diff options
Diffstat (limited to 'compiler/rustc_pattern_analysis/src/rustc.rs')
| -rw-r--r-- | compiler/rustc_pattern_analysis/src/rustc.rs | 123 |
1 files changed, 69 insertions, 54 deletions
diff --git a/compiler/rustc_pattern_analysis/src/rustc.rs b/compiler/rustc_pattern_analysis/src/rustc.rs index 0085f0ab656..fd51fbedeef 100644 --- a/compiler/rustc_pattern_analysis/src/rustc.rs +++ b/compiler/rustc_pattern_analysis/src/rustc.rs @@ -18,20 +18,19 @@ use rustc_target::abi::{FieldIdx, Integer, VariantIdx, FIRST_VARIANT}; use crate::constructor::{ IntRange, MaybeInfiniteInt, OpaqueId, RangeEnd, Slice, SliceKind, VariantVisibility, }; -use crate::{errors, Captures, PrivateUninhabitedField, TypeCx}; +use crate::{errors, Captures, PatCx, PrivateUninhabitedField}; use crate::constructor::Constructor::*; // Re-export rustc-specific versions of all these types. -pub type Constructor<'p, 'tcx> = crate::constructor::Constructor<RustcMatchCheckCtxt<'p, 'tcx>>; -pub type ConstructorSet<'p, 'tcx> = - crate::constructor::ConstructorSet<RustcMatchCheckCtxt<'p, 'tcx>>; -pub type DeconstructedPat<'p, 'tcx> = crate::pat::DeconstructedPat<RustcMatchCheckCtxt<'p, 'tcx>>; -pub type MatchArm<'p, 'tcx> = crate::MatchArm<'p, RustcMatchCheckCtxt<'p, 'tcx>>; -pub type Usefulness<'p, 'tcx> = crate::usefulness::Usefulness<'p, RustcMatchCheckCtxt<'p, 'tcx>>; +pub type Constructor<'p, 'tcx> = crate::constructor::Constructor<RustcPatCtxt<'p, 'tcx>>; +pub type ConstructorSet<'p, 'tcx> = crate::constructor::ConstructorSet<RustcPatCtxt<'p, 'tcx>>; +pub type DeconstructedPat<'p, 'tcx> = crate::pat::DeconstructedPat<RustcPatCtxt<'p, 'tcx>>; +pub type MatchArm<'p, 'tcx> = crate::MatchArm<'p, RustcPatCtxt<'p, 'tcx>>; +pub type Usefulness<'p, 'tcx> = crate::usefulness::Usefulness<'p, RustcPatCtxt<'p, 'tcx>>; pub type UsefulnessReport<'p, 'tcx> = - crate::usefulness::UsefulnessReport<'p, RustcMatchCheckCtxt<'p, 'tcx>>; -pub type WitnessPat<'p, 'tcx> = crate::pat::WitnessPat<RustcMatchCheckCtxt<'p, 'tcx>>; + crate::usefulness::UsefulnessReport<'p, RustcPatCtxt<'p, 'tcx>>; +pub type WitnessPat<'p, 'tcx> = crate::pat::WitnessPat<RustcPatCtxt<'p, 'tcx>>; /// A type which has gone through `cx.reveal_opaque_ty`, i.e. if it was opaque it was replaced by /// the hidden type if allowed in the current body. This ensures we consistently inspect the hidden @@ -62,7 +61,7 @@ impl<'tcx> RevealedTy<'tcx> { } #[derive(Clone)] -pub struct RustcMatchCheckCtxt<'p, 'tcx: 'p> { +pub struct RustcPatCtxt<'p, 'tcx: 'p> { pub tcx: TyCtxt<'tcx>, pub typeck_results: &'tcx ty::TypeckResults<'tcx>, /// The module in which the match occurs. This is necessary for @@ -87,22 +86,19 @@ pub struct RustcMatchCheckCtxt<'p, 'tcx: 'p> { pub known_valid_scrutinee: bool, } -impl<'p, 'tcx: 'p> fmt::Debug for RustcMatchCheckCtxt<'p, 'tcx> { +impl<'p, 'tcx: 'p> fmt::Debug for RustcPatCtxt<'p, 'tcx> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("RustcMatchCheckCtxt").finish() + f.debug_struct("RustcPatCtxt").finish() } } -impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { +impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> { /// Type inference occasionally gives us opaque types in places where corresponding patterns /// have more specific types. To avoid inconsistencies as well as detect opaque uninhabited /// types, we use the corresponding concrete type if possible. #[inline] pub fn reveal_opaque_ty(&self, ty: Ty<'tcx>) -> RevealedTy<'tcx> { - fn reveal_inner<'tcx>( - cx: &RustcMatchCheckCtxt<'_, 'tcx>, - ty: Ty<'tcx>, - ) -> RevealedTy<'tcx> { + fn reveal_inner<'tcx>(cx: &RustcPatCtxt<'_, 'tcx>, ty: Ty<'tcx>) -> RevealedTy<'tcx> { let ty::Alias(ty::Opaque, alias_ty) = *ty.kind() else { bug!