1 //! The SourceMap tracks all the source code used within a single crate, mapping
2 //! from integer byte positions to the original source code location. Each bit
3 //! of source parsed during crate parsing (typically files, in-memory strings,
4 //! or various bits of macro expansion) cover a continuous range of bytes in the
5 //! SourceMap and are represented by SourceFiles. Byte positions are stored in
6 //! `spans` and used pervasively in the compiler. They are absolute positions
7 //! within the SourceMap, which upon request can be converted to line and column
8 //! information, source code snippets, etc.
11 pub use syntax_pos::*;
12 pub use syntax_pos::hygiene::{ExpnFormat, ExpnInfo};
13 pub use ExpnFormat::*;
15 use rustc_data_structures::fx::FxHashMap;
16 use rustc_data_structures::stable_hasher::StableHasher;
17 use rustc_data_structures::sync::{Lrc, Lock, LockGuard, MappedLockGuard};
20 use std::path::{Path, PathBuf};
27 use errors::SourceMapper;
29 /// Returns the span itself if it doesn't come from a macro expansion,
30 /// otherwise return the call site span up to the `enclosing_sp` by
31 /// following the `expn_info` chain.
32 pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span {
33 let call_site1 = sp.ctxt().outer().expn_info().map(|ei| ei.call_site);
34 let call_site2 = enclosing_sp.ctxt().outer().expn_info().map(|ei| ei.call_site);
35 match (call_site1, call_site2) {
37 (Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp,
38 (Some(call_site1), _) => original_sp(call_site1, enclosing_sp),
42 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
43 pub struct Spanned<T> {
48 pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
49 Spanned {node: t, span: sp}
52 pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
56 // _____________________________________________________________________________
57 // SourceFile, MultiByteChar, FileName, FileLines
60 /// An abstraction over the fs operations used by the Parser.
61 pub trait FileLoader {
62 /// Query the existence of a file.
63 fn file_exists(&self, path: &Path) -> bool;
65 /// Returns an absolute path to a file, if possible.
66 fn abs_path(&self, path: &Path) -> Option<PathBuf>;
68 /// Read the contents of an UTF-8 file into memory.
69 fn read_file(&self, path: &Path) -> io::Result<String>;
72 /// A FileLoader that uses std::fs to load real files.
73 pub struct RealFileLoader;
75 impl FileLoader for RealFileLoader {
76 fn file_exists(&self, path: &Path) -> bool {
77 fs::metadata(path).is_ok()
80 fn abs_path(&self, path: &Path) -> Option<PathBuf> {
81 if path.is_absolute() {
82 Some(path.to_path_buf())
86 .map(|cwd| cwd.join(path))
90 fn read_file(&self, path: &Path) -> io::Result<String> {
91 fs::read_to_string(path)
95 // This is a SourceFile identifier that is used to correlate SourceFiles between
96 // subsequent compilation sessions (which is something we need to do during
97 // incremental compilation).
98 #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
99 pub struct StableSourceFileId(u128);
101 impl StableSourceFileId {
102 pub fn new(source_file: &SourceFile) -> StableSourceFileId {
103 StableSourceFileId::new_from_pieces(&source_file.name,
104 source_file.name_was_remapped,
105 source_file.unmapped_path.as_ref())
108 pub fn new_from_pieces(name: &FileName,
109 name_was_remapped: bool,
110 unmapped_path: Option<&FileName>) -> StableSourceFileId {
111 let mut hasher = StableHasher::new();
113 name.hash(&mut hasher);
114 name_was_remapped.hash(&mut hasher);
115 unmapped_path.hash(&mut hasher);
117 StableSourceFileId(hasher.finish())
121 // _____________________________________________________________________________
126 pub(super) struct SourceMapFiles {
127 pub(super) source_files: Vec<Lrc<SourceFile>>,
128 stable_id_to_source_file: FxHashMap<StableSourceFileId, Lrc<SourceFile>>
131 pub struct SourceMap {
132 pub(super) files: Lock<SourceMapFiles>,
133 file_loader: Box<dyn FileLoader + Sync + Send>,
134 // This is used to apply the file path remapping as specified via
135 // --remap-path-prefix to all SourceFiles allocated within this SourceMap.
