src/tools/rustfmt/src/lib.rs

   1 #![feature(rustc_private)]
   2 #![deny(rust_2018_idioms)]
   3 #![warn(unreachable_pub)]
   4 #![recursion_limit = "256"]
   5 #![allow(clippy::match_like_matches_macro)]
   6
   7 #[macro_use]
   8 extern crate derive_new;
   9 #[cfg(test)]
  10 #[macro_use]
  11 extern crate lazy_static;
  12 #[macro_use]
  13 extern crate log;
  14
  15 // N.B. these crates are loaded from the sysroot, so they need extern crate.
  16 extern crate rustc_ast;
  17 extern crate rustc_ast_pretty;
  18 extern crate rustc_data_structures;
  19 extern crate rustc_errors;
  20 extern crate rustc_expand;
  21 extern crate rustc_parse;
  22 extern crate rustc_session;
  23 extern crate rustc_span;
  24
  25 use std::cell::RefCell;
  26 use std::collections::HashMap;
  27 use std::fmt;
  28 use std::io::{self, Write};
  29 use std::mem;
  30 use std::panic;
  31 use std::path::PathBuf;
  32 use std::rc::Rc;
  33
  34 use rustc_ast::ast;
  35 use rustc_span::symbol;
  36 use thiserror::Error;
  37
  38 use crate::comment::LineClasses;
  39 use crate::emitter::Emitter;
  40 use crate::formatting::{FormatErrorMap, FormattingError, ReportedErrors, SourceFile};
  41 use crate::issues::Issue;
  42 use crate::modules::ModuleResolutionError;
  43 use crate::shape::Indent;
  44 use crate::syntux::parser::DirectoryOwnership;
  45 use crate::utils::indent_next_line;
  46
  47 pub use crate::config::{
  48     load_config, CliOptions, Color, Config, Edition, EmitMode, FileLines, FileName, NewlineStyle,
  49     Range, Verbosity,
  50 };
  51
  52 pub use crate::format_report_formatter::{FormatReportFormatter, FormatReportFormatterBuilder};
  53
  54 pub use crate::rustfmt_diff::{ModifiedChunk, ModifiedLines};
  55
  56 #[macro_use]
  57 mod utils;
  58
  59 mod attr;
  60 mod chains;
  61 mod closures;
  62 mod comment;
  63 pub(crate) mod config;
  64 mod coverage;
  65 mod emitter;
  66 mod expr;
  67 mod format_report_formatter;
  68 pub(crate) mod formatting;
  69 mod ignore_path;
  70 mod imports;
  71 mod issues;
  72 mod items;
  73 mod lists;
  74 mod macros;
  75 mod matches;
  76 mod missed_spans;
  77 pub(crate) mod modules;
  78 mod overflow;
  79 mod pairs;
  80 mod patterns;
  81 mod release_channel;
  82 mod reorder;
  83 mod rewrite;
  84 pub(crate) mod rustfmt_diff;
  85 mod shape;
  86 mod skip;
  87 pub(crate) mod source_file;
  88 pub(crate) mod source_map;
  89 mod spanned;
  90 mod stmt;
  91 mod string;
  92 mod syntux;
  93 #[cfg(test)]
  94 mod test;
  95 mod types;
  96 mod vertical;
  97 pub(crate) mod visitor;
  98
  99 /// The various errors that can occur during formatting. Note that not all of
 100 /// these can currently be propagated to clients.
 101 #[derive(Error, Debug)]
 102 pub enum ErrorKind {
 103     /// Line has exceeded character limit (found, maximum).
 104     #[error(
 105         "line formatted, but exceeded maximum width \
 106          (maximum: {1} (see `max_width` option), found: {0})"
 107     )]
 108     LineOverflow(usize, usize),
 109     /// Line ends in whitespace.
 110     #[error("left behind trailing whitespace")]
 111     TrailingWhitespace,
 112     /// TODO or FIXME item without an issue number.
 113     #[error("found {0}")]
 114     BadIssue(Issue),
 115     /// License check has failed.
 116     #[error("license check failed")]
 117     LicenseCheck,
 118     /// Used deprecated skip attribute.
