Google Git
Sign in
fuchsia / third_party / rust / 346aec9b02f3c74f3fce97fd6bda24709d220e49 / . / src / librustc_span / lib.rs
blob: 699871f1c61ce766cf2776ba8c2e65f5d631126c [file] [log] [blame]
//! The source positions and related helper functions.
//!
//! ## Note
//!
//! This API is completely unstable and subject to change.
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
#![feature(crate_visibility_modifier)]
#![cfg_attr(bootstrap, feature(const_if_match))]
#![feature(const_fn)]
#![feature(const_panic)]
#![feature(negative_impls)]
#![feature(nll)]
#![feature(optin_builtin_traits)]
#![feature(min_specialization)]
// FIXME(#56935): Work around ICEs during cross-compilation.
#[allow(unused)]
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;
pub use hygiene::SyntaxContext;
use hygiene::Transparency;
pub use hygiene::{DesugaringKind, ExpnData, ExpnId, ExpnKind, ForLoopLoc, MacroKind};
pub mod def_id;
use def_id::{CrateNum, DefId, LOCAL_CRATE};
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::fingerprint::Fingerprint;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::sync::{Lock, Lrc};
use std::borrow::Cow;
use std::cell::RefCell;
use std::cmp::{self, Ordering};
use std::fmt;
use std::hash::Hash;
use std::ops::{Add, Sub};
use std::path::{Path, PathBuf};
use std::str::FromStr;
use md5::Md5;
use sha1::Digest;
use sha1::Sha1;
#[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),
}
}
}
scoped_tls::scoped_thread_local!(pub static SESSION_GLOBALS: SessionGlobals);
// FIXME: Perhaps this should not implement Rustc{Decodable, Encodable}
//
// 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, Hash, RustcDecodable, RustcEncodable)]
#[derive(HashStable_Generic)]
pub enum RealFileName {
Named(PathBuf),
/// For de-virtualized paths (namely paths into libstd that have been mapped
/// to the appropriate spot on the local host's file system),
Devirtualized {
/// `local_path` is the (host-dependent) local path to the file.
local_path: PathBuf,
/// `virtual_name` is the stable path rustc will store internally within
/// build artifacts.
virtual_name: PathBuf,
},
}
impl RealFileName {
/// Returns the path suitable for reading from the file system on the local host.
/// Avoid embedding this in build artifacts; see `stable_name` for that.
pub fn local_path(&self) -> &Path {
match self {
RealFileName::Named(p)
| RealFileName::Devirtualized { local_path: p, virtual_name: _ } => &p,
}
}
/// Returns the path suitable for reading from the file system on the local host.
/// Avoid embedding this in build artifacts; see `stable_name` for that.
pub fn into_local_path(self) -> PathBuf {
match self {
RealFileName::Named(p)
| RealFileName::Devirtualized { local_path: p, virtual_name: _ } => p,
}
}
/// Returns the path suitable for embedding into build artifacts. Note that
/// a virtualized path will not correspond to a valid file system path; see
/// `local_path` for something that is more likely to return paths into the
/// local host file system.
pub fn stable_name(&self) -> &Path {
match self {
RealFileName::Named(p)
| RealFileName::Devirtualized { local_path: _, virtual_name: p } => &p,
}
}
}
/// Differentiates between real files and common virtual files.
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Hash, RustcDecodable, RustcEncodable)]
#[derive(HashStable_Generic)]
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 std::fmt::Display for FileName {
fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
use FileName::*;
match *self {
Real(RealFileName::Named(ref path)) => write!(fmt, "{}", path.display()),
// FIXME: might be nice to display both compoments of Devirtualized.
// But for now (to backport fix for issue #70924), best to not
// perturb diagnostics so its obvious test suite still works.