136 path_mapping: FilePathMapping,
140 pub fn new(path_mapping: FilePathMapping) -> SourceMap {
142 files: Default::default(),
143 file_loader: Box::new(RealFileLoader),
148 pub fn with_file_loader(file_loader: Box<dyn FileLoader + Sync + Send>,
149 path_mapping: FilePathMapping)
152 files: Default::default(),
153 file_loader: file_loader,
158 pub fn path_mapping(&self) -> &FilePathMapping {
162 pub fn file_exists(&self, path: &Path) -> bool {
163 self.file_loader.file_exists(path)
166 pub fn load_file(&self, path: &Path) -> io::Result<Lrc<SourceFile>> {
167 let src = self.file_loader.read_file(path)?;
168 let filename = path.to_owned().into();
169 Ok(self.new_source_file(filename, src))
172 pub fn files(&self) -> MappedLockGuard<'_, Vec<Lrc<SourceFile>>> {
173 LockGuard::map(self.files.borrow(), |files| &mut files.source_files)
176 pub fn source_file_by_stable_id(&self, stable_id: StableSourceFileId) ->
177 Option<Lrc<SourceFile>> {
178 self.files.borrow().stable_id_to_source_file.get(&stable_id).map(|sf| sf.clone())
181 fn next_start_pos(&self) -> usize {
182 match self.files.borrow().source_files.last() {
184 // Add one so there is some space between files. This lets us distinguish
185 // positions in the source_map, even in the presence of zero-length files.
186 Some(last) => last.end_pos.to_usize() + 1,
190 /// Creates a new source_file.
191 /// If a file already exists in the source_map with the same id, that file is returned
193 pub fn new_source_file(&self, filename: FileName, src: String) -> Lrc<SourceFile> {
194 let start_pos = self.next_start_pos();
196 // The path is used to determine the directory for loading submodules and
197 // include files, so it must be before remapping.
198 // Note that filename may not be a valid path, eg it may be `<anon>` etc,
199 // but this is okay because the directory determined by `path.pop()` will
200 // be empty, so the working directory will be used.
201 let unmapped_path = filename.clone();
203 let (filename, was_remapped) = match filename {
204 FileName::Real(filename) => {
205 let (filename, was_remapped) = self.path_mapping.map_prefix(filename);
206 (FileName::Real(filename), was_remapped)
208 other => (other, false),
211 let file_id = StableSourceFileId::new_from_pieces(&filename,
213 Some(&unmapped_path));
215 return match self.source_file_by_stable_id(file_id) {
216 Some(lrc_sf) => lrc_sf,
218 let source_file = Lrc::new(SourceFile::new(
223 Pos::from_usize(start_pos),
226 let mut files = self.files.borrow_mut();
228 files.source_files.push(source_file.clone());
229 files.stable_id_to_source_file.insert(file_id, source_file.clone());
236 /// Allocates a new SourceFile representing a source file from an external
237 /// crate. The source code of such an "imported source_file" is not available,
238 /// but we still know enough to generate accurate debuginfo location
239 /// information for things inlined from other crates.
240 pub fn new_imported_source_file(
243 name_was_remapped: bool,
244 crate_of_origin: u32,
248 mut file_local_lines: Vec<BytePos>,
249 mut file_local_multibyte_chars: Vec<MultiByteChar>,
250 mut file_local_non_narrow_chars: Vec<NonNarrowChar>,
251 ) -> Lrc<SourceFile> {
252 let start_pos = self.next_start_pos();
254 let end_pos = Pos::from_usize(start_pos + source_len);
255 let start_pos = Pos::from_usize(start_pos);
257 for pos in &mut file_local_lines {
258 *pos = *pos + start_pos;
261 for mbc in &mut file_local_multibyte_chars {
262 mbc.pos = mbc.pos + start_pos;
265 for swc in &mut file_local_non_narrow_chars {
266 *swc = *swc + start_pos;
269 let source_file = Lrc::new(SourceFile {
276 external_src: Lock::new(ExternalSource::AbsentOk),
279 lines: file_local_lines,
280 multibyte_chars: file_local_multibyte_chars,
281 non_narrow_chars: file_local_non_narrow_chars,
285 let mut files = self.files.borrow_mut();
287 files.source_files.push(source_file.clone());
288 files.stable_id_to_source_file.insert(StableSourceFileId::new(&source_file),
289 source_file.clone());
294 pub fn mk_substr_filename(&self, sp: Span) -> String {
295 let pos = self.lookup_char_pos(sp.lo());
296 format!("<{}:{}:{}>",
299 pos.col.to_usize() + 1)
302 // If there is a doctest_offset, apply it to the line
303 pub fn doctest_offset_line(&self, file: &FileName, orig: usize) -> usize {
305 FileName::DocTest(_, offset) => {
306 return if *offset >= 0 {
307 orig + *offset as usize
309 orig - (-(*offset)) as usize
316 /// Lookup source information about a BytePos
317 pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
318 let chpos = self.bytepos_to_file_charpos(pos);
319 match self.lookup_line(pos) {
320 Ok(SourceFileAndLine { sf: f, line: a }) => {
321 let line = a + 1; // Line numbers start at 1
322 let linebpos = f.lines[a];
323 let linechpos = self.bytepos_to_file_charpos(linebpos);
324 let col = chpos - linechpos;
327 let start_width_idx = f
329 .binary_search_by_key(&linebpos, |x| x.pos())
330 .unwrap_or_else(|x| x);
331 let end_width_idx = f
333 .binary_search_by_key(&pos, |x| x.pos())
334 .unwrap_or_else(|x| x);
335 let special_chars = end_width_idx - start_width_idx;
336 let non_narrow: usize = f
337 .non_narrow_chars[start_width_idx..end_width_idx]
341 col.0 - special_chars + non_narrow
343 debug!("byte pos {:?} is on the line at byte pos {:?}",
345 debug!("char pos {:?} is on the line at char pos {:?}",
347 debug!("byte is on line: {}", line);
348 assert!(chpos >= linechpos);
358 let end_width_idx = f
360 .binary_search_by_key(&pos, |x| x.pos())
361 .unwrap_or_else(|x| x);
362 let non_narrow: usize = f
363 .non_narrow_chars[0..end_width_idx]
367 chpos.0 - end_width_idx + non_narrow
379 // If the relevant source_file is empty, we don't return a line number.
