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1 // Copyright 2012 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.
4 //
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.
10
11 //! The CodeMap tracks all the source code used within a single crate, mapping
12 //! from integer byte positions to the original source code location. Each bit
13 //! of source parsed during crate parsing (typically files, in-memory strings,
14 //! or various bits of macro expansion) cover a continuous range of bytes in the
15 //! CodeMap and are represented by FileMaps. Byte positions are stored in
16 //! `spans` and used pervasively in the compiler. They are absolute positions
17 //! within the CodeMap, which upon request can be converted to line and column
18 //! information, source code snippets, etc.
19
20 pub use self::ExpnFormat::*;
21
22 use std::cell::{Cell, RefCell};
23 use std::ops::{Add, Sub};
24 use std::path::Path;
25 use std::rc::Rc;
26 use std::cmp;
27
28 use std::{fmt, fs};
29 use std::io::{self, Read};
30
31 use serialize::{Encodable, Decodable, Encoder, Decoder};
32
33 use ast::Name;
34
35 use errors::emitter::MAX_HIGHLIGHT_LINES;
36
37 // _____________________________________________________________________________
38 // Pos, BytePos, CharPos
39 //
40
41 pub trait Pos {
42 fn from_usize(n: usize) -> Self;
43 fn to_usize(&self) -> usize;
44 }
45
46 /// A byte offset. Keep this small (currently 32-bits), as AST contains
47 /// a lot of them.
48 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
49 pub struct BytePos(pub u32);
50
51 /// A character offset. Because of multibyte utf8 characters, a byte offset
52 /// is not equivalent to a character offset. The CodeMap will convert BytePos
53 /// values to CharPos values as necessary.
54 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Debug)]
55 pub struct CharPos(pub usize);
56
57 // FIXME: Lots of boilerplate in these impls, but so far my attempts to fix
58 // have been unsuccessful
59
60 impl Pos for BytePos {
61 fn from_usize(n: usize) -> BytePos { BytePos(n as u32) }
62 fn to_usize(&self) -> usize { let BytePos(n) = *self; n as usize }
63 }
64
65 impl Add for BytePos {
66 type Output = BytePos;
67
68 fn add(self, rhs: BytePos) -> BytePos {
69 BytePos((self.to_usize() + rhs.to_usize()) as u32)
70 }
71 }
72
73 impl Sub for BytePos {
74 type Output = BytePos;
75
76 fn sub(self, rhs: BytePos) -> BytePos {
77 BytePos((self.to_usize() - rhs.to_usize()) as u32)
78 }
79 }
80
81 impl Encodable for BytePos {
82 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
83 s.emit_u32(self.0)
84 }
85 }
86
87 impl Decodable for BytePos {
88 fn decode<D: Decoder>(d: &mut D) -> Result<BytePos, D::Error> {
89 Ok(BytePos(d.read_u32()?))
90 }
91 }
92
93 impl Pos for CharPos {
94 fn from_usize(n: usize) -> CharPos { CharPos(n) }
95 fn to_usize(&self) -> usize { let CharPos(n) = *self; n }
96 }
97
98 impl Add for CharPos {
99 type Output = CharPos;
100
101 fn add(self, rhs: CharPos) -> CharPos {
102 CharPos(self.to_usize() + rhs.to_usize())
103 }
104 }
105
106 impl Sub for CharPos {
107 type Output = CharPos;
108
109 fn sub(self, rhs: CharPos) -> CharPos {
110 CharPos(self.to_usize() - rhs.to_usize())
111 }
112 }
113
114 // _____________________________________________________________________________
115 // Span, MultiSpan, Spanned
116 //
117
118 /// Spans represent a region of code, used for error reporting. Positions in spans
119 /// are *absolute* positions from the beginning of the codemap, not positions
120 /// relative to FileMaps. Methods on the CodeMap can be used to relate spans back
121 /// to the original source.
122 /// You must be careful if the span crosses more than one file - you will not be
123 /// able to use many of the functions on spans in codemap and you cannot assume
124 /// that the length of the span = hi - lo; there may be space in the BytePos
125 /// range between files.
126 #[derive(Clone, Copy, Hash, PartialEq, Eq)]
127 pub struct Span {
128 pub lo: BytePos,
129 pub hi: BytePos,
130 /// Information about where the macro came from, if this piece of
131 /// code was created by a macro expansion.
132 pub expn_id: ExpnId
133 }
134
135 /// Spans are converted to MultiSpans just before error reporting, either automatically,
136 /// generated by line grouping, or manually constructed.
137 /// In the latter case care should be taken to ensure that spans are ordered, disjoint,
138 /// and point into the same FileMap.
139 #[derive(Clone)]
140 pub struct MultiSpan {
141 pub spans: Vec<Span>
142 }
143
144 pub const DUMMY_SP: Span = Span { lo: BytePos(0), hi: BytePos(0), expn_id: NO_EXPANSION };
145
146 // Generic span to be used for code originating from the command line
147 pub const COMMAND_LINE_SP: Span = Span { lo: BytePos(0),
148 hi: BytePos(0),
149 expn_id: COMMAND_LINE_EXPN };
150
151 impl Span {
152 /// Returns `self` if `self` is not the dummy span, and `other` otherwise.
153 pub fn substitute_dummy(self, other: Span) -> Span {
154 if self.source_equal(&DUMMY_SP) { other } else { self }
155 }
156
157 pub fn contains(self, other: Span) -> bool {
158 self.lo <= other.lo && other.hi <= self.hi
159 }
160
161 /// Return true if the spans are equal with regards to the source text.
162 ///
163 /// Use this instead of `==` when either span could be generated code,
164 /// and you only care that they point to the same bytes of source text.
165 pub fn source_equal(&self, other: &Span) -> bool {
166 self.lo == other.lo && self.hi == other.hi
167 }
168
169 /// Returns `Some(span)`, a union of `self` and `other`, on overlap.
170 pub fn merge(self, other: Span) -> Option<Span> {
171 if self.expn_id != other.expn_id {
172 return None;
173 }
174
175 if (self.lo <= other.lo && self.hi > other.lo) ||
176 (self.lo >= other.lo && self.lo < other.hi) {
177 Some(Span {
178 lo: cmp::min(self.lo, other.lo),
179 hi: cmp::max(self.hi, other.hi),
180 expn_id: self.expn_id,
181 })
182 } else {
183 None
184 }
185 }
186
187 /// Returns `Some(span)`, where the start is trimmed by the end of `other`
188 pub fn trim_start(self, other: Span) -> Option<Span> {
189 if self.hi > other.hi {
190 Some(Span { lo: cmp::max(self.lo, other.hi), .. self })
191 } else {
192 None
193 }
194 }
195 }
196
197 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
198 pub struct Spanned<T> {
199 pub node: T,
200 pub span: Span,
201 }
202
203 impl Encodable for Span {
204 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
205 s.emit_struct("Span", 2, |s| {
206 s.emit_struct_field("lo", 0, |s| {
207 self.lo.encode(s)
208 })?;
209
210 s.emit_struct_field("hi", 1, |s| {
211 self.hi.encode(s)
212 })
213 })
214 }
215 }
216
217 impl Decodable for Span {
218 fn decode<D: Decoder>(d: &mut D) -> Result<Span, D::Error> {
219 d.read_struct("Span", 2, |d| {
220 let lo = d.read_struct_field("lo", 0, |d| {
221 BytePos::decode(d)
222 })?;
223
224 let hi = d.read_struct_field("hi", 1, |d| {
225 BytePos::decode(d)
226 })?;
227
228 Ok(mk_sp(lo, hi))
229 })
230 }
231 }
232
233 fn default_span_debug(span: Span, f: &mut fmt::Formatter) -> fmt::Result {
234 write!(f, "Span {{ lo: {:?}, hi: {:?}, expn_id: {:?} }}",
235 span.lo, span.hi, span.expn_id)
236 }
237
238 thread_local!(pub static SPAN_DEBUG: Cell<fn(Span, &mut fmt::Formatter) -> fmt::Result> =
239 Cell::new(default_span_debug));
240
241 impl fmt::Debug for Span {
242 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
243 SPAN_DEBUG.with(|span_debug| span_debug.get()(*self, f))
244 }
245 }
246
247 pub fn spanned<T>(lo: BytePos, hi: BytePos, t: T) -> Spanned<T> {
248 respan(mk_sp(lo, hi), t)
249 }
250
251 pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
252 Spanned {node: t, span: sp}
253 }
254
255 pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
256 respan(DUMMY_SP, t)
257 }
258
259 /* assuming that we're not in macro expansion */
260 pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
261 Span {lo: lo, hi: hi, expn_id: NO_EXPANSION}
262 }
263
264 /// Return the span itself if it doesn't come from a macro expansion,
265 /// otherwise return the call site span up to the `enclosing_sp` by
266 /// following the `expn_info` chain.
