| //! Source positions and related helper functions. |
| //! |
| //! Important concepts in this module include: |
| //! |
| //! - the *span*, represented by [`SpanData`] and related types; |
| //! - source code as represented by a [`SourceMap`]; and |
| //! - interned strings, represented by [`Symbol`]s, with some common symbols available statically in the [`sym`] module. |
| //! |
| //! Unlike most compilers, the span contains not only the position in the source code, but also various other metadata, |
| //! such as the edition and macro hygiene. This metadata is stored in [`SyntaxContext`] and [`ExpnData`]. |
| //! |
| //! ## Note |
| //! |
| //! This API is completely unstable and subject to change. |
| |
| #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")] |
| #![feature(array_windows)] |
| #![feature(crate_visibility_modifier)] |
| #![feature(negative_impls)] |
| #![feature(nll)] |
| #![feature(min_specialization)] |
| #![feature(thread_local_const_init)] |
| |
| #[macro_use] |
| extern crate rustc_macros; |
| |
| use rustc_data_structures::AtomicRef; |
| use rustc_macros::HashStable_Generic; |
| use rustc_serialize::{Decodable, Decoder, Encodable, Encoder}; |
| |
| mod caching_source_map_view; |
| pub mod source_map; |
| pub use self::caching_source_map_view::CachingSourceMapView; |
| use source_map::SourceMap; |
| |
| pub mod edition; |
| use edition::Edition; |
| pub mod hygiene; |
| use hygiene::Transparency; |
| pub use hygiene::{DesugaringKind, ExpnKind, ForLoopLoc, MacroKind}; |
| pub use hygiene::{ExpnData, ExpnHash, ExpnId, LocalExpnId, SyntaxContext}; |
| pub mod def_id; |
| use def_id::{CrateNum, DefId, DefPathHash, LOCAL_CRATE}; |
| pub mod lev_distance; |
| mod span_encoding; |
| pub use span_encoding::{Span, DUMMY_SP}; |
| |
| pub mod symbol; |
| pub use symbol::{sym, Symbol}; |
| |
| mod analyze_source_file; |
| pub mod fatal_error; |
| |
| use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; |
| use rustc_data_structures::sync::{Lock, Lrc}; |
| |
| use std::borrow::Cow; |
| use std::cmp::{self, Ordering}; |
| use std::fmt; |
| use std::hash::Hash; |
| use std::ops::{Add, Range, Sub}; |
| use std::path::{Path, PathBuf}; |
| use std::str::FromStr; |
| |
| use md5::Md5; |
| use sha1::Digest; |
| use sha1::Sha1; |
| use sha2::Sha256; |
| |
| use tracing::debug; |
| |
| #[cfg(test)] |
| mod tests; |
| |
| // Per-session global variables: this struct is stored in thread-local storage |
| // in such a way that it is accessible without any kind of handle to all |
| // threads within the compilation session, but is not accessible outside the |
| // session. |
| pub struct SessionGlobals { |
| symbol_interner: Lock<symbol::Interner>, |
| span_interner: Lock<span_encoding::SpanInterner>, |
| hygiene_data: Lock<hygiene::HygieneData>, |
| source_map: Lock<Option<Lrc<SourceMap>>>, |
| } |
| |
| impl SessionGlobals { |
| pub fn new(edition: Edition) -> SessionGlobals { |
| SessionGlobals { |
| symbol_interner: Lock::new(symbol::Interner::fresh()), |
| span_interner: Lock::new(span_encoding::SpanInterner::default()), |
| hygiene_data: Lock::new(hygiene::HygieneData::new(edition)), |
| source_map: Lock::new(None), |
| } |
| } |
| } |
| |
| #[inline] |
| pub fn create_session_globals_then<R>(edition: Edition, f: impl FnOnce() -> R) -> R { |
| assert!( |
| !SESSION_GLOBALS.is_set(), |
| "SESSION_GLOBALS should never be overwritten! \ |
| Use another thread if you need another SessionGlobals" |
| ); |
| let session_globals = SessionGlobals::new(edition); |
| SESSION_GLOBALS.set(&session_globals, f) |
| } |
| |
| #[inline] |
| pub fn set_session_globals_then<R>(session_globals: &SessionGlobals, f: impl FnOnce() -> R) -> R { |
| assert!( |
| !SESSION_GLOBALS.is_set(), |
| "SESSION_GLOBALS should never be overwritten! \ |
| Use another thread if you need another SessionGlobals" |
| ); |
| SESSION_GLOBALS.set(session_globals, f) |
| } |
| |
| #[inline] |
| pub fn create_default_session_if_not_set_then<R, F>(f: F) -> R |
| where |
| F: FnOnce(&SessionGlobals) -> R, |
| { |
| create_session_if_not_set_then(edition::DEFAULT_EDITION, f) |
| } |
| |
| #[inline] |
| pub fn create_session_if_not_set_then<R, F>(edition: Edition, f: F) -> R |
| where |
| F: FnOnce(&SessionGlobals) -> R, |
| { |
| if !SESSION_GLOBALS.is_set() { |
| let session_globals = SessionGlobals::new(edition); |
| SESSION_GLOBALS.set(&session_globals, || SESSION_GLOBALS.with(f)) |
| } else { |
| SESSION_GLOBALS.with(f) |
| } |
| } |
| |
| #[inline] |
| pub fn with_session_globals<R, F>(f: F) -> R |
| where |
| F: FnOnce(&SessionGlobals) -> R, |
| { |
| SESSION_GLOBALS.with(f) |
| } |
| |
| #[inline] |
| pub fn create_default_session_globals_then<R>(f: impl FnOnce() -> R) -> R { |
| create_session_globals_then(edition::DEFAULT_EDITION, f) |
| } |
| |
| // If this ever becomes non thread-local, `decode_syntax_context` |
| // and `decode_expn_id` will need to be updated to handle concurrent |
| // deserialization. |
| scoped_tls::scoped_thread_local!(static SESSION_GLOBALS: SessionGlobals); |
| |
| // FIXME: We should use this enum or something like it to get rid of the |
| // use of magic `/rust/1.x/...` paths across the board. |
| #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd)] |
| #[derive(HashStable_Generic, Decodable)] |
| pub enum RealFileName { |
| LocalPath(PathBuf), |
| /// For remapped paths (namely paths into libstd that have been mapped |
| /// to the appropriate spot on the local host's file system, and local file |
| /// system paths that have been remapped with `FilePathMapping`), |
| Remapped { |
| /// `local_path` is the (host-dependent) local path to the file. This is |
| /// None if the file was imported from another crate |
| local_path: Option<PathBuf>, |
| /// `virtual_name` is the stable path rustc will store internally within |
| /// build artifacts. |
| virtual_name: PathBuf, |
| }, |
| } |
| |
| impl Hash for RealFileName { |
| fn hash<H: std::hash::Hasher>(&self, state: &mut H) { |
| // To prevent #70924 from happening again we should only hash the |
| // remapped (virtualized) path if that exists. This is because |
| // virtualized paths to sysroot crates (/rust/$hash or /rust/$version) |
| // remain stable even if the corresponding local_path changes |
| self.remapped_path_if_available().hash(state) |
| } |
| } |
| |
| // This is functionally identical to #[derive(Encodable)], with the exception of |
| // an added assert statement |
| impl<S: Encoder> Encodable<S> for RealFileName { |
| fn encode(&self, encoder: &mut S) -> Result<(), S::Error> { |
| encoder.emit_enum(|encoder| match *self { |
| RealFileName::LocalPath(ref local_path) => { |
| encoder.emit_enum_variant("LocalPath", 0, 1, |encoder| { |
| Ok({ |
| encoder |
| .emit_enum_variant_arg(true, |encoder| local_path.encode(encoder))?; |
| }) |
| }) |
| } |
| |
| RealFileName::Remapped { ref local_path, ref virtual_name } => encoder |
| .emit_enum_variant("Remapped", 1, 2, |encoder| { |
| // For privacy and build reproducibility, we must not embed host-dependant path in artifacts |
| // if they have been remapped by --remap-path-prefix |
| assert!(local_path.is_none()); |
| Ok({ |
| encoder |
| .emit_enum_variant_arg(true, |encoder| local_path.encode(encoder))?; |
| encoder |
| .emit_enum_variant_arg(false, |encoder| virtual_name.encode(encoder))?; |
| }) |
| }), |
| }) |
| } |
| } |
| |
| impl RealFileName { |
| /// Returns the path suitable for reading from the file system on the local host, |
| /// if this information exists. |
| /// Avoid embedding this in build artifacts; see `remapped_path_if_available()` for that. |
| pub fn local_path(&self) -> Option<&Path> { |
| match self { |
| RealFileName::LocalPath(p) => Some(p), |
| RealFileName::Remapped { local_path: p, virtual_name: _ } => { |
| p.as_ref().map(PathBuf::as_path) |
| } |
| } |
| } |
| |
| /// Returns the path suitable for reading from the file system on the local host, |
| /// if this information exists. |
| /// Avoid embedding this in build artifacts; see `remapped_path_if_available()` for that. |
| pub fn into_local_path(self) -> Option<PathBuf> { |
| match self { |
| RealFileName::LocalPath(p) => Some(p), |
