1 //! Source positions and related helper functions.
3 //! Important concepts in this module include:
5 //! - the *span*, represented by [`SpanData`] and related types;
6 //! - source code as represented by a [`SourceMap`]; and
7 //! - interned strings, represented by [`Symbol`]s, with some common symbols available statically in the [`sym`] module.
9 //! Unlike most compilers, the span contains not only the position in the source code, but also various other metadata,
10 //! such as the edition and macro hygiene. This metadata is stored in [`SyntaxContext`] and [`ExpnData`].
14 //! This API is completely unstable and subject to change.
16 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
17 #![feature(array_windows)]
18 #![feature(crate_visibility_modifier)]
20 #![feature(const_panic)]
21 #![feature(negative_impls)]
23 #![feature(min_specialization)]
26 extern crate rustc_macros
;
28 use rustc_data_structures
::AtomicRef
;
29 use rustc_macros
::HashStable_Generic
;
30 use rustc_serialize
::{Decodable, Decoder, Encodable, Encoder}
;
32 mod caching_source_map_view
;
34 pub use self::caching_source_map_view
::CachingSourceMapView
;
35 use source_map
::SourceMap
;
40 pub use hygiene
::SyntaxContext
;
41 use hygiene
::Transparency
;
42 pub use hygiene
::{DesugaringKind, ExpnData, ExpnId, ExpnKind, ForLoopLoc, MacroKind}
;
44 use def_id
::{CrateNum, DefId, LOCAL_CRATE}
;
47 pub use span_encoding
::{Span, DUMMY_SP}
;
49 pub mod crate_disambiguator
;
52 pub use symbol
::{sym, Symbol}
;
54 mod analyze_source_file
;
57 use rustc_data_structures
::fingerprint
::Fingerprint
;
58 use rustc_data_structures
::stable_hasher
::{HashStable, StableHasher}
;
59 use rustc_data_structures
::sync
::{Lock, Lrc}
;
62 use std
::cell
::RefCell
;
63 use std
::cmp
::{self, Ordering}
;
66 use std
::ops
::{Add, Range, Sub}
;
67 use std
::path
::{Path, PathBuf}
;
68 use std
::str::FromStr
;
69 use std
::thread
::LocalKey
;
81 // Per-session global variables: this struct is stored in thread-local storage
82 // in such a way that it is accessible without any kind of handle to all
83 // threads within the compilation session, but is not accessible outside the
85 pub struct SessionGlobals
{
86 symbol_interner
: Lock
<symbol
::Interner
>,
87 span_interner
: Lock
<span_encoding
::SpanInterner
>,
88 hygiene_data
: Lock
<hygiene
::HygieneData
>,
89 source_map
: Lock
<Option
<Lrc
<SourceMap
>>>,
93 pub fn new(edition
: Edition
) -> SessionGlobals
{
95 symbol_interner
: Lock
::new(symbol
::Interner
::fresh()),
96 span_interner
: Lock
::new(span_encoding
::SpanInterner
::default()),
97 hygiene_data
: Lock
::new(hygiene
::HygieneData
::new(edition
)),
98 source_map
: Lock
::new(None
),
103 pub fn with_session_globals
<R
>(edition
: Edition
, f
: impl FnOnce() -> R
) -> R
{
104 let session_globals
= SessionGlobals
::new(edition
);
105 SESSION_GLOBALS
.set(&session_globals
, f
)
108 pub fn with_default_session_globals
<R
>(f
: impl FnOnce() -> R
) -> R
{
109 with_session_globals(edition
::DEFAULT_EDITION
, f
)
112 // If this ever becomes non thread-local, `decode_syntax_context`
113 // and `decode_expn_id` will need to be updated to handle concurrent
115 scoped_tls
::scoped_thread_local
!(pub static SESSION_GLOBALS
: SessionGlobals
);
117 // FIXME: Perhaps this should not implement Rustc{Decodable, Encodable}
119 // FIXME: We should use this enum or something like it to get rid of the
120 // use of magic `/rust/1.x/...` paths across the board.
121 #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash)]
122 #[derive(HashStable_Generic, Decodable, Encodable)]
123 pub enum RealFileName
{
125 /// For de-virtualized paths (namely paths into libstd that have been mapped
126 /// to the appropriate spot on the local host's file system),
128 /// `local_path` is the (host-dependent) local path to the file.
130 /// `virtual_name` is the stable path rustc will store internally within
132 virtual_name
: PathBuf
,
137 /// Returns the path suitable for reading from the file system on the local host.
138 /// Avoid embedding this in build artifacts; see `stable_name()` for that.
139 pub fn local_path(&self) -> &Path
{
141 RealFileName
::Named(p
)
142 | RealFileName
::Devirtualized { local_path: p, virtual_name: _ }
=> &p
,
146 /// Returns the path suitable for reading from the file system on the local host.
147 /// Avoid embedding this in build artifacts; see `stable_name()` for that.
148 pub fn into_local_path(self) -> PathBuf
{
150 RealFileName
::Named(p
)
151 | RealFileName
::Devirtualized { local_path: p, virtual_name: _ }
=> p
,
155 /// Returns the path suitable for embedding into build artifacts. Note that
156 /// a virtualized path will not correspond to a valid file system path; see
157 /// `local_path()` for something that is more likely to return paths into the
158 /// local host file system.
159 pub fn stable_name(&self) -> &Path
{
161 RealFileName
::Named(p
)
162 | RealFileName
::Devirtualized { local_path: _, virtual_name: p }
=> &p
,
167 /// Differentiates between real files and common virtual files.
168 #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash)]
169 #[derive(HashStable_Generic, Decodable, Encodable)]
172 /// Call to `quote!`.
176 /// Hack in `src/librustc_ast/parse.rs`.
179 ProcMacroSourceCode(u64),
180 /// Strings provided as `--cfg [cfgspec]` stored in a `crate_cfg`.
182 /// Strings provided as crate attributes in the CLI.
184 /// Custom sources for explicit parser calls from plugins and drivers.
186 DocTest(PathBuf
, isize),
187 /// Post-substitution inline assembly from LLVM.
191 impl std
::fmt
::Display
for FileName
{
192 fn fmt(&self, fmt
: &mut std
::fmt
::Formatter
<'_
>) -> std
::fmt
::Result
{
195 Real(RealFileName
::Named(ref path
)) => write
!(fmt
, "{}", path
.display()),
196 // FIXME: might be nice to display both components of Devirtualized.
197 // But for now (to backport fix for issue #70924), best to not
198 // perturb diagnostics so its obvious test suite still works.
199 Real(RealFileName
::Devirtualized { ref local_path, virtual_name: _ }
) => {
200 write
!(fmt
, "{}", local_path
.display())
202 QuoteExpansion(_
) => write
!(fmt
, "<quote expansion>"),
203 MacroExpansion(_
) => write
!(fmt
, "<macro expansion>"),
204 Anon(_
) => write
!(fmt
, "<anon>"),
205 ProcMacroSourceCode(_
) => write
!(fmt
, "<proc-macro source code>"),
206 CfgSpec(_
) => write
!(fmt
, "<cfgspec>"),
207 CliCrateAttr(_
) => write
!(fmt
, "<crate attribute>"),
208 Custom(ref s
) => write
!(fmt
, "<{}>", s
),
209 DocTest(ref path
, _
) => write
!(fmt
, "{}", path
.display()),
210 InlineAsm(_
) => write
!(fmt
, "<inline asm>"),
215 impl From
<PathBuf
> for FileName
{
216 fn from(p
: PathBuf
) -> Self {
217 assert
!(!p
.to_string_lossy().ends_with('
>'
));
218 FileName
::Real(RealFileName
::Named(p
))
223 pub fn is_real(&self) -> bool
{
229 | ProcMacroSourceCode(_
)
235 | InlineAsm(_
) => false,
239 pub fn macro_expansion_source_code(src
: &str) -> FileName
{
240 let mut hasher
= StableHasher
::new();
241 src
.hash(&mut hasher
);
242 FileName
::MacroExpansion(hasher
.finish())
245 pub fn anon_source_code(src
: &str) -> FileName
{
246 let mut hasher
= StableHasher
::new();
247 src
.hash(&mut hasher
);
248 FileName
::Anon(hasher
.finish())
251 pub fn proc_macro_source_code(src
: &str) -> FileName
{
252 let mut hasher
= StableHasher
::new();
253 src
.hash(&mut hasher
);
254 FileName
::ProcMacroSourceCode(hasher
.finish())
257 pub fn cfg_spec_source_code(src
: &str) -> FileName
{
258 let mut hasher
= StableHasher
::new();
259 src
.hash(&mut hasher
);
260 FileName
::QuoteExpansion(hasher
.finish())
263 pub fn cli_crate_attr_source_code(src
: &str) -> FileName
{
264 let mut hasher
= StableHasher
::new();
265 src
.hash(&mut hasher
);
266 FileName
::CliCrateAttr(hasher
.finish())
269 pub fn doc_test_source_code(path
: PathBuf
, line
: isize) -> FileName
{
270 FileName
::DocTest(path
, line
)
273 pub fn inline_asm_source_code(src
: &str) -> FileName
{
274 let mut hasher
= StableHasher
::new();
275 src
.hash(&mut hasher
);
276 FileName
::InlineAsm(hasher
.finish())
280 /// Represents a span.
