user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Rollup merge of #146090 - Kobzol:invisible-origin-eq, r=petrochenkov

Browse source 
Derive `PartialEq` for `InvisibleOrigin`

For https://github.com/rust-lang/rust/pull/145354, we need `PartialEq` for `TokenStream` to "just work". However, due to the special comparison implementation that was used for `InvisibleOrigin`, this wasn't the case.

So I derived `PartialEq` for `InvisibleOrigin`, and used the previous special comparison logic only on the single place where it was actually required.

r? `````````@petrochenkov`````````
This commit is contained in:
Stuart Cook 2025-09-04 10:01:58 +10:00 • committed by GitHub
commit 57e8a5317a
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
2 changed files with 21 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

20
compiler/rustc_ast/src/token.rs
View file

@ -22,8 +22,7 @@ pub enum CommentKind {
Block,
}
// This type must not implement `Hash` due to the unusual `PartialEq` impl below.
#[derive(Copy, Clone, Debug, Encodable, Decodable, HashStable_Generic)]
#[derive(Copy, Clone, PartialEq, Debug, Encodable, Decodable, HashStable_Generic)]
pub enum InvisibleOrigin {
// From the expansion of a metavariable in a declarative macro.
MetaVar(MetaVarKind),
@ -45,20 +44,6 @@ impl InvisibleOrigin {
}
}
impl PartialEq for InvisibleOrigin {
#[inline]
fn eq(&self, _other: &InvisibleOrigin) -> bool {
// When we had AST-based nonterminals we couldn't compare them, and the
// old `Nonterminal` type had an `eq` that always returned false,
// resulting in this restriction:
// https://doc.rust-lang.org/nightly/reference/macros-by-example.html#forwarding-a-matched-fragment
// This `eq` emulates that behaviour. We could consider lifting this
// restriction now but there are still cases involving invisible
// delimiters that make it harder than it first appears.
false
}
}
/// Annoyingly similar to `NonterminalKind`, but the slight differences are important.
#[derive(Debug, Copy, Clone, PartialEq, Eq, Encodable, Decodable, Hash, HashStable_Generic)]
pub enum MetaVarKind {
@ -142,7 +127,8 @@ impl Delimiter {
}
}
// This exists because `InvisibleOrigin`s should be compared. It is only used for assertions.
// This exists because `InvisibleOrigin`s should not be compared. It is only used for
// assertions.
pub fn eq_ignoring_invisible_origin(&self, other: &Delimiter) -> bool {
match (self, other) {
(Delimiter::Parenthesis, Delimiter::Parenthesis) => true,

20
compiler/rustc_expand/src/mbe/macro_parser.rs
View file

@ -77,7 +77,7 @@ use std::rc::Rc;
pub(crate) use NamedMatch::*;
pub(crate) use ParseResult::*;
use rustc_ast::token::{self, DocComment, NonterminalKind, Token};
use rustc_ast::token::{self, DocComment, NonterminalKind, Token, TokenKind};
use rustc_data_structures::fx::FxHashMap;
use rustc_errors::ErrorGuaranteed;
use rustc_lint_defs::pluralize;
@ -397,7 +397,23 @@ fn token_name_eq(t1: &Token, t2: &Token) -> bool {
{
ident1.name == ident2.name && is_raw1 == is_raw2
} else {
t1.kind == t2.kind
// Note: we SHOULD NOT use `t1.kind == t2.kind` here, and we should instead compare the
// tokens using the special comparison logic below.
// It makes sure that variants containing `InvisibleOrigin` will
// never compare equal to one another.
//
// When we had AST-based nonterminals we couldn't compare them, and the
// old `Nonterminal` type had an `eq` that always returned false,
// resulting in this restriction:
// <https://doc.rust-lang.org/nightly/reference/macros-by-example.html#forwarding-a-matched-fragment>
// This comparison logic emulates that behaviour. We could consider lifting this
// restriction now but there are still cases involving invisible
// delimiters that make it harder than it first appears.
match (t1.kind, t2.kind) {
(TokenKind::OpenInvisible(_) | TokenKind::CloseInvisible(_), _)
| (_, TokenKind::OpenInvisible(_) | TokenKind::CloseInvisible(_)) => false,
(a, b) => a == b,
}
}
}