src/tools/tidy/src/style.rs

   1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Tidy check to enforce various stylistic guidelines on the Rust codebase.
  12 //!
  13 //! Example checks are:
  14 //!
  15 //! * No lines over 100 characters
  16 //! * No tabs
  17 //! * No trailing whitespace
  18 //! * No CR characters
  19 //! * No `TODO` or `XXX` directives
  20 //! * A valid license header is at the top
  21 //! * No unexplained ` ```ignore ` or ` ```rust,ignore ` doc tests
  22 //!
  23 //! A number of these checks can be opted-out of with various directives like
  24 //! `// ignore-tidy-linelength`.
  25
  26 use std::fs::File;
  27 use std::io::prelude::*;
  28 use std::path::Path;
  29
  30 const COLS: usize = 100;
  31 const LICENSE: &'static str = "\
  32 Copyright <year> The Rust Project Developers. See the COPYRIGHT
  33 file at the top-level directory of this distribution and at
  34 http://rust-lang.org/COPYRIGHT.
  35
  36 Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
  37 http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
  38 <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
  39 option. This file may not be copied, modified, or distributed
  40 except according to those terms.";
  41
  42 const UNEXPLAINED_IGNORE_DOCTEST_INFO: &str = r#"unexplained "```ignore" doctest; try one:
  43
  44 * make the test actually pass, by adding necessary imports and declarations, or
  45 * use "```text", if the code is not Rust code, or
  46 * use "```compile_fail,Ennnn", if the code is expected to fail at compile time, or
  47 * use "```should_panic", if the code is expected to fail at run time, or
  48 * use "```no_run", if the code should type-check but not necessary linkable/runnable, or
  49 * explain it like "```ignore (cannot-test-this-because-xxxx)", if the annotation cannot be avoided.
  50
  51 "#;
  52
  53 /// Parser states for line_is_url.
  54 #[derive(PartialEq)]
  55 #[allow(non_camel_case_types)]
  56 enum LIUState { EXP_COMMENT_START,
  57                 EXP_LINK_LABEL_OR_URL,
  58                 EXP_URL,
  59                 EXP_END }
  60
  61 /// True if LINE appears to be a line comment containing an URL,
  62 /// possibly with a Markdown link label in front, and nothing else.
  63 /// The Markdown link label, if present, may not contain whitespace.
  64 /// Lines of this form are allowed to be overlength, because Markdown
  65 /// offers no way to split a line in the middle of a URL, and the lengths
  66 /// of URLs to external references are beyond our control.
  67 fn line_is_url(line: &str) -> bool {
  68     use self::LIUState::*;
  69     let mut state: LIUState = EXP_COMMENT_START;
  70
  71     for tok in line.split_whitespace() {
  72         match (state, tok) {
  73             (EXP_COMMENT_START, "//") => state = EXP_LINK_LABEL_OR_URL,
  74             (EXP_COMMENT_START, "///") => state = EXP_LINK_LABEL_OR_URL,
  75             (EXP_COMMENT_START, "//!") => state = EXP_LINK_LABEL_OR_URL,
  76
  77             (EXP_LINK_LABEL_OR_URL, w)
  78                 if w.len() >= 4 && w.starts_with("[") && w.ends_with("]:")
  79                 => state = EXP_URL,
  80
  81             (EXP_LINK_LABEL_OR_URL, w)
  82                 if w.starts_with("http://") || w.starts_with("https://")
  83                 => state = EXP_END,
  84
  85             (EXP_URL, w)
  86                 if w.starts_with("http://") || w.starts_with("https://")
  87                 => state = EXP_END,
  88
  89             (_, _) => return false,
  90         }
  91     }
  92
  93     state == EXP_END
  94 }
  95
  96 /// True if LINE is allowed to be longer than the normal limit.
  97 /// Currently there is only one exception, for long URLs, but more
  98 /// may be added in the future.
