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.
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 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.
20 pub use self::ExpnFormat::*;
22 use std::cell::{Cell, RefCell};
23 use std::ops::{Add, Sub};
28 use std::io::{self, Read};
30 use serialize::{Encodable, Decodable, Encoder, Decoder};
34 // _____________________________________________________________________________
35 // Pos, BytePos, CharPos
39 fn from_usize(n: usize) -> Self;
40 fn to_usize(&self) -> usize;
43 /// A byte offset. Keep this small (currently 32-bits), as AST contains
45 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Debug)]
46 pub struct BytePos(pub u32);
48 /// A character offset. Because of multibyte utf8 characters, a byte offset
49 /// is not equivalent to a character offset. The CodeMap will convert BytePos
50 /// values to CharPos values as necessary.
51 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Debug)]
52 pub struct CharPos(pub usize);
54 // FIXME: Lots of boilerplate in these impls, but so far my attempts to fix
55 // have been unsuccessful
57 impl Pos for BytePos {
58 fn from_usize(n: usize) -> BytePos { BytePos(n as u32) }
59 fn to_usize(&self) -> usize { let BytePos(n) = *self; n as usize }
62 impl Add for BytePos {
63 type Output = BytePos;
65 fn add(self, rhs: BytePos) -> BytePos {
66 BytePos((self.to_usize() + rhs.to_usize()) as u32)
70 impl Sub for BytePos {
71 type Output = BytePos;
73 fn sub(self, rhs: BytePos) -> BytePos {
74 BytePos((self.to_usize() - rhs.to_usize()) as u32)
78 impl Encodable for BytePos {
79 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
84 impl Decodable for BytePos {
85 fn decode<D: Decoder>(d: &mut D) -> Result<BytePos, D::Error> {
86 Ok(BytePos(try!{ d.read_u32() }))
90 impl Pos for CharPos {
91 fn from_usize(n: usize) -> CharPos { CharPos(n) }
92 fn to_usize(&self) -> usize { let CharPos(n) = *self; n }
95 impl Add for CharPos {
96 type Output = CharPos;
98 fn add(self, rhs: CharPos) -> CharPos {
99 CharPos(self.to_usize() + rhs.to_usize())
103 impl Sub for CharPos {
104 type Output = CharPos;
106 fn sub(self, rhs: CharPos) -> CharPos {
107 CharPos(self.to_usize() - rhs.to_usize())
111 // _____________________________________________________________________________
115 /// Spans represent a region of code, used for error reporting. Positions in spans
116 /// are *absolute* positions from the beginning of the codemap, not positions
117 /// relative to FileMaps. Methods on the CodeMap can be used to relate spans back
118 /// to the original source.
119 /// You must be careful if the span crosses more than one file - you will not be
120 /// able to use many of the functions on spans in codemap and you cannot assume
121 /// that the length of the span = hi - lo; there may be space in the BytePos
122 /// range between files.
123 #[derive(Clone, Copy, Hash)]
127 /// Information about where the macro came from, if this piece of
128 /// code was created by a macro expansion.
132 pub const DUMMY_SP: Span = Span { lo: BytePos(0), hi: BytePos(0), expn_id: NO_EXPANSION };
134 // Generic span to be used for code originating from the command line
135 pub const COMMAND_LINE_SP: Span = Span { lo: BytePos(0),
137 expn_id: COMMAND_LINE_EXPN };
140 /// Returns `self` if `self` is not the dummy span, and `other` otherwise.
141 pub fn substitute_dummy(self, other: Span) -> Span {
142 if self == DUMMY_SP { other } else { self }
145 pub fn contains(self, other: Span) -> bool {
146 self.lo <= other.lo && other.hi <= self.hi
150 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
151 pub struct Spanned<T> {
156 impl PartialEq for Span {
157 fn eq(&self, other: &Span) -> bool {
158 return (*self).lo == (*other).lo && (*self).hi == (*other).hi;
160 fn ne(&self, other: &Span) -> bool { !(*self).eq(other) }
165 impl Encodable for Span {
166 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
167 s.emit_struct("Span", 2, |s| {
168 try!(s.emit_struct_field("lo", 0, |s| {
172 s.emit_struct_field("hi", 1, |s| {
179 impl Decodable for Span {
180 fn decode<D: Decoder>(d: &mut D) -> Result<Span, D::Error> {
181 d.read_struct("Span", 2, |d| {
182 let lo = try!(d.read_struct_field("lo", 0, |d| {
186 let hi = try!(d.read_struct_field("hi", 1, |d| {
195 fn default_span_debug(span: Span, f: &mut fmt::Formatter) -> fmt::Result {
196 write!(f, "Span {{ lo: {:?}, hi: {:?}, expn_id: {:?} }}",
197 span.lo, span.hi, span.expn_id)
200 thread_local!(pub static SPAN_DEBUG: Cell<fn(Span, &mut fmt::Formatter) -> fmt::Result> =
201 Cell::new(default_span_debug));
203 impl fmt::Debug for Span {
204 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
205 SPAN_DEBUG.with(|span_debug| span_debug.get()(*self, f))
209 pub fn spanned<T>(lo: BytePos, hi: BytePos, t: T) -> Spanned<T> {
210 respan(mk_sp(lo, hi), t)
213 pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
214 Spanned {node: t, span: sp}
217 pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
221 /* assuming that we're not in macro expansion */
222 pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
223 Span {lo: lo, hi: hi, expn_id: NO_EXPANSION}
226 /// Return the span itself if it doesn't come from a macro expansion,
227 /// otherwise return the call site span up to the `enclosing_sp` by
228 /// following the `expn_info` chain.
