1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! The source positions and related helper functions
15 //! This API is completely unstable and subject to change.
17 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
18 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
19 html_root_url = "https://doc.rust-lang.org/nightly/")]
23 #![feature(custom_attribute)]
24 #![feature(i128_type)]
25 #![feature(optin_builtin_traits)]
26 #![allow(unused_attributes)]
27 #![feature(specialization)]
30 use std::cell::{Cell, RefCell};
31 use std::cmp::{self, Ordering};
33 use std::hash::{Hasher, Hash};
34 use std::ops::{Add, Sub};
35 use std::path::PathBuf;
38 use rustc_data_structures::stable_hasher::StableHasher;
40 extern crate rustc_data_structures;
42 use serialize::{Encodable, Decodable, Encoder, Decoder};
44 extern crate serialize;
45 extern crate serialize as rustc_serialize; // used by deriving
47 extern crate unicode_width;
50 pub use hygiene::{SyntaxContext, ExpnInfo, ExpnFormat, NameAndSpan, CompilerDesugaringKind};
53 pub use span_encoding::{Span, DUMMY_SP};
57 /// Differentiates between real files and common virtual files
58 #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash, RustcDecodable, RustcEncodable)]
67 /// Hack in src/libsyntax/parse.rs
71 /// Strings provided as --cfg [cfgspec] stored in a crate_cfg
73 /// Custom sources for explicit parser calls from plugins and drivers
77 impl std::fmt::Display for FileName {
78 fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
79 use self::FileName::*;
81 Real(ref path) => write!(fmt, "{}", path.display()),
82 Macros(ref name) => write!(fmt, "<{} macros>", name),
83 QuoteExpansion => write!(fmt, "<quote expansion>"),
84 MacroExpansion => write!(fmt, "<macro expansion>"),
85 Anon => write!(fmt, "<anon>"),
86 ProcMacroSourceCode => write!(fmt, "<proc-macro source code>"),
87 CfgSpec => write!(fmt, "cfgspec"),
88 Custom(ref s) => write!(fmt, "<{}>", s),
93 impl From<PathBuf> for FileName {
94 fn from(p: PathBuf) -> Self {
95 assert!(!p.to_string_lossy().ends_with('>'));
101 pub fn is_real(&self) -> bool {
102 use self::FileName::*;
108 ProcMacroSourceCode |
111 QuoteExpansion => false,
115 pub fn is_macros(&self) -> bool {
116 use self::FileName::*;
121 ProcMacroSourceCode |
124 QuoteExpansion => false,
130 /// Spans represent a region of code, used for error reporting. Positions in spans
131 /// are *absolute* positions from the beginning of the codemap, not positions
132 /// relative to FileMaps. Methods on the CodeMap can be used to relate spans back
133 /// to the original source.
134 /// You must be careful if the span crosses more than one file - you will not be
135 /// able to use many of the functions on spans in codemap and you cannot assume
136 /// that the length of the span = hi - lo; there may be space in the BytePos
137 /// range between files.
139 /// `SpanData` is public because `Span` uses a thread-local interner and can't be
140 /// sent to other threads, but some pieces of performance infra run in a separate thread.
141 /// Using `Span` is generally preferred.
142 #[derive(Clone, Copy, Hash, PartialEq, Eq, Ord, PartialOrd)]
143 pub struct SpanData {
146 /// Information about where the macro came from, if this piece of
147 /// code was created by a macro expansion.
148 pub ctxt: SyntaxContext,
153 pub fn with_lo(&self, lo: BytePos) -> Span {
154 Span::new(lo, self.hi, self.ctxt)
157 pub fn with_hi(&self, hi: BytePos) -> Span {
158 Span::new(self.lo, hi, self.ctxt)
161 pub fn with_ctxt(&self, ctxt: SyntaxContext) -> Span {
162 Span::new(self.lo, self.hi, ctxt)
166 // The interner in thread-local, so `Span` shouldn't move between threads.
167 impl !Send for Span {}
168 impl !Sync for Span {}
170 impl PartialOrd for Span {
171 fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> {
172 PartialOrd::partial_cmp(&self.data(), &rhs.data())
176 fn cmp(&self, rhs: &Self) -> Ordering {
177 Ord::cmp(&self.data(), &rhs.data())
181 /// A collection of spans. Spans have two orthogonal attributes:
183 /// - they can be *primary spans*. In this case they are the locus of
184 /// the error, and would be rendered with `^^^`.
