rust-analyzer

diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs
index 35372ee9a9..322ef51167 100644
--- a/crates/hir-ty/src/infer/expr.rs
+++ b/crates/hir-ty/src/infer/expr.rs

@@ -793,10 +793,12 @@ impl<'a> InferenceContext<'a> {

canonicalized.value,

index_trait,

);

- let (self_ty, adj) = receiver_adjustments

+ let (self_ty, mut adj) = receiver_adjustments

.map_or((self.err_ty(), Vec::new()), |adj| {

adj.apply(&mut self.table, base_ty)

});

+ // mutability will be fixed up in `InferenceContext::infer_mut`;

+ adj.push(Adjustment::borrow(Mutability::Not, self_ty.clone()));

self.write_expr_adj(*base, adj);

if let Some(func) =

self.db.trait_data(index_trait).method_by_name(&name!(index))

diff --git a/crates/hir-ty/src/infer/mutability.rs b/crates/hir-ty/src/infer/mutability.rs
index 7ed21d230c..6f5ca2cf95 100644
--- a/crates/hir-ty/src/infer/mutability.rs
+++ b/crates/hir-ty/src/infer/mutability.rs

@@ -8,7 +8,7 @@ use hir_def::{

};

use hir_expand::name;

-use crate::{lower::lower_to_chalk_mutability, Adjust, AutoBorrow, OverloadedDeref};

+use crate::{lower::lower_to_chalk_mutability, Adjust, Adjustment, AutoBorrow, OverloadedDeref};

use super::InferenceContext;

@@ -18,15 +18,15 @@ impl<'a> InferenceContext<'a> {

}

fn infer_mut_expr(&mut self, tgt_expr: ExprId, mut mutability: Mutability) {

- let mut v = vec![];

- let adjustments = self.result.expr_adjustments.get_mut(&tgt_expr).unwrap_or(&mut v);

- for adj in adjustments.iter_mut().rev() {

- match &mut adj.kind {

- Adjust::NeverToAny | Adjust::Deref(None) | Adjust::Pointer(_) => (),

- Adjust::Deref(Some(d)) => *d = OverloadedDeref(Some(mutability)),

- Adjust::Borrow(b) => match b {

- AutoBorrow::Ref(m) | AutoBorrow::RawPtr(m) => mutability = *m,

- },

+ if let Some(adjustments) = self.result.expr_adjustments.get_mut(&tgt_expr) {

+ for adj in adjustments.iter_mut().rev() {

+ match &mut adj.kind {

+ Adjust::NeverToAny | Adjust::Deref(None) | Adjust::Pointer(_) => (),

+ Adjust::Deref(Some(d)) => *d = OverloadedDeref(Some(mutability)),

+ Adjust::Borrow(b) => match b {

+ AutoBorrow::Ref(m) | AutoBorrow::RawPtr(m) => mutability = *m,

+ },

+ }

}

self.infer_mut_expr_without_adjust(tgt_expr, mutability);

@@ -94,8 +94,8 @@ impl<'a> InferenceContext<'a> {

self.infer_mut_not_expr_iter(fields.iter().map(|x| x.expr).chain(*spread))

}

&Expr::Index { base, index } => {

- if let Some((f, _)) = self.result.method_resolutions.get_mut(&tgt_expr) {

- if mutability == Mutability::Mut {

+ if mutability == Mutability::Mut {

+ if let Some((f, _)) = self.result.method_resolutions.get_mut(&tgt_expr) {

if let Some(index_trait) = self

.db

.lang_item(self.table.trait_env.krate, LangItem::IndexMut)

@@ -105,6 +105,18 @@ impl<'a> InferenceContext<'a> {

self.db.trait_data(index_trait).method_by_name(&name![index_mut])

{

*f = index_fn;

+ let base_adjustments = self

+ .result

+ .expr_adjustments

+ .get_mut(&base)

+ .and_then(|it| it.last_mut());

+ if let Some(Adjustment {

+ kind: Adjust::Borrow(AutoBorrow::Ref(mutability)),

+ ..

