| //! Types for tracking pieces of source code within a crate. |
| //! |
| //! The [`SourceMap`] tracks all the source code used within a single crate, mapping |
| //! from integer byte positions to the original source code location. Each bit |
| //! of source parsed during crate parsing (typically files, in-memory strings, |
| //! or various bits of macro expansion) cover a continuous range of bytes in the |
| //! `SourceMap` and are represented by [`SourceFile`]s. Byte positions are stored in |
| //! [`Span`] and used pervasively in the compiler. They are absolute positions |
| //! within the `SourceMap`, which upon request can be converted to line and column |
| //! information, source code snippets, etc. |
| |
| use crate::*; |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_data_structures::stable_hasher::{Hash128, Hash64, StableHasher}; |
| use rustc_data_structures::sync::{IntoDynSyncSend, Lrc, MappedReadGuard, ReadGuard, RwLock}; |
| use std::cmp; |
| use std::fs; |
| use std::hash::Hash; |
| use std::io::{self, BorrowedBuf, Read}; |
| use std::path::{self, Path, PathBuf}; |
| |
| #[cfg(test)] |
| mod tests; |
| |
| /// Returns the span itself if it doesn't come from a macro expansion, |
| /// otherwise return the call site span up to the `enclosing_sp` by |
| /// following the `expn_data` chain. |
| pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span { |
| let expn_data1 = sp.ctxt().outer_expn_data(); |
| let expn_data2 = enclosing_sp.ctxt().outer_expn_data(); |
| if expn_data1.is_root() || !expn_data2.is_root() && expn_data1.call_site == expn_data2.call_site |
| { |
| sp |
| } else { |
| original_sp(expn_data1.call_site, enclosing_sp) |
| } |
| } |
| |
| mod monotonic { |
| use std::ops::{Deref, DerefMut}; |
| |
| /// A `MonotonicVec` is a `Vec` which can only be grown. |
| /// Once inserted, an element can never be removed or swapped, |
| /// guaranteeing that any indices into a `MonotonicVec` are stable |
| // This is declared in its own module to ensure that the private |
| // field is inaccessible |
| pub struct MonotonicVec<T>(Vec<T>); |
| impl<T> MonotonicVec<T> { |
| pub(super) fn push(&mut self, val: T) { |
| self.0.push(val); |
| } |
| } |
| |
| impl<T> Default for MonotonicVec<T> { |
| fn default() -> Self { |
| MonotonicVec(vec![]) |
| } |
| } |
| |
| impl<T> Deref for MonotonicVec<T> { |
| type Target = Vec<T>; |
| fn deref(&self) -> &Self::Target { |
| &self.0 |
| } |
| } |
| |
| impl<T> !DerefMut for MonotonicVec<T> {} |
| } |
| |
| #[derive(Clone, Encodable, Decodable, Debug, Copy, HashStable_Generic)] |
| pub struct Spanned<T> { |
| pub node: T, |
| pub span: Span, |
| } |
| |
| pub fn respan<T>(sp: Span, t: T) -> Spanned<T> { |
| Spanned { node: t, span: sp } |
| } |
| |
| pub fn dummy_spanned<T>(t: T) -> Spanned<T> { |
| respan(DUMMY_SP, t) |
| } |
| |
| // _____________________________________________________________________________ |
| // SourceFile, MultiByteChar, FileName, FileLines |
| // |
| |
| /// An abstraction over the fs operations used by the Parser. |
| pub trait FileLoader { |
| /// Query the existence of a file. |
| fn file_exists(&self, path: &Path) -> bool; |
| |
| /// Read the contents of a UTF-8 file into memory. |
| /// This function must return a String because we normalize |
| /// source files, which may require resizing. |
| fn read_file(&self, path: &Path) -> io::Result<String>; |
| |
| /// Read the contents of a potentially non-UTF-8 file into memory. |
| /// We don't normalize binary files, so we can start in an Lrc. |
| fn read_binary_file(&self, path: &Path) -> io::Result<Lrc<[u8]>>; |
| } |
| |
| /// A FileLoader that uses std::fs to load real files. |
| pub struct RealFileLoader; |
| |
| impl FileLoader for RealFileLoader { |
| fn file_exists(&self, path: &Path) -> bool { |
| path.exists() |
| } |
| |
| fn read_file(&self, path: &Path) -> io::Result<String> { |
| fs::read_to_string(path) |
| } |
| |
| fn read_binary_file(&self, path: &Path) -> io::Result<Lrc<[u8]>> { |
| let mut file = fs::File::open(path)?; |
| let len = file.metadata()?.len(); |
| |
| let mut bytes = Lrc::new_uninit_slice(len as usize); |
| let mut buf = BorrowedBuf::from(Lrc::get_mut(&mut bytes).unwrap()); |
| match file.read_buf_exact(buf.unfilled()) { |
| Ok(()) => {} |
| Err(e) if e.kind() == io::ErrorKind::UnexpectedEof => { |
| drop(bytes); |
| return fs::read(path).map(Vec::into); |
| } |
| Err(e) => return Err(e), |
| } |
| // SAFETY: If the read_buf_exact call returns Ok(()), then we have |
| // read len bytes and initialized the buffer. |
| let bytes = unsafe { bytes.assume_init() }; |
| |
| // At this point, we've read all the bytes that filesystem metadata reported exist. |
| // But we are not guaranteed to be at the end of the file, because we did not attempt to do |
| // a read with a non-zero-sized buffer and get Ok(0). |
| // So we do small read to a fixed-size buffer. If the read returns no bytes then we're |
| // already done, and we just return the Lrc we built above. |
| // If the read returns bytes however, we just fall back to reading into a Vec then turning |
| // that into an Lrc, losing our nice peak memory behavior. This fallback code path should |
| // be rarely exercised. |
| |
| let mut probe = [0u8; 32]; |
| let n = loop { |
| match file.read(&mut probe) { |
| Ok(0) => return Ok(bytes), |
| Err(e) if e.kind() == io::ErrorKind::Interrupted => continue, |
| Err(e) => return Err(e), |
| Ok(n) => break n, |
| } |
| }; |
| let mut bytes: Vec<u8> = bytes.iter().copied().chain(probe[..n].iter().copied()).collect(); |
| file.read_to_end(&mut bytes)?; |
| Ok(bytes.into()) |
| } |
| } |
| |
| /// This is a [SourceFile] identifier that is used to correlate source files between |
| /// subsequent compilation sessions (which is something we need to do during |
| /// incremental compilation). |
| /// |