229 pub fn original_sp(cm: &CodeMap, sp: Span, enclosing_sp: Span) -> Span {
230 let call_site1 = cm.with_expn_info(sp.expn_id, |ei| ei.map(|ei| ei.call_site));
231 let call_site2 = cm.with_expn_info(enclosing_sp.expn_id, |ei| ei.map(|ei| ei.call_site));
232 match (call_site1, call_site2) {
234 (Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp,
235 (Some(call_site1), _) => original_sp(cm, call_site1, enclosing_sp),
239 // _____________________________________________________________________________
240 // Loc, LocWithOpt, FileMapAndLine, FileMapAndBytePos
243 /// A source code location used for error reporting
246 /// Information about the original source
247 pub file: Rc<FileMap>,
248 /// The (1-based) line number
250 /// The (0-based) column offset
254 /// A source code location used as the result of lookup_char_pos_adj
255 // Actually, *none* of the clients use the filename *or* file field;
256 // perhaps they should just be removed.
258 pub struct LocWithOpt {
259 pub filename: FileName,
262 pub file: Option<Rc<FileMap>>,
265 // used to be structural records. Better names, anyone?
267 pub struct FileMapAndLine { pub fm: Rc<FileMap>, pub line: usize }
269 pub struct FileMapAndBytePos { pub fm: Rc<FileMap>, pub pos: BytePos }
272 // _____________________________________________________________________________
273 // ExpnFormat, NameAndSpan, ExpnInfo, ExpnId
276 /// The source of expansion.
277 #[derive(Clone, Hash, Debug, PartialEq, Eq)]
278 pub enum ExpnFormat {
279 /// e.g. #[derive(...)] <item>
280 MacroAttribute(Name),
285 #[derive(Clone, Hash, Debug)]
286 pub struct NameAndSpan {
287 /// The format with which the macro was invoked.
288 pub format: ExpnFormat,
289 /// Whether the macro is allowed to use #[unstable]/feature-gated
290 /// features internally without forcing the whole crate to opt-in
292 pub allow_internal_unstable: bool,
293 /// The span of the macro definition itself. The macro may not
294 /// have a sensible definition span (e.g. something defined
295 /// completely inside libsyntax) in which case this is None.
296 pub span: Option<Span>
300 pub fn name(&self) -> Name {
302 ExpnFormat::MacroAttribute(s) => s,
303 ExpnFormat::MacroBang(s) => s,
308 /// Extra information for tracking spans of macro and syntax sugar expansion
309 #[derive(Hash, Debug)]
310 pub struct ExpnInfo {
311 /// The location of the actual macro invocation or syntax sugar , e.g.
312 /// `let x = foo!();` or `if let Some(y) = x {}`
314 /// This may recursively refer to other macro invocations, e.g. if
315 /// `foo!()` invoked `bar!()` internally, and there was an
316 /// expression inside `bar!`; the call_site of the expression in
317 /// the expansion would point to the `bar!` invocation; that
318 /// call_site span would have its own ExpnInfo, with the call_site
319 /// pointing to the `foo!` invocation.
321 /// Information about the expansion.
322 pub callee: NameAndSpan
325 #[derive(PartialEq, Eq, Clone, Debug, Hash, RustcEncodable, RustcDecodable, Copy)]
326 pub struct ExpnId(u32);
328 pub const NO_EXPANSION: ExpnId = ExpnId(!0);
329 // For code appearing from the command line
330 pub const COMMAND_LINE_EXPN: ExpnId = ExpnId(!1);
333 pub fn from_u32(id: u32) -> ExpnId {
337 pub fn into_u32(self) -> u32 {
342 // _____________________________________________________________________________
343 // FileMap, MultiByteChar, FileName, FileLines
346 pub type FileName = String;
348 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
349 pub struct LineInfo {
350 /// Index of line, starting from 0.
351 pub line_index: usize,
353 /// Column in line where span begins, starting from 0.
354 pub start_col: CharPos,
356 /// Column in line where span ends, starting from 0, exclusive.
357 pub end_col: CharPos,
360 pub struct FileLines {
361 pub file: Rc<FileMap>,
362 pub lines: Vec<LineInfo>
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 /// A single source in the CodeMap.
376 /// The name of the file that the source came from, source that doesn't
377 /// originate from files has names between angle brackets by convention,
380 /// The complete source code
381 pub src: Option<Rc<String>>,
382 /// The start position of this source in the CodeMap
383 pub start_pos: BytePos,
384 /// The end position of this source in the CodeMap
385 pub end_pos: BytePos,
386 /// Locations of lines beginnings in the source code
387 pub lines: RefCell<Vec<BytePos>>,
388 /// Locations of multi-byte characters in the source code
389 pub multibyte_chars: RefCell<Vec<MultiByteChar>>,
392 impl Encodable for FileMap {
393 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
394 s.emit_struct("FileMap", 5, |s| {
395 try! { s.emit_struct_field("name", 0, |s| self.name.encode(s)) };
396 try! { s.emit_struct_field("start_pos", 1, |s| self.start_pos.encode(s)) };
397 try! { s.emit_struct_field("end_pos", 2, |s| self.end_pos.encode(s)) };
398 try! { s.emit_struct_field("lines", 3, |s| {
399 let lines = self.lines.borrow();
401 try! { s.emit_u32(lines.len() as u32) };
403 if !lines.is_empty() {
404 // In order to preserve some space, we exploit the fact that
405 // the lines list is sorted and individual lines are
406 // probably not that long. Because of that we can store lines
407 // as a difference list, using as little space as possible
408 // for the differences.
