Commit Graph

163503 Commits

Author SHA1 Message Date
Johannes Schindelin
725cece7f6 Merge pull request #2974 from derrickstolee/maintenance-and-headless
Include Windows-specific maintenance and headless-git
2025-02-06 19:33:11 +01:00
Johannes Schindelin
9e6675b707 Merge 'git-gui/js/intent-to-add'
This merges the current version of the patch that tries to address Git
GUI's problems with intent-to-add files.

This patch will likely be improved substantially before it is merged
into Git GUI's main branch, but we want to have _something_ resembling a
fix already in Git for Windows v2.29.0.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:11 +01:00
Johannes Schindelin
264a5b7c31 Merge pull request #2655 from jglathe/jg/t0014_trace_extra_info
t/t0014: fix: eliminate additional lines from trace
2025-02-06 19:33:10 +01:00
Johannes Schindelin
84d2f3e9cb Merge pull request #2714 from lbonanomi/crlf-scissors
Rationalize line endings for scissors-cleanup
2025-02-06 19:33:10 +01:00
Johannes Schindelin
de2a638281 Merge pull request #2730 from dscho/crlf-aware-git-add-i
git add -i: handle CR/LF line endings in the interactive input
2025-02-06 19:33:10 +01:00
Johannes Schindelin
bd93e76c95 Merge 'add-p-many-files'
This topic branch allows `add -p` and `add -i` with a large number of
files. It is kind of a hack that was never really meant to be
upstreamed. Let's see if we can do better in the built-in `add -p`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:09 +01:00
Johannes Schindelin
42b57b3ff8 Merge pull request #2618 from dscho/avoid-d/f-conflict-in-vs/master
ci: avoid d/f conflict in vs/master
2025-02-06 19:33:09 +01:00
Johannes Schindelin
7b3ad38767 Merge pull request #2535 from dscho/schannel-revoke-best-effort
Introduce and use the new "best effort" strategy for Secure Channel revoke checking
2025-02-06 19:33:09 +01:00
Johannes Schindelin
2902e7c16b Merge pull request #2506 from dscho/issue-2283
Allow running Git directly from `C:\Program Files\Git\mingw64\bin\git.exe`
2025-02-06 19:33:09 +01:00
Johannes Schindelin
fd9dd3aeda Merge pull request #2504 from dscho/access-repo-via-junction
Handle `git add <file>` where <file> traverses an NTFS junction
2025-02-06 19:33:08 +01:00
Johannes Schindelin
608a7dc8a6 Merge pull request #2501 from jeffhostetler/clink-debug-curl
clink.pl: fix MSVC compile script to handle libcurl-d.lib
2025-02-06 19:33:08 +01:00
Johannes Schindelin
d7fb911609 Merge pull request #2488 from bmueller84/master
mingw: fix fatal error working on mapped network drives on Windows
2025-02-06 19:33:08 +01:00
Johannes Schindelin
d2c6b78784 Merge pull request #2449 from dscho/mingw-getcwd-and-symlinks
Do resolve symlinks in `getcwd()`
2025-02-06 19:33:07 +01:00
Johannes Schindelin
f8e5376145 Merge pull request #2375 from assarbad/reintroduce-sideband-config
Config option to disable side-band-64k for transport
2025-02-06 19:33:07 +01:00
Johannes Schindelin
42f05068ac Merge branch 'mimalloc-v2.0.9'
This topic vendors in mimalloc v2.0.9, a fast allocator that allows Git
for Windows to perform efficiently.

Switch Git for Windows to using mimalloc instead of nedmalloc
2025-02-06 19:33:07 +01:00
Johannes Schindelin
e21d007606 Merge branch 'msys2-python'
In MSYS2, we have two Python interpreters at our disposal, so we can
include the Python stuff in the build.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:07 +01:00
Johannes Schindelin
7c05b999b8 Merge branch 'dont-clean-junctions'
This topic branch teaches `git clean` to respect NTFS junctions and Unix
bind mounts: it will now stop at those boundaries.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:06 +01:00
Johannes Schindelin
60a870d8bf Merge branch 'drive-prefix'
This topic branch allows us to specify absolute paths without the drive
prefix e.g. when cloning.

