From 831f4549cd1b23915729cbd2f1dd841621c4e8b8 Mon Sep 17 00:00:00 2001 From: uellenberg Date: Mon, 11 Nov 2024 19:20:59 -0800 Subject: Suggest using deref in patterns Fixes #132784 --- compiler/rustc_middle/src/traits/mod.rs | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'compiler/rustc_middle') diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs index 0a77c3bc42f..8c434265d27 100644 --- a/compiler/rustc_middle/src/traits/mod.rs +++ b/compiler/rustc_middle/src/traits/mod.rs @@ -316,8 +316,8 @@ pub enum ObligationCauseCode<'tcx> { span: Option, /// The root expected type induced by a scrutinee or type expression. root_ty: Ty<'tcx>, - /// Whether the `Span` came from an expression or a type expression. - origin_expr: bool, + /// Information about the `Span`, if it came from an expression, otherwise `None`. + origin_expr: Option, }, /// Computing common supertype in an if expression @@ -530,6 +530,25 @@ pub struct MatchExpressionArmCause<'tcx> { pub tail_defines_return_position_impl_trait: Option, } +/// Information about the origin expression of a pattern, relevant to diagnostics. +/// Fields here refer to the scrutinee of a pattern. +/// If the scrutinee isn't given in the diagnostic, then this won't exist. +#[derive(Copy, Clone, Debug, PartialEq, Eq)] +#[derive(TypeFoldable, TypeVisitable, HashStable, TyEncodable, TyDecodable)] +pub struct PatternOriginExpr { + /// A span representing the scrutinee expression, with all leading references + /// peeled from the expression. + /// Only references in the expression are peeled - if the expression refers to a variable + /// whose type is a reference, then that reference is kept because it wasn't created + /// in the expression. + pub peeled_span: Span, + /// The number of references that were peeled to produce `peeled_span`. + pub peeled_count: usize, + /// Does the peeled expression need to be wrapped in parentheses for + /// a prefix suggestion (i.e., dereference) to be valid. + pub peeled_prefix_suggestion_parentheses: bool, +} + #[derive(Copy, Clone, Debug, PartialEq, Eq)] #[derive(TypeFoldable, TypeVisitable, HashStable, TyEncodable, TyDecodable)] pub struct IfExpressionCause<'tcx> { -- cgit 1.4.1-3-g733a5