409 let max_line_length = if lines.len() == 1 {
413 .map(|w| w[1] - w[0])
414 .map(|bp| bp.to_usize())
419 let bytes_per_diff: u8 = match max_line_length {
421 0x100 ... 0xFFFF => 2,
425 // Encode the number of bytes used per diff.
426 try! { bytes_per_diff.encode(s) };
428 // Encode the first element.
429 try! { lines[0].encode(s) };
431 let diff_iter = (&lines[..]).windows(2)
432 .map(|w| (w[1] - w[0]));
434 match bytes_per_diff {
435 1 => for diff in diff_iter { try! { (diff.0 as u8).encode(s) } },
436 2 => for diff in diff_iter { try! { (diff.0 as u16).encode(s) } },
437 4 => for diff in diff_iter { try! { diff.0.encode(s) } },
445 s.emit_struct_field("multibyte_chars", 4, |s| {
446 (*self.multibyte_chars.borrow()).encode(s)
452 impl Decodable for FileMap {
453 fn decode<D: Decoder>(d: &mut D) -> Result<FileMap, D::Error> {
455 d.read_struct("FileMap", 5, |d| {
456 let name: String = try! {
457 d.read_struct_field("name", 0, |d| Decodable::decode(d))
459 let start_pos: BytePos = try! {
460 d.read_struct_field("start_pos", 1, |d| Decodable::decode(d))
462 let end_pos: BytePos = try! {
463 d.read_struct_field("end_pos", 2, |d| Decodable::decode(d))
465 let lines: Vec<BytePos> = try! {
466 d.read_struct_field("lines", 3, |d| {
467 let num_lines: u32 = try! { Decodable::decode(d) };
468 let mut lines = Vec::with_capacity(num_lines as usize);
471 // Read the number of bytes used per diff.
472 let bytes_per_diff: u8 = try! { Decodable::decode(d) };
474 // Read the first element.
475 let mut line_start: BytePos = try! { Decodable::decode(d) };
476 lines.push(line_start);
478 for _ in 1..num_lines {
479 let diff = match bytes_per_diff {
480 1 => try! { d.read_u8() } as u32,
481 2 => try! { d.read_u16() } as u32,
482 4 => try! { d.read_u32() },
486 line_start = line_start + BytePos(diff);
488 lines.push(line_start);
495 let multibyte_chars: Vec<MultiByteChar> = try! {
496 d.read_struct_field("multibyte_chars", 4, |d| Decodable::decode(d))
500 start_pos: start_pos,
503 lines: RefCell::new(lines),
504 multibyte_chars: RefCell::new(multibyte_chars)
510 impl fmt::Debug for FileMap {
511 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
512 write!(fmt, "FileMap({})", self.name)
517 /// EFFECT: register a start-of-line offset in the
518 /// table of line-beginnings.
519 /// UNCHECKED INVARIANT: these offsets must be added in the right
520 /// order and must be in the right places; there is shared knowledge
521 /// about what ends a line between this file and parse.rs
522 /// WARNING: pos param here is the offset relative to start of CodeMap,
523 /// and CodeMap will append a newline when adding a filemap without a newline at the end,
524 /// so the safe way to call this is with value calculated as
525 /// filemap.start_pos + newline_offset_relative_to_the_start_of_filemap.
526 pub fn next_line(&self, pos: BytePos) {
527 // the new charpos must be > the last one (or it's the first one).
528 let mut lines = self.lines.borrow_mut();
529 let line_len = lines.len();
530 assert!(line_len == 0 || ((*lines)[line_len - 1] < pos));
534 /// get a line from the list of pre-computed line-beginnings.
535 /// line-number here is 0-based.
536 pub fn get_line(&self, line_number: usize) -> Option<&str> {
539 let lines = self.lines.borrow();
540 lines.get(line_number).map(|&line| {
541 let begin: BytePos = line - self.start_pos;
542 let begin = begin.to_usize();
543 // We can't use `lines.get(line_number+1)` because we might
544 // be parsing when we call this function and thus the current
545 // line is the last one we have line info for.
546 let slice = &src[begin..];
547 match slice.find('\n') {
548 Some(e) => &slice[..e],
557 pub fn record_multibyte_char(&self, pos: BytePos, bytes: usize) {
558 assert!(bytes >=2 && bytes <= 4);
559 let mbc = MultiByteChar {
563 self.multibyte_chars.borrow_mut().push(mbc);
566 pub fn is_real_file(&self) -> bool {
567 !(self.name.starts_with("<") &&
568 self.name.ends_with(">"))
571 pub fn is_imported(&self) -> bool {
575 fn count_lines(&self) -> usize {
576 self.lines.borrow().len()
580 /// An abstraction over the fs operations used by the Parser.
581 pub trait FileLoader {
582 /// Query the existence of a file.
583 fn file_exists(&self, path: &Path) -> bool;
585 /// Read the contents of an UTF-8 file into memory.
586 fn read_file(&self, path: &Path) -> io::Result<String>;
589 /// A FileLoader that uses std::fs to load real files.
590 pub struct RealFileLoader;
592 impl FileLoader for RealFileLoader {
593 fn file_exists(&self, path: &Path) -> bool {
594 fs::metadata(path).is_ok()
597 fn read_file(&self, path: &Path) -> io::Result<String> {
598 let mut src = String::new();
599 try!(try!(fs::File::open(path)).read_to_string(&mut src));
604 // _____________________________________________________________________________
609 pub files: RefCell<Vec<Rc<FileMap>>>,
610 expansions: RefCell<Vec<ExpnInfo>>,
611 file_loader: Box<FileLoader>
615 pub fn new() -> CodeMap {
617 files: RefCell::new(Vec::new()),
618 expansions: RefCell::new(Vec::new()),
619 file_loader: Box::new(RealFileLoader)
623 pub fn with_file_loader(file_loader: Box<FileLoader>) -> CodeMap {
625 files: RefCell::new(Vec::new()),
626 expansions: RefCell::new(Vec::new()),
627 file_loader: file_loader
631 pub fn file_exists(&self, path: &Path) -> bool {
632 self.file_loader.file_exists(path)
635 pub fn load_file(&self, path: &Path) -> io::Result<Rc<FileMap>> {
636 let src = try!(self.file_loader.read_file(path));
637 Ok(self.new_filemap(path.to_str().unwrap().to_string(), src))
640 fn next_start_pos(&self) -> usize {
641 let files = self.files.borrow();
644 // Add one so there is some space between files. This lets us distinguish
645 // positions in the codemap, even in the presence of zero-length files.
