Commit Graph

2881 Commits

Author SHA1 Message Date
Junio C Hamano
cacfd1d018 Merge branch 'pw/test-malloc-with-sanitize-address'
Avoid problems from interaction between malloc_check and address
sanitizer.

* pw/test-malloc-with-sanitize-address:
  tests: make SANITIZE=address imply TEST_NO_MALLOC_CHECK
2022-05-11 13:56:22 -07:00
Elia Pinto
96ddfecc5b Makefile: add a prerequisite to the coverage-report target
Directly invoking make coverage-report as a target results in an error because
its prerequisites are missing,

This patch adds the compile-test prerequisite, which is run only once each time
the compile-report target is invoked. In practice, the developer may decide to
review the coverage-report results without necessarily rerunning for this
coverage-test, if it has already been run.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-13 22:16:36 -07:00
Phillip Wood
067109a5e7 tests: make SANITIZE=address imply TEST_NO_MALLOC_CHECK
As the address sanitizer checks for a superset of the issues detected
by setting MALLOC_CHECK_ (which tries to detect things like double
frees and off-by-one errors) there is no need to set the latter when
compiling with -fsanitize=address.

This fixes a regression introduced by 131b94a10a ("test-lib.sh: Use
GLIBC_TUNABLES instead of MALLOC_CHECK_ on glibc >= 2.34", 2022-03-04)
which causes all the tests to fail with the message

    ASan runtime does not come first in initial library list;
    you should either link runtime to your application or
    manually preload it with LD_PRELOAD.

when git is compiled with SANITIZE=address on systems with glibc >=
2.34. I have tested SANITIZE=leak and SANITIZE=undefined and they do
not suffer from this regression so the fix in this patch should be
sufficient.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-11 12:12:02 -07:00
Junio C Hamano
95acb13a55 Merge branch 'bc/csprng-mktemps'
Build fix.

* bc/csprng-mktemps:
  git-compat-util: really support openssl as a source of entropy
2022-04-06 15:21:59 -07:00
Carlo Marcelo Arenas Belón
5b52d9f15e git-compat-util: really support openssl as a source of entropy
05cd988dce (wrapper: add a helper to generate numbers from a CSPRNG,
2022-01-17), configure openssl as the source for entropy in NON-STOP
but doesn't add the needed header or link options.

Since the only system that is configured to use openssl as a source
of entropy is NON-STOP, add the header unconditionally, and -lcrypto
to the list of external libraries.

An additional change is required to make sure a NO_OPENSSL=1 build
will be able to work as well (tested on Linux with a modified value
of CSPRNG_METHOD = openssl), and the more complex logic that allows
for compatibility with APPLE_COMMON_CRYPTO or allowing for simpler
ways to link (without libssl) has been punted for now.

Reported-by: Randall Becker <rsbecker@nexbridge.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-06 09:04:50 -07:00
Junio C Hamano
439c1e6d5d Merge branch 'jh/builtin-fsmonitor-part2'
Built-in fsmonitor (part 2).

* jh/builtin-fsmonitor-part2: (30 commits)
  t7527: test status with untracked-cache and fsmonitor--daemon
  fsmonitor: force update index after large responses
  fsmonitor--daemon: use a cookie file to sync with file system
  fsmonitor--daemon: periodically truncate list of modified files
  t/perf/p7519: add fsmonitor--daemon test cases
  t/perf/p7519: speed up test on Windows
  t/perf/p7519: fix coding style
  t/helper/test-chmtime: skip directories on Windows
  t/perf: avoid copying builtin fsmonitor files into test repo
  t7527: create test for fsmonitor--daemon
  t/helper/fsmonitor-client: create IPC client to talk to FSMonitor Daemon
  help: include fsmonitor--daemon feature flag in version info
  fsmonitor--daemon: implement handle_client callback
  compat/fsmonitor/fsm-listen-darwin: implement FSEvent listener on MacOS
  compat/fsmonitor/fsm-listen-darwin: add MacOS header files for FSEvent
  compat/fsmonitor/fsm-listen-win32: implement FSMonitor backend on Windows
  fsmonitor--daemon: create token-based changed path cache
  fsmonitor--daemon: define token-ids
  fsmonitor--daemon: add pathname classification
  fsmonitor--daemon: implement 'start' command
  ...
2022-04-04 10:56:24 -07:00
Junio C Hamano
eb804cd405 Merge branch 'ns/core-fsyncmethod'
Replace core.fsyncObjectFiles with two new configuration variables,
core.fsync and core.fsyncMethod.

* ns/core-fsyncmethod:
  core.fsync: documentation and user-friendly aggregate options
  core.fsync: new option to harden the index
  core.fsync: add configuration parsing
  core.fsync: introduce granular fsync control infrastructure
  core.fsyncmethod: add writeout-only mode
  wrapper: make inclusion of Windows csprng header tightly scoped
2022-03-25 16:38:24 -07:00
Jeff Hostetler
148405fb27 t/helper/fsmonitor-client: create IPC client to talk to FSMonitor Daemon
Create an IPC client to send query and flush commands to the daemon.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:16 -07:00
Jeff Hostetler
62c7367133 compat/fsmonitor/fsm-listen-win32: stub in backend for Windows
Stub in empty filesystem listener backend for fsmonitor--daemon on Windows.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:15 -07:00
Jeff Hostetler
16d9d6175b fsmonitor--daemon: add a built-in fsmonitor daemon
Create a built-in file system monitoring daemon that can be used by
the existing `fsmonitor` feature (protocol API and index extension)
to improve the performance of various Git commands, such as `status`.

The `fsmonitor--daemon` feature builds upon the `Simple IPC` API and
provides an alternative to hook access to existing fsmonitors such
as `watchman`.

This commit merely adds the new command without any functionality.

Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:15 -07:00
Jeff Hostetler
1e0ea5c431 fsmonitor: config settings are repository-specific
Move fsmonitor config settings to a new and opaque
`struct fsmonitor_settings` structure.  Add a lazily-loaded pointer
to this into `struct repo_settings`

Create an `enum fsmonitor_mode` type in `struct fsmonitor_settings` to
represent the state of fsmonitor.  This lets us represent which, if
any, fsmonitor provider (hook or IPC) is enabled.

Create `fsm_settings__get_*()` getters to lazily look up fsmonitor-
related config settings.

Get rid of the `core_fsmonitor` global variable.  Move the code to
lookup the existing `core.fsmonitor` config value into the fsmonitor
settings.

Create a hook pathname variable in `struct fsmonitor-settings` and
only set it when in hook mode.

Extend the definition of `core.fsmonitor` to be either a boolean
or a hook pathname.  When true, the builtin FSMonitor is used.
When false or unset, no FSMonitor (neither builtin nor hook) is
used.

The existing `core_fsmonitor` global variable was used to store the
pathname to the fsmonitor hook *and* it was used as a boolean to see
if fsmonitor was enabled.  This dual usage and global visibility leads
to confusion when we add the IPC-based provider.  So lets hide the
details in fsmonitor-settings.c and let it decide which provider to
use in the case of multiple settings.  This avoids cluttering up
repo-settings.c with these private details.

A future commit in builtin-fsmonitor series will add the ability to
disqualify worktrees for various reasons, such as being mounted from a
remote volume, where fsmonitor should not be started.  Having the
config settings hidden in fsmonitor-settings.c allows such worktree
restrictions to override the config values used.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:15 -07:00
Jeff Hostetler
d2bd862e7a fsmonitor-ipc: create client routines for git-fsmonitor--daemon
Create fsmonitor_ipc__*() client routines to spawn the built-in file
system monitor daemon and send it an IPC request using the `Simple
IPC` API.

Stub in empty fsmonitor_ipc__*() functions for unsupported platforms.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:15 -07:00
Junio C Hamano
a2fc9c3c40 Merge branch 'jc/stash-drop'
"git stash drop" is reimplemented as an internal call to
reflog_delete() function, instead of invoking "git reflog delete"
via run_command() API.

* jc/stash-drop:
  stash: call reflog_delete() in reflog.c
  reflog: libify delete reflog function and helpers
  stash: add tests to ensure reflog --rewrite --updatref behavior
2022-03-16 17:53:08 -07:00
Neeraj Singh
abf38abec2 core.fsyncmethod: add writeout-only mode
This commit introduces the `core.fsyncMethod` configuration
knob, which can currently be set to `fsync` or `writeout-only`.

The new writeout-only mode attempts to tell the operating system to
flush its in-memory page cache to the storage hardware without issuing a
CACHE_FLUSH command to the storage controller.

Writeout-only fsync is significantly faster than a vanilla fsync on
common hardware, since data is written to a disk-side cache rather than
all the way to a durable medium. Later changes in this patch series will
take advantage of this primitive to implement batching of hardware
flushes.

When git_fsync is called with FSYNC_WRITEOUT_ONLY, it may fail and the
caller is expected to do an ordinary fsync as needed.

On Apple platforms, the fsync system call does not issue a CACHE_FLUSH
directive to the storage controller. This change updates fsync to do
fcntl(F_FULLFSYNC) to make fsync actually durable. We maintain parity
with existing behavior on Apple platforms by setting the default value
of the new core.fsyncMethod option.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-10 15:10:22 -08:00
Ævar Arnfjörð Bjarmason
0b6d0bc924 Makefiles: add and use wildcard "mkdir -p" template
Add a template to do the "mkdir -p" of $(@D) (the parent dir of $@)
for us, and use it for the "make lint-docs" targets I added in
8650c6298c (doc lint: make "lint-docs" non-.PHONY, 2021-10-15).

As seen in 4c64fb5aad (Documentation/Makefile: fix lint-docs mkdir
dependency, 2021-10-26) maintaining these manual lists of parent
directory dependencies is fragile, in addition to being obviously
verbose.

I used this pattern at the time because I couldn't find another method
than "order-only" prerequisites to avoid doing a "mkdir -p $(@D)" for
every file being created, which as noted in [1] would be significantly
slower.

But as it turns out we can use this neat trick of only doing a "mkdir
-p" if the $(wildcard) macro tells us the path doesn't exist. A re-run
of a performance test similar to that noted downthread of [1] in [2]
shows that this is faster, in addition to being less verbose and more
reliable (this uses my "git-hyperfine" thin wrapper for "hyperfine"[3]):

    $ git -c hyperfine.hook.setup= hyperfine -L rev HEAD~1,HEAD~0 -s 'make -C Documentation lint-docs' -p 'rm -rf Documentation/.build' 'make -C Documentation -j1 lint-docs'
    Benchmark 1: make -C Documentation -j1 lint-docs' in 'HEAD~1
      Time (mean ± σ):      2.914 s ±  0.062 s    [User: 2.449 s, System: 0.489 s]
      Range (min … max):    2.834 s …  3.020 s    10 runs

    Benchmark 2: make -C Documentation -j1 lint-docs' in 'HEAD~0
      Time (mean ± σ):      2.315 s ±  0.062 s    [User: 1.950 s, System: 0.386 s]
      Range (min … max):    2.229 s …  2.397 s    10 runs

    Summary
      'make -C Documentation -j1 lint-docs' in 'HEAD~0' ran
        1.26 ± 0.04 times faster than 'make -C Documentation -j1 lint-docs' in 'HEAD~1'

So let's use that pattern both for the "lint-docs" target, and a few
miscellaneous other targets.

This method of creating parent directories is explicitly racy in that
we don't know if we're going to say always create a "foo" followed by
a "foo/bar" under parallelism, or skip the "foo" because we created
"foo/bar" first. In this case it doesn't matter for anything except
that we aren't guaranteed to get the same number of rules firing when
running make in parallel.

1. https://lore.kernel.org/git/211028.861r45y3pt.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/211028.86o879vvtp.gmgdl@evledraar.gmail.com/
3. https://gitlab.com/avar/git-hyperfine/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-03 14:14:55 -08:00
Ævar Arnfjörð Bjarmason
a9fda017f4 Makefile: add "$(QUIET)" boilerplate to shared.mak
The $(QUIET) variables we define are largely duplicated between our
various Makefiles, let's define them in the new "shared.mak" instead.

Since we're not using the environment to pass these around we don't
need to export the "QUIET_GEN" and "QUIET_BUILT_IN" variables
anymore. The "QUIET_GEN" variable is used in "git-gui/Makefile" and
"gitweb/Makefile", but they've got their own definition for those. The
"QUIET_BUILT_IN" variable is only used in the top-level "Makefile". We
still need to export the "V" variable.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-03 14:14:55 -08:00
Ævar Arnfjörð Bjarmason
fd15f8a5fa Makefile: move $(comma), $(empty) and $(space) to shared.mak
Move these variables over to the shared.mak, we'll make use of them in
a subsequent commit.

Note that there's reason for these to be "simply expanded variables",
i.e. to use ":=" assignments instead of lazily expanded "="
assignments. We could use "=", but let's leave this as-is for now for
ease of review.

See 425ca6710b (Makefile: allow combining UBSan with other
sanitizers, 2017-07-15) for the commit that introduced these.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-03 14:14:55 -08:00
Ævar Arnfjörð Bjarmason
dad9cd7d51 Makefile: move ".SUFFIXES" rule to shared.mak
This was added in 30248886ce (Makefile: disable default implicit
rules, 2010-01-26), let's move it to the top of "shared.mak" so it'll
apply to all our Makefiles.

This doesn't benefit the main Makefile at all, since it already had
the rule, but since we're including shared.mak in other Makefiles
starts to benefit them. E.g. running the 'man" target is now faster:

    $ git -c hyperfine.hook.setup= hyperfine -L rev HEAD~1,HEAD~0 -s 'make -C Documentation man' 'make -C Documentation -j1 man'
    Benchmark 1: make -C Documentation -j1 man' in 'HEAD~1
      Time (mean ± σ):     121.7 ms ±   8.8 ms    [User: 105.8 ms, System: 18.6 ms]
      Range (min … max):   112.8 ms … 148.4 ms    26 runs

    Benchmark 2: make -C Documentation -j1 man' in 'HEAD~0
      Time (mean ± σ):      97.5 ms ±   8.0 ms    [User: 80.1 ms, System: 20.1 ms]
      Range (min … max):    89.8 ms … 111.8 ms    32 runs

    Summary
      'make -C Documentation -j1 man' in 'HEAD~0' ran
        1.25 ± 0.14 times faster than 'make -C Documentation -j1 man' in 'HEAD~1'

The reason for that can be seen when comparing that run with
"--debug=a". Without this change making a target like "git-status.1"
will cause "make" to consider not only "git-status.txt", but
"git-status.txt.o", as well as numerous other implicit suffixes such
as ".c", ".cc", ".cpp" etc. See [1] for a more detailed before/after
example.

