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 CodeMap 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 //! CodeMap and are represented by FileMaps. Byte positions are stored in
16 //! `spans` and used pervasively in the compiler. They are absolute positions
17 //! within the CodeMap, 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::CodeMapper;
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 // FileMap, 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 FileMap identifier that is used to correlate FileMaps 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(filemap: &FileMap) -> StableFilemapId {
113 let mut hasher = StableHasher::new();
115 filemap.name.hash(&mut hasher);
116 filemap.name_was_remapped.hash(&mut hasher);
117 filemap.unmapped_path.hash(&mut hasher);
119 StableFilemapId(hasher.finish())
123 // _____________________________________________________________________________
127 pub(super) struct CodeMapFiles {
128 pub(super) file_maps: Vec<Lrc<FileMap>>,
129 stable_id_to_filemap: FxHashMap<StableFilemapId, Lrc<FileMap>>
133 pub(super) files: Lock<CodeMapFiles>,
134 file_loader: Box<FileLoader + Sync + Send>,
135 // This is used to apply the file path remapping as specified via
136 // --remap-path-prefix to all FileMaps allocated within this CodeMap.
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) -> CodeMap {
146 files: Lock::new(CodeMapFiles {
147 file_maps: Vec::new(),
148 stable_id_to_filemap: FxHashMap(),
150 file_loader: Box::new(RealFileLoader),
152 doctest_offset: None,
156 pub fn new_doctest(path_mapping: FilePathMapping,
157 file: FileName, line: isize) -> CodeMap {
159 doctest_offset: Some((file, line)),
160 ..CodeMap::new(path_mapping)
165 pub fn with_file_loader(file_loader: Box<FileLoader + Sync + Send>,
166 path_mapping: FilePathMapping)
169 files: Lock::new(CodeMapFiles {
170 file_maps: Vec::new(),
171 stable_id_to_filemap: 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<FileMap>> {
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_filemap(filename, src))
197 pub fn files(&self) -> LockGuard<Vec<Lrc<FileMap>>> {
198 LockGuard::map(self.files.borrow(), |files| &mut files.file_maps)
201 pub fn filemap_by_stable_id(&self, stable_id: StableFilemapId) -> Option<Lrc<FileMap>> {
202 self.files.borrow().stable_id_to_filemap.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 codemap, even in the presence of zero-length files.
210 Some(last) => last.end_pos.to_usize() + 1,
214 /// Creates a new filemap.
215 /// This does not ensure that only one FileMap exists per file name.
216 pub fn new_filemap(&self, filename: FileName, src: String) -> Lrc<FileMap> {
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 filemap = Lrc::new(FileMap::new(
238 Pos::from_usize(start_pos),
241 let mut files = self.files.borrow_mut();
243 files.file_maps.push(filemap.clone());
244 files.stable_id_to_filemap.insert(StableFilemapId::new(&filemap), filemap.clone());
249 /// Allocates a new FileMap representing a source file from an external
250 /// crate. The source code of such an "imported filemap" is not available,
251 /// but we still know enough to generate accurate debuginfo location
252 /// information for things inlined from other crates.