| /// The [StableSourceFileId] also contains the CrateNum of the crate the source |
| /// file was originally parsed for. This way we get two separate entries in |
| /// the [SourceMap] if the same file is part of both the local and an upstream |
| /// crate. Trying to only have one entry for both cases is problematic because |
| /// at the point where we discover that there's a local use of the file in |
| /// addition to the upstream one, we might already have made decisions based on |
| /// the assumption that it's an upstream file. Treating the two files as |
| /// different has no real downsides. |
| #[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, Debug)] |
| pub struct StableSourceFileId { |
| /// A hash of the source file's [`FileName`]. This is hash so that it's size |
| /// is more predictable than if we included the actual [`FileName`] value. |
| pub file_name_hash: Hash64, |
| |
| /// The [`CrateNum`] of the crate this source file was originally parsed for. |
| /// We cannot include this information in the hash because at the time |
| /// of hashing we don't have the context to map from the [`CrateNum`]'s numeric |
| /// value to a `StableCrateId`. |
| pub cnum: CrateNum, |
| } |
| |
| // FIXME: we need a more globally consistent approach to the problem solved by |
| // StableSourceFileId, perhaps built atop source_file.name_hash. |
| impl StableSourceFileId { |
| pub fn new(source_file: &SourceFile) -> StableSourceFileId { |
| StableSourceFileId::new_from_name(&source_file.name, source_file.cnum) |
| } |
| |
| fn new_from_name(name: &FileName, cnum: CrateNum) -> StableSourceFileId { |
| let mut hasher = StableHasher::new(); |
| name.hash(&mut hasher); |
| StableSourceFileId { file_name_hash: hasher.finish(), cnum } |
| } |
| } |
| |
| // _____________________________________________________________________________ |
| // SourceMap |
| // |
| |
| #[derive(Default)] |
| struct SourceMapFiles { |
| source_files: monotonic::MonotonicVec<Lrc<SourceFile>>, |
| stable_id_to_source_file: FxHashMap<StableSourceFileId, Lrc<SourceFile>>, |
| } |
| |
| pub struct SourceMap { |
| files: RwLock<SourceMapFiles>, |
| file_loader: IntoDynSyncSend<Box<dyn FileLoader + Sync + Send>>, |
| // This is used to apply the file path remapping as specified via |
| // `--remap-path-prefix` to all `SourceFile`s allocated within this `SourceMap`. |
| path_mapping: FilePathMapping, |
| |
| /// The algorithm used for hashing the contents of each source file. |
| hash_kind: SourceFileHashAlgorithm, |
| } |
| |
| impl SourceMap { |
| pub fn new(path_mapping: FilePathMapping) -> SourceMap { |
| Self::with_file_loader_and_hash_kind( |
| Box::new(RealFileLoader), |
| path_mapping, |
| SourceFileHashAlgorithm::Md5, |
| ) |
| } |
| |
| pub fn with_file_loader_and_hash_kind( |
| file_loader: Box<dyn FileLoader + Sync + Send>, |
| path_mapping: FilePathMapping, |
| hash_kind: SourceFileHashAlgorithm, |
| ) -> SourceMap { |
| SourceMap { |
| files: Default::default(), |
| file_loader: IntoDynSyncSend(file_loader), |
| path_mapping, |
| hash_kind, |
| } |
| } |
| |
| pub fn path_mapping(&self) -> &FilePathMapping { |
| &self.path_mapping |
| } |
| |
| pub fn file_exists(&self, path: &Path) -> bool { |
| self.file_loader.file_exists(path) |
| } |
| |
| pub fn load_file(&self, path: &Path) -> io::Result<Lrc<SourceFile>> { |
| let src = self.file_loader.read_file(path)?; |
| let filename = path.to_owned().into(); |
| Ok(self.new_source_file(filename, src)) |
| } |
| |
| /// Loads source file as a binary blob. |
| /// |
| /// Unlike `load_file`, guarantees that no normalization like BOM-removal |
| /// takes place. |
| pub fn load_binary_file(&self, path: &Path) -> io::Result<Lrc<[u8]>> { |
| let bytes = self.file_loader.read_binary_file(path)?; |
| |
| // We need to add file to the `SourceMap`, so that it is present |
| // in dep-info. There's also an edge case that file might be both |
| // loaded as a binary via `include_bytes!` and as proper `SourceFile` |
| // via `mod`, so we try to use real file contents and not just an |
| // empty string. |
| let text = std::str::from_utf8(&bytes).unwrap_or("").to_string(); |
| self.new_source_file(path.to_owned().into(), text); |
| Ok(bytes) |
| } |
| |
| // By returning a `MonotonicVec`, we ensure that consumers cannot invalidate |
| // any existing indices pointing into `files`. |
| pub fn files(&self) -> MappedReadGuard<'_, monotonic::MonotonicVec<Lrc<SourceFile>>> { |
| ReadGuard::map(self.files.borrow(), |files| &files.source_files) |
| } |
| |
| pub fn source_file_by_stable_id( |
| &self, |
| stable_id: StableSourceFileId, |
| ) -> Option<Lrc<SourceFile>> { |
| self.files.borrow().stable_id_to_source_file.get(&stable_id).cloned() |
| } |
| |
| fn register_source_file( |
| &self, |
| file_id: StableSourceFileId, |
| mut file: SourceFile, |
| ) -> Result<Lrc<SourceFile>, OffsetOverflowError> { |
| let mut files = self.files.borrow_mut(); |
| |
| file.start_pos = BytePos(if let Some(last_file) = files.source_files.last() { |
| // Add one so there is some space between files. This lets us distinguish |
| // positions in the `SourceMap`, even in the presence of zero-length files. |
| last_file.end_position().0.checked_add(1).ok_or(OffsetOverflowError)? |
| } else { |
| 0 |
| }); |
| |
| let file = Lrc::new(file); |
| files.source_files.push(file.clone()); |
| files.stable_id_to_source_file.insert(file_id, file.clone()); |
| |
| Ok(file) |
| } |
| |
| /// Creates a new `SourceFile`. |
| /// If a file already exists in the `SourceMap` with the same ID, that file is returned |
| /// unmodified. |
| pub fn new_source_file(&self, filename: FileName, src: String) -> Lrc<SourceFile> { |
| self.try_new_source_file(filename, src).unwrap_or_else(|OffsetOverflowError| { |
| eprintln!("fatal error: rustc does not support files larger than 4GB"); |
| crate::fatal_error::FatalError.raise() |
