1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! The source positions and related helper functions
15 //! This API is completely unstable and subject to change.
17 #![crate_name = "syntax_pos"]
18 #![crate_type = "dylib"]
19 #![crate_type = "rlib"]
20 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
21 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
22 html_root_url = "https://doc.rust-lang.org/nightly/")]
26 #![feature(custom_attribute)]
27 #![feature(i128_type)]
28 #![feature(optin_builtin_traits)]
29 #![allow(unused_attributes)]
30 #![feature(specialization)]
33 use std::cell::{Cell, RefCell};
36 use std::hash::Hasher;
37 use std::ops::{Add, Sub};
40 use rustc_data_structures::stable_hasher::StableHasher;
42 extern crate rustc_data_structures;
44 use serialize::{Encodable, Decodable, Encoder, Decoder};
46 extern crate serialize;
47 extern crate serialize as rustc_serialize; // used by deriving
50 pub use hygiene::{SyntaxContext, ExpnInfo, ExpnFormat, NameAndSpan};
54 pub type FileName = String;
56 /// Spans represent a region of code, used for error reporting. Positions in spans
57 /// are *absolute* positions from the beginning of the codemap, not positions
58 /// relative to FileMaps. Methods on the CodeMap can be used to relate spans back
59 /// to the original source.
60 /// You must be careful if the span crosses more than one file - you will not be
61 /// able to use many of the functions on spans in codemap and you cannot assume
62 /// that the length of the span = hi - lo; there may be space in the BytePos
63 /// range between files.
64 #[derive(Clone, Copy, Hash, PartialEq, Eq, Ord, PartialOrd)]
68 /// Information about where the macro came from, if this piece of
69 /// code was created by a macro expansion.
70 pub ctxt: SyntaxContext,
73 /// A collection of spans. Spans have two orthogonal attributes:
75 /// - they can be *primary spans*. In this case they are the locus of
76 /// the error, and would be rendered with `^^^`.
77 /// - they can have a *label*. In this case, the label is written next
78 /// to the mark in the snippet when we render.
79 #[derive(Clone, Debug, Hash, PartialEq, Eq, RustcEncodable, RustcDecodable)]
80 pub struct MultiSpan {
81 primary_spans: Vec<Span>,
82 span_labels: Vec<(Span, String)>,
86 /// Returns a new span representing just the end-point of this span
87 pub fn end_point(self) -> Span {
88 let lo = cmp::max(self.hi.0 - 1, self.lo.0);
89 Span { lo: BytePos(lo), ..self }
92 /// Returns a new span representing the next character after the end-point of this span
93 pub fn next_point(self) -> Span {
94 let lo = cmp::max(self.hi.0, self.lo.0 + 1);
95 Span { lo: BytePos(lo), hi: BytePos(lo), ..self }
98 /// Returns `self` if `self` is not the dummy span, and `other` otherwise.
99 pub fn substitute_dummy(self, other: Span) -> Span {
100 if self.source_equal(&DUMMY_SP) { other } else { self }
103 pub fn contains(self, other: Span) -> bool {
104 self.lo <= other.lo && other.hi <= self.hi
107 /// Return true if the spans are equal with regards to the source text.
109 /// Use this instead of `==` when either span could be generated code,
110 /// and you only care that they point to the same bytes of source text.
111 pub fn source_equal(&self, other: &Span) -> bool {
112 self.lo == other.lo && self.hi == other.hi
115 /// Returns `Some(span)`, where the start is trimmed by the end of `other`
116 pub fn trim_start(self, other: Span) -> Option<Span> {
117 if self.hi > other.hi {
118 Some(Span { lo: cmp::max(self.lo, other.hi), .. self })
124 /// Return the source span - this is either the supplied span, or the span for
125 /// the macro callsite that expanded to it.
126 pub fn source_callsite(self) -> Span {
127 self.ctxt.outer().expn_info().map(|info| info.call_site.source_callsite()).unwrap_or(self)
130 /// Return the source callee.
132 /// Returns None if the supplied span has no expansion trace,
133 /// else returns the NameAndSpan for the macro definition
134 /// corresponding to the source callsite.
135 pub fn source_callee(self) -> Option<NameAndSpan> {
136 fn source_callee(info: ExpnInfo) -> NameAndSpan {
137 match info.call_site.ctxt.outer().expn_info() {
138 Some(info) => source_callee(info),
142 self.ctxt.outer().expn_info().map(source_callee)
145 /// Check if a span is "internal" to a macro in which #[unstable]
146 /// items can be used (that is, a macro marked with
147 /// `#[allow_internal_unstable]`).