 119     #[error("`rustfmt_skip` is deprecated; use `rustfmt::skip`")]
 120     DeprecatedAttr,
 121     /// Used a rustfmt:: attribute other than skip or skip::macros.
 122     #[error("invalid attribute")]
 123     BadAttr,
 124     /// An io error during reading or writing.
 125     #[error("io error: {0}")]
 126     IoError(io::Error),
 127     /// Error during module resolution.
 128     #[error("{0}")]
 129     ModuleResolutionError(#[from] ModuleResolutionError),
 130     /// Parse error occurred when parsing the input.
 131     #[error("parse error")]
 132     ParseError,
 133     /// The user mandated a version and the current version of Rustfmt does not
 134     /// satisfy that requirement.
 135     #[error("version mismatch")]
 136     VersionMismatch,
 137     /// If we had formatted the given node, then we would have lost a comment.
 138     #[error("not formatted because a comment would be lost")]
 139     LostComment,
 140     /// Invalid glob pattern in `ignore` configuration option.
 141     #[error("Invalid glob pattern found in ignore list: {0}")]
 142     InvalidGlobPattern(ignore::Error),
 143 }
 144
 145 impl ErrorKind {
 146     fn is_comment(&self) -> bool {
 147         matches!(self, ErrorKind::LostComment)
 148     }
 149 }
 150
 151 impl From<io::Error> for ErrorKind {
 152     fn from(e: io::Error) -> ErrorKind {
 153         ErrorKind::IoError(e)
 154     }
 155 }
 156
 157 /// Result of formatting a snippet of code along with ranges of lines that didn't get formatted,
 158 /// i.e., that got returned as they were originally.
 159 #[derive(Debug)]
 160 struct FormattedSnippet {
 161     snippet: String,
 162     non_formatted_ranges: Vec<(usize, usize)>,
 163 }
 164
 165 impl FormattedSnippet {
 166     /// In case the snippet needed to be wrapped in a function, this shifts down the ranges of
 167     /// non-formatted code.
 168     fn unwrap_code_block(&mut self) {
 169         self.non_formatted_ranges
 170             .iter_mut()
 171             .for_each(|(low, high)| {
 172                 *low -= 1;
 173                 *high -= 1;
 174             });
 175     }
 176
 177     /// Returns `true` if the line n did not get formatted.
 178     fn is_line_non_formatted(&self, n: usize) -> bool {
 179         self.non_formatted_ranges
 180             .iter()
 181             .any(|(low, high)| *low <= n && n <= *high)
 182     }
 183 }
 184
 185 /// Reports on any issues that occurred during a run of Rustfmt.
 186 ///
 187 /// Can be reported to the user using the `Display` impl on [`FormatReportFormatter`].
 188 #[derive(Clone)]
 189 pub struct FormatReport {
 190     // Maps stringified file paths to their associated formatting errors.
 191     internal: Rc<RefCell<(FormatErrorMap, ReportedErrors)>>,
 192     non_formatted_ranges: Vec<(usize, usize)>,
 193 }
 194
 195 impl FormatReport {
 196     fn new() -> FormatReport {
 197         FormatReport {
 198             internal: Rc::new(RefCell::new((HashMap::new(), ReportedErrors::default()))),
 199             non_formatted_ranges: Vec::new(),
 200         }
 201     }
 202
 203     fn add_non_formatted_ranges(&mut self, mut ranges: Vec<(usize, usize)>) {
 204         self.non_formatted_ranges.append(&mut ranges);
 205     }
 206
 207     fn append(&self, f: FileName, mut v: Vec<FormattingError>) {
 208         self.track_errors(&v);
 209         self.internal
 210             .borrow_mut()
 211             .0
 212             .entry(f)
 213             .and_modify(|fe| fe.append(&mut v))
 214             .or_insert(v);
 215     }
 216
 217     fn track_errors(&self, new_errors: &[FormattingError]) {
 218         let errs = &mut self.internal.borrow_mut().1;
 219         if !new_errors.is_empty() {
 220             errs.has_formatting_errors = true;
 221         }
 222         if errs.has_operational_errors && errs.has_check_errors && errs.has_unformatted_code_errors
 223         {
 224             return;
 225         }
 226         for err in new_errors {
 227             match err.kind {
 228                 ErrorKind::LineOverflow(..) => {
 229                     errs.has_operational_errors = true;
 230                 }
 231                 ErrorKind::TrailingWhitespace => {
 232                     errs.has_operational_errors = true;