So this is causing us to omit a bunch of work we didn't need to
do. For making "git-status.1" the "--debug=a" output is reduced from
~140k lines to ~6k.

1. https://lore.kernel.org/git/220222.86bkyz875k.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-03 14:14:55 -08:00
Ævar Arnfjörð Bjarmason
f4c6a526a1 Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES)
Combine the definitions of $(FIND_SOURCE_FILES) and $(LIB_H) to speed
up the Makefile, as these are the two main expensive $(shell) commands
that we execute unconditionally.

When see what was in $(FOUND_SOURCE_FILES) that wasn't in $(LIB_H) via
the ad-hoc test of:

    $(error $(filter-out $(LIB_H),$(filter %.h,$(ALL_SOURCE_FILES))))
    $(error $(filter-out $(ALL_SOURCE_FILES),$(filter %.h,$(LIB_H))))

We'll get, respectively:

    Makefile:850: *** t/helper/test-tool.h.  Stop.
    Makefile:850: *** .  Stop.

I.e. we only had a discrepancy when it came to
t/helper/test-tool.h. In terms of correctness this was broken before,
but now works:

    $ make t/helper/test-tool.hco
        HDR t/helper/test-tool.h

This speeds things up a lot:

    $ git -c hyperfine.hook.setup= hyperfine -L rev HEAD~1,HEAD~0 -s 'make NO_TCLTK=Y' 'make -j1 NO_TCLTK=Y' --warmup 10 -M 10
    Benchmark 1: make -j1 NO_TCLTK=Y' in 'HEAD~1
      Time (mean ± σ):     159.9 ms ±   6.8 ms    [User: 137.2 ms, System: 28.0 ms]
      Range (min … max):   154.6 ms … 175.9 ms    10 runs

    Benchmark 2: make -j1 NO_TCLTK=Y' in 'HEAD~0
      Time (mean ± σ):     100.0 ms ±   1.3 ms    [User: 84.2 ms, System: 20.2 ms]
      Range (min … max):    98.8 ms … 102.8 ms    10 runs

    Summary
      'make -j1 NO_TCLTK=Y' in 'HEAD~0' ran
        1.60 ± 0.07 times faster than 'make -j1 NO_TCLTK=Y' in 'HEAD~1'

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-03 14:14:55 -08:00
Ævar Arnfjörð Bjarmason
8df786d298 Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it
We have various behavior that's shared across our Makefiles, or that
really should be (e.g. via defined templates). Let's create a
top-level "shared.mak" to house those sorts of things, and start by
adding the ".DELETE_ON_ERROR" flag to it.

See my own 7b76d6bf22 (Makefile: add and use the ".DELETE_ON_ERROR"
flag, 2021-06-29) and db10fc6c09 (doc: simplify Makefile using
.DELETE_ON_ERROR, 2021-05-21) for the addition and use of the
".DELETE_ON_ERROR" flag.

I.e. this changes the behavior of existing rules in the altered
Makefiles (except "Makefile" & "Documentation/Makefile"). I'm
confident that this is safe having read the relevant rules in those
Makfiles, and as the GNU make manual notes that it isn't the default
behavior is out of an abundance of backwards compatibility
caution. From edition 0.75 of its manual, covering GNU make 4.3:

    [Enabling '.DELETE_ON_ERROR' is] almost always what you want
    'make' to do, but it is not historical practice; so for
    compatibility, you must explicitly request it.

This doesn't introduce a bug by e.g. having this
".DELETE_ON_ERROR" flag only apply to this new shared.mak, Makefiles
have no such scoping semantics.

It does increase the danger that any Makefile without an explicit "The
default target of this Makefile is..." snippet to define the default
target as "all" could have its default rule changed if our new
shared.mak ever defines a "real" rule. In subsequent commits we'll be
careful not to do that, and such breakage would be obvious e.g. in the
case of "make -C t".

We might want to make that less fragile still (e.g. by using
".DEFAULT_GOAL" as noted in the preceding commit), but for now let's
simply include "shared.mak" without adding that boilerplate to all the
Makefiles that don't have it already. Most of those are already
exposed to that potential caveat e.g. due to including "config.mak*".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-03 14:14:55 -08:00
John Cai
7d3d226e70 reflog: libify delete reflog function and helpers
Currently stash shells out to reflog in order to delete refs. In an
effort to reduce how much we shell out to a subprocess, libify the
functionality that stash needs into reflog.c.

Add a reflog_delete function that is pretty much the logic in the while
loop in builtin/reflog.c cmd_reflog_delete(). This is a function that
builtin/reflog.c and builtin/stash.c can both call.

Also move functions needed by reflog_delete and export them.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-02 15:24:47 -08:00
Junio C Hamano
00e38ba6d8 Merge branch 'ab/auto-detect-zlib-compress2'
The build procedure has been taught to notice older version of zlib
and enable our replacement uncompress2() automatically.

* ab/auto-detect-zlib-compress2:
  compat: auto-detect if zlib has uncompress2()
2022-02-16 15:14:30 -08:00
Junio C Hamano
d073bdc6a0 Merge branch 'bc/csprng-mktemps'
Pick a better random number generator and use it when we prepare
temporary filenames.

* bc/csprng-mktemps:
  wrapper: use a CSPRNG to generate random file names
  wrapper: add a helper to generate numbers from a CSPRNG
2022-02-11 16:55:57 -08:00
Junio C Hamano
c70bc338e9 Merge branch 'ab/config-based-hooks-2'
More "config-based hooks".

* ab/config-based-hooks-2:
  run-command: remove old run_hook_{le,ve}() hook API
  receive-pack: convert push-to-checkout hook to hook.h
  read-cache: convert post-index-change to use hook.h
  commit: convert {pre-commit,prepare-commit-msg} hook to hook.h
  git-p4: use 'git hook' to run hooks
  send-email: use 'git hook run' for 'sendemail-validate'
  git hook run: add an --ignore-missing flag
  hooks: convert worktree 'post-checkout' hook to hook library
  hooks: convert non-worktree 'post-checkout' hook to hook library
  merge: convert post-merge to use hook.h
  am: convert applypatch-msg to use hook.h
  rebase: convert pre-rebase to use hook.h
  hook API: add a run_hooks_l() wrapper
  am: convert {pre,post}-applypatch to use hook.h
  gc: use hook library for pre-auto-gc hook
  hook API: add a run_hooks() wrapper
  hook: add 'run' subcommand
2022-02-09 14:21:00 -08:00
Ævar Arnfjörð Bjarmason
07564773c2 compat: auto-detect if zlib has uncompress2()
We have a copy of uncompress2() implementation in compat/ so that we
can build with an older version of zlib that lack the function, and
the build procedure selects if it is used via the NO_UNCOMPRESS2
$(MAKE) variable.  This is yet another "annoying" knob the porters
need to tweak on platforms that are not common enough to have the
default set in the config.mak.uname file.

Attempt to instead ask the system header <zlib.h> to decide if we
need the compatibility implementation.  This is a deviation from the
way we have been handling the "compatiblity" features so far, and if
it can be done cleanly enough, it could work as a model for features
that need compatibility definition we discover in the future.  With
that goal in mind, avoid expedient but ugly hacks, like shoving the
code that is conditionally compiled into an unrelated .c file, which
may not work in future cases---instead, take an approach that uses a
file that is independently compiled and stands on its own.

Compile and link compat/zlib-uncompress2.c file unconditionally, but
conditionally hide the implementation behind #if/#endif when zlib
version is 1.2.9 or newer, and unconditionally archive the resulting
object file in the libgit.a to be picked up by the linker.

There are a few things to note in the shape of the code base after
this change:

 - We no longer use NO_UNCOMPRESS2 knob; if the system header
   <zlib.h> claims a version that is more cent than the library
   actually is, this would break, but it is easy to add it back when
   we find such a system.

 - The object file compat/zlib-uncompress2.o is always compiled and
   archived in libgit.a, just like a few other compat/ object files
   already are.

 - The inclusion of <zlib.h> is done in <git-compat-util.h>; we used
   to do so from <cache.h> which includes <git-compat-util.h> as the
   first thing it does, so from the *.c codes, there is no practical
   change.

 - Until objects in libgit.a that is already used gains a reference
   to the function, the reftable code will be the only one that
   wants it, so libgit.a on the linker command line needs to appear
   once more at the end to satisify the mutual dependency.

 - Beat found a trick used by OpenSSL to avoid making the
   conditionally-compiled object truly empty (apparently because
   they had to deal with compilers that do not want to see an
   effectively empty input file).  Our compat/zlib-uncompress2.c
   file borrows the same trick for portabilty.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: Beat Bolli <dev+git@drbeat.li>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-26 09:05:55 -08:00
brian m. carlson
05cd988dce wrapper: add a helper to generate numbers from a CSPRNG
There are many situations in which having access to a cryptographically
secure pseudorandom number generator (CSPRNG) is helpful.  In the
future, we'll encounter one of these when dealing with temporary files.
To make this possible, let's add a function which reads from a system
CSPRNG and returns some bytes.

We know that all systems will have such an interface.  A CSPRNG is
required for a secure TLS or SSH implementation and a Git implementation
which provided neither would be of little practical use.  In addition,
POSIX is set to standardize getentropy(2) in the next version, so in the
(potentially distant) future we can rely on that.

For systems which lack one of the other interfaces, we provide the
ability to use OpenSSL's CSPRNG.  OpenSSL is highly portable and
functions on practically every known OS, and we know it will have access
to some source of cryptographically secure randomness.  We also provide
support for the arc4random in libbsd for folks who would prefer to use
that.

Because this is a security sensitive interface, we take some
precautions.  We either succeed by filling the buffer completely as we
requested, or we fail.  We don't return partial data because the caller
will almost never find that to be a useful behavior.

Specify a makefile knob which users can use to specify one or more
suitable CSPRNGs, and turn the multiple string options into a set of
defines, since we cannot match on strings in the preprocessor.  We allow
multiple options to make the job of handling this in autoconf easier.

The order of options is important here.  On systems with arc4random,
which is most of the BSDs, we use that, since, except on MirBSD and
macOS, it uses ChaCha20, which is extremely fast, and sits entirely in
userspace, avoiding a system call.  We then prefer getrandom over
getentropy, because the former has been available longer on Linux, and
then OpenSSL. Finally, if none of those are available, we use
/dev/urandom, because most Unix-like operating systems provide that API.
We prefer options that don't involve device files when possible because
those work in some restricted environments where device files may not be
available.

Set the configuration variables appropriately for Linux and the BSDs,
including macOS, as well as Windows and NonStop.  We specifically only
consider versions which receive publicly available security support
here.  For the same reason, we don't specify getrandom(2) on Linux,
because CentOS 7 doesn't support it in glibc (although its kernel does)
and we don't want to resort to making syscalls.

Finally, add a test helper to allow this to be tested by hand and in
tests.  We don't add any tests, since invoking the CSPRNG is not likely
to produce interesting, reproducible results.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-17 14:17:48 -08:00
Junio C Hamano
077e120a1e Merge branch 'ab/makefile-hook-list-dependency-fix'
Fix dependency rules to generate hook-list.h header file.

* ab/makefile-hook-list-dependency-fix:
  Makefile: correct the dependency graph of hook-list.h
2022-01-10 11:52:52 -08:00
Junio C Hamano
114d64b783 Merge branch 'ab/makefile-pager-env-is-used-only-by-pager.c'
* ab/makefile-pager-env-is-used-only-by-pager.c:
  Makefile: move -DPAGER_ENV from BASIC_CFLAGS to EXTRA_CPPFLAGS
2022-01-10 11:52:51 -08:00
Junio C Hamano
43f196cec2 Merge branch 'ab/makefile-msgfmt-wo-stats'
Make the recipe that runs msgfmt less noisy.

* ab/makefile-msgfmt-wo-stats:
  Makefile: don't invoke msgfmt with --statistics
2022-01-10 11:52:51 -08:00
Emily Shaffer
96e7225b31 hook: add 'run' subcommand
In order to enable hooks to be run as an external process, by a
standalone Git command, or by tools which wrap Git, provide an external
means to run all configured hook commands for a given hook event.

Most of our hooks require more complex functionality than this, but
let's start with the bare minimum required to support our simplest
hooks.

In terms of implementation the usage_with_options() and "goto usage"
pattern here mirrors that of
builtin/{commit-graph,multi-pack-index}.c.

Some of the implementation here, such as a function being named
run_hooks_opt() when it's tasked with running one hook, to using the
run_processes_parallel_tr2() API to run with jobs=1 is somewhere
between a bit odd and and an overkill for the current features of this
"hook run" command and the hook.[ch] API.

This code will eventually be able to run multiple hooks declared in
config in parallel, by starting out with these names and APIs we
reduce the later churn of renaming functions, switching from the
run_command() to run_processes_parallel_tr2() API etc.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-07 15:19:34 -08:00
Ævar Arnfjörð Bjarmason
2f12b31b74 Makefile: don't invoke msgfmt with --statistics
Remove the --statistics flag that I added in 5e9637c629 (i18n: add
infrastructure for translating Git with gettext, 2011-11-18). Our
Makefile output is good about reducing verbosity by default, except in
this case:

    $ rm -rf po/build/locale/e*; time make -j $(nproc) all
        SUBDIR templates
        MKDIR -p po/build/locale/el/LC_MESSAGES
        MSGFMT po/build/locale/el/LC_MESSAGES/git.mo
        MKDIR -p po/build/locale/es/LC_MESSAGES
        MSGFMT po/build/locale/es/LC_MESSAGES/git.mo
    1038 translated messages, 3325 untranslated messages.
    5230 translated messages.

