src/tools/rustfmt/src/lib.rs

   1 #![feature(rustc_private)]
   2 #![deny(rust_2018_idioms)]
   3 #![warn(unreachable_pub)]
   4
   5 #[macro_use]
   6 extern crate derive_new;
   7 #[cfg(test)]
   8 #[macro_use]
   9 extern crate lazy_static;
  10 #[macro_use]
  11 extern crate log;
  12
  13 // N.B. these crates are loaded from the sysroot, so they need extern crate.
  14 extern crate rustc_ast;
  15 extern crate rustc_ast_pretty;
  16 extern crate rustc_data_structures;
  17 extern crate rustc_errors;
  18 extern crate rustc_expand;
  19 extern crate rustc_parse;
  20 extern crate rustc_session;
  21 extern crate rustc_span;
  22
  23 use std::cell::RefCell;
  24 use std::collections::HashMap;
  25 use std::fmt;
  26 use std::io::{self, Write};
  27 use std::mem;
  28 use std::panic;
  29 use std::path::PathBuf;
  30 use std::rc::Rc;
  31
  32 use ignore;
  33 use rustc_ast::ast;
  34 use rustc_span::symbol;
  35 use thiserror::Error;
  36
  37 use crate::comment::LineClasses;
  38 use crate::emitter::Emitter;
  39 use crate::formatting::{FormatErrorMap, FormattingError, ReportedErrors, SourceFile};
  40 use crate::issues::Issue;
  41 use crate::modules::ModuleResolutionError;
  42 use crate::shape::Indent;
  43 use crate::syntux::parser::DirectoryOwnership;
  44 use crate::utils::indent_next_line;
  45
  46 pub use crate::config::{
  47     load_config, CliOptions, Color, Config, Edition, EmitMode, FileLines, FileName, NewlineStyle,
  48     Range, Verbosity,
  49 };
  50
  51 pub use crate::format_report_formatter::{FormatReportFormatter, FormatReportFormatterBuilder};
  52
  53 pub use crate::rustfmt_diff::{ModifiedChunk, ModifiedLines};
  54
  55 #[macro_use]
  56 mod utils;
  57
  58 mod attr;
  59 mod chains;
  60 mod closures;
  61 mod comment;
  62 pub(crate) mod config;
  63 mod coverage;
  64 mod emitter;
  65 mod expr;
  66 mod format_report_formatter;
  67 pub(crate) mod formatting;
  68 mod ignore_path;
  69 mod imports;
  70 mod issues;
  71 mod items;
  72 mod lists;
  73 mod macros;
  74 mod matches;
  75 mod missed_spans;
  76 pub(crate) mod modules;
  77 mod overflow;
  78 mod pairs;
  79 mod patterns;
  80 mod release_channel;
  81 mod reorder;
  82 mod rewrite;
  83 pub(crate) mod rustfmt_diff;
  84 mod shape;
  85 mod skip;
  86 pub(crate) mod source_file;
  87 pub(crate) mod source_map;
  88 mod spanned;
  89 mod stmt;
  90 mod string;
  91 mod syntux;
  92 #[cfg(test)]
  93 mod test;
  94 mod types;
  95 mod vertical;
  96 pub(crate) mod visitor;
  97
  98 /// The various errors that can occur during formatting. Note that not all of
  99 /// these can currently be propagated to clients.
 100 #[derive(Error, Debug)]
 101 pub enum ErrorKind {
 102     /// Line has exceeded character limit (found, maximum).
 103     #[error(
 104         "line formatted, but exceeded maximum width \
 105          (maximum: {1} (see `max_width` option), found: {0})"
 106     )]
 107     LineOverflow(usize, usize),
 108     /// Line ends in whitespace.
 109     #[error("left behind trailing whitespace")]
 110     TrailingWhitespace,
 111     /// TODO or FIXME item without an issue number.
 112     #[error("found {0}")]
 113     BadIssue(Issue),
 114     /// License check has failed.
 115     #[error("license check failed")]
 116     LicenseCheck,
 117     /// Used deprecated skip attribute.
 118     #[error("`rustfmt_skip` is deprecated; use `rustfmt::skip`")]
 119     DeprecatedAttr,
 120     /// Used a rustfmt:: attribute other than skip or skip::macros.