646 Some(last) => last.end_pos.to_usize() + 1,
650 /// Creates a new filemap without setting its line information. If you don't
651 /// intend to set the line information yourself, you should use new_filemap_and_lines.
652 pub fn new_filemap(&self, filename: FileName, mut src: String) -> Rc<FileMap> {
653 let start_pos = self.next_start_pos();
654 let mut files = self.files.borrow_mut();
656 // Remove utf-8 BOM if any.
657 if src.starts_with("\u{feff}") {
661 let end_pos = start_pos + src.len();
663 let filemap = Rc::new(FileMap {
665 src: Some(Rc::new(src)),
666 start_pos: Pos::from_usize(start_pos),
667 end_pos: Pos::from_usize(end_pos),
668 lines: RefCell::new(Vec::new()),
669 multibyte_chars: RefCell::new(Vec::new()),
672 files.push(filemap.clone());
677 /// Creates a new filemap and sets its line information.
678 pub fn new_filemap_and_lines(&self, filename: &str, src: &str) -> Rc<FileMap> {
679 let fm = self.new_filemap(filename.to_string(), src.to_owned());
680 let mut byte_pos: u32 = 0;
681 for line in src.lines() {
682 // register the start of this line
683 fm.next_line(BytePos(byte_pos));
685 // update byte_pos to include this line and the \n at the end
686 byte_pos += line.len() as u32 + 1;
692 /// Allocates a new FileMap representing a source file from an external
693 /// crate. The source code of such an "imported filemap" is not available,
694 /// but we still know enough to generate accurate debuginfo location
695 /// information for things inlined from other crates.
696 pub fn new_imported_filemap(&self,
699 mut file_local_lines: Vec<BytePos>,
700 mut file_local_multibyte_chars: Vec<MultiByteChar>)
702 let start_pos = self.next_start_pos();
703 let mut files = self.files.borrow_mut();
705 let end_pos = Pos::from_usize(start_pos + source_len);
706 let start_pos = Pos::from_usize(start_pos);
708 for pos in &mut file_local_lines {
709 *pos = *pos + start_pos;
712 for mbc in &mut file_local_multibyte_chars {
713 mbc.pos = mbc.pos + start_pos;
716 let filemap = Rc::new(FileMap {
719 start_pos: start_pos,
721 lines: RefCell::new(file_local_lines),
722 multibyte_chars: RefCell::new(file_local_multibyte_chars),
725 files.push(filemap.clone());
730 pub fn mk_substr_filename(&self, sp: Span) -> String {
731 let pos = self.lookup_char_pos(sp.lo);
732 (format!("<{}:{}:{}>",
735 pos.col.to_usize() + 1)).to_string()
738 /// Lookup source information about a BytePos
739 pub fn lookup_char_pos(&self, pos: BytePos) -> Loc {
740 let chpos = self.bytepos_to_file_charpos(pos);
741 match self.lookup_line(pos) {
742 Ok(FileMapAndLine { fm: f, line: a }) => {
743 let line = a + 1; // Line numbers start at 1
744 let linebpos = (*f.lines.borrow())[a];
745 let linechpos = self.bytepos_to_file_charpos(linebpos);
746 debug!("byte pos {:?} is on the line at byte pos {:?}",
748 debug!("char pos {:?} is on the line at char pos {:?}",
750 debug!("byte is on line: {}", line);
751 assert!(chpos >= linechpos);
755 col: chpos - linechpos,
768 // If the relevant filemap is empty, we don't return a line number.
769 fn lookup_line(&self, pos: BytePos) -> Result<FileMapAndLine, Rc<FileMap>> {
770 let idx = self.lookup_filemap_idx(pos);
772 let files = self.files.borrow();
773 let f = (*files)[idx].clone();
775 let len = f.lines.borrow().len();
782 let lines = f.lines.borrow();
783 let mut b = lines.len();
786 if (*lines)[m] > pos {
792 assert!(a <= lines.len());
794 Ok(FileMapAndLine { fm: f, line: a })
797 pub fn lookup_char_pos_adj(&self, pos: BytePos) -> LocWithOpt {
798 let loc = self.lookup_char_pos(pos);
800 filename: loc.file.name.to_string(),
807 pub fn span_to_string(&self, sp: Span) -> String {
808 if self.files.borrow().is_empty() && sp == DUMMY_SP {
809 return "no-location".to_string();
812 let lo = self.lookup_char_pos_adj(sp.lo);
813 let hi = self.lookup_char_pos_adj(sp.hi);
814 return (format!("{}:{}:{}: {}:{}",
817 lo.col.to_usize() + 1,
819 hi.col.to_usize() + 1)).to_string()
822 // Returns true if two spans have the same callee
823 // (Assumes the same ExpnFormat implies same callee)
824 fn match_callees(&self, sp_a: &Span, sp_b: &Span) -> bool {
826 .with_expn_info(sp_a.expn_id,
827 |ei| ei.map(|ei| ei.callee.format.clone()));
830 .with_expn_info(sp_b.expn_id,
831 |ei| ei.map(|ei| ei.callee.format.clone()));
835 /// Returns a formatted string showing the expansion chain of a span
837 /// Spans are printed in the following format:
839 /// filename:start_line:col: end_line:col
846 /// Callees and callsites are printed recursively (if available, otherwise header
847 /// and span is omitted), expanding into their own callee/callsite spans.
