1 //! The source positions and related helper functions.
5 //! This API is completely unstable and subject to change.
7 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
10 #![feature(crate_visibility_modifier)]
12 #![feature(non_exhaustive)]
13 #![feature(optin_builtin_traits)]
14 #![feature(rustc_attrs)]
15 #![feature(proc_macro_hygiene)]
16 #![feature(specialization)]
17 #![feature(step_trait)]
19 use rustc_serialize::{Encodable, Decodable, Encoder, Decoder};
24 pub use hygiene::{ExpnId, SyntaxContext, ExpnData, ExpnKind, MacroKind, DesugaringKind};
27 pub use span_encoding::{Span, DUMMY_SP};
30 pub use symbol::{Symbol, sym};
32 mod analyze_source_file;
34 use rustc_data_structures::stable_hasher::StableHasher;
35 use rustc_data_structures::sync::{Lrc, Lock};
39 use std::cmp::{self, Ordering};
41 use std::hash::{Hasher, Hash};
42 use std::ops::{Add, Sub};
43 use std::path::PathBuf;
49 symbol_interner: Lock<symbol::Interner>,
50 span_interner: Lock<span_encoding::SpanInterner>,
51 hygiene_data: Lock<hygiene::HygieneData>,
55 pub fn new(edition: Edition) -> Globals {
57 symbol_interner: Lock::new(symbol::Interner::fresh()),
58 span_interner: Lock::new(span_encoding::SpanInterner::default()),
59 hygiene_data: Lock::new(hygiene::HygieneData::new(edition)),
64 scoped_tls::scoped_thread_local!(pub static GLOBALS: Globals);
66 /// Differentiates between real files and common virtual files.
67 #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash, RustcDecodable, RustcEncodable)]
70 /// A macro. This includes the full name of the macro, so that there are no clashes.
76 /// Hack in `src/libsyntax/parse.rs`.
79 ProcMacroSourceCode(u64),
80 /// Strings provided as `--cfg [cfgspec]` stored in a `crate_cfg`.
82 /// Strings provided as crate attributes in the CLI.
84 /// Custom sources for explicit parser calls from plugins and drivers.
86 DocTest(PathBuf, isize),
89 impl std::fmt::Display for FileName {
90 fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
93 Real(ref path) => write!(fmt, "{}", path.display()),
94 Macros(ref name) => write!(fmt, "<{} macros>", name),
95 QuoteExpansion(_) => write!(fmt, "<quote expansion>"),
96 MacroExpansion(_) => write!(fmt, "<macro expansion>"),
97 Anon(_) => write!(fmt, "<anon>"),
98 ProcMacroSourceCode(_) =>
99 write!(fmt, "<proc-macro source code>"),
100 CfgSpec(_) => write!(fmt, "<cfgspec>"),
101 CliCrateAttr(_) => write!(fmt, "<crate attribute>"),
102 Custom(ref s) => write!(fmt, "<{}>", s),
103 DocTest(ref path, _) => write!(fmt, "{}", path.display()),
108 impl From<PathBuf> for FileName {
109 fn from(p: PathBuf) -> Self {
110 assert!(!p.to_string_lossy().ends_with('>'));
116 pub fn is_real(&self) -> bool {
123 ProcMacroSourceCode(_) |
128 DocTest(_, _) => false,
132 pub fn is_macros(&self) -> bool {
138 ProcMacroSourceCode(_) |
143 DocTest(_, _) => false,
148 pub fn quote_expansion_source_code(src: &str) -> FileName {
149 let mut hasher = StableHasher::new();
150 src.hash(&mut hasher);
151 FileName::QuoteExpansion(hasher.finish())
154 pub fn macro_expansion_source_code(src: &str) -> FileName {
155 let mut hasher = StableHasher::new();
156 src.hash(&mut hasher);
157 FileName::MacroExpansion(hasher.finish())
160 pub fn anon_source_code(src: &str) -> FileName {
161 let mut hasher = StableHasher::new();
162 src.hash(&mut hasher);
163 FileName::Anon(hasher.finish())
166 pub fn proc_macro_source_code(src: &str) -> FileName {
167 let mut hasher = StableHasher::new();
168 src.hash(&mut hasher);
169 FileName::ProcMacroSourceCode(hasher.finish())
172 pub fn cfg_spec_source_code(src: &str) -> FileName {
173 let mut hasher = StableHasher::new();
174 src.hash(&mut hasher);
175 FileName::QuoteExpansion(hasher.finish())
178 pub fn cli_crate_attr_source_code(src: &str) -> FileName {
179 let mut hasher = StableHasher::new();
180 src.hash(&mut hasher);
181 FileName::CliCrateAttr(hasher.finish())
184 pub fn doc_test_source_code(path: PathBuf, line: isize) -> FileName{
185 FileName::DocTest(path, line)
189 /// Spans represent a region of code, used for error reporting. Positions in spans
190 /// are *absolute* positions from the beginning of the source_map, not positions
191 /// relative to `SourceFile`s. Methods on the `SourceMap` can be used to relate spans back
192 /// to the original source.
193 /// You must be careful if the span crosses more than one file - you will not be
194 /// able to use many of the functions on spans in source_map and you cannot assume
195 /// that the length of the `span = hi - lo`; there may be space in the `BytePos`
196 /// range between files.
