--- /dev/null
+//! 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.
+
+pub use crate::hygiene::{ExpnData, ExpnKind};
+pub use crate::*;
+
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::stable_hasher::StableHasher;
+use rustc_data_structures::sync::{AtomicU32, Lrc, MappedReadGuard, ReadGuard, RwLock};
+use std::cmp;
+use std::convert::TryFrom;
+use std::hash::Hash;
+use std::path::{Path, PathBuf};
+use std::sync::atomic::Ordering;
+
+use std::fs;
+use std::io;
+use tracing::debug;
+
+#[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)
+ }
+}
+
+pub 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 fn new(val: Vec<T>) -> MonotonicVec<T> {
+ MonotonicVec(val)
+ }
+
+ pub fn push(&mut self, val: T) {
+ self.0.push(val);
+ }
+ }
+
+ impl<T> Default for MonotonicVec<T> {
+ fn default() -> Self {
+ MonotonicVec::new(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 an UTF-8 file into memory.
+ fn read_file(&self, path: &Path) -> io::Result<String>;
+}
+
+/// A FileLoader that uses std::fs to load real files.
+pub struct RealFileLoader;
+
+impl FileLoader for RealFileLoader {
+ fn file_exists(&self, path: &Path) -> bool {
+ fs::metadata(path).is_ok()
+ }
+
+ fn read_file(&self, path: &Path) -> io::Result<String> {
+ fs::read_to_string(path)
+ }
+}
+
+// This is a `SourceFile` identifier that is used to correlate `SourceFile`s between
+// subsequent compilation sessions (which is something we need to do during
+// incremental compilation).
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, Debug)]
+pub struct StableSourceFileId(u128);
+
+// 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_pieces(
+ &source_file.name,
+ source_file.name_was_remapped,
+ source_file.unmapped_path.as_ref(),
+ )
+ }
+
+ fn new_from_pieces(
+ name: &FileName,
+ name_was_remapped: bool,
+ unmapped_path: Option<&FileName>,
+ ) -> StableSourceFileId {
+ let mut hasher = StableHasher::new();
+
+ if let FileName::Real(real_name) = name {
+ // rust-lang/rust#70924: Use the stable (virtualized) name when
+ // available. (We do not want artifacts from transient file system
+ // paths for libstd to leak into our build artifacts.)
+ real_name.stable_name().hash(&mut hasher)
+ } else {
+ name.hash(&mut hasher);
+ }
+ name_was_remapped.hash(&mut hasher);
+ unmapped_path.hash(&mut hasher);
+
+ StableSourceFileId(hasher.finish())
+ }
+}
+
+// _____________________________________________________________________________
+// SourceMap
+//
+
+#[derive(Default)]
+pub(super) struct SourceMapFiles {
+ source_files: monotonic::MonotonicVec<Lrc<SourceFile>>,
+ stable_id_to_source_file: FxHashMap<StableSourceFileId, Lrc<SourceFile>>,
+}
+
+pub struct SourceMap {
+ /// The address space below this value is currently used by the files in the source map.
+ used_address_space: AtomicU32,
+
+ files: RwLock<SourceMapFiles>,
+ file_loader: 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 {
+ used_address_space: AtomicU32::new(0),
+ files: Default::default(),
+ 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<Vec<u8>> {
+ // Ideally, this should use `self.file_loader`, but it can't
+ // deal with binary files yet.
+ let bytes = fs::read(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 allocate_address_space(&self, size: usize) -> Result<usize, OffsetOverflowError> {
+ let size = u32::try_from(size).map_err(|_| OffsetOverflowError)?;
+
+ loop {
+ let current = self.used_address_space.load(Ordering::Relaxed);
+ let next = current
+ .checked_add(size)
+ // 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.
+ .and_then(|next| next.checked_add(1))
+ .ok_or(OffsetOverflowError)?;
+
+ if self
+ .used_address_space
+ .compare_exchange(current, next, Ordering::Relaxed, Ordering::Relaxed)
+ .is_ok()
+ {
+ return Ok(usize::try_from(current).unwrap());
+ }
+ }
+ }
+
+ /// 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,
+ mut filename: FileName,
+ src: String,
+ ) -> Result<Lrc<SourceFile>, OffsetOverflowError> {
+ // The path is used to determine the directory for loading submodules and
+ // include files, so it must be before remapping.
