diff options
| -rw-r--r-- | compiler/rustc_parse/src/parser/diagnostics.rs | 35 | ||||
| -rw-r--r-- | src/test/ui/anon-params/anon-params-denied-2018.stderr | 8 |
2 files changed, 29 insertions, 14 deletions
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index 975b9cc15bd..77e85c06ff5 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -640,7 +640,7 @@ impl<'a> Parser<'a> { } } Err(mut err) => { - // We could't parse generic parameters, unlikely to be a turbofish. Rely on + // We couldn't parse generic parameters, unlikely to be a turbofish. Rely on // generic parse error instead. err.cancel(); *self = snapshot; @@ -1242,7 +1242,7 @@ impl<'a> Parser<'a> { let is_question = self.eat(&token::Question); // Handle `await? <expr>`. let expr = if self.token == token::OpenDelim(token::Brace) { // Handle `await { <expr> }`. - // This needs to be handled separatedly from the next arm to avoid + // This needs to be handled separately from the next arm to avoid // interpreting `await { <expr> }?` as `<expr>?.await`. self.parse_block_expr(None, self.token.span, BlockCheckMode::Default, AttrVec::new()) } else { @@ -1618,6 +1618,8 @@ impl<'a> Parser<'a> { || self.token == token::Lt || self.token == token::CloseDelim(token::Paren)) { + let rfc_note = "anonymous parameters are removed in the 2018 edition (see RFC 1685)"; + let (ident, self_sugg, param_sugg, type_sugg) = match pat.kind { PatKind::Ident(_, ident, _) => ( ident, @@ -1626,7 +1628,9 @@ impl<'a> Parser<'a> { format!("_: {}", ident), ), // Also catches `fn foo(&a)`. - PatKind::Ref(ref pat, mutab) => { + PatKind::Ref(ref pat, mutab) + if matches!(pat.clone().into_inner().kind, PatKind::Ident(..)) => + { match pat.clone().into_inner().kind { PatKind::Ident(_, ident, _) => { let mutab = mutab.prefix_str(); @@ -1637,20 +1641,23 @@ impl<'a> Parser<'a> { format!("_: &{}{}", mutab, ident), ) } - PatKind::Path(..) => { - err.note("anonymous parameters are removed in the 2018 edition (see RFC 1685)"); - return None; - } - _ => return None, + _ => unreachable!(), } } - // Also catches `fn foo(<Bar as T>::Baz)` - PatKind::Path(..) => { - err.note("anonymous parameters are removed in the 2018 edition (see RFC 1685)"); + _ => { + // Otherwise, try to get a type and emit a suggestion. + if let Some(ty) = pat.to_ty() { + err.span_suggestion_verbose( + pat.span, + "explicitly ignore the parameter name", + format!("_: {}", pprust::ty_to_string(&ty)), + Applicability::MachineApplicable, + ); + err.note(rfc_note); + } + return None; } - // Ignore other `PatKind`. - _ => return None, }; // `fn foo(a, b) {}`, `fn foo(a<x>, b<y>) {}` or `fn foo(usize, usize) {}` @@ -1678,7 +1685,7 @@ impl<'a> Parser<'a> { type_sugg, Applicability::MachineApplicable, ); - err.note("anonymous parameters are removed in the 2018 edition (see RFC 1685)"); + err.note(rfc_note); // Don't attempt to recover by using the `X` in `X<Y>` as the parameter name. return if self.token == token::Lt { None } else { Some(ident) }; diff --git a/src/test/ui/anon-params/anon-params-denied-2018.stderr b/src/test/ui/anon-params/anon-params-denied-2018.stderr index f57578f0174..39f18dff250 100644 --- a/src/test/ui/anon-params/anon-params-denied-2018.stderr +++ b/src/test/ui/anon-params/anon-params-denied-2018.stderr @@ -45,6 +45,10 @@ LL | fn foo_with_qualified_path(<Bar as T>::Baz); | ^ expected one of 8 possible tokens | = note: anonymous parameters are removed in the 2018 edition (see RFC 1685) +help: explicitly ignore the parameter name + | +LL | fn foo_with_qualified_path(_: <Bar as T>::Baz); + | ^^^^^^^^^^^^^^^^^^ error: expected one of `(`, `...`, `..=`, `..`, `::`, `:`, `{`, or `|`, found `)` --> $DIR/anon-params-denied-2018.rs:15:56 @@ -53,6 +57,10 @@ LL | fn foo_with_qualified_path_and_ref(&<Bar as T>::Baz); | ^ expected one of 8 possible tokens | = note: anonymous parameters are removed in the 2018 edition (see RFC 1685) +help: explicitly ignore the parameter name + | +LL | fn foo_with_qualified_path_and_ref(_: &<Bar as T>::Baz); + | ^^^^^^^^^^^^^^^^^^^ error: expected one of `:`, `@`, or `|`, found `,` --> $DIR/anon-params-denied-2018.rs:18:36 |