1 use clippy_utils::attrs::is_doc_hidden;
2 use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_note, span_lint_and_then};
3 use clippy_utils::macros::{is_panic, root_macro_call_first_node};
4 use clippy_utils::source::{first_line_of_span, snippet_with_applicability};
5 use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
6 use clippy_utils::{is_entrypoint_fn, method_chain_args, return_ty};
7 use if_chain::if_chain;
8 use itertools::Itertools;
9 use rustc_ast::ast::{Async, AttrKind, Attribute, Fn, FnRetTy, ItemKind};
10 use rustc_ast::token::CommentKind;
11 use rustc_data_structures::fx::FxHashSet;
12 use rustc_data_structures::sync::Lrc;
13 use rustc_errors::emitter::EmitterWriter;
14 use rustc_errors::{Applicability, Handler, SuggestionStyle};
16 use rustc_hir::intravisit::{self, Visitor};
17 use rustc_hir::{AnonConst, Expr};
18 use rustc_lint::{LateContext, LateLintPass};
19 use rustc_middle::hir::nested_filter;
20 use rustc_middle::lint::in_external_macro;
22 use rustc_parse::maybe_new_parser_from_source_str;
23 use rustc_parse::parser::ForceCollect;
24 use rustc_session::parse::ParseSess;
25 use rustc_session::{declare_tool_lint, impl_lint_pass};
26 use rustc_span::def_id::LocalDefId;
27 use rustc_span::edition::Edition;
28 use rustc_span::source_map::{BytePos, FilePathMapping, SourceMap, Span};
29 use rustc_span::{sym, FileName, Pos};
35 declare_clippy_lint! {
37 /// Checks for the presence of `_`, `::` or camel-case words
38 /// outside ticks in documentation.
40 /// ### Why is this bad?
41 /// *Rustdoc* supports markdown formatting, `_`, `::` and
42 /// camel-case probably indicates some code which should be included between
43 /// ticks. `_` can also be used for emphasis in markdown, this lint tries to
46 /// ### Known problems
47 /// Lots of bad docs won’t be fixed, what the lint checks
48 /// for is limited, and there are still false positives. HTML elements and their
49 /// content are not linted.
51 /// In addition, when writing documentation comments, including `[]` brackets
52 /// inside a link text would trip the parser. Therefore, documenting link with
53 /// `[`SmallVec<[T; INLINE_CAPACITY]>`]` and then [`SmallVec<[T; INLINE_CAPACITY]>`]: SmallVec
58 /// /// Do something with the foo_bar parameter. See also
59 /// /// that::other::module::foo.
60 /// // ^ `foo_bar` and `that::other::module::foo` should be ticked.
61 /// fn doit(foo_bar: usize) {}
65 /// // Link text with `[]` brackets should be written as following:
66 /// /// Consume the array and return the inner
67 /// /// [`SmallVec<[T; INLINE_CAPACITY]>`][SmallVec].
68 /// /// [SmallVec]: SmallVec
71 #[clippy::version = "pre 1.29.0"]
74 "presence of `_`, `::` or camel-case outside backticks in documentation"
77 declare_clippy_lint! {
79 /// Checks for the doc comments of publicly visible
80 /// unsafe functions and warns if there is no `# Safety` section.
82 /// ### Why is this bad?
83 /// Unsafe functions should document their safety
84 /// preconditions, so that users can be sure they are using them safely.
88 ///# type Universe = ();
89 /// /// This function should really be documented
90 /// pub unsafe fn start_apocalypse(u: &mut Universe) {
95 /// At least write a line about safety:
98 ///# type Universe = ();
101 /// /// This function should not be called before the horsemen are ready.
102 /// pub unsafe fn start_apocalypse(u: &mut Universe) {
103 /// unimplemented!();
106 #[clippy::version = "1.39.0"]
107 pub MISSING_SAFETY_DOC,
109 "`pub unsafe fn` without `# Safety` docs"
112 declare_clippy_lint! {
114 /// Checks the doc comments of publicly visible functions that
115 /// return a `Result` type and warns if there is no `# Errors` section.