148 pub fn allows_unstable(&self) -> bool {
149 match self.ctxt.outer().expn_info() {
150 Some(info) => info.callee.allow_internal_unstable,
155 pub fn macro_backtrace(mut self) -> Vec<MacroBacktrace> {
156 let mut prev_span = DUMMY_SP;
157 let mut result = vec![];
159 let info = match self.ctxt.outer().expn_info() {
164 let (pre, post) = match info.callee.format {
165 ExpnFormat::MacroAttribute(..) => ("#[", "]"),
166 ExpnFormat::MacroBang(..) => ("", "!"),
167 ExpnFormat::CompilerDesugaring(..) => ("desugaring of `", "`"),
169 let macro_decl_name = format!("{}{}{}", pre, info.callee.name(), post);
170 let def_site_span = info.callee.span;
172 // Don't print recursive invocations
173 if !info.call_site.source_equal(&prev_span) {
174 result.push(MacroBacktrace {
175 call_site: info.call_site,
176 macro_decl_name: macro_decl_name,
177 def_site_span: def_site_span,
182 self = info.call_site;
187 pub fn to(self, end: Span) -> Span {
188 // FIXME(jseyfried): self.ctxt should always equal end.ctxt here (c.f. issue #23480)
189 if self.ctxt == SyntaxContext::empty() {
190 Span { lo: self.lo, ..end }
192 Span { hi: end.hi, ..self }
196 pub fn between(self, end: Span) -> Span {
200 ctxt: if end.ctxt == SyntaxContext::empty() {
208 pub fn until(self, end: Span) -> Span {
212 ctxt: if end.ctxt == SyntaxContext::empty() {
221 #[derive(Clone, Debug)]
222 pub struct SpanLabel {
223 /// The span we are going to include in the final snippet.
226 /// Is this a primary span? This is the "locus" of the message,
227 /// and is indicated with a `^^^^` underline, versus `----`.
228 pub is_primary: bool,
230 /// What label should we attach to this span (if any)?
231 pub label: Option<String>,
234 impl serialize::UseSpecializedEncodable for Span {
235 fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
236 s.emit_struct("Span", 2, |s| {
237 s.emit_struct_field("lo", 0, |s| {
241 s.emit_struct_field("hi", 1, |s| {
248 impl serialize::UseSpecializedDecodable for Span {
249 fn default_decode<D: Decoder>(d: &mut D) -> Result<Span, D::Error> {
250 d.read_struct("Span", 2, |d| {
251 let lo = d.read_struct_field("lo", 0, Decodable::decode)?;
252 let hi = d.read_struct_field("hi", 1, Decodable::decode)?;
253 Ok(Span { lo: lo, hi: hi, ctxt: NO_EXPANSION })
258 fn default_span_debug(span: Span, f: &mut fmt::Formatter) -> fmt::Result {
259 write!(f, "Span {{ lo: {:?}, hi: {:?}, ctxt: {:?} }}",
260 span.lo, span.hi, span.ctxt)
263 impl fmt::Debug for Span {
264 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
265 SPAN_DEBUG.with(|span_debug| span_debug.get()(*self, f))
269 pub const DUMMY_SP: Span = Span { lo: BytePos(0), hi: BytePos(0), ctxt: NO_EXPANSION };
272 pub fn new() -> MultiSpan {
274 primary_spans: vec![],
279 pub fn from_span(primary_span: Span) -> MultiSpan {
281 primary_spans: vec![primary_span],
286 pub fn from_spans(vec: Vec<Span>) -> MultiSpan {
293 pub fn push_span_label(&mut self, span: Span, label: String) {
294 self.span_labels.push((span, label));
297 /// Selects the first primary span (if any)
298 pub fn primary_span(&self) -> Option<Span> {
299 self.primary_spans.first().cloned()
302 /// Returns all primary spans.
303 pub fn primary_spans(&self) -> &[Span] {
307 /// Replaces all occurances of one Span with another. Used to move Spans in areas that don't
308 /// display well (like std macros). Returns true if replacements occurred.
