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2892 commits

Author SHA1 Message Date
Jeff King d3775de074 Makefile: force -O0 when compiling with SANITIZE=leak
Compiling with -O2 can interact badly with LSan's leak-checker, causing
false positives. Imagine a simplified example like:

  char *str = allocate_some_string();
  if (some_func(str) < 0)
          die("bad str");
  free(str);

The compiler may eliminate "str" as a stack variable, and just leave it
in a register. The register is preserved through most of the function,
including across the call to some_func(), since we'd eventually need to
free it. But because die() is marked with NORETURN, the compiler knows
that it doesn't need to save registers, and just clobbers it.

When die() eventually exits, the leak-checker runs. It looks in
registers and on the stack for any reference to the memory allocated by
str (which would indicate that it's not leaked), but can't find one.  So
it reports it as a leak.

Neither system is wrong, really. The C standard (mostly section 5.1.2.3)
defines an abstract machine, and compilers are allowed to modify the
program as long as the observable behavior of that abstract machine is
unchanged. Looking at random memory values on the stack is undefined
behavior, and not something that the optimizer needs to support. But
there really isn't any other way for a leak checker to work; it
inherently has to do undefined things like scouring memory for pointers.
So the two things are inherently at odds with each other. We can't fix
it by changing the code, because from the perspective of the program
running in an abstract machine, there is no leak.

This has caused real false positives in the past, like:

  - https://lore.kernel.org/git/patch-v3-5.6-9a44204c4c9-20211022T175227Z-avarab@gmail.com/

  - https://lore.kernel.org/git/Yy4eo6500C0ijhk+@coredump.intra.peff.net/

  - https://lore.kernel.org/git/Y07yeEQu+C7AH7oN@nand.local/

This patch makes those go away by forcing -O0 when compiling with LSan.
There are a few ways we could do this:

  - we could just teach the linux-leaks CI job to set -O0. That's the
    smallest change, and means we wouldn't get spurious CI failures. But
    it doesn't help people looking for leaks manually or in a specific
    test (and because the problem depends on the vagaries of the
    optimizer, investigating these can waste a lot of time in
    head-scratching as the problem comes and goes)

  - we default to -O2 in CFLAGS; we could pull this out to a separate
    variable ("-O$(O)" or something) and modify "O" when LSan is in use.
    This is the most flexible, in that you could still build with "make
    O=2 SANITIZE=leak" if you really wanted to (say, for experimenting).
    But it would also fail to kick in if the user defines their own
    CFLAGS variable, which again leads to head-scratching.

  - we can just stick -O0 into BASIC_CFLAGS when enabling LSan. Since
    this comes after the user-provided CFLAGS, it will override any
    previous -O setting found there. This is more foolproof, albeit less
    flexible. If you want to experiment with an optimized leak-checking
    build, you'll have to put "-O2 -fsanitize=leak" into CFLAGS
    manually, rather than using our SANITIZE=leak Makefile magic.

Since the final one is the least likely to break in normal use, this
patch uses that approach.

The resulting build is a little slower, of course, but since LSan is
already about 2x slower than a regular build, another 10% slowdown isn't
that big a deal.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-19 08:32:39 -07:00
Junio C Hamano 8e28728cbb Merge branch 'dd/document-runtime-prefix-better'
Update comment in the Makefile about the RUNTIME_PREFIX config knob.

* dd/document-runtime-prefix-better:
  Makefile: clarify runtime relative gitexecdir
2022-10-17 14:56:34 -07:00
Junio C Hamano 7b8cfe34d9 Merge branch 'ed/fsmonitor-on-networked-macos'
By default, use of fsmonitor on a repository on networked
filesystem is disabled. Add knobs to make it workable on macOS.

* ed/fsmonitor-on-networked-macos:
  fsmonitor: fix leak of warning message
  fsmonitor: add documentation for allowRemote and socketDir options
  fsmonitor: check for compatability before communicating with fsmonitor
  fsmonitor: deal with synthetic firmlinks on macOS
  fsmonitor: avoid socket location check if using hook
  fsmonitor: relocate socket file if .git directory is remote
  fsmonitor: refactor filesystem checks to common interface
2022-10-17 14:56:31 -07:00
Ævar Arnfjörð Bjarmason d796cedbe8 bundle-uri: unit test "key=value" parsing
Create a new 'test-tool bundle-uri' test helper. This helper will assist
in testing logic deep in the bundle URI feature.

This change introduces the 'parse-key-values' subcommand, which parses
an input file as a list of lines. These are fed into
bundle_uri_parse_line() to test how we construct a 'struct bundle_list'
from that data. The list is then output to stdout as if the key-value
pairs were a Git config file.

We use an input file instead of stdin because of a future change to
parse in config-file format that works better as an input file.

Co-authored-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-12 09:13:24 -07:00
Junio C Hamano 9b89c08cae Merge branch 'ac/fuzzers'
Source file shuffling.

* ac/fuzzers:
  fuzz: reorganise the path for existing oss-fuzz fuzzers
2022-10-07 17:19:59 -07:00
Junio C Hamano 410a0e520d Merge branch 'ds/use-platform-regex-on-macos'
With a bit of header twiddling, use the native regexp library on
macOS instead of the compat/ one.

* ds/use-platform-regex-on-macos:
  grep: fix multibyte regex handling under macOS
2022-10-07 17:19:59 -07:00
Đoàn Trần Công Danh ebb6c16607 Makefile: clarify runtime relative gitexecdir
"git" built with RUNTIME_PREFIX flag turned on could figure out
gitexecdir and other paths as relative to "git" executable.

However, in the section specifies gitexecdir, RUNTIME_PREFIX wasn't
mentioned, thus users may wrongly assume that "git" always locates
gitexecdir as relative path to the executable.

Let's clarify that only "git" built with RUNTIME_PREFIX will locate
gitexecdir as relative path.

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-05 19:06:01 -07:00
Eric DeCosta 6beb2688d3 fsmonitor: relocate socket file if .git directory is remote
If the .git directory is on a remote filesystem, create the socket
file in 'fsmonitor.socketDir' if it is defined, else create it in $HOME.

Signed-off-by: Eric DeCosta <edecosta@mathworks.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-05 11:05:22 -07:00
Eric DeCosta 508c1a572d fsmonitor: refactor filesystem checks to common interface
Provide a common interface for getting basic filesystem information
including filesystem type and whether the filesystem is remote.

Refactor existing code for getting basic filesystem info and detecting
remote file systems to the new interface.

Refactor filesystem checks to leverage new interface. For macOS,
error-out if the Unix Domain socket (UDS) file is on a remote
filesystem.