() }; if let Some(local_def_id) = alias_ty.def_id.as_local() { let key = ty::OpaqueTypeKey { def_id: local_def_id, args: alias_ty.args }; @@ -199,7 +195,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { + ExactSizeIterator + Captures<'a> { fn reveal_and_alloc<'a, 'tcx>( - cx: &'a RustcMatchCheckCtxt<'_, 'tcx>, + cx: &'a RustcPatCtxt<'_, 'tcx>, iter: impl Iterator<Item = Ty<'tcx>>, ) -> &'a [(RevealedTy<'tcx>, PrivateUninhabitedField)] { cx.dropless_arena.alloc_from_iter( @@ -218,7 +214,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { reveal_and_alloc(cx, once(args.type_at(0))) } else { let variant = - &adt.variant(RustcMatchCheckCtxt::variant_index_for_adt(&ctor, *adt)); + &adt.variant(RustcPatCtxt::variant_index_for_adt(&ctor, *adt)); // In the cases of either a `#[non_exhaustive]` field list or a non-public // field, we skip uninhabited fields in order not to reveal the @@ -270,7 +266,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { // patterns. If we're here we can assume this is a box pattern. 1 } else { - let variant_idx = RustcMatchCheckCtxt::variant_index_for_adt(&ctor, *adt); + let variant_idx = RustcPatCtxt::variant_index_for_adt(&ctor, *adt); adt.variant(variant_idx).fields.len() } } @@ -445,7 +441,8 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { let cx = self; let ty = cx.reveal_opaque_ty(pat.ty); let ctor; - let mut fields: Vec<_>; + let arity; + let fields: Vec<_>; match &pat.kind { PatKind::AscribeUserType { subpattern, .. } | PatKind::InlineConstant { subpattern, .. } => return self.lower_pat(subpattern), @@ -453,9 +450,11 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { PatKind::Binding { subpattern: None, .. } | PatKind::Wild => { ctor = Wildcard; fields = vec![]; + arity = 0; } PatKind::Deref { subpattern } => { - fields = vec![self.lower_pat(subpattern)]; + fields = vec![self.lower_pat(subpattern).at_index(0)]; + arity = 1; ctor = match ty.kind() { // This is a box pattern. ty::Adt(adt, ..) if adt.is_box() => Struct, @@ -467,16 +466,13 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { match ty.kind() { ty::Tuple(fs) => { ctor = Struct; - fields = fs + arity = fs.len(); + fields = subpatterns .iter() - .map(|ty| cx.reveal_opaque_ty(ty)) - .map(|ty| DeconstructedPat::wildcard(ty)) + .map(|ipat| self.lower_pat(&ipat.pattern).at_index(ipat.field.index())) .collect(); - for pat in subpatterns { - fields[pat.field.index()] = self.lower_pat(&pat.pattern); - } } - ty::Adt(adt, args) if adt.is_box() => { + ty::Adt(adt, _) if adt.is_box() => { // The only legal patterns of type `Box` (outside `std`) are `_` and box // patterns. If we're here we can assume this is a box pattern. // FIXME(Nadrieril): A `Box` can in theory be matched either with `Box(_, @@ -490,13 +486,13 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { // solution when we