282 /// Spans represent a region of code, used for error reporting. Positions in spans
283 /// are *absolute* positions from the beginning of the [`SourceMap`], not positions
284 /// relative to [`SourceFile`]s. Methods on the `SourceMap` can be used to relate spans back
285 /// to the original source.
287 /// You must be careful if the span crosses more than one file, since you will not be
288 /// able to use many of the functions on spans in source_map and you cannot assume
289 /// that the length of the span is equal to `span.hi - span.lo`; there may be space in the
290 /// [`BytePos`] range between files.
292 /// `SpanData` is public because `Span` uses a thread-local interner and can't be
293 /// sent to other threads, but some pieces of performance infra run in a separate thread.
294 /// Using `Span` is generally preferred.
295 #[derive(Clone, Copy, Hash, PartialEq, Eq, Ord, PartialOrd)]
296 pub struct SpanData
{
299 /// Information about where the macro came from, if this piece of
300 /// code was created by a macro expansion.
301 pub ctxt
: SyntaxContext
,
306 pub fn span(&self) -> Span
{
307 Span
::new(self.lo
, self.hi
, self.ctxt
)
310 pub fn with_lo(&self, lo
: BytePos
) -> Span
{
311 Span
::new(lo
, self.hi
, self.ctxt
)
314 pub fn with_hi(&self, hi
: BytePos
) -> Span
{
315 Span
::new(self.lo
, hi
, self.ctxt
)
318 pub fn with_ctxt(&self, ctxt
: SyntaxContext
) -> Span
{
319 Span
::new(self.lo
, self.hi
, ctxt
)
323 // The interner is pointed to by a thread local value which is only set on the main thread
324 // with parallelization is disabled. So we don't allow `Span` to transfer between threads
325 // to avoid panics and other errors, even though it would be memory safe to do so.
326 #[cfg(not(parallel_compiler))]
327 impl !Send
for Span {}
328 #[cfg(not(parallel_compiler))]
329 impl !Sync
for Span {}
331 impl PartialOrd
for Span
{
332 fn partial_cmp(&self, rhs
: &Self) -> Option
<Ordering
> {
333 PartialOrd
::partial_cmp(&self.data(), &rhs
.data())
337 fn cmp(&self, rhs
: &Self) -> Ordering
{
338 Ord
::cmp(&self.data(), &rhs
.data())
342 /// A collection of `Span`s.
344 /// Spans have two orthogonal attributes:
346 /// - They can be *primary spans*. In this case they are the locus of
347 /// the error, and would be rendered with `^^^`.
348 /// - They can have a *label*. In this case, the label is written next
349 /// to the mark in the snippet when we render.
350 #[derive(Clone, Debug, Hash, PartialEq, Eq, Encodable, Decodable)]
351 pub struct MultiSpan
{
352 primary_spans
: Vec
<Span
>,
353 span_labels
: Vec
<(Span
, String
)>,
358 pub fn lo(self) -> BytePos
{
362 pub fn with_lo(self, lo
: BytePos
) -> Span
{
363 self.data().with_lo(lo
)
366 pub fn hi(self) -> BytePos
{
370 pub fn with_hi(self, hi
: BytePos
) -> Span
{
371 self.data().with_hi(hi
)
374 pub fn ctxt(self) -> SyntaxContext
{
378 pub fn with_ctxt(self, ctxt
: SyntaxContext
) -> Span
{
379 self.data().with_ctxt(ctxt
)
382 /// Returns `true` if this is a dummy span with any hygienic context.
384 pub fn is_dummy(self) -> bool
{
385 let span
= self.data();
386 span
.lo
.0 == 0 && span
.hi
.0 == 0
389 /// Returns `true` if this span comes from a macro or desugaring.
391 pub fn from_expansion(self) -> bool
{
392 self.ctxt() != SyntaxContext
::root()
395 /// Returns `true` if `span` originates in a derive-macro's expansion.
396 pub fn in_derive_expansion(self) -> bool
{
397 matches
!(self.ctxt().outer_expn_data().kind
, ExpnKind
::Macro(MacroKind
::Derive
, _
))
401 pub fn with_root_ctxt(lo
: BytePos
, hi
: BytePos
) -> Span
{
402 Span
::new(lo
, hi
, SyntaxContext
::root())
405 /// Returns a new span representing an empty span at the beginning of this span.
407 pub fn shrink_to_lo(self) -> Span
{
408 let span
= self.data();
409 span
.with_hi(span
.lo
)
411 /// Returns a new span representing an empty span at the end of this span.
413 pub fn shrink_to_hi(self) -> Span
{
414 let span
= self.data();
415 span
.with_lo(span
.hi
)
419 /// Returns `true` if `hi == lo`.
420 pub fn is_empty(&self) -> bool
{
421 let span
= self.data();
425 /// Returns `self` if `self` is not the dummy span, and `other` otherwise.
426 pub fn substitute_dummy(self, other
: Span
) -> Span
{
427 if self.is_dummy() { other }
else { self }
430 /// Returns `true` if `self` fully encloses `other`.
431 pub fn contains(self, other
: Span
) -> bool
{
432 let span
= self.data();
433 let other
= other
.data();
434 span
.lo
<= other
.lo
&& other
.hi
<= span
.hi
437 /// Returns `true` if `self` touches `other`.
438 pub fn overlaps(self, other
: Span
) -> bool
{
439 let span
= self.data();
440 let other
= other
.data();
441 span
.lo
< other
.hi
&& other
.lo
< span
.hi
444 /// Returns `true` if the spans are equal with regards to the source text.
446 /// Use this instead of `==` when either span could be generated code,
447 /// and you only care that they point to the same bytes of source text.
448 pub fn source_equal(&self, other
: &Span
) -> bool
{
449 let span
= self.data();
450 let other
= other
.data();
451 span
.lo
== other
.lo
&& span
.hi
== other
.hi
454 /// Returns `Some(span)`, where the start is trimmed by the end of `other`.
455 pub fn trim_start(self, other
: Span
) -> Option
<Span
> {
456 let span
= self.data();
457 let other
= other
.data();
458 if span
.hi
> other
.hi { Some(span.with_lo(cmp::max(span.lo, other.hi))) }
else { None }
461 /// Returns the source span -- this is either the supplied span, or the span for
462 /// the macro callsite that expanded to it.
463 pub fn source_callsite(self) -> Span
{
464 let expn_data
= self.ctxt().outer_expn_data();
465 if !expn_data
.is_root() { expn_data.call_site.source_callsite() }
else { self }
468 /// The `Span` for the tokens in the previous macro expansion from which `self` was generated,
470 pub fn parent(self) -> Option
<Span
> {
471 let expn_data
= self.ctxt().outer_expn_data();
472 if !expn_data
.is_root() { Some(expn_data.call_site) }
else { None }
475 /// Edition of the crate from which this span came.
476 pub fn edition(self) -> edition
::Edition
{
477 self.ctxt().edition()
481 pub fn rust_2015(&self) -> bool
{
482 self.edition() == edition
::Edition
::Edition2015
486 pub fn rust_2018(&self) -> bool
{
487 self.edition() >= edition
::Edition
::Edition2018
491 pub fn rust_2021(&self) -> bool
{
492 self.edition() >= edition
::Edition
::Edition2021
495 /// Returns the source callee.
497 /// Returns `None` if the supplied span has no expansion trace,
498 /// else returns the `ExpnData` for the macro definition
499 /// corresponding to the source callsite.
500 pub fn source_callee(self) -> Option
<ExpnData
> {
501 fn source_callee(expn_data
: ExpnData
) -> ExpnData
{
502 let next_expn_data
= expn_data
.call_site
.ctxt().outer_expn_data();
503 if !next_expn_data
.is_root() { source_callee(next_expn_data) }
else { expn_data }
505 let expn_data
= self.ctxt().outer_expn_data();
506 if !expn_data
.is_root() { Some(source_callee(expn_data)) }
else { None }
509 /// Checks if a span is "internal" to a macro in which `#[unstable]`
510 /// items can be used (that is, a macro marked with
511 /// `#[allow_internal_unstable]`).