| }) |
| } |
| |
| fn try_new_source_file( |
| &self, |
| filename: FileName, |
| src: String, |
| ) -> Result<Lrc<SourceFile>, OffsetOverflowError> { |
| // Note that filename may not be a valid path, eg it may be `<anon>` etc, |
| // but this is okay because the directory determined by `path.pop()` will |
| // be empty, so the working directory will be used. |
| let (filename, _) = self.path_mapping.map_filename_prefix(&filename); |
| |
| let file_id = StableSourceFileId::new_from_name(&filename, LOCAL_CRATE); |
| match self.source_file_by_stable_id(file_id) { |
| Some(lrc_sf) => Ok(lrc_sf), |
| None => { |
| let source_file = SourceFile::new(filename, src, self.hash_kind)?; |
| |
| // Let's make sure the file_id we generated above actually matches |
| // the ID we generate for the SourceFile we just created. |
| debug_assert_eq!(StableSourceFileId::new(&source_file), file_id); |
| |
| self.register_source_file(file_id, source_file) |
| } |
| } |
| } |
| |
| /// Allocates a new `SourceFile` representing a source file from an external |
| /// crate. The source code of such an "imported `SourceFile`" is not available, |
| /// but we still know enough to generate accurate debuginfo location |
| /// information for things inlined from other crates. |
| pub fn new_imported_source_file( |
| &self, |
| filename: FileName, |
| src_hash: SourceFileHash, |
| name_hash: Hash128, |
| source_len: u32, |
| cnum: CrateNum, |
| file_local_lines: FreezeLock<SourceFileLines>, |
| multibyte_chars: Vec<MultiByteChar>, |
| non_narrow_chars: Vec<NonNarrowChar>, |
| normalized_pos: Vec<NormalizedPos>, |
| metadata_index: u32, |
| ) -> Lrc<SourceFile> { |
| let source_len = RelativeBytePos::from_u32(source_len); |
| |
| let source_file = SourceFile { |
| name: filename, |
| src: None, |
| src_hash, |
| external_src: FreezeLock::new(ExternalSource::Foreign { |
| kind: ExternalSourceKind::AbsentOk, |
| metadata_index, |
| }), |
| start_pos: BytePos(0), |
| source_len, |
| lines: file_local_lines, |
| multibyte_chars, |
| non_narrow_chars, |
| normalized_pos, |
| name_hash, |
| cnum, |
| }; |
| |
| let file_id = StableSourceFileId::new(&source_file); |
| self.register_source_file(file_id, source_file) |
| .expect("not enough address space for imported source file") |
| } |
| |
| /// If there is a doctest offset, applies it to the line. |
| pub fn doctest_offset_line(&self, file: &FileName, orig: usize) -> usize { |
| match file { |
| FileName::DocTest(_, offset) => { |
| if *offset < 0 { |
| orig - (-(*offset)) as usize |
| } else { |
| orig + *offset as usize |
| } |
| } |
| _ => orig, |
| } |
| } |
| |
| /// Return the SourceFile that contains the given `BytePos` |
| pub fn lookup_source_file(&self, pos: BytePos) -> Lrc<SourceFile> { |
| let idx = self.lookup_source_file_idx(pos); |
| (*self.files.borrow().source_files)[idx].clone() |
| } |
| |
| /// Looks up source information about a `BytePos`. |
| pub fn lookup_char_pos(&self, pos: BytePos) -> Loc { |
| let sf = self.lookup_source_file(pos); |
| let (line, col, col_display) = sf.lookup_file_pos_with_col_display(pos); |
| Loc { file: sf, line, col, col_display } |
| } |
| |
| /// If the corresponding `SourceFile` is empty, does not return a line number. |
| pub fn lookup_line(&self, pos: BytePos) -> Result<SourceFileAndLine, Lrc<SourceFile>> { |
| let f = self.lookup_source_file(pos); |
| |
| let pos = f.relative_position(pos); |
| match f.lookup_line(pos) { |
| Some(line) => Ok(SourceFileAndLine { sf: f, line }), |
| None => Err(f), |
| } |
| } |
| |
| pub fn span_to_string( |
| &self, |
| sp: Span, |
| filename_display_pref: FileNameDisplayPreference, |
| ) -> String { |
| let (source_file, lo_line, lo_col, hi_line, hi_col) = self.span_to_location_info(sp); |
| |
| let file_name = match source_file { |
| Some(sf) => sf.name.display(filename_display_pref).to_string(), |
| None => return "no-location".to_string(), |
| }; |
| |
| format!( |
| "{file_name}:{lo_line}:{lo_col}{}", |
| if let FileNameDisplayPreference::Short = filename_display_pref { |
| String::new() |
| } else { |
| format!(": {hi_line}:{hi_col}") |
| } |
| ) |
| } |
| |
| pub fn span_to_location_info( |
| &self, |
| sp: Span, |
| ) -> (Option<Lrc<SourceFile>>, usize, usize, usize, usize) { |
| if self.files.borrow().source_files.is_empty() || sp.is_dummy() { |
| return (None, 0, 0, 0, 0); |
| } |
| |
| let lo = self.lookup_char_pos(sp.lo()); |
| let hi = self.lookup_char_pos(sp.hi()); |
| (Some(lo.file), lo.line, lo.col.to_usize() + 1, hi.line, hi.col.to_usize() + 1) |
| } |
| |
| /// Format the span location suitable for embedding in build artifacts |
| pub fn span_to_embeddable_string(&self, sp: Span) -> String { |
| self.span_to_string(sp, FileNameDisplayPreference::Remapped) |
| } |
| |
| /// Format the span location to be printed in diagnostics. Must not be emitted |
| /// to build artifacts as this may leak local file paths. Use span_to_embeddable_string |
| /// for string suitable for embedding. |
| pub fn span_to_diagnostic_string(&self, sp: Span) -> String { |
| self.span_to_string(sp, self.path_mapping.filename_display_for_diagnostics) |
| } |
| |
| pub fn span_to_filename(&self, sp: Span) -> FileName { |
| self.lookup_char_pos(sp.lo()).file.name.clone() |
| } |
| |
| pub fn filename_for_diagnostics<'a>(&self, filename: &'a FileName) -> FileNameDisplay<'a> { |
| filename.display(self.path_mapping.filename_display_for_diagnostics) |
| } |
| |
| pub fn is_multiline(&self, sp: Span) -> bool { |
| let lo = self.lookup_source_file_idx(sp.lo()); |
| let hi = self.lookup_source_file_idx(sp.hi()); |
| if lo != hi { |
| return true; |
| } |
| let f = (*self.files.borrow().source_files)[lo].clone(); |
| let lo = f.relative_position(sp.lo()); |
| let hi = f.relative_position(sp.hi()); |
| f.lookup_line(lo) != f.lookup_line(hi) |
| } |
| |
| #[instrument(skip(self), level = "trace")] |