253 pub fn new_imported_filemap(&self,
255 name_was_remapped: bool,
256 crate_of_origin: u32,
260 mut file_local_lines: Vec<BytePos>,
261 mut file_local_multibyte_chars: Vec<MultiByteChar>,
262 mut file_local_non_narrow_chars: Vec<NonNarrowChar>)
264 let start_pos = self.next_start_pos();
266 let end_pos = Pos::from_usize(start_pos + source_len);
267 let start_pos = Pos::from_usize(start_pos);
269 for pos in &mut file_local_lines {
270 *pos = *pos + start_pos;
273 for mbc in &mut file_local_multibyte_chars {
274 mbc.pos = mbc.pos + start_pos;
277 for swc in &mut file_local_non_narrow_chars {
278 *swc = *swc + start_pos;
281 let filemap = Lrc::new(FileMap {
288 external_src: Lock::new(ExternalSource::AbsentOk),
291 lines: file_local_lines,
292 multibyte_chars: file_local_multibyte_chars,
293 non_narrow_chars: file_local_non_narrow_chars,
297 let mut files = self.files.borrow_mut();
299 files.file_maps.push(filemap.clone());
300 files.stable_id_to_filemap.insert(StableFilemapId::new(&filemap), filemap.clone());
305 pub fn mk_substr_filename(&self, sp: Span) -> String {
306 let pos = self.lookup_char_pos(sp.lo());
307 format!("<{}:{}:{}>",
310 pos.col.to_usize() + 1)
313 // If there is a doctest_offset, apply it to the line
314 pub fn doctest_offset_line(&self, mut orig: usize) -> usize {
315 if let Some((_, line)) = self.doctest_offset {
317 orig = orig + line as usize;
319 orig = orig - (-line) as usize;
325 /// Lookup source information about a BytePos
326 pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
327 let chpos = self.bytepos_to_file_charpos(pos);
328 match self.lookup_line(pos) {
329 Ok(FileMapAndLine { fm: f, line: a }) => {
330 let line = a + 1; // Line numbers start at 1
331 let linebpos = f.lines[a];
332 let linechpos = self.bytepos_to_file_charpos(linebpos);
333 let col = chpos - linechpos;
336 let start_width_idx = f
338 .binary_search_by_key(&linebpos, |x| x.pos())
339 .unwrap_or_else(|x| x);
340 let end_width_idx = f
342 .binary_search_by_key(&pos, |x| x.pos())
343 .unwrap_or_else(|x| x);
344 let special_chars = end_width_idx - start_width_idx;
345 let non_narrow: usize = f
346 .non_narrow_chars[start_width_idx..end_width_idx]
350 col.0 - special_chars + non_narrow
352 debug!("byte pos {:?} is on the line at byte pos {:?}",
354 debug!("char pos {:?} is on the line at char pos {:?}",
356 debug!("byte is on line: {}", line);
357 assert!(chpos >= linechpos);
367 let end_width_idx = f
369 .binary_search_by_key(&pos, |x| x.pos())
370 .unwrap_or_else(|x| x);
371 let non_narrow: usize = f
372 .non_narrow_chars[0..end_width_idx]
376 chpos.0 - end_width_idx + non_narrow
388 // If the relevant filemap is empty, we don't return a line number.
389 pub fn lookup_line(&self, pos: BytePos) -> Result<FileMapAndLine, Lrc<FileMap>> {
390 let idx = self.lookup_filemap_idx(pos);
392 let f = (*self.files.borrow().file_maps)[idx].clone();
394 match f.lookup_line(pos) {
395 Some(line) => Ok(FileMapAndLine { fm: f, line: line }),
400 pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
401 let loc = self.lookup_char_pos(pos);
403 filename: loc.file.name.clone(),
410 /// Returns `Some(span)`, a union of the lhs and rhs span. The lhs must precede the rhs. If
411 /// there are gaps between lhs and rhs, the resulting union will cross these gaps.
412 /// For this to work, the spans have to be:
414 /// * the ctxt of both spans much match
415 /// * the lhs span needs to end on the same line the rhs span begins
416 /// * the lhs span must start at or before the rhs span
417 pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
418 // make sure we're at the same expansion id
419 if sp_lhs.ctxt() != sp_rhs.ctxt() {
423 let lhs_end = match self.lookup_line(sp_lhs.hi()) {
425 Err(_) => return None
427 let rhs_begin = match self.lookup_line(sp_rhs.lo()) {
429 Err(_) => return None
432 // if we must cross lines to merge, don't merge
433 if lhs_end.line != rhs_begin.line {
437 // ensure these follow the expected order and we don't overlap
438 if (sp_lhs.lo() <= sp_rhs.lo()) && (sp_lhs.hi() <= sp_rhs.lo()) {
439 Some(sp_lhs.to(sp_rhs))
445 pub fn span_to_string(&self, sp: Span) -> String {
446 if self.files.borrow().file_maps.is_empty() && sp.is_dummy() {
447 return "no-location".to_string();
450 let lo = self.lookup_char_pos_adj(sp.lo());
451 let hi = self.lookup_char_pos_adj(sp.hi());
452 format!("{}:{}:{}: {}:{}",
455 lo.col.to_usize() + 1,
457 hi.col.to_usize() + 1)
460 pub fn span_to_filename(&self, sp: Span) -> FileName {
461 self.lookup_char_pos(sp.lo()).file.name.clone()
464 pub fn span_to_unmapped_path(&self, sp: Span) -> FileName {
465 self.lookup_char_pos(sp.lo()).file.unmapped_path.clone()
466 .expect("CodeMap::span_to_unmapped_path called for imported FileMap?")
