diff options
Diffstat (limited to 'compiler/rustc_pattern_analysis/src')
| -rw-r--r-- | compiler/rustc_pattern_analysis/src/lib.rs | 14 | ||||
| -rw-r--r-- | compiler/rustc_pattern_analysis/src/lints.rs | 24 | ||||
| -rw-r--r-- | compiler/rustc_pattern_analysis/src/rustc.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_pattern_analysis/src/usefulness.rs | 21 |
4 files changed, 35 insertions, 26 deletions
diff --git a/compiler/rustc_pattern_analysis/src/lib.rs b/compiler/rustc_pattern_analysis/src/lib.rs index 8ea8dd61ab4..4d2d66c88a5 100644 --- a/compiler/rustc_pattern_analysis/src/lib.rs +++ b/compiler/rustc_pattern_analysis/src/lib.rs @@ -24,6 +24,8 @@ use std::fmt; use rustc_index::Idx; #[cfg(feature = "rustc")] use rustc_middle::ty::Ty; +#[cfg(feature = "rustc")] +use rustc_span::ErrorGuaranteed; use crate::constructor::{Constructor, ConstructorSet}; #[cfg(feature = "rustc")] @@ -52,6 +54,8 @@ impl<'a, T: ?Sized> Captures<'a> for T {} pub trait TypeCx: Sized + fmt::Debug { /// The type of a pattern. type Ty: Copy + Clone + fmt::Debug; // FIXME: remove Copy + /// Errors that can abort analysis. + type Error: fmt::Debug; /// The index of an enum variant. type VariantIdx: Clone + Idx; /// A string literal @@ -109,25 +113,25 @@ pub fn analyze_match<'p, 'tcx>( tycx: &RustcMatchCheckCtxt<'p, 'tcx>, arms: &[rustc::MatchArm<'p, 'tcx>], scrut_ty: Ty<'tcx>, -) -> rustc::UsefulnessReport<'p, 'tcx> { +) -> Result<rustc::UsefulnessReport<'p, 'tcx>, ErrorGuaranteed> { // Arena to store the extra wildcards we construct during analysis. let wildcard_arena = tycx.pattern_arena; let scrut_ty = tycx.reveal_opaque_ty(scrut_ty); let scrut_validity = ValidityConstraint::from_bool(tycx.known_valid_scrutinee); let cx = MatchCtxt { tycx, wildcard_arena }; - let report = compute_match_usefulness(cx, arms, scrut_ty, scrut_validity); + let report = compute_match_usefulness(cx, arms, scrut_ty, scrut_validity)?; let pat_column = PatternColumn::new(arms); // Lint on ranges that overlap on their endpoints, which is likely a mistake. - lint_overlapping_range_endpoints(cx, &pat_column); + lint_overlapping_range_endpoints(cx, &pat_column)?; // Run the non_exhaustive_omitted_patterns lint. Only run on refutable patterns to avoid hitting // `if let`s. Only run if the match is exhaustive otherwise the error is redundant. if tycx.refutable && report.non_exhaustiveness_witnesses.is_empty() { - lint_nonexhaustive_missing_variants(cx, arms, &pat_column, scrut_ty) + lint_nonexhaustive_missing_variants(cx, arms, &pat_column, scrut_ty)?; } - report + Ok(report) } diff --git a/compiler/rustc_pattern_analysis/src/lints.rs b/compiler/rustc_pattern_analysis/src/lints.rs index f1237ecf83c..f74e00342d0 100644 --- a/compiler/rustc_pattern_analysis/src/lints.rs +++ b/compiler/rustc_pattern_analysis/src/lints.rs @@ -4,7 +4,7 @@ use rustc_data_structures::captures::Captures; use rustc_middle::ty; use rustc_session::lint; use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS; -use rustc_span::Span; +use rustc_span::{ErrorGuaranteed, Span}; use crate::constructor::{IntRange, MaybeInfiniteInt}; use crate::errors::{ @@ -110,9 +110,9 @@ impl<'p, 'tcx> PatternColumn<'p, 'tcx> { fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>( cx: MatchCtxt<'a, 'p, 'tcx>, column: &PatternColumn<'p, 'tcx>, -) -> Vec<WitnessPat<'p, 'tcx>> { +) -> Result<Vec<WitnessPat<'p, 'tcx>>, ErrorGuaranteed> { let