| pub fn is_valid_span(&self, sp: Span) -> Result<(Loc, Loc), SpanLinesError> { |
| let lo = self.lookup_char_pos(sp.lo()); |
| trace!(?lo); |
| let hi = self.lookup_char_pos(sp.hi()); |
| trace!(?hi); |
| if lo.file.start_pos != hi.file.start_pos { |
| return Err(SpanLinesError::DistinctSources(Box::new(DistinctSources { |
| begin: (lo.file.name.clone(), lo.file.start_pos), |
| end: (hi.file.name.clone(), hi.file.start_pos), |
| }))); |
| } |
| Ok((lo, hi)) |
| } |
| |
| pub fn is_line_before_span_empty(&self, sp: Span) -> bool { |
| match self.span_to_prev_source(sp) { |
| Ok(s) => s.rsplit_once('\n').unwrap_or(("", &s)).1.trim_start().is_empty(), |
| Err(_) => false, |
| } |
| } |
| |
| pub fn span_to_lines(&self, sp: Span) -> FileLinesResult { |
| debug!("span_to_lines(sp={:?})", sp); |
| let (lo, hi) = self.is_valid_span(sp)?; |
| assert!(hi.line >= lo.line); |
| |
| if sp.is_dummy() { |
| return Ok(FileLines { file: lo.file, lines: Vec::new() }); |
| } |
| |
| let mut lines = Vec::with_capacity(hi.line - lo.line + 1); |
| |
| // The span starts partway through the first line, |
| // but after that it starts from offset 0. |
| let mut start_col = lo.col; |
| |
| // For every line but the last, it extends from `start_col` |
| // and to the end of the line. Be careful because the line |
| // numbers in Loc are 1-based, so we subtract 1 to get 0-based |
| // lines. |
| // |
| // FIXME: now that we handle DUMMY_SP up above, we should consider |
| // asserting that the line numbers here are all indeed 1-based. |
| let hi_line = hi.line.saturating_sub(1); |
| for line_index in lo.line.saturating_sub(1)..hi_line { |
| let line_len = lo.file.get_line(line_index).map_or(0, |s| s.chars().count()); |
| lines.push(LineInfo { line_index, start_col, end_col: CharPos::from_usize(line_len) }); |
| start_col = CharPos::from_usize(0); |
| } |
| |
| // For the last line, it extends from `start_col` to `hi.col`: |
| lines.push(LineInfo { line_index: hi_line, start_col, end_col: hi.col }); |
| |
| Ok(FileLines { file: lo.file, lines }) |
| } |
| |
| /// Extracts the source surrounding the given `Span` using the `extract_source` function. The |
| /// extract function takes three arguments: a string slice containing the source, an index in |
| /// the slice for the beginning of the span and an index in the slice for the end of the span. |
| fn span_to_source<F, T>(&self, sp: Span, extract_source: F) -> Result<T, SpanSnippetError> |
| where |
| F: Fn(&str, usize, usize) -> Result<T, SpanSnippetError>, |
| { |
| let local_begin = self.lookup_byte_offset(sp.lo()); |
| let local_end = self.lookup_byte_offset(sp.hi()); |
| |
| if local_begin.sf.start_pos != local_end.sf.start_pos { |
| Err(SpanSnippetError::DistinctSources(Box::new(DistinctSources { |
| begin: (local_begin.sf.name.clone(), local_begin.sf.start_pos), |
| end: (local_end.sf.name.clone(), local_end.sf.start_pos), |
| }))) |
| } else { |
| self.ensure_source_file_source_present(&local_begin.sf); |
| |
| let start_index = local_begin.pos.to_usize(); |
| let end_index = local_end.pos.to_usize(); |
| let source_len = local_begin.sf.source_len.to_usize(); |
| |
| if start_index > end_index || end_index > source_len { |
| return Err(SpanSnippetError::MalformedForSourcemap(MalformedSourceMapPositions { |
| name: local_begin.sf.name.clone(), |
| source_len, |
| begin_pos: local_begin.pos, |
| end_pos: local_end.pos, |
| })); |
| } |
| |
| if let Some(ref src) = local_begin.sf.src { |
| extract_source(src, start_index, end_index) |
| } else if let Some(src) = local_begin.sf.external_src.read().get_source() { |
| extract_source(src, start_index, end_index) |
| } else { |
| Err(SpanSnippetError::SourceNotAvailable { filename: local_begin.sf.name.clone() }) |
| } |
| } |
| } |
| |
| pub fn is_span_accessible(&self, sp: Span) -> bool { |
| self.span_to_source(sp, |src, start_index, end_index| { |
| Ok(src.get(start_index..end_index).is_some()) |
| }) |
| .is_ok_and(|is_accessible| is_accessible) |
| } |
| |
| /// Returns the source snippet as `String` corresponding to the given `Span`. |
| pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> { |
| self.span_to_source(sp, |src, start_index, end_index| { |
| src.get(start_index..end_index) |
| .map(|s| s.to_string()) |
| .ok_or(SpanSnippetError::IllFormedSpan(sp)) |
| }) |
| } |
| |
| pub fn span_to_margin(&self, sp: Span) -> Option<usize> { |
| Some(self.indentation_before(sp)?.len()) |
| } |
| |
| pub fn indentation_before(&self, sp: Span) -> Option<String> { |
| self.span_to_source(sp, |src, start_index, _| { |
| let before = &src[..start_index]; |
| let last_line = before.rsplit_once('\n').map_or(before, |(_, last)| last); |
| Ok(last_line |
| .split_once(|c: char| !c.is_whitespace()) |
| .map_or(last_line, |(indent, _)| indent) |
| .to_string()) |
| }) |
| .ok() |
| } |
| |
| /// Returns the source snippet as `String` before the given `Span`. |
| pub fn span_to_prev_source(&self, sp: Span) -> Result<String, SpanSnippetError> { |
| self.span_to_source(sp, |src, start_index, _| { |
| src.get(..start_index).map(|s| s.to_string()).ok_or(SpanSnippetError::IllFormedSpan(sp)) |
| }) |
| } |
| |
| /// Extends the given `Span` to just after the previous occurrence of `c`. Return the same span |
| /// if no character could be found or if an error occurred while retrieving the code snippet. |
| pub fn span_extend_to_prev_char(&self, sp: Span, c: char, accept_newlines: bool) -> Span { |
| if let Ok(prev_source) = self.span_to_prev_source(sp) { |
| let prev_source = prev_source.rsplit(c).next().unwrap_or(""); |
| if !prev_source.is_empty() && (accept_newlines || !prev_source.contains('\n')) { |
| return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32)); |
| } |
| } |
| |
| sp |
| } |
| |
| /// Extends the given `Span` to just after the previous occurrence of `pat` when surrounded by |
