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Auto merge of #134478 - compiler-errors:attr-span, r=oli-obk

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Properly record metavar spans for other expansions other than TT

This properly records metavar spans for nonterminals other than tokentree. This means that we operations like `span.to(other_span)` work correctly for macros. As you can see, other diagnostics involving metavars have improved as a result.

Fixes #132908
Alternative to #133270

cc `@ehuss`
cc `@petrochenkov`
This commit is contained in:
bors 2025-01-22 14:46:41 +00:00
commit dee7d0e730
12 changed files with 105 additions and 34 deletions
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20
compiler/rustc_expand/src/mbe/transcribe.rs
View file

@ -282,11 +282,13 @@ pub(super) fn transcribe<'a>(
}
MatchedSingle(ParseNtResult::Ident(ident, is_raw)) => {
marker.visit_span(&mut sp);
with_metavar_spans(|mspans| mspans.insert(ident.span, sp));
let kind = token::NtIdent(*ident, *is_raw);
TokenTree::token_alone(kind, sp)
}
MatchedSingle(ParseNtResult::Lifetime(ident, is_raw)) => {
marker.visit_span(&mut sp);
with_metavar_spans(|mspans| mspans.insert(ident.span, sp));
let kind = token::NtLifetime(*ident, *is_raw);
TokenTree::token_alone(kind, sp)
}
@ -295,6 +297,8 @@ pub(super) fn transcribe<'a>(
// `Delimiter::Invisible` to maintain parsing priorities.
// `Interpolated` is currently used for such groups in rustc parser.
marker.visit_span(&mut sp);
let use_span = nt.use_span();
with_metavar_spans(|mspans| mspans.insert(use_span, sp));
TokenTree::token_alone(token::Interpolated(Lrc::clone(nt)), sp)
}
MatchedSeq(..) => {
@ -410,19 +414,15 @@ fn maybe_use_metavar_location(
return orig_tt.clone();
}
let insert = |mspans: &mut FxHashMap<_, _>, s, ms| match mspans.try_insert(s, ms) {
Ok(_) => true,
Err(err) => *err.entry.get() == ms, // Tried to insert the same span, still success
};
marker.visit_span(&mut metavar_span);
let no_collision = match orig_tt {
TokenTree::Token(token, ..) => {
with_metavar_spans(|mspans| insert(mspans, token.span, metavar_span))
with_metavar_spans(|mspans| mspans.insert(token.span, metavar_span))
}
TokenTree::Delimited(dspan, ..) => with_metavar_spans(|mspans| {
insert(mspans, dspan.open, metavar_span)
&& insert(mspans, dspan.close, metavar_span)
&& insert(mspans, dspan.entire(), metavar_span)
mspans.insert(dspan.open, metavar_span)
&& mspans.insert(dspan.close, metavar_span)
&& mspans.insert(dspan.entire(), metavar_span)
}),
};
if no_collision || psess.source_map().is_imported(metavar_span) {
@ -434,14 +434,14 @@ fn maybe_use_metavar_location(
match orig_tt {
TokenTree::Token(Token { kind, span }, spacing) => {
let span = metavar_span.with_ctxt(span.ctxt());
with_metavar_spans(|mspans| insert(mspans, span, metavar_span));
with_metavar_spans(|mspans| mspans.insert(span, metavar_span));
TokenTree::Token(Token { kind: kind.clone(), span }, *spacing)
}
TokenTree::Delimited(dspan, dspacing, delimiter, tts) => {
let open = metavar_span.with_ctxt(dspan.open.ctxt());
let close = metavar_span.with_ctxt(dspan.close.ctxt());
with_metavar_spans(|mspans| {
insert(mspans, open, metavar_span) && insert(mspans, close, metavar_span)
mspans.insert(open, metavar_span) && mspans.insert(close, metavar_span)
});
let dspan = DelimSpan::from_pair(open, close);
TokenTree::Delimited(dspan, *dspacing, *delimiter, tts.clone())

5
compiler/rustc_middle/src/hir/map/mod.rs
View file

@ -12,7 +12,7 @@ use rustc_hir::*;
use rustc_hir_pretty as pprust_hir;
use rustc_middle::hir::nested_filter;
use rustc_span::def_id::StableCrateId;
use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, kw, sym, with_metavar_spans};
use crate::hir::ModuleItems;
use crate::middle::debugger_visualizer::DebuggerVisualizerFile;
@ -1117,6 +1117,9 @@ pub(super) fn crate_hash(tcx: TyCtxt<'_>, _: LocalCrate) -> Svh {
// the fly in the resolver, storing only their accumulated hash in `ResolverGlobalCtxt`,
// and combining it with other hashes here.
resolutions.visibilities_for_hashing.hash_stable(&mut hcx, &mut stable_hasher);
with_metavar_spans(|mspans| {
mspans.freeze_and_get_read_spans().hash_stable(&mut hcx, &mut stable_hasher);
});
stable_hasher.finish()
});