Example:

	C:\Users\me> git clone https://github.com/git/git \upstream-git

This will clone into a new directory C:\upstream-git, in line with how
Windows interprets absolute paths.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:06 +01:00
Johannes Schindelin
772b0b15b7 Merge 'remote-hg-prerequisites' into HEAD
These fixes were necessary for Sverre Rabbelier's remote-hg to work,
but for some magic reason they are not necessary for the current
remote-hg. Makes you wonder how that one gets away with it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:06 +01:00
Johannes Schindelin
10fb02278e Merge branch 'safe-PATH-lookup-in-gitk-on-Windows'
This topic branch extends the protections introduced for Git GUI's
CVE-2022-41953 to cover `gitk`, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:05 +01:00
Johannes Schindelin
3783582eb2 Merge branch 'ci-fixes'
Backport a couple fixes to make the CI build run again (so much for
reproducible builds...).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:33:05 +01:00
Jeff Hostetler
0c71605029 clink.pl: move default linker options for MSVC=1 builds
Move the default `-ENTRY` and `-SUBSYSTEM` arguments for
MSVC=1 builds from `config.mak.uname` into `clink.pl`.
These args are constant for console-mode executables.

Add support to `clink.pl` for generating a Win32 GUI application
using the `-mwindows` argument (to match how GCC does it).  This
changes the `-ENTRY` and `-SUBSYSTEM` arguments accordingly.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2025-02-06 19:32:50 +01:00
Jeff Hostetler
f8e8a92bb5 clink.pl: ignore no-stack-protector arg on MSVC=1 builds
Ignore the `-fno-stack-protector` compiler argument when building
with MSVC.  This will be used in a later commit that needs to build
a Win32 GUI app.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2025-02-06 19:32:50 +01:00
Jeff Hostetler
bbc45a0acc config.mak.uname: add git.rc to MSVC builds
Teach MSVC=1 builds to depend on the `git.rc` file so that
the resulting executables have Windows-style resources and
version number information within them.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2025-02-06 19:32:50 +01:00
Jeff Hostetler
4d15032937 vcbuild: add support for compiling Windows resource files
Create a wrapper for the Windows Resource Compiler (RC.EXE)
for use by the MSVC=1 builds. This is similar to the CL.EXE
and LIB.EXE wrappers used for the MSVC=1 builds.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2025-02-06 19:32:50 +01:00
Jeff Hostetler
c1ef925bb0 Makefile: clean up .ilk files when MSVC=1
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2025-02-06 19:32:50 +01:00
Jeff Hostetler
77f2c6be49 clink.pl: fix libexpatd.lib link error when using MSVC
When building with `make MSVC=1 DEBUG=1`, link to `libexpatd.lib`
rather than `libexpat.lib`.

It appears that the `vcpkg` package for "libexpat" has changed and now
creates `libexpatd.lib` for debug mode builds.  Previously, both debug
and release builds created a ".lib" with the same basename.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2025-02-06 19:32:50 +01:00
Johannes Schindelin
b0c56b07a3 Merge branch 'dscho-avoid-d-f-conflict-in-vs-master'
Merge this early to resolve merge conflicts early.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:50 +01:00
Johannes Schindelin
95c51726a0 git-gui: accommodate for intent-to-add files
As of Git v2.28.0, the diff for files staged via `git add -N` marks them
as new files. Git GUI was ill-prepared for that, and this patch teaches
Git GUI about them.

Please note that this will not even fix things with v2.28.0, as the
`rp/apply-cached-with-i-t-a` patches are required on Git's side, too.

This fixes https://github.com/git-for-windows/git/issues/2779

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
2025-02-06 19:32:49 +01:00
Jens Glathe
222b837762 t0014: fix indentation
For some reason, this test case was indented with 4 spaces instead of 1
horizontal tab. The other test cases in the same test script are fine.

Signed-off-by: Jens Glathe <jens.glathe@oldschoolsolutions.biz>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:49 +01:00
Luke Bonanomi
8c1e12cf83 commit: accept "scissors" with CR/LF line endings
This change enhances `git commit --cleanup=scissors` by detecting
scissors lines ending in either LF (UNIX-style) or CR/LF (DOS-style).

Regression tests are included to specifically test for trailing
comments after a CR/LF-terminated scissors line.

