1 //! Tidy check to enforce various stylistic guidelines on the Rust codebase.
3 //! Example checks are:
5 //! * No lines over 100 characters (in non-Rust files).
6 //! * No files with over 3000 lines (in non-Rust files).
8 //! * No trailing whitespace.
9 //! * No CR characters.
10 //! * No `TODO` or `XXX` directives.
11 //! * No unexplained ` ```ignore ` or ` ```rust,ignore ` doc tests.
13 //! Note that some of these rules are excluded from Rust files because we enforce rustfmt. It is
14 //! preferable to be formatted rather than tidy-clean.
16 //! A number of these checks can be opted-out of with various directives of the form:
17 //! `// ignore-tidy-CHECK-NAME`.
19 use crate::walk::{filter_dirs, walk};
23 /// Error code markdown is restricted to 80 columns because they can be
24 /// displayed on the console with --example.
25 const ERROR_CODE_COLS: usize = 80;
26 const COLS: usize = 100;
28 const LINES: usize = 3000;
30 const UNEXPLAINED_IGNORE_DOCTEST_INFO: &str = r#"unexplained "```ignore" doctest; try one:
32 * make the test actually pass, by adding necessary imports and declarations, or
33 * use "```text", if the code is not Rust code, or
34 * use "```compile_fail,Ennnn", if the code is expected to fail at compile time, or
35 * use "```should_panic", if the code is expected to fail at run time, or
36 * use "```no_run", if the code should type-check but not necessary linkable/runnable, or
37 * explain it like "```ignore (cannot-test-this-because-xxxx)", if the annotation cannot be avoided.
41 const LLVM_UNREACHABLE_INFO: &str = r"\
42 C++ code used llvm_unreachable, which triggers undefined behavior
43 when executed when assertions are disabled.
44 Use llvm::report_fatal_error for increased robustness.";
46 const ANNOTATIONS_TO_IGNORE: &[&str] = &[
57 "// normalize-stderr-test",
60 // Intentionally written in decimal rather than hex
61 const PROBLEMATIC_CONSTS: &[u32] = &[
62 184594741, 2880289470, 2881141438, 2965027518, 2976579765, 3203381950, 3405691582, 3405697037,
63 3735927486, 4027431614, 4276992702,
66 /// Parser states for `line_is_url`.
67 #[derive(Clone, Copy, PartialEq)]
68 #[allow(non_camel_case_types)]
71 EXP_LINK_LABEL_OR_URL,
76 /// Returns `true` if `line` appears to be a line comment containing a URL,
77 /// possibly with a Markdown link label in front, and nothing else.
78 /// The Markdown link label, if present, may not contain whitespace.
79 /// Lines of this form are allowed to be overlength, because Markdown
80 /// offers no way to split a line in the middle of a URL, and the lengths
81 /// of URLs to external references are beyond our control.
82 fn line_is_url(is_error_code: bool, columns: usize, line: &str) -> bool {
83 // more basic check for markdown, to avoid complexity in implementing two state machines
85 return line.starts_with('[') && line.contains("]:") && line.contains("http");
88 use self::LIUState::*;
89 let mut state: LIUState = EXP_COMMENT_START;
90 let is_url = |w: &str| w.starts_with("http://") || w.starts_with("https://");
92 for tok in line.split_whitespace() {
94 (EXP_COMMENT_START, "//") | (EXP_COMMENT_START, "///") | (EXP_COMMENT_START, "//!") => {
95 state = EXP_LINK_LABEL_OR_URL
98 (EXP_LINK_LABEL_OR_URL, w)
99 if w.len() >= 4 && w.starts_with('[') && w.ends_with("]:") =>
104 (EXP_LINK_LABEL_OR_URL, w) if is_url(w) => state = EXP_END,
106 (EXP_URL, w) if is_url(w) || w.starts_with("../") => state = EXP_END,
108 (_, w) if w.len() > columns && is_url(w) => state = EXP_END,
117 /// Returns `true` if `line` can be ignored. This is the case when it contains
118 /// an annotation that is explicitly ignored.
119 fn should_ignore(line: &str) -> bool {
120 // Matches test annotations like `//~ ERROR text`.
121 // This mirrors the regex in src/tools/compiletest/src/runtest.rs, please
122 // update both if either are changed.
123 let re = Regex::new("\\s*//(\\[.*\\])?~.*").unwrap();
124 re.is_match(line) || ANNOTATIONS_TO_IGNORE.iter().any(|a| line.contains(a))
127 /// Returns `true` if `line` is allowed to be longer than the normal limit.
128 fn long_line_is_ok(extension: &str, is_error_code: bool, max_columns: usize, line: &str) -> bool {
130 // fluent files are allowed to be any length
132 // non-error code markdown is allowed to be any length
133 "md" if !is_error_code => true,
134 _ => line_is_url(is_error_code, max_columns, line) || should_ignore(line),
139 /// By default, tidy always warns against style issues.
