1 use crate::utils::{match_type, paths, return_ty, span_lint};
2 use itertools::Itertools;
5 use rustc::impl_lint_pass;
6 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
7 use rustc_data_structures::fx::FxHashSet;
8 use rustc_session::declare_tool_lint;
10 use syntax::ast::{AttrKind, Attribute};
11 use syntax::source_map::{BytePos, MultiSpan, Span};
15 declare_clippy_lint! {
16 /// **What it does:** Checks for the presence of `_`, `::` or camel-case words
17 /// outside ticks in documentation.
19 /// **Why is this bad?** *Rustdoc* supports markdown formatting, `_`, `::` and
20 /// camel-case probably indicates some code which should be included between
21 /// ticks. `_` can also be used for emphasis in markdown, this lint tries to
24 /// **Known problems:** Lots of bad docs won’t be fixed, what the lint checks
25 /// for is limited, and there are still false positives.
29 /// /// Do something with the foo_bar parameter. See also
30 /// /// that::other::module::foo.
31 /// // ^ `foo_bar` and `that::other::module::foo` should be ticked.
32 /// fn doit(foo_bar: usize) {}
36 "presence of `_`, `::` or camel-case outside backticks in documentation"
39 declare_clippy_lint! {
40 /// **What it does:** Checks for the doc comments of publicly visible
41 /// unsafe functions and warns if there is no `# Safety` section.
43 /// **Why is this bad?** Unsafe functions should document their safety
44 /// preconditions, so that users can be sure they are using them safely.
46 /// **Known problems:** None.
50 ///# type Universe = ();
51 /// /// This function should really be documented
52 /// pub unsafe fn start_apocalypse(u: &mut Universe) {
57 /// At least write a line about safety:
60 ///# type Universe = ();
63 /// /// This function should not be called before the horsemen are ready.
64 /// pub unsafe fn start_apocalypse(u: &mut Universe) {
68 pub MISSING_SAFETY_DOC,
70 "`pub unsafe fn` without `# Safety` docs"
73 declare_clippy_lint! {
74 /// **What it does:** Checks the doc comments of publicly visible functions that
75 /// return a `Result` type and warns if there is no `# Errors` section.
77 /// **Why is this bad?** Documenting the type of errors that can be returned from a
78 /// function can help callers write code to handle the errors appropriately.
80 /// **Known problems:** None.
84 /// Since the following function returns a `Result` it has an `# Errors` section in
91 /// /// Will return `Err` if `filename` does not exist or the user does not have
92 /// /// permission to read it.
93 /// pub fn read(filename: String) -> io::Result<String> {
97 pub MISSING_ERRORS_DOC,
99 "`pub fn` returns `Result` without `# Errors` in doc comment"
102 declare_clippy_lint! {
103 /// **What it does:** Checks for `fn main() { .. }` in doctests
105 /// **Why is this bad?** The test can be shorter (and likely more readable)
106 /// if the `fn main()` is left implicit.
108 /// **Known problems:** None.
112 /// /// An example of a doctest with a `main()` function
118 /// /// // this needs not be in an `fn`
121 /// fn needless_main() {
122 /// unimplemented!();
125 pub NEEDLESS_DOCTEST_MAIN,
127 "presence of `fn main() {` in code examples"
130 #[allow(clippy::module_name_repetitions)]
132 pub struct DocMarkdown {
133 valid_idents: FxHashSet<String>,
138 pub fn new(valid_idents: FxHashSet<String>) -> Self {
141 in_trait_impl: false,
146 impl_lint_pass!(DocMarkdown => [DOC_MARKDOWN, MISSING_SAFETY_DOC, MISSING_ERRORS_DOC, NEEDLESS_DOCTEST_MAIN]);
148 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
149 fn check_crate(&mut self, cx: &LateContext<'a, 'tcx>, krate: &'tcx hir::Crate) {
150 check_attrs(cx, &self.valid_idents, &krate.attrs);
153 fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item) {
154 let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
156 hir::ItemKind::Fn(ref sig, ..) => {
157 lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
159 hir::ItemKind::Impl(_, _, _, _, ref trait_ref, ..) => {
160 self.in_trait_impl = trait_ref.is_some();
166 fn check_item_post(&mut self, _cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item) {
167 if let hir::ItemKind::Impl(..) = item.kind {
168 self.in_trait_impl = false;
172 fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::TraitItem) {
173 let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
174 if let hir::TraitItemKind::Method(ref sig, ..) = item.kind {
175 lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
179 fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ImplItem) {
180 let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
181 if self.in_trait_impl {
184 if let hir::ImplItemKind::Method(ref sig, ..) = item.kind {
185 lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers);
190 fn lint_for_missing_headers<'a, 'tcx>(
191 cx: &LateContext<'a, 'tcx>,
193 span: impl Into<MultiSpan> + Copy,
197 if !cx.access_levels.is_exported(hir_id) {
198 return; // Private functions do not require doc comments
200 if !headers.safety && sig.header.unsafety == hir::Unsafety::Unsafe {
205 "unsafe function's docs miss `# Safety` section",
208 if !headers.errors && match_type(cx, return_ty(cx, hir_id), &paths::RESULT) {
213 "docs for function returning `Result` missing `# Errors` section",
218 /// Cleanup documentation decoration (`///` and such).
