit
reachable from any ref with log message that match the given
pattern" syntax (i.e. ':/<text>') started to return results in
reverse recency order. This regression was introduced in Git v2.47.0
and is caused by a memory leak fix done in 57fb139b5e (object-name:
fix leaking commit list items, 2024-08-01).

The intent of the identified commit is to stop modifying the commit list
provided by the caller such that the caller can properly free all commit
list items, including those that the called function might potentially
remove from the list. This was done by creating a copy of the passed-in
commit list and modifying this copy instead of the caller-provided list.

We already knew to create such a copy beforehand with the `backup` list,
which was used to clear the `ONELINE_SEEN` commit mark after we were
done. So the refactoring simply renamed that list to `copy` and started
to operate on that list instead. There is a gotcha though: the backup
list, and thus now also the copied list, is always being prepended to,
so the resulting list is in reverse order! The end result is that we
pop commits from the wrong end of the commit list, returning commits in
reverse recency order.

Fix the bug by appending to the list instead.

[1]: <CAKOEJdcPYn3O01p29rVa+xv=Qr504FQyKJeSB-Moze04ViCGGg@mail.gmail.com>

Reported-by: Aarni Koskela <aarni@valohai.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-08 08:23:14 +09:00
Junio C Hamano 6c915c3f85 fetch: do not ask for HEAD unnecessarily
In 3f763ddf28 (fetch: set remote/HEAD if it does not exist,
2024-11-22), git-fetch learned to opportunistically set $REMOTE/HEAD
when fetching by always asking for remote HEAD, in the hope that it
will help setting refs/remotes/<name>/HEAD if missing.

But it is not needed to always ask for remote HEAD.  When we are
fetching from a remote, for which we have remote-tracking branches,
we do need to know about HEAD.  But if we are doing one-shot fetch,
e.g.,

  $ git fetch --tags https://github.com/git/git

we do not even know what sub-hierarchy of refs/remotes/<remote>/
we need to adjust the remote HEAD for.  There is no need to ask for
HEAD in such a case.

Incidentally, because the unconditional request to list "HEAD"
affected the number of ref-prefixes requested in the ls-remote
request, this affected how the requests for tags are added to the
same ls-remote request, breaking "git fetch --tags $URL" performed
against a URL that is not configured as a remote.

Reported-by: Josh Steadmon <steadmon@google.com>
[jc: tests are also borrowed from Josh's patch]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 21:58:59 +09:00
Karthik Nayak 49c6b912e2 reftable/writer: ensure valid range for log's update_index
Each reftable addition has an associated update_index. While writing
refs, the update_index is verified to be within the range of the
reftable writer, i.e. `writer.min_update_index <= ref.update_index` and
`writer.max_update_index => ref.update_index`.

The corresponding check for reflogs in `reftable_writer_add_log` is
however missing. Add a similar check, but only check for the upper
limit. This is because reflogs are treated a bit differently than refs.
Each reflog entry in reftable has an associated update_index and we also
allow expiring entries in the middle, which is done by simply writing a
new reflog entry with the same update_index. This means, writing reflog
entries with update_index lesser than the writer's update_index is an
expected scenario.

Add a new unit test to check for the limits and fix some of the existing
tests, which were setting arbitrary values for the update_index by
ensuring they stay within the now checked limits.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 08:04:46 +09:00
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
Patrick Steinhardt 00ab97b1bc Documentation: add comparison of build systems
We're contemplating whether to eventually replace our build systems with
a build system that is easier to use. Add a comparison of build systems
to our technical documentation as a baseline for discussion.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:13 +09:00
Patrick Steinhardt 5ee8927824 t: allow overriding build dir
Our "test-lib.sh" assumes that our build directory is the parent
directory of "t/". While true when using our Makefile, it's not when
using build systems that support out-of-tree builds.

In commit ee9e66e4e7 (cmake: avoid editing t/test-lib.sh, 2022-10-18),
we have introduce support for overriding the GIT_BUILD_DIR by creating
the file "$GIT_BUILD_DIR/GIT-BUILD-DIR" with its contents pointing to
the location of the build directory. The intent was to stop modifying
"t/test-lib.sh" with the CMake build systems while allowing out-of-tree
builds. But "$GIT_BUILD_DIR" is somewhat misleadingly named, as it in
fact points to the _source_ directory. So while that commit solved part
of the problem for out-of-tree builds, CMake still has to write files
into the source tree.

