Commit Graph

63 Commits

Author SHA1 Message Date
Patrick Steinhardt
23633466df meson: distinguish build and target host binaries
Almost all of the tools we discover during the build process need to be
native programs. There are only a handful of exceptions, which typically
are programs whose paths we need to embed into the resulting executable
so that they can be found on the target system when Git executes. While
this distinction typically doesn't matter, it does start to matter when
considering cross-compilation where the build and target machines are
different.

Meson supports cross-compilation via so-called machine files. These
machine files allow the user to override parameters for the build
machine, but also for the target machine when cross-compiling. Part of
the machine file is a section that allows the user to override the
location where binaries are to be found in the target system. The
following machine file would for example override the path of the POSIX
shell:

    [binaries]
    sh = '/usr/xpg4/bin/sh'

It can be handed over to Meson via `meson setup --cross-file`.

We do not handle this correctly right now though because we don't know
to distinguish binaries for the build and target hosts at all. Address
this by explicitly passing the `native:` parameter to `find_program()`:

  - When set to `true`, we get binaries discovered on the build host.

  - When set to `false`, we get either the path specified in the
    machine file. Or, if no machine file exists or it doesn't specify
    the binary path, then we fall back to the binary discovered on the
    build host.

As mentioned, only a handful of binaries are not native: only the system
shell, Python and Perl need to be treated specially here.

Reported-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-01 02:20:44 -07:00
Patrick Steinhardt
5a69234b86 meson: fix handling of '-Dcurl=auto'
The "curl" option controls whether or not a couple of features that
depend on curl shall be included. Most importantly, these features
include the HTTP remote helpers, which are rather quintessential for a
well-functioning Git installation. So while the dependency can in theory
be dropped, most users wouldn't consider the resulting installation to
be fully functional.

The "curl" option is defined as a feature, which means that it can be
"enabled", "disabled" or "auto", which has the effect that the feature
will be enabled if the dependency itself has been found. While most of
the other features have "auto" as default value, the "curl" option is
set to "enabled" by default due to it being so important. Consequently,
autoconfiguration of Git will fail by default if the library cannot be
found.

There is a bug though with how we handle the option in case the user
overrides the feature with `meson setup -Dcurl=auto`: while we will try
to find the library in that case, we won't ever use it because we later
on check for `get_option('curl').enabled()` when deciding whether or not
we want to build dependent sources. But `enabled()` only returns true if
the option has the value "enabled", for "auto" it will return false.

Fix the issue by instead checking for `curl.found()`, which is only true
if the library has been found. And as we only try to find the library
when `get_option('curl')` returns "true" or "auto" this is exactly what
we want.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-01 02:20:43 -07:00
Johannes Schindelin
31761f3911 meson: fix sorting
In 904339edbd (Introduce support for the Meson build system,
2024-12-06) the `meson.build` file was introduced, adding also a
Windows-specific list of source files. This list was obviously meant to
be sorted alphabetically, but there is one mistake. Let's fix that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-06 08:35:07 -08:00
Junio C Hamano
ca39da6997 Merge branch 'ps/meson-contrib-bits'
Update meson-based build procedure to cover contrib/ and other
places as well.

* ps/meson-contrib-bits:
  ci: exercise credential helpers
  ci: fix propagating UTF-8 test locale in musl-based Meson job
  meson: wire up static analysis via Coccinelle
  meson: wire up git-contacts(1)
  meson: wire up credential helpers
  contrib/credential: fix compilation of "osxkeychain" helper
  contrib/credential: fix compiling "libsecret" helper
  contrib/credential: fix compilation of wincred helper with MSVC
  contrib/credential: fix "netrc" tests with out-of-tree builds
  GIT-BUILD-OPTIONS: propagate project's source directory
2025-03-03 08:53:03 -08:00
Junio C Hamano
ab09eddf60 Merge branch 'ps/build-meson-fixes-0130'
Assorted fixes and improvements to the build procedure based on
meson.