848 /// Each layer of recursion has an increased indent, and snippets are truncated
849 /// to at most 50 characters. Finally, recursive calls to the same macro are squashed,
850 /// with '...' used to represent any number of recursive calls.
851 pub fn span_to_expanded_string(&self, sp: Span) -> String {
852 self.span_to_expanded_string_internal(sp, "")
855 fn span_to_expanded_string_internal(&self, sp:Span, indent: &str) -> String {
856 let mut indent = indent.to_owned();
857 let mut output = "".to_owned();
858 let span_str = self.span_to_string(sp);
859 let mut span_snip = self.span_to_snippet(sp)
860 .unwrap_or("Snippet unavailable".to_owned());
862 // Truncate by code points - in worst case this will be more than 50 characters,
863 // but ensures at least 50 characters and respects byte boundaries.
864 let char_vec: Vec<(usize, char)> = span_snip.char_indices().collect();
865 if char_vec.len() > 50 {
866 span_snip.truncate(char_vec[49].0);
867 span_snip.push_str("...");
870 output.push_str(&format!("{}{}\n{}`{}`\n", indent, span_str, indent, span_snip));
872 if sp.expn_id == NO_EXPANSION || sp.expn_id == COMMAND_LINE_EXPN {
876 let mut callee = self.with_expn_info(sp.expn_id,
877 |ei| ei.and_then(|ei| ei.callee.span.clone()));
878 let mut callsite = self.with_expn_info(sp.expn_id,
879 |ei| ei.map(|ei| ei.call_site.clone()));
881 indent.push_str(" ");
882 let mut is_recursive = false;
884 while callee.is_some() && self.match_callees(&sp, &callee.unwrap()) {
885 callee = self.with_expn_info(callee.unwrap().expn_id,
886 |ei| ei.and_then(|ei| ei.callee.span.clone()));
889 if let Some(span) = callee {
890 output.push_str(&indent);
891 output.push_str("Callee:\n");
893 output.push_str(&indent);
894 output.push_str("...\n");
896 output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
899 is_recursive = false;
900 while callsite.is_some() && self.match_callees(&sp, &callsite.unwrap()) {
901 callsite = self.with_expn_info(callsite.unwrap().expn_id,
902 |ei| ei.map(|ei| ei.call_site.clone()));
905 if let Some(span) = callsite {
906 output.push_str(&indent);
907 output.push_str("Callsite:\n");
909 output.push_str(&indent);
910 output.push_str("...\n");
912 output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
917 /// Return the source span - this is either the supplied span, or the span for
918 /// the macro callsite that expanded to it.
919 pub fn source_callsite(&self, sp: Span) -> Span {
921 while span.expn_id != NO_EXPANSION && span.expn_id != COMMAND_LINE_EXPN {
922 if let Some(callsite) = self.with_expn_info(span.expn_id,
923 |ei| ei.map(|ei| ei.call_site.clone())) {
933 pub fn span_to_filename(&self, sp: Span) -> FileName {
934 self.lookup_char_pos(sp.lo).file.name.to_string()
937 pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
939 return Err(SpanLinesError::IllFormedSpan(sp));
942 let lo = self.lookup_char_pos(sp.lo);
943 let hi = self.lookup_char_pos(sp.hi);
945 if lo.file.start_pos != hi.file.start_pos {
946 return Err(SpanLinesError::DistinctSources(DistinctSources {
947 begin: (lo.file.name.clone(), lo.file.start_pos),
948 end: (hi.file.name.clone(), hi.file.start_pos),
951 assert!(hi.line >= lo.line);
953 let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
955 // The span starts partway through the first line,
956 // but after that it starts from offset 0.
957 let mut start_col = lo.col;
959 // For every line but the last, it extends from `start_col`
960 // and to the end of the line. Be careful because the line
961 // numbers in Loc are 1-based, so we subtract 1 to get 0-based
963 for line_index in lo.line-1 .. hi.line-1 {
964 let line_len = lo.file.get_line(line_index).map(|s| s.len()).unwrap_or(0);
965 lines.push(LineInfo { line_index: line_index,
966 start_col: start_col,
967 end_col: CharPos::from_usize(line_len) });
968 start_col = CharPos::from_usize(0);
971 // For the last line, it extends from `start_col` to `hi.col`:
972 lines.push(LineInfo { line_index: hi.line - 1,
973 start_col: start_col,
976 Ok(FileLines {file: lo.file, lines: lines})
979 pub fn span_to_snippet(&self, sp: Span) -> Result<String, SpanSnippetError> {
981 return Err(SpanSnippetError::IllFormedSpan(sp));
984 let local_begin = self.lookup_byte_offset(sp.lo);
985 let local_end = self.lookup_byte_offset(sp.hi);
987 if local_begin.fm.start_pos != local_end.fm.start_pos {
988 return Err(SpanSnippetError::DistinctSources(DistinctSources {
989 begin: (local_begin.fm.name.clone(),
990 local_begin.fm.start_pos),
991 end: (local_end.fm.name.clone(),
992 local_end.fm.start_pos)
995 match local_begin.fm.src {
997 let start_index = local_begin.pos.to_usize();
998 let end_index = local_end.pos.to_usize();
999 let source_len = (local_begin.fm.end_pos -
1000 local_begin.fm.start_pos).to_usize();
1002 if start_index > end_index || end_index > source_len {
1003 return Err(SpanSnippetError::MalformedForCodemap(
1004 MalformedCodemapPositions {
1005 name: local_begin.fm.name.clone(),
1006 source_len: source_len,
1007 begin_pos: local_begin.pos,
1008 end_pos: local_end.pos,
1012 return Ok((&src[start_index..end_index]).to_string())
1015 return Err(SpanSnippetError::SourceNotAvailable {
1016 filename: local_begin.fm.name.clone()
1023 pub fn get_filemap(&self, filename: &str) -> Rc<FileMap> {
1024 for fm in self.files.borrow().iter() {
1025 if filename == fm.name {
1029 panic!("asking for {} which we don't know about", filename);
1032 /// For a global BytePos compute the local offset within the containing FileMap
1033 pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
1034 let idx = self.lookup_filemap_idx(bpos);
1035 let fm = (*self.files.borrow())[idx].clone();
1036 let offset = bpos - fm.start_pos;
1037 FileMapAndBytePos {fm: fm, pos: offset}
1040 /// Converts an absolute BytePos to a CharPos relative to the filemap.
