1 // High level formatting functions.
2
3 use std::collections::HashMap;
4 use std::io::{self, Write};
5 use std::time::{Duration, Instant};
6
7 use rustc_ast::ast;
8 use rustc_span::Span;
9
10 use self::newline_style::apply_newline_style;
11 use crate::comment::{CharClasses, FullCodeCharKind};
12 use crate::config::{Config, FileName, Verbosity};
13 use crate::formatting::generated::is_generated_file;
14 use crate::modules::Module;
15 use crate::parse::parser::{DirectoryOwnership, Parser, ParserError};
16 use crate::parse::session::ParseSess;
17 use crate::utils::{contains_skip, count_newlines};
18 use crate::visitor::FmtVisitor;
19 use crate::{modules, source_file, ErrorKind, FormatReport, Input, Session};
20
21 mod generated;
22 mod newline_style;
23
24 // A map of the files of a crate, with their new content
25 pub(crate) type SourceFile = Vec<FileRecord>;
26 pub(crate) type FileRecord = (FileName, String);
27
28 impl<'b, T: Write + 'b> Session<'b, T> {
format_input_inner( &mut self, input: Input, is_macro_def: bool, ) -> Result<FormatReport, ErrorKind>29 pub(crate) fn format_input_inner(
30 &mut self,
31 input: Input,
32 is_macro_def: bool,
33 ) -> Result<FormatReport, ErrorKind> {
34 if !self.config.version_meets_requirement() {
35 return Err(ErrorKind::VersionMismatch);
36 }
37
38 rustc_span::create_session_if_not_set_then(self.config.edition().into(), |_| {
39 if self.config.disable_all_formatting() {
40 // When the input is from stdin, echo back the input.
41 return match input {
42 Input::Text(ref buf) => echo_back_stdin(buf),
43 _ => Ok(FormatReport::new()),
44 };
45 }
46
47 let config = &self.config.clone();
48 let format_result = format_project(input, config, self, is_macro_def);
49
50 format_result.map(|report| {
51 self.errors.add(&report.internal.borrow().1);
52 report
53 })
54 })
55 }
56 }
57
58 /// Determine if a module should be skipped. True if the module should be skipped, false otherwise.
should_skip_module<T: FormatHandler>( config: &Config, context: &FormatContext<'_, T>, input_is_stdin: bool, main_file: &FileName, path: &FileName, module: &Module<'_>, ) -> bool59 fn should_skip_module<T: FormatHandler>(
60 config: &Config,
61 context: &FormatContext<'_, T>,
62 input_is_stdin: bool,
63 main_file: &FileName,
64 path: &FileName,
65 module: &Module<'_>,
66 ) -> bool {
67 if contains_skip(module.attrs()) {
68 return true;
69 }
70
71 if config.skip_children() && path != main_file {
72 return true;
73 }
74
75 if !input_is_stdin && context.ignore_file(path) {
76 return true;
77 }
78
79 // FIXME(calebcartwright) - we need to determine how we'll handle the
80 // `format_generated_files` option with stdin based input.
81 if !input_is_stdin && !config.format_generated_files() {
82 let source_file = context.parse_session.span_to_file_contents(module.span);
83 let src = source_file.src.as_ref().expect("SourceFile without src");
84
85 if is_generated_file(src) {
86 return true;
87 }
88 }
89
90 false
91 }
92
echo_back_stdin(input: &str) -> Result<FormatReport, ErrorKind>93 fn echo_back_stdin(input: &str) -> Result<FormatReport, ErrorKind> {
94 if let Err(e) = io::stdout().write_all(input.as_bytes()) {
95 return Err(From::from(e));
96 }
97 Ok(FormatReport::new())
98 }
99
100 // Format an entire crate (or subset of the module tree).
format_project<T: FormatHandler>( input: Input, config: &Config, handler: &mut T, is_macro_def: bool, ) -> Result<FormatReport, ErrorKind>101 fn format_project<T: FormatHandler>(
102 input: Input,
103 config: &Config,
104 handler: &mut T,
105 is_macro_def: bool,
106 ) -> Result<FormatReport, ErrorKind> {
107 let mut timer = Timer::start();
108
109 let main_file = input.file_name();
110 let input_is_stdin = main_file == FileName::Stdin;
111
112 let parse_session = ParseSess::new(config)?;
113 if config.skip_children() && parse_session.ignore_file(&main_file) {
114 return Ok(FormatReport::new());
115 }
116
117 // Parse the crate.