309 pub fn replace(&mut self, before: Span, after: Span) -> bool {
310 let mut replacements_occurred = false;
311 for primary_span in &mut self.primary_spans {
312 if *primary_span == before {
313 *primary_span = after;
314 replacements_occurred = true;
317 for span_label in &mut self.span_labels {
318 if span_label.0 == before {
319 span_label.0 = after;
320 replacements_occurred = true;
323 replacements_occurred
326 /// Returns the strings to highlight. We always ensure that there
327 /// is an entry for each of the primary spans -- for each primary
328 /// span P, if there is at least one label with span P, we return
329 /// those labels (marked as primary). But otherwise we return
330 /// `SpanLabel` instances with empty labels.
331 pub fn span_labels(&self) -> Vec<SpanLabel> {
332 let is_primary = |span| self.primary_spans.contains(&span);
333 let mut span_labels = vec![];
335 for &(span, ref label) in &self.span_labels {
336 span_labels.push(SpanLabel {
338 is_primary: is_primary(span),
339 label: Some(label.clone())
343 for &span in &self.primary_spans {
344 if !span_labels.iter().any(|sl| sl.span == span) {
345 span_labels.push(SpanLabel {
357 impl From<Span> for MultiSpan {
358 fn from(span: Span) -> MultiSpan {
359 MultiSpan::from_span(span)
363 pub const NO_EXPANSION: SyntaxContext = SyntaxContext::empty();
365 /// Identifies an offset of a multi-byte character in a FileMap
366 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Eq, PartialEq)]
367 pub struct MultiByteChar {
368 /// The absolute offset of the character in the CodeMap
370 /// The number of bytes, >=2
374 /// The state of the lazy external source loading mechanism of a FileMap.
375 #[derive(PartialEq, Eq, Clone)]
376 pub enum ExternalSource {
377 /// The external source has been loaded already.
379 /// No attempt has been made to load the external source.
381 /// A failed attempt has been made to load the external source.
383 /// No external source has to be loaded, since the FileMap represents a local crate.
387 impl ExternalSource {
388 pub fn is_absent(&self) -> bool {
390 ExternalSource::Present(_) => false,
395 pub fn get_source(&self) -> Option<&str> {
397 ExternalSource::Present(ref src) => Some(src),
403 /// A single source in the CodeMap.
406 /// The name of the file that the source came from, source that doesn't
407 /// originate from files has names between angle brackets by convention,
410 /// True if the `name` field above has been modified by -Zremap-path-prefix
411 pub name_was_remapped: bool,
412 /// Indicates which crate this FileMap was imported from.
413 pub crate_of_origin: u32,
414 /// The complete source code
415 pub src: Option<Rc<String>>,
416 /// The source code's hash
418 /// The external source code (used for external crates, which will have a `None`
419 /// value as `self.src`.
420 pub external_src: RefCell<ExternalSource>,
421 /// The start position of this source in the CodeMap
422 pub start_pos: BytePos,
423 /// The end position of this source in the CodeMap
424 pub end_pos: BytePos,
425 /// Locations of lines beginnings in the source code
426 pub lines: RefCell<Vec<BytePos>>,
427 /// Locations of multi-byte characters in the source code
428 pub multibyte_chars: RefCell<Vec<MultiByteChar>>,
431 impl Encodable for FileMap {
432 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
433 s.emit_struct("FileMap", 7, |s| {
434 s.emit_struct_field("name", 0, |s| self.name.encode(s))?;
435 s.emit_struct_field("name_was_remapped", 1, |s| self.name_was_remapped.encode(s))?;
436 s.emit_struct_field("src_hash", 6, |s| self.src_hash.encode(s))?;
437 s.emit_struct_field("start_pos", 2, |s| self.start_pos.encode(s))?;
438 s.emit_struct_field("end_pos", 3, |s| self.end_pos.encode(s))?;
439 s.emit_struct_field("lines", 4, |s| {
440 let lines = self.lines.borrow();
442 s.emit_u32(lines.len() as u32)?;
444 if !lines.is_empty() {
445 // In order to preserve some space, we exploit the fact that
446 // the lines list is sorted and individual lines are
447 // probably not that long. Because of that we can store lines
448 // as a difference list, using as little space as possible
449 // for the differences.
450 let max_line_length = if lines.len() == 1 {
454 .map(|w| w[1] - w[0])
455 .map(|bp| bp.to_usize())
460 let bytes_per_diff: u8 = match max_line_length {
462 0x100 ... 0xFFFF => 2,
466 // Encode the number of bytes used per diff.
467 bytes_per_diff.encode(s)?;
469 // Encode the first element.
