// Copyright 2012 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! The CodeMap 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 //! CodeMap and are represented by FileMaps. Byte positions are stored in //! `spans` and used pervasively in the compiler. They are absolute positions //! within the CodeMap, which upon request can be converted to line and column //! information, source code snippets, etc. pub use syntax_pos::*; pub use syntax_pos::hygiene::{ExpnFormat, ExpnInfo, NameAndSpan}; pub use self::ExpnFormat::*; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::stable_hasher::StableHasher; use rustc_data_structures::sync::{Lrc, Lock, LockGuard}; use std::cmp; use std::hash::Hash; use std::path::{Path, PathBuf}; use std::env; use std::fs; use std::io::{self, Read}; use errors::CodeMapper; /// Return 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_info` chain. pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span { let call_site1 = sp.ctxt().outer().expn_info().map(|ei| ei.call_site); let call_site2 = enclosing_sp.ctxt().outer().expn_info().map(|ei| ei.call_site); match (call_site1, call_site2) { (None, _) => sp, (Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp, (Some(call_site1), _) => original_sp(call_site1, enclosing_sp), } } #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)] pub struct Spanned { pub node: T, pub span: Span, } pub fn respan(sp: Span, t: T) -> Spanned { Spanned {node: t, span: sp} } pub fn dummy_spanned(t: T) -> Spanned { respan(DUMMY_SP, t) } // _____________________________________________________________________________ // FileMap, 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; /// Return an absolute path to a file, if possible. fn abs_path(&self, path: &Path) -> Option; /// Read the contents of an UTF-8 file into memory. fn read_file(&self, path: &Path) -> io::Result; } /// 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 { 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 { let mut src = String::new(); fs::File::open(path)?.read_to_string(&mut src)?; Ok(src) } } // This is a FileMap identifier that is used to correlate FileMaps 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 StableFilemapId(u128); impl StableFilemapId { pub fn new(filemap: &FileMap) -> StableFilemapId { let mut hasher = StableHasher::new(); filemap.name.hash(&mut hasher); filemap.name_was_remapped.hash(&mut hasher); filemap.unmapped_path.hash(&mut hasher); StableFilemapId(hasher.finish()) } } // _____________________________________________________________________________ // CodeMap // pub(super) struct CodeMapFiles { pub(super) file_maps: Vec>, stable_id_to_filemap: FxHashMap> } pub struct CodeMap { pub(super) files: Lock, file_loader: Box, // This is used to apply the file path remapping as specified via // --remap-path-prefix to all FileMaps allocated within this CodeMap. path_mapping: FilePathMapping, /// In case we are in a doctest, replace all file names with the PathBuf, /// and add the given offsets to the line info doctest_offset: Option<(FileName, isize)>, } impl CodeMap { pub fn new(path_mapping: FilePathMapping) -> CodeMap { CodeMap { files: Lock::new(CodeMapFiles { file_maps: Vec::new(), stable_id_to_filemap: FxHashMap(), }), file_loader: Box::new(RealFileLoader), path_mapping, doctest_offset: None, } } pub fn new_doctest(path_mapping: FilePathMapping, file: FileName, line: isize) -> CodeMap { CodeMap { doctest_offset: Some((file, line)), ..CodeMap::new(path_mapping) } } pub fn with_file_loader(file_loader: Box, path_mapping: FilePathMapping) -> CodeMap { CodeMap { files: Lock::new(CodeMapFiles { file_maps: Vec::new(), stable_id_to_filemap: FxHashMap(), }), file_loader: file_loader, path_mapping, doctest_offset: None, } } 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> { let src = self.file_loader.read_file(path)?; let filename = if let Some((ref name, _)) = self.doctest_offset { name.clone() } else { path.to_owned().into() }; Ok(self.new_filemap(filename, src)) } pub fn files(&self) -> LockGuard>> { LockGuard::map(self.files.borrow(), |files| &mut files.file_maps) } pub fn filemap_by_stable_id(&self, stable_id: StableFilemapId) -> Option> { self.files.borrow().stable_id_to_filemap.get(&stable_id).map(|fm| fm.clone()) } fn next_start_pos(&self) -> usize { match self.files.borrow().file_maps.last() { None => 0, // Add one so there is some space between files. This lets us distinguish // positions in the codemap, even in the presence of zero-length files. Some(last) => last.end_pos.to_usize() + 1, } } /// Creates a new filemap without setting its line information. If you don't /// intend