1 use crate::utils::span_lint;
2 use itertools::Itertools;
5 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
6 use rustc::{declare_tool_lint, impl_lint_pass};
7 use rustc_data_structures::fx::FxHashSet;
9 use syntax::ast::{AttrKind, Attribute};
10 use syntax::source_map::{BytePos, Span};
14 declare_clippy_lint! {
15 /// **What it does:** Checks for the presence of `_`, `::` or camel-case words
16 /// outside ticks in documentation.
18 /// **Why is this bad?** *Rustdoc* supports markdown formatting, `_`, `::` and
19 /// camel-case probably indicates some code which should be included between
20 /// ticks. `_` can also be used for emphasis in markdown, this lint tries to
23 /// **Known problems:** Lots of bad docs won’t be fixed, what the lint checks
24 /// for is limited, and there are still false positives.
28 /// /// Do something with the foo_bar parameter. See also
29 /// /// that::other::module::foo.
30 /// // ^ `foo_bar` and `that::other::module::foo` should be ticked.
31 /// fn doit(foo_bar: usize) {}
35 "presence of `_`, `::` or camel-case outside backticks in documentation"
38 declare_clippy_lint! {
39 /// **What it does:** Checks for the doc comments of publicly visible
40 /// unsafe functions and warns if there is no `# Safety` section.
42 /// **Why is this bad?** Unsafe functions should document their safety
43 /// preconditions, so that users can be sure they are using them safely.
45 /// **Known problems:** None.
49 ///# type Universe = ();
50 /// /// This function should really be documented
51 /// pub unsafe fn start_apocalypse(u: &mut Universe) {
56 /// At least write a line about safety:
59 ///# type Universe = ();
62 /// /// This function should not be called before the horsemen are ready.
63 /// pub unsafe fn start_apocalypse(u: &mut Universe) {
67 pub MISSING_SAFETY_DOC,
69 "`pub unsafe fn` without `# Safety` docs"
72 declare_clippy_lint! {
73 /// **What it does:** Checks for `fn main() { .. }` in doctests
75 /// **Why is this bad?** The test can be shorter (and likely more readable)
76 /// if the `fn main()` is left implicit.
78 /// **Known problems:** None.
82 /// /// An example of a doctest with a `main()` function
88 /// /// // this needs not be in an `fn`
91 /// fn needless_main() {
95 pub NEEDLESS_DOCTEST_MAIN,
97 "presence of `fn main() {` in code examples"
100 #[allow(clippy::module_name_repetitions)]
102 pub struct DocMarkdown {
103 valid_idents: FxHashSet<String>,
108 pub fn new(valid_idents: FxHashSet<String>) -> Self {
111 in_trait_impl: false,
116 impl_lint_pass!(DocMarkdown => [DOC_MARKDOWN, MISSING_SAFETY_DOC, NEEDLESS_DOCTEST_MAIN]);
118 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
119 fn check_crate(&mut self, cx: &LateContext<'a, 'tcx>, krate: &'tcx hir::Crate) {
120 check_attrs(cx, &self.valid_idents, &krate.attrs);
123 fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item) {
124 if check_attrs(cx, &self.valid_idents, &item.attrs) {
129 hir::ItemKind::Fn(ref sig, ..) => {
130 if cx.access_levels.is_exported(item.hir_id) && sig.header.unsafety == hir::Unsafety::Unsafe {
135 "unsafe function's docs miss `# Safety` section",
139 hir::ItemKind::Impl(_, _, _, _, ref trait_ref, ..) => {
140 self.in_trait_impl = trait_ref.is_some();
146 fn check_item_post(&mut self, _cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item) {
147 if let hir::ItemKind::Impl(..) = item.kind {
148 self.in_trait_impl = false;
152 fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::TraitItem) {
153 if check_attrs(cx, &self.valid_idents, &item.attrs) {
157 if let hir::TraitItemKind::Method(ref sig, ..) = item.kind {
158 if cx.access_levels.is_exported(item.hir_id) && sig.header.unsafety == hir::Unsafety::Unsafe {
163 "unsafe function's docs miss `# Safety` section",
169 fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ImplItem) {
170 if check_attrs(cx, &self.valid_idents, &item.attrs) || self.in_trait_impl {
174 if let hir::ImplItemKind::Method(ref sig, ..) = item.kind {
175 if cx.access_levels.is_exported(item.hir_id) && sig.header.unsafety == hir::Unsafety::Unsafe {
180 "unsafe function's docs miss `# Safety` section",
187 /// Cleanup documentation decoration (`///` and such).