| /// whitespace. Returns None if the pattern could not be found or if an error occurred while |
| /// retrieving the code snippet. |
| pub fn span_extend_to_prev_str( |
| &self, |
| sp: Span, |
| pat: &str, |
| accept_newlines: bool, |
| include_whitespace: bool, |
| ) -> Option<Span> { |
| // assure that the pattern is delimited, to avoid the following |
| // fn my_fn() |
| // ^^^^ returned span without the check |
| // ---------- correct span |
| let prev_source = self.span_to_prev_source(sp).ok()?; |
| for ws in &[" ", "\t", "\n"] { |
| let pat = pat.to_owned() + ws; |
| if let Some(pat_pos) = prev_source.rfind(&pat) { |
| let just_after_pat_pos = pat_pos + pat.len() - 1; |
| let just_after_pat_plus_ws = if include_whitespace { |
| just_after_pat_pos |
| + prev_source[just_after_pat_pos..] |
| .find(|c: char| !c.is_whitespace()) |
| .unwrap_or(0) |
| } else { |
| just_after_pat_pos |
| }; |
| let len = prev_source.len() - just_after_pat_plus_ws; |
| let prev_source = &prev_source[just_after_pat_plus_ws..]; |
| if accept_newlines || !prev_source.trim_start().contains('\n') { |
| return Some(sp.with_lo(BytePos(sp.lo().0 - len as u32))); |
| } |
| } |
| } |
| |
| None |
| } |
| |
| /// Returns the source snippet as `String` after the given `Span`. |
| pub fn span_to_next_source(&self, sp: Span) -> Result<String, SpanSnippetError> { |
| self.span_to_source(sp, |src, _, end_index| { |
| src.get(end_index..).map(|s| s.to_string()).ok_or(SpanSnippetError::IllFormedSpan(sp)) |
| }) |
| } |
| |
| /// Extends the given `Span` while the next character matches the predicate |
| pub fn span_extend_while( |
| &self, |
| span: Span, |
| f: impl Fn(char) -> bool, |
| ) -> Result<Span, SpanSnippetError> { |
| self.span_to_source(span, |s, _start, end| { |
| let n = s[end..].char_indices().find(|&(_, c)| !f(c)).map_or(s.len() - end, |(i, _)| i); |
| Ok(span.with_hi(span.hi() + BytePos(n as u32))) |
| }) |
| } |
| |
| /// Extends the given `Span` to previous character while the previous character matches the predicate |
| pub fn span_extend_prev_while( |
| &self, |
| span: Span, |
| f: impl Fn(char) -> bool, |
| ) -> Result<Span, SpanSnippetError> { |
| self.span_to_source(span, |s, start, _end| { |
| let n = s[..start] |
| .char_indices() |
| .rfind(|&(_, c)| !f(c)) |
| .map_or(start, |(i, _)| start - i - 1); |
| Ok(span.with_lo(span.lo() - BytePos(n as u32))) |
| }) |
| } |
| |
| /// Extends the given `Span` to just before the next occurrence of `c`. |
| pub fn span_extend_to_next_char(&self, sp: Span, c: char, accept_newlines: bool) -> Span { |
| if let Ok(next_source) = self.span_to_next_source(sp) { |
| let next_source = next_source.split(c).next().unwrap_or(""); |
| if !next_source.is_empty() && (accept_newlines || !next_source.contains('\n')) { |
| return sp.with_hi(BytePos(sp.hi().0 + next_source.len() as u32)); |
| } |
| } |
| |
| sp |
| } |
| |
| /// Extends the given `Span` to contain the entire line it is on. |
| pub fn span_extend_to_line(&self, sp: Span) -> Span { |
| self.span_extend_to_prev_char(self.span_extend_to_next_char(sp, '\n', true), '\n', true) |
| } |
| |
| /// Given a `Span`, tries to get a shorter span ending before the first occurrence of `char` |
| /// `c`. |
| pub fn span_until_char(&self, sp: Span, c: char) -> Span { |
| match self.span_to_snippet(sp) { |
| Ok(snippet) => { |
| let snippet = snippet.split(c).next().unwrap_or("").trim_end(); |
| if !snippet.is_empty() && !snippet.contains('\n') { |
| sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32)) |
| } else { |
| sp |
| } |
| } |
| _ => sp, |
| } |
| } |
| |
| /// Given a 'Span', tries to tell if it's wrapped by "<>" or "()" |
| /// the algorithm searches if the next character is '>' or ')' after skipping white space |
| /// then searches the previous character to match '<' or '(' after skipping white space |
| /// return true if wrapped by '<>' or '()' |
| pub fn span_wrapped_by_angle_or_parentheses(&self, span: Span) -> bool { |
| self.span_to_source(span, |src, start_index, end_index| { |
| if src.get(start_index..end_index).is_none() { |
| return Ok(false); |
| } |
| // test the right side to match '>' after skipping white space |
| let end_src = &src[end_index..]; |
| let mut i = 0; |
| let mut found_right_parentheses = false; |
| let mut found_right_angle = false; |
| while let Some(cc) = end_src.chars().nth(i) { |
| if cc == ' ' { |
| i = i + 1; |
| } else if cc == '>' { |
| // found > in the right; |
| found_right_angle = true; |
| break; |
| } else if cc == ')' { |
| found_right_parentheses = true; |
| break; |
| } else { |
| // failed to find '>' return false immediately |
| return Ok(false); |
| } |
| } |
| // test the left side to match '<' after skipping white space |
| i = start_index; |
| let start_src = &src[0..start_index]; |
| while let Some(cc) = start_src.chars().nth(i) { |
| if cc == ' ' { |
| if i == 0 { |
| return Ok(false); |
| } |
| i = i - 1; |
| } else if cc == '<' { |
| // found < in the left |
| if !found_right_angle { |
| // skip something like "(< )>" |
| return Ok(false); |
| } |
| break; |
| } else if cc == '(' { |
| if !found_right_parentheses { |
| // skip something like "<(>)" |
| return Ok(false); |
| } |
| break; |
| } else { |
| // failed to find '<' return false immediately |
| return Ok(false); |
| } |
| } |
| return Ok(true); |
| }) |
| .is_ok_and(|is_accessible| is_accessible) |
| } |
| |
| /// Given a `Span`, tries to get a shorter span ending just after the first occurrence of `char` |
| /// `c`. |
| pub fn span_through_char(&self, sp: Span, c: char) -> Span { |
| if let Ok(snippet) = self.span_to_snippet(sp) { |
| if let Some(offset) = snippet.find(c) { |
| return sp.with_hi(BytePos(sp.lo().0 + (offset + c.len_utf8()) as u32)); |
| } |
| } |
| sp |
| } |
| |
| /// Given a `Span`, gets a new `Span` covering the first token and all its trailing whitespace |
