diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs index b1a2df8ace40a..bd40e6c10476f 100644 --- a/compiler/rustc_hir_typeck/src/method/suggest.rs +++ b/compiler/rustc_hir_typeck/src/method/suggest.rs @@ -481,7 +481,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ); probe.is_ok() }); - self.note_internal_mutation_in_method( &mut err, rcvr_expr, @@ -1240,7 +1239,40 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } } } - + // If an appropriate error source is not found, check method chain for possible candiates + if unsatisfied_predicates.is_empty() && let Mode::MethodCall = mode && let SelfSource::MethodCall(mut source_expr) = source { + let mut stack_methods = vec![]; + while let hir::ExprKind::MethodCall(_path_segment, rcvr_expr, _args, method_span) = + source_expr.kind + { + // Pop the matching receiver, to align on it's notional span + if let Some(prev_match) = stack_methods.pop() { + err.span_label(method_span, format!("{item_kind} `{item_name}` is available on `{prev_match}`")); + } + let rcvr_ty = self.resolve_vars_if_possible( + self.typeck_results + .borrow() + .expr_ty_adjusted_opt(rcvr_expr) + .unwrap_or(Ty::new_misc_error(self.tcx)),); + + for _matched_method in self.probe_for_name_many( + Mode::MethodCall, + item_name, + None, + IsSuggestion(true), + rcvr_ty, + source_expr.hir_id, + ProbeScope::TraitsInScope,) { + // found a match, push to stack + stack_methods.push(rcvr_ty); + } + source_expr = rcvr_expr; + } + // If there is a match at the start of the chain, add a label for it too! + if let Some(prev_match) = stack_methods.pop() { + err.span_label(source_expr.span, format!("{item_kind} `{item_name}` is available on `{prev_match}`")); + } + } self.note_derefed_ty_has_method(&mut err, source, rcvr_ty, item_name, expected); return Some(err); } diff --git a/tests/ui/structs/method-chain-expression-failure.rs b/tests/ui/structs/method-chain-expression-failure.rs new file mode 100644 index 0000000000000..43ebc5bac8cbe --- /dev/null +++ b/tests/ui/structs/method-chain-expression-failure.rs @@ -0,0 +1,31 @@ +struct A; +struct B; +struct C; +struct D; +struct E; + +impl A { + fn b(&self) -> B { B } + fn foo(&self) {} +} + +impl B { + fn c(&self) -> C { C } +} + +impl C { + fn d(&self) -> D { D } + fn foo(&self) {} +} + +impl D { + fn e(&self) -> E { E } +} + +impl E { + fn f(&self) {} +} +fn main() { + A.b().c().d().e().foo(); +//~^ ERROR no method named `foo` found for struct `E` in the current scope +} diff --git a/tests/ui/structs/method-chain-expression-failure.stderr b/tests/ui/structs/method-chain-expression-failure.stderr new file mode 100644 index 0000000000000..ba635ab1fe676 --- /dev/null +++ b/tests/ui/structs/method-chain-expression-failure.stderr @@ -0,0 +1,15 @@ +error[E0599]: no method named `foo` found for struct `E` in the current scope + --> $DIR/method-chain-expression-failure.rs:29:23 + | +LL | struct E; + | -------- method `foo` not found for this struct +... +LL | A.b().c().d().e().foo(); + | - --- ^^^ method not found in `E` + | | | + | | method `foo` is available on `&C` + | method `foo` is available on `&A` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0599`. diff --git a/tests/ui/suggestions/chain-method-call-mutation-in-place.stderr b/tests/ui/suggestions/chain-method-call-mutation-in-place.stderr index 128160f10adb3..2dd6fb6a3bf6d 100644 --- a/tests/ui/suggestions/chain-method-call-mutation-in-place.stderr +++ b/tests/ui/suggestions/chain-method-call-mutation-in-place.stderr @@ -18,7 +18,10 @@ error[E0599]: no method named `sort` found for unit type `()` in the current sco --> $DIR/chain-method-call-mutation-in-place.rs:3:72 | LL | vec![1, 2, 3].into_iter().collect::>().sort_by_key(|i| i).sort(); - | ^^^^ method not found in `()` + | ------------- --------------------- ^^^^ method not found in `()` + | | | + | | method `sort` is available on `&mut [i32]` + | method `sort` is available on `Vec` | note: method `sort_by_key` modifies its receiver in-place, it is not meant to be used in method chains. --> $DIR/chain-method-call-mutation-in-place.rs:3:53