380 pub fn lookup_line(&self, pos: BytePos) -> Result<SourceFileAndLine, Lrc<SourceFile>> {
381 let idx = self.lookup_source_file_idx(pos);
383 let f = (*self.files.borrow().source_files)[idx].clone();
385 match f.lookup_line(pos) {
386 Some(line) => Ok(SourceFileAndLine { sf: f, line: line }),
391 pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
392 let loc = self.lookup_char_pos(pos);
394 filename: loc.file.name.clone(),
401 /// Returns `Some(span)`, a union of the lhs and rhs span. The lhs must precede the rhs. If
402 /// there are gaps between lhs and rhs, the resulting union will cross these gaps.
403 /// For this to work, the spans have to be:
405 /// * the ctxt of both spans much match
406 /// * the lhs span needs to end on the same line the rhs span begins
407 /// * the lhs span must start at or before the rhs span
408 pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
409 // make sure we're at the same expansion id
410 if sp_lhs.ctxt() != sp_rhs.ctxt() {
414 let lhs_end = match self.lookup_line(sp_lhs.hi()) {
416 Err(_) => return None
418 let rhs_begin = match self.lookup_line(sp_rhs.lo()) {
420 Err(_) => return None
423 // if we must cross lines to merge, don't merge
424 if lhs_end.line != rhs_begin.line {
428 // ensure these follow the expected order and we don't overlap
429 if (sp_lhs.lo() <= sp_rhs.lo()) && (sp_lhs.hi() <= sp_rhs.lo()) {
430 Some(sp_lhs.to(sp_rhs))
436 pub fn span_to_string(&self, sp: Span) -> String {
437 if self.files.borrow().source_files.is_empty() && sp.is_dummy() {
438 return "no-location".to_string();
441 let lo = self.lookup_char_pos_adj(sp.lo());
442 let hi = self.lookup_char_pos_adj(sp.hi());
443 format!("{}:{}:{}: {}:{}",
446 lo.col.to_usize() + 1,
448 hi.col.to_usize() + 1)
451 pub fn span_to_filename(&self, sp: Span) -> FileName {
452 self.lookup_char_pos(sp.lo()).file.name.clone()
455 pub fn span_to_unmapped_path(&self, sp: Span) -> FileName {
456 self.lookup_char_pos(sp.lo()).file.unmapped_path.clone()
457 .expect("SourceMap::span_to_unmapped_path called for imported SourceFile?")
460 pub fn is_multiline(&self, sp: Span) -> bool {
461 let lo = self.lookup_char_pos(sp.lo());
462 let hi = self.lookup_char_pos(sp.hi());
466 pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
467 debug!("span_to_lines(sp={:?})", sp);
469 if sp.lo() > sp.hi() {
470 return Err(SpanLinesError::IllFormedSpan(sp));
473 let lo = self.lookup_char_pos(sp.lo());
474 debug!("span_to_lines: lo={:?}", lo);
475 let hi = self.lookup_char_pos(sp.hi());
476 debug!("span_to_lines: hi={:?}", hi);
478 if lo.file.start_pos != hi.file.start_pos {
479 return Err(SpanLinesError::DistinctSources(DistinctSources {
480 begin: (lo.file.name.clone(), lo.file.start_pos),
481 end: (hi.file.name.clone(), hi.file.start_pos),
484 assert!(hi.line >= lo.line);
486 let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
488 // The span starts partway through the first line,
489 // but after that it starts from offset 0.