I didn't have any good reason for using --statistics at the time other
than ad-hoc eyeballing of the output. We don't need to spew out
exactly how many messages we've got translated every time. Now we'll
instead emit:

    $ rm -rf po/build/locale/e*; time make -j $(nproc) all
        SUBDIR templates
        MKDIR -p po/build/locale/el/LC_MESSAGES
        MSGFMT po/build/locale/el/LC_MESSAGES/git.mo
        MKDIR -p po/build/locale/es/LC_MESSAGES
        MSGFMT po/build/locale/es/LC_MESSAGES/git.mo

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-25 15:07:09 -08:00
Ævar Arnfjörð Bjarmason
451a7dbe28 Makefile: move -DPAGER_ENV from BASIC_CFLAGS to EXTRA_CPPFLAGS
Remove -DPAGER_ENV from the BASIC_CFLAGS and instead have it passed
via the EXTRA_CPPFLAGS passed when compiling pager.c.

This doesn't change anything except to make it clear that only pager.c
needs this, as it's the only user of this define. See
995bc22d7f (pager: move pager-specific setup into the build,
2016-08-04) for the commit that originally added this.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-25 14:49:56 -08:00
Ævar Arnfjörð Bjarmason
d3fd1a6667 Makefile: correct the dependency graph of hook-list.h
Fix an issue in my cfe853e66b (hook-list.h: add a generated list of
hooks, like config-list.h, 2021-09-26), the builtin/help.c was
inadvertently made to depend on hook-list.h, but it's used by
builtin/bugreport.c.

The hook.c also does not depend on hook-list.h. It did in an earlier
version of the greater series cfe853e66b was extracted from, but not
anymore. We might end up needing that line again, but let's remove it
for now.

Reported-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-25 14:43:05 -08:00
Junio C Hamano
62e83d4f69 Merge branch 'js/scalar'
Add pieces from "scalar" to contrib/.

* js/scalar:
  scalar: implement the `version` command
  scalar: implement the `delete` command
  scalar: teach 'reconfigure' to optionally handle all registered enlistments
  scalar: allow reconfiguring an existing enlistment
  scalar: implement the `run` command
  scalar: teach 'clone' to support the --single-branch option
  scalar: implement the `clone` subcommand
  scalar: implement 'scalar list'
  scalar: let 'unregister' handle a deleted enlistment directory gracefully
  scalar: 'unregister' stops background maintenance
  scalar: 'register' sets recommended config and starts maintenance
  scalar: create test infrastructure
  scalar: start documenting the command
  scalar: create a rudimentary executable
  scalar: add a README with a roadmap
2021-12-21 15:03:17 -08:00
Junio C Hamano
5a4069a1d8 Merge branch 'jc/c99-var-decl-in-for-loop'
Weather balloon to find compilers that do not grok variable
declaration in the for() loop.

* jc/c99-var-decl-in-for-loop:
  revision: use C99 declaration of variable in for() loop
2021-12-21 15:03:15 -08:00
Junio C Hamano
a4bbd13be3 Merge branch 'hn/reftable'
The "reftable" backend for the refs API, without integrating into
the refs subsystem, has been added.

* hn/reftable:
  Add "test-tool dump-reftable" command.
  reftable: add dump utility
  reftable: implement stack, a mutable database of reftable files.
  reftable: implement refname validation
  reftable: add merged table view
  reftable: add a heap-based priority queue for reftable records
  reftable: reftable file level tests
  reftable: read reftable files
  reftable: generic interface to tables
  reftable: write reftable files
  reftable: a generic binary tree implementation
  reftable: reading/writing blocks
  Provide zlib's uncompress2 from compat/zlib-compat.c
  reftable: (de)serialization for the polymorphic record type.
  reftable: add blocksource, an abstraction for random access reads
  reftable: utility functions
  reftable: add error related functionality
  reftable: add LICENSE
  hash.h: provide constants for the hash IDs
2021-12-15 09:39:45 -08:00
Junio C Hamano
d67fc4bf0b Merge branch 'bc/require-c99'
Weather balloon to break people with compilers that do not support
C99.

* bc/require-c99:
  git-compat-util: add a test balloon for C99 support
2021-12-10 14:35:14 -08:00
Johannes Schindelin
0a43fb2202 scalar: create a rudimentary executable
The idea of Scalar (https://github.com/microsoft/scalar), and before
that, of VFS for Git, has always been to prove that Git _can_ scale, and
to upstream whatever strategies have been demonstrated to help.

With this patch, we start the journey from that C# project to move what
is left to Git's own `contrib/` directory, reimplementing it in pure C,
with the intention to facilitate integrating the functionality into core
Git all while maintaining backwards-compatibility for existing Scalar
users (which will be much easier when both live in the same worktree).
It has always been the plan to contribute all of the proven strategies
back to core Git.

For example, while the virtual filesystem provided by VFS for Git helped
the team developing the Windows operating system to move onto Git, while
trying to upstream it we realized that it cannot be done: getting the
virtual filesystem to work (which we only managed to implement fully on
Windows, but not on, say, macOS or Linux), and the required server-side
support for the GVFS protocol, made this not quite feasible.

The Scalar project learned from that and tackled the problem with
different tactics: instead of pretending to Git that the working
directory is fully populated, it _specifically_ teaches Git about
partial clone (which is based on VFS for Git's cache server), about
sparse checkout (which VFS for Git tried to do transparently, in the
file system layer), and regularly runs maintenance tasks to keep the
repository in a healthy state.

With partial clone, sparse checkout and `git maintenance` having been
upstreamed, there is little left that `scalar.exe` does which `git.exe`
cannot do. One such thing is that `scalar clone <url>` will
automatically set up a partial, sparse clone, and configure
known-helpful settings from the start.

So let's bring this convenience into Git's tree.

The idea here is that you can (optionally) build Scalar via

	make -C contrib/scalar/

This will build the `scalar` executable and put it into the
contrib/scalar/ subdirectory.

The slightly awkward addition of the `contrib/scalar/*` bits to the
top-level `Makefile` are actually really required: we want to link to
`libgit.a`, which means that we will need to use the very same `CFLAGS`
and `LDFLAGS` as the rest of Git.

An early development version of this patch tried to replicate all the
conditional code in `contrib/scalar/Makefile` (e.g. `NO_POLL`) just like
`contrib/svn-fe/Makefile` used to do before it was retired. It turned
out to be quite the whack-a-mole game: the SHA-1-related flags, the
flags enabling/disabling `compat/poll/`, `compat/regex/`,
`compat/win32mmap.c` & friends depending on the current platform... To
put it mildly: it was a major mess.

Instead, this patch makes minimal changes to the top-level `Makefile` so
that the bits in `contrib/scalar/` can be compiled and linked, and
adds a `contrib/scalar/Makefile` that uses the top-level `Makefile` in a
most minimal way to do the actual compiling.

Note: With this commit, we only establish the infrastructure, no
Scalar functionality is implemented yet; We will do that incrementally
over the next few commits.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Junio C Hamano
44ba10d671 revision: use C99 declaration of variable in for() loop
There are certain C99 features that might be nice to use in our code
base, but we've hesitated to do so in order to avoid breaking
compatibility with older compilers. But we don't actually know if
people are even using pre-C99 compilers these days.

One way to figure that out is to introduce a very small use of a
feature, and see if anybody complains, and we've done so to probe
the portability for a few features like "trailing comma in enum
declaration", "designated initializer for struct", and "designated
initializer for array".  A few years ago, we tried to use a handy

    for (int i = 0; i < n; i++)
	use(i);

to introduce a new variable valid only in the loop, but found that
some compilers we cared about didn't like it back then.  Two years
is a long-enough time, so let's try it again.

If this patch can survive a few releases without complaint, then we
can feel more confident that variable declaration in for() loop is
supported by the compilers our user base use.  And if we do get
complaints, then we'll have gained some data and we can easily
revert this patch.

Helped-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-03 10:16:00 -08:00
brian m. carlson
7bc341e21b git-compat-util: add a test balloon for C99 support
The C99 standard was released in January 1999, now 22 years ago.  It
provides a variety of useful features, including variadic arguments for
macros, declarations after statements, designated initializers, and a
wide variety of other useful features, many of which we already use.

We'd like to take advantage of these features, but we want to be
cautious.  As far as we know, all major compilers now support C99 or a
later C standard, such as C11 or C17.  POSIX has required C99 support as
a requirement for the 2001 revision, so we can safely assume any POSIX
system which we are interested in supporting has C99.

Even MSVC, long a holdout against modern C, now supports both C11 and
C17 with an appropriate update.  Moreover, even if people are using an
older version of MSVC on these systems, they will generally need some
implementation of the standard Unix utilities for the testsuite, and GNU
coreutils, the most common option, has required C99 since 2009.
Therefore, we can safely assume that a suitable version of GCC or clang
is available to users even if their version of MSVC is not sufficiently
capable.

Let's add a test balloon to git-compat-util.h to see if anyone is using
an older compiler.  We'll add a comment telling people how to enable
this functionality on GCC and Clang, even though modern versions of both
will automatically do the right thing, and ask people still experiencing
a problem to report that to us on the list.

Note that C89 compilers don't provide the __STDC_VERSION__ macro, so we
use a well-known hack of using "- 0".  On compilers with this macro, it
doesn't change the value, and on C89 compilers, the macro will be
replaced with nothing, and our value will be 0.

For sparse, we explicitly request the gnu99 style because we've
traditionally taken advantage of some GCC- and clang-specific extensions
when available and we'd like to retain the ability to do that.  sparse
also defaults to C89 without it, so things will fail for us if we don't.

Update the cmake configuration to require C11 for MSVC.  We do this
because this will make MSVC to use C11, since it does not explicitly
support C99.  We do this with a compiler options because setting the
C_STANDARD option does not work in our CI on MSVC and at the moment, we
don't want to require C11 for Unix compilers.

In the Makefile, don't set any compiler flags for the compiler itself,
since on some systems, such as FreeBSD, we actually need C11, and asking
for C99 causes things to fail to compile.  The error message should make
it obvious what's going wrong and allow a user to set the appropriate
option when building in the event they're using a Unix compiler that
doesn't support it by default.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 14:50:01 -08:00
Junio C Hamano
ad1260b6c9 Merge branch 'ab/sh-retire-helper-functions'
Make a few helper functions unused and then lose them.

* ab/sh-retire-helper-functions:
  git-sh-setup: remove "sane_grep", it's not needed anymore
  git-sh-setup: remove unused sane_egrep() function
  git-instaweb: unconditionally assume that gitweb is mod_perl capable
  Makefile: remove $(NO_CURL) from $(SCRIPT_DEFINES)
  Makefile: remove $(GIT_VERSION) from $(SCRIPT_DEFINES)
  Makefile: move git-SCRIPT-DEFINES adjacent to $(SCRIPT_DEFINES)
2021-11-29 15:41:50 -08:00
Junio C Hamano
23112fc28c Merge branch 'ab/make-sparse-for-real'
Fix-up for a recent topic.

* ab/make-sparse-for-real:
  Makefile: remove redundant GIT-CFLAGS dependency from "sparse"
2021-10-29 15:43:12 -07:00
Ævar Arnfjörð Bjarmason
8a7a90bc3d Makefile: remove redundant GIT-CFLAGS dependency from "sparse"
The "sparse" target needed the GIT-CFLAGS dependency before my
c234e8a0ec (Makefile: make the "sparse" target non-.PHONY,
2021-09-23), but since then it depends on the corresponding *.o files,
which in turn depend on the correct header files, as well as on
GIT-CFLAGS. There's no need to re-state this dependency here.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-21 16:19:52 -07:00
Ævar Arnfjörð Bjarmason
ebeb39faad git-sh-setup: remove "sane_grep", it's not needed anymore
Remove the sane_grep() shell function in git-sh-setup. The two reasons
for why it existed don't apply anymore:

1. It was added due to GNU grep supporting GREP_OPTIONS. See
   e1622bfcba (Protect scripted Porcelains from GREP_OPTIONS insanity,
   2009-11-23).

   Newer versions of GNU grep ignore that, but even on older versions
   its existence won't matter, none of these sane_grep() uses care
   about grep's output, they're merely using it to check if a string
   exists in a file or stream. We also don't care about the "LC_ALL=C"
   that "sane_grep" was using, these greps for fixed or ASCII strings
   will behave the same under any locale.

2. The SANE_TEXT_GREP added in 71b401032b (sane_grep: pass "-a" if
   grep accepts it, 2016-03-08) isn't needed either, none of these grep
   uses deal with binary data.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-21 16:17:57 -07:00
Ævar Arnfjörð Bjarmason
c7c9692897 Makefile: remove $(NO_CURL) from $(SCRIPT_DEFINES)
Stop including $(NO_CURL) in $(SCRIPT_DEFINES). The "@NO_CURL@"
replacement added in 6c5c62f340 (Print an error if cloning a http
repo and NO_CURL is set, 2006-02-15) has not been referenced by
anything in-tree since 49eb8d39c7 (Remove contrib/examples/*,
2018-03-25).

That commit removed the reference from contrib/examples/*, but this
@@NO_CURL@@ hasn't been used since git-pull.sh was the primary entry
point for "git pull".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-21 16:17:57 -07:00
Ævar Arnfjörð Bjarmason
ab77294a2a Makefile: remove $(GIT_VERSION) from $(SCRIPT_DEFINES)
Remove the $(GIT_VERSION) from $(SCRIPT_DEFINES). Now every time HEAD
changes in a development copy we don't need to re-build the scripts
and script libraries.

This has not been needed since 2b9391bc67 (Makefile: do not replace
@@GIT_VERSION@@ in shell scripts, 2012-06-20). On my setup this
changes the re-making of 44 targets in a development copy where moved
HEAD to 27.

The $(GIT_VERSION) was seemingly left here by mistake or omission. We
didn't need it since 2b9391bc67, but in the later
e4dd89ab98 (Makefile: update scripts when build-time parameters
change, 2012-06-20) it was added to SCRIPT_DEFINES.