| RealFileName::Remapped { local_path: p, virtual_name: _ } => p, |
| } |
| } |
| |
| /// Returns the path suitable for embedding into build artifacts. This would still |
| /// be a local path if it has not been remapped. A remapped path will not correspond |
| /// to a valid file system path: see `local_path_if_available()` for something that |
| /// is more likely to return paths into the local host file system. |
| pub fn remapped_path_if_available(&self) -> &Path { |
| match self { |
| RealFileName::LocalPath(p) |
| | RealFileName::Remapped { local_path: _, virtual_name: p } => &p, |
| } |
| } |
| |
| /// Returns the path suitable for reading from the file system on the local host, |
| /// if this information exists. Otherwise returns the remapped name. |
| /// Avoid embedding this in build artifacts; see `remapped_path_if_available()` for that. |
| pub fn local_path_if_available(&self) -> &Path { |
| match self { |
| RealFileName::LocalPath(path) |
| | RealFileName::Remapped { local_path: None, virtual_name: path } |
| | RealFileName::Remapped { local_path: Some(path), virtual_name: _ } => path, |
| } |
| } |
| |
| pub fn to_string_lossy(&self, prefer_local: bool) -> Cow<'_, str> { |
| if prefer_local { |
| self.local_path_if_available().to_string_lossy() |
| } else { |
| self.remapped_path_if_available().to_string_lossy() |
| } |
| } |
| } |
| |
| /// Differentiates between real files and common virtual files. |
| #[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash)] |
| #[derive(HashStable_Generic, Decodable, Encodable)] |
| pub enum FileName { |
| Real(RealFileName), |
| /// Call to `quote!`. |
| QuoteExpansion(u64), |
| /// Command line. |
| Anon(u64), |
| /// Hack in `src/librustc_ast/parse.rs`. |
| // FIXME(jseyfried) |
| MacroExpansion(u64), |
| ProcMacroSourceCode(u64), |
| /// Strings provided as `--cfg [cfgspec]` stored in a `crate_cfg`. |
| CfgSpec(u64), |
| /// Strings provided as crate attributes in the CLI. |
| CliCrateAttr(u64), |
| /// Custom sources for explicit parser calls from plugins and drivers. |
| Custom(String), |
| DocTest(PathBuf, isize), |
| /// Post-substitution inline assembly from LLVM. |
| InlineAsm(u64), |
| } |
| |
| impl From<PathBuf> for FileName { |
| fn from(p: PathBuf) -> Self { |
| assert!(!p.to_string_lossy().ends_with('>')); |
| FileName::Real(RealFileName::LocalPath(p)) |
| } |
| } |
| |
| pub struct FileNameDisplay<'a> { |
| inner: &'a FileName, |
| prefer_local: bool, |
| } |
| |
| impl fmt::Display for FileNameDisplay<'_> { |
| fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { |
| use FileName::*; |
| match *self.inner { |
| Real(ref name) => { |
| write!(fmt, "{}", name.to_string_lossy(self.prefer_local)) |
| } |
| QuoteExpansion(_) => write!(fmt, "<quote expansion>"), |
| MacroExpansion(_) => write!(fmt, "<macro expansion>"), |
| Anon(_) => write!(fmt, "<anon>"), |
| ProcMacroSourceCode(_) => write!(fmt, "<proc-macro source code>"), |
| CfgSpec(_) => write!(fmt, "<cfgspec>"), |
| CliCrateAttr(_) => write!(fmt, "<crate attribute>"), |
| Custom(ref s) => write!(fmt, "<{}>", s), |
| DocTest(ref path, _) => write!(fmt, "{}", path.display()), |
| InlineAsm(_) => write!(fmt, "<inline asm>"), |
| } |
| } |
| } |
| |
| impl FileNameDisplay<'_> { |
| pub fn to_string_lossy(&self) -> Cow<'_, str> { |
| match self.inner { |
| FileName::Real(ref inner) => inner.to_string_lossy(self.prefer_local), |
| _ => Cow::from(format!("{}", self)), |
| } |
| } |
| } |
| |
| impl FileName { |
| pub fn is_real(&self) -> bool { |
| use FileName::*; |
| match *self { |
| Real(_) => true, |
| Anon(_) |
| | MacroExpansion(_) |
| | ProcMacroSourceCode(_) |
| | CfgSpec(_) |
| | CliCrateAttr(_) |
| | Custom(_) |
| | QuoteExpansion(_) |
| | DocTest(_, _) |
| | InlineAsm(_) => false, |
| } |
| } |
| |
| pub fn prefer_remapped(&self) -> FileNameDisplay<'_> { |
| FileNameDisplay { inner: self, prefer_local: false } |
| } |
| |
| // This may include transient local filesystem information. |
| // Must not be embedded in build outputs. |
| pub fn prefer_local(&self) -> FileNameDisplay<'_> { |
| FileNameDisplay { inner: self, prefer_local: true } |
| } |
| |
| pub fn macro_expansion_source_code(src: &str) -> FileName { |
| let mut hasher = StableHasher::new(); |
| src.hash(&mut hasher); |
| FileName::MacroExpansion(hasher.finish()) |
| } |
| |
| pub fn anon_source_code(src: &str) -> FileName { |
| let mut hasher = StableHasher::new(); |
| src.hash(&mut hasher); |
| FileName::Anon(hasher.finish()) |
| } |
| |
| pub fn proc_macro_source_code(src: &str) -> FileName { |
| let mut hasher = StableHasher::new(); |
| src.hash(&mut hasher); |
| FileName::ProcMacroSourceCode(hasher.finish()) |
| } |
| |
| pub fn cfg_spec_source_code(src: &str) -> FileName { |
| let mut hasher = StableHasher::new(); |
| src.hash(&mut hasher); |
| FileName::QuoteExpansion(hasher.finish()) |
| } |
| |
| pub fn cli_crate_attr_source_code(src: &str) -> FileName { |
| let mut hasher = StableHasher::new(); |
| src.hash(&mut hasher); |
| FileName::CliCrateAttr(hasher.finish()) |
| } |
| |
| pub fn doc_test_source_code(path: PathBuf, line: isize) -> FileName { |
| FileName::DocTest(path, line) |
| } |
| |
| pub fn inline_asm_source_code(src: &str) -> FileName { |
| let mut hasher = StableHasher::new(); |
| src.hash(&mut hasher); |
| FileName::InlineAsm(hasher.finish()) |
| } |
| } |
| |
| /// Represents a span. |
| /// |
| /// Spans represent a region of code, used for error reporting. Positions in spans |
| /// are *absolute* positions from the beginning of the [`SourceMap`], not positions |
| /// relative to [`SourceFile`]s. Methods on the `SourceMap` can be used to relate spans back |
| /// to the original source. |
| /// |
| /// You must be careful if the span crosses more than one file, since you will not be |
| /// able to use many of the functions on spans in source_map and you cannot assume |
| /// that the length of the span is equal to `span.hi - span.lo`; there may be space in the |
| /// [`BytePos`] range between files. |
| /// |
| /// `SpanData` is public because `Span` uses a thread-local interner and can't be |
| /// sent to other threads, but some pieces of performance infra run in a separate thread. |
| /// Using `Span` is generally preferred. |
| #[derive(Clone, Copy, Hash, PartialEq, Eq, Ord, PartialOrd)] |
| pub struct SpanData { |
| pub lo: BytePos, |
| pub hi: BytePos, |
| /// Information about where the macro came from, if this piece of |
| /// code was created by a macro expansion. |
| pub ctxt: SyntaxContext, |
| } |
| |
| impl SpanData { |
| #[inline] |
| pub fn span(&self) -> Span { |
| Span::new(self.lo, self.hi, self.ctxt) |
| } |
| #[inline] |
| pub fn with_lo(&self, lo: BytePos) -> Span { |
| Span::new(lo, self.hi, self.ctxt) |
| } |
| #[inline] |
| pub fn with_hi(&self, hi: BytePos) -> Span { |
| Span::new(self.lo, hi, self.ctxt) |
| } |
| #[inline] |
| pub fn with_ctxt(&self, ctxt: SyntaxContext) -> Span { |
| Span::new(self.lo, self.hi, ctxt) |
| } |
| } |
| |
| // The interner is pointed to by a thread local value which is only set on the main thread |
| // with parallelization is disabled. So we don't allow `Span` to transfer between threads |
| // to avoid panics and other errors, even though it would be memory safe to do so. |
| #[cfg(not(parallel_compiler))] |
| impl !Send for Span {} |
| #[cfg(not(parallel_compiler))] |
| impl !Sync for Span {} |
| |
| impl PartialOrd for Span { |
| fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> { |
| PartialOrd::partial_cmp(&self.data(), &rhs.data()) |
| } |
| } |
| impl Ord for Span { |
| fn cmp(&self, rhs: &Self) -> Ordering { |
| Ord::cmp(&self.data(), &rhs.data()) |
| } |
| } |
| |
| /// A collection of `Span`s. |
| /// |
| /// Spans have two orthogonal attributes: |
| /// |
| /// - They can be *primary spans*. In this case they are the locus of |
| /// the error, and would be rendered with `^^^`. |
| /// - They can have a *label*. In this case, the label is written next |
| /// to the mark in the snippet when we render. |
| #[derive(Clone, Debug, Hash, PartialEq, Eq, Encodable, Decodable)] |
| pub struct MultiSpan { |
| primary_spans: Vec<Span>, |
| span_labels: Vec<(Span, String)>, |
