src/tools/linkchecker/main.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 //! Script to check the validity of `href` links in our HTML documentation.
  12 //!
  13 //! In the past we've been quite error prone to writing in broken links as most
  14 //! of them are manually rather than automatically added. As files move over
  15 //! time or apis change old links become stale or broken. The purpose of this
  16 //! script is to check all relative links in our documentation to make sure they
  17 //! actually point to a valid place.
  18 //!
  19 //! Currently this doesn't actually do any HTML parsing or anything fancy like
  20 //! that, it just has a simple "regex" to search for `href` and `id` tags.
  21 //! These values are then translated to file URLs if possible and then the
  22 //! destination is asserted to exist.
  23 //!
  24 //! A few whitelisted exceptions are allowed as there's known bugs in rustdoc,
  25 //! but this should catch the majority of "broken link" cases.
  26
  27 extern crate url;
  28
  29 use std::env;
  30 use std::fs::File;
  31 use std::io::prelude::*;
  32 use std::path::{Path, PathBuf};
  33 use std::collections::{HashMap, HashSet};
  34 use std::collections::hash_map::Entry;
  35
  36 use url::{Url, UrlParser};
  37
  38 use Redirect::*;
  39
  40 macro_rules! t {
  41     ($e:expr) => (match $e {
  42         Ok(e) => e,
  43         Err(e) => panic!("{} failed with {:?}", stringify!($e), e),
  44     })
  45 }
  46
  47 fn main() {
  48     let docs = env::args().nth(1).unwrap();
  49     let docs = env::current_dir().unwrap().join(docs);
  50     let mut url = Url::from_file_path(&docs).unwrap();
  51     let mut errors = false;
  52     walk(&mut HashMap::new(), &docs, &docs, &mut url, &mut errors);
  53     if errors {
  54         panic!("found some broken links");
  55     }
  56 }
  57
  58 #[derive(Debug)]
  59 pub enum LoadError {
  60     IOError(std::io::Error),
  61     BrokenRedirect(PathBuf, std::io::Error),
  62     IsRedirect,
  63 }
  64
  65 enum Redirect {
  66     SkipRedirect,
  67     FromRedirect(bool),
  68 }
  69
  70 struct FileEntry {
  71     source: String,
  72     ids: HashSet<String>,
  73 }
  74
  75 type Cache = HashMap<PathBuf, FileEntry>;
  76
  77 impl FileEntry {
  78     fn parse_ids(&mut self,
  79                 file: &Path,
  80                 contents: &str,
  81                 errors: &mut bool)
  82 {
  83         if self.ids.is_empty() {
  84             with_attrs_in_source(contents, " id", |fragment, i| {
  85                 let frag = fragment.trim_left_matches("#").to_owned();
  86                 if !self.ids.insert(frag) {
  87                     *errors = true;
  88                     println!("{}:{}: id is not unique: `{}`",
  89                              file.display(), i, fragment);
  90                 }
  91             });
  92         }
  93     }
  94 }
  95
  96 fn walk(cache: &mut Cache,
  97         root: &Path,
  98         dir: &Path,
  99         url: &mut Url,
 100         errors: &mut bool)
 101 {
 102     for entry in t!(dir.read_dir()).map(|e| t!(e)) {
 103         let path = entry.path();
 104         let kind = t!(entry.file_type());
 105         url.path_mut().unwrap().push(entry.file_name().into_string().unwrap());
 106         if kind.is_dir() {
 107             walk(cache, root, &path, url, errors);
 108         } else {
 109             let pretty_path = check(cache, root, &path, url, errors);
 110             if let Some(pretty_path) = pretty_path {
 111                 let entry = cache.get_mut(&pretty_path).unwrap();
 112                 // we don't need the source anymore,
 113                 // so drop to to reduce memory-usage
 114                 entry.source = String::new();
 115             }
 116         }
 117         url.path_mut().unwrap().pop();
 118     }
 119 }
 120
 121 fn check(cache: &mut Cache,
 122          root: &Path,
 123          file: &Path,
 124          base: &Url,
 125          errors: &mut bool) -> Option<PathBuf>
 126 {
 127     // ignore js files as they are not prone to errors as the rest of the
 128     // documentation is and they otherwise bring up false positives.