 121     #[error("invalid attribute")]
 122     BadAttr,
 123     /// An io error during reading or writing.
 124     #[error("io error: {0}")]
 125     IoError(io::Error),
 126     /// Error during module resolution.
 127     #[error("{0}")]
 128     ModuleResolutionError(#[from] ModuleResolutionError),
 129     /// Parse error occurred when parsing the input.
 130     #[error("parse error")]
 131     ParseError,
 132     /// The user mandated a version and the current version of Rustfmt does not
 133     /// satisfy that requirement.
 134     #[error("version mismatch")]
 135     VersionMismatch,
 136     /// If we had formatted the given node, then we would have lost a comment.
 137     #[error("not formatted because a comment would be lost")]
 138     LostComment,
 139     /// Invalid glob pattern in `ignore` configuration option.
 140     #[error("Invalid glob pattern found in ignore list: {0}")]
 141     InvalidGlobPattern(ignore::Error),
 142 }
 143
 144 impl ErrorKind {
 145     fn is_comment(&self) -> bool {
 146         match self {
 147             ErrorKind::LostComment => true,
 148             _ => false,
 149         }
 150     }
 151 }
 152
 153 impl From<io::Error> for ErrorKind {
 154     fn from(e: io::Error) -> ErrorKind {
 155         ErrorKind::IoError(e)
 156     }
 157 }
 158
 159 /// Result of formatting a snippet of code along with ranges of lines that didn't get formatted,
 160 /// i.e., that got returned as they were originally.
 161 #[derive(Debug)]
 162 struct FormattedSnippet {
 163     snippet: String,
 164     non_formatted_ranges: Vec<(usize, usize)>,
 165 }
 166
 167 impl FormattedSnippet {
 168     /// In case the snippet needed to be wrapped in a function, this shifts down the ranges of
 169     /// non-formatted code.
 170     fn unwrap_code_block(&mut self) {
 171         self.non_formatted_ranges
 172             .iter_mut()
 173             .for_each(|(low, high)| {
 174                 *low -= 1;
 175                 *high -= 1;
 176             });
 177     }
 178
 179     /// Returns `true` if the line n did not get formatted.
 180     fn is_line_non_formatted(&self, n: usize) -> bool {
 181         self.non_formatted_ranges
 182             .iter()
 183             .any(|(low, high)| *low <= n && n <= *high)
 184     }
 185 }
 186
 187 /// Reports on any issues that occurred during a run of Rustfmt.
 188 ///
 189 /// Can be reported to the user using the `Display` impl on [`FormatReportFormatter`].
 190 #[derive(Clone)]
 191 pub struct FormatReport {
 192     // Maps stringified file paths to their associated formatting errors.
 193     internal: Rc<RefCell<(FormatErrorMap, ReportedErrors)>>,
 194     non_formatted_ranges: Vec<(usize, usize)>,
 195 }
 196
 197 impl FormatReport {
 198     fn new() -> FormatReport {
 199         FormatReport {
 200             internal: Rc::new(RefCell::new((HashMap::new(), ReportedErrors::default()))),
 201             non_formatted_ranges: Vec::new(),
 202         }
 203     }
 204
 205     fn add_non_formatted_ranges(&mut self, mut ranges: Vec<(usize, usize)>) {
 206         self.non_formatted_ranges.append(&mut ranges);
 207     }
 208
 209     fn append(&self, f: FileName, mut v: Vec<FormattingError>) {
 210         self.track_errors(&v);
 211         self.internal
 212             .borrow_mut()
 213             .0
 214             .entry(f)
 215             .and_modify(|fe| fe.append(&mut v))
 216             .or_insert(v);
 217     }
 218
 219     fn track_errors(&self, new_errors: &[FormattingError]) {
 220         let errs = &mut self.internal.borrow_mut().1;
 221         if !new_errors.is_empty() {
 222             errs.has_formatting_errors = true;
 223         }
 224         if errs.has_operational_errors && errs.has_check_errors && errs.has_unformatted_code_errors
 225         {
 226             return;
 227         }
 228         for err in new_errors {
 229             match err.kind {
 230                 ErrorKind::LineOverflow(..) => {
 231                     errs.has_operational_errors = true;
 232                 }
 233                 ErrorKind::TrailingWhitespace => {
 234                     errs.has_operational_errors = true;
