diff options
| -rw-r--r-- | compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs | 24 | ||||
| -rw-r--r-- | compiler/rustc_expand/src/build.rs | 4 | ||||
| -rw-r--r-- | tests/ui/deriving/deriving-all-codegen.stdout | 6 |
3 files changed, 26 insertions, 8 deletions
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs index 88d454fbc11..bad47db0de1 100644 --- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs +++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs @@ -29,16 +29,30 @@ pub fn expand_deriving_partial_eq( cx.span_bug(field.span, "not exactly 2 arguments in `derive(PartialEq)`"); }; - // We received `&T` arguments. Convert them to `T` by - // stripping `&` or adding `*`. This isn't necessary for - // type checking, but it results in much better error - // messages if something goes wrong. + // We received arguments of type `&T`. Convert them to type `T` by stripping + // any leading `&` or adding `*`. This isn't necessary for type checking, but + // it results in better error messages if something goes wrong. + // + // Note: for arguments that look like `&{ x }`, which occur with packed + // structs, this would cause expressions like `{ self.x } == { other.x }`, + // which isn't valid Rust syntax. This wouldn't break compilation because these + // AST nodes are constructed within the compiler. But it would mean that code + // printed by `-Zunpretty=expanded` (or `cargo expand`) would have invalid + // syntax, which would be suboptimal. So we wrap these in parens, giving + // `({ self.x }) == ({ other.x })`, which is valid syntax. let convert = |expr: &P<Expr>| { if let ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, inner) = &expr.kind { - inner.clone() + if let ExprKind::Block(..) = &inner.kind { + // `&{ x }` form: remove the `&`, add parens. + cx.expr_paren(field.span, inner.clone()) + } else { + // `&x` form: remove the `&`. + inner.clone() + } } else { + // No leading `&`: add a leading `*`. cx.expr_deref(field.span, expr.clone()) } }; diff --git a/compiler/rustc_expand/src/build.rs b/compiler/rustc_expand/src/build.rs index 9b16e79d49a..6cd56852f9d 100644 --- a/compiler/rustc_expand/src/build.rs +++ b/compiler/rustc_expand/src/build.rs @@ -272,6 +272,10 @@ impl<'a> ExtCtxt<'a> { self.expr(sp, ast::ExprKind::AddrOf(ast::BorrowKind::Ref, ast::Mutability::Not, e)) } + pub fn expr_paren(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> { + self.expr(sp, ast::ExprKind::Paren(e)) + } + pub fn expr_call( &self, span: Span, diff --git a/tests/ui/deriving/deriving-all-codegen.stdout b/tests/ui/deriving/deriving-all-codegen.stdout index b4874cef134..8e238a509d2 100644 --- a/tests/ui/deriving/deriving-all-codegen.stdout +++ b/tests/ui/deriving/deriving-all-codegen.stdout @@ -209,7 +209,7 @@ impl ::core::marker::StructuralPartialEq for PackedPoint { } impl ::core::cmp::PartialEq for PackedPoint { #[inline] fn eq(&self, other: &PackedPoint) -> bool { - { self.x } == { other.x } && { self.y } == { other.y } + ({ self.x }) == ({ other.x }) && ({ self.y }) == ({ other.y }) } } #[automatically_derived] @@ -718,8 +718,8 @@ impl<T: ::core::cmp::PartialEq + ::core::marker::Copy + Trait, ::core::marker::Copy { #[inline] fn eq(&self, other: &PackedGeneric<T, U>) -> bool { - { self.0 } == { other.0 } && { self.1 } == { other.1 } && - { self.2 } == { other.2 } + ({ self.0 }) == ({ other.0 }) && ({ self.1 }) == ({ other.1 }) && + ({ self.2 }) == ({ other.2 }) } } #[automatically_derived] |