118 let mut report = FormatReport::new();
119 let directory_ownership = input.to_directory_ownership();
120 let krate = match Parser::parse_crate(input, &parse_session) {
121 Ok(krate) => krate,
122 // Surface parse error via Session (errors are merged there from report)
123 Err(e) => {
124 let forbid_verbose = input_is_stdin || e != ParserError::ParsePanicError;
125 should_emit_verbose(forbid_verbose, config, || {
126 eprintln!("The Rust parser panicked");
127 });
128 report.add_parsing_error();
129 return Ok(report);
130 }
131 };
132
133 let mut context = FormatContext::new(&krate, report, parse_session, config, handler);
134 let files = modules::ModResolver::new(
135 &context.parse_session,
136 directory_ownership.unwrap_or(DirectoryOwnership::UnownedViaBlock),
137 !input_is_stdin && !config.skip_children(),
138 )
139 .visit_crate(&krate)?
140 .into_iter()
141 .filter(|(path, module)| {
142 input_is_stdin
143 || !should_skip_module(config, &context, input_is_stdin, &main_file, path, module)
144 })
145 .collect::<Vec<_>>();
146
147 timer = timer.done_parsing();
148
149 // Suppress error output if we have to do any further parsing.
150 context.parse_session.set_silent_emitter();
151
152 for (path, module) in files {
153 if input_is_stdin && contains_skip(module.attrs()) {
154 return echo_back_stdin(
155 context
156 .parse_session
157 .snippet_provider(module.span)
158 .entire_snippet(),
159 );
160 }
161 should_emit_verbose(input_is_stdin, config, || println!("Formatting {}", path));
162 context.format_file(path, &module, is_macro_def)?;
163 }
164 timer = timer.done_formatting();
165
166 should_emit_verbose(input_is_stdin, config, || {
167 println!(
168 "Spent {0:.3} secs in the parsing phase, and {1:.3} secs in the formatting phase",
169 timer.get_parse_time(),
170 timer.get_format_time(),
171 )
172 });
173
174 Ok(context.report)
175 }
176
177 // Used for formatting files.
178 struct FormatContext<'a, T: FormatHandler> {
179 krate: &'a ast::Crate,
180 report: FormatReport,
181 parse_session: ParseSess,
182 config: &'a Config,
183 handler: &'a mut T,
184 }
185
186 impl<'a, T: FormatHandler + 'a> FormatContext<'a, T> {
new( krate: &'a ast::Crate, report: FormatReport, parse_session: ParseSess, config: &'a Config, handler: &'a mut T, ) -> Self187 fn new(
188 krate: &'a ast::Crate,
189 report: FormatReport,
190 parse_session: ParseSess,
191 config: &'a Config,
192 handler: &'a mut T,
193 ) -> Self {
194 FormatContext {
195 krate,
196 report,
197 parse_session,
198 config,
199 handler,
200 }
201 }
202
ignore_file(&self, path: &FileName) -> bool203 fn ignore_file(&self, path: &FileName) -> bool {
204 self.parse_session.ignore_file(path)
205 }
206
207 // Formats a single file/module.
