1 // Copyright 2012 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 //! The SourceMap tracks all the source code used within a single crate, mapping
12 //! from integer byte positions to the original source code location. Each bit
13 //! of source parsed during crate parsing (typically files, in-memory strings,
14 //! or various bits of macro expansion) cover a continuous range of bytes in the
15 //! SourceMap and are represented by SourceFiles. Byte positions are stored in
16 //! `spans` and used pervasively in the compiler. They are absolute positions
17 //! within the SourceMap, which upon request can be converted to line and column
18 //! information, source code snippets, etc.
21 pub use syntax_pos::*;
22 pub use syntax_pos::hygiene::{ExpnFormat, ExpnInfo};
23 pub use self::ExpnFormat::*;
25 use rustc_data_structures::fx::FxHashMap;
26 use rustc_data_structures::stable_hasher::StableHasher;
27 use rustc_data_structures::sync::{Lrc, Lock, LockGuard};
30 use std::path::{Path, PathBuf};
34 use std::io::{self, Read};
35 use errors::SourceMapper;
37 /// Return the span itself if it doesn't come from a macro expansion,
38 /// otherwise return the call site span up to the `enclosing_sp` by
39 /// following the `expn_info` chain.
40 pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span {
41 let call_site1 = sp.ctxt().outer().expn_info().map(|ei| ei.call_site);
42 let call_site2 = enclosing_sp.ctxt().outer().expn_info().map(|ei| ei.call_site);
43 match (call_site1, call_site2) {
45 (Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp,
46 (Some(call_site1), _) => original_sp(call_site1, enclosing_sp),
50 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
51 pub struct Spanned<T> {
56 pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
57 Spanned {node: t, span: sp}
60 pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
64 // _____________________________________________________________________________
65 // SourceFile, MultiByteChar, FileName, FileLines
68 /// An abstraction over the fs operations used by the Parser.
69 pub trait FileLoader {
70 /// Query the existence of a file.
71 fn file_exists(&self, path: &Path) -> bool;
73 /// Return an absolute path to a file, if possible.
74 fn abs_path(&self, path: &Path) -> Option<PathBuf>;
76 /// Read the contents of an UTF-8 file into memory.
77 fn read_file(&self, path: &Path) -> io::Result<String>;
80 /// A FileLoader that uses std::fs to load real files.
81 pub struct RealFileLoader;
83 impl FileLoader for RealFileLoader {
84 fn file_exists(&self, path: &Path) -> bool {
85 fs::metadata(path).is_ok()
88 fn abs_path(&self, path: &Path) -> Option<PathBuf> {
89 if path.is_absolute() {
90 Some(path.to_path_buf())
94 .map(|cwd| cwd.join(path))
98 fn read_file(&self, path: &Path) -> io::Result<String> {
99 let mut src = String::new();
100 fs::File::open(path)?.read_to_string(&mut src)?;
105 // This is a SourceFile identifier that is used to correlate SourceFiles between
106 // subsequent compilation sessions (which is something we need to do during
107 // incremental compilation).
108 #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
109 pub struct StableFilemapId(u128);
111 impl StableFilemapId {
112 pub fn new(source_file: &SourceFile) -> StableFilemapId {
113 let mut hasher = StableHasher::new();
115 source_file.name.hash(&mut hasher);
116 source_file.name_was_remapped.hash(&mut hasher);
117 source_file.unmapped_path.hash(&mut hasher);
119 StableFilemapId(hasher.finish())
123 // _____________________________________________________________________________
127 pub(super) struct SourceMapFiles {
128 pub(super) file_maps: Vec<Lrc<SourceFile>>,
129 stable_id_to_source_file: FxHashMap<StableFilemapId, Lrc<SourceFile>>
132 pub struct SourceMap {
133 pub(super) files: Lock<SourceMapFiles>,
134 file_loader: Box<dyn FileLoader + Sync + Send>,
135 // This is used to apply the file path remapping as specified via
136 // --remap-path-prefix to all SourceFiles allocated within this SourceMap.
