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.
11 #![deny(rust_2018_idioms)]
14 extern crate derive_new;
17 extern crate lazy_static;
21 extern crate serde_derive;
23 use std::cell::RefCell;
24 use std::collections::HashMap;
26 use std::io::{self, Write};
29 use std::path::PathBuf;
35 use crate::comment::LineClasses;
36 use crate::formatting::{FormatErrorMap, FormattingError, ReportedErrors, SourceFile};
37 use crate::issues::Issue;
38 use crate::shape::Indent;
40 pub use crate::config::{
41 load_config, CliOptions, Color, Config, Edition, EmitMode, FileLines, FileName, NewlineStyle,
50 pub(crate) mod checkstyle;
53 pub(crate) mod config;
55 pub(crate) mod formatting;
63 pub(crate) mod modules;
69 pub(crate) mod rustfmt_diff;
71 pub(crate) mod source_file;
72 pub(crate) mod source_map;
79 pub(crate) mod visitor;
81 /// The various errors that can occur during formatting. Note that not all of
82 /// these can currently be propagated to clients.
83 #[derive(Fail, Debug)]
85 /// Line has exceeded character limit (found, maximum).
87 display = "line formatted, but exceeded maximum width \
88 (maximum: {} (see `max_width` option), found: {})",
91 LineOverflow(usize, usize),
92 /// Line ends in whitespace.
93 #[fail(display = "left behind trailing whitespace")]
95 /// TODO or FIXME item without an issue number.
96 #[fail(display = "found {}", _0)]
98 /// License check has failed.
99 #[fail(display = "license check failed")]
101 /// Used deprecated skip attribute.
102 #[fail(display = "`rustfmt_skip` is deprecated; use `rustfmt::skip`")]
104 /// Used a rustfmt:: attribute other than skip.
105 #[fail(display = "invalid attribute")]
107 /// An io error during reading or writing.
108 #[fail(display = "io error: {}", _0)]
110 /// Parse error occurred when parsing the input.
111 #[fail(display = "parse error")]
113 /// The user mandated a version and the current version of Rustfmt does not
114 /// satisfy that requirement.
115 #[fail(display = "version mismatch")]
117 /// If we had formatted the given node, then we would have lost a comment.
118 #[fail(display = "not formatted because a comment would be lost")]
123 fn is_comment(&self) -> bool {
125 ErrorKind::LostComment => true,
131 impl From<io::Error> for ErrorKind {
132 fn from(e: io::Error) -> ErrorKind {
133 ErrorKind::IoError(e)
137 /// Result of formatting a snippet of code along with ranges of lines that didn't get formatted,
138 /// i.e., that got returned as they were originally.
140 struct FormattedSnippet {
142 non_formatted_ranges: Vec<(usize, usize)>,
145 impl FormattedSnippet {
146 /// In case the snippet needed to be wrapped in a function, this shifts down the ranges of
147 /// non-formatted code.
148 fn unwrap_code_block(&mut self) {
149 self.non_formatted_ranges
151 .for_each(|(low, high)| {
157 /// Returns true if the line n did not get formatted.
158 fn is_line_non_formatted(&self, n: usize) -> bool {
159 self.non_formatted_ranges
161 .any(|(low, high)| *low <= n && n <= *high)
165 /// Reports on any issues that occurred during a run of Rustfmt.
167 /// Can be reported to the user via its `Display` implementation of `print_fancy`.
169 pub struct FormatReport {
170 // Maps stringified file paths to their associated formatting errors.
