Commit Graph

3099 Commits (v2.49.1)

Author SHA1 Message Date
Đoàn Trần Công Danh da87b58014 sparse: ignore warning from new glibc headers
With at least glibc 2.39, glibc provides a function declaration that
matches with this POSIX interface:

    int regexec(const regex_t *restrict preg, const char *restrict string,
           size_t nmatch, regmatch_t pmatch[restrict], int eflags);

such prototype requires variable-length-array for `pmatch'.

Thus, sparse reports this error:

> ../add-patch.c: note: in included file (through ../git-compat-util.h):
> /usr/include/regex.h:682:41: error: undefined identifier '__nmatch'
> /usr/include/regex.h:682:41: error: bad constant expression type
> /usr/include/regex.h:682:41: error: Variable length array is used.

Note: `__nmatch' is POSIX's nmatch.

The glibc's intention is informing their users to provides a large
enough buffer to hold `__nmatch' results and provides diagnosis if
necessary.  It's merely a glibc' implementation detail.

Hide that usage from sparse by using standard C11's macro:
__STDC_NO_VLA__

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-09 08:42:59 -07:00
Junio C Hamano 62c58891e1 Merge branch 'tz/doc-txt-to-adoc-fixes'
Fallouts from recent renaming of documentation files from .txt
suffix to the new .adoc suffix have been corrected.

* tz/doc-txt-to-adoc-fixes: (38 commits)
  xdiff: *.txt -> *.adoc fixes
  unpack-trees.c: *.txt -> *.adoc fixes
  transport.h: *.txt -> *.adoc fixes
  trace2/tr2_sysenv.c: *.txt -> *.adoc fixes
  trace2.h: *.txt -> *.adoc fixes
  t6434: *.txt -> *.adoc fixes
  t6012: *.txt -> *.adoc fixes
  t/helper/test-rot13-filter.c: *.txt -> *.adoc fixes
  simple-ipc.h: *.txt -> *.adoc fixes
  setup.c: *.txt -> *.adoc fixes
  refs.h: *.txt -> *.adoc fixes
  pseudo-merge.h: *.txt -> *.adoc fixes
  parse-options.h: *.txt -> *.adoc fixes
  object-name.c: *.txt -> *.adoc fixes
  list-objects-filter-options.h: *.txt -> *.adoc fixes
  fsck.h: *.txt -> *.adoc fixes
  diffcore.h: *.txt -> *.adoc fixes
  diff.h: *.txt -> *.adoc fixes
  contrib/long-running-filter: *.txt -> *.adoc fixes
  config.c: *.txt -> *.adoc fixes
  ...
2025-03-06 14:06:31 -08:00
Junio C Hamano 6024f321d4 Merge branch 'sk/unit-test-oid'
Convert a few unit tests to the clar framework.

* sk/unit-test-oid:
  t/unit-tests: convert oidtree test to use clar test framework
  t/unit-tests: convert oidmap test to use clar test framework
  t/unit-tests: convert oid-array test to use clar test framework
  t/unit-tests: implement clar specific oid helper functions
2025-03-05 10:37:43 -08:00
Todd Zullinger d40da0bd4b Makefile: update reference to technical/racy-git.adoc
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:19 -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 2a1530a953 Merge branch 'ps/meson-contrib-bits' into tz/doc-txt-to-adoc-fixes
* 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
2025-03-01 10:00:45 -08:00
Junio C Hamano 5ce6e0e242 Merge branch 'tb/new-make-fix'
Workaround the overly picky HT/SP rule in newer GNU Make.

* tb/new-make-fix:
  Makefile: remove accidental recipe prefix in conditional
2025-02-25 14:19:35 -08:00
Seyi Kuforiji 149585079f t/unit-tests: convert oidtree test to use clar test framework
Adapt oidtree test script to clar framework by using clar assertions
where necessary. `cl_parse_any_oid()` ensures the hash algorithm is set
before parsing. This prevents issues from an uninitialized or invalid
hash algorithm.

Introduce 'test_oidtree__initialize` handles the to set up of the global
oidtree variable and `test_oidtree__cleanup` frees the oidtree when all
tests are completed.