 233                     errs.has_unformatted_code_errors = true;
 234                 }
 235                 ErrorKind::LostComment => {
 236                     errs.has_unformatted_code_errors = true;
 237                 }
 238                 ErrorKind::BadIssue(_)
 239                 | ErrorKind::LicenseCheck
 240                 | ErrorKind::DeprecatedAttr
 241                 | ErrorKind::BadAttr
 242                 | ErrorKind::VersionMismatch => {
 243                     errs.has_check_errors = true;
 244                 }
 245                 _ => {}
 246             }
 247         }
 248     }
 249
 250     fn add_diff(&mut self) {
 251         self.internal.borrow_mut().1.has_diff = true;
 252     }
 253
 254     fn add_macro_format_failure(&mut self) {
 255         self.internal.borrow_mut().1.has_macro_format_failure = true;
 256     }
 257
 258     fn add_parsing_error(&mut self) {
 259         self.internal.borrow_mut().1.has_parsing_errors = true;
 260     }
 261
 262     fn warning_count(&self) -> usize {
 263         self.internal
 264             .borrow()
 265             .0
 266             .iter()
 267             .map(|(_, errors)| errors.len())
 268             .sum()
 269     }
 270
 271     /// Whether any warnings or errors are present in the report.
 272     pub fn has_warnings(&self) -> bool {
 273         self.internal.borrow().1.has_formatting_errors
 274     }
 275
 276     /// Print the report to a terminal using colours and potentially other
 277     /// fancy output.
 278     #[deprecated(note = "Use FormatReportFormatter with colors enabled instead")]
 279     pub fn fancy_print(
 280         &self,
 281         mut t: Box<dyn term::Terminal<Output = io::Stderr>>,
 282     ) -> Result<(), term::Error> {
 283         writeln!(
 284             t,
 285             "{}",
 286             FormatReportFormatterBuilder::new(self)
 287                 .enable_colors(true)
 288                 .build()
 289         )?;
 290         Ok(())
 291     }
 292 }
 293
 294 /// Deprecated - Use FormatReportFormatter instead
 295 // https://github.com/rust-lang/rust/issues/78625
 296 // https://github.com/rust-lang/rust/issues/39935
 297 impl fmt::Display for FormatReport {
 298     // Prints all the formatting errors.
 299     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
 300         write!(fmt, "{}", FormatReportFormatterBuilder::new(self).build())?;
 301         Ok(())
 302     }
 303 }
 304
 305 /// Format the given snippet. The snippet is expected to be *complete* code.
 306 /// When we cannot parse the given snippet, this function returns `None`.
 307 fn format_snippet(snippet: &str, config: &Config, is_macro_def: bool) -> Option<FormattedSnippet> {
 308     let mut config = config.clone();
 309     panic::catch_unwind(|| {
 310         let mut out: Vec<u8> = Vec::with_capacity(snippet.len() * 2);
 311         config.set().emit_mode(config::EmitMode::Stdout);
 312         config.set().verbose(Verbosity::Quiet);
 313         config.set().hide_parse_errors(true);
 314         if is_macro_def {
 315             config.set().error_on_unformatted(true);
 316         }
 317
 318         let (formatting_error, result) = {
 319             let input = Input::Text(snippet.into());
 320             let mut session = Session::new(config, Some(&mut out));
 321             let result = session.format_input_inner(input, is_macro_def);
 322             (
 323                 session.errors.has_macro_format_failure
 324                     || session.out.as_ref().unwrap().is_empty() && !snippet.is_empty()
 325                     || result.is_err()
 326                     || (is_macro_def && session.has_unformatted_code_errors()),
 327                 result,
 328             )
 329         };
 330         if formatting_error {
 331             None
 332         } else {
 333             String::from_utf8(out).ok().map(|snippet| FormattedSnippet {
 334                 snippet,
 335                 non_formatted_ranges: result.unwrap().non_formatted_ranges,
 336             })
 337         }
 338     })
 339     // Discard panics encountered while formatting the snippet
 340     // The ? operator is needed to remove the extra Option
 341     .ok()?
