| // Copyright 2012-2013 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! The source positions and related helper functions |
| //! |
| //! # Note |
| //! |
| //! This API is completely unstable and subject to change. |
| |
| #![crate_name = "syntax_pos"] |
| #![unstable(feature = "rustc_private", issue = "27812")] |
| #![crate_type = "dylib"] |
| #![crate_type = "rlib"] |
| #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png", |
| html_favicon_url = "https://doc.rust-lang.org/favicon.ico", |
| html_root_url = "https://doc.rust-lang.org/nightly/")] |
| #![cfg_attr(not(stage0), deny(warnings))] |
| |
| #![feature(custom_attribute)] |
| #![allow(unused_attributes)] |
| #![feature(rustc_private)] |
| #![feature(staged_api)] |
| #![feature(question_mark)] |
| |
| use std::cell::{Cell, RefCell}; |
| use std::ops::{Add, Sub}; |
| use std::rc::Rc; |
| use std::cmp; |
| |
| use std::fmt; |
| |
| use serialize::{Encodable, Decodable, Encoder, Decoder}; |
| |
| extern crate serialize; |
| extern crate serialize as rustc_serialize; // used by deriving |
| |
| pub type FileName = String; |
| |
| /// Spans represent a region of code, used for error reporting. Positions in spans |
| /// are *absolute* positions from the beginning of the codemap, not positions |
| /// relative to FileMaps. Methods on the CodeMap can be used to relate spans back |
| /// to the original source. |
| /// You must be careful if the span crosses more than one file - you will not be |
| /// able to use many of the functions on spans in codemap and you cannot assume |
| /// that the length of the span = hi - lo; there may be space in the BytePos |
| /// range between files. |
| #[derive(Clone, Copy, Hash, PartialEq, Eq)] |
| pub struct Span { |
| pub lo: BytePos, |
| pub hi: BytePos, |
| /// Information about where the macro came from, if this piece of |
| /// code was created by a macro expansion. |
| pub expn_id: ExpnId |
| } |
| |
| /// A collection of spans. Spans have two orthogonal attributes: |
| /// |
| /// - they can be *primary spans*. In this case they are the locus of |
| /// the error, and would be rendered with `^^^`. |
| /// - they can have a *label*. In this case, the label is written next |
| /// to the mark in the snippet when we render. |
| #[derive(Clone)] |
| pub struct MultiSpan { |
| primary_spans: Vec<Span>, |
| span_labels: Vec<(Span, String)>, |
| } |
| |
| impl Span { |
| /// Returns a new span representing just the end-point of this span |
| pub fn end_point(self) -> Span { |
| let lo = cmp::max(self.hi.0 - 1, self.lo.0); |
| Span { lo: BytePos(lo), hi: self.hi, expn_id: self.expn_id} |
| } |
| |
| /// Returns `self` if `self` is not the dummy span, and `other` otherwise. |
| pub fn substitute_dummy(self, other: Span) -> Span { |
| if self.source_equal(&DUMMY_SP) { other } else { self } |
| } |
| |
| pub fn contains(self, other: Span) -> bool { |
| self.lo <= other.lo && other.hi <= self.hi |
| } |
| |
| /// Return true if the spans are equal with regards to the source text. |
| /// |
| /// Use this instead of `==` when either span could be generated code, |
| /// and you only care that they point to the same bytes of source text. |
| pub fn source_equal(&self, other: &Span) -> bool { |
| self.lo == other.lo && self.hi == other.hi |
| } |
| |
| /// Returns `Some(span)`, a union of `self` and `other`, on overlap. |
| pub fn merge(self, other: Span) -> Option<Span> { |
| if self.expn_id != other.expn_id { |
| return None; |
| } |
| |
| if (self.lo <= other.lo && self.hi > other.lo) || |
| (self.lo >= other.lo && self.lo < other.hi) { |
| Some(Span { |
| lo: cmp::min(self.lo, other.lo), |
| hi: cmp::max(self.hi, other.hi), |
| expn_id: self.expn_id, |
| }) |
| } else { |
| None |
| } |
| } |
| |
| /// Returns `Some(span)`, where the start is trimmed by the end of `other` |
| pub fn trim_start(self, other: Span) -> Option<Span> { |
| if self.hi > other.hi { |
