diff options
Diffstat (limited to 'src/libsyntax_pos/source_map.rs')
| -rw-r--r-- | src/libsyntax_pos/source_map.rs | 984 |
1 files changed, 0 insertions, 984 deletions
diff --git a/src/libsyntax_pos/source_map.rs b/src/libsyntax_pos/source_map.rs deleted file mode 100644 index 0b9b9fe7887..00000000000 --- a/src/libsyntax_pos/source_map.rs +++ /dev/null @@ -1,984 +0,0 @@ -//! 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::{Lock, LockGuard, Lrc, MappedLockGuard}; -use std::cmp; -use std::hash::Hash; -use std::path::{Path, PathBuf}; - -use log::debug; -use std::env; -use std::fs; -use std::io; - -#[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) - } -} - -#[derive(Clone, RustcEncodable, RustcDecodable, 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; - - /// Returns an absolute path to a file, if possible. - fn abs_path(&self, path: &Path) -> Option<PathBuf>; - - /// 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 abs_path(&self, path: &Path) -> Option<PathBuf> { - if path.is_absolute() { - Some(path.to_path_buf()) - } else { - env::current_dir().ok().map(|cwd| cwd.join(path)) - } - } - - 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, RustcEncodable, RustcDecodable, Debug)] -pub struct StableSourceFileId(u128); - -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(), - ) - } - - pub fn new_from_pieces( - name: &FileName, - name_was_remapped: bool, - unmapped_path: Option<&FileName>, - ) -> StableSourceFileId { - let mut hasher = StableHasher::new(); - - 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: Vec<Lrc<SourceFile>>, - stable_id_to_source_file: FxHashMap<StableSourceFileId, Lrc<SourceFile>>, -} - -pub struct SourceMap { - files: Lock<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, -} - -impl SourceMap { - pub fn new(path_mapping: FilePathMapping) -> SourceMap { - SourceMap { files: Default::default(), file_loader: Box::new(RealFileLoader), path_mapping } - } - - pub fn with_file_loader( - file_loader: Box<dyn FileLoader + Sync + Send>, - path_mapping: FilePathMapping, - ) -> SourceMap { - SourceMap { files: Default::default(), file_loader, path_mapping } - } - - 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) - } - - pub fn files(&self) -> MappedLockGuard<'_, Vec<Lrc<SourceFile>>> { - LockGuard::map(self.files.borrow(), |files| &mut 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).map(|sf| sf.clone()) - } - - fn next_start_pos(&self) -> usize { - match self.files.borrow().source_files.last() { - None => 0, - // 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. - Some(last) => last.end_pos.to_usize() + 1, - } - } - - /// 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> { - let start_pos = self.next_start_pos(); - - // 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 (filename, was_remapped) = match filename { - FileName::Real(filename) => { - let (filename, was_remapped) = self.path_mapping.map_prefix(filename); - (FileName::Real(filename), was_remapped) - } - other => (other, 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 source_file = Lrc::new(SourceFile::new( - filename, - was_remapped, - unmapped_path, - src, - Pos::from_usize(start_pos), - )?); - - 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, - crate_of_origin: u32, - src_hash: u128, - name_hash: u128, - source_len: usize, - 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>, - ) -> Lrc<SourceFile> { - let start_pos = self.next_start_pos(); - - 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, - crate_of_origin, - src: None, - src_hash, - external_src: Lock::new(ExternalSource::AbsentOk), - 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, - }); - - 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 { - return match file { - FileName::DocTest(_, offset) => { - return if *offset >= 0 { - orig + *offset as usize - } else { - orig - (-(*offset)) as usize - }; - } - _ => orig, - }; - } - - /// Looks up source information about a `BytePos`. - pub fn lookup_char_pos(&self, pos: BytePos) -> Loc { - let chpos = self.bytepos_to_file_charpos(pos); - match self.lookup_line(pos) { - Ok(SourceFileAndLine { sf: f, line: a }) => { - let line = a + 1; // Line numbers start at 1 - let linebpos = f.lines[a]; - let linechpos = self.bytepos_to_file_charpos(linebpos); - let col = chpos - linechpos; - - let col_display = { - let start_width_idx = f - .non_narrow_chars - .binary_search_by_key(&linebpos, |x| x.pos()) - .unwrap_or_else(|x| x); - let end_width_idx = f - .non_narrow_chars - .binary_search_by_key(&pos, |x| x.pos()) - .unwrap_or_else(|x| x); - let special_chars = end_width_idx - start_width_idx; - let non_narrow: usize = f.non_narrow_chars[start_width_idx..end_width_idx] - .into_iter() - .map(|x| x.width()) - .sum(); - col.0 - special_chars + non_narrow - }; - debug!