469 pub fn is_multiline(&self, sp: Span) -> bool {
470 let lo = self.lookup_char_pos(sp.lo());
471 let hi = self.lookup_char_pos(sp.hi());
475 pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
476 debug!("span_to_lines(sp={:?})", sp);
478 if sp.lo() > sp.hi() {
479 return Err(SpanLinesError::IllFormedSpan(sp));
482 let lo = self.lookup_char_pos(sp.lo());
483 debug!("span_to_lines: lo={:?}", lo);
484 let hi = self.lookup_char_pos(sp.hi());
485 debug!("span_to_lines: hi={:?}", hi);
487 if lo.file.start_pos != hi.file.start_pos {
488 return Err(SpanLinesError::DistinctSources(DistinctSources {
489 begin: (lo.file.name.clone(), lo.file.start_pos),
490 end: (hi.file.name.clone(), hi.file.start_pos),
493 assert!(hi.line >= lo.line);
495 let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
497 // The span starts partway through the first line,
498 // but after that it starts from offset 0.
499 let mut start_col = lo.col;
501 // For every line but the last, it extends from `start_col`
502 // and to the end of the line. Be careful because the line
503 // numbers in Loc are 1-based, so we subtract 1 to get 0-based
505 for line_index in lo.line-1 .. hi.line-1 {
506 let line_len = lo.file.get_line(line_index)
507 .map(|s| s.chars().count())
509 lines.push(LineInfo { line_index,
511 end_col: CharPos::from_usize(line_len) });
512 start_col = CharPos::from_usize(0);
515 // For the last line, it extends from `start_col` to `hi.col`:
516 lines.push(LineInfo { line_index: hi.line - 1,
520 Ok(FileLines {file: lo.file, lines: lines})
523 /// Extract the source surrounding the given `Span` using the `extract_source` function. The
524 /// extract function takes three arguments: a string slice containing the source, an index in
525 /// the slice for the beginning of the span and an index in the slice for the end of the span.
526 fn span_to_source<F>(&self, sp: Span, extract_source: F) -> Result<String, SpanSnippetError>
527 where F: Fn(&str, usize, usize) -> String
529 if sp.lo() > sp.hi() {
530 return Err(SpanSnippetError::IllFormedSpan(sp));
533 let local_begin = self.lookup_byte_offset(sp.lo());
534 let local_end = self.lookup_byte_offset(sp.hi());
536 if local_begin.fm.start_pos != local_end.fm.start_pos {
537 return Err(SpanSnippetError::DistinctSources(DistinctSources {
538 begin: (local_begin.fm.name.clone(),
539 local_begin.fm.start_pos),
540 end: (local_end.fm.name.clone(),
541 local_end.fm.start_pos)
544 self.ensure_filemap_source_present(local_begin.fm.clone());
546 let start_index = local_begin.pos.to_usize();
547 let end_index = local_end.pos.to_usize();
548 let source_len = (local_begin.fm.end_pos -
549 local_begin.fm.start_pos).to_usize();
551 if start_index > end_index || end_index > source_len {
552 return Err(SpanSnippetError::MalformedForCodemap(
553 MalformedCodemapPositions {
554 name: local_begin.fm.name.clone(),
556 begin_pos: local_begin.pos,
557 end_pos: local_end.pos,
561 if let Some(ref src) = local_begin.fm.src {
562 return Ok(extract_source(src, start_index, end_index));
563 } else if let Some(src) = local_begin.fm.external_src.borrow().get_source() {
564 return Ok(extract_source(src, start_index, end_index));
566 return Err(SpanSnippetError::SourceNotAvailable {
567 filename: local_begin.fm.name.clone()
573 /// Return the source snippet as `String` corresponding to the given `Span`
574 pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
575 self.span_to_source(sp, |src, start_index, end_index| src[start_index..end_index]
579 /// Return 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_left();
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_left();
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_right();
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 end-point of this span
693 pub fn end_point(&self, sp: Span) -> Span {
696 let width = self.find_width_of_character_at_span(sp, false);
697 let corrected_end_position = pos.checked_sub(width).unwrap_or(pos);
699 let end_point = BytePos(cmp::max(corrected_end_position, sp.lo().0));
700 sp.with_lo(end_point)
703 /// Returns a new span representing the next character after the end-point of this span
704 pub fn next_point(&self, sp: Span) -> Span {
705 let start_of_next_point = sp.hi().0;
707 let width = self.find_width_of_character_at_span(sp, true);
708 // If the width is 1, then the next span should point to the same `lo` and `hi`. However,
709 // in the case of a multibyte character, where the width != 1, the next span should
710 // span multiple bytes to include the whole character.
