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;
18 extern crate itertools;
21 extern crate lazy_static;
25 extern crate rustc_target;
28 extern crate serde_derive;
29 extern crate serde_json;
31 extern crate syntax_pos;
33 extern crate unicode_categories;
34 extern crate unicode_segmentation;
35 extern crate unicode_width;
37 use std::cell::RefCell;
38 use std::collections::HashMap;
40 use std::io::{self, Write};
43 use std::path::PathBuf;
47 use comment::LineClasses;
49 use formatting::{FormatErrorMap, FormattingError, ReportedErrors, SourceFile};
54 load_config, CliOptions, Color, Config, Edition, EmitMode, FileLines, FileName, NewlineStyle,
63 pub(crate) mod checkstyle;
66 pub(crate) mod config;
68 pub(crate) mod formatting;
76 pub(crate) mod modules;
82 pub(crate) mod rustfmt_diff;
84 pub(crate) mod source_file;
85 pub(crate) mod source_map;
92 pub(crate) mod visitor;
94 /// The various errors that can occur during formatting. Note that not all of
95 /// these can currently be propagated to clients.
96 #[derive(Fail, Debug)]
98 /// Line has exceeded character limit (found, maximum).
100 display = "line formatted, but exceeded maximum width \
101 (maximum: {} (see `max_width` option), found: {})",
104 LineOverflow(usize, usize),
105 /// Line ends in whitespace.
106 #[fail(display = "left behind trailing whitespace")]
108 /// TODO or FIXME item without an issue number.
109 #[fail(display = "found {}", _0)]
111 /// License check has failed.
112 #[fail(display = "license check failed")]
114 /// Used deprecated skip attribute.
115 #[fail(display = "`rustfmt_skip` is deprecated; use `rustfmt::skip`")]
117 /// Used a rustfmt:: attribute other than skip.
118 #[fail(display = "invalid attribute")]
120 /// An io error during reading or writing.
121 #[fail(display = "io error: {}", _0)]
123 /// Parse error occurred when parsing the input.
124 #[fail(display = "parse error")]
126 /// The user mandated a version and the current version of Rustfmt does not
127 /// satisfy that requirement.
128 #[fail(display = "version mismatch")]
130 /// If we had formatted the given node, then we would have lost a comment.
131 #[fail(display = "not formatted because a comment would be lost")]
136 fn is_comment(&self) -> bool {
138 ErrorKind::LostComment => true,
144 impl From<io::Error> for ErrorKind {
145 fn from(e: io::Error) -> ErrorKind {
146 ErrorKind::IoError(e)
150 /// Result of formatting a snippet of code along with ranges of lines that didn't get formatted,
151 /// i.e., that got returned as they were originally.
153 struct FormattedSnippet {
155 non_formatted_ranges: Vec<(usize, usize)>,
158 impl FormattedSnippet {
159 /// In case the snippet needed to be wrapped in a function, this shifts down the ranges of
160 /// non-formatted code.
161 fn unwrap_code_block(&mut self) {
162 self.non_formatted_ranges
164 .for_each(|(low, high)| {
170 /// Returns true if the line n did not get formatted.
171 fn is_line_non_formatted(&self, n: usize) -> bool {
172 self.non_formatted_ranges
174 .any(|(low, high)| *low <= n && n <= *high)
178 /// Reports on any issues that occurred during a run of Rustfmt.
180 /// Can be reported to the user via its `Display` implementation of `print_fancy`.
182 pub struct FormatReport {
183 // Maps stringified file paths to their associated formatting errors.