 342 }
 343
 344 /// Format the given code block. Mainly targeted for code block in comment.
 345 /// The code block may be incomplete (i.e., parser may be unable to parse it).
 346 /// To avoid panic in parser, we wrap the code block with a dummy function.
 347 /// The returned code block does **not** end with newline.
 348 fn format_code_block(
 349     code_snippet: &str,
 350     config: &Config,
 351     is_macro_def: bool,
 352 ) -> Option<FormattedSnippet> {
 353     const FN_MAIN_PREFIX: &str = "fn main() {\n";
 354
 355     fn enclose_in_main_block(s: &str, config: &Config) -> String {
 356         let indent = Indent::from_width(config, config.tab_spaces());
 357         let mut result = String::with_capacity(s.len() * 2);
 358         result.push_str(FN_MAIN_PREFIX);
 359         let mut need_indent = true;
 360         for (kind, line) in LineClasses::new(s) {
 361             if need_indent {
 362                 result.push_str(&indent.to_string(config));
 363             }
 364             result.push_str(&line);
 365             result.push('\n');
 366             need_indent = indent_next_line(kind, &line, config);
 367         }
 368         result.push('}');
 369         result
 370     }
 371
 372     // Wrap the given code block with `fn main()` if it does not have one.
 373     let snippet = enclose_in_main_block(code_snippet, config);
 374     let mut result = String::with_capacity(snippet.len());
 375     let mut is_first = true;
 376
 377     // While formatting the code, ignore the config's newline style setting and always use "\n"
 378     // instead of "\r\n" for the newline characters. This is ok because the output here is
 379     // not directly outputted by rustfmt command, but used by the comment formatter's input.
 380     // We have output-file-wide "\n" ==> "\r\n" conversion process after here if it's necessary.
 381     let mut config_with_unix_newline = config.clone();
 382     config_with_unix_newline
 383         .set()
 384         .newline_style(NewlineStyle::Unix);
 385     let mut formatted = format_snippet(&snippet, &config_with_unix_newline, is_macro_def)?;
 386     // Remove wrapping main block
 387     formatted.unwrap_code_block();
 388
 389     // Trim "fn main() {" on the first line and "}" on the last line,
 390     // then unindent the whole code block.
 391     let block_len = formatted
 392         .snippet
 393         .rfind('}')
 394         .unwrap_or_else(|| formatted.snippet.len());
 395     let mut is_indented = true;
 396     let indent_str = Indent::from_width(config, config.tab_spaces()).to_string(config);
 397     for (kind, ref line) in LineClasses::new(&formatted.snippet[FN_MAIN_PREFIX.len()..block_len]) {
 398         if !is_first {
 399             result.push('\n');
 400         } else {
 401             is_first = false;
 402         }
 403         let trimmed_line = if !is_indented {
 404             line
 405         } else if line.len() > config.max_width() {
 406             // If there are lines that are larger than max width, we cannot tell
 407             // whether we have succeeded but have some comments or strings that
 408             // are too long, or we have failed to format code block. We will be
 409             // conservative and just return `None` in this case.
 410             return None;
 411         } else if line.len() > indent_str.len() {
 412             // Make sure that the line has leading whitespaces.
 413             if line.starts_with(indent_str.as_ref()) {
 414                 let offset = if config.hard_tabs() {
 415                     1
 416                 } else {
 417                     config.tab_spaces()
 418                 };
 419                 &line[offset..]
 420             } else {
 421                 line
 422             }
 423         } else {
 424             line
 425         };
 426         result.push_str(trimmed_line);
 427         is_indented = indent_next_line(kind, line, config);
 428     }
 429     Some(FormattedSnippet {
 430         snippet: result,
 431         non_formatted_ranges: formatted.non_formatted_ranges,
 432     })
 433 }
 434
 435 /// A session is a run of rustfmt across a single or multiple inputs.
