bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat
-rw-r--r--crates/hir-ty/src/infer.rs8
-rw-r--r--crates/hir-ty/src/infer/expr.rs93
-rw-r--r--crates/hir-ty/src/tests/coercion.rs18
-rw-r--r--crates/hir-ty/src/tests/simple.rs300
4 files changed, 416 insertions, 3 deletions
diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index 4b80f06a3a..ecadfb6ce4 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs
@@ -137,6 +137,14 @@ trait PatLike: Into<ExprOrPatId> + Copy {
) -> Ty;
}
+impl PatLike for ExprId {
+ type BindingMode = ();
+
+ fn infer(this: &mut InferenceContext, id: Self, expected_ty: &Ty, _: Self::BindingMode) -> Ty {
+ this.infer_assignee_expr(id, expected_ty)
+ }
+}
+
impl PatLike for PatId {
type BindingMode = BindingMode;
diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs
index 4d4d187fe8..620d889bd5 100644
--- a/crates/hir-ty/src/infer/expr.rs
+++ b/crates/hir-ty/src/infer/expr.rs
@@ -593,8 +593,8 @@ impl<'a> InferenceContext<'a> {
}
Expr::BinaryOp { lhs, rhs, op } => match op {
Some(BinaryOp::Assignment { op: None }) => {
- let lhs_ty = self.infer_expr(*lhs, &Expectation::none());
- self.infer_expr_coerce(*rhs, &Expectation::has_type(lhs_ty));
+ let rhs_ty = self.infer_expr(*rhs, &Expectation::none());
+ self.infer_assignee_expr(*lhs, &rhs_ty);
self.result.standard_types.unit.clone()
}
Some(BinaryOp::LogicOp(_)) => {
@@ -817,6 +817,95 @@ impl<'a> InferenceContext<'a> {
}
}
+ pub(super) fn infer_assignee_expr(&mut self, lhs: ExprId, rhs_ty: &Ty) -> Ty {
+ let is_rest_expr = |expr| {
+ matches!(
+ &self.body[expr],
+ Expr::Range { lhs: None, rhs: None, range_type: RangeOp::Exclusive },
+ )
+ };
+
+ let rhs_ty = self.resolve_ty_shallow(rhs_ty);
+
+ let ty = match &self.body[lhs] {
+ Expr::Tuple { exprs } => {
+ // We don't consider multiple ellipses. This is analogous to
+ // `hir_def::body::lower::ExprCollector::collect_tuple_pat()`.
+ let ellipsis = exprs.iter().position(|e| is_rest_expr(*e));
+ let exprs: Vec<_> = exprs.iter().filter(|e| !is_rest_expr(**e)).copied().collect();
+
+ self.infer_tuple_pat_like(&rhs_ty, (), ellipsis, &exprs)
+ }
+ Expr::Call { callee, args } => {
+ // Tuple structs
+ let path = match &self.body[*callee] {
+ Expr::Path(path) => Some(path),
+ _ => None,
+ };
+
+ // We don't consider multiple ellipses. This is analogous to
+ // `hir_def::body::lower::ExprCollector::collect_tuple_pat()`.
+ let ellipsis = args.iter().position(|e| is_rest_expr(*e));
+ let args: Vec<_> = args.iter().filter(|e| !is_rest_expr(**e)).copied().collect();
+
+ self.infer_tuple_struct_pat_like(path, &rhs_ty, (), lhs, ellipsis, &args)
+ }
+ Expr::Array(Array::ElementList(elements)) => {
+ let elem_ty = match rhs_ty.kind(Interner) {
+ TyKind::Array(st, _) => st.clone(),
+ _ => self.err_ty(),
+ };
+
+ // There's no need to handle `..` as it cannot be bound.
+ let sub_exprs = elements.iter().filter(|e| !is_rest_expr(**e));
+
+ for e in sub_exprs {
+ self.infer_assignee_expr(*e, &elem_ty);
+ }
+
+ match rhs_ty.kind(Interner) {
+ TyKind::Array(_, _) => rhs_ty.clone(),
+ // Even when `rhs_ty` is not an array type, this assignee
+ // expression is infered to be an array (of unknown element
+ // type and length). This should not be just an error type,
+ // because we are to compute the unifiability of this type and
+ // `rhs_ty` in the end of this function to issue type mismatches.
+ _ => TyKind::Array(self.err_ty(), crate::consteval::usize_const(None))
+ .intern(Interner),
+ }
+ }
+ Expr::RecordLit { path, fields, .. } => {
+ let subs = fields.iter().map(|f| (f.name.clone(), f.expr));
+
+ self.infer_record_pat_like(path.as_deref(), &rhs_ty, (), lhs.into(), subs)
+ }
+ Expr::Underscore => rhs_ty.clone(),
+ _ => {
+ // `lhs` is a place expression, a unit struct, or an enum variant.