189 /// We can't use `syntax::attr::AttributeMethods::with_desugared_doc` or
190 /// `syntax::parse::lexer::comments::strip_doc_comment_decoration` because we
191 /// need to keep track of
192 /// the spans but this function is inspired from the later.
193 #[allow(clippy::cast_possible_truncation)]
195 pub fn strip_doc_comment_decoration(comment: &str, span: Span) -> (String, Vec<(usize, Span)>) {
196 // one-line comments lose their prefix
197 const ONELINERS: &[&str] = &["///!", "///", "//!", "//"];
198 for prefix in ONELINERS {
199 if comment.starts_with(*prefix) {
200 let doc = &comment[prefix.len()..];
201 let mut doc = doc.to_owned();
205 vec![(doc.len(), span.with_lo(span.lo() + BytePos(prefix.len() as u32)))],
210 if comment.starts_with("/*") {
211 let doc = &comment[3..comment.len() - 2];
212 let mut sizes = vec![];
213 let mut contains_initial_stars = false;
214 for line in doc.lines() {
215 let offset = line.as_ptr() as usize - comment.as_ptr() as usize;
216 debug_assert_eq!(offset as u32 as usize, offset);
217 contains_initial_stars |= line.trim_start().starts_with('*');
218 // +1 for the newline
219 sizes.push((line.len() + 1, span.with_lo(span.lo() + BytePos(offset as u32))));
221 if !contains_initial_stars {
222 return (doc.to_string(), sizes);
224 // remove the initial '*'s if any
225 let mut no_stars = String::with_capacity(doc.len());
226 for line in doc.lines() {
227 let mut chars = line.chars();
228 while let Some(c) = chars.next() {
229 if c.is_whitespace() {
232 no_stars.push(if c == '*' { ' ' } else { c });
236 no_stars.push_str(chars.as_str());
239 return (no_stars, sizes);
242 panic!("not a doc-comment: {}", comment);
245 pub fn check_attrs<'a>(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String>, attrs: &'a [Attribute]) -> bool {
246 let mut doc = String::new();
247 let mut spans = vec![];
250 if let AttrKind::DocComment(ref comment) = attr.kind {
251 let comment = comment.to_string();
252 let (comment, current_spans) = strip_doc_comment_decoration(&comment, attr.span);
253 spans.extend_from_slice(¤t_spans);
254 doc.push_str(&comment);
255 } else if attr.check_name(sym!(doc)) {
256 // ignore mix of sugared and non-sugared doc
257 return true; // don't trigger the safety check
262 for &mut (ref mut offset, _) in &mut spans {
263 let offset_copy = *offset;
265 current += offset_copy;
272 let parser = pulldown_cmark::Parser::new(&doc).into_offset_iter();
273 // Iterate over all `Events` and combine consecutive events into one
274 let events = parser.coalesce(|previous, current| {
275 use pulldown_cmark::Event::*;
277 let previous_range = previous.1;
278 let current_range = current.1;
280 match (previous.0, current.0) {
281 (Text(previous), Text(current)) => {
282 let mut previous = previous.to_string();
283 previous.push_str(¤t);
284 Ok((Text(previous.into()), previous_range))
286 (previous, current) => Err(((previous, previous_range), (current, current_range))),
289 check_doc(cx, valid_idents, events, &spans)
292 fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize>)>>(
293 cx: &LateContext<'_, '_>,
294 valid_idents: &FxHashSet<String>,
296 spans: &[(usize, Span)],
298 // true if a safety header was found
299 use pulldown_cmark::Event::*;
300 use pulldown_cmark::Tag::*;
302 let mut safety_header = false;
303 let mut in_code = false;