| /// or the original `Span`. |
| /// |
| /// If `sp` points to `"let mut x"`, then a span pointing at `"let "` will be returned. |
| pub fn span_until_non_whitespace(&self, sp: Span) -> Span { |
| let mut whitespace_found = false; |
| |
| self.span_take_while(sp, |c| { |
| if !whitespace_found && c.is_whitespace() { |
| whitespace_found = true; |
| } |
| |
| !whitespace_found || c.is_whitespace() |
| }) |
| } |
| |
| /// Given a `Span`, gets a new `Span` covering the first token without its trailing whitespace |
| /// or the original `Span` in case of error. |
| /// |
| /// If `sp` points to `"let mut x"`, then a span pointing at `"let"` will be returned. |
| pub fn span_until_whitespace(&self, sp: Span) -> Span { |
| self.span_take_while(sp, |c| !c.is_whitespace()) |
| } |
| |
| /// Given a `Span`, gets a shorter one until `predicate` yields `false`. |
| pub fn span_take_while<P>(&self, sp: Span, predicate: P) -> Span |
| where |
| P: for<'r> FnMut(&'r char) -> bool, |
| { |
| if let Ok(snippet) = self.span_to_snippet(sp) { |
| let offset = snippet.chars().take_while(predicate).map(|c| c.len_utf8()).sum::<usize>(); |
| |
| sp.with_hi(BytePos(sp.lo().0 + (offset as u32))) |
| } else { |
| sp |
| } |
| } |
| |
| /// Given a `Span`, return a span ending in the closest `{`. This is useful when you have a |
| /// `Span` enclosing a whole item but we need to point at only the head (usually the first |
| /// line) of that item. |
| /// |
| /// *Only suitable for diagnostics.* |
| pub fn guess_head_span(&self, sp: Span) -> Span { |
| // FIXME: extend the AST items to have a head span, or replace callers with pointing at |
| // the item's ident when appropriate. |
| self.span_until_char(sp, '{') |
| } |
| |
| /// Returns a new span representing just the first character of the given span. |
| pub fn start_point(&self, sp: Span) -> Span { |
| let width = { |
| let sp = sp.data(); |
| let local_begin = self.lookup_byte_offset(sp.lo); |
| let start_index = local_begin.pos.to_usize(); |
| let src = local_begin.sf.external_src.read(); |
| |
| let snippet = if let Some(ref src) = local_begin.sf.src { |
| Some(&src[start_index..]) |
| } else { |
| src.get_source().map(|src| &src[start_index..]) |
| }; |
| |
| match snippet { |
| None => 1, |
| Some(snippet) => match snippet.chars().next() { |
| None => 1, |
| Some(c) => c.len_utf8(), |
| }, |
| } |
| }; |
| |
| sp.with_hi(BytePos(sp.lo().0 + width as u32)) |
| } |
| |
| /// Returns a new span representing just the last character of this span. |
| pub fn end_point(&self, sp: Span) -> Span { |
| let pos = sp.hi().0; |
| |
| let width = self.find_width_of_character_at_span(sp, false); |
| let corrected_end_position = pos.checked_sub(width).unwrap_or(pos); |
| |
| let end_point = BytePos(cmp::max(corrected_end_position, sp.lo().0)); |
| sp.with_lo(end_point) |
| } |
| |
| /// Returns a new span representing the next character after the end-point of this span. |
| /// Special cases: |
| /// - if span is a dummy one, returns the same span |
| /// - if next_point reached the end of source, return a span exceeding the end of source, |
| /// which means sm.span_to_snippet(next_point) will get `Err` |
| /// - respect multi-byte characters |
| pub fn next_point(&self, sp: Span) -> Span { |
| if sp.is_dummy() { |
| return sp; |
| } |
| let start_of_next_point = sp.hi().0; |
| |
| let width = self.find_width_of_character_at_span(sp, true); |
| // If the width is 1, then the next span should only contain the next char besides current ending. |
| // However, in the case of a multibyte character, where the width != 1, the next span should |
| // span multiple bytes to include the whole character. |
| let end_of_next_point = |
| start_of_next_point.checked_add(width).unwrap_or(start_of_next_point); |
| |
| let end_of_next_point = BytePos(cmp::max(start_of_next_point + 1, end_of_next_point)); |
| Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt(), None) |
| } |
| |
| /// Check whether span is followed by some specified expected string in limit scope |
| pub fn span_look_ahead(&self, span: Span, expect: &str, limit: Option<usize>) -> Option<Span> { |
| let mut sp = span; |
| for _ in 0..limit.unwrap_or(100_usize) { |
| sp = self.next_point(sp); |
| if let Ok(ref snippet) = self.span_to_snippet(sp) { |
| if snippet == expect { |
| return Some(sp); |
| } |
| if snippet.chars().any(|c| !c.is_whitespace()) { |
| break; |
| } |
| } |
| } |
| None |
| } |
| |
| /// Finds the width of the character, either before or after the end of provided span, |
| /// depending on the `forwards` parameter. |
| #[instrument(skip(self, sp))] |
| fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 { |
| let sp = sp.data(); |
| |
| if sp.lo == sp.hi && !forwards { |
| debug!("early return empty span"); |
| return 1; |
| } |
| |
| let local_begin = self.lookup_byte_offset(sp.lo); |
| let local_end = self.lookup_byte_offset(sp.hi); |
| debug!("local_begin=`{:?}`, local_end=`{:?}`", local_begin, local_end); |
| |
| if local_begin.sf.start_pos != local_end.sf.start_pos { |
| debug!("begin and end are in different files"); |
| return 1; |
| } |
| |
| let start_index = local_begin.pos.to_usize(); |
| let end_index = local_end.pos.to_usize(); |
| debug!("start_index=`{:?}`, end_index=`{:?}`", start_index, end_index); |
| |
| // Disregard indexes that are at the start or end of their spans, they can't fit bigger |
| // characters. |
| if (!forwards && end_index == usize::MIN) || (forwards && start_index == usize::MAX) { |
| debug!("start or end of span, cannot be multibyte"); |
| return 1; |
| } |
| |
| let source_len = local_begin.sf.source_len.to_usize(); |
| debug!("source_len=`{:?}`", source_len); |
| // Ensure indexes are also not malformed. |
| if start_index > end_index || end_index > source_len - 1 { |
| debug!("source indexes are malformed"); |
| return 1; |
| } |