142 /// `Ignore(false)` means that an `ignore-tidy-*` directive
143 /// has been provided, but is unnecessary. `Ignore(true)`
144 /// means that it is necessary (i.e. a warning would be
145 /// produced if `ignore-tidy-*` was not present).
149 fn contains_ignore_directive(can_contain: bool, contents: &str, check: &str) -> Directive {
151 return Directive::Deny;
153 // Update `can_contain` when changing this
154 if contents.contains(&format!("// ignore-tidy-{check}"))
155 || contents.contains(&format!("# ignore-tidy-{check}"))
156 || contents.contains(&format!("/* ignore-tidy-{check} */"))
158 Directive::Ignore(false)
164 macro_rules! suppressible_tidy_err {
165 ($err:ident, $skip:ident, $msg:expr) => {
166 if let Directive::Deny = $skip {
169 $skip = Directive::Ignore(true);
174 pub fn is_in(full_path: &Path, parent_folder_to_find: &str, folder_to_find: &str) -> bool {
175 if let Some(parent) = full_path.parent() {
176 if parent.file_name().map_or_else(
179 f.to_string_lossy() == folder_to_find
182 .and_then(|f| f.file_name())
183 .map_or_else(|| false, |f| f == parent_folder_to_find)
188 is_in(parent, parent_folder_to_find, folder_to_find)
195 fn skip_markdown_path(path: &Path) -> bool {
196 // These aren't ready for tidy.
197 const SKIP_MD: &[&str] = &[
198 "src/doc/edition-guide",
199 "src/doc/embedded-book",
202 "src/doc/rust-by-example",
203 "src/doc/rustc-dev-guide",
205 SKIP_MD.iter().any(|p| path.ends_with(p))
208 fn is_unexplained_ignore(extension: &str, line: &str) -> bool {
209 if !line.ends_with("```ignore") && !line.ends_with("```rust,ignore") {
212 if extension == "md" && line.trim().starts_with("//") {
213 // Markdown examples may include doc comments with ignore inside a
220 pub fn check(path: &Path, bad: &mut bool) {
221 fn skip(path: &Path) -> bool {
222 filter_dirs(path) || skip_markdown_path(path)
224 let problematic_consts_strings: Vec<String> = (PROBLEMATIC_CONSTS.iter().map(u32::to_string))
225 .chain(PROBLEMATIC_CONSTS.iter().map(|v| format!("{:x}", v)))
226 .chain(PROBLEMATIC_CONSTS.iter().map(|v| format!("{:X}", v)))
228 walk(path, &mut skip, &mut |entry, contents| {
229 let file = entry.path();
230 let filename = file.file_name().unwrap().to_string_lossy();
231 let extensions = [".rs", ".py", ".js", ".sh", ".c", ".cpp", ".h", ".md", ".css", ".ftl"];
232 if extensions.iter().all(|e| !filename.ends_with(e)) || filename.starts_with(".#") {
236 let is_style_file = filename.ends_with(".css");
237 let under_rustfmt = filename.ends_with(".rs") &&
238 // This list should ideally be sourced from rustfmt.toml but we don't want to add a toml
240 !file.ancestors().any(|a| {
241 a.ends_with("src/test") ||
242 a.ends_with("src/doc/book")
245 if is_style_file && !is_in(file, "src", "librustdoc") {
246 // We only check CSS files in rustdoc.