185 /// - they can have a *label*. In this case, the label is written next
186 /// to the mark in the snippet when we render.
187 #[derive(Clone, Debug, Hash, PartialEq, Eq, RustcEncodable, RustcDecodable)]
188 pub struct MultiSpan {
189 primary_spans: Vec<Span>,
190 span_labels: Vec<(Span, String)>,
195 pub fn lo(self) -> BytePos {
199 pub fn with_lo(self, lo: BytePos) -> Span {
200 self.data().with_lo(lo)
203 pub fn hi(self) -> BytePos {
207 pub fn with_hi(self, hi: BytePos) -> Span {
208 self.data().with_hi(hi)
211 pub fn ctxt(self) -> SyntaxContext {
215 pub fn with_ctxt(self, ctxt: SyntaxContext) -> Span {
216 self.data().with_ctxt(ctxt)
219 /// Returns `self` if `self` is not the dummy span, and `other` otherwise.
220 pub fn substitute_dummy(self, other: Span) -> Span {
221 if self.source_equal(&DUMMY_SP) { other } else { self }
224 /// Return true if `self` fully encloses `other`.
225 pub fn contains(self, other: Span) -> bool {
226 let span = self.data();
227 let other = other.data();
228 span.lo <= other.lo && other.hi <= span.hi
231 /// Return true if the spans are equal with regards to the source text.
233 /// Use this instead of `==` when either span could be generated code,
234 /// and you only care that they point to the same bytes of source text.
235 pub fn source_equal(&self, other: &Span) -> bool {
236 let span = self.data();
237 let other = other.data();
238 span.lo == other.lo && span.hi == other.hi
241 /// Returns `Some(span)`, where the start is trimmed by the end of `other`
242 pub fn trim_start(self, other: Span) -> Option<Span> {
243 let span = self.data();
244 let other = other.data();
245 if span.hi > other.hi {
246 Some(span.with_lo(cmp::max(span.lo, other.hi)))
252 /// Return the source span - this is either the supplied span, or the span for
253 /// the macro callsite that expanded to it.
254 pub fn source_callsite(self) -> Span {
255 self.ctxt().outer().expn_info().map(|info| info.call_site.source_callsite()).unwrap_or(self)
258 /// Return the source callee.
260 /// Returns None if the supplied span has no expansion trace,
261 /// else returns the NameAndSpan for the macro definition
262 /// corresponding to the source callsite.
263 pub fn source_callee(self) -> Option<NameAndSpan> {
264 fn source_callee(info: ExpnInfo) -> NameAndSpan {
265 match info.call_site.ctxt().outer().expn_info() {
266 Some(info) => source_callee(info),
270 self.ctxt().outer().expn_info().map(source_callee)
273 /// Check if a span is "internal" to a macro in which #[unstable]
274 /// items can be used (that is, a macro marked with
275 /// `#[allow_internal_unstable]`).
276 pub fn allows_unstable(&self) -> bool {
277 match self.ctxt().outer().expn_info() {
278 Some(info) => info.callee.allow_internal_unstable,
283 /// Check if this span arises from a compiler desugaring of kind `kind`.
284 pub fn is_compiler_desugaring(&self, kind: CompilerDesugaringKind) -> bool {
285 match self.ctxt().outer().expn_info() {
286 Some(info) => match info.callee.format {
287 ExpnFormat::CompilerDesugaring(k) => k == kind,
294 /// Return the compiler desugaring that created this span, or None
295 /// if this span is not from a desugaring.
296 pub fn compiler_desugaring_kind(&self) -> Option<CompilerDesugaringKind> {
297 match self.ctxt().outer().expn_info() {
298 Some(info) => match info.callee.format {
299 ExpnFormat::CompilerDesugaring(k) => Some(k),
306 /// Check if a span is "internal" to a macro in which `unsafe`
307 /// can be used without triggering the `unsafe_code` lint
308 // (that is, a macro marked with `#[allow_internal_unsafe]`).