+ // 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 unmapped_path = filename.clone();
+
+ let was_remapped;
+ if let FileName::Real(real_filename) = &mut filename {
+ match real_filename {
+ RealFileName::Named(path_to_be_remapped)
+ | RealFileName::Devirtualized {
+ local_path: path_to_be_remapped,
+ virtual_name: _,
+ } => {
+ let mapped = self.path_mapping.map_prefix(path_to_be_remapped.clone());
+ was_remapped = mapped.1;
+ *path_to_be_remapped = mapped.0;
+ }
+ }
+ } else {
+ was_remapped = false;
+ }
+
+ let file_id =
+ StableSourceFileId::new_from_pieces(&filename, was_remapped, Some(&unmapped_path));
+
+ let lrc_sf = match self.source_file_by_stable_id(file_id) {
+ Some(lrc_sf) => lrc_sf,
+ None => {
+ let start_pos = self.allocate_address_space(src.len())?;
+
+ let source_file = Lrc::new(SourceFile::new(
+ filename,
+ was_remapped,
+ unmapped_path,
+ src,
+ Pos::from_usize(start_pos),
+ self.hash_kind,
+ ));
+
+ let mut files = self.files.borrow_mut();
+
+ files.source_files.push(source_file.clone());
+ files.stable_id_to_source_file.insert(file_id, source_file.clone());
+
+ source_file
+ }
+ };
+ Ok(lrc_sf)
+ }
+
+ /// 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,
+ name_was_remapped: bool,
+ src_hash: SourceFileHash,
+ name_hash: u128,
+ source_len: usize,
+ cnum: CrateNum,
+ mut file_local_lines: Vec<BytePos>,
+ mut file_local_multibyte_chars: Vec<MultiByteChar>,
+ mut file_local_non_narrow_chars: Vec<NonNarrowChar>,
+ mut file_local_normalized_pos: Vec<NormalizedPos>,
+ original_start_pos: BytePos,
+ original_end_pos: BytePos,
+ ) -> Lrc<SourceFile> {
+ let start_pos = self
+ .allocate_address_space(source_len)
+ .expect("not enough address space for imported source file");
+
+ let end_pos = Pos::from_usize(start_pos + source_len);
+ let start_pos = Pos::from_usize(start_pos);
+
+ for pos in &mut file_local_lines {
+ *pos = *pos + start_pos;
+ }
+
+ for mbc in &mut file_local_multibyte_chars {
+ mbc.pos = mbc.pos + start_pos;
+ }
+
+ for swc in &mut file_local_non_narrow_chars {
+ *swc = *swc + start_pos;
+ }
+
+ for nc in &mut file_local_normalized_pos {
+ nc.pos = nc.pos + start_pos;
+ }
+
+ let source_file = Lrc::new(SourceFile {
+ name: filename,
+ name_was_remapped,
+ unmapped_path: None,
+ src: None,
+ src_hash,
+ external_src: Lock::new(ExternalSource::Foreign {
+ kind: ExternalSourceKind::AbsentOk,
+ original_start_pos,
+ original_end_pos,
+ }),
+ start_pos,
+ end_pos,
+ lines: file_local_lines,
+ multibyte_chars: file_local_multibyte_chars,
+ non_narrow_chars: file_local_non_narrow_chars,
+ normalized_pos: file_local_normalized_pos,
+ name_hash,
+ cnum,
+ });
+
+ let mut files = self.files.borrow_mut();
+
+ files.source_files.push(source_file.clone());
+ files
+ .stable_id_to_source_file
+ .insert(StableSourceFileId::new(&source_file), source_file.clone());
+
+ source_file
+ }
+
+ pub fn mk_substr_filename(&self, sp: Span) -> String {
+ let pos = self.lookup_char_pos(sp.lo());
+ format!("<{}:{}:{}>", pos.file.name, pos.line, pos.col.to_usize() + 1)
+ }
+
+ // 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);
+
+ match f.lookup_line(pos) {
+ Some(line) => Ok(SourceFileAndLine { sf: f, line }),
+ None => Err(f),
+ }
+ }
+
+ /// Returns `Some(span)`, a union of the LHS and RHS span. The LHS must precede the RHS. If
+ /// there are gaps between LHS and RHS, the resulting union will cross these gaps.
