1 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
2 #![feature(rustc_private)]
4 // FIXME: switch to something more ergonomic here, once available.
5 // (Currently there is no way to opt into sysroot crates without `extern crate`.)
6 #[allow(unused_extern_crates)]
8 #[allow(unused_extern_crates)]
9 extern crate rustc_driver;
10 #[allow(unused_extern_crates)]
11 extern crate rustc_errors;
12 #[allow(unused_extern_crates)]
13 extern crate rustc_interface;
15 use rustc::ty::TyCtxt;
16 use rustc_interface::interface;
17 use rustc_tools_util::*;
19 use lazy_static::lazy_static;
22 use std::path::{Path, PathBuf};
23 use std::process::{exit, Command};
27 /// If a command-line option matches `find_arg`, then apply the predicate `pred` on its value. If
28 /// true, then return it. The parameter is assumed to be either `--arg=value` or `--arg value`.
30 args: impl IntoIterator<Item = &'a String>,
32 pred: impl Fn(&str) -> bool,
33 ) -> Option<&'a str> {
34 let mut args = args.into_iter().map(String::as_str);
36 while let Some(arg) = args.next() {
37 let arg: Vec<_> = arg.splitn(2, '=').collect();
38 if arg.get(0) != Some(&find_arg) {
42 let value = arg.get(1).cloned().or_else(|| args.next());
43 if value.as_ref().map_or(false, |p| pred(p)) {
52 let args: Vec<_> = ["--bar=bar", "--foobar", "123", "--foo"]
54 .map(std::string::ToString::to_string)
57 assert_eq!(arg_value(None, "--foobar", |_| true), None);
58 assert_eq!(arg_value(&args, "--bar", |_| false), None);
59 assert_eq!(arg_value(&args, "--bar", |_| true), Some("bar"));
60 assert_eq!(arg_value(&args, "--bar", |p| p == "bar"), Some("bar"));
61 assert_eq!(arg_value(&args, "--bar", |p| p == "foo"), None);
62 assert_eq!(arg_value(&args, "--foobar", |p| p == "foo"), None);
63 assert_eq!(arg_value(&args, "--foobar", |p| p == "123"), Some("123"));
64 assert_eq!(arg_value(&args, "--foo", |_| true), None);
67 #[allow(clippy::too_many_lines)]
69 struct ClippyCallbacks;
71 impl rustc_driver::Callbacks for ClippyCallbacks {
72 fn config(&mut self, config: &mut interface::Config) {
73 let previous = config.register_lints.take();
74 config.register_lints = Some(Box::new(move |sess, mut lint_store| {
75 // technically we're ~guaranteed that this is none but might as well call anything that
76 // is there already. Certainly it can't hurt.
77 if let Some(previous) = &previous {
78 (previous)(sess, lint_store);
81 let conf = clippy_lints::read_conf(&[], &sess);
82 clippy_lints::register_plugins(&mut lint_store, &sess, &conf);
83 clippy_lints::register_pre_expansion_lints(&mut lint_store, &conf);
84 clippy_lints::register_renamed(&mut lint_store);
87 // FIXME: #4825; This is required, because Clippy lints that are based on MIR have to be
88 // run on the unoptimized MIR. On the other hand this results in some false negatives. If
89 // MIR passes can be enabled / disabled separately, we should figure out, what passes to
91 config.opts.debugging_opts.mir_opt_level = 0;
95 #[allow(clippy::find_map, clippy::filter_map)]
98 use std::collections::HashSet;
102 Available lint options:
103 -W <foo> Warn about <foo>
106 -F <foo> Forbid <foo> (deny <foo> and all attempts to override)
111 let lint_level = |lint: &Lint| {
114 .find(|level_mapping| level_mapping.0 == lint.group)
115 .map(|(_, level)| match level {
116 Level::Allow => "allow",
117 Level::Warn => "warn",
118 Level::Deny => "deny",
123 let mut lints: Vec<_> = ALL_LINTS.iter().collect();
124 // The sort doesn't case-fold but it's doubtful we care.
125 lints.sort_by_cached_key(|x: &&Lint| (lint_level(x), x.name));
127 let max_lint_name_len = lints
129 .map(|lint| lint.name.len())
130 .map(|len| len + "clippy::".len())
134 let padded = |x: &str| {
135 let mut s = " ".repeat(max_lint_name_len - x.chars().count());
140 let scoped = |x: &str| format!("clippy::{}", x);
142 let lint_groups: HashSet<_> = lints.iter().map(|lint| lint.group).collect();
144 println!("Lint checks provided by clippy:\n");
145 println!(" {} {:7.7} meaning", padded("name"), "default");
146 println!(" {} {:7.7} -------", padded("----"), "-------");
148 let print_lints = |lints: &[&Lint]| {
150 let name = lint.name.replace("_", "-");
153 padded(&scoped(&name)),
163 let max_group_name_len = std::cmp::max(
167 .map(|group| group.len())
168 .map(|len| len + "clippy::".len())
173 let padded_group = |x: &str| {
174 let mut s = " ".repeat(max_group_name_len - x.chars().count());
179 println!("Lint groups provided by clippy:\n");
180 println!(" {} sub-lints", padded_group("name"));
181 println!(" {} ---------", padded_group("----"));
182 println!(" {} the set of all clippy lints", padded_group("clippy::all"));
184 let print_lint_groups = || {
185 for group in lint_groups {
186 let name = group.to_lowercase().replace("_", "-");
189 .filter(|&lint| lint.group == group)
190 .map(|lint| lint.name)
191 .map(|name| name.replace("_", "-"))
192 .collect::<Vec<String>>()
194 println!(" {} {}", padded_group(&scoped(&name)), desc);
205 Checks a package to catch common mistakes and improve your Rust code.
208 cargo clippy [options] [--] [<opts>...]