introduce generalized deref patterns. Also need to // prevent mixing of those two options. let pattern = subpatterns.into_iter().find(|pat| pat.field.index() == 0); - let pat = if let Some(pat) = pattern { - self.lower_pat(&pat.pattern) + if let Some(pat) = pattern { + fields = vec![self.lower_pat(&pat.pattern).at_index(0)]; } else { - DeconstructedPat::wildcard(self.reveal_opaque_ty(args.type_at(0))) - }; + fields = vec![]; + } ctor = Struct; - fields = vec![pat]; + arity = 1; } ty::Adt(adt, _) => { ctor = match pat.kind { @@ -506,14 +502,12 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { _ => bug!(), }; let variant = - &adt.variant(RustcMatchCheckCtxt::variant_index_for_adt(&ctor, *adt)); - fields = cx - .variant_sub_tys(ty, variant) - .map(|(_, ty)| DeconstructedPat::wildcard(ty)) + &adt.variant(RustcPatCtxt::variant_index_for_adt(&ctor, *adt)); + arity = variant.fields.len(); + fields = subpatterns + .iter() + .map(|ipat| self.lower_pat(&ipat.pattern).at_index(ipat.field.index())) .collect(); - for pat in subpatterns { - fields[pat.field.index()] = self.lower_pat(&pat.pattern); - } } _ => bug!("pattern has unexpected type: pat: {:?}, ty: {:?}", pat, ty), } @@ -526,6 +520,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { None => Opaque(OpaqueId::new()), }; fields = vec![]; + arity = 0; } ty::Char | ty::Int(_) | ty::Uint(_) => { ctor = match value.try_eval_bits(cx.tcx, cx.param_env) { @@ -542,6 +537,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { None => Opaque(OpaqueId::new()), }; fields = vec![]; + arity = 0; } ty::Float(ty::FloatTy::F32) => { ctor = match value.try_eval_bits(cx.tcx, cx.param_env) { @@ -553,6 +549,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { None => Opaque(OpaqueId::new()), }; fields = vec![]; + arity = 0; } ty::Float(ty::FloatTy::F64) => { ctor = match value.try_eval_bits(cx.tcx, cx.param_env) { @@ -564,6 +561,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { None => Opaque(OpaqueId::new()), }; fields = vec![]; + arity = 0; } ty::Ref(_, t, _) if t.is_str() => { // We want a `&str` constant to behave like a `Deref` pattern, to be compatible @@ -574,9 +572,10 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { // subfields. // Note: `t` is `str`, not `&str`. let ty = self.reveal_opaque_ty(*t); - let subpattern = DeconstructedPat::new(Str(*value), Vec::new(), ty, pat); + let subpattern = DeconstructedPat::new(Str(*value), Vec::new(), 0, ty, pat); ctor = Ref; - fields = vec![subpattern] + fields = vec![subpattern.at_index(0)]; + arity = 1; } // All constants that can be structurally matched have already been expanded // into the corresponding `Pat`s by `const_to_pat`. Constants that remain are @@ -584,6 +583,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { _ => { ctor = Opaque(OpaqueId::new()); fields = vec![]; + arity = 0; } } } @@ -623,6 +623,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { _ => bug!