| //! 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 std::fs::File; | |
| use std::io::{self, BorrowedBuf, Read}; | |
| use std::{fs, path}; | |
| use rustc_data_structures::sync::{IntoDynSyncSend, MappedReadGuard, ReadGuard, RwLock}; | |
| use rustc_data_structures::unhash::UnhashMap; | |
| use tracing::{debug, instrument, trace}; | |
| use crate::*; | |
| #[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 ctxt = sp.ctxt(); | |
| if ctxt.is_root() { | |
| return sp; | |
| } | |
| let enclosing_ctxt = enclosing_sp.ctxt(); | |
| let expn_data1 = ctxt.outer_expn_data(); | |
| if !enclosing_ctxt.is_root() | |
| && expn_data1.call_site == enclosing_ctxt.outer_expn_data().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> {} | |
| } | |
| // _____________________________________________________________________________ | |
| // 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 Arc. | |
| fn read_binary_file(&self, path: &Path) -> io::Result<Arc<[u8]>>; | |
| /// Current working directory | |
| fn current_directory(&self) -> io::Result<PathBuf>; | |
| } | |
| /// 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> { | |
| let mut file = File::open(path)?; | |
| let size = file.metadata().map(|metadata| metadata.len()).ok().unwrap_or(0); | |
| if size > SourceFile::MAX_FILE_SIZE.into() { | |
| return Err(io::Error::other(format!( | |
| "text files larger than {} bytes are unsupported", | |
| SourceFile::MAX_FILE_SIZE | |
| ))); | |
| } | |
| let mut contents = String::new(); | |
| file.read_to_string(&mut contents)?; | |
| Ok(contents) | |
| } | |
| fn read_binary_file(&self, path: &Path) -> io::Result<Arc<[u8]>> { | |
| let mut file = fs::File::open(path)?; | |
| let len = file.metadata()?.len(); | |
| let mut bytes = Arc::new_uninit_slice(len as usize); | |
| let mut buf = BorrowedBuf::from(Arc::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 Arc we built above. | |
| // If the read returns bytes however, we just fall back to reading into a Vec then turning | |
| // that into an Arc, 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()) | |
| } | |
| fn current_directory(&self) -> io::Result<PathBuf> { | |
| std::env::current_dir() | |
| } | |
| } | |
| // _____________________________________________________________________________ | |
| // SourceMap | |
| // | |
| #[derive(Default)] | |
| struct SourceMapFiles { | |
| source_files: monotonic::MonotonicVec<Arc<SourceFile>>, | |
| stable_id_to_source_file: UnhashMap<StableSourceFileId, Arc<SourceFile>>, | |
| } | |
| impl std::fmt::Debug for SourceMapFiles { | |
| fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { | |
| let SourceMapFiles { source_files, stable_id_to_source_file: _ } = self; | |
| f.debug_list() | |
| .entries( | |
| source_files.iter().map(|f| f.name.prefer_remapped_unconditionally().to_string()), | |
| ) | |
| .finish() | |
| } | |
| } | |
| /// Used to construct a `SourceMap` with `SourceMap::with_inputs`. | |
| pub struct SourceMapInputs { | |
| pub file_loader: Box<dyn FileLoader + Send + Sync>, | |
| pub path_mapping: FilePathMapping, | |
| pub hash_kind: SourceFileHashAlgorithm, | |
| pub checksum_hash_kind: Option<SourceFileHashAlgorithm>, | |
| } | |
| 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, | |
| /// Current working directory | |
| working_dir: RealFileName, | |
| /// The algorithm used for hashing the contents of each source file. | |
| hash_kind: SourceFileHashAlgorithm, | |
| /// Similar to `hash_kind`, however this algorithm is used for checksums to determine if a crate is fresh. | |
| /// `cargo` is the primary user of these. | |
| /// | |
| /// If this is equal to `hash_kind` then the checksum won't be computed twice. | |
| checksum_hash_kind: Option<SourceFileHashAlgorithm>, | |
| } | |
| impl std::fmt::Debug for SourceMap { | |
| fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { | |
| let SourceMap { | |
| files, | |
| file_loader, | |
| path_mapping, | |
| working_dir, | |
| hash_kind, | |
| checksum_hash_kind, | |
| } = self; | |
| f.debug_struct("SourceMap") | |
| .field("files", files) | |
| .field("file_loader", &format_args!("<file_loader@{file_loader:p}>")) | |