117 /// ### Why is this bad?
118 /// Documenting the type of errors that can be returned from a
119 /// function can help callers write code to handle the errors appropriately.
122 /// Since the following function returns a `Result` it has an `# Errors` section in
129 /// /// Will return `Err` if `filename` does not exist or the user does not have
130 /// /// permission to read it.
131 /// pub fn read(filename: String) -> io::Result<String> {
132 /// unimplemented!();
135 #[clippy::version = "1.41.0"]
136 pub MISSING_ERRORS_DOC,
138 "`pub fn` returns `Result` without `# Errors` in doc comment"
141 declare_clippy_lint! {
143 /// Checks the doc comments of publicly visible functions that
144 /// may panic and warns if there is no `# Panics` section.
146 /// ### Why is this bad?
147 /// Documenting the scenarios in which panicking occurs
148 /// can help callers who do not want to panic to avoid those situations.
151 /// Since the following function may panic it has a `# Panics` section in
157 /// /// Will panic if y is 0
158 /// pub fn divide_by(x: i32, y: i32) -> i32 {
160 /// panic!("Cannot divide by 0")
166 #[clippy::version = "1.51.0"]
167 pub MISSING_PANICS_DOC,
169 "`pub fn` may panic without `# Panics` in doc comment"
172 declare_clippy_lint! {
174 /// Checks for `fn main() { .. }` in doctests
176 /// ### Why is this bad?
177 /// The test can be shorter (and likely more readable)
178 /// if the `fn main()` is left implicit.
182 /// /// An example of a doctest with a `main()` function
188 /// /// // this needs not be in an `fn`
191 /// fn needless_main() {
192 /// unimplemented!();
195 #[clippy::version = "1.40.0"]
196 pub NEEDLESS_DOCTEST_MAIN,
198 "presence of `fn main() {` in code examples"
201 declare_clippy_lint! {
203 /// Detects the syntax `['foo']` in documentation comments (notice quotes instead of backticks)
204 /// outside of code blocks
205 /// ### Why is this bad?
206 /// It is likely a typo when defining an intra-doc link
210 /// /// See also: ['foo']
215 /// /// See also: [`foo`]
218 #[clippy::version = "1.63.0"]
219 pub DOC_LINK_WITH_QUOTES,
221 "possible typo for an intra-doc link"
224 declare_clippy_lint! {
226 /// Checks for the doc comments of publicly visible
227 /// safe functions and traits and warns if there is a `# Safety` section.
229 /// ### Why is this bad?
230 /// Safe functions and traits are safe to implement and therefore do not
231 /// need to describe safety preconditions that users are required to uphold.
235 ///# type Universe = ();
238 /// /// This function should not be called before the horsemen are ready.
239 /// pub fn start_apocalypse_but_safely(u: &mut Universe) {
240 /// unimplemented!();
244 /// The function is safe, so there shouldn't be any preconditions
245 /// that have to be explained for safety reasons.