184 internal: Rc<RefCell<(FormatErrorMap, ReportedErrors)>>,
185 non_formatted_ranges: Vec<(usize, usize)>,
189 fn new() -> FormatReport {
191 internal: Rc::new(RefCell::new((HashMap::new(), ReportedErrors::default()))),
192 non_formatted_ranges: Vec::new(),
196 fn add_non_formatted_ranges(&mut self, mut ranges: Vec<(usize, usize)>) {
197 self.non_formatted_ranges.append(&mut ranges);
200 fn append(&self, f: FileName, mut v: Vec<FormattingError>) {
201 self.track_errors(&v);
206 .and_modify(|fe| fe.append(&mut v))
210 fn track_errors(&self, new_errors: &[FormattingError]) {
211 let errs = &mut self.internal.borrow_mut().1;
212 if !new_errors.is_empty() {
213 errs.has_formatting_errors = true;
215 if errs.has_operational_errors && errs.has_check_errors {
218 for err in new_errors {
220 ErrorKind::LineOverflow(..) | ErrorKind::TrailingWhitespace => {
221 errs.has_operational_errors = true;
223 ErrorKind::BadIssue(_)
224 | ErrorKind::LicenseCheck
225 | ErrorKind::DeprecatedAttr
227 | ErrorKind::VersionMismatch => {
228 errs.has_check_errors = true;
235 fn add_diff(&mut self) {
236 self.internal.borrow_mut().1.has_diff = true;
239 fn add_macro_format_failure(&mut self) {
240 self.internal.borrow_mut().1.has_macro_format_failure = true;
243 fn add_parsing_error(&mut self) {
244 self.internal.borrow_mut().1.has_parsing_errors = true;
247 fn warning_count(&self) -> usize {
252 .map(|(_, errors)| errors.len())
256 /// Whether any warnings or errors are present in the report.
257 pub fn has_warnings(&self) -> bool {
258 self.internal.borrow().1.has_formatting_errors
261 /// Print the report to a terminal using colours and potentially other
265 mut t: Box<term::Terminal<Output = io::Stderr>>,
266 ) -> Result<(), term::Error> {
267 for (file, errors) in &self.internal.borrow().0 {
268 for error in errors {
269 let prefix_space_len = error.line.to_string().len();
270 let prefix_spaces = " ".repeat(1 + prefix_space_len);
272 // First line: the overview of error
273 t.fg(term::color::RED)?;
274 t.attr(term::Attr::Bold)?;
275 write!(t, "{} ", error.msg_prefix())?;
277 t.attr(term::Attr::Bold)?;
278 writeln!(t, "{}", error.kind)?;
280 // Second line: file info
281 write!(t, "{}--> ", &prefix_spaces[1..])?;
283 writeln!(t, "{}:{}", file, error.line)?;
285 // Third to fifth lines: show the line which triggered error, if available.
286 if !error.line_buffer.is_empty() {
287 let (space_len, target_len) = error.format_len();
288 t.attr(term::Attr::Bold)?;
289 write!(t, "{}|\n{} | ", prefix_spaces, error.line)?;
291 writeln!(t, "{}", error.line_buffer)?;
292 t.attr(term::Attr::Bold)?;
293 write!(t, "{}| ", prefix_spaces)?;
294 t.fg(term::color::RED)?;
295 writeln!(t, "{}", FormatReport::target_str(space_len, target_len))?;
299 // The last line: show note if available.
300 let msg_suffix = error.msg_suffix();
301 if !msg_suffix.is_empty() {
302 t.attr(term::Attr::Bold)?;
303 write!(t, "{}= note: ", prefix_spaces)?;
305 writeln!(t, "{}", error.msg_suffix())?;
313 if !self.internal.borrow().0.is_empty() {
314 t.attr(term::Attr::Bold)?;
315 write!(t, "warning: ")?;
319 "rustfmt may have failed to format. See previous {} errors.\n\n",
320 self.warning_count(),
327 fn target_str(space_len: usize, target_len: usize) -> String {
328 let empty_line = " ".repeat(space_len);
329 let overflowed = "^".repeat(target_len);
330 empty_line + &overflowed
334 impl fmt::Display for FormatReport {
335 // Prints all the formatting errors.
336 fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
337 for (file, errors) in &self.internal.borrow().0 {
338 for error in errors {
339 let prefix_space_len = error.line.to_string().len();
340 let prefix_spaces = " ".repeat(1 + prefix_space_len);
342 let error_line_buffer = if error.line_buffer.is_empty() {
345 let (space_len, target_len) = error.format_len();
347 "{}|\n{} | {}\n{}| {}",
352 FormatReport::target_str(space_len, target_len)
356 let error_info = format!("{} {}", error.msg_prefix(), error.kind);
357 let file_info = format!("{}--> {}:{}", &prefix_spaces[1..], file, error.line);
358 let msg_suffix = error.msg_suffix();
359 let note = if msg_suffix.is_empty() {
362 format!("{}note= ", prefix_spaces)
376 if !self.internal.borrow().0.is_empty() {
379 "warning: rustfmt may have failed to format. See previous {} errors.",
380 self.warning_count(),
387 /// Format the given snippet. The snippet is expected to be *complete* code.
