1 #![feature(rustc_private)]
3 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
4 // warn on lints, that are included in `rust-lang/rust`s bootstrap
5 #![warn(rust_2018_idioms, unused_lifetimes)]
6 // warn on rustc internal lints
7 #![deny(rustc::internal)]
9 // FIXME: switch to something more ergonomic here, once available.
10 // (Currently there is no way to opt into sysroot crates without `extern crate`.)
11 extern crate rustc_driver;
12 extern crate rustc_errors;
13 extern crate rustc_interface;
15 use rustc_interface::interface;
16 use rustc_tools_util::VersionInfo;
20 use std::lazy::SyncLazy;
23 use std::path::{Path, PathBuf};
24 use std::process::{exit, Command};
26 /// If a command-line option matches `find_arg`, then apply the predicate `pred` on its value. If
27 /// true, then return it. The parameter is assumed to be either `--arg=value` or `--arg value`.
28 fn arg_value<'a, T: Deref<Target = str>>(
31 pred: impl Fn(&str) -> bool,
32 ) -> Option<&'a str> {
33 let mut args = args.iter().map(Deref::deref);
34 while let Some(arg) = args.next() {
35 let mut arg = arg.splitn(2, '=');
36 if arg.next() != Some(find_arg) {
40 match arg.next().or_else(|| args.next()) {
41 Some(v) if pred(v) => return Some(v),
50 let args = &["--bar=bar", "--foobar", "123", "--foo"];
52 assert_eq!(arg_value(&[] as &[&str], "--foobar", |_| true), None);
53 assert_eq!(arg_value(args, "--bar", |_| false), None);
54 assert_eq!(arg_value(args, "--bar", |_| true), Some("bar"));
55 assert_eq!(arg_value(args, "--bar", |p| p == "bar"), Some("bar"));
56 assert_eq!(arg_value(args, "--bar", |p| p == "foo"), None);
57 assert_eq!(arg_value(args, "--foobar", |p| p == "foo"), None);
58 assert_eq!(arg_value(args, "--foobar", |p| p == "123"), Some("123"));
59 assert_eq!(arg_value(args, "--foo", |_| true), None);
62 struct DefaultCallbacks;
63 impl rustc_driver::Callbacks for DefaultCallbacks {}
65 struct ClippyCallbacks;
66 impl rustc_driver::Callbacks for ClippyCallbacks {
67 fn config(&mut self, config: &mut interface::Config) {
68 let previous = config.register_lints.take();
69 config.register_lints = Some(Box::new(move |sess, mut lint_store| {
70 // technically we're ~guaranteed that this is none but might as well call anything that
71 // is there already. Certainly it can't hurt.
72 if let Some(previous) = &previous {
73 (previous)(sess, lint_store);
76 let conf = clippy_lints::read_conf(&[], &sess);
77 clippy_lints::register_plugins(&mut lint_store, &sess, &conf);
78 clippy_lints::register_pre_expansion_lints(&mut lint_store);
79 clippy_lints::register_renamed(&mut lint_store);
82 // FIXME: #4825; This is required, because Clippy lints that are based on MIR have to be
83 // run on the unoptimized MIR. On the other hand this results in some false negatives. If
84 // MIR passes can be enabled / disabled separately, we should figure out, what passes to
86 config.opts.debugging_opts.mir_opt_level = Some(0);
93 Checks a package to catch common mistakes and improve your Rust code.
96 cargo clippy [options] [--] [<opts>...]
99 -h, --help Print this message
100 --rustc Pass all args to rustc
101 -V, --version Print version info and exit
103 Other options are the same as `cargo check`.
105 To allow or deny a lint from the command line you can use `cargo clippy --`
108 -W --warn OPT Set lint warnings
109 -A --allow OPT Set lint allowed
110 -D --deny OPT Set lint denied
111 -F --forbid OPT Set lint forbidden
113 You can use tool lints to allow or deny lints from your code, eg.:
115 #[allow(clippy::needless_lifetimes)]
120 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust-clippy/issues/new";
122 static ICE_HOOK: SyncLazy<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> = SyncLazy::new(|| {
123 let hook = panic::take_hook();
124 panic::set_hook(Box::new(|info| report_clippy_ice(info, BUG_REPORT_URL)));
128 fn report_clippy_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
129 // Invoke our ICE handler, which prints the actual panic message and optionally a backtrace
132 // Separate the output with an empty line
135 let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
136 rustc_errors::ColorConfig::Auto,
143 let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
145 // a .span_bug or .bug call has already printed what
146 // it wants to print.