711 let end_of_next_point = start_of_next_point.checked_add(
712 width - 1).unwrap_or(start_of_next_point);
714 let end_of_next_point = BytePos(cmp::max(sp.lo().0 + 1, end_of_next_point));
715 Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt())
718 /// Finds the width of a character, either before or after the provided span.
719 fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 {
720 // Disregard malformed spans and assume a one-byte wide character.
721 if sp.lo() >= sp.hi() {
722 debug!("find_width_of_character_at_span: early return malformed span");
726 let local_begin = self.lookup_byte_offset(sp.lo());
727 let local_end = self.lookup_byte_offset(sp.hi());
728 debug!("find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`",
729 local_begin, local_end);
731 let start_index = local_begin.pos.to_usize();
732 let end_index = local_end.pos.to_usize();
733 debug!("find_width_of_character_at_span: start_index=`{:?}`, end_index=`{:?}`",
734 start_index, end_index);
736 // Disregard indexes that are at the start or end of their spans, they can't fit bigger
738 if (!forwards && end_index == usize::min_value()) ||
739 (forwards && start_index == usize::max_value()) {
740 debug!("find_width_of_character_at_span: start or end of span, cannot be multibyte");
744 let source_len = (local_begin.fm.end_pos - local_begin.fm.start_pos).to_usize();
745 debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len);
746 // Ensure indexes are also not malformed.
747 if start_index > end_index || end_index > source_len {
748 debug!("find_width_of_character_at_span: source indexes are malformed");
752 let src = local_begin.fm.external_src.borrow();
754 // We need to extend the snippet to the end of the src rather than to end_index so when
755 // searching forwards for boundaries we've got somewhere to search.
756 let snippet = if let Some(ref src) = local_begin.fm.src {
758 (&src[start_index..len])
759 } else if let Some(src) = src.get_source() {
761 (&src[start_index..len])
765 debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet);
767 let mut target = if forwards { end_index + 1 } else { end_index - 1 };
768 debug!("find_width_of_character_at_span: initial target=`{:?}`", target);
770 while !snippet.is_char_boundary(target - start_index) && target < source_len {
771 target = if forwards {
774 match target.checked_sub(1) {
775 Some(target) => target,
781 debug!("find_width_of_character_at_span: target=`{:?}`", target);
783 debug!("find_width_of_character_at_span: final target=`{:?}`", target);
786 (target - end_index) as u32
788 (end_index - target) as u32
792 pub fn get_filemap(&self, filename: &FileName) -> Option<Lrc<FileMap>> {
793 for fm in self.files.borrow().file_maps.iter() {
794 if *filename == fm.name {
795 return Some(fm.clone());
801 /// For a global BytePos compute the local offset within the containing FileMap
802 pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
803 let idx = self.lookup_filemap_idx(bpos);
804 let fm = (*self.files.borrow().file_maps)[idx].clone();
805 let offset = bpos - fm.start_pos;
806 FileMapAndBytePos {fm: fm, pos: offset}
809 /// Converts an absolute BytePos to a CharPos relative to the filemap.
810 pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
811 let idx = self.lookup_filemap_idx(bpos);
812 let map = &(*self.files.borrow().file_maps)[idx];
814 // The number of extra bytes due to multibyte chars in the FileMap
815 let mut total_extra_bytes = 0;
817 for mbc in map.multibyte_chars.iter() {
818 debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos);
820 // every character is at least one byte, so we only
821 // count the actual extra bytes.