+ let lhs_ty = self.infer_expr(lhs, &Expectation::none());
+
+ // This is the only branch where this function may coerce any type.
+ // We are returning early to avoid the unifiability check below.
+ let lhs_ty = self.insert_type_vars_shallow(lhs_ty);
+ let ty = match self.coerce(None, &rhs_ty, &lhs_ty) {
+ Ok(ty) => ty,
+ Err(_) => self.err_ty(),
+ };
+ self.write_expr_ty(lhs, ty.clone());
+ return ty;
+ }
+ };
+
+ let ty = self.insert_type_vars_shallow(ty);
+ if !self.unify(&ty, &rhs_ty) {
+ self.result
+ .type_mismatches
+ .insert(lhs.into(), TypeMismatch { expected: rhs_ty.clone(), actual: ty.clone() });
+ }
+ self.write_expr_ty(lhs, ty.clone());
+ ty
+ }
+
fn infer_overloadable_binop(
&mut self,
lhs: ExprId,
diff --git a/crates/hir-ty/src/tests/coercion.rs b/crates/hir-ty/src/tests/coercion.rs
index 268faf8cb3..0e512ef5ec 100644
--- a/crates/hir-ty/src/tests/coercion.rs
+++ b/crates/hir-ty/src/tests/coercion.rs
@@ -313,6 +313,24 @@ fn f(text: &str) {
}
#[test]
+fn destructuring_assign_coerce() {
+ check_no_mismatches(
+ r"
+//- minicore: deref
+struct String;
+impl core::ops::Deref for String { type Target = str; }
+fn g(_text: &str) {}
+fn f(text: &str) {
+ let mut text = text;
+ let tmp = String;
+ [text, _] = [&tmp, &tmp];
+ g(text);
+}
+",
+ );
+}
+
+#[test]
fn coerce_fn_item_to_fn_ptr() {
check_no_mismatches(
r"
diff --git a/crates/hir-ty/src/tests/simple.rs b/crates/hir-ty/src/tests/simple.rs
index 46ab2377b5..535b948371 100644
--- a/crates/hir-ty/src/tests/simple.rs
+++ b/crates/hir-ty/src/tests/simple.rs
@@ -1,6 +1,6 @@
use expect_test::expect;
-use super::{check_infer, check_no_mismatches, check_types};
+use super::{check, check_infer, check_no_mismatches, check_types};
#[test]
fn infer_box() {
@@ -2745,3 +2745,301 @@ fn f() {
"#,
);
}
+
+#[test]
+fn destructuring_assignment_slice() {
+ check_types(
+ r#"
+fn main() {
+ let a;
+ //^usize
+ [a,] = [0usize];
+
+ let a;
+ //^usize
+ [a, ..] = [0usize; 5];
+
+ let a;
+ //^usize
+ [.., a] = [0usize; 5];
+
+ let a;
+ //^usize
+ [.., a, _] = [0usize; 5];
+
+ let a;
+ //^usize
+ [_, a, ..] = [0usize; 5];
+
+ let a: &mut i64 = &mut 0;
+ [*a, ..] = [1, 2, 3];
+
+ let a: usize;
+ let b;
+ //^usize
+ [a, _, b] = [3, 4, 5];
+ //^usize
+
+ let a;
+ //^i64
+ let b;
+ //^i64
+ [[a, ..], .., [.., b]] = [[1, 2], [3i64, 4], [5, 6], [7, 8]];
+}
+ "#,
+ );
+}
+
+#[test]
+fn destructuring_assignment_tuple() {
+ check_types(
+ r#"
+fn main() {
+ let a;
+ //^char
+ let b;
+ //^i64
+ (a, b) = ('c', 0i64);
+
+ let a;
+ //^char
+ (a, ..) = ('c', 0i64);
+
+ let a;
+ //^i64
+ (.., a) = ('c', 0i64);
+
+ let a;
+ //^char
+ let b;
+ //^i64
+ (a, .., b) = ('c', 0i64);
+
+ let a;
+ //^char
+ let b;
+ //^bool
+ (a, .., b) = ('c', 0i64, true);
+
+ let a;
+ //^i64
+ let b;
+ //^bool
+ (_, a, .., b) = ('c', 0i64, true);
+
+ let a;
+ //^i64
+ let b;
+ //^usize
+ (_, a, .., b) = ('c', 0i64, true, 0usize);
+
+ let mut a = 1;
+ //^^^^^i64
+ let mut b: i64 = 0;
+ (a, b) = (b, a);
+}
+ "#,