472 let diff_iter = (&lines[..]).windows(2)
473 .map(|w| (w[1] - w[0]));
475 match bytes_per_diff {
476 1 => for diff in diff_iter { (diff.0 as u8).encode(s)? },
477 2 => for diff in diff_iter { (diff.0 as u16).encode(s)? },
478 4 => for diff in diff_iter { diff.0.encode(s)? },
485 s.emit_struct_field("multibyte_chars", 5, |s| {
486 (*self.multibyte_chars.borrow()).encode(s)
492 impl Decodable for FileMap {
493 fn decode<D: Decoder>(d: &mut D) -> Result<FileMap, D::Error> {
495 d.read_struct("FileMap", 6, |d| {
496 let name: String = d.read_struct_field("name", 0, |d| Decodable::decode(d))?;
497 let name_was_remapped: bool =
498 d.read_struct_field("name_was_remapped", 1, |d| Decodable::decode(d))?;
500 d.read_struct_field("src_hash", 6, |d| Decodable::decode(d))?;
501 let start_pos: BytePos =
502 d.read_struct_field("start_pos", 2, |d| Decodable::decode(d))?;
503 let end_pos: BytePos = d.read_struct_field("end_pos", 3, |d| Decodable::decode(d))?;
504 let lines: Vec<BytePos> = d.read_struct_field("lines", 4, |d| {
505 let num_lines: u32 = Decodable::decode(d)?;
506 let mut lines = Vec::with_capacity(num_lines as usize);
509 // Read the number of bytes used per diff.
510 let bytes_per_diff: u8 = Decodable::decode(d)?;
512 // Read the first element.
513 let mut line_start: BytePos = Decodable::decode(d)?;
514 lines.push(line_start);
516 for _ in 1..num_lines {
517 let diff = match bytes_per_diff {
518 1 => d.read_u8()? as u32,
519 2 => d.read_u16()? as u32,
524 line_start = line_start + BytePos(diff);
526 lines.push(line_start);
532 let multibyte_chars: Vec<MultiByteChar> =
533 d.read_struct_field("multibyte_chars", 5, |d| Decodable::decode(d))?;
536 name_was_remapped: name_was_remapped,
537 // `crate_of_origin` has to be set by the importer.
538 // This value matches up with rustc::hir::def_id::INVALID_CRATE.
539 // That constant is not available here unfortunately :(
540 crate_of_origin: ::std::u32::MAX - 1,
541 start_pos: start_pos,
545 external_src: RefCell::new(ExternalSource::AbsentOk),
546 lines: RefCell::new(lines),
547 multibyte_chars: RefCell::new(multibyte_chars)
553 impl fmt::Debug for FileMap {
554 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
555 write!(fmt, "FileMap({})", self.name)
560 pub fn new(name: FileName,
561 name_was_remapped: bool,
563 start_pos: BytePos) -> FileMap {
564 remove_bom(&mut src);
566 let mut hasher: StableHasher<u128> = StableHasher::new();
567 hasher.write(src.as_bytes());
568 let src_hash = hasher.finish();
570 let end_pos = start_pos.to_usize() + src.len();
574 name_was_remapped: name_was_remapped,
576 src: Some(Rc::new(src)),
578 external_src: RefCell::new(ExternalSource::Unneeded),
579 start_pos: start_pos,
580 end_pos: Pos::from_usize(end_pos),
581 lines: RefCell::new(Vec::new()),
582 multibyte_chars: RefCell::new(Vec::new()),
586 /// EFFECT: register a start-of-line offset in the
587 /// table of line-beginnings.
588 /// UNCHECKED INVARIANT: these offsets must be added in the right
589 /// order and must be in the right places; there is shared knowledge
590 /// about what ends a line between this file and parse.rs
591 /// WARNING: pos param here is the offset relative to start of CodeMap,
592 /// and CodeMap will append a newline when adding a filemap without a newline at the end,
593 /// so the safe way to call this is with value calculated as
594 /// filemap.start_pos + newline_offset_relative_to_the_start_of_filemap.
595 pub fn next_line(&self, pos: BytePos) {
596 // the new charpos must be > the last one (or it's the first one).
597 let mut lines = self.lines.borrow_mut();
598 let line_len = lines.len();
599 assert!(line_len == 0 || ((*lines)[line_len - 1] < pos));
603 /// Add externally loaded source.
604 /// If the hash of the input doesn't match or no input is supplied via None,
605 /// it is interpreted as an error and the corresponding enum variant is set.
606 /// The return value signifies whether some kind of source is present.