248 ///# type Universe = ();
249 /// /// This function should really be documented
250 /// pub fn start_apocalypse(u: &mut Universe) {
251 /// unimplemented!();
254 #[clippy::version = "1.66.0"]
255 pub UNNECESSARY_SAFETY_DOC,
257 "`pub fn` or `pub trait` with `# Safety` docs"
260 #[expect(clippy::module_name_repetitions)]
262 pub struct DocMarkdown {
263 valid_idents: FxHashSet<String>,
268 pub fn new(valid_idents: FxHashSet<String>) -> Self {
271 in_trait_impl: false,
276 impl_lint_pass!(DocMarkdown => [
277 DOC_LINK_WITH_QUOTES,
282 NEEDLESS_DOCTEST_MAIN,
283 UNNECESSARY_SAFETY_DOC,
286 impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
287 fn check_crate(&mut self, cx: &LateContext<'tcx>) {
288 let attrs = cx.tcx.hir().attrs(hir::CRATE_HIR_ID);
289 check_attrs(cx, &self.valid_idents, attrs);
292 fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
293 let attrs = cx.tcx.hir().attrs(item.hir_id());
294 let Some(headers) = check_attrs(cx, &self.valid_idents, attrs) else { return };
296 hir::ItemKind::Fn(ref sig, _, body_id) => {
297 if !(is_entrypoint_fn(cx, item.owner_id.to_def_id()) || in_external_macro(cx.tcx.sess, item.span)) {
298 let body = cx.tcx.hir().body(body_id);
299 let mut fpu = FindPanicUnwrap {
301 typeck_results: cx.tcx.typeck(item.owner_id.def_id),
304 fpu.visit_expr(body.value);
305 lint_for_missing_headers(cx, item.owner_id.def_id, sig, headers, Some(body_id), fpu.panic_span);
308 hir::ItemKind::Impl(impl_) => {
309 self.in_trait_impl = impl_.of_trait.is_some();
311 hir::ItemKind::Trait(_, unsafety, ..) => match (headers.safety, unsafety) {
312 (false, hir::Unsafety::Unsafe) => span_lint(
315 cx.tcx.def_span(item.owner_id),
316 "docs for unsafe trait missing `# Safety` section",
318 (true, hir::Unsafety::Normal) => span_lint(
320 UNNECESSARY_SAFETY_DOC,
321 cx.tcx.def_span(item.owner_id),
322 "docs for safe trait have unnecessary `# Safety` section",
330 fn check_item_post(&mut self, _cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
331 if let hir::ItemKind::Impl { .. } = item.kind {
332 self.in_trait_impl = false;
336 fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'_>) {
337 let attrs = cx.tcx.hir().attrs(item.hir_id());
338 let Some(headers) = check_attrs(cx, &self.valid_idents, attrs) else { return };
339 if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
340 if !in_external_macro(cx.tcx.sess, item.span) {
341 lint_for_missing_headers(cx, item.owner_id.def_id, sig, headers, None, None);
346 fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'_>) {
347 let attrs = cx.tcx.hir().attrs(item.hir_id());
348 let Some(headers) = check_attrs(cx, &self.valid_idents, attrs) else { return };
349 if self.in_trait_impl || in_external_macro(cx.tcx.sess, item.span) {
352 if let hir::ImplItemKind::Fn(ref sig, body_id) = item.kind {
353 let body = cx.tcx.hir().body(body_id);
354 let mut fpu = FindPanicUnwrap {
356 typeck_results: cx.tcx.typeck(item.owner_id.def_id),
359 fpu.visit_expr(body.value);
360 lint_for_missing_headers(cx, item.owner_id.def_id, sig, headers, Some(body_id), fpu.panic_span);
365 fn lint_for_missing_headers(
366 cx: &LateContext<'_>,
368 sig: &hir::FnSig<'_>,
370 body_id: Option<hir::BodyId>,
371 panic_span: Option<Span>,
373 if !cx.effective_visibilities.is_exported(def_id) {
374 return; // Private functions do not require doc comments
377 // do not lint if any parent has `#[doc(hidden)]` attribute (#7347)
381 .parent_iter(cx.tcx.hir().local_def_id_to_hir_id(def_id))
382 .any(|(id, _node)| is_doc_hidden(cx.tcx.hir().attrs(id)))
387 let span = cx.tcx.def_span(def_id);
388 match (headers.safety, sig.header.unsafety) {
389 (false, hir::Unsafety::Unsafe) => span_lint(
393 "unsafe function's docs miss `# Safety` section",
395 (true, hir::Unsafety::Normal) => span_lint(
397 UNNECESSARY_SAFETY_DOC,
399 "safe function's docs have unnecessary `# Safety` section",
403 if !headers.panics && panic_span.is_some() {
408 "docs for function which may panic missing `# Panics` section",
410 "first possible panic found here",
414 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id);
415 if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::Result) {
420 "docs for function returning `Result` missing `# Errors` section",
424 if let Some(body_id) = body_id;
425 if let Some(future) = cx.tcx.lang_items().future_trait();
426 let typeck = cx.tcx.typeck_body(body_id);
427 let body = cx.tcx.hir().body(body_id);
428 let ret_ty = typeck.expr_ty(body.value);
429 if implements_trait(cx, ret_ty, future, &[]);
430 if let ty::Opaque(_, subs) = ret_ty.kind();
431 if let Some(gen) = subs.types().next();
432 if let ty::Generator(_, subs, _) = gen.kind();
433 if is_type_diagnostic_item(cx, subs.as_generator().return_ty(), sym::Result);
439 "docs for function returning `Result` missing `# Errors` section",
447 /// Cleanup documentation decoration.