137 path_mapping: FilePathMapping,
138 /// In case we are in a doctest, replace all file names with the PathBuf,
139 /// and add the given offsets to the line info
140 doctest_offset: Option<(FileName, isize)>,
144 pub fn new(path_mapping: FilePathMapping) -> SourceMap {
146 files: Lock::new(SourceMapFiles {
147 file_maps: Vec::new(),
148 stable_id_to_source_file: FxHashMap(),
150 file_loader: Box::new(RealFileLoader),
152 doctest_offset: None,
156 pub fn new_doctest(path_mapping: FilePathMapping,
157 file: FileName, line: isize) -> SourceMap {
159 doctest_offset: Some((file, line)),
160 ..SourceMap::new(path_mapping)
165 pub fn with_file_loader(file_loader: Box<dyn FileLoader + Sync + Send>,
166 path_mapping: FilePathMapping)
169 files: Lock::new(SourceMapFiles {
170 file_maps: Vec::new(),
171 stable_id_to_source_file: FxHashMap(),
173 file_loader: file_loader,
175 doctest_offset: None,
179 pub fn path_mapping(&self) -> &FilePathMapping {
183 pub fn file_exists(&self, path: &Path) -> bool {
184 self.file_loader.file_exists(path)
187 pub fn load_file(&self, path: &Path) -> io::Result<Lrc<SourceFile>> {
188 let src = self.file_loader.read_file(path)?;
189 let filename = if let Some((ref name, _)) = self.doctest_offset {
192 path.to_owned().into()
194 Ok(self.new_source_file(filename, src))
197 pub fn files(&self) -> LockGuard<Vec<Lrc<SourceFile>>> {
198 LockGuard::map(self.files.borrow(), |files| &mut files.file_maps)
201 pub fn source_file_by_stable_id(&self, stable_id: StableFilemapId) -> Option<Lrc<SourceFile>> {
202 self.files.borrow().stable_id_to_source_file.get(&stable_id).map(|fm| fm.clone())
205 fn next_start_pos(&self) -> usize {
206 match self.files.borrow().file_maps.last() {
208 // Add one so there is some space between files. This lets us distinguish
209 // positions in the source_map, even in the presence of zero-length files.
210 Some(last) => last.end_pos.to_usize() + 1,
214 /// Creates a new source_file.
215 /// This does not ensure that only one SourceFile exists per file name.
216 pub fn new_source_file(&self, filename: FileName, src: String) -> Lrc<SourceFile> {
217 let start_pos = self.next_start_pos();
219 // The path is used to determine the directory for loading submodules and
220 // include files, so it must be before remapping.
221 // Note that filename may not be a valid path, eg it may be `<anon>` etc,
222 // but this is okay because the directory determined by `path.pop()` will
223 // be empty, so the working directory will be used.
224 let unmapped_path = filename.clone();
226 let (filename, was_remapped) = match filename {
227 FileName::Real(filename) => {
228 let (filename, was_remapped) = self.path_mapping.map_prefix(filename);
229 (FileName::Real(filename), was_remapped)
231 other => (other, false),
233 let source_file = Lrc::new(SourceFile::new(
238 Pos::from_usize(start_pos),
241 let mut files = self.files.borrow_mut();
243 files.file_maps.push(source_file.clone());
244 files.stable_id_to_source_file.insert(StableFilemapId::new(&source_file),
245 source_file.clone());
250 /// Allocates a new SourceFile representing a source file from an external
251 /// crate. The source code of such an "imported source_file" is not available,
252 /// but we still know enough to generate accurate debuginfo location
253 /// information for things inlined from other crates.
254 pub fn new_imported_source_file(&self,
256 name_was_remapped: bool,
257 crate_of_origin: u32,
261 mut file_local_lines: Vec<BytePos>,
262 mut file_local_multibyte_chars: Vec<MultiByteChar>,
263 mut file_local_non_narrow_chars: Vec<NonNarrowChar>)
265 let start_pos = self.next_start_pos();
267 let end_pos = Pos::from_usize(start_pos + source_len);
268 let start_pos = Pos::from_usize(start_pos);
270 for pos in &mut file_local_lines {
271 *pos = *pos + start_pos;
274 for mbc in &mut file_local_multibyte_chars {
275 mbc.pos = mbc.pos + start_pos;
278 for swc in &mut file_local_non_narrow_chars {
279 *swc = *swc + start_pos;
282 let source_file = Lrc::new(SourceFile {
289 external_src: Lock::new(ExternalSource::AbsentOk),
292 lines: file_local_lines,
293 multibyte_chars: file_local_multibyte_chars,
294 non_narrow_chars: file_local_non_narrow_chars,
298 let mut files = self.files.borrow_mut();
300 files.file_maps.push(source_file.clone());
301 files.stable_id_to_source_file.insert(StableFilemapId::new(&source_file),
302 source_file.clone());
307 pub fn mk_substr_filename(&self, sp: Span) -> String {
308 let pos = self.lookup_char_pos(sp.lo());
309 format!("<{}:{}:{}>",
312 pos.col.to_usize() + 1)
315 // If there is a doctest_offset, apply it to the line
316 pub fn doctest_offset_line(&self, mut orig: usize) -> usize {
317 if let Some((_, line)) = self.doctest_offset {
319 orig = orig + line as usize;
321 orig = orig - (-line) as usize;
327 /// Lookup source information about a BytePos
328 pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
329 let chpos = self.bytepos_to_file_charpos(pos);
330 match self.lookup_line(pos) {
331 Ok(SourceFileAndLine { fm: f, line: a }) => {
332 let line = a + 1; // Line numbers start at 1
333 let linebpos = f.lines[a];
334 let linechpos = self.bytepos_to_file_charpos(linebpos);
335 let col = chpos - linechpos;
338 let start_width_idx = f
340 .binary_search_by_key(&linebpos, |x| x.pos())
341 .unwrap_or_else(|x| x);
342 let end_width_idx = f
344 .binary_search_by_key(&pos, |x| x.pos())
345 .unwrap_or_else(|x| x);
346 let special_chars = end_width_idx - start_width_idx;
347 let non_narrow: usize = f
348 .non_narrow_chars[start_width_idx..end_width_idx]
352 col.0 - special_chars + non_narrow
354 debug!("byte pos {:?} is on the line at byte pos {:?}",
356 debug!("char pos {:?} is on the line at char pos {:?}",
358 debug!("byte is on line: {}", line);
359 assert!(chpos >= linechpos);
369 let end_width_idx = f
371 .binary_search_by_key(&pos, |x| x.pos())
372 .unwrap_or_else(|x| x);
373 let non_narrow: usize = f
374 .non_narrow_chars[0..end_width_idx]
378 chpos.0 - end_width_idx + non_narrow
390 // If the relevant source_file is empty, we don't return a line number.