Signed-off-by: Luke Bonanomi <lbonanomi@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:49 +01:00
Johannes Schindelin
28d17c2685 git add -i: handle CR/LF line endings in the interactive input
As of Git for Windows v2.27.0, there is an option to use Windows'
newly-introduced Pseudo Console support. When running an interactive add
operation with this support enabled, Git will receive CR/LF line
endings.

Therefore, let's not pretend that we are expecting Unix line endings.

This fixes https://github.com/git-for-windows/git/issues/2729

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:49 +01:00
Johannes Schindelin
50b263693f Merge branch 'ci-fixes'
Backport a couple fixes to make the CI build run again (so much for
reproducible builds...).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:49 +01:00
Johannes Schindelin
fd3c3fa4f4 t3701: verify that we can add *lots* of files interactively
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:48 +01:00
Johannes Schindelin
49b452c41a t5505/t5516: fix white-space around redirectors
The convention in Git project's shell scripts is to have white-space
_before_, but not _after_ the `>` (or `<`).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:48 +01:00
Johannes Schindelin
8cc8048a46 http: use new "best effort" strategy for Secure Channel revoke checking
The native Windows HTTPS backend is based on Secure Channel which lets
the caller decide how to handle revocation checking problems caused by
missing information in the certificate or offline CRL distribution
points.

Unfortunately, cURL chose to handle these problems differently than
OpenSSL by default: while OpenSSL happily ignores those problems
(essentially saying "¯\_(ツ)_/¯"), the Secure Channel backend will error
out instead.

As a remedy, the "no revoke" mode was introduced, which turns off
revocation checking altogether. This is a bit heavy-handed. We support
this via the `http.schannelCheckRevoke` setting.

In https://github.com/curl/curl/pull/4981, we contributed an opt-in
"best effort" strategy that emulates what OpenSSL seems to do.

In Git for Windows, we actually want this to be the default. This patch
makes it so, introducing it as a new value for the
`http.schannelCheckRevoke" setting, which now becmes a tristate: it
accepts the values "false", "true" or "best-effort" (defaulting to the
last one).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:48 +01:00
Johannes Schindelin
9d1485e2fc t5505/t5516: allow running without .git/branches/ in the templates
When we commit the template directory as part of `make vcxproj`, the
`branches/` directory is not actually commited, as it is empty.

Two tests were not prepared for that situation.

This developer tried to get rid of the support for `.git/branches/` a
long time ago, but that effort did not bear fruit, so the best we can do
is work around in these here tests.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:48 +01:00
Johannes Schindelin
d704de7e13 mingw: ignore HOMEDRIVE/HOMEPATH if it points to Windows' system directory
Internally, Git expects the environment variable `HOME` to be set, and
to point to the current user's home directory.

This environment variable is not set by default on Windows, and
therefore Git tries its best to construct one if it finds `HOME` unset.

There are actually two different approaches Git tries: first, it looks
at `HOMEDRIVE`/`HOMEPATH` because this is widely used in corporate
environments with roaming profiles, and a user generally wants their
global Git settings to be in a roaming profile.

Only when `HOMEDRIVE`/`HOMEPATH` is either unset or does not point to a
valid location, Git will fall back to using `USERPROFILE` instead.

However, starting with Windows Vista, for secondary logons and services,
the environment variables `HOMEDRIVE`/`HOMEPATH` point to Windows'
system directory (usually `C:\Windows\system32`).

That is undesirable, and that location is usually write-protected anyway.

So let's verify that the `HOMEDRIVE`/`HOMEPATH` combo does not point to
Windows' system directory before using it, falling back to `USERPROFILE`
if it does.

This fixes git-for-windows#2709

Initial-Path-by: Ivan Pozdeev <vano@mail.mipt.ru>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:47 +01:00
Johannes Schindelin
da40ce6bf6 mingw: implement a platform-specific strbuf_realpath()
There is a Win32 API function to resolve symbolic links, and we can use
that instead of resolving them manually. Even better, this function also
resolves NTFS junction points (which are somewhat similar to bind
mounts).