267 pub fn original_sp(cm: &CodeMap, sp: Span, enclosing_sp: Span) -> Span {
268 let call_site1 = cm.with_expn_info(sp.expn_id, |ei| ei.map(|ei| ei.call_site));
269 let call_site2 = cm.with_expn_info(enclosing_sp.expn_id, |ei| ei.map(|ei| ei.call_site));
270 match (call_site1, call_site2) {
271 (None, _) => sp,
272 (Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp,
273 (Some(call_site1), _) => original_sp(cm, call_site1, enclosing_sp),
274 }
275 }
276
277 impl MultiSpan {
278 pub fn new() -> MultiSpan {
279 MultiSpan { spans: Vec::new() }
280 }
281
282 pub fn to_span_bounds(&self) -> Span {
283 assert!(!self.spans.is_empty());
284 let Span { lo, expn_id, .. } = *self.spans.first().unwrap();
285 let Span { hi, .. } = *self.spans.last().unwrap();
286 Span { lo: lo, hi: hi, expn_id: expn_id }
287 }
288
289 /// Merges or inserts the given span into itself.
290 pub fn push_merge(&mut self, mut sp: Span) {
291 let mut idx_merged = None;
292
293 for idx in 0.. {
294 let cur = match self.spans.get(idx) {
295 Some(s) => *s,
296 None => break,
297 };
298 // Try to merge with a contained Span
299 if let Some(union) = cur.merge(sp) {
300 self.spans[idx] = union;
301 sp = union;
302 idx_merged = Some(idx);
303 break;
304 }
305 // Or insert into the first sorted position
306 if sp.hi <= cur.lo {
307 self.spans.insert(idx, sp);
308 idx_merged = Some(idx);
309 break;
310 }
311 }
312 if let Some(idx) = idx_merged {
313 // Merge with spans trailing the insertion/merging position
314 while (idx + 1) < self.spans.len() {
315 if let Some(union) = self.spans[idx + 1].merge(sp) {
316 self.spans[idx] = union;
317 self.spans.remove(idx + 1);
318 } else {
319 break;
320 }
321 }
322 } else {
323 self.spans.push(sp);
324 }
325 }
326
327 /// Inserts the given span into itself, for use with `end_highlight_lines`.
328 pub fn push_trim(&mut self, mut sp: Span) {
329 let mut prev = mk_sp(BytePos(0), BytePos(0));
330
331 if let Some(first) = self.spans.get_mut(0) {
332 if first.lo > sp.lo {
333 // Prevent us here from spanning fewer lines
334 // because of trimming the start of the span
335 // (this should not be visible, because this method ought
336 // to not be used in conjunction with `highlight_lines`)
337 first.lo = sp.lo;
338 }
339 }
340
341 for idx in 0.. {
342 if let Some(sp_trim) = sp.trim_start(prev) {
343 // Implies `sp.hi > prev.hi`
344 let cur = match self.spans.get(idx) {
345 Some(s) => *s,
346 None => {
347 sp = sp_trim;
348 break;
349 }
350 };
351 // `cur` may overlap with `sp_trim`
352 if let Some(cur_trim) = cur.trim_start(sp_trim) {
353 // Implies `sp.hi < cur.hi`
354 self.spans.insert(idx, sp_trim);
355 self.spans[idx + 1] = cur_trim;
356 return;
357 } else if sp.hi == cur.hi {
358 return;
359 }
360 prev = cur;
361 }
362 }
363 self.spans.push(sp);
364 }
365 }
366
367 impl From<Span> for MultiSpan {
368 fn from(span: Span) -> MultiSpan {
369 MultiSpan { spans: vec![span] }
370 }
371 }
372
373 // _____________________________________________________________________________
374 // Loc, LocWithOpt, FileMapAndLine, FileMapAndBytePos
375 //
376
377 /// A source code location used for error reporting
378 #[derive(Debug)]
379 pub struct Loc {
380 /// Information about the original source
381 pub file: Rc<FileMap>,
382 /// The (1-based) line number
383 pub line: usize,
384 /// The (0-based) column offset
385 pub col: CharPos
386 }
387
388 /// A source code location used as the result of lookup_char_pos_adj
389 // Actually, *none* of the clients use the filename *or* file field;
390 // perhaps they should just be removed.
391 #[derive(Debug)]
392 pub struct LocWithOpt {
393 pub filename: FileName,
394 pub line: usize,
395 pub col: CharPos,
396 pub file: Option<Rc<FileMap>>,
397 }
398
399 // used to be structural records. Better names, anyone?
400 #[derive(Debug)]
401 pub struct FileMapAndLine { pub fm: Rc<FileMap>, pub line: usize }
402 #[derive(Debug)]
403 pub struct FileMapAndBytePos { pub fm: Rc<FileMap>, pub pos: BytePos }
404
405
406 // _____________________________________________________________________________
407 // ExpnFormat, NameAndSpan, ExpnInfo, ExpnId
408 //
409
410 /// The source of expansion.
411 #[derive(Clone, Hash, Debug, PartialEq, Eq)]
412 pub enum ExpnFormat {
413 /// e.g. #[derive(...)] <item>
414 MacroAttribute(Name),
415 /// e.g. `format!()`
416 MacroBang(Name),
417 }
418
419 #[derive(Clone, Hash, Debug)]
420 pub struct NameAndSpan {
421 /// The format with which the macro was invoked.
422 pub format: ExpnFormat,
423 /// Whether the macro is allowed to use #[unstable]/feature-gated
424 /// features internally without forcing the whole crate to opt-in
425 /// to them.
426 pub allow_internal_unstable: bool,
427 /// The span of the macro definition itself. The macro may not
428 /// have a sensible definition span (e.g. something defined
429 /// completely inside libsyntax) in which case this is None.
430 pub span: Option<Span>
431 }
432
433 impl NameAndSpan {
434 pub fn name(&self) -> Name {
435 match self.format {
436 ExpnFormat::MacroAttribute(s) => s,
437 ExpnFormat::MacroBang(s) => s,
438 }
439 }
440 }
441
442 /// Extra information for tracking spans of macro and syntax sugar expansion
443 #[derive(Hash, Debug)]
444 pub struct ExpnInfo {
445 /// The location of the actual macro invocation or syntax sugar , e.g.
446 /// `let x = foo!();` or `if let Some(y) = x {}`
447 ///
448 /// This may recursively refer to other macro invocations, e.g. if
449 /// `foo!()` invoked `bar!()` internally, and there was an
450 /// expression inside `bar!`; the call_site of the expression in
451 /// the expansion would point to the `bar!` invocation; that
452 /// call_site span would have its own ExpnInfo, with the call_site
453 /// pointing to the `foo!` invocation.
454 pub call_site: Span,
455 /// Information about the expansion.
456 pub callee: NameAndSpan
457 }
458
459 #[derive(PartialEq, Eq, Clone, Debug, Hash, RustcEncodable, RustcDecodable, Copy)]
460 pub struct ExpnId(u32);
461
462 pub const NO_EXPANSION: ExpnId = ExpnId(!0);
463 // For code appearing from the command line
464 pub const COMMAND_LINE_EXPN: ExpnId = ExpnId(!1);
465
466 impl ExpnId {
467 pub fn from_u32(id: u32) -> ExpnId {
468 ExpnId(id)
469 }
470
471 pub fn into_u32(self) -> u32 {
472 self.0
473 }
474 }
475
476 // _____________________________________________________________________________
477 // FileMap, MultiByteChar, FileName, FileLines
478 //
479
480 pub type FileName = String;
481
482 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
483 pub struct LineInfo {
484 /// Index of line, starting from 0.
485 pub line_index: usize,
486
487 /// Column in line where span begins, starting from 0.
488 pub start_col: CharPos,
489
490 /// Column in line where span ends, starting from 0, exclusive.