The two were part of the same series of patches, and given the summary
in [1] and [2] it looks like this was probably a case of some earlier
version of a later patch being combined with an updated earlier patch.

1. https://lore.kernel.org/git/20120619232231.GA6328@sigill.intra.peff.net/
2. https://lore.kernel.org/git/20120619232453.GB6496@sigill.intra.peff.net/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-21 16:17:57 -07:00
Ævar Arnfjörð Bjarmason
7212f2887a Makefile: move git-SCRIPT-DEFINES adjacent to $(SCRIPT_DEFINES)
When "GIT-SCRIPT-DEFINES" was added in e4dd89ab98 (Makefile: update
scripts when build-time parameters change, 2012-06-20) the rules for
generating the scripts themselves were moved further away from the
"cmd_munge_script" added in 46bac90458 (Do not install shell
libraries executable, 2010-01-31).

Let's move these around so that the variables and defines needed by
given targets immediately precede them. This is not needed for any
subsequent changes to work, but makes the code consistent with how
GIT-PERL-DEFINES is structured.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-21 16:17:56 -07:00
Junio C Hamano
223a1bfb58 Merge branch 'js/retire-preserve-merges'
The "--preserve-merges" option of "git rebase" has been removed.

* js/retire-preserve-merges:
  sequencer: restrict scope of a formerly public function
  rebase: remove a no-longer-used function
  rebase: stop mentioning the -p option in comments
  rebase: remove obsolete code comment
  rebase: drop the internal `rebase--interactive` command
  git-svn: drop support for `--preserve-merges`
  rebase: drop support for `--preserve-merges`
  pull: remove support for `--rebase=preserve`
  tests: stop testing `git rebase --preserve-merges`
  remote: warn about unhandled branch.<name>.rebase values
  t5520: do not use `pull.rebase=preserve`
2021-10-18 15:47:56 -07:00
Junio C Hamano
f0beebdb7b Merge branch 'ab/make-sparse-for-real'
Prevent "make sparse" from running for the source files that
haven't been modified.

* ab/make-sparse-for-real:
  Makefile: make the "sparse" target non-.PHONY
2021-10-13 15:15:58 -07:00
Junio C Hamano
a5e61a4225 Merge branch 'ab/config-based-hooks-1'
Mostly preliminary clean-up in the hook API.

* ab/config-based-hooks-1:
  hook-list.h: add a generated list of hooks, like config-list.h
  hook.c users: use "hook_exists()" instead of "find_hook()"
  hook.c: add a hook_exists() wrapper and use it in bugreport.c
  hook.[ch]: move find_hook() from run-command.c to hook.c
  Makefile: remove an out-of-date comment
  Makefile: don't perform "mv $@+ $@" dance for $(GENERATED_H)
  Makefile: stop hardcoding {command,config}-list.h
  Makefile: mark "check" target as .PHONY
2021-10-13 15:15:57 -07:00
Junio C Hamano
bbfc8212e1 Merge branch 'ab/make-clean-depend-dirs' into maint
"make clean" has been updated to remove leftover .depend/
directories, even when it is not told to use them to compute header
dependencies.

* ab/make-clean-depend-dirs:
  Makefile: clean .depend dirs under COMPUTE_HEADER_DEPENDENCIES != yes
2021-10-12 13:51:49 -07:00
Junio C Hamano
32b6c51888 Merge branch 'ab/no-more-check-bindir' into maint
Build simplification.

* ab/no-more-check-bindir:
  Makefile: remove the check_bindir script
2021-10-12 13:51:32 -07:00
Junio C Hamano
5586bd2de2 Merge branch 'sg/make-fix-ar-invocation' into maint
Build fix.

* sg/make-fix-ar-invocation:
  Makefile: remove archives before manipulating them with 'ar'
2021-10-12 13:51:25 -07:00
Junio C Hamano
859a585bdf Merge branch 'ab/sanitize-leak-ci'
CI learns to run the leak sanitizer builds.

* ab/sanitize-leak-ci:
  tests: add a test mode for SANITIZE=leak, run it in CI
  Makefile: add SANITIZE=leak flag to GIT-BUILD-OPTIONS
2021-10-11 10:21:47 -07:00
Han-Wen Nienhuys
d860c86ba5 Add "test-tool dump-reftable" command.
This command dumps individual tables or a stack of of tables.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
e48d427268 reftable: implement stack, a mutable database of reftable files.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
acb533440f reftable: implement refname validation
The packed/loose format has restrictions on refnames: a and a/b cannot
coexist. This limitation does not apply to reftable per se, but must be
maintained for interoperability. This code adds validation routines to
abort transactions that are trying to add invalid names.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
1ae2b8cda8 reftable: add merged table view
This adds an abstract, read-only interface to the ref database.

This primitive is used to construct the read view of the ref database
(the read view is constructed by merging several *.ref files). It also
provides the mechanism to provide a unified view of the refs in the main
repository and the per-worktree refs.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
3b34f636df reftable: add a heap-based priority queue for reftable records
This is needed to create a merged view multiple reftables

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
ffc97f1a9e reftable: reftable file level tests
With support for reading and writing files in place, we can construct files (in
memory) and attempt to read them back.

Because some sections of the format are optional (eg. indices, log entries), we
have to exercise this code using multiple sizes of input data

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
46bc0e731a reftable: read reftable files
This supports reading a single reftable file.

The commit introduces an abstract iterator type, which captures the usecases
both of reading individual refs, and iterating over a segment of the ref
namespace.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
17df8dbeba reftable: generic interface to tables
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
f14bd71934 reftable: write reftable files
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
35425d1034 reftable: a generic binary tree implementation
The reftable format includes support for an (OID => ref) map. This map can speed
up visibility and reachability checks. In particular, various operations along
the fetch/push path within Gerrit have ben sped up by using this structure.

The map is constructed with help of a binary tree. Object IDs are hashes, so
they are uniformly distributed. Hence, the tree does not attempt forced
rebalancing.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
e581fd7231 reftable: reading/writing blocks
The reftable format is structured as a sequence of block. Within a block,
records are prefix compressed, with an index of offsets for fully expand keys to
enable binary search within blocks.

This commit provides the logic to read and write these blocks.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
a322920d0b Provide zlib's uncompress2 from compat/zlib-compat.c
This will be needed for reading reflog blocks in reftable.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
e303bf22f9 reftable: (de)serialization for the polymorphic record type.
The reftable format is structured as a sequence of blocks, and each block
contains a sequence of prefix-compressed key-value records. There are 4 types of
records, and they have similarities in how they must be handled. This is
achieved by introducing a polymorphic 'record' type that encapsulates ref, log,
index and object records.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
1214aa841b reftable: add blocksource, an abstraction for random access reads
The reftable format is usually used with files for storage. However, we abstract
away this using the blocksource data structure. This has two advantages:

* log blocks are zlib compressed, and handling them is simplified if we can
  discard byte segments from within the block layer.

* for unittests, it is useful to read and write in-memory. The blocksource
  allows us to abstract the data away from on-disk files.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Han-Wen Nienhuys
ef8a6c6268 reftable: utility functions
This commit provides basic utility classes for the reftable library.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Junio C Hamano
93cccedb8f Merge branch 'ab/make-compdb-fix'
Build update.

* ab/make-compdb-fix:
  Makefile: pass -Wno-pendantic under GENERATE_COMPILATION_DATABASE=yes
2021-10-03 21:49:21 -07:00
Junio C Hamano
65351024eb Merge branch 'ab/auto-depend-with-pedantic'
Improve build procedure for developers.

* ab/auto-depend-with-pedantic:
  Makefile: make COMPUTE_HEADER_DEPENDENCIES=auto work with DEVOPTS=pedantic
2021-10-03 21:49:20 -07:00
Junio C Hamano
2498121cd6 Merge branch 'ab/make-clean-depend-dirs'
"make clean" has been updated to remove leftover .depend/
directories, even when it is not told to use them to compute header
dependencies.

* ab/make-clean-depend-dirs:
  Makefile: clean .depend dirs under COMPUTE_HEADER_DEPENDENCIES != yes
2021-10-03 21:49:19 -07:00
Ævar Arnfjörð Bjarmason
dd20e4a6db Makefile: pass -Wno-pendantic under GENERATE_COMPILATION_DATABASE=yes
The same bug fixed in the "COMPUTE_HEADER_DEPENDENCIES=auto" mode in
the preceding commit was also present with
"GENERATE_COMPILATION_DATABASE=yes". Let's fix it so it works again
with "DEVOPTS=1".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 13:54:02 -07:00
Ævar Arnfjörð Bjarmason
cfe853e66b hook-list.h: add a generated list of hooks, like config-list.h
Make githooks(5) the source of truth for what hooks git supports, and
punt out early on hooks we don't know about in find_hook(). This
ensures that the documentation and the C code's idea about existing
hooks doesn't diverge.

We still have Perl and Python code running its own hooks, but that'll
be addressed by Emily Shaffer's upcoming "git hook run" command.

This resolves a long-standing TODO item in bugreport.c of there being
no centralized listing of hooks, and fixes a bug with the bugreport
listing only knowing about 1/4 of the p4 hooks. It didn't know about
the recent "reference-transaction" hook either.

We could make the find_hook() function die() or BUG() out if the new
known_hook() returned 0, but let's make it return NULL just as it does
when it can't find a hook of a known type. Making it die() is overly
anal, and unlikely to be what we need in catching stupid typos in the
name of some new hook hardcoded in git.git's sources. By making this
be tolerant of unknown hook names, changes in a later series to make
"git hook run" run arbitrary user-configured hook names will be easier
to implement.

I have not been able to directly test the CMake change being made
here. Since 4c2c38e800 (ci: modification of main.yml to use cmake for
vs-build job, 2020-06-26) some of the Windows CI has a hard dependency
on CMake, this change works there, and is to my eyes an obviously
correct use of a pattern established in previous CMake changes,
namely:

 - 061c2240b1 (Introduce CMake support for configuring Git,
    2020-06-12)
 - 709df95b78 (help: move list_config_help to builtin/help,
    2020-04-16)
 - 976aaedca0 (msvc: add a Makefile target to pre-generate the Visual
   Studio solution, 2019-07-29)

The LC_ALL=C is needed because at least in my locale the dash ("-") is
ignored for the purposes of sorting, which results in a different
order. I'm not aware of anything in git that has a hard dependency on
the order, but e.g. the bugreport output would end up using whatever
locale was in effect when git was compiled.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 09:44:54 -07:00
Ævar Arnfjörð Bjarmason
5e3aba33da hook.[ch]: move find_hook() from run-command.c to hook.c
Move the find_hook() function from run-command.c to a new hook.c
library. This change establishes a stub library that's pretty
pointless right now, but will see much wider use with Emily Shaffer's
upcoming "configuration-based hooks" series.

Eventually all the hook related code will live in hook.[ch]. Let's
start that process by moving the simple find_hook() function over
as-is.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 09:44:54 -07:00
Ævar Arnfjörð Bjarmason
f53df0bdf6 Makefile: remove an out-of-date comment
This comment added in dfea575017 (Makefile: lazily compute header
dependencies, 2010-01-26) has been out of date since
92b88eba9f (Makefile: use `git ls-files` to list header files, if
possible, 2019-03-04), when we did exactly what it tells us not to do
and added $(GENERATED_H) to $(OBJECTS) dependencies.

The rest of it was also somewhere between inaccurate and outdated,
since as of b8ba629264 (Makefile: fold MISC_H into LIB_H, 2012-06-20)
it's not followed by a list of header files, that got moved earlier in
the file into LIB_H in 60d24dd255 (Makefile: fold XDIFF_H and VCSSVN_H
into LIB_H, 2012-07-06).

Let's just remove it entirely, to the extent that we have anything
useful to say here the comment on the
"USE_COMPUTED_HEADER_DEPENDENCIES" variable a few lines above this
change does the job for us.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-23 15:06:47 -07:00
Ævar Arnfjörð Bjarmason
7c81295382 Makefile: don't perform "mv $@+ $@" dance for $(GENERATED_H)
Change the "cmd.sh > $@+ && mv $@+ $@" pattern used for generating the
config-list.h and command-list.h to just "cmd.sh >$@". This was needed
as a guard to ensure that we don't have an empty file if the script
failed, but since 7b76d6bf22 (Makefile: add and use the
".DELETE_ON_ERROR" flag, 2021-06-29) GNU make ensures that doesn't
happen.

There's still a lot of other places in the Makefile where we
needlessly use this pattern, but I'm just changing these because I'm
about to add a new $(GENERATED_H) target, let's have them all look and
act the same way.

Even with ".DELETE_ON_ERROR" there is still a point to using the "mv
$@+ $@" pattern in some cases, e.g. to ensure that you have a working
binary during recompilation (see [1] for the start of a long
discussion about that), but that doesn't apply here. Nothing external
uses $(GENERATED_H) directly, it's only ever used in the context of
the Makefile's own dependency (re-)generation.

1. https://lore.kernel.org/git/8735t93h0u.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-23 15:06:47 -07:00
Ævar Arnfjörð Bjarmason
7c3c0a99cc Makefile: stop hardcoding {command,config}-list.h
Change various places that hardcode the names of these two files to
refer to either $(GENERATED_H), or to a new generated-hdrs
target. That target is consistent with the *-objs targets I recently
added in 029bac01a8 (Makefile: add {program,xdiff,test,git,fuzz}-objs
& objects targets, 2021-02-23).

A subsequent commit will add a new generated hook-list.h. By doing
this refactoring we'll only need to add the new file to the
GENERATED_H variable, not EXCEPT_HDRS, the vcbuild/README etc.

Hardcoding command-list.h there seems to have been a case of
copy/paste programming in 976aaedca0 (msvc: add a Makefile target to
pre-generate the Visual Studio solution, 2019-07-29). The
config-list.h was added later in 709df95b78 (help: move
list_config_help to builtin/help, 2020-04-16).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-23 15:06:47 -07:00
Ævar Arnfjörð Bjarmason
ea47e59fe3 Makefile: mark "check" target as .PHONY
Fix a bug in 44c9e8594e (Fix up header file dependencies and add
sparse checking rules, 2005-07-03), we never marked the phony "check"
target as such.

