rust/clippy_lints/src/doc.rs
2017-03-21 00:22:19 +01:00

410 lines
14 KiB
Rust
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

use rustc::lint::*;
use syntax::ast;
use syntax::codemap::{Span, BytePos};
use utils::span_lint;
/// **What it does:** Checks for the presence of `_`, `::` or camel-case words
/// outside ticks in documentation.
///
/// **Why is this bad?** *Rustdoc* supports markdown formatting, `_`, `::` and
/// camel-case probably indicates some code which should be included between
/// ticks. `_` can also be used for empasis in markdown, this lint tries to
/// consider that.
///
/// **Known problems:** Lots of bad docs wont be fixed, what the lint checks
/// for is limited, and there are still false positives.
///
/// **Examples:**
/// ```rust
/// /// Do something with the foo_bar parameter. See also that::other::module::foo.
/// // ^ `foo_bar` and `that::other::module::foo` should be ticked.
/// fn doit(foo_bar) { .. }
/// ```
declare_lint! {
pub DOC_MARKDOWN,
Warn,
"presence of `_`, `::` or camel-case outside backticks in documentation"
}
#[derive(Clone)]
pub struct Doc {
valid_idents: Vec<String>,
}
impl Doc {
pub fn new(valid_idents: Vec<String>) -> Self {
Doc { valid_idents: valid_idents }
}
}
impl LintPass for Doc {
fn get_lints(&self) -> LintArray {
lint_array![DOC_MARKDOWN]
}
}
impl EarlyLintPass for Doc {
fn check_crate(&mut self, cx: &EarlyContext, krate: &ast::Crate) {
check_attrs(cx, &self.valid_idents, &krate.attrs);
}
fn check_item(&mut self, cx: &EarlyContext, item: &ast::Item) {
check_attrs(cx, &self.valid_idents, &item.attrs);
}
}
/// Cleanup documentation decoration (`///` and such).
///
/// We can't use `syntax::attr::AttributeMethods::with_desugared_doc` or
/// `syntax::parse::lexer::comments::strip_doc_comment_decoration` because we need to keep track of
/// the span but this function is inspired from the later.
#[allow(cast_possible_truncation)]
pub fn strip_doc_comment_decoration((comment, span): (String, Span)) -> Vec<(String, Span)> {
// one-line comments lose their prefix
const ONELINERS: &'static [&'static str] = &["///!", "///", "//!", "//"];
for prefix in ONELINERS {
if comment.starts_with(*prefix) {
return vec![(comment[prefix.len()..].to_owned(),
Span { lo: span.lo + BytePos(prefix.len() as u32), ..span })];
}
}
if comment.starts_with("/*") {
return comment[3..comment.len() - 2]
.lines()
.map(|line| {
let offset = line.as_ptr() as usize - comment.as_ptr() as usize;
debug_assert_eq!(offset as u32 as usize, offset);
(line.to_owned(), Span { lo: span.lo + BytePos(offset as u32), ..span })
})
.collect();
}
panic!("not a doc-comment: {}", comment);
}
pub fn check_attrs<'a>(cx: &EarlyContext, valid_idents: &[String], attrs: &'a [ast::Attribute]) {
let mut docs = vec![];
for attr in attrs {
if attr.is_sugared_doc {
if let Some(ref doc) = attr.value_str() {
let doc = (*doc.as_str()).to_owned();
docs.extend_from_slice(&strip_doc_comment_decoration((doc, attr.span)));
}
}
}
if !docs.is_empty() {
let _ = check_doc(cx, valid_idents, &docs);
}
}
#[allow(while_let_loop)] // #362
fn check_doc(cx: &EarlyContext, valid_idents: &[String], docs: &[(String, Span)]) -> Result<(), ()> {
// In markdown, `_` can be used to emphasize something, or, is a raw `_` depending on context.
// There really is no markdown specification that would disambiguate this properly. This is
// what GitHub and Rustdoc do:
//
// foo_bar test_quz → foo_bar test_quz
// foo_bar_baz → foo_bar_baz (note that the “official” spec says this should be emphasized)
// _foo bar_ test_quz_ → <em>foo bar</em> test_quz_
// \_foo bar\_ → _foo bar_
// (_baz_) → (<em>baz</em>)
// foo _ bar _ baz → foo _ bar _ baz
/// Character that can appear in a path
fn is_path_char(c: char) -> bool {
match c {
t if t.is_alphanumeric() => true,
':' | '_' => true,
_ => false,
}
}
#[derive(Clone, Debug)]
/// This type is used to iterate through the documentation characters, keeping the span at the
/// same time.