391 pub fn lookup_line(&self, pos: BytePos) -> Result<SourceFileAndLine, Lrc<SourceFile>> {
392 let idx = self.lookup_source_file_idx(pos);
394 let f = (*self.files.borrow().file_maps)[idx].clone();
396 match f.lookup_line(pos) {
397 Some(line) => Ok(SourceFileAndLine { fm: f, line: line }),
402 pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
403 let loc = self.lookup_char_pos(pos);
405 filename: loc.file.name.clone(),
412 /// Returns `Some(span)`, a union of the lhs and rhs span. The lhs must precede the rhs. If
413 /// there are gaps between lhs and rhs, the resulting union will cross these gaps.
414 /// For this to work, the spans have to be:
416 /// * the ctxt of both spans much match
417 /// * the lhs span needs to end on the same line the rhs span begins
418 /// * the lhs span must start at or before the rhs span
419 pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
420 // make sure we're at the same expansion id
421 if sp_lhs.ctxt() != sp_rhs.ctxt() {
425 let lhs_end = match self.lookup_line(sp_lhs.hi()) {
427 Err(_) => return None
429 let rhs_begin = match self.lookup_line(sp_rhs.lo()) {
431 Err(_) => return None
434 // if we must cross lines to merge, don't merge
435 if lhs_end.line != rhs_begin.line {
439 // ensure these follow the expected order and we don't overlap
440 if (sp_lhs.lo() <= sp_rhs.lo()) && (sp_lhs.hi() <= sp_rhs.lo()) {
441 Some(sp_lhs.to(sp_rhs))
447 pub fn span_to_string(&self, sp: Span) -> String {
448 if self.files.borrow().file_maps.is_empty() && sp.is_dummy() {
449 return "no-location".to_string();
452 let lo = self.lookup_char_pos_adj(sp.lo());
453 let hi = self.lookup_char_pos_adj(sp.hi());
454 format!("{}:{}:{}: {}:{}",
457 lo.col.to_usize() + 1,
459 hi.col.to_usize() + 1)
462 pub fn span_to_filename(&self, sp: Span) -> FileName {
463 self.lookup_char_pos(sp.lo()).file.name.clone()
466 pub fn span_to_unmapped_path(&self, sp: Span) -> FileName {
467 self.lookup_char_pos(sp.lo()).file.unmapped_path.clone()
468 .expect("SourceMap::span_to_unmapped_path called for imported SourceFile?")
471 pub fn is_multiline(&self, sp: Span) -> bool {
472 let lo = self.lookup_char_pos(sp.lo());
473 let hi = self.lookup_char_pos(sp.hi());
477 pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
478 debug!("span_to_lines(sp={:?})", sp);
480 if sp.lo() > sp.hi() {
481 return Err(SpanLinesError::IllFormedSpan(sp));
484 let lo = self.lookup_char_pos(sp.lo());
485 debug!("span_to_lines: lo={:?}", lo);
486 let hi = self.lookup_char_pos(sp.hi());
487 debug!("span_to_lines: hi={:?}", hi);
489 if lo.file.start_pos != hi.file.start_pos {
490 return Err(SpanLinesError::DistinctSources(DistinctSources {
491 begin: (lo.file.name.clone(), lo.file.start_pos),
492 end: (hi.file.name.clone(), hi.file.start_pos),
495 assert!(hi.line >= lo.line);
497 let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
499 // The span starts partway through the first line,
500 // but after that it starts from offset 0.
