ci: simplify Rust tool and release verification setup

Format generated slang Rust bindings in-process with prettyplease instead of shelling out to rustfmt from the build script. This lets build and release jobs use the minimal pinned Rust toolchain without depending on clippy or rustfmt components. Also remove the duplicate Dev Release Verification workflow now that release.yml exercises the shared artifact workflow on PRs.

Author: hongjr03

.github/workflows/build-artifacts.yml

@@ -69,7 +69,6 @@ jobs:
       - name: Setup Rust
         uses: ./.github/actions/setup-rust
         with:
-          components: rustfmt
           targets: ${{ matrix.rustup-target }}
 
       - name: Setup cargo-zigbuild
@@ -194,8 +193,6 @@ jobs:
       - name: Setup Rust
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'
         uses: ./.github/actions/setup-rust
-        with:
-          components: rustfmt
 
       - name: Setup sccache
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'

.github/workflows/ci.yml

@@ -101,8 +101,6 @@ jobs:
       - uses: actions/checkout@v4
       - name: Install Rust
         uses: ./.github/actions/setup-rust
-        with:
-          components: rustfmt
       - name: Setup sccache
         uses: ./.github/actions/setup-sccache
         with:
@@ -165,8 +163,6 @@ jobs:
       - name: Install Rust
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'
         uses: ./.github/actions/setup-rust
-        with:
-          components: rustfmt
       - name: Setup sccache
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'
         uses: ./.github/actions/setup-sccache

.github/workflows/deploy-docs.yml

@@ -345,8 +345,6 @@ jobs:
       - name: Install Rust
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'
         uses: ./.github/actions/setup-rust
-        with:
-          components: rustfmt
 
       - name: Setup sccache
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'

.github/workflows/dev-release-verification.yml

@@ -93,8 +93,6 @@ jobs:
       - name: Install Rust
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'
         uses: ./.github/actions/setup-rust
-        with:
-          components: rustfmt
 
       - name: Setup sccache
         if: steps.playground-wasm-cache.outputs.cache-hit != 'true'

.github/workflows/docs-preview.yml

@@ -37,9 +37,10 @@ cmake = "0.1.50"
 cxx-build = "1.0.124"
 itertools = "0.14.0"
 proc-macro2 = "1.0.86"
+prettyplease = "0.2.25"
 quote = "1.0.36"
 regex = "1.11.1"
+syn = "2.0.86"
 which = "7.0.2"
-
 [dev-dependencies]
 utils = { workspace = true, features = ["test-support"] }

crates/slang/Cargo.toml

@@ -217,12 +217,9 @@ pub mod loader {
 pub mod generator {
     use std::{
         collections::{BTreeMap, HashMap, HashSet},
-        env,
-        ffi::OsString,
-        fs,
-        io::{self, BufRead, Write},
+        env, fs,
+        io::BufRead,
         path::{Path, PathBuf},
-        process::{Command, Stdio},
     };
 
     use inflector::Inflector;
@@ -232,56 +229,16 @@ pub mod generator {
 
     use super::{Ty, TypeInfo, reader_from_file};
 
-    // From https://docs.rs/bindgen/0.51.1/src/bindgen/lib.rs.html#1945
-    fn rustfmt_path() -> io::Result<OsString> {
-        if let Ok(rustfmt) = env::var("RUSTFMT") {
-            return Ok(OsString::from(rustfmt));
-        }
-
-        which::which("rustfmt")
-            .map_or_else(|e| Err(io::Error::other(format!("{}", e))), |p| Ok(p.into_os_string()))
+    fn format_generated_rust(contents: String) -> String {
+        syn::parse_file(&contents).map(|file| prettyplease::unparse(&file)).unwrap_or(contents)
     }
 
     fn mkdir_and_write(file: &Path, contents: String) -> Result<(), std::io::Error> {
         if let Some(parent) = file.parent() {
             fs::create_dir_all(parent)?;
         }
 
-        let rustfmt = rustfmt_path().expect("Failed to find rustfmt");
-        let mut cmd = Command::new(&*rustfmt);
-        cmd.arg("--config").arg("use_small_heuristics=Max");
-
-        cmd.stdin(Stdio::piped()).stdout(Stdio::piped());
-
-        let mut child = cmd.spawn().unwrap();
-        let mut child_stdin = child.stdin.take().unwrap();
-        let mut child_stdout = child.stdout.take().unwrap();
-
-        let stdin_handle = std::thread::spawn(move || {
-            let _ = child_stdin.write_all(contents.as_bytes());
-            contents
-        });
-
-        let mut output = vec![];
-        io::copy(&mut child_stdout, &mut output).expect("Failed to read rustfmt output");
-
-        let status = child.wait().unwrap();
-        let contents =
-            stdin_handle.join().expect("The thread writing to rustfmt's stdin doesn't do any");
-
-        match (String::from_utf8(output), status.code()) {
-            (Ok(output), Some(0)) => fs::write(file, output),
-            (Ok(_), Some(2)) => {
-                panic!("Rustfmt parsing errors");
-            }
-            (Ok(_), Some(3)) => {
-                panic!("Rustfmt could not format some lines");
-            }
-            (Ok(_), _) => {
-                panic!("Internal rustfmt errors");
-            }
-            (Err(_), _) => fs::write(file, contents),
-        }
+        fs::write(file, format_generated_rust(contents))
     }
 
     fn out_dir(file: &str) -> PathBuf {

crates/slang/bindings/rust/sourcegen.rs

@@ -1,4 +1,3 @@
 [toolchain]
 channel = "nightly-2026-05-24"
-components = ["clippy", "rustfmt"]
 profile = "minimal"