to set the line information yourself, you should use new_filemap_and_lines. /// This does not ensure that only one FileMap exists per file name. pub fn new_filemap(&self, filename: FileName, src: String) -> Lrc { 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 `` 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 filemap = Lrc::new(FileMap::new( filename, was_remapped, unmapped_path, src, Pos::from_usize(start_pos), )); let mut files = self.files.borrow_mut(); files.file_maps.push(filemap.clone()); files.stable_id_to_filemap.insert(StableFilemapId::new(&filemap), filemap.clone()); filemap } /// Creates a new filemap and sets its line information. /// This does not ensure that only one FileMap exists per file name. pub fn new_filemap_and_lines(&self, filename: &Path, src: &str) -> Lrc { let fm = self.new_filemap(filename.to_owned().into(), src.to_owned()); let mut byte_pos: u32 = fm.start_pos.0; for line in src.lines() { // register the start of this line fm.next_line(BytePos(byte_pos)); // update byte_pos to include this line and the \n at the end byte_pos += line.len() as u32 + 1; } fm } /// Allocates a new FileMap representing a source file from an external /// crate. The source code of such an "imported filemap" is not available, /// but we still know enough to generate accurate debuginfo location /// information for things inlined from other crates. pub fn new_imported_filemap(&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, mut file_local_multibyte_chars: Vec, mut file_local_non_narrow_chars: Vec) -> Lrc { 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; } let filemap = Lrc::new(FileMap { 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: Lock::new(file_local_lines), multibyte_chars: Lock::new(file_local_multibyte_chars), non_narrow_chars: Lock::new(file_local_non_narrow_chars), name_hash, }); let mut files = self.files.borrow_mut(); files.file_maps.push(filemap.clone()); files.stable_id_to_filemap.insert(StableFilemapId::new(&filemap), filemap.clone()); filemap } 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, apply it to the line pub fn doctest_offset_line(&self, mut orig: usize) -> usize { if let Some((_, line)) = self.doctest_offset { if line >= 0 { orig = orig + line as usize; } else { orig = orig - (-line) as usize; } } orig } /// Lookup 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(FileMapAndLine { fm: f, line: a }) => { let line = a + 1; // Line numbers start at 1 let linebpos = (*f.lines.borrow())[a]; let linechpos = self.bytepos_to_file_charpos(linebpos); let col = chpos - linechpos; let col_display = { let non_narrow_chars = f.non_narrow_chars.borrow(); let start_width_idx = non_narrow_chars .binary_search_by_key(&linebpos, |x| x.pos()) .unwrap_or_else(|x| x); let end_width_idx = 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 = 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 non_narrow_chars = f.non_narrow_chars.borrow(); let end_width_idx = non_narrow_chars .binary_search_by_key(&pos, |x| x.pos()) .unwrap_or_else(|x| x); let non_narrow: usize = 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 relevant filemap is empty, we don't return a line number. pub fn lookup_line(&self, pos: BytePos) -> Result> { let idx = self.lookup_filemap_idx(pos); let f = (*self.files.borrow().file_maps)[idx].clone(); match f.lookup_line(pos) { Some(line) => Ok(FileMapAndLine { fm: f, line: line }), None => Err(f) } } pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt { let loc = self.lookup_char_pos(pos); LocWithOpt { filename: loc.file.name.clone(), line: loc.line, col: loc.col, file: Some(loc.file) } } /// 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 spans have to be: /// /// * the ctxt 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 { // make sure 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 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().file_maps.is_empty() && sp.source_equal(&DUMMY_SP) { return "no-location".to_string(); } let lo = self.lookup_char_pos_adj(sp.lo()); let hi = self.lookup_char_pos_adj(sp.hi()); format!