Perhaps we should just remove it, since as of a combination of
912f9980d2 (Makefile: help people who run 'make check' by mistake,
2008-11-11) 0bcd9ae85d (sparse: Fix errors due to missing
target-specific variables, 2011-04-21) we've been suggesting the user
run "make sparse" directly.

But under that mode it still does something, as well as directing the
user to run "make test" under non-sparse. So let's punt that and
narrowly fix the PHONY bug.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-23 15:06:47 -07:00
Junio C Hamano
8f79fb6445 Merge branch 'ab/http-drop-old-curl-plus'
Conditional compilation around versions of libcURL has been
straightened out.

* ab/http-drop-old-curl-plus:
  http: don't hardcode the value of CURL_SOCKOPT_OK
  http: centralize the accounting of libcurl dependencies
  http: correct curl version check for CURLOPT_PINNEDPUBLICKEY
  http: correct version check for CURL_HTTP_VERSION_2
  http: drop support for curl < 7.18.0 (again)
  Makefile: drop support for curl < 7.9.8 (again)
  INSTALL: mention that we need libcurl 7.19.4 or newer to build
  INSTALL: reword and copy-edit the "libcurl" section
  INSTALL: don't mention the "curl" executable at all
2021-09-23 13:44:47 -07:00
Ævar Arnfjörð Bjarmason
2cdc292b31 Makefile: add SANITIZE=leak flag to GIT-BUILD-OPTIONS
When SANITIZE=leak is specified we'll now add a SANITIZE_LEAK flag to
GIT-BUILD-OPTIONS, this can then be picked up by the test-lib.sh,
which sets a SANITIZE_LEAK prerequisite.

We can then skip specific tests that are known to fail under
SANITIZE=leak, add one such annotation to t0004-unwritable.sh, which
now passes under SANITIZE=leak.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-23 11:29:45 -07:00
Ævar Arnfjörð Bjarmason
731b6859c4 Makefile: make COMPUTE_HEADER_DEPENDENCIES=auto work with DEVOPTS=pedantic
The "COMPUTE_HEADER_DEPENDENCIES" feature added in [1] was extended to
use auto-detection in [2], that "auto" detection has always piped
STDERR to /dev/null, so any failures on compilers that didn't support
these GCC flags would silently fall back to
"COMPUTE_HEADER_DEPENDENCIES=no".

Later when -Wpedantic support was added to DEVOPTS in [3] we started
passing -Wpedantic in combination with -Werror to the compiler
here. Note (to the pedantic): [3] actually passed "-pedantic", but it
and "-Wpedantic" are synonyms.

Turning on -Wpedantic in [3] broke the auto-detection, since this
relies on compiling an empty program. GCC would loudly complain on
STDERR:

    /dev/null:1: error: ISO C forbids an empty translation unit
    [-Werror=pedantic]
    cc1: note: unrecognized command-line option
    ‘-Wno-pedantic-ms-format’ may have been intended to silence
    earlier diagnostics
    cc1: all warnings being treated as errors

But as that ended up in the "$(dep_check)" variable due to the "2>&1"
in [2] we didn't see it.

Then when [4] made DEVOPTS=pedantic the default specifying
"DEVELOPER=1" would effectively set "COMPUTE_HEADER_DEPENDENCIES=no".

To fix these issues let's unconditionally pass -Wno-pedantic after
$(ALL_CFLAGS), we might get a -Wpedantic via config.mak.dev after, or
the builder might specify it via CFLAGS. In either case this will undo
current and future problems with -Wpedantic.

I think it would make sense to simply remove the "2>&1", it would mean
that anyone using a non-GCC-like compiler would get warnings under
COMPUTE_HEADER_DEPENDENCIES=auto, e.g on AIX's xlc would emit:

    /opt/IBM/xlc/13.1.3/bin/.orig/xlc: 1501-208 (S) command option D is missing a subargument
    Non-zero 40 exit with COMPUTE_HEADER_DEPENDENCIES=auto, set it to "yes" or "no" to quiet auto-detect

And on Solaris with SunCC:

    cc: Warning: Option -x passed to ld, if ld is invoked, ignored otherwise
    cc: refused to overwrite input file by output file: /dev/null
    cc: Warning: Option -x passed to ld, if ld is invoked, ignored otherwise
    cc: refused to overwrite input file by output file: /dev/null
    Non-zero 1 exit with COMPUTE_HEADER_DEPENDENCIES=auto, set it to "yes" or "no" to quiet auto-detect

Both could be quieted by setting COMPUTE_HEADER_DEPENDENCIES=no
explicitly, as suggested, but let's see if this'll fix it without
emitting too much noise at those that aren't using "gcc" or "clang".

1. f2fabbf76e (Teach Makefile to check header dependencies,
   2010-01-26)
2. 111ee18c31 (Makefile: Use computed header dependencies if the
   compiler supports it, 2011-08-18)
3. 729b3925ed (Makefile: add a DEVOPTS flag to get pedantic
   compilation, 2018-07-24)
4. 6a8cbc41ba (developer: enable pedantic by default, 2021-09-03)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-22 21:38:57 -07:00
Ævar Arnfjörð Bjarmason
c234e8a0ec Makefile: make the "sparse" target non-.PHONY
Change the "sparse" target and its *.sp dependencies to be
non-.PHONY. Before this change "make sparse" would take ~5s to re-run
all the *.c files through "cgcc", after it it'll create an empty *.sp
file sitting alongside the *.c file, only if the *.c file or its
dependencies are newer than the *.sp is the *.sp re-made.

We ensure that the recursive dependencies are correct by depending on
the *.o file, which in turn will have correct dependencies by either
depending on all header files, or under
"COMPUTE_HEADER_DEPENDENCIES=yes" the headers it needs.

This means that a plain "make sparse" is much slower, as we'll now
need to make the *.o files just to create the *.sp files, but
incrementally creating the *.sp files is *much* faster and less
verbose, it thus becomes viable to run "sparse" along with "all" as
e.g. "git rebase --exec 'make all sparse'".

On my box with -j8 "make sparse" was fast before, or around 5 seconds,
now it only takes that long the first time, and the common case is
<100ms, or however long it takes GNU make to stat the *.sp file and
see that all the corresponding *.c file and its dependencies are
older.

See 0bcd9ae85d (sparse: Fix errors due to missing target-specific
variables, 2011-04-21) for the modern implementation of the sparse
target being changed here.

It is critical that we use -Wsparse-error here, otherwise the error
would only show up once, but we'd successfully create the empty *.sp
file, and running a second time wouldn't show the error. I'm therefore
not putting it into SPARSE_FLAGS or SP_EXTRA_FLAGS, it's not optional,
the Makefile logic won't behave properly without it.

Appending to $@ without a move is OK here because we're using the
.DELETE_ON_ERROR Makefile feature. See 7b76d6bf22 (Makefile: add and
use the ".DELETE_ON_ERROR" flag, 2021-06-29). GNU make ensures that on
error this file will be removed.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-22 21:36:11 -07:00
Ævar Arnfjörð Bjarmason
f0a74bcb03 Makefile: clean .depend dirs under COMPUTE_HEADER_DEPENDENCIES != yes
Fix a logic error in dfea575017 (Makefile: lazily compute header
dependencies, 2010-01-26) where we'd make whether we cleaned the
.depend dirs contingent on the currently configured
COMPUTE_HEADER_DEPENDENCIES value. Before this running e.g.:

    make COMPUTE_HEADER_DEPENDENCIES=yes grep.o
    make COMPUTE_HEADER_DEPENDENCIES=no clean

Would leave behind the .depend directory, now it'll be removed.

Normally we'd need to use another variable, but in this case there's
no other uses of $(dep_dirs), as opposed to $(dep_args) which is used
as an argument to $(CC). So just deleting this line makes everything
work correctly.

See http://lore.kernel.org/git/xmqqmto48ufz.fsf@gitster.g for a report
about this issue.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-22 13:34:34 -07:00
Junio C Hamano
1b8bd2243e Merge branch 'ab/make-tags-cleanup'
Build clean-up for "make tags" and friends.

* ab/make-tags-cleanup:
  Makefile: normalize clobbering & xargs for tags targets
  Makefile: remove "cscope.out", not "cscope*" in cscope.out target
  Makefile: don't use "FORCE" for tags targets
  Makefile: add QUIET_GEN to "cscope" target
  Makefile: move ".PHONY: cscope" near its target
2021-09-20 15:20:43 -07:00
Junio C Hamano
403192acb6 Merge branch 'cb/pedantic-build-for-developers'
Update the build procedure to use the "-pedantic" build when
DEVELOPER makefile macro is in effect.

* cb/pedantic-build-for-developers:
  developer: enable pedantic by default
  win32: allow building with pedantic mode enabled
  gettext: remove optional non-standard parens in N_() definition
2021-09-20 15:20:41 -07:00
Junio C Hamano
5639a8d144 Merge branch 'bs/install-strip'
"make INSTALL_STRIP=-s install" allows the installation step to use
"install -s" to strip the binaries as they get installed.

* bs/install-strip:
  make: add INSTALL_STRIP option variable
2021-09-15 13:15:26 -07:00
Junio C Hamano
59a29d1644 Merge branch 'ab/no-more-check-bindir'
Build simplification.

* ab/no-more-check-bindir:
  Makefile: remove the check_bindir script
2021-09-15 13:15:25 -07:00
Ævar Arnfjörð Bjarmason
2d4032c2fb Makefile: drop support for curl < 7.9.8 (again)
In 1119a15b5c (http: drop support for curl < 7.11.1, 2021-07-30)
support for curl versions older than 7.11.1 was removed, and we
currently require at least version 7.19.4, see 644de29e22 (http: drop
support for curl < 7.19.4, 2021-07-30).

In those changes this Makefile-specific check added in
0890098780 (Decide whether to build http-push in the Makefile,
2005-11-18) was missed, now that we're never going to use such an
ancient curl version we don't need to check that we have at least
7.9.8 here. I have no idea what in http-push.c broke on versions older
than that.

This does not impact "NO_CURL" setups, as this is in the "else" branch
after that check.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-13 10:39:04 -07:00
Johannes Schindelin
a74b35081c rebase: drop support for --preserve-merges
This option was deprecated in favor of `--rebase-merges` some time ago,
and now we retire it.

To assist users to transition away, we do not _actually_ remove the
option, but now we no longer implement the functionality. Instead, we
offer a helpful error message suggesting which option to use.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 21:45:33 -07:00
Ævar Arnfjörð Bjarmason
72b113e562 Makefile: remove the check_bindir script
This script was added in f28ac70f48 (Move all dashed-form commands to
libexecdir, 2007-11-28) when commands such as "git-add" lived in the
bin directory, instead of the git exec directory.

This notice helped someone incorrectly installing version v1.6.0 and
later into a directory built for a pre-v1.6.0 git version.

We're now long past the point where anyone who'd be helped by this
warning is likely to be doing that, so let's just remove this check
and warning to simplify the Makefile.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 13:27:40 -07:00
Bagas Sanjaya
3231f41009 make: add INSTALL_STRIP option variable
Add $(INSTALL_STRIP), which allows passing stripping options to
$(INSTALL).

For this to work, installing executables must be split to installing
compiled binaries and scripts portions, since $(INSTALL_STRIP) is only
meaningful to the former.

Users can set this variable depending on their system. For example,
Linux users can use `-s --strip-program=strip`, while FreeBSD users can
simply set to `-s` and choose strip program with $STRIPBIN.

[original outline by Đoàn Trần Công Danh]

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-05 23:49:41 -07:00
Junio C Hamano
d868e4d9ee Merge branch 'sg/make-fix-ar-invocation'
Build fix.

* sg/make-fix-ar-invocation:
  Makefile: remove archives before manipulating them with 'ar'
2021-09-03 13:49:30 -07:00
Carlo Marcelo Arenas Belón
6a8cbc41ba developer: enable pedantic by default
With the codebase firmly C99 compatible and most compilers supporting
newer versions by default, it could help bring visibility to problems.

Reverse the DEVOPTS=pedantic flag to provide a fallback for people stuck
with gcc < 5 or some other compiler that either doesn't support this flag
or has issues with it, and while at it also enable -Wpedantic which used
to be controversial[1] when Apple compilers and clang had widely divergent
version numbers.

Ideally any compiler found to have issues with these flags will be added
to an exception, and indeed, one was added to safely process windows
headers that would use non standard print identifiers, but it is expected
that more will be needed, so it could be considered a weather balloon.

[1] https://lore.kernel.org/git/20181127100557.53891-1-carenas@gmail.com/

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-03 11:40:30 -07:00
Ævar Arnfjörð Bjarmason
153fb49e60 gettext: remove optional non-standard parens in N_() definition
Remove the USE_PARENS_AROUND_GETTEXT_N compile-time option which was
meant to catch an inadvertent mistake which is too obscure to
maintain this facility.

The backstory of how USE_PARENS_AROUND_GETTEXT_N came about is: When I
added the N_() macro in 6578483036 (i18n: add no-op _() and N_()
wrappers, 2011-02-22) it was defined as:

    #define N_(msgid) (msgid)

This is non-standard C, as was noticed and fixed in 642f85faab (i18n:
avoid parenthesized string as array initializer, 2011-04-07).
I.e. this needed to be defined as:

    #define N_(msgid) msgid

Then in e62cd35a3e (i18n: log: mark parseopt strings for translation,
2012-08-20) when "builtin_log_usage" was marked for translation the
string concatenation for passing to usage() added in 1c370ea4e5
(Show usage string for 'git log -h', 'git show -h' and 'git diff -h',
2009-08-06) was faithfully preserved:

-       "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
-       "   or: git show [options] <object>...",
+       N_("git log [<options>] [<since>..<until>] [[--] <path>...]\n")
+       N_("   or: git show [options] <object>..."),

This was then fixed to be the expected array of usage strings in
e66dc0cc4b (log.c: fix translation markings, 2015-01-06) rather than
a string with multiple "\n"-delimited usage strings, and finally in
290c8e7a3f (gettext.h: add parentheses around N_ expansion if
supported, 2015-01-11) USE_PARENS_AROUND_GETTEXT_N was added to ensure
this mistake didn't happen again.