Real(RealFileName::Devirtualized { ref local_path, virtual_name: _ }) => {
write!(fmt, "{}", local_path.display())
}
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 From<PathBuf> for FileName {
fn from(p: PathBuf) -> Self {
assert!(!p.to_string_lossy().ends_with('>'));
FileName::Real(RealFileName::Named(p))
}
}
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 quote_expansion_source_code(src: &str) -> FileName {
let mut hasher = StableHasher::new();
src.hash(&mut hasher);
FileName::QuoteExpansion(hasher.finish())
}
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())
}
}
/// Spans represent a region of code, used for error reporting. Positions in spans
/// are *absolute* positions from the beginning of the source_map, 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 - 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 = hi - 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 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, RustcEncodable, RustcDecodable)]
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)
}
/// 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().outer_expn_data().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
}
/// 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 || f == sym::allow_internal_unstable_backcompat_hack)
})
}
/// 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`.
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`.
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` between the beginning of `self` to the beginning of `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())
}
}
#[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 rustc_serialize::UseSpecializedEncodable for Span {
fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
let span = self.data();
s.emit_struct("Span", 2, |s| {
s.emit_struct_field("lo", 0, |s| span.lo.encode(s))?;
s.emit_struct_field("hi", 1, |s| span.hi.encode(s))
})
}
}
impl rustc_serialize::UseSpecializedDecodable for Span {
fn default_decode<D: Decoder>(d: &mut D) -> Result<Span, D::Error> {
d.read_struct("Span", 2, |d| {
let lo = d.read_struct_field("lo", 0, Decodable::decode)?;
let hi = d.read_struct_field("hi", 1, Decodable::decode)?;
Ok(Span::with_root_ctxt(lo, hi))
})
}
}
/// Calls the provided closure, using the provided `SourceMap` to format
/// any spans that are debug-printed during the closure'e exectuino.
///
/// 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 {
SESSION_GLOBALS.with(|session_globals| {
*session_globals.source_map.borrow_mut() = Some(source_map);
});
struct ClearSourceMap;
impl Drop for ClearSourceMap {
fn drop(&mut self) {
SESSION_GLOBALS.with(|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_string(span), span.ctxt())
}
pub fn default_span_debug(span: Span, f: &mut fmt::Formatter<'_>) -> fmt::Result {
SESSION_GLOBALS.with(|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, RustcEncodable, RustcDecodable, 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, RustcEncodable, RustcDecodable, 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, RustcEncodable, RustcDecodable, 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 is_absent(&self) -> bool {
match self {
ExternalSource::Foreign { kind: ExternalSourceKind::Present(_), .. } => false,
_ => true,
}
}
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, RustcEncodable, RustcDecodable)]
pub enum SourceFileHashAlgorithm {
Md5,
Sha1,
}
impl FromStr for SourceFileHashAlgorithm {
type Err = ();
fn from_str(s: &str) -> Result<SourceFileHashAlgorithm, ()> {
match s {
"md5" => Ok(SourceFileHashAlgorithm::Md5),
"sha1" => Ok(SourceFileHashAlgorithm::Sha1),
_ => 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, RustcEncodable, RustcDecodable)]
#[derive(HashStable_Generic)]
pub struct SourceFileHash {
pub kind: SourceFileHashAlgorithm,
value: [u8; 20],
}
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));
}
}
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,
}
}
}
/// 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,
/// `true` if the `name` field above has been modified by `--remap-path-prefix`.
pub name_was_remapped: bool,
/// The unmapped path of the file that the source came from.