| } |
| |
| impl Span { |
| #[inline] |
| pub fn lo(self) -> BytePos { |
| self.data().lo |
| } |
| #[inline] |
| pub fn with_lo(self, lo: BytePos) -> Span { |
| self.data().with_lo(lo) |
| } |
| #[inline] |
| pub fn hi(self) -> BytePos { |
| self.data().hi |
| } |
| #[inline] |
| pub fn with_hi(self, hi: BytePos) -> Span { |
| self.data().with_hi(hi) |
| } |
| #[inline] |
| pub fn ctxt(self) -> SyntaxContext { |
| self.data().ctxt |
| } |
| #[inline] |
| pub fn with_ctxt(self, ctxt: SyntaxContext) -> Span { |
| self.data().with_ctxt(ctxt) |
| } |
| |
| /// Returns `true` if this is a dummy span with any hygienic context. |
| #[inline] |
| pub fn is_dummy(self) -> bool { |
| let span = self.data(); |
| span.lo.0 == 0 && span.hi.0 == 0 |
| } |
| |
| /// Returns `true` if this span comes from a macro or desugaring. |
| #[inline] |
| pub fn from_expansion(self) -> bool { |
| self.ctxt() != SyntaxContext::root() |
| } |
| |
| /// Returns `true` if `span` originates in a derive-macro's expansion. |
| pub fn in_derive_expansion(self) -> bool { |
| matches!(self.ctxt().outer_expn_data().kind, ExpnKind::Macro(MacroKind::Derive, _)) |
| } |
| |
| #[inline] |
| pub fn with_root_ctxt(lo: BytePos, hi: BytePos) -> Span { |
| Span::new(lo, hi, SyntaxContext::root()) |
| } |
| |
| /// Returns a new span representing an empty span at the beginning of this span. |
| #[inline] |
| pub fn shrink_to_lo(self) -> Span { |
| let span = self.data(); |
| span.with_hi(span.lo) |
| } |
| /// Returns a new span representing an empty span at the end of this span. |
| #[inline] |
| pub fn shrink_to_hi(self) -> Span { |
| let span = self.data(); |
| span.with_lo(span.hi) |
| } |
| |
| #[inline] |
| /// Returns `true` if `hi == lo`. |
| pub fn is_empty(&self) -> bool { |
| let span = self.data(); |
| span.hi == span.lo |
| } |
| |
| /// Returns `self` if `self` is not the dummy span, and `other` otherwise. |
| pub fn substitute_dummy(self, other: Span) -> Span { |
| if self.is_dummy() { other } else { self } |
| } |
| |
| /// Returns `true` if `self` fully encloses `other`. |
| pub fn contains(self, other: Span) -> bool { |
| let span = self.data(); |
| let other = other.data(); |
| span.lo <= other.lo && other.hi <= span.hi |
| } |
| |
| /// Returns `true` if `self` touches `other`. |
| pub fn overlaps(self, other: Span) -> bool { |
| let span = self.data(); |
| let other = other.data(); |
| span.lo < other.hi && other.lo < span.hi |
| } |
| |
| /// Returns `true` if the spans are equal with regards to the source text. |
| /// |
| /// Use this instead of `==` when either span could be generated code, |
| /// and you only care that they point to the same bytes of source text. |
| pub fn source_equal(&self, other: &Span) -> bool { |
| let span = self.data(); |
| let other = other.data(); |
| span.lo == other.lo && span.hi == other.hi |
| } |
| |
| /// Returns `Some(span)`, where the start is trimmed by the end of `other`. |
| pub fn trim_start(self, other: Span) -> Option<Span> { |
| let span = self.data(); |
| let other = other.data(); |
| if span.hi > other.hi { Some(span.with_lo(cmp::max(span.lo, other.hi))) } else { None } |
| } |
| |
| /// Returns the source span -- this is either the supplied span, or the span for |
| /// the macro callsite that expanded to it. |
| pub fn source_callsite(self) -> Span { |
| let expn_data = self.ctxt().outer_expn_data(); |
| if !expn_data.is_root() { expn_data.call_site.source_callsite() } else { self } |
| } |
| |
| /// The `Span` for the tokens in the previous macro expansion from which `self` was generated, |
| /// if any. |
| pub fn parent(self) -> Option<Span> { |
| let expn_data = self.ctxt().outer_expn_data(); |
| if !expn_data.is_root() { Some(expn_data.call_site) } else { None } |
| } |
| |
| /// Edition of the crate from which this span came. |
| pub fn edition(self) -> edition::Edition { |
| self.ctxt().edition() |
| } |
| |
| #[inline] |
| pub fn rust_2015(&self) -> bool { |
| self.edition() == edition::Edition::Edition2015 |
| } |
| |
| #[inline] |
| pub fn rust_2018(&self) -> bool { |
| self.edition() >= edition::Edition::Edition2018 |
| } |
| |
| #[inline] |
| pub fn rust_2021(&self) -> bool { |
| self.edition() >= edition::Edition::Edition2021 |
| } |
| |
| /// Returns the source callee. |
| /// |
| /// Returns `None` if the supplied span has no expansion trace, |
| /// else returns the `ExpnData` for the macro definition |
| /// corresponding to the source callsite. |
| pub fn source_callee(self) -> Option<ExpnData> { |
| fn source_callee(expn_data: ExpnData) -> ExpnData { |
| let next_expn_data = expn_data.call_site.ctxt().outer_expn_data(); |
| if !next_expn_data.is_root() { source_callee(next_expn_data) } else { expn_data } |
| } |
| let expn_data = self.ctxt().outer_expn_data(); |
| if !expn_data.is_root() { Some(source_callee(expn_data)) } else { None } |
| } |
| |
| /// Checks if a span is "internal" to a macro in which `#[unstable]` |
| /// items can be used (that is, a macro marked with |
| /// `#[allow_internal_unstable]`). |
| pub fn allows_unstable(&self, feature: Symbol) -> bool { |
| self.ctxt() |
| .outer_expn_data() |
| .allow_internal_unstable |
| .map_or(false, |features| features.iter().any(|&f| f == feature)) |
| } |
| |
| /// Checks if this span arises from a compiler desugaring of kind `kind`. |
| pub fn is_desugaring(&self, kind: DesugaringKind) -> bool { |
| match self.ctxt().outer_expn_data().kind { |
| ExpnKind::Desugaring(k) => k == kind, |
| _ => false, |
| } |
| } |
| |
| /// Returns the compiler desugaring that created this span, or `None` |
| /// if this span is not from a desugaring. |
| pub fn desugaring_kind(&self) -> Option<DesugaringKind> { |
| match self.ctxt().outer_expn_data().kind { |
| ExpnKind::Desugaring(k) => Some(k), |
| _ => None, |
| } |
| } |
| |
| /// Checks if a span is "internal" to a macro in which `unsafe` |
| /// can be used without triggering the `unsafe_code` lint. |
| // (that is, a macro marked with `#[allow_internal_unsafe]`). |
| pub fn allows_unsafe(&self) -> bool { |
| self.ctxt().outer_expn_data().allow_internal_unsafe |
| } |
| |
| pub fn macro_backtrace(mut self) -> impl Iterator<Item = ExpnData> { |
| let mut prev_span = DUMMY_SP; |
| std::iter::from_fn(move || { |
| loop { |
| let expn_data = self.ctxt().outer_expn_data(); |
| if expn_data.is_root() { |
| return None; |
| } |
| |
| let is_recursive = expn_data.call_site.source_equal(&prev_span); |
| |
| prev_span = self; |
| self = expn_data.call_site; |
| |
| // Don't print recursive invocations. |
| if !is_recursive { |
| return Some(expn_data); |
| } |
| } |
| }) |
| } |
| |
| /// Returns a `Span` that would enclose both `self` and `end`. |
| /// |
| /// ```text |
| /// ____ ___ |
| /// self lorem ipsum end |
| /// ^^^^^^^^^^^^^^^^^^^^ |
| /// ``` |
| pub fn to(self, end: Span) -> Span { |
| let span_data = self.data(); |
| let end_data = end.data(); |
| // FIXME(jseyfried): `self.ctxt` should always equal `end.ctxt` here (cf. issue #23480). |
| // Return the macro span on its own to avoid weird diagnostic output. It is preferable to |
| // have an incomplete span than a completely nonsensical one. |
| if span_data.ctxt != end_data.ctxt { |
| if span_data.ctxt == SyntaxContext::root() { |
| return end; |
| } else if end_data.ctxt == SyntaxContext::root() { |
| return self; |
| } |
| // Both spans fall within a macro. |
| // FIXME(estebank): check if it is the *same* macro. |
| } |
| Span::new( |
| cmp::min(span_data.lo, end_data.lo), |
| cmp::max(span_data.hi, end_data.hi), |
| if span_data.ctxt == SyntaxContext::root() { end_data.ctxt } else { span_data.ctxt }, |
| ) |
| } |
| |
| /// Returns a `Span` between the end of `self` to the beginning of `end`. |
| /// |
| /// ```text |
| /// ____ ___ |
| /// self lorem ipsum end |
| /// ^^^^^^^^^^^^^ |
| /// ``` |
| pub fn between(self, end: Span) -> Span { |
| let span = self.data(); |
| let end = end.data(); |
| Span::new( |
| span.hi, |
| end.lo, |
| if end.ctxt == SyntaxContext::root() { end.ctxt } else { span.ctxt }, |
| ) |
| } |
| |
| /// Returns a `Span` from the beginning of `self` until the beginning of `end`. |
| /// |
| /// ```text |
