diff options
| -rw-r--r-- | compiler/rustc_hir_typeck/src/demand.rs | 19 | ||||
| -rw-r--r-- | compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs | 47 | ||||
| -rw-r--r-- | src/test/ui/suggestions/format-borrow.stderr | 16 | ||||
| -rw-r--r-- | src/test/ui/suggestions/issue-102892.rs | 25 | ||||
| -rw-r--r-- | src/test/ui/suggestions/issue-102892.stderr | 57 |
5 files changed, 160 insertions, 4 deletions
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs index 2974ac97f23..be14234afe2 100644 --- a/compiler/rustc_hir_typeck/src/demand.rs +++ b/compiler/rustc_hir_typeck/src/demand.rs @@ -714,7 +714,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { expr: &hir::Expr<'tcx>, checked_ty: Ty<'tcx>, expected: Ty<'tcx>, - ) -> Option<(Span, String, String, Applicability, bool /* verbose */)> { + ) -> Option<( + Span, + String, + String, + Applicability, + bool, /* verbose */ + bool, /* suggest `&` or `&mut` type annotation */ + )> { let sess = self.sess(); let sp = expr.span; @@ -746,6 +753,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { String::new(), Applicability::MachineApplicable, true, + false, )); } } @@ -760,6 +768,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { "b".to_string(), Applicability::MachineApplicable, true, + false, )); } } @@ -817,6 +826,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { sugg.2, Applicability::MachineApplicable, false, + false, )); } @@ -844,6 +854,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { format!("{prefix}&mut {sugg_expr}"), Applicability::MachineApplicable, false, + false, ), hir::Mutability::Not => ( sp, @@ -851,6 +862,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { format!("{prefix}&{sugg_expr}"), Applicability::MachineApplicable, false, + false, ), }); } @@ -880,6 +892,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { String::new(), Applicability::MachineApplicable, true, + true )); } return None; @@ -893,6 +906,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { String::new(), Applicability::MachineApplicable, true, + true, )); } } @@ -959,6 +973,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { src, applicability, true, + false, )); } } @@ -999,6 +1014,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { Applicability::MachineApplicable }, true, + false, )); } @@ -1050,6 +1066,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { suggestion, Applicability::MachineApplicable, true, + false, )); } } diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs index cd2e41aff0f..4db9c56f98f 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs @@ -327,7 +327,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, ) -> bool { let expr = expr.peel_blocks(); - if let Some((sp, msg, suggestion, applicability, verbose)) = + if let Some((sp, msg, suggestion, applicability, verbose, annotation)) = self.check_ref(expr, found, expected) { if verbose { @@ -335,9 +335,50 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } else { err.span_suggestion(sp, &msg, suggestion, applicability); } + if annotation { + let suggest_annotation = match expr.peel_drop_temps().kind { + hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Not, _) => "&", + hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Mut, _) => "&mut ", + _ => return true, + }; + let mut tuple_indexes = Vec::new(); + let mut expr_id = expr.hir_id; + for (parent_id, node) in self.tcx.hir().parent_iter(expr.hir_id) { + match node { + Node::Expr(&Expr { kind: ExprKind::Tup(subs), .. }) => { + tuple_indexes.push( + subs.iter() + .enumerate() + .find(|(_, sub_expr)| sub_expr.hir_id == expr_id) + .unwrap() + .0, + ); + expr_id = parent_id; + } + Node::Local(local) => { + if let Some(mut ty) = local.ty { + while let Some(index) = tuple_indexes.pop() { + match ty.kind { + TyKind::Tup(tys) => ty = &tys[index], + _ => return true, + } + } + let annotation_span = ty.span; + err.span_suggestion( + annotation_span.with_hi(annotation_span.lo()), + format!("alternatively, consider changing the type annotation"), + suggest_annotation, + Applicability::MaybeIncorrect, + ); + } + break; + } + _ => break, + } + } + } return true; - } else if self.suggest_else_fn_with_closure(err, expr, found, expected) - { + } else if self.suggest_else_fn_with_closure(err, expr, found, expected) { return true; } else if self.suggest_fn_call(err, expr, found, |output| self.can_coerce(output, expected)) && let ty::FnDef(def_id, ..) = &found.kind() diff --git a/src/test/ui/suggestions/format-borrow.stderr b/src/test/ui/suggestions/format-borrow.stderr index fac6a5a5f48..8ed2b9c9a63 100644 --- a/src/test/ui/suggestions/format-borrow.stderr +++ b/src/test/ui/suggestions/format-borrow.stderr @@ -11,6 +11,10 @@ help: consider removing the borrow LL - let a: String = &String::from("a"); LL + let a: String = String::from("a"); | +help: alternatively, consider changing the type annotation + | +LL | let a: &String = &String::from("a"); + | + error[E0308]: mismatched types --> $DIR/format-borrow.rs:4:21 @@ -25,6 +29,10 @@ help: consider removing the borrow LL - let b: String = &format!