309 pub fn allows_unsafe(&self) -> bool {
310 match self.ctxt().outer().expn_info() {
311 Some(info) => info.callee.allow_internal_unsafe,
316 pub fn macro_backtrace(mut self) -> Vec<MacroBacktrace> {
317 let mut prev_span = DUMMY_SP;
318 let mut result = vec![];
320 let info = match self.ctxt().outer().expn_info() {
325 let (pre, post) = match info.callee.format {
326 ExpnFormat::MacroAttribute(..) => ("#[", "]"),
327 ExpnFormat::MacroBang(..) => ("", "!"),
328 ExpnFormat::CompilerDesugaring(..) => ("desugaring of `", "`"),
330 let macro_decl_name = format!("{}{}{}", pre, info.callee.name(), post);
331 let def_site_span = info.callee.span;
333 // Don't print recursive invocations
334 if !info.call_site.source_equal(&prev_span) {
335 result.push(MacroBacktrace {
336 call_site: info.call_site,
343 self = info.call_site;
348 /// Return a `Span` that would enclose both `self` and `end`.
349 pub fn to(self, end: Span) -> Span {
350 let span = self.data();
351 let end = end.data();
353 cmp::min(span.lo, end.lo),
354 cmp::max(span.hi, end.hi),
355 // FIXME(jseyfried): self.ctxt should always equal end.ctxt here (c.f. issue #23480)
356 if span.ctxt == SyntaxContext::empty() { end.ctxt } else { span.ctxt },
360 /// Return a `Span` between the end of `self` to the beginning of `end`.
361 pub fn between(self, end: Span) -> Span {
362 let span = self.data();
363 let end = end.data();
367 if end.ctxt == SyntaxContext::empty() { end.ctxt } else { span.ctxt },
371 /// Return a `Span` between the beginning of `self` to the beginning of `end`.
372 pub fn until(self, end: Span) -> Span {
373 let span = self.data();
374 let end = end.data();
378 if end.ctxt == SyntaxContext::empty() { end.ctxt } else { span.ctxt },
383 #[derive(Clone, Debug)]
384 pub struct SpanLabel {
385 /// The span we are going to include in the final snippet.
388 /// Is this a primary span? This is the "locus" of the message,
389 /// and is indicated with a `^^^^` underline, versus `----`.
390 pub is_primary: bool,
392 /// What label should we attach to this span (if any)?
393 pub label: Option<String>,
396 impl Default for Span {
397 fn default() -> Self {
402 impl serialize::UseSpecializedEncodable for Span {
403 fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
404 let span = self.data();
405 s.emit_struct("Span", 2, |s| {
406 s.emit_struct_field("lo", 0, |s| {
410 s.emit_struct_field("hi", 1, |s| {
417 impl serialize::UseSpecializedDecodable for Span {
418 fn default_decode<D: Decoder>(d: &mut D) -> Result<Span, D::Error> {
419 d.read_struct("Span", 2, |d| {
420 let lo = d.read_struct_field("lo", 0, Decodable::decode)?;
421 let hi = d.read_struct_field("hi", 1, Decodable::decode)?;
422 Ok(Span::new(lo, hi, NO_EXPANSION))
427 fn default_span_debug(span: Span, f: &mut fmt::Formatter) -> fmt::Result {
428 f.debug_struct("Span")
429 .field("lo", &span.lo())
430 .field("hi", &span.hi())
431 .field("ctxt", &span.ctxt())
435 impl fmt::Debug for Span {
436 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
437 SPAN_DEBUG.with(|span_debug| span_debug.get()(*self, f))
441 impl fmt::Debug for SpanData {
442 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
443 SPAN_DEBUG.with(|span_debug| span_debug.get()(Span::new(self.lo, self.hi, self.ctxt), f))
448 pub fn new() -> MultiSpan {
450 primary_spans: vec![],
455 pub fn from_span(primary_span: Span) -> MultiSpan {
457 primary_spans: vec![primary_span],
462 pub fn from_spans(vec: Vec<Span>) -> MultiSpan {
469 pub fn push_span_label(&mut self, span: Span, label: String) {
470 self.span_labels.push((span, label));
473 /// Selects the first primary span (if any)
474 pub fn primary_span(&self) -> Option<Span> {
475 self.primary_spans.first().cloned()
478 /// Returns all primary spans.
479 pub fn primary_spans(&self) -> &[Span] {
483 /// Replaces all occurrences of one Span with another. Used to move Spans in areas that don't
484 /// display well (like std macros). Returns true if replacements occurred.
485 pub fn replace(&mut self, before: Span, after: Span) -> bool {
486 let mut replacements_occurred = false;
487 for primary_span in &mut self.primary_spans {
488 if *primary_span == before {
489 *primary_span = after;
490 replacements_occurred = true;
493 for span_label in &mut self.span_labels {
494 if span_label.0 == before {
495 span_label.0 = after;
496 replacements_occurred = true;
499 replacements_occurred
502 /// Returns the strings to highlight. We always ensure that there
503 /// is an entry for each of the primary spans -- for each primary
504 /// span P, if there is at least one label with span P, we return
505 /// those labels (marked as primary). But otherwise we return
506 /// `SpanLabel` instances with empty labels.
