1 // Copyright 2015-2018 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.
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.
12 extern crate derive_new;
14 extern crate bytecount;
17 extern crate itertools;
20 extern crate lazy_static;
24 extern crate rustc_target;
27 extern crate serde_derive;
28 extern crate serde_json;
30 extern crate syntax_pos;
32 extern crate unicode_categories;
33 extern crate unicode_segmentation;
34 extern crate unicode_width;
36 use std::cell::RefCell;
37 use std::collections::HashMap;
39 use std::io::{self, Write};
42 use std::path::PathBuf;
46 use comment::LineClasses;
48 use formatting::{FormatErrorMap, FormattingError, ReportedErrors, SourceFile};
53 load_config, CliOptions, Color, Config, Edition, EmitMode, FileLines, FileName, NewlineStyle,
62 pub(crate) mod checkstyle;
65 pub(crate) mod config;
67 pub(crate) mod formatting;
75 pub(crate) mod modules;
81 pub(crate) mod rustfmt_diff;
83 pub(crate) mod source_file;
84 pub(crate) mod source_map;
91 pub(crate) mod visitor;
93 /// The various errors that can occur during formatting. Note that not all of
94 /// these can currently be propagated to clients.
95 #[derive(Fail, Debug)]
97 /// Line has exceeded character limit (found, maximum).
99 display = "line formatted, but exceeded maximum width \
100 (maximum: {} (see `max_width` option), found: {})",
103 LineOverflow(usize, usize),
104 /// Line ends in whitespace.
105 #[fail(display = "left behind trailing whitespace")]
107 /// TODO or FIXME item without an issue number.
108 #[fail(display = "found {}", _0)]
110 /// License check has failed.
111 #[fail(display = "license check failed")]
113 /// Used deprecated skip attribute.
114 #[fail(display = "`rustfmt_skip` is deprecated; use `rustfmt::skip`")]
116 /// Used a rustfmt:: attribute other than skip.
117 #[fail(display = "invalid attribute")]
119 /// An io error during reading or writing.
120 #[fail(display = "io error: {}", _0)]
122 /// Parse error occurred when parsing the input.
123 #[fail(display = "parse error")]
125 /// The user mandated a version and the current version of Rustfmt does not
126 /// satisfy that requirement.
127 #[fail(display = "version mismatch")]
129 /// If we had formatted the given node, then we would have lost a comment.
130 #[fail(display = "not formatted because a comment would be lost")]
135 fn is_comment(&self) -> bool {
137 ErrorKind::LostComment => true,
143 impl From<io::Error> for ErrorKind {
144 fn from(e: io::Error) -> ErrorKind {
145 ErrorKind::IoError(e)
149 /// Result of formatting a snippet of code along with ranges of lines that didn't get formatted,
150 /// i.e., that got returned as they were originally.
152 struct FormattedSnippet {
154 non_formatted_ranges: Vec<(usize, usize)>,
157 impl FormattedSnippet {
158 /// In case the snippet needed to be wrapped in a function, this shifts down the ranges of
159 /// non-formatted code.
160 fn unwrap_code_block(&mut self) {
161 self.non_formatted_ranges
163 .for_each(|(low, high)| {
169 /// Returns true if the line n did not get formatted.
170 fn is_line_non_formatted(&self, n: usize) -> bool {
171 self.non_formatted_ranges
173 .any(|(low, high)| *low <= n && n <= *high)
177 /// Reports on any issues that occurred during a run of Rustfmt.
179 /// Can be reported to the user via its `Display` implementation of `print_fancy`.
181 pub struct FormatReport {
182 // Maps stringified file paths to their associated formatting errors.