  99 fn long_line_is_ok(line: &str) -> bool {
 100     if line_is_url(line) {
 101         return true;
 102     }
 103
 104     false
 105 }
 106
 107 pub fn check(path: &Path, bad: &mut bool) {
 108     let mut contents = String::new();
 109     super::walk(path, &mut super::filter_dirs, &mut |file| {
 110         let filename = file.file_name().unwrap().to_string_lossy();
 111         let extensions = [".rs", ".py", ".js", ".sh", ".c", ".h"];
 112         if extensions.iter().all(|e| !filename.ends_with(e)) ||
 113            filename.starts_with(".#") {
 114             return
 115         }
 116
 117         contents.truncate(0);
 118         t!(t!(File::open(file), file).read_to_string(&mut contents));
 119
 120         if contents.is_empty() {
 121             tidy_error!(bad, "{}: empty file", file.display());
 122         }
 123
 124         let skip_cr = contents.contains("ignore-tidy-cr");
 125         let skip_tab = contents.contains("ignore-tidy-tab");
 126         let skip_length = contents.contains("ignore-tidy-linelength");
 127         let skip_end_whitespace = contents.contains("ignore-tidy-end-whitespace");
 128         for (i, line) in contents.split("\n").enumerate() {
 129             let mut err = |msg: &str| {
 130                 tidy_error!(bad, "{}:{}: {}", file.display(), i + 1, msg);
 131             };
 132             if !skip_length && line.chars().count() > COLS
 133                 && !long_line_is_ok(line) {
 134                     err(&format!("line longer than {} chars", COLS));
 135             }
 136             if line.contains("\t") && !skip_tab {
 137                 err("tab character");
 138             }
 139             if !skip_end_whitespace && (line.ends_with(" ") || line.ends_with("\t")) {
 140                 err("trailing whitespace");
 141             }
 142             if line.contains("\r") && !skip_cr {
 143                 err("CR character");
 144             }
 145             if filename != "style.rs" {
 146                 if line.contains("TODO") {
 147                     err("TODO is deprecated; use FIXME")
 148                 }
 149                 if line.contains("//") && line.contains(" XXX") {
 150                     err("XXX is deprecated; use FIXME")
 151                 }
 152             }
 153             if line.ends_with("```ignore") || line.ends_with("```rust,ignore") {
 154                 err(UNEXPLAINED_IGNORE_DOCTEST_INFO);
 155             }
 156         }
 157         if !licenseck(file, &contents) {
 158             tidy_error!(bad, "{}: incorrect license", file.display());
 159         }
 160     })
 161 }
 162
 163 fn licenseck(file: &Path, contents: &str) -> bool {
 164     if contents.contains("ignore-license") {
 165         return true
 166     }
 167     let exceptions = [
 168         "libstd/sync/mpsc/mpsc_queue.rs",
 169         "libstd/sync/mpsc/spsc_queue.rs",
 170     ];
 171     if exceptions.iter().any(|f| file.ends_with(f)) {
 172         return true
 173     }
 174
 175     // Skip the BOM if it's there
 176     let bom = "\u{feff}";
 177     let contents = if contents.starts_with(bom) {&contents[3..]} else {contents};
 178
 179     // See if the license shows up in the first 100 lines
 180     let lines = contents.lines().take(100).collect::<Vec<_>>();
 181     lines.windows(LICENSE.lines().count()).any(|window| {
 182         let offset = if window.iter().all(|w| w.starts_with("//")) {
 183             2
 184         } else if window.iter().all(|w| w.starts_with('#')) {
 185             1
 186         } else if window.iter().all(|w| w.starts_with(" *")) {
 187             2
 188         } else {
 189             return false
 190         };
 191         window.iter().map(|a| a[offset..].trim())
 192               .zip(LICENSE.lines()).all(|(a, b)| {
 193             a == b || match b.find("<year>") {
 194                 Some(i) => a.starts_with(&b[..i]) && a.ends_with(&b[i+6..]),
 195                 None => false,
 196             }
 197         })
 198     })
 199
 200 }