+ /// For this to work,
+ ///
+ /// * the syntax contexts of both spans much match,
+ /// * the LHS span needs to end on the same line the RHS span begins,
+ /// * the LHS span must start at or before the RHS span.
+ pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
+ // Ensure we're at the same expansion ID.
+ if sp_lhs.ctxt() != sp_rhs.ctxt() {
+ return None;
+ }
+
+ let lhs_end = match self.lookup_line(sp_lhs.hi()) {
+ Ok(x) => x,
+ Err(_) => return None,
+ };
+ let rhs_begin = match self.lookup_line(sp_rhs.lo()) {
+ Ok(x) => x,
+ Err(_) => return None,
+ };
+
+ // If we must cross lines to merge, don't merge.
+ if lhs_end.line != rhs_begin.line {
+ return None;
+ }
+
+ // Ensure these follow the expected order and that we don't overlap.
+ if (sp_lhs.lo() <= sp_rhs.lo()) && (sp_lhs.hi() <= sp_rhs.lo()) {
+ Some(sp_lhs.to(sp_rhs))
+ } else {
+ None
+ }
+ }
+
+ pub fn span_to_string(&self, sp: Span) -> String {
+ if self.files.borrow().source_files.is_empty() && sp.is_dummy() {
+ return "no-location".to_string();
+ }
+
+ let lo = self.lookup_char_pos(sp.lo());
+ let hi = self.lookup_char_pos(sp.hi());
+ format!(
+ "{}:{}:{}: {}:{}",
+ lo.file.name,
+ lo.line,
+ lo.col.to_usize() + 1,
+ hi.line,
+ hi.col.to_usize() + 1,
+ )
+ }
+
+ pub fn span_to_filename(&self, sp: Span) -> FileName {
+ self.lookup_char_pos(sp.lo()).file.name.clone()
+ }
+
+ pub fn span_to_unmapped_path(&self, sp: Span) -> FileName {
+ self.lookup_char_pos(sp.lo())
+ .file
+ .unmapped_path
+ .clone()
+ .expect("`SourceMap::span_to_unmapped_path` called for imported `SourceFile`?")
+ }
+
+ pub fn is_multiline(&self, sp: Span) -> bool {
+ let lo = self.lookup_char_pos(sp.lo());
+ let hi = self.lookup_char_pos(sp.hi());
+ lo.line != hi.line
+ }
+
+ pub fn is_valid_span(&self, sp: Span) -> Result<(Loc, Loc), SpanLinesError> {
+ let lo = self.lookup_char_pos(sp.lo());
+ debug!("span_to_lines: lo={:?}", lo);
+ let hi = self.lookup_char_pos(sp.hi());
+ debug!("span_to_lines: hi={:?}", hi);
+ if lo.file.start_pos != hi.file.start_pos {
+ return Err(SpanLinesError::DistinctSources(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.split('\n').last().map_or(false, |l| l.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(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.clone());
+
+ let start_index = local_begin.pos.to_usize();
+ let end_index = local_end.pos.to_usize();
+ let source_len = (local_begin.sf.end_pos - local_begin.sf.start_pos).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.borrow().get_source() {
+ extract_source(src, start_index, end_index)
+ } else {
+ Err(SpanSnippetError::SourceNotAvailable { filename: local_begin.sf.name.clone() })
+ }
+ }
+ }
+
+ /// 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> {
+ match self.span_to_prev_source(sp) {
+ Err(_) => None,
+ Ok(source) => source
+ .split('\n')
+ .last()
+ .map(|last_line| last_line.len() - last_line.trim_start().len()),
+ }
+ }
+
+ /// 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() && (!prev_source.contains('\n') || accept_newlines) {
+ 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 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_str(&self, sp: Span, pat: &str, accept_newlines: bool) -> Span {
+ // assure that the pattern is delimited, to avoid the following
+ // fn my_fn()
+ // ^^^^ returned span without the check
+ // ---------- correct span
+ for ws in &[" ", "\t", "\n"] {
+ let pat = pat.to_owned() + ws;
+ if let Ok(prev_source) = self.span_to_prev_source(sp) {
+ let prev_source = prev_source.rsplit(&pat).next().unwrap_or("").trim_start();
+ if prev_source.is_empty() && sp.lo().0 != 0 {
+ return sp.with_lo(BytePos(sp.lo().0 - 1));
+ } else if !prev_source.contains('\n') || accept_newlines {
+ return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32));
+ }
+ }
+ }
+
+ sp
+ }
+
+ /// 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` to just after 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() && (!next_source.contains('\n') || accept_newlines) {
+ return sp.with_hi(BytePos(sp.hi().0 + next_source.len() as u32));
+ }
+ }
+
+ sp
+ }
+
+ /// 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 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 start point of this span.