198 /// `SpanData` is public because `Span` uses a thread-local interner and can't be
199 /// sent to other threads, but some pieces of performance infra run in a separate thread.
200 /// Using `Span` is generally preferred.
201 #[derive(Clone, Copy, Hash, PartialEq, Eq, Ord, PartialOrd)]
202 pub struct SpanData {
205 /// Information about where the macro came from, if this piece of
206 /// code was created by a macro expansion.
207 pub ctxt: SyntaxContext,
212 pub fn with_lo(&self, lo: BytePos) -> Span {
213 Span::new(lo, self.hi, self.ctxt)
216 pub fn with_hi(&self, hi: BytePos) -> Span {
217 Span::new(self.lo, hi, self.ctxt)
220 pub fn with_ctxt(&self, ctxt: SyntaxContext) -> Span {
221 Span::new(self.lo, self.hi, ctxt)
225 // The interner is pointed to by a thread local value which is only set on the main thread
226 // with parallelization is disabled. So we don't allow `Span` to transfer between threads
227 // to avoid panics and other errors, even though it would be memory safe to do so.
228 #[cfg(not(parallel_compiler))]
229 impl !Send for Span {}
230 #[cfg(not(parallel_compiler))]
231 impl !Sync for Span {}
233 impl PartialOrd for Span {
234 fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> {
235 PartialOrd::partial_cmp(&self.data(), &rhs.data())
239 fn cmp(&self, rhs: &Self) -> Ordering {
240 Ord::cmp(&self.data(), &rhs.data())
244 /// A collection of spans. Spans have two orthogonal attributes:
246 /// - They can be *primary spans*. In this case they are the locus of
247 /// the error, and would be rendered with `^^^`.
248 /// - They can have a *label*. In this case, the label is written next
249 /// to the mark in the snippet when we render.
250 #[derive(Clone, Debug, Hash, PartialEq, Eq, RustcEncodable, RustcDecodable)]
251 pub struct MultiSpan {
252 primary_spans: Vec<Span>,
253 span_labels: Vec<(Span, String)>,
258 pub fn lo(self) -> BytePos {
262 pub fn with_lo(self, lo: BytePos) -> Span {
263 self.data().with_lo(lo)
266 pub fn hi(self) -> BytePos {
270 pub fn with_hi(self, hi: BytePos) -> Span {
271 self.data().with_hi(hi)
274 pub fn ctxt(self) -> SyntaxContext {
278 pub fn with_ctxt(self, ctxt: SyntaxContext) -> Span {
279 self.data().with_ctxt(ctxt)
282 /// Returns `true` if this is a dummy span with any hygienic context.
284 pub fn is_dummy(self) -> bool {
285 let span = self.data();
286 span.lo.0 == 0 && span.hi.0 == 0
289 /// Returns `true` if this span comes from a macro or desugaring.
291 pub fn from_expansion(self) -> bool {
292 self.ctxt() != SyntaxContext::root()
296 pub fn with_root_ctxt(lo: BytePos, hi: BytePos) -> Span {
297 Span::new(lo, hi, SyntaxContext::root())
300 /// Returns a new span representing an empty span at the beginning of this span
302 pub fn shrink_to_lo(self) -> Span {
303 let span = self.data();
304 span.with_hi(span.lo)
306 /// Returns a new span representing an empty span at the end of this span.
308 pub fn shrink_to_hi(self) -> Span {
309 let span = self.data();
310 span.with_lo(span.hi)
313 /// Returns `self` if `self` is not the dummy span, and `other` otherwise.
314 pub fn substitute_dummy(self, other: Span) -> Span {
315 if self.is_dummy() { other } else { self }
318 /// Returns `true` if `self` fully encloses `other`.
319 pub fn contains(self, other: Span) -> bool {
320 let span = self.data();
321 let other = other.data();
322 span.lo <= other.lo && other.hi <= span.hi
325 /// Returns `true` if `self` touches `other`.
326 pub fn overlaps(self, other: Span) -> bool {
327 let span = self.data();
328 let other = other.data();
329 span.lo < other.hi && other.lo < span.hi
332 /// Returns `true` if the spans are equal with regards to the source text.
334 /// Use this instead of `==` when either span could be generated code,
335 /// and you only care that they point to the same bytes of source text.
336 pub fn source_equal(&self, other: &Span) -> bool {
337 let span = self.data();
338 let other = other.data();
339 span.lo == other.lo && span.hi == other.hi
342 /// Returns `Some(span)`, where the start is trimmed by the end of `other`.
343 pub fn trim_start(self, other: Span) -> Option<Span> {
344 let span = self.data();
345 let other = other.data();
346 if span.hi > other.hi {
347 Some(span.with_lo(cmp::max(span.lo, other.hi)))
353 /// Returns the source span -- this is either the supplied span, or the span for
354 /// the macro callsite that expanded to it.
355 pub fn source_callsite(self) -> Span {
356 let expn_data = self.ctxt().outer_expn_data();
357 if !expn_data.is_root() { expn_data.call_site.source_callsite() } else { self }
360 /// The `Span` for the tokens in the previous macro expansion from which `self` was generated,
362 pub fn parent(self) -> Option<Span> {
363 let expn_data = self.ctxt().outer_expn_data();
364 if !expn_data.is_root() { Some(expn_data.call_site) } else { None }
367 /// Edition of the crate from which this span came.