507 pub fn span_labels(&self) -> Vec<SpanLabel> {
508 let is_primary = |span| self.primary_spans.contains(&span);
509 let mut span_labels = vec![];
511 for &(span, ref label) in &self.span_labels {
512 span_labels.push(SpanLabel {
514 is_primary: is_primary(span),
515 label: Some(label.clone())
519 for &span in &self.primary_spans {
520 if !span_labels.iter().any(|sl| sl.span == span) {
521 span_labels.push(SpanLabel {
533 impl From<Span> for MultiSpan {
534 fn from(span: Span) -> MultiSpan {
535 MultiSpan::from_span(span)
539 impl From<Vec<Span>> for MultiSpan {
540 fn from(spans: Vec<Span>) -> MultiSpan {
541 MultiSpan::from_spans(spans)
545 pub const NO_EXPANSION: SyntaxContext = SyntaxContext::empty();
547 /// Identifies an offset of a multi-byte character in a FileMap
548 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Eq, PartialEq)]
549 pub struct MultiByteChar {
550 /// The absolute offset of the character in the CodeMap
552 /// The number of bytes, >=2
556 /// Identifies an offset of a non-narrow character in a FileMap
557 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Eq, PartialEq)]
558 pub enum NonNarrowChar {
559 /// Represents a zero-width character
561 /// Represents a wide (fullwidth) character
563 /// Represents a tab character, represented visually with a width of 4 characters
568 fn new(pos: BytePos, width: usize) -> Self {
570 0 => NonNarrowChar::ZeroWidth(pos),
571 2 => NonNarrowChar::Wide(pos),
572 4 => NonNarrowChar::Tab(pos),
573 _ => panic!("width {} given for non-narrow character", width),
577 /// Returns the absolute offset of the character in the CodeMap
578 pub fn pos(&self) -> BytePos {
580 NonNarrowChar::ZeroWidth(p) |
581 NonNarrowChar::Wide(p) |
582 NonNarrowChar::Tab(p) => p,
586 /// Returns the width of the character, 0 (zero-width) or 2 (wide)
587 pub fn width(&self) -> usize {
589 NonNarrowChar::ZeroWidth(_) => 0,
590 NonNarrowChar::Wide(_) => 2,
591 NonNarrowChar::Tab(_) => 4,
596 impl Add<BytePos> for NonNarrowChar {
599 fn add(self, rhs: BytePos) -> Self {
601 NonNarrowChar::ZeroWidth(pos) => NonNarrowChar::ZeroWidth(pos + rhs),
602 NonNarrowChar::Wide(pos) => NonNarrowChar::Wide(pos + rhs),
603 NonNarrowChar::Tab(pos) => NonNarrowChar::Tab(pos + rhs),
608 impl Sub<BytePos> for NonNarrowChar {
611 fn sub(self, rhs: BytePos) -> Self {
613 NonNarrowChar::ZeroWidth(pos) => NonNarrowChar::ZeroWidth(pos - rhs),
614 NonNarrowChar::Wide(pos) => NonNarrowChar::Wide(pos - rhs),
615 NonNarrowChar::Tab(pos) => NonNarrowChar::Tab(pos - rhs),
620 /// The state of the lazy external source loading mechanism of a FileMap.
621 #[derive(PartialEq, Eq, Clone)]
622 pub enum ExternalSource {
623 /// The external source has been loaded already.
625 /// No attempt has been made to load the external source.
627 /// A failed attempt has been made to load the external source.
629 /// No external source has to be loaded, since the FileMap represents a local crate.
633 impl ExternalSource {
634 pub fn is_absent(&self) -> bool {
636 ExternalSource::Present(_) => false,
641 pub fn get_source(&self) -> Option<&str> {
643 ExternalSource::Present(ref src) => Some(src),
649 /// A single source in the CodeMap.
652 /// The name of the file that the source came from, source that doesn't
653 /// originate from files has names between angle brackets by convention,
656 /// True if the `name` field above has been modified by -Zremap-path-prefix
657 pub name_was_remapped: bool,
658 /// The unmapped path of the file that the source came from.
659 /// Set to `None` if the FileMap was imported from an external crate.