/// Set to `None` if the `SourceFile` was imported from an external crate.
pub unmapped_path: Option<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 Encodable for SourceFile {
fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
s.emit_struct("SourceFile", 8, |s| {
s.emit_struct_field("name", 0, |s| self.name.encode(s))?;
s.emit_struct_field("name_was_remapped", 1, |s| self.name_was_remapped.encode(s))?;
s.emit_struct_field("src_hash", 2, |s| self.src_hash.encode(s))?;
s.emit_struct_field("start_pos", 3, |s| self.start_pos.encode(s))?;
s.emit_struct_field("end_pos", 4, |s| self.end_pos.encode(s))?;
s.emit_struct_field("lines", 5, |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.windows(2).map(|w| w[1] - w[0]).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[..]).windows(2).map(|w| (w[1] - w[0]));
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", 6, |s| self.multibyte_chars.encode(s))?;
s.emit_struct_field("non_narrow_chars", 7, |s| self.non_narrow_chars.encode(s))?;
s.emit_struct_field("name_hash", 8, |s| self.name_hash.encode(s))?;
s.emit_struct_field("normalized_pos", 9, |s| self.normalized_pos.encode(s))?;
s.emit_struct_field("cnum", 10, |s| self.cnum.encode(s))
})
}
}
impl Decodable for SourceFile {
fn decode<D: Decoder>(d: &mut D) -> Result<SourceFile, D::Error> {
d.read_struct("SourceFile", 8, |d| {
let name: FileName = d.read_struct_field("name", 0, |d| Decodable::decode(d))?;
let name_was_remapped: bool =
d.read_struct_field("name_was_remapped", 1, |d| Decodable::decode(d))?;
let src_hash: SourceFileHash =
d.read_struct_field("src_hash", 2, |d| Decodable::decode(d))?;
let start_pos: BytePos =
d.read_struct_field("start_pos", 3, |d| Decodable::decode(d))?;
let end_pos: BytePos = d.read_struct_field("end_pos", 4, |d| Decodable::decode(d))?;
let lines: Vec<BytePos> = d.read_struct_field("lines", 5, |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", 6, |d| Decodable::decode(d))?;
let non_narrow_chars: Vec<NonNarrowChar> =
d.read_struct_field("non_narrow_chars", 7, |d| Decodable::decode(d))?;
let name_hash: u128 = d.read_struct_field("name_hash", 8, |d| Decodable::decode(d))?;
let normalized_pos: Vec<NormalizedPos> =
d.read_struct_field("normalized_pos", 9, |d| Decodable::decode(d))?;
let cnum: CrateNum = d.read_struct_field("cnum", 10, |d| Decodable::decode(d))?;
Ok(SourceFile {
name,
name_was_remapped,
unmapped_path: None,
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,
name_was_remapped: bool,
unmapped_path: 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,
name_was_remapped,
unmapped_path: Some(unmapped_path),
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 byte_length(&self) -> u32 {
self.end_pos.0 - self.start_pos.0
}
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> {
if self.lines.is_empty() {
return None;
}
let line_index = lookup_line(&self.lines[..], pos);
assert!(line_index < self.lines.len() as isize);
if line_index >= 0 { Some(line_index as usize) } else { None }
}
pub fn line_bounds(&self, line_index: usize) -> (BytePos, BytePos) {
if self.start_pos == self.end_pos {
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])
}
}
#[inline]
pub fn contains(&self, byte_pos: BytePos) -> bool {
byte_pos >= self.start_pos && byte_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)
}
}
/// 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;
}
/// 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(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
pub struct CharPos(pub usize);
// FIXME: lots of boilerplate in these impls, but so far my attempts to fix
// have been unsuccessful.
impl Pos for BytePos {
#[inline(always)]
fn from_usize(n: usize) -> BytePos {
BytePos(n as u32)
}
#[inline(always)]
fn to_usize(&self) -> usize {
self.0 as usize
}
#[inline(always)]
fn from_u32(n: u32) -> BytePos {
BytePos(n)
}
#[inline(always)]
fn to_u32(&self) -> u32 {
self.0
}
}
impl Add for BytePos {
type Output = BytePos;
#[inline(always)]
fn add(self, rhs: BytePos) -> BytePos {
BytePos((self.to_usize() + rhs.to_usize()) as u32)
}
}
impl Sub for BytePos {
type Output = BytePos;
#[inline(always)]
fn sub(self, rhs: BytePos) -> BytePos {
BytePos((self.to_usize() - rhs.to_usize()) as u32)
}
}
impl Encodable for BytePos {
fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
s.emit_u32(self.0)
}
}
impl Decodable for BytePos {
fn decode<D: Decoder>(d: &mut D) -> Result<BytePos, D::Error> {
Ok(BytePos(d.read_u32()?))
