bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Add sugar for &pin (const|mut) types

Browse source
This commit is contained in:
Eric Holk 2024-09-20 12:09:18 -07:00
parent 7caad69253
commit ae698f8199
No known key found for this signature in database
GPG key ID: F1A772BB658A63E1
23 changed files with 284 additions and 63 deletions
Download patch file Download diff file Expand all files Collapse all files

39
compiler/rustc_parse/src/parser/ty.rs
View file

@ -2,9 +2,7 @@ use rustc_ast::ptr::P;
use rustc_ast::token::{self, BinOpToken, Delimiter, IdentIsRaw, Token, TokenKind};
use rustc_ast::util::case::Case;
use rustc_ast::{
self as ast, BareFnTy, BoundAsyncness, BoundConstness, BoundPolarity, DUMMY_NODE_ID, FnRetTy,
GenericBound, GenericBounds, GenericParam, Generics, Lifetime, MacCall, MutTy, Mutability,
PolyTraitRef, PreciseCapturingArg, TraitBoundModifiers, TraitObjectSyntax, Ty, TyKind,
self as ast, BareFnTy, BoundAsyncness, BoundConstness, BoundPolarity, FnRetTy, GenericBound, GenericBounds, GenericParam, Generics, Lifetime, MacCall, MutTy, Mutability, Pinnedness, PolyTraitRef, PreciseCapturingArg, TraitBoundModifiers, TraitObjectSyntax, Ty, TyKind, DUMMY_NODE_ID
};
use rustc_errors::{Applicability, PResult};
use rustc_span::symbol::{Ident, kw, sym};
@ -529,7 +527,10 @@ impl<'a> Parser<'a> {
fn parse_borrowed_pointee(&mut self) -> PResult<'a, TyKind> {
let and_span = self.prev_token.span;
let mut opt_lifetime = self.check_lifetime().then(|| self.expect_lifetime());
let mut mutbl = self.parse_mutability();
let (pinned, mut mutbl) = match self.parse_pin_and_mut() {
Some(pin_mut) => pin_mut,
None => (Pinnedness::Not, self.parse_mutability()),
};
if self.token.is_lifetime() && mutbl == Mutability::Mut && opt_lifetime.is_none() {
// A lifetime is invalid here: it would be part of a bare trait bound, which requires
// it to be followed by a plus, but we disallow plus in the pointee type.
@ -565,7 +566,35 @@ impl<'a> Parser<'a> {
self.bump_with((dyn_tok, dyn_tok_sp));
}
let ty = self.parse_ty_no_plus()?;
Ok(TyKind::Ref(opt_lifetime, MutTy { ty, mutbl }))
Ok(match pinned {
Pinnedness::Not => TyKind::Ref(opt_lifetime, MutTy { ty, mutbl }),
Pinnedness::Pinned => TyKind::PinnedRef(opt_lifetime, MutTy { ty, mutbl }),
})
}
/// Parses `pin` and `mut` annotations on references.
///
/// It must be either `pin const` or `pin mut`.
pub(crate) fn parse_pin_and_mut(&mut self) -> Option<(Pinnedness, Mutability)> {
if self.token.is_ident_named(sym::pin) {
let result = self.look_ahead(1, |token| {
if token.is_keyword(kw::Const) {
Some((Pinnedness::Pinned, Mutability::Not))
} else if token.is_keyword(kw::Mut) {
Some((Pinnedness::Pinned, Mutability::Mut))
} else {
None
}
});
if result.is_some() {
self.psess.gated_spans.gate(sym::pin_ergonomics, self.token.span);
self.bump();
self.bump();
}
result
} else {
None
}
}
// Parses the `typeof(EXPR)`.