("invalid type for range pattern: {}", ty.inner()), }; fields = vec![]; + arity = 0; } PatKind::Array { prefix, slice, suffix } | PatKind::Slice { prefix, slice, suffix } => { let array_len = match ty.kind() { @@ -638,12 +639,25 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { SliceKind::FixedLen(prefix.len() + suffix.len()) }; ctor = Slice(Slice::new(array_len, kind)); - fields = prefix.iter().chain(suffix.iter()).map(|p| self.lower_pat(&*p)).collect(); + fields = prefix + .iter() + .chain(suffix.iter()) + .map(|p| self.lower_pat(&*p)) + .enumerate() + .map(|(i, p)| p.at_index(i)) + .collect(); + arity = kind.arity(); } PatKind::Or { .. } => { ctor = Or; let pats = expand_or_pat(pat); - fields = pats.into_iter().map(|p| self.lower_pat(p)).collect(); + fields = pats + .into_iter() + .map(|p| self.lower_pat(p)) + .enumerate() + .map(|(i, p)| p.at_index(i)) + .collect(); + arity = fields.len(); } PatKind::Never => { // A never pattern matches all the values of its type (namely none). Moreover it @@ -651,13 +665,15 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { // `Result<!, !>` which has other constructors. Hence we lower it as a wildcard. ctor = Wildcard; fields = vec![]; + arity = 0; } PatKind::Error(_) => { ctor = Opaque(OpaqueId::new()); fields = vec![]; + arity = 0; } } - DeconstructedPat::new(ctor, fields, ty, pat) + DeconstructedPat::new(ctor, fields, arity, ty, pat) } /// Convert back to a `thir::PatRangeBoundary` for diagnostic purposes. @@ -690,7 +706,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { None => PatRangeBoundary::PosInfinity, } } - JustAfterMax | PosInfinity => PatRangeBoundary::PosInfinity, + PosInfinity => PatRangeBoundary::PosInfinity, } } @@ -754,8 +770,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { PatKind::Deref { subpattern: subpatterns.next().unwrap() } } ty::Adt(adt_def, args) => { - let variant_index = - RustcMatchCheckCtxt::variant_index_for_adt(&pat.ctor(), *adt_def); + let variant_index = RustcPatCtxt::variant_index_for_adt(&pat.ctor(), *adt_def); let subpatterns = subpatterns .enumerate() .map(|(i, pattern)| FieldPat { field: FieldIdx::new(i), pattern }) @@ -823,7 +838,7 @@ impl<'p, 'tcx: 'p> RustcMatchCheckCtxt<'p, 'tcx> { } } -impl<'p, 'tcx: 'p> TypeCx for RustcMatchCheckCtxt<'p, 'tcx> { +impl<'p, 'tcx: 'p> PatCx for RustcPatCtxt<'p, 'tcx> { type Ty = RevealedTy<'tcx>; type Error = ErrorGuaranteed; type VariantIdx = VariantIdx; @@ -884,10 +899,10 @@ impl<'p, 'tcx: 'p> TypeCx for RustcMatchCheckCtxt<'p, 'tcx> { let overlap_as_pat = self.hoist_pat_range(&overlaps_on, *pat.ty()); let overlaps: Vec<_> = overlaps_with .iter() - .map(|pat| pat.data().unwrap().span) + .map(|pat| pat.data().span) .map(|span| errors::Overlap { range: overlap_as_pat.clone(), span }) .collect(); - let pat_span = pat.data().unwrap().span; + let pat_span = pat.data().span; self.tcx.emit_node_span_lint( lint::builtin::OVERLAPPING_RANGE_ENDPOINTS, self.match_lint_level, @@ -907,7 +922,7 @@ impl<'p, 'tcx: 'p> TypeCx for RustcMatchCheckCtxt<'p, 'tcx> { gap: IntRange, gapped_with: &[&crate::pat::DeconstructedPat<Self>], ) { - let Some(&thir_pat) = pat.data() else { return }; + let &thir_pat = pat.data(); let thir::PatKind::Range(range) = &thir_pat.kind else { return }; // Only lint when the left range is an exclusive range. if range.end != rustc_hir::RangeEnd::Excluded { @@ -955,7 +970,7 @@ impl<'p, 'tcx: 'p> TypeCx for RustcMatchCheckCtxt<'p, 'tcx> { gap_with: gapped_with .iter() .map(|pat| errors::GappedRange { - span: pat.data().unwrap().span, + span: pat.data().span, gap: gap_as_pat.clone(), first_range: thir_pat.clone(), }) |