822 total_extra_bytes += mbc.bytes as u32 - 1;
823 // We should never see a byte position in the middle of a
825 assert!(bpos.to_u32() >= mbc.pos.to_u32() + mbc.bytes as u32);
831 assert!(map.start_pos.to_u32() + total_extra_bytes <= bpos.to_u32());
832 CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes as usize)
835 // Return the index of the filemap (in self.files) which contains pos.
836 pub fn lookup_filemap_idx(&self, pos: BytePos) -> usize {
837 let files = self.files.borrow();
838 let files = &files.file_maps;
839 let count = files.len();
841 // Binary search for the filemap.
846 if files[m].start_pos > pos {
853 assert!(a < count, "position {} does not resolve to a source location", pos.to_usize());
858 pub fn count_lines(&self) -> usize {
859 self.files().iter().fold(0, |a, f| a + f.count_lines())
863 pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> {
864 let prev_span = self.span_extend_to_prev_str(span, "fn", true);
865 self.span_to_snippet(prev_span).map(|snippet| {
866 let len = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
867 .expect("no label after fn");
868 prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32))
872 /// Take the span of a type parameter in a function signature and try to generate a span for the
873 /// function name (with generics) and a new snippet for this span with the pointed type
874 /// parameter as a new local type parameter.
877 /// ```rust,ignore (pseudo-Rust)
879 /// fn my_function(param: T)
880 /// // ^ Original span
883 /// fn my_function(param: T)
884 /// // ^^^^^^^^^^^ Generated span with snippet `my_function<T>`
887 /// Attention: The method used is very fragile since it essentially duplicates the work of the
888 /// parser. If you need to use this function or something similar, please consider updating the
889 /// codemap functions and this function to something more robust.
890 pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> {
891 // Try to extend the span to the previous "fn" keyword to retrieve the function
893 let sugg_span = self.span_extend_to_prev_str(span, "fn", false);
894 if sugg_span != span {
895 if let Ok(snippet) = self.span_to_snippet(sugg_span) {
896 // Consume the function name
897 let mut offset = snippet.find(|c: char| !c.is_alphanumeric() && c != '_')
898 .expect("no label after fn");
900 // Consume the generics part of the function signature
901 let mut bracket_counter = 0;
902 let mut last_char = None;
903 for c in snippet[offset..].chars() {
905 '<' => bracket_counter += 1,
906 '>' => bracket_counter -= 1,
907 '(' => if bracket_counter == 0 { break; }
910 offset += c.len_utf8();
914 // Adjust the suggestion span to encompass the function name with its generics
915 let sugg_span = sugg_span.with_hi(BytePos(sugg_span.lo().0 + offset as u32));
917 // Prepare the new suggested snippet to append the type parameter that triggered
918 // the error in the generics of the function signature
919 let mut new_snippet = if last_char == Some('>') {
920 format!("{}, ", &snippet[..(offset - '>'.len_utf8())])
922 format!("{}<", &snippet[..offset])
924 new_snippet.push_str(&self.span_to_snippet(span).unwrap_or("T".to_string()));
925 new_snippet.push('>');
927 return Some((sugg_span, new_snippet));
935 impl CodeMapper for CodeMap {
936 fn lookup_char_pos(&self, pos: BytePos) -> Loc {
937 self.lookup_char_pos(pos)
939 fn span_to_lines(&self, sp: Span) -> FileLinesResult {
940 self.span_to_lines(sp)
942 fn span_to_string(&self, sp: Span) -> String {
943 self.span_to_string(sp)
945 fn span_to_filename(&self, sp: Span) -> FileName {
946 self.span_to_filename(sp)
948 fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
949 self.merge_spans(sp_lhs, sp_rhs)
951 fn call_span_if_macro(&self, sp: Span) -> Span {
952 if self.span_to_filename(sp.clone()).is_macros() {
953 let v = sp.macro_backtrace();
954 if let Some(use_site) = v.last() {
955 return use_site.call_site;
960 fn ensure_filemap_source_present(&self, file_map: Lrc<FileMap>) -> bool {
961 file_map.add_external_src(
962 || match file_map.name {
963 FileName::Real(ref name) => self.file_loader.read_file(name).ok(),
968 fn doctest_offset_line(&self, line: usize) -> usize {
969 self.doctest_offset_line(line)
974 pub struct FilePathMapping {
975 mapping: Vec<(PathBuf, PathBuf)>,
978 impl FilePathMapping {
979 pub fn empty() -> FilePathMapping {
985 pub fn new(mapping: Vec<(PathBuf, PathBuf)>) -> FilePathMapping {
991 /// Applies any path prefix substitution as defined by the mapping.