With this change, `check_each` stops at the first error encountered,
making it easier to address it.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-25 10:31:23 -08:00
Seyi Kuforiji 69bc044def t/unit-tests: convert oidmap test to use clar test framework
Adapt oidmap test script to clar framework by using clar assertions
where necessary. `cl_parse_any_oid()` ensures the hash algorithm is set
before parsing. This prevents issues from an uninitialized or invalid
hash algorithm.

Introduce 'test_oidmap__initialize` handles the to set up of the global
oidmap map with predefined key-value pairs, and `test_oidmap__cleanup`
frees the oidmap and its entries when all tests are completed.

The test loops through all entries to detect multiple errors. With this
change, it stops at the first error encountered, making it easier to
address it.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-25 10:31:22 -08:00
Seyi Kuforiji 869a1edf44 t/unit-tests: convert oid-array test to use clar test framework
Adapt oid-array test script to clar framework by using clar assertions
where necessary. Remove descriptions from macros to reduce
redundancy, and move test input arrays to global scope for reuse across
multiple test functions. Introduce `test_oid_array__initialize()` to
explicitly initialize the hash algorithm.

These changes streamline the test suite, making individual tests
self-contained and reducing redundant code.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-25 10:31:22 -08:00
Seyi Kuforiji a16a2ee312 t/unit-tests: implement clar specific oid helper functions
`get_oid_arbitrary_hex()` and `init_hash_algo()` are both required for
oid-related tests to run without errors. In the current implementation,
both functions are defined and declared in the
`t/unit-tests/lib-oid.{c,h}` which is utilized by oid-related tests in
the homegrown unit tests structure.

Adapt functions in lib-oid.{c,h} to use clar. Both these functions
become available for oid-related test files implemented using the clar
testing framework, which requires them. This will be used by subsequent
commits.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-25 10:31:22 -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 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
Taylor Blau f23179924b Makefile: remove accidental recipe prefix in conditional
Back in 728b9ac0c3 (Makefile(s): avoid recipe prefix in conditional
statements, 2024-04-08), we prepared our Makefiles for a forthcoming
change in upstream Make that would ban the recipe prefix within a
conditional statement by replacing tabs (the prefix) with eight spaces.

In b9d6f64393 (compat/zlib: allow use of zlib-ng as backend,
2025-01-28), a handful of recipe prefix characters were introduced in a
conditional statement ('ifdef ZLIB_NG'), causing 'make' to fail on my
system, which uses GNU Make 4.4.90.

Remove the recipe prefix characters by replacing them with the same
script as is mentioned in 728b9ac0c3.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-13 13:16:34 -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 aae91a86fb Merge branch 'ds/name-hash-tweaks'
"git pack-objects" and its wrapper "git repack" learned an option
to use an alternative path-hash function to improve delta-base
selection to produce a packfile with deeper history than window
size.

* ds/name-hash-tweaks:
  pack-objects: prevent name hash version change
  test-tool: add helper for name-hash values
  p5313: add size comparison test
  pack-objects: add GIT_TEST_NAME_HASH_VERSION
  repack: add --name-hash-version option
  pack-objects: add --name-hash-version option
  pack-objects: create new name-hash function version
2025-02-12 10:08:51 -08:00
Junio C Hamano 6f0b72205d Merge branch 'sk/unit-tests-0130'
Convert a handful of unit tests to work with the clar framework.

* sk/unit-tests-0130:
  t/unit-tests: convert strcmp-offset test to use clar test framework
  t/unit-tests: convert strbuf test to use clar test framework
  t/unit-tests: adapt example decorate test to use clar test framework
  t/unit-tests: convert hashmap test to use clar test framework
2025-02-10 10:18:31 -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 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
Seyi Kuforiji af8bf677c1 t/unit-tests: convert strcmp-offset test to use clar test framework
Adapt strcmp-offset test script to clar framework by using clar
assertions where necessary. Introduce `test_strcmp_offset__empty()` to
verify `check_strcmp_offset()` behavior when both input strings are
empty. This ensures the function correctly handles edge cases and
returns expected values.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-31 14:58:45 -08:00
Seyi Kuforiji 4b995465b2 t/unit-tests: convert strbuf test to use clar test framework
Adapt strbuf test script to clar framework by using clar assertions
where necessary.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-31 14:58:45 -08:00
Seyi Kuforiji e0f807bdad t/unit-tests: adapt example decorate test to use clar test framework
Introduce `test_example_decorate__initialize()` to explicitly set up
object IDs and retrieve corresponding objects before tests run. This
ensures a consistent and predictable test state without relying on data
from previous tests.