| /// ____ ___ |
| /// self lorem ipsum end |
| /// ^^^^^^^^^^^^^^^^^ |
| /// ``` |
| pub fn until(self, end: Span) -> Span { |
| let span = self.data(); |
| let end = end.data(); |
| Span::new( |
| span.lo, |
| end.lo, |
| if end.ctxt == SyntaxContext::root() { end.ctxt } else { span.ctxt }, |
| ) |
| } |
| |
| pub fn from_inner(self, inner: InnerSpan) -> Span { |
| let span = self.data(); |
| Span::new( |
| span.lo + BytePos::from_usize(inner.start), |
| span.lo + BytePos::from_usize(inner.end), |
| span.ctxt, |
| ) |
| } |
| |
| /// Equivalent of `Span::def_site` from the proc macro API, |
| /// except that the location is taken from the `self` span. |
| pub fn with_def_site_ctxt(self, expn_id: ExpnId) -> Span { |
| self.with_ctxt_from_mark(expn_id, Transparency::Opaque) |
| } |
| |
| /// Equivalent of `Span::call_site` from the proc macro API, |
| /// except that the location is taken from the `self` span. |
| pub fn with_call_site_ctxt(&self, expn_id: ExpnId) -> Span { |
| self.with_ctxt_from_mark(expn_id, Transparency::Transparent) |
| } |
| |
| /// Equivalent of `Span::mixed_site` from the proc macro API, |
| /// except that the location is taken from the `self` span. |
| pub fn with_mixed_site_ctxt(&self, expn_id: ExpnId) -> Span { |
| self.with_ctxt_from_mark(expn_id, Transparency::SemiTransparent) |
| } |
| |
| /// Produces a span with the same location as `self` and context produced by a macro with the |
| /// given ID and transparency, assuming that macro was defined directly and not produced by |
| /// some other macro (which is the case for built-in and procedural macros). |
| pub fn with_ctxt_from_mark(self, expn_id: ExpnId, transparency: Transparency) -> Span { |
| self.with_ctxt(SyntaxContext::root().apply_mark(expn_id, transparency)) |
| } |
| |
| #[inline] |
| pub fn apply_mark(self, expn_id: ExpnId, transparency: Transparency) -> Span { |
| let span = self.data(); |
| span.with_ctxt(span.ctxt.apply_mark(expn_id, transparency)) |
| } |
| |
| #[inline] |
| pub fn remove_mark(&mut self) -> ExpnId { |
| let mut span = self.data(); |
| let mark = span.ctxt.remove_mark(); |
| *self = Span::new(span.lo, span.hi, span.ctxt); |
| mark |
| } |
| |
| #[inline] |
| pub fn adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> { |
| let mut span = self.data(); |
| let mark = span.ctxt.adjust(expn_id); |
| *self = Span::new(span.lo, span.hi, span.ctxt); |
| mark |
| } |
| |
| #[inline] |
| pub fn normalize_to_macros_2_0_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> { |
| let mut span = self.data(); |
| let mark = span.ctxt.normalize_to_macros_2_0_and_adjust(expn_id); |
| *self = Span::new(span.lo, span.hi, span.ctxt); |
| mark |
| } |
| |
| #[inline] |
| pub fn glob_adjust(&mut self, expn_id: ExpnId, glob_span: Span) -> Option<Option<ExpnId>> { |
| let mut span = self.data(); |
| let mark = span.ctxt.glob_adjust(expn_id, glob_span); |
| *self = Span::new(span.lo, span.hi, span.ctxt); |
| mark |
| } |
| |
| #[inline] |
| pub fn reverse_glob_adjust( |
| &mut self, |
| expn_id: ExpnId, |
| glob_span: Span, |
| ) -> Option<Option<ExpnId>> { |
| let mut span = self.data(); |
| let mark = span.ctxt.reverse_glob_adjust(expn_id, glob_span); |
| *self = Span::new(span.lo, span.hi, span.ctxt); |
| mark |
| } |
| |
| #[inline] |
| pub fn normalize_to_macros_2_0(self) -> Span { |
| let span = self.data(); |
| span.with_ctxt(span.ctxt.normalize_to_macros_2_0()) |
| } |
| |
| #[inline] |
| pub fn normalize_to_macro_rules(self) -> Span { |
| let span = self.data(); |
| span.with_ctxt(span.ctxt.normalize_to_macro_rules()) |
| } |
| } |
| |
| /// A span together with some additional data. |
| #[derive(Clone, Debug)] |
| pub struct SpanLabel { |
| /// The span we are going to include in the final snippet. |
| pub span: Span, |
| |
| /// Is this a primary span? This is the "locus" of the message, |
| /// and is indicated with a `^^^^` underline, versus `----`. |
| pub is_primary: bool, |
| |
| /// What label should we attach to this span (if any)? |
| pub label: Option<String>, |
| } |
| |
| impl Default for Span { |
| fn default() -> Self { |
| DUMMY_SP |
| } |
| } |
| |
| impl<E: Encoder> Encodable<E> for Span { |
| default fn encode(&self, s: &mut E) -> Result<(), E::Error> { |
| let span = self.data(); |
| s.emit_struct(false, |s| { |
| s.emit_struct_field("lo", true, |s| span.lo.encode(s))?; |
| s.emit_struct_field("hi", false, |s| span.hi.encode(s)) |
| }) |
| } |
| } |
| impl<D: Decoder> Decodable<D> for Span { |
| default fn decode(s: &mut D) -> Result<Span, D::Error> { |
| s.read_struct(|d| { |
| let lo = d.read_struct_field("lo", Decodable::decode)?; |
| let hi = d.read_struct_field("hi", Decodable::decode)?; |
| |
| Ok(Span::new(lo, hi, SyntaxContext::root())) |
| }) |
| } |
| } |
| |
| /// Calls the provided closure, using the provided `SourceMap` to format |
| /// any spans that are debug-printed during the closure's execution. |
| /// |
| /// Normally, the global `TyCtxt` is used to retrieve the `SourceMap` |
| /// (see `rustc_interface::callbacks::span_debug1`). However, some parts |
| /// of the compiler (e.g. `rustc_parse`) may debug-print `Span`s before |
| /// a `TyCtxt` is available. In this case, we fall back to |
| /// the `SourceMap` provided to this function. If that is not available, |
| /// we fall back to printing the raw `Span` field values. |
| pub fn with_source_map<T, F: FnOnce() -> T>(source_map: Lrc<SourceMap>, f: F) -> T { |
| with_session_globals(|session_globals| { |
| *session_globals.source_map.borrow_mut() = Some(source_map); |
| }); |
| struct ClearSourceMap; |
| impl Drop for ClearSourceMap { |
| fn drop(&mut self) { |
| with_session_globals(|session_globals| { |
| session_globals.source_map.borrow_mut().take(); |
| }); |
| } |
| } |
| |
| let _guard = ClearSourceMap; |
| f() |
| } |
| |
| pub fn debug_with_source_map( |
| span: Span, |
| f: &mut fmt::Formatter<'_>, |
| source_map: &SourceMap, |
| ) -> fmt::Result { |
| write!(f, "{} ({:?})", source_map.span_to_diagnostic_string(span), span.ctxt()) |
| } |
| |
| pub fn default_span_debug(span: Span, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| with_session_globals(|session_globals| { |
| if let Some(source_map) = &*session_globals.source_map.borrow() { |
| debug_with_source_map(span, f, source_map) |
| } else { |
| f.debug_struct("Span") |
| .field("lo", &span.lo()) |
| .field("hi", &span.hi()) |
| .field("ctxt", &span.ctxt()) |
| .finish() |
| } |
| }) |
| } |
| |
| impl fmt::Debug for Span { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| (*SPAN_DEBUG)(*self, f) |
| } |
| } |
| |
| impl fmt::Debug for SpanData { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| (*SPAN_DEBUG)(Span::new(self.lo, self.hi, self.ctxt), f) |
| } |
| } |
| |
| impl MultiSpan { |
| #[inline] |
| pub fn new() -> MultiSpan { |
| MultiSpan { primary_spans: vec![], span_labels: vec![] } |
| } |
| |
| pub fn from_span(primary_span: Span) -> MultiSpan { |
| MultiSpan { primary_spans: vec![primary_span], span_labels: vec![] } |
| } |
| |
| pub fn from_spans(mut vec: Vec<Span>) -> MultiSpan { |
| vec.sort(); |
| MultiSpan { primary_spans: vec, span_labels: vec![] } |
| } |
| |
| pub fn push_span_label(&mut self, span: Span, label: String) { |
| self.span_labels.push((span, label)); |
| } |
| |
| /// Selects the first primary span (if any). |
| pub fn primary_span(&self) -> Option<Span> { |
| self.primary_spans.first().cloned() |
| } |
| |
| /// Returns all primary spans. |
| pub fn primary_spans(&self) -> &[Span] { |
| &self.primary_spans |
| } |
| |
| /// Returns `true` if any of the primary spans are displayable. |
| pub fn has_primary_spans(&self) -> bool { |
| self.primary_spans.iter().any(|sp| !sp.is_dummy()) |
| } |
| |
| /// Returns `true` if this contains only a dummy primary span with any hygienic context. |
| pub fn is_dummy(&self) -> bool { |
| let mut is_dummy = true; |
| for span in &self.primary_spans { |
| if !span.is_dummy() { |
| is_dummy = false; |
| } |
| } |
| is_dummy |
| } |
| |
| /// Replaces all occurrences of one Span with another. Used to move `Span`s in areas that don't |
| /// display well (like std macros). Returns whether replacements occurred. |