+ }) = base_adjustments

+ {

+ *mutability = Mutability::Mut;

+ }

}

diff --git a/crates/hir-ty/src/mir/lower/as_place.rs b/crates/hir-ty/src/mir/lower/as_place.rs
index 425904850b..86fee99b78 100644
--- a/crates/hir-ty/src/mir/lower/as_place.rs
+++ b/crates/hir-ty/src/mir/lower/as_place.rs

@@ -192,7 +192,10 @@ impl MirLowerCtx<'_> {

let base_ty = self.expr_ty_after_adjustments(*base);

let index_ty = self.expr_ty_after_adjustments(*index);

if index_ty != TyBuilder::usize()

- || !matches!(base_ty.kind(Interner), TyKind::Array(..) | TyKind::Slice(..))

+ || !matches!(

+ base_ty.strip_reference().kind(Interner),

+ TyKind::Array(..) | TyKind::Slice(..)

+ )

{

let Some(index_fn) = self.infer.method_resolution(expr_id) else {

return Err(MirLowerError::UnresolvedMethod);

@@ -206,7 +209,7 @@ impl MirLowerCtx<'_> {

return self.lower_overloaded_index(

current,

base_place,

- self.expr_ty_after_adjustments(*base),

+ base_ty,

self.expr_ty(expr_id),

index_operand,

expr_id.into(),

@@ -214,7 +217,8 @@ impl MirLowerCtx<'_> {

);

}

let Some((mut p_base, current)) =

- self.lower_expr_as_place(current, *base, true)? else {

+ self.lower_expr_as_place_without_adjust(current, *base, true)?

+ else {

return Ok(None);

};

let l_index = self.temp(self.expr_ty_after_adjustments(*index))?;

@@ -238,23 +242,14 @@ impl MirLowerCtx<'_> {

span: MirSpan,

index_fn: (FunctionId, Substitution),

) -> Result<Option<(Place, BasicBlockId)>> {

- let is_mutable = 'b: {

- if let Some(index_mut_trait) = self.resolve_lang_item(LangItem::IndexMut)?.as_trait() {

- if let Some(index_mut_fn) =

- self.db.trait_data(index_mut_trait).method_by_name(&name![index_mut])

- {

- break 'b index_mut_fn == index_fn.0;

- }

+ let (mutability, borrow_kind) = match base_ty.as_reference() {

+ Some((_, _, mutability)) => {

+ (mutability, BorrowKind::Mut { allow_two_phase_borrow: false })

}

- false

- };

- let (mutability, borrow_kind) = match is_mutable {

- true => (Mutability::Mut, BorrowKind::Mut { allow_two_phase_borrow: false }),

- false => (Mutability::Not, BorrowKind::Shared),

+ None => (Mutability::Not, BorrowKind::Shared),

};

- let base_ref = TyKind::Ref(mutability, static_lifetime(), base_ty).intern(Interner);

let result_ref = TyKind::Ref(mutability, static_lifetime(), result_ty).intern(Interner);

- let ref_place: Place = self.temp(base_ref)?.into();

+ let ref_place: Place = self.temp(base_ty)?.into();

self.push_assignment(current, ref_place.clone(), Rvalue::Ref(borrow_kind, place), span);

let mut result: Place = self.temp(result_ref)?.into();

let index_fn_op = Operand::const_zst(

diff --git a/crates/hir-ty/src/tests/coercion.rs b/crates/hir-ty/src/tests/coercion.rs
index ce1a22cc51..e63a674a3f 100644
--- a/crates/hir-ty/src/tests/coercion.rs
+++ b/crates/hir-ty/src/tests/coercion.rs

@@ -870,3 +870,35 @@ fn test() {

}",

);

}

+#[test]

+fn adjust_index() {

+ check_no_mismatches(

+ r"

+//- minicore: index

+struct Struct;

+impl core::ops::Index<usize> for Struct {

+ type Output = ();

+ fn index(&self, index: usize) -> &Self::Output { &() }

+struct StructMut;

+impl core::ops::Index<usize> for StructMut {

+ type Output = ();

+ fn index(&self, index: usize) -> &Self::Output { &() }

+impl core::ops::IndexMut for StructMut {

+ fn index_mut(&mut self, index: usize) -> &mut Self::Output { &mut () }

+fn test() {

+ Struct[0];