501 let mut start_col = lo.col;
503 // For every line but the last, it extends from `start_col`
504 // and to the end of the line. Be careful because the line
505 // numbers in Loc are 1-based, so we subtract 1 to get 0-based
507 for line_index in lo.line-1 .. hi.line-1 {
508 let line_len = lo.file.get_line(line_index)
509 .map(|s| s.chars().count())
511 lines.push(LineInfo { line_index,
513 end_col: CharPos::from_usize(line_len) });
514 start_col = CharPos::from_usize(0);
517 // For the last line, it extends from `start_col` to `hi.col`:
518 lines.push(LineInfo { line_index: hi.line - 1,
522 Ok(FileLines {file: lo.file, lines: lines})
525 /// Extract the source surrounding the given `Span` using the `extract_source` function. The
526 /// extract function takes three arguments: a string slice containing the source, an index in
527 /// the slice for the beginning of the span and an index in the slice for the end of the span.
528 fn span_to_source<F>(&self, sp: Span, extract_source: F) -> Result<String, SpanSnippetError>
529 where F: Fn(&str, usize, usize) -> String
531 if sp.lo() > sp.hi() {
532 return Err(SpanSnippetError::IllFormedSpan(sp));
535 let local_begin = self.lookup_byte_offset(sp.lo());
536 let local_end = self.lookup_byte_offset(sp.hi());
538 if local_begin.fm.start_pos != local_end.fm.start_pos {
539 return Err(SpanSnippetError::DistinctSources(DistinctSources {
540 begin: (local_begin.fm.name.clone(),
541 local_begin.fm.start_pos),
542 end: (local_end.fm.name.clone(),
543 local_end.fm.start_pos)
546 self.ensure_source_file_source_present(local_begin.fm.clone());
548 let start_index = local_begin.pos.to_usize();
549 let end_index = local_end.pos.to_usize();
550 let source_len = (local_begin.fm.end_pos -
551 local_begin.fm.start_pos).to_usize();
553 if start_index > end_index || end_index > source_len {
554 return Err(SpanSnippetError::MalformedForCodemap(
555 MalformedCodemapPositions {
556 name: local_begin.fm.name.clone(),
558 begin_pos: local_begin.pos,
559 end_pos: local_end.pos,
563 if let Some(ref src) = local_begin.fm.src {
564 return Ok(extract_source(src, start_index, end_index));
565 } else if let Some(src) = local_begin.fm.external_src.borrow().get_source() {
566 return Ok(extract_source(src, start_index, end_index));
568 return Err(SpanSnippetError::SourceNotAvailable {
569 filename: local_begin.fm.name.clone()
575 /// Return the source snippet as `String` corresponding to the given `Span`
576 pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
577 self.span_to_source(sp, |src, start_index, end_index| src[start_index..end_index]
581 /// Return the source snippet as `String` before the given `Span`
582 pub fn span_to_prev_source(&self, sp: Span) -> Result<String, SpanSnippetError> {
583 self.span_to_source(sp, |src, start_index, _| src[..start_index].to_string())
586 /// Extend the given `Span` to just after the previous occurrence of `c`. Return the same span
587 /// if no character could be found or if an error occurred while retrieving the code snippet.
588 pub fn span_extend_to_prev_char(&self, sp: Span, c: char) -> Span {
589 if let Ok(prev_source) = self.span_to_prev_source(sp) {
590 let prev_source = prev_source.rsplit(c).nth(0).unwrap_or("").trim_left();
591 if !prev_source.is_empty() && !prev_source.contains('\n') {
592 return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
599 /// Extend the given `Span` to just after the previous occurrence of `pat` when surrounded by
600 /// whitespace. Return the same span if no character could be found or if an error occurred
601 /// while retrieving the code snippet.
602 pub fn span_extend_to_prev_str(&self, sp: Span, pat: &str, accept_newlines: bool) -> Span {
603 // assure that the pattern is delimited, to avoid the following
605 // ^^^^ returned span without the check
606 // ---------- correct span
607 for ws in &[" ", "\t", "\n"] {
608 let pat = pat.to_owned() + ws;
609 if let Ok(prev_source) = self.span_to_prev_source(sp) {
610 let prev_source = prev_source.rsplit(&pat).nth(0).unwrap_or("").trim_left();
611 if !prev_source.is_empty() && (!prev_source.contains('\n') || accept_newlines) {
612 return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
620 /// Given a `Span`, try to get a shorter span ending before the first occurrence of `c` `char`
621 pub fn span_until_char(&self, sp: Span, c: char) -> Span {
622 match self.span_to_snippet(sp) {
624 let snippet = snippet.split(c).nth(0).unwrap_or("").trim_right();
625 if !snippet.is_empty() && !snippet.contains('\n') {
626 sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32))
635 /// Given a `Span`, try to get a shorter span ending just after the first occurrence of `char`
637 pub fn span_through_char(&self, sp: Span, c: char) -> Span {
638 if let Ok(snippet) = self.span_to_snippet(sp) {
639 if let Some(offset) = snippet.find(c) {
640 return sp.with_hi(BytePos(sp.lo().0 + (offset + c.len_utf8()) as u32));
646 /// Given a `Span`, get a new `Span` covering the first token and all its trailing whitespace or
647 /// the original `Span`.