| pub fn replace(&mut self, before: Span, after: Span) -> bool { |
| let mut replacements_occurred = false; |
| for primary_span in &mut self.primary_spans { |
| if *primary_span == before { |
| *primary_span = after; |
| replacements_occurred = true; |
| } |
| } |
| for span_label in &mut self.span_labels { |
| if span_label.0 == before { |
| span_label.0 = after; |
| replacements_occurred = true; |
| } |
| } |
| replacements_occurred |
| } |
| |
| /// Returns the strings to highlight. We always ensure that there |
| /// is an entry for each of the primary spans -- for each primary |
| /// span `P`, if there is at least one label with span `P`, we return |
| /// those labels (marked as primary). But otherwise we return |
| /// `SpanLabel` instances with empty labels. |
| pub fn span_labels(&self) -> Vec<SpanLabel> { |
| let is_primary = |span| self.primary_spans.contains(&span); |
| |
| let mut span_labels = self |
| .span_labels |
| .iter() |
| .map(|&(span, ref label)| SpanLabel { |
| span, |
| is_primary: is_primary(span), |
| label: Some(label.clone()), |
| }) |
| .collect::<Vec<_>>(); |
| |
| for &span in &self.primary_spans { |
| if !span_labels.iter().any(|sl| sl.span == span) { |
| span_labels.push(SpanLabel { span, is_primary: true, label: None }); |
| } |
| } |
| |
| span_labels |
| } |
| |
| /// Returns `true` if any of the span labels is displayable. |
| pub fn has_span_labels(&self) -> bool { |
| self.span_labels.iter().any(|(sp, _)| !sp.is_dummy()) |
| } |
| } |
| |
| impl From<Span> for MultiSpan { |
| fn from(span: Span) -> MultiSpan { |
| MultiSpan::from_span(span) |
| } |
| } |
| |
| impl From<Vec<Span>> for MultiSpan { |
| fn from(spans: Vec<Span>) -> MultiSpan { |
| MultiSpan::from_spans(spans) |
| } |
| } |
| |
| /// Identifies an offset of a multi-byte character in a `SourceFile`. |
| #[derive(Copy, Clone, Encodable, Decodable, Eq, PartialEq, Debug)] |
| pub struct MultiByteChar { |
| /// The absolute offset of the character in the `SourceMap`. |
| pub pos: BytePos, |
| /// The number of bytes, `>= 2`. |
| pub bytes: u8, |
| } |
| |
| /// Identifies an offset of a non-narrow character in a `SourceFile`. |
| #[derive(Copy, Clone, Encodable, Decodable, Eq, PartialEq, Debug)] |
| pub enum NonNarrowChar { |
| /// Represents a zero-width character. |
| ZeroWidth(BytePos), |
| /// Represents a wide (full-width) character. |
| Wide(BytePos), |
| /// Represents a tab character, represented visually with a width of 4 characters. |
| Tab(BytePos), |
| } |
| |
| impl NonNarrowChar { |
| fn new(pos: BytePos, width: usize) -> Self { |
| match width { |
| 0 => NonNarrowChar::ZeroWidth(pos), |
| 2 => NonNarrowChar::Wide(pos), |
| 4 => NonNarrowChar::Tab(pos), |
| _ => panic!("width {} given for non-narrow character", width), |
| } |
| } |
| |
| /// Returns the absolute offset of the character in the `SourceMap`. |
| pub fn pos(&self) -> BytePos { |
| match *self { |
| NonNarrowChar::ZeroWidth(p) | NonNarrowChar::Wide(p) | NonNarrowChar::Tab(p) => p, |
| } |
| } |
| |
| /// Returns the width of the character, 0 (zero-width) or 2 (wide). |
| pub fn width(&self) -> usize { |
| match *self { |
| NonNarrowChar::ZeroWidth(_) => 0, |
| NonNarrowChar::Wide(_) => 2, |
| NonNarrowChar::Tab(_) => 4, |
| } |
| } |
| } |
| |
| impl Add<BytePos> for NonNarrowChar { |
| type Output = Self; |
| |
| fn add(self, rhs: BytePos) -> Self { |
| match self { |
| NonNarrowChar::ZeroWidth(pos) => NonNarrowChar::ZeroWidth(pos + rhs), |
| NonNarrowChar::Wide(pos) => NonNarrowChar::Wide(pos + rhs), |
| NonNarrowChar::Tab(pos) => NonNarrowChar::Tab(pos + rhs), |
| } |
| } |
| } |
| |
| impl Sub<BytePos> for NonNarrowChar { |
| type Output = Self; |
| |
| fn sub(self, rhs: BytePos) -> Self { |
| match self { |
| NonNarrowChar::ZeroWidth(pos) => NonNarrowChar::ZeroWidth(pos - rhs), |
| NonNarrowChar::Wide(pos) => NonNarrowChar::Wide(pos - rhs), |
| NonNarrowChar::Tab(pos) => NonNarrowChar::Tab(pos - rhs), |
| } |
| } |
| } |
| |
| /// Identifies an offset of a character that was normalized away from `SourceFile`. |
| #[derive(Copy, Clone, Encodable, Decodable, Eq, PartialEq, Debug)] |
| pub struct NormalizedPos { |
| /// The absolute offset of the character in the `SourceMap`. |
| pub pos: BytePos, |
| /// The difference between original and normalized string at position. |
| pub diff: u32, |
| } |
| |
| #[derive(PartialEq, Eq, Clone, Debug)] |
| pub enum ExternalSource { |
| /// No external source has to be loaded, since the `SourceFile` represents a local crate. |
| Unneeded, |
| Foreign { |
| kind: ExternalSourceKind, |
| /// This SourceFile's byte-offset within the source_map of its original crate. |
| original_start_pos: BytePos, |
| /// The end of this SourceFile within the source_map of its original crate. |
| original_end_pos: BytePos, |
| }, |
| } |
| |
| /// The state of the lazy external source loading mechanism of a `SourceFile`. |
| #[derive(PartialEq, Eq, Clone, Debug)] |
| pub enum ExternalSourceKind { |
| /// The external source has been loaded already. |
| Present(Lrc<String>), |
| /// No attempt has been made to load the external source. |
| AbsentOk, |
| /// A failed attempt has been made to load the external source. |
| AbsentErr, |
| Unneeded, |
| } |
| |
| impl ExternalSource { |
| pub fn get_source(&self) -> Option<&Lrc<String>> { |
| match self { |
| ExternalSource::Foreign { kind: ExternalSourceKind::Present(ref src), .. } => Some(src), |
| _ => None, |
| } |
| } |
| } |
| |
| #[derive(Debug)] |
| pub struct OffsetOverflowError; |
| |
| #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)] |
| pub enum SourceFileHashAlgorithm { |
| Md5, |
| Sha1, |
| Sha256, |
| } |
| |
| impl FromStr for SourceFileHashAlgorithm { |
| type Err = (); |
| |
| fn from_str(s: &str) -> Result<SourceFileHashAlgorithm, ()> { |
| match s { |
| "md5" => Ok(SourceFileHashAlgorithm::Md5), |
| "sha1" => Ok(SourceFileHashAlgorithm::Sha1), |
| "sha256" => Ok(SourceFileHashAlgorithm::Sha256), |
| _ => Err(()), |
| } |
| } |
| } |
| |
| rustc_data_structures::impl_stable_hash_via_hash!(SourceFileHashAlgorithm); |
| |
| /// The hash of the on-disk source file used for debug info. |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| #[derive(HashStable_Generic, Encodable, Decodable)] |
| pub struct SourceFileHash { |
| pub kind: SourceFileHashAlgorithm, |
| value: [u8; 32], |
| } |
| |
| impl SourceFileHash { |
| pub fn new(kind: SourceFileHashAlgorithm, src: &str) -> SourceFileHash { |
| let mut hash = SourceFileHash { kind, value: Default::default() }; |
| let len = hash.hash_len(); |
| let value = &mut hash.value[..len]; |
| let data = src.as_bytes(); |
| match kind { |
| SourceFileHashAlgorithm::Md5 => { |
| value.copy_from_slice(&Md5::digest(data)); |
| } |
| SourceFileHashAlgorithm::Sha1 => { |
| value.copy_from_slice(&Sha1::digest(data)); |
| } |
| SourceFileHashAlgorithm::Sha256 => { |
| value.copy_from_slice(&Sha256::digest(data)); |
| } |
| } |
| hash |
| } |
| |
| /// Check if the stored hash matches the hash of the string. |
| pub fn matches(&self, src: &str) -> bool { |
| Self::new(self.kind, src) == *self |
| } |
| |
| /// The bytes of the hash. |
| pub fn hash_bytes(&self) -> &[u8] { |
| let len = self.hash_len(); |
| &self.value[..len] |
| } |
| |
| fn hash_len(&self) -> usize { |
| match self.kind { |
| SourceFileHashAlgorithm::Md5 => 16, |
| SourceFileHashAlgorithm::Sha1 => 20, |
| SourceFileHashAlgorithm::Sha256 => 32, |
| } |
| } |
| } |
| |
| /// A single source in the [`SourceMap`]. |
| #[derive(Clone)] |
| pub struct SourceFile { |
| /// The name of the file that the source came from. Source that doesn't |
| /// originate from files has names between angle brackets by convention |
| /// (e.g., `<anon>`). |
| pub name: FileName, |
| /// The complete source code. |
| pub src: Option<Lrc<String>>, |
| /// The source code's hash. |
| pub src_hash: SourceFileHash, |
| /// The external source code (used for external crates, which will have a `None` |
| /// value as `self.src`. |
| pub external_src: Lock<ExternalSource>, |
| /// The start position of this source in the `SourceMap`. |
| pub start_pos: BytePos, |
| /// The end position of this source in the `SourceMap`. |