| .field("path_mapping", path_mapping) | |
| .field("working_dir", working_dir) | |
| .field("hash_kind", hash_kind) | |
| .field("checksum_hash_kind", checksum_hash_kind) | |
| .finish() | |
| } | |
| } | |
| impl SourceMap { | |
| pub fn new(path_mapping: FilePathMapping) -> SourceMap { | |
| Self::with_inputs(SourceMapInputs { | |
| file_loader: Box::new(RealFileLoader), | |
| path_mapping, | |
| hash_kind: SourceFileHashAlgorithm::Md5, | |
| checksum_hash_kind: None, | |
| }) | |
| } | |
| pub fn with_inputs( | |
| SourceMapInputs { file_loader, path_mapping, hash_kind, checksum_hash_kind }: SourceMapInputs, | |
| ) -> SourceMap { | |
| let cwd = file_loader | |
| .current_directory() | |
| .expect("expecting a current working directory to exist"); | |
| let working_dir = path_mapping.to_real_filename(&RealFileName::empty(), &cwd); | |
| debug!(?working_dir); | |
| SourceMap { | |
| files: Default::default(), | |
| working_dir, | |
| file_loader: IntoDynSyncSend(file_loader), | |
| path_mapping, | |
| hash_kind, | |
| checksum_hash_kind, | |
| } | |
| } | |
| pub fn path_mapping(&self) -> &FilePathMapping { | |
| &self.path_mapping | |
| } | |
| pub fn working_dir(&self) -> &RealFileName { | |
| &self.working_dir | |
| } | |
| pub fn file_exists(&self, path: &Path) -> bool { | |
| self.file_loader.file_exists(path) | |
| } | |
| pub fn load_file(&self, path: &Path) -> io::Result<Arc<SourceFile>> { | |
| let src = self.file_loader.read_file(path)?; | |
| let filename = FileName::Real(self.path_mapping.to_real_filename(&self.working_dir, path)); | |
| 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<(Arc<[u8]>, Span)> { | |
| 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(); | |
| let filename = FileName::Real(self.path_mapping.to_real_filename(&self.working_dir, path)); | |
| let file = self.new_source_file(filename, text); | |
| Ok(( | |
| bytes, | |
| Span::new( | |
| file.start_pos, | |
| BytePos(file.start_pos.0 + file.normalized_source_len.0), | |
| SyntaxContext::root(), | |
| None, | |
| ), | |
| )) | |
| } | |
| // By returning a `MonotonicVec`, we ensure that consumers cannot invalidate | |
| // any existing indices pointing into `files`. | |
| pub fn files(&self) -> MappedReadGuard<'_, monotonic::MonotonicVec<Arc<SourceFile>>> { | |
| ReadGuard::map(self.files.borrow(), |files| &files.source_files) | |
| } | |
| pub fn source_file_by_stable_id( | |
| &self, | |
| stable_id: StableSourceFileId, | |
| ) -> Option<Arc<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<Arc<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 = Arc::new(file); | |
| files.source_files.push(Arc::clone(&file)); | |
| files.stable_id_to_source_file.insert(file_id, Arc::clone(&file)); | |
| 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) -> Arc<SourceFile> { | |
| self.try_new_source_file(filename, src).unwrap_or_else(|OffsetOverflowError| { | |
| eprintln!( | |
| "fatal error: rustc does not support text files larger than {} bytes", | |
| SourceFile::MAX_FILE_SIZE | |
| ); | |
| crate::fatal_error::FatalError.raise() | |
| }) | |
| } | |
| fn try_new_source_file( | |
| &self, | |
| filename: FileName, | |
| src: String, | |
| ) -> Result<Arc<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 stable_id = StableSourceFileId::from_filename_in_current_crate(&filename); | |
| match self.source_file_by_stable_id(stable_id) { | |
| Some(lrc_sf) => Ok(lrc_sf), | |
| None => { | |
| let source_file = | |
| SourceFile::new(filename, src, self.hash_kind, self.checksum_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!(source_file.stable_id, stable_id); | |
| self.register_source_file(stable_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, | |
| checksum_hash: Option<SourceFileHash>, | |
| stable_id: StableSourceFileId, | |
| normalized_source_len: u32, | |
| unnormalized_source_len: u32, | |
| cnum: CrateNum, | |
| file_local_lines: FreezeLock<SourceFileLines>, | |
| multibyte_chars: Vec<MultiByteChar>, | |
| normalized_pos: Vec<NormalizedPos>, | |
| metadata_index: u32, | |
| ) -> Arc<SourceFile> { | |
| let normalized_source_len = RelativeBytePos::from_u32(normalized_source_len); | |