171 internal: Rc<RefCell<(FormatErrorMap, ReportedErrors)>>,
172 non_formatted_ranges: Vec<(usize, usize)>,
176 fn new() -> FormatReport {
178 internal: Rc::new(RefCell::new((HashMap::new(), ReportedErrors::default()))),
179 non_formatted_ranges: Vec::new(),
183 fn add_non_formatted_ranges(&mut self, mut ranges: Vec<(usize, usize)>) {
184 self.non_formatted_ranges.append(&mut ranges);
187 fn append(&self, f: FileName, mut v: Vec<FormattingError>) {
188 self.track_errors(&v);
193 .and_modify(|fe| fe.append(&mut v))
197 fn track_errors(&self, new_errors: &[FormattingError]) {
198 let errs = &mut self.internal.borrow_mut().1;
199 if !new_errors.is_empty() {
200 errs.has_formatting_errors = true;
202 if errs.has_operational_errors && errs.has_check_errors {
205 for err in new_errors {
207 ErrorKind::LineOverflow(..) | ErrorKind::TrailingWhitespace => {
208 errs.has_operational_errors = true;
210 ErrorKind::BadIssue(_)
211 | ErrorKind::LicenseCheck
212 | ErrorKind::DeprecatedAttr
214 | ErrorKind::VersionMismatch => {
215 errs.has_check_errors = true;
222 fn add_diff(&mut self) {
223 self.internal.borrow_mut().1.has_diff = true;
226 fn add_macro_format_failure(&mut self) {
227 self.internal.borrow_mut().1.has_macro_format_failure = true;
230 fn add_parsing_error(&mut self) {
231 self.internal.borrow_mut().1.has_parsing_errors = true;
234 fn warning_count(&self) -> usize {
239 .map(|(_, errors)| errors.len())
243 /// Whether any warnings or errors are present in the report.
244 pub fn has_warnings(&self) -> bool {
245 self.internal.borrow().1.has_formatting_errors
248 /// Print the report to a terminal using colours and potentially other
252 mut t: Box<term::Terminal<Output = io::Stderr>>,
253 ) -> Result<(), term::Error> {
254 for (file, errors) in &self.internal.borrow().0 {
255 for error in errors {
256 let prefix_space_len = error.line.to_string().len();
257 let prefix_spaces = " ".repeat(1 + prefix_space_len);
259 // First line: the overview of error
260 t.fg(term::color::RED)?;
261 t.attr(term::Attr::Bold)?;
262 write!(t, "{} ", error.msg_prefix())?;
264 t.attr(term::Attr::Bold)?;
265 writeln!(t, "{}", error.kind)?;
267 // Second line: file info
268 write!(t, "{}--> ", &prefix_spaces[1..])?;
270 writeln!(t, "{}:{}", file, error.line)?;
272 // Third to fifth lines: show the line which triggered error, if available.
273 if !error.line_buffer.is_empty() {
274 let (space_len, target_len) = error.format_len();
275 t.attr(term::Attr::Bold)?;
276 write!(t, "{}|\n{} | ", prefix_spaces, error.line)?;
278 writeln!(t, "{}", error.line_buffer)?;
279 t.attr(term::Attr::Bold)?;
280 write!(t, "{}| ", prefix_spaces)?;
281 t.fg(term::color::RED)?;
282 writeln!(t, "{}", FormatReport::target_str(space_len, target_len))?;
286 // The last line: show note if available.
287 let msg_suffix = error.msg_suffix();
288 if !msg_suffix.is_empty() {
289 t.attr(term::Attr::Bold)?;
290 write!(t, "{}= note: ", prefix_spaces)?;
292 writeln!(t, "{}", error.msg_suffix())?;
300 if !self.internal.borrow().0.is_empty() {
301 t.attr(term::Attr::Bold)?;
302 write!(t, "warning: ")?;
306 "rustfmt may have failed to format. See previous {} errors.\n\n",
307 self.warning_count(),
314 fn target_str(space_len: usize, target_len: usize) -> String {
315 let empty_line = " ".repeat(space_len);
316 let overflowed = "^".repeat(target_len);
317 empty_line + &overflowed
321 impl fmt::Display for FormatReport {
322 // Prints all the formatting errors.
323 fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
324 for (file, errors) in &self.internal.borrow().0 {
325 for error in errors {
326 let prefix_space_len = error.line.to_string().len();
327 let prefix_spaces = " ".repeat(1 + prefix_space_len);
329 let error_line_buffer = if error.line_buffer.is_empty() {
332 let (space_len, target_len) = error.format_len();
334 "{}|\n{} | {}\n{}| {}",
339 FormatReport::target_str(space_len, target_len)
343 let error_info = format!("{} {}", error.msg_prefix(), error.kind);
344 let file_info = format!("{}--> {}:{}", &prefix_spaces[1..], file, error.line);
345 let msg_suffix = error.msg_suffix();
346 let note = if msg_suffix.is_empty() {
349 format!("{}note= ", prefix_spaces)
363 if !self.internal.borrow().0.is_empty() {
366 "warning: rustfmt may have failed to format. See previous {} errors.",
367 self.warning_count(),
374 /// Format the given snippet. The snippet is expected to be *complete* code.
375 /// When we cannot parse the given snippet, this function returns `None`.