| pub end_pos: BytePos, |
| /// Locations of lines beginnings in the source code. |
| pub lines: Vec<BytePos>, |
| /// Locations of multi-byte characters in the source code. |
| pub multibyte_chars: Vec<MultiByteChar>, |
| /// Width of characters that are not narrow in the source code. |
| pub non_narrow_chars: Vec<NonNarrowChar>, |
| /// Locations of characters removed during normalization. |
| pub normalized_pos: Vec<NormalizedPos>, |
| /// A hash of the filename, used for speeding up hashing in incremental compilation. |
| pub name_hash: u128, |
| /// Indicates which crate this `SourceFile` was imported from. |
| pub cnum: CrateNum, |
| } |
| |
| impl<S: Encoder> Encodable<S> for SourceFile { |
| fn encode(&self, s: &mut S) -> Result<(), S::Error> { |
| s.emit_struct(false, |s| { |
| s.emit_struct_field("name", true, |s| self.name.encode(s))?; |
| s.emit_struct_field("src_hash", false, |s| self.src_hash.encode(s))?; |
| s.emit_struct_field("start_pos", false, |s| self.start_pos.encode(s))?; |
| s.emit_struct_field("end_pos", false, |s| self.end_pos.encode(s))?; |
| s.emit_struct_field("lines", false, |s| { |
| let lines = &self.lines[..]; |
| // Store the length. |
| s.emit_u32(lines.len() as u32)?; |
| |
| if !lines.is_empty() { |
| // In order to preserve some space, we exploit the fact that |
| // the lines list is sorted and individual lines are |
| // probably not that long. Because of that we can store lines |
| // as a difference list, using as little space as possible |
| // for the differences. |
| let max_line_length = if lines.len() == 1 { |
| 0 |
| } else { |
| lines |
| .array_windows() |
| .map(|&[fst, snd]| snd - fst) |
| .map(|bp| bp.to_usize()) |
| .max() |
| .unwrap() |
| }; |
| |
| let bytes_per_diff: u8 = match max_line_length { |
| 0..=0xFF => 1, |
| 0x100..=0xFFFF => 2, |
| _ => 4, |
| }; |
| |
| // Encode the number of bytes used per diff. |
| bytes_per_diff.encode(s)?; |
| |
| // Encode the first element. |
| lines[0].encode(s)?; |
| |
| let diff_iter = lines[..].array_windows().map(|&[fst, snd]| snd - fst); |
| |
| match bytes_per_diff { |
| 1 => { |
| for diff in diff_iter { |
| (diff.0 as u8).encode(s)? |
| } |
| } |
| 2 => { |
| for diff in diff_iter { |
| (diff.0 as u16).encode(s)? |
| } |
| } |
| 4 => { |
| for diff in diff_iter { |
| diff.0.encode(s)? |
| } |
| } |
| _ => unreachable!(), |
| } |
| } |
| |
| Ok(()) |
| })?; |
| s.emit_struct_field("multibyte_chars", false, |s| self.multibyte_chars.encode(s))?; |
| s.emit_struct_field("non_narrow_chars", false, |s| self.non_narrow_chars.encode(s))?; |
| s.emit_struct_field("name_hash", false, |s| self.name_hash.encode(s))?; |
| s.emit_struct_field("normalized_pos", false, |s| self.normalized_pos.encode(s))?; |
| s.emit_struct_field("cnum", false, |s| self.cnum.encode(s)) |
| }) |
| } |
| } |
| |
| impl<D: Decoder> Decodable<D> for SourceFile { |
| fn decode(d: &mut D) -> Result<SourceFile, D::Error> { |
| d.read_struct(|d| { |
| let name: FileName = d.read_struct_field("name", |d| Decodable::decode(d))?; |
| let src_hash: SourceFileHash = |
| d.read_struct_field("src_hash", |d| Decodable::decode(d))?; |
| let start_pos: BytePos = d.read_struct_field("start_pos", |d| Decodable::decode(d))?; |
| let end_pos: BytePos = d.read_struct_field("end_pos", |d| Decodable::decode(d))?; |
| let lines: Vec<BytePos> = d.read_struct_field("lines", |d| { |
| let num_lines: u32 = Decodable::decode(d)?; |
| let mut lines = Vec::with_capacity(num_lines as usize); |
| |
| if num_lines > 0 { |
| // Read the number of bytes used per diff. |
| let bytes_per_diff: u8 = Decodable::decode(d)?; |
| |
| // Read the first element. |
| let mut line_start: BytePos = Decodable::decode(d)?; |
| lines.push(line_start); |
| |
| for _ in 1..num_lines { |
| let diff = match bytes_per_diff { |
| 1 => d.read_u8()? as u32, |
| 2 => d.read_u16()? as u32, |
| 4 => d.read_u32()?, |
| _ => unreachable!(), |
| }; |
| |
| line_start = line_start + BytePos(diff); |
| |
| lines.push(line_start); |
| } |
| } |
| |
| Ok(lines) |
| })?; |
| let multibyte_chars: Vec<MultiByteChar> = |
| d.read_struct_field("multibyte_chars", |d| Decodable::decode(d))?; |
| let non_narrow_chars: Vec<NonNarrowChar> = |
| d.read_struct_field("non_narrow_chars", |d| Decodable::decode(d))?; |
| let name_hash: u128 = d.read_struct_field("name_hash", |d| Decodable::decode(d))?; |
| let normalized_pos: Vec<NormalizedPos> = |
| d.read_struct_field("normalized_pos", |d| Decodable::decode(d))?; |
| let cnum: CrateNum = d.read_struct_field("cnum", |d| Decodable::decode(d))?; |
| Ok(SourceFile { |
| name, |
| start_pos, |
| end_pos, |
| src: None, |
| src_hash, |
| // Unused - the metadata decoder will construct |
| // a new SourceFile, filling in `external_src` properly |
| external_src: Lock::new(ExternalSource::Unneeded), |
| lines, |
| multibyte_chars, |
| non_narrow_chars, |
| normalized_pos, |
| name_hash, |
| cnum, |
| }) |
| }) |
| } |
| } |
| |
| impl fmt::Debug for SourceFile { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| write!(fmt, "SourceFile({:?})", self.name) |
| } |
| } |
| |
| impl SourceFile { |
| pub fn new( |
| name: FileName, |
| mut src: String, |
| start_pos: BytePos, |
| hash_kind: SourceFileHashAlgorithm, |
| ) -> Self { |
| // Compute the file hash before any normalization. |
| let src_hash = SourceFileHash::new(hash_kind, &src); |
| let normalized_pos = normalize_src(&mut src, start_pos); |
| |
| let name_hash = { |
| let mut hasher: StableHasher = StableHasher::new(); |
| name.hash(&mut hasher); |
| hasher.finish::<u128>() |
| }; |
| let end_pos = start_pos.to_usize() + src.len(); |
| assert!(end_pos <= u32::MAX as usize); |
| |
| let (lines, multibyte_chars, non_narrow_chars) = |
| analyze_source_file::analyze_source_file(&src[..], start_pos); |
| |
| SourceFile { |
| name, |
| src: Some(Lrc::new(src)), |
| src_hash, |
| external_src: Lock::new(ExternalSource::Unneeded), |
| start_pos, |
| end_pos: Pos::from_usize(end_pos), |
| lines, |
| multibyte_chars, |
| non_narrow_chars, |
| normalized_pos, |
| name_hash, |
| cnum: LOCAL_CRATE, |
| } |
| } |
| |
| /// Returns the `BytePos` of the beginning of the current line. |
| pub fn line_begin_pos(&self, pos: BytePos) -> BytePos { |
| let line_index = self.lookup_line(pos).unwrap(); |
| self.lines[line_index] |
| } |
| |
| /// Add externally loaded source. |
| /// If the hash of the input doesn't match or no input is supplied via None, |
| /// it is interpreted as an error and the corresponding enum variant is set. |
| /// The return value signifies whether some kind of source is present. |
| pub fn add_external_src<F>(&self, get_src: F) -> bool |
| where |
| F: FnOnce() -> Option<String>, |
| { |
| if matches!( |
| *self.external_src.borrow(), |
| ExternalSource::Foreign { kind: ExternalSourceKind::AbsentOk, .. } |
| ) { |
| let src = get_src(); |
| let mut external_src = self.external_src.borrow_mut(); |
| // Check that no-one else have provided the source while we were getting it |
| if let ExternalSource::Foreign { |
| kind: src_kind @ ExternalSourceKind::AbsentOk, .. |
| } = &mut *external_src |
| { |
| if let Some(mut src) = src { |
| // The src_hash needs to be computed on the pre-normalized src. |
| if self.src_hash.matches(&src) { |
| normalize_src(&mut src, BytePos::from_usize(0)); |
| *src_kind = ExternalSourceKind::Present(Lrc::new(src)); |
| return true; |
| } |
| } else { |
| *src_kind = ExternalSourceKind::AbsentErr; |
| } |
| |
| false |
| } else { |
| self.src.is_some() || external_src.get_source().is_some() |
| } |
| } else { |
| self.src.is_some() || self.external_src.borrow().get_source().is_some() |
| } |
| } |
| |
| /// Gets a line from the list of pre-computed line-beginnings. |
| /// The line number here is 0-based. |
| pub fn get_line(&self, line_number: usize) -> Option<Cow<'_, str>> { |
| fn get_until_newline(src: &str, begin: usize) -> &str { |
| // We can't use `lines.get(line_number+1)` because we might |
| // be parsing when we call this function and thus the current |
| // line is the last one we have line info for. |
| let slice = &src[begin..]; |
| match slice.find('\n') { |
| Some(e) => &slice[..e], |