512 pub fn allows_unstable(&self, feature
: Symbol
) -> bool
{
515 .allow_internal_unstable
516 .map_or(false, |features
| features
.iter().any(|&f
| f
== feature
))
519 /// Checks if this span arises from a compiler desugaring of kind `kind`.
520 pub fn is_desugaring(&self, kind
: DesugaringKind
) -> bool
{
521 match self.ctxt().outer_expn_data().kind
{
522 ExpnKind
::Desugaring(k
) => k
== kind
,
527 /// Returns the compiler desugaring that created this span, or `None`
528 /// if this span is not from a desugaring.
529 pub fn desugaring_kind(&self) -> Option
<DesugaringKind
> {
530 match self.ctxt().outer_expn_data().kind
{
531 ExpnKind
::Desugaring(k
) => Some(k
),
536 /// Checks if a span is "internal" to a macro in which `unsafe`
537 /// can be used without triggering the `unsafe_code` lint.
538 // (that is, a macro marked with `#[allow_internal_unsafe]`).
539 pub fn allows_unsafe(&self) -> bool
{
540 self.ctxt().outer_expn_data().allow_internal_unsafe
543 pub fn macro_backtrace(mut self) -> impl Iterator
<Item
= ExpnData
> {
544 let mut prev_span
= DUMMY_SP
;
545 std
::iter
::from_fn(move || {
547 let expn_data
= self.ctxt().outer_expn_data();
548 if expn_data
.is_root() {
552 let is_recursive
= expn_data
.call_site
.source_equal(&prev_span
);
555 self = expn_data
.call_site
;
557 // Don't print recursive invocations.
559 return Some(expn_data
);
565 /// Returns a `Span` that would enclose both `self` and `end`.
569 /// self lorem ipsum end
570 /// ^^^^^^^^^^^^^^^^^^^^
572 pub fn to(self, end
: Span
) -> Span
{
573 let span_data
= self.data();
574 let end_data
= end
.data();
575 // FIXME(jseyfried): `self.ctxt` should always equal `end.ctxt` here (cf. issue #23480).
576 // Return the macro span on its own to avoid weird diagnostic output. It is preferable to
577 // have an incomplete span than a completely nonsensical one.
578 if span_data
.ctxt
!= end_data
.ctxt
{
579 if span_data
.ctxt
== SyntaxContext
::root() {
581 } else if end_data
.ctxt
== SyntaxContext
::root() {
584 // Both spans fall within a macro.
585 // FIXME(estebank): check if it is the *same* macro.
588 cmp
::min(span_data
.lo
, end_data
.lo
),
589 cmp
::max(span_data
.hi
, end_data
.hi
),
590 if span_data
.ctxt
== SyntaxContext
::root() { end_data.ctxt }
else { span_data.ctxt }
,
594 /// Returns a `Span` between the end of `self` to the beginning of `end`.
598 /// self lorem ipsum end
601 pub fn between(self, end
: Span
) -> Span
{
602 let span
= self.data();
603 let end
= end
.data();
607 if end
.ctxt
== SyntaxContext
::root() { end.ctxt }
else { span.ctxt }
,
611 /// Returns a `Span` from the beginning of `self` until the beginning of `end`.
615 /// self lorem ipsum end
616 /// ^^^^^^^^^^^^^^^^^
618 pub fn until(self, end
: Span
) -> Span
{
619 let span
= self.data();
620 let end
= end
.data();
624 if end
.ctxt
== SyntaxContext
::root() { end.ctxt }
else { span.ctxt }
,
628 pub fn from_inner(self, inner
: InnerSpan
) -> Span
{
629 let span
= self.data();
631 span
.lo
+ BytePos
::from_usize(inner
.start
),
632 span
.lo
+ BytePos
::from_usize(inner
.end
),
637 /// Equivalent of `Span::def_site` from the proc macro API,
638 /// except that the location is taken from the `self` span.
639 pub fn with_def_site_ctxt(self, expn_id
: ExpnId
) -> Span
{
640 self.with_ctxt_from_mark(expn_id
, Transparency
::Opaque
)
643 /// Equivalent of `Span::call_site` from the proc macro API,
644 /// except that the location is taken from the `self` span.
645 pub fn with_call_site_ctxt(&self, expn_id
: ExpnId
) -> Span
{
646 self.with_ctxt_from_mark(expn_id
, Transparency
::Transparent
)
649 /// Equivalent of `Span::mixed_site` from the proc macro API,
650 /// except that the location is taken from the `self` span.
651 pub fn with_mixed_site_ctxt(&self, expn_id
: ExpnId
) -> Span
{
652 self.with_ctxt_from_mark(expn_id
, Transparency
::SemiTransparent
)
655 /// Produces a span with the same location as `self` and context produced by a macro with the
656 /// given ID and transparency, assuming that macro was defined directly and not produced by
657 /// some other macro (which is the case for built-in and procedural macros).
658 pub fn with_ctxt_from_mark(self, expn_id
: ExpnId
, transparency
: Transparency
) -> Span
{
659 self.with_ctxt(SyntaxContext
::root().apply_mark(expn_id
, transparency
))
663 pub fn apply_mark(self, expn_id
: ExpnId
, transparency
: Transparency
) -> Span
{
664 let span
= self.data();
665 span
.with_ctxt(span
.ctxt
.apply_mark(expn_id
, transparency
))
669 pub fn remove_mark(&mut self) -> ExpnId
{
670 let mut span
= self.data();
671 let mark
= span
.ctxt
.remove_mark();
672 *self = Span
::new(span
.lo
, span
.hi
, span
.ctxt
);
677 pub fn adjust(&mut self, expn_id
: ExpnId
) -> Option
<ExpnId
> {
678 let mut span
= self.data();
679 let mark
= span
.ctxt
.adjust(expn_id
);
680 *self = Span
::new(span
.lo
, span
.hi
, span
.ctxt
);
685 pub fn normalize_to_macros_2_0_and_adjust(&mut self, expn_id
: ExpnId
) -> Option
<ExpnId
> {
686 let mut span
= self.data();
687 let mark
= span
.ctxt
.normalize_to_macros_2_0_and_adjust(expn_id
);
688 *self = Span
::new(span
.lo
, span
.hi
, span
.ctxt
);
693 pub fn glob_adjust(&mut self, expn_id
: ExpnId
, glob_span
: Span
) -> Option
<Option
<ExpnId
>> {
694 let mut span
= self.data();
695 let mark
= span
.ctxt
.glob_adjust(expn_id
, glob_span
);
696 *self = Span
::new(span
.lo
, span
.hi
, span
.ctxt
);
701 pub fn reverse_glob_adjust(
705 ) -> Option
<Option
<ExpnId
>> {
706 let mut span
= self.data();
707 let mark
= span
.ctxt
.reverse_glob_adjust(expn_id
, glob_span
);
708 *self = Span
::new(span
.lo
, span
.hi
, span
.ctxt
);
713 pub fn normalize_to_macros_2_0(self) -> Span
{
714 let span
= self.data();
715 span
.with_ctxt(span
.ctxt
.normalize_to_macros_2_0())
719 pub fn normalize_to_macro_rules(self) -> Span
{
720 let span
= self.data();
721 span
.with_ctxt(span
.ctxt
.normalize_to_macro_rules())
725 /// A span together with some additional data.
726 #[derive(Clone, Debug)]
727 pub struct SpanLabel
{
728 /// The span we are going to include in the final snippet.
731 /// Is this a primary span? This is the "locus" of the message,
732 /// and is indicated with a `^^^^` underline, versus `----`.
733 pub is_primary
: bool
,
735 /// What label should we attach to this span (if any)?
736 pub label
: Option
<String
>,
739 impl Default
for Span
{
740 fn default() -> Self {
745 impl<E
: Encoder
> Encodable
<E
> for Span
{
746 default fn encode(&self, s
: &mut E
) -> Result
<(), E
::Error
> {
747 let span
= self.data();
748 s
.emit_struct("Span", 2, |s
| {
749 s
.emit_struct_field("lo", 0, |s
| span
.lo
.encode(s
))?
;
750 s
.emit_struct_field("hi", 1, |s
| span
.hi
.encode(s
))
754 impl<D
: Decoder
> Decodable
<D
> for Span
{
755 default fn decode(s
: &mut D
) -> Result
<Span
, D
::Error
> {
756 s
.read_struct("Span", 2, |d
| {
757 let lo
= d
.read_struct_field("lo", 0, Decodable
::decode
)?
;
758 let hi
= d
.read_struct_field("hi", 1, Decodable
::decode
)?
;
760 Ok(Span
::new(lo
, hi
, SyntaxContext
::root()))
765 /// Calls the provided closure, using the provided `SourceMap` to format
766 /// any spans that are debug-printed during the closure's execution.