Signed-off-by: Eric DeCosta <edecosta@mathworks.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-05 11:05:22 -07:00
Victoria Dye 9b1dc1c9d8 version: fix builtin linking & documentation
Like most builtins, 'version' is documented in a corresponding
'Documentation/git-version.txt' and can be invoked with 'git version'.
However, the 'check-docs' Makefile target showed that it was "removed but
documented: git-version." This was cause by the fact that it is not built as
a standalone 'git-version' executable, therefore appearing "removed" to
'check-docs'.

Without a precedent for documented builtins that aren't built into an
executable *or* any clear reason why a standalone 'git-version' shouldn't
exist, the 'check-docs' error appears to correctly identify an issue. To
correct that mismatch, add 'git-version' to the 'BUILT_INS' list in the root
Makefile (indicating that the 'cmd_version()' function appears in a file
that is *not* 'builtin/version.c'). Additionally, to avoid the "no link"
message in 'check-docs', list 'git-version' as an "ancilliaryinterrogator"
(like 'git help') in 'command-list.txt'.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-19 17:28:25 -07:00
Junio C Hamano 42bf77c7d0 Merge branch 'vd/scalar-to-main'
Hoist the remainder of "scalar" out of contrib/ to the main part of
the codebase.

* vd/scalar-to-main:
  Documentation/technical: include Scalar technical doc
  t/perf: add 'GIT_PERF_USE_SCALAR' run option
  t/perf: add Scalar performance tests
  scalar-clone: add test coverage
  scalar: add to 'git help -a' command list
  scalar: implement the `help` subcommand
  git help: special-case `scalar`
  scalar: include in standard Git build & installation
  scalar: fix command documentation section header
2022-09-19 14:35:25 -07:00
Arthur Chan 6713bfc70c fuzz: reorganise the path for existing oss-fuzz fuzzers
In order to provide a better organisation for oss-fuzz fuzzers and
to avoid top-level clustters in the git repository when more fuzzers
are introduced, move the existing fuzzer-related sources to their
own oss-fuzz/ hierarchy.  Grouping the fuzzers into their own
directory, separate their application on fuzz-testing from the core
functionalities of the git code, prvides better and tidier structure
the oss-fuzz fuzzing library to manage, locate, build and execute
those fuzzers for fuzz-testing purposes in future development.

Signed-off-by: Arthur Chan <arthur.chan@adalogics.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-19 09:34:35 -07:00
Junio C Hamano f322e9f51b Merge branch 'ab/submodule-helper-prep'
Code clean-up of "git submodule--helper".

* ab/submodule-helper-prep: (33 commits)
  submodule--helper: fix bad config API usage
  submodule--helper: libify even more "die" paths for module_update()
  submodule--helper: libify more "die" paths for module_update()
  submodule--helper: check repo{_submodule,}_init() return values
  submodule--helper: libify "must_die_on_failure" code paths (for die)
  submodule--helper update: don't override 'checkout' exit code
  submodule--helper: libify "must_die_on_failure" code paths
  submodule--helper: libify determine_submodule_update_strategy()
  submodule--helper: don't exit() on failure, return
  submodule--helper: use "code" in run_update_command()
  submodule API: don't handle SM_..{UNSPECIFIED,COMMAND} in to_string()
  submodule--helper: don't call submodule_strategy_to_string() in BUG()
  submodule--helper: add missing braces to "else" arm
  submodule--helper: return "ret", not "1" from update_submodule()
  submodule--helper: rename "int res" to "int ret"
  submodule--helper: don't redundantly check "else if (res)"
  submodule--helper: refactor "errmsg_str" to be a "struct strbuf"
  submodule--helper: add "const" to passed "struct update_data"
  submodule--helper: add "const" to copy of "update_data"
  submodule--helper: add "const" to passed "module_clone_data"
  ...
2022-09-13 11:38:23 -07:00
Junio C Hamano fd1ec82547 Merge branch 'ab/retire-ppc-sha1'
Remove the assembly version of SHA-1 implementation for PPC.

* ab/retire-ppc-sha1:
  Makefile: use $(OBJECTS) instead of $(C_OBJ)
  Makefile + hash.h: remove PPC_SHA1 implementation
2022-09-09 12:02:25 -07:00
Victoria Dye 7b5c93c6c6 scalar: include in standard Git build & installation
Move 'scalar' out of 'contrib/' and into the root of the Git tree. The goal
of this change is to build 'scalar' as part of the standard Git build &
install processes.

This patch includes both the physical move of Scalar's files out of
'contrib/' ('scalar.c', 'scalar.txt', and 't9xxx-scalar.sh'), and the
changes to the build definitions in 'Makefile' and 'CMakelists.txt' to
accommodate the new program.

At a high level, Scalar is built so that:
- there is a 'scalar-objs' target (similar to those created in 029bac01a8
  (Makefile: add {program,xdiff,test,git,fuzz}-objs & objects targets,
  2021-02-23)) for debugging purposes.
- it appears in the root of the install directory (rather than the
  gitexecdir).
- it is included in the 'bin-wrappers/' directory for use in tests.
- it receives a platform-specific executable suffix (e.g., '.exe'), if
  applicable.
- 'scalar.txt' is installed as 'man1' documentation.
- the 'clean' target removes the 'scalar' executable.

Additionally, update the root level '.gitignore' file to ignore the Scalar
executable.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-02 10:02:55 -07:00
Ævar Arnfjörð Bjarmason 9fb2a970e9 submodule--helper: move "is-active" to a test-tool
Create a new "test-tool submodule" and move the "is-active" subcommand
over to it. It was added in 5c2bd8b77a (submodule--helper: add
is-active subcommand, 2017-03-16), since
a452128a36 (submodule--helper: introduce add-config subcommand,
2021-08-06) it hasn't been used by git-submodule.sh.

Since we're creating a command dispatch similar to test-tool.c itself
let's split out the "struct test_cmd" into a new test-tool-utils.h,
which both this new code and test-tool.c itself can use.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-02 09:16:23 -07:00
Junio C Hamano 68ef0425d9 Merge branch 'ds/bundle-uri-clone'
Implement "git clone --bundle-uri".

* ds/bundle-uri-clone:
  clone: warn on failure to repo_init()
  clone: --bundle-uri cannot be combined with --depth
  bundle-uri: add support for http(s):// and file://
  clone: add --bundle-uri option
  bundle-uri: create basic file-copy logic
  remote-curl: add 'get' capability
2022-09-01 13:40:17 -07:00
Ævar Arnfjörð Bjarmason 3221597433 Makefile: use $(OBJECTS) instead of $(C_OBJ)
In the preceding commit $(C_OBJ) added in c373991375 (Makefile: list
generated object files in OBJECTS, 2010-01-26) became synonymous with
$(OBJECTS). Let's avoid the indirection and use the $(OBJECTS)
variable directly instead.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-31 14:44:39 -07:00
Ævar Arnfjörð Bjarmason 9dc523aa0e Makefile + hash.h: remove PPC_SHA1 implementation
Remove the PPC_SHA1 implementation added in a6ef3518f9 ([PATCH] PPC
assembly implementation of SHA1, 2005-04-22). When this was added
Apple consumer hardware used the PPC architecture, and the
implementation was intended to improve SHA-1 speed there.