format_file( &mut self, path: FileName, module: &Module<'_>, is_macro_def: bool, ) -> Result<(), ErrorKind>208 fn format_file(
209 &mut self,
210 path: FileName,
211 module: &Module<'_>,
212 is_macro_def: bool,
213 ) -> Result<(), ErrorKind> {
214 let snippet_provider = self.parse_session.snippet_provider(module.span);
215 let mut visitor = FmtVisitor::from_parse_sess(
216 &self.parse_session,
217 self.config,
218 &snippet_provider,
219 self.report.clone(),
220 );
221 visitor.skip_context.update_with_attrs(&self.krate.attrs);
222 visitor.is_macro_def = is_macro_def;
223 visitor.last_pos = snippet_provider.start_pos();
224 visitor.skip_empty_lines(snippet_provider.end_pos());
225 visitor.format_separate_mod(module, snippet_provider.end_pos());
226
227 debug_assert_eq!(
228 visitor.line_number,
229 count_newlines(&visitor.buffer),
230 "failed in format_file visitor.buffer:\n {:?}",
231 &visitor.buffer
232 );
233
234 // For some reason, the source_map does not include terminating
235 // newlines so we must add one on for each file. This is sad.
236 source_file::append_newline(&mut visitor.buffer);
237
238 format_lines(
239 &mut visitor.buffer,
240 &path,
241 &visitor.skipped_range.borrow(),
242 self.config,
243 &self.report,
244 );
245
246 apply_newline_style(
247 self.config.newline_style(),
248 &mut visitor.buffer,
249 snippet_provider.entire_snippet(),
250 );
251
252 if visitor.macro_rewrite_failure {
253 self.report.add_macro_format_failure();
254 }
255 self.report
256 .add_non_formatted_ranges(visitor.skipped_range.borrow().clone());
257
258 self.handler.handle_formatted_file(
259 &self.parse_session,
260 path,
261 visitor.buffer.to_owned(),
262 &mut self.report,
263 )
264 }
265 }
266
267 // Handle the results of formatting.
268 trait FormatHandler {
handle_formatted_file( &mut self, parse_session: &ParseSess, path: FileName, result: String, report: &mut FormatReport, ) -> Result<(), ErrorKind>269 fn handle_formatted_file(
270 &mut self,
271 parse_session: &ParseSess,
272 path: FileName,
273 result: String,
274 report: &mut FormatReport,
275 ) -> Result<(), ErrorKind>;
276 }
277
278 impl<'b, T: Write + 'b> FormatHandler for Session<'b, T> {
279 // Called for each formatted file.
handle_formatted_file( &mut self, parse_session: &ParseSess, path: FileName, result: String, report: &mut FormatReport, ) -> Result<(), ErrorKind>280 fn handle_formatted_file(
281 &mut self,
282 parse_session: &ParseSess,
283 path: FileName,
284 result: String,
285 report: &mut FormatReport,
286 ) -> Result<(), ErrorKind> {
287 if let Some(ref mut out) = self.out {
288 match source_file::write_file(
289 Some(parse_session),
290 &path,
291 &result,
292 out,
293 &mut *self.emitter,
294 self.config.newline_style(),
295 ) {
296 Ok(ref result) if result.has_diff => report.add_diff(),
297 Err(e) => {
298 // Create a new error with path_str to help users see which files failed
299 let err_msg = format!("{}: {}", path, e);
300 return Err(io::Error::new(e.kind(), err_msg).into());
301 }
302 _ => {}
303 }
304 }
305
306 self.source_file.push((path, result));
307 Ok(())
308 }
309 }
310
311 pub(crate) struct FormattingError {
312 pub(crate) line: usize,
313 pub(crate) kind: ErrorKind,
314 is_comment: bool,
315 is_string: bool,
316 pub(crate) line_buffer: String,
317 }
318
319 impl FormattingError {
from_span( span: Span, parse_sess: &ParseSess, kind: ErrorKind, ) -> FormattingError320 pub(crate) fn from_span(