660 pub unmapped_path: Option<FileName>,
661 /// Indicates which crate this FileMap was imported from.
662 pub crate_of_origin: u32,
663 /// The complete source code
664 pub src: Option<Rc<String>>,
665 /// The source code's hash
667 /// The external source code (used for external crates, which will have a `None`
668 /// value as `self.src`.
669 pub external_src: RefCell<ExternalSource>,
670 /// The start position of this source in the CodeMap
671 pub start_pos: BytePos,
672 /// The end position of this source in the CodeMap
673 pub end_pos: BytePos,
674 /// Locations of lines beginnings in the source code
675 pub lines: RefCell<Vec<BytePos>>,
676 /// Locations of multi-byte characters in the source code
677 pub multibyte_chars: RefCell<Vec<MultiByteChar>>,
678 /// Width of characters that are not narrow in the source code
679 pub non_narrow_chars: RefCell<Vec<NonNarrowChar>>,
680 /// A hash of the filename, used for speeding up the incr. comp. hashing.
684 impl Encodable for FileMap {
685 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
686 s.emit_struct("FileMap", 8, |s| {
687 s.emit_struct_field("name", 0, |s| self.name.encode(s))?;
688 s.emit_struct_field("name_was_remapped", 1, |s| self.name_was_remapped.encode(s))?;
689 s.emit_struct_field("src_hash", 2, |s| self.src_hash.encode(s))?;
690 s.emit_struct_field("start_pos", 4, |s| self.start_pos.encode(s))?;
691 s.emit_struct_field("end_pos", 5, |s| self.end_pos.encode(s))?;
692 s.emit_struct_field("lines", 6, |s| {
693 let lines = self.lines.borrow();
695 s.emit_u32(lines.len() as u32)?;
697 if !lines.is_empty() {
698 // In order to preserve some space, we exploit the fact that
699 // the lines list is sorted and individual lines are
700 // probably not that long. Because of that we can store lines
701 // as a difference list, using as little space as possible
702 // for the differences.
703 let max_line_length = if lines.len() == 1 {
707 .map(|w| w[1] - w[0])
708 .map(|bp| bp.to_usize())
713 let bytes_per_diff: u8 = match max_line_length {
715 0x100 ... 0xFFFF => 2,
719 // Encode the number of bytes used per diff.
720 bytes_per_diff.encode(s)?;
722 // Encode the first element.
725 let diff_iter = (&lines[..]).windows(2)
726 .map(|w| (w[1] - w[0]));
728 match bytes_per_diff {
729 1 => for diff in diff_iter { (diff.0 as u8).encode(s)? },
730 2 => for diff in diff_iter { (diff.0 as u16).encode(s)? },
731 4 => for diff in diff_iter { diff.0.encode(s)? },
738 s.emit_struct_field("multibyte_chars", 7, |s| {
739 (*self.multibyte_chars.borrow()).encode(s)
741 s.emit_struct_field("non_narrow_chars", 8, |s| {
742 (*self.non_narrow_chars.borrow()).encode(s)
744 s.emit_struct_field("name_hash", 9, |s| {
745 self.name_hash.encode(s)
751 impl Decodable for FileMap {
752 fn decode<D: Decoder>(d: &mut D) -> Result<FileMap, D::Error> {
754 d.read_struct("FileMap", 8, |d| {
755 let name: FileName = d.read_struct_field("name", 0, |d| Decodable::decode(d))?;
756 let name_was_remapped: bool =
757 d.read_struct_field("name_was_remapped", 1, |d| Decodable::decode(d))?;
759 d.read_struct_field("src_hash", 2, |d| Decodable::decode(d))?;
760 let start_pos: BytePos =
761 d.read_struct_field("start_pos", 4, |d| Decodable::decode(d))?;
762 let end_pos: BytePos = d.read_struct_field("end_pos", 5, |d| Decodable::decode(d))?;
763 let lines: Vec<BytePos> = d.read_struct_field("lines", 6, |d| {
764 let num_lines: u32 = Decodable::decode(d)?;
765 let mut lines = Vec::with_capacity(num_lines as usize);
768 // Read the number of bytes used per diff.
769 let bytes_per_diff: u8 = Decodable::decode(d)?;
771 // Read the first element.