183 internal: Rc<RefCell<(FormatErrorMap, ReportedErrors)>>,
184 non_formatted_ranges: Vec<(usize, usize)>,
188 fn new() -> FormatReport {
190 internal: Rc::new(RefCell::new((HashMap::new(), ReportedErrors::default()))),
191 non_formatted_ranges: Vec::new(),
195 fn add_non_formatted_ranges(&mut self, mut ranges: Vec<(usize, usize)>) {
196 self.non_formatted_ranges.append(&mut ranges);
199 fn append(&self, f: FileName, mut v: Vec<FormattingError>) {
200 self.track_errors(&v);
205 .and_modify(|fe| fe.append(&mut v))
209 fn track_errors(&self, new_errors: &[FormattingError]) {
210 let errs = &mut self.internal.borrow_mut().1;
211 if !new_errors.is_empty() {
212 errs.has_formatting_errors = true;
214 if errs.has_operational_errors && errs.has_check_errors {
217 for err in new_errors {
219 ErrorKind::LineOverflow(..) | ErrorKind::TrailingWhitespace => {
220 errs.has_operational_errors = true;
222 ErrorKind::BadIssue(_)
223 | ErrorKind::LicenseCheck
224 | ErrorKind::DeprecatedAttr
226 | ErrorKind::VersionMismatch => {
227 errs.has_check_errors = true;
234 fn add_diff(&mut self) {
235 self.internal.borrow_mut().1.has_diff = true;
238 fn add_macro_format_failure(&mut self) {
239 self.internal.borrow_mut().1.has_macro_format_failure = true;
242 fn add_parsing_error(&mut self) {
243 self.internal.borrow_mut().1.has_parsing_errors = true;
246 fn warning_count(&self) -> usize {
251 .map(|(_, errors)| errors.len())
255 /// Whether any warnings or errors are present in the report.
256 pub fn has_warnings(&self) -> bool {
257 self.internal.borrow().1.has_formatting_errors
260 /// Print the report to a terminal using colours and potentially other
264 mut t: Box<term::Terminal<Output = io::Stderr>>,
265 ) -> Result<(), term::Error> {
266 for (file, errors) in &self.internal.borrow().0 {
267 for error in errors {
268 let prefix_space_len = error.line.to_string().len();
269 let prefix_spaces = " ".repeat(1 + prefix_space_len);
271 // First line: the overview of error
272 t.fg(term::color::RED)?;
273 t.attr(term::Attr::Bold)?;
274 write!(t, "{} ", error.msg_prefix())?;
276 t.attr(term::Attr::Bold)?;
277 writeln!(t, "{}", error.kind)?;
279 // Second line: file info
280 write!(t, "{}--> ", &prefix_spaces[1..])?;
282 writeln!(t, "{}:{}", file, error.line)?;
284 // Third to fifth lines: show the line which triggered error, if available.
285 if !error.line_buffer.is_empty() {
286 let (space_len, target_len) = error.format_len();
287 t.attr(term::Attr::Bold)?;
288 write!(t, "{}|\n{} | ", prefix_spaces, error.line)?;
290 writeln!(t, "{}", error.line_buffer)?;
291 t.attr(term::Attr::Bold)?;
292 write!(t, "{}| ", prefix_spaces)?;
293 t.fg(term::color::RED)?;
294 writeln!(t, "{}", FormatReport::target_str(space_len, target_len))?;
298 // The last line: show note if available.
299 let msg_suffix = error.msg_suffix();
300 if !msg_suffix.is_empty() {
301 t.attr(term::Attr::Bold)?;
302 write!(t, "{}= note: ", prefix_spaces)?;
304 writeln!(t, "{}", error.msg_suffix())?;
312 if !self.internal.borrow().0.is_empty() {
313 t.attr(term::Attr::Bold)?;
314 write!(t, "warning: ")?;
318 "rustfmt may have failed to format. See previous {} errors.\n\n",
319 self.warning_count(),
326 fn target_str(space_len: usize, target_len: usize) -> String {
327 let empty_line = " ".repeat(space_len);
328 let overflowed = "^".repeat(target_len);
329 empty_line + &overflowed
333 impl fmt::Display for FormatReport {
334 // Prints all the formatting errors.
335 fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
336 for (file, errors) in &self.internal.borrow().0 {
337 for error in errors {
338 let prefix_space_len = error.line.to_string().len();
339 let prefix_spaces = " ".repeat(1 + prefix_space_len);
341 let error_line_buffer = if error.line_buffer.is_empty() {
344 let (space_len, target_len) = error.format_len();
346 "{}|\n{} | {}\n{}| {}",
351 FormatReport::target_str(space_len, target_len)
355 let error_info = format!("{} {}", error.msg_prefix(), error.kind);
356 let file_info = format!("{}--> {}:{}", &prefix_spaces[1..], file, error.line);
357 let msg_suffix = error.msg_suffix();
358 let note = if msg_suffix.is_empty() {
361 format!("{}note= ", prefix_spaces)
375 if !self.internal.borrow().0.is_empty() {
378 "warning: rustfmt may have failed to format. See previous {} errors.",
379 self.warning_count(),
386 /// Format the given snippet. The snippet is expected to be *complete* code.