607 pub fn add_external_src(&self, src: Option<String>) -> bool {
608 if *self.external_src.borrow() == ExternalSource::AbsentOk {
609 let mut external_src = self.external_src.borrow_mut();
610 if let Some(src) = src {
611 let mut hasher: StableHasher<u128> = StableHasher::new();
612 hasher.write(src.as_bytes());
614 if hasher.finish() == self.src_hash {
615 *external_src = ExternalSource::Present(src);
619 *external_src = ExternalSource::AbsentErr;
624 self.src.is_some() || self.external_src.borrow().get_source().is_some()
628 /// Get a line from the list of pre-computed line-beginnings.
629 /// The line number here is 0-based.
630 pub fn get_line(&self, line_number: usize) -> Option<Cow<str>> {
631 fn get_until_newline(src: &str, begin: usize) -> &str {
632 // We can't use `lines.get(line_number+1)` because we might
633 // be parsing when we call this function and thus the current
634 // line is the last one we have line info for.
635 let slice = &src[begin..];
636 match slice.find('\n') {
637 Some(e) => &slice[..e],
642 let lines = self.lines.borrow();
643 let line = if let Some(line) = lines.get(line_number) {
648 let begin: BytePos = *line - self.start_pos;
649 let begin = begin.to_usize();
651 if let Some(ref src) = self.src {
652 Some(Cow::from(get_until_newline(src, begin)))
653 } else if let Some(src) = self.external_src.borrow().get_source() {
654 Some(Cow::Owned(String::from(get_until_newline(src, begin))))
660 pub fn record_multibyte_char(&self, pos: BytePos, bytes: usize) {
661 assert!(bytes >=2 && bytes <= 4);
662 let mbc = MultiByteChar {
666 self.multibyte_chars.borrow_mut().push(mbc);
669 pub fn is_real_file(&self) -> bool {
670 !(self.name.starts_with("<") &&
671 self.name.ends_with(">"))
674 pub fn is_imported(&self) -> bool {
678 pub fn byte_length(&self) -> u32 {
679 self.end_pos.0 - self.start_pos.0
681 pub fn count_lines(&self) -> usize {
682 self.lines.borrow().len()
685 /// Find the line containing the given position. The return value is the
686 /// index into the `lines` array of this FileMap, not the 1-based line
687 /// number. If the filemap is empty or the position is located before the
688 /// first line, None is returned.
689 pub fn lookup_line(&self, pos: BytePos) -> Option<usize> {
690 let lines = self.lines.borrow();
691 if lines.len() == 0 {
695 let line_index = lookup_line(&lines[..], pos);
696 assert!(line_index < lines.len() as isize);
698 Some(line_index as usize)
704 pub fn line_bounds(&self, line_index: usize) -> (BytePos, BytePos) {
705 if self.start_pos == self.end_pos {
706 return (self.start_pos, self.end_pos);
709 let lines = self.lines.borrow();
710 assert!(line_index < lines.len());
711 if line_index == (lines.len() - 1) {
712 (lines[line_index], self.end_pos)
714 (lines[line_index], lines[line_index + 1])
719 /// Remove utf-8 BOM if any.
720 fn remove_bom(src: &mut String) {
721 if src.starts_with("\u{feff}") {
726 // _____________________________________________________________________________
727 // Pos, BytePos, CharPos
731 fn from_usize(n: usize) -> Self;
732 fn to_usize(&self) -> usize;
735 /// A byte offset. Keep this small (currently 32-bits), as AST contains
737 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
738 pub struct BytePos(pub u32);
740 /// A character offset. Because of multibyte utf8 characters, a byte offset
741 /// is not equivalent to a character offset. The CodeMap will convert BytePos
742 /// values to CharPos values as necessary.
743 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
744 pub struct CharPos(pub usize);
746 // FIXME: Lots of boilerplate in these impls, but so far my attempts to fix
747 // have been unsuccessful
749 impl Pos for BytePos {
750 fn from_usize(n: usize) -> BytePos { BytePos(n as u32) }
751 fn to_usize(&self) -> usize { let BytePos(n) = *self; n as usize }
754 impl Add for BytePos {
755 type Output = BytePos;
757 fn add(self, rhs: BytePos) -> BytePos {
758 BytePos((self.to_usize() + rhs.to_usize()) as u32)
762 impl Sub for BytePos {
763 type Output = BytePos;