772 let mut line_start: BytePos = Decodable::decode(d)?;
773 lines.push(line_start);
775 for _ in 1..num_lines {
776 let diff = match bytes_per_diff {
777 1 => d.read_u8()? as u32,
778 2 => d.read_u16()? as u32,
783 line_start = line_start + BytePos(diff);
785 lines.push(line_start);
791 let multibyte_chars: Vec<MultiByteChar> =
792 d.read_struct_field("multibyte_chars", 7, |d| Decodable::decode(d))?;
793 let non_narrow_chars: Vec<NonNarrowChar> =
794 d.read_struct_field("non_narrow_chars", 8, |d| Decodable::decode(d))?;
795 let name_hash: u128 =
796 d.read_struct_field("name_hash", 9, |d| Decodable::decode(d))?;
801 // `crate_of_origin` has to be set by the importer.
802 // This value matches up with rustc::hir::def_id::INVALID_CRATE.
803 // That constant is not available here unfortunately :(
804 crate_of_origin: ::std::u32::MAX - 1,
809 external_src: RefCell::new(ExternalSource::AbsentOk),
810 lines: RefCell::new(lines),
811 multibyte_chars: RefCell::new(multibyte_chars),
812 non_narrow_chars: RefCell::new(non_narrow_chars),
819 impl fmt::Debug for FileMap {
820 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
821 write!(fmt, "FileMap({})", self.name)
826 pub fn new(name: FileName,
827 name_was_remapped: bool,
828 unmapped_path: FileName,
830 start_pos: BytePos) -> FileMap {
831 remove_bom(&mut src);
834 let mut hasher: StableHasher<u128> = StableHasher::new();
835 hasher.write(src.as_bytes());
839 let mut hasher: StableHasher<u128> = StableHasher::new();
840 name.hash(&mut hasher);
843 let end_pos = start_pos.to_usize() + src.len();
848 unmapped_path: Some(unmapped_path),
850 src: Some(Rc::new(src)),
852 external_src: RefCell::new(ExternalSource::Unneeded),
854 end_pos: Pos::from_usize(end_pos),
855 lines: RefCell::new(Vec::new()),
856 multibyte_chars: RefCell::new(Vec::new()),
857 non_narrow_chars: RefCell::new(Vec::new()),
862 /// EFFECT: register a start-of-line offset in the
863 /// table of line-beginnings.
864 /// UNCHECKED INVARIANT: these offsets must be added in the right
865 /// order and must be in the right places; there is shared knowledge
866 /// about what ends a line between this file and parse.rs
867 /// WARNING: pos param here is the offset relative to start of CodeMap,
868 /// and CodeMap will append a newline when adding a filemap without a newline at the end,
869 /// so the safe way to call this is with value calculated as
870 /// filemap.start_pos + newline_offset_relative_to_the_start_of_filemap.
871 pub fn next_line(&self, pos: BytePos) {
872 // the new charpos must be > the last one (or it's the first one).
873 let mut lines = self.lines.borrow_mut();
874 let line_len = lines.len();
875 assert!(line_len == 0 || ((*lines)[line_len - 1] < pos));
879 /// Add externally loaded source.
880 /// If the hash of the input doesn't match or no input is supplied via None,
881 /// it is interpreted as an error and the corresponding enum variant is set.
882 /// The return value signifies whether some kind of source is present.
883 pub fn add_external_src<F>(&self, get_src: F) -> bool
884 where F: FnOnce() -> Option<String>
886 if *self.external_src.borrow() == ExternalSource::AbsentOk {
888 let mut external_src = self.external_src.borrow_mut();
889 if let Some(src) = src {
890 let mut hasher: StableHasher<u128> = StableHasher::new();
891 hasher.write(src.as_bytes());
893 if hasher.finish() == self.src_hash {
894 *external_src = ExternalSource::Present(src);
898 *external_src = ExternalSource::AbsentErr;
903 self.src.is_some() || self.external_src.borrow().get_source().is_some()
907 /// Get a line from the list of pre-computed line-beginnings.
908 /// The line number here is 0-based.
909 pub fn get_line(&self, line_number: usize) -> Option<Cow<str>> {
910 fn get_until_newline(src: &str, begin: usize) -> &str {
911 // We can't use `lines.get(line_number+1)` because we might
912 // be parsing when we call this function and thus the current
913 // line is the last one we have line info for.