+ );
+}
+
+#[test]
+fn destructuring_assignment_tuple_struct() {
+ check_types(
+ r#"
+struct S2(char, i64);
+struct S3(char, i64, bool);
+struct S4(char, i64, bool usize);
+fn main() {
+ let a;
+ //^char
+ let b;
+ //^i64
+ S2(a, b) = S2('c', 0i64);
+
+ let a;
+ //^char
+ let b;
+ //^i64
+ S2(a, .., b) = S2('c', 0i64);
+
+ let a;
+ //^char
+ let b;
+ //^bool
+ S3(a, .., b) = S3('c', 0i64, true);
+
+ let a;
+ //^i64
+ let b;
+ //^bool
+ S3(_, a, .., b) = S3('c', 0i64, true);
+
+ let a;
+ //^i64
+ let b;
+ //^usize
+ S4(_, a, .., b) = S4('c', 0i64, true, 0usize);
+
+ struct Swap(i64, i64);
+
+ let mut a = 1;
+ //^^^^^i64
+ let mut b = 0;
+ //^^^^^i64
+ Swap(a, b) = Swap(b, a);
+}
+ "#,
+ );
+}
+
+#[test]
+fn destructuring_assignment_struct() {
+ check_types(
+ r#"
+struct S {
+ a: usize,
+ b: char,
+}
+struct T {
+ s: S,
+ t: i64,
+}
+
+fn main() {
+ let a;
+ //^usize
+ let c;
+ //^char
+ S { a, b: c } = S { a: 3, b: 'b' };
+
+ let a;
+ //^char
+ S { b: a, .. } = S { a: 3, b: 'b' };
+
+ let a;
+ //^char
+ S { b: a, _ } = S { a: 3, b: 'b' };
+
+ let a;
+ //^usize
+ let c;
+ //^char
+ let t;
+ //^i64
+ T { s: S { a, b: c }, t } = T { s: S { a: 3, b: 'b' }, t: 0 };
+}
+ "#,
+ );
+}
+
+#[test]
+fn destructuring_assignment_nested() {
+ check_types(
+ r#"
+struct S {
+ a: TS,
+ b: [char; 3],
+}
+struct TS(usize, i64);
+
+fn main() {
+ let a;
+ //^i32
+ let b;
+ //^bool
+ ([.., a], .., b, _) = ([0, 1, 2], true, 'c');
+
+ let a;
+ //^i32
+ let b;
+ //^i32
+ [(.., a, _), .., (b, ..)] = [(1, 2); 5];
+
+ let a;
+ //^usize
+ let b;
+ //^char
+ S { a: TS(a, ..), b: [_, b, ..] } = S { a: TS(0, 0), b: ['a'; 3] };
+}
+ "#,
+ );
+}
+
+#[test]
+fn destructuring_assignment_unit_struct() {
+ // taken from rustc; see https://github.com/rust-lang/rust/pull/95380
+ check_no_mismatches(
+ r#"
+struct S;
+enum E { V, }
+type A = E;
+
+fn main() {
+ let mut a;
+
+ (S, a) = (S, ());
+
+ (E::V, a) = (E::V, ());
+
+ (<E>::V, a) = (E::V, ());
+ (A::V, a) = (E::V, ());
+}
+
+impl S {
+ fn check() {
+ let a;
+ (Self, a) = (S, ());
+ }
+}
+
+impl E {
+ fn check() {
+ let a;
+ (Self::V, a) = (E::V, ());
+ }
+}
+ "#,
+ );
+}
+
+#[test]
+fn destructuring_assignment_no_default_binding_mode() {
+ check(
+ r#"
+struct S { a: usize }
+struct TS(usize);
+fn main() {
+ let x;
+ [x,] = &[1,];
+ //^^^^expected &[i32; 1], got [{unknown}; _]
+
+ // FIXME we only want the outermost error, but this matches the current
+ // behavior of slice patterns
+ let x;
+ [(x,),] = &[(1,),];
+ // ^^^^expected {unknown}, got ({unknown},)
+ //^^^^^^^expected &[(i32,); 1], got [{unknown}; _]
+
+ let x;
+ ((x,),) = &((1,),);
+ //^^^^^^^expected &((i32,),), got (({unknown},),)
+
+ let x;
+ (x,) = &(1,);
+ //^^^^expected &(i32,), got ({unknown},)
+
+ let x;
+ (S { a: x },) = &(S { a: 42 },);
+ //^^^^^^^^^^^^^expected &(S,), got (S,)
+
+ let x;
+ S { a: x } = &S { a: 42 };
+ //^^^^^^^^^^expected &S, got S
+
+ let x;
+ TS(x) = &TS(42);
+ //^^^^^expected &TS, got TS
+}
+ "#,
+ );
+}