765 fn sub(self, rhs: BytePos) -> BytePos {
766 BytePos((self.to_usize() - rhs.to_usize()) as u32)
770 impl Encodable for BytePos {
771 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
776 impl Decodable for BytePos {
777 fn decode<D: Decoder>(d: &mut D) -> Result<BytePos, D::Error> {
778 Ok(BytePos(d.read_u32()?))
782 impl Pos for CharPos {
783 fn from_usize(n: usize) -> CharPos { CharPos(n) }
784 fn to_usize(&self) -> usize { let CharPos(n) = *self; n }
787 impl Add for CharPos {
788 type Output = CharPos;
790 fn add(self, rhs: CharPos) -> CharPos {
791 CharPos(self.to_usize() + rhs.to_usize())
795 impl Sub for CharPos {
796 type Output = CharPos;
798 fn sub(self, rhs: CharPos) -> CharPos {
799 CharPos(self.to_usize() - rhs.to_usize())
803 // _____________________________________________________________________________
804 // Loc, LocWithOpt, FileMapAndLine, FileMapAndBytePos
807 /// A source code location used for error reporting
808 #[derive(Debug, Clone)]
810 /// Information about the original source
811 pub file: Rc<FileMap>,
812 /// The (1-based) line number
814 /// The (0-based) column offset
818 /// A source code location used as the result of lookup_char_pos_adj
819 // Actually, *none* of the clients use the filename *or* file field;
820 // perhaps they should just be removed.
822 pub struct LocWithOpt {
823 pub filename: FileName,
826 pub file: Option<Rc<FileMap>>,
829 // used to be structural records. Better names, anyone?
831 pub struct FileMapAndLine { pub fm: Rc<FileMap>, pub line: usize }
833 pub struct FileMapAndBytePos { pub fm: Rc<FileMap>, pub pos: BytePos }
835 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
836 pub struct LineInfo {
837 /// Index of line, starting from 0.
838 pub line_index: usize,
840 /// Column in line where span begins, starting from 0.
841 pub start_col: CharPos,
843 /// Column in line where span ends, starting from 0, exclusive.
844 pub end_col: CharPos,
847 pub struct FileLines {
848 pub file: Rc<FileMap>,
849 pub lines: Vec<LineInfo>
852 thread_local!(pub static SPAN_DEBUG: Cell<fn(Span, &mut fmt::Formatter) -> fmt::Result> =
853 Cell::new(default_span_debug));
855 pub struct MacroBacktrace {
856 /// span where macro was applied to generate this code
859 /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]")
860 pub macro_decl_name: String,
862 /// span where macro was defined (if known)
863 pub def_site_span: Option<Span>,
866 // _____________________________________________________________________________
867 // SpanLinesError, SpanSnippetError, DistinctSources, MalformedCodemapPositions
870 pub type FileLinesResult = Result<FileLines, SpanLinesError>;
872 #[derive(Clone, PartialEq, Eq, Debug)]
873 pub enum SpanLinesError {
875 DistinctSources(DistinctSources),
878 #[derive(Clone, PartialEq, Eq, Debug)]
879 pub enum SpanSnippetError {
881 DistinctSources(DistinctSources),
882 MalformedForCodemap(MalformedCodemapPositions),
883 SourceNotAvailable { filename: String }
886 #[derive(Clone, PartialEq, Eq, Debug)]
887 pub struct DistinctSources {
888 pub begin: (String, BytePos),
889 pub end: (String, BytePos)
892 #[derive(Clone, PartialEq, Eq, Debug)]
893 pub struct MalformedCodemapPositions {
895 pub source_len: usize,
896 pub begin_pos: BytePos,
900 // Given a slice of line start positions and a position, returns the index of
901 // the line the position is on. Returns -1 if the position is located before
903 fn lookup_line(lines: &[BytePos], pos: BytePos) -> isize {
904 match lines.binary_search(&pos) {
905 Ok(line) => line as isize,
906 Err(line) => line as isize - 1
912 use super::{lookup_line, BytePos};
915 fn test_lookup_line() {
917 let lines = &[BytePos(3), BytePos(17), BytePos(28)];
919 assert_eq!(lookup_line(lines, BytePos(0)), -1);
920 assert_eq!(lookup_line(lines, BytePos(3)), 0);
921 assert_eq!(lookup_line(lines, BytePos(4)), 0);
923 assert_eq!(lookup_line(lines, BytePos(16)), 0);
924 assert_eq!(lookup_line(lines, BytePos(17)), 1);
925 assert_eq!(lookup_line(lines, BytePos(18)), 1);
927 assert_eq!(lookup_line(lines, BytePos(28)), 2);
928 assert_eq!(lookup_line(lines, BytePos(29)), 2);