914 let slice = &src[begin..];
915 match slice.find('\n') {
916 Some(e) => &slice[..e],
921 let lines = self.lines.borrow();
922 let line = if let Some(line) = lines.get(line_number) {
927 let begin: BytePos = *line - self.start_pos;
928 let begin = begin.to_usize();
930 if let Some(ref src) = self.src {
931 Some(Cow::from(get_until_newline(src, begin)))
932 } else if let Some(src) = self.external_src.borrow().get_source() {
933 Some(Cow::Owned(String::from(get_until_newline(src, begin))))
939 pub fn record_multibyte_char(&self, pos: BytePos, bytes: usize) {
940 assert!(bytes >=2 && bytes <= 4);
941 let mbc = MultiByteChar {
945 self.multibyte_chars.borrow_mut().push(mbc);
948 pub fn record_width(&self, pos: BytePos, ch: char) {
949 let width = match ch {
951 // Tabs will consume 4 columns.
954 // Make newlines take one column so that displayed spans can point them.
957 // Assume control characters are zero width.
958 // FIXME: How can we decide between `width` and `width_cjk`?
959 unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0),
961 // Only record non-narrow characters.
963 self.non_narrow_chars.borrow_mut().push(NonNarrowChar::new(pos, width));
967 pub fn is_real_file(&self) -> bool {
971 pub fn is_imported(&self) -> bool {
975 pub fn byte_length(&self) -> u32 {
976 self.end_pos.0 - self.start_pos.0
978 pub fn count_lines(&self) -> usize {
979 self.lines.borrow().len()
982 /// Find the line containing the given position. The return value is the
983 /// index into the `lines` array of this FileMap, not the 1-based line
984 /// number. If the filemap is empty or the position is located before the
985 /// first line, None is returned.
986 pub fn lookup_line(&self, pos: BytePos) -> Option<usize> {
987 let lines = self.lines.borrow();
988 if lines.len() == 0 {
992 let line_index = lookup_line(&lines[..], pos);
993 assert!(line_index < lines.len() as isize);
995 Some(line_index as usize)
1001 pub fn line_bounds(&self, line_index: usize) -> (BytePos, BytePos) {
1002 if self.start_pos == self.end_pos {
1003 return (self.start_pos, self.end_pos);
1006 let lines = self.lines.borrow();
1007 assert!(line_index < lines.len());
1008 if line_index == (lines.len() - 1) {
1009 (lines[line_index], self.end_pos)
1011 (lines[line_index], lines[line_index + 1])
1016 pub fn contains(&self, byte_pos: BytePos) -> bool {
1017 byte_pos >= self.start_pos && byte_pos <= self.end_pos
1021 /// Remove utf-8 BOM if any.
1022 fn remove_bom(src: &mut String) {
1023 if src.starts_with("\u{feff}") {
1028 // _____________________________________________________________________________
1029 // Pos, BytePos, CharPos
1033 fn from_usize(n: usize) -> Self;
1034 fn to_usize(&self) -> usize;
1037 /// A byte offset. Keep this small (currently 32-bits), as AST contains
1039 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
1040 pub struct BytePos(pub u32);
1042 /// A character offset. Because of multibyte utf8 characters, a byte offset
1043 /// is not equivalent to a character offset. The CodeMap will convert BytePos
1044 /// values to CharPos values as necessary.
1045 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
1046 pub struct CharPos(pub usize);
1048 // FIXME: Lots of boilerplate in these impls, but so far my attempts to fix
1049 // have been unsuccessful
1051 impl Pos for BytePos {
1052 fn from_usize(n: usize) -> BytePos { BytePos(n as u32) }
1053 fn to_usize(&self) -> usize { let BytePos(n) = *self; n as usize }
1056 impl Add for BytePos {
1057 type Output = BytePos;
1059 fn add(self, rhs: BytePos) -> BytePos {
1060 BytePos((self.to_usize() + rhs.to_usize()) as u32)
1064 impl Sub for BytePos {
1065 type Output = BytePos;