Some(ty) = column.head_ty() else { - return Vec::new(); + return Ok(Vec::new()); }; let pcx = &PlaceCtxt::new_dummy(cx, ty); @@ -121,7 +121,7 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>( // We can't consistently handle the case where no constructors are present (since this would // require digging deep through any type in case there's a non_exhaustive enum somewhere), // so for consistency we refuse to handle the top-level case, where we could handle it. - return vec![]; + return Ok(Vec::new()); } let mut witnesses = Vec::new(); @@ -141,7 +141,7 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>( let wild_pat = WitnessPat::wild_from_ctor(pcx, ctor); for (i, col_i) in specialized_columns.iter().enumerate() { // Compute witnesses for each column. - let wits_for_col_i = collect_nonexhaustive_missing_variants(cx, col_i); + let wits_for_col_i = collect_nonexhaustive_missing_variants(cx, col_i)?; // For each witness, we build a new pattern in the shape of `ctor(_, _, wit, _, _)`, // adding enough wildcards to match `arity`. for wit in wits_for_col_i { @@ -151,7 +151,7 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>( } } } - witnesses + Ok(witnesses) } pub(crate) fn lint_nonexhaustive_missing_variants<'a, 'p, 'tcx>( @@ -159,13 +159,13 @@ pub(crate) fn lint_nonexhaustive_missing_variants<'a, 'p, 'tcx>( arms: &[MatchArm<'p, 'tcx>], pat_column: &PatternColumn<'p, 'tcx>, scrut_ty: RevealedTy<'tcx>, -) { +) -> Result<(), ErrorGuaranteed> { let rcx: &RustcMatchCheckCtxt<'_, '_> = cx.tycx; if !matches!( rcx.tcx.lint_level_at_node(NON_EXHAUSTIVE_OMITTED_PATTERNS, rcx.match_lint_level).0, rustc_session::lint::Level::Allow ) { - let witnesses = collect_nonexhaustive_missing_variants(cx, pat_column); + let witnesses = collect_nonexhaustive_missing_variants(cx, pat_column)?; if !witnesses.is_empty() { // Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns` // is not exhaustive enough. @@ -204,6 +204,7 @@ pub(crate) fn lint_nonexhaustive_missing_variants<'a, 'p, 'tcx>( } } } + Ok(()) } /// Traverse the patterns to warn the user about ranges that overlap on their endpoints. @@ -211,9 +212,9 @@ pub(crate) fn lint_nonexhaustive_missing_variants<'a, 'p, 'tcx>( pub(crate) fn lint_overlapping_range_endpoints<'a, 'p, 'tcx>( cx: MatchCtxt<'a, 'p, 'tcx>, column: &PatternColumn<'p, 'tcx>, -) { +) -> Result<(), ErrorGuaranteed> { let Some(ty) = column.head_ty() else { - return; + return Ok(()); }; let pcx = &PlaceCtxt::new_dummy(cx, ty); let rcx: &RustcMatchCheckCtxt<'_, '_> = cx.tycx; @@ -275,8 +276,9 @@ pub(crate) fn lint_overlapping_range_endpoints<'a, 'p, 'tcx>( // Recurse into the fields. for ctor in set.present { for col in column.specialize(pcx, &ctor) { - lint_overlapping_range_endpoints(cx, &col); + lint_overlapping_range_endpoints(cx, &col)?; } } } + Ok(()) } diff --git a/compiler/rustc_pattern_analysis/src/rustc.rs b/compiler/rustc_pattern_analysis/src/rustc.rs index b6f67b7c56f..d757c5be602 100644 --- a/compiler/rustc_pattern_analysis/src/rustc.rs +++ b/compiler/rustc_pattern_analysis/src/rustc.rs @@ -13,6 +13,7 @@ use rustc_middle::mir::{self, Const}; use rustc_middle::thir::{FieldPat, Pat, PatKind, PatRange, PatRangeBoundary}; use rustc_middle::ty::layout::IntegerExt; use rustc_middle::ty::{self, OpaqueTypeKey, Ty, TyCtxt, VariantDef}; +use rustc_span::ErrorGuaranteed; use rustc_span::{Span, DUMMY_SP}; use