Since it was added we've moved to using sha1collisiondetection by
default, and anyone wanting hard-rolled non-DC SHA-1 implementation
can use OpenSSL's via the OPENSSL_SHA1 knob.

The PPC_SHA1 originally originally targeted 32 bit PPC, and later the
64 bit PPC 970 (a.k.a. Apple PowerPC G5). See 926172c5e4 (block-sha1:
improve code on large-register-set machines, 2009-08-10) for a
reference about the performance on G5 (a comment in block-sha1/sha1.c
being removed here).

I can't get it to do anything but segfault on both the BE and LE POWER
machines in the GCC compile farm[1]. Anyone who's concerned about
performance on PPC these days is likely to be using the IBM POWER
processors.

There have been proposals to entirely remove non-sha1collisiondetection
implementations from the tree[2]. I think per [3] that would be a bit
overzealous. I.e. there are various set-ups git's speed is going to be
more important than the relatively implausible SHA-1 collision attack,
or where such attacks are entirely mitigated by other means (e.g. by
incoming objects being checked with DC_SHA1).

But that really doesn't apply to PPC_SHA1 in particular, which seems
to have outlived its usefulness.

As this gets rid of the only in-tree *.S assembly file we can remove
the small bits of logic from the Makefile needed to build objects
from *.S (as opposed to *.c)

The code being removed here was also throwing warnings with the
"-pedantic" flag, it could have been fixed as 544d93bc3b (block-sha1:
remove use of obsolete x86 assembly, 2022-03-10) did for block-sha1/*,
but as noted above let's remove it instead.

1. https://cfarm.tetaneutral.net/machines/list/
   Tested on gcc{110,112,135,203}, a mixture of POWER [789] ppc64 and
   ppc64le. All segfault in anything needing object
   hashing (e.g. t/t1007-hash-object.sh) when compiled with
   PPC_SHA1=Y.
2. https://lore.kernel.org/git/20200223223758.120941-1-mh@glandium.org/
3. https://lore.kernel.org/git/20200224044732.GK1018190@coredump.intra.peff.net/

Acked-by: brian m. carlson" <sandals@crustytoothpaste.net>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-31 14:37:31 -07:00
Junio C Hamano 64cb4c34d1 Merge branch 'mt/rot13-in-c'
Test portability improvements.

* mt/rot13-in-c:
  tests: use the new C rot13-filter helper to avoid PERL prereq
  t0021: implementation the rot13-filter.pl script in C
  t0021: avoid grepping for a Perl-specific string at filter output
2022-08-29 14:55:11 -07:00
Diomidis Spinellis 1819ad327b grep: fix multibyte regex handling under macOS
The commit 29de20504e (Makefile: fix default regex settings on
Darwin, 2013-05-11) fixed t0070-fundamental.sh under Darwin (macOS) by
adopting Git's regex library.  However, this library is compiled with
NO_MBSUPPORT, which causes git-grep to work incorrectly on multibyte
(e.g. UTF-8) files.  Current macOS versions pass t0070-fundamental.sh
with the native macOS regex library, which also supports multibyte
characters.

Adjust the Makefile to use the native regex library, and call
setlocale(3) to set CTYPE according to the user's preference.
The setlocale call is required on all platforms, but in platforms
supporting gettext(3), setlocale was called as a side-effect of
initializing gettext.  Therefore, move the CTYPE setlocale call from
gettext.c to common-main.c and the corresponding locale.h include
into git-compat-util.h.

Thanks to the global initialization of CTYPE setlocale, the test-tool
regex command now works correctly with supported multibyte regexes, and
is used to set the MB_REGEX test prerequisite by assessing a platform's
support for them.

Signed-off-by: Diomidis Spinellis <dds@aueb.gr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-26 11:45:52 -07:00
Junio C Hamano f00ddc9f48 Merge branch 'vd/scalar-generalize-diagnose'
The "diagnose" feature to create a zip archive for diagnostic
material has been lifted from "scalar" and made into a feature of
"git bugreport".

* vd/scalar-generalize-diagnose:
  scalar: update technical doc roadmap
  scalar-diagnose: use 'git diagnose --mode=all'
  builtin/bugreport.c: create '--diagnose' option
  builtin/diagnose.c: add '--mode' option
  builtin/diagnose.c: create 'git diagnose' builtin
  diagnose.c: add option to configure archive contents
  scalar-diagnose: move functionality to common location
  scalar-diagnose: move 'get_disk_info()' to 'compat/'
  scalar-diagnose: add directory to archiver more gently
  scalar-diagnose: avoid 32-bit overflow of size_t
  scalar-diagnose: use "$GIT_UNZIP" in test
2022-08-25 14:42:32 -07:00
Junio C Hamano a103ad6f3d Merge branch 'jk/pipe-command-nonblock'
Fix deadlocks between main Git process and subprocess spawned via
the pipe_command() API, that can kill "git add -p" that was
reimplemented in C recently.

* jk/pipe-command-nonblock:
  pipe_command(): mark stdin descriptor as non-blocking
  pipe_command(): handle ENOSPC when writing to a pipe
  pipe_command(): avoid xwrite() for writing to pipe
  git-compat-util: make MAX_IO_SIZE define globally available
  nonblock: support Windows
  compat: add function to enable nonblocking pipes
2022-08-25 14:42:32 -07:00
Junio C Hamano f677f62970 Merge branch 'ds/bundle-uri-clone' into ds/bundle-uri-3
* ds/bundle-uri-clone:
  clone: warn on failure to repo_init()
  clone: --bundle-uri cannot be combined with --depth
  bundle-uri: add support for http(s):// and file://
  clone: add --bundle-uri option
  bundle-uri: create basic file-copy logic
  remote-curl: add 'get' capability
2022-08-24 16:05:16 -07:00
Jeff King 10f743389c compat: add function to enable nonblocking pipes
We'd like to be able to make some of our pipes nonblocking so that
poll() can be used effectively, but O_NONBLOCK isn't portable. Let's
introduce a compat wrapper so this can be abstracted for each platform.

The interface is as narrow as possible to let platforms do what's
natural there (rather than having to implement fcntl() and a fake
O_NONBLOCK for example, or having to handle other types of descriptors).

The next commit will add Windows support, at which point we should be
covering all platforms in practice. But if we do find some other
platform without O_NONBLOCK, we'll return ENOSYS. Arguably we could just
trigger a build-time #error in this case, which would catch the problem
earlier. But since we're not planning to use this compat wrapper in many
code paths, a seldom-seen runtime error may be friendlier for such a
platform than blocking compilation completely. Our test suite would
still notice it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-17 09:21:40 -07:00
Junio C Hamano c0f6dd49f1 Merge branch 'ab/tech-docs-to-help'
Expose a lot of "tech docs" via "git help" interface.