211 -h, --help Print this message
212 -V, --version Print version info and exit
214 Other options are the same as `cargo check`.
216 To allow or deny a lint from the command line you can use `cargo clippy --`
219 -W --warn OPT Set lint warnings
220 -A --allow OPT Set lint allowed
221 -D --deny OPT Set lint denied
222 -F --forbid OPT Set lint forbidden
224 You can use tool lints to allow or deny lints from your code, eg.:
226 #[allow(clippy::needless_lifetimes)]
231 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust-clippy/issues/new";
234 static ref ICE_HOOK: Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static> = {
235 let hook = panic::take_hook();
236 panic::set_hook(Box::new(|info| report_clippy_ice(info, BUG_REPORT_URL)));
241 fn report_clippy_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
242 // Invoke our ICE handler, which prints the actual panic message and optionally a backtrace
245 // Separate the output with an empty line
248 let emitter = Box::new(rustc_errors::emitter::EmitterWriter::stderr(
249 rustc_errors::ColorConfig::Auto,
256 let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
258 // a .span_bug or .bug call has already printed what
259 // it wants to print.
260 if !info.payload().is::<rustc_errors::ExplicitBug>() {
261 let d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
262 handler.emit_diagnostic(&d);
263 handler.abort_if_errors_and_should_abort();
266 let version_info = rustc_tools_util::get_version_info!();
268 let xs: Vec<Cow<'static, str>> = vec![
269 "the compiler unexpectedly panicked. this is a bug.".into(),
270 format!("we would appreciate a bug report: {}", bug_report_url).into(),
271 format!("Clippy version: {}", version_info).into(),
275 handler.note_without_error(¬e);
278 // If backtraces are enabled, also print the query stack
279 let backtrace = std::env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0");
282 TyCtxt::try_print_query_stack(&handler);
287 rustc_driver::init_rustc_env_logger();
288 lazy_static::initialize(&ICE_HOOK);
290 rustc_driver::catch_fatal_errors(move || {
293 if std::env::args().any(|a| a == "--version" || a == "-V") {
294 let version_info = rustc_tools_util::get_version_info!();
295 println!("{}", version_info);
299 let mut orig_args: Vec<String> = env::args().collect();
301 // Get the sysroot, looking from most specific to this invocation to the least:
303 // - runtime environment
305 // - RUSTUP_HOME, MULTIRUST_HOME, RUSTUP_TOOLCHAIN, MULTIRUST_TOOLCHAIN
306 // - sysroot from rustc in the path
307 // - compile-time environment
308 let sys_root_arg = arg_value(&orig_args, "--sysroot", |_| true);
309 let have_sys_root_arg = sys_root_arg.is_some();
310 let sys_root = sys_root_arg
312 .or_else(|| std::env::var("SYSROOT").ok().map(PathBuf::from))
314 let home = option_env!("RUSTUP_HOME").or(option_env!("MULTIRUST_HOME"));
315 let toolchain = option_env!("RUSTUP_TOOLCHAIN").or(option_env!("MULTIRUST_TOOLCHAIN"));
316 home.and_then(|home| {
317 toolchain.map(|toolchain| {
318 let mut path = PathBuf::from(home);
319 path.push("toolchains");
320 path.push(toolchain);
326 Command::new("rustc")
331 .and_then(|out| String::from_utf8(out.stdout).ok())
332 .map(|s| PathBuf::from(s.trim()))
334 .or_else(|| option_env!("SYSROOT").map(PathBuf::from))
335 .map(|pb| pb.to_string_lossy().to_string())
336 .expect("need to specify SYSROOT env var during clippy compilation, or use rustup or multirust");
338 // Setting RUSTC_WRAPPER causes Cargo to pass 'rustc' as the first argument.
339 // We're invoking the compiler programmatically, so we ignore this/
340 let wrapper_mode = orig_args.get(1).map(Path::new).and_then(Path::file_stem) == Some("rustc".as_ref());
343 // we still want to be able to invoke it normally though
347 if !wrapper_mode && (orig_args.iter().any(|a| a == "--help" || a == "-h") || orig_args.len() == 1) {
352 let should_describe_lints = || {
353 let args: Vec<_> = std::env::args().collect();
354 args.windows(2).any(|args| {
356 && match args[0].as_str() {
357 "-W" | "-A" | "-D" | "-F" => true,
363 if !wrapper_mode && should_describe_lints() {
368 // this conditional check for the --sysroot flag is there so users can call
369 // `clippy_driver` directly
370 // without having to pass --sysroot or anything
371 let mut args: Vec<String> = if have_sys_root_arg {
377 .chain(Some("--sysroot".to_owned()))
378 .chain(Some(sys_root))
382 // this check ensures that dependencies are built but not linted and the final
383 // crate is linted but not built
384 let clippy_enabled = env::var("CLIPPY_TESTS").map_or(false, |val| val == "true")
385 || arg_value(&orig_args, "--cap-lints", |val| val == "allow").is_none();
388 args.extend_from_slice(&["--cfg".to_owned(), r#"feature="cargo-clippy""#.to_owned()]);
389 if let Ok(extra_args) = env::var("CLIPPY_ARGS") {
390 args.extend(extra_args.split("__CLIPPY_HACKERY__").filter_map(|s| {
400 let mut clippy = ClippyCallbacks;
401 let mut default = rustc_driver::DefaultCallbacks;
402 let callbacks: &mut (dyn rustc_driver::Callbacks + Send) =
403 if clippy_enabled { &mut clippy } else { &mut default };
405 rustc_driver::run_compiler(&args, callbacks, None, None)
407 .and_then(|result| result)