449 /// We can't use `rustc_ast::attr::AttributeMethods::with_desugared_doc` or
450 /// `rustc_ast::parse::lexer::comments::strip_doc_comment_decoration` because we
451 /// need to keep track of
452 /// the spans but this function is inspired from the later.
453 #[expect(clippy::cast_possible_truncation)]
455 pub fn strip_doc_comment_decoration(doc: &str, comment_kind: CommentKind, span: Span) -> (String, Vec<(usize, Span)>) {
456 // one-line comments lose their prefix
457 if comment_kind == CommentKind::Line {
458 let mut doc = doc.to_owned();
461 // +3 skips the opening delimiter
462 return (doc, vec![(len, span.with_lo(span.lo() + BytePos(3)))]);
465 let mut sizes = vec![];
466 let mut contains_initial_stars = false;
467 for line in doc.lines() {
468 let offset = line.as_ptr() as usize - doc.as_ptr() as usize;
469 debug_assert_eq!(offset as u32 as usize, offset);
470 contains_initial_stars |= line.trim_start().starts_with('*');
471 // +1 adds the newline, +3 skips the opening delimiter
472 sizes.push((line.len() + 1, span.with_lo(span.lo() + BytePos(3 + offset as u32))));
474 if !contains_initial_stars {
475 return (doc.to_string(), sizes);
477 // remove the initial '*'s if any
478 let mut no_stars = String::with_capacity(doc.len());
479 for line in doc.lines() {
480 let mut chars = line.chars();
481 for c in &mut chars {
482 if c.is_whitespace() {
485 no_stars.push(if c == '*' { ' ' } else { c });
489 no_stars.push_str(chars.as_str());
496 #[derive(Copy, Clone, Default)]
503 fn check_attrs(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &[Attribute]) -> Option<DocHeaders> {
504 use pulldown_cmark::{BrokenLink, CowStr, Options};
505 /// We don't want the parser to choke on intra doc links. Since we don't
506 /// actually care about rendering them, just pretend that all broken links are
507 /// point to a fake address.