* ab/tech-docs-to-help:
  docs: move http-protocol docs to man section 5
  docs: move cruft pack docs to gitformat-pack
  docs: move pack format docs to man section 5
  docs: move signature docs to man section 5
  docs: move index format docs to man section 5
  docs: move protocol-related docs to man section 5
  docs: move commit-graph format docs to man section 5
  git docs: add a category for file formats, protocols and interfaces
  git docs: add a category for user-facing file, repo and command UX
  git help doc: use "<doc>" instead of "<guide>"
  help.c: remove common category behavior from drop_prefix() behavior
  help.c: refactor drop_prefix() to use a "switch" statement"
2022-08-14 23:19:28 -07:00
Matheus Tavares 52917a998e t0021: implementation the rot13-filter.pl script in C
This script is currently used by three test files: t0021-conversion.sh,
t2080-parallel-checkout-basics.sh, and
t2082-parallel-checkout-attributes.sh. To avoid the need for the PERL
dependency at these tests, let's convert the script to a C test-tool
command. The following commit will take care of actually modifying the
said tests to use the new C helper and removing the Perl script.

The Perl script flushes the log file handler after each write. As
commented in [1], this seems to be an early design decision that was
later reconsidered, but possibly ended up being left in the code by
accident:

	>> +$debug->flush();
	>
	> Isn't $debug flushed automatically?

	Maybe, but autoflush is not explicitly enabled. I will
	enable it again (I disabled it because of Eric's comment
	but I re-read the comment and he is only talking about
	pipes).

Anyways, this behavior is not really needed for the tests and the
flush() calls make the code slightly larger, so let's avoid them
altogether in the new C version.

[1]: https://lore.kernel.org/git/7F1F1A0E-8FC3-4FBD-81AA-37786DE0EF50@gmail.com/

Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-14 22:57:12 -07:00
Victoria Dye 6783fd3cef builtin/diagnose.c: create 'git diagnose' builtin
Create a 'git diagnose' builtin to generate a standalone zip archive of
repository diagnostics.

The "diagnose" functionality was originally implemented for Scalar in
aa5c79a331 (scalar: implement `scalar diagnose`, 2022-05-28). However, the
diagnostics gathered are not specific to Scalar-cloned repositories and
can be useful when diagnosing issues in any Git repository.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-12 13:20:02 -07:00
Victoria Dye bb2c34956a scalar-diagnose: move functionality to common location
Move the core functionality of 'scalar diagnose' into a new 'diagnose.[c,h]'
library to prepare for new callers in the main Git tree generating
diagnostic archives. These callers will be introduced in subsequent patches.

While this patch appears large, it is mostly made up of moving code out of
'scalar.c' and into 'diagnose.c'. Specifically, the functions

- dir_file_stats_objects()
- dir_file_stats()
- count_files()
- loose_objs_stats()
- add_directory_to_archiver()

are all copied verbatim from 'scalar.c'. The 'create_diagnostics_archive()'
function is a mostly identical (partial) copy of 'cmd_diagnose()', with the
primary changes being that 'zip_path' is an input and "Enlistment root" is
corrected to "Repository root" in the archiver log.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-12 13:20:02 -07:00
Derrick Stolee 53a50892be bundle-uri: create basic file-copy logic
Before implementing a way to fetch bundles into a repository, create the
basic logic. Assume that the URI is actually a file path. Future logic
will make this more careful to other protocols.

For now, we also only succeed if the content at the URI is a bundle
file, not a bundle list. Bundle lists will be implemented in a future
change.

Note that the discovery of a temporary filename is slightly racy because
the odb_mkstemp() relies on the temporary file not existing. With the
current implementation being limited to file copies, we could replace
the copy_file() with copy_fd(). The tricky part comes in future changes
that send the filename to 'git remote-https' and its 'get' capability.
At that point, we need the file descriptor closed _and_ the file
unlinked. If we were to keep the file descriptor open for the sake of
normal file copies, then we would pollute the rest of the code for
little benefit. This is especially the case because we expect that most
bundle URI use will be based on HTTPS instead of file copies.

Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-10 14:07:37 -07:00
Ævar Arnfjörð Bjarmason d976c5100f git docs: add a category for user-facing file, repo and command UX
Create a new "Repository, command and file interfaces" section in the
main "git help git" manual page. Move things that belong under this
new criteria from the generic "Guides" section.

The "Guides" section was added in f442f28a81 (git.txt: add list of
guides, 2020-08-05). It makes sense to have e.g. "giteveryday(7)" and
"gitfaq(7)" listed under "Guides".

But placing e.g. "gitignore(5)" in it is stretching the meaning of
what a "guide" is, ideally that section should list things similar to
"giteveryday(7)" and "gitcore-tutorial(7)".

An alternate name that was considered for this new section was "User
formats", for consistency with the nomenclature used for man section 5
in general. My man(1) lists it as "File formats and conventions,
e.g. /etc/passwd".

So calling this "git help --formats" or "git help --user-formats"
would make sense for e.g. gitignore(5), but would be stretching it
somewhat for githooks(5), and would seem really suspect for the likes
of gitcli(7).

Let's instead pick a name that's closer to the generic term "User
interface", which is really what this documentation discusses: General
user-interface documentation that doesn't obviously belong elsewhere.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-04 14:12:23 -07:00
Junio C Hamano 4e0d160bbc Merge branch 'rs/mergesort'
Make our mergesort implementation type-safe.

* rs/mergesort:
  mergesort: remove llist_mergesort()
  packfile: use DEFINE_LIST_SORT
  fetch-pack: use DEFINE_LIST_SORT
  commit: use DEFINE_LIST_SORT
  blame: use DEFINE_LIST_SORT
  test-mergesort: use DEFINE_LIST_SORT
  test-mergesort: use DEFINE_LIST_SORT_DEBUG
  mergesort: add macros for typed sort of linked lists
  mergesort: tighten merge loop
  mergesort: unify ranks loops
2022-08-03 13:36:09 -07:00
Junio C Hamano 4af2138417 Merge branch 'bc/nettle-sha256'
Support for libnettle as SHA256 implementation has been added.

* bc/nettle-sha256:
  sha256: add support for Nettle
2022-07-18 13:31:58 -07:00
Junio C Hamano 7f8d098b1b Merge branch 'ab/cocci-unused'
Add Coccinelle rules to detect the pattern of initializing and then
finalizing a structure without using it in between at all, which
happens after code restructuring and the compilers fail to
recognize as an unused variable.