490 let mut start_col = lo.col;
492 // For every line but the last, it extends from `start_col`
493 // and to the end of the line. Be careful because the line
494 // numbers in Loc are 1-based, so we subtract 1 to get 0-based
496 for line_index in lo.line-1 .. hi.line-1 {
497 let line_len = lo.file.get_line(line_index)
498 .map(|s| s.chars().count())
500 lines.push(LineInfo { line_index,
502 end_col: CharPos::from_usize(line_len) });
503 start_col = CharPos::from_usize(0);
506 // For the last line, it extends from `start_col` to `hi.col`:
507 lines.push(LineInfo { line_index: hi.line - 1,
511 Ok(FileLines {file: lo.file, lines: lines})
514 /// Extracts the source surrounding the given `Span` using the `extract_source` function. The
515 /// extract function takes three arguments: a string slice containing the source, an index in
516 /// the slice for the beginning of the span and an index in the slice for the end of the span.
517 fn span_to_source<F>(&self, sp: Span, extract_source: F) -> Result<String, SpanSnippetError>
518 where F: Fn(&str, usize, usize) -> String
520 if sp.lo() > sp.hi() {
521 return Err(SpanSnippetError::IllFormedSpan(sp));
524 let local_begin = self.lookup_byte_offset(sp.lo());
525 let local_end = self.lookup_byte_offset(sp.hi());
527 if local_begin.sf.start_pos != local_end.sf.start_pos {
528 return Err(SpanSnippetError::DistinctSources(DistinctSources {
529 begin: (local_begin.sf.name.clone(),
530 local_begin.sf.start_pos),
531 end: (local_end.sf.name.clone(),
532 local_end.sf.start_pos)
535 self.ensure_source_file_source_present(local_begin.sf.clone());
537 let start_index = local_begin.pos.to_usize();
538 let end_index = local_end.pos.to_usize();
539 let source_len = (local_begin.sf.end_pos -
540 local_begin.sf.start_pos).to_usize();
542 if start_index > end_index || end_index > source_len {
543 return Err(SpanSnippetError::MalformedForSourcemap(
544 MalformedSourceMapPositions {
545 name: local_begin.sf.name.clone(),
547 begin_pos: local_begin.pos,
548 end_pos: local_end.pos,
552 if let Some(ref src) = local_begin.sf.src {
553 return Ok(extract_source(src, start_index, end_index));
554 } else if let Some(src) = local_begin.sf.external_src.borrow().get_source() {
555 return Ok(extract_source(src, start_index, end_index));
557 return Err(SpanSnippetError::SourceNotAvailable {
558 filename: local_begin.sf.name.clone()
564 /// Returns the source snippet as `String` corresponding to the given `Span`
565 pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
566 self.span_to_source(sp, |src, start_index, end_index| src[start_index..end_index]
570 pub fn span_to_margin(&self, sp: Span) -> Option<usize> {
571 match self.span_to_prev_source(sp) {
573 Ok(source) => source.split('\n').last().map(|last_line| {
574 last_line.len() - last_line.trim_start().len()
579 /// Returns the source snippet as `String` before the given `Span`
580 pub fn span_to_prev_source(&self, sp: Span) -> Result<String, SpanSnippetError> {
581 self.span_to_source(sp, |src, start_index, _| src[..start_index].to_string())
584 /// Extend the given `Span` to just after the previous occurrence of `c`. Return the same span
585 /// if no character could be found or if an error occurred while retrieving the code snippet.
586 pub fn span_extend_to_prev_char(&self, sp: Span, c: char) -> Span {
587 if let Ok(prev_source) = self.span_to_prev_source(sp) {
588 let prev_source = prev_source.rsplit(c).nth(0).unwrap_or("").trim_start();
589 if !prev_source.is_empty() && !prev_source.contains('\n') {
590 return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
597 /// Extend the given `Span` to just after the previous occurrence of `pat` when surrounded by
598 /// whitespace. Return the same span if no character could be found or if an error occurred
599 /// while retrieving the code snippet.
600 pub fn span_extend_to_prev_str(&self, sp: Span, pat: &str, accept_newlines: bool) -> Span {
601 // assure that the pattern is delimited, to avoid the following
603 // ^^^^ returned span without the check
604 // ---------- correct span
605 for ws in &[" ", "\t", "\n"] {
606 let pat = pat.to_owned() + ws;
607 if let Ok(prev_source) = self.span_to_prev_source(sp) {
608 let prev_source = prev_source.rsplit(&pat).nth(0).unwrap_or("").trim_start();
609 if !prev_source.is_empty() && (!prev_source.contains('\n') || accept_newlines) {
610 return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
618 /// Given a `Span`, try to get a shorter span ending before the first occurrence of `c` `char`
619 pub fn span_until_char(&self, sp: Span, c: char) -> Span {
620 match self.span_to_snippet(sp) {
622 let snippet = snippet.split(c).nth(0).unwrap_or("").trim_end();
623 if !snippet.is_empty() && !snippet.contains('\n') {
624 sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32))
633 /// Given a `Span`, try to get a shorter span ending just after the first occurrence of `char`
635 pub fn span_through_char(&self, sp: Span, c: char) -> Span {
636 if let Ok(snippet) = self.span_to_snippet(sp) {
637 if let Some(offset) = snippet.find(c) {
638 return sp.with_hi(BytePos(sp.lo().0 + (offset + c.len_utf8()) as u32));
644 /// Given a `Span`, get a new `Span` covering the first token and all its trailing whitespace or
645 /// the original `Span`.