304 let mut in_link = None;
305 let mut in_heading = false;
307 for (event, range) in events {
309 Start(CodeBlock(_)) => in_code = true,
310 End(CodeBlock(_)) => in_code = false,
311 Start(Link(_, url, _)) => in_link = Some(url),
312 End(Link(..)) => in_link = None,
313 Start(Heading(_)) => in_heading = true,
314 End(Heading(_)) => in_heading = false,
315 Start(_tag) | End(_tag) => (), // We don't care about other tags
316 Html(_html) => (), // HTML is weird, just ignore it
317 SoftBreak | HardBreak | TaskListMarker(_) | Code(_) | Rule => (),
318 FootnoteReference(text) | Text(text) => {
319 if Some(&text) == in_link.as_ref() {
320 // Probably a link of the form `<http://example.com>`
321 // Which are represented as a link to "http://example.com" with
322 // text "http://example.com" by pulldown-cmark
325 safety_header |= in_heading && text.trim() == "Safety";
326 let index = match spans.binary_search_by(|c| c.0.cmp(&range.start)) {
330 let (begin, span) = spans[index];
332 check_code(cx, &text, span);
334 // Adjust for the beginning of the current `Event`
335 let span = span.with_lo(span.lo() + BytePos::from_usize(range.start - begin));
337 check_text(cx, valid_idents, &text, span);
345 fn check_code(cx: &LateContext<'_, '_>, text: &str, span: Span) {
346 if text.contains("fn main() {") {
347 span_lint(cx, NEEDLESS_DOCTEST_MAIN, span, "needless `fn main` in doctest");
351 fn check_text(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet<String>, text: &str, span: Span) {
352 for word in text.split(|c: char| c.is_whitespace() || c == '\'') {
353 // Trim punctuation as in `some comment (see foo::bar).`
355 // Or even as in `_foo bar_` which is emphasized.
356 let word = word.trim_matches(|c: char| !c.is_alphanumeric());
358 if valid_idents.contains(word) {
362 // Adjust for the current word
363 let offset = word.as_ptr() as usize - text.as_ptr() as usize;
364 let span = Span::new(
365 span.lo() + BytePos::from_usize(offset),
366 span.lo() + BytePos::from_usize(offset + word.len()),
370 check_word(cx, word, span);
374 fn check_word(cx: &LateContext<'_, '_>, word: &str, span: Span) {
375 /// Checks if a string is camel-case, i.e., contains at least two uppercase
376 /// letters (`Clippy` is ok) and one lower-case letter (`NASA` is ok).
377 /// Plurals are also excluded (`IDs` is ok).
378 fn is_camel_case(s: &str) -> bool {
379 if s.starts_with(|c: char| c.is_digit(10)) {
383 let s = if s.ends_with('s') { &s[..s.len() - 1] } else { s };
385 s.chars().all(char::is_alphanumeric)
386 && s.chars().filter(|&c| c.is_uppercase()).take(2).count() > 1
387 && s.chars().filter(|&c| c.is_lowercase()).take(1).count() > 0
390 fn has_underscore(s: &str) -> bool {
391 s != "_" && !s.contains("\\_") && s.contains('_')
394 fn has_hyphen(s: &str) -> bool {
395 s != "-" && s.contains('-')
398 if let Ok(url) = Url::parse(word) {
399 // try to get around the fact that `foo::bar` parses as a valid URL
400 if !url.cannot_be_a_base() {
405 "you should put bare URLs between `<`/`>` or make a proper Markdown link",
412 // We assume that mixed-case words are not meant to be put inside bacticks. (Issue #2343)
413 if has_underscore(word) && has_hyphen(word) {
417 if has_underscore(word) || word.contains("::") || is_camel_case(word) {
422 &format!("you should put `{}` between ticks in the documentation", word),