rust-analyzer

diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs
index 023e19d25e..8895dc095f 100644
--- a/crates/hir-ty/src/infer/expr.rs
+++ b/crates/hir-ty/src/infer/expr.rs

@@ -84,6 +84,30 @@ impl<'a> InferenceContext<'a> {

}

+ pub(super) fn infer_expr_coerce_never(&mut self, expr: ExprId, expected: &Expectation) -> Ty {

+ let ty = self.infer_expr_inner(expr, expected);

+ // While we don't allow *arbitrary* coercions here, we *do* allow

+ // coercions from ! to `expected`.

+ if ty.is_never() {

+ if let Some(adjustments) = self.result.expr_adjustments.get(&expr) {

+ return if let [Adjustment { kind: Adjust::NeverToAny, target }] = &**adjustments {

+ target.clone()

+ } else {

+ self.err_ty()

+ };

+ }

+ let adj_ty = self.table.new_type_var();

+ self.write_expr_adj(

+ expr,

+ vec![Adjustment { kind: Adjust::NeverToAny, target: adj_ty.clone() }],

+ );

+ adj_ty

+ } else {

+ ty

+ }

fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {

self.db.unwind_if_cancelled();

@@ -91,7 +115,7 @@ impl<'a> InferenceContext<'a> {

Expr::Missing => self.err_ty(),

&Expr::If { condition, then_branch, else_branch } => {

let expected = &expected.adjust_for_branches(&mut self.table);

- self.infer_expr(

+ self.infer_expr_coerce_never(

condition,

&Expectation::HasType(self.result.standard_types.bool_.clone()),

);

@@ -415,7 +439,7 @@ impl<'a> InferenceContext<'a> {

for arm in arms.iter() {

if let Some(guard_expr) = arm.guard {

self.diverges = Diverges::Maybe;

- self.infer_expr(

+ self.infer_expr_coerce_never(

guard_expr,

&Expectation::HasType(self.result.standard_types.bool_.clone()),

);

@@ -1146,7 +1170,6 @@ impl<'a> InferenceContext<'a> {

let coerce_ty = expected.coercion_target_type(&mut self.table);

let old_resolver =

mem::replace(&mut self.resolver, resolver_for_expr(self.db.upcast(), self.owner, expr));

let (break_ty, ty) =

self.with_breakable_ctx(BreakableKind::Block, Some(coerce_ty.clone()), label, |this| {

for stmt in statements {

@@ -1188,14 +1211,14 @@ impl<'a> InferenceContext<'a> {

}

&Statement::Expr { expr, has_semi } => {

- this.infer_expr(

- expr,

- &if has_semi {

- Expectation::none()

- } else {

- Expectation::HasType(this.result.standard_types.unit.clone())

- },

- );

+ if has_semi {

+ this.infer_expr(expr, &Expectation::none());

+ } else {

+ this.infer_expr_coerce(

+ expr,

+ &Expectation::HasType(this.result.standard_types.unit.clone()),

+ );

+ }

}

diff --git a/crates/hir-ty/src/tests/patterns.rs b/crates/hir-ty/src/tests/patterns.rs
index be67329fee..74bcab6caa 100644
--- a/crates/hir-ty/src/tests/patterns.rs
+++ b/crates/hir-ty/src/tests/patterns.rs

@@ -476,7 +476,7 @@ fn infer_adt_pattern() {

183..184 'x': usize

190..191 'x': usize

201..205 'E::B': E

- 209..212 'foo': bool

+ 209..212 'foo': {unknown}

216..217 '1': usize

227..231 'E::B': E

235..237 '10': usize

diff --git a/crates/hir-ty/src/tests/regression.rs b/crates/hir-ty/src/tests/regression.rs
index 5fc2f46d56..2fa6234da1 100644
--- a/crates/hir-ty/src/tests/regression.rs
+++ b/crates/hir-ty/src/tests/regression.rs

@@ -270,7 +270,7 @@ fn infer_std_crash_5() {

61..320 '{ ... }': ()

75..79 'name': &{unknown}

82..166 'if doe... }': &{unknown}

- 85..98 'doesnt_matter': bool

+ 85..98 'doesnt_matter': {unknown}

99..128 '{ ... }': &{unknown}

113..118 'first': &{unknown}

134..166 '{ ... }': &{unknown}

@@ -279,7 +279,7 @@ fn infer_std_crash_5() {

181..188 'content': &{unknown}

191..313 'if ICE... }': &{unknown}

194..231 'ICE_RE..._VALUE': {unknown}

- 194..247 'ICE_RE...&name)': bool

+ 194..247 'ICE_RE...&name)': {unknown}

241..246 '&name': &&{unknown}

242..246 'name': &{unknown}

248..276 '{ ... }': &{unknown}