992 /// The return value is the remapped path and a boolean indicating whether
993 /// the path was affected by the mapping.
994 pub fn map_prefix(&self, path: PathBuf) -> (PathBuf, bool) {
995 // NOTE: We are iterating over the mapping entries from last to first
996 // because entries specified later on the command line should
998 for &(ref from, ref to) in self.mapping.iter().rev() {
999 if let Ok(rest) = path.strip_prefix(from) {
1000 return (to.join(rest), true);
1008 // _____________________________________________________________________________
1015 use rustc_data_structures::sync::Lrc;
1017 fn init_code_map() -> CodeMap {
1018 let cm = CodeMap::new(FilePathMapping::empty());
1019 cm.new_filemap(PathBuf::from("blork.rs").into(),
1020 "first line.\nsecond line".to_string());
1021 cm.new_filemap(PathBuf::from("empty.rs").into(),
1023 cm.new_filemap(PathBuf::from("blork2.rs").into(),
1024 "first line.\nsecond line".to_string());
1030 // Test lookup_byte_offset
1031 let cm = init_code_map();
1033 let fmabp1 = cm.lookup_byte_offset(BytePos(23));
1034 assert_eq!(fmabp1.fm.name, PathBuf::from("blork.rs").into());
1035 assert_eq!(fmabp1.pos, BytePos(23));
1037 let fmabp1 = cm.lookup_byte_offset(BytePos(24));
1038 assert_eq!(fmabp1.fm.name, PathBuf::from("empty.rs").into());
1039 assert_eq!(fmabp1.pos, BytePos(0));
1041 let fmabp2 = cm.lookup_byte_offset(BytePos(25));
1042 assert_eq!(fmabp2.fm.name, PathBuf::from("blork2.rs").into());
1043 assert_eq!(fmabp2.pos, BytePos(0));
1048 // Test bytepos_to_file_charpos
1049 let cm = init_code_map();
1051 let cp1 = cm.bytepos_to_file_charpos(BytePos(22));
1052 assert_eq!(cp1, CharPos(22));
1054 let cp2 = cm.bytepos_to_file_charpos(BytePos(25));
1055 assert_eq!(cp2, CharPos(0));
1060 // Test zero-length filemaps.
1061 let cm = init_code_map();
1063 let loc1 = cm.lookup_char_pos(BytePos(22));
1064 assert_eq!(loc1.file.name, PathBuf::from("blork.rs").into());
1065 assert_eq!(loc1.line, 2);
1066 assert_eq!(loc1.col, CharPos(10));
1068 let loc2 = cm.lookup_char_pos(BytePos(25));
1069 assert_eq!(loc2.file.name, PathBuf::from("blork2.rs").into());
1070 assert_eq!(loc2.line, 1);
1071 assert_eq!(loc2.col, CharPos(0));
1074 fn init_code_map_mbc() -> CodeMap {
1075 let cm = CodeMap::new(FilePathMapping::empty());
1076 // € is a three byte utf8 char.
