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

fix #102182, recover from impl Trait in type param bound

Browse source
This commit is contained in:
yukang 2022-09-27 14:25:29 +08:00
parent 672e3f4d77
commit 7b2f04a2b3
3 changed files with 51 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

36
compiler/rustc_parse/src/parser/generics.rs
View file

@ -1,7 +1,9 @@
use super::{ForceCollect, Parser, TrailingToken};
use rustc_ast::token;
use rustc_ast::{self as ast, AttrVec, GenericBounds, GenericParam, GenericParamKind, WhereClause};
use rustc_ast::{
self as ast, AttrVec, GenericBounds, GenericParam, GenericParamKind, TyKind, WhereClause,
};
use rustc_errors::{Applicability, PResult};
use rustc_span::symbol::kw;
@ -31,13 +33,43 @@ impl<'a> Parser<'a> {
let mut colon_span = None;
let bounds = if self.eat(&token::Colon) {
colon_span = Some(self.prev_token.span);
// recover from `impl Trait` in type param bound
if self.token.is_keyword(kw::Impl) {
let impl_span = self.token.span;
let snapshot = self.create_snapshot_for_diagnostic();
match self.parse_ty() {
Ok(p) => {
if let TyKind::ImplTrait(_, bounds) = &(*p).kind {
let span = impl_span.to(self.token.span.shrink_to_lo());
let mut err = self.struct_span_err(
span,
"expected trait bound, found `impl Trait` type",
);
err.span_label(span, "not a trait");
if let [bound, ..] = &bounds[..] {
err.span_suggestion_verbose(
impl_span.until(bound.span()),
"use the trait bounds directly",
String::new(),
Applicability::MachineApplicable,
);
}
err.emit();
return Err(err);
}
}
Err(err) => {
err.cancel();
}
}
self.restore_snapshot(snapshot);
}
self.parse_generic_bounds(colon_span)?
} else {
Vec::new()
};
let default = if self.eat(&token::Eq) { Some(self.parse_ty()?) } else { None };
Ok(GenericParam {
ident,
id: ast::DUMMY_NODE_ID,