1041 pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos {
1042 let idx = self.lookup_filemap_idx(bpos);
1043 let files = self.files.borrow();
1044 let map = &(*files)[idx];
1046 // The number of extra bytes due to multibyte chars in the FileMap
1047 let mut total_extra_bytes = 0;
1049 for mbc in map.multibyte_chars.borrow().iter() {
1050 debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos);
1052 // every character is at least one byte, so we only
1053 // count the actual extra bytes.
1054 total_extra_bytes += mbc.bytes - 1;
1055 // We should never see a byte position in the middle of a
1057 assert!(bpos.to_usize() >= mbc.pos.to_usize() + mbc.bytes);
1063 assert!(map.start_pos.to_usize() + total_extra_bytes <= bpos.to_usize());
1064 CharPos(bpos.to_usize() - map.start_pos.to_usize() - total_extra_bytes)
1067 // Return the index of the filemap (in self.files) which contains pos.
1068 fn lookup_filemap_idx(&self, pos: BytePos) -> usize {
1069 let files = self.files.borrow();
1070 let files = &*files;
1071 let count = files.len();
1073 // Binary search for the filemap.
1077 let m = (a + b) / 2;
1078 if files[m].start_pos > pos {
1085 assert!(a < count, "position {} does not resolve to a source location", pos.to_usize());
1090 pub fn record_expansion(&self, expn_info: ExpnInfo) -> ExpnId {
1091 let mut expansions = self.expansions.borrow_mut();
1092 expansions.push(expn_info);
1093 let len = expansions.len();
1094 if len > u32::max_value() as usize {
1095 panic!("too many ExpnInfo's!");
1097 ExpnId(len as u32 - 1)
1100 pub fn with_expn_info<T, F>(&self, id: ExpnId, f: F) -> T where
1101 F: FnOnce(Option<&ExpnInfo>) -> T,
1104 NO_EXPANSION | COMMAND_LINE_EXPN => f(None),
1105 ExpnId(i) => f(Some(&(*self.expansions.borrow())[i as usize]))
1109 /// Check if a span is "internal" to a macro in which #[unstable]
1110 /// items can be used (that is, a macro marked with
1111 /// `#[allow_internal_unstable]`).
1112 pub fn span_allows_unstable(&self, span: Span) -> bool {
1113 debug!("span_allows_unstable(span = {:?})", span);
1114 let mut allows_unstable = false;
1115 let mut expn_id = span.expn_id;
1117 let quit = self.with_expn_info(expn_id, |expninfo| {
1118 debug!("span_allows_unstable: expninfo = {:?}", expninfo);
1119 expninfo.map_or(/* hit the top level */ true, |info| {
1121 let span_comes_from_this_expansion =
1122 info.callee.span.map_or(span == info.call_site, |mac_span| {
1123 mac_span.contains(span)
1126 debug!("span_allows_unstable: span: {:?} call_site: {:?} callee: {:?}",
1128 (info.call_site.lo, info.call_site.hi),
1129 info.callee.span.map(|x| (x.lo, x.hi)));
1130 debug!("span_allows_unstable: from this expansion? {}, allows unstable? {}",
1131 span_comes_from_this_expansion,
1132 info.callee.allow_internal_unstable);
1133 if span_comes_from_this_expansion {
1134 allows_unstable = info.callee.allow_internal_unstable;
1135 // we've found the right place, stop looking
1138 // not the right place, keep looking
1139 expn_id = info.call_site.expn_id;
1148 debug!("span_allows_unstable? {}", allows_unstable);
1152 pub fn count_lines(&self) -> usize {
1153 self.files.borrow().iter().fold(0, |a, f| a + f.count_lines())
1157 // _____________________________________________________________________________
1158 // SpanLinesError, SpanSnippetError, DistinctSources, MalformedCodemapPositions
1161 pub type FileLinesResult = Result<FileLines, SpanLinesError>;
1163 #[derive(Clone, PartialEq, Eq, Debug)]
1164 pub enum SpanLinesError {
1165 IllFormedSpan(Span),
1166 DistinctSources(DistinctSources),
1169 #[derive(Clone, PartialEq, Eq, Debug)]
1170 pub enum SpanSnippetError {
1171 IllFormedSpan(Span),
1172 DistinctSources(DistinctSources),
1173 MalformedForCodemap(MalformedCodemapPositions),
1174 SourceNotAvailable { filename: String }
1177 #[derive(Clone, PartialEq, Eq, Debug)]
1178 pub struct DistinctSources {
1179 begin: (String, BytePos),
1180 end: (String, BytePos)
1183 #[derive(Clone, PartialEq, Eq, Debug)]
1184 pub struct MalformedCodemapPositions {
1192 // _____________________________________________________________________________
1202 let cm = CodeMap::new();
1203 let fm = cm.new_filemap("blork.rs".to_string(),
1204 "first line.\nsecond line".to_string());
1205 fm.next_line(BytePos(0));
1206 // Test we can get lines with partial line info.