* ab/cocci-unused:
  cocci: generalize "unused" rule to cover more than "strbuf"
  cocci: add and apply a rule to find "unused" strbufs
  cocci: have "coccicheck{,-pending}" depend on "coccicheck-test"
  cocci: add a "coccicheck-test" target and test *.cocci rules
  Makefile & .gitignore: ignore & clean "git.res", not "*.res"
  Makefile: remove mandatory "spatch" arguments from SPATCH_FLAGS
2022-07-18 13:31:57 -07:00
Junio C Hamano 48e88a4862 Merge branch 'ab/build-gitweb'
Teach "make all" to build gitweb as well.

* ab/build-gitweb:
  gitweb/Makefile: add a "NO_GITWEB" parameter
  Makefile: build 'gitweb' in the default target
  gitweb/Makefile: include in top-level Makefile
  gitweb: remove "test" and "test-installed" targets
  gitweb/Makefile: prepare to merge into top-level Makefile
  gitweb/Makefile: clear up and de-duplicate the gitweb.{css,js} vars
  gitweb/Makefile: add a $(GITWEB_ALL) variable
  gitweb/Makefile: define all .PHONY prerequisites inline
2022-07-18 13:31:55 -07:00
René Scharfe 0f1eb7d6e9 mergesort: remove llist_mergesort()
Now that all of its callers are gone, remove llist_mergesort().

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-17 15:20:39 -07:00
brian m. carlson e555735836 sha256: add support for Nettle
For SHA-256, we currently have support for OpenSSL and libgcrypt because
these two libraries contain optimized implementations that can take
advantage of native processor instructions.  However, OpenSSL is not
suitable for linking against for Linux distros due to licensing
incompatibilities with the GPLv2, and libgcrypt has been less favored by
cryptographers due to some security-related implementation issues,
which, while not affecting our use of hash algorithms, has affected its
reputation.

Let's add another option that's compatible with the GPLv2, which is
Nettle.  This is an option which is generally better than libgcrypt
because on many distros GnuTLS (which uses Nettle) is used for HTTPS and
therefore as a practical matter it will be available on most systems.
As a result, prefer it over libgcrypt and our built-in implementation.

Nettle also has recently gained support for Intel's SHA-NI instructions,
which compare very favorably to other implementations, as well as
assembly implementations for when SHA-NI is not available.

A git gc on git.git sees a 12% performance improvement with Nettle over
our block SHA-256 implementation due to general assembly improvements.
With SHA-NI, the performance of raw SHA-256 on a 2 GiB file goes from
7.296 seconds with block SHA-256 to 1.523 seconds with Nettle.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-10 14:43:34 -07:00
Ævar Arnfjörð Bjarmason 7a9a10b10e cocci: have "coccicheck{,-pending}" depend on "coccicheck-test"
Have the newly introduced "coccicheck-test" target run implicitly when
"coccicheck" itself is run. As with e.g. the "check-chainlint"
target (see [1]) it makes sense to run this unconditionally before we
run other "spatch" rules as a basic sanity check. See

1. 803394459d (t/Makefile: add machinery to check correctness of
   chainlint.sed, 2018-07-11)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06 12:24:43 -07:00
Ævar Arnfjörð Bjarmason f7ff6597a7 cocci: add a "coccicheck-test" target and test *.cocci rules
Add a "coccicheck-test" target to test our *.cocci rules, and as a
demonstration add tests for the rules added in 39ea59a257 (remove
unnecessary NULL check before free(3), 2016-10-08) and
1b83d1251e (coccinelle: add a rule to make "expression" code use
FREE_AND_NULL(), 2017-06-15).

I considered making use of the "spatch --test" option, and the choice
of a "tests" over a "t" directory is to make these tests compatible
with such a future change.

Unfortunately "spatch --test" doesn't return meaningful exit codes,
AFAICT you need to "grep" its output to see if the *.res is what you
expect. There's "--test-okfailed", but I didn't find a way to sensibly
integrate those (it relies on some in-between status files, but
doesn't help with the status codes).

Instead let's use a "--sp-file" pattern similar to the main
"coccicheck" rule, with the difference that we use and compare the
two *.res files with cmp(1).

The --very-quiet and --no-show-diff options ensure that we don't need
to pipe stdout and stderr somewhere. Unlike the "%.cocci.patch" rule
we're not using the diff.

The "cmp || git diff" is optimistically giving us better output on
failure, but even if we only have POSIX cmp and no system git
installed we'll still fail with the "cmp", just with an error message
that isn't as friendly. The "2>/dev/null" is in case we don't have a
"git" installed.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06 12:24:43 -07:00
Ævar Arnfjörð Bjarmason af0aa6904b Makefile & .gitignore: ignore & clean "git.res", not "*.res"
Adjust the overly broad .gitignore and "make clean" rule added in
ce39c2e04c (Provide a Windows version resource for the git
executables., 2012-05-24).

For now this is merely a correctness fix, but needed because a
subsequent commit will want to check in *.res files elsewhere in the
tree, which we shouldn't have to "git add -f".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06 12:24:43 -07:00
Ævar Arnfjörð Bjarmason 7b63ea5750 Makefile: remove mandatory "spatch" arguments from SPATCH_FLAGS
The "--patch ." part of SPATCH_FLAGS added in f57d11728d (coccinelle:
put sane filenames into output patches, 2018-07-23) should have been
added unconditionally to the "spatch" invocation instead, using it
isn't optional.

Let's also move the other mandatory flag to come after
$(SPATCH_FLAGS), to ensure that our "--sp-file" overrides any provided
in the environment, both --sp-file <arg> and --patch <arg> are
last-option-wins as far as spatch(1) option parsing is concerned.

The environment variable override was initially added in
a9a884aea5 (coccicheck: use --all-includes by default,
2016-09-30). In practice there's probably nobody that's using
SPATCH_FLAGS to try to intentionally break our invocations, but since
we're changing this let's make it clear what (if anything) we expect
to be overridden by user-supplied flags.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-06 12:24:43 -07:00
Ævar Arnfjörð Bjarmason a35258c62a gitweb/Makefile: add a "NO_GITWEB" parameter
From looking at the {Free,Net,Dragonfly}BSD packages for git[1]
they've been monkeypatching "gitweb" out of the Makefile, let's be
nicer and provide a NO_GITWEB=Y for their use.

For the "all" target this allows for optionally restoring what's been
the status quo before the preceding commit, but now we'll also behave
correctly on the subsequent "make install".

As before our installation of gitweb can be suppressed with
NO_PERL. For backwards compatibility the NO_PERL=Y flag by itself
still doesn't change whether or not we build gitweb, unlike the new
NO_GITWEB=Y flag.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-28 13:20:05 -07:00
SZEDER Gábor d3b827408c Makefile: build 'gitweb' in the default target
Our Makefile's default target used to build 'gitweb', though
indirectly: the 'all' target depended on 'git-instaweb', which in turn
depended on 'gitweb'.  Then e25c7cc146 (Makefile: drop dependency
between git-instaweb and gitweb, 2015-05-29) removed the latter
dependency, and for good reasons (quoting its commit message):

  "1. git-instaweb has no build-time dependency on gitweb; it
      is a run-time dependency

   2. gitweb is a directory that we want to recursively make
      in. As a result, its recipe is marked .PHONY, which
      causes "make" to rebuild git-instaweb every time it is
      run."