368 pub fn edition(self) -> edition::Edition {
369 self.ctxt().outer_expn_data().edition
373 pub fn rust_2015(&self) -> bool {
374 self.edition() == edition::Edition::Edition2015
378 pub fn rust_2018(&self) -> bool {
379 self.edition() >= edition::Edition::Edition2018
382 /// Returns the source callee.
384 /// Returns `None` if the supplied span has no expansion trace,
385 /// else returns the `ExpnData` for the macro definition
386 /// corresponding to the source callsite.
387 pub fn source_callee(self) -> Option<ExpnData> {
388 fn source_callee(expn_data: ExpnData) -> ExpnData {
389 let next_expn_data = expn_data.call_site.ctxt().outer_expn_data();
390 if !next_expn_data.is_root() { source_callee(next_expn_data) } else { expn_data }
392 let expn_data = self.ctxt().outer_expn_data();
393 if !expn_data.is_root() { Some(source_callee(expn_data)) } else { None }
396 /// Checks if a span is "internal" to a macro in which `#[unstable]`
397 /// items can be used (that is, a macro marked with
398 /// `#[allow_internal_unstable]`).
399 pub fn allows_unstable(&self, feature: Symbol) -> bool {
400 self.ctxt().outer_expn_data().allow_internal_unstable.map_or(false, |features| {
401 features.iter().any(|&f| {
402 f == feature || f == sym::allow_internal_unstable_backcompat_hack
407 /// Checks if this span arises from a compiler desugaring of kind `kind`.
408 pub fn is_desugaring(&self, kind: DesugaringKind) -> bool {
409 match self.ctxt().outer_expn_data().kind {
410 ExpnKind::Desugaring(k) => k == kind,
415 /// Returns the compiler desugaring that created this span, or `None`
416 /// if this span is not from a desugaring.
417 pub fn desugaring_kind(&self) -> Option<DesugaringKind> {
418 match self.ctxt().outer_expn_data().kind {
419 ExpnKind::Desugaring(k) => Some(k),
424 /// Checks if a span is "internal" to a macro in which `unsafe`
425 /// can be used without triggering the `unsafe_code` lint
426 // (that is, a macro marked with `#[allow_internal_unsafe]`).
427 pub fn allows_unsafe(&self) -> bool {
428 self.ctxt().outer_expn_data().allow_internal_unsafe
431 pub fn macro_backtrace(mut self) -> Vec<MacroBacktrace> {
432 let mut prev_span = DUMMY_SP;
433 let mut result = vec![];
435 let expn_data = self.ctxt().outer_expn_data();
436 if expn_data.is_root() {
439 // Don't print recursive invocations.
440 if !expn_data.call_site.source_equal(&prev_span) {
441 let (pre, post) = match expn_data.kind {
442 ExpnKind::Root => break,
443 ExpnKind::Desugaring(..) => ("desugaring of ", ""),
444 ExpnKind::Macro(macro_kind, _) => match macro_kind {
445 MacroKind::Bang => ("", "!"),
446 MacroKind::Attr => ("#[", "]"),
447 MacroKind::Derive => ("#[derive(", ")]"),
450 result.push(MacroBacktrace {
451 call_site: expn_data.call_site,
452 macro_decl_name: format!("{}{}{}", pre, expn_data.kind.descr(), post),
453 def_site_span: expn_data.def_site,
458 self = expn_data.call_site;
463 /// Returns a `Span` that would enclose both `self` and `end`.
464 pub fn to(self, end: Span) -> Span {
465 let span_data = self.data();
466 let end_data = end.data();
467 // FIXME(jseyfried): `self.ctxt` should always equal `end.ctxt` here (cf. issue #23480).
468 // Return the macro span on its own to avoid weird diagnostic output. It is preferable to
469 // have an incomplete span than a completely nonsensical one.
470 if span_data.ctxt != end_data.ctxt {
471 if span_data.ctxt == SyntaxContext::root() {
473 } else if end_data.ctxt == SyntaxContext::root() {
476 // Both spans fall within a macro.
477 // FIXME(estebank): check if it is the *same* macro.
480 cmp::min(span_data.lo, end_data.lo),
481 cmp::max(span_data.hi, end_data.hi),
482 if span_data.ctxt == SyntaxContext::root() { end_data.ctxt } else { span_data.ctxt },
486 /// Returns a `Span` between the end of `self` to the beginning of `end`.
487 pub fn between(self, end: Span) -> Span {
488 let span = self.data();
489 let end = end.data();
493 if end.ctxt == SyntaxContext::root() { end.ctxt } else { span.ctxt },
497 /// Returns a `Span` between the beginning of `self` to the beginning of `end`.