387 /// When we cannot parse the given snippet, this function returns `None`.
388 fn format_snippet(snippet: &str, config: &Config) -> Option<FormattedSnippet> {
389 let mut config = config.clone();
390 panic::catch_unwind(|| {
391 let mut out: Vec<u8> = Vec::with_capacity(snippet.len() * 2);
392 config.set().emit_mode(config::EmitMode::Stdout);
393 config.set().verbose(Verbosity::Quiet);
394 config.set().hide_parse_errors(true);
396 let (formatting_error, result) = {
397 let input = Input::Text(snippet.into());
398 let mut session = Session::new(config, Some(&mut out));
399 let result = session.format(input);
401 session.errors.has_macro_format_failure
402 || session.out.as_ref().unwrap().is_empty() && !snippet.is_empty()
407 if formatting_error {
410 String::from_utf8(out).ok().map(|snippet| FormattedSnippet {
412 non_formatted_ranges: result.unwrap().non_formatted_ranges,
416 // Discard panics encountered while formatting the snippet
417 // The ? operator is needed to remove the extra Option
421 /// Format the given code block. Mainly targeted for code block in comment.
422 /// The code block may be incomplete (i.e. parser may be unable to parse it).
423 /// To avoid panic in parser, we wrap the code block with a dummy function.
424 /// The returned code block does *not* end with newline.
425 fn format_code_block(code_snippet: &str, config: &Config) -> Option<FormattedSnippet> {
426 const FN_MAIN_PREFIX: &str = "fn main() {\n";
428 fn enclose_in_main_block(s: &str, config: &Config) -> String {
429 let indent = Indent::from_width(config, config.tab_spaces());
430 let mut result = String::with_capacity(s.len() * 2);
431 result.push_str(FN_MAIN_PREFIX);
432 let mut need_indent = true;
433 for (kind, line) in LineClasses::new(s) {
435 result.push_str(&indent.to_string(config));
437 result.push_str(&line);
439 need_indent = !kind.is_string() || line.ends_with('\\');
445 // Wrap the given code block with `fn main()` if it does not have one.
446 let snippet = enclose_in_main_block(code_snippet, config);
447 let mut result = String::with_capacity(snippet.len());
448 let mut is_first = true;
450 // While formatting the code, ignore the config's newline style setting and always use "\n"
451 // instead of "\r\n" for the newline characters. This is okay because the output here is
452 // not directly outputted by rustfmt command, but used by the comment formatter's input.
453 // We have output-file-wide "\n" ==> "\r\n" conversion process after here if it's necessary.
454 let mut config_with_unix_newline = config.clone();
455 config_with_unix_newline
457 .newline_style(NewlineStyle::Unix);
458 let mut formatted = format_snippet(&snippet, &config_with_unix_newline)?;
459 // Remove wrapping main block
460 formatted.unwrap_code_block();
462 // Trim "fn main() {" on the first line and "}" on the last line,
463 // then unindent the whole code block.
464 let block_len = formatted
467 .unwrap_or(formatted.snippet.len());
468 let mut is_indented = true;
469 for (kind, ref line) in LineClasses::new(&formatted.snippet[FN_MAIN_PREFIX.len()..block_len]) {
475 let trimmed_line = if !is_indented {
477 } else if line.len() > config.max_width() {
478 // If there are lines that are larger than max width, we cannot tell
479 // whether we have succeeded but have some comments or strings that
480 // are too long, or we have failed to format code block. We will be
481 // conservative and just return `None` in this case.
483 } else if line.len() > config.tab_spaces() {
484 // Make sure that the line has leading whitespaces.
485 let indent_str = Indent::from_width(config, config.tab_spaces()).to_string(config);
486 if line.starts_with(indent_str.as_ref()) {
487 let offset = if config.hard_tabs() {
499 result.push_str(trimmed_line);
500 is_indented = !kind.is_string() || line.ends_with('\\');
502 Some(FormattedSnippet {
504 non_formatted_ranges: formatted.non_formatted_ranges,
508 /// A session is a run of rustfmt across a single or multiple inputs.
