bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Implment #[cfg] and #[cfg_attr] in where clauses

Browse source
This commit is contained in:
Frank King 2025-02-05 18:58:29 +08:00
parent 30508faeb3
commit 42f51d4fd4
38 changed files with 3296 additions and 88 deletions
Download patch file Download diff file Expand all files Collapse all files

65
compiler/rustc_parse/src/parser/generics.rs
View file

@ -367,34 +367,47 @@ impl<'a> Parser<'a> {
loop {
let where_sp = where_lo.to(self.prev_token.span);
let attrs = self.parse_outer_attributes()?;
let pred_lo = self.token.span;
let kind = if self.check_lifetime() && self.look_ahead(1, |t| !t.is_like_plus()) {
let lifetime = self.expect_lifetime();
// Bounds starting with a colon are mandatory, but possibly empty.
self.expect(exp!(Colon))?;
let bounds = self.parse_lt_param_bounds();
ast::WherePredicateKind::RegionPredicate(ast::WhereRegionPredicate {
lifetime,
bounds,
})
} else if self.check_type() {
match self.parse_ty_where_predicate_kind_or_recover_tuple_struct_body(
struct_, pred_lo, where_sp,
)? {
PredicateKindOrStructBody::PredicateKind(kind) => kind,
PredicateKindOrStructBody::StructBody(body) => {
tuple_struct_body = Some(body);
break;
}
let predicate = self.collect_tokens(None, attrs, ForceCollect::No, |this, attrs| {
for attr in &attrs {
self.psess.gated_spans.gate(sym::where_clause_attrs, attr.span);
}
} else {
break;
};
where_clause.predicates.push(ast::WherePredicate {
kind,
id: DUMMY_NODE_ID,
span: pred_lo.to(self.prev_token.span),
});
let kind = if this.check_lifetime() && this.look_ahead(1, |t| !t.is_like_plus()) {
let lifetime = this.expect_lifetime();
// Bounds starting with a colon are mandatory, but possibly empty.
this.expect(exp!(Colon))?;
let bounds = this.parse_lt_param_bounds();
Some(ast::WherePredicateKind::RegionPredicate(ast::WhereRegionPredicate {
lifetime,
bounds,
}))
} else if this.check_type() {
match this.parse_ty_where_predicate_kind_or_recover_tuple_struct_body(
struct_, pred_lo, where_sp,
)? {
PredicateKindOrStructBody::PredicateKind(kind) => Some(kind),
PredicateKindOrStructBody::StructBody(body) => {
tuple_struct_body = Some(body);
None
}
}
} else {
None
};
let predicate = kind.map(|kind| ast::WherePredicate {
attrs,
kind,
id: DUMMY_NODE_ID,
span: pred_lo.to(this.prev_token.span),
is_placeholder: false,
});
Ok((predicate, Trailing::No, UsePreAttrPos::No))
})?;
match predicate {
Some(predicate) => where_clause.predicates.push(predicate),
None => break,
}
let prev_token = self.prev_token.span;
let ate_comma = self.eat(exp!(Comma));