1207 assert_eq!(fm.get_line(0), Some("first line."));
1208 // TESTING BROKEN BEHAVIOR: line break declared before actual line break.
1209 fm.next_line(BytePos(10));
1210 assert_eq!(fm.get_line(1), Some("."));
1211 fm.next_line(BytePos(12));
1212 assert_eq!(fm.get_line(2), Some("second line"));
1218 let cm = CodeMap::new();
1219 let fm = cm.new_filemap("blork.rs".to_string(),
1220 "first line.\nsecond line".to_string());
1221 // TESTING *REALLY* BROKEN BEHAVIOR:
1222 fm.next_line(BytePos(0));
1223 fm.next_line(BytePos(10));
1224 fm.next_line(BytePos(2));
1227 fn init_code_map() -> CodeMap {
1228 let cm = CodeMap::new();
1229 let fm1 = cm.new_filemap("blork.rs".to_string(),
1230 "first line.\nsecond line".to_string());
1231 let fm2 = cm.new_filemap("empty.rs".to_string(),
1233 let fm3 = cm.new_filemap("blork2.rs".to_string(),
1234 "first line.\nsecond line".to_string());
1236 fm1.next_line(BytePos(0));
1237 fm1.next_line(BytePos(12));
1238 fm2.next_line(fm2.start_pos);
1239 fm3.next_line(fm3.start_pos);
1240 fm3.next_line(fm3.start_pos + BytePos(12));
1247 // Test lookup_byte_offset
1248 let cm = init_code_map();
1250 let fmabp1 = cm.lookup_byte_offset(BytePos(23));
1251 assert_eq!(fmabp1.fm.name, "blork.rs");
1252 assert_eq!(fmabp1.pos, BytePos(23));
1254 let fmabp1 = cm.lookup_byte_offset(BytePos(24));
1255 assert_eq!(fmabp1.fm.name, "empty.rs");
1256 assert_eq!(fmabp1.pos, BytePos(0));
1258 let fmabp2 = cm.lookup_byte_offset(BytePos(25));
1259 assert_eq!(fmabp2.fm.name, "blork2.rs");
1260 assert_eq!(fmabp2.pos, BytePos(0));
1265 // Test bytepos_to_file_charpos
1266 let cm = init_code_map();
1268 let cp1 = cm.bytepos_to_file_charpos(BytePos(22));
1269 assert_eq!(cp1, CharPos(22));
1271 let cp2 = cm.bytepos_to_file_charpos(BytePos(25));
1272 assert_eq!(cp2, CharPos(0));
1277 // Test zero-length filemaps.
1278 let cm = init_code_map();
1280 let loc1 = cm.lookup_char_pos(BytePos(22));
1281 assert_eq!(loc1.file.name, "blork.rs");
1282 assert_eq!(loc1.line, 2);
1283 assert_eq!(loc1.col, CharPos(10));
1285 let loc2 = cm.lookup_char_pos(BytePos(25));
1286 assert_eq!(loc2.file.name, "blork2.rs");
1287 assert_eq!(loc2.line, 1);
1288 assert_eq!(loc2.col, CharPos(0));
1291 fn init_code_map_mbc() -> CodeMap {
1292 let cm = CodeMap::new();
1293 // € is a three byte utf8 char.
1295 cm.new_filemap("blork.rs".to_string(),
1296 "fir€st €€€€ line.\nsecond line".to_string());
1297 let fm2 = cm.new_filemap("blork2.rs".to_string(),
1298 "first line€€.\n€ second line".to_string());
1300 fm1.next_line(BytePos(0));
1301 fm1.next_line(BytePos(28));
1302 fm2.next_line(fm2.start_pos);
1303 fm2.next_line(fm2.start_pos + BytePos(20));
1305 fm1.record_multibyte_char(BytePos(3), 3);
1306 fm1.record_multibyte_char(BytePos(9), 3);
1307 fm1.record_multibyte_char(BytePos(12), 3);
1308 fm1.record_multibyte_char(BytePos(15), 3);
1309 fm1.record_multibyte_char(BytePos(18), 3);
1310 fm2.record_multibyte_char(fm2.start_pos + BytePos(10), 3);
1311 fm2.record_multibyte_char(fm2.start_pos + BytePos(13), 3);
1312 fm2.record_multibyte_char(fm2.start_pos + BytePos(18), 3);
1319 // Test bytepos_to_file_charpos in the presence of multi-byte chars
1320 let cm = init_code_map_mbc();
1322 let cp1 = cm.bytepos_to_file_charpos(BytePos(3));
1323 assert_eq!(cp1, CharPos(3));
1325 let cp2 = cm.bytepos_to_file_charpos(BytePos(6));
1326 assert_eq!(cp2, CharPos(4));
1328 let cp3 = cm.bytepos_to_file_charpos(BytePos(56));
1329 assert_eq!(cp3, CharPos(12));
1331 let cp4 = cm.bytepos_to_file_charpos(BytePos(61));
1332 assert_eq!(cp4, CharPos(15));
1337 // Test span_to_lines for a span ending at the end of filemap
1338 let cm = init_code_map();
1339 let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
1340 let file_lines = cm.span_to_lines(span).unwrap();
1342 assert_eq!(file_lines.file.name, "blork.rs");
1343 assert_eq!(file_lines.lines.len(), 1);
1344 assert_eq!(file_lines.lines[0].line_index, 1);
1347 /// Given a string like " ^~~~~~~~~~~~ ", produces a span
1348 /// coverting that range. The idea is that the string has the same
1349 /// length as the input, and we uncover the byte positions. Note
1350 /// that this can span lines and so on.