509 pub struct Session<'b, T: Write + 'b> {
511 pub out: Option<&'b mut T>,
512 pub(crate) errors: ReportedErrors,
513 source_file: SourceFile,
516 impl<'b, T: Write + 'b> Session<'b, T> {
517 pub fn new(config: Config, out: Option<&'b mut T>) -> Session<'b, T> {
518 if config.emit_mode() == EmitMode::Checkstyle {
519 println!("{}", checkstyle::header());
525 errors: ReportedErrors::default(),
526 source_file: SourceFile::new(),
530 /// The main entry point for Rustfmt. Formats the given input according to the
531 /// given config. `out` is only necessary if required by the configuration.
532 pub fn format(&mut self, input: Input) -> Result<FormatReport, ErrorKind> {
533 self.format_input_inner(input)
536 pub fn override_config<F, U>(&mut self, mut config: Config, f: F) -> U
538 F: FnOnce(&mut Session<'b, T>) -> U,
540 mem::swap(&mut config, &mut self.config);
541 let result = f(self);
542 mem::swap(&mut config, &mut self.config);
546 pub fn add_operational_error(&mut self) {
547 self.errors.has_operational_errors = true;
550 pub fn has_operational_errors(&self) -> bool {
551 self.errors.has_operational_errors
554 pub fn has_parsing_errors(&self) -> bool {
555 self.errors.has_parsing_errors
558 pub fn has_formatting_errors(&self) -> bool {
559 self.errors.has_formatting_errors
562 pub fn has_check_errors(&self) -> bool {
563 self.errors.has_check_errors
566 pub fn has_diff(&self) -> bool {
570 pub fn has_no_errors(&self) -> bool {
571 !(self.has_operational_errors()
572 || self.has_parsing_errors()
573 || self.has_formatting_errors()
574 || self.has_check_errors()
576 || self.errors.has_macro_format_failure
580 impl<'b, T: Write + 'b> Drop for Session<'b, T> {
582 if self.config.emit_mode() == EmitMode::Checkstyle {
583 println!("{}", checkstyle::footer());
595 fn is_text(&self) -> bool {
597 Input::File(_) => false,
598 Input::Text(_) => true,
602 fn file_name(&self) -> FileName {
604 Input::File(ref file) => FileName::Real(file.clone()),
605 Input::Text(..) => FileName::Stdin,
615 fn test_no_panic_on_format_snippet_and_format_code_block() {
616 // `format_snippet()` and `format_code_block()` should not panic
617 // even when we cannot parse the given snippet.
619 assert!(format_snippet(snippet, &Config::default()).is_none());
620 assert!(format_code_block(snippet, &Config::default()).is_none());
623 fn test_format_inner<F>(formatter: F, input: &str, expected: &str) -> bool
625 F: Fn(&str, &Config) -> Option<FormattedSnippet>,
627 let output = formatter(input, &Config::default());
628 output.is_some() && output.unwrap().snippet == expected
632 fn test_format_snippet() {
633 let snippet = "fn main() { println!(\"hello, world\"); }";
635 let expected = "fn main() {\n \
636 println!(\"hello, world\");\n\
639 let expected = "fn main() {\r\n \
640 println!(\"hello, world\");\r\n\
642 assert!(test_format_inner(format_snippet, snippet, expected));
646 fn test_format_code_block_fail() {
648 let code_block = "this_line_is_100_characters_long_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx(x, y, z);";
649 assert!(format_code_block(code_block, &Config::default()).is_none());
653 fn test_format_code_block() {
655 let code_block = "let x=3;";
656 let expected = "let x = 3;";
657 assert!(test_format_inner(format_code_block, code_block, expected));
659 // more complex code block, taken from chains.rs.
661 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
663 chain_indent(context, shape.add_offset(parent_rewrite.len())),
664 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
666 } else if is_block_expr(context, &parent, &parent_rewrite) {
667 match context.config.indent_style() {
668 // Try to put the first child on the same line with parent's last line
669 IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
670 // The parent is a block, so align the rest of the chain with the closing
672 IndentStyle::Visual => (parent_shape, false),
676 chain_indent(context, shape.add_offset(parent_rewrite.len())),
682 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
684 chain_indent(context, shape.add_offset(parent_rewrite.len())),
685 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
687 } else if is_block_expr(context, &parent, &parent_rewrite) {
688 match context.config.indent_style() {
689 // Try to put the first child on the same line with parent's last line
690 IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
691 // The parent is a block, so align the rest of the chain with the closing
693 IndentStyle::Visual => (parent_shape, false),
697 chain_indent(context, shape.add_offset(parent_rewrite.len())),
701 assert!(test_format_inner(format_code_block, code_block, expected));