+ pub fn start_point(&self, sp: Span) -> Span {
+ let pos = sp.lo().0;
+ let width = self.find_width_of_character_at_span(sp, false);
+ let corrected_start_position = pos.checked_add(width).unwrap_or(pos);
+ let end_point = BytePos(cmp::max(corrected_start_position, sp.lo().0));
+ sp.with_hi(end_point)
+ }
+
+ /// Returns a new span representing just the end point 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.
+ 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.shrink_to_hi(), true);
+ // If the width is 1, then the next span should point to the same `lo` and `hi`. 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 - 1).unwrap_or(start_of_next_point);
+
+ let end_of_next_point = BytePos(cmp::max(sp.lo().0 + 1, end_of_next_point));
+ Span::new(BytePos(start_of_next_point), end_of_next_point, sp.ctxt())
+ }
+
+ /// Finds the width of a character, either before or after the provided span.
+ fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 {
+ let sp = sp.data();
+ if sp.lo == sp.hi {
+ debug!("find_width_of_character_at_span: 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!(
+ "find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`",
+ local_begin, local_end
+ );
+
+ if local_begin.sf.start_pos != local_end.sf.start_pos {
+ debug!("find_width_of_character_at_span: 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!(
+ "find_width_of_character_at_span: 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!("find_width_of_character_at_span: start or end of span, cannot be multibyte");
+ return 1;
+ }
+
+ let source_len = (local_begin.sf.end_pos - local_begin.sf.start_pos).to_usize();
+ debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len);
+ // Ensure indexes are also not malformed.
+ if start_index > end_index || end_index > source_len {
+ debug!("find_width_of_character_at_span: source indexes are malformed");
+ return 1;
+ }
+
+ let src = local_begin.sf.external_src.borrow();
+
+ // We need to extend the snippet to the end of the src rather than to end_index so when
+ // searching forwards for boundaries we've got somewhere to search.
+ let snippet = if let Some(ref src) = local_begin.sf.src {
+ let len = src.len();
+ &src[start_index..len]
+ } else if let Some(src) = src.get_source() {
+ let len = src.len();
+ &src[start_index..len]
+ } else {
+ return 1;
+ };
+ debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet);
+
+ let mut target = if forwards { end_index + 1 } else { end_index - 1 };
+ debug!("find_width_of_character_at_span: initial target=`{:?}`", target);
+
+ while !snippet.is_char_boundary(target - start_index) && target < source_len {
+ target = if forwards {
+ target + 1
+ } else {
+ match target.checked_sub(1) {
+ Some(target) => target,
+ None => {
+ break;
+ }
+ }
+ };
+ debug!("find_width_of_character_at_span: target=`{:?}`", target);
+ }
+ debug!("find_width_of_character_at_span: final target=`{:?}`", target);
+
+ if forwards { (target - end_index) as u32 } else { (end_index - target) 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 }
+ }
+
+ /// Converts an absolute `BytePos` to a `CharPos` relative to the `SourceFile`.
+ pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
+ let idx = self.lookup_source_file_idx(bpos);
+ let sf = &(*self.files.borrow().source_files)[idx];
+ sf.bytepos_to_file_charpos(bpos)
+ }
+
+ // 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
+ .binary_search_by_key(&pos, |key| key.start_pos)
+ .unwrap_or_else(|p| p - 1)
+ }
+
+ pub fn count_lines(&self) -> usize {
+ self.files().iter().fold(0, |a, f| a + f.count_lines())
+ }
+
+ pub fn generate_fn_name_span(&self, span: Span) -> Option<Span> {
+ let prev_span = self.span_extend_to_prev_str(span, "fn", true);
+ if let Ok(snippet) = self.span_to_snippet(prev_span) {
+ debug!(
+ "generate_fn_name_span: span={:?}, prev_span={:?}, snippet={:?}",
+ span, prev_span, snippet
+ );
+
+ if snippet.is_empty() {
+ return None;
+ };
+
+ let len = snippet
+ .find(|c: char| !c.is_alphanumeric() && c != '_')
+ .expect("no label after fn");
+ Some(prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32)))
+ } else {
+ None
+ }
+ }
+
+ /// Takes the span of a type parameter in a function signature and try to generate a span for
+ /// the function name (with generics) and a new snippet for this span with the pointed type
+ /// parameter as a new local type parameter.
