[PATCH v2 6/6] rust: support for Windows

From: Patrick Steinhardt <ps@pks.im>
Date: Oct 8, 2025, 06:27 UTC
Message-ID: <20251008-b4-pks-ci-rust-v2-6-d556ee83c381@pks.im>
In-Reply-To: <20251008-b4-pks-ci-rust-v2-0-d556ee83c381@pks.im>

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>
---
 .gitlab-ci.yml     |  2 +-
 Makefile           | 14 ++++++++++++--
 meson.build        |  4 ++++
 src/cargo-meson.sh | 11 +++++++++--
 4 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a47d839e39..b419a84e2c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -161,7 +161,7 @@ test:mingw64:
     - saas-windows-medium-amd64
   before_script:
     - *windows_before_script
-    - choco install -y git meson ninja
+    - choco install -y git meson ninja rust-ms
     - Import-Module $env:ChocolateyInstall\helpers\chocolateyProfile.psm1
     - refreshenv
 
diff --git a/Makefile b/Makefile
index 7ea149598d..366fd173e7 100644
--- a/Makefile
+++ b/Makefile
@@ -929,10 +929,17 @@ TEST_SHELL_PATH = $(SHELL_PATH)
 LIB_FILE = libgit.a
 XDIFF_LIB = xdiff/lib.a
 REFTABLE_LIB = reftable/libreftable.a
+
 ifdef DEBUG
-RUST_LIB = target/debug/libgitcore.a
+RUST_TARGET_DIR = target/debug
 else
-RUST_LIB = target/release/libgitcore.a
+RUST_TARGET_DIR = target/release
+endif
+
+ifeq ($(uname_S),Windows)
+RUST_LIB = $(RUST_TARGET_DIR)/gitcore.lib
+else
+RUST_LIB = $(RUST_TARGET_DIR)/libgitcore.a
 endif
 
 # xdiff and reftable libs may in turn depend on what is in libgit.a
@@ -1538,6 +1545,9 @@ ALL_LDFLAGS = $(LDFLAGS) $(LDFLAGS_APPEND)
 ifdef WITH_RUST
 BASIC_CFLAGS += -DWITH_RUST
 GITLIBS += $(RUST_LIB)
+ifeq ($(uname_S),Windows)
+EXTLIBS += -luserenv
+endif
 endif
 
 ifdef SANITIZE
diff --git a/meson.build b/meson.build
index ec55d6a5fd..a9c865b2af 100644
--- a/meson.build
+++ b/meson.build
@@ -1707,6 +1707,10 @@ rust_option = get_option('rust').disable_auto_if(not cargo.found())
 if rust_option.allowed()
   subdir('src')
   libgit_c_args += '-DWITH_RUST'
+
+  if host_machine.system() == 'windows'
+    libgit_dependencies += compiler.find_library('userenv')
+  endif
 else
   libgit_sources += [
     'varint.c',
diff --git a/src/cargo-meson.sh b/src/cargo-meson.sh
index 99400986d9..3998db0435 100755
--- a/src/cargo-meson.sh
+++ b/src/cargo-meson.sh
@@ -26,7 +26,14 @@ then
 	exit $RET
 fi
 
-if ! cmp "$BUILD_DIR/$BUILD_TYPE/libgitcore.a" "$BUILD_DIR/libgitcore.a" >/dev/null 2>&1
+case "$(cargo -vV | sed -s 's/^host: \(.*\)$/\1/')" in
+	*-windows-*)
+		LIBNAME=gitcore.lib;;
+	*)
+		LIBNAME=libgitcore.a;;
+esac
+
+if ! cmp "$BUILD_DIR/$BUILD_TYPE/$LIBNAME" "$BUILD_DIR/libgitcore.a" >/dev/null 2>&1
 then
-	cp "$BUILD_DIR/$BUILD_TYPE/libgitcore.a" "$BUILD_DIR/libgitcore.a"
+	cp "$BUILD_DIR/$BUILD_TYPE/$LIBNAME" "$BUILD_DIR/libgitcore.a"
 fi

-- 
2.51.0.764.g787ff6f08a.dirty