491 pub end_col: CharPos,
492 }
493
494 pub struct FileLines {
495 pub file: Rc<FileMap>,
496 pub lines: Vec<LineInfo>
497 }
498
499 /// Identifies an offset of a multi-byte character in a FileMap
500 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Eq, PartialEq)]
501 pub struct MultiByteChar {
502 /// The absolute offset of the character in the CodeMap
503 pub pos: BytePos,
504 /// The number of bytes, >=2
505 pub bytes: usize,
506 }
507
508 /// A single source in the CodeMap.
509 pub struct FileMap {
510 /// The name of the file that the source came from, source that doesn't
511 /// originate from files has names between angle brackets by convention,
512 /// e.g. `<anon>`
513 pub name: FileName,
514 /// The complete source code
515 pub src: Option<Rc<String>>,
516 /// The start position of this source in the CodeMap
517 pub start_pos: BytePos,
518 /// The end position of this source in the CodeMap
519 pub end_pos: BytePos,
520 /// Locations of lines beginnings in the source code
521 pub lines: RefCell<Vec<BytePos>>,
522 /// Locations of multi-byte characters in the source code
523 pub multibyte_chars: RefCell<Vec<MultiByteChar>>,
524 }
525
526 impl Encodable for FileMap {
527 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
528 s.emit_struct("FileMap", 5, |s| {
529 s.emit_struct_field("name", 0, |s| self.name.encode(s))?;
530 s.emit_struct_field("start_pos", 1, |s| self.start_pos.encode(s))?;
531 s.emit_struct_field("end_pos", 2, |s| self.end_pos.encode(s))?;
532 s.emit_struct_field("lines", 3, |s| {
533 let lines = self.lines.borrow();
534 // store the length
535 s.emit_u32(lines.len() as u32)?;
536
537 if !lines.is_empty() {
538 // In order to preserve some space, we exploit the fact that
539 // the lines list is sorted and individual lines are
540 // probably not that long. Because of that we can store lines
541 // as a difference list, using as little space as possible
542 // for the differences.
543 let max_line_length = if lines.len() == 1 {
544 0
545 } else {
546 lines.windows(2)
547 .map(|w| w[1] - w[0])
548 .map(|bp| bp.to_usize())
549 .max()
550 .unwrap()
551 };
552
553 let bytes_per_diff: u8 = match max_line_length {
554 0 ... 0xFF => 1,
555 0x100 ... 0xFFFF => 2,
556 _ => 4
557 };
558
559 // Encode the number of bytes used per diff.
560 bytes_per_diff.encode(s)?;
561
562 // Encode the first element.
563 lines[0].encode(s)?;
564
565 let diff_iter = (&lines[..]).windows(2)
566 .map(|w| (w[1] - w[0]));
567
568 match bytes_per_diff {
569 1 => for diff in diff_iter { (diff.0 as u8).encode(s)? },
570 2 => for diff in diff_iter { (diff.0 as u16).encode(s)? },
571 4 => for diff in diff_iter { diff.0.encode(s)? },
572 _ => unreachable!()
573 }
574 }
575
576 Ok(())
577 })?;
578 s.emit_struct_field("multibyte_chars", 4, |s| {
579 (*self.multibyte_chars.borrow()).encode(s)
580 })
581 })
582 }
583 }
584
585 impl Decodable for FileMap {
586 fn decode<D: Decoder>(d: &mut D) -> Result<FileMap, D::Error> {
587
588 d.read_struct("FileMap", 5, |d| {
589 let name: String = d.read_struct_field("name", 0, |d| Decodable::decode(d))?;
590 let start_pos: BytePos = d.read_struct_field("start_pos", 1, |d| Decodable::decode(d))?;
591 let end_pos: BytePos = d.read_struct_field("end_pos", 2, |d| Decodable::decode(d))?;
592 let lines: Vec<BytePos> = d.read_struct_field("lines", 3, |d| {
593 let num_lines: u32 = Decodable::decode(d)?;
594 let mut lines = Vec::with_capacity(num_lines as usize);
595
596 if num_lines > 0 {
597 // Read the number of bytes used per diff.
598 let bytes_per_diff: u8 = Decodable::decode(d)?;
599
600 // Read the first element.
601 let mut line_start: BytePos = Decodable::decode(d)?;
602 lines.push(line_start);
603
604 for _ in 1..num_lines {
605 let diff = match bytes_per_diff {
606 1 => d.read_u8()? as u32,
607 2 => d.read_u16()? as u32,
608 4 => d.read_u32()?,
609 _ => unreachable!()
610 };
611
612 line_start = line_start + BytePos(diff);
613
614 lines.push(line_start);
615 }
616 }
617
618 Ok(lines)
619 })?;
620 let multibyte_chars: Vec<MultiByteChar> =
621 d.read_struct_field("multibyte_chars", 4, |d| Decodable::decode(d))?;
622 Ok(FileMap {
623 name: name,
624 start_pos: start_pos,
625 end_pos: end_pos,
626 src: None,
627 lines: RefCell::new(lines),
628 multibyte_chars: RefCell::new(multibyte_chars)
629 })
630 })
631 }
632 }
633
634 impl fmt::Debug for FileMap {
635 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
636 write!(fmt, "FileMap({})", self.name)
637 }
638 }
639
640 impl FileMap {
641 /// EFFECT: register a start-of-line offset in the
642 /// table of line-beginnings.
643 /// UNCHECKED INVARIANT: these offsets must be added in the right
644 /// order and must be in the right places; there is shared knowledge
645 /// about what ends a line between this file and parse.rs
646 /// WARNING: pos param here is the offset relative to start of CodeMap,
647 /// and CodeMap will append a newline when adding a filemap without a newline at the end,
648 /// so the safe way to call this is with value calculated as
649 /// filemap.start_pos + newline_offset_relative_to_the_start_of_filemap.
650 pub fn next_line(&self, pos: BytePos) {
651 // the new charpos must be > the last one (or it's the first one).
652 let mut lines = self.lines.borrow_mut();
653 let line_len = lines.len();
654 assert!(line_len == 0 || ((*lines)[line_len - 1] < pos));
655 lines.push(pos);
656 }
657
658 /// get a line from the list of pre-computed line-beginnings.
659 /// line-number here is 0-based.
660 pub fn get_line(&self, line_number: usize) -> Option<&str> {
661 match self.src {
662 Some(ref src) => {
663 let lines = self.lines.borrow();
664 lines.get(line_number).map(|&line| {
665 let begin: BytePos = line - self.start_pos;
666 let begin = begin.to_usize();
667 // We can't use `lines.get(line_number+1)` because we might
668 // be parsing when we call this function and thus the current
669 // line is the last one we have line info for.
670 let slice = &src[begin..];
671 match slice.find('\n') {
672 Some(e) => &slice[..e],
673 None => slice
674 }
675 })
676 }
677 None => None
678 }
679 }
680
681 pub fn record_multibyte_char(&self, pos: BytePos, bytes: usize) {
682 assert!(bytes >=2 && bytes <= 4);
683 let mbc = MultiByteChar {
684 pos: pos,
685 bytes: bytes,
686 };
687 self.multibyte_chars.borrow_mut().push(mbc);
688 }
689
690 pub fn is_real_file(&self) -> bool {
691 !(self.name.starts_with("<") &&
692 self.name.ends_with(">"))
693 }
694
695 pub fn is_imported(&self) -> bool {
696 self.src.is_none()
697 }
698
699 fn count_lines(&self) -> usize {
700 self.lines.borrow().len()
701 }
702 }
703
704 /// An abstraction over the fs operations used by the Parser.
705 pub trait FileLoader {
706 /// Query the existence of a file.
707 fn file_exists(&self, path: &Path) -> bool;
708
709 /// Read the contents of an UTF-8 file into memory.
710 fn read_file(&self, path: &Path) -> io::Result<String>;
711 }
712
713 /// A FileLoader that uses std::fs to load real files.