768 /// Normally, the global `TyCtxt` is used to retrieve the `SourceMap`
769 /// (see `rustc_interface::callbacks::span_debug1`). However, some parts
770 /// of the compiler (e.g. `rustc_parse`) may debug-print `Span`s before
771 /// a `TyCtxt` is available. In this case, we fall back to
772 /// the `SourceMap` provided to this function. If that is not available,
773 /// we fall back to printing the raw `Span` field values.
774 pub fn with_source_map
<T
, F
: FnOnce() -> T
>(source_map
: Lrc
<SourceMap
>, f
: F
) -> T
{
775 SESSION_GLOBALS
.with(|session_globals
| {
776 *session_globals
.source_map
.borrow_mut() = Some(source_map
);
778 struct ClearSourceMap
;
779 impl Drop
for ClearSourceMap
{
781 SESSION_GLOBALS
.with(|session_globals
| {
782 session_globals
.source_map
.borrow_mut().take();
787 let _guard
= ClearSourceMap
;
791 pub fn debug_with_source_map(
793 f
: &mut fmt
::Formatter
<'_
>,
794 source_map
: &SourceMap
,
796 write
!(f
, "{} ({:?})", source_map
.span_to_string(span
), span
.ctxt())
799 pub fn default_span_debug(span
: Span
, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
800 SESSION_GLOBALS
.with(|session_globals
| {
801 if let Some(source_map
) = &*session_globals
.source_map
.borrow() {
802 debug_with_source_map(span
, f
, source_map
)
804 f
.debug_struct("Span")
805 .field("lo", &span
.lo())
806 .field("hi", &span
.hi())
807 .field("ctxt", &span
.ctxt())
813 impl fmt
::Debug
for Span
{
814 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
815 (*SPAN_DEBUG
)(*self, f
)
819 impl fmt
::Debug
for SpanData
{
820 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
821 (*SPAN_DEBUG
)(Span
::new(self.lo
, self.hi
, self.ctxt
), f
)
827 pub fn new() -> MultiSpan
{
828 MultiSpan { primary_spans: vec![], span_labels: vec![] }
831 pub fn from_span(primary_span
: Span
) -> MultiSpan
{
832 MultiSpan { primary_spans: vec![primary_span], span_labels: vec![] }
835 pub fn from_spans(mut vec
: Vec
<Span
>) -> MultiSpan
{
837 MultiSpan { primary_spans: vec, span_labels: vec![] }
840 pub fn push_span_label(&mut self, span
: Span
, label
: String
) {
841 self.span_labels
.push((span
, label
));
844 /// Selects the first primary span (if any).
845 pub fn primary_span(&self) -> Option
<Span
> {
846 self.primary_spans
.first().cloned()
849 /// Returns all primary spans.
850 pub fn primary_spans(&self) -> &[Span
] {
854 /// Returns `true` if any of the primary spans are displayable.
855 pub fn has_primary_spans(&self) -> bool
{
856 self.primary_spans
.iter().any(|sp
| !sp
.is_dummy())
859 /// Returns `true` if this contains only a dummy primary span with any hygienic context.
860 pub fn is_dummy(&self) -> bool
{
861 let mut is_dummy
= true;
862 for span
in &self.primary_spans
{
863 if !span
.is_dummy() {
870 /// Replaces all occurrences of one Span with another. Used to move `Span`s in areas that don't
871 /// display well (like std macros). Returns whether replacements occurred.
872 pub fn replace(&mut self, before
: Span
, after
: Span
) -> bool
{
873 let mut replacements_occurred
= false;
874 for primary_span
in &mut self.primary_spans
{
875 if *primary_span
== before
{
876 *primary_span
= after
;
877 replacements_occurred
= true;
880 for span_label
in &mut self.span_labels
{
881 if span_label
.0 == before
{
882 span_label
.0 = after
;
883 replacements_occurred
= true;
886 replacements_occurred
889 /// Returns the strings to highlight. We always ensure that there
890 /// is an entry for each of the primary spans -- for each primary
891 /// span `P`, if there is at least one label with span `P`, we return
892 /// those labels (marked as primary). But otherwise we return
893 /// `SpanLabel` instances with empty labels.
894 pub fn span_labels(&self) -> Vec
<SpanLabel
> {
895 let is_primary
= |span
| self.primary_spans
.contains(&span
);
897 let mut span_labels
= self
900 .map(|&(span
, ref label
)| SpanLabel
{
902 is_primary
: is_primary(span
),
903 label
: Some(label
.clone()),
905 .collect
::<Vec
<_
>>();
907 for &span
in &self.primary_spans
{
908 if !span_labels
.iter().any(|sl
| sl
.span
== span
) {
909 span_labels
.push(SpanLabel { span, is_primary: true, label: None }
);
916 /// Returns `true` if any of the span labels is displayable.
917 pub fn has_span_labels(&self) -> bool
{
918 self.span_labels
.iter().any(|(sp
, _
)| !sp
.is_dummy())
922 impl From
<Span
> for MultiSpan
{
923 fn from(span
: Span
) -> MultiSpan
{
924 MultiSpan
::from_span(span
)
928 impl From
<Vec
<Span
>> for MultiSpan
{
929 fn from(spans
: Vec
<Span
>) -> MultiSpan
{
930 MultiSpan
::from_spans(spans
)
934 /// Identifies an offset of a multi-byte character in a `SourceFile`.
935 #[derive(Copy, Clone, Encodable, Decodable, Eq, PartialEq, Debug)]
936 pub struct MultiByteChar
{
937 /// The absolute offset of the character in the `SourceMap`.
939 /// The number of bytes, `>= 2`.
943 /// Identifies an offset of a non-narrow character in a `SourceFile`.
944 #[derive(Copy, Clone, Encodable, Decodable, Eq, PartialEq, Debug)]
945 pub enum NonNarrowChar
{
946 /// Represents a zero-width character.
948 /// Represents a wide (full-width) character.
950 /// Represents a tab character, represented visually with a width of 4 characters.
955 fn new(pos
: BytePos
, width
: usize) -> Self {
957 0 => NonNarrowChar
::ZeroWidth(pos
),
958 2 => NonNarrowChar
::Wide(pos
),
959 4 => NonNarrowChar
::Tab(pos
),
960 _
=> panic
!("width {} given for non-narrow character", width
),
964 /// Returns the absolute offset of the character in the `SourceMap`.
965 pub fn pos(&self) -> BytePos
{
967 NonNarrowChar
::ZeroWidth(p
) | NonNarrowChar
::Wide(p
) | NonNarrowChar
::Tab(p
) => p
,
971 /// Returns the width of the character, 0 (zero-width) or 2 (wide).
972 pub fn width(&self) -> usize {
974 NonNarrowChar
::ZeroWidth(_
) => 0,
975 NonNarrowChar
::Wide(_
) => 2,
976 NonNarrowChar
::Tab(_
) => 4,
981 impl Add
<BytePos
> for NonNarrowChar
{
984 fn add(self, rhs
: BytePos
) -> Self {
986 NonNarrowChar
::ZeroWidth(pos
) => NonNarrowChar
::ZeroWidth(pos
+ rhs
),
987 NonNarrowChar
::Wide(pos
) => NonNarrowChar
::Wide(pos
+ rhs
),
988 NonNarrowChar
::Tab(pos
) => NonNarrowChar
::Tab(pos
+ rhs
),
993 impl Sub
<BytePos
> for NonNarrowChar
{
996 fn sub(self, rhs
: BytePos
) -> Self {
998 NonNarrowChar
::ZeroWidth(pos
) => NonNarrowChar
::ZeroWidth(pos
- rhs
),
999 NonNarrowChar
::Wide(pos
) => NonNarrowChar
::Wide(pos
- rhs
),
1000 NonNarrowChar
::Tab(pos
) => NonNarrowChar
::Tab(pos
- rhs
),
1005 /// Identifies an offset of a character that was normalized away from `SourceFile`.
1006 #[derive(Copy, Clone, Encodable, Decodable, Eq, PartialEq, Debug)]
1007 pub struct NormalizedPos
{
1008 /// The absolute offset of the character in the `SourceMap`.
1010 /// The difference between original and normalized string at position.
1014 #[derive(PartialEq, Eq, Clone, Debug)]
1015 pub enum ExternalSource
{
1016 /// No external source has to be loaded, since the `SourceFile` represents a local crate.
1019 kind
: ExternalSourceKind
,
1020 /// This SourceFile's byte-offset within the source_map of its original crate.
1021 original_start_pos
: BytePos
,
1022 /// The end of this SourceFile within the source_map of its original crate.
1023 original_end_pos
: BytePos
,
1027 /// The state of the lazy external source loading mechanism of a `SourceFile`.
1028 #[derive(PartialEq, Eq, Clone, Debug)]
1029 pub enum ExternalSourceKind
{
1030 /// The external source has been loaded already.