struct Parser<'a> {
/// First byte of the current potential match
current_word_begin: usize,
/// List of lines and their associated span
docs: &'a [(String, Span)],
/// Index of the current line we are parsing
line: usize,
/// Whether we are in a link
link: bool,
/// Whether we are at the beginning of a line
new_line: bool,
/// Whether we were to the end of a line last time `next` was called
reset: bool,
/// The position of the current character within the current line
pos: usize,
}
impl<'a> Parser<'a> {
fn advance_begin(&mut self) {
self.current_word_begin = self.pos;
}
fn line(&self) -> (&'a str, Span) {
let (ref doc, span) = self.docs[self.line];
(doc, span)
}
fn peek(&self) -> Option<char> {
self.line().0[self.pos..].chars().next()
}
#[allow(while_let_on_iterator)] // borrowck complains about for
fn jump_to(&mut self, n: char) -> Result<bool, ()> {
while let Some((new_line, c)) = self.next() {
if c == n {
self.advance_begin();
return Ok(new_line);
}
}
Err(())
}
fn next_line(&mut self) {
self.pos = 0;
self.current_word_begin = 0;
self.line += 1;
self.new_line = true;
}
fn put_back(&mut self, c: char) {
self.pos -= c.len_utf8();
}
#[allow(cast_possible_truncation)]
fn word(&self) -> (&'a str, Span) {
let begin = self.current_word_begin;
let end = self.pos;
debug_assert_eq!(end as u32 as usize, end);
debug_assert_eq!(begin as u32 as usize, begin);
let (doc, mut span) = self.line();
span.hi = span.lo + BytePos(end as u32);
span.lo = span.lo + BytePos(begin as u32);
(&doc[begin..end], span)
}
}
impl<'a> Iterator for Parser<'a> {
type Item = (bool, char);
fn next(&mut self) -> Option<(bool, char)> {
while self.line < self.docs.len() {
if self.reset {
self.line += 1;
self.reset = false;
self.pos = 0;
self.current_word_begin = 0;
}
let mut chars = self.line().0[self.pos..].chars();
let c = chars.next();
if let Some(c) = c {
self.pos += c.len_utf8();
let new_line = self.new_line;
self.new_line = c == '\n' || (self.new_line && c.is_whitespace());
return Some((new_line, c));
} else if self.line == self.docs.len() - 1 {
return None;
} else {
self.new_line = true;
self.reset = true;
self.pos += 1;
return Some((true, '\n'));
}
}
None
}
}
let mut parser = Parser {
current_word_begin: 0,
docs: docs,
line: 0,
link: false,
new_line: true,
reset: false,
pos: 0,
};
/// Check for fanced code block.
macro_rules! check_block {
($parser:expr, $c:tt, $new_line:expr) => {{
check_block!($parser, $c, $c, $new_line)
}};
($parser:expr, $c:pat, $c_expr:expr, $new_line:expr) => {{
fn check_block(parser: &mut Parser, new_line: bool) -> Result<bool, ()> {
if new_line {
let mut lookup_parser = parser.clone();
if let (Some((false, $c)), Some((false, $c))) = (lookup_parser.next(), lookup_parser.next()) {
*parser = lookup_parser;
// 3 or more ` or ~ open a code block to be closed with the same number of ` or ~
let mut open_count = 3;
while let Some((false, $c)) = parser.next() {
open_count += 1;
}
loop {
loop {
if try!(parser.jump_to($c_expr)) {
break;
}
}
lookup_parser = parser.clone();
let a = lookup_parser.next();
let b = lookup_parser.next();
if let (Some((false, $c)), Some((false, $c))) = (a, b) {
let mut close_count = 3;
while let Some((false, $c)) = lookup_parser.next() {
close_count += 1;
}
if close_count == open_count {
*parser = lookup_parser;
return Ok(true);
}
}
}
}
}
Ok(false)
}
check_block(&mut $parser, $new_line)
}};
}
loop {
match parser.next() {
Some((new_line, c)) => {
match c {
'#' if new_line => {
// dont warn on titles
parser.next_line();
},
'`' => {
if try!(check_block!(parser, '`', new_line)) {
continue;
}
// not a code block, just inline code
try!(parser.jump_to('`'));
},
'~' => {
if try!(check_block!(parser, '~', new_line)) {
continue;
}
// ~ does not introduce inline code, but two of them introduce
// strikethrough. Too bad for the consistency but we don't care about
// strikethrough.
},
'[' => {
// Check for a reference definition `[foo]:` at the beginning of a line
let mut link = true;
if new_line {
let mut lookup_parser = parser.clone();
if lookup_parser.any(|(_, c)| c == ']') {
if let Some((_, ':')) = lookup_parser.next() {
lookup_parser.next_line();
parser = lookup_parser;
link = false;
}
}
}
parser.advance_begin();
parser.link = link;
},
']' if parser.link => {
parser.link = false;
match parser.peek() {
Some('(') => {
try!(parser.jump_to(')'));
},
Some('[') => {
try!(parser.jump_to(']'));
},
Some(_) => continue,
None => return Err(()),
}
},
c if !is_path_char(c) => {
parser.advance_begin();
},
_ => {
if let Some((_, c)) = parser.find(|&(_, c)| !is_path_char(c)) {
parser.put_back(c);
}
let (word, span) = parser.word();
check_word(cx, valid_idents, word, span);
parser.advance_begin();
},
}
},
None => break,
}
}
Ok(())
}
fn check_word(cx: &EarlyContext, valid_idents: &[String], word: &str, span: Span) {
/// Checks if a string a camel-case, ie. contains at least two uppercase letter (`Clippy` is
/// ok) and one lower-case letter (`NASA` is ok). Plural are also excluded (`IDs` is ok).
fn is_camel_case(s: &str) -> bool {
if s.starts_with(|c: char| c.is_digit(10)) {
return false;
}
let s = if s.ends_with('s') {
&s[..s.len() - 1]
} else {
s
};
s.chars().all(char::is_alphanumeric) && s.chars().filter(|&c| c.is_uppercase()).take(2).count() > 1 &&
s.chars().filter(|&c| c.is_lowercase()).take(1).count() > 0
}
fn has_underscore(s: &str) -> bool {
s != "_" && !s.contains("\\_") && s.contains('_')
}
// Trim punctuation as in `some comment (see foo::bar).`
// ^^
// Or even as in `_foo bar_` which is emphasized.
let word = word.trim_matches(|c: char| !c.is_alphanumeric());
if valid_idents.iter().any(|i| i == word) {
return;
}
if has_underscore(word) || word.contains("::") || is_camel_case(word) {
span_lint(cx,
DOC_MARKDOWN,
span,
&format!("you should put `{}` between ticks in the documentation", word));
}
}