* ps/build-meson-fixes-0130:
  gitlab-ci: restrict maximum number of link jobs on Windows
  meson: consistently use custom program paths to resolve programs
  meson: fix overwritten `git` variable
  meson: prevent finding sed(1) in a loop
  meson: improve handling of `sane_tool_path` option
  meson: improve PATH handling
  meson: drop separate version library
  meson: stop linking libcurl into all executables
  meson: introduce `libgit_curl` dependency
  meson: simplify use of the common-main library
  meson: inline the static 'git' library
  meson: fix OpenSSL fallback when not explicitly required
  meson: fix exec path with enabled runtime prefix
2025-03-03 08:53:02 -08:00
Patrick Steinhardt
3ee3a6eb52 meson: fix overwritten git variable
We're assigning the `git` variable in three places:

  - In "meson.build" to store the external Git executable.

  - In "meson.build" to store the compiled Git executable.

  - In "Documentation/meson.build" to store the external Git executable,
    a second time.

The last case is only needed because we overwrite the original variable
with the built version. Rename the variable used for the built Git
executable so that we don't have to resolve the external Git executable
multiple times.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:37 -08:00
Patrick Steinhardt
16c89dcf80 meson: prevent finding sed(1) in a loop
We're searching for the sed(1) executable in a loop, which will make us
try to find it multiple times. Starting with the preceding commit we
already declare a variable for that program in the top-level build file.
Use it so that we only need to search for the program once.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:36 -08:00
Patrick Steinhardt
42846efc3b meson: improve handling of sane_tool_path option
The `sane_tool_path` option can be used to override the PATH variable
from which the build process, tests and ultimately Git will end up
picking programs from. It is currently lacking though because we only
use it to populate the PATH environment variable for executed scripts
and for the `BROKEN_PATH_FIX` mechanism, but we don't use it to find
programs used in the build process itself.

Fix this issue by treating it similar to the Windows-specific paths,
which will make us use it both to find programs and to populate the PATH
environment variable.

To help with this fix, change the type of the option to be an array of
paths, which makes the handling a bit easier for us. It's also the
correct thing to do as the input indeed is a list of paths.

Furthermore, the option now overrides the default behaviour on Windows,
which si to pick up tools from Git for Windows. This is done so that it
becomes easier to override that default behaviour in case it's not
desired.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:36 -08:00
Patrick Steinhardt
454d79b61b meson: improve PATH handling
When locating programs required for the build we give some special
treatment to Windows systems so that we know to also look up tools
provided by a Git for Windows installation. This ensures that the build
doesn't have any prerequisites other than Microsoft Visual Studio, Meson
and Git for Windows.

Consequently, some of the programs returned by `find_program()` may not
be found via PATH, but via these extra directories. But while Meson can
use these tools directly without any special treatment, any scripts that
we execute may not be able to find those programs. To help them we thus
prepend the directories of a subset of the found programs to PATH.

This doesn't make much sense though: we don't need to prepend PATH for
any program that was found via PATH, but we really only need to do so
for programs located via the extraneous Windows-specific paths. So
instead of prepending all programs paths, we really only need to prepend
the Windows-specific paths.

Adapt the code accordingly by only prepeding Windows-specific paths to
PATH, which both simplifies the code and clarifies intent.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:36 -08:00
Patrick Steinhardt
eee25bbd84 meson: drop separate version library
When building `libgit.a` we link it against a `libgit_version.a` library
that contains the version information that we inject at build time. The
intent of this is to avoid rebuilding all of `libgit.a` whenever the
version changes. But that wouldn't happen in the first place, as we know
to just rebuild the files that depend on the generated "version-def.h"
file.

This is an artifact of an earlier version of the Meson build infra that
didn't ultimately land. We didn't yet have "version-def.h", and instead
injected the version via preprocessor directives. And here we would have
rebuilt all of `libgit.a` indeed in case the version changes, because
the preprocessor directive applied to all files.

Stop building the separate library and instead add "version-def.h" to
the list of source files directly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:36 -08:00
Patrick Steinhardt
f5fac42e07 meson: stop linking libcurl into all executables
We set up libcurl via the `libgit_dependencies` variable, which gets
propagated into every user of the `libgit` dependency. This is not
necessary though, as most of our executables aren't even supposed to
link against libcurl.

Fix this by only propagating include directories as a libgit dependency
and propagating the full curl dependency via `libgit_curl`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:35 -08:00
Patrick Steinhardt
dfc88bd647 meson: introduce libgit_curl dependency
We've got a set of common source files that we use for those executables
that link against libcurl. The setup is somewhat repetitive though.
Simplify it by declaring a `libgit_curl` dependency that bundles all of
it together.