1031 Present(Lrc
<String
>),
1032 /// No attempt has been made to load the external source.
1034 /// A failed attempt has been made to load the external source.
1039 impl ExternalSource
{
1040 pub fn is_absent(&self) -> bool
{
1041 !matches
!(self, ExternalSource
::Foreign { kind: ExternalSourceKind::Present(_), .. }
)
1044 pub fn get_source(&self) -> Option
<&Lrc
<String
>> {
1046 ExternalSource
::Foreign { kind: ExternalSourceKind::Present(ref src), .. }
=> Some(src
),
1053 pub struct OffsetOverflowError
;
1055 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
1056 pub enum SourceFileHashAlgorithm
{
1062 impl FromStr
for SourceFileHashAlgorithm
{
1065 fn from_str(s
: &str) -> Result
<SourceFileHashAlgorithm
, ()> {
1067 "md5" => Ok(SourceFileHashAlgorithm
::Md5
),
1068 "sha1" => Ok(SourceFileHashAlgorithm
::Sha1
),
1069 "sha256" => Ok(SourceFileHashAlgorithm
::Sha256
),
1075 rustc_data_structures
::impl_stable_hash_via_hash
!(SourceFileHashAlgorithm
);
1077 /// The hash of the on-disk source file used for debug info.
1078 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
1079 #[derive(HashStable_Generic, Encodable, Decodable)]
1080 pub struct SourceFileHash
{
1081 pub kind
: SourceFileHashAlgorithm
,
1085 impl SourceFileHash
{
1086 pub fn new(kind
: SourceFileHashAlgorithm
, src
: &str) -> SourceFileHash
{
1087 let mut hash
= SourceFileHash { kind, value: Default::default() }
;
1088 let len
= hash
.hash_len();
1089 let value
= &mut hash
.value
[..len
];
1090 let data
= src
.as_bytes();
1092 SourceFileHashAlgorithm
::Md5
=> {
1093 value
.copy_from_slice(&Md5
::digest(data
));
1095 SourceFileHashAlgorithm
::Sha1
=> {
1096 value
.copy_from_slice(&Sha1
::digest(data
));
1098 SourceFileHashAlgorithm
::Sha256
=> {
1099 value
.copy_from_slice(&Sha256
::digest(data
));
1105 /// Check if the stored hash matches the hash of the string.
1106 pub fn matches(&self, src
: &str) -> bool
{
1107 Self::new(self.kind
, src
) == *self
1110 /// The bytes of the hash.
1111 pub fn hash_bytes(&self) -> &[u8] {
1112 let len
= self.hash_len();
1116 fn hash_len(&self) -> usize {
1118 SourceFileHashAlgorithm
::Md5
=> 16,
1119 SourceFileHashAlgorithm
::Sha1
=> 20,
1120 SourceFileHashAlgorithm
::Sha256
=> 32,
1125 /// A single source in the [`SourceMap`].
1127 pub struct SourceFile
{
1128 /// The name of the file that the source came from. Source that doesn't
1129 /// originate from files has names between angle brackets by convention
1130 /// (e.g., `<anon>`).
1132 /// `true` if the `name` field above has been modified by `--remap-path-prefix`.
1133 pub name_was_remapped
: bool
,
1134 /// The unmapped path of the file that the source came from.
1135 /// Set to `None` if the `SourceFile` was imported from an external crate.
1136 pub unmapped_path
: Option
<FileName
>,
1137 /// The complete source code.
1138 pub src
: Option
<Lrc
<String
>>,
1139 /// The source code's hash.
1140 pub src_hash
: SourceFileHash
,
1141 /// The external source code (used for external crates, which will have a `None`
1142 /// value as `self.src`.
1143 pub external_src
: Lock
<ExternalSource
>,
1144 /// The start position of this source in the `SourceMap`.
1145 pub start_pos
: BytePos
,
1146 /// The end position of this source in the `SourceMap`.
1147 pub end_pos
: BytePos
,
1148 /// Locations of lines beginnings in the source code.
1149 pub lines
: Vec
<BytePos
>,
1150 /// Locations of multi-byte characters in the source code.
1151 pub multibyte_chars
: Vec
<MultiByteChar
>,
1152 /// Width of characters that are not narrow in the source code.
1153 pub non_narrow_chars
: Vec
<NonNarrowChar
>,
1154 /// Locations of characters removed during normalization.
1155 pub normalized_pos
: Vec
<NormalizedPos
>,
1156 /// A hash of the filename, used for speeding up hashing in incremental compilation.
1157 pub name_hash
: u128
,
1158 /// Indicates which crate this `SourceFile` was imported from.
1162 impl<S
: Encoder
> Encodable
<S
> for SourceFile
{
1163 fn encode(&self, s
: &mut S
) -> Result
<(), S
::Error
> {
1164 s
.emit_struct("SourceFile", 8, |s
| {
1165 s
.emit_struct_field("name", 0, |s
| self.name
.encode(s
))?
;
1166 s
.emit_struct_field("name_was_remapped", 1, |s
| self.name_was_remapped
.encode(s
))?
;
1167 s
.emit_struct_field("src_hash", 2, |s
| self.src_hash
.encode(s
))?
;
1168 s
.emit_struct_field("start_pos", 3, |s
| self.start_pos
.encode(s
))?
;
1169 s
.emit_struct_field("end_pos", 4, |s
| self.end_pos
.encode(s
))?
;
1170 s
.emit_struct_field("lines", 5, |s
| {
1171 let lines
= &self.lines
[..];
1172 // Store the length.
1173 s
.emit_u32(lines
.len() as u32)?
;
1175 if !lines
.is_empty() {
1176 // In order to preserve some space, we exploit the fact that
1177 // the lines list is sorted and individual lines are
1178 // probably not that long. Because of that we can store lines
1179 // as a difference list, using as little space as possible
1180 // for the differences.
1181 let max_line_length
= if lines
.len() == 1 {
1186 .map(|&[fst
, snd
]| snd
- fst
)
1187 .map(|bp
| bp
.to_usize())
1192 let bytes_per_diff
: u8 = match max_line_length
{
1194 0x100..=0xFFFF => 2,
1198 // Encode the number of bytes used per diff.
1199 bytes_per_diff
.encode(s
)?
;
1201 // Encode the first element.
1202 lines
[0].encode(s
)?
;
1204 let diff_iter
= lines
[..].array_windows().map(|&[fst
, snd
]| snd
- fst
);
1206 match bytes_per_diff
{
1208 for diff
in diff_iter
{
1209 (diff
.0 as u8).encode(s
)?
1213 for diff
in diff_iter
{
1214 (diff
.0 as u16).encode(s
)?
1218 for diff
in diff_iter
{
1222 _
=> unreachable
!(),
1228 s
.emit_struct_field("multibyte_chars", 6, |s
| self.multibyte_chars
.encode(s
))?
;
1229 s
.emit_struct_field("non_narrow_chars", 7, |s
| self.non_narrow_chars
.encode(s
))?
;
1230 s
.emit_struct_field("name_hash", 8, |s
| self.name_hash
.encode(s
))?
;
1231 s
.emit_struct_field("normalized_pos", 9, |s
| self.normalized_pos
.encode(s
))?
;
1232 s
.emit_struct_field("cnum", 10, |s
| self.cnum
.encode(s
))
1237 impl<D
: Decoder
> Decodable
<D
> for SourceFile
{
1238 fn decode(d
: &mut D
) -> Result
<SourceFile
, D
::Error
> {
1239 d
.read_struct("SourceFile", 8, |d
| {
1240 let name
: FileName
= d
.read_struct_field("name", 0, |d
| Decodable
::decode(d
))?
;
1241 let name_was_remapped
: bool
=
1242 d
.read_struct_field("name_was_remapped", 1, |d
| Decodable
::decode(d
))?
;
1243 let src_hash
: SourceFileHash
=
1244 d
.read_struct_field("src_hash", 2, |d
| Decodable
::decode(d
))?
;
1245 let start_pos
: BytePos
=
1246 d
.read_struct_field("start_pos", 3, |d
| Decodable
::decode(d
))?
;
1247 let end_pos
: BytePos
= d
.read_struct_field("end_pos", 4, |d
| Decodable
::decode(d
))?
;
1248 let lines
: Vec
<BytePos
> = d
.read_struct_field("lines", 5, |d
| {
1249 let num_lines
: u32 = Decodable
::decode(d
)?
;
1250 let mut lines
= Vec
::with_capacity(num_lines
as usize);
1253 // Read the number of bytes used per diff.
1254 let bytes_per_diff
: u8 = Decodable
::decode(d
)?
;
1256 // Read the first element.
1257 let mut line_start
: BytePos
= Decodable
::decode(d
)?