| |
| let src = local_begin.sf.external_src.read(); |
| |
| let snippet = if let Some(src) = &local_begin.sf.src { |
| src |
| } else if let Some(src) = src.get_source() { |
| src |
| } else { |
| return 1; |
| }; |
| |
| if forwards { |
| (snippet.ceil_char_boundary(end_index + 1) - end_index) as u32 |
| } else { |
| (end_index - snippet.floor_char_boundary(end_index - 1)) as u32 |
| } |
| } |
| |
| pub fn get_source_file(&self, filename: &FileName) -> Option<Lrc<SourceFile>> { |
| // Remap filename before lookup |
| let filename = self.path_mapping().map_filename_prefix(filename).0; |
| for sf in self.files.borrow().source_files.iter() { |
| if filename == sf.name { |
| return Some(sf.clone()); |
| } |
| } |
| None |
| } |
| |
| /// For a global `BytePos`, computes the local offset within the containing `SourceFile`. |
| pub fn lookup_byte_offset(&self, bpos: BytePos) -> SourceFileAndBytePos { |
| let idx = self.lookup_source_file_idx(bpos); |
| let sf = (*self.files.borrow().source_files)[idx].clone(); |
| let offset = bpos - sf.start_pos; |
| SourceFileAndBytePos { sf, pos: offset } |
| } |
| |
| /// Returns the index of the [`SourceFile`] (in `self.files`) that contains `pos`. |
| /// This index is guaranteed to be valid for the lifetime of this `SourceMap`, |
| /// since `source_files` is a `MonotonicVec` |
| pub fn lookup_source_file_idx(&self, pos: BytePos) -> usize { |
| self.files.borrow().source_files.partition_point(|x| x.start_pos <= pos) - 1 |
| } |
| |
| pub fn count_lines(&self) -> usize { |
| self.files().iter().fold(0, |a, f| a + f.count_lines()) |
| } |
| |
| pub fn ensure_source_file_source_present(&self, source_file: &SourceFile) -> bool { |
| source_file.add_external_src(|| { |
| let FileName::Real(ref name) = source_file.name else { |
| return None; |
| }; |
| |
| let local_path: Cow<'_, Path> = match name { |
| RealFileName::LocalPath(local_path) => local_path.into(), |
| RealFileName::Remapped { local_path: Some(local_path), .. } => local_path.into(), |
| RealFileName::Remapped { local_path: None, virtual_name } => { |
| // The compiler produces better error messages if the sources of dependencies |
| // are available. Attempt to undo any path mapping so we can find remapped |
| // dependencies. |
| // We can only use the heuristic because `add_external_src` checks the file |
| // content hash. |
| self.path_mapping.reverse_map_prefix_heuristically(virtual_name)?.into() |
| } |
| }; |
| |
| self.file_loader.read_file(&local_path).ok() |
| }) |
| } |
| |
| pub fn is_imported(&self, sp: Span) -> bool { |
| let source_file_index = self.lookup_source_file_idx(sp.lo()); |
| let source_file = &self.files()[source_file_index]; |
| source_file.is_imported() |
| } |
| |
| /// Gets the span of a statement. If the statement is a macro expansion, the |
| /// span in the context of the block span is found. The trailing semicolon is included |
| /// on a best-effort basis. |
| pub fn stmt_span(&self, stmt_span: Span, block_span: Span) -> Span { |
| if !stmt_span.from_expansion() { |
| return stmt_span; |
| } |
| let mac_call = original_sp(stmt_span, block_span); |
| self.mac_call_stmt_semi_span(mac_call).map_or(mac_call, |s| mac_call.with_hi(s.hi())) |
| } |
| |
| /// Tries to find the span of the semicolon of a macro call statement. |
| /// The input must be the *call site* span of a statement from macro expansion. |
| /// ```ignore (illustrative) |
| /// // v output |
| /// mac!(); |
| /// // ^^^^^^ input |
| /// ``` |
| pub fn mac_call_stmt_semi_span(&self, mac_call: Span) -> Option<Span> { |
| let span = self.span_extend_while(mac_call, char::is_whitespace).ok()?; |
| let span = span.shrink_to_hi().with_hi(BytePos(span.hi().0.checked_add(1)?)); |
| if self.span_to_snippet(span).as_deref() != Ok(";") { |
| return None; |
| } |
| Some(span) |
| } |
| } |
| |
| #[derive(Clone)] |
| pub struct FilePathMapping { |
| mapping: Vec<(PathBuf, PathBuf)>, |
| filename_display_for_diagnostics: FileNameDisplayPreference, |
| } |
| |
| impl FilePathMapping { |
| pub fn empty() -> FilePathMapping { |
| FilePathMapping::new(Vec::new(), FileNameDisplayPreference::Local) |
| } |
| |
| pub fn new( |
| mapping: Vec<(PathBuf, PathBuf)>, |
| filename_display_for_diagnostics: FileNameDisplayPreference, |
| ) -> FilePathMapping { |
| FilePathMapping { mapping, filename_display_for_diagnostics } |
| } |
| |
| /// Applies any path prefix substitution as defined by the mapping. |
| /// The return value is the remapped path and a boolean indicating whether |
| /// the path was affected by the mapping. |
| pub fn map_prefix<'a>(&'a self, path: impl Into<Cow<'a, Path>>) -> (Cow<'a, Path>, bool) { |
| let path = path.into(); |
| if path.as_os_str().is_empty() { |
| // Exit early if the path is empty and therefore there's nothing to remap. |
| // This is mostly to reduce spam for `RUSTC_LOG=[remap_path_prefix]`. |
| return (path, false); |
| } |
| |
| return remap_path_prefix(&self.mapping, path); |
| |
| #[instrument(level = "debug", skip(mapping), ret)] |
| fn remap_path_prefix<'a>( |
| mapping: &'a [(PathBuf, PathBuf)], |
| path: Cow<'a, Path>, |
| ) -> (Cow<'a, Path>, bool) { |
| // NOTE: We are iterating over the mapping entries from last to first |
| // because entries specified later on the command line should |
| // take precedence. |
| for (from, to) in mapping.iter().rev() { |
| debug!("Trying to apply {from:?} => {to:?}"); |
| |
| if let Ok(rest) = path.strip_prefix(from) { |
| let remapped = if rest.as_os_str().is_empty() { |
| // This is subtle, joining an empty path onto e.g. `foo/bar` will |
| // result in `foo/bar/`, that is, there'll be an additional directory |
| // separator at the end. This can lead to duplicated directory separators |
| // in remapped paths down the line. |
| // So, if we have an exact match, we just return that without a call |
| // to `Path::join()`. |