220 /// We can't use `syntax::attr::AttributeMethods::with_desugared_doc` or
221 /// `syntax::parse::lexer::comments::strip_doc_comment_decoration` because we
222 /// need to keep track of
223 /// the spans but this function is inspired from the later.
224 #[allow(clippy::cast_possible_truncation)]
226 pub fn strip_doc_comment_decoration(comment: &str, span: Span) -> (String, Vec<(usize, Span)>) {
227 // one-line comments lose their prefix
228 const ONELINERS: &[&str] = &["///!", "///", "//!", "//"];
229 for prefix in ONELINERS {
230 if comment.starts_with(*prefix) {
231 let doc = &comment[prefix.len()..];
232 let mut doc = doc.to_owned();
236 vec![(doc.len(), span.with_lo(span.lo() + BytePos(prefix.len() as u32)))],
241 if comment.starts_with("/*") {
242 let doc = &comment[3..comment.len() - 2];
243 let mut sizes = vec![];
244 let mut contains_initial_stars = false;
245 for line in doc.lines() {
246 let offset = line.as_ptr() as usize - comment.as_ptr() as usize;
247 debug_assert_eq!(offset as u32 as usize, offset);
248 contains_initial_stars |= line.trim_start().starts_with('*');
249 // +1 for the newline
250 sizes.push((line.len() + 1, span.with_lo(span.lo() + BytePos(offset as u32))));
252 if !contains_initial_stars {
253 return (doc.to_string(), sizes);
255 // remove the initial '*'s if any
256 let mut no_stars = String::with_capacity(doc.len());
257 for line in doc.lines() {
258 let mut chars = line.chars();
259 while let Some(c) = chars.next() {
260 if c.is_whitespace() {
263 no_stars.push(if c == '*' { ' ' } else { c });
267 no_stars.push_str(chars.as_str());
270 return (no_stars, sizes);
273 panic!("not a doc-comment: {}", comment);
276 #[derive(Copy, Clone)]
282 fn check_attrs<'a>(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String>, attrs: &'a [Attribute]) -> DocHeaders {
283 let mut doc = String::new();
284 let mut spans = vec![];
287 if let AttrKind::DocComment(ref comment) = attr.kind {
288 let comment = comment.to_string();
289 let (comment, current_spans) = strip_doc_comment_decoration(&comment, attr.span);
290 spans.extend_from_slice(¤t_spans);
291 doc.push_str(&comment);
292 } else if attr.check_name(sym!(doc)) {
293 // ignore mix of sugared and non-sugared doc
294 // don't trigger the safety or errors check
303 for &mut (ref mut offset, _) in &mut spans {
304 let offset_copy = *offset;
306 current += offset_copy;
316 let parser = pulldown_cmark::Parser::new(&doc).into_offset_iter();
317 // Iterate over all `Events` and combine consecutive events into one
318 let events = parser.coalesce(|previous, current| {
319 use pulldown_cmark::Event::*;
321 let previous_range = previous.1;
322 let current_range = current.1;
324 match (previous.0, current.0) {
325 (Text(previous), Text(current)) => {
326 let mut previous = previous.to_string();
327 previous.push_str(¤t);
328 Ok((Text(previous.into()), previous_range))
330 (previous, current) => Err(((previous, previous_range), (current, current_range))),
333 check_doc(cx, valid_idents, events, &spans)
336 fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize>)>>(
337 cx: &LateContext<'_, '_>,
338 valid_idents: &FxHashSet<String>,
340 spans: &[(usize, Span)],
342 // true if a safety header was found
343 use pulldown_cmark::Event::*;
344 use pulldown_cmark::Tag::*;
346 let mut headers = DocHeaders {
350 let mut in_code = false;
351 let mut in_link = None;
352 let mut in_heading = false;