498 pub fn until(self, end: Span) -> Span {
499 let span = self.data();
500 let end = end.data();
504 if end.ctxt == SyntaxContext::root() { end.ctxt } else { span.ctxt },
508 pub fn from_inner(self, inner: InnerSpan) -> Span {
509 let span = self.data();
510 Span::new(span.lo + BytePos::from_usize(inner.start),
511 span.lo + BytePos::from_usize(inner.end),
516 pub fn apply_mark(self, mark: ExpnId) -> Span {
517 let span = self.data();
518 span.with_ctxt(span.ctxt.apply_mark(mark))
522 pub fn remove_mark(&mut self) -> ExpnId {
523 let mut span = self.data();
524 let mark = span.ctxt.remove_mark();
525 *self = Span::new(span.lo, span.hi, span.ctxt);
530 pub fn adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> {
531 let mut span = self.data();
532 let mark = span.ctxt.adjust(expn_id);
533 *self = Span::new(span.lo, span.hi, span.ctxt);
538 pub fn modernize_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> {
539 let mut span = self.data();
540 let mark = span.ctxt.modernize_and_adjust(expn_id);
541 *self = Span::new(span.lo, span.hi, span.ctxt);
546 pub fn glob_adjust(&mut self, expn_id: ExpnId, glob_span: Span) -> Option<Option<ExpnId>> {
547 let mut span = self.data();
548 let mark = span.ctxt.glob_adjust(expn_id, glob_span);
549 *self = Span::new(span.lo, span.hi, span.ctxt);
554 pub fn reverse_glob_adjust(&mut self, expn_id: ExpnId, glob_span: Span)
555 -> Option<Option<ExpnId>> {
556 let mut span = self.data();
557 let mark = span.ctxt.reverse_glob_adjust(expn_id, glob_span);
558 *self = Span::new(span.lo, span.hi, span.ctxt);
563 pub fn modern(self) -> Span {
564 let span = self.data();
565 span.with_ctxt(span.ctxt.modern())
569 pub fn modern_and_legacy(self) -> Span {
570 let span = self.data();
571 span.with_ctxt(span.ctxt.modern_and_legacy())
575 #[derive(Clone, Debug)]
576 pub struct SpanLabel {
577 /// The span we are going to include in the final snippet.
580 /// Is this a primary span? This is the "locus" of the message,
581 /// and is indicated with a `^^^^` underline, versus `----`.
582 pub is_primary: bool,
584 /// What label should we attach to this span (if any)?
585 pub label: Option<String>,
588 impl Default for Span {
589 fn default() -> Self {
594 impl rustc_serialize::UseSpecializedEncodable for Span {
595 fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
596 let span = self.data();
597 s.emit_struct("Span", 2, |s| {
598 s.emit_struct_field("lo", 0, |s| {
602 s.emit_struct_field("hi", 1, |s| {
609 impl rustc_serialize::UseSpecializedDecodable for Span {
610 fn default_decode<D: Decoder>(d: &mut D) -> Result<Span, D::Error> {
611 d.read_struct("Span", 2, |d| {
612 let lo = d.read_struct_field("lo", 0, Decodable::decode)?;
613 let hi = d.read_struct_field("hi", 1, Decodable::decode)?;
614 Ok(Span::with_root_ctxt(lo, hi))
619 pub fn default_span_debug(span: Span, f: &mut fmt::Formatter<'_>) -> fmt::Result {
620 f.debug_struct("Span")
621 .field("lo", &span.lo())
622 .field("hi", &span.hi())
623 .field("ctxt", &span.ctxt())
627 impl fmt::Debug for Span {
628 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
629 SPAN_DEBUG.with(|span_debug| span_debug.get()(*self, f))
633 impl fmt::Debug for SpanData {
634 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
635 SPAN_DEBUG.with(|span_debug| span_debug.get()(Span::new(self.lo, self.hi, self.ctxt), f))
641 pub fn new() -> MultiSpan {
643 primary_spans: vec![],
648 pub fn from_span(primary_span: Span) -> MultiSpan {
650 primary_spans: vec![primary_span],
655 pub fn from_spans(vec: Vec<Span>) -> MultiSpan {
662 pub fn push_span_label(&mut self, span: Span, label: String) {
663 self.span_labels.push((span, label));
666 /// Selects the first primary span (if any).
667 pub fn primary_span(&self) -> Option<Span> {
668 self.primary_spans.first().cloned()
671 /// Returns all primary spans.
672 pub fn primary_spans(&self) -> &[Span] {
676 /// Returns `true` if any of the primary spans are displayable.
677 pub fn has_primary_spans(&self) -> bool {
678 self.primary_spans.iter().any(|sp| !sp.is_dummy())
681 /// Returns `true` if this contains only a dummy primary span with any hygienic context.
682 pub fn is_dummy(&self) -> bool {
683 let mut is_dummy = true;
684 for span in &self.primary_spans {
685 if !span.is_dummy() {
692 /// Replaces all occurrences of one Span with another. Used to move `Span`s in areas that don't
693 /// display well (like std macros). Returns whether replacements occurred.
694 pub fn replace(&mut self, before: Span, after: Span) -> bool {
695 let mut replacements_occurred = false;
696 for primary_span in &mut self.primary_spans {
697 if *primary_span == before {
698 *primary_span = after;
699 replacements_occurred = true;
702 for span_label in &mut self.span_labels {
703 if span_label.0 == before {
704 span_label.0 = after;
705 replacements_occurred = true;
708 replacements_occurred
711 /// Returns the strings to highlight. We always ensure that there
712 /// is an entry for each of the primary spans -- for each primary
713 /// span `P`, if there is at least one label with span `P`, we return
714 /// those labels (marked as primary). But otherwise we return
715 /// `SpanLabel` instances with empty labels.