Note that we don't include curl itself as a dependency. This is because
we already pull it in transitively via the libgit dependency, which is
unfortunate because libgit itself shouldn't actually link against curl
in the first place. This will get fixed in the next commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:35 -08:00
Patrick Steinhardt
ebb35369f1 meson: simplify use of the common-main library
The "common-main.c" file is used by multiple executables. In order to
make it easy to set it up we have created a separate library that these
executables can link against. All of these executables also want to link
against `libgit.a` though, which makes it necessary to specify both of
these as dependencies for every executable.

Simplify this a bit by declaring the library as a source dependency:
instead of creating a static library, we now instead compile the common
set of files into each executable separately.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:35 -08:00
Patrick Steinhardt
ce9432889c meson: inline the static 'git' library
When setting up `libgit.a` we first create the static library itself,
and then declare it as part of a dependency such that compile arguments,
include directories and transitive dependencies get propagated to the
users of that library. As such, the static library isn't expected to be
used by anything but the declared dependency.

Inline the static library so that we don't even use a separate variable
for it. This avoids any kind of confusion that may arise and clarifies
how the library is supposed to be used.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:35 -08:00
Patrick Steinhardt
6128301075 meson: fix OpenSSL fallback when not explicitly required
When OpenSSL isn't provided by the system we know to fall back to the
subproject wrapper. This is especially helpful on Windows systems, where
you typically don't have OpenSSL available, in order to reduce the
number of required dependencies.

The fallback is broken though when the OpenSSL backend is set to 'auto'
as we end up calling `dependency('openssl', required: false)` in that
case, which implicitly disables falling back to the wrapper.

Fix the issue by re-allowing the fallback in case either OpenSSL is
required or in case the backend is set to 'auto'. While at it, fix
reporting of the backend in case the user asked us to pick no HTTPS
backend at all.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:35 -08:00
Patrick Steinhardt
bd262d07b6 meson: fix exec path with enabled runtime prefix
When the runtime prefix option is enabled, Git is built such that it
knows to locate its binaries relative to the directory a binary is being
executed from. This requires us to figure out relative paths, which is
handled in `system_prefix()` by trying to strip a couple of well-known
paths.

One of these paths, GIT_EXEC_PATH, is expected to be absolute when
runtime prefixes are enabled, but relative otherwise. And while our
Makefile gets this correctly, in Meson we always wire up the absolute
path, which may result in us not being able to find binaries.

Fix this by conditionally injecting the paths depending on whether or
not the `runtime_prefix` option is enabled.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-26 09:09:34 -08:00
Junio C Hamano
f65d9cfd3f Merge branch 'po/meson-perl-fix'
Upgrade the minimum Perl version enforced by meson-based build to
match what Makefile-based build uses.

* po/meson-perl-fix:
  meson: fix Perl version check for Meson versions before 1.7.0
  meson: bump minimum required Perl version to 5.26.0
2025-02-25 14:19:37 -08:00
Peter Oliver
0bf8d1b395 meson: fix Perl version check for Meson versions before 1.7.0
Command `perl --version` says, e.g., “This is perl 5, version 26,
subversion 0 (v5.26.0)”, which older versions of Meson interpret as
version 26.

This will be fixed in Meson 1.7.0, but at the time of writing that isn’t
yet released.

If we run `perl -V:version` we get the unambiguous response
“version='5.26.0';”, but we need at least Meson 1.5.0 to be able to do that.

Note that Perl are seriously considering dropping the leading 5 entirely
in the near future (https://perl.github.io/PPCs/ppc0025-perl-version/),
but that shouldn’t affect us.

Signed-off-by: Peter Oliver <git@mavit.org.uk>
Co-authored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-19 08:04:26 -08:00
Peter Oliver
d874d37837 meson: bump minimum required Perl version to 5.26.0
Commit 702d8c1f3b (Require Perl 5.26.0, 2024-10-23) dropped support
for Perl versions older than 5.26.0. The Meson build system, which
has been developed in parallel to that commit, hasn't been bumped
accordingly and thus still requires Perl 5.8.1 or newer.