647 /// If `sp` points to `"let mut x"`, then a span pointing at `"let "` will be returned.
648 pub fn span_until_non_whitespace(&self, sp: Span) -> Span {
649 let mut whitespace_found = false;
651 self.span_take_while(sp, |c| {
652 if !whitespace_found && c.is_whitespace() {
653 whitespace_found = true;
656 if whitespace_found && !c.is_whitespace() {
664 /// Given a `Span`, get a new `Span` covering the first token without its trailing whitespace or
665 /// the original `Span` in case of error.
667 /// If `sp` points to `"let mut x"`, then a span pointing at `"let"` will be returned.
668 pub fn span_until_whitespace(&self, sp: Span) -> Span {
669 self.span_take_while(sp, |c| !c.is_whitespace())
672 /// Given a `Span`, get a shorter one until `predicate` yields false.
673 pub fn span_take_while<P>(&self, sp: Span, predicate: P) -> Span
674 where P: for <'r> FnMut(&'r char) -> bool
676 if let Ok(snippet) = self.span_to_snippet(sp) {
677 let offset = snippet.chars()
678 .take_while(predicate)
679 .map(|c| c.len_utf8())
682 sp.with_hi(BytePos(sp.lo().0 + (offset as u32)))
688 pub fn def_span(&self, sp: Span) -> Span {
689 self.span_until_char(sp, '{')
692 /// Returns a new span representing just the start-point of this span
693 pub fn start_point(&self, sp: Span) -> Span {
695 let width = self.find_width_of_character_at_span(sp, false);
696 let corrected_start_position = pos.checked_add(width).unwrap_or(pos);
697 let end_point = BytePos(cmp::max(corrected_start_position, sp.lo().0));
698 sp.with_hi(end_point)
701 /// Returns a new span representing just the end-point of this span
702 pub fn end_point(&self, sp: Span) -> Span {
705 let width = self.find_width_of_character_at_span(sp, false);
706 let corrected_end_position = pos.checked_sub(width).unwrap_or(pos);
708 let end_point = BytePos(cmp::max(corrected_end_position, sp.lo().0));
709 sp.with_lo(end_point)
712 /// Returns a new span representing the next character after the end-point of this span
713 pub fn next_point(&self, sp: Span) -> Span {
714 let start_of_next_point = sp.hi().0;
716 let width = self.find_width_of_character_at_span(sp, true);
717 // If the width is 1, then the next span should point to the same `lo` and `hi`. However,
718 // in the case of a multibyte character, where the width != 1, the next span should
719 // span multiple bytes to include the whole character.
720 let end_of_next_point = start_of_next_point.checked_add(
721 width - 1).unwrap_or(start_of_next_point);
723 let end_of_next_point = BytePos(cmp::max(sp.lo().0 + 1, end_of_next_point));
724 Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt())
727 /// Finds the width of a character, either before or after the provided span.
728 fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 {
729 // Disregard malformed spans and assume a one-byte wide character.
730 if sp.lo() >= sp.hi() {
731 debug!("find_width_of_character_at_span: early return malformed span");
735 let local_begin = self.lookup_byte_offset(sp.lo());
736 let local_end = self.lookup_byte_offset(sp.hi());
737 debug!("find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`",
738 local_begin, local_end);
740 let start_index = local_begin.pos.to_usize();
741 let end_index = local_end.pos.to_usize();
742 debug!("find_width_of_character_at_span: start_index=`{:?}`, end_index=`{:?}`",
743 start_index, end_index);
745 // Disregard indexes that are at the start or end of their spans, they can't fit bigger
747 if (!forwards && end_index == usize::min_value()) ||
748 (forwards && start_index == usize::max_value()) {
749 debug!("find_width_of_character_at_span: start or end of span, cannot be multibyte");
753 let source_len = (local_begin.sf.end_pos - local_begin.sf.start_pos).to_usize();
754 debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len);
755 // Ensure indexes are also not malformed.
756 if start_index > end_index || end_index > source_len {
757 debug!("find_width_of_character_at_span: source indexes are malformed");
761 let src = local_begin.sf.external_src.borrow();
763 // We need to extend the snippet to the end of the src rather than to end_index so when
764 // searching forwards for boundaries we've got somewhere to search.