716 pub fn span_labels(&self) -> Vec<SpanLabel> {
717 let is_primary = |span| self.primary_spans.contains(&span);
719 let mut span_labels = self.span_labels.iter().map(|&(span, ref label)|
722 is_primary: is_primary(span),
723 label: Some(label.clone())
725 ).collect::<Vec<_>>();
727 for &span in &self.primary_spans {
728 if !span_labels.iter().any(|sl| sl.span == span) {
729 span_labels.push(SpanLabel {
740 /// Returns `true` if any of the span labels is displayable.
741 pub fn has_span_labels(&self) -> bool {
742 self.span_labels.iter().any(|(sp, _)| !sp.is_dummy())
746 impl From<Span> for MultiSpan {
747 fn from(span: Span) -> MultiSpan {
748 MultiSpan::from_span(span)
752 impl From<Vec<Span>> for MultiSpan {
753 fn from(spans: Vec<Span>) -> MultiSpan {
754 MultiSpan::from_spans(spans)
758 /// Identifies an offset of a multi-byte character in a `SourceFile`.
759 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Eq, PartialEq, Debug)]
760 pub struct MultiByteChar {
761 /// The absolute offset of the character in the `SourceMap`.
763 /// The number of bytes, `>= 2`.
767 /// Identifies an offset of a non-narrow character in a `SourceFile`.
768 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Eq, PartialEq, Debug)]
769 pub enum NonNarrowChar {
770 /// Represents a zero-width character.
772 /// Represents a wide (full-width) character.
774 /// Represents a tab character, represented visually with a width of 4 characters.
779 fn new(pos: BytePos, width: usize) -> Self {
781 0 => NonNarrowChar::ZeroWidth(pos),
782 2 => NonNarrowChar::Wide(pos),
783 4 => NonNarrowChar::Tab(pos),
784 _ => panic!("width {} given for non-narrow character", width),
788 /// Returns the absolute offset of the character in the `SourceMap`.
789 pub fn pos(&self) -> BytePos {
791 NonNarrowChar::ZeroWidth(p) |
792 NonNarrowChar::Wide(p) |
793 NonNarrowChar::Tab(p) => p,
797 /// Returns the width of the character, 0 (zero-width) or 2 (wide).
798 pub fn width(&self) -> usize {
800 NonNarrowChar::ZeroWidth(_) => 0,
801 NonNarrowChar::Wide(_) => 2,
802 NonNarrowChar::Tab(_) => 4,
807 impl Add<BytePos> for NonNarrowChar {
810 fn add(self, rhs: BytePos) -> Self {
812 NonNarrowChar::ZeroWidth(pos) => NonNarrowChar::ZeroWidth(pos + rhs),
813 NonNarrowChar::Wide(pos) => NonNarrowChar::Wide(pos + rhs),
814 NonNarrowChar::Tab(pos) => NonNarrowChar::Tab(pos + rhs),
819 impl Sub<BytePos> for NonNarrowChar {
822 fn sub(self, rhs: BytePos) -> Self {
824 NonNarrowChar::ZeroWidth(pos) => NonNarrowChar::ZeroWidth(pos - rhs),
825 NonNarrowChar::Wide(pos) => NonNarrowChar::Wide(pos - rhs),
826 NonNarrowChar::Tab(pos) => NonNarrowChar::Tab(pos - rhs),
831 /// The state of the lazy external source loading mechanism of a `SourceFile`.
832 #[derive(PartialEq, Eq, Clone)]
833 pub enum ExternalSource {
834 /// The external source has been loaded already.
836 /// No attempt has been made to load the external source.
838 /// A failed attempt has been made to load the external source.
840 /// No external source has to be loaded, since the `SourceFile` represents a local crate.
844 impl ExternalSource {
845 pub fn is_absent(&self) -> bool {
847 ExternalSource::Present(_) => false,
852 pub fn get_source(&self) -> Option<&str> {
854 ExternalSource::Present(ref src) => Some(src),
861 pub struct OffsetOverflowError;
863 /// A single source in the `SourceMap`.
865 pub struct SourceFile {
866 /// The name of the file that the source came from, source that doesn't
867 /// originate from files has names between angle brackets by convention
868 /// (e.g., `<anon>`).
870 /// `true` if the `name` field above has been modified by `--remap-path-prefix`.
871 pub name_was_remapped: bool,
872 /// The unmapped path of the file that the source came from.
873 /// Set to `None` if the `SourceFile` was imported from an external crate.
874 pub unmapped_path: Option<FileName>,
875 /// Indicates which crate this `SourceFile` was imported from.
876 pub crate_of_origin: u32,
877 /// The complete source code.
878 pub src: Option<Lrc<String>>,
879 /// The source code's hash.
881 /// The external source code (used for external crates, which will have a `None`
882 /// value as `self.src`.
883 pub external_src: Lock<ExternalSource>,
884 /// The start position of this source in the `SourceMap`.
885 pub start_pos: BytePos,
886 /// The end position of this source in the `SourceMap`.
