Add `cargo dev setup toolchain`

2 files changed, 76 insertions, 0 deletions

diff --git a/clippy_dev/src/setup/mod.rs b/clippy_dev/src/setup/mod.rs
index f691ae4fa45..b0d31814639 100644
--- a/clippy_dev/src/setup/mod.rs
+++ b/clippy_dev/src/setup/mod.rs
@@ -1,5 +1,6 @@
 pub mod git_hook;
 pub mod intellij;
+pub mod toolchain;
 pub mod vscode;
 
 use std::path::Path;
diff --git a/clippy_dev/src/setup/toolchain.rs b/clippy_dev/src/setup/toolchain.rs
new file mode 100644
index 00000000000..8d98c6c92d9
--- /dev/null
+++ b/clippy_dev/src/setup/toolchain.rs
@@ -0,0 +1,75 @@
+use std::env::consts::EXE_SUFFIX;
+use std::env::current_dir;
+use std::ffi::OsStr;
+use std::fs;
+use std::path::{Path, PathBuf};
+use walkdir::WalkDir;
+
+use super::verify_inside_clippy_dir;
+
+pub fn create(force: bool, release: bool, name: &str) {
+    if !verify_inside_clippy_dir() {
+        return;
+    }
+
+    let rustup_home = std::env::var("RUSTUP_HOME").unwrap();
+    let toolchain = std::env::var("RUSTUP_TOOLCHAIN").unwrap();
+
+    let src = PathBuf::from_iter([&rustup_home, "toolchains", &toolchain]);
+    let dest = PathBuf::from_iter([&rustup_home, "toolchains", name]);
+
+    if dest.exists() {
+        if force {
+            fs::remove_dir_all(&dest).unwrap();
+        } else {
+            println!("{} already exists, pass `--force` to override it", dest.display());
+            return;
+        }
+    }
+
+    for entry in WalkDir::new(&src) {
+        let entry = entry.unwrap();
+        let relative = entry.path().strip_prefix(&src).unwrap();
+
+        if relative.starts_with("bin")
+            && matches!(
+                relative.file_stem().and_then(OsStr::to_str),
+                Some("cargo-clippy" | "clippy-driver")
+            )
+        {
+            continue;
+        }
+
+        let target = dest.join(relative);
+        if entry.file_type().is_dir() {
+            fs::create_dir(&target).unwrap();
+        } else {
+            fs::hard_link(entry.path(), target).unwrap();
+        }
+    }
+
+    symlink_bin("cargo-clippy", &dest, release);
+    symlink_bin("clippy-driver", &dest, release);
+
+    println!("Created toolchain {name}, use it in other projects with e.g. `cargo +{name} clippy`");
+    println!("Note: This will need to be re-run whenever the Clippy `rust-toolchain` changes");
+}
+
+fn symlink_bin(bin: &str, dest: &Path, release: bool) {
+    #[cfg(windows)]
+    use std::os::windows::fs::symlink_file as symlink;
+
+    #[cfg(not(windows))]
+    use std::os::unix::fs::symlink;
+
+    let profile = if release { "release" } else { "debug" };
+    let file_name = format!("{bin}{EXE_SUFFIX}");
+
+    let mut src = current_dir().unwrap();
+    src.extend(["target", profile, &file_name]);
+
+    let mut dest = dest.to_path_buf();
+    dest.extend(["bin", &file_name]);
+
+    symlink(src, dest).unwrap();
+}