Support x86 windows (#3873)

Add trampolines for x86 windows.

Closes https://github.com/astral-sh/uv/issues/3660.

.github/workflows/ci.yml

@@ -266,7 +266,7 @@ jobs:
           RUSTUP_HOME: ${{ env.DEV_DRIVE }}/.rustup
         run: |
           rustup target add x86_64-pc-windows-msvc
-          rustup component add clippy rust-src --toolchain nightly-2024-03-19-x86_64-pc-windows-msvc
+          rustup component add clippy rust-src --toolchain nightly-2024-05-27-x86_64-pc-windows-msvc
 
       - uses: rui314/setup-mold@v1
 

crates/install-wheel-rs/src/lib.rs

@@ -70,7 +70,9 @@ pub enum Error {
     RecordCsv(#[from] csv::Error),
     #[error("Broken virtualenv: {0}")]
     BrokenVenv(String),
-    #[error("Unable to create Windows launcher for {0} (only x64_64 is supported)")]
+    #[error(
+        "Unable to create Windows launcher for: {0} (only x86_64, x86, and arm64 are supported)"
+    )]
     UnsupportedWindowsArch(&'static str),
     #[error("Unable to create Windows launcher on non-Windows platform")]
     NotWindows,

crates/install-wheel-rs/src/wheel.rs

@@ -23,6 +23,14 @@ use crate::{Error, Layout};
 
 const LAUNCHER_MAGIC_NUMBER: [u8; 4] = [b'U', b'V', b'U', b'V'];
 
+#[cfg(all(windows, target_arch = "x86"))]
+const LAUNCHER_I686_GUI: &[u8] =
+    include_bytes!("../../uv-trampoline/trampolines/uv-trampoline-i686-gui.exe");
+
+#[cfg(all(windows, target_arch = "x86"))]
+const LAUNCHER_I686_CONSOLE: &[u8] =
+    include_bytes!("../../uv-trampoline/trampolines/uv-trampoline-i686-console.exe");
+
 #[cfg(all(windows, target_arch = "x86_64"))]
 const LAUNCHER_X86_64_GUI: &[u8] =
     include_bytes!("../../uv-trampoline/trampolines/uv-trampoline-x86_64-gui.exe");
@@ -161,6 +169,14 @@ pub(crate) fn windows_script_launcher(
     }
 
     let launcher_bin: &[u8] = match env::consts::ARCH {
+        #[cfg(all(windows, target_arch = "x86"))]
+        "x86" => {
+            if is_gui {
+                LAUNCHER_I686_GUI
+            } else {
+                LAUNCHER_I686_CONSOLE
+            }
+        }
         #[cfg(all(windows, target_arch = "x86_64"))]
         "x86_64" => {
             if is_gui {

crates/uv-trampoline/README.md

@@ -11,6 +11,7 @@ package manager to install LLD and add the `rustup` targets:
 
 ```shell
 sudo apt install llvm clang lld
+rustup target add i686-pc-windows-msvc
 rustup target add x86_64-pc-windows-msvc
 rustup target add aarch64-pc-windows-msvc
 ```
@@ -18,8 +19,9 @@ rustup target add aarch64-pc-windows-msvc
 Then, build the trampolines for both supported architectures:
 
 ```shell
-cargo +nightly-2024-03-19 xwin build --release --target x86_64-pc-windows-msvc
+cargo +nightly-2024-05-27 xwin build --xwin-arch x86 --release --target i686-pc-windows-msvc
-cargo +nightly-2024-03-19 xwin build --release --target aarch64-pc-windows-msvc
+cargo +nightly-2024-05-27 xwin build --release --target x86_64-pc-windows-msvc
+cargo +nightly-2024-05-27 xwin build --release --target aarch64-pc-windows-msvc
 ```
 
 ### Cross-compiling from macOS
@@ -29,6 +31,7 @@ package manager to install LLVM and add the `rustup` targets:
 
 ```shell
 brew install llvm
+rustup target add i686-pc-windows-msvc
 rustup target add x86_64-pc-windows-msvc
 rustup target add aarch64-pc-windows-msvc
 ```
@@ -36,8 +39,9 @@ rustup target add aarch64-pc-windows-msvc
 Then, build the trampolines for both supported architectures:
 
 ```shell
-cargo +nightly-2024-03-19 xwin build --release --target x86_64-pc-windows-msvc
+cargo +nightly-2024-05-27 xwin build --release --target i686-pc-windows-msvc
-cargo +nightly-2024-03-19 xwin build --release --target aarch64-pc-windows-msvc
+cargo +nightly-2024-05-27 xwin build --release --target x86_64-pc-windows-msvc
+cargo +nightly-2024-05-27 xwin build --release --target aarch64-pc-windows-msvc
 ```
 
 ### Updating the prebuilt executables
@@ -49,6 +53,8 @@ cp target/aarch64-pc-windows-msvc/release/uv-trampoline-console.exe trampolines/
 cp target/aarch64-pc-windows-msvc/release/uv-trampoline-gui.exe trampolines/uv-trampoline-aarch64-gui.exe
 cp target/x86_64-pc-windows-msvc/release/uv-trampoline-console.exe trampolines/uv-trampoline-x86_64-console.exe
 cp target/x86_64-pc-windows-msvc/release/uv-trampoline-gui.exe trampolines/uv-trampoline-x86_64-gui.exe
+cp target/i686-pc-windows-msvc/release/uv-trampoline-console.exe trampolines/uv-trampoline-i686-console.exe
+cp target/i686-pc-windows-msvc/release/uv-trampoline-gui.exe trampolines/uv-trampoline-i686-gui.exe
 ```
 
 ### Testing the trampolines
@@ -167,6 +173,7 @@ might not realize that, and still emit references to the unwinding helper
 exist.
 
 ```
+cargo build --release --target i686-pc-windows-msvc
 cargo build --release --target x86_64-pc-windows-msvc
 cargo build --release --target aarch64-pc-windows-msvc
 ```

crates/uv-trampoline/rust-toolchain.toml

@@ -1,2 +1,2 @@
 [toolchain]
-channel = "nightly-2024-03-19"
+channel = "nightly-2024-05-27"