Solve the second part of the problem, namely not having to write any
data into the source directory at all, by also supporting an environment
variable that allows us to point to a different build directory. This
allows us to perform properly self-contained out-of-tree builds.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:13 +09:00
Patrick Steinhardt 7e0730c8ba t: better support for out-of-tree builds
Our in-tree builds used by the Makefile use various different build
directories scattered around different locations. The paths to those
build directories have to be propagated to our tests such that they can
find the contained files. This is done via a mixture of hardcoded paths
in our test library and injected variables in our bin-wrappers or
"GIT-BUILD-OPTIONS".

The latter two mechanisms are preferable over using hardcoded paths. For
one, we have all paths which are subject to change stored in a small set
of central files instead of having the knowledge of build paths in many
files. And second, it allows build systems which build files elsewhere
to adapt those paths based on their own needs. This is especially nice
in the context of build systems that use out-of-tree builds like CMake
or Meson.

Remove hardcoded knowledge of build paths from our test library and move
it into our bin-wrappers and "GIT-BUILD-OPTIONS".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:13 +09:00
Patrick Steinhardt 023c3370ac Documentation: extract script to generate a list of mergetools
We include the list of available mergetools into our manpages. Extract
the script that performs this logic such that we can reuse it in other
build systems.

While at it, refactor the Makefile targets such that we don't create
"mergetools-list.made" anymore. It shouldn't be necessary, as we can
instead have other targets depend on "mergetools-{diff,merge}.txt"
directly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:13 +09:00
Patrick Steinhardt 628d49f6e5 Documentation: teach "cmd-list.perl" about out-of-tree builds
The "cmd-list.perl" script generates a list of commands that can be
included into our manpages. The script doesn't know about out-of-tree
builds and instead writes resulting files into the source directory.

Adapt it such that we can read data from the source directory and write
data into the build directory.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:12 +09:00
Patrick Steinhardt 9219325be7 Documentation: allow sourcing generated includes from separate dir
Our documentation uses "include::" directives to include parts that are
either reused across multiple documents or parts that we generate at
build time. Unfortunately, top-level includes are only ever resolved
relative to the base directory, which is typically the directory of the
including document. Most importantly, it is not possible to have either
asciidoc or asciidoctor search multiple directories.

It follows that both kinds of includes must live in the same directory.
This is of course a bummer for out-of-tree builds, because here the
dynamically-built includes live in the build directory whereas the
static includes live in the source directory.

Introduce a `build_dir` attribute and prepend it to all of our includes
for dynamically-built files. This attribute gets set to the build
directory and thus converts the include path to an absolute path, which
asciidoc and asciidoctor know how to resolve.

Note that this change also requires us to update "build-docdep.perl",
which tries to figure out included files such our Makefile can set up
proper build-time dependencies. This script simply scans through the
source files for any lines that match "^include::" and treats the
remainder of the line as included file path. But given that those may
now contain the "{build_dir}" variable we have to teach the script to
replace that attribute with the actual build directory.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:12 +09:00
Patrick Steinhardt ed060aa0a3 Makefile: simplify building of templates
When we install Git we also install a set of default templates that both
git-init(1) and git-clone(1) populate into our build directories. The
way the pristine templates are laid out in our source directory is
somewhat weird though: instead of reconstructing the actual directory
hierarchy in "templates/", we represent directory separators with "--".

The only reason I could come up with for why we have this is the
"branches/" directory, which is supposed to be empty when installing it.
And as Git famously doesn't store empty directories at all we have to
work around this limitation.

Now the thing is that the "branches/" directory is a leftover to how
branches used to be stored in the dark ages. gitrepository-layout(5)
lists this directory as "slightly deprecated", which I would claim is a
strong understatement. I have never encountered anybody using it today
and would be surprised if it even works as expected. So having the "--"
hack in place for an item that is basically unused, unmaintained and
deprecated doesn't only feel unreasonable, but installing that entry by
default may also cause confusion for users that do not know what this is
supposed to be in the first place.

