Support file formatting and linting (#38)

This PR will add code quality checks to CI through [cargo
clippy](https://doc.rust-lang.org/clippy/index.html) and [cargo
fmt](https://github.com/rust-lang/rustfmt)

Closes #37

Author: dkcumming

.github/workflows/test.yml

@@ -13,8 +13,38 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
+  code-quality:
+    name: "Code Quality"
+    runs-on: [self-hosted, linux, normal]
+    steps:
+      - name: 'Check out code'
+        uses: actions/checkout@v4
+        with:
+          # Check out pull request HEAD instead of merge commit.
+          ref: ${{ github.event.pull_request.head.sha }}
+          submodules: recursive
+
+      - name: "Set up nightly Rust" # https://github.com/rust-lang/rustup/issues/3409
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: nightly-2024-11-29 # Hardcoded version, same as is in the build.rs
+
+      - name: 'Build smir_pretty' # rustfmt documentation claims it is unstable on code that doesn't build
+        run: |
+          cargo build -vv
+
+      - name: "Check `cargo clippy`"
+        run: |
+          rustup component add clippy
+          cargo clippy -- -Dwarnings
+
+      - name: "Check `cargo fmt`"
+        run: |
+          rustup component add rustfmt
+          cargo fmt --check
 
   integration-tests:
+    needs: code-quality
     name: "Integration tests"
     runs-on: [self-hosted, linux, normal]
     steps:
@@ -31,8 +61,8 @@ jobs:
           toolchain: nightly-2024-11-29 # Hardcoded version, same as is in the build.rs
 
       - name: 'Build smir_pretty'
-        run: |
-          cargo build -vv
+        run: | # Warning check should be redundant since code-quality runs first
+          RUSTFLAGS='--deny warnings' cargo build -vv
 
       - name: 'Run smir integration tests'
         run: |

README.md

@@ -36,6 +36,10 @@ There are a few environment variables that can be set to control the tools outpu
 2.  `LINK_INST`  - use a richer key-structure for the link-time `functions` map which uses keys that are pairs of a function type (`Ty`) _and_ an function instance kind (`InstanceKind`)
 3.  `DEBUG` - serialize additional data in the JSON file and dump logs to stdout
 
+## Development
+
+To ensure code quality, all code is required to pass `cargo clippy` and `cargo fmt` without warning to pass CI.
+
 ## Tests
 
 ### Running the Tests

build.rs

@@ -2,30 +2,30 @@ use std::process::Command;
 
 fn main() {
     let status = Command::new("rustup")
-        .args(&["install", "nightly-2024-11-29"])
+        .args(["install", "nightly-2024-11-29"])
         .status()
         .expect("build.rs failed to install nightly-2024-11-29");
 
     println!("Installed nightly-2024-11-29: {}", status);
 
     let status = Command::new("rustup")
-        .args(&["default", "nightly-2024-11-29"])
+        .args(["default", "nightly-2024-11-29"])
         .status()
         .expect("build.rs failed to default nightly-2024-11-29");
 
     println!("Defaulted nightly-2024-11-29: {}", status);
 
     let status = Command::new("rustup")
-        .args(&["component", "add", "rustc-dev"])
+        .args(["component", "add", "rustc-dev"])
         .status()
         .expect("build.rs failed to install rustc-dev");
 
     println!("Added component rustc-dev: {}", status);
 
     let status = Command::new("rustup")
-        .args(&["component", "add", "llvm-tools"])
+        .args(["component", "add", "llvm-tools"])
         .status()
         .expect("build.rs failed to install llvm-tools");
 
     println!("Added component llvm-tools: {}", status);
-}
+}

src/driver.rs

@@ -17,36 +17,32 @@
 //!
 //! However, we prefer a non-macro version for clarity and build simplicity.
 
-extern crate rustc_middle;
 extern crate rustc_driver;
 extern crate rustc_interface;
-extern crate rustc_smir;
+extern crate rustc_middle;
 extern crate rustc_session;
-use rustc_middle::ty::TyCtxt;
+extern crate rustc_smir;
 use rustc_driver::Compilation;
 use rustc_interface::interface::Compiler;
+use rustc_middle::ty::TyCtxt;
 use rustc_smir::rustc_internal;
 
 struct StableMirCallbacks {
-  callback_fn: fn (TyCtxt) -> (),
+    callback_fn: fn(TyCtxt) -> (),
 }
 
 impl rustc_driver::Callbacks for StableMirCallbacks {
-    fn after_analysis<'tcx>(
-        &mut self,
-        _compiler: &Compiler,
-        tcx: TyCtxt<'tcx>,
-    ) -> Compilation {
-
+    fn after_analysis(&mut self, _compiler: &Compiler, tcx: TyCtxt) -> Compilation {
         let _ = rustc_internal::run(tcx, || (self.callback_fn)(tcx));
 
         Compilation::Continue
     }
 }
 
-pub fn stable_mir_driver(args_outer: &Vec<String>, callback_fn: fn (TyCtxt) -> ()) {
+pub fn stable_mir_driver(args_outer: &[String], callback_fn: fn(TyCtxt) -> ()) {
     let mut callbacks = StableMirCallbacks { callback_fn };
-    let early_dcx = rustc_session::EarlyDiagCtxt::new(rustc_session::config::ErrorOutputType::default());
+    let early_dcx =
+        rustc_session::EarlyDiagCtxt::new(rustc_session::config::ErrorOutputType::default());
     rustc_driver::init_rustc_env_logger(&early_dcx);
     let _ = rustc_driver::RunCompiler::new(args_outer, &mut callbacks).run();
 }

src/main.rs

@@ -10,8 +10,7 @@ fn main() {
     let mut args: Vec<String> = env::args().collect();
 
     match args.get(1) {
-        None =>
-            stable_mir_driver(&args, emit_smir), // backward compatibility
+        None => stable_mir_driver(&args, emit_smir), // backward compatibility
         Some(arg) if arg == "--json" => {
             args.remove(1);
             stable_mir_driver(&args, emit_smir)
@@ -20,7 +19,6 @@ fn main() {
             args.remove(1);
             stable_mir_driver(&args, emit_dotfile)
         }
-        Some(_other) =>
-            stable_mir_driver(&args, emit_smir), // backward compatibility
+        Some(_other) => stable_mir_driver(&args, emit_smir), // backward compatibility
     }
 }