("{}:{}:{}: {}:{}", lo.filename, 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("CodeMap::span_to_unmapped_path called for imported FileMap?") } 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); if sp.lo() > sp.hi() { return Err(SpanLinesError::IllFormedSpan(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: lines}) } /// Extract 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(&self, sp: Span, extract_source: F) -> Result where F: Fn(&str, usize, usize) -> String { if sp.lo() > sp.hi() { return Err(SpanSnippetError::IllFormedSpan(sp)); } let local_begin = self.lookup_byte_offset(sp.lo()); let local_end = self.lookup_byte_offset(sp.hi()); if local_begin.fm.start_pos != local_end.fm.start_pos { return Err(SpanSnippetError::DistinctSources(DistinctSources { begin: (local_begin.fm.name.clone(), local_begin.fm.start_pos), end: (local_end.fm.name.clone(), local_end.fm.start_pos) })); } else { self.ensure_filemap_source_present(local_begin.fm.clone()); let start_index = local_begin.pos.to_usize(); let end_index = local_end.pos.to_usize(); let source_len = (local_begin.fm.end_pos - local_begin.fm.start_pos).to_usize(); if start_index > end_index || end_index > source_len { return Err(SpanSnippetError::MalformedForCodemap( MalformedCodemapPositions { name: local_begin.fm.name.clone(), source_len, begin_pos: local_begin.pos, end_pos: local_end.pos, })); } if let Some(ref src) = local_begin.fm.src { return Ok(extract_source(src, start_index, end_index)); } else if let Some(src) = local_begin.fm.external_src.borrow().get_source() { return Ok(extract_source(src, start_index, end_index)); } else { return Err(SpanSnippetError::SourceNotAvailable { filename: local_begin.fm.name.clone() }); } } } /// Return the source snippet as `String` corresponding to the given `Span` pub fn span_to_snippet(&self, sp: Span) -> Result { self.span_to_source(sp, |src, start_index, end_index| src[start_index..end_index] .to_string()) } /// Return the source snippet as `String` before the given `Span` pub fn span_to_prev_source(&self, sp: Span) -> Result { self.span_to_source(sp, |src, start_index, _| src[..start_index].to_string()) } /// Extend 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_left(); if !prev_source.is_empty() && !prev_source.contains('\n') { return sp.with_lo(BytePos(sp.lo().0 - prev_source.len() as u32)); } } sp } /// Extend the given `Span` to just after the previous occurrence of `pat` when surrounded by /// whitespace. 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_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_left(); 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`, try to get a shorter span ending before the first occurrence of `c` `char` 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_right(); if !snippet.is_empty() && !snippet.contains('\n') { sp.with_hi(BytePos(sp.lo().0 + snippet.len() as u32)) } else { sp } } _ => sp, } } /// Given a `Span`, try 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`, get 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`, get 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`, get a shorter one until `predicate` yields false. pub fn span_take_while

(&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::(); 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 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 { // Disregard malformed spans and assume a one-byte wide character. if sp.lo() >= sp.hi() { debug!("find_width_of_character_at_span: early return malformed 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); 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.fm.end_pos - local_begin.fm.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.fm.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.fm.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_filemap(&self, filename: &FileName) -> Option> { for fm in self.files.borrow().file_maps.iter() { if *filename == fm.name { return Some(fm.clone()); } } None } /// For a global BytePos compute the local offset within the containing FileMap pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos { let idx = self.lookup_filemap_idx(bpos); let fm = (*self.files.borrow().file_maps)[idx].clone(); let offset = bpos - fm.start_pos; FileMapAndBytePos {fm: fm, pos: offset} } /// Converts an absolute BytePos to a CharPos relative to the filemap. pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos { let idx = self.lookup_filemap_idx(bpos); let map = &(*self.files.borrow().file_maps)[idx]; // The number of extra bytes due to multibyte chars in the FileMap let mut total_extra_bytes = 0; for mbc in map.multibyte_chars.borrow().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 - 1; // We should never see a byte position in the middle of a // character assert!(bpos.to_usize() >= mbc.pos.to_usize() + mbc.bytes); } else { break; } } assert!(map.start_pos.to_usize() + total_extra_bytes <= bpos.to_usize()); CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes) } // Return the index of the filemap (in self.files) which contains pos. pub fn lookup_filemap_idx(&self, pos: BytePos) -> usize { let files = self.files.borrow(); let files = &files.file_maps; let count = files.len(); // Binary search for the filemap. let mut a = 0; let mut b = count; while b - a > 1 { let m = (a + b) / 2; if files[m].start_pos > pos { b = m; } else { a = m; } } assert!