Fix this by requiring Perl 5.26.0 or newer with Meson.

Signed-off-by: Peter Oliver <git@mavit.org.uk>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-19 08:04:11 -08:00
Junio C Hamano
e565f37553 Merge branch 'ds/backfill'
Lazy-loading missing files in a blobless clone on demand is costly
as it tends to be one-blob-at-a-time.  "git backfill" is introduced
to help bulk-download necessary files beforehand.

* ds/backfill:
  backfill: assume --sparse when sparse-checkout is enabled
  backfill: add --sparse option
  backfill: add --min-batch-size=<n> option
  backfill: basic functionality and tests
  backfill: add builtin boilerplate
2025-02-18 15:30:31 -08:00
Patrick Steinhardt
1cee22ebff meson: wire up credential helpers
We've got a couple of credential helpers in "contrib/credential", all
of which aren't yet wired up via Meson. Do so.

Note that ideally, we'd also wire up t0303 to be executed with each of
the credential helpers to verify their functionality. Unfortunately
though, none of them pass the test suite right now, so this is left for
a future change.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-18 11:40:03 -08:00
Patrick Steinhardt
c5823641a6 GIT-BUILD-OPTIONS: propagate project's source directory
A couple of our tests require knowledge around where to find the
project's source directory in order to locate files required for the
test itself. Until now we have been wiring these up ad-hoc via new,
specialized variables catered to the specific usecase. This is quite
awkward though, as every test that potentially needs to locate paths
relative to the source directory needs to grow another variable.

Introduce a new "GIT_SOURCE_DIR" variable into GIT-BUILD-OPTIONS to stop
this proliferation. Remove existing variables that can be derived from
it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-18 11:40:02 -08:00
Junio C Hamano
0cc13007e5 Merge branch 'bc/doc-adoc-not-txt'
All the documentation .txt files have been renamed to .adoc to help
content aware editors.

* bc/doc-adoc-not-txt:
  Remove obsolete ".txt" extensions for AsciiDoc files
  doc: use .adoc extension for AsciiDoc files
  gitattributes: mark AsciiDoc files as LF-only
  editorconfig: add .adoc extension
  doc: update gitignore for .adoc extension
2025-02-14 17:53:47 -08:00
Junio C Hamano
a4af0b6288 Merge branch 'js/libgit-rust'
Foreign language interface for Rust into our code base has been added.

* js/libgit-rust:
  libgit: add higher-level libgit crate
  libgit-sys: also export some config_set functions
  libgit-sys: introduce Rust wrapper for libgit.a
  common-main: split init and exit code into new files
2025-02-12 10:08:53 -08:00
Junio C Hamano
9d0e81e2ae Merge branch 'ps/zlib-ng'
The code paths to interact with zlib has been cleaned up in
preparation for building with zlib-ng.

* ps/zlib-ng:
  ci: make "linux-musl" job use zlib-ng
  ci: switch linux-musl to use Meson
  compat/zlib: allow use of zlib-ng as backend
  git-zlib: cast away potential constness of `next_in` pointer
  compat/zlib: provide stubs for `deflateSetHeader()`
  compat/zlib: provide `deflateBound()` shim centrally
  git-compat-util: move include of "compat/zlib.h" into "git-zlib.h"
  compat: introduce new "zlib.h" header
  git-compat-util: drop `z_const` define
  compat: drop `uncompress2()` compatibility shim
2025-02-06 14:56:45 -08:00
Derrick Stolee
a3f79e9abd backfill: add builtin boilerplate
In anticipation of implementing 'git backfill', populate the necessary files
with the boilerplate of a new builtin. Mark the builtin as experimental at
this time, allowing breaking changes in the near future, if necessary.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-03 16:12:41 -08:00
Junio C Hamano
f49905d47d Merge branch 'ps/build-meson-fixes'
More build fixes and enhancements on meson based build procedure.