 436 pub struct Session<'b, T: Write> {
 437     pub config: Config,
 438     pub out: Option<&'b mut T>,
 439     pub(crate) errors: ReportedErrors,
 440     source_file: SourceFile,
 441     emitter: Box<dyn Emitter + 'b>,
 442 }
 443
 444 impl<'b, T: Write + 'b> Session<'b, T> {
 445     pub fn new(config: Config, mut out: Option<&'b mut T>) -> Session<'b, T> {
 446         let emitter = create_emitter(&config);
 447
 448         if let Some(ref mut out) = out {
 449             let _ = emitter.emit_header(out);
 450         }
 451
 452         Session {
 453             config,
 454             out,
 455             emitter,
 456             errors: ReportedErrors::default(),
 457             source_file: SourceFile::new(),
 458         }
 459     }
 460
 461     /// The main entry point for Rustfmt. Formats the given input according to the
 462     /// given config. `out` is only necessary if required by the configuration.
 463     pub fn format(&mut self, input: Input) -> Result<FormatReport, ErrorKind> {
 464         self.format_input_inner(input, false)
 465     }
 466
 467     pub fn override_config<F, U>(&mut self, mut config: Config, f: F) -> U
 468     where
 469         F: FnOnce(&mut Session<'b, T>) -> U,
 470     {
 471         mem::swap(&mut config, &mut self.config);
 472         let result = f(self);
 473         mem::swap(&mut config, &mut self.config);
 474         result
 475     }
 476
 477     pub fn add_operational_error(&mut self) {
 478         self.errors.has_operational_errors = true;
 479     }
 480
 481     pub fn has_operational_errors(&self) -> bool {
 482         self.errors.has_operational_errors
 483     }
 484
 485     pub fn has_parsing_errors(&self) -> bool {
 486         self.errors.has_parsing_errors
 487     }
 488
 489     pub fn has_formatting_errors(&self) -> bool {
 490         self.errors.has_formatting_errors
 491     }
 492
 493     pub fn has_check_errors(&self) -> bool {
 494         self.errors.has_check_errors
 495     }
 496
 497     pub fn has_diff(&self) -> bool {
 498         self.errors.has_diff
 499     }
 500
 501     pub fn has_unformatted_code_errors(&self) -> bool {
 502         self.errors.has_unformatted_code_errors
 503     }
 504
 505     pub fn has_no_errors(&self) -> bool {
 506         !(self.has_operational_errors()
 507             || self.has_parsing_errors()
 508             || self.has_formatting_errors()
 509             || self.has_check_errors()
 510             || self.has_diff()
 511             || self.has_unformatted_code_errors()
 512             || self.errors.has_macro_format_failure)
 513     }
 514 }
 515
 516 pub(crate) fn create_emitter<'a>(config: &Config) -> Box<dyn Emitter + 'a> {
 517     match config.emit_mode() {
 518         EmitMode::Files if config.make_backup() => {
 519             Box::new(emitter::FilesWithBackupEmitter::default())
 520         }
 521         EmitMode::Files => Box::new(emitter::FilesEmitter::new(
 522             config.print_misformatted_file_names(),
 523         )),
 524         EmitMode::Stdout | EmitMode::Coverage => {
 525             Box::new(emitter::StdoutEmitter::new(config.verbose()))
 526         }
 527         EmitMode::Json => Box::new(emitter::JsonEmitter::default()),
 528         EmitMode::ModifiedLines => Box::new(emitter::ModifiedLinesEmitter::default()),
 529         EmitMode::Checkstyle => Box::new(emitter::CheckstyleEmitter::default()),
 530         EmitMode::Diff => Box::new(emitter::DiffEmitter::new(config.clone())),
 531     }
 532 }
 533
 534 impl<'b, T: Write + 'b> Drop for Session<'b, T> {
 535     fn drop(&mut self) {
 536         if let Some(ref mut out) = self.out {
 537             let _ = self.emitter.emit_footer(out);
 538         }
 539     }
 540 }
 541
 542 #[derive(Debug)]
 543 pub enum Input {
 544     File(PathBuf),
 545     Text(String),
 546 }
 547
 548 impl Input {
 549     fn file_name(&self) -> FileName {
 550         match *self {
 551             Input::File(ref file) => FileName::Real(file.clone()),
 552             Input::Text(..) => FileName::Stdin,
 553         }
 554     }
 555
 556     fn to_directory_ownership(&self) -> Option<DirectoryOwnership> {
 557         match self {
 558             Input::File(ref file) => {
 559                 // If there exists a directory with the same name as an input,
 560                 // then the input should be parsed as a sub module.