+ // ^^^^^^ adjustments: Borrow(Ref(Not))

+ StructMut[0];

+ // ^^^^^^^^^ adjustments: Borrow(Ref(Not))

+ &mut StructMut[0];

+ // ^^^^^^^^^ adjustments: Borrow(Ref(Mut))

+}",

+ );

diff --git a/crates/ide-diagnostics/src/handlers/mutability_errors.rs b/crates/ide-diagnostics/src/handlers/mutability_errors.rs
index 0b66350894..ecd1db7ea8 100644
--- a/crates/ide-diagnostics/src/handlers/mutability_errors.rs
+++ b/crates/ide-diagnostics/src/handlers/mutability_errors.rs

@@ -589,17 +589,17 @@ fn f() {

let y = &x[2];

let x = Foo;

let y = &mut x[2];

- //^^^^ 💡 error: cannot mutate immutable variable `x`

+ //^💡 error: cannot mutate immutable variable `x`

let mut x = &mut Foo;

//^^^^^ 💡 weak: variable does not need to be mutable

let y: &mut (i32, u8) = &mut x[2];

let x = Foo;

let ref mut y = x[7];

- //^^^^ 💡 error: cannot mutate immutable variable `x`

+ //^ 💡 error: cannot mutate immutable variable `x`

let (ref mut y, _) = x[3];

- //^^^^ 💡 error: cannot mutate immutable variable `x`

+ //^ 💡 error: cannot mutate immutable variable `x`

match x[10] {

- //^^^^^ 💡 error: cannot mutate immutable variable `x`

+ //^ 💡 error: cannot mutate immutable variable `x`

(ref y, _) => (),

(_, ref mut y) => (),

}

diff --git a/crates/ide/src/inlay_hints/adjustment.rs b/crates/ide/src/inlay_hints/adjustment.rs
index 46505b3044..f279c91a9e 100644
--- a/crates/ide/src/inlay_hints/adjustment.rs
+++ b/crates/ide/src/inlay_hints/adjustment.rs

@@ -264,7 +264,7 @@ mod tests {

check_with_config(

InlayHintsConfig { adjustment_hints: AdjustmentHints::Always, ..DISABLED_CONFIG },

r#"

-//- minicore: coerce_unsized, fn, eq

+//- minicore: coerce_unsized, fn, eq, index

fn main() {

let _: u32 = loop {};

//^^^^^^^<never-to-any>

@@ -360,6 +360,19 @@ fn main() {

(()) == {()};

// ^^&

// ^^^^&

+ let closure: dyn Fn = || ();

+ closure();

+ //^^^^^^^(

+ //^^^^^^^&

+ //^^^^^^^)

+ Struct[0];

+ //^^^^^^(

+ //^^^^^^&

+ //^^^^^^)

+ &mut Struct[0];

+ //^^^^^^(

+ //^^^^^^&mut $

+ //^^^^^^)

}

#[derive(Copy, Clone)]

@@ -369,8 +382,13 @@ impl Struct {

fn by_ref(&self) {}

fn by_ref_mut(&mut self) {}

}

+struct StructMut;

+impl core::ops::Index<usize> for Struct {

+ type Output = ();

+impl core::ops::IndexMut for Struct {}

"#,

- )

+ );

}

#[test]

@@ -382,7 +400,7 @@ impl Struct {

..DISABLED_CONFIG

r#"

-//- minicore: coerce_unsized, fn, eq

+//- minicore: coerce_unsized, fn, eq, index

fn main() {

Struct.consume();

@@ -457,6 +475,13 @@ fn main() {

(()) == {()};

// ^^.&

// ^^^^.&

+ let closure: dyn Fn = || ();

+ closure();

+ //^^^^^^^.&

+ Struct[0];

+ //^^^^^^.&

+ &mut Struct[0];

+ //^^^^^^.&mut

}

#[derive(Copy, Clone)]

@@ -466,6 +491,11 @@ impl Struct {

fn by_ref(&self) {}

fn by_ref_mut(&mut self) {}

}

+struct StructMut;

+impl core::ops::Index<usize> for Struct {

+ type Output = ();

+impl core::ops::IndexMut for Struct {}

"#,

);

}