* ps/build-meson-fixes:
  ci: wire up Visual Studio build with Meson
  ci: raise error when Meson generates warnings
  meson: fix compilation with Visual Studio
  meson: make the CSPRNG backend configurable
  meson: wire up fuzzers
  meson: wire up generation of distribution archive
  meson: wire up development environments
  meson: fix dependencies for generated headers
  meson: populate project version via GIT-VERSION-GEN
  GIT-VERSION-GEN: allow running without input and output files
  GIT-VERSION-GEN: simplify computing the dirty marker
2025-02-03 10:23:34 -08:00
Junio C Hamano
803b5acaa7 Merge branch 'ps/3.0-remote-deprecation'
Following the procedure we established to introduce breaking
changes for Git 3.0, allow an early opt-in for removing support of
$GIT_DIR/branches/ and $GIT_DIR/remotes/ directories to configure
remotes.

* ps/3.0-remote-deprecation:
  remote: announce removal of "branches/" and "remotes/"
  builtin/pack-redundant: remove subcommand with breaking changes
  ci: repurpose "linux-gcc" job for deprecations
  ci: merge linux-gcc-default into linux-gcc
  Makefile: wire up build option for deprecated features
2025-02-03 10:23:33 -08:00
Junio C Hamano
72f1ddfbc9 Merge branch 'ps/build-meson-fixes' into ps/build-meson-fixes-0130
* ps/build-meson-fixes:
  ci: wire up Visual Studio build with Meson
  ci: raise error when Meson generates warnings
  meson: fix compilation with Visual Studio
  meson: make the CSPRNG backend configurable
  meson: wire up fuzzers
  meson: wire up generation of distribution archive
  meson: wire up development environments
  meson: fix dependencies for generated headers
  meson: populate project version via GIT-VERSION-GEN
  GIT-VERSION-GEN: allow running without input and output files
  GIT-VERSION-GEN: simplify computing the dirty marker
2025-01-30 14:53:50 -08:00
Junio C Hamano
f046ab2dd4 Merge branch 'ds/path-walk-1'
Introduce a new API to visit objects in batches based on a common
path, or by type.

* ds/path-walk-1:
  path-walk: drop redundant parse_tree() call
  path-walk: reorder object visits
  path-walk: mark trees and blobs as UNINTERESTING
  path-walk: visit tags and cached objects
  path-walk: allow consumer to specify object types
  t6601: add helper for testing path-walk API
  test-lib-functions: add test_cmp_sorted
  path-walk: introduce an object walk by path
2025-01-29 14:05:09 -08:00
Josh Steadmon
3f8f2abe05 common-main: split init and exit code into new files
Currently, object files in libgit.a reference common_exit(), which is
contained in common-main.o. However, common-main.o also includes main(),
which references cmd_main() in git.o, which in turn depends on all the
builtin/*.o objects.

We would like to allow external users to link libgit.a without needing
to include so many extra objects. Enable this by splitting common_exit()
and check_bug_if_BUG() into a new file common-exit.c, and add
common-exit.o to LIB_OBJS so that these are included in libgit.a.

This split has previously been proposed ([1], [2]) to support fuzz tests
and unit tests by avoiding conflicting definitions for main(). However,
both of those issues were resolved by other methods of avoiding symbol
conflicts. Now we are trying to make libgit.a more self-contained, so
hopefully we can revisit this approach.

Additionally, move the initialization code out of main() into a new
init_git() function in its own file. Include this in libgit.a as well,
so that external users can share our setup code without calling our
main().

[1] https://lore.kernel.org/git/Yp+wjCPhqieTku3X@google.com/
[2] https://lore.kernel.org/git/20230517-unit-tests-v2-v2-1-21b5b60f4b32@google.com/

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-28 14:39:16 -08:00
Patrick Steinhardt
84bb5eeace ci: switch linux-musl to use Meson
Switch over the "linux-musl" job to use Meson instead of Makefiles. This
is done due to multiple reasons:

  - It simplifies our CI infrastructure a bit as we don't have to
    manually specify a couple of build options anymore.

  - It verifies that Meson detects and sets those build options
    automatically.

  - It makes it easier for us to wire up a new CI job using zlib-ng as
    backend.

One platform compatibility that Meson cannot easily detect automatically
is the `GIT_TEST_UTF8_LOCALE` variable used in tests. Wire up a build
option for it, which we set via a new "MESONFLAGS" environment variable.