649 /// If `sp` points to `"let mut x"`, then a span pointing at `"let "` will be returned.
650 pub fn span_until_non_whitespace(&self, sp: Span) -> Span {
651 let mut whitespace_found = false;
653 self.span_take_while(sp, |c| {
654 if !whitespace_found && c.is_whitespace() {
655 whitespace_found = true;
658 if whitespace_found && !c.is_whitespace() {
666 /// Given a `Span`, get a new `Span` covering the first token without its trailing whitespace or
667 /// the original `Span` in case of error.
669 /// If `sp` points to `"let mut x"`, then a span pointing at `"let"` will be returned.
670 pub fn span_until_whitespace(&self, sp: Span) -> Span {
671 self.span_take_while(sp, |c| !c.is_whitespace())
674 /// Given a `Span`, get a shorter one until `predicate` yields false.
675 pub fn span_take_while<P>(&self, sp: Span, predicate: P) -> Span
676 where P: for <'r> FnMut(&'r char) -> bool
678 if let Ok(snippet) = self.span_to_snippet(sp) {
679 let offset = snippet.chars()
680 .take_while(predicate)
681 .map(|c| c.len_utf8())
684 sp.with_hi(BytePos(sp.lo().0 + (offset as u32)))
690 pub fn def_span(&self, sp: Span) -> Span {
691 self.span_until_char(sp, '{')
694 /// Returns a new span representing just the start-point of this span
695 pub fn start_point(&self, sp: Span) -> Span {
697 let width = self.find_width_of_character_at_span(sp, false);
698 let corrected_start_position = pos.checked_add(width).unwrap_or(pos);
699 let end_point = BytePos(cmp::max(corrected_start_position, sp.lo().0));
700 sp.with_hi(end_point)
703 /// Returns a new span representing just the end-point of this span
704 pub fn end_point(&self, sp: Span) -> Span {
707 let width = self.find_width_of_character_at_span(sp, false);
708 let corrected_end_position = pos.checked_sub(width).unwrap_or(pos);
710 let end_point = BytePos(cmp::max(corrected_end_position, sp.lo().0));
711 sp.with_lo(end_point)
714 /// Returns a new span representing the next character after the end-point of this span
715 pub fn next_point(&self, sp: Span) -> Span {
716 let start_of_next_point = sp.hi().0;
718 let width = self.find_width_of_character_at_span(sp, true);
719 // If the width is 1, then the next span should point to the same `lo` and `hi`. However,
720 // in the case of a multibyte character, where the width != 1, the next span should
721 // span multiple bytes to include the whole character.
722 let end_of_next_point = start_of_next_point.checked_add(
723 width - 1).unwrap_or(start_of_next_point);
725 let end_of_next_point = BytePos(cmp::max(sp.lo().0 + 1, end_of_next_point));
726 Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt())
729 /// Finds the width of a character, either before or after the provided span.
730 fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 {
731 // Disregard malformed spans and assume a one-byte wide character.
732 if sp.lo() >= sp.hi() {
733 debug!("find_width_of_character_at_span: early return malformed span");
737 let local_begin = self.lookup_byte_offset(sp.lo());
738 let local_end = self.lookup_byte_offset(sp.hi());
739 debug!("find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`",
740 local_begin, local_end);
742 let start_index = local_begin.pos.to_usize();
743 let end_index = local_end.pos.to_usize();
744 debug!("find_width_of_character_at_span: start_index=`{:?}`, end_index=`{:?}`",
745 start_index, end_index);
747 // Disregard indexes that are at the start or end of their spans, they can't fit bigger
749 if (!forwards && end_index == usize::min_value()) ||
750 (forwards && start_index == usize::max_value()) {
751 debug!("find_width_of_character_at_span: start or end of span, cannot be multibyte");
755 let source_len = (local_begin.fm.end_pos - local_begin.fm.start_pos).to_usize();
756 debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len);
757 // Ensure indexes are also not malformed.
758 if start_index > end_index || end_index > source_len {
759 debug!("find_width_of_character_at_span: source indexes are malformed");
763 let src = local_begin.fm.external_src.borrow();
765 // We need to extend the snippet to the end of the src rather than to end_index so when
766 // searching forwards for boundaries we've got somewhere to search.