250 if contents.is_empty() {
251 tidy_error!(bad, "{}: empty file", file.display());
254 let extension = file.extension().unwrap().to_string_lossy();
255 let is_error_code = extension == "md" && is_in(file, "src", "error_codes");
257 let max_columns = if is_error_code { ERROR_CODE_COLS } else { COLS };
259 let can_contain = contents.contains("// ignore-tidy-")
260 || contents.contains("# ignore-tidy-")
261 || contents.contains("/* ignore-tidy-");
262 // Enable testing ICE's that require specific (untidy)
263 // file formats easily eg. `issue-1234-ignore-tidy.rs`
264 if filename.contains("ignore-tidy") {
267 let mut skip_cr = contains_ignore_directive(can_contain, &contents, "cr");
268 let mut skip_undocumented_unsafe =
269 contains_ignore_directive(can_contain, &contents, "undocumented-unsafe");
270 let mut skip_tab = contains_ignore_directive(can_contain, &contents, "tab");
271 let mut skip_line_length = contains_ignore_directive(can_contain, &contents, "linelength");
272 let mut skip_file_length = contains_ignore_directive(can_contain, &contents, "filelength");
273 let mut skip_end_whitespace =
274 contains_ignore_directive(can_contain, &contents, "end-whitespace");
275 let mut skip_trailing_newlines =
276 contains_ignore_directive(can_contain, &contents, "trailing-newlines");
277 let mut skip_leading_newlines =
278 contains_ignore_directive(can_contain, &contents, "leading-newlines");
279 let mut skip_copyright = contains_ignore_directive(can_contain, &contents, "copyright");
280 let mut leading_new_lines = false;
281 let mut trailing_new_lines = 0;
283 let mut last_safety_comment = false;
284 for (i, line) in contents.split('\n').enumerate() {
285 let mut err = |msg: &str| {
286 tidy_error!(bad, "{}:{}: {}", file.display(), i + 1, msg);
289 && line.chars().count() > max_columns
290 && !long_line_is_ok(&extension, is_error_code, max_columns, line)
292 suppressible_tidy_err!(
295 &format!("line longer than {max_columns} chars")
298 if !is_style_file && line.contains('\t') {
299 suppressible_tidy_err!(err, skip_tab, "tab character");
301 if line.ends_with(' ') || line.ends_with('\t') {
302 suppressible_tidy_err!(err, skip_end_whitespace, "trailing whitespace");
304 if is_style_file && line.starts_with(' ') {
305 err("CSS files use tabs for indent");
307 if line.contains('\r') {
308 suppressible_tidy_err!(err, skip_cr, "CR character");
310 if filename != "style.rs" {
311 if line.contains("TODO") {
312 err("TODO is deprecated; use FIXME")
314 if line.contains("//") && line.contains(" XXX") {
315 err("XXX is deprecated; use FIXME")
317 for s in problematic_consts_strings.iter() {
318 if line.contains(s) {
319 err("Don't use magic numbers that spell things (consider 0x12345678)");
323 let is_test = || file.components().any(|c| c.as_os_str() == "tests");
324 // for now we just check libcore
325 if line.contains("unsafe {") && !line.trim().starts_with("//") && !last_safety_comment {
326 if file.components().any(|c| c.as_os_str() == "core") && !is_test() {
327 suppressible_tidy_err!(err, skip_undocumented_unsafe, "undocumented unsafe");
330 if line.contains("// SAFETY:") {
331 last_safety_comment = true;
332 } else if line.trim().starts_with("//") || line.trim().is_empty() {
333 // keep previous value
335 last_safety_comment = false;
337 if (line.starts_with("// Copyright")
338 || line.starts_with("# Copyright")
339 || line.starts_with("Copyright"))
340 && (line.contains("Rust Developers") || line.contains("Rust Project Developers"))
342 suppressible_tidy_err!(
345 "copyright notices attributed to the Rust Project Developers are deprecated"
348 if is_unexplained_ignore(&extension, line) {
349 err(UNEXPLAINED_IGNORE_DOCTEST_INFO);
351 if filename.ends_with(".cpp") && line.contains("llvm_unreachable") {
352 err(LLVM_UNREACHABLE_INFO);
356 leading_new_lines = true;
358 trailing_new_lines += 1;
360 trailing_new_lines = 0;
363 if !line.trim().starts_with("//") {
367 if leading_new_lines {
369 tidy_error!(bad, "{}: leading newline", file.display());
371 suppressible_tidy_err!(err, skip_leading_newlines, "mising leading newline");
373 let mut err = |msg: &str| {
374 tidy_error!(bad, "{}: {}", file.display(), msg);
376 match trailing_new_lines {
377 0 => suppressible_tidy_err!(err, skip_trailing_newlines, "missing trailing newline"),
379 n => suppressible_tidy_err!(
381 skip_trailing_newlines,
382 &format!("too many trailing newlines ({n})")
389 "{}: too many lines ({}) (add `// \
390 ignore-tidy-filelength` to the file to suppress this error)",
395 suppressible_tidy_err!(err, skip_file_length, "");
398 if let Directive::Ignore(false) = skip_cr {
399 tidy_error!(bad, "{}: ignoring CR characters unnecessarily", file.display());
401 if let Directive::Ignore(false) = skip_tab {
402 tidy_error!(bad, "{}: ignoring tab characters unnecessarily", file.display());
404 if let Directive::Ignore(false) = skip_end_whitespace {
405 tidy_error!(bad, "{}: ignoring trailing whitespace unnecessarily", file.display());
407 if let Directive::Ignore(false) = skip_trailing_newlines {
408 tidy_error!(bad, "{}: ignoring trailing newlines unnecessarily", file.display());
410 if let Directive::Ignore(false) = skip_leading_newlines {
411 tidy_error!(bad, "{}: ignoring leading newlines unnecessarily", file.display());
413 if let Directive::Ignore(false) = skip_copyright {
414 tidy_error!(bad, "{}: ignoring copyright unnecessarily", file.display());
416 // We deliberately do not warn about these being unnecessary,
417 // that would just lead to annoying churn.
418 let _unused = skip_line_length;
419 let _unused = skip_file_length;