Add `test_example_decorate__cleanup()` to clear decorations after each
test, preventing interference between tests and ensuring each runs in
isolation.

Adapt example decorate test script to clar framework by using clar
assertions where necessary. Previously, tests relied on data written by
earlier tests, leading to unintended dependencies between them. This
explicitly initializes the necessary state within
`test_example_decorate__readd`, ensuring it does not depend on prior
test executions.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-31 14:58:44 -08:00
Seyi Kuforiji 38b066ee76 t/unit-tests: convert hashmap test to use clar test framework
Adapts hashmap test script to clar framework by using clar assertions
where necessary.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-31 14:58:44 -08:00
Calvin Wan 65c10aa8d5 libgit: add higher-level libgit crate
The C functions exported by libgit-sys do not provide an idiomatic Rust
interface. To make it easier to use these functions via Rust, add a
higher-level "libgit" crate, that wraps the lower-level configset API
with an interface that is more Rust-y.

This combination of $X and $X-sys crates is a common pattern for FFI in
Rust, as documented in "The Cargo Book" [1].

[1] https://doc.rust-lang.org/cargo/reference/build-scripts.html#-sys-packages

Co-authored-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-29 15:06:50 -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 e7f8bf125c libgit-sys: introduce Rust wrapper for libgit.a
Introduce libgit-sys, a Rust wrapper crate that allows Rust code to call
functions in libgit.a. This initial patch defines build rules and an
interface that exposes user agent string getter functions as a proof of
concept. This library can be tested with `cargo test`. In later commits,
a higher-level library containing a more Rust-friendly interface will be
added at `contrib/libgit-rs`.

Symbols in libgit can collide with symbols from other libraries such as
libgit2. We avoid this by first exposing library symbols in
public_symbol_export.[ch]. These symbols are prepended with "libgit_" to
avoid collisions and set to visible using a visibility pragma. In
build.rs, Rust builds contrib/libgit-rs/libgit-sys/libgitpub.a, which also
contains libgit.a and other dependent libraries, with
-fvisibility=hidden to hide all symbols within those libraries that
haven't been exposed with a visibility pragma.

Co-authored-by: Kyle Lippincott <spectral@google.com>
Co-authored-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Kyle Lippincott <spectral@google.com>
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-28 14:45:47 -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 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 8d335468ec Merge branch 'sk/unit-tests'
Move a few more unit tests to the clar test framework.

* sk/unit-tests:
  t/unit-tests: convert reftable tree test to use clar test framework
  t/unit-tests: adapt priority queue test to use clar test framework
  t/unit-tests: convert mem-pool test to use clar test framework
  t/unit-tests: handle dashes in test suite filenames
2025-01-28 13:02:22 -08:00
Derrick Stolee 7f9870794f test-tool: add helper for name-hash values
Add a new test-tool helper, name-hash, to output the value of the
name-hash algorithms for the input list of strings, one per line.

Since the name-hash values can be stored in the .bitmap files, it is
important that these hash functions do not change across Git versions.
Add a simple test to t5310-pack-bitmaps.sh to provide some testing of
the current values. Due to how these functions are implemented, it would
be difficult to change them without disturbing these values. The paths
used for this test are carefully selected to demonstrate some of the
behavior differences of the two current name hash versions, including
which conditions will cause them to collide.

Create a performance test that uses test_size to demonstrate how
collisions occur for these hash algorithms. This test helps inform
someone as to the behavior of the name-hash algorithms for their repo
based on the paths at HEAD.

My copy of the Git repository shows modest statistics around the
collisions of the default name-hash algorithm:

Test                               this tree
--------------------------------------------------
5314.1: paths at head                         4.5K
5314.2: distinct hash value: v1               4.1K
5314.3: maximum multiplicity: v1                13
5314.4: distinct hash value: v2               4.2K
5314.5: maximum multiplicity: v2                 9

Here, the maximum collision multiplicity is 13, but around 10% of paths
have a collision with another path.