("b"); LL + let b: String = format!("b"); | +help: alternatively, consider changing the type annotation + | +LL | let b: &String = &format!("b"); + | + error[E0308]: mismatched types --> $DIR/format-borrow.rs:6:21 @@ -39,6 +47,10 @@ help: consider removing the borrow LL - let c: String = &mut format!("c"); LL + let c: String = format!("c"); | +help: alternatively, consider changing the type annotation + | +LL | let c: &mut String = &mut format!("c"); + | ++++ error[E0308]: mismatched types --> $DIR/format-borrow.rs:8:21 @@ -53,6 +65,10 @@ help: consider removing the borrow LL - let d: String = &mut (format!("d")); LL + let d: String = format!("d")); | +help: alternatively, consider changing the type annotation + | +LL | let d: &mut String = &mut (format!("d")); + | ++++ error: aborting due to 4 previous errors diff --git a/src/test/ui/suggestions/issue-102892.rs b/src/test/ui/suggestions/issue-102892.rs new file mode 100644 index 00000000000..c1a791d8d85 --- /dev/null +++ b/src/test/ui/suggestions/issue-102892.rs @@ -0,0 +1,25 @@ +#![allow(dead_code, unused_variables)] + +use std::sync::Arc; + +#[derive(Debug)] +struct A; +#[derive(Debug)] +struct B; + +fn process_without_annot(arc: &Arc<(A, B)>) { + let (a, b) = **arc; // suggests putting `&**arc` here; with that, fixed! +} + +fn process_with_annot(arc: &Arc<(A, B)>) { + let (a, b): (A, B) = &**arc; // suggests putting `&**arc` here too + //~^ ERROR mismatched types +} + +fn process_with_tuple_annot(mutation: &mut (A, B), arc: &Arc<(A, B)>) { + let (a, b): ((A, B), A) = (&mut *mutation, &(**arc).0); // suggests putting `&**arc` here too + //~^ ERROR mismatched types + //~| ERROR mismatched types +} + +fn main() {} diff --git a/src/test/ui/suggestions/issue-102892.stderr b/src/test/ui/suggestions/issue-102892.stderr new file mode 100644 index 00000000000..a3dbc7cb861 --- /dev/null +++ b/src/test/ui/suggestions/issue-102892.stderr @@ -0,0 +1,57 @@ +error[E0308]: mismatched types + --> $DIR/issue-102892.rs:15:26 + | +LL | let (a, b): (A, B) = &**arc; // suggests putting `&**arc` here too + | ------ ^^^^^^ expected tuple, found `&(A, B)` + | | + | expected due to this + | + = note: expected tuple `(A, B)` + found reference `&(A, B)` +help: consider removing the borrow + | +LL - let (a, b): (A, B) = &**arc; // suggests putting `&**arc` here too +LL + let (a, b): (A, B) = **arc; // suggests putting `&**arc` here too + | +help: alternatively, consider changing the type annotation + | +LL | let (a, b): &(A, B) = &**arc; // suggests putting `&**arc` here too + | + + +error[E0308]: mismatched types + --> $DIR/issue-102892.rs:20:32 + | +LL | let (a, b): ((A, B), A) = (&mut *mutation, &(**arc).0); // suggests putting `&**arc` here too + | ^^^^^^^^^^^^^^ expected tuple, found `&mut (A, B)` + | + = note: expected tuple `(A, B)` + found mutable reference `&mut (A, B)` +help: consider removing the borrow + | +LL - let (a, b): ((A, B), A) = (&mut *mutation, &(**arc).0); // suggests putting `&**arc` here too +LL + let (a, b): ((A, B), A) = (*mutation, &(**arc).0); // suggests putting `&**arc` here too + | +help: alternatively, consider changing the type annotation + | +LL | let (a, b): (&mut (A, B), A) = (&mut *mutation, &(**arc).0); // suggests putting `&**arc` here too + | ++++ + +error[E0308]: mismatched types + --> $DIR/issue-102892.rs:20:48 + | +LL | let (a, b): ((A, B), A) = (&mut *mutation, &(**arc).0); // suggests putting `&**arc` here too + | ^^^^^^^^^^ expected struct `A`, found `&A` + | +help: consider removing the borrow + | +LL - let (a, b): ((A, B), A) = (&mut *mutation, &(**arc).0); // suggests putting `&**arc` here too +LL + let (a, b): ((A, B), A) = (&mut *mutation, (**arc).0); // suggests putting `&**arc` here too + | +help: alternatively, consider changing the type annotation + | +LL | let (a, b): ((A, B), &A) = (&mut *mutation, &(**arc).0); // suggests putting `&**arc` here too + | + + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0308`. |