;
1258 lines
.push(line_start
);
1260 for _
in 1..num_lines
{
1261 let diff
= match bytes_per_diff
{
1262 1 => d
.read_u8()?
as u32,
1263 2 => d
.read_u16()?
as u32,
1265 _
=> unreachable
!(),
1268 line_start
= line_start
+ BytePos(diff
);
1270 lines
.push(line_start
);
1276 let multibyte_chars
: Vec
<MultiByteChar
> =
1277 d
.read_struct_field("multibyte_chars", 6, |d
| Decodable
::decode(d
))?
;
1278 let non_narrow_chars
: Vec
<NonNarrowChar
> =
1279 d
.read_struct_field("non_narrow_chars", 7, |d
| Decodable
::decode(d
))?
;
1280 let name_hash
: u128
= d
.read_struct_field("name_hash", 8, |d
| Decodable
::decode(d
))?
;
1281 let normalized_pos
: Vec
<NormalizedPos
> =
1282 d
.read_struct_field("normalized_pos", 9, |d
| Decodable
::decode(d
))?
;
1283 let cnum
: CrateNum
= d
.read_struct_field("cnum", 10, |d
| Decodable
::decode(d
))?
;
1287 unmapped_path
: None
,
1292 // Unused - the metadata decoder will construct
1293 // a new SourceFile, filling in `external_src` properly
1294 external_src
: Lock
::new(ExternalSource
::Unneeded
),
1306 impl fmt
::Debug
for SourceFile
{
1307 fn fmt(&self, fmt
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
1308 write
!(fmt
, "SourceFile({})", self.name
)
1315 name_was_remapped
: bool
,
1316 unmapped_path
: FileName
,
1319 hash_kind
: SourceFileHashAlgorithm
,
1321 // Compute the file hash before any normalization.
1322 let src_hash
= SourceFileHash
::new(hash_kind
, &src
);
1323 let normalized_pos
= normalize_src(&mut src
, start_pos
);
1326 let mut hasher
: StableHasher
= StableHasher
::new();
1327 name
.hash(&mut hasher
);
1328 hasher
.finish
::<u128
>()
1330 let end_pos
= start_pos
.to_usize() + src
.len();
1331 assert
!(end_pos
<= u32::MAX
as usize);
1333 let (lines
, multibyte_chars
, non_narrow_chars
) =
1334 analyze_source_file
::analyze_source_file(&src
[..], start_pos
);
1339 unmapped_path
: Some(unmapped_path
),
1340 src
: Some(Lrc
::new(src
)),
1342 external_src
: Lock
::new(ExternalSource
::Unneeded
),
1344 end_pos
: Pos
::from_usize(end_pos
),
1354 /// Returns the `BytePos` of the beginning of the current line.
1355 pub fn line_begin_pos(&self, pos
: BytePos
) -> BytePos
{
1356 let line_index
= self.lookup_line(pos
).unwrap();
1357 self.lines
[line_index
]
1360 /// Add externally loaded source.
1361 /// If the hash of the input doesn't match or no input is supplied via None,
1362 /// it is interpreted as an error and the corresponding enum variant is set.
1363 /// The return value signifies whether some kind of source is present.
1364 pub fn add_external_src
<F
>(&self, get_src
: F
) -> bool
1366 F
: FnOnce() -> Option
<String
>,
1369 *self.external_src
.borrow(),
1370 ExternalSource
::Foreign { kind: ExternalSourceKind::AbsentOk, .. }
1372 let src
= get_src();
1373 let mut external_src
= self.external_src
.borrow_mut();
1374 // Check that no-one else have provided the source while we were getting it
1375 if let ExternalSource
::Foreign
{
1376 kind
: src_kind @ ExternalSourceKind
::AbsentOk
, ..
1377 } = &mut *external_src
1379 if let Some(mut src
) = src
{
1380 // The src_hash needs to be computed on the pre-normalized src.
1381 if self.src_hash
.matches(&src
) {
1382 normalize_src(&mut src
, BytePos
::from_usize(0));
1383 *src_kind
= ExternalSourceKind
::Present(Lrc
::new(src
));
1387 *src_kind
= ExternalSourceKind
::AbsentErr
;
1392 self.src
.is_some() || external_src
.get_source().is_some()
1395 self.src
.is_some() || self.external_src
.borrow().get_source().is_some()
1399 /// Gets a line from the list of pre-computed line-beginnings.
1400 /// The line number here is 0-based.
1401 pub fn get_line(&self, line_number
: usize) -> Option
<Cow
<'_
, str>> {
1402 fn get_until_newline(src
: &str, begin
: usize) -> &str {
1403 // We can't use `lines.get(line_number+1)` because we might
1404 // be parsing when we call this function and thus the current
1405 // line is the last one we have line info for.
1406 let slice
= &src
[begin
..];
1407 match slice
.find('
\n'
) {
1408 Some(e
) => &slice
[..e
],
1414 let line
= self.lines
.get(line_number
)?
;
1415 let begin
: BytePos
= *line
- self.start_pos
;
1419 if let Some(ref src
) = self.src
{
1420 Some(Cow
::from(get_until_newline(src
, begin
)))
1421 } else if let Some(src
) = self.external_src
.borrow().get_source() {
1422 Some(Cow
::Owned(String
::from(get_until_newline(src
, begin
))))
1428 pub fn is_real_file(&self) -> bool
{
1432 pub fn is_imported(&self) -> bool
{
1436 pub fn byte_length(&self) -> u32 {
1437 self.end_pos
.0 - self.start_pos
.0
1439 pub fn count_lines(&self) -> usize {
1443 /// Finds the line containing the given position. The return value is the
1444 /// index into the `lines` array of this `SourceFile`, not the 1-based line
1445 /// number. If the source_file is empty or the position is located before the
1446 /// first line, `None` is returned.
1447 pub fn lookup_line(&self, pos
: BytePos
) -> Option
<usize> {
1448 if self.lines
.is_empty() {
1452 let line_index
= lookup_line(&self.lines
[..], pos
);
1453 assert
!(line_index
< self.lines
.len() as isize);
1454 if line_index
>= 0 { Some(line_index as usize) }
else { None }
1457 pub fn line_bounds(&self, line_index
: usize) -> Range
<BytePos
> {
1458 if self.is_empty() {
1459 return self.start_pos
..self.end_pos
;
1462 assert
!(line_index
< self.lines
.len());
1463 if line_index
== (self.lines
.len() - 1) {
1464 self.lines
[line_index
]..self.end_pos
1466 self.lines
[line_index
]..self.lines
[line_index
+ 1]
1470 /// Returns whether or not the file contains the given `SourceMap` byte
1471 /// position. The position one past the end of the file is considered to be
1472 /// contained by the file. This implies that files for which `is_empty`
1473 /// returns true still contain one byte position according to this function.
1475 pub fn contains(&self, byte_pos
: BytePos
) -> bool
{
1476 byte_pos
>= self.start_pos
&& byte_pos
<= self.end_pos
1480 pub fn is_empty(&self) -> bool
{
1481 self.start_pos
== self.end_pos
1484 /// Calculates the original byte position relative to the start of the file
1485 /// based on the given byte position.
1486 pub fn original_relative_byte_pos(&self, pos
: BytePos
) -> BytePos
{
1487 // Diff before any records is 0. Otherwise use the previously recorded
1488 // diff as that applies to the following characters until a new diff
1490 let diff
= match self.normalized_pos
.binary_search_by(|np
| np
.pos
.cmp(&pos
)) {
1491 Ok(i
) => self.normalized_pos
[i
].diff
,
1492 Err(i
) if i
== 0 => 0,
1493 Err(i
) => self.normalized_pos
[i
- 1].diff
,
1496 BytePos
::from_u32(pos
.0 - self.start_pos
.0 + diff
)
1499 /// Converts an absolute `BytePos` to a `CharPos` relative to the `SourceFile`.
1500 pub fn bytepos_to_file_charpos(&self, bpos
: BytePos
) -> CharPos
{
1501 // The number of extra bytes due to multibyte chars in the `SourceFile`.
1502 let mut total_extra_bytes
= 0;
1504 for mbc
in self.multibyte_chars
.iter() {
1505 debug
!("{}-byte char at {:?}", mbc
.bytes
, mbc
.pos
);
1507 // Every character is at least one byte, so we only
1508 // count the actual extra bytes.
1509 total_extra_bytes
+= mbc
.bytes
as u32 - 1;
1510 // We should never see a byte position in the middle of a
1512 assert
!(bpos
.to_u32() >= mbc
.pos
.to_u32() + mbc
.bytes
as u32);
1518 assert
!(self.start_pos
.to_u32() + total_extra_bytes
<= bpos
.to_u32());
1519 CharPos(bpos
.to_usize() - self.start_pos
.to_usize() - total_extra_bytes
as usize)
1522 /// Looks up the file's (1-based) line number and (0-based `CharPos`) column offset, for a
1523 /// given `BytePos`.