In a more interesting example, the microsoft/fluentui [1] repo had these
statistics at time of committing:

Test                               this tree
--------------------------------------------------
5314.1: paths at head                        19.5K
5314.2: distinct hash value: v1               8.2K
5314.3: maximum multiplicity: v1               279
5314.4: distinct hash value: v2              17.8K
5314.5: maximum multiplicity: v2                44

[1] https://github.com/microsoft/fluentui

That demonstrates that of the nearly twenty thousand path names, they
are assigned around eight thousand distinct values. 279 paths are
assigned to a single value, leading the packing algorithm to sort
objects from those paths together, by size.

With the v2 name hash function, the maximum multiplicity lowers to 44,
leaving some room for further improvement.

In a more extreme example, an internal monorepo had a much worse
collision rate:

Test                               this tree
--------------------------------------------------
5314.1: paths at head                       227.3K
5314.2: distinct hash value: v1              72.3K
5314.3: maximum multiplicity: v1             14.4K
5314.4: distinct hash value: v2             166.5K
5314.5: maximum multiplicity: v2               138

Here, we can see that the v2 name hash function provides somem
improvements, but there are still a number of collisions that could lead
to repacking problems at this scale.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-27 13:21:43 -08:00
Patrick Steinhardt 68f51871df builtin/pack-redundant: remove subcommand with breaking changes
The git-pack-redundant(1) subcommand has been castrated to require
the "--i-still-use-this" option to do anything since 4406522b
(pack-redundant: escalate deprecation warning to an error,
2023-03-23), which appeared in Git 2.41 and was announced for
removal with 53a92c9552 (Documentation/BreakingChanges: announce
removal of git-pack-redundant(1), 2024-09-02). Stop compiling the
subcommand in case the `WITH_BREAKING_CHANGES` build flag is set.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-22 12:34:05 -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
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
Seyi Kuforiji ffbd3f98f9 t/unit-tests: convert reftable tree test to use clar test framework
Adapts reftable tree test script to clar framework by using clar
assertions where necessary.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-17 14:35:12 -08:00
Seyi Kuforiji 8b702f93dd t/unit-tests: adapt priority queue test to use clar test framework
Convert the prio-queue test script to clar framework by using clar
assertions where necessary. Test functions are created as a standalone
to test different cases.

update the type of the variable `j` from int to `size_t`, this ensures
compatibility with the type used for result_size, which is also size_t,
preventing a potential warning or error caused by comparisons between
signed and unsigned integers.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-17 14:35:12 -08:00
Seyi Kuforiji c143dfa7ed t/unit-tests: convert mem-pool test to use clar test framework
Adapt the mem-pool test script to use clar framework by using clar
assertions where necessary.Test functions are created as a standalone to
test different test cases.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-17 14:35:11 -08:00
Seyi Kuforiji 43850dcf9c t/unit-tests: convert hash to use clar test framework
Adapt the hash test functions to clar framework by using clar
assertions where necessary. Following the consensus to convert
the unit-tests scripts found in the t/unit-tests folder to clar driven by
Patrick Steinhardt. Test functions are structured as a standalone to
test individual hash string and literal case.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Seyi Kuforiji <kuforiji98@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-09 07:55:00 -08:00
Junio C Hamano fc89d14c63 Revert barrier-based LSan threading race workaround
The extra "barrier" approach was too much code whose sole purpose
was to work around a race that is not even ours (i.e. in LSan's
teardown code).

In preparation for queuing a solution taking a much-less-invasive
approach, let's revert them.
2025-01-01 14:13:01 -08:00
Jeff King 7d0037b59a thread-utils: introduce optional barrier type
One thread primitive we don't yet support is a barrier: it waits for all
threads to reach a synchronization point before letting any of them
continue. This would be useful for avoiding the LSan race we see in
index-pack (and other places) by having all threads complete their
initialization before any of them start to do real work.