767 let snippet = if let Some(ref src) = local_begin.fm.src {
769 (&src[start_index..len])
770 } else if let Some(src) = src.get_source() {
772 (&src[start_index..len])
776 debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet);
778 let mut target = if forwards { end_index + 1 } else { end_index - 1 };
779 debug!("find_width_of_character_at_span: initial target=`{:?}`", target);
781 while !snippet.is_char_boundary(target - start_index) && target < source_len {
782 target = if forwards {
785 match target.checked_sub(1) {
786 Some(target) => target,
792 debug!("find_width_of_character_at_span: target=`{:?}`", target);
794 debug!("find_width_of_character_at_span: final target=`{:?}`", target);
797 (target - end_index) as u32
799 (end_index - target) as u32
803 pub fn get_source_file(&self, filename: &FileName) -> Option<Lrc<SourceFile>> {
804 for fm in self.files.borrow().file_maps.iter() {
805 if *filename == fm.name {
806 return Some(fm.clone());
812 /// For a global BytePos compute the local offset within the containing SourceFile
813 pub fn lookup_byte_offset(&self, bpos: BytePos) -> SourceFileAndBytePos {
814 let idx = self.lookup_source_file_idx(bpos);
815 let fm = (*self.files.borrow().file_maps)[idx].clone();
816 let offset = bpos - fm.start_pos;
817 SourceFileAndBytePos {fm: fm, pos: offset}
820 /// Converts an absolute BytePos to a CharPos relative to the source_file.
821 pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
822 let idx = self.lookup_source_file_idx(bpos);
823 let map = &(*self.files.borrow().file_maps)[idx];
825 // The number of extra bytes due to multibyte chars in the SourceFile
826 let mut total_extra_bytes = 0;
828 for mbc in map.multibyte_chars.iter() {
829 debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos);
831 // every character is at least one byte, so we only
832 // count the actual extra bytes.
833 total_extra_bytes += mbc.bytes as u32 - 1;
834 // We should never see a byte position in the middle of a
836 assert!(bpos.to_u32() >= mbc.pos.to_u32() + mbc.bytes as u32);
842 assert!(map.start_pos.to_u32() + total_extra_bytes <= bpos.to_u32());
843 CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes as usize)
846 // Return the index of the source_file (in self.files) which contains pos.
847 pub fn lookup_source_file_idx(&self, pos: BytePos) -> usize {
848 let files = self.files.borrow();
849 let files = &files.file_maps;
850 let count = files.len();
852 // Binary search for the source_file.
857 if files[m].start_pos > pos {
864 assert!(a < count, "position {} does not resolve to a source location", pos.to_usize());
869 pub fn count_lines(&self) -> usize {
870 self.files().iter().fold(0, |a, f| a + f.count_lines())
874 pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> {
875 let prev_span = self.span_extend_to_prev_str(span, "fn", true);
876 self.span_to_snippet(prev_span).map(|snippet| {
877 let len = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
878 .expect("no label after fn");
879 prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32))
883 /// Take the span of a type parameter in a function signature and try to generate a span for the
884 /// function name (with generics) and a new snippet for this span with the pointed type
885 /// parameter as a new local type parameter.
888 /// ```rust,ignore (pseudo-Rust)
890 /// fn my_function(param: T)
891 /// // ^ Original span
894 /// fn my_function(param: T)
895 /// // ^^^^^^^^^^^ Generated span with snippet `my_function<T>`
898 /// Attention: The method used is very fragile since it essentially duplicates the work of the
899 /// parser. If you need to use this function or something similar, please consider updating the
900 /// source_map functions and this function to something more robust.