714 pub struct RealFileLoader;
715
716 impl FileLoader for RealFileLoader {
717 fn file_exists(&self, path: &Path) -> bool {
718 fs::metadata(path).is_ok()
719 }
720
721 fn read_file(&self, path: &Path) -> io::Result<String> {
722 let mut src = String::new();
723 fs::File::open(path)?.read_to_string(&mut src)?;
724 Ok(src)
725 }
726 }
727
728 // _____________________________________________________________________________
729 // CodeMap
730 //
731
732 pub struct CodeMap {
733 pub files: RefCell<Vec<Rc<FileMap>>>,
734 expansions: RefCell<Vec<ExpnInfo>>,
735 file_loader: Box<FileLoader>
736 }
737
738 impl CodeMap {
739 pub fn new() -> CodeMap {
740 CodeMap {
741 files: RefCell::new(Vec::new()),
742 expansions: RefCell::new(Vec::new()),
743 file_loader: Box::new(RealFileLoader)
744 }
745 }
746
747 pub fn with_file_loader(file_loader: Box<FileLoader>) -> CodeMap {
748 CodeMap {
749 files: RefCell::new(Vec::new()),
750 expansions: RefCell::new(Vec::new()),
751 file_loader: file_loader
752 }
753 }
754
755 pub fn file_exists(&self, path: &Path) -> bool {
756 self.file_loader.file_exists(path)
757 }
758
759 pub fn load_file(&self, path: &Path) -> io::Result<Rc<FileMap>> {
760 let src = self.file_loader.read_file(path)?;
761 Ok(self.new_filemap(path.to_str().unwrap().to_string(), src))
762 }
763
764 fn next_start_pos(&self) -> usize {
765 let files = self.files.borrow();
766 match files.last() {
767 None => 0,
768 // Add one so there is some space between files. This lets us distinguish
769 // positions in the codemap, even in the presence of zero-length files.
770 Some(last) => last.end_pos.to_usize() + 1,
771 }
772 }
773
774 /// Creates a new filemap without setting its line information. If you don't
775 /// intend to set the line information yourself, you should use new_filemap_and_lines.
776 pub fn new_filemap(&self, filename: FileName, mut src: String) -> Rc<FileMap> {
777 let start_pos = self.next_start_pos();
778 let mut files = self.files.borrow_mut();
779
780 // Remove utf-8 BOM if any.
781 if src.starts_with("\u{feff}") {
782 src.drain(..3);
783 }
784
785 let end_pos = start_pos + src.len();
786
787 let filemap = Rc::new(FileMap {
788 name: filename,
789 src: Some(Rc::new(src)),
790 start_pos: Pos::from_usize(start_pos),
791 end_pos: Pos::from_usize(end_pos),
792 lines: RefCell::new(Vec::new()),
793 multibyte_chars: RefCell::new(Vec::new()),
794 });
795
796 files.push(filemap.clone());
797
798 filemap
799 }
800
801 /// Creates a new filemap and sets its line information.
802 pub fn new_filemap_and_lines(&self, filename: &str, src: &str) -> Rc<FileMap> {
803 let fm = self.new_filemap(filename.to_string(), src.to_owned());
804 let mut byte_pos: u32 = 0;
805 for line in src.lines() {
806 // register the start of this line
807 fm.next_line(BytePos(byte_pos));
808
809 // update byte_pos to include this line and the \n at the end
810 byte_pos += line.len() as u32 + 1;
811 }
812 fm
813 }
814
815
816 /// Allocates a new FileMap representing a source file from an external
817 /// crate. The source code of such an "imported filemap" is not available,
818 /// but we still know enough to generate accurate debuginfo location
819 /// information for things inlined from other crates.
820 pub fn new_imported_filemap(&self,
821 filename: FileName,
822 source_len: usize,
823 mut file_local_lines: Vec<BytePos>,
824 mut file_local_multibyte_chars: Vec<MultiByteChar>)
825 -> Rc<FileMap> {
826 let start_pos = self.next_start_pos();
827 let mut files = self.files.borrow_mut();
828
829 let end_pos = Pos::from_usize(start_pos + source_len);
830 let start_pos = Pos::from_usize(start_pos);
831
832 for pos in &mut file_local_lines {
833 *pos = *pos + start_pos;
834 }
835
836 for mbc in &mut file_local_multibyte_chars {
837 mbc.pos = mbc.pos + start_pos;
838 }
839
840 let filemap = Rc::new(FileMap {
841 name: filename,
842 src: None,
843 start_pos: start_pos,
844 end_pos: end_pos,
845 lines: RefCell::new(file_local_lines),
846 multibyte_chars: RefCell::new(file_local_multibyte_chars),
847 });
848
849 files.push(filemap.clone());
850
851 filemap
852 }
853
854 pub fn mk_substr_filename(&self, sp: Span) -> String {
855 let pos = self.lookup_char_pos(sp.lo);
856 (format!("<{}:{}:{}>",
857 pos.file.name,
858 pos.line,
859 pos.col.to_usize() + 1)).to_string()
860 }
861
862 /// Lookup source information about a BytePos
863 pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
864 let chpos = self.bytepos_to_file_charpos(pos);
865 match self.lookup_line(pos) {
866 Ok(FileMapAndLine { fm: f, line: a }) => {
867 let line = a + 1; // Line numbers start at 1
868 let linebpos = (*f.lines.borrow())[a];
869 let linechpos = self.bytepos_to_file_charpos(linebpos);
870 debug!("byte pos {:?} is on the line at byte pos {:?}",
871 pos, linebpos);
872 debug!("char pos {:?} is on the line at char pos {:?}",
873 chpos, linechpos);
874 debug!("byte is on line: {}", line);
875 assert!(chpos >= linechpos);
876 Loc {
877 file: f,
878 line: line,
879 col: chpos - linechpos,
880 }
881 }
882 Err(f) => {
883 Loc {
884 file: f,
885 line: 0,
886 col: chpos,
887 }
888 }
889 }
890 }
891
892 // If the relevant filemap is empty, we don't return a line number.
893 fn lookup_line(&self, pos: BytePos) -> Result<FileMapAndLine, Rc<FileMap>> {
894 let idx = self.lookup_filemap_idx(pos);
895
896 let files = self.files.borrow();
897 let f = (*files)[idx].clone();
898
899 let len = f.lines.borrow().len();
900 if len == 0 {
901 return Err(f);
902 }
903
904 let mut a = 0;
905 {
906 let lines = f.lines.borrow();
907 let mut b = lines.len();
908 while b - a > 1 {
909 let m = (a + b) / 2;
910 if (*lines)[m] > pos {
911 b = m;
912 } else {
913 a = m;
914 }
915 }
916 assert!(a <= lines.len());
917 }
918 Ok(FileMapAndLine { fm: f, line: a })
919 }
920
921 pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
922 let loc = self.lookup_char_pos(pos);
923 LocWithOpt {
924 filename: loc.file.name.to_string(),
925 line: loc.line,
926 col: loc.col,
927 file: Some(loc.file)
928 }
929 }
930
931 pub fn span_to_string(&self, sp: Span) -> String {
932 if self.files.borrow().is_empty() && sp.source_equal(&DUMMY_SP) {
933 return "no-location".to_string();
934 }
935
936 let lo = self.lookup_char_pos_adj(sp.lo);
937 let hi = self.lookup_char_pos_adj(sp.hi);
938 return (format!("{}:{}:{}: {}:{}",
939 lo.filename,
940 lo.line,
941 lo.col.to_usize() + 1,
942 hi.line,
943 hi.col.to_usize() + 1)).to_string()
944 }
945
946 // Returns true if two spans have the same callee
947 // (Assumes the same ExpnFormat implies same callee)
948 fn match_callees(&self, sp_a: &Span, sp_b: &Span) -> bool {
949 let fmt_a = self
950 .with_expn_info(sp_a.expn_id,
951 |ei| ei.map(|ei| ei.callee.format.clone()));
952
953 let fmt_b = self
954 .with_expn_info(sp_b.expn_id,
955 |ei| ei.map(|ei| ei.callee.format.clone()));
956 fmt_a == fmt_b
957 }
958
959 /// Returns a formatted string showing the expansion chain of a span
960 ///
961 /// Spans are printed in the following format:
962 ///
963 /// filename:start_line:col: end_line:col
964 /// snippet
965 /// Callee:
966 /// Callee span
967 /// Callsite:
968 /// Callsite span
969 ///
970 /// Callees and callsites are printed recursively (if available, otherwise header
971 /// and span is omitted), expanding into their own callee/callsite spans.
972 /// Each layer of recursion has an increased indent, and snippets are truncated
973 /// to at most 50 characters. Finally, recursive calls to the same macro are squashed,
974 /// with '...' used to represent any number of recursive calls.
975 pub fn span_to_expanded_string(&self, sp: Span) -> String {
976 self.span_to_expanded_string_internal(sp, "")
977 }
978
979 fn span_to_expanded_string_internal(&self, sp:Span, indent: &str) -> String {
980 let mut indent = indent.to_owned();
981 let mut output = "".to_owned();
982 let span_str = self.span_to_string(sp);
983 let mut span_snip = self.span_to_snippet(sp)
984 .unwrap_or("Snippet unavailable".to_owned());
985
986 // Truncate by code points - in worst case this will be more than 50 characters,
987 // but ensures at least 50 characters and respects byte boundaries.