765 let snippet = if let Some(ref src) = local_begin.sf.src {
767 (&src[start_index..len])
768 } else if let Some(src) = src.get_source() {
770 (&src[start_index..len])
774 debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet);
776 let mut target = if forwards { end_index + 1 } else { end_index - 1 };
777 debug!("find_width_of_character_at_span: initial target=`{:?}`", target);
779 while !snippet.is_char_boundary(target - start_index) && target < source_len {
780 target = if forwards {
783 match target.checked_sub(1) {
784 Some(target) => target,
790 debug!("find_width_of_character_at_span: target=`{:?}`", target);
792 debug!("find_width_of_character_at_span: final target=`{:?}`", target);
795 (target - end_index) as u32
797 (end_index - target) as u32
801 pub fn get_source_file(&self, filename: &FileName) -> Option<Lrc<SourceFile>> {
802 for sf in self.files.borrow().source_files.iter() {
803 if *filename == sf.name {
804 return Some(sf.clone());
810 /// For a global BytePos compute the local offset within the containing SourceFile
811 pub fn lookup_byte_offset(&self, bpos: BytePos) -> SourceFileAndBytePos {
812 let idx = self.lookup_source_file_idx(bpos);
813 let sf = (*self.files.borrow().source_files)[idx].clone();
814 let offset = bpos - sf.start_pos;
815 SourceFileAndBytePos {sf: sf, pos: offset}
818 /// Converts an absolute BytePos to a CharPos relative to the source_file.
819 pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
820 let idx = self.lookup_source_file_idx(bpos);
821 let map = &(*self.files.borrow().source_files)[idx];
823 // The number of extra bytes due to multibyte chars in the SourceFile
824 let mut total_extra_bytes = 0;
826 for mbc in map.multibyte_chars.iter() {
827 debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos);
829 // every character is at least one byte, so we only
830 // count the actual extra bytes.
831 total_extra_bytes += mbc.bytes as u32 - 1;
832 // We should never see a byte position in the middle of a
834 assert!(bpos.to_u32() >= mbc.pos.to_u32() + mbc.bytes as u32);
840 assert!(map.start_pos.to_u32() + total_extra_bytes <= bpos.to_u32());
841 CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes as usize)
844 // Return the index of the source_file (in self.files) which contains pos.
845 pub fn lookup_source_file_idx(&self, pos: BytePos) -> usize {
846 let files = self.files.borrow();
847 let files = &files.source_files;
848 let count = files.len();
850 // Binary search for the source_file.
855 if files[m].start_pos > pos {
862 assert!(a < count, "position {} does not resolve to a source location", pos.to_usize());
867 pub fn count_lines(&self) -> usize {
868 self.files().iter().fold(0, |a, f| a + f.count_lines())
872 pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> {
873 let prev_span = self.span_extend_to_prev_str(span, "fn", true);
874 self.span_to_snippet(prev_span).map(|snippet| {
875 let len = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
876 .expect("no label after fn");
877 prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32))
881 /// Take the span of a type parameter in a function signature and try to generate a span for the
882 /// function name (with generics) and a new snippet for this span with the pointed type
883 /// parameter as a new local type parameter.
886 /// ```rust,ignore (pseudo-Rust)
888 /// fn my_function(param: T)
889 /// // ^ Original span
892 /// fn my_function(param: T)
893 /// // ^^^^^^^^^^^ Generated span with snippet `my_function<T>`
896 /// Attention: The method used is very fragile since it essentially duplicates the work of the
897 /// parser. If you need to use this function or something similar, please consider updating the
898 /// source_map functions and this function to something more robust.
