rust-analyzer

diff --git a/crates/hir-ty/src/consteval/tests.rs b/crates/hir-ty/src/consteval/tests.rs
index 7ad3659a4f..b395e7f4a8 100644
--- a/crates/hir-ty/src/consteval/tests.rs
+++ b/crates/hir-ty/src/consteval/tests.rs

@@ -1159,6 +1159,20 @@ fn pattern_matching_slice() {

"#,

33213,

);

+ check_number(

+ r#"

+ //- minicore: slice, index, coerce_unsized, copy

+ const fn f(mut slice: &[u32]) -> usize {

+ slice = match slice {

+ [0, rest @ ..] | rest => rest,

+ };

+ slice.len()

+ }

+ const GOAL: usize = f(&[]) + f(&[10]) + f(&[0, 100])

+ + f(&[1000, 1000, 1000]) + f(&[0, 57, 34, 46, 10000, 10000]);

+ "#,

+ 10,

+ );

}

#[test]

diff --git a/crates/hir-ty/src/diagnostics/match_check.rs b/crates/hir-ty/src/diagnostics/match_check.rs
index f8cdeaa5e3..2e04bbfee8 100644
--- a/crates/hir-ty/src/diagnostics/match_check.rs
+++ b/crates/hir-ty/src/diagnostics/match_check.rs

@@ -147,7 +147,7 @@ impl<'a> PatCtxt<'a> {

}

hir_def::hir::Pat::Bind { id, subpat, .. } => {

- let bm = self.infer.binding_modes[id];

+ let bm = self.infer.binding_modes[pat];

ty = &self.infer[id];

let name = &self.body.bindings[id].name;

match (bm, ty.kind(Interner)) {

diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index 78d3c667a1..3d5ed1f93c 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs

@@ -420,7 +420,19 @@ pub struct InferenceResult {

standard_types: InternedStandardTypes,

/// Stores the types which were implicitly dereferenced in pattern binding modes.

pub pat_adjustments: FxHashMap<PatId, Vec<Ty>>,

- pub binding_modes: ArenaMap<BindingId, BindingMode>,

+ /// Stores the binding mode (`ref` in `let ref x = 2`) of bindings.

+ ///

+ /// This one is tied to the `PatId` instead of `BindingId`, because in some rare cases, a binding in an

+ /// or pattern can have multiple binding modes. For example:

+ /// ```

+ /// fn foo(mut slice: &[u32]) -> usize {

+ /// slice = match slice {

+ /// [0, rest @ ..] | rest => rest,

+ /// };

+ /// }

+ /// ```

+ /// the first `rest` has implicit `ref` binding mode, but the second `rest` binding mode is `move`.

+ pub binding_modes: ArenaMap<PatId, BindingMode>,

pub expr_adjustments: FxHashMap<ExprId, Vec<Adjustment>>,

pub(crate) closure_info: FxHashMap<ClosureId, (Vec<CapturedItem>, FnTrait)>,

// FIXME: remove this field

diff --git a/crates/hir-ty/src/infer/closure.rs b/crates/hir-ty/src/infer/closure.rs
index 13d6b5643a..0805e20447 100644
--- a/crates/hir-ty/src/infer/closure.rs
+++ b/crates/hir-ty/src/infer/closure.rs

@@ -679,7 +679,7 @@ impl InferenceContext<'_> {

| Pat::Range { .. } => {

update_result(CaptureKind::ByRef(BorrowKind::Shared));

}

- Pat::Bind { id, .. } => match self.result.binding_modes[*id] {

+ Pat::Bind { id, .. } => match self.result.binding_modes[p] {

crate::BindingMode::Move => {

if self.is_ty_copy(self.result.type_of_binding[*id].clone()) {

update_result(CaptureKind::ByRef(BorrowKind::Shared));

@@ -838,8 +838,8 @@ impl InferenceContext<'_> {

| Pat::ConstBlock(_)

| Pat::Path(_)

| Pat::Lit(_) => self.consume_place(place, pat.into()),

- Pat::Bind { id, subpat: _ } => {

- let mode = self.result.binding_modes[*id];