376 fn format_snippet(snippet: &str, config: &Config) -> Option<FormattedSnippet> {
377 let mut config = config.clone();
378 panic::catch_unwind(|| {
379 let mut out: Vec<u8> = Vec::with_capacity(snippet.len() * 2);
380 config.set().emit_mode(config::EmitMode::Stdout);
381 config.set().verbose(Verbosity::Quiet);
382 config.set().hide_parse_errors(true);
384 let (formatting_error, result) = {
385 let input = Input::Text(snippet.into());
386 let mut session = Session::new(config, Some(&mut out));
387 let result = session.format(input);
389 session.errors.has_macro_format_failure
390 || session.out.as_ref().unwrap().is_empty() && !snippet.is_empty()
395 if formatting_error {
398 String::from_utf8(out).ok().map(|snippet| FormattedSnippet {
400 non_formatted_ranges: result.unwrap().non_formatted_ranges,
404 // Discard panics encountered while formatting the snippet
405 // The ? operator is needed to remove the extra Option
409 /// Format the given code block. Mainly targeted for code block in comment.
410 /// The code block may be incomplete (i.e. parser may be unable to parse it).
411 /// To avoid panic in parser, we wrap the code block with a dummy function.
412 /// The returned code block does *not* end with newline.
413 fn format_code_block(code_snippet: &str, config: &Config) -> Option<FormattedSnippet> {
414 const FN_MAIN_PREFIX: &str = "fn main() {\n";
416 fn enclose_in_main_block(s: &str, config: &Config) -> String {
417 let indent = Indent::from_width(config, config.tab_spaces());
418 let mut result = String::with_capacity(s.len() * 2);
419 result.push_str(FN_MAIN_PREFIX);
420 let mut need_indent = true;
421 for (kind, line) in LineClasses::new(s) {
423 result.push_str(&indent.to_string(config));
425 result.push_str(&line);
427 need_indent = !kind.is_string() || line.ends_with('\\');
433 // Wrap the given code block with `fn main()` if it does not have one.
434 let snippet = enclose_in_main_block(code_snippet, config);
435 let mut result = String::with_capacity(snippet.len());
436 let mut is_first = true;
438 // While formatting the code, ignore the config's newline style setting and always use "\n"
439 // instead of "\r\n" for the newline characters. This is okay because the output here is
440 // not directly outputted by rustfmt command, but used by the comment formatter's input.
441 // We have output-file-wide "\n" ==> "\r\n" conversion process after here if it's necessary.
442 let mut config_with_unix_newline = config.clone();
443 config_with_unix_newline
445 .newline_style(NewlineStyle::Unix);
446 let mut formatted = format_snippet(&snippet, &config_with_unix_newline)?;
447 // Remove wrapping main block
448 formatted.unwrap_code_block();
450 // Trim "fn main() {" on the first line and "}" on the last line,
451 // then unindent the whole code block.
452 let block_len = formatted
455 .unwrap_or(formatted.snippet.len());
456 let mut is_indented = true;
457 for (kind, ref line) in LineClasses::new(&formatted.snippet[FN_MAIN_PREFIX.len()..block_len]) {
463 let trimmed_line = if !is_indented {
465 } else if line.len() > config.max_width() {
466 // If there are lines that are larger than max width, we cannot tell
467 // whether we have succeeded but have some comments or strings that
468 // are too long, or we have failed to format code block. We will be
469 // conservative and just return `None` in this case.
471 } else if line.len() > config.tab_spaces() {
472 // Make sure that the line has leading whitespaces.
473 let indent_str = Indent::from_width(config, config.tab_spaces()).to_string(config);
474 if line.starts_with(indent_str.as_ref()) {
475 let offset = if config.hard_tabs() {
487 result.push_str(trimmed_line);
488 is_indented = !kind.is_string() || line.ends_with('\\');
490 Some(FormattedSnippet {
492 non_formatted_ranges: formatted.non_formatted_ranges,
496 /// A session is a run of rustfmt across a single or multiple inputs.
497 pub struct Session<'b, T: Write + 'b> {
499 pub out: Option<&'b mut T>,
500 pub(crate) errors: ReportedErrors,
501 source_file: SourceFile,
504 impl<'b, T: Write + 'b> Session<'b, T> {
505 pub fn new(config: Config, out: Option<&'b mut T>) -> Session<'b, T> {
506 if config.emit_mode() == EmitMode::Checkstyle {
507 println!("{}", checkstyle::header());
513 errors: ReportedErrors::default(),
514 source_file: SourceFile::new(),
518 /// The main entry point for Rustfmt. Formats the given input according to the
519 /// given config. `out` is only necessary if required by the configuration.