| Some(Span { lo: cmp::max(self.lo, other.hi), .. self }) |
| } else { |
| None |
| } |
| } |
| } |
| |
| #[derive(Clone, Debug)] |
| pub struct SpanLabel { |
| /// The span we are going to include in the final snippet. |
| pub span: Span, |
| |
| /// Is this a primary span? This is the "locus" of the message, |
| /// and is indicated with a `^^^^` underline, versus `----`. |
| pub is_primary: bool, |
| |
| /// What label should we attach to this span (if any)? |
| pub label: Option<String>, |
| } |
| |
| impl Encodable for Span { |
| fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> { |
| s.emit_struct("Span", 2, |s| { |
| s.emit_struct_field("lo", 0, |s| { |
| self.lo.encode(s) |
| })?; |
| |
| s.emit_struct_field("hi", 1, |s| { |
| self.hi.encode(s) |
| }) |
| }) |
| } |
| } |
| |
| impl Decodable for Span { |
| fn decode<D: Decoder>(d: &mut D) -> Result<Span, D::Error> { |
| d.read_struct("Span", 2, |d| { |
| let lo = d.read_struct_field("lo", 0, |d| { |
| BytePos::decode(d) |
| })?; |
| |
| let hi = d.read_struct_field("hi", 1, |d| { |
| BytePos::decode(d) |
| })?; |
| |
| Ok(mk_sp(lo, hi)) |
| }) |
| } |
| } |
| |
| fn default_span_debug(span: Span, f: &mut fmt::Formatter) -> fmt::Result { |
| write!(f, "Span {{ lo: {:?}, hi: {:?}, expn_id: {:?} }}", |
| span.lo, span.hi, span.expn_id) |
| } |
| |
| impl fmt::Debug for Span { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| SPAN_DEBUG.with(|span_debug| span_debug.get()(*self, f)) |
| } |
| } |
| |
| pub const DUMMY_SP: Span = Span { lo: BytePos(0), hi: BytePos(0), expn_id: NO_EXPANSION }; |
| |
| // Generic span to be used for code originating from the command line |
| pub const COMMAND_LINE_SP: Span = Span { lo: BytePos(0), |
| hi: BytePos(0), |
| expn_id: COMMAND_LINE_EXPN }; |
| |
| impl MultiSpan { |
| pub fn new() -> MultiSpan { |
| MultiSpan { |
| primary_spans: vec![], |
| span_labels: vec![] |
| } |
| } |
| |
| pub fn push_span_label(&mut self, span: Span, label: String) { |
| self.span_labels.push((span, label)); |
| } |
| |
| /// Selects the first primary span (if any) |
| pub fn primary_span(&self) -> Option<Span> { |
| self.primary_spans.first().cloned() |
| } |
| |
| /// Returns all primary spans. |
| pub fn primary_spans(&self) -> &[Span] { |
| &self.primary_spans |
| } |
| |
| /// Returns the strings to highlight. We always ensure that there |
| /// is an entry for each of the primary spans -- for each primary |
| /// span P, if there is at least one label with span P, we return |
| /// those labels (marked as primary). But otherwise we return |
| /// `SpanLabel` instances with empty labels. |
| pub fn span_labels(&self) -> Vec<SpanLabel> { |
| let is_primary = |span| self.primary_spans.contains(&span); |
| let mut span_labels = vec![]; |
| |
| for &(span, ref label) in &self.span_labels { |
| span_labels.push(SpanLabel { |
| span: span, |
| is_primary: is_primary(span), |
| label: Some(label.clone()) |
| }); |
| } |
| |
| for &span in &self.primary_spans { |
| if !span_labels.iter().any(|sl| sl.span == span) { |
| span_labels.push(SpanLabel { |
| span: span, |
| is_primary: true, |
| label: None |
| }); |
| } |
| } |
| |
| span_labels |
| } |
| } |
| |
| impl From<Span> for MultiSpan { |
| fn from(span: Span) -> MultiSpan { |
| MultiSpan { |
| primary_spans: vec![span], |
| span_labels: vec![] |
| } |
| } |
| } |
| |
| #[derive(PartialEq, Eq, Clone, Debug, Hash, RustcEncodable, RustcDecodable, Copy)] |
| pub struct ExpnId(pub u32); |
| |
| pub const NO_EXPANSION: ExpnId = ExpnId(!0); |
| // For code appearing from the command line |
| pub const COMMAND_LINE_EXPN: ExpnId = ExpnId(!1); |
| |
| impl ExpnId { |
| pub fn from_u32(id: u32) -> ExpnId { |
| ExpnId(id) |
| } |
| |
| pub fn into_u32(self) -> u32 { |
| self.0 |
| } |
| } |
| |
| /// Identifies an offset of a multi-byte character in a FileMap |
| #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Eq, PartialEq)] |
| pub struct MultiByteChar { |