I think that even if this was a N_()-specific issue this
USE_PARENS_AROUND_GETTEXT_N facility wouldn't be worth it, the issue
would be too rare to worry about.

But I also think that 290c8e7a3f which introduced
USE_PARENS_AROUND_GETTEXT_N misattributed the problem. The issue
wasn't with the N_() macro added in e62cd35a3e, but that before the
N_() macro existed in the codebase the initial migration to
parse_options() in 1c370ea4e5 continued passsing in a "\n"-delimited
string, when the new API it was migrating to supported and expected
the passing of an array.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-03 11:40:30 -07:00
Junio C Hamano
6f64eeab60 Merge branch 'es/trace2-log-parent-process-name'
trace2 logs learned to show parent process name to see in what
context Git was invoked.

* es/trace2-log-parent-process-name:
  tr2: log parent process name
  tr2: make process info collection platform-generic
2021-08-24 15:32:40 -07:00
Junio C Hamano
aab0eeaba5 Merge branch 'js/expand-runtime-prefix'
Pathname expansion (like "~username/") learned a way to specify a
location relative to Git installation (e.g. its $sharedir which is
$(prefix)/share), with "%(prefix)".

* js/expand-runtime-prefix:
  expand_user_path: allow in-flight topics to keep using the old name
  interpolate_path(): allow specifying paths relative to the runtime prefix
  Use a better name for the function interpolating paths
  expand_user_path(): clarify the role of the `real_home` parameter
  expand_user_path(): remove stale part of the comment
  tests: exercise the RUNTIME_PREFIX feature
2021-08-24 15:32:38 -07:00
SZEDER Gábor
325b06deda Makefile: remove archives before manipulating them with 'ar'
The rules creating the $(LIB_FILE) and $(XDIFF_LIB) archives used to
be:

  $(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^

until commit 7b76d6bf22 (Makefile: add and use the ".DELETE_ON_ERROR"
flag, 2021-06-29) removed the '$(RM) $@' part, claiming that "we can
rely on the "c" (create) being present in ARFLAGS", and (I presume)
assuming that it means that the named archive is created from scratch.

Unfortunately, that's not what the 'c' flag does, it merely "Suppress
the diagnostic message that is written to standard error by default
when the archive is created" [1].  Consequently, all object files that
are already present in an existing archive and are not replaced will
remain there.  This leads to linker errors in back-to-back builds of
different revisions without a 'make clean' between them if source
files going into these archives are renamed in between:

  # The last commit renaming files that go into 'libgit.a':
  # bc62692757 (hash-lookup: rename from sha1-lookup, 2020-12-31)
  #  sha1-lookup.c => hash-lookup.c | 14 +++++++-------
  #  sha1-lookup.h => hash-lookup.h | 12 ++++++------
  $ git checkout bc62692757^
  HEAD is now at 7a7d992d0d sha1-lookup: rename `sha1_pos()` as `hash_pos()`
  $ make
  [...]
  $ git checkout 7b76d6bf22
  HEAD is now at 7b76d6bf22 Makefile: add and use the ".DELETE_ON_ERROR" flag
  $ make
  [...]
      AR libgit.a
      LINK git
  /usr/bin/ld: libgit.a(hash-lookup.o): in function `bsearch_hash':
  /home/szeder/src/git/hash-lookup.c:105: multiple definition of `bsearch_hash'; libgit.a(sha1-lookup.o):/home/szeder/src/git/sha1-lookup.c:105: first defined here
  collect2: error: ld returned 1 exit status
  make: *** [Makefile:2213: git] Error 1

Restore the original make rules to first remove $(LIB_FILE) and
$(XDIFF_LIB) and then create them from scratch to avoid these build
errors.

[1] Quoting POSIX at:
    https://pubs.opengroup.org/onlinepubs/9699919799/utilities/ar.html

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-19 16:44:32 -07:00
Ævar Arnfjörð Bjarmason
899062438f Makefile: normalize clobbering & xargs for tags targets
Since the "tags", "TAGS" and "cscope.out" targets rely on piping into
xargs with an "echo <list> | xargs" pattern, we need to make sure
we're in an append mode.

Unlike my recent change to make use of ".DELETE_ON_ERROR" in
7b76d6bf22 (Makefile: add and use the ".DELETE_ON_ERROR" flag,
2021-06-29), we really do need the "rm $@+" at the beginning (note,
not "rm $@").

This is because the xargs command may decide to invoke the program
multiple times. We need to make sure we've got a union of its results
at the end.

For "ctags" and "etags" we used the "-a" flag for this, for cscope
that behavior is the default. Its "-u" flag disables its equivalent of
an implicit "-a" flag.

Let's also consistently use the $@ and $@+ names instead of needlessly
hardcoding or referring to more verbose names in the "tags" and "TAGS"
rules.

These targets could perhaps be improved in the future by factoring
this "echo <list> | xargs" pattern so that we make intermediate tags
files for each source file, and then assemble them into one "tags"
file at the end.

The etags manual page suggests that doing that (or perhaps just
--update) might be counter-productive, in any case, the tag building
is fast enough for me, so I'm leaving that for now.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05 09:31:15 -07:00
Ævar Arnfjörð Bjarmason
530a446d4a Makefile: remove "cscope.out", not "cscope*" in cscope.out target
Before we generate a "cscope.out" file, remove that file explicitly,
and not everything matching "cscope*". This doesn't change any
behavior of the Makefile in practice, but makes this rule less
confusing, and consistent with other similar rules.

The cscope target was added in a2a9150bf0 (makefile: Add a cscope
target, 2007-10-06). It has always referred to cscope* instead of to
cscope.out in .gitignore and the "clean" target, even though we only
ever generated a cscope.out file.

This was seemingly done to aid use-cases where someone invoked cscope
with the "-q" flag, which would make it create a "cscope.in.out" and
"cscope.po.out" files in addition to "cscope.out".

But us removing those files we never generated is confusing, so let's
only remove the file we need to, furthermore let's use the "-f" flag
to explicitly name the cscope.out file, even though it's the default
if not "-f" argument is supplied.

It is somewhat inconsistent to change from the glob here but not in
the "clean" rule and .gitignore, an earlier version of this change
updated those as well, but see [1][2] for why they were kept.

1. https://lore.kernel.org/git/87k0lit57x.fsf@evledraar.gmail.com/
2. https://lore.kernel.org/git/87im0kn983.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05 09:31:15 -07:00
Junio C Hamano
fea3738ac5 Merge branch 'ab/getcwd-test'
Portability test update.

* ab/getcwd-test:
  t0001: fix broken not-quite getcwd(3) test in bed67874e2
2021-08-04 13:28:55 -07:00
Ævar Arnfjörð Bjarmason
482e1488a9 t0001: fix broken not-quite getcwd(3) test in bed67874e2
With a54e938e5b (strbuf: support long paths w/o read rights in
strbuf_getcwd() on FreeBSD, 2017-03-26) we had t0001 break on systems
like OpenBSD and AIX whose getcwd(3) has standard (but not like glibc
et al) behavior.

This was partially fixed in bed67874e2 (t0001: skip test with
restrictive permissions if getpwd(3) respects them, 2017-08-07).

The problem with that fix is that while its analysis of the problem is
correct, it doesn't actually call getcwd(3), instead it invokes "pwd
-P". There is no guarantee that "pwd -P" is going to call getcwd(3),
as opposed to e.g. being a shell built-in.

On AIX under both bash and ksh this test breaks because "pwd -P" will
happily display the current working directory, but getcwd(3) called by
the "git init" we're testing here will fail to get it.

I checked whether clobbering the $PWD environment variable would
affect it, and it didn't. Presumably these shells keep track of their
working directory internally.

There's possible follow-up work here in teaching strbuf_getcwd() to
get the working directory with whatever method "pwd" uses on these
platforms. See [1] for a discussion of that, but let's take the easy
way out here and just skip these tests by fixing the
GETCWD_IGNORES_PERMS prerequisite to match the limitations of
strbuf_getcwd().

1. https://lore.kernel.org/git/b650bef5-d739-d98d-e9f1-fa292b6ce982@web.de/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-30 10:18:27 -07:00
Junio C Hamano
e5cc59c77c Merge branch 'ew/many-alternate-optim'
Optimization for repositories with many alternate object store.

* ew/many-alternate-optim:
  oidtree: a crit-bit tree for odb_loose_cache
  oidcpy_with_padding: constify `src' arg
  make object_directory.loose_objects_subdir_seen a bitmap
  avoid strlen via strbuf_addstr in link_alt_odb_entry
  speed up alt_odb_usable() with many alternates
2021-07-28 13:17:57 -07:00
Johannes Schindelin
b7d11a0f5d tests: exercise the RUNTIME_PREFIX feature
Originally, we refrained from adding a regression test in 7b6c6496374
(system_path(): Add prefix computation at runtime if RUNTIME_PREFIX set,
2008-08-10), and in 226c0ddd0d (exec_cmd: RUNTIME_PREFIX on some POSIX
systems, 2018-04-10).

The reason was that it was deemed too tricky to test.

Turns out that it is not tricky to test at all: we simply create a
pseudo-root, copy the `git` executable into the `git/` subdirectory of
that pseudo-root, then copy a script into the `libexec/git-core/`
directory and expect that to be picked up.

As long as the trash directory is in a location where binaries can be
executed, this works.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-26 12:17:16 -07:00
Emily Shaffer
b7e6a41622 tr2: make process info collection platform-generic
To pave the way for non-Windows platforms to define
trace2_collect_process_info(), reorganize the stub-or-definition schema
to something which doesn't directly reference Windows.

Platforms which want to collect parent process information in the
future should:

 1. Add an implementation to compat/ (e.g. compat/somearch/procinfo.c)
 2. Add that object to COMPAT_OBJS to config.mak.uname
    (e.g. COMPAT_OBJS += compat/somearch/procinfo.o)
 3. Define HAVE_PLATFORM_PROCINFO in config.mak.uname

In the Windows case, this definition lives in
compat/win32/trace2_win32_process_info.c, which is already conditionally
added to COMPAT_OBJS; so let's add HAVE_PLATFORM_PROCINFO to hint to the
build that compat/stub/procinfo.c should not be used.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-22 13:35:20 -07:00
Junio C Hamano
dae59cb263 Merge branch 'js/ci-windows-update'
GitHub Actions / CI update.

* js/ci-windows-update:
  ci: accelerate the checkout
  ci (vs-build): build with NO_GETTEXT
  artifacts-tar: respect NO_GETTEXT
  ci (windows): transfer also the Git-tracked files to the test jobs
  ci: upgrade to using actions/{up,down}load-artifacts v2
  ci (vs-build): use `cmd` to copy the DLLs, not `powershell`
  ci: use the new GitHub Action to download git-sdk-64-minimal
2021-07-22 13:05:55 -07:00
Ævar Arnfjörð Bjarmason
7171221d82 Makefile: don't use "FORCE" for tags targets
Remove the "FORCE" dependency from the "tags", "TAGS" and "cscope"
targets, instead make them depend on whether or not the relevant
source files have changed.

For the cscope target we need to change it to depend on the actual
generated file while we generate while we're at it, as the next commit
will discuss we always generate a cscope.out file.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-22 09:29:24 -07:00
Junio C Hamano
8721e2eaed Merge branch 'jt/partial-clone-submodule-1'
Prepare the internals for lazily fetching objects in submodules
from their promisor remotes.

* jt/partial-clone-submodule-1:
  promisor-remote: teach lazy-fetch in any repo
  run-command: refactor subprocess env preparation
  submodule: refrain from filtering GIT_CONFIG_COUNT
  promisor-remote: support per-repository config
  repository: move global r_f_p_c to repo struct
2021-07-16 17:42:53 -07:00
Junio C Hamano
368cab75c1 Merge branch 'ab/make-delete-on-error'
Use ".DELETE_ON_ERROR" pseudo target to simplify our Makefile.

* ab/make-delete-on-error:
  Makefile: add and use the ".DELETE_ON_ERROR" flag
2021-07-16 17:42:47 -07:00
Junio C Hamano
0800bedcc7 Merge branch 'dd/svn-test-wo-locale-a'
"git-svn" tests assumed that "locale -a", which is used to pick an
available UTF-8 locale, is available everywhere.  A knob has been
introduced to allow testers to specify a suitable locale to use.

* dd/svn-test-wo-locale-a:
  t: use user-specified utf-8 locale for testing svn
2021-07-08 13:14:58 -07:00
Eric Wong
92d8ed8ac1 oidtree: a crit-bit tree for odb_loose_cache
This saves 8K per `struct object_directory', meaning it saves
around 800MB in my case involving 100K alternates (half or more
of those alternates are unlikely to hold loose objects).

This is implemented in two parts: a generic, allocation-free
`cbtree' and the `oidtree' wrapper on top of it.  The latter
provides allocation using alloc_state as a memory pool to
improve locality and reduce free(3) overhead.

Unlike oid-array, the crit-bit tree does not require sorting.
Performance is bound by the key length, for oidtree that is
fixed at sizeof(struct object_id).  There's no need to have
256 oidtrees to mitigate the O(n log n) overhead like we did
with oid-array.

Being a prefix trie, it is natively suited for expanding short
object IDs via prefix-limited iteration in
`find_short_object_filename'.

On my busy workstation, p4205 performance seems to be roughly
unchanged (+/-8%).  Startup with 100K total alternates with no
loose objects seems around 10-20% faster on a hot cache.
(800MB in memory savings means more memory for the kernel FS
cache).

The generic cbtree implementation does impose some extra
overhead for oidtree in that it uses memcmp(3) on
"struct object_id" so it wastes cycles comparing 12 extra bytes
on SHA-1 repositories.  I've not yet explored reducing this
overhead, but I expect there are many places in our code base
where we'd want to investigate this.