8
compiler/rustc_parse/src/validate_attr.rs
View file

@ -11,7 +11,7 @@ use rustc_session::errors::report_lit_error;
use rustc_session::lint::BuiltinLintDiag;
use rustc_session::lint::builtin::{ILL_FORMED_ATTRIBUTE_INPUT, UNSAFE_ATTR_OUTSIDE_UNSAFE};
use rustc_session::parse::ParseSess;
use rustc_span::{BytePos, Span, Symbol, sym};
use rustc_span::{Span, Symbol, sym};
use crate::{errors, parse_in};
@ -164,11 +164,7 @@ pub fn check_attribute_safety(psess: &ParseSess, safety: AttributeSafety, attr:
// wrapping it in `unsafe(...)`. Otherwise, we suggest putting the
// `unsafe(`, `)` right after and right before the opening and closing
// square bracket respectively.
let diag_span = if attr_item.span().can_be_used_for_suggestions() {
attr_item.span()
} else {
attr.span.with_lo(attr.span.lo() + BytePos(2)).with_hi(attr.span.hi() - BytePos(1))
};
let diag_span = attr_item.span();
if attr.span.at_least_rust_2024() {
psess.dcx().emit_err(errors::UnsafeAttrOutsideUnsafe {

45
compiler/rustc_span/src/lib.rs
View file

@ -25,6 +25,7 @@
#![feature(hash_set_entry)]
#![feature(if_let_guard)]
#![feature(let_chains)]
#![feature(map_try_insert)]
#![feature(negative_impls)]
#![feature(read_buf)]
#![feature(round_char_boundary)]
@ -85,9 +86,9 @@ use std::str::FromStr;
use std::{fmt, iter};
use md5::{Digest, Md5};
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::{Hash64, Hash128, HashStable, StableHasher};
use rustc_data_structures::sync::{FreezeLock, FreezeWriteGuard, Lock, Lrc};
use rustc_data_structures::unord::UnordMap;
use sha1::Sha1;
use sha2::Sha256;
@ -103,7 +104,7 @@ pub struct SessionGlobals {
span_interner: Lock<span_encoding::SpanInterner>,
/// Maps a macro argument token into use of the corresponding metavariable in the macro body.
/// Collisions are possible and processed in `maybe_use_metavar_location` on best effort basis.
metavar_spans: Lock<FxHashMap<Span, Span>>,
metavar_spans: MetavarSpansMap,
hygiene_data: Lock<hygiene::HygieneData>,
/// The session's source map, if there is one. This field should only be
@ -177,9 +178,42 @@ pub fn create_default_session_globals_then<R>(f: impl FnOnce() -> R) -> R {
// deserialization.
scoped_tls::scoped_thread_local!(static SESSION_GLOBALS: SessionGlobals);
#[derive(Default)]
pub struct MetavarSpansMap(FreezeLock<UnordMap<Span, (Span, bool)>>);
impl MetavarSpansMap {
pub fn insert(&self, span: Span, var_span: Span) -> bool {
match self.0.write().try_insert(span, (var_span, false)) {
Ok(_) => true,
Err(entry) => entry.entry.get().0 == var_span,
}
}
/// Read a span and record that it was read.
pub fn get(&self, span: Span) -> Option<Span> {
if let Some(mut mspans) = self.0.try_write() {
if let Some((var_span, read)) = mspans.get_mut(&span) {
*read = true;
Some(*var_span)
} else {
None
}
} else {
if let Some((span, true)) = self.0.read().get(&span) { Some(*span) } else { None }
}
}
/// Freeze the set, and return the spans which have been read.
///
/// After this is frozen, no spans that have not been read can be read.
pub fn freeze_and_get_read_spans(&self) -> UnordMap<Span, Span> {
self.0.freeze().items().filter(|(_, (_, b))| *b).map(|(s1, (s2, _))| (*s1, *s2)).collect()
}
}
#[inline]
pub fn with_metavar_spans<R>(f: impl FnOnce(&mut FxHashMap<Span, Span>) -> R) -> R {
with_session_globals(|session_globals| f(&mut session_globals.metavar_spans.lock()))
pub fn with_metavar_spans<R>(f: impl FnOnce(&MetavarSpansMap) -> R) -> R {
with_session_globals(|session_globals| f(&session_globals.metavar_spans))
}
// FIXME: We should use this enum or something like it to get rid of the
@ -872,8 +906,7 @@ impl Span {
/// Check if you can select metavar spans for the given spans to get matching contexts.
fn try_metavars(a: SpanData, b: SpanData, a_orig: Span, b_orig: Span) -> (SpanData, SpanData) {
let get = |mspans: &FxHashMap<_, _>, s| mspans.get(&s).copied();
match with_metavar_spans(|mspans| (get(mspans, a_orig), get(mspans, b_orig))) {
match with_metavar_spans(|mspans| (mspans.get(a_orig), mspans.get(b_orig))) {
(None, None) => {}
(Some(meta_a), None) => {
let meta_a = meta_a.data();