| to.into() |
| } else { |
| to.join(rest).into() |
| }; |
| debug!("Match - remapped"); |
| |
| return (remapped, true); |
| } else { |
| debug!("No match - prefix {from:?} does not match"); |
| } |
| } |
| |
| debug!("not remapped"); |
| (path, false) |
| } |
| } |
| |
| fn map_filename_prefix(&self, file: &FileName) -> (FileName, bool) { |
| match file { |
| FileName::Real(realfile) if let RealFileName::LocalPath(local_path) = realfile => { |
| let (mapped_path, mapped) = self.map_prefix(local_path); |
| let realfile = if mapped { |
| RealFileName::Remapped { |
| local_path: Some(local_path.clone()), |
| virtual_name: mapped_path.into_owned(), |
| } |
| } else { |
| realfile.clone() |
| }; |
| (FileName::Real(realfile), mapped) |
| } |
| FileName::Real(_) => unreachable!("attempted to remap an already remapped filename"), |
| other => (other.clone(), false), |
| } |
| } |
| |
| /// Expand a relative path to an absolute path with remapping taken into account. |
| /// Use this when absolute paths are required (e.g. debuginfo or crate metadata). |
| /// |
| /// The resulting `RealFileName` will have its `local_path` portion erased if |
| /// possible (i.e. if there's also a remapped path). |
| pub fn to_embeddable_absolute_path( |
| &self, |
| file_path: RealFileName, |
| working_directory: &RealFileName, |
| ) -> RealFileName { |
| match file_path { |
| // Anything that's already remapped we don't modify, except for erasing |
| // the `local_path` portion. |
| RealFileName::Remapped { local_path: _, virtual_name } => { |
| RealFileName::Remapped { |
| // We do not want any local path to be exported into metadata |
| local_path: None, |
| // We use the remapped name verbatim, even if it looks like a relative |
| // path. The assumption is that the user doesn't want us to further |
| // process paths that have gone through remapping. |
| virtual_name, |
| } |
| } |
| |
| RealFileName::LocalPath(unmapped_file_path) => { |
| // If no remapping has been applied yet, try to do so |
| let (new_path, was_remapped) = self.map_prefix(unmapped_file_path); |
| if was_remapped { |
| // It was remapped, so don't modify further |
| return RealFileName::Remapped { |
| local_path: None, |
| virtual_name: new_path.into_owned(), |
| }; |
| } |
| |
| if new_path.is_absolute() { |
| // No remapping has applied to this path and it is absolute, |
| // so the working directory cannot influence it either, so |
| // we are done. |
| return RealFileName::LocalPath(new_path.into_owned()); |
| } |
| |
| debug_assert!(new_path.is_relative()); |
| let unmapped_file_path_rel = new_path; |
| |
| match working_directory { |
| RealFileName::LocalPath(unmapped_working_dir_abs) => { |
| let file_path_abs = unmapped_working_dir_abs.join(unmapped_file_path_rel); |
| |
| // Although neither `working_directory` nor the file name were subject |
| // to path remapping, the concatenation between the two may be. Hence |
| // we need to do a remapping here. |
| let (file_path_abs, was_remapped) = self.map_prefix(file_path_abs); |
| if was_remapped { |
| RealFileName::Remapped { |
| // Erase the actual path |
| local_path: None, |
| virtual_name: file_path_abs.into_owned(), |
| } |
| } else { |
| // No kind of remapping applied to this path, so |
| // we leave it as it is. |
| RealFileName::LocalPath(file_path_abs.into_owned()) |
| } |
| } |
| RealFileName::Remapped { |
| local_path: _, |
| virtual_name: remapped_working_dir_abs, |
| } => { |
| // If working_directory has been remapped, then we emit |
| // Remapped variant as the expanded path won't be valid |
| RealFileName::Remapped { |
| local_path: None, |
| virtual_name: Path::new(remapped_working_dir_abs) |
| .join(unmapped_file_path_rel), |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| /// Expand a relative path to an absolute path **without** remapping taken into account. |
| /// |
| /// The resulting `RealFileName` will have its `virtual_path` portion erased if |
| /// possible (i.e. if there's also a remapped path). |
| pub fn to_local_embeddable_absolute_path( |
| &self, |
| file_path: RealFileName, |
| working_directory: &RealFileName, |
| ) -> RealFileName { |
| let file_path = file_path.local_path_if_available(); |
| if file_path.is_absolute() { |
| // No remapping has applied to this path and it is absolute, |
| // so the working directory cannot influence it either, so |
| // we are done. |
| return RealFileName::LocalPath(file_path.to_path_buf()); |
| } |
| debug_assert!(file_path.is_relative()); |
| let working_directory = working_directory.local_path_if_available(); |
| RealFileName::LocalPath(Path::new(working_directory).join(file_path)) |
| } |
| |
| /// Attempts to (heuristically) reverse a prefix mapping. |
| /// |
| /// Returns [`Some`] if there is exactly one mapping where the "to" part is |
| /// a prefix of `path` and has at least one non-empty |
| /// [`Normal`](path::Component::Normal) component. The component |
| /// restriction exists to avoid reverse mapping overly generic paths like |
| /// `/` or `.`). |
| /// |
| /// This is a heuristic and not guaranteed to return the actual original |
| /// path! Do not rely on the result unless you have other means to verify |
| /// that the mapping is correct (e.g. by checking the file content hash). |
| #[instrument(level = "debug", skip(self), ret)] |
| fn reverse_map_prefix_heuristically(&self, path: &Path) -> Option<PathBuf> { |
| let mut found = None; |
| |
| for (from, to) in self.mapping.iter() { |
| let has_normal_component = to.components().any(|c| match c { |
| path::Component::Normal(s) => !s.is_empty(), |
| _ => false, |
| }); |
| |
| if !has_normal_component { |
| continue; |
| } |
| |
| let Ok(rest) = path.strip_prefix(to) else { |
| continue; |
| }; |
| |
| if found.is_some() { |
| return None; |
| } |
| |
| found = Some(from.join(rest)); |
| } |
| |
| found |
| } |
| } |