988 let char_vec: Vec<(usize, char)> = span_snip.char_indices().collect();
989 if char_vec.len() > 50 {
990 span_snip.truncate(char_vec[49].0);
991 span_snip.push_str("...");
992 }
993
994 output.push_str(&format!("{}{}\n{}`{}`\n", indent, span_str, indent, span_snip));
995
996 if sp.expn_id == NO_EXPANSION || sp.expn_id == COMMAND_LINE_EXPN {
997 return output;
998 }
999
1000 let mut callee = self.with_expn_info(sp.expn_id,
1001 |ei| ei.and_then(|ei| ei.callee.span.clone()));
1002 let mut callsite = self.with_expn_info(sp.expn_id,
1003 |ei| ei.map(|ei| ei.call_site.clone()));
1004
1005 indent.push_str(" ");
1006 let mut is_recursive = false;
1007
1008 while callee.is_some() && self.match_callees(&sp, &callee.unwrap()) {
1009 callee = self.with_expn_info(callee.unwrap().expn_id,
1010 |ei| ei.and_then(|ei| ei.callee.span.clone()));
1011 is_recursive = true;
1012 }
1013 if let Some(span) = callee {
1014 output.push_str(&indent);
1015 output.push_str("Callee:\n");
1016 if is_recursive {
1017 output.push_str(&indent);
1018 output.push_str("...\n");
1019 }
1020 output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
1021 }
1022
1023 is_recursive = false;
1024 while callsite.is_some() && self.match_callees(&sp, &callsite.unwrap()) {
1025 callsite = self.with_expn_info(callsite.unwrap().expn_id,
1026 |ei| ei.map(|ei| ei.call_site.clone()));
1027 is_recursive = true;
1028 }
1029 if let Some(span) = callsite {
1030 output.push_str(&indent);
1031 output.push_str("Callsite:\n");
1032 if is_recursive {
1033 output.push_str(&indent);
1034 output.push_str("...\n");
1035 }
1036 output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
1037 }
1038 output
1039 }
1040
1041 /// Return the source span - this is either the supplied span, or the span for
1042 /// the macro callsite that expanded to it.
1043 pub fn source_callsite(&self, sp: Span) -> Span {
1044 let mut span = sp;
1045 // Special case - if a macro is parsed as an argument to another macro, the source
1046 // callsite is the first callsite, which is also source-equivalent to the span.
1047 let mut first = true;
1048 while span.expn_id != NO_EXPANSION && span.expn_id != COMMAND_LINE_EXPN {
1049 if let Some(callsite) = self.with_expn_info(span.expn_id,
1050 |ei| ei.map(|ei| ei.call_site.clone())) {
1051 if first && span.source_equal(&callsite) {
1052 if self.lookup_char_pos(span.lo).file.is_real_file() {
1053 return Span { expn_id: NO_EXPANSION, .. span };
1054 }
1055 }
1056 first = false;
1057 span = callsite;
1058 }
1059 else {
1060 break;
1061 }
1062 }
1063 span
1064 }
1065
1066 /// Return the source callee.
1067 ///
1068 /// Returns None if the supplied span has no expansion trace,
1069 /// else returns the NameAndSpan for the macro definition
1070 /// corresponding to the source callsite.
1071 pub fn source_callee(&self, sp: Span) -> Option<NameAndSpan> {
1072 let mut span = sp;
1073 // Special case - if a macro is parsed as an argument to another macro, the source
1074 // callsite is source-equivalent to the span, and the source callee is the first callee.
1075 let mut first = true;
1076 while let Some(callsite) = self.with_expn_info(span.expn_id,
1077 |ei| ei.map(|ei| ei.call_site.clone())) {
1078 if first && span.source_equal(&callsite) {
1079 if self.lookup_char_pos(span.lo).file.is_real_file() {
1080 return self.with_expn_info(span.expn_id,
1081 |ei| ei.map(|ei| ei.callee.clone()));
1082 }
1083 }
1084 first = false;
1085 if let Some(_) = self.with_expn_info(callsite.expn_id,
1086 |ei| ei.map(|ei| ei.call_site.clone())) {
1087 span = callsite;
1088 }
1089 else {
1090 return self.with_expn_info(span.expn_id,
1091 |ei| ei.map(|ei| ei.callee.clone()));
1092 }
1093 }
1094 None
1095 }
1096
1097 pub fn span_to_filename(&self, sp: Span) -> FileName {
1098 self.lookup_char_pos(sp.lo).file.name.to_string()
1099 }
1100
1101 pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
1102 if sp.lo > sp.hi {
1103 return Err(SpanLinesError::IllFormedSpan(sp));
1104 }
1105
1106 let lo = self.lookup_char_pos(sp.lo);
1107 let hi = self.lookup_char_pos(sp.hi);
1108
1109 if lo.file.start_pos != hi.file.start_pos {
1110 return Err(SpanLinesError::DistinctSources(DistinctSources {
1111 begin: (lo.file.name.clone(), lo.file.start_pos),
1112 end: (hi.file.name.clone(), hi.file.start_pos),
1113 }));
1114 }
1115 assert!(hi.line >= lo.line);
1116
1117 let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
1118
1119 // The span starts partway through the first line,
1120 // but after that it starts from offset 0.
1121 let mut start_col = lo.col;
1122
1123 // For every line but the last, it extends from `start_col`
1124 // and to the end of the line. Be careful because the line
1125 // numbers in Loc are 1-based, so we subtract 1 to get 0-based
1126 // lines.
1127 for line_index in lo.line-1 .. hi.line-1 {
1128 let line_len = lo.file.get_line(line_index).map(|s| s.len()).unwrap_or(0);
1129 lines.push(LineInfo { line_index: line_index,
1130 start_col: start_col,
1131 end_col: CharPos::from_usize(line_len) });
1132 start_col = CharPos::from_usize(0);
1133 }
1134
1135 // For the last line, it extends from `start_col` to `hi.col`:
1136 lines.push(LineInfo { line_index: hi.line - 1,
1137 start_col: start_col,
1138 end_col: hi.col });
1139
1140 Ok(FileLines {file: lo.file, lines: lines})
1141 }
1142
1143 pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
1144 if sp.lo > sp.hi {
1145 return Err(SpanSnippetError::IllFormedSpan(sp));
1146 }
1147
1148 let local_begin = self.lookup_byte_offset(sp.lo);
1149 let local_end = self.lookup_byte_offset(sp.hi);
1150
1151 if local_begin.fm.start_pos != local_end.fm.start_pos {
1152 return Err(SpanSnippetError::DistinctSources(DistinctSources {
1153 begin: (local_begin.fm.name.clone(),
1154 local_begin.fm.start_pos),
1155 end: (local_end.fm.name.clone(),
1156 local_end.fm.start_pos)
1157 }));
1158 } else {
1159 match local_begin.fm.src {
1160 Some(ref src) => {
1161 let start_index = local_begin.pos.to_usize();
1162 let end_index = local_end.pos.to_usize();
1163 let source_len = (local_begin.fm.end_pos -
1164 local_begin.fm.start_pos).to_usize();
1165
1166 if start_index > end_index || end_index > source_len {
1167 return Err(SpanSnippetError::MalformedForCodemap(
1168 MalformedCodemapPositions {
1169 name: local_begin.fm.name.clone(),
1170 source_len: source_len,
1171 begin_pos: local_begin.pos,
1172 end_pos: local_end.pos,
1173 }));
1174 }
1175
1176 return Ok((&src[start_index..end_index]).to_string())
1177 }
1178 None => {
1179 return Err(SpanSnippetError::SourceNotAvailable {
1180 filename: local_begin.fm.name.clone()
1181 });
1182 }
1183 }
1184 }
1185 }
1186
1187 /// Groups and sorts spans by lines into `MultiSpan`s, where `push` adds them to their group,
1188 /// specifying the unification behaviour for overlapping spans.
1189 /// Spans overflowing a line are put into their own one-element-group.
