rust_code_analysis_code_split/
comment_rm.rs

1use std::io::{self, Write};
2use std::path::PathBuf;
3
4use crate::checker::Checker;
5
6use crate::tools::*;
7use crate::traits::*;
8
9const CR: [u8; 8192] = [b'\n'; 8192];
10
11/// Removes comments from a code.
12pub fn rm_comments<T: ParserTrait>(parser: &T) -> Option<Vec<u8>> {
13    let node = parser.get_root();
14    let mut stack = Vec::new();
15    let mut cursor = node.cursor();
16    let mut spans = Vec::new();
17
18    stack.push(node);
19
20    while let Some(node) = stack.pop() {
21        if T::Checker::is_comment(&node) && !T::Checker::is_useful_comment(&node, parser.get_code())
22        {
23            let lines = node.end_row() - node.start_row();
24            spans.push((node.start_byte(), node.end_byte(), lines));
25        } else {
26            cursor.reset(&node);
27            if cursor.goto_first_child() {
28                loop {
29                    stack.push(cursor.node());
30                    if !cursor.goto_next_sibling() {
31                        break;
32                    }
33                }
34            }
35        }
36    }
37    if !spans.is_empty() {
38        Some(remove_from_code(parser.get_code(), spans))
39    } else {
40        None
41    }
42}
43
44fn remove_from_code(code: &[u8], mut spans: Vec<(usize, usize, usize)>) -> Vec<u8> {
45    let mut new_code = Vec::with_capacity(code.len());
46    let mut code_start = 0;
47    for (start, end, lines) in spans.drain(..).rev() {
48        new_code.extend(&code[code_start..start]);
49        if lines != 0 {
50            if lines <= CR.len() {
51                new_code.extend(&CR[..lines]);
52            } else {
53                new_code.resize_with(new_code.len() + lines, || b'\n');
54            }
55        }
56        code_start = end;
57    }
58    if code_start < code.len() {
59        new_code.extend(&code[code_start..]);
60    }
61    new_code
62}
63
64/// Configuration options for removing comments from a code.
65#[derive(Debug)]
66pub struct CommentRmCfg {
67    /// If `true`, the modified code is saved on a file
68    pub in_place: bool,
69    /// Path to output file
70    pub path: PathBuf,
71}
72
73pub struct CommentRm {
74    _guard: (),
75}
76
77impl Callback for CommentRm {
78    type Res = std::io::Result<()>;
79    type Cfg = CommentRmCfg;
80
81    fn call<T: ParserTrait>(cfg: Self::Cfg, parser: &T) -> Self::Res {
82        if let Some(new_source) = rm_comments(parser) {
83            if cfg.in_place {
84                write_file(&cfg.path, &new_source)?;
85            } else if let Ok(new_source) = std::str::from_utf8(&new_source) {
86                println!("{new_source}");
87            } else {
88                io::stdout().write_all(&new_source)?;
89            }
90        }
91        Ok(())
92    }
93}
94
95#[cfg(test)]
96mod tests {
97    use std::path::PathBuf;
98
99    use crate::{CcommentParser, ParserTrait};
100
101    use super::rm_comments;
102
103    const SOURCE_CODE: &str = "/* Remove this code block */\n\
104                               int a = 42; // Remove this comment\n\
105                               // Remove this comment\n\
106                               int b = 42;\n\
107                               /* Remove\n\
108                                * this\n\
109                                * comment\n\
110                                */";
111
112    const SOURCE_CODE_NO_COMMENTS: &str = "\n\
113                                           int a = 42; \n\
114                                           \n\
115                                           int b = 42;\n\
116                                           \n\
117                                           \n\
118                                           \n\
119                                           \n";
120
121    #[test]
122    fn ccomment_remove_comments() {
123        let path = PathBuf::from("foo.c");
124        let mut trimmed_bytes = SOURCE_CODE.as_bytes().to_vec();
125        trimmed_bytes.push(b'\n');
126        let parser = CcommentParser::new(trimmed_bytes, &path, None);
127
128        let no_comments = rm_comments(&parser).unwrap();
129
130        assert_eq!(no_comments.as_slice(), SOURCE_CODE_NO_COMMENTS.as_bytes());
131    }
132}
rust_code_analysis_code_split/comment_rm.rs

rust_code_analysis_code_split/
comment_rm.rs