+ ///
+ /// For instance:
+ /// ```rust,ignore (pseudo-Rust)
+ /// // Given span
+ /// fn my_function(param: T)
+ /// // ^ Original span
+ ///
+ /// // Result
+ /// fn my_function(param: T)
+ /// // ^^^^^^^^^^^ Generated span with snippet `my_function<T>`
+ /// ```
+ ///
+ /// Attention: The method used is very fragile since it essentially duplicates the work of the
+ /// parser. If you need to use this function or something similar, please consider updating the
+ /// `SourceMap` functions and this function to something more robust.
+ pub fn generate_local_type_param_snippet(&self, span: Span) -> Option<(Span, String)> {
+ // Try to extend the span to the previous "fn" keyword to retrieve the function
+ // signature.
+ let sugg_span = self.span_extend_to_prev_str(span, "fn", false);
+ if sugg_span != span {
+ if let Ok(snippet) = self.span_to_snippet(sugg_span) {
+ // Consume the function name.
+ let mut offset = snippet
+ .find(|c: char| !c.is_alphanumeric() && c != '_')
+ .expect("no label after fn");
+
+ // Consume the generics part of the function signature.
+ let mut bracket_counter = 0;
+ let mut last_char = None;
+ for c in snippet[offset..].chars() {
+ match c {
+ '<' => bracket_counter += 1,
+ '>' => bracket_counter -= 1,
+ '(' => {
+ if bracket_counter == 0 {
+ break;
+ }
+ }
+ _ => {}
+ }
+ offset += c.len_utf8();
+ last_char = Some(c);
+ }
+
+ // Adjust the suggestion span to encompass the function name with its generics.
+ let sugg_span = sugg_span.with_hi(BytePos(sugg_span.lo().0 + offset as u32));
+
+ // Prepare the new suggested snippet to append the type parameter that triggered
+ // the error in the generics of the function signature.
+ let mut new_snippet = if last_char == Some('>') {
+ format!("{}, ", &snippet[..(offset - '>'.len_utf8())])
+ } else {
+ format!("{}<", &snippet[..offset])
+ };
+ new_snippet
+ .push_str(&self.span_to_snippet(span).unwrap_or_else(|_| "T".to_string()));
+ new_snippet.push('>');
+
+ return Some((sugg_span, new_snippet));
+ }
+ }
+
+ None
+ }
+ pub fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool {
+ source_file.add_external_src(|| match source_file.name {
+ FileName::Real(ref name) => self.file_loader.read_file(name.local_path()).ok(),
+ _ => None,
+ })
+ }
+
+ 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()
+ }
+}
+
+#[derive(Clone)]
+pub struct FilePathMapping {
+ mapping: Vec<(PathBuf, PathBuf)>,
+}
+
+impl FilePathMapping {
+ pub fn empty() -> FilePathMapping {
+ FilePathMapping { mapping: vec![] }
+ }
+
+ pub fn new(mapping: Vec<(PathBuf, PathBuf)>) -> FilePathMapping {
+ FilePathMapping { mapping }
+ }
+
+ /// 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(&self, path: PathBuf) -> (PathBuf, 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 &(ref from, ref to) in self.mapping.iter().rev() {
+ if let Ok(rest) = path.strip_prefix(from) {
+ return (to.join(rest), true);
+ }
+ }
+
+ (path, false)
+ }
+
+ fn map_filename_prefix(&self, file: &FileName) -> (FileName, bool) {
+ match file {
+ FileName::Real(realfile) => {
+ let path = realfile.local_path();
+ let (path, mapped) = self.map_prefix(path.to_path_buf());
+ (FileName::Real(RealFileName::Named(path)), mapped)
+ }
+ other => (other.clone(), false),
+ }
+ }
+}
projects / rustc.git / blobdiff