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pub use CommentStyle::*;
use crate::ast;
use rustc_span::source_map::SourceMap;
use rustc_span::{BytePos, CharPos, FileName, Pos};
use log::debug;
#[cfg(test)]
mod tests;
#[derive(Clone, Copy, PartialEq, Debug)]
pub enum CommentStyle {
Isolated,
Trailing,
Mixed,
BlankLine,
}
#[derive(Clone)]
pub struct Comment {
pub style: CommentStyle,
pub lines: Vec<String>,
pub pos: BytePos,
}
pub fn is_line_doc_comment(s: &str) -> bool {
let res = (s.starts_with("///") && *s.as_bytes().get(3).unwrap_or(&b' ') != b'/')
|| s.starts_with("//!");
debug!("is {:?} a doc comment? {}", s, res);
res
}
pub fn is_block_doc_comment(s: &str) -> bool {
let res = ((s.starts_with("/**") && *s.as_bytes().get(3).unwrap_or(&b' ') != b'*')
|| s.starts_with("/*!"))
&& s.len() >= 5;
debug!("is {:?} a doc comment? {}", s, res);
res
}
pub fn is_doc_comment(s: &str) -> bool {
(s.starts_with("///") && is_line_doc_comment(s))
|| s.starts_with("//!")
|| (s.starts_with("/**") && is_block_doc_comment(s))
|| s.starts_with("/*!")
}
pub fn doc_comment_style(comment: &str) -> ast::AttrStyle {
assert!(is_doc_comment(comment));
if comment.starts_with("//!") || comment.starts_with("/*!") {
ast::AttrStyle::Inner
} else {
ast::AttrStyle::Outer
}
}
pub fn strip_doc_comment_decoration(comment: &str) -> String {
fn vertical_trim(lines: Vec<String>) -> Vec<String> {
let mut i = 0;
let mut j = lines.len();
if !lines.is_empty() && lines[0].chars().all(|c| c == '*') {
i += 1;
}
while i < j && lines[i].trim().is_empty() {
i += 1;
}
if j > i && lines[j - 1].chars().skip(1).all(|c| c == '*') {
j -= 1;
}
while j > i && lines[j - 1].trim().is_empty() {
j -= 1;
}
lines[i..j].to_vec()
}
fn horizontal_trim(lines: Vec<String>) -> Vec<String> {
let mut i = usize::MAX;
let mut can_trim = true;
let mut first = true;
for line in &lines {
for (j, c) in line.chars().enumerate() {
if j > i || !"* \t".contains(c) {
can_trim = false;
break;
}
if c == '*' {
if first {
i = j;
first = false;
} else if i != j {
can_trim = false;
}
break;
}
}
if i >= line.len() {
can_trim = false;
}
if !can_trim {
break;
}
}
if can_trim {
lines.iter().map(|line| (&line[i + 1..line.len()]).to_string()).collect()
} else {
lines
}
}
const ONELINERS: &[&str] = &["///!", "///", "//!", "//"];
for prefix in ONELINERS {
if comment.starts_with(*prefix) {
return (&comment[prefix.len()..]).to_string();
}
}
if comment.starts_with("/*") {
let lines =
comment[3..comment.len() - 2].lines().map(|s| s.to_string()).collect::<Vec<String>>();
let lines = vertical_trim(lines);
let lines = horizontal_trim(lines);
return lines.join("\n");
}
panic!("not a doc-comment: {}", comment);
}
fn all_whitespace(s: &str, col: CharPos) -> Option<usize> {
let mut idx = 0;
for (i, ch) in s.char_indices().take(col.to_usize()) {
if !ch.is_whitespace() {
return None;
}
idx = i + ch.len_utf8();
}
Some(idx)
}
fn trim_whitespace_prefix(s: &str, col: CharPos) -> &str {
let len = s.len();
match all_whitespace(&s, col) {
Some(col) => {
if col < len {
&s[col..]
} else {
""
}
}
None => s,
}
}
fn split_block_comment_into_lines(text: &str, col: CharPos) -> Vec<String> {
let mut res: Vec<String> = vec![];
let mut lines = text.lines();
res.extend(lines.next().map(|it| it.to_string()));
for line in lines {
res.push(trim_whitespace_prefix(line, col).to_string())
}
res
}
pub fn gather_comments(sm: &SourceMap, path: FileName, src: String) -> Vec<Comment> {
let sm = SourceMap::new(sm.path_mapping().clone());
let source_file = sm.new_source_file(path, src);
let text = (*source_file.src.as_ref().unwrap()).clone();
let text: &str = text.as_str();
let start_bpos = source_file.start_pos;
let mut pos = 0;
let mut comments: Vec<Comment> = Vec::new();
let mut code_to_the_left = false;
if let Some(shebang_len) = rustc_lexer::strip_shebang(text) {
comments.push(Comment {
style: Isolated,
lines: vec![text[..shebang_len].to_string()],
pos: start_bpos,
});
pos += shebang_len;
}
for token in rustc_lexer::tokenize(&text[pos..]) {
let token_text = &text[pos..pos + token.len];
match token.kind {
rustc_lexer::TokenKind::Whitespace => {
if let Some(mut idx) = token_text.find('\n') {
code_to_the_left = false;
while let Some(next_newline) = &token_text[idx + 1..].find('\n') {
idx = idx + 1 + next_newline;
comments.push(Comment {
style: BlankLine,
lines: vec![],
pos: start_bpos + BytePos((pos + idx) as u32),
});
}
}
}
rustc_lexer::TokenKind::BlockComment { terminated: _ } => {
if !is_block_doc_comment(token_text) {
let code_to_the_right = match text[pos + token.len..].chars().next() {
Some('\r') | Some('\n') => false,
_ => true,
};
let style = match (code_to_the_left, code_to_the_right) {
(true, true) | (false, true) => Mixed,
(false, false) => Isolated,
(true, false) => Trailing,
};
let pos_in_file = start_bpos + BytePos(pos as u32);
let line_begin_in_file = source_file.line_begin_pos(pos_in_file);
let line_begin_pos = (line_begin_in_file - start_bpos).to_usize();
let col = CharPos(text[line_begin_pos..pos].chars().count());
let lines = split_block_comment_into_lines(token_text, col);
comments.push(Comment { style, lines, pos: pos_in_file })
}
}
rustc_lexer::TokenKind::LineComment => {
if !is_doc_comment(token_text) {
comments.push(Comment {
style: if code_to_the_left { Trailing } else { Isolated },
lines: vec![token_text.to_string()],
pos: start_bpos + BytePos(pos as u32),
})
}
}
_ => {
code_to_the_left = true;
}
}
pos += token.len;
}
comments
}