321 span: Span,
322 parse_sess: &ParseSess,
323 kind: ErrorKind,
324 ) -> FormattingError {
325 FormattingError {
326 line: parse_sess.line_of_byte_pos(span.lo()),
327 is_comment: kind.is_comment(),
328 kind,
329 is_string: false,
330 line_buffer: parse_sess.span_to_first_line_string(span),
331 }
332 }
333
is_internal(&self) -> bool334 pub(crate) fn is_internal(&self) -> bool {
335 match self.kind {
336 ErrorKind::LineOverflow(..)
337 | ErrorKind::TrailingWhitespace
338 | ErrorKind::IoError(_)
339 | ErrorKind::ParseError
340 | ErrorKind::LostComment => true,
341 _ => false,
342 }
343 }
344
msg_suffix(&self) -> &str345 pub(crate) fn msg_suffix(&self) -> &str {
346 if self.is_comment || self.is_string {
347 "set `error_on_unformatted = false` to suppress \
348 the warning against comments or string literals\n"
349 } else {
350 ""
351 }
352 }
353
354 // (space, target)
format_len(&self) -> (usize, usize)355 pub(crate) fn format_len(&self) -> (usize, usize) {
356 match self.kind {
357 ErrorKind::LineOverflow(found, max) => (max, found - max),
358 ErrorKind::TrailingWhitespace
359 | ErrorKind::DeprecatedAttr
360 | ErrorKind::BadAttr
361 | ErrorKind::LostComment => {
362 let trailing_ws_start = self
363 .line_buffer
364 .rfind(|c: char| !c.is_whitespace())
365 .map(|pos| pos + 1)
366 .unwrap_or(0);
367 (
368 trailing_ws_start,
369 self.line_buffer.len() - trailing_ws_start,
370 )
371 }
372 _ => unreachable!(),
373 }
374 }
375 }
376
377 pub(crate) type FormatErrorMap = HashMap<FileName, Vec<FormattingError>>;
378
379 #[derive(Default, Debug, PartialEq)]
380 pub(crate) struct ReportedErrors {
381 // Encountered e.g., an IO error.
382 pub(crate) has_operational_errors: bool,
383
384 // Failed to reformat code because of parsing errors.
385 pub(crate) has_parsing_errors: bool,
386
387 // Code is valid, but it is impossible to format it properly.
388 pub(crate) has_formatting_errors: bool,
389
390 // Code contains macro call that was unable to format.
391 pub(crate) has_macro_format_failure: bool,
392
393 // Failed an opt-in checking.
394 pub(crate) has_check_errors: bool,
395
396 /// Formatted code differs from existing code (--check only).
397 pub(crate) has_diff: bool,
398
399 /// Formatted code missed something, like lost comments or extra trailing space
400 pub(crate) has_unformatted_code_errors: bool,
401 }
402
403 impl ReportedErrors {
404 /// Combine two summaries together.
add(&mut self, other: &ReportedErrors)405 pub(crate) fn add(&mut self, other: &ReportedErrors) {
406 self.has_operational_errors |= other.has_operational_errors;
407 self.has_parsing_errors |= other.has_parsing_errors;
408 self.has_formatting_errors |= other.has_formatting_errors;
409 self.has_macro_format_failure |= other.has_macro_format_failure;
410 self.has_check_errors |= other.has_check_errors;
411 self.has_diff |= other.has_diff;
412 self.has_unformatted_code_errors |= other.has_unformatted_code_errors;
413 }
414 }
415
416 #[derive(Clone, Copy, Debug)]
417 enum Timer {
418 Disabled,
419 Initialized(Instant),
420 DoneParsing(Instant, Instant),
421 DoneFormatting(Instant, Instant, Instant),
422 }
423
424 impl Timer {
start() -> Timer425 fn start() -> Timer {
426 if cfg!(target_arch = "wasm32") {
427 Timer::Disabled
428 } else {
429 Timer::Initialized(Instant::now())
430 }
431 }
done_parsing(self) -> Self432 fn done_parsing(self) -> Self {
433 match self {
434 Timer::Disabled => Timer::Disabled,
435 Timer::Initialized(init_time) => Timer::DoneParsing(init_time, Instant::now()),
436 _ => panic!("Timer can only transition to DoneParsing from Initialized state"),
437 }
438 }
439
done_formatting(self) -> Self440 fn done_formatting(self) -> Self {
441 match self {
442 Timer::Disabled => Timer::Disabled,
443 Timer::DoneParsing(init_time, parse_time) => {
444 Timer::DoneFormatting(init_time, parse_time, Instant::now())
445 }
446 _ => panic!("Timer can only transition to DoneFormatting from DoneParsing state"),
447 }
448 }
449
450 /// Returns the time it took to parse the source files in seconds.