(a < count, "position {} does not resolve to a source location", pos.to_usize()); return a; } 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 { 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() } /// Take 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` /// ``` /// /// 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 /// codemap 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("T".to_string())); new_snippet.push('>'); return Some((sugg_span, new_snippet)); } } None } } impl CodeMapper for CodeMap { fn lookup_char_pos(&self, pos: BytePos) -> Loc { self.lookup_char_pos(pos) } fn span_to_lines(&self, sp: Span) -> FileLinesResult { self.span_to_lines(sp) } fn span_to_string(&self, sp: Span) -> String { self.span_to_string(sp) } fn span_to_filename(&self, sp: Span) -> FileName { self.span_to_filename(sp) } fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option { self.merge_spans(sp_lhs, sp_rhs) } 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 } fn ensure_filemap_source_present(&self, file_map: Lrc) -> bool { file_map.add_external_src( || match file_map.name { FileName::Real(ref name) => self.file_loader.read_file(name).ok(), _ => None, } ) } fn doctest_offset_line(&self, line: usize) -> usize { self.doctest_offset_line(line) } } #[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) } } // _____________________________________________________________________________ // Tests // #[cfg(test)] mod tests { use super::*; use std::borrow::Cow; use rustc_data_structures::sync::Lrc; #[test] fn t1 () { let cm = CodeMap::new(FilePathMapping::empty()); let fm = cm.new_filemap(PathBuf::from("blork.rs").into(), "first line.\nsecond line".to_string()); fm.next_line(BytePos(0)); // Test we can get lines with partial line info. assert_eq!(fm.get_line(0), Some(Cow::from("first line."))); // TESTING BROKEN BEHAVIOR: line break declared before actual line break. fm.next_line(BytePos(10)); assert_eq!(fm.get_line(1), Some(Cow::from("."))); fm.next_line(BytePos(12)); assert_eq!(fm.get_line(2), Some(Cow::from("second line"))); } #[test] #[should_panic] fn t2 () { let cm = CodeMap::new(FilePathMapping::empty()); let fm = cm.new_filemap(PathBuf::from("blork.rs").into(), "first line.\nsecond line".to_string()); // TESTING *REALLY* BROKEN BEHAVIOR: fm.next_line(BytePos(0)); fm.next_line(BytePos(10)); fm.next_line(BytePos(2)); } fn init_code_map() -> CodeMap { let cm = CodeMap::new(FilePathMapping::empty()); let fm1 = cm.new_filemap(PathBuf::from("blork.rs").into(), "first line.\nsecond line".to_string()); let fm2 = cm.new_filemap(PathBuf::from("empty.rs").into(), "".to_string()); let fm3 = cm.new_filemap(PathBuf::from("blork2.rs").into(), "first line.\nsecond line".to_string()); fm1.next_line(BytePos(0)); fm1.next_line(BytePos(12)); fm2.next_line(fm2.start_pos); fm3.next_line(fm3.start_pos); fm3.next_line(fm3.start_pos + BytePos(12)); cm } #[test] fn t3() { // Test lookup_byte_offset let cm = init_code_map(); let fmabp1 = cm.lookup_byte_offset(BytePos(23)); assert_eq!(fmabp1.fm.name, PathBuf::from("blork.rs").into()); assert_eq!(fmabp1.pos, BytePos(23)); let fmabp1 = cm.lookup_byte_offset(BytePos(24)); assert_eq!(fmabp1.fm.name, PathBuf::from("empty.rs").into()); assert_eq!(fmabp1.pos, BytePos(0)); let fmabp2 = cm.lookup_byte_offset(BytePos(25)); assert_eq!(fmabp2.fm.name, PathBuf::from("blork2.rs").into()); assert_eq!(fmabp2.pos, BytePos(0)); } #[test] fn t4() { // Test bytepos_to_file_charpos let cm = init_code_map(); let cp1 = cm.bytepos_to_file_charpos(BytePos(22)); assert_eq!(cp1, CharPos(22)); let cp2 = cm.bytepos_to_file_charpos(BytePos(25)); assert_eq!(cp2, CharPos(0)); } #[test] fn t5() { // Test zero-length filemaps. let cm = init_code_map(); let loc1 = cm.lookup_char_pos(BytePos(22)); assert_eq!(loc1.file.name, PathBuf::from("blork.rs").into()); assert_eq!(loc1.line, 2); assert_eq!(loc1.col, CharPos(10)); let loc2 = cm.lookup_char_pos(BytePos(25)); assert_eq!(loc2.file.name, PathBuf::from("blork2.rs").into()); assert_eq!(loc2.line, 1); assert_eq!(loc2.col, CharPos(0)); } fn init_code_map_mbc() -> CodeMap { let cm = CodeMap::new(FilePathMapping::empty()); // € is a three byte utf8 char. let fm1 = cm.new_filemap(PathBuf::from("blork.rs").into(), "fir€st €€€€ line.\nsecond line".to_string()); let fm2 = cm.new_filemap(PathBuf::from("blork2.rs").into(), "first line€€.