POSIX introduced a pthread_barrier_t in 2004, which does what we want.
But if we want to rely on it:

  1. Our Windows pthread emulation would need a new set of wrapper
     functions. There's a Synchronization Barrier primitive there, which
     was introduced in Windows 8 (which is old enough for us to depend
     on).

  2. macOS (and possibly other systems) has pthreads but not
     pthread_barrier_t. So there we'd have to implement our own barrier
     based on the mutex and cond primitives.

Those are do-able, but since we only care about avoiding races in our
LSan builds, there's an easier way: make it a noop on systems without a
native pthread barrier.

This patch introduces a "maybe_thread_barrier" API. The clunky name
(rather than just using pthread_barrier directly) should hopefully clue
people in that on some systems it will do nothing. It's wired to a
Makefile knob which has to be triggered manually, and we enable it for
the linux-leaks CI jobs (since we know we'll have it there).

There are some other possible options:

  - we could turn it on all the time for Linux systems based on uname.
    But we really only care about it for LSan builds, and there is no
    need to add extra code to regular builds.

  - we could turn it on only for LSan builds. But that would break
    builds on non-Linux platforms (like macOS) that otherwise should
    support sanitizers.

  - we could trigger only on the combination of Linux and LSan together.
    This isn't too hard to do, but the uname check isn't completely
    accurate. It is really about what your libc supports, and non-glibc
    systems might not have it (though at least musl seems to).

    So we'd risk breaking builds on those systems, which would need to
    add a new knob. Though the upside would be that running local "make
    SANITIZE=leak test" would be protected automatically.

And of course none of this protects LSan runs from races on systems
without pthread barriers. It's probably OK in practice to protect only
our CI jobs, though. The race is rare-ish and most leak-checking happens
through CI.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-30 06:18:57 -08:00
Patrick Steinhardt cbcc2f7911 GIT-BUILD-OPTIONS: wire up NO_GITWEB option
Building our "gitweb" interface is optional in our Makefile and in Meson
and not wired up at all with CMake, but disabling it causes a couple of
tests in the t950* range that pull in "t/lib-gitweb.sh". This is because
the test library knows to execute gitweb-tests based on whether or not
Perl is available, but we may have Perl available and still end up not
building gitweb e.g. with `make test NO_GITWEB=YesPlease`.

Fix this issue by wiring up a new "NO_GITWEB" build option so that we
can skip these tests in case gitweb is not built.

Note that this new build option requires us to move the configuration of
GIT-BUILD-OPTIONS to a later point in our Meson build instructions. But
as that file is only consumed by our tests at runtime this change does
not cause any issues.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:17:19 -08:00
Patrick Steinhardt cfa1f2ae96 GIT-BUILD-OPTIONS: sort variables alphabetically
The variables declared and substituted in GIT-BUILD-OPTIONS are not
ordered in any obvious way. Sort them alphabetically so that it becomes
obvious where new variables should go.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:17:19 -08:00
Junio C Hamano f074cdea46 Merge branch 'ps/build-hotfix'
A topic to optionally build with meson, which has graduated to
'master' recently, has regressed the normal Makefile build, which
is being corrected.

* ps/build-hotfix:
  meson: add options to override build information
  GIT-VERSION-GEN: fix overriding GIT_BUILT_FROM_COMMIT and GIT_DATE
  GIT-VERSION-GEN: fix overriding GIT_VERSION
  Makefile: introduce template for GIT-VERSION-GEN
  Makefile: drop unneeded indirection for GIT-VERSION-GEN outputs
  Makefile: stop including "GIT-VERSION-FILE" in docs
2024-12-23 09:32:26 -08:00
Junio C Hamano 83c8f76235 Merge branch 'ps/ci-meson'
The meson-build procedure is integrated into CI to catch and
prevent bitrotting.

* ps/ci-meson:
  ci: wire up Meson builds
  t: introduce compatibility options to clar-based tests
  t: fix out-of-tree tests for some git-p4 tests
  Makefile: detect missing Meson tests
  meson: detect missing tests at configure time
  t/unit-tests: rename clar-based unit tests to have a common prefix
  Makefile: drop -DSUPPRESS_ANNOTATED_LEAKS
  ci/lib: support custom output directories when creating test artifacts
2024-12-23 09:32:25 -08:00
Patrick Steinhardt 992bc5618f GIT-VERSION-GEN: fix overriding GIT_VERSION
GIT-VERSION-GEN tries to derive the version that Git is being built from
via multiple different sources in the following order:

  1. A file called "version" in the source tree's root directory, if it
     exists.

  2. The current commit in case Git is built from a Git repository.

  3. Otherwise, we use a fallback version stored in a variable which is
     bumped whenever a new Git version is getting tagged.