 235                     errs.has_unformatted_code_errors = true;
 236                 }
 237                 ErrorKind::LostComment => {
 238                     errs.has_unformatted_code_errors = true;
 239                 }
 240                 ErrorKind::BadIssue(_)
 241                 | ErrorKind::LicenseCheck
 242                 | ErrorKind::DeprecatedAttr
 243                 | ErrorKind::BadAttr
 244                 | ErrorKind::VersionMismatch => {
 245                     errs.has_check_errors = true;
 246                 }
 247                 _ => {}
 248             }
 249         }
 250     }
 251
 252     fn add_diff(&mut self) {
 253         self.internal.borrow_mut().1.has_diff = true;
 254     }
 255
 256     fn add_macro_format_failure(&mut self) {
 257         self.internal.borrow_mut().1.has_macro_format_failure = true;
 258     }
 259
 260     fn add_parsing_error(&mut self) {
 261         self.internal.borrow_mut().1.has_parsing_errors = true;
 262     }
 263
 264     fn warning_count(&self) -> usize {
 265         self.internal
 266             .borrow()
 267             .0
 268             .iter()
 269             .map(|(_, errors)| errors.len())
 270             .sum()
 271     }
 272
 273     /// Whether any warnings or errors are present in the report.
 274     pub fn has_warnings(&self) -> bool {
 275         self.internal.borrow().1.has_formatting_errors
 276     }
 277
 278     /// Print the report to a terminal using colours and potentially other
 279     /// fancy output.
 280     #[deprecated(note = "Use FormatReportFormatter with colors enabled instead")]
 281     pub fn fancy_print(
 282         &self,
 283         mut t: Box<dyn term::Terminal<Output = io::Stderr>>,
 284     ) -> Result<(), term::Error> {
 285         writeln!(
 286             t,
 287             "{}",
 288             FormatReportFormatterBuilder::new(&self)
 289                 .enable_colors(true)
 290                 .build()
 291         )?;
 292         Ok(())
 293     }
 294 }
 295
 296 /// Deprecated - Use FormatReportFormatter instead
 297 // https://github.com/rust-lang/rust/issues/78625
 298 // https://github.com/rust-lang/rust/issues/39935
 299 impl fmt::Display for FormatReport {
 300     // Prints all the formatting errors.
 301     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
 302         write!(fmt, "{}", FormatReportFormatterBuilder::new(&self).build())?;
 303         Ok(())
 304     }
 305 }
 306
 307 /// Format the given snippet. The snippet is expected to be *complete* code.
 308 /// When we cannot parse the given snippet, this function returns `None`.
 309 fn format_snippet(snippet: &str, config: &Config, is_macro_def: bool) -> Option<FormattedSnippet> {
 310     let mut config = config.clone();
 311     panic::catch_unwind(|| {
 312         let mut out: Vec<u8> = Vec::with_capacity(snippet.len() * 2);
 313         config.set().emit_mode(config::EmitMode::Stdout);
 314         config.set().verbose(Verbosity::Quiet);
 315         config.set().hide_parse_errors(true);
 316         if is_macro_def {
 317             config.set().error_on_unformatted(true);
 318         }
 319
 320         let (formatting_error, result) = {
 321             let input = Input::Text(snippet.into());
 322             let mut session = Session::new(config, Some(&mut out));
 323             let result = session.format_input_inner(input, is_macro_def);
 324             (
 325                 session.errors.has_macro_format_failure
 326                     || session.out.as_ref().unwrap().is_empty() && !snippet.is_empty()
 327                     || result.is_err()
 328                     || (is_macro_def && session.has_unformatted_code_errors()),
 329                 result,
 330             )
 331         };
 332         if formatting_error {
 333             None
 334         } else {
 335             String::from_utf8(out).ok().map(|snippet| FormattedSnippet {
 336                 snippet,
 337                 non_formatted_ranges: result.unwrap().non_formatted_ranges,
 338             })
 339         }
 340     })
 341     // Discard panics encountered while formatting the snippet
 342     // The ? operator is needed to remove the extra Option
 343     .ok()?