901 pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> {
902 // Try to extend the span to the previous "fn" keyword to retrieve the function
904 let sugg_span = self.span_extend_to_prev_str(span, "fn", false);
905 if sugg_span != span {
906 if let Ok(snippet) = self.span_to_snippet(sugg_span) {
907 // Consume the function name
908 let mut offset = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
909 .expect("no label after fn");
911 // Consume the generics part of the function signature
912 let mut bracket_counter = 0;
913 let mut last_char = None;
914 for c in snippet[offset..].chars() {
916 '<' => bracket_counter += 1,
917 '>' => bracket_counter -= 1,
918 '(' => if bracket_counter == 0 { break; }
921 offset += c.len_utf8();
925 // Adjust the suggestion span to encompass the function name with its generics
926 let sugg_span = sugg_span.with_hi(BytePos(sugg_span.lo().0 + offset as u32));
928 // Prepare the new suggested snippet to append the type parameter that triggered
929 // the error in the generics of the function signature
930 let mut new_snippet = if last_char == Some('>') {
931 format!("{}, ", &snippet[..(offset - '>'.len_utf8())])
933 format!("{}<", &snippet[..offset])
935 new_snippet.push_str(&self.span_to_snippet(span).unwrap_or("T".to_string()));
936 new_snippet.push('>');
938 return Some((sugg_span, new_snippet));
946 impl SourceMapper for SourceMap {
947 fn lookup_char_pos(&self, pos: BytePos) -> Loc {
948 self.lookup_char_pos(pos)
950 fn span_to_lines(&self, sp: Span) -> FileLinesResult {
951 self.span_to_lines(sp)
953 fn span_to_string(&self, sp: Span) -> String {
954 self.span_to_string(sp)
956 fn span_to_filename(&self, sp: Span) -> FileName {
957 self.span_to_filename(sp)
959 fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
960 self.merge_spans(sp_lhs, sp_rhs)
962 fn call_span_if_macro(&self, sp: Span) -> Span {
963 if self.span_to_filename(sp.clone()).is_macros() {
964 let v = sp.macro_backtrace();
965 if let Some(use_site) = v.last() {
966 return use_site.call_site;
971 fn ensure_source_file_source_present(&self, file_map: Lrc<SourceFile>) -> bool {
972 file_map.add_external_src(
973 || match file_map.name {
974 FileName::Real(ref name) => self.file_loader.read_file(name).ok(),
979 fn doctest_offset_line(&self, line: usize) -> usize {
980 self.doctest_offset_line(line)
985 pub struct FilePathMapping {
986 mapping: Vec<(PathBuf, PathBuf)>,
989 impl FilePathMapping {
990 pub fn empty() -> FilePathMapping {
996 pub fn new(mapping: Vec<(PathBuf, PathBuf)>) -> FilePathMapping {
1002 /// Applies any path prefix substitution as defined by the mapping.
1003 /// The return value is the remapped path and a boolean indicating whether
1004 /// the path was affected by the mapping.
1005 pub fn map_prefix(&self, path: PathBuf) -> (PathBuf, bool) {
1006 // NOTE: We are iterating over the mapping entries from last to first
1007 // because entries specified later on the command line should
1009 for &(ref from, ref to) in self.mapping.iter().rev() {
1010 if let Ok(rest) = path.strip_prefix(from) {
1011 return (to.join(rest), true);
1019 // _____________________________________________________________________________
1026 use rustc_data_structures::sync::Lrc;
1028 fn init_code_map() -> SourceMap {
1029 let cm = SourceMap::new(FilePathMapping::empty());
1030 cm.new_source_file(PathBuf::from("blork.rs").into(),
1031 "first line.\nsecond line".to_string());
1032 cm.new_source_file(PathBuf::from("empty.rs").into(),
1034 cm.new_source_file(PathBuf::from("blork2.rs").into(),
1035 "first line.\nsecond line".to_string());
1041 // Test lookup_byte_offset
1042 let cm = init_code_map();
1044 let fmabp1 = cm.lookup_byte_offset(BytePos(23));
1045 assert_eq!(fmabp1.fm.name, PathBuf::from("blork.rs").into());
1046 assert_eq!(fmabp1.pos, BytePos(23));
1048 let fmabp1 = cm.lookup_byte_offset(BytePos(24));
1049 assert_eq!(fmabp1.fm.name, PathBuf::from("empty.rs").into());
1050 assert_eq!(fmabp1.pos, BytePos(0));
1052 let fmabp2 = cm.lookup_byte_offset(BytePos(25));
1053 assert_eq!(fmabp2.fm.name, PathBuf::from("blork2.rs").into());
1054 assert_eq!(fmabp2.pos, BytePos(0));
1059 // Test bytepos_to_file_charpos
1060 let cm = init_code_map();
1062 let cp1 = cm.bytepos_to_file_charpos(BytePos(22));
1063 assert_eq!(cp1, CharPos(22));
1065 let cp2 = cm.bytepos_to_file_charpos(BytePos(25));
1066 assert_eq!(cp2, CharPos(0));
1071 // Test zero-length source_files.
1072 let cm = init_code_map();
1074 let loc1 = cm.lookup_char_pos(BytePos(22));
1075 assert_eq!(loc1.file.name, PathBuf::from("blork.rs").into());
1076 assert_eq!(loc1.line, 2);
1077 assert_eq!(loc1.col, CharPos(10));
1079 let loc2 = cm.lookup_char_pos(BytePos(25));
1080 assert_eq!(loc2.file.name, PathBuf::from("blork2.rs").into());
1081 assert_eq!(loc2.line, 1);
1082 assert_eq!(loc2.col, CharPos(0));
1085 fn init_code_map_mbc() -> SourceMap {
1086 let cm = SourceMap::new(FilePathMapping::empty());
1087 // € is a three byte utf8 char.