1351 fn span_from_selection(input: &str, selection: &str) -> Span {
1352 assert_eq!(input.len(), selection.len());
1353 let left_index = selection.find('^').unwrap() as u32;
1354 let right_index = selection.rfind('~').unwrap() as u32;
1355 Span { lo: BytePos(left_index), hi: BytePos(right_index + 1), expn_id: NO_EXPANSION }
1358 /// Test span_to_snippet and span_to_lines for a span coverting 3
1359 /// lines in the middle of a file.
1361 fn span_to_snippet_and_lines_spanning_multiple_lines() {
1362 let cm = CodeMap::new();
1363 let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
1364 let selection = " \n ^~\n~~~\n~~~~~ \n \n";
1365 cm.new_filemap_and_lines("blork.rs", inputtext);
1366 let span = span_from_selection(inputtext, selection);
1368 // check that we are extracting the text we thought we were extracting
1369 assert_eq!(&cm.span_to_snippet(span).unwrap(), "BB\nCCC\nDDDDD");
1371 // check that span_to_lines gives us the complete result with the lines/cols we expected
1372 let lines = cm.span_to_lines(span).unwrap();
1373 let expected = vec![
1374 LineInfo { line_index: 1, start_col: CharPos(4), end_col: CharPos(6) },
1375 LineInfo { line_index: 2, start_col: CharPos(0), end_col: CharPos(3) },
1376 LineInfo { line_index: 3, start_col: CharPos(0), end_col: CharPos(5) }
1378 assert_eq!(lines.lines, expected);
1383 // Test span_to_snippet for a span ending at the end of filemap
1384 let cm = init_code_map();
1385 let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
1386 let snippet = cm.span_to_snippet(span);
1388 assert_eq!(snippet, Ok("second line".to_string()));
1393 // Test span_to_str for a span ending at the end of filemap
1394 let cm = init_code_map();
1395 let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
1396 let sstr = cm.span_to_string(span);
1398 assert_eq!(sstr, "blork.rs:2:1: 2:12");
1403 // Test span_to_expanded_string works in base case (no expansion)
1404 let cm = init_code_map();
1405 let span = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
1406 let sstr = cm.span_to_expanded_string(span);
1407 assert_eq!(sstr, "blork.rs:1:1: 1:12\n`first line.`\n");
1409 let span = Span { lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION };
1410 let sstr = cm.span_to_expanded_string(span);
1411 assert_eq!(sstr, "blork.rs:2:1: 2:12\n`second line`\n");
1416 // Test span_to_expanded_string works with expansion
1418 let cm = init_code_map();
1419 let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
1420 let format = ExpnFormat::MacroBang(Name(0u32));
1421 let callee = NameAndSpan { format: format,
1422 allow_internal_unstable: false,
1425 let info = ExpnInfo { call_site: root, callee: callee };
1426 let id = cm.record_expansion(info);
1427 let sp = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id };
1429 let sstr = cm.span_to_expanded_string(sp);
1431 "blork.rs:2:1: 2:12\n`second line`\n Callsite:\n \
1432 blork.rs:1:1: 1:12\n `first line.`\n");
1435 fn init_expansion_chain(cm: &CodeMap) -> Span {
1436 // Creates an expansion chain containing two recursive calls
1437 // root -> expA -> expA -> expB -> expB -> end
1440 let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
1442 let format_root = ExpnFormat::MacroBang(Name(0u32));
1443 let callee_root = NameAndSpan { format: format_root,
1444 allow_internal_unstable: false,
1447 let info_a1 = ExpnInfo { call_site: root, callee: callee_root };
1448 let id_a1 = cm.record_expansion(info_a1);
1449 let span_a1 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a1 };
1451 let format_a = ExpnFormat::MacroBang(Name(1u32));
1452 let callee_a = NameAndSpan { format: format_a,
1453 allow_internal_unstable: false,
1454 span: Some(span_a1) };
1456 let info_a2 = ExpnInfo { call_site: span_a1, callee: callee_a.clone() };
1457 let id_a2 = cm.record_expansion(info_a2);
1458 let span_a2 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a2 };
1460 let info_b1 = ExpnInfo { call_site: span_a2, callee: callee_a };
1461 let id_b1 = cm.record_expansion(info_b1);
1462 let span_b1 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b1 };
1464 let format_b = ExpnFormat::MacroBang(Name(2u32));
1465 let callee_b = NameAndSpan { format: format_b,
1466 allow_internal_unstable: false,
1469 let info_b2 = ExpnInfo { call_site: span_b1, callee: callee_b.clone() };
1470 let id_b2 = cm.record_expansion(info_b2);
1471 let span_b2 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b2 };
1473 let info_end = ExpnInfo { call_site: span_b2, callee: callee_b };
1474 let id_end = cm.record_expansion(info_end);
1475 Span { lo: BytePos(37), hi: BytePos(48), expn_id: id_end }
1480 // Test span_to_expanded_string collapses recursive macros and handles
1481 // recursive callsite and callee expansions
1482 let cm = init_code_map();
1483 let end = init_expansion_chain(&cm);
1484 let sstr = cm.span_to_expanded_string(end);
1486 r"blork2.rs:2:1: 2:12
1512 assert_eq!(sstr, res_str);