Since then a simple 'make' doesn't build 'gitweb'.

Luckily, installing 'gitweb' is not broken: although 'make install'
doesn't depend on the 'gitweb' target, it has a dependency on the
'install-gitweb' target, which does generate all the necessary files
for 'gitweb' and installs them.  However, if someone runs 'make &&
sudo make install', then those files in the 'gitweb' directory will be
generated and owned by root, which is not nice.

List 'gitweb' as a direct dependency of the default target, so a plain
'make' will build it.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-28 13:20:05 -07:00
Ævar Arnfjörð Bjarmason affc3b755c gitweb/Makefile: include in top-level Makefile
Include the gitweb/Makefile in the top-level Makefile rather than
calling it as a sub-Makefile. As noted in the thread starting at at
[1] (in particular [2]) we'll pay a high cost on NOOP runs of "make"
just to figure out that we have nothing to do for "make gitweb".

The "gitweb" script also isn't maintained out-of-tree, unlike
"gitk-git" or "git-gui", which both have their own "Makefile". Other
parts of it are already integrated into our main Makefiles, e.g. the
documentation is built by Documentation/Makefile since
07ea4df278 (gitweb: Add gitweb(1) manpage for gitweb itself,
2011-10-16).

1. https://lore.kernel.org/git/20220525205651.825669-1-szeder.dev@gmail.com/
2. https://lore.kernel.org/git/220526.86k0a96sv2.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-28 13:20:05 -07:00
Junio C Hamano 9e496fffc8 Merge branch 'jh/builtin-fsmonitor-part3'
More fsmonitor--daemon.

* jh/builtin-fsmonitor-part3: (30 commits)
  t7527: improve implicit shutdown testing in fsmonitor--daemon
  fsmonitor--daemon: allow --super-prefix argument
  t7527: test Unicode NFC/NFD handling on MacOS
  t/lib-unicode-nfc-nfd: helper prereqs for testing unicode nfc/nfd
  t/helper/hexdump: add helper to print hexdump of stdin
  fsmonitor: on macOS also emit NFC spelling for NFD pathname
  t7527: test FSMonitor on case insensitive+preserving file system
  fsmonitor: never set CE_FSMONITOR_VALID on submodules
  t/perf/p7527: add perf test for builtin FSMonitor
  t7527: FSMonitor tests for directory moves
  fsmonitor: optimize processing of directory events
  fsm-listen-darwin: shutdown daemon if worktree root is moved/renamed
  fsm-health-win32: force shutdown daemon if worktree root moves
  fsm-health-win32: add polling framework to monitor daemon health
  fsmonitor--daemon: stub in health thread
  fsmonitor--daemon: rename listener thread related variables
  fsmonitor--daemon: prepare for adding health thread
  fsmonitor--daemon: cd out of worktree root
  fsm-listen-darwin: ignore FSEvents caused by xattr changes on macOS
  unpack-trees: initialize fsmonitor_has_run_once in o->result
  ...
2022-06-10 15:04:15 -07:00
Junio C Hamano a50036da1a Merge branch 'tb/cruft-packs'
A mechanism to pack unreachable objects into a "cruft pack",
instead of ejecting them into loose form to be reclaimed later, has
been introduced.

* tb/cruft-packs:
  sha1-file.c: don't freshen cruft packs
  builtin/gc.c: conditionally avoid pruning objects via loose
  builtin/repack.c: add cruft packs to MIDX during geometric repack
  builtin/repack.c: use named flags for existing_packs
  builtin/repack.c: allow configuring cruft pack generation
  builtin/repack.c: support generating a cruft pack
  builtin/pack-objects.c: --cruft with expiration
  reachable: report precise timestamps from objects in cruft packs
  reachable: add options to add_unseen_recent_objects_to_traversal
  builtin/pack-objects.c: --cruft without expiration
  builtin/pack-objects.c: return from create_object_entry()
  t/helper: add 'pack-mtimes' test-tool
  pack-mtimes: support writing pack .mtimes files
  chunk-format.h: extract oid_version()
  pack-write: pass 'struct packing_data' to 'stage_tmp_packfiles'
  pack-mtimes: support reading .mtimes files
  Documentation/technical: add cruft-packs.txt
2022-06-03 14:30:37 -07:00
Junio C Hamano 28db3b7b71 Merge branch 'jx/l10n-workflow-change'
A workflow change for translators are being proposed.

* jx/l10n-workflow-change:
  l10n: Document the new l10n workflow
  Makefile: add "po-init" rule to initialize po/XX.po
  Makefile: add "po-update" rule to update po/XX.po
  po/git.pot: don't check in result of "make pot"
  po/git.pot: this is now a generated file
  Makefile: remove duplicate and unwanted files in FOUND_SOURCE_FILES
  i18n CI: stop allowing non-ASCII source messages in po/git.pot
  Makefile: have "make pot" not "reset --hard"
  Makefile: generate "po/git.pot" from stable LOCALIZED_C
  Makefile: sort source files before feeding to xgettext
2022-06-03 14:30:36 -07:00
Jeff Hostetler 9915e08f9b t/helper/hexdump: add helper to print hexdump of stdin
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:59:27 -07:00
Jeff Hostetler d06055501b fsmonitor--daemon: stub in health thread
Create another thread to watch over the daemon process and
automatically shut it down if necessary.

This commit creates the basic framework for a "health" thread
to monitor the daemon and/or the file system.  Later commits
will add platform-specific code to do the actual work.

The "health" thread is intended to monitor conditions that
would be difficult to track inside the IPC thread pool and/or
the file system listener threads.  For example, when there are
file system events outside of the watched worktree root or if
we want to have an idle-timeout auto-shutdown feature.

This commit creates the health thread itself, defines the thread-proc
and sets up the thread's event loop.  It integrates this new thread
into the existing IPC and Listener thread models.

This commit defines the API to the platform-specific code where all of
the monitoring will actually happen.

The platform-specific code for MacOS is just stubs.  Meaning that the
health thread will immediately exit on MacOS, but that is OK and
expected.  Future work can define MacOS-specific monitoring.

The platform-specific code for Windows sets up enough of the
WaitForMultipleObjects() machinery to watch for system and/or custom
events.  Currently, the set of wait handles only includes our custom
shutdown event (sent from our other theads).  Later commits in this
series will extend the set of wait handles to monitor other
conditions.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:59:27 -07:00
Jeff Hostetler d33c804dae fsmonitor-settings: stub in Win32-specific incompatibility checking
Extend generic incompatibility checkout with platform-specific
mechanism.  Stub in Win32 version.