508 #[expect(clippy::unnecessary_wraps)] // we're following a type signature
509 fn fake_broken_link_callback<'a>(_: BrokenLink<'_>) -> Option<(CowStr<'a>, CowStr<'a>)> {
510 Some(("fake".into(), "fake".into()))
513 let mut doc = String::new();
514 let mut spans = vec![];
517 if let AttrKind::DocComment(comment_kind, comment) = attr.kind {
518 let (comment, current_spans) = strip_doc_comment_decoration(comment.as_str(), comment_kind, attr.span);
519 spans.extend_from_slice(¤t_spans);
520 doc.push_str(&comment);
521 } else if attr.has_name(sym::doc) {
522 // ignore mix of sugared and non-sugared doc
523 // don't trigger the safety or errors check
529 for &mut (ref mut offset, _) in &mut spans {
530 let offset_copy = *offset;
532 current += offset_copy;
536 return Some(DocHeaders::default());
539 let mut cb = fake_broken_link_callback;
542 pulldown_cmark::Parser::new_with_broken_link_callback(&doc, Options::empty(), Some(&mut cb)).into_offset_iter();
543 // Iterate over all `Events` and combine consecutive events into one
544 let events = parser.coalesce(|previous, current| {
545 use pulldown_cmark::Event::Text;
547 let previous_range = previous.1;
548 let current_range = current.1;
550 match (previous.0, current.0) {
551 (Text(previous), Text(current)) => {
552 let mut previous = previous.to_string();
553 previous.push_str(¤t);
554 Ok((Text(previous.into()), previous_range))
556 (previous, current) => Err(((previous, previous_range), (current, current_range))),
559 Some(check_doc(cx, valid_idents, events, &spans))
562 const RUST_CODE: &[&str] = &["rust", "no_run", "should_panic", "compile_fail"];
564 fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize>)>>(
565 cx: &LateContext<'_>,
566 valid_idents: &FxHashSet<String>,
568 spans: &[(usize, Span)],
570 // true if a safety header was found
571 use pulldown_cmark::Event::{
572 Code, End, FootnoteReference, HardBreak, Html, Rule, SoftBreak, Start, TaskListMarker, Text,
574 use pulldown_cmark::Tag::{CodeBlock, Heading, Item, Link, Paragraph};
575 use pulldown_cmark::{CodeBlockKind, CowStr};
577 let mut headers = DocHeaders::default();
578 let mut in_code = false;
579 let mut in_link = None;
580 let mut in_heading = false;
581 let mut is_rust = false;
582 let mut edition = None;
583 let mut ticks_unbalanced = false;
584 let mut text_to_check: Vec<(CowStr<'_>, Span)> = Vec::new();
585 let mut paragraph_span = spans.get(0).expect("function isn't called if doc comment is empty").1;
586 for (event, range) in events {
588 Start(CodeBlock(ref kind)) => {
590 if let CodeBlockKind::Fenced(lang) = kind {
591 for item in lang.split(',') {
592 if item == "ignore" {
596 if let Some(stripped) = item.strip_prefix("edition") {
598 edition = stripped.parse::<Edition>().ok();
599 } else if item.is_empty() || RUST_CODE.contains(&item) {
605 End(CodeBlock(_)) => {
609 Start(Link(_, url, _)) => in_link = Some(url),
610 End(Link(..)) => in_link = None,
611 Start(Heading(_, _, _) | Paragraph | Item) => {
612 if let Start(Heading(_, _, _)) = event {
615 ticks_unbalanced = false;
616 let (_, span) = get_current_span(spans, range.start);
617 paragraph_span = first_line_of_span(cx, span);
619 End(Heading(_, _, _) | Paragraph | Item) => {
620 if let End(Heading(_, _, _)) = event {
623 if ticks_unbalanced {
628 "backticks are unbalanced",
630 "a backtick may be missing a pair",
633 for (text, span) in text_to_check {
634 check_text(cx, valid_idents, &text, span);
637 text_to_check = Vec::new();
639 Start(_tag) | End(_tag) => (), // We don't care about other tags
640 Html(_html) => (), // HTML is weird, just ignore it
641 SoftBreak | HardBreak | TaskListMarker(_) | Code(_) | Rule => (),
642 FootnoteReference(text) | Text(text) => {
643 let (begin, span) = get_current_span(spans, range.start);
644 paragraph_span = paragraph_span.with_hi(span.hi());
645 ticks_unbalanced |= text.contains('`') && !in_code;