| None => slice, |
| } |
| } |
| |
| let begin = { |
| let line = self.lines.get(line_number)?; |
| let begin: BytePos = *line - self.start_pos; |
| begin.to_usize() |
| }; |
| |
| if let Some(ref src) = self.src { |
| Some(Cow::from(get_until_newline(src, begin))) |
| } else if let Some(src) = self.external_src.borrow().get_source() { |
| Some(Cow::Owned(String::from(get_until_newline(src, begin)))) |
| } else { |
| None |
| } |
| } |
| |
| pub fn is_real_file(&self) -> bool { |
| self.name.is_real() |
| } |
| |
| pub fn is_imported(&self) -> bool { |
| self.src.is_none() |
| } |
| |
| pub fn count_lines(&self) -> usize { |
| self.lines.len() |
| } |
| |
| /// Finds the line containing the given position. The return value is the |
| /// index into the `lines` array of this `SourceFile`, not the 1-based line |
| /// number. If the source_file is empty or the position is located before the |
| /// first line, `None` is returned. |
| pub fn lookup_line(&self, pos: BytePos) -> Option<usize> { |
| match self.lines.binary_search(&pos) { |
| Ok(idx) => Some(idx), |
| Err(0) => None, |
| Err(idx) => Some(idx - 1), |
| } |
| } |
| |
| pub fn line_bounds(&self, line_index: usize) -> Range<BytePos> { |
| if self.is_empty() { |
| return self.start_pos..self.end_pos; |
| } |
| |
| assert!(line_index < self.lines.len()); |
| if line_index == (self.lines.len() - 1) { |
| self.lines[line_index]..self.end_pos |
| } else { |
| self.lines[line_index]..self.lines[line_index + 1] |
| } |
| } |
| |
| /// Returns whether or not the file contains the given `SourceMap` byte |
| /// position. The position one past the end of the file is considered to be |
| /// contained by the file. This implies that files for which `is_empty` |
| /// returns true still contain one byte position according to this function. |
| #[inline] |
| pub fn contains(&self, byte_pos: BytePos) -> bool { |
| byte_pos >= self.start_pos && byte_pos <= self.end_pos |
| } |
| |
| #[inline] |
| pub fn is_empty(&self) -> bool { |
| self.start_pos == self.end_pos |
| } |
| |
| /// Calculates the original byte position relative to the start of the file |
| /// based on the given byte position. |
| pub fn original_relative_byte_pos(&self, pos: BytePos) -> BytePos { |
| // Diff before any records is 0. Otherwise use the previously recorded |
| // diff as that applies to the following characters until a new diff |
| // is recorded. |
| let diff = match self.normalized_pos.binary_search_by(|np| np.pos.cmp(&pos)) { |
| Ok(i) => self.normalized_pos[i].diff, |
| Err(i) if i == 0 => 0, |
| Err(i) => self.normalized_pos[i - 1].diff, |
| }; |
| |
| BytePos::from_u32(pos.0 - self.start_pos.0 + diff) |
| } |
| |
| /// Converts an absolute `BytePos` to a `CharPos` relative to the `SourceFile`. |
| pub fn bytepos_to_file_charpos(&self, bpos: BytePos) -> CharPos { |
| // The number of extra bytes due to multibyte chars in the `SourceFile`. |
| let mut total_extra_bytes = 0; |
| |
| for mbc in self.multibyte_chars.iter() { |
| debug!("{}-byte char at {:?}", mbc.bytes, mbc.pos); |
| if mbc.pos < bpos { |
| // Every character is at least one byte, so we only |
| // count the actual extra bytes. |
| total_extra_bytes += mbc.bytes as u32 - 1; |
| // We should never see a byte position in the middle of a |
| // character. |
| assert!(bpos.to_u32() >= mbc.pos.to_u32() + mbc.bytes as u32); |
| } else { |
| break; |
| } |
| } |
| |
| assert!(self.start_pos.to_u32() + total_extra_bytes <= bpos.to_u32()); |
| CharPos(bpos.to_usize() - self.start_pos.to_usize() - total_extra_bytes as usize) |
| } |
| |
| /// Looks up the file's (1-based) line number and (0-based `CharPos`) column offset, for a |
| /// given `BytePos`. |
| pub fn lookup_file_pos(&self, pos: BytePos) -> (usize, CharPos) { |
| let chpos = self.bytepos_to_file_charpos(pos); |
| match self.lookup_line(pos) { |
| Some(a) => { |
| let line = a + 1; // Line numbers start at 1 |
| let linebpos = self.lines[a]; |
| let linechpos = self.bytepos_to_file_charpos(linebpos); |
| let col = chpos - linechpos; |
| debug!("byte pos {:?} is on the line at byte pos {:?}", pos, linebpos); |
| debug!("char pos {:?} is on the line at char pos {:?}", chpos, linechpos); |
| debug!("byte is on line: {}", line); |
| assert!(chpos >= linechpos); |
| (line, col) |
| } |
| None => (0, chpos), |
| } |
| } |
| |
| /// Looks up the file's (1-based) line number, (0-based `CharPos`) column offset, and (0-based) |
| /// column offset when displayed, for a given `BytePos`. |
| pub fn lookup_file_pos_with_col_display(&self, pos: BytePos) -> (usize, CharPos, usize) { |
| let (line, col_or_chpos) = self.lookup_file_pos(pos); |
| if line > 0 { |
| let col = col_or_chpos; |
| let linebpos = self.lines[line - 1]; |
| let col_display = { |
| let start_width_idx = self |
| .non_narrow_chars |
| .binary_search_by_key(&linebpos, |x| x.pos()) |
| .unwrap_or_else(|x| x); |
| let end_width_idx = self |
| .non_narrow_chars |
| .binary_search_by_key(&pos, |x| x.pos()) |
| .unwrap_or_else(|x| x); |
| let special_chars = end_width_idx - start_width_idx; |
| let non_narrow: usize = self.non_narrow_chars[start_width_idx..end_width_idx] |
| .iter() |
| .map(|x| x.width()) |
| .sum(); |
| col.0 - special_chars + non_narrow |
| }; |
| (line, col, col_display) |
| } else { |
| let chpos = col_or_chpos; |
| let col_display = { |
| let end_width_idx = self |
| .non_narrow_chars |
| .binary_search_by_key(&pos, |x| x.pos()) |
| .unwrap_or_else(|x| x); |
| let non_narrow: usize = |
| self.non_narrow_chars[0..end_width_idx].iter().map(|x| x.width()).sum(); |
| chpos.0 - end_width_idx + non_narrow |
| }; |
| (0, chpos, col_display) |
| } |
| } |
| } |
| |
| /// Normalizes the source code and records the normalizations. |
| fn normalize_src(src: &mut String, start_pos: BytePos) -> Vec<NormalizedPos> { |
| let mut normalized_pos = vec![]; |
| remove_bom(src, &mut normalized_pos); |
| normalize_newlines(src, &mut normalized_pos); |
| |
| // Offset all the positions by start_pos to match the final file positions. |
| for np in &mut normalized_pos { |
| np.pos.0 += start_pos.0; |
| } |
| |
| normalized_pos |
| } |
| |
| /// Removes UTF-8 BOM, if any. |
| fn remove_bom(src: &mut String, normalized_pos: &mut Vec<NormalizedPos>) { |
| if src.starts_with('\u{feff}') { |
| src.drain(..3); |
| normalized_pos.push(NormalizedPos { pos: BytePos(0), diff: 3 }); |
| } |
| } |
| |
| /// Replaces `\r\n` with `\n` in-place in `src`. |
| /// |
| /// Returns error if there's a lone `\r` in the string. |
| fn normalize_newlines(src: &mut String, normalized_pos: &mut Vec<NormalizedPos>) { |
| if !src.as_bytes().contains(&b'\r') { |
| return; |
| } |
| |
| // We replace `\r\n` with `\n` in-place, which doesn't break utf-8 encoding. |
| // While we *can* call `as_mut_vec` and do surgery on the live string |
| // directly, let's rather steal the contents of `src`. This makes the code |
| // safe even if a panic occurs. |
| |
| let mut buf = std::mem::replace(src, String::new()).into_bytes(); |
| let mut gap_len = 0; |
| let mut tail = buf.as_mut_slice(); |
| let mut cursor = 0; |
| let original_gap = normalized_pos.last().map_or(0, |l| l.diff); |
| loop { |
| let idx = match find_crlf(&tail[gap_len..]) { |
| None => tail.len(), |
| Some(idx) => idx + gap_len, |
| }; |
| tail.copy_within(gap_len..idx, 0); |
| tail = &mut tail[idx - gap_len..]; |
| if tail.len() == gap_len { |
| break; |
| } |
| cursor += idx - gap_len; |
| gap_len += 1; |
| normalized_pos.push(NormalizedPos { |
| pos: BytePos::from_usize(cursor + 1), |
| diff: original_gap + gap_len as u32, |
| }); |
| } |
| |
| // Account for removed `\r`. |
| // After `set_len`, `buf` is guaranteed to contain utf-8 again. |
| let new_len = buf.len() - gap_len; |
| unsafe { |
| buf.set_len(new_len); |
| *src = String::from_utf8_unchecked(buf); |
| } |
| |
| fn find_crlf(src: &[u8]) -> Option<usize> { |
| let mut search_idx = 0; |
| while let Some(idx) = find_cr(&src[search_idx..]) { |
| if src[search_idx..].get(idx + 1) != Some(&b'\n') { |
| search_idx += idx + 1; |
| continue; |
| } |
| return Some(search_idx + idx); |
| } |
| None |
| } |
| |
| fn find_cr(src: &[u8]) -> Option<usize> { |