1190 pub fn custom_group_spans<F>(&self, mut spans: Vec<Span>, push: F) -> Vec<MultiSpan>
1191 where F: Fn(&mut MultiSpan, Span)
1192 {
1193 spans.sort_by(|a, b| a.lo.cmp(&b.lo));
1194 let mut groups = Vec::<MultiSpan>::new();
1195 let mut overflowing = vec![];
1196 let mut prev_expn = ExpnId(!2u32);
1197 let mut prev_file = !0usize;
1198 let mut prev_line = !0usize;
1199 let mut err_size = 0;
1200
1201 for sp in spans {
1202 let line = self.lookup_char_pos(sp.lo).line;
1203 let line_hi = self.lookup_char_pos(sp.hi).line;
1204 if line != line_hi {
1205 overflowing.push(sp.into());
1206 continue
1207 }
1208 let file = self.lookup_filemap_idx(sp.lo);
1209
1210 if err_size < MAX_HIGHLIGHT_LINES && sp.expn_id == prev_expn && file == prev_file {
1211 // `push` takes care of sorting, trimming, and merging
1212 push(&mut groups.last_mut().unwrap(), sp);
1213 if line != prev_line {
1214 err_size += 1;
1215 }
1216 } else {
1217 groups.push(sp.into());
1218 err_size = 1;
1219 }
1220 prev_expn = sp.expn_id;
1221 prev_file = file;
1222 prev_line = line;
1223 }
1224 groups.extend(overflowing);
1225 groups
1226 }
1227
1228 /// Groups and sorts spans by lines into `MultiSpan`s, merging overlapping spans.
1229 /// Spans overflowing a line are put into their own one-element-group.
1230 pub fn group_spans(&self, spans: Vec<Span>) -> Vec<MultiSpan> {
1231 self.custom_group_spans(spans, |msp, sp| msp.push_merge(sp))
1232 }
1233
1234 /// Like `group_spans`, but trims overlapping spans instead of
1235 /// merging them (for use with `end_highlight_lines`)
1236 pub fn end_group_spans(&self, spans: Vec<Span>) -> Vec<MultiSpan> {
1237 self.custom_group_spans(spans, |msp, sp| msp.push_trim(sp))
1238 }
1239
1240 pub fn get_filemap(&self, filename: &str) -> Rc<FileMap> {
1241 for fm in self.files.borrow().iter() {
1242 if filename == fm.name {
1243 return fm.clone();
1244 }
1245 }
1246 panic!("asking for {} which we don't know about", filename);
1247 }
1248
1249 /// For a global BytePos compute the local offset within the containing FileMap
1250 pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
1251 let idx = self.lookup_filemap_idx(bpos);
1252 let fm = (*self.files.borrow())[idx].clone();
1253 let offset = bpos - fm.start_pos;
1254 FileMapAndBytePos {fm: fm, pos: offset}
1255 }
1256
1257 /// Converts an absolute BytePos to a CharPos relative to the filemap.
1258 pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
1259 let idx = self.lookup_filemap_idx(bpos);
1260 let files = self.files.borrow();
1261 let map = &(*files)[idx];
1262
1263 // The number of extra bytes due to multibyte chars in the FileMap
1264 let mut total_extra_bytes = 0;
1265
1266 for mbc in map.multibyte_chars.borrow().iter() {
1267 debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos);
1268 if mbc.pos < bpos {
1269 // every character is at least one byte, so we only
1270 // count the actual extra bytes.
1271 total_extra_bytes += mbc.bytes - 1;
1272 // We should never see a byte position in the middle of a
1273 // character
1274 assert!(bpos.to_usize() >= mbc.pos.to_usize() + mbc.bytes);
1275 } else {
1276 break;
1277 }
1278 }
1279
1280 assert!(map.start_pos.to_usize() + total_extra_bytes <= bpos.to_usize());
1281 CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes)
1282 }
1283
1284 // Return the index of the filemap (in self.files) which contains pos.
1285 fn lookup_filemap_idx(&self, pos: BytePos) -> usize {
1286 let files = self.files.borrow();
1287 let files = &*files;
1288 let count = files.len();
1289
1290 // Binary search for the filemap.
1291 let mut a = 0;
1292 let mut b = count;
1293 while b - a > 1 {
1294 let m = (a + b) / 2;
1295 if files[m].start_pos > pos {
1296 b = m;
1297 } else {
1298 a = m;
1299 }
1300 }
1301
1302 assert!(a < count, "position {} does not resolve to a source location", pos.to_usize());
1303
1304 return a;
1305 }
1306
1307 /// Check if the backtrace `subtrace` contains `suptrace` as a prefix.
1308 pub fn more_specific_trace(&self,
1309 mut subtrace: ExpnId,
1310 suptrace: ExpnId)
1311 -> bool {
1312 loop {
1313 if subtrace == suptrace {
1314 return true;
1315 }
1316
1317 let stop = self.with_expn_info(subtrace, |opt_expn_info| {
1318 if let Some(expn_info) = opt_expn_info {
1319 subtrace = expn_info.call_site.expn_id;
1320 false
1321 } else {
1322 true
1323 }
1324 });
1325
1326 if stop {
1327 return false;
1328 }
1329 }
1330 }
1331
1332 pub fn record_expansion(&self, expn_info: ExpnInfo) -> ExpnId {
1333 let mut expansions = self.expansions.borrow_mut();
1334 expansions.push(expn_info);
1335 let len = expansions.len();
1336 if len > u32::max_value() as usize {
1337 panic!("too many ExpnInfo's!");
1338 }
1339 ExpnId(len as u32 - 1)
1340 }
1341
1342 pub fn with_expn_info<T, F>(&self, id: ExpnId, f: F) -> T where
1343 F: FnOnce(Option<&ExpnInfo>) -> T,
1344 {
1345 match id {
1346 NO_EXPANSION | COMMAND_LINE_EXPN => f(None),
1347 ExpnId(i) => f(Some(&(*self.expansions.borrow())[i as usize]))
1348 }
1349 }
1350
1351 /// Check if a span is "internal" to a macro in which #[unstable]
1352 /// items can be used (that is, a macro marked with
1353 /// `#[allow_internal_unstable]`).
1354 pub fn span_allows_unstable(&self, span: Span) -> bool {
1355 debug!("span_allows_unstable(span = {:?})", span);
1356 let mut allows_unstable = false;
1357 let mut expn_id = span.expn_id;
1358 loop {
1359 let quit = self.with_expn_info(expn_id, |expninfo| {
1360 debug!("span_allows_unstable: expninfo = {:?}", expninfo);
1361 expninfo.map_or(/* hit the top level */ true, |info| {
1362
1363 let span_comes_from_this_expansion =
1364 info.callee.span.map_or(span.source_equal(&info.call_site), |mac_span| {
1365 mac_span.contains(span)
1366 });
1367
1368 debug!("span_allows_unstable: span: {:?} call_site: {:?} callee: {:?}",
1369 (span.lo, span.hi),
1370 (info.call_site.lo, info.call_site.hi),
1371 info.callee.span.map(|x| (x.lo, x.hi)));
1372 debug!("span_allows_unstable: from this expansion? {}, allows unstable? {}",
1373 span_comes_from_this_expansion,
1374 info.callee.allow_internal_unstable);
1375 if span_comes_from_this_expansion {
1376 allows_unstable = info.callee.allow_internal_unstable;
1377 // we've found the right place, stop looking
1378 true
1379 } else {
1380 // not the right place, keep looking
1381 expn_id = info.call_site.expn_id;
1382 false
1383 }
1384 })
1385 });
1386 if quit {
1387 break
1388 }
1389 }
1390 debug!("span_allows_unstable? {}", allows_unstable);
1391 allows_unstable
1392 }
1393
1394 pub fn count_lines(&self) -> usize {
1395 self.files.borrow().iter().fold(0, |a, f| a + f.count_lines())
1396 }
1397 }
1398
1399 // _____________________________________________________________________________
1400 // SpanLinesError, SpanSnippetError, DistinctSources, MalformedCodemapPositions
1401 //
1402
1403 pub type FileLinesResult = Result<FileLines, SpanLinesError>;
1404
1405 #[derive(Clone, PartialEq, Eq, Debug)]
1406 pub enum SpanLinesError {
1407 IllFormedSpan(Span),
1408 DistinctSources(DistinctSources),
1409 }
1410
1411 #[derive(Clone, PartialEq, Eq, Debug)]
1412 pub enum SpanSnippetError {
1413 IllFormedSpan(Span),
1414 DistinctSources(DistinctSources),
1415 MalformedForCodemap(MalformedCodemapPositions),
1416 SourceNotAvailable { filename: String }
1417 }
1418
1419 #[derive(Clone, PartialEq, Eq, Debug)]
1420 pub struct DistinctSources {
1421 begin: (String, BytePos),
1422 end: (String, BytePos)
1423 }
1424
1425 #[derive(Clone, PartialEq, Eq, Debug)]
1426 pub struct MalformedCodemapPositions {
1427 name: String,
1428 source_len: usize,
1429 begin_pos: BytePos,
1430 end_pos: BytePos
1431 }
1432
1433
1434 // _____________________________________________________________________________
1435 // Tests
1436 //
1437
1438 #[cfg(test)]
1439 mod tests {
1440 use super::*;
1441
1442 #[test]
1443 fn t1 () {
1444 let cm = CodeMap::new();
1445 let fm = cm.new_filemap("blork.rs".to_string(),
1446 "first line.\nsecond line".to_string());
1447 fm.next_line(BytePos(0));
1448 // Test we can get lines with partial line info.