| /// The absolute offset of the character in the CodeMap |
| pub pos: BytePos, |
| /// The number of bytes, >=2 |
| pub bytes: usize, |
| } |
| |
| /// A single source in the CodeMap. |
| pub struct FileMap { |
| /// The name of the file that the source came from, source that doesn't |
| /// originate from files has names between angle brackets by convention, |
| /// e.g. `<anon>` |
| pub name: FileName, |
| /// The absolute path of the file that the source came from. |
| pub abs_path: Option<FileName>, |
| /// The complete source code |
| pub src: Option<Rc<String>>, |
| /// The start position of this source in the CodeMap |
| pub start_pos: BytePos, |
| /// The end position of this source in the CodeMap |
| pub end_pos: BytePos, |
| /// Locations of lines beginnings in the source code |
| pub lines: RefCell<Vec<BytePos>>, |
| /// Locations of multi-byte characters in the source code |
| pub multibyte_chars: RefCell<Vec<MultiByteChar>>, |
| } |
| |
| impl Encodable for FileMap { |
| fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> { |
| s.emit_struct("FileMap", 6, |s| { |
| s.emit_struct_field("name", 0, |s| self.name.encode(s))?; |
| s.emit_struct_field("abs_path", 1, |s| self.abs_path.encode(s))?; |
| s.emit_struct_field("start_pos", 2, |s| self.start_pos.encode(s))?; |
| s.emit_struct_field("end_pos", 3, |s| self.end_pos.encode(s))?; |
| s.emit_struct_field("lines", 4, |s| { |
| let lines = self.lines.borrow(); |
| // store the length |
| s.emit_u32(lines.len() as u32)?; |
| |
| if !lines.is_empty() { |
| // In order to preserve some space, we exploit the fact that |
| // the lines list is sorted and individual lines are |
| // probably not that long. Because of that we can store lines |
| // as a difference list, using as little space as possible |
| // for the differences. |
| let max_line_length = if lines.len() == 1 { |
| 0 |
| } else { |
| lines.windows(2) |
| .map(|w| w[1] - w[0]) |
| .map(|bp| bp.to_usize()) |
| .max() |
| .unwrap() |
| }; |
| |
| let bytes_per_diff: u8 = match max_line_length { |
| 0 ... 0xFF => 1, |
| 0x100 ... 0xFFFF => 2, |
| _ => 4 |
| }; |
| |
| // Encode the number of bytes used per diff. |
| bytes_per_diff.encode(s)?; |
| |
| // Encode the first element. |
| lines[0].encode(s)?; |
| |
| let diff_iter = (&lines[..]).windows(2) |
| .map(|w| (w[1] - w[0])); |
| |
| match bytes_per_diff { |
| 1 => for diff in diff_iter { (diff.0 as u8).encode(s)? }, |
| 2 => for diff in diff_iter { (diff.0 as u16).encode(s)? }, |
| 4 => for diff in diff_iter { diff.0.encode(s)? }, |
| _ => unreachable!() |
| } |
| } |
| |
| Ok(()) |
| })?; |
| s.emit_struct_field("multibyte_chars", 5, |s| { |
| (*self.multibyte_chars.borrow()).encode(s) |
| }) |
| }) |
| } |
| } |
| |
| impl Decodable for FileMap { |
| fn decode<D: Decoder>(d: &mut D) -> Result<FileMap, D::Error> { |
| |
| d.read_struct("FileMap", 6, |d| { |
| let name: String = d.read_struct_field("name", 0, |d| Decodable::decode(d))?; |
| let abs_path: Option<String> = |
| d.read_struct_field("abs_path", 1, |d| Decodable::decode(d))?; |
| let start_pos: BytePos = d.read_struct_field("start_pos", 2, |d| Decodable::decode(d))?; |
| let end_pos: BytePos = d.read_struct_field("end_pos", 3, |d| Decodable::decode(d))?; |
| let lines: Vec<BytePos> = d.read_struct_field("lines", 4, |d| { |
| let num_lines: u32 = Decodable::decode(d)?; |
| let mut lines = Vec::with_capacity(num_lines as usize); |
| |
| if num_lines > 0 { |
| // Read the number of bytes used per diff. |
| let bytes_per_diff: u8 = Decodable::decode(d)?; |
| |
| // Read the first element. |
| let mut line_start: BytePos = Decodable::decode(d)?; |
| lines.push(line_start); |
| |
| for _ in 1..num_lines { |
| let diff = match bytes_per_diff { |
| 1 => d.read_u8()? as u32, |
| 2 => d.read_u16()? as u32, |
| 4 => d.read_u32()?, |
| _ => unreachable!() |
| }; |
| |
| line_start = line_start + BytePos(diff); |
| |
| lines.push(line_start); |
| } |