1067 fn sub(self, rhs: BytePos) -> BytePos {
1068 BytePos((self.to_usize() - rhs.to_usize()) as u32)
1072 impl Encodable for BytePos {
1073 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
1078 impl Decodable for BytePos {
1079 fn decode<D: Decoder>(d: &mut D) -> Result<BytePos, D::Error> {
1080 Ok(BytePos(d.read_u32()?))
1084 impl Pos for CharPos {
1085 fn from_usize(n: usize) -> CharPos { CharPos(n) }
1086 fn to_usize(&self) -> usize { let CharPos(n) = *self; n }
1089 impl Add for CharPos {
1090 type Output = CharPos;
1092 fn add(self, rhs: CharPos) -> CharPos {
1093 CharPos(self.to_usize() + rhs.to_usize())
1097 impl Sub for CharPos {
1098 type Output = CharPos;
1100 fn sub(self, rhs: CharPos) -> CharPos {
1101 CharPos(self.to_usize() - rhs.to_usize())
1105 // _____________________________________________________________________________
1106 // Loc, LocWithOpt, FileMapAndLine, FileMapAndBytePos
1109 /// A source code location used for error reporting
1110 #[derive(Debug, Clone)]
1112 /// Information about the original source
1113 pub file: Rc<FileMap>,
1114 /// The (1-based) line number
1116 /// The (0-based) column offset
1118 /// The (0-based) column offset when displayed
1119 pub col_display: usize,
1122 /// A source code location used as the result of lookup_char_pos_adj
1123 // Actually, *none* of the clients use the filename *or* file field;
1124 // perhaps they should just be removed.
1126 pub struct LocWithOpt {
1127 pub filename: FileName,
1130 pub file: Option<Rc<FileMap>>,
1133 // used to be structural records. Better names, anyone?
1135 pub struct FileMapAndLine { pub fm: Rc<FileMap>, pub line: usize }
1137 pub struct FileMapAndBytePos { pub fm: Rc<FileMap>, pub pos: BytePos }
1139 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1140 pub struct LineInfo {
1141 /// Index of line, starting from 0.
1142 pub line_index: usize,
1144 /// Column in line where span begins, starting from 0.
1145 pub start_col: CharPos,
1147 /// Column in line where span ends, starting from 0, exclusive.
1148 pub end_col: CharPos,
1151 pub struct FileLines {
1152 pub file: Rc<FileMap>,
1153 pub lines: Vec<LineInfo>
1156 thread_local!(pub static SPAN_DEBUG: Cell<fn(Span, &mut fmt::Formatter) -> fmt::Result> =
1157 Cell::new(default_span_debug));
1160 pub struct MacroBacktrace {
1161 /// span where macro was applied to generate this code
1162 pub call_site: Span,
1164 /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]")
1165 pub macro_decl_name: String,
1167 /// span where macro was defined (if known)
1168 pub def_site_span: Option<Span>,
1171 // _____________________________________________________________________________
1172 // SpanLinesError, SpanSnippetError, DistinctSources, MalformedCodemapPositions
1175 pub type FileLinesResult = Result<FileLines, SpanLinesError>;
1177 #[derive(Clone, PartialEq, Eq, Debug)]
1178 pub enum SpanLinesError {
1179 IllFormedSpan(Span),
1180 DistinctSources(DistinctSources),
1183 #[derive(Clone, PartialEq, Eq, Debug)]
1184 pub enum SpanSnippetError {
1185 IllFormedSpan(Span),
1186 DistinctSources(DistinctSources),
1187 MalformedForCodemap(MalformedCodemapPositions),
1188 SourceNotAvailable { filename: FileName }
1191 #[derive(Clone, PartialEq, Eq, Debug)]
1192 pub struct DistinctSources {
1193 pub begin: (FileName, BytePos),
1194 pub end: (FileName, BytePos)
1197 #[derive(Clone, PartialEq, Eq, Debug)]
1198 pub struct MalformedCodemapPositions {
1200 pub source_len: usize,
1201 pub begin_pos: BytePos,
1202 pub end_pos: BytePos
1205 // Given a slice of line start positions and a position, returns the index of
1206 // the line the position is on. Returns -1 if the position is located before
1208 fn lookup_line(lines: &[BytePos], pos: BytePos) -> isize {
1209 match lines.binary_search(&pos) {
1210 Ok(line) => line as isize,
1211 Err(line) => line as isize - 1
1217 use super::{lookup_line, BytePos};
1220 fn test_lookup_line() {
1222 let lines = &[BytePos(3), BytePos(17), BytePos(28)];
1224 assert_eq!(lookup_line(lines, BytePos(0)), -1);
1225 assert_eq!(lookup_line(lines, BytePos(3)), 0);
1226 assert_eq!(lookup_line(lines, BytePos(4)), 0);
1228 assert_eq!(lookup_line(lines, BytePos(16)), 0);
1229 assert_eq!(lookup_line(lines, BytePos(17)), 1);
1230 assert_eq!(lookup_line(lines, BytePos(18)), 1);
1232 assert_eq!(lookup_line(lines, BytePos(28)), 2);
1233 assert_eq!(lookup_line(lines, BytePos(29)), 2);