Note that we also drop the CC variable, which is set to "gcc". We
already default to GCC when CC is unset in "ci/lib.sh", so this is not
needed.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-28 13:03:23 -08:00
Patrick Steinhardt
b9d6f64393 compat/zlib: allow use of zlib-ng as backend
The zlib-ng library is a hard fork of the old and venerable zlib
library. It describes itself as zlib replacement with optimizations for
"next generation" systems. As such, it contains several implementations
of central algorithms using for example SSE2, AVX2 and other vectorized
CPU intrinsics that supposedly speed up in- and deflating data.

And indeed, compiling Git against zlib-ng leads to a significant speedup
when reading objects. The following benchmark uses git-cat-file(1) with
`--batch --batch-all-objects` in the Git repository:

    Benchmark 1: zlib
      Time (mean ± σ):     52.085 s ±  0.141 s    [User: 51.500 s, System: 0.456 s]
      Range (min … max):   52.004 s … 52.335 s    5 runs

    Benchmark 2: zlib-ng
      Time (mean ± σ):     40.324 s ±  0.134 s    [User: 39.731 s, System: 0.490 s]
      Range (min … max):   40.135 s … 40.484 s    5 runs

    Summary
      zlib-ng ran
        1.29 ± 0.01 times faster than zlib

So we're looking at a ~25% speedup compared to zlib. This is of course
an extreme example, as it makes us read through all objects in the
repository. But regardless, it should be possible to see some sort of
speedup in most commands that end up accessing the object database.

The zlib-ng library provides a compatibility layer that makes it a
proper drop-in replacement for zlib: nothing needs to change in the
build system to support it. Unfortunately though, this mode isn't easy
to use on most systems because distributions do not allow you to install
zlib-ng in that way, as that would mean that the zlib library would be
globally replaced. Instead, many distributions provide a package that
installs zlib-ng without the compatibility layer. This version does
provide effectively the same APIs like zlib does, but all of the symbols
are prefixed with `zng_` to avoid symbol collisions.

Implement a new build option that allows us to link against zlib-ng
directly. If set, we redefine zlib symbols so that we use the `zng_`
prefixed versions thereof provided by that library. Like this, it
becomes possible to install both zlib and zlib-ng (without the compat
layer) and then pick whichever library one wants to link against for
Git.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-28 13:03:23 -08:00
Patrick Steinhardt
3656d57bbf compat: drop uncompress2() compatibility shim
Our compat library has an implementation of zlib's `uncompress2()`
function that gets used when linking against an old version of zlib
that doesn't yet have it. The last user of `uncompress2()` got removed
in 15a60b747e (reftable/block: open-code call to `uncompress2()`,
2024-04-08), so the compatibility code is not required anymore. Drop it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-28 13:03:22 -08:00
Junio C Hamano
a17fd7dd3a Merge branch 'ps/reftable-sign-compare'
The reftable/ library code has been made -Wsign-compare clean.

* ps/reftable-sign-compare:
  reftable: address trivial -Wsign-compare warnings
  reftable/blocksource: adjust `read_block()` to return `ssize_t`
  reftable/blocksource: adjust type of the block length
  reftable/block: adjust type of the restart length
  reftable/block: adapt header and footer size to return a `size_t`
  reftable/basics: adjust `hash_size()` to return `uint32_t`
  reftable/basics: adjust `common_prefix_size()` to return `size_t`
  reftable/record: handle overflows when decoding varints
  reftable/record: drop unused `print` function pointer
  meson: stop disabling -Wsign-compare
2025-01-28 13:02:24 -08:00
Junio C Hamano
3ddeb7f337 Merge branch 'ps/build-meson-subtree'
The meson-driven build is now aware of "git-subtree" housed in
contrib/subtree hierarchy.

* ps/build-meson-subtree:
  meson: wire up the git-subtree(1) command
  meson: introduce build option for contrib
  contrib/subtree: fix building docs
2025-01-28 13:02:23 -08:00
Junio C Hamano
d8093fd6c1 Merge branch 'tc/meson-use-our-version-def-h'
The meson build procedure looked for the 'version-def.h' file in a
wrong directory, which has been corrected.

* tc/meson-use-our-version-def-h:
  meson: ensure correct version-def.h is used
2025-01-23 15:07:01 -08:00
Patrick Steinhardt
13cb20fc46 meson: fix compilation with Visual Studio
The Visual Studio compiler defaults to C89 unless explicitly asked to
use a different version of the C standard. We don't specify any C
standard at all though in our Meson build, and consequently compiling
Git fails:

    ...\git\git-compat-util.h(14): fatal error C1189: #error:  "Required C99 support is in a test phase.  Please see git-compat-util.h for more details."