| } |
| |
| Ok(lines) |
| })?; |
| let multibyte_chars: Vec<MultiByteChar> = |
| d.read_struct_field("multibyte_chars", 5, |d| Decodable::decode(d))?; |
| Ok(FileMap { |
| name: name, |
| abs_path: abs_path, |
| start_pos: start_pos, |
| end_pos: end_pos, |
| src: None, |
| lines: RefCell::new(lines), |
| multibyte_chars: RefCell::new(multibyte_chars) |
| }) |
| }) |
| } |
| } |
| |
| impl fmt::Debug for FileMap { |
| fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { |
| write!(fmt, "FileMap({})", self.name) |
| } |
| } |
| |
| impl FileMap { |
| /// EFFECT: register a start-of-line offset in the |
| /// table of line-beginnings. |
| /// UNCHECKED INVARIANT: these offsets must be added in the right |
| /// order and must be in the right places; there is shared knowledge |
| /// about what ends a line between this file and parse.rs |
| /// WARNING: pos param here is the offset relative to start of CodeMap, |
| /// and CodeMap will append a newline when adding a filemap without a newline at the end, |
| /// so the safe way to call this is with value calculated as |
| /// filemap.start_pos + newline_offset_relative_to_the_start_of_filemap. |
| pub fn next_line(&self, pos: BytePos) { |
| // the new charpos must be > the last one (or it's the first one). |
| let mut lines = self.lines.borrow_mut(); |
| let line_len = lines.len(); |
| assert!(line_len == 0 || ((*lines)[line_len - 1] < pos)); |
| lines.push(pos); |
| } |
| |
| /// get a line from the list of pre-computed line-beginnings. |
| /// line-number here is 0-based. |
| pub fn get_line(&self, line_number: usize) -> Option<&str> { |
| match self.src { |
| Some(ref src) => { |
| let lines = self.lines.borrow(); |
| lines.get(line_number).map(|&line| { |
| let begin: BytePos = line - self.start_pos; |
| let begin = begin.to_usize(); |
| // We can't use `lines.get(line_number+1)` because we might |
| // be parsing when we call this function and thus the current |
| // line is the last one we have line info for. |
| let slice = &src[begin..]; |
| match slice.find('\n') { |
| Some(e) => &slice[..e], |
| None => slice |
| } |
| }) |
| } |
| None => None |
| } |
| } |
| |
| pub fn record_multibyte_char(&self, pos: BytePos, bytes: usize) { |
| assert!(bytes >=2 && bytes <= 4); |
| let mbc = MultiByteChar { |
| pos: pos, |
| bytes: bytes, |
| }; |
| self.multibyte_chars.borrow_mut().push(mbc); |
| } |
| |
| pub fn is_real_file(&self) -> bool { |
| !(self.name.starts_with("<") && |
| self.name.ends_with(">")) |
| } |
| |
| pub fn is_imported(&self) -> bool { |
| self.src.is_none() |
| } |
| |
| pub fn count_lines(&self) -> usize { |
| self.lines.borrow().len() |
| } |
| } |
| |
| // _____________________________________________________________________________ |
| // Pos, BytePos, CharPos |
| // |
| |
| pub trait Pos { |
| fn from_usize(n: usize) -> Self; |
| fn to_usize(&self) -> usize; |
| } |
| |
| /// A byte offset. Keep this small (currently 32-bits), as AST contains |
| /// a lot of them. |
| #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)] |
| pub struct BytePos(pub u32); |
| |
| /// A character offset. Because of multibyte utf8 characters, a byte offset |
| /// is not equivalent to a character offset. The CodeMap will convert BytePos |
| /// values to CharPos values as necessary. |
| #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)] |
| pub struct CharPos(pub usize); |
| |
| // FIXME: Lots of boilerplate in these impls, but so far my attempts to fix |
| // have been unsuccessful |
| |
| impl Pos for BytePos { |
| fn from_usize(n: usize) -> BytePos { BytePos(n as u32) } |
| fn to_usize(&self) -> usize { let BytePos(n) = *self; n as usize } |
| } |
| |
| impl Add for BytePos { |
| type Output = BytePos; |
| |
| fn add(self, rhs: BytePos) -> BytePos { |
| BytePos((self.to_usize() + rhs.to_usize()) as u32) |
| } |
| } |
| |
| impl Sub for BytePos { |
| type Output = BytePos; |
| |
| fn sub(self, rhs: BytePos) -> BytePos { |