646 if Some(&text) == in_link.as_ref() || ticks_unbalanced {
647 // Probably a link of the form `<http://example.com>`
648 // Which are represented as a link to "http://example.com" with
649 // text "http://example.com" by pulldown-cmark
652 let trimmed_text = text.trim();
653 headers.safety |= in_heading && trimmed_text == "Safety";
654 headers.safety |= in_heading && trimmed_text == "Implementation safety";
655 headers.safety |= in_heading && trimmed_text == "Implementation Safety";
656 headers.errors |= in_heading && trimmed_text == "Errors";
657 headers.panics |= in_heading && trimmed_text == "Panics";
660 let edition = edition.unwrap_or_else(|| cx.tcx.sess.edition());
661 check_code(cx, &text, edition, span);
664 check_link_quotes(cx, in_link.is_some(), trimmed_text, span, &range, begin, text.len());
665 // Adjust for the beginning of the current `Event`
666 let span = span.with_lo(span.lo() + BytePos::from_usize(range.start - begin));
667 text_to_check.push((text, span));
675 fn check_link_quotes(
676 cx: &LateContext<'_>,
680 range: &Range<usize>,
684 if in_link && trimmed_text.starts_with('\'') && trimmed_text.ends_with('\'') {
685 // fix the span to only point at the text within the link
686 let lo = span.lo() + BytePos::from_usize(range.start - begin);
689 DOC_LINK_WITH_QUOTES,
690 span.with_lo(lo).with_hi(lo + BytePos::from_usize(text_len)),
691 "possible intra-doc link using quotes instead of backticks",
696 fn get_current_span(spans: &[(usize, Span)], idx: usize) -> (usize, Span) {
697 let index = match spans.binary_search_by(|c| c.0.cmp(&idx)) {
704 fn check_code(cx: &LateContext<'_>, text: &str, edition: Edition, span: Span) {
705 fn has_needless_main(code: String, edition: Edition) -> bool {
706 rustc_driver::catch_fatal_errors(|| {
707 rustc_span::create_session_globals_then(edition, || {
708 let filename = FileName::anon_source_code(&code);
710 let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
711 let fallback_bundle =
712 rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
713 let emitter = EmitterWriter::new(
714 Box::new(io::sink()),
725 let handler = Handler::with_emitter(false, None, Box::new(emitter));
726 let sess = ParseSess::with_span_handler(handler, sm);
728 let mut parser = match maybe_new_parser_from_source_str(&sess, filename, code) {
736 let mut relevant_main_found = false;
738 match parser.parse_item(ForceCollect::No) {
739 Ok(Some(item)) => match &item.kind {
740 ItemKind::Fn(box Fn {
741 sig, body: Some(block), ..
742 }) if item.ident.name == sym::main => {
743 let is_async = matches!(sig.header.asyncness, Async::Yes { .. });
744 let returns_nothing = match &sig.decl.output {
745 FnRetTy::Default(..) => true,
746 FnRetTy::Ty(ty) if ty.kind.is_unit() => true,
747 FnRetTy::Ty(_) => false,
750 if returns_nothing && !is_async && !block.stmts.is_empty() {
751 // This main function should be linted, but only if there are no other functions
752 relevant_main_found = true;
754 // This main function should not be linted, we're done
758 // Tests with one of these items are ignored
760 | ItemKind::Const(..)
761 | ItemKind::ExternCrate(..)
762 | ItemKind::ForeignMod(..)
763 // Another function was found; this case is ignored
764 | ItemKind::Fn(..) => return false,
782 // Because of the global session, we need to create a new session in a different thread with
783 // the edition we need.
784 let text = text.to_owned();
785 if thread::spawn(move || has_needless_main(text, edition))
787 .expect("thread::spawn failed")
789 span_lint(cx, NEEDLESS_DOCTEST_MAIN, span, "needless `fn main` in doctest");
793 fn check_text(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, text: &str, span: Span) {
794 for word in text.split(|c: char| c.is_whitespace() || c == '\'') {
795 // Trim punctuation as in `some comment (see foo::bar).`
797 // Or even as in `_foo bar_` which is emphasized. Also preserve `::` as a prefix/suffix.