In the existing fsmonitor-settings code we have a way to mark
types of repos as incompatible with fsmonitor (whether via the
hook and IPC APIs).  For example, we do this for bare repos,
since there are no files to watch.

Extend this exclusion mechanism for platform-specific reasons.
This commit just creates the framework and adds a stub for Win32.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:59:26 -07:00
Taylor Blau 2bd4427824 t/helper: add 'pack-mtimes' test-tool
In the next patch, we will implement and test support for writing a
cruft pack via a special mode of `git pack-objects`. To make sure that
objects are written with the correct timestamps, and a new test-tool
that can dump the object names and corresponding timestamps from a given
`.mtimes` file.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau 94cd775a6c pack-mtimes: support reading .mtimes files
To store the individual mtimes of objects in a cruft pack, introduce a
new `.mtimes` format that can optionally accompany a single pack in the
repository.

The format is defined in Documentation/technical/pack-format.txt, and
stores a 4-byte network order timestamp for each object in name (index)
order.

This patch prepares for cruft packs by defining the `.mtimes` format,
and introducing a basic API that callers can use to read out individual
mtimes.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Ævar Arnfjörð Bjarmason b9832f7e3b Makefile: add "po-init" rule to initialize po/XX.po
The core translation is the minimum set of work that must be done for a
new language translation.

There are over 5000 messages in the template message file "po/git.pot"
that need to be translated. It is not a piece of cake for such a huge
workload. So we used to define a small set of messages called "core
translation" that a new l10n contributor must complete before sending
pull request to the l10n coordinator.

By pulling in some parts of the git-po-helper[^1] logic, we add a new
rule to create this core translation message "po/git-core.pot":

    make po/git-core.pot

To help new l10n contributors to initialized their "po/XX.pot" from
"po/git-core.pot", we also add new rules "po-init":

    make po-init PO_FILE=po/XX.po

[^1]: https://github.com/git-l10n/git-po-helper/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:32:57 -07:00
Jiang Xin fbb3d32393 Makefile: add "po-update" rule to update po/XX.po
Since there is no longer a "po/git.pot" file in tree, a l10n team leader
has to run several commands to update their "po/XX.po" file:

    $ make pot
    $ msgmerge --add-location --backup=off -U po/XX.po po/git.pot

To make this process easier, add a new rule so that l10n team leaders
can update their "po/XX.po" with one command. E.g.:

    $ make po-update PO_FILE=po/zh_CN.po

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:32:55 -07:00
Ævar Arnfjörð Bjarmason 5377abc0c9 po/git.pot: don't check in result of "make pot"
Remove the "po/git.pot" file from being tracked, which started with
dce37b66fb (l10n: initial git.pot for 1.7.10 upcoming release,
2012-02-13).

The reason the po/git.pot started being checked in was because the
po/*.po files were changed a schema where we'd generate them from a
known-good snapshot of po/git.pot, instead of each translator running
"make pot" themselves.

This makes sense, but we don't need to carry this file in-tree just to
achieve that aim, and doing so has resulted in a significant amount of
"diff churn" since this method of doing it was introduced:

    $ git log -p --oneline -- po/git.pot|wc -l
    553743

We can instead let l10n contributors to generate "po/git.pot" in runtime
to update their own "po/XX.po", and the l10n coordinator can check
pull requests using CI pipeline.

This reverts to the schema introduced initially in cd5513a716 (i18n:
Makefile: "pot" target to extract messages marked for translation,
2011-02-22).

The actual "git rm" of po/git.pot was in preceding commit to make this
change easier to review, and to preempt the mailing list from blocking
it due to it being too large.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:32:53 -07:00
Jiang Xin 15fe4069d7 Makefile: remove duplicate and unwanted files in FOUND_SOURCE_FILES
We get source files saved in "$(FOUND_SOURCE_FILES)" by running the
command "git ls-files" or the command "find". We tried to have the
both commands return the same list of files, but apparently the "find"
command will return more files, such as the generated headers. We can
filter out these generated headers to get closer results.

In addition to this, "$(FOUND_SOURCE_FILES)" may contain duplicate
files. E.g. "git-ls-files" may have duplicate entries for the same file
in different staging areas if there are unresolved conflicts in the
working tree. For this case, we can reduce duplicate entries by passing
the option "--deduplicate" to git-ls-files.

Junio reported that when running "make" in a working tree with
unresolved conflicts, "make" may report warnings like below:

    Makefile:xxxx: target '.build/pot/po/FOO.c.po' given more than once
                   in the same rule

The duplicate targets are introduced by the following pattern rule we
added in the preceding commit for incremental build of "po/git.pot".

    $(LOCALIZED_C_GEN_PO): .build/pot/po/%.po: %

Although we have resolved this issue by sorting to create a unique
$(LOCALIZED_C), other targets may benefit from this. Such as: tags,
cscope.out, etc.

Reported-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:30:29 -07:00
Ævar Arnfjörð Bjarmason 6dd9a91c32 i18n CI: stop allowing non-ASCII source messages in po/git.pot
In the preceding commit we moved away from using xgettext(1) to both
generate the po/git.pot, and to merge the incrementally generated
po/git.pot+ file as we sourced translations from C, shell and Perl.

Doing it this way, which dates back to my initial
implementation[1][2][3] was conflating two things: With xgettext(1)
the --from-code both controls what encoding is specified in the
po/git.pot's header, and what encoding we allow in source messages.

We don't ever want to allow non-ASCII in *source messages*, and doing
so has hid e.g. a buggy message introduced in
a6226fd772 (submodule--helper: convert the bulk of cmd_add() to C,
2021-08-10) from us, we'd warn about it before, but only when running
"make pot", but the operation would still succeed. Now we'll error out
on it when running "make pot".

Since the preceding Makefile changes made this easy: let's add a "make
check-pot" target with the same prerequisites as the "po/git.pot"
target, but without changing the file "po/git.pot". Running it as part
of the "static-analysis" CI target will ensure that we catch any such
issues in the future. E.g.:

    $ make check-pot
        XGETTEXT .build/pot/po/builtin/submodule--helper.c.po
    xgettext: Non-ASCII string at builtin/submodule--helper.c:3381.
              Please specify the source encoding through --from-code.
    make: *** [.build/pot/po/builtin/submodule--helper.c.po] Error 1

1. cd5513a716 (i18n: Makefile: "pot" target to extract messages
   marked for translation, 2011-02-22)
2. adc3b2b276 (Makefile: add xgettext target for *.sh files,
   2011-05-14)
3. 5e9637c629 (i18n: add infrastructure for translating Git with
   gettext, 2011-11-18)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:30:28 -07:00
Ævar Arnfjörð Bjarmason 1cc0425a27 Makefile: have "make pot" not "reset --hard"
Before commit fc0fd5b23b (Makefile: help gettext tools to cope with our
custom PRItime format, 2017-07-20), we'd consider source files as-is
with gettext, but because we need to understand PRItime in the same way
that gettext itself understands PRIuMAX, we'd first check if we had a
clean checkout, then munge all of the processed files in-place with
"sed", generate "po/git.pot", and then finally "reset --hard" to undo
our changes.