More information on crit-bit trees: https://cr.yp.to/critbit.html

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-07 21:28:04 -07:00
Johannes Schindelin
4348824059 artifacts-tar: respect NO_GETTEXT
We obviously do not want to bundle `.mo` files during `make
artifacts-tar NO_GETTEXT=Yep`, but that was the case.

To fix that, go a step beyond just fixing the symptom, and simply
define the lists of `.po` and `.mo` files as empty if `NO_GETTEXT` is
set.

Helped-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-06 12:20:58 -07:00
Ævar Arnfjörð Bjarmason
033395be32 Makefile: add QUIET_GEN to "cscope" target
Don't show the very verbose $(FIND_SOURCE_FILES) command on every
"make cscope" invocation.

See my recent 3c80fcb591 (Makefile: add QUIET_GEN to "tags" and "TAGS"
targets, 2021-03-28) for the same fix for the other adjacent targets.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-29 13:04:00 -07:00
Ævar Arnfjörð Bjarmason
922f8bbbf1 Makefile: move ".PHONY: cscope" near its target
Move the ".PHONY: cscope" rule to live alongside the "cscope" target
itself, not to be all the way near the bottom where we define the
"FORCE" rule.

That line was last modified in 2f76919517 (MinGW: avoid collisions
between "tags" and "TAGS", 2010-09-28).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-29 13:04:00 -07:00
Ævar Arnfjörð Bjarmason
7b76d6bf22 Makefile: add and use the ".DELETE_ON_ERROR" flag
Use the GNU make ".DELETE_ON_ERROR" flag in our main Makefile, as we
already do in the Documentation/Makefile since db10fc6c09 (doc:
simplify Makefile using .DELETE_ON_ERROR, 2021-05-21).

Now if a command to make X fails X will be removed, the default
behavior of GNU make is to only do so if "make" itself is interrupted
with a signal.

E.g. if we now intentionally break one of the rules with:

    -       mv $@+ $@
    +       mv $@+ $@ && \
    +       false

We'll get output like:

    $ make git
        CC git.o
        LINK git
    make: *** [Makefile:2179: git] Error 1
    make: *** Deleting file 'git'
    $ file git
    git: cannot open `git' (No such file or directory)

Before this change we'd leave the file in place in under this
scenario.

As in db10fc6c09 this allows us to remove patterns of removing
leftover $@ files at the start of rules, since previous failing runs
of the Makefile won't have left those littered around anymore.

I'm not as confident that we should be replacing the "mv $@+ $@"
pattern entirely, since that means that external programs or one of
our other Makefiles might race and get partial content.

I'm not changing $(REMOTE_CURL_ALIASES) since that uses a ln/ln -s/cp
dance, and would require the addition of "-f" flags if the "rm" at the
start was removed. I've also got plans to fix that ln/ln -s/cp pattern
in another series.

For $(LIB_FILE) and $(XDIFF_LIB) we can rely on the "c" (create) being
present in ARFLAGS.

I'm not changing "$(ETAGS_TARGET)", "tags" and "cscope" because
they've got a messy combination of removing "$@+" not "$@" at the
beginning, or "$@*". I'm also addressing those in another series.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-29 08:03:45 -07:00
Jonathan Tan
ef830cc434 promisor-remote: teach lazy-fetch in any repo
This is one step towards supporting partial clone submodules.

Even after this patch, we will still lack partial clone submodules
support, primarily because a lot of Git code that accesses submodule
objects does so by adding their object stores as alternates, meaning
that any lazy fetches that would occur in the submodule would be done
based on the config of the superproject, not of the submodule. This also
prevents testing of the functionality in this patch by user-facing
commands. So for now, test this mechanism using a test helper.

Besides that, there is some code that uses the wrapper functions
like has_promisor_remote(). Those will need to be checked to see if they
could support the non-wrapper functions instead (and thus support any
repository, not just the_repository).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-28 09:58:01 -07:00
Đoàn Trần Công Danh
482c962de4 t: use user-specified utf-8 locale for testing svn
In some test-cases, UTF-8 locale is required. To find such locale,
we're using the first available UTF-8 locale that returned by
"locale -a".

However, the locale(1) utility is unavailable on some systems,
e.g. Linux with musl libc.

However, without "locale -a", we can't guess provided UTF-8 locale.

Add a Makefile knob GIT_TEST_UTF8_LOCALE and activate it for
linux-musl in our CI system.

Rename t/lib-git-svn.sh:prepare_a_utf8_locale to prepare_utf8_locale,
since we no longer prepare the variable named "a_utf8_locale",
but set up a fallback value for GIT_TEST_UTF8_LOCALE instead.
The fallback will be LC_ALL, LANG environment variable,
or the first UTF-8 locale from output of "locale -a", in that order.

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-08 16:07:37 +09:00
Junio C Hamano
6aae0e2ad2 Merge branch 'jh/simple-ipc-sans-pthread'
The "simple-ipc" did not compile without pthreads support, but the
build procedure was not properly account for it.

* jh/simple-ipc-sans-pthread:
  simple-ipc: correct ifdefs when NO_PTHREADS is defined
2021-05-22 18:29:01 +09:00
Jeff Hostetler
6aac70a870 simple-ipc: correct ifdefs when NO_PTHREADS is defined
Simple IPC always requires threads (in addition to various
platform-specific IPC support).  Fix the ifdefs in the Makefile
to define SUPPORTS_SIMPLE_IPC when appropriate.

Previously, the Unix version of the code would only verify that
Unix domain sockets were available.

This problem was reported here:
https://lore.kernel.org/git/YKN5lXs4AoK%2FJFTO@coredump.intra.peff.net/T/#m08be8f1942ea8a2c36cfee0e51cdf06489fdeafc

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-21 07:55:00 +09:00
Junio C Hamano
2e2ed74be0 Merge branch 'ab/perl-makefile-cleanup'
Build procedure clean-up.

* ab/perl-makefile-cleanup:
  Makefile: make PERL_DEFINES recursively expanded
  perl: use mock i18n functions under NO_GETTEXT=Y
  Makefile: regenerate *.pm on NO_PERL_CPAN_FALLBACKS change
  Makefile: regenerate perl/build/* if GIT-PERL-DEFINES changes
  Makefile: don't re-define PERL_DEFINES
2021-05-20 08:54:58 +09:00
Junio C Hamano
eede71149e Merge branch 'ba/object-info'
Over-the-wire protocol learns a new request type to ask for object
sizes given a list of object names.

* ba/object-info:
  object-info: support for retrieving object info
2021-05-14 08:26:08 +09:00
Ævar Arnfjörð Bjarmason
8c55753c68 Makefile: make PERL_DEFINES recursively expanded
Since 07d90eadb5 (Makefile: add Perl runtime prefix support,
2018-04-10) PERL_DEFINES has been a simply-expanded variable, let's
make it recursively expanded instead.

This change doesn't matter for the correctness of the logic. Whether
we used simply-expanded or recursively expanded didn't change what we
wrote out in GIT-PERL-DEFINES, but being consistent with other rules
makes this easier to understand.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-13 07:45:39 +09:00
Ævar Arnfjörð Bjarmason
256c2dc42c perl: use mock i18n functions under NO_GETTEXT=Y
Change the logic of the i18n functions I added in 5e9637c629 (i18n:
add infrastructure for translating Git with gettext, 2011-11-18) to
use pass-through functions when NO_GETTEXT is defined.

This speeds up the compilation time of commands that use this library
when NO_GETTEXT=Y is in effect. Loading it and POSIX.pm is around 20ms
on my machine, whereas it takes 2ms to just instantiate perl itself.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:33 +09:00
Ævar Arnfjörð Bjarmason
368a50d9ee Makefile: regenerate *.pm on NO_PERL_CPAN_FALLBACKS change
Regenerate the *.pm files in perl/build/* if the
NO_PERL_CPAN_FALLBACKS flag added to the *.pm files in
1aca69c019 (perl Git::LoadCPAN: emit better errors under
NO_PERL_CPAN_FALLBACKS, 2018-03-03) is changed.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:32 +09:00
Ævar Arnfjörð Bjarmason
3d49f7220a Makefile: regenerate perl/build/* if GIT-PERL-DEFINES changes
Change the logic to generate perl/build/* to regenerate those files if
GIT-PERL-DEFINES changes. This ensures that e.g. changing localedir
will result in correctly re-generated files.

I don't think that ever worked. The brokenness pre-dates my
20d2a30f8f (Makefile: replace perl/Makefile.PL with simple make
rules, 2017-12-10).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:30 +09:00
Ævar Arnfjörð Bjarmason
4070c9e09f Makefile: don't re-define PERL_DEFINES
Since 07d90eadb5 (Makefile: add Perl runtime prefix support,
2018-04-10) we have been declaring PERL_DEFINES right after assigning
to it, with the effect that the first PERL_DEFINES was ignored.

That bug didn't matter in practice since the first line had all the
same variables as the second, so we'd correctly re-generate
everything. It just made for confusing reading.

Let's remove that first assignment, and while we're at it split these
across lines to make them more maintainable.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-06 12:58:27 +09:00
Junio C Hamano
a1cac26cc6 Merge branch 'mt/parallel-checkout-part-2'
The checkout machinery has been taught to perform the actual
write-out of the files in parallel when able.

* mt/parallel-checkout-part-2:
  parallel-checkout: add design documentation
  parallel-checkout: support progress displaying
  parallel-checkout: add configuration options
  parallel-checkout: make it truly parallel
  unpack-trees: add basic support for parallel checkout
2021-04-30 13:50:26 +09:00
Junio C Hamano
8e97852919 Merge branch 'ds/sparse-index-protections'
Builds on top of the sparse-index infrastructure to mark operations
that are not ready to mark with the sparse index, causing them to
fall back on fully-populated index that they always have worked with.

* ds/sparse-index-protections: (47 commits)
  name-hash: use expand_to_path()
  sparse-index: expand_to_path()
  name-hash: don't add directories to name_hash
  revision: ensure full index
  resolve-undo: ensure full index
  read-cache: ensure full index
  pathspec: ensure full index
  merge-recursive: ensure full index
  entry: ensure full index
  dir: ensure full index
  update-index: ensure full index
  stash: ensure full index
  rm: ensure full index
  merge-index: ensure full index
  ls-files: ensure full index
  grep: ensure full index
  fsck: ensure full index
  difftool: ensure full index
  commit: ensure full index
  checkout: ensure full index
  ...
2021-04-30 13:50:26 +09:00
Bruno Albuquerque
a2ba162cda object-info: support for retrieving object info
Sometimes it is useful to get information of an object without having to
download it completely.

Add the "object-info" capability that lets the client ask for
object-related information with their full hexadecimal object names.

Only sizes are returned for now.

Signed-off-by: Bruno Albuquerque <bga@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-20 17:41:13 -07:00
Junio C Hamano
b9fa3ba0ca Merge branch 'sg/bugreport-fixes'
The dependencies for config-list.h and command-list.h were broken
when the former was split out of the latter, which has been
corrected.

* sg/bugreport-fixes:
  Makefile: add missing dependencies of 'config-list.h'
2021-04-20 17:23:37 -07:00
Junio C Hamano
ab99efc817 Merge branch 'ab/userdiff-tests'
A bit of code clean-up and a lot of test clean-up around userdiff
area.

* ab/userdiff-tests:
  blame tests: simplify userdiff driver test
  blame tests: don't rely on t/t4018/ directory
  userdiff: remove support for "broken" tests
  userdiff tests: list builtin drivers via test-tool
  userdiff tests: explicitly test "default" pattern
  userdiff: add and use for_each_userdiff_driver()
  userdiff style: normalize pascal regex declaration
  userdiff style: declare patterns with consistent style
  userdiff style: re-order drivers in alphabetical order
2021-04-20 17:23:34 -07:00
Matheus Tavares
e9e8adf1a8 parallel-checkout: make it truly parallel
Use multiple worker processes to distribute the queued entries and call
write_pc_item() in parallel for them. The items are distributed
uniformly in contiguous chunks. This minimizes the chances of two
workers writing to the same directory simultaneously, which could affect
performance due to lock contention in the kernel. Work stealing (or any
other format of re-distribution) is not implemented yet.

The protocol between the main process and the workers is quite simple.
They exchange binary messages packed in pkt-line format, and use
PKT-FLUSH to mark the end of input (from both sides). The main process
starts the communication by sending N pkt-lines, each corresponding to
an item that needs to be written. These packets contain all the
necessary information to load, smudge, and write the blob associated
with each item. Then it waits for the worker to send back N pkt-lines
containing the results for each item. The resulting packet must contain:
the identification number of the item that it refers to, the status of
the operation, and the lstat() data gathered after writing the file (iff
the operation was successful).

For now, checkout always uses a hardcoded value of 2 workers, only to
demonstrate that the parallel checkout framework correctly divides and
writes the queued entries. The next patch will add user configurations
and define a more reasonable default, based on tests with the said
settings.

Co-authored-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 11:57:05 -07:00
Matheus Tavares
04155bdad8 unpack-trees: add basic support for parallel checkout
This new interface allows us to enqueue some of the entries being
checked out to later uncompress them, apply in-process filters, and
write out the files in parallel. For now, the parallel checkout
machinery is enabled by default and there is no user configuration, but
run_parallel_checkout() just writes the queued entries in sequence
(without spawning additional workers). The next patch will actually
implement the parallelism and, later, we will make it configurable.

Note that, to avoid potential data races, not all entries are eligible
for parallel checkout. Also, paths that collide on disk (e.g.
case-sensitive paths in case-insensitive file systems), are detected by
the parallel checkout code and skipped, so that they can be safely
sequentially handled later. The collision detection works like the
following:

- If the collision was at basename (e.g. 'a/b' and 'a/B'), the framework
  detects it by looking for EEXIST and EISDIR errors after an
  open(O_CREAT | O_EXCL) failure.

- If the collision was at dirname (e.g. 'a/b' and 'A'), it is detected
  at the has_dirs_only_path() check, which is done for the leading path
  of each item in the parallel checkout queue.