 344 }
 345
 346 /// Format the given code block. Mainly targeted for code block in comment.
 347 /// The code block may be incomplete (i.e., parser may be unable to parse it).
 348 /// To avoid panic in parser, we wrap the code block with a dummy function.
 349 /// The returned code block does **not** end with newline.
 350 fn format_code_block(
 351     code_snippet: &str,
 352     config: &Config,
 353     is_macro_def: bool,
 354 ) -> Option<FormattedSnippet> {
 355     const FN_MAIN_PREFIX: &str = "fn main() {\n";
 356
 357     fn enclose_in_main_block(s: &str, config: &Config) -> String {
 358         let indent = Indent::from_width(config, config.tab_spaces());
 359         let mut result = String::with_capacity(s.len() * 2);
 360         result.push_str(FN_MAIN_PREFIX);
 361         let mut need_indent = true;
 362         for (kind, line) in LineClasses::new(s) {
 363             if need_indent {
 364                 result.push_str(&indent.to_string(config));
 365             }
 366             result.push_str(&line);
 367             result.push('\n');
 368             need_indent = indent_next_line(kind, &line, config);
 369         }
 370         result.push('}');
 371         result
 372     }
 373
 374     // Wrap the given code block with `fn main()` if it does not have one.
 375     let snippet = enclose_in_main_block(code_snippet, config);
 376     let mut result = String::with_capacity(snippet.len());
 377     let mut is_first = true;
 378
 379     // While formatting the code, ignore the config's newline style setting and always use "\n"
 380     // instead of "\r\n" for the newline characters. This is ok because the output here is
 381     // not directly outputted by rustfmt command, but used by the comment formatter's input.
 382     // We have output-file-wide "\n" ==> "\r\n" conversion process after here if it's necessary.
 383     let mut config_with_unix_newline = config.clone();
 384     config_with_unix_newline
 385         .set()
 386         .newline_style(NewlineStyle::Unix);
 387     let mut formatted = format_snippet(&snippet, &config_with_unix_newline, is_macro_def)?;
 388     // Remove wrapping main block
 389     formatted.unwrap_code_block();
 390
 391     // Trim "fn main() {" on the first line and "}" on the last line,
 392     // then unindent the whole code block.
 393     let block_len = formatted
 394         .snippet
 395         .rfind('}')
 396         .unwrap_or_else(|| formatted.snippet.len());
 397     let mut is_indented = true;
 398     let indent_str = Indent::from_width(config, config.tab_spaces()).to_string(config);
 399     for (kind, ref line) in LineClasses::new(&formatted.snippet[FN_MAIN_PREFIX.len()..block_len]) {
 400         if !is_first {
 401             result.push('\n');
 402         } else {
 403             is_first = false;
 404         }
 405         let trimmed_line = if !is_indented {
 406             line
 407         } else if line.len() > config.max_width() {
 408             // If there are lines that are larger than max width, we cannot tell
 409             // whether we have succeeded but have some comments or strings that
 410             // are too long, or we have failed to format code block. We will be
 411             // conservative and just return `None` in this case.
 412             return None;
 413         } else if line.len() > indent_str.len() {
 414             // Make sure that the line has leading whitespaces.
 415             if line.starts_with(indent_str.as_ref()) {
 416                 let offset = if config.hard_tabs() {
 417                     1
 418                 } else {
 419                     config.tab_spaces()
 420                 };
 421                 &line[offset..]
 422             } else {
 423                 line
 424             }
 425         } else {
 426             line
 427         };
 428         result.push_str(trimmed_line);
 429         is_indented = indent_next_line(kind, line, config);
 430     }
 431     Some(FormattedSnippet {
 432         snippet: result,
 433         non_formatted_ranges: formatted.non_formatted_ranges,
 434     })
 435 }
 436
 437 /// A session is a run of rustfmt across a single or multiple inputs.