By generating "pot" snippets in ".build/pot/po" for each source file
and rewriting certain source files with PRItime macros to temporary
files in ".build/pot/po", we can avoid running "make pot" by altering
files in place and doing a "reset --hard" afterwards.

This speed of "make pot" is slower than before on an initial run,
because we run "xgettext" many times (once per source file), but it
can be boosted by parallelization. It is *much* faster for incremental
runs, and will allow us to implement related targets in subsequent
commits.

When the "pot" target was originally added in cd5513a716 (i18n:
Makefile: "pot" target to extract messages marked for translation,
2011-02-22) it behaved like a "normal" target. I.e. we'd skip the
re-generation of the po/git.pot if nothing had to be done.

Then after po/git.pot was checked in in dce37b66fb (l10n: initial
git.pot for 1.7.10 upcoming release, 2012-02-13) the target was broken
until 1f31963e92 (i18n: treat "make pot" as an explicitly-invoked
target, 2014-08-22) when it was made to depend on "FORCE". I.e. the
Makefile's dependency resolution inherently can't handle incremental
building when the target file may be updated by git (or something else
external to "make"). But this case no longer applies, so FORCE is no
longer needed.

That out of the way, the main logic change here is getting rid of the
"reset --hard":

We'll generate intermediate ".build/pot/po/%.po" files from "%", which
is handy to see at a glance what strings (if any) in a given file are
marked for translation:

	$ make .build/pot/po/pretty.c.po
	[...]
	$ cat .build/pot/po/pretty.c.po
	#: pretty.c:1051
	msgid "unable to parse --pretty format"
	msgstr ""
	$

For these C source files which contain the PRItime macros, we will
create temporary munged "*.c" files in a tree in ".build/pot/po"
corresponding to our source tree, and have "xgettext" consider those.
The rule needs to be careful to "(cd .build/pot/po && ...)", because
otherwise the comments in the po/git.pot file wouldn't refer to the
correct source locations (they'd be prefixed with ".build/pot/po").
These temporary munged "*.c” files will be removed immediately after
the corresponding po files are generated, because some development tools
cannot ignore the duplicate source files in the ".build" directory
according to the ".gitignore" file, and that may cause trouble.

The output of the generated po/git.pot file is changed in one minor
way: Because we're using msgcat(1) instead of xgettext(1) to
concatenate the output we'll now disambiguate where "TRANSLATORS"
comments come from, in cases where a message is the same in N files,
and either only one has a "TRANSLATORS" comment, or they're
different. E.g. for the "Your edited hunk[...]" message we'll now
apply this change (comment content elided):

	+#. #-#-#-#-#  add-patch.c.po  #-#-#-#-#
	 #. TRANSLATORS: do not translate [y/n]
	[...]
	+#. #-#-#-#-#  git-add--interactive.perl.po  #-#-#-#-#
	 #. TRANSLATORS: do not translate [y/n]
	[...]
	 #: add-patch.c:1253 git-add--interactive.perl:1244
	 msgid ""
	 "Your edited hunk does not apply. Edit again (saying \"no\" discards!) [y/n]? "
	 msgstr ""

There are six such changes, and they all make the context more
understandable, as msgcat(1) is better at handling these edge cases
than xgettext(1)'s previously used "--join-existing" flag.

But filenames in the above disambiguation lines of extracted-comments
have an extra ".po" extension compared to the filenames at the file
locations. While we could rename the intermediate ".build/pot/po/%.po"
files without the ".po" extension to use more intuitive filenames in
the disambiguation lines of extracted-comments, but that will confuse
developer tools with lots of invalid C or other source files in
".build/pot/po" directory.

The addition of "--omit-header" option for xgettext makes the "pot"
snippets in ".build/pot/po/*.po" smaller. But as we'll see in a
subsequent commit this header behavior has been hiding an
encoding-related bug from us, so let's carry it forward instead of
re-generating it with xgettext(1).

The "po/git.pot" file should have a header entry, because a proper
header entry will increase the speed of creating a new po file using
msginit and set a proper "POT-Creation-Date:" field in the header
entry of a "po/XX.po" file. We use xgettext to generate a separate
header file at ".build/pot/git.header" from "/dev/null", and use this
header to assemble "po/git.pot".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:30:27 -07:00
Jiang Xin 9f555783c0 Makefile: generate "po/git.pot" from stable LOCALIZED_C
Different users may generate a different message template file
"po/git.pot". This is because the POT file is generated from
"$(LOCALIZED_C)", which is supposed to list all the sources that we
extract the strings to be translated from. But "$(LOCALIZED_C)"
includes "$(C_OBJ)", which only lists the source files used in the
current build for a specific platform and specific compiler
conditions.

Instead of using "$(C_OBJ)", we use "$(FOUND_C_SOURCES)", which lists
all source files we keep track of (or ship in a tarball extract), to
form a stable "LOCALIZED_C". We also add "$(SCALAR_SOURCES)", which
is part of "$(C_OBJ)" but not included in "$(FOUND_C_SOURCES)".

With this update, the newly generated "po/git.pot" will have 30 new
entries coming from the following C source files:

 * compat/fsmonitor/fsm-listen-win32.c
 * compat/mingw.c
 * compat/regex/regcomp.c
 * compat/simple-ipc/ipc-win32.c

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:30:26 -07:00
Jiang Xin ea3f639fe7 Makefile: sort source files before feeding to xgettext
We will feed xgettext with more C source files and in different order
in subsequent commit. To generate a stable "po/git.pot" regardless of
the number and order of input source files, we sort the c, perl, and
shell source files in groups before feeding them to xgettext.

Ævar suggested that we should not pass the option "--sort-by-file" to
xgettext to sort the translatable strings, as it will mix the three
groups of source files (c, perl and shell) in the file "po/git.pot",
and change the order of translatable strings in the same line of a file.

With this update, the newly generated "po/git.pot" will have the same
entries while in a different order.

With the help of a custom diff driver as shown below,

    git config --global diff.gettext-fmt.textconv \
        "msgcat --no-location --sort-by-file"

and appending a new entry "*.pot diff=gettext-fmt" to git attributes,
we can see that there are no substantial changes in "po/git.pot".

We won't checkin the newly generated "po/git.pot", because we will
remove it from tree in a later commit.

Suggested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 10:30:24 -07:00
Junio C Hamano 296bdc4f36 Merge branch 'ep/coverage-report-wants-test-to-have-run'
"make coverage-report" without first running "make coverage" did
not produce any meaningful result, which has been corrected.

* ep/coverage-report-wants-test-to-have-run:
  Makefile: add a prerequisite to the coverage-report target
2022-05-25 16:42:47 -07:00
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