| src.iter().position(|&b| b == b'\r') |
| } |
| } |
| |
| // _____________________________________________________________________________ |
| // Pos, BytePos, CharPos |
| // |
| |
| pub trait Pos { |
| fn from_usize(n: usize) -> Self; |
| fn to_usize(&self) -> usize; |
| fn from_u32(n: u32) -> Self; |
| fn to_u32(&self) -> u32; |
| } |
| |
| macro_rules! impl_pos { |
| ( |
| $( |
| $(#[$attr:meta])* |
| $vis:vis struct $ident:ident($inner_vis:vis $inner_ty:ty); |
| )* |
| ) => { |
| $( |
| $(#[$attr])* |
| $vis struct $ident($inner_vis $inner_ty); |
| |
| impl Pos for $ident { |
| #[inline(always)] |
| fn from_usize(n: usize) -> $ident { |
| $ident(n as $inner_ty) |
| } |
| |
| #[inline(always)] |
| fn to_usize(&self) -> usize { |
| self.0 as usize |
| } |
| |
| #[inline(always)] |
| fn from_u32(n: u32) -> $ident { |
| $ident(n as $inner_ty) |
| } |
| |
| #[inline(always)] |
| fn to_u32(&self) -> u32 { |
| self.0 as u32 |
| } |
| } |
| |
| impl Add for $ident { |
| type Output = $ident; |
| |
| #[inline(always)] |
| fn add(self, rhs: $ident) -> $ident { |
| $ident(self.0 + rhs.0) |
| } |
| } |
| |
| impl Sub for $ident { |
| type Output = $ident; |
| |
| #[inline(always)] |
| fn sub(self, rhs: $ident) -> $ident { |
| $ident(self.0 - rhs.0) |
| } |
| } |
| )* |
| }; |
| } |
| |
| impl_pos! { |
| /// A byte offset. |
| /// |
| /// Keep this small (currently 32-bits), as AST contains a lot of them. |
| #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)] |
| pub struct BytePos(pub u32); |
| |
| /// A character offset. |
| /// |
| /// Because of multibyte UTF-8 characters, a byte offset |
| /// is not equivalent to a character offset. The [`SourceMap`] will convert [`BytePos`] |
| /// values to `CharPos` values as necessary. |
| #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug)] |
| pub struct CharPos(pub usize); |
| } |
| |
| impl<S: rustc_serialize::Encoder> Encodable<S> for BytePos { |
| fn encode(&self, s: &mut S) -> Result<(), S::Error> { |
| s.emit_u32(self.0) |
| } |
| } |
| |
| impl<D: rustc_serialize::Decoder> Decodable<D> for BytePos { |
| fn decode(d: &mut D) -> Result<BytePos, D::Error> { |
| Ok(BytePos(d.read_u32()?)) |
| } |
| } |
| |
| // _____________________________________________________________________________ |
| // Loc, SourceFileAndLine, SourceFileAndBytePos |
| // |
| |
| /// A source code location used for error reporting. |
| #[derive(Debug, Clone)] |
| pub struct Loc { |
| /// Information about the original source. |
| pub file: Lrc<SourceFile>, |
| /// The (1-based) line number. |
| pub line: usize, |
| /// The (0-based) column offset. |
| pub col: CharPos, |
| /// The (0-based) column offset when displayed. |
| pub col_display: usize, |
| } |
| |
| // Used to be structural records. |
| #[derive(Debug)] |
| pub struct SourceFileAndLine { |
| pub sf: Lrc<SourceFile>, |
| pub line: usize, |
| } |
| #[derive(Debug)] |
| pub struct SourceFileAndBytePos { |
| pub sf: Lrc<SourceFile>, |
| pub pos: BytePos, |
| } |
| |
| #[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| pub struct LineInfo { |
| /// Index of line, starting from 0. |
| pub line_index: usize, |
| |
| /// Column in line where span begins, starting from 0. |
| pub start_col: CharPos, |
| |
| /// Column in line where span ends, starting from 0, exclusive. |
| pub end_col: CharPos, |
| } |
| |
| pub struct FileLines { |
| pub file: Lrc<SourceFile>, |
| pub lines: Vec<LineInfo>, |
| } |
| |
| pub static SPAN_DEBUG: AtomicRef<fn(Span, &mut fmt::Formatter<'_>) -> fmt::Result> = |
| AtomicRef::new(&(default_span_debug as fn(_, &mut fmt::Formatter<'_>) -> _)); |
| |
| // _____________________________________________________________________________ |
| // SpanLinesError, SpanSnippetError, DistinctSources, MalformedSourceMapPositions |
| // |
| |
| pub type FileLinesResult = Result<FileLines, SpanLinesError>; |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub enum SpanLinesError { |
| DistinctSources(DistinctSources), |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub enum SpanSnippetError { |
| IllFormedSpan(Span), |
| DistinctSources(DistinctSources), |
| MalformedForSourcemap(MalformedSourceMapPositions), |
| SourceNotAvailable { filename: FileName }, |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct DistinctSources { |
| pub begin: (FileName, BytePos), |
| pub end: (FileName, BytePos), |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct MalformedSourceMapPositions { |
| pub name: FileName, |
| pub source_len: usize, |
| pub begin_pos: BytePos, |
| pub end_pos: BytePos, |
| } |
| |
| /// Range inside of a `Span` used for diagnostics when we only have access to relative positions. |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| pub struct InnerSpan { |
| pub start: usize, |
| pub end: usize, |
| } |
| |
| impl InnerSpan { |
| pub fn new(start: usize, end: usize) -> InnerSpan { |
| InnerSpan { start, end } |
| } |
| } |
| |
| /// Requirements for a `StableHashingContext` to be used in this crate. |
| /// |
| /// This is a hack to allow using the [`HashStable_Generic`] derive macro |
| /// instead of implementing everything in rustc_middle. |
| pub trait HashStableContext { |
| fn def_path_hash(&self, def_id: DefId) -> DefPathHash; |
| fn hash_spans(&self) -> bool; |
| fn span_data_to_lines_and_cols( |
| &mut self, |
| span: &SpanData, |
| ) -> Option<(Lrc<SourceFile>, usize, BytePos, usize, BytePos)>; |
| } |
| |
| impl<CTX> HashStable<CTX> for Span |
| where |
| CTX: HashStableContext, |
| { |
| /// Hashes a span in a stable way. We can't directly hash the span's `BytePos` |
| /// fields (that would be similar to hashing pointers, since those are just |
| /// offsets into the `SourceMap`). Instead, we hash the (file name, line, column) |
| /// triple, which stays the same even if the containing `SourceFile` has moved |
| /// within the `SourceMap`. |
| /// |
| /// Also note that we are hashing byte offsets for the column, not unicode |
| /// codepoint offsets. For the purpose of the hash that's sufficient. |
| /// Also, hashing filenames is expensive so we avoid doing it twice when the |
| /// span starts and ends in the same file, which is almost always the case. |
| fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
| const TAG_VALID_SPAN: u8 = 0; |
| const TAG_INVALID_SPAN: u8 = 1; |
| |
| if !ctx.hash_spans() { |
| return; |
| } |
| |
| self.ctxt().hash_stable(ctx, hasher); |
| |
| if self.is_dummy() { |
| Hash::hash(&TAG_INVALID_SPAN, hasher); |
| return; |
| } |
| |
| // If this is not an empty or invalid span, we want to hash the last |
| // position that belongs to it, as opposed to hashing the first |
| // position past it. |
| let span = self.data(); |
| let (file, line_lo, col_lo, line_hi, col_hi) = match ctx.span_data_to_lines_and_cols(&span) |
| { |
| Some(pos) => pos, |
| None => { |
| Hash::hash(&TAG_INVALID_SPAN, hasher); |
| return; |
| } |
| }; |
| |
| Hash::hash(&TAG_VALID_SPAN, hasher); |
| // We truncate the stable ID hash and line and column numbers. The chances |
| // of causing a collision this way should be minimal. |
| Hash::hash(&(file.name_hash as u64), hasher); |
| |
| // Hash both the length and the end location (line/column) of a span. If we |
| // hash only the length, for example, then two otherwise equal spans with |
| // different end locations will have the same hash. This can cause a problem |
| // during incremental compilation wherein a previous result for a query that |
| // depends on the end location of a span will be incorrectly reused when the |
| // end location of the span it depends on has changed (see issue #74890). A |
| // similar analysis applies if some query depends specifically on the length |
| // of the span, but we only hash the end location. So hash both. |
| |
| let col_lo_trunc = (col_lo.0 as u64) & 0xFF; |
| let line_lo_trunc = ((line_lo as u64) & 0xFF_FF_FF) << 8; |
| let col_hi_trunc = (col_hi.0 as u64) & 0xFF << 32; |
| let line_hi_trunc = ((line_hi as u64) & 0xFF_FF_FF) << 40; |
| let col_line = col_lo_trunc | line_lo_trunc | col_hi_trunc | line_hi_trunc; |
| let len = (span.hi - span.lo).0; |
| Hash::hash(&col_line, hasher); |
| Hash::hash(&len, hasher); |
| } |
| } |