From 1ca4bc966ec5215a8daacf584d337f75322c0e9a Mon Sep 17 00:00:00 2001 From: Deadbeef Date: Sun, 6 Aug 2023 14:00:12 +0000 Subject: [PATCH] Migrate a trait selection error to use diagnostic translation --- compiler/rustc_middle/src/ty/closure.rs | 19 ++++++- compiler/rustc_middle/src/ty/print/pretty.rs | 6 +-- compiler/rustc_trait_selection/messages.ftl | 9 ++++ compiler/rustc_trait_selection/src/errors.rs | 36 ++++++++++++- .../src/traits/error_reporting/mod.rs | 50 +++++++------------ 5 files changed, 79 insertions(+), 41 deletions(-) diff --git a/compiler/rustc_middle/src/ty/closure.rs b/compiler/rustc_middle/src/ty/closure.rs index 2e5c6a4457900..74bdd07a1c946 100644 --- a/compiler/rustc_middle/src/ty/closure.rs +++ b/compiler/rustc_middle/src/ty/closure.rs @@ -7,6 +7,7 @@ use std::fmt::Write; use crate::query::Providers; use rustc_data_structures::fx::FxIndexMap; +use rustc_errors::{DiagnosticArgValue, IntoDiagnosticArg}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::{self as hir, LangItem}; use rustc_span::def_id::LocalDefIdMap; @@ -89,10 +90,18 @@ pub enum ClosureKind { FnOnce, } -impl<'tcx> ClosureKind { +impl ClosureKind { /// This is the initial value used when doing upvar inference. pub const LATTICE_BOTTOM: ClosureKind = ClosureKind::Fn; + pub const fn as_str(self) -> &'static str { + match self { + ClosureKind::Fn => "Fn", + ClosureKind::FnMut => "FnMut", + ClosureKind::FnOnce => "FnOnce", + } + } + /// Returns `true` if a type that impls this closure kind /// must also implement `other`. pub fn extends(self, other: ty::ClosureKind) -> bool { @@ -115,7 +124,7 @@ impl<'tcx> ClosureKind { /// Returns the representative scalar type for this closure kind. /// See `Ty::to_opt_closure_kind` for more details. - pub fn to_ty(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { + pub fn to_ty<'tcx>(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { match self { ClosureKind::Fn => tcx.types.i8, ClosureKind::FnMut => tcx.types.i16, @@ -124,6 +133,12 @@ impl<'tcx> ClosureKind { } } +impl IntoDiagnosticArg for ClosureKind { + fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> { + DiagnosticArgValue::Str(self.as_str().into()) + } +} + /// A composite describing a `Place` that is captured by a closure. #[derive(PartialEq, Clone, Debug, TyEncodable, TyDecodable, HashStable)] #[derive(TypeFoldable, TypeVisitable)] diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs index d3fd49150ba2a..0c90e223a84c4 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -2870,11 +2870,7 @@ define_print_and_forward_display! { } ty::ClosureKind { - match *self { - ty::ClosureKind::Fn => p!("Fn"), - ty::ClosureKind::FnMut => p!("FnMut"), - ty::ClosureKind::FnOnce => p!("FnOnce"), - } + p!(write("{}", self.as_str())) } ty::Predicate<'tcx> { diff --git a/compiler/rustc_trait_selection/messages.ftl b/compiler/rustc_trait_selection/messages.ftl index f57f1bad15dca..f4c9dfa34882e 100644 --- a/compiler/rustc_trait_selection/messages.ftl +++ b/compiler/rustc_trait_selection/messages.ftl @@ -8,6 +8,15 @@ trait_selection_adjust_signature_remove_borrow = consider adjusting the signatur *[other] arguments } +trait_selection_closure_fn_mut_label = closure is `FnMut` because it mutates the variable `{$place}` here + +trait_selection_closure_fn_once_label = closure is `FnOnce` because it moves the variable `{$place}` out of its environment + +trait_selection_closure_kind_mismatch = expected a closure that implements the `{$expected}` trait, but this closure only implements `{$found}` + .label = this closure implements `{$found}`, not `{$expected}` + +trait_selection_closure_kind_requirement = the requirement to implement `{$expected}` derives from here + trait_selection_dump_vtable_entries = vtable entries for `{$trait_ref}`: {$entries} trait_selection_empty_on_clause_in_rustc_on_unimplemented = empty `on`-clause in `#[rustc_on_unimplemented]` diff --git a/compiler/rustc_trait_selection/src/errors.rs b/compiler/rustc_trait_selection/src/errors.rs index dde9e9c9ac694..c1fb287d63efa 100644 --- a/compiler/rustc_trait_selection/src/errors.rs +++ b/compiler/rustc_trait_selection/src/errors.rs @@ -4,7 +4,7 @@ use rustc_errors::{ SubdiagnosticMessage, }; use rustc_macros::Diagnostic; -use rustc_middle::ty::{self, PolyTraitRef, Ty}; +use rustc_middle::ty::{self, ClosureKind, PolyTraitRef, Ty}; use rustc_span::{Span, Symbol}; #[derive(Diagnostic)] @@ -131,3 +131,37 @@ impl AddToDiagnostic for AdjustSignatureBorrow { } } } + +#[derive(Diagnostic)] +#[diag(trait_selection_closure_kind_mismatch, code = "E0525")] +pub struct ClosureKindMismatch { + #[primary_span] + #[label] + pub closure_span: Span, + pub expected: ClosureKind, + pub found: ClosureKind, + #[label(trait_selection_closure_kind_requirement)] + pub cause_span: Span, + + #[subdiagnostic] + pub fn_once_label: Option, + + #[subdiagnostic] + pub fn_mut_label: Option, +} + +#[derive(Subdiagnostic)] +#[label(trait_selection_closure_fn_once_label)] +pub struct ClosureFnOnceLabel { + #[primary_span] + pub span: Span, + pub place: String, +} + +#[derive(Subdiagnostic)] +#[label(trait_selection_closure_fn_mut_label)] +pub struct ClosureFnMutLabel { + #[primary_span] + pub span: Span, + pub place: String, +} diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index 4d85e2b60893e..071d545251d80 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -7,6 +7,7 @@ use super::{ ObligationCauseCode, ObligationCtxt, OutputTypeParameterMismatch, Overflow, PredicateObligation, SelectionError, TraitNotObjectSafe, }; +use crate::errors::{ClosureFnMutLabel, ClosureFnOnceLabel, ClosureKindMismatch}; use crate::infer::error_reporting::{TyCategory, TypeAnnotationNeeded as ErrorCode}; use crate::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use crate::infer::{self, InferCtxt}; @@ -3142,24 +3143,15 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { kind: ty::ClosureKind, ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> { let closure_span = self.tcx.def_span(closure_def_id); - let mut err = struct_span_err!( - self.tcx.sess, - closure_span, - E0525, - "expected a closure that implements the `{}` trait, \ - but this closure only implements `{}`", - kind, - found_kind - ); - err.span_label( + let mut err = ClosureKindMismatch { closure_span, - format!("this closure implements `{found_kind}`, not `{kind}`"), - ); - err.span_label( - obligation.cause.span, - format!("the requirement to implement `{kind}` derives from here"), - ); + expected: kind, + found: found_kind, + cause_span: obligation.cause.span, + fn_once_label: None, + fn_mut_label: None, + }; // Additional context information explaining why the closure only implements // a particular trait. @@ -3167,30 +3159,22 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { let hir_id = self.tcx.hir().local_def_id_to_hir_id(closure_def_id.expect_local()); match (found_kind, typeck_results.closure_kind_origins().get(hir_id)) { (ty::ClosureKind::FnOnce, Some((span, place))) => { - err.span_label( - *span, - format!( - "closure is `FnOnce` because it moves the \ - variable `{}` out of its environment", - ty::place_to_string_for_capture(self.tcx, place) - ), - ); + err.fn_once_label = Some(ClosureFnOnceLabel { + span: *span, + place: ty::place_to_string_for_capture(self.tcx, &place), + }) } (ty::ClosureKind::FnMut, Some((span, place))) => { - err.span_label( - *span, - format!( - "closure is `FnMut` because it mutates the \ - variable `{}` here", - ty::place_to_string_for_capture(self.tcx, place) - ), - ); + err.fn_mut_label = Some(ClosureFnMutLabel { + span: *span, + place: ty::place_to_string_for_capture(self.tcx, &place), + }) } _ => {} } } - err + self.tcx.sess.create_err(err) } fn report_type_parameter_mismatch_cyclic_type_error(