 129     if file.extension().and_then(|s| s.to_str()) == Some("js") {
 130         return None;
 131     }
 132
 133     // Unfortunately we're not 100% full of valid links today to we need a few
 134     // whitelists to get this past `make check` today.
 135     // FIXME(#32129)
 136     if file.ends_with("std/string/struct.String.html") {
 137         return None;
 138     }
 139     // FIXME(#32553)
 140     if file.ends_with("collections/string/struct.String.html") {
 141         return None;
 142     }
 143     // FIXME(#32130)
 144     if file.ends_with("btree_set/struct.BTreeSet.html") ||
 145        file.ends_with("collections/struct.BTreeSet.html") ||
 146        file.ends_with("collections/btree_map/struct.BTreeMap.html") ||
 147        file.ends_with("collections/hash_map/struct.HashMap.html") {
 148         return None;
 149     }
 150
 151     if file.ends_with("std/sys/ext/index.html") {
 152         return None;
 153     }
 154
 155     if let Some(file) = file.to_str() {
 156         // FIXME(#31948)
 157         if file.contains("ParseFloatError") {
 158             return None;
 159         }
 160         // weird reexports, but this module is on its way out, so chalk it up to
 161         // "rustdoc weirdness" and move on from there
 162         if file.contains("scoped_tls") {
 163             return None;
 164         }
 165     }
 166
 167     let mut parser = UrlParser::new();
 168     parser.base_url(base);
 169
 170     let res = load_file(cache, root, PathBuf::from(file), SkipRedirect);
 171     let (pretty_file, contents) = match res {
 172         Ok(res) => res,
 173         Err(_) => return None,
 174     };
 175     {
 176         cache.get_mut(&pretty_file).unwrap()
 177                                    .parse_ids(&pretty_file, &contents, errors);
 178     }
 179
 180     // Search for anything that's the regex 'href[ ]*=[ ]*".*?"'
 181     with_attrs_in_source(&contents, " href", |url, i| {
 182         // Once we've plucked out the URL, parse it using our base url and
 183         // then try to extract a file path. If either of these fail then we
 184         // just keep going.
 185         let (parsed_url, path) = match url_to_file_path(&parser, url) {
 186             Some((url, path)) => (url, PathBuf::from(path)),
 187             None => return,
 188         };
 189
 190         // Alright, if we've found a file name then this file had better
 191         // exist! If it doesn't then we register and print an error.
 192         if path.exists() {
 193             if path.is_dir() {
 194                 return;
 195             }
 196             let res = load_file(cache, root, path.clone(), FromRedirect(false));
 197             let (pretty_path, contents) = match res {
 198                 Ok(res) => res,
 199                 Err(LoadError::IOError(err)) => panic!(format!("{}", err)),
 200                 Err(LoadError::BrokenRedirect(target, _)) => {
 201                     print!("{}:{}: broken redirect to {}",
 202                            pretty_file.display(), i + 1, target.display());
 203                     return;
 204                 }
 205                 Err(LoadError::IsRedirect) => unreachable!(),
 206             };
 207
 208             if let Some(ref fragment) = parsed_url.fragment {
 209                 // Fragments like `#1-6` are most likely line numbers to be
 210                 // interpreted by javascript, so we're ignoring these
 211                 if fragment.splitn(2, '-')
 212                            .all(|f| f.chars().all(|c| c.is_numeric())) {
 213                     return;
 214                 }
 215
 216                 let entry = &mut cache.get_mut(&pretty_path).unwrap();
 217                 entry.parse_ids(&pretty_path, &contents, errors);
 218
 219                 if !entry.ids.contains(fragment) {
 220                     *errors = true;
 221                     print!("{}:{}: broken link fragment  ",
 222                            pretty_file.display(), i + 1);
 223                     println!("`#{}` pointing to `{}`",
 224                              fragment, pretty_path.display());
 225                 };
 226             }
 227         } else {
 228             *errors = true;
 229             print!("{}:{}: broken link - ", pretty_file.display(), i + 1);