This fixes https://github.com/git-for-windows/git/issues/2481.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:47 +01:00
Jeff Hostetler
2e178928db clink.pl: fix MSVC compile script to handle libcurl-d.lib
Update clink.pl to link with either libcurl.lib or libcurl-d.lib
depending on whether DEBUG=1 is set.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:47 +01:00
Bjoern Mueller
ca6841cd48 mingw: fix fatal error working on mapped network drives on Windows
In 1e64d18 (mingw: do resolve symlinks in `getcwd()`) a problem was
introduced that causes git for Windows to stop working with certain
mapped network drives (in particular, drives that are mapped to
locations with long path names). Error message was "fatal: Unable to
read current working directory: No such file or directory". Present
change fixes this issue as discussed in
https://github.com/git-for-windows/git/issues/2480

Signed-off-by: Bjoern Mueller <bjoernm@gmx.de>
2025-02-06 19:32:47 +01:00
Johannes Schindelin
2b2dd030c3 mingw: allow git.exe to be used instead of the "Git wrapper"
Git for Windows wants to add `git.exe` to the users' `PATH`, without
cluttering the latter with unnecessary executables such as `wish.exe`.
To that end, it invented the concept of its "Git wrapper", i.e. a tiny
executable located in `C:\Program Files\Git\cmd\git.exe` (originally a
CMD script) whose sole purpose is to set up a couple of environment
variables and then spawn the _actual_ `git.exe` (which nowadays lives in
`C:\Program Files\Git\mingw64\bin\git.exe` for 64-bit, and the obvious
equivalent for 32-bit installations).

Currently, the following environment variables are set unless already
initialized:

- `MSYSTEM`, to make sure that the MSYS2 Bash and the MSYS2 Perl
  interpreter behave as expected, and

- `PLINK_PROTOCOL`, to force PuTTY's `plink.exe` to use the SSH
  protocol instead of Telnet,

- `PATH`, to make sure that the `bin` folder in the user's home
  directory, as well as the `/mingw64/bin` and the `/usr/bin`
  directories are included. The trick here is that the `/mingw64/bin/`
  and `/usr/bin/` directories are relative to the top-level installation
  directory of Git for Windows (which the included Bash interprets as
  `/`, i.e. as the MSYS pseudo root directory).

Using the absence of `MSYSTEM` as a tell-tale, we can detect in
`git.exe` whether these environment variables have been initialized
properly. Therefore we can call `C:\Program Files\Git\mingw64\bin\git`
in-place after this change, without having to call Git through the Git
wrapper.

Obviously, above-mentioned directories must be _prepended_ to the `PATH`
variable, otherwise we risk picking up executables from unrelated Git
installations. We do that by constructing the new `PATH` value from
scratch, appending `$HOME/bin` (if `HOME` is set), then the MSYS2 system
directories, and then appending the original `PATH`.

Side note: this modification of the `PATH` variable is independent of
the modification necessary to reach the executables and scripts in
`/mingw64/libexec/git-core/`, i.e. the `GIT_EXEC_PATH`. That
modification is still performed by Git, elsewhere, long after making the
changes described above.

While we _still_ cannot simply hard-link `mingw64\bin\git.exe` to `cmd`
(because the former depends on a couple of `.dll` files that are only in
`mingw64\bin`, i.e. calling `...\cmd\git.exe` would fail to load due to
missing dependencies), at least we can now avoid that extra process of
running the Git wrapper (which then has to wait for the spawned
`git.exe` to finish) by calling `...\mingw64\bin\git.exe` directly, via
its absolute path.

Testing this is in Git's test suite tricky: we set up a "new" MSYS
pseudo-root and copy the `git.exe` file into the appropriate location,
then verify that `MSYSTEM` is set properly, and also that the `PATH` is
modified so that scripts can be found in `$HOME/bin`, `/mingw64/bin/`
and `/usr/bin/`.

This addresses https://github.com/git-for-windows/git/issues/2283

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:47 +01:00
Johannes Schindelin
84c2c79e3a strbuf_realpath(): use platform-dependent API if available
Some platforms (e.g. Windows) provide API functions to resolve paths
much quicker. Let's offer a way to short-cut `strbuf_realpath()` on
those platforms.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:47 +01:00
Johannes Schindelin
317e4b40d3 mingw: ensure valid CTYPE
A change between versions 2.4.1 and 2.6.0 of the MSYS2 runtime modified
how Cygwin's runtime (and hence Git for Windows' MSYS2 runtime
derivative) handles locales: d16a56306d (Consolidate wctomb/mbtowc calls
for POSIX-1.2008, 2016-07-20).