| let source_file = SourceFile { | |
| name: filename, | |
| src: None, | |
| src_hash, | |
| checksum_hash, | |
| external_src: FreezeLock::new(ExternalSource::Foreign { | |
| kind: ExternalSourceKind::AbsentOk, | |
| metadata_index, | |
| }), | |
| start_pos: BytePos(0), | |
| normalized_source_len, | |
| unnormalized_source_len, | |
| lines: file_local_lines, | |
| multibyte_chars, | |
| normalized_pos, | |
| stable_id, | |
| cnum, | |
| }; | |
| self.register_source_file(stable_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) -> Arc<SourceFile> { | |
| let idx = self.lookup_source_file_idx(pos); | |
| Arc::clone(&(*self.files.borrow().source_files)[idx]) | |
| } | |
| /// 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, Arc<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, display_scope: RemapPathScopeComponents) -> String { | |
| self.span_to_string_ext(sp, display_scope, false) | |
| } | |
| pub fn span_to_short_string( | |
| &self, | |
| sp: Span, | |
| display_scope: RemapPathScopeComponents, | |
| ) -> String { | |
| self.span_to_string_ext(sp, display_scope, true) | |
| } | |
| fn span_to_string_ext( | |
| &self, | |
| sp: Span, | |
| display_scope: RemapPathScopeComponents, | |
| short: bool, | |
| ) -> 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) => { | |
| if short { sf.name.short() } else { sf.name.display(display_scope) }.to_string() | |
| } | |
| None => return "no-location".to_string(), | |
| }; | |
| format!( | |
| "{file_name}:{lo_line}:{lo_col}{}", | |
| if short { String::new() } else { format!(": {hi_line}:{hi_col}") } | |
| ) | |
| } | |
| pub fn span_to_location_info( | |
| &self, | |
| sp: Span, | |
| ) -> (Option<Arc<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 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, RemapPathScopeComponents::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(RemapPathScopeComponents::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 = Arc::clone(&(*self.files.borrow().source_files)[lo]); | |
| 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. | |
| pub fn span_to_source<F, T>( | |
| &self, | |
| sp: Span, | |
| mut extract_source: F, | |
| ) -> Result<T, SpanSnippetError> | |
| where | |
| F: FnMut(&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.normalized_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 before the previous occurrence of `c`. Return the same span | |
| /// if an error occurred while retrieving the code snippet. | |
| pub fn span_extend_to_prev_char_before( | |
| &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 accept_newlines || !prev_source.contains('\n') { | |
| return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32 - 1_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, | |
| mut f: impl FnMut(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 span to include any trailing whitespace, or returns the original | |
| /// span if a `SpanSnippetError` was encountered. | |
| pub fn span_extend_while_whitespace(&self, span: Span) -> Span { | |
| self.span_extend_while(span, char::is_whitespace).unwrap_or(span) | |
| } | |
| /// 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, c)| start - i - c.len_utf8()); | |
| 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); | |
| } | |
| } | |
| 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) | |
| && 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 sp = sp.data(); | |
| 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 sp = sp.data(); | |
| 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 target string, ignoring whitespace. | |
| /// *Only suitable for diagnostics.* | |
| pub fn span_followed_by(&self, span: Span, target: &str) -> Option<Span> { | |
| let span = self.span_extend_while_whitespace(span); | |
| self.span_to_next_source(span).ok()?.strip_prefix(target).map(|_| { | |
| Span::new(span.hi(), span.hi() + BytePos(target.len() as u32), span.ctxt(), 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: SpanData, forwards: bool) -> u32 { | |
| 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.normalized_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<Arc<SourceFile>> { | |