rustc_target::abi::{FieldIdx, Integer, VariantIdx, FIRST_VARIANT}; use smallvec::SmallVec; @@ -944,6 +945,7 @@ impl<'p, 'tcx> RustcMatchCheckCtxt<'p, 'tcx> { impl<'p, 'tcx> TypeCx for RustcMatchCheckCtxt<'p, 'tcx> { type Ty = RevealedTy<'tcx>; + type Error = ErrorGuaranteed; type VariantIdx = VariantIdx; type StrLit = Const<'tcx>; type ArmData = HirId; diff --git a/compiler/rustc_pattern_analysis/src/usefulness.rs b/compiler/rustc_pattern_analysis/src/usefulness.rs index 16bf709881b..8d81a79b796 100644 --- a/compiler/rustc_pattern_analysis/src/usefulness.rs +++ b/compiler/rustc_pattern_analysis/src/usefulness.rs @@ -1341,14 +1341,14 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>( mcx: MatchCtxt<'a, 'p, Cx>, matrix: &mut Matrix<'p, Cx>, is_top_level: bool, -) -> WitnessMatrix<Cx> { +) -> Result<WitnessMatrix<Cx>, Cx::Error> { debug_assert!(matrix.rows().all(|r| r.len() == matrix.column_count())); if !matrix.wildcard_row_is_relevant && matrix.rows().all(|r| !r.pats.relevant) { // Here we know that nothing will contribute further to exhaustiveness or usefulness. This // is purely an optimization: skipping this check doesn't affect correctness. See the top of // the file for details. - return WitnessMatrix::empty(); + return Ok(WitnessMatrix::empty()); } let Some(ty) = matrix.head_ty() else { @@ -1360,16 +1360,16 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>( // When there's an unguarded row, the match is exhaustive and any subsequent row is not // useful. if !row.is_under_guard { - return WitnessMatrix::empty(); + return Ok(WitnessMatrix::empty()); } } // No (unguarded) rows, so the match is not exhaustive. We return a new witness unless // irrelevant. return if matrix.wildcard_row_is_relevant { - WitnessMatrix::unit_witness() + Ok(WitnessMatrix::unit_witness()) } else { // We choose to not report anything here; see at the top for details. - WitnessMatrix::empty() + Ok(WitnessMatrix::empty()) }; }; @@ -1422,7 +1422,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>( let mut spec_matrix = matrix.specialize_constructor(pcx, &ctor, ctor_is_relevant); let mut witnesses = ensure_sufficient_stack(|| { compute_exhaustiveness_and_usefulness(mcx, &mut spec_matrix, false) - }); + })?; // Transform witnesses for `spec_matrix` into witnesses for `matrix`. witnesses.apply_constructor(pcx, &missing_ctors, &ctor, report_individual_missing_ctors); @@ -1443,7 +1443,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>( } } - ret + Ok(ret) } /// Indicates whether or not a given arm is useful. @@ -1474,9 +1474,10 @@ pub fn compute_match_usefulness<'p, Cx: TypeCx>( arms: &[MatchArm<'p, Cx>], scrut_ty: Cx::Ty, scrut_validity: ValidityConstraint, -) -> UsefulnessReport<'p, Cx> { +) -> Result<UsefulnessReport<'p, Cx>, Cx::Error> { let mut matrix = Matrix::new(arms, scrut_ty, scrut_validity); - let non_exhaustiveness_witnesses = compute_exhaustiveness_and_usefulness(cx, &mut matrix, true); + let non_exhaustiveness_witnesses = + compute_exhaustiveness_and_usefulness(cx, &mut matrix, true)?; let non_exhaustiveness_witnesses: Vec<_> = non_exhaustiveness_witnesses.single_column(); let arm_usefulness: Vec<_> = arms @@ -1493,5 +1494,5 @@ pub fn compute_match_usefulness<'p, Cx: TypeCx>( (arm, usefulness) }) .collect(); - UsefulnessReport { arm_usefulness, non_exhaustiveness_witnesses } + Ok(UsefulnessReport { arm_usefulness, non_exhaustiveness_witnesses }) } |