1077 cm.new_filemap(PathBuf::from("blork.rs").into(),
1078 "fir€st €€€€ line.\nsecond line".to_string());
1079 cm.new_filemap(PathBuf::from("blork2.rs").into(),
1080 "first line€€.\n€ second line".to_string());
1086 // Test bytepos_to_file_charpos in the presence of multi-byte chars
1087 let cm = init_code_map_mbc();
1089 let cp1 = cm.bytepos_to_file_charpos(BytePos(3));
1090 assert_eq!(cp1, CharPos(3));
1092 let cp2 = cm.bytepos_to_file_charpos(BytePos(6));
1093 assert_eq!(cp2, CharPos(4));
1095 let cp3 = cm.bytepos_to_file_charpos(BytePos(56));
1096 assert_eq!(cp3, CharPos(12));
1098 let cp4 = cm.bytepos_to_file_charpos(BytePos(61));
1099 assert_eq!(cp4, CharPos(15));
1104 // Test span_to_lines for a span ending at the end of filemap
1105 let cm = init_code_map();
1106 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1107 let file_lines = cm.span_to_lines(span).unwrap();
1109 assert_eq!(file_lines.file.name, PathBuf::from("blork.rs").into());
1110 assert_eq!(file_lines.lines.len(), 1);
1111 assert_eq!(file_lines.lines[0].line_index, 1);
1114 /// Given a string like " ~~~~~~~~~~~~ ", produces a span
1115 /// converting that range. The idea is that the string has the same
1116 /// length as the input, and we uncover the byte positions. Note
1117 /// that this can span lines and so on.
1118 fn span_from_selection(input: &str, selection: &str) -> Span {
1119 assert_eq!(input.len(), selection.len());
1120 let left_index = selection.find('~').unwrap() as u32;
1121 let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
1122 Span::new(BytePos(left_index), BytePos(right_index + 1), NO_EXPANSION)
1125 /// Test span_to_snippet and span_to_lines for a span converting 3
1126 /// lines in the middle of a file.
1128 fn span_to_snippet_and_lines_spanning_multiple_lines() {
1129 let cm = CodeMap::new(FilePathMapping::empty());
1130 let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
1131 let selection = " \n ~~\n~~~\n~~~~~ \n \n";
1132 cm.new_filemap(Path::new("blork.rs").to_owned().into(), inputtext.to_string());
1133 let span = span_from_selection(inputtext, selection);
1135 // check that we are extracting the text we thought we were extracting
1136 assert_eq!(&cm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD");
1138 // check that span_to_lines gives us the complete result with the lines/cols we expected
1139 let lines = cm.span_to_lines(span).unwrap();
1140 let expected = vec![
1141 LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) },
1142 LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) },
1143 LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) }
1145 assert_eq!(lines.lines, expected);
1150 // Test span_to_snippet for a span ending at the end of filemap
1151 let cm = init_code_map();
1152 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1153 let snippet = cm.span_to_snippet(span);
1155 assert_eq!(snippet, Ok("second line".to_string()));
1160 // Test span_to_str for a span ending at the end of filemap
1161 let cm = init_code_map();
1162 let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION);
1163 let sstr = cm.span_to_string(span);
1165 assert_eq!(sstr, "blork.rs:2:1: 2:12");
1168 /// Test failing to merge two spans on different lines
1170 fn span_merging_fail() {
1171 let cm = CodeMap::new(FilePathMapping::empty());
1172 let inputtext = "bbbb BB\ncc CCC\n";
1173 let selection1 = " ~~\n \n";
1174 let selection2 = " \n ~~~\n";
1175 cm.new_filemap(Path::new("blork.rs").to_owned().into(), inputtext.to_owned());
1176 let span1 = span_from_selection(inputtext, selection1);
1177 let span2 = span_from_selection(inputtext, selection2);
1179 assert!(cm.merge_spans(span1, span2).is_none());
1182 /// Returns the span corresponding to the `n`th occurrence of
1183 /// `substring` in `source_text`.
1184 trait CodeMapExtension {
1185 fn span_substr(&self,
1186 file: &Lrc<FileMap>,
1193 impl CodeMapExtension for CodeMap {
1194 fn span_substr(&self,
1195 file: &Lrc<FileMap>,
1201 println!("span_substr(file={:?}/{:?}, substring={:?}, n={})",
1202 file.name, file.start_pos, substring, n);
1206 let offset = source_text[hi..].find(substring).unwrap_or_else(|| {
1207 panic!("source_text `{}` does not have {} occurrences of `{}`, only {}",
1208 source_text, n, substring, i);
1210 let lo = hi + offset;
1211 hi = lo + substring.len();
1213 let span = Span::new(
1214 BytePos(lo as u32 + file.start_pos.0),
1215 BytePos(hi as u32 + file.start_pos.0),
1218 assert_eq!(&self.span_to_snippet(span).unwrap()[..],