899 pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> {
900 // Try to extend the span to the previous "fn" keyword to retrieve the function
902 let sugg_span = self.span_extend_to_prev_str(span, "fn", false);
903 if sugg_span != span {
904 if let Ok(snippet) = self.span_to_snippet(sugg_span) {
905 // Consume the function name
906 let mut offset = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
907 .expect("no label after fn");
909 // Consume the generics part of the function signature
910 let mut bracket_counter = 0;
911 let mut last_char = None;
912 for c in snippet[offset..].chars() {
914 '<' => bracket_counter += 1,
915 '>' => bracket_counter -= 1,
916 '(' => if bracket_counter == 0 { break; }
919 offset += c.len_utf8();
923 // Adjust the suggestion span to encompass the function name with its generics
924 let sugg_span = sugg_span.with_hi(BytePos(sugg_span.lo().0 + offset as u32));
926 // Prepare the new suggested snippet to append the type parameter that triggered
927 // the error in the generics of the function signature
928 let mut new_snippet = if last_char == Some('>') {
929 format!("{}, ", &snippet[..(offset - '>'.len_utf8())])
931 format!("{}<", &snippet[..offset])
933 new_snippet.push_str(
934 &self.span_to_snippet(span).unwrap_or_else(|_| "T".to_string()));
935 new_snippet.push('>');
937 return Some((sugg_span, new_snippet));
945 impl SourceMapper for SourceMap {
946 fn lookup_char_pos(&self, pos: BytePos) -> Loc {
947 self.lookup_char_pos(pos)
949 fn span_to_lines(&self, sp: Span) -> FileLinesResult {
950 self.span_to_lines(sp)
952 fn span_to_string(&self, sp: Span) -> String {
953 self.span_to_string(sp)
955 fn span_to_filename(&self, sp: Span) -> FileName {
956 self.span_to_filename(sp)
958 fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
959 self.merge_spans(sp_lhs, sp_rhs)
961 fn call_span_if_macro(&self, sp: Span) -> Span {
962 if self.span_to_filename(sp.clone()).is_macros() {
963 let v = sp.macro_backtrace();
964 if let Some(use_site) = v.last() {
965 return use_site.call_site;
970 fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool {
971 source_file.add_external_src(
972 || match source_file.name {
973 FileName::Real(ref name) => self.file_loader.read_file(name).ok(),
978 fn doctest_offset_line(&self, file: &FileName, line: usize) -> usize {
979 self.doctest_offset_line(file, line)
984 pub struct FilePathMapping {
985 mapping: Vec<(PathBuf, PathBuf)>,
988 impl FilePathMapping {
989 pub fn empty() -> FilePathMapping {
995 pub fn new(mapping: Vec<(PathBuf, PathBuf)>) -> FilePathMapping {
1001 /// Applies any path prefix substitution as defined by the mapping.
1002 /// The return value is the remapped path and a boolean indicating whether
1003 /// the path was affected by the mapping.
1004 pub fn map_prefix(&self, path: PathBuf) -> (PathBuf, bool) {
1005 // NOTE: We are iterating over the mapping entries from last to first
1006 // because entries specified later on the command line should
1008 for &(ref from, ref to) in self.mapping.iter().rev() {
1009 if let Ok(rest) = path.strip_prefix(from) {
1010 return (to.join(rest), true);
1018 // _____________________________________________________________________________
1025 use rustc_data_structures::sync::Lrc;
1027 fn init_source_map() -> SourceMap {
1028 let sm = SourceMap::new(FilePathMapping::empty());
1029 sm.new_source_file(PathBuf::from("blork.rs").into(),
1030 "first line.\nsecond line".to_string());
1031 sm.new_source_file(PathBuf::from("empty.rs").into(),
1033 sm.new_source_file(PathBuf::from("blork2.rs").into(),
1034 "first line.\nsecond line".to_string());
1040 // Test lookup_byte_offset
1041 let sm = init_source_map();
1043 let srcfbp1 = sm.lookup_byte_offset(BytePos(23));
1044 assert_eq!(srcfbp1.sf.name, PathBuf::from("blork.rs").into());
1045 assert_eq!(srcfbp1.pos, BytePos(23));
1047 let srcfbp1 = sm.lookup_byte_offset(BytePos(24));
1048 assert_eq!(srcfbp1.sf.name, PathBuf::from("empty.rs").into());
1049 assert_eq!(srcfbp1.pos, BytePos(0));
1051 let srcfbp2 = sm.lookup_byte_offset(BytePos(25));
1052 assert_eq!(srcfbp2.sf.name, PathBuf::from("blork2.rs").into());
1053 assert_eq!(srcfbp2.pos, BytePos(0));
1058 // Test bytepos_to_file_charpos
1059 let sm = init_source_map();
1061 let cp1 = sm.bytepos_to_file_charpos(BytePos(22));
1062 assert_eq!(cp1, CharPos(22));
1064 let cp2 = sm.bytepos_to_file_charpos(BytePos(25));
1065 assert_eq!(cp2, CharPos(0));
1070 // Test zero-length source_files.
1071 let sm = init_source_map();
1073 let loc1 = sm.lookup_char_pos(BytePos(22));
1074 assert_eq!(loc1.file.name, PathBuf::from("blork.rs").into());
1075 assert_eq!(loc1.line, 2);
1076 assert_eq!(loc1.col, CharPos(10));
1078 let loc2 = sm.lookup_char_pos(BytePos(25));
1079 assert_eq!(loc2.file.name, PathBuf::from("blork2.rs").into());
1080 assert_eq!(loc2.line, 1);
1081 assert_eq!(loc2.col, CharPos(0));
1084 fn init_source_map_mbc() -> SourceMap {
1085 let sm = SourceMap::new(FilePathMapping::empty());
1086 // € is a three byte utf8 char.