520 pub fn format(&mut self, input: Input) -> Result<FormatReport, ErrorKind> {
521 self.format_input_inner(input)
524 pub fn override_config<F, U>(&mut self, mut config: Config, f: F) -> U
526 F: FnOnce(&mut Session<'b, T>) -> U,
528 mem::swap(&mut config, &mut self.config);
529 let result = f(self);
530 mem::swap(&mut config, &mut self.config);
534 pub fn add_operational_error(&mut self) {
535 self.errors.has_operational_errors = true;
538 pub fn has_operational_errors(&self) -> bool {
539 self.errors.has_operational_errors
542 pub fn has_parsing_errors(&self) -> bool {
543 self.errors.has_parsing_errors
546 pub fn has_formatting_errors(&self) -> bool {
547 self.errors.has_formatting_errors
550 pub fn has_check_errors(&self) -> bool {
551 self.errors.has_check_errors
554 pub fn has_diff(&self) -> bool {
558 pub fn has_no_errors(&self) -> bool {
559 !(self.has_operational_errors()
560 || self.has_parsing_errors()
561 || self.has_formatting_errors()
562 || self.has_check_errors()
564 || self.errors.has_macro_format_failure
568 impl<'b, T: Write + 'b> Drop for Session<'b, T> {
570 if self.config.emit_mode() == EmitMode::Checkstyle {
571 println!("{}", checkstyle::footer());
583 fn is_text(&self) -> bool {
585 Input::File(_) => false,
586 Input::Text(_) => true,
590 fn file_name(&self) -> FileName {
592 Input::File(ref file) => FileName::Real(file.clone()),
593 Input::Text(..) => FileName::Stdin,
603 fn test_no_panic_on_format_snippet_and_format_code_block() {
604 // `format_snippet()` and `format_code_block()` should not panic
605 // even when we cannot parse the given snippet.
607 assert!(format_snippet(snippet, &Config::default()).is_none());
608 assert!(format_code_block(snippet, &Config::default()).is_none());
611 fn test_format_inner<F>(formatter: F, input: &str, expected: &str) -> bool
613 F: Fn(&str, &Config) -> Option<FormattedSnippet>,
615 let output = formatter(input, &Config::default());
616 output.is_some() && output.unwrap().snippet == expected
620 fn test_format_snippet() {
621 let snippet = "fn main() { println!(\"hello, world\"); }";
623 let expected = "fn main() {\n \
624 println!(\"hello, world\");\n\
627 let expected = "fn main() {\r\n \
628 println!(\"hello, world\");\r\n\
630 assert!(test_format_inner(format_snippet, snippet, expected));
634 fn test_format_code_block_fail() {
636 let code_block = "this_line_is_100_characters_long_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx(x, y, z);";
637 assert!(format_code_block(code_block, &Config::default()).is_none());
641 fn test_format_code_block() {
643 let code_block = "let x=3;";
644 let expected = "let x = 3;";
645 assert!(test_format_inner(format_code_block, code_block, expected));
647 // more complex code block, taken from chains.rs.
649 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
651 chain_indent(context, shape.add_offset(parent_rewrite.len())),
652 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
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
660 IndentStyle::Visual => (parent_shape, false),
664 chain_indent(context, shape.add_offset(parent_rewrite.len())),
670 "let (nested_shape, extend) = if !parent_rewrite_contains_newline && is_continuable(&parent) {
672 chain_indent(context, shape.add_offset(parent_rewrite.len())),
673 context.config.indent_style() == IndentStyle::Visual || is_small_parent,
675 } else if is_block_expr(context, &parent, &parent_rewrite) {
676 match context.config.indent_style() {
677 // Try to put the first child on the same line with parent's last line
678 IndentStyle::Block => (parent_shape.block_indent(context.config.tab_spaces()), true),
679 // The parent is a block, so align the rest of the chain with the closing
681 IndentStyle::Visual => (parent_shape, false),
685 chain_indent(context, shape.add_offset(parent_rewrite.len())),
689 assert!(test_format_inner(format_code_block, code_block, expected));