When Cargo links binaries with MSVC, it uses the link.exe linker from
PATH to do so. However, when running under a shell from MSYS, such as
when building with the Git for Windows SDK, which we do in CI, the
/ming64/bin and /usr/bin entries are first in PATH. That means that the
Unix link binary shows up first, which obviously does not work for
linking binaries in any useful way.
To solve this problem, adjust PATH to place those binaries at the end of
the list instead of the beginning. This allows access to the normal
Unix tools, but link.exe will be the compiler's linker. Make sure to
export PATH explicitly: while this should be the default, it's more
robust to not rely on the shell operating in a certain way.
The reason this has not shown up before is that we typically link our
binaries from the C compiler. However, now that we're about to
introduce a Rust build script (build.rs file), Rust will end up linking
that script to further drive Cargo, in which case we'll invoke the
linker from it. There are other solutions, such as using LLD, but this
one is simple and reliable and is most likely to work with existing
systems.
Signed-off-by: Ezekiel Newren <ezekielnewren@gmail.com>
Signed-off-by: brian m. carlson <bk2204@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
From e509b5b8be (rust: support for Windows, 2025-10-15), we check
cargo's information to decide which library to build. However, that
check mistakenly used "sed -s" ("consider files as separate rather than
as a single, continuous long stream"), which is a GNU extension. The
build thus fails on macOS with "meson -Drust=enabled", which comes with
BSD-derived sed.
Instead, use the intended "sed -n" and print the matching section of the
output. This failure mode likely went unnoticed on systems with GNU sed
(common for developer machines and CI) because, in those instances, the
output being matched by case is the full cargo output (which either
contains the string "-windows-" or doesn't).
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: D. Ben Knoble <ben.knoble+github@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The initial patch series that introduced Rust into the core of Git only
cared about macOS and Linux. This specifically leaves out Windows, which
indeed fails to build right now due to two issues:
- The Rust runtime requires `GetUserProfileDirectoryW()`, but we don't
link against "userenv.dll".
- The path of the Rust library built on Windows is different than on
most other systems systems.
Fix both of these issues to support Windows.
Note that this commit fixes the Meson-based job in GitHub's CI. Meson
auto-detects the availability of Rust, and as the Windows runner has
Rust installed by default it already enabled Rust support there. But due
to the above issues that job fails consistently.
Install Rust on GitLab CI, as well, to improve test coverage there.
Based-on-patch-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Based-on-patch-by: Ezekiel Newren <ezekielnewren@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the infrastructure into Meson to build an internal Rust library.
Building the Rust parts of Git are for now entirely optional, as they
are mostly intended as a test balloon for both Git developers, but also
for distributors of Git. So for now, they may contain:
- New features that are not mission critical to Git and that users can
easily live without.
- Alternative implementations of small subsystems.
If these test balloons are successful, we will eventually make Rust a
mandatory dependency for our build process in Git 3.0.
The availability of a Rust toolchain will be auto-detected by Meson at
setup time. This behaviour can be tweaked via the `-Drust=` feature
toggle.
Next to the linkable Rust library, also wire up tests that can be
executed via `meson test`. This allows us to use the native unit testing
capabilities of Rust.
Note that the Rust edition is currently set to 2018. This edition is
supported by Rust 1.49, which is the target for the upcoming gcc-rs
backend. For now we don't use any features of Rust that would require a
newer version, so settling on this old version makes sense so that
gcc-rs may become an alternative backend for compiling Git. If we _do_
want to introduce features that were added in more recent editions of
Rust though we should reevaluate that choice.
Inspired-by: Ezekiel Newren <ezekielnewren@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