| BytePos((self.to_usize() - rhs.to_usize()) as u32) |
| } |
| } |
| |
| impl Encodable for BytePos { |
| fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> { |
| s.emit_u32(self.0) |
| } |
| } |
| |
| impl Decodable for BytePos { |
| fn decode<D: Decoder>(d: &mut D) -> Result<BytePos, D::Error> { |
| Ok(BytePos(d.read_u32()?)) |
| } |
| } |
| |
| impl Pos for CharPos { |
| fn from_usize(n: usize) -> CharPos { CharPos(n) } |
| fn to_usize(&self) -> usize { let CharPos(n) = *self; n } |
| } |
| |
| impl Add for CharPos { |
| type Output = CharPos; |
| |
| fn add(self, rhs: CharPos) -> CharPos { |
| CharPos(self.to_usize() + rhs.to_usize()) |
| } |
| } |
| |
| impl Sub for CharPos { |
| type Output = CharPos; |
| |
| fn sub(self, rhs: CharPos) -> CharPos { |
| CharPos(self.to_usize() - rhs.to_usize()) |
| } |
| } |
| |
| // _____________________________________________________________________________ |
| // Loc, LocWithOpt, FileMapAndLine, FileMapAndBytePos |
| // |
| |
| /// A source code location used for error reporting |
| #[derive(Debug, Clone)] |
| pub struct Loc { |
| /// Information about the original source |
| pub file: Rc<FileMap>, |
| /// The (1-based) line number |
| pub line: usize, |
| /// The (0-based) column offset |
| pub col: CharPos |
| } |
| |
| /// A source code location used as the result of lookup_char_pos_adj |
| // Actually, *none* of the clients use the filename *or* file field; |
| // perhaps they should just be removed. |
| #[derive(Debug)] |
| pub struct LocWithOpt { |
| pub filename: FileName, |
| pub line: usize, |
| pub col: CharPos, |
| pub file: Option<Rc<FileMap>>, |
| } |
| |
| // used to be structural records. Better names, anyone? |
| #[derive(Debug)] |
| pub struct FileMapAndLine { pub fm: Rc<FileMap>, pub line: usize } |
| #[derive(Debug)] |
| pub struct FileMapAndBytePos { pub fm: Rc<FileMap>, pub pos: BytePos } |
| |
| #[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| pub struct LineInfo { |
| /// Index of line, starting from 0. |
| pub line_index: usize, |
| |
| /// Column in line where span begins, starting from 0. |
| pub start_col: CharPos, |
| |
| /// Column in line where span ends, starting from 0, exclusive. |
| pub end_col: CharPos, |
| } |
| |
| pub struct FileLines { |
| pub file: Rc<FileMap>, |
| pub lines: Vec<LineInfo> |
| } |
| |
| thread_local!(pub static SPAN_DEBUG: Cell<fn(Span, &mut fmt::Formatter) -> fmt::Result> = |
| Cell::new(default_span_debug)); |
| |
| /* assuming that we're not in macro expansion */ |
| pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span { |
| Span {lo: lo, hi: hi, expn_id: NO_EXPANSION} |
| } |
| |
| pub struct MacroBacktrace { |
| /// span where macro was applied to generate this code |
| pub call_site: Span, |
| |
| /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]") |
| pub macro_decl_name: String, |
| |
| /// span where macro was defined (if known) |
| pub def_site_span: Option<Span>, |
| } |
| |
| // _____________________________________________________________________________ |
| // SpanLinesError, SpanSnippetError, DistinctSources, MalformedCodemapPositions |
| // |
| |
| pub type FileLinesResult = Result<FileLines, SpanLinesError>; |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub enum SpanLinesError { |
| IllFormedSpan(Span), |
| DistinctSources(DistinctSources), |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub enum SpanSnippetError { |
| IllFormedSpan(Span), |
| DistinctSources(DistinctSources), |
| MalformedForCodemap(MalformedCodemapPositions), |
| SourceNotAvailable { filename: String } |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct DistinctSources { |
| pub begin: (String, BytePos), |
| pub end: (String, BytePos) |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct MalformedCodemapPositions { |
| pub name: String, |
| pub source_len: usize, |
| pub begin_pos: BytePos, |
| pub end_pos: BytePos |
| } |
| |