1449 assert_eq!(fm.get_line(0), Some("first line."));
1450 // TESTING BROKEN BEHAVIOR: line break declared before actual line break.
1451 fm.next_line(BytePos(10));
1452 assert_eq!(fm.get_line(1), Some("."));
1453 fm.next_line(BytePos(12));
1454 assert_eq!(fm.get_line(2), Some("second line"));
1455 }
1456
1457 #[test]
1458 #[should_panic]
1459 fn t2 () {
1460 let cm = CodeMap::new();
1461 let fm = cm.new_filemap("blork.rs".to_string(),
1462 "first line.\nsecond line".to_string());
1463 // TESTING *REALLY* BROKEN BEHAVIOR:
1464 fm.next_line(BytePos(0));
1465 fm.next_line(BytePos(10));
1466 fm.next_line(BytePos(2));
1467 }
1468
1469 fn init_code_map() -> CodeMap {
1470 let cm = CodeMap::new();
1471 let fm1 = cm.new_filemap("blork.rs".to_string(),
1472 "first line.\nsecond line".to_string());
1473 let fm2 = cm.new_filemap("empty.rs".to_string(),
1474 "".to_string());
1475 let fm3 = cm.new_filemap("blork2.rs".to_string(),
1476 "first line.\nsecond line".to_string());
1477
1478 fm1.next_line(BytePos(0));
1479 fm1.next_line(BytePos(12));
1480 fm2.next_line(fm2.start_pos);
1481 fm3.next_line(fm3.start_pos);
1482 fm3.next_line(fm3.start_pos + BytePos(12));
1483
1484 cm
1485 }
1486
1487 #[test]
1488 fn t3() {
1489 // Test lookup_byte_offset
1490 let cm = init_code_map();
1491
1492 let fmabp1 = cm.lookup_byte_offset(BytePos(23));
1493 assert_eq!(fmabp1.fm.name, "blork.rs");
1494 assert_eq!(fmabp1.pos, BytePos(23));
1495
1496 let fmabp1 = cm.lookup_byte_offset(BytePos(24));
1497 assert_eq!(fmabp1.fm.name, "empty.rs");
1498 assert_eq!(fmabp1.pos, BytePos(0));
1499
1500 let fmabp2 = cm.lookup_byte_offset(BytePos(25));
1501 assert_eq!(fmabp2.fm.name, "blork2.rs");
1502 assert_eq!(fmabp2.pos, BytePos(0));
1503 }
1504
1505 #[test]
1506 fn t4() {
1507 // Test bytepos_to_file_charpos
1508 let cm = init_code_map();
1509
1510 let cp1 = cm.bytepos_to_file_charpos(BytePos(22));
1511 assert_eq!(cp1, CharPos(22));
1512
1513 let cp2 = cm.bytepos_to_file_charpos(BytePos(25));
1514 assert_eq!(cp2, CharPos(0));
1515 }
1516
1517 #[test]
1518 fn t5() {
1519 // Test zero-length filemaps.
1520 let cm = init_code_map();
1521
1522 let loc1 = cm.lookup_char_pos(BytePos(22));
1523 assert_eq!(loc1.file.name, "blork.rs");
1524 assert_eq!(loc1.line, 2);
1525 assert_eq!(loc1.col, CharPos(10));
1526
1527 let loc2 = cm.lookup_char_pos(BytePos(25));
1528 assert_eq!(loc2.file.name, "blork2.rs");
1529 assert_eq!(loc2.line, 1);
1530 assert_eq!(loc2.col, CharPos(0));
1531 }
1532
1533 fn init_code_map_mbc() -> CodeMap {
1534 let cm = CodeMap::new();
1535 // € is a three byte utf8 char.
1536 let fm1 =
1537 cm.new_filemap("blork.rs".to_string(),
1538 "fir€st €€€€ line.\nsecond line".to_string());
1539 let fm2 = cm.new_filemap("blork2.rs".to_string(),
1540 "first line€€.\n€ second line".to_string());
1541
1542 fm1.next_line(BytePos(0));
1543 fm1.next_line(BytePos(28));
1544 fm2.next_line(fm2.start_pos);
1545 fm2.next_line(fm2.start_pos + BytePos(20));
1546
1547 fm1.record_multibyte_char(BytePos(3), 3);
1548 fm1.record_multibyte_char(BytePos(9), 3);
1549 fm1.record_multibyte_char(BytePos(12), 3);
1550 fm1.record_multibyte_char(BytePos(15), 3);
1551 fm1.record_multibyte_char(BytePos(18), 3);
1552 fm2.record_multibyte_char(fm2.start_pos + BytePos(10), 3);
1553 fm2.record_multibyte_char(fm2.start_pos + BytePos(13), 3);
1554 fm2.record_multibyte_char(fm2.start_pos + BytePos(18), 3);
1555
1556 cm
1557 }
1558
1559 #[test]
1560 fn t6() {
1561 // Test bytepos_to_file_charpos in the presence of multi-byte chars
1562 let cm = init_code_map_mbc();
1563
1564 let cp1 = cm.bytepos_to_file_charpos(BytePos(3));
1565 assert_eq!(cp1, CharPos(3));
1566
1567 let cp2 = cm.bytepos_to_file_charpos(BytePos(6));
1568 assert_eq!(cp2, CharPos(4));
1569
1570 let cp3 = cm.bytepos_to_file_charpos(BytePos(56));
1571 assert_eq!(cp3, CharPos(12));
1572
1573 let cp4 = cm.bytepos_to_file_charpos(BytePos(61));
1574 assert_eq!(cp4, CharPos(15));
1575 }
1576
1577 #[test]
1578 fn t7() {
1579 // Test span_to_lines for a span ending at the end of filemap
1580 let cm = init_code_map();
1581 let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
1582 let file_lines = cm.span_to_lines(span).unwrap();
1583
1584 assert_eq!(file_lines.file.name, "blork.rs");
1585 assert_eq!(file_lines.lines.len(), 1);
1586 assert_eq!(file_lines.lines[0].line_index, 1);
1587 }
1588
1589 /// Given a string like " ^~~~~~~~~~~~ ", produces a span
1590 /// coverting that range. The idea is that the string has the same
1591 /// length as the input, and we uncover the byte positions. Note
1592 /// that this can span lines and so on.
1593 fn span_from_selection(input: &str, selection: &str) -> Span {
1594 assert_eq!(input.len(), selection.len());
1595 let left_index = selection.find('^').unwrap() as u32;
1596 let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
1597 Span { lo: BytePos(left_index), hi: BytePos(right_index + 1), expn_id: NO_EXPANSION }
1598 }
1599
1600 /// Test span_to_snippet and span_to_lines for a span coverting 3
1601 /// lines in the middle of a file.