Fix the issue by specifying the project's C standard. Funny enough,
specifying C99 does not work because apparently, `__STDC_VERSION__` is
not getting defined in that version at all. Instead, we have to specify
C11 as the project's C standard, which is also done in our CMake build
instructions.

We don't want to generally enforce C11 though, as our requiremets only
state that a C99 compiler is required. In fact, we don't even require
plain C99, but rather the GNU variant thereof.

Meson allows us to handle this case rather easily by specifying
"gnu99,c11", which will cause it to fall back to C11 in case GNU C99 is
unsupported. This feature has only been introduced with Meson 1.3.0
though, and we support 0.61.0 and newer. In case we use such an oldish
version though we fall back to requiring GNU99 unconditionally. This
means that Windows essentially requires Meson 1.3.0 and newer when using
Visual Studio, but I doubt that this is ever going to be a real problem.

Tested-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:37:34 -08:00
Patrick Steinhardt
ef8c3a1b8a meson: make the CSPRNG backend configurable
The CSPRNG backend is not configurable in Meson and isn't quite
discoverable, either. Make it configurable and add the actual backend
used to the summary.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:37:34 -08:00
Patrick Steinhardt
28911f7dca meson: wire up fuzzers
Meson does not yet know to build our fuzzers. Introduce a new build
option "fuzzers" and wire up the fuzzers in case it is enabled. Adapt
our CI jobs so that they build the fuzzers by default.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:37:33 -08:00
Patrick Steinhardt
88d4bff8c3 meson: wire up generation of distribution archive
Meson knows to generate distribution archives via `meson dist`. In
addition to generating the archive itself, this target also knows to
compile and execute tests from that archive, which helps to ensure that
the result is an adequate drop-in replacement for the versioned project.

While this already works as-is, one omission is that we don't propagate
the commit that this is built from into the resulting archive. This can
be fixed though by adding a distribution script that propagates the
version into the "version" file, which GIT-VERSION-GEN knows to read if
present.

Use GIT-VERSION-GEN to populate that file. As the script is executed in
the build directory, not in the directory where we generate the archive,
we have to use a shell to resolve the "MESON_DIST_ROOT" environment
variable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:37:33 -08:00
Patrick Steinhardt
5d0cf6bb3a meson: wire up development environments
The Meson build system is able to wire up development environments. The
intent is to make build artifacts of the project available. This is
typically used to export e.g. paths to linkable libraries, which isn't
all that interesting in our context given that we don't have an official
library interface.

But what we can use this mechanism for is to expose the built Git
executables as well as the build directory. This allows users to play
around with the built Git version in the devenv, and allows them to
execute our test scripts directly with the built distribution.

Wire up this feature, which can then be used via `meson devenv` in the
build directory.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:37:33 -08:00
Patrick Steinhardt
53d75bd3e4 meson: fix dependencies for generated headers
We generate a couple of headers from our documentation. These headers
are added to the libgit sources, but two of them aren't used by the
library, but instead by our builtins. This can cause parallel builds to
fail because the builtin object may be compiled before the header was
generated.

Fix the issue by adding both "config-list.h" and "hook-list.h" to the
list of builtin sources. While "command-list.h" is generated similarly,
it is used by "help.c" and thus part of the libgit sources indeed.

Reported-by: Evan Martin <evan.martin@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:37:33 -08:00
Patrick Steinhardt
6ff99174d1 meson: populate project version via GIT-VERSION-GEN
The Git version for Meson is currently wired up manually. It can thus
grow (and already has grown) stale quite easily, as having multiple
sources of truth is never a good idea. This issue is mostly of cosmetic
nature as we don't use the project version anywhere, and instead use the
GIT-VERSION-GEN script to propagate the correct version into our build.
But it is somewhat puzzling when `meson setup` announces to build an old
Git release.

There are a couple of alternatives for how to solve this:

  - We can keep the version undefined, but this makes Meson output
    "undefined" for the version, as well.

