Skip to content

Commit

Permalink
Rollup merge of #114548 - fee1-dead-contrib:migrate-to-trans, r=david…
Browse files Browse the repository at this point in the history
…twco

Migrate a trait selection error to use diagnostic translation
  • Loading branch information
matthiaskrgr authored Aug 9, 2023
2 parents 3feab00 + 1ca4bc9 commit 0c2f179
Show file tree
Hide file tree
Showing 5 changed files with 79 additions and 41 deletions.
19 changes: 17 additions & 2 deletions compiler/rustc_middle/src/ty/closure.rs
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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 {
Expand All @@ -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,
Expand All @@ -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)]
Expand Down
6 changes: 1 addition & 5 deletions compiler/rustc_middle/src/ty/print/pretty.rs
Original file line number Diff line number Diff line change
Expand Up @@ -2875,11 +2875,7 @@ 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> {
Expand Down
9 changes: 9 additions & 0 deletions compiler/rustc_trait_selection/messages.ftl
Original file line number Diff line number Diff line change
Expand Up @@ -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]`
Expand Down
36 changes: 35 additions & 1 deletion compiler/rustc_trait_selection/src/errors.rs
Original file line number Diff line number Diff line change
Expand Up @@ -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)]
Expand Down Expand Up @@ -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<ClosureFnOnceLabel>,

#[subdiagnostic]
pub fn_mut_label: Option<ClosureFnMutLabel>,
}

#[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,
}
50 changes: 17 additions & 33 deletions compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -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};
Expand Down Expand Up @@ -3121,55 +3122,38 @@ 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.
if let Some(typeck_results) = &self.typeck_results {
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(
Expand Down

0 comments on commit 0c2f179

Please sign in to comment.