Both verifications rely on the fact that, before enqueueing an entry for
parallel checkout, checkout_entry() makes sure that there is no file at
the entry's path and that its leading components are all real
directories. So, any later change in these conditions indicates that
there was a collision (either between two parallel-eligible entries or
between an eligible and an ineligible one).

After all parallel-eligible entries have been processed, the collided
(and thus, skipped) entries are sequentially fed to checkout_entry()
again. This is similar to the way the current code deals with
collisions, overwriting the previously checked out entries with the
subsequent ones. The only difference is that, since we no longer create
the files in the same order that they appear on index, we are not able
to determine which of the colliding entries will survive on disk (for
the classic code, it is always the last entry).

Co-authored-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 11:57:05 -07:00
Junio C Hamano
0623669fc6 Merge branch 'tb/pack-preferred-tips-to-give-bitmap'
A configuration variable has been added to force tips of certain
refs to be given a reachability bitmap.

* tb/pack-preferred-tips-to-give-bitmap:
  builtin/pack-objects.c: respect 'pack.preferBitmapTips'
  t/helper/test-bitmap.c: initial commit
  pack-bitmap: add 'test_bitmap_commits()' helper
2021-04-13 15:28:50 -07:00
SZEDER Gábor
56550ea718 Makefile: add missing dependencies of 'config-list.h'
We auto-generate the list of supported configuration variables from
'Documentation/config/*.txt', and that list used to be created by the
'generate-cmdlist.sh' helper script and stored in the 'command-list.h'
header.  Commit 709df95b78 (help: move list_config_help to
builtin/help, 2020-04-16) extracted this into a dedicated
'generate-configlist.sh' script and 'config-list.h' header, and added
a new target in the 'Makefile' as well, but while doing so it forgot
to extract the dependencies of the latter.  Consequently, since then
'config-list.h' is not re-generated when 'Documentation/config/*.txt'
is updated, while 'command-list.h' is re-generated unnecessarily:

  $ touch Documentation/config/log.txt
  $ make -j4
      GEN command-list.h
      CC help.o
      AR libgit.a

Fix this and list all config-related documentation files as
dependencies of 'config-list.h' and remove them from the dependencies
of 'command-list.h'.

  $ touch Documentation/config/log.txt
  $ make
      GEN config-list.h
      CC builtin/help.o
      LINK git

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-08 15:04:58 -07:00
Junio C Hamano
14cc08de23 Merge branch 'ab/make-tags-quiet'
Generate [ec]tags under $(QUIET_GEN).

* ab/make-tags-quiet:
  Makefile: add QUIET_GEN to "tags" and "TAGS" targets
2021-04-08 13:23:26 -07:00
Ævar Arnfjörð Bjarmason
28e8f0d5e5 userdiff tests: list builtin drivers via test-tool
Change the userdiff test to list the builtin drivers via the
test-tool, using the new for_each_userdiff_driver() API function.

This gets rid of the need to modify this part of the test every time a
new pattern is added, see 2ff6c34612 (userdiff: support Bash,
2020-10-22) and 09dad9256a (userdiff: support Markdown, 2020-05-02)
for two recent examples.

I only need the "list-builtin-drivers "argument here, but let's add
"list-custom-drivers" and "list-drivers" too, just because it's easy.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-08 12:19:10 -07:00
Junio C Hamano
861794b60d Merge branch 'jh/simple-ipc'
A simple IPC interface gets introduced to build services like
fsmonitor on top.

* jh/simple-ipc:
  t0052: add simple-ipc tests and t/helper/test-simple-ipc tool
  simple-ipc: add Unix domain socket implementation
  unix-stream-server: create unix domain socket under lock
  unix-socket: disallow chdir() when creating unix domain sockets
  unix-socket: add backlog size option to unix_stream_listen()
  unix-socket: eliminate static unix_stream_socket() helper function
  simple-ipc: add win32 implementation
  simple-ipc: design documentation for new IPC mechanism
  pkt-line: add options argument to read_packetized_to_strbuf()
  pkt-line: add PACKET_READ_GENTLE_ON_READ_ERROR option
  pkt-line: do not issue flush packets in write_packetized_*()
  pkt-line: eliminate the need for static buffer in packet_write_gently()
2021-04-02 14:43:14 -07:00
Ævar Arnfjörð Bjarmason
3c80fcb591 Makefile: add QUIET_GEN to "tags" and "TAGS" targets
Don't show the very verbose $(FIND_SOURCE_FILES) command on every
"make TAGS" invocation.

Let's use "generate into temporary and rename to the final file,
after seeing the command that generated the output finished
successfully" pattern, to avoid leaving a file with an incorrect
output generated by a failed command.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-01 22:23:39 -07:00
Taylor Blau
483fa7f42d t/helper/test-bitmap.c: initial commit
Add a new 'bitmap' test-tool which can be used to list the commits that
have received bitmaps.

In theory, a determined tester could run 'git rev-list --test-bitmap
<commit>' to check if '<commit>' received a bitmap or not, since
'--test-bitmap' exits with a non-zero code when it can't find the
requested commit.

But this is a dubious behavior to rely on, since arguably 'git
rev-list' could continue its object walk outside of which commits are
covered by bitmaps.

This will be used to test the behavior of 'pack.preferBitmapTips', which
will be added in the following patch.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-31 23:14:03 -07:00
Derrick Stolee
3964fc2aae sparse-index: add guard to ensure full index
Upcoming changes will introduce modifications to the index format that
allow sparse directories. It will be useful to have a mechanism for
converting those sparse index files into full indexes by walking the
tree at those sparse directories. Name this method ensure_full_index()
as it will guarantee that the index is fully expanded.

This method is not implemented yet, and instead we focus on the
scaffolding to declare it and call it at the appropriate time.

Add a 'command_requires_full_index' member to struct repo_settings. This
will be an indicator that we need the index in full mode to do certain
index operations. This starts as being true for every command, then we
will set it to false as some commands integrate with sparse indexes.

If 'command_requires_full_index' is true, then we will immediately
expand a sparse index to a full one upon reading from disk. This
suffices for now, but we will want to add more callers to
ensure_full_index() later.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-30 12:57:45 -07:00
Junio C Hamano
ed953e1076 Merge branch 'ab/make-cleanup'
Reorganize Makefile to allow building git.o and other essential
objects without extra stuff needed only for testing.

* ab/make-cleanup:
  Makefile: add {program,xdiff,test,git,fuzz}-objs & objects targets
  Makefile: split OBJECTS into OBJECTS and GIT_OBJS
  Makefile: sort OBJECTS assignment for subsequent change
  Makefile: split up long OBJECTS line
  Makefile: guard against TEST_OBJS in the environment
2021-03-26 14:59:02 -07:00
Jeff Hostetler
36a7eb6876 t0052: add simple-ipc tests and t/helper/test-simple-ipc tool
Create t0052-simple-ipc.sh with unit tests for the "simple-ipc" mechanism.

Create t/helper/test-simple-ipc test tool to exercise the "simple-ipc"
functions.

When the tool is invoked with "run-daemon", it runs a server to listen
for "simple-ipc" connections on a test socket or named pipe and
responds to a set of commands to exercise/stress the communication
setup.

When the tool is invoked with "start-daemon", it spawns a "run-daemon"
command in the background and waits for the server to become ready
before exiting.  (This helps make unit tests in t0052 more predictable
and avoids the need for arbitrary sleeps in the test script.)

The tool also has a series of client "send" commands to send commands
and data to a server instance.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-22 11:52:54 -07:00
Jeff Hostetler
7cd5dbcaba simple-ipc: add Unix domain socket implementation
Create Unix domain socket based implementation of "simple-ipc".

A set of `ipc_client` routines implement a client library to connect
to an `ipc_server` over a Unix domain socket, send a simple request,
and receive a single response.  Clients use blocking IO on the socket.

A set of `ipc_server` routines implement a thread pool to listen for
and concurrently service client connections.

The server creates a new Unix domain socket at a known location.  If a
socket already exists with that name, the server tries to determine if
another server is already listening on the socket or if the socket is
dead.  If socket is busy, the server exits with an error rather than
stealing the socket.  If the socket is dead, the server creates a new
one and starts up.

If while running, the server detects that its socket has been stolen
by another server, it automatically exits.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-22 11:52:54 -07:00
Jeff Hostetler
9fd1902762 unix-stream-server: create unix domain socket under lock
Create a wrapper class for `unix_stream_listen()` that uses a ".lock"
lockfile to create the unix domain socket in a race-free manner.

Unix domain sockets have a fundamental problem on Unix systems because
they persist in the filesystem until they are deleted.  This is
independent of whether a server is actually listening for connections.
Well-behaved servers are expected to delete the socket when they
shutdown.  A new server cannot easily tell if a found socket is
attached to an active server or is leftover cruft from a dead server.
The traditional solution used by `unix_stream_listen()` is to force
delete the socket pathname and then create a new socket.  This solves
the latter (cruft) problem, but in the case of the former, it orphans
the existing server (by stealing the pathname associated with the
socket it is listening on).

We cannot directly use a .lock lockfile to create the socket because
the socket is created by `bind(2)` rather than the `open(2)` mechanism
used by `tempfile.c`.

As an alternative, we hold a plain lockfile ("<path>.lock") as a
mutual exclusion device.  Under the lock, we test if an existing
socket ("<path>") is has an active server.  If not, we create a new
socket and begin listening.  Then we use "rollback" to delete the
lockfile in all cases.

This wrapper code conceptually exists at a higher-level than the core
unix_stream_connect() and unix_stream_listen() routines that it
consumes.  It is isolated in a wrapper class for clarity.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:51 -07:00
Jeff Hostetler
59c7b88198 simple-ipc: add win32 implementation
Create Windows implementation of "simple-ipc" using named pipes.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Andrzej Hunt
68b5c3aa48 Makefile: update 'make fuzz-all' docs to reflect modern clang
Clang no longer produces a libFuzzer.a. Instead, you can include
libFuzzer by using -fsanitize=fuzzer. Therefore we should use that in
the example command for building fuzzers.

We also add -fsanitize=fuzzer-no-link to the CFLAGS to ensure that all
the required instrumentation is added when compiling git [1], and remove
 -fsanitize-coverage=trace-pc-guard as it is deprecated.

I happen to have tested with LLVM 11 - however -fsanitize=fuzzer appears
to work in a wide range of reasonably modern clangs.

(On my system: what used to be libFuzzer.a now lives under the following
 path, which is tricky albeit not impossible for a novice such as myself
 to find:
/usr/lib64/clang/11.0.0/lib/linux/libclang_rt.fuzzer-x86_64.a )

[1] https://releases.llvm.org/11.0.0/docs/LibFuzzer.html#fuzzer-usage

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-08 10:26:25 -08:00
Junio C Hamano
921846fa22 Merge branch 'jk/open-returns-eintr'
Work around platforms whose open() is reported to return EINTR (it
shouldn't, as we do our signals with SA_RESTART).

* jk/open-returns-eintr:
  config.mak.uname: enable OPEN_RETURNS_EINTR for macOS Big Sur
  Makefile: add OPEN_RETURNS_EINTR knob
2021-03-04 15:34:45 -08:00
Junio C Hamano
660dd97a62 Merge branch 'ds/chunked-file-api'
The common code to deal with "chunked file format" that is shared
by the multi-pack-index and commit-graph files have been factored
out, to help codepaths for both filetypes to become more robust.

* ds/chunked-file-api:
  commit-graph.c: display correct number of chunks when writing
  chunk-format: add technical docs
  chunk-format: restore duplicate chunk checks
  midx: use 64-bit multiplication for chunk sizes
  midx: use chunk-format read API
  commit-graph: use chunk-format read API
  chunk-format: create read chunk API
  midx: use chunk-format API in write_midx_internal()
  midx: drop chunk progress during write
  midx: return success/failure in chunk write methods
  midx: add num_large_offsets to write_midx_context
  midx: add pack_perm to write_midx_context
  midx: add entries to write_midx_context
  midx: use context in write_midx_pack_names()
  midx: rename pack_info to write_midx_context
  commit-graph: use chunk-format write API
  chunk-format: create chunk format write API
  commit-graph: anonymize data in chunk_write_fn
2021-03-01 14:02:57 -08:00
Jeff King
2b08101204 Makefile: add OPEN_RETURNS_EINTR knob
On some platforms, open() reportedly returns EINTR when opening regular
files and we receive a signal (usually SIGALRM from our progress meter).
This shouldn't happen, as open() should be a restartable syscall, and we
specify SA_RESTART when setting up the alarm handler. So it may actually
be a kernel or libc bug for this to happen. But it has been reported on
at least one version of Linux (on a network filesystem):

  https://lore.kernel.org/git/c8061cce-71e4-17bd-a56a-a5fed93804da@neanderfunk.de/

as well as on macOS starting with Big Sur even on a regular filesystem.

We can work around it by retrying open() calls that get EINTR, just as
we do for read(), etc. Since we don't ever _want_ to interrupt an open()
call, we can get away with just redefining open, rather than insisting
all callsites use xopen().

We actually do have an xopen() wrapper already (and it even does this
retry, though there's no indication of it being an observed problem back
then; it seems simply to have been lifted from xread(), etc). But it is
used hardly anywhere, and isn't suitable for general use because it will
die() on error. In theory we could combine the two, but it's awkward to
do so because of the variable-args interface of open().

This patch adds a Makefile knob for enabling the workaround. It's not
enabled by default for any platforms in config.mak.uname yet, as we
don't have enough data to decide how common this is (I have not been
able to reproduce on either Linux or Big Sur myself). It may be worth
enabling preemptively anyway, since the cost is pretty low (if we don't
see an EINTR, it's just an extra conditional).

However, note that we must not enable this on Windows. It doesn't do
anything there, and the macro overrides the existing mingw_open()
redirection. I've added a preemptive #undef here in the mingw header
(which is processed first) to just quietly disable it (we could also
make it an #error, but there is little point in being so aggressive).

Reported-by: Aleksey Kliger <alklig@microsoft.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-26 14:15:51 -08:00