An unintended side-effect is that "cold-calling" into the POSIX
emulation will start with a locale based on the current code page,
something that Git for Windows is very ill-prepared for, as it expects
to be able to pass a command-line containing non-ASCII characters to the
shell without having those characters munged.

One symptom of this behavior: when `git clone` or `git fetch` shell out
to call `git-upload-pack` with a path that contains non-ASCII
characters, the shell tried to interpret the entire command-line
(including command-line parameters) as executable path, which obviously
must fail.

This fixes https://github.com/git-for-windows/git/issues/1036

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:47 +01:00
Johannes Schindelin
78d0becb89 mingw: demonstrate a git add issue with NTFS junctions
NTFS junctions are somewhat similar in spirit to Unix bind mounts: they
point to a different directory and are resolved by the filesystem
driver. As such, they appear to `lstat()` as if they are directories,
not as if they are symbolic links.

_Any_ user can create junctions, while symbolic links can only be
created by non-administrators in Developer Mode on Windows 10. Hence
NTFS junctions are much more common "in the wild" than NTFS symbolic
links.

It was reported in https://github.com/git-for-windows/git/issues/2481
that adding files via an absolute path that traverses an NTFS junction:
since 1e64d18 (mingw: do resolve symlinks in `getcwd()`), we resolve not
only symbolic links but also NTFS junctions when determining the
absolute path of the current directory. The same is not true for `git
add <file>`, where symbolic links are resolved in `<file>`, but not NTFS
junctions.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:47 +01:00
Johannes Schindelin
87aca61523 mingw: do resolve symlinks in getcwd()
As pointed out in https://github.com/git-for-windows/git/issues/1676,
the `git rev-parse --is-inside-work-tree` command currently fails when
the current directory's path contains symbolic links.

The underlying reason for this bug is that `getcwd()` is supposed to
resolve symbolic links, but our `mingw_getcwd()` implementation did not.

We do have all the building blocks for that, though: the
`GetFinalPathByHandleW()` function will resolve symbolic links. However,
we only called that function if `GetLongPathNameW()` failed, for
historical reasons: the latter function was supported for a long time,
but the former API function was introduced only with Windows Vista, and
we used to support also Windows XP. With that support having been
dropped, we are free to call the symbolic link-resolving function right
away.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:46 +01:00
Thomas Braun
d59c78d525 transport: optionally disable side-band-64k
Since commit 0c499ea60f (send-pack: demultiplex a sideband stream with
status data, 2010-02-05) the send-pack builtin uses the side-band-64k
capability if advertised by the server.

Unfortunately this breaks pushing over the dump git protocol if used
over a network connection.

The detailed reasons for this breakage are (by courtesy of Jeff Preshing,
quoted from https://groups.google.com/d/msg/msysgit/at8D7J-h7mw/eaLujILGUWoJ):

	MinGW wraps Windows sockets in CRT file descriptors in order to
	mimic the functionality of POSIX sockets. This causes msvcrt.dll
	to treat sockets as Installable File System (IFS) handles,
	calling ReadFile, WriteFile, DuplicateHandle and CloseHandle on
	them. This approach works well in simple cases on recent
	versions of Windows, but does not support all usage patterns. In
	particular, using this approach, any attempt to read & write
	concurrently on the same socket (from one or more processes)
	will deadlock in a scenario where the read waits for a response
	from the server which is only invoked after the write. This is
	what send_pack currently attempts to do in the use_sideband
	codepath.

The new config option `sendpack.sideband` allows to override the
side-band-64k capability of the server, and thus makes the dumb git
protocol work.

Other transportation methods like ssh and http/https still benefit from
the sideband channel, therefore the default value of `sendpack.sideband`
is still true.