+ Pat::Bind { id: _, subpat: _ } => {

+ let mode = self.result.binding_modes[pat];

let capture_kind = match mode {

BindingMode::Move => {

self.consume_place(place, pat.into());

diff --git a/crates/hir-ty/src/infer/pat.rs b/crates/hir-ty/src/infer/pat.rs
index 4e28ec0602..7ff12e5b7f 100644
--- a/crates/hir-ty/src/infer/pat.rs
+++ b/crates/hir-ty/src/infer/pat.rs

@@ -421,7 +421,7 @@ impl InferenceContext<'_> {

} else {

BindingMode::convert(mode)

};

- self.result.binding_modes.insert(binding, mode);

+ self.result.binding_modes.insert(pat, mode);

let inner_ty = match subpat {

Some(subpat) => self.infer_pat(subpat, &expected, default_bm),

diff --git a/crates/hir-ty/src/mir/lower/pattern_matching.rs b/crates/hir-ty/src/mir/lower/pattern_matching.rs
index 270f75ad96..1120bb1c11 100644
--- a/crates/hir-ty/src/mir/lower/pattern_matching.rs
+++ b/crates/hir-ty/src/mir/lower/pattern_matching.rs

@@ -284,6 +284,7 @@ impl MirLowerCtx<'_> {

);

(current, current_else) = self.pattern_match_binding(

id,

+ *slice,

next_place,

(*slice).into(),

current,

@@ -395,6 +396,7 @@ impl MirLowerCtx<'_> {

if mode == MatchingMode::Bind {

self.pattern_match_binding(

*id,

+ pattern,

cond_place,

pattern.into(),

current,

@@ -431,13 +433,14 @@ impl MirLowerCtx<'_> {

fn pattern_match_binding(

&mut self,

id: BindingId,

+ pat: PatId,

cond_place: Place,

span: MirSpan,

current: BasicBlockId,

current_else: Option<BasicBlockId>,

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

let target_place = self.binding_local(id)?;

- let mode = self.infer.binding_modes[id];

+ let mode = self.infer.binding_modes[pat];

self.push_storage_live(id, current)?;

self.push_assignment(

current,

diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index 8d8ba48ad9..55c2f8324c 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs

@@ -236,9 +236,9 @@ impl SourceAnalyzer {

_db: &dyn HirDatabase,

pat: &ast::IdentPat,

) -> Option<BindingMode> {

- let binding_id = self.binding_id_of_pat(pat)?;

+ let id = self.pat_id(&pat.clone().into())?;

let infer = self.infer.as_ref()?;

- infer.binding_modes.get(binding_id).map(|bm| match bm {

+ infer.binding_modes.get(id).map(|bm| match bm {

hir_ty::BindingMode::Move => BindingMode::Move,

hir_ty::BindingMode::Ref(hir_ty::Mutability::Mut) => BindingMode::Ref(Mutability::Mut),

hir_ty::BindingMode::Ref(hir_ty::Mutability::Not) => {

diff --git a/crates/ide-diagnostics/src/handlers/moved_out_of_ref.rs b/crates/ide-diagnostics/src/handlers/moved_out_of_ref.rs
index 20175b3fd5..886aefeb57 100644
--- a/crates/ide-diagnostics/src/handlers/moved_out_of_ref.rs
+++ b/crates/ide-diagnostics/src/handlers/moved_out_of_ref.rs

@@ -175,4 +175,19 @@ fn main() {

"#,

);

}

+ #[test]

+ fn regression_15787() {

+ check_diagnostics(

+ r#"

+//- minicore: coerce_unsized, slice, copy

+fn foo(mut slice: &[u32]) -> usize {

+ slice = match slice {

+ [0, rest @ ..] | rest => rest,

+ };

+ slice.len()

+"#,

+ );

+ }

}