| for sf in self.files.borrow().source_files.iter() { | |
| if *filename == sf.name { | |
| return Some(Arc::clone(&sf)); | |
| } | |
| } | |
| 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 = Arc::clone(&(*self.files.borrow().source_files)[idx]); | |
| 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.local_path() { | |
| Some(local) => local.into(), | |
| None => { | |
| // 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. | |
| let maybe_remapped_path = name.path(RemapPathScopeComponents::DIAGNOSTICS); | |
| self.path_mapping | |
| .reverse_map_prefix_heuristically(maybe_remapped_path) | |
| .map(Cow::from) | |
| .unwrap_or(maybe_remapped_path.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_whitespace(mac_call); | |
| let span = self.next_point(span); | |
| if self.span_to_snippet(span).as_deref() == Ok(";") { Some(span) } else { None } | |
| } | |
| } | |
| pub fn get_source_map() -> Option<Arc<SourceMap>> { | |
| with_session_globals(|session_globals| session_globals.source_map.clone()) | |
| } | |
| #[derive(Clone, Debug)] | |
| pub struct FilePathMapping { | |
| mapping: Vec<(PathBuf, PathBuf)>, | |
| filename_remapping_scopes: RemapPathScopeComponents, | |
| } | |
| impl FilePathMapping { | |
| pub fn empty() -> FilePathMapping { | |
| FilePathMapping::new(Vec::new(), RemapPathScopeComponents::empty()) | |
| } | |
| pub fn new( | |
| mapping: Vec<(PathBuf, PathBuf)>, | |
| filename_remapping_scopes: RemapPathScopeComponents, | |
| ) -> FilePathMapping { | |
| FilePathMapping { mapping, filename_remapping_scopes } | |
| } | |
| /// 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. | |
| 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) | |
| } | |
| } | |
| /// Applies any path prefix substitution as defined by the mapping. | |
| /// | |
| /// The returned filename contains the a remapped path representing the remapped | |
| /// part if any remapping was performed. | |
| pub fn to_real_filename<'a>( | |
| &self, | |
| working_directory: &RealFileName, | |
| local_path: impl Into<Cow<'a, Path>>, | |
| ) -> RealFileName { | |
| let local_path = local_path.into(); | |
| let (remapped_path, mut was_remapped) = self.map_prefix(&*local_path); | |
| debug!(?local_path, ?remapped_path, ?was_remapped, ?self.filename_remapping_scopes); | |
| // Always populate the local part, even if we just remapped it and the scopes are | |
| // total, so that places that load the file from disk still have access to it. | |
| let local = InnerRealFileName { | |
| name: local_path.to_path_buf(), | |
| working_directory: working_directory | |
| .local_path() | |
| .expect("working directory should be local") | |
| .to_path_buf(), | |
| embeddable_name: if local_path.is_absolute() { | |
| local_path.to_path_buf() | |
| } else { | |
| working_directory | |
| .local_path() | |
| .expect("working directory should be local") | |
| .to_path_buf() | |
| .join(&local_path) | |
| }, | |
| }; | |
| RealFileName { | |
| maybe_remapped: InnerRealFileName { | |
| working_directory: working_directory.maybe_remapped.name.clone(), | |
| embeddable_name: if remapped_path.is_absolute() || was_remapped { | |
| // The current directory may have been remapped so we take that | |
| // into account, otherwise we'll forget to include the scopes | |
| was_remapped = was_remapped || working_directory.was_remapped(); | |
| remapped_path.to_path_buf() | |
| } else { | |
| // Create an absolute path and remap it as well. | |
| let (abs_path, abs_was_remapped) = self.map_prefix( | |
| working_directory.maybe_remapped.name.clone().join(&remapped_path), | |
| ); | |
| // If either the embeddable name or the working directory was | |
| // remapped, then the filename was remapped | |
| was_remapped = abs_was_remapped || working_directory.was_remapped(); | |
| abs_path.to_path_buf() | |
| }, | |
| name: remapped_path.to_path_buf(), | |
| }, | |
| local: Some(local), | |
| scopes: if was_remapped { | |
| self.filename_remapping_scopes | |
| } else { | |
| RemapPathScopeComponents::empty() | |
| }, | |
| } | |
| } | |
| /// 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 | |
| } | |
| } |