get_parse_time(&self) -> f32451 fn get_parse_time(&self) -> f32 {
452 match *self {
453 Timer::Disabled => panic!("this platform cannot time execution"),
454 Timer::DoneParsing(init, parse_time) | Timer::DoneFormatting(init, parse_time, _) => {
455 // This should never underflow since `Instant::now()` guarantees monotonicity.
456 Self::duration_to_f32(parse_time.duration_since(init))
457 }
458 Timer::Initialized(..) => unreachable!(),
459 }
460 }
461
462 /// Returns the time it took to go from the parsed AST to the formatted output. Parsing time is
463 /// not included.
get_format_time(&self) -> f32464 fn get_format_time(&self) -> f32 {
465 match *self {
466 Timer::Disabled => panic!("this platform cannot time execution"),
467 Timer::DoneFormatting(_init, parse_time, format_time) => {
468 Self::duration_to_f32(format_time.duration_since(parse_time))
469 }
470 Timer::DoneParsing(..) | Timer::Initialized(..) => unreachable!(),
471 }
472 }
473
duration_to_f32(d: Duration) -> f32474 fn duration_to_f32(d: Duration) -> f32 {
475 d.as_secs() as f32 + d.subsec_nanos() as f32 / 1_000_000_000f32
476 }
477 }
478
479 // Formatting done on a char by char or line by line basis.
480 // FIXME(#20): other stuff for parity with make tidy.
format_lines( text: &mut String, name: &FileName, skipped_range: &[(usize, usize)], config: &Config, report: &FormatReport, )481 fn format_lines(
482 text: &mut String,
483 name: &FileName,
484 skipped_range: &[(usize, usize)],
485 config: &Config,
486 report: &FormatReport,
487 ) {
488 let mut formatter = FormatLines::new(name, skipped_range, config);
489 formatter.iterate(text);
490
491 if formatter.newline_count > 1 {
492 debug!("track truncate: {} {}", text.len(), formatter.newline_count);
493 let line = text.len() - formatter.newline_count + 1;
494 text.truncate(line);
495 }
496
497 report.append(name.clone(), formatter.errors);
498 }
499
500 struct FormatLines<'a> {
501 name: &'a FileName,
502 skipped_range: &'a [(usize, usize)],
503 last_was_space: bool,
504 line_len: usize,
505 cur_line: usize,
506 newline_count: usize,
507 errors: Vec<FormattingError>,
508 line_buffer: String,
509 current_line_contains_string_literal: bool,
510 format_line: bool,
511 config: &'a Config,
512 }
513
514 impl<'a> FormatLines<'a> {
new( name: &'a FileName, skipped_range: &'a [(usize, usize)], config: &'a Config, ) -> FormatLines<'a>515 fn new(
516 name: &'a FileName,
517 skipped_range: &'a [(usize, usize)],
518 config: &'a Config,
519 ) -> FormatLines<'a> {
520 FormatLines {
521 name,
522 skipped_range,
523 last_was_space: false,
524 line_len: 0,
525 cur_line: 1,
526 newline_count: 0,
527 errors: vec![],
528 line_buffer: String::with_capacity(config.max_width() * 2),
529 current_line_contains_string_literal: false,
530 format_line: config.file_lines().contains_line(name, 1),
531 config,
532 }
533 }
534
535 // Iterate over the chars in the file map.
iterate(&mut self, text: &mut String)536 fn iterate(&mut self, text: &mut String) {
537 for (kind, c) in CharClasses::new(text.chars()) {
538 if c == '\r' {
539 continue;
540 }
541
542 if c == '\n' {
543 self.new_line(kind);
544 } else {
545 self.char(c, kind);
546 }
547 }
548 }
549
new_line(&mut self, kind: FullCodeCharKind)550 fn new_line(&mut self, kind: FullCodeCharKind) {
551 if self.format_line {
552 // Check for (and record) trailing whitespace.