 438 pub struct Session<'b, T: Write> {
 439     pub config: Config,
 440     pub out: Option<&'b mut T>,
 441     pub(crate) errors: ReportedErrors,
 442     source_file: SourceFile,
 443     emitter: Box<dyn Emitter + 'b>,
 444 }
 445
 446 impl<'b, T: Write + 'b> Session<'b, T> {
 447     pub fn new(config: Config, mut out: Option<&'b mut T>) -> Session<'b, T> {
 448         let emitter = create_emitter(&config);
 449
 450         if let Some(ref mut out) = out {
 451             let _ = emitter.emit_header(out);
 452         }
 453
 454         Session {
 455             config,
 456             out,
 457             emitter,
 458             errors: ReportedErrors::default(),
 459             source_file: SourceFile::new(),
 460         }
 461     }
 462
 463     /// The main entry point for Rustfmt. Formats the given input according to the
 464     /// given config. `out` is only necessary if required by the configuration.
 465     pub fn format(&mut self, input: Input) -> Result<FormatReport, ErrorKind> {
 466         self.format_input_inner(input, false)
 467     }
 468
 469     pub fn override_config<F, U>(&mut self, mut config: Config, f: F) -> U
 470     where
 471         F: FnOnce(&mut Session<'b, T>) -> U,
 472     {
 473         mem::swap(&mut config, &mut self.config);
 474         let result = f(self);
 475         mem::swap(&mut config, &mut self.config);
 476         result
 477     }
 478
 479     pub fn add_operational_error(&mut self) {
 480         self.errors.has_operational_errors = true;
 481     }
 482
 483     pub fn has_operational_errors(&self) -> bool {
 484         self.errors.has_operational_errors
 485     }
 486
 487     pub fn has_parsing_errors(&self) -> bool {
 488         self.errors.has_parsing_errors
 489     }
 490
 491     pub fn has_formatting_errors(&self) -> bool {
 492         self.errors.has_formatting_errors
 493     }
 494
 495     pub fn has_check_errors(&self) -> bool {
 496         self.errors.has_check_errors
 497     }
 498
 499     pub fn has_diff(&self) -> bool {
 500         self.errors.has_diff
 501     }
 502
 503     pub fn has_unformatted_code_errors(&self) -> bool {
 504         self.errors.has_unformatted_code_errors
 505     }
 506
 507     pub fn has_no_errors(&self) -> bool {
 508         !(self.has_operational_errors()
 509             || self.has_parsing_errors()
 510             || self.has_formatting_errors()
 511             || self.has_check_errors()
 512             || self.has_diff()
 513             || self.has_unformatted_code_errors()
 514             || self.errors.has_macro_format_failure)
 515     }
 516 }
 517
 518 pub(crate) fn create_emitter<'a>(config: &Config) -> Box<dyn Emitter + 'a> {
 519     match config.emit_mode() {
 520         EmitMode::Files if config.make_backup() => {
 521             Box::new(emitter::FilesWithBackupEmitter::default())
 522         }
 523         EmitMode::Files => Box::new(emitter::FilesEmitter::new(
 524             config.print_misformatted_file_names(),
 525         )),
 526         EmitMode::Stdout | EmitMode::Coverage => {
 527             Box::new(emitter::StdoutEmitter::new(config.verbose()))
 528         }
 529         EmitMode::Json => Box::new(emitter::JsonEmitter::default()),
 530         EmitMode::ModifiedLines => Box::new(emitter::ModifiedLinesEmitter::default()),
 531         EmitMode::Checkstyle => Box::new(emitter::CheckstyleEmitter::default()),
 532         EmitMode::Diff => Box::new(emitter::DiffEmitter::new(config.clone())),
 533     }
 534 }
 535
 536 impl<'b, T: Write + 'b> Drop for Session<'b, T> {
 537     fn drop(&mut self) {
 538         if let Some(ref mut out) = self.out {
 539             let _ = self.emitter.emit_footer(out);
 540         }
 541     }
 542 }
 543
 544 #[derive(Debug)]
 545 pub enum Input {
 546     File(PathBuf),
 547     Text(String),
 548 }
 549
 550 impl Input {
 551     fn file_name(&self) -> FileName {
 552         match *self {
 553             Input::File(ref file) => FileName::Real(file.clone()),
 554             Input::Text(..) => FileName::Stdin,
 555         }
 556     }
 557
 558     fn to_directory_ownership(&self) -> Option<DirectoryOwnership> {
 559         match self {
 560             Input::File(ref file) => {
 561                 // If there exists a directory with the same name as an input,
 562                 // then the input should be parsed as a sub module.