Signed-off-by: Thomas Braun <thomas.braun@byte-physics.de>
Signed-off-by: Oliver Schneider <oliver@assarbad.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:46 +01:00
Johannes Schindelin
fc7f8f8fb0 mingw: use mimalloc
Thorough benchmarking with repacking a subset of linux.git (the commit
history reachable from 93a6fefe2f ([PATCH] fix the SYSCTL=n compilation,
2007-02-28), to be precise) suggest that this allocator is on par, in
multi-threaded situations maybe even better than nedmalloc:

`git repack -adfq` with mimalloc, 8 threads:

31.166991900 27.576763800 28.712311000 27.373859000 27.163141900

`git repack -adfq` with nedmalloc, 8 threads:

31.915032900 27.149883100 28.244933700 27.240188800 28.580849500

In a different test using GitHub Actions build agents (probably
single-threaded, a core-strength of nedmalloc)):

`git repack -q -d -l -A --unpack-unreachable=2.weeks.ago` with mimalloc:

943.426 978.500 939.709 959.811 954.605

`git repack -q -d -l -A --unpack-unreachable=2.weeks.ago` with nedmalloc:

995.383 952.179 943.253 963.043 980.468

While these measurements were not executed with complete scientific
rigor, as no hardware was set aside specifically for these benchmarks,
it shows that mimalloc and nedmalloc perform almost the same, nedmalloc
with a bit higher variance and also slightly higher average (further
testing suggests that nedmalloc performs worse in multi-threaded
situations than in single-threaded ones).

In short: mimalloc seems to be slightly better suited for our purposes
than nedmalloc.

Seeing that mimalloc is developed actively, while nedmalloc ceased to
see any updates in eight years, let's use mimalloc on Windows instead.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:46 +01:00
Jeff Hostetler
3bce96c182 mimalloc: use "weak" random seed when statically linked
Always use the internal "use_weak" random seed when initializing
the "mimalloc" heap when statically linked on Windows.

The imported "mimalloc" routines support several random sources
to seed the heap data structures, including BCrypt.dll and
RtlGenRandom.  Crashes have been reported when using BCrypt.dll
if it initialized during an `atexit()` handler function.  Granted,
such DLL initialization should not happen in an atexit handler,
but yet the crashes remain.

It should be noted that on Windows when statically linked, the
mimalloc startup code (called by the GCC CRT to initialize static
data prior to calling `main()`) always uses the internal "weak"
random seed.  "mimalloc" does not try to load an alternate
random source until after the OS initialization has completed.

Heap data is stored in `__declspec(thread)` TLS data and in theory
each Git thread will have its own heap data.  However, testing
shows that the "mimalloc" library doesn't actually call
`os_random_buf()` (to load a new random source) when creating these
new per-thread heap structures.

However, if an atexit handler is forced to run on a non-main
thread, the "mimalloc" library *WILL* try to create a new heap
and seed it with `os_random_buf()`.  (The reason for this is still
a mystery to this author.)  The `os_random_buf()` call can cause
the (previously uninitialized BCrypt.dll library) to be dynamically
loaded and a call made into it.  Crashes have been reported in
v2.40.1.vfs.0.0 while in this call.

As a workaround, the fix here forces the use of the internal
"use_weak" random code for the subsequent `os_random_buf()` calls.
Since we have been using that random generator for the majority
of the program, it seems safe to use it for the final few mallocs
in the atexit handler (of which there really shouldn't be that many.

Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:46 +01:00
Johannes Schindelin
27712a73ef mimalloc: offer a build-time option to enable it
By defining `USE_MIMALLOC`, Git can now be compiled with that
nicely-fast and small allocator.

Note that we have to disable a couple `DEVELOPER` options to build
mimalloc's source code, as it makes heavy use of declarations after
statements, among other things that disagree with Git's conventions.

We even have to silence some GCC warnings in non-DEVELOPER mode. For
example, the `-Wno-array-bounds` flag is needed because in `-O2` builds,
trying to call `NtCurrentTeb()` (which `_mi_thread_id()` does on
Windows) causes the bogus warning about a system header, likely related
to https://sourceforge.net/p/mingw-w64/mailman/message/37674519/ and to
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578:

C:/git-sdk-64-minimal/mingw64/include/psdk_inc/intrin-impl.h:838:1:
        error: array subscript 0 is outside array bounds of 'long long unsigned int[0]' [-Werror=array-bounds]
  838 | __buildreadseg(__readgsqword, unsigned __int64, "gs", "q")
      | ^~~~~~~~~~~~~~

Also: The `mimalloc` library uses C11-style atomics, therefore we must
require that standard when compiling with GCC if we want to use
`mimalloc` (instead of requiring "only" C99). This is what we do in the
CMake definition already, therefore this commit does not need to touch
`contrib/buildsystems/`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2025-02-06 19:32:46 +01:00