553 if self.last_was_space {
554 if self.should_report_error(kind, &ErrorKind::TrailingWhitespace)
555 && !self.is_skipped_line()
556 {
557 self.push_err(
558 ErrorKind::TrailingWhitespace,
559 kind.is_comment(),
560 kind.is_string(),
561 );
562 }
563 self.line_len -= 1;
564 }
565
566 // Check for any line width errors we couldn't correct.
567 let error_kind = ErrorKind::LineOverflow(self.line_len, self.config.max_width());
568 if self.line_len > self.config.max_width()
569 && !self.is_skipped_line()
570 && self.should_report_error(kind, &error_kind)
571 {
572 let is_string = self.current_line_contains_string_literal;
573 self.push_err(error_kind, kind.is_comment(), is_string);
574 }
575 }
576
577 self.line_len = 0;
578 self.cur_line += 1;
579 self.format_line = self
580 .config
581 .file_lines()
582 .contains_line(self.name, self.cur_line);
583 self.newline_count += 1;
584 self.last_was_space = false;
585 self.line_buffer.clear();
586 self.current_line_contains_string_literal = false;
587 }
588
char(&mut self, c: char, kind: FullCodeCharKind)589 fn char(&mut self, c: char, kind: FullCodeCharKind) {
590 self.newline_count = 0;
591 self.line_len += if c == '\t' {
592 self.config.tab_spaces()
593 } else {
594 1
595 };
596 self.last_was_space = c.is_whitespace();
597 self.line_buffer.push(c);
598 if kind.is_string() {
599 self.current_line_contains_string_literal = true;
600 }
601 }
602
push_err(&mut self, kind: ErrorKind, is_comment: bool, is_string: bool)603 fn push_err(&mut self, kind: ErrorKind, is_comment: bool, is_string: bool) {
604 self.errors.push(FormattingError {
605 line: self.cur_line,
606 kind,
607 is_comment,
608 is_string,
609 line_buffer: self.line_buffer.clone(),
610 });
611 }
612
should_report_error(&self, char_kind: FullCodeCharKind, error_kind: &ErrorKind) -> bool613 fn should_report_error(&self, char_kind: FullCodeCharKind, error_kind: &ErrorKind) -> bool {
614 let allow_error_report = if char_kind.is_comment()
615 || self.current_line_contains_string_literal
616 || error_kind.is_comment()
617 {
618 self.config.error_on_unformatted()
619 } else {
620 true
621 };
622
623 match error_kind {
624 ErrorKind::LineOverflow(..) => {
625 self.config.error_on_line_overflow() && allow_error_report
626 }
627 ErrorKind::TrailingWhitespace | ErrorKind::LostComment => allow_error_report,
628 _ => true,
629 }
630 }
631
632 /// Returns `true` if the line with the given line number was skipped by `#[rustfmt::skip]`.
is_skipped_line(&self) -> bool633 fn is_skipped_line(&self) -> bool {
634 self.skipped_range
635 .iter()
636 .any(|&(lo, hi)| lo <= self.cur_line && self.cur_line <= hi)
637 }
638 }
639
should_emit_verbose<F>(forbid_verbose_output: bool, config: &Config, f: F) where F: Fn(),640 fn should_emit_verbose<F>(forbid_verbose_output: bool, config: &Config, f: F)
641 where
642 F: Fn(),
643 {
644 if config.verbose() == Verbosity::Verbose && !forbid_verbose_output {
645 f();
646 }
647 }
648