Remove this directory from our templates and, now that we do not require
the workaround anymore, restructure the templates to form a proper
hierarchy. This makes it way easier for build systems to install these
templates into place.

We should likely think about removing support for "branch/" altogether,
but that is outside of the scope of this patch series.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:12 +09:00
Patrick Steinhardt d2407bb8dc Makefile: write absolute program path into bin-wrappers
Write the absolute program path into our bin-wrappers. This allows us to
simplify the Meson build instructions we are about to introduce a bit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:12 +09:00
Patrick Steinhardt 95bcd6f0b7 Makefile: allow "bin-wrappers/" directory to exist
The "bin-wrappers/" directory gets created by our build system and is
populated with one script for each of our binaries. There isn't anything
inherently wrong with the current layout, but it is somewhat hard to
adapt for out-of-tree build systems.

Adapt the layout such that our "bin-wrappers/" directory always exists
and contains our "wrap-for-bin.sh" script to make things a little bit
easier for subsequent steps.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:11 +09:00
Patrick Steinhardt 3f145a4fe3 Makefile: refactor generators to be PWD-independent
We have multiple scripts that generate headers from other data. All of
these scripts have the assumption built-in that they are executed in the
current source directory, which makes them a bit unwieldy to use during
out-of-tree builds.

Refactor them to instead take the source directory as well as the output
file as arguments.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:11 +09:00
Patrick Steinhardt 19d8fe7da6 Makefile: extract script to generate gitweb.js
Similar to the preceding commit, also extract the script to generate the
"gitweb.js" file. While the logic itself is trivial, it helps us avoid
duplication of logic across build systems and ensures that the build
systems will remain in sync with each other in case the logic ever needs
to change.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:11 +09:00
Patrick Steinhardt d2507bbbf4 Makefile: extract script to generate gitweb.cgi
In order to generate "gitweb.cgi" we have to replace various different
placeholders. This is done ad-hoc and is thus not easily reusable across
different build systems.

Introduce a new GITWEB-BUILD-OPTIONS.in template that we populate at
configuration time with the expected options. This script is then used
as input for a new "generate-gitweb.sh" script that generates the final
"gitweb.cgi" file. While this requires us to repeat the options multiple
times, it is in line to how we generate other build options like our
GIT-BUILD-OPTIONS file.

While at it, refactor how we replace the GITWEB_PROJECT_MAXDEPTH. Even
though this variable is supposed to be an integer, the source file has
the value quoted. The quotes are eventually stripped via sed(1), which
replaces `"@GITWEB_PROJECT_MAXDEPTH@"` with the actual value, which is
rather nonsensical. This is made clearer by just dropping the quotes in
the source file.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:11 +09:00
Patrick Steinhardt b7835b941b Makefile: extract script to massage Python scripts
Extract a script that massages Python scripts. This provides a couple of
benefits:

  - The build logic is deduplicated across Make, CMake and Meson.

  - CMake learns to rewrite scripts as-needed at build time instead of
    only writing them at configure time.

Furthermore, we will use this script when introducing Meson to
deduplicate the logic across build systems.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:10 +09:00
Patrick Steinhardt eb98cb835c Makefile: extract script to massage Shell scripts
Same as in the preceding commits, extract a script that allows us to
unify how we massage shell scripts.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:10 +09:00
Patrick Steinhardt ccfba9e0c4 Makefile: use "generate-perl.sh" to massage Perl library
Extend "generate-perl.sh" such that it knows to also massage the Perl
library files. There are two major differences:

  - We do not read in the Perl header. This is handled by matching on
    whether or not we have a Perl shebang.

  - We substitute some more variables, which we read in via our
    GIT-BUILD-OPTIONS.

Adapt both our Makefile and the CMake build instructions to use this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:10 +09:00
Patrick Steinhardt a38edab7c8 Makefile: generate doc versions via GIT-VERSION-GEN
The documentation we generate embeds information for the exact Git
version used as well as the date of the commit. This information is
injected by injecting attributes into the build process via command line
argument.

Refactor the logic so that we write the information into "asciidoc.conf"
and "asciidoctor-extensions.rb" via `GIT-VERSION-GEN` for AsciiDoc and
AsciiDoctor, respectively.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:09 +09:00