1524 pub fn lookup_file_pos(&self, pos
: BytePos
) -> (usize, CharPos
) {
1525 let chpos
= self.bytepos_to_file_charpos(pos
);
1526 match self.lookup_line(pos
) {
1528 let line
= a
+ 1; // Line numbers start at 1
1529 let linebpos
= self.lines
[a
];
1530 let linechpos
= self.bytepos_to_file_charpos(linebpos
);
1531 let col
= chpos
- linechpos
;
1532 debug
!("byte pos {:?} is on the line at byte pos {:?}", pos
, linebpos
);
1533 debug
!("char pos {:?} is on the line at char pos {:?}", chpos
, linechpos
);
1534 debug
!("byte is on line: {}", line
);
1535 assert
!(chpos
>= linechpos
);
1542 /// Looks up the file's (1-based) line number, (0-based `CharPos`) column offset, and (0-based)
1543 /// column offset when displayed, for a given `BytePos`.
1544 pub fn lookup_file_pos_with_col_display(&self, pos
: BytePos
) -> (usize, CharPos
, usize) {
1545 let (line
, col_or_chpos
) = self.lookup_file_pos(pos
);
1547 let col
= col_or_chpos
;
1548 let linebpos
= self.lines
[line
- 1];
1550 let start_width_idx
= self
1552 .binary_search_by_key(&linebpos
, |x
| x
.pos())
1553 .unwrap_or_else(|x
| x
);
1554 let end_width_idx
= self
1556 .binary_search_by_key(&pos
, |x
| x
.pos())
1557 .unwrap_or_else(|x
| x
);
1558 let special_chars
= end_width_idx
- start_width_idx
;
1559 let non_narrow
: usize = self.non_narrow_chars
[start_width_idx
..end_width_idx
]
1563 col
.0 - special_chars
+ non_narrow
1565 (line
, col
, col_display
)
1567 let chpos
= col_or_chpos
;
1569 let end_width_idx
= self
1571 .binary_search_by_key(&pos
, |x
| x
.pos())
1572 .unwrap_or_else(|x
| x
);
1573 let non_narrow
: usize =
1574 self.non_narrow_chars
[0..end_width_idx
].iter().map(|x
| x
.width()).sum();
1575 chpos
.0 - end_width_idx
+ non_narrow
1577 (0, chpos
, col_display
)
1582 /// Normalizes the source code and records the normalizations.
1583 fn normalize_src(src
: &mut String
, start_pos
: BytePos
) -> Vec
<NormalizedPos
> {
1584 let mut normalized_pos
= vec
![];
1585 remove_bom(src
, &mut normalized_pos
);
1586 normalize_newlines(src
, &mut normalized_pos
);
1588 // Offset all the positions by start_pos to match the final file positions.
1589 for np
in &mut normalized_pos
{
1590 np
.pos
.0 += start_pos
.0;
1596 /// Removes UTF-8 BOM, if any.
1597 fn remove_bom(src
: &mut String
, normalized_pos
: &mut Vec
<NormalizedPos
>) {
1598 if src
.starts_with('
\u{feff}'
) {
1600 normalized_pos
.push(NormalizedPos { pos: BytePos(0), diff: 3 }
);
1604 /// Replaces `\r\n` with `\n` in-place in `src`.
1606 /// Returns error if there's a lone `\r` in the string.
1607 fn normalize_newlines(src
: &mut String
, normalized_pos
: &mut Vec
<NormalizedPos
>) {
1608 if !src
.as_bytes().contains(&b'
\r'
) {
1612 // We replace `\r\n` with `\n` in-place, which doesn't break utf-8 encoding.
1613 // While we *can* call `as_mut_vec` and do surgery on the live string
1614 // directly, let's rather steal the contents of `src`. This makes the code
1615 // safe even if a panic occurs.
1617 let mut buf
= std
::mem
::replace(src
, String
::new()).into_bytes();
1618 let mut gap_len
= 0;
1619 let mut tail
= buf
.as_mut_slice();
1621 let original_gap
= normalized_pos
.last().map_or(0, |l
| l
.diff
);
1623 let idx
= match find_crlf(&tail
[gap_len
..]) {
1625 Some(idx
) => idx
+ gap_len
,
1627 tail
.copy_within(gap_len
..idx
, 0);
1628 tail
= &mut tail
[idx
- gap_len
..];
1629 if tail
.len() == gap_len
{
1632 cursor
+= idx
- gap_len
;
1634 normalized_pos
.push(NormalizedPos
{
1635 pos
: BytePos
::from_usize(cursor
+ 1),
1636 diff
: original_gap
+ gap_len
as u32,
1640 // Account for removed `\r`.
1641 // After `set_len`, `buf` is guaranteed to contain utf-8 again.
1642 let new_len
= buf
.len() - gap_len
;
1644 buf
.set_len(new_len
);
1645 *src
= String
::from_utf8_unchecked(buf
);
1648 fn find_crlf(src
: &[u8]) -> Option
<usize> {
1649 let mut search_idx
= 0;
1650 while let Some(idx
) = find_cr(&src
[search_idx
..]) {
1651 if src
[search_idx
..].get(idx
+ 1) != Some(&b'
\n'
) {
1652 search_idx
+= idx
+ 1;
1655 return Some(search_idx
+ idx
);
1660 fn find_cr(src
: &[u8]) -> Option
<usize> {
1661 src
.iter().position(|&b
| b
== b'
\r'
)
1665 // _____________________________________________________________________________
1666 // Pos, BytePos, CharPos
1670 fn from_usize(n
: usize) -> Self;
1671 fn to_usize(&self) -> usize;
1672 fn from_u32(n
: u32) -> Self;
1673 fn to_u32(&self) -> u32;
1676 macro_rules
! impl_pos
{
1680 $vis
:vis
struct $ident
:ident($inner_vis
:vis $inner_ty
:ty
);
1685 $vis
struct $
ident($inner_vis $inner_ty
);
1687 impl Pos
for $ident
{
1689 fn from_usize(n
: usize) -> $ident
{
1690 $
ident(n
as $inner_ty
)
1694 fn to_usize(&self) -> usize {
1699 fn from_u32(n
: u32) -> $ident
{
1700 $
ident(n
as $inner_ty
)
1704 fn to_u32(&self) -> u32 {
1709 impl Add
for $ident
{
1710 type Output
= $ident
;
1713 fn add(self, rhs
: $ident
) -> $ident
{
1714 $
ident(self.0 + rhs
.0)
1718 impl Sub
for $ident
{
1719 type Output
= $ident
;
1722 fn sub(self, rhs
: $ident
) -> $ident
{
1723 $
ident(self.0 - rhs
.0)
1733 /// Keep this small (currently 32-bits), as AST contains a lot of them.
1734 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
1735 pub struct BytePos(pub u32);
1737 /// A character offset.
1739 /// Because of multibyte UTF-8 characters, a byte offset
1740 /// is not equivalent to a character offset. The [`SourceMap`] will convert [`BytePos`]
1741 /// values to `CharPos` values as necessary.
1742 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug)]
1743 pub struct CharPos(pub usize);
1746 impl<S
: rustc_serialize
::Encoder
> Encodable
<S
> for BytePos
{
1747 fn encode(&self, s
: &mut S
) -> Result
<(), S
::Error
> {
1752 impl<D
: rustc_serialize
::Decoder
> Decodable
<D
> for BytePos
{
1753 fn decode(d
: &mut D
) -> Result
<BytePos
, D
::Error
> {
1754 Ok(BytePos(d
.read_u32()?
))
1758 // _____________________________________________________________________________
1759 // Loc, SourceFileAndLine, SourceFileAndBytePos
1762 /// A source code location used for error reporting.
1763 #[derive(Debug, Clone)]
1765 /// Information about the original source.
1766 pub file
: Lrc
<SourceFile
>,
1767 /// The (1-based) line number.
1769 /// The (0-based) column offset.
1771 /// The (0-based) column offset when displayed.
1772 pub col_display
: usize,
1775 // Used to be structural records.
1777 pub struct SourceFileAndLine
{
1778 pub sf
: Lrc
<SourceFile
>,
1782 pub struct SourceFileAndBytePos
{
1783 pub sf
: Lrc
<SourceFile
>,
1787 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1788 pub struct LineInfo
{
1789 /// Index of line, starting from 0.
1790 pub line_index
: usize,
1792 /// Column in line where span begins, starting from 0.
1793 pub start_col
: CharPos
,
1795 /// Column in line where span ends, starting from 0, exclusive.