 230             let pretty_path = path.strip_prefix(root).unwrap_or(&path);
 231             println!("{}", pretty_path.display());
 232         }
 233     });
 234     Some(pretty_file)
 235 }
 236
 237 fn load_file(cache: &mut Cache,
 238              root: &Path,
 239              file: PathBuf,
 240              redirect: Redirect) -> Result<(PathBuf, String), LoadError> {
 241     let mut contents = String::new();
 242     let pretty_file = PathBuf::from(file.strip_prefix(root).unwrap_or(&file));
 243
 244     let maybe_redirect = match cache.entry(pretty_file.clone()) {
 245         Entry::Occupied(entry) => {
 246             contents = entry.get().source.clone();
 247             None
 248         },
 249         Entry::Vacant(entry) => {
 250             let mut fp = try!(File::open(file.clone()).map_err(|err| {
 251                 if let FromRedirect(true) = redirect {
 252                     LoadError::BrokenRedirect(file.clone(), err)
 253                 } else {
 254                     LoadError::IOError(err)
 255                 }
 256             }));
 257             try!(fp.read_to_string(&mut contents)
 258                    .map_err(|err| LoadError::IOError(err)));
 259
 260             let maybe = maybe_redirect(&contents);
 261             if maybe.is_some() {
 262                 if let SkipRedirect = redirect {
 263                     return Err(LoadError::IsRedirect);
 264                 }
 265             } else {
 266                 entry.insert(FileEntry {
 267                     source: contents.clone(),
 268                     ids: HashSet::new(),
 269                 });
 270             }
 271             maybe
 272         },
 273     };
 274     let base = Url::from_file_path(&file).unwrap();
 275     let mut parser = UrlParser::new();
 276     parser.base_url(&base);
 277
 278     match maybe_redirect.and_then(|url| url_to_file_path(&parser, &url)) {
 279         Some((_, redirect_file)) => {
 280             let path = PathBuf::from(redirect_file);
 281             load_file(cache, root, path, FromRedirect(true))
 282         }
 283         None => Ok((pretty_file, contents))
 284     }
 285 }
 286
 287 fn maybe_redirect(source: &str) -> Option<String> {
 288     const REDIRECT: &'static str = "<p>Redirecting to <a href=";
 289
 290     let mut lines = source.lines();
 291     let redirect_line = match lines.nth(6) {
 292         Some(l) => l,
 293         None => return None,
 294     };
 295
 296     redirect_line.find(REDIRECT).map(|i| {
 297         let rest = &redirect_line[(i + REDIRECT.len() + 1)..];
 298         let pos_quote = rest.find('"').unwrap();
 299         rest[..pos_quote].to_owned()
 300     })
 301 }
 302
 303 fn url_to_file_path(parser: &UrlParser, url: &str) -> Option<(Url, PathBuf)> {
 304     parser.parse(url).ok().and_then(|parsed_url| {
 305         parsed_url.to_file_path().ok().map(|f| (parsed_url, f))
 306     })
 307 }
 308
 309 fn with_attrs_in_source<F: FnMut(&str, usize)>(contents: &str,
 310                                                attr: &str,
 311                                                mut f: F)
 312 {
 313     for (i, mut line) in contents.lines().enumerate() {
 314         while let Some(j) = line.find(attr) {
 315             let rest = &line[j + attr.len() ..];
 316             line = rest;
 317             let pos_equals = match rest.find("=") {
 318                 Some(i) => i,
 319                 None => continue,
 320             };
 321             if rest[..pos_equals].trim_left_matches(" ") != "" {
 322                 continue
 323             }
 324
 325             let rest = &rest[pos_equals + 1..];
 326
 327             let pos_quote = match rest.find(&['"', '\''][..]) {
 328                 Some(i) => i,
 329                 None => continue,
 330             };
 331             let quote_delim = rest.as_bytes()[pos_quote] as char;
 332
 333             if rest[..pos_quote].trim_left_matches(" ") != "" {
 334                 continue
 335             }
 336             let rest = &rest[pos_quote + 1..];
 337             let url = match rest.find(quote_delim) {
 338                 Some(i) => &rest[..i],
 339                 None => continue,
 340             };
 341             f(url, i)
 342         }
 343     }
 344 }