("byte pos {:?} is on the line at byte pos {:?}", pos, linebpos); - debug!("char pos {:?} is on the line at char pos {:?}", chpos, linechpos); - debug!("byte is on line: {}", line); - assert!(chpos >= linechpos); - Loc { file: f, line, col, col_display } - } - Err(f) => { - let col_display = { - let end_width_idx = f - .non_narrow_chars - .binary_search_by_key(&pos, |x| x.pos()) - .unwrap_or_else(|x| x); - let non_narrow: usize = - f.non_narrow_chars[0..end_width_idx].into_iter().map(|x| x.width()).sum(); - chpos.0 - end_width_idx + non_narrow - }; - Loc { file: f, line: 0, col: chpos, 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 idx = self.lookup_source_file_idx(pos); - - let f = (*self.files.borrow().source_files)[idx].clone(); - - 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 span_to_lines(&self, sp: Span) -> FileLinesResult { - debug!("span_to_lines(sp={:?})", sp); - - 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), - })); - } - assert!(hi.line >= lo.line); - - 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. - for line_index in lo.line - 1..hi.line - 1 { - let line_len = lo.file.get_line(line_index).map(|s| s.chars().count()).unwrap_or(0); - 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 - 1, 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>(&self, sp: Span, extract_source: F) -> Result<String, SpanSnippetError> - where - F: Fn(&str, usize, usize) -> Result<String, 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 { - return 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 { - return extract_source(src, start_index, end_index); - } else if let Some(src) = local_begin.sf.external_src.borrow().get_source() { - return extract_source(src, start_index, end_index); - } else { - return 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_else(|| 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_else(|| 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) -> Span { - if let Ok(prev_source) = self.span_to_prev_source(sp) { - let prev_source = prev_source.rsplit(c).nth(0).unwrap_or("").trim_start(); - if !prev_source.is_empty() && !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 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).nth(0).unwrap_or("").trim_start(); - 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 - } - - /// 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).nth(0).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; - } - - if whitespace_found && !c.is_whitespace() { false } else { true } - }) - } - - /// 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 - } - } - - pub fn def_span(&self, sp: Span) -> Span { - 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 { - 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 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_value()) - || (forwards && start_index == usize::max_value()) - { - 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>> { - 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 map = &(*self.files.borrow().source_files)[idx]; - - // The number of extra bytes due to multibyte chars in the `SourceFile`. - let mut total_extra_bytes = 0; - - for mbc in map.multibyte_chars.iter() { - debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos); - if mbc.pos < bpos { - // Every character is at least one byte, so we only - // count the actual extra bytes. - total_extra_bytes += mbc.bytes as u32 - 1; - // We should never see a byte position in the middle of a - // character. - assert!(bpos.to_u32() >= mbc.pos.to_u32() + mbc.bytes as u32); - } else { - break; - } - } - - assert!(map.start_pos.to_u32() + total_extra_bytes <= bpos.to_u32()); - CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes as usize) - } - - // Returns the index of the `SourceFile` (in `self.files`) that contains `pos`. - 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); - self.span_to_snippet(prev_span) - .map(|snippet| { - let len = snippet - .find(|c: char| !c.is_alphanumeric() && c != '_') - .expect("no label after fn"); - prev_span.with_hi(BytePos(prev_span.lo().0 + len as u32)) - }) - .ok() - } - - /// 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).ok(), - _ => None, - }) - } - pub fn call_span_if_macro(&self, sp: Span) -> Span { - if self.span_to_filename(sp.clone()).is_macros() { - let v = sp.macro_backtrace(); - if let Some(use_site) = v.last() { - return use_site.call_site; - } - } - sp - } -} - -#[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) - } -} |