1796 pub end_col
: CharPos
,
1799 pub struct FileLines
{
1800 pub file
: Lrc
<SourceFile
>,
1801 pub lines
: Vec
<LineInfo
>,
1804 pub static SPAN_DEBUG
: AtomicRef
<fn(Span
, &mut fmt
::Formatter
<'_
>) -> fmt
::Result
> =
1805 AtomicRef
::new(&(default_span_debug
as fn(_
, &mut fmt
::Formatter
<'_
>) -> _
));
1807 // _____________________________________________________________________________
1808 // SpanLinesError, SpanSnippetError, DistinctSources, MalformedSourceMapPositions
1811 pub type FileLinesResult
= Result
<FileLines
, SpanLinesError
>;
1813 #[derive(Clone, PartialEq, Eq, Debug)]
1814 pub enum SpanLinesError
{
1815 DistinctSources(DistinctSources
),
1818 #[derive(Clone, PartialEq, Eq, Debug)]
1819 pub enum SpanSnippetError
{
1820 IllFormedSpan(Span
),
1821 DistinctSources(DistinctSources
),
1822 MalformedForSourcemap(MalformedSourceMapPositions
),
1823 SourceNotAvailable { filename: FileName }
,
1826 #[derive(Clone, PartialEq, Eq, Debug)]
1827 pub struct DistinctSources
{
1828 pub begin
: (FileName
, BytePos
),
1829 pub end
: (FileName
, BytePos
),
1832 #[derive(Clone, PartialEq, Eq, Debug)]
1833 pub struct MalformedSourceMapPositions
{
1835 pub source_len
: usize,
1836 pub begin_pos
: BytePos
,
1837 pub end_pos
: BytePos
,
1840 /// Range inside of a `Span` used for diagnostics when we only have access to relative positions.
1841 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
1842 pub struct InnerSpan
{
1848 pub fn new(start
: usize, end
: usize) -> InnerSpan
{
1849 InnerSpan { start, end }
1853 // Given a slice of line start positions and a position, returns the index of
1854 // the line the position is on. Returns -1 if the position is located before
1856 fn lookup_line(lines
: &[BytePos
], pos
: BytePos
) -> isize {
1857 match lines
.binary_search(&pos
) {
1858 Ok(line
) => line
as isize,
1859 Err(line
) => line
as isize - 1,
1863 /// Requirements for a `StableHashingContext` to be used in this crate.
1865 /// This is a hack to allow using the [`HashStable_Generic`] derive macro
1866 /// instead of implementing everything in rustc_middle.
1867 pub trait HashStableContext
{
1868 fn hash_def_id(&mut self, _
: DefId
, hasher
: &mut StableHasher
);
1869 /// Obtains a cache for storing the `Fingerprint` of an `ExpnId`.
1870 /// This method allows us to have multiple `HashStableContext` implementations
1871 /// that hash things in a different way, without the results of one polluting
1872 /// the cache of the other.
1873 fn expn_id_cache() -> &'
static LocalKey
<ExpnIdCache
>;
1874 fn hash_crate_num(&mut self, _
: CrateNum
, hasher
: &mut StableHasher
);
1875 fn hash_spans(&self) -> bool
;
1876 fn span_data_to_lines_and_cols(
1879 ) -> Option
<(Lrc
<SourceFile
>, usize, BytePos
, usize, BytePos
)>;
1882 impl<CTX
> HashStable
<CTX
> for Span
1884 CTX
: HashStableContext
,
1886 /// Hashes a span in a stable way. We can't directly hash the span's `BytePos`
1887 /// fields (that would be similar to hashing pointers, since those are just
1888 /// offsets into the `SourceMap`). Instead, we hash the (file name, line, column)
1889 /// triple, which stays the same even if the containing `SourceFile` has moved
1890 /// within the `SourceMap`.
1892 /// Also note that we are hashing byte offsets for the column, not unicode
1893 /// codepoint offsets. For the purpose of the hash that's sufficient.
1894 /// Also, hashing filenames is expensive so we avoid doing it twice when the
1895 /// span starts and ends in the same file, which is almost always the case.
1896 fn hash_stable(&self, ctx
: &mut CTX
, hasher
: &mut StableHasher
) {
1897 const TAG_VALID_SPAN
: u8 = 0;
1898 const TAG_INVALID_SPAN
: u8 = 1;
1900 if !ctx
.hash_spans() {
1904 self.ctxt().hash_stable(ctx
, hasher
);
1906 if self.is_dummy() {
1907 Hash
::hash(&TAG_INVALID_SPAN
, hasher
);
1911 // If this is not an empty or invalid span, we want to hash the last
1912 // position that belongs to it, as opposed to hashing the first
1913 // position past it.
1914 let span
= self.data();
1915 let (file
, line_lo
, col_lo
, line_hi
, col_hi
) = match ctx
.span_data_to_lines_and_cols(&span
)
1919 Hash
::hash(&TAG_INVALID_SPAN
, hasher
);
1924 Hash
::hash(&TAG_VALID_SPAN
, hasher
);
1925 // We truncate the stable ID hash and line and column numbers. The chances
1926 // of causing a collision this way should be minimal.
1927 Hash
::hash(&(file
.name_hash
as u64), hasher
);
1929 // Hash both the length and the end location (line/column) of a span. If we
1930 // hash only the length, for example, then two otherwise equal spans with
1931 // different end locations will have the same hash. This can cause a problem
1932 // during incremental compilation wherein a previous result for a query that
1933 // depends on the end location of a span will be incorrectly reused when the
1934 // end location of the span it depends on has changed (see issue #74890). A
1935 // similar analysis applies if some query depends specifically on the length
1936 // of the span, but we only hash the end location. So hash both.
1938 let col_lo_trunc
= (col_lo
.0 as u64) & 0xFF;
1939 let line_lo_trunc
= ((line_lo
as u64) & 0xFF_FF_FF) << 8;
1940 let col_hi_trunc
= (col_hi
.0 as u64) & 0xFF << 32;
1941 let line_hi_trunc
= ((line_hi
as u64) & 0xFF_FF_FF) << 40;
1942 let col_line
= col_lo_trunc
| line_lo_trunc
| col_hi_trunc
| line_hi_trunc
;
1943 let len
= (span
.hi
- span
.lo
).0;
1944 Hash
::hash(&col_line
, hasher
);
1945 Hash
::hash(&len
, hasher
);
1949 impl<CTX
: HashStableContext
> HashStable
<CTX
> for SyntaxContext
{
1950 fn hash_stable(&self, ctx
: &mut CTX
, hasher
: &mut StableHasher
) {
1951 const TAG_EXPANSION
: u8 = 0;
1952 const TAG_NO_EXPANSION
: u8 = 1;
1954 if *self == SyntaxContext
::root() {
1955 TAG_NO_EXPANSION
.hash_stable(ctx
, hasher
);
1957 TAG_EXPANSION
.hash_stable(ctx
, hasher
);
1958 let (expn_id
, transparency
) = self.outer_mark();
1959 expn_id
.hash_stable(ctx
, hasher
);
1960 transparency
.hash_stable(ctx
, hasher
);
1965 pub type ExpnIdCache
= RefCell
<Vec
<Option
<Fingerprint
>>>;
1967 impl<CTX
: HashStableContext
> HashStable
<CTX
> for ExpnId
{
1968 fn hash_stable(&self, ctx
: &mut CTX
, hasher
: &mut StableHasher
) {
1969 const TAG_ROOT
: u8 = 0;
1970 const TAG_NOT_ROOT
: u8 = 1;
1972 if *self == ExpnId
::root() {
1973 TAG_ROOT
.hash_stable(ctx
, hasher
);
1977 // Since the same expansion context is usually referenced many
1978 // times, we cache a stable hash of it and hash that instead of
1979 // recursing every time.
1980 let index
= self.as_u32() as usize;
1981 let res
= CTX
::expn_id_cache().with(|cache
| cache
.borrow().get(index
).copied().flatten());
1983 if let Some(res
) = res
{
1984 res
.hash_stable(ctx
, hasher
);
1986 let new_len
= index
+ 1;
1988 let mut sub_hasher
= StableHasher
::new();
1989 TAG_NOT_ROOT
.hash_stable(ctx
, &mut sub_hasher
);
1990 self.expn_data().hash_stable(ctx
, &mut sub_hasher
);
1991 let sub_hash
: Fingerprint
= sub_hasher
.finish();
1993 CTX
::expn_id_cache().with(|cache
| {
1994 let mut cache
= cache
.borrow_mut();
1995 if cache
.len() < new_len
{
1996 cache
.resize(new_len
, None
);
1998 let prev
= cache
[index
].replace(sub_hash
);
1999 assert_eq
!(prev
, None
, "Cache slot was filled");
2001 sub_hash
.hash_stable(ctx
, hasher
);