388 /// When we cannot parse the given snippet, this function returns `None`.
389 fn format_snippet(snippet: &str, config: &Config) -> Option<FormattedSnippet> {
390 let mut config = config.clone();
391 panic::catch_unwind(|| {
392 let mut out: Vec<u8> = Vec::with_capacity(snippet.len() * 2);
393 config.set().emit_mode(config::EmitMode::Stdout);
394 config.set().verbose(Verbosity::Quiet);
395 config.set().hide_parse_errors(true);
397 let (formatting_error, result) = {
398 let input = Input::Text(snippet.into());
399 let mut session = Session::new(config, Some(&mut out));
400 let result = session.format(input);
402 session.errors.has_macro_format_failure
403 || session.out.as_ref().unwrap().is_empty() && !snippet.is_empty()
408 if formatting_error {
411 String::from_utf8(out).ok().map(|snippet| FormattedSnippet {
413 non_formatted_ranges: result.unwrap().non_formatted_ranges,
417 // Discard panics encountered while formatting the snippet
418 // The ? operator is needed to remove the extra Option
422 /// Format the given code block. Mainly targeted for code block in comment.
423 /// The code block may be incomplete (i.e. parser may be unable to parse it).
424 /// To avoid panic in parser, we wrap the code block with a dummy function.
425 /// The returned code block does *not* end with newline.
426 fn format_code_block(code_snippet: &str, config: &Config) -> Option<FormattedSnippet> {
427 const FN_MAIN_PREFIX: &str = "fn main() {\n";
429 fn enclose_in_main_block(s: &str, config: &Config) -> String {
430 let indent = Indent::from_width(config, config.tab_spaces());
431 let mut result = String::with_capacity(s.len() * 2);
432 result.push_str(FN_MAIN_PREFIX);
433 let mut need_indent = true;
434 for (kind, line) in LineClasses::new(s) {
436 result.push_str(&indent.to_string(config));
438 result.push_str(&line);
440 need_indent = !kind.is_string() || line.ends_with('\\');
446 // Wrap the given code block with `fn main()` if it does not have one.
447 let snippet = enclose_in_main_block(code_snippet, config);
448 let mut result = String::with_capacity(snippet.len());
449 let mut is_first = true;
451 // While formatting the code, ignore the config's newline style setting and always use "\n"
452 // instead of "\r\n" for the newline characters. This is okay because the output here is
453 // not directly outputted by rustfmt command, but used by the comment formatter's input.
454 // We have output-file-wide "\n" ==> "\r\n" conversion process after here if it's necessary.
455 let mut config_with_unix_newline = config.clone();
456 config_with_unix_newline
458 .newline_style(NewlineStyle::Unix);
459 let mut formatted = format_snippet(&snippet, &config_with_unix_newline)?;
460 // Remove wrapping main block
461 formatted.unwrap_code_block();
463 // Trim "fn main() {" on the first line and "}" on the last line,
464 // then unindent the whole code block.
465 let block_len = formatted
468 .unwrap_or(formatted.snippet.len());
469 let mut is_indented = true;
470 for (kind, ref line) in LineClasses::new(&formatted.snippet[FN_MAIN_PREFIX.len()..block_len]) {
476 let trimmed_line = if !is_indented {
478 } else if line.len() > config.max_width() {
479 // If there are lines that are larger than max width, we cannot tell
480 // whether we have succeeded but have some comments or strings that
481 // are too long, or we have failed to format code block. We will be
482 // conservative and just return `None` in this case.
484 } else if line.len() > config.tab_spaces() {
485 // Make sure that the line has leading whitespaces.
486 let indent_str = Indent::from_width(config, config.tab_spaces()).to_string(config);
487 if line.starts_with(indent_str.as_ref()) {
488 let offset = if config.hard_tabs() {
500 result.push_str(trimmed_line);
501 is_indented = !kind.is_string() || line.ends_with('\\');
503 Some(FormattedSnippet {
505 non_formatted_ranges: formatted.non_formatted_ranges,
509 /// A session is a run of rustfmt across a single or multiple inputs.