1602 #[test]
1603 fn span_to_snippet_and_lines_spanning_multiple_lines() {
1604 let cm = CodeMap::new();
1605 let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
1606 let selection = " \n ^~\n~~~\n~~~~~ \n \n";
1607 cm.new_filemap_and_lines("blork.rs", inputtext);
1608 let span = span_from_selection(inputtext, selection);
1609
1610 // check that we are extracting the text we thought we were extracting
1611 assert_eq!(&cm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD");
1612
1613 // check that span_to_lines gives us the complete result with the lines/cols we expected
1614 let lines = cm.span_to_lines(span).unwrap();
1615 let expected = vec![
1616 LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) },
1617 LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) },
1618 LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) }
1619 ];
1620 assert_eq!(lines.lines, expected);
1621 }
1622
1623 #[test]
1624 fn t8() {
1625 // Test span_to_snippet for a span ending at the end of filemap
1626 let cm = init_code_map();
1627 let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
1628 let snippet = cm.span_to_snippet(span);
1629
1630 assert_eq!(snippet, Ok("second line".to_string()));
1631 }
1632
1633 #[test]
1634 fn t9() {
1635 // Test span_to_str for a span ending at the end of filemap
1636 let cm = init_code_map();
1637 let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
1638 let sstr = cm.span_to_string(span);
1639
1640 assert_eq!(sstr, "blork.rs:2:1: 2:12");
1641 }
1642
1643 #[test]
1644 fn t10() {
1645 // Test span_to_expanded_string works in base case (no expansion)
1646 let cm = init_code_map();
1647 let span = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
1648 let sstr = cm.span_to_expanded_string(span);
1649 assert_eq!(sstr, "blork.rs:1:1: 1:12\n`first line.`\n");
1650
1651 let span = Span { lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION };
1652 let sstr = cm.span_to_expanded_string(span);
1653 assert_eq!(sstr, "blork.rs:2:1: 2:12\n`second line`\n");
1654 }
1655
1656 #[test]
1657 fn t11() {
1658 // Test span_to_expanded_string works with expansion
1659 use ast::Name;
1660 let cm = init_code_map();
1661 let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
1662 let format = ExpnFormat::MacroBang(Name(0u32));
1663 let callee = NameAndSpan { format: format,
1664 allow_internal_unstable: false,
1665 span: None };
1666
1667 let info = ExpnInfo { call_site: root, callee: callee };
1668 let id = cm.record_expansion(info);
1669 let sp = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id };
1670
1671 let sstr = cm.span_to_expanded_string(sp);
1672 assert_eq!(sstr,
1673 "blork.rs:2:1: 2:12\n`second line`\n Callsite:\n \
1674 blork.rs:1:1: 1:12\n `first line.`\n");
1675 }
1676
1677 fn init_expansion_chain(cm: &CodeMap) -> Span {
1678 // Creates an expansion chain containing two recursive calls
1679 // root -> expA -> expA -> expB -> expB -> end
1680 use ast::Name;
1681
1682 let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
1683
1684 let format_root = ExpnFormat::MacroBang(Name(0u32));
1685 let callee_root = NameAndSpan { format: format_root,
1686 allow_internal_unstable: false,
1687 span: Some(root) };
1688
1689 let info_a1 = ExpnInfo { call_site: root, callee: callee_root };
1690 let id_a1 = cm.record_expansion(info_a1);
1691 let span_a1 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a1 };
1692
1693 let format_a = ExpnFormat::MacroBang(Name(1u32));
1694 let callee_a = NameAndSpan { format: format_a,
1695 allow_internal_unstable: false,
1696 span: Some(span_a1) };
1697
1698 let info_a2 = ExpnInfo { call_site: span_a1, callee: callee_a.clone() };
1699 let id_a2 = cm.record_expansion(info_a2);
1700 let span_a2 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a2 };
1701
1702 let info_b1 = ExpnInfo { call_site: span_a2, callee: callee_a };
1703 let id_b1 = cm.record_expansion(info_b1);
1704 let span_b1 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b1 };
1705
1706 let format_b = ExpnFormat::MacroBang(Name(2u32));
1707 let callee_b = NameAndSpan { format: format_b,
1708 allow_internal_unstable: false,
1709 span: None };
1710
1711 let info_b2 = ExpnInfo { call_site: span_b1, callee: callee_b.clone() };
1712 let id_b2 = cm.record_expansion(info_b2);
1713 let span_b2 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b2 };
1714
1715 let info_end = ExpnInfo { call_site: span_b2, callee: callee_b };
1716 let id_end = cm.record_expansion(info_end);
1717 Span { lo: BytePos(37), hi: BytePos(48), expn_id: id_end }
1718 }
1719
1720 #[test]
1721 fn t12() {
1722 // Test span_to_expanded_string collapses recursive macros and handles
1723 // recursive callsite and callee expansions
1724 let cm = init_code_map();
1725 let end = init_expansion_chain(&cm);
1726 let sstr = cm.span_to_expanded_string(end);
1727 let res_str =
1728 r"blork2.rs:2:1: 2:12
1729 `second line`
1730 Callsite:
1731 ...
1732 blork2.rs:1:1: 1:12
1733 `first line.`
1734 Callee:
1735 blork.rs:2:1: 2:12
1736 `second line`
1737 Callee:
1738 blork.rs:1:1: 1:12
1739 `first line.`
1740 Callsite:
1741 blork.rs:1:1: 1:12
1742 `first line.`
1743 Callsite:
1744 ...
1745 blork.rs:2:1: 2:12
1746 `second line`
1747 Callee:
1748 blork.rs:1:1: 1:12
1749 `first line.`
1750 Callsite:
1751 blork.rs:1:1: 1:12
1752 `first line.`
1753 ";
1754 assert_eq!(sstr, res_str);
1755 }
1756
1757 #[test]
1758 fn t13() {
1759 // Test that collecting multiple spans into line-groups works correctly
1760 let cm = CodeMap::new();
1761 let inp = "_aaaaa__bbb\nvv\nw\nx\ny\nz\ncccccc__ddddee__";
1762 let sp1 = " ^~~~~ \n \n \n \n \n \n ";
1763 let sp2 = " \n \n \n \n \n^\n ";
1764 let sp3 = " ^~~\n~~\n \n \n \n \n ";
1765 let sp4 = " \n \n \n \n \n \n^~~~~~ ";
1766 let sp5 = " \n \n \n \n \n \n ^~~~ ";
1767 let sp6 = " \n \n \n \n \n \n ^~~~ ";
1768 let sp_trim = " \n \n \n \n \n \n ^~ ";
1769 let sp_merge = " \n \n \n \n \n \n ^~~~~~ ";
1770 let sp7 = " \n ^\n \n \n \n \n ";
1771 let sp8 = " \n \n^\n \n \n \n ";
1772 let sp9 = " \n \n \n^\n \n \n ";
1773 let sp10 = " \n \n \n \n^\n \n ";
1774
1775 let span = |sp, expected| {
1776 let sp = span_from_selection(inp, sp);
1777 assert_eq!(&cm.span_to_snippet(sp).unwrap(), expected);
1778 sp
1779 };
1780
1781 cm.new_filemap_and_lines("blork.rs", inp);
1782 let sp1 = span(sp1, "aaaaa");
1783 let sp2 = span(sp2, "z");
1784 let sp3 = span(sp3, "bbb\nvv");
1785 let sp4 = span(sp4, "cccccc");
1786 let sp5 = span(sp5, "dddd");
1787 let sp6 = span(sp6, "ddee");
1788 let sp7 = span(sp7, "v");
1789 let sp8 = span(sp8, "w");
1790 let sp9 = span(sp9, "x");
1791 let sp10 = span(sp10, "y");
1792 let sp_trim = span(sp_trim, "ee");
1793 let sp_merge = span(sp_merge, "ddddee");
1794
1795 let spans = vec![sp5, sp2, sp4, sp9, sp10, sp7, sp3, sp8, sp1, sp6];
1796
1797 macro_rules! check_next {
1798 ($groups: expr, $expected: expr) => ({
1799 let actual = $groups.next().map(|g|&g.spans[..]);
1800 let expected = $expected;
1801 println!("actual:\n{:?}\n", actual);
1802 println!("expected:\n{:?}\n", expected);
1803 assert_eq!(actual, expected.as_ref().map(|x|&x[..]));
1804 });
1805 }
1806
1807 let _groups = cm.group_spans(spans.clone());
1808 let it = &mut _groups.iter();
1809
1810 check_next!(it, Some([sp1, sp7, sp8, sp9, sp10, sp2]));
1811 // New group because we're exceeding MAX_HIGHLIGHT_LINES
1812 check_next!(it, Some([sp4, sp_merge]));
1813 check_next!(it, Some([sp3]));
1814 check_next!(it, None::<[Span; 0]>);
1815
1816 let _groups = cm.end_group_spans(spans);
1817 let it = &mut _groups.iter();
1818
1819 check_next!(it, Some([sp1, sp7, sp8, sp9, sp10, sp2]));
1820 // New group because we're exceeding MAX_HIGHLIGHT_LINES
1821 check_next!(it, Some([sp4, sp5, sp_trim]));
1822 check_next!(it, Some([sp3]));
1823 check_next!(it, None::<[Span; 0]>);
1824 }
1825 }