887 pub end_pos: BytePos,
888 /// Locations of lines beginnings in the source code.
889 pub lines: Vec<BytePos>,
890 /// Locations of multi-byte characters in the source code.
891 pub multibyte_chars: Vec<MultiByteChar>,
892 /// Width of characters that are not narrow in the source code.
893 pub non_narrow_chars: Vec<NonNarrowChar>,
894 /// A hash of the filename, used for speeding up hashing in incremental compilation.
898 impl Encodable for SourceFile {
899 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
900 s.emit_struct("SourceFile", 8, |s| {
901 s.emit_struct_field("name", 0, |s| self.name.encode(s))?;
902 s.emit_struct_field("name_was_remapped", 1, |s| self.name_was_remapped.encode(s))?;
903 s.emit_struct_field("src_hash", 2, |s| self.src_hash.encode(s))?;
904 s.emit_struct_field("start_pos", 4, |s| self.start_pos.encode(s))?;
905 s.emit_struct_field("end_pos", 5, |s| self.end_pos.encode(s))?;
906 s.emit_struct_field("lines", 6, |s| {
907 let lines = &self.lines[..];
909 s.emit_u32(lines.len() as u32)?;
911 if !lines.is_empty() {
912 // In order to preserve some space, we exploit the fact that
913 // the lines list is sorted and individual lines are
914 // probably not that long. Because of that we can store lines
915 // as a difference list, using as little space as possible
916 // for the differences.
917 let max_line_length = if lines.len() == 1 {
921 .map(|w| w[1] - w[0])
922 .map(|bp| bp.to_usize())
927 let bytes_per_diff: u8 = match max_line_length {
929 0x100 ..= 0xFFFF => 2,
933 // Encode the number of bytes used per diff.
934 bytes_per_diff.encode(s)?;
936 // Encode the first element.
939 let diff_iter = (&lines[..]).windows(2)
940 .map(|w| (w[1] - w[0]));
942 match bytes_per_diff {
943 1 => for diff in diff_iter { (diff.0 as u8).encode(s)? },
944 2 => for diff in diff_iter { (diff.0 as u16).encode(s)? },
945 4 => for diff in diff_iter { diff.0.encode(s)? },
952 s.emit_struct_field("multibyte_chars", 7, |s| {
953 self.multibyte_chars.encode(s)
955 s.emit_struct_field("non_narrow_chars", 8, |s| {
956 self.non_narrow_chars.encode(s)
958 s.emit_struct_field("name_hash", 9, |s| {
959 self.name_hash.encode(s)
965 impl Decodable for SourceFile {
966 fn decode<D: Decoder>(d: &mut D) -> Result<SourceFile, D::Error> {
968 d.read_struct("SourceFile", 8, |d| {
969 let name: FileName = d.read_struct_field("name", 0, |d| Decodable::decode(d))?;
970 let name_was_remapped: bool =
971 d.read_struct_field("name_was_remapped", 1, |d| Decodable::decode(d))?;
973 d.read_struct_field("src_hash", 2, |d| Decodable::decode(d))?;
974 let start_pos: BytePos =
975 d.read_struct_field("start_pos", 4, |d| Decodable::decode(d))?;
976 let end_pos: BytePos = d.read_struct_field("end_pos", 5, |d| Decodable::decode(d))?;
977 let lines: Vec<BytePos> = d.read_struct_field("lines", 6, |d| {
978 let num_lines: u32 = Decodable::decode(d)?;
979 let mut lines = Vec::with_capacity(num_lines as usize);
982 // Read the number of bytes used per diff.
983 let bytes_per_diff: u8 = Decodable::decode(d)?;
985 // Read the first element.
986 let mut line_start: BytePos = Decodable::decode(d)?;
987 lines.push(line_start);
989 for _ in 1..num_lines {
990 let diff = match bytes_per_diff {
991 1 => d.read_u8()? as u32,
992 2 => d.read_u16()? as u32,
997 line_start = line_start + BytePos(diff);
999 lines.push(line_start);
1005 let multibyte_chars: Vec<MultiByteChar> =
1006 d.read_struct_field("multibyte_chars", 7, |d| Decodable::decode(d))?;
1007 let non_narrow_chars: Vec<NonNarrowChar> =
1008 d.read_struct_field("non_narrow_chars", 8, |d| Decodable::decode(d))?;
1009 let name_hash: u128 =
1010 d.read_struct_field("name_hash", 9, |d| Decodable::decode(d))?;
1014 unmapped_path: None,
1015 // `crate_of_origin` has to be set by the importer.
1016 // This value matches up with rustc::hir::def_id::INVALID_CRATE.