354 for (event, range) in events {
356 Start(CodeBlock(_)) => in_code = true,
357 End(CodeBlock(_)) => in_code = false,
358 Start(Link(_, url, _)) => in_link = Some(url),
359 End(Link(..)) => in_link = None,
360 Start(Heading(_)) => in_heading = true,
361 End(Heading(_)) => in_heading = false,
362 Start(_tag) | End(_tag) => (), // We don't care about other tags
363 Html(_html) => (), // HTML is weird, just ignore it
364 SoftBreak | HardBreak | TaskListMarker(_) | Code(_) | Rule => (),
365 FootnoteReference(text) | Text(text) => {
366 if Some(&text) == in_link.as_ref() {
367 // Probably a link of the form `<http://example.com>`
368 // Which are represented as a link to "http://example.com" with
369 // text "http://example.com" by pulldown-cmark
372 headers.safety |= in_heading && text.trim() == "Safety";
373 headers.errors |= in_heading && text.trim() == "Errors";
374 let index = match spans.binary_search_by(|c| c.0.cmp(&range.start)) {
378 let (begin, span) = spans[index];
380 check_code(cx, &text, span);
382 // Adjust for the beginning of the current `Event`
383 let span = span.with_lo(span.lo() + BytePos::from_usize(range.start - begin));
385 check_text(cx, valid_idents, &text, span);
393 fn check_code(cx: &LateContext<'_, '_>, text: &str, span: Span) {
394 if text.contains("fn main() {") && !(text.contains("static") || text.contains("fn main() {}")) {
395 span_lint(cx, NEEDLESS_DOCTEST_MAIN, span, "needless `fn main` in doctest");
399 fn check_text(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String>, text: &str, span: Span) {
400 for word in text.split(|c: char| c.is_whitespace() || c == '\'') {
401 // Trim punctuation as in `some comment (see foo::bar).`
403 // Or even as in `_foo bar_` which is emphasized.
404 let word = word.trim_matches(|c: char| !c.is_alphanumeric());
406 if valid_idents.contains(word) {
410 // Adjust for the current word
411 let offset = word.as_ptr() as usize - text.as_ptr() as usize;
412 let span = Span::new(
413 span.lo() + BytePos::from_usize(offset),
414 span.lo() + BytePos::from_usize(offset + word.len()),
418 check_word(cx, word, span);
422 fn check_word(cx: &LateContext<'_, '_>, word: &str, span: Span) {
423 /// Checks if a string is camel-case, i.e., contains at least two uppercase
424 /// letters (`Clippy` is ok) and one lower-case letter (`NASA` is ok).
425 /// Plurals are also excluded (`IDs` is ok).
426 fn is_camel_case(s: &str) -> bool {
427 if s.starts_with(|c: char| c.is_digit(10)) {
431 let s = if s.ends_with('s') { &s[..s.len() - 1] } else { s };
433 s.chars().all(char::is_alphanumeric)
434 && s.chars().filter(|&c| c.is_uppercase()).take(2).count() > 1
435 && s.chars().filter(|&c| c.is_lowercase()).take(1).count() > 0
438 fn has_underscore(s: &str) -> bool {
439 s != "_" && !s.contains("\\_") && s.contains('_')
442 fn has_hyphen(s: &str) -> bool {
443 s != "-" && s.contains('-')
446 if let Ok(url) = Url::parse(word) {
447 // try to get around the fact that `foo::bar` parses as a valid URL
448 if !url.cannot_be_a_base() {
453 "you should put bare URLs between `<`/`>` or make a proper Markdown link",
460 // We assume that mixed-case words are not meant to be put inside bacticks. (Issue #2343)
461 if has_underscore(word) && has_hyphen(word) {
465 if has_underscore(word) || word.contains("::") || is_camel_case(word) {
470 &format!("you should put `{}` between ticks in the documentation", word),