1087 sm.new_source_file(PathBuf::from("blork.rs").into(),
1088 "fir€st €€€€ line.\nsecond line".to_string());
1089 sm.new_source_file(PathBuf::from("blork2.rs").into(),
1090 "first line€€.\n€ second line".to_string());
1096 // Test bytepos_to_file_charpos in the presence of multi-byte chars
1097 let sm = init_source_map_mbc();
1099 let cp1 = sm.bytepos_to_file_charpos(BytePos(3));
1100 assert_eq!(cp1, CharPos(3));
1102 let cp2 = sm.bytepos_to_file_charpos(BytePos(6));
1103 assert_eq!(cp2, CharPos(4));
1105 let cp3 = sm.bytepos_to_file_charpos(BytePos(56));
1106 assert_eq!(cp3, CharPos(12));
1108 let cp4 = sm.bytepos_to_file_charpos(BytePos(61));
1109 assert_eq!(cp4, CharPos(15));
1114 // Test span_to_lines for a span ending at the end of source_file
1115 let sm = init_source_map();
1116 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1117 let file_lines = sm.span_to_lines(span).unwrap();
1119 assert_eq!(file_lines.file.name, PathBuf::from("blork.rs").into());
1120 assert_eq!(file_lines.lines.len(), 1);
1121 assert_eq!(file_lines.lines[0].line_index, 1);
1124 /// Given a string like " ~~~~~~~~~~~~ ", produces a span
1125 /// converting that range. The idea is that the string has the same
1126 /// length as the input, and we uncover the byte positions. Note
1127 /// that this can span lines and so on.
1128 fn span_from_selection(input: &str, selection: &str) -> Span {
1129 assert_eq!(input.len(), selection.len());
1130 let left_index = selection.find('~').unwrap() as u32;
1131 let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
1132 Span::new(BytePos(left_index), BytePos(right_index + 1), NO_EXPANSION)
1135 /// Tests span_to_snippet and span_to_lines for a span converting 3
1136 /// lines in the middle of a file.
1138 fn span_to_snippet_and_lines_spanning_multiple_lines() {
1139 let sm = SourceMap::new(FilePathMapping::empty());
1140 let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
1141 let selection = " \n ~~\n~~~\n~~~~~ \n \n";
1142 sm.new_source_file(Path::new("blork.rs").to_owned().into(), inputtext.to_string());
1143 let span = span_from_selection(inputtext, selection);
1145 // check that we are extracting the text we thought we were extracting
1146 assert_eq!(&sm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD");
1148 // check that span_to_lines gives us the complete result with the lines/cols we expected
1149 let lines = sm.span_to_lines(span).unwrap();
1150 let expected = vec![
1151 LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) },
1152 LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) },
1153 LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) }
1155 assert_eq!(lines.lines, expected);
1160 // Test span_to_snippet for a span ending at the end of source_file
1161 let sm = init_source_map();
1162 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1163 let snippet = sm.span_to_snippet(span);
1165 assert_eq!(snippet, Ok("second line".to_string()));
1170 // Test span_to_str for a span ending at the end of source_file
1171 let sm = init_source_map();
1172 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1173 let sstr = sm.span_to_string(span);
1175 assert_eq!(sstr, "blork.rs:2:1: 2:12");
1178 /// Tests failing to merge two spans on different lines
1180 fn span_merging_fail() {
1181 let sm = SourceMap::new(FilePathMapping::empty());
1182 let inputtext = "bbbb BB\ncc CCC\n";
1183 let selection1 = " ~~\n \n";
1184 let selection2 = " \n ~~~\n";
1185 sm.new_source_file(Path::new("blork.rs").to_owned().into(), inputtext.to_owned());
1186 let span1 = span_from_selection(inputtext, selection1);
1187 let span2 = span_from_selection(inputtext, selection2);
1189 assert!(sm.merge_spans(span1, span2).is_none());
1192 /// Returns the span corresponding to the `n`th occurrence of
1193 /// `substring` in `source_text`.
1194 trait SourceMapExtension {
1195 fn span_substr(&self,
1196 file: &Lrc<SourceFile>,
1203 impl SourceMapExtension for SourceMap {
1204 fn span_substr(&self,
1205 file: &Lrc<SourceFile>,
1211 println!("span_substr(file={:?}/{:?}, substring={:?}, n={})",
1212 file.name, file.start_pos, substring, n);
1216 let offset = source_text[hi..].find(substring).unwrap_or_else(|| {
1217 panic!("source_text `{}` does not have {} occurrences of `{}`, only {}",
1218 source_text, n, substring, i);
1220 let lo = hi + offset;
1221 hi = lo + substring.len();
1223 let span = Span::new(
1224 BytePos(lo as u32 + file.start_pos.0),
1225 BytePos(hi as u32 + file.start_pos.0),
1228 assert_eq!(&self.span_to_snippet(span).unwrap()[..],