1017 // That constant is not available here unfortunately :(
1018 crate_of_origin: std::u32::MAX - 1,
1023 external_src: Lock::new(ExternalSource::AbsentOk),
1033 impl fmt::Debug for SourceFile {
1034 fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
1035 write!(fmt, "SourceFile({})", self.name)
1040 pub fn new(name: FileName,
1041 name_was_remapped: bool,
1042 unmapped_path: FileName,
1044 start_pos: BytePos) -> Result<SourceFile, OffsetOverflowError> {
1045 remove_bom(&mut src);
1048 let mut hasher: StableHasher<u128> = StableHasher::new();
1049 hasher.write(src.as_bytes());
1053 let mut hasher: StableHasher<u128> = StableHasher::new();
1054 name.hash(&mut hasher);
1057 let end_pos = start_pos.to_usize() + src.len();
1058 if end_pos > u32::max_value() as usize {
1059 return Err(OffsetOverflowError);
1062 let (lines, multibyte_chars, non_narrow_chars) =
1063 analyze_source_file::analyze_source_file(&src[..], start_pos);
1068 unmapped_path: Some(unmapped_path),
1070 src: Some(Lrc::new(src)),
1072 external_src: Lock::new(ExternalSource::Unneeded),
1074 end_pos: Pos::from_usize(end_pos),
1082 /// Returns the `BytePos` of the beginning of the current line.
1083 pub fn line_begin_pos(&self, pos: BytePos) -> BytePos {
1084 let line_index = self.lookup_line(pos).unwrap();
1085 self.lines[line_index]
1088 /// Add externally loaded source.
1089 /// If the hash of the input doesn't match or no input is supplied via None,
1090 /// it is interpreted as an error and the corresponding enum variant is set.
1091 /// The return value signifies whether some kind of source is present.
1092 pub fn add_external_src<F>(&self, get_src: F) -> bool
1093 where F: FnOnce() -> Option<String>
1095 if *self.external_src.borrow() == ExternalSource::AbsentOk {
1096 let src = get_src();
1097 let mut external_src = self.external_src.borrow_mut();
1098 // Check that no-one else have provided the source while we were getting it
1099 if *external_src == ExternalSource::AbsentOk {
1100 if let Some(src) = src {
1101 let mut hasher: StableHasher<u128> = StableHasher::new();
1102 hasher.write(src.as_bytes());
1104 if hasher.finish() == self.src_hash {
1105 *external_src = ExternalSource::Present(src);
1109 *external_src = ExternalSource::AbsentErr;
1114 self.src.is_some() || external_src.get_source().is_some()
1117 self.src.is_some() || self.external_src.borrow().get_source().is_some()
1121 /// Gets a line from the list of pre-computed line-beginnings.
1122 /// The line number here is 0-based.
1123 pub fn get_line(&self, line_number: usize) -> Option<Cow<'_, str>> {
1124 fn get_until_newline(src: &str, begin: usize) -> &str {
1125 // We can't use `lines.get(line_number+1)` because we might
1126 // be parsing when we call this function and thus the current
1127 // line is the last one we have line info for.
1128 let slice = &src[begin..];
1129 match slice.find('\n') {
1130 Some(e) => &slice[..e],
1136 let line = if let Some(line) = self.lines.get(line_number) {
1141 let begin: BytePos = *line - self.start_pos;
1145 if let Some(ref src) = self.src {
1146 Some(Cow::from(get_until_newline(src, begin)))
1147 } else if let Some(src) = self.external_src.borrow().get_source() {
1148 Some(Cow::Owned(String::from(get_until_newline(src, begin))))
1154 pub fn is_real_file(&self) -> bool {
1158 pub fn is_imported(&self) -> bool {
1162 pub fn byte_length(&self) -> u32 {
1163 self.end_pos.0 - self.start_pos.0
1165 pub fn count_lines(&self) -> usize {
1169 /// Finds the line containing the given position. The return value is the
1170 /// index into the `lines` array of this `SourceFile`, not the 1-based line
1171 /// number. If the source_file is empty or the position is located before the
1172 /// first line, `None` is returned.
1173 pub fn lookup_line(&self, pos: BytePos) -> Option<usize> {
1174 if self.lines.len() == 0 {
1178 let line_index = lookup_line(&self.lines[..], pos);
1179 assert!(line_index < self.lines.len() as isize);
1180 if line_index >= 0 {
1181 Some(line_index as usize)
1187 pub fn line_bounds(&self, line_index: usize) -> (BytePos, BytePos) {
1188 if self.start_pos == self.end_pos {
1189 return (self.start_pos, self.end_pos);
1192 assert!(line_index < self.lines.len());
1193 if line_index == (self.lines.len() - 1) {
1194 (self.lines[line_index], self.end_pos)
1196 (self.lines[line_index], self.lines[line_index + 1])
1201 pub fn contains(&self, byte_pos: BytePos) -> bool {
1202 byte_pos >= self.start_pos && byte_pos <= self.end_pos
1206 /// Removes UTF-8 BOM, if any.
1207 fn remove_bom(src: &mut String) {
1208 if src.starts_with("\u{feff}") {
1213 // _____________________________________________________________________________
1214 // Pos, BytePos, CharPos
1218 fn from_usize(n: usize) -> Self;
1219 fn to_usize(&self) -> usize;
1220 fn from_u32(n: u32) -> Self;
1221 fn to_u32(&self) -> u32;
1224 /// A byte offset. Keep this small (currently 32-bits), as AST contains
1226 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
1227 pub struct BytePos(pub u32);
1229 /// A character offset. Because of multibyte UTF-8 characters, a byte offset
1230 /// is not equivalent to a character offset. The `SourceMap` will convert `BytePos`
1231 /// values to `CharPos` values as necessary.