1088 cm.new_source_file(PathBuf::from("blork.rs").into(),
1089 "fir€st €€€€ line.\nsecond line".to_string());
1090 cm.new_source_file(PathBuf::from("blork2.rs").into(),
1091 "first line€€.\n€ second line".to_string());
1097 // Test bytepos_to_file_charpos in the presence of multi-byte chars
1098 let cm = init_code_map_mbc();
1100 let cp1 = cm.bytepos_to_file_charpos(BytePos(3));
1101 assert_eq!(cp1, CharPos(3));
1103 let cp2 = cm.bytepos_to_file_charpos(BytePos(6));
1104 assert_eq!(cp2, CharPos(4));
1106 let cp3 = cm.bytepos_to_file_charpos(BytePos(56));
1107 assert_eq!(cp3, CharPos(12));
1109 let cp4 = cm.bytepos_to_file_charpos(BytePos(61));
1110 assert_eq!(cp4, CharPos(15));
1115 // Test span_to_lines for a span ending at the end of source_file
1116 let cm = init_code_map();
1117 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1118 let file_lines = cm.span_to_lines(span).unwrap();
1120 assert_eq!(file_lines.file.name, PathBuf::from("blork.rs").into());
1121 assert_eq!(file_lines.lines.len(), 1);
1122 assert_eq!(file_lines.lines[0].line_index, 1);
1125 /// Given a string like " ~~~~~~~~~~~~ ", produces a span
1126 /// converting that range. The idea is that the string has the same
1127 /// length as the input, and we uncover the byte positions. Note
1128 /// that this can span lines and so on.
1129 fn span_from_selection(input: &str, selection: &str) -> Span {
1130 assert_eq!(input.len(), selection.len());
1131 let left_index = selection.find('~').unwrap() as u32;
1132 let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
1133 Span::new(BytePos(left_index), BytePos(right_index + 1), NO_EXPANSION)
1136 /// Test span_to_snippet and span_to_lines for a span converting 3
1137 /// lines in the middle of a file.
1139 fn span_to_snippet_and_lines_spanning_multiple_lines() {
1140 let cm = SourceMap::new(FilePathMapping::empty());
1141 let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
1142 let selection = " \n ~~\n~~~\n~~~~~ \n \n";
1143 cm.new_source_file(Path::new("blork.rs").to_owned().into(), inputtext.to_string());
1144 let span = span_from_selection(inputtext, selection);
1146 // check that we are extracting the text we thought we were extracting
1147 assert_eq!(&cm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD");
1149 // check that span_to_lines gives us the complete result with the lines/cols we expected
1150 let lines = cm.span_to_lines(span).unwrap();
1151 let expected = vec![
1152 LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) },
1153 LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) },
1154 LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) }
1156 assert_eq!(lines.lines, expected);
1161 // Test span_to_snippet for a span ending at the end of source_file
1162 let cm = init_code_map();
1163 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1164 let snippet = cm.span_to_snippet(span);
1166 assert_eq!(snippet, Ok("second line".to_string()));
1171 // Test span_to_str for a span ending at the end of source_file
1172 let cm = init_code_map();
1173 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1174 let sstr = cm.span_to_string(span);
1176 assert_eq!(sstr, "blork.rs:2:1: 2:12");
1179 /// Test failing to merge two spans on different lines
1181 fn span_merging_fail() {
1182 let cm = SourceMap::new(FilePathMapping::empty());
1183 let inputtext = "bbbb BB\ncc CCC\n";
1184 let selection1 = " ~~\n \n";
1185 let selection2 = " \n ~~~\n";
1186 cm.new_source_file(Path::new("blork.rs").to_owned().into(), inputtext.to_owned());
1187 let span1 = span_from_selection(inputtext, selection1);
1188 let span2 = span_from_selection(inputtext, selection2);
1190 assert!(cm.merge_spans(span1, span2).is_none());
1193 /// Returns the span corresponding to the `n`th occurrence of
1194 /// `substring` in `source_text`.
1195 trait SourceMapExtension {
1196 fn span_substr(&self,
1197 file: &Lrc<SourceFile>,
1204 impl SourceMapExtension for SourceMap {
1205 fn span_substr(&self,
1206 file: &Lrc<SourceFile>,
1212 println!("span_substr(file={:?}/{:?}, substring={:?}, n={})",
1213 file.name, file.start_pos, substring, n);
1217 let offset = source_text[hi..].find(substring).unwrap_or_else(|| {
1218 panic!("source_text `{}` does not have {} occurrences of `{}`, only {}",
1219 source_text, n, substring, i);
1221 let lo = hi + offset;
1222 hi = lo + substring.len();
1224 let span = Span::new(
1225 BytePos(lo as u32 + file.start_pos.0),
1226 BytePos(hi as u32 + file.start_pos.0),
1229 assert_eq!(&self.span_to_snippet(span).unwrap()[..],