510 pub struct Session<'b, T: Write + 'b> {
512 pub out: Option<&'b mut T>,
513 pub(crate) errors: ReportedErrors,
514 source_file: SourceFile,
517 impl<'b, T: Write + 'b> Session<'b, T> {
518 pub fn new(config: Config, out: Option<&'b mut T>) -> Session<'b, T> {
519 if config.emit_mode() == EmitMode::Checkstyle {
520 println!("{}", checkstyle::header());
526 errors: ReportedErrors::default(),
527 source_file: SourceFile::new(),
531 /// The main entry point for Rustfmt. Formats the given input according to the
532 /// given config. `out` is only necessary if required by the configuration.
533 pub fn format(&mut self, input: Input) -> Result<FormatReport, ErrorKind> {
534 self.format_input_inner(input)
537 pub fn override_config<F, U>(&mut self, mut config: Config, f: F) -> U
539 F: FnOnce(&mut Session<'b, T>) -> U,
541 mem::swap(&mut config, &mut self.config);
542 let result = f(self);
543 mem::swap(&mut config, &mut self.config);
547 pub fn add_operational_error(&mut self) {
548 self.errors.has_operational_errors = true;
551 pub fn has_operational_errors(&self) -> bool {
552 self.errors.has_operational_errors
555 pub fn has_parsing_errors(&self) -> bool {
556 self.errors.has_parsing_errors
559 pub fn has_formatting_errors(&self) -> bool {
560 self.errors.has_formatting_errors
563 pub fn has_check_errors(&self) -> bool {
564 self.errors.has_check_errors
567 pub fn has_diff(&self) -> bool {
571 pub fn has_no_errors(&self) -> bool {
572 !(self.has_operational_errors()
573 || self.has_parsing_errors()
574 || self.has_formatting_errors()
575 || self.has_check_errors()
577 || self.errors.has_macro_format_failure
581 impl<'b, T: Write + 'b> Drop for Session<'b, T> {
583 if self.config.emit_mode() == EmitMode::Checkstyle {
584 println!("{}", checkstyle::footer());
596 fn is_text(&self) -> bool {
598 Input::File(_) => false,
599 Input::Text(_) => true,
603 fn file_name(&self) -> FileName {
605 Input::File(ref file) => FileName::Real(file.clone()),
606 Input::Text(..) => FileName::Stdin,
616 fn test_no_panic_on_format_snippet_and_format_code_block() {
617 // `format_snippet()` and `format_code_block()` should not panic
618 // even when we cannot parse the given snippet.
620 assert!(format_snippet(snippet, &Config::default()).is_none());
621 assert!(format_code_block(snippet, &Config::default()).is_none());
624 fn test_format_inner<F>(formatter: F, input: &str, expected: &str) -> bool
626 F: Fn(&str, &Config) -> Option<FormattedSnippet>,
628 let output = formatter(input, &Config::default());
629 output.is_some() && output.unwrap().snippet == expected
633 fn test_format_snippet() {
634 let snippet = "fn main() { println!(\"hello, world\"); }";
636 let expected = "fn main() {\n \
637 println!(\"hello, world\");\n\
640 let expected = "fn main() {\r\n \
641 println!(\"hello, world\");\r\n\
643 assert!(test_format_inner(format_snippet, snippet, expected));
647 fn test_format_code_block_fail() {
649 let code_block = "this_line_is_100_characters_long_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx(x, y, z);";
650 assert!(format_code_block(code_block, &Config::default()).is_none());
654 fn test_format_code_block() {
656 let code_block = "let x=3;";
657 let expected = "let x = 3;";
658 assert!(test_format_inner(format_code_block, code_block, expected));
660 // more complex code block, taken from chains.rs.
662 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
664 chain_indent(context, shape.add_offset(parent_rewrite.len())),
665 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
667 } else if is_block_expr(context, &parent, &parent_rewrite) {
668 match context.config.indent_style() {
669 // Try to put the first child on the same line with parent's last line
670 IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
671 // The parent is a block, so align the rest of the chain with the closing
673 IndentStyle::Visual => (parent_shape, false),
677 chain_indent(context, shape.add_offset(parent_rewrite.len())),
683 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
685 chain_indent(context, shape.add_offset(parent_rewrite.len())),
686 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
688 } else if is_block_expr(context, &parent, &parent_rewrite) {
689 match context.config.indent_style() {
690 // Try to put the first child on the same line with parent's last line
691 IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
692 // The parent is a block, so align the rest of the chain with the closing
694 IndentStyle::Visual => (parent_shape, false),
698 chain_indent(context, shape.add_offset(parent_rewrite.len())),
702 assert!(test_format_inner(format_code_block, code_block, expected));