It used to be possible to override the version by overriding the
`GIT_VERSION` Makefile variable (e.g. `make GIT_VERSION=foo`). This
worked somewhat by chance, only: `GIT-VERSION-GEN` would write the
actual Git version into `GIT-VERSION-FILE`, not the overridden value,
but when including the file into our Makefile we would not override the
`GIT_VERSION` variable because it has already been set by the user. And
because our Makefile used the variable to propagate the version to our
build tools instead of using `GIT-VERSION-FILE` the resulting build
artifacts used the overridden version.

But that subtle mechanism broke with 4838deab65 (Makefile: refactor
GIT-VERSION-GEN to be reusable, 2024-12-06) and subsequent commits
because the version information is not propagated via the Makefile
variable anymore, but instead via the files that `GIT-VERSION-GEN`
started to write. And as the script never knew about the `GIT_VERSION`
environment variable in the first place it uses one of the values listed
above instead of the overridden value.

Fix this issue by making `GIT-VERSION-GEN` handle the case where
`GIT_VERSION` has been set via the environment.

Note that this requires us to introduce a new GIT_VERSION_OVERRIDE
variable that stores a potential user-provided value, either via the
environment or via "config.mak". Ideally we wouldn't need it and could
just continue to use GIT_VERSION for this. But unfortunately, Makefiles
will first include all sub-Makefiles before figuring out whether it
needs to re-make any of them [1]. Consequently, if there already is a
GIT-VERSION-FILE, we would have slurped in its value of GIT_VERSION
before we call GIT-VERSION-GEN, and because GIT-VERSION-GEN now uses
that value as an override it would mean that the first generated value
for GIT_VERSION will remain unchanged.

Furthermore we have to move the include for "GIT-VERSION-FILE" after the
includes for "config.mak" and related so that GIT_VERSION_OVERRIDE can
be set to the value provided by "config.mak".

[1]: https://www.gnu.org/software/make/manual/html_node/Remaking-Makefiles.html

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 12:36:45 -08:00
Patrick Steinhardt 114494ae2c Makefile: introduce template for GIT-VERSION-GEN
Introduce a new template to call GIT-VERSION-GEN. This will allow us to
iterate on how exactly the script is called in subsequent commits
without having to adapt all call sites every time.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 12:36:45 -08:00
Patrick Steinhardt b329f2eb00 Makefile: drop unneeded indirection for GIT-VERSION-GEN outputs
Some of the callsites of GIT-VERSION-GEN generate the target file with a
"+" suffix first and then move the file into place when the new contents
are different compared to the old contents. This allows us to avoid a
needless rebuild by not updating timestamps of the target file when its
contents will remain unchanged anyway.

In fact though, this exact logic is already handled in GIT-VERSION-GEN,
so doing this manually is pointless. This is a leftover from an earlier
version of 4838deab65 (Makefile: refactor GIT-VERSION-GEN to be
reusable, 2024-12-06), where the script didn't handle that logic for us.

Drop the needless indirection.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 12:36:44 -08:00
Derrick Stolee d190124f27 t6601: add helper for testing path-walk API
Add some tests based on the current behavior, doing interesting checks
for different sets of branches, ranges, and the --boundary option. This
sets a baseline for the behavior and we can extend it as new options are
introduced.

Store and output a 'batch_nr' value so we can demonstrate that the paths are
grouped together in a batch and not following some other ordering. This
allows us to test the depth-first behavior of the path-walk API. However, we
purposefully do not test the order of the objects in the batch, so the
output is compared to the expected output through a sort.

It is important to mention that the behavior of the API will change soon as
we start to handle UNINTERESTING objects differently, but these tests will
demonstrate the change in behavior.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 08:37:04 -08:00