798 let mut word = word.trim_matches(|c: char| !c.is_alphanumeric() && c != ':');
800 // Remove leading or trailing single `:` which may be part of a sentence.
801 if word.starts_with(':') && !word.starts_with("::") {
802 word = word.trim_start_matches(':');
804 if word.ends_with(':') && !word.ends_with("::") {
805 word = word.trim_end_matches(':');
808 if valid_idents.contains(word) || word.chars().all(|c| c == ':') {
812 // Adjust for the current word
813 let offset = word.as_ptr() as usize - text.as_ptr() as usize;
814 let span = Span::new(
815 span.lo() + BytePos::from_usize(offset),
816 span.lo() + BytePos::from_usize(offset + word.len()),
821 check_word(cx, word, span);
825 fn check_word(cx: &LateContext<'_>, word: &str, span: Span) {
826 /// Checks if a string is camel-case, i.e., contains at least two uppercase
827 /// letters (`Clippy` is ok) and one lower-case letter (`NASA` is ok).
828 /// Plurals are also excluded (`IDs` is ok).
829 fn is_camel_case(s: &str) -> bool {
830 if s.starts_with(|c: char| c.is_ascii_digit()) {
834 let s = s.strip_suffix('s').unwrap_or(s);
836 s.chars().all(char::is_alphanumeric)
837 && s.chars().filter(|&c| c.is_uppercase()).take(2).count() > 1
838 && s.chars().filter(|&c| c.is_lowercase()).take(1).count() > 0
841 fn has_underscore(s: &str) -> bool {
842 s != "_" && !s.contains("\\_") && s.contains('_')
845 fn has_hyphen(s: &str) -> bool {
846 s != "-" && s.contains('-')
849 if let Ok(url) = Url::parse(word) {
850 // try to get around the fact that `foo::bar` parses as a valid URL
851 if !url.cannot_be_a_base() {
856 "you should put bare URLs between `<`/`>` or make a proper Markdown link",
863 // We assume that mixed-case words are not meant to be put inside backticks. (Issue #2343)
864 if has_underscore(word) && has_hyphen(word) {
868 if has_underscore(word) || word.contains("::") || is_camel_case(word) {
869 let mut applicability = Applicability::MachineApplicable;
875 "item in documentation is missing backticks",
877 let snippet = snippet_with_applicability(cx, span, "..", &mut applicability);
878 diag.span_suggestion_with_style(
881 format!("`{snippet}`"),
883 // always show the suggestion in a separate line, since the
884 // inline presentation adds another pair of backticks
885 SuggestionStyle::ShowAlways,
892 struct FindPanicUnwrap<'a, 'tcx> {
893 cx: &'a LateContext<'tcx>,
894 panic_span: Option<Span>,
895 typeck_results: &'tcx ty::TypeckResults<'tcx>,
898 impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
899 type NestedFilter = nested_filter::OnlyBodies;
901 fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
902 if self.panic_span.is_some() {
906 if let Some(macro_call) = root_macro_call_first_node(self.cx, expr) {
907 if is_panic(self.cx, macro_call.def_id)
909 self.cx.tcx.item_name(macro_call.def_id).as_str(),
910 "assert" | "assert_eq" | "assert_ne" | "todo"
913 self.panic_span = Some(macro_call.span);
917 // check for `unwrap`
918 if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
919 let receiver_ty = self.typeck_results.expr_ty(arglists[0].0).peel_refs();
920 if is_type_diagnostic_item(self.cx, receiver_ty, sym::Option)
921 || is_type_diagnostic_item(self.cx, receiver_ty, sym::Result)
923 self.panic_span = Some(expr.span);
927 // and check sub-expressions
928 intravisit::walk_expr(self, expr);
931 // Panics in const blocks will cause compilation to fail.
932 fn visit_anon_const(&mut self, _: &'tcx AnonConst) {}
934 fn nested_visit_map(&mut self) -> Self::Map {