 561                 let file_stem = file.file_stem()?;
 562                 if file.parent()?.to_path_buf().join(file_stem).is_dir() {
 563                     Some(DirectoryOwnership::Owned {
 564                         relative: file_stem.to_str().map(symbol::Ident::from_str),
 565                     })
 566                 } else {
 567                     None
 568                 }
 569             }
 570             _ => None,
 571         }
 572     }
 573 }
 574
 575 #[cfg(test)]
 576 mod unit_tests {
 577     use super::*;
 578
 579     #[test]
 580     fn test_no_panic_on_format_snippet_and_format_code_block() {
 581         // `format_snippet()` and `format_code_block()` should not panic
 582         // even when we cannot parse the given snippet.
 583         let snippet = "let";
 584         assert!(format_snippet(snippet, &Config::default(), false).is_none());
 585         assert!(format_code_block(snippet, &Config::default(), false).is_none());
 586     }
 587
 588     fn test_format_inner<F>(formatter: F, input: &str, expected: &str) -> bool
 589     where
 590         F: Fn(&str, &Config, bool) -> Option<FormattedSnippet>,
 591     {
 592         let output = formatter(input, &Config::default(), false);
 593         output.is_some() && output.unwrap().snippet == expected
 594     }
 595
 596     #[test]
 597     fn test_format_snippet() {
 598         let snippet = "fn main() { println!(\"hello, world\"); }";
 599         #[cfg(not(windows))]
 600         let expected = "fn main() {\n    \
 601                         println!(\"hello, world\");\n\
 602                         }\n";
 603         #[cfg(windows)]
 604         let expected = "fn main() {\r\n    \
 605                         println!(\"hello, world\");\r\n\
 606                         }\r\n";
 607         assert!(test_format_inner(format_snippet, snippet, expected));
 608     }
 609
 610     #[test]
 611     fn test_format_code_block_fail() {
 612         #[rustfmt::skip]
 613         let code_block = "this_line_is_100_characters_long_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx(x, y, z);";
 614         assert!(format_code_block(code_block, &Config::default(), false).is_none());
 615     }
 616
 617     #[test]
 618     fn test_format_code_block() {
 619         // simple code block
 620         let code_block = "let x=3;";
 621         let expected = "let x = 3;";
 622         assert!(test_format_inner(format_code_block, code_block, expected));
 623
 624         // more complex code block, taken from chains.rs.
 625         let code_block =
 626 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
 627 (
 628 chain_indent(context, shape.add_offset(parent_rewrite.len())),
 629 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
 630 )
 631 } else if is_block_expr(context, &parent, &parent_rewrite) {
 632 match context.config.indent_style() {
 633 // Try to put the first child on the same line with parent's last line
 634 IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
 635 // The parent is a block, so align the rest of the chain with the closing
 636 // brace.
 637 IndentStyle::Visual => (parent_shape, false),
 638 }
 639 } else {
 640 (
 641 chain_indent(context, shape.add_offset(parent_rewrite.len())),
 642 false,
 643 )
 644 };
 645 ";
 646         let expected =
 647 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
 648     (
 649         chain_indent(context, shape.add_offset(parent_rewrite.len())),
 650         context.config.indent_style() == IndentStyle::Visual || is_small_parent,
 651     )
 652 } else if is_block_expr(context, &parent, &parent_rewrite) {
 653     match context.config.indent_style() {
 654         // Try to put the first child on the same line with parent's last line
 655         IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
 656         // The parent is a block, so align the rest of the chain with the closing
 657         // brace.
 658         IndentStyle::Visual => (parent_shape, false),
 659     }
 660 } else {
 661     (
 662         chain_indent(context, shape.add_offset(parent_rewrite.len())),
 663         false,
 664     )
 665 };";
 666         assert!(test_format_inner(format_code_block, code_block, expected));
 667     }
 668 }