  - We can use GIT-VERSION-GEN to generate the version for us. At the
    point of configuring the project we haven't yet figured out host
    details though, and thus we didn't yet set up the shell environment.
    While not an issue for Unix-based systems, this would be an issue in
    Windows, where the shell typically gets provided via Git for Windows
    and thus requires some special setup.

  - We can pull the default version out of GIT-VERSION-GEN and move it
    into its own file. This likely requires some adjustments for scripts
    that bump the version, but allows Meson to read the version from
    that file trivially.

Pick the second option and use GIT-VERSION-GEN as it gives us the most
accurate version. In order to fix the bootstrapping issue on Windows
systems we simply set the version to 'unknown' in case no shell was
found. As the version is only of cosmetic value this isn't really much
of an issue.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:37:32 -08:00
Patrick Steinhardt
c5bc9a7f94 Makefile: wire up build option for deprecated features
With 57ec9254eb (docs: introduce document to announce breaking changes,
2024-06-14), we have introduced a new document that tracks upcoming
breaking changes in the Git project. In 2454970930 (BreakingChanges:
early adopter option, 2024-10-11) we have amended the document a bit to
mention that any introduced breaking changes must be accompanied by
logic that allows us to enable the breaking change at compile-time.
While we already have two breaking changes lined up, neither of them has
such a switch because they predate those instructions.

Introduce the proposed `WITH_BREAKING_CHANGES` preprocessor macro and
wire it up with both our Makefiles and Meson. This does not yet wire up
the build flag for existing deprecations.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:28:27 -08:00
Patrick Steinhardt
eb8728d88a meson: stop disabling -Wsign-compare
In 4f9264b0cd (config.mak.dev: drop `-Wno-sign-compare`, 2024-12-06) we
have started an effort to make our codebase compile with -Wsign-compare.
But while we removed the -Wno-sign-compare flag from "config.mak.dev",
we didn't adjust the Meson build instructions in the same way.

Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-21 14:20:28 -08:00
brian m. carlson
1f010d6bdf doc: use .adoc extension for AsciiDoc files
We presently use the ".txt" extension for our AsciiDoc files.  While not
wrong, most editors do not associate this extension with AsciiDoc,
meaning that contributors don't get automatic editor functionality that
could be useful, such as syntax highlighting and prose linting.

It is much more common to use the ".adoc" extension for AsciiDoc files,
since this helps editors automatically detect files and also allows
various forges to provide rich (HTML-like) rendering.  Let's do that
here, renaming all of the files and updating the includes where
relevant.  Adjust the various build scripts and makefiles to use the new
extension as well.

Note that this should not result in any user-visible changes to the
documentation.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-21 12:56:06 -08:00
Patrick Steinhardt
8454b42f94 meson: wire up the git-subtree(1) command
Wire up the git-subtree(1) command, which is part of "contrib/". Note
that we have to move around the exact location where we include the
"contrib/" subdirectory so that it comes after building the docs so that
we have access to some of the common functionality.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-17 09:56:38 -08:00
Toon Claes
4771501c0a meson: ensure correct version-def.h is used
To build the libgit-version library, Meson first generates
`version-def.h` in the build directory. Then it compiles `version.c`
into a library. During compilation, Meson tells to include both the
build directory and the project root directory.

However, when the user previously has compiled Git using Make, they will
have a `version-def.h` file in project root directory as well. Because
`version-def.h` is included in `version.c` using the #include directive
with double quotes, some preprocessors will look for the header file in
the same directory as the source file. This will cause compilation of
`version.c` ran by Meson to include `version-def.h` previously made by
Make, which might be out of date.

To explicitly tell the preprocessor which `version-def.h` to use, pass
the absolute path of this file as macro GIT_VERSION_H to the
preprocessor using option `-D` and have `version.c` `#include
GIT_VERSION_H`. To remain working with other build systems than Meson,
include "version-def.h" if that macro is not defined.

Co-authored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Toon Claes <toon@iotcl.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-14 11:14:54 -08:00
Patrick Steinhardt
6a0ee54f9a meson: provide a summary of configured backends
There are a couple of backends from which the user can choose for HTTPS,
SHA1, its unsafe variant as well as SHA256. Provide a summary of the
configured values to make these more discoverable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-30 06:50:49 -08:00