147 if !info.payload().is::<rustc_errors::ExplicitBug>() {
148 let d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
149 handler.emit_diagnostic(&d);
152 let version_info = rustc_tools_util::get_version_info!();
154 let xs: Vec<Cow<'static, str>> = vec![
155 "the compiler unexpectedly panicked. this is a bug.".into(),
156 format!("we would appreciate a bug report: {}", bug_report_url).into(),
157 format!("Clippy version: {}", version_info).into(),
161 handler.note_without_error(¬e);
164 // If backtraces are enabled, also print the query stack
165 let backtrace = env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0");
167 let num_frames = if backtrace { None } else { Some(2) };
169 interface::try_print_query_stack(&handler, num_frames);
172 fn toolchain_path(home: Option<String>, toolchain: Option<String>) -> Option<PathBuf> {
173 home.and_then(|home| {
174 toolchain.map(|toolchain| {
175 let mut path = PathBuf::from(home);
176 path.push("toolchains");
177 path.push(toolchain);
183 #[allow(clippy::too_many_lines)]
185 rustc_driver::init_rustc_env_logger();
186 SyncLazy::force(&ICE_HOOK);
187 exit(rustc_driver::catch_with_exit_code(move || {
188 let mut orig_args: Vec<String> = env::args().collect();
190 // Get the sysroot, looking from most specific to this invocation to the least:
192 // - runtime environment
194 // - RUSTUP_HOME, MULTIRUST_HOME, RUSTUP_TOOLCHAIN, MULTIRUST_TOOLCHAIN
195 // - sysroot from rustc in the path
196 // - compile-time environment
198 // - RUSTUP_HOME, MULTIRUST_HOME, RUSTUP_TOOLCHAIN, MULTIRUST_TOOLCHAIN
199 let sys_root_arg = arg_value(&orig_args, "--sysroot", |_| true);
200 let have_sys_root_arg = sys_root_arg.is_some();
201 let sys_root = sys_root_arg
203 .or_else(|| std::env::var("SYSROOT").ok().map(PathBuf::from))
205 let home = std::env::var("RUSTUP_HOME")
206 .or_else(|_| std::env::var("MULTIRUST_HOME"))
208 let toolchain = std::env::var("RUSTUP_TOOLCHAIN")
209 .or_else(|_| std::env::var("MULTIRUST_TOOLCHAIN"))
211 toolchain_path(home, toolchain)
214 Command::new("rustc")
219 .and_then(|out| String::from_utf8(out.stdout).ok())
220 .map(|s| PathBuf::from(s.trim()))
222 .or_else(|| option_env!("SYSROOT").map(PathBuf::from))
224 let home = option_env!("RUSTUP_HOME")
225 .or(option_env!("MULTIRUST_HOME"))
226 .map(ToString::to_string);
227 let toolchain = option_env!("RUSTUP_TOOLCHAIN")
228 .or(option_env!("MULTIRUST_TOOLCHAIN"))
229 .map(ToString::to_string);
230 toolchain_path(home, toolchain)
232 .map(|pb| pb.to_string_lossy().to_string())
233 .expect("need to specify SYSROOT env var during clippy compilation, or use rustup or multirust");
235 // make "clippy-driver --rustc" work like a subcommand that passes further args to "rustc"
236 // for example `clippy-driver --rustc --version` will print the rustc version that clippy-driver
238 if let Some(pos) = orig_args.iter().position(|arg| arg == "--rustc") {
239 orig_args.remove(pos);
240 orig_args[0] = "rustc".to_string();
242 // if we call "rustc", we need to pass --sysroot here as well
243 let mut args: Vec<String> = orig_args.clone();
244 if !have_sys_root_arg {
245 args.extend(vec!["--sysroot".into(), sys_root]);
248 return rustc_driver::RunCompiler::new(&args, &mut DefaultCallbacks).run();
251 if orig_args.iter().any(|a| a == "--version" || a == "-V") {
252 let version_info = rustc_tools_util::get_version_info!();
253 println!("{}", version_info);
257 // Setting RUSTC_WRAPPER causes Cargo to pass 'rustc' as the first argument.
258 // We're invoking the compiler programmatically, so we ignore this/
259 let wrapper_mode = orig_args.get(1).map(Path::new).and_then(Path::file_stem) == Some("rustc".as_ref());
262 // we still want to be able to invoke it normally though
266 if !wrapper_mode && (orig_args.iter().any(|a| a == "--help" || a == "-h") || orig_args.len() == 1) {
271 // this conditional check for the --sysroot flag is there so users can call
272 // `clippy_driver` directly
273 // without having to pass --sysroot or anything
274 let mut args: Vec<String> = orig_args.clone();
275 if !have_sys_root_arg {
276 args.extend(vec!["--sysroot".into(), sys_root]);
279 let mut no_deps = false;
280 let clippy_args = env::var("CLIPPY_ARGS")
282 .split("__CLIPPY_HACKERY__")
283 .filter_map(|s| match s {
289 _ => Some(s.to_string()),
291 .chain(vec!["--cfg".into(), r#"feature="cargo-clippy""#.into()])
292 .collect::<Vec<String>>();
294 // We enable Clippy if one of the following conditions is met
295 // - IF Clippy is run on its test suite OR
296 // - IF Clippy is run on the main crate, not on deps (`!cap_lints_allow`) THEN
297 // - IF `--no-deps` is not set (`!no_deps`) OR
298 // - IF `--no-deps` is set and Clippy is run on the specified primary package
299 let clippy_tests_set = env::var("__CLIPPY_INTERNAL_TESTS").map_or(false, |val| val == "true");
300 let cap_lints_allow = arg_value(&orig_args, "--cap-lints", |val| val == "allow").is_some();
301 let in_primary_package = env::var("CARGO_PRIMARY_PACKAGE").is_ok();
303 let clippy_enabled = clippy_tests_set || (!cap_lints_allow && (!no_deps || in_primary_package));
305 args.extend(clippy_args);
308 let mut clippy = ClippyCallbacks;
309 let mut default = DefaultCallbacks;
310 let callbacks: &mut (dyn rustc_driver::Callbacks + Send) =
311 if clippy_enabled { &mut clippy } else { &mut default };
313 rustc_driver::RunCompiler::new(&args, callbacks).run()