}
}
impl Pos for CharPos {
#[inline(always)]
fn from_usize(n: usize) -> CharPos {
CharPos(n)
}
#[inline(always)]
fn to_usize(&self) -> usize {
self.0
}
#[inline(always)]
fn from_u32(n: u32) -> CharPos {
CharPos(n as usize)
}
#[inline(always)]
fn to_u32(&self) -> u32 {
self.0 as u32
}
}
impl Add for CharPos {
type Output = CharPos;
#[inline(always)]
fn add(self, rhs: CharPos) -> CharPos {
CharPos(self.to_usize() + rhs.to_usize())
}
}
impl Sub for CharPos {
type Output = CharPos;
#[inline(always)]
fn sub(self, rhs: CharPos) -> CharPos {
CharPos(self.to_usize() - rhs.to_usize())
}
}
// _____________________________________________________________________________
// 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 }
}
}
// Given a slice of line start positions and a position, returns the index of
// the line the position is on. Returns -1 if the position is located before
// the first line.
fn lookup_line(lines: &[BytePos], pos: BytePos) -> isize {
match lines.binary_search(&pos) {
Ok(line) => line as isize,
Err(line) => line as isize - 1,
}
}
/// 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 librustc_middle.
pub trait HashStableContext {
fn hash_spans(&self) -> bool;
fn hash_def_id(&mut self, _: DefId, hasher: &mut StableHasher);
fn byte_pos_to_line_and_col(
&mut self,
byte: BytePos,
) -> Option<(Lrc<SourceFile>, 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;
const TAG_EXPANSION: u8 = 0;
const TAG_NO_EXPANSION: u8 = 1;
if !ctx.hash_spans() {
return;
}
if *self == DUMMY_SP {
return std::hash::Hash::hash(&TAG_INVALID_SPAN, hasher);
}
// 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_lo, line_lo, col_lo) = match ctx.byte_pos_to_line_and_col(span.lo) {
Some(pos) => pos,
None => {
return std::hash::Hash::hash(&TAG_INVALID_SPAN, hasher);
}
};
if !file_lo.contains(span.hi) {
return std::hash::Hash::hash(&TAG_INVALID_SPAN, hasher);
}
std::hash::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.
std::hash::Hash::hash(&(file_lo.name_hash as u64), hasher);
let col = (col_lo.0 as u64) & 0xFF;
let line = ((line_lo as u64) & 0xFF_FF_FF) << 8;
let len = ((span.hi - span.lo).0 as u64) << 32;
let line_col_len = col | line | len;
std::hash::Hash::hash(&line_col_len, hasher);
if span.ctxt == SyntaxContext::root() {
TAG_NO_EXPANSION.hash_stable(ctx, hasher);
} else {
TAG_EXPANSION.hash_stable(ctx, hasher);
// Since the same expansion context is usually referenced many
// times, we cache a stable hash of it and hash that instead of
// recursing every time.
thread_local! {
static CACHE: RefCell<FxHashMap<hygiene::ExpnId, u64>> = Default::default();
}
let sub_hash: u64 = CACHE.with(|cache| {
let expn_id = span.ctxt.outer_expn();
if let Some(&sub_hash) = cache.borrow().get(&expn_id) {
return sub_hash;
}
let mut hasher = StableHasher::new();
expn_id.expn_data().hash_stable(ctx, &mut hasher);
let sub_hash: Fingerprint = hasher.finish();
let sub_hash = sub_hash.to_smaller_hash();
cache.borrow_mut().insert(expn_id, sub_hash);
sub_hash
});
sub_hash.hash_stable(ctx, hasher);
}
}
}