\n€ second line".to_string()); fm1.next_line(BytePos(0)); fm1.next_line(BytePos(28)); fm2.next_line(fm2.start_pos); fm2.next_line(fm2.start_pos + BytePos(20)); fm1.record_multibyte_char(BytePos(3), 3); fm1.record_multibyte_char(BytePos(9), 3); fm1.record_multibyte_char(BytePos(12), 3); fm1.record_multibyte_char(BytePos(15), 3); fm1.record_multibyte_char(BytePos(18), 3); fm2.record_multibyte_char(fm2.start_pos + BytePos(10), 3); fm2.record_multibyte_char(fm2.start_pos + BytePos(13), 3); fm2.record_multibyte_char(fm2.start_pos + BytePos(18), 3); cm } #[test] fn t6() { // Test bytepos_to_file_charpos in the presence of multi-byte chars let cm = init_code_map_mbc(); let cp1 = cm.bytepos_to_file_charpos(BytePos(3)); assert_eq!(cp1, CharPos(3)); let cp2 = cm.bytepos_to_file_charpos(BytePos(6)); assert_eq!(cp2, CharPos(4)); let cp3 = cm.bytepos_to_file_charpos(BytePos(56)); assert_eq!(cp3, CharPos(12)); let cp4 = cm.bytepos_to_file_charpos(BytePos(61)); assert_eq!(cp4, CharPos(15)); } #[test] fn t7() { // Test span_to_lines for a span ending at the end of filemap let cm = init_code_map(); let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION); let file_lines = cm.span_to_lines(span).unwrap(); assert_eq!(file_lines.file.name, PathBuf::from("blork.rs").into()); assert_eq!(file_lines.lines.len(), 1); assert_eq!(file_lines.lines[0].line_index, 1); } /// Given a string like " ~~~~~~~~~~~~ ", produces a span /// converting that range. The idea is that the string has the same /// length as the input, and we uncover the byte positions. Note /// that this can span lines and so on. fn span_from_selection(input: &str, selection: &str) -> Span { assert_eq!(input.len(), selection.len()); let left_index = selection.find('~').unwrap() as u32; let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index); Span::new(BytePos(left_index), BytePos(right_index + 1), NO_EXPANSION) } /// Test span_to_snippet and span_to_lines for a span converting 3 /// lines in the middle of a file. #[test] fn span_to_snippet_and_lines_spanning_multiple_lines() { let cm = CodeMap::new(FilePathMapping::empty()); let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n"; let selection = " \n ~~\n~~~\n~~~~~ \n \n"; cm.new_filemap_and_lines(Path::new("blork.rs"), inputtext); let span = span_from_selection(inputtext, selection); // check that we are extracting the text we thought we were extracting assert_eq!(&cm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD"); // check that span_to_lines gives us the complete result with the lines/cols we expected let lines = cm.span_to_lines(span).unwrap(); let expected = vec![ LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) }, LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) }, LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) } ]; assert_eq!(lines.lines, expected); } #[test] fn t8() { // Test span_to_snippet for a span ending at the end of filemap let cm = init_code_map(); let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION); let snippet = cm.span_to_snippet(span); assert_eq!(snippet, Ok("second line".to_string())); } #[test] fn t9() { // Test span_to_str for a span ending at the end of filemap let cm = init_code_map(); let span = Span::new(BytePos(12), BytePos(23), NO_EXPANSION); let sstr = cm.span_to_string(span); assert_eq!(sstr, "blork.rs:2:1: 2:12"); } /// Test failing to merge two spans on different lines #[test] fn span_merging_fail() { let cm = CodeMap::new(FilePathMapping::empty()); let inputtext = "bbbb BB\ncc CCC\n"; let selection1 = " ~~\n \n"; let selection2 = " \n ~~~\n"; cm.new_filemap_and_lines(Path::new("blork.rs"), inputtext); let span1 = span_from_selection(inputtext, selection1); let span2 = span_from_selection(inputtext, selection2); assert!(cm.merge_spans(span1, span2).is_none()); } /// Returns the span corresponding to the `n`th occurrence of /// `substring` in `source_text`. trait CodeMapExtension { fn span_substr(&self, file: &Lrc, source_text: &str, substring: &str, n: usize) -> Span; } impl CodeMapExtension for CodeMap { fn span_substr(&self, file: &Lrc, source_text: &str, substring: &str, n: usize) -> Span { println!("span_substr(file={:?}/{:?}, substring={:?}, n={})", file.name, file.start_pos, substring, n); let mut i = 0; let mut hi = 0; loop { let offset = source_text[hi..].find(substring).unwrap_or_else(|| { panic!("source_text `{}` does not have {} occurrences of `{}`, only {}", source_text, n, substring, i); }); let lo = hi + offset; hi = lo + substring.len(); if i == n { let span = Span::new( BytePos(lo as u32 + file.start_pos.0), BytePos(hi as u32 + file.start_pos.0), NO_EXPANSION, ); assert_eq!(&self.span_to_snippet(span).unwrap()[..], substring); return span; } i += 1; } } } }