1232 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
1233 pub struct CharPos(pub usize);
1235 // FIXME: lots of boilerplate in these impls, but so far my attempts to fix
1236 // have been unsuccessful.
1238 impl Pos for BytePos {
1240 fn from_usize(n: usize) -> BytePos { BytePos(n as u32) }
1243 fn to_usize(&self) -> usize { self.0 as usize }
1246 fn from_u32(n: u32) -> BytePos { BytePos(n) }
1249 fn to_u32(&self) -> u32 { self.0 }
1252 impl Add for BytePos {
1253 type Output = BytePos;
1256 fn add(self, rhs: BytePos) -> BytePos {
1257 BytePos((self.to_usize() + rhs.to_usize()) as u32)
1261 impl Sub for BytePos {
1262 type Output = BytePos;
1265 fn sub(self, rhs: BytePos) -> BytePos {
1266 BytePos((self.to_usize() - rhs.to_usize()) as u32)
1270 impl Encodable for BytePos {
1271 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
1276 impl Decodable for BytePos {
1277 fn decode<D: Decoder>(d: &mut D) -> Result<BytePos, D::Error> {
1278 Ok(BytePos(d.read_u32()?))
1282 impl Pos for CharPos {
1284 fn from_usize(n: usize) -> CharPos { CharPos(n) }
1287 fn to_usize(&self) -> usize { self.0 }
1290 fn from_u32(n: u32) -> CharPos { CharPos(n as usize) }
1293 fn to_u32(&self) -> u32 { self.0 as u32}
1296 impl Add for CharPos {
1297 type Output = CharPos;
1300 fn add(self, rhs: CharPos) -> CharPos {
1301 CharPos(self.to_usize() + rhs.to_usize())
1305 impl Sub for CharPos {
1306 type Output = CharPos;
1309 fn sub(self, rhs: CharPos) -> CharPos {
1310 CharPos(self.to_usize() - rhs.to_usize())
1314 // _____________________________________________________________________________
1315 // Loc, SourceFileAndLine, SourceFileAndBytePos
1318 /// A source code location used for error reporting.
1319 #[derive(Debug, Clone)]
1321 /// Information about the original source.
1322 pub file: Lrc<SourceFile>,
1323 /// The (1-based) line number.
1325 /// The (0-based) column offset.
1327 /// The (0-based) column offset when displayed.
1328 pub col_display: usize,
1331 // Used to be structural records.
1333 pub struct SourceFileAndLine { pub sf: Lrc<SourceFile>, pub line: usize }
1335 pub struct SourceFileAndBytePos { pub sf: Lrc<SourceFile>, pub pos: BytePos }
1337 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1338 pub struct LineInfo {
1339 /// Index of line, starting from 0.
1340 pub line_index: usize,
1342 /// Column in line where span begins, starting from 0.
1343 pub start_col: CharPos,
1345 /// Column in line where span ends, starting from 0, exclusive.
1346 pub end_col: CharPos,
1349 pub struct FileLines {
1350 pub file: Lrc<SourceFile>,
1351 pub lines: Vec<LineInfo>
1354 thread_local!(pub static SPAN_DEBUG: Cell<fn(Span, &mut fmt::Formatter<'_>) -> fmt::Result> =
1355 Cell::new(default_span_debug));
1358 pub struct MacroBacktrace {
1359 /// span where macro was applied to generate this code
1360 pub call_site: Span,
1362 /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]")
1363 pub macro_decl_name: String,
1365 /// span where macro was defined (possibly dummy)
1366 pub def_site_span: Span,
1369 // _____________________________________________________________________________
1370 // SpanLinesError, SpanSnippetError, DistinctSources, MalformedSourceMapPositions
1373 pub type FileLinesResult = Result<FileLines, SpanLinesError>;
1375 #[derive(Clone, PartialEq, Eq, Debug)]
1376 pub enum SpanLinesError {
1377 IllFormedSpan(Span),
1378 DistinctSources(DistinctSources),
1381 #[derive(Clone, PartialEq, Eq, Debug)]
1382 pub enum SpanSnippetError {
1383 IllFormedSpan(Span),
1384 DistinctSources(DistinctSources),
1385 MalformedForSourcemap(MalformedSourceMapPositions),
1386 SourceNotAvailable { filename: FileName }
1389 #[derive(Clone, PartialEq, Eq, Debug)]
1390 pub struct DistinctSources {
1391 pub begin: (FileName, BytePos),
1392 pub end: (FileName, BytePos)
1395 #[derive(Clone, PartialEq, Eq, Debug)]
1396 pub struct MalformedSourceMapPositions {
1398 pub source_len: usize,
1399 pub begin_pos: BytePos,
1400 pub end_pos: BytePos
1403 /// Range inside of a `Span` used for diagnostics when we only have access to relative positions.
1404 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
1405 pub struct InnerSpan {
1411 pub fn new(start: usize, end: usize) -> InnerSpan {
1412 InnerSpan { start, end }
1416 // Given a slice of line start positions and a position, returns the index of
1417 // the line the position is on. Returns -1 if the position is located before
1419 fn lookup_line(lines: &[BytePos], pos: BytePos) -> isize {
1420 match lines.binary_search(&pos) {
1421 Ok(line) => line as isize,
1422 Err(line) => line as isize - 1