 563                 let file_stem = file.file_stem()?;
 564                 if file.parent()?.to_path_buf().join(file_stem).is_dir() {
 565                     Some(DirectoryOwnership::Owned {
 566                         relative: file_stem.to_str().map(symbol::Ident::from_str),
 567                     })
 568                 } else {
 569                     None
 570                 }
 571             }
 572             _ => None,
 573         }
 574     }
 575 }
 576
 577 #[cfg(test)]
 578 mod unit_tests {
 579     use super::*;
 580
 581     #[test]
 582     fn test_no_panic_on_format_snippet_and_format_code_block() {
 583         // `format_snippet()` and `format_code_block()` should not panic
 584         // even when we cannot parse the given snippet.
 585         let snippet = "let";
 586         assert!(format_snippet(snippet, &Config::default(), false).is_none());
 587         assert!(format_code_block(snippet, &Config::default(), false).is_none());
 588     }
 589
 590     fn test_format_inner<F>(formatter: F, input: &str, expected: &str) -> bool
 591     where
 592         F: Fn(&str, &Config, bool) -> Option<FormattedSnippet>,
 593     {
 594         let output = formatter(input, &Config::default(), false);
 595         output.is_some() && output.unwrap().snippet == expected
 596     }
 597
 598     #[test]
 599     fn test_format_snippet() {
 600         let snippet = "fn main() { println!(\"hello, world\"); }";
 601         #[cfg(not(windows))]
 602         let expected = "fn main() {\n    \
 603                         println!(\"hello, world\");\n\
 604                         }\n";
 605         #[cfg(windows)]
 606         let expected = "fn main() {\r\n    \
 607                         println!(\"hello, world\");\r\n\
 608                         }\r\n";
 609         assert!(test_format_inner(format_snippet, snippet, expected));
 610     }
 611
 612     #[test]
 613     fn test_format_code_block_fail() {
 614         #[rustfmt::skip]
 615         let code_block = "this_line_is_100_characters_long_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx(x, y, z);";
 616         assert!(format_code_block(code_block, &Config::default(), false).is_none());
 617     }
 618
 619     #[test]
 620     fn test_format_code_block() {
 621         // simple code block
 622         let code_block = "let x=3;";
 623         let expected = "let x = 3;";
 624         assert!(test_format_inner(format_code_block, code_block, expected));
 625
 626         // more complex code block, taken from chains.rs.
 627         let code_block =
 628 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
 629 (
 630 chain_indent(context, shape.add_offset(parent_rewrite.len())),
 631 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
 632 )
 633 } else if is_block_expr(context, &parent, &parent_rewrite) {
 634 match context.config.indent_style() {
 635 // Try to put the first child on the same line with parent's last line
 636 IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
 637 // The parent is a block, so align the rest of the chain with the closing
 638 // brace.
 639 IndentStyle::Visual => (parent_shape, false),
 640 }
 641 } else {
 642 (
 643 chain_indent(context, shape.add_offset(parent_rewrite.len())),
 644 false,
 645 )
 646 };
 647 ";
 648         let expected =
 649 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
 650     (
 651         chain_indent(context, shape.add_offset(parent_rewrite.len())),
 652         context.config.indent_style() == IndentStyle::Visual || is_small_parent,
 653     )
 654 } else if is_block_expr(context, &parent, &parent_rewrite) {
 655     match context.config.indent_style() {
 656         // Try to put the first child on the same line with parent's last line
 657         IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
 658         // The parent is a block, so align the rest of the chain with the closing
 659         // brace.
 660         IndentStyle::Visual => (parent_shape, false),
 661     }
 662 } else {
 663     (
 664         chain_indent(context, shape.add_offset(parent_rewrite.len())),
 665         false,
 666     )
 667 };";
 668         assert!(test_format_inner(format_code_block, code_block, expected));
 669     }
 670 }