diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/thir/pattern')
5 files changed, 164 insertions, 118 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs index 063c07647..d45b88690 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -491,8 +491,8 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { err.span_suggestion_verbose( semi_span.shrink_to_lo(), &format!( - "alternatively, on nightly, you might want to use \ - `#![feature(let_else)]` to handle the variant{} that {} matched", + "alternatively, you might want to use \ + let else to handle the variant{} that {} matched", pluralize!(witnesses.len()), match witnesses.len() { 1 => "isn't", @@ -849,22 +849,22 @@ fn non_exhaustive_match<'p, 'tcx>( )); } [.., prev, last] if prev.span.eq_ctxt(last.span) => { - if let Ok(snippet) = sm.span_to_snippet(prev.span.between(last.span)) { - let comma = if matches!(last.body.kind, hir::ExprKind::Block(..)) - && last.span.eq_ctxt(last.body.span) - { - "" - } else { - "," - }; + let comma = if matches!(last.body.kind, hir::ExprKind::Block(..)) + && last.span.eq_ctxt(last.body.span) + { + "" + } else { + "," + }; + let spacing = if sm.is_multiline(prev.span.between(last.span)) { + sm.indentation_before(last.span).map(|indent| format!("\n{indent}")) + } else { + Some(" ".to_string()) + }; + if let Some(spacing) = spacing { suggestion = Some(( last.span.shrink_to_hi(), - format!( - "{}{}{} => todo!()", - comma, - snippet.strip_prefix(',').unwrap_or(&snippet), - pattern - ), + format!("{}{}{} => todo!()", comma, spacing, pattern), )); } } diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs index d6dd0f017..b58685e89 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs @@ -19,21 +19,18 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { /// Converts an evaluated constant to a pattern (if possible). /// This means aggregate values (like structs and enums) are converted /// to a pattern that matches the value (as if you'd compared via structural equality). - #[instrument(level = "debug", skip(self))] + #[instrument(level = "debug", skip(self), ret)] pub(super) fn const_to_pat( &self, cv: mir::ConstantKind<'tcx>, id: hir::HirId, span: Span, mir_structural_match_violation: bool, - ) -> Pat<'tcx> { - let pat = self.tcx.infer_ctxt().enter(|infcx| { + ) -> Box<Pat<'tcx>> { + self.tcx.infer_ctxt().enter(|infcx| { let mut convert = ConstToPat::new(self, id, span, infcx); convert.to_pat(cv, mir_structural_match_violation) - }); - - debug!(?pat); - pat + }) } } @@ -159,7 +156,7 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { &mut self, cv: mir::ConstantKind<'tcx>, mir_structural_match_violation: bool, - ) -> Pat<'tcx> { + ) -> Box<Pat<'tcx>> { trace!(self.treat_byte_string_as_slice); // This method is just a wrapper handling a validity check; the heavy lifting is // performed by the recursive `recur` method, which is not meant to be @@ -168,7 +165,14 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { // once indirect_structural_match is a full fledged error, this // level of indirection can be eliminated - let inlined_const_as_pat = self.recur(cv, mir_structural_match_violation).unwrap(); + let inlined_const_as_pat = + self.recur(cv, mir_structural_match_violation).unwrap_or_else(|_| { + Box::new(Pat { + span: self.span, + ty: cv.ty(), + kind: PatKind::Constant { value: cv }, + }) + }); if self.include_lint_checks && !self.saw_const_match_error.get() { // If we were able to successfully convert the const to some pat, @@ -269,7 +273,7 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { &self, cv: mir::ConstantKind<'tcx>, mir_structural_match_violation: bool, - ) -> Result<Pat<'tcx>, FallbackToConstRef> { + ) -> Result<Box<Pat<'tcx>>, FallbackToConstRef> { let id = self.id; let span = self.span; let tcx = self.tcx(); @@ -396,7 +400,7 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { .map(|val| self.recur(*val, false)) .collect::<Result<_, _>>()?, slice: None, - suffix: Vec::new(), + suffix: Box::new([]), }, ty::Ref(_, pointee_ty, ..) => match *pointee_ty.kind() { // These are not allowed and will error elsewhere anyway. @@ -423,8 +427,8 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { let old = self.behind_reference.replace(true); let array = tcx.deref_mir_constant(self.param_env.and(cv)); let val = PatKind::Deref { - subpattern: Pat { - kind: Box::new(PatKind::Array { + subpattern: Box::new(Pat { + kind: PatKind::Array { prefix: tcx .destructure_mir_constant(param_env, array) .fields @@ -432,11 +436,11 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { .map(|val| self.recur(*val, false)) .collect::<Result<_, _>>()?, slice: None, - suffix: vec![], - }), + suffix: Box::new([]), + }, span, ty: *pointee_ty, - }, + }), }; self.behind_reference.set(old); val @@ -449,8 +453,8 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { let old = self.behind_reference.replace(true); let array = tcx.deref_mir_constant(self.param_env.and(cv)); let val = PatKind::Deref { - subpattern: Pat { - kind: Box::new(PatKind::Slice { + subpattern: Box::new(Pat { + kind: PatKind::Slice { prefix: tcx .destructure_mir_constant(param_env, array) .fields @@ -458,11 +462,11 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { .map(|val| self.recur(*val, false)) .collect::<Result<_, _>>()?, slice: None, - suffix: vec![], - }), + suffix: Box::new([]), + }, span, ty: tcx.mk_slice(elem_ty), - }, + }), }; self.behind_reference.set(old); val @@ -596,6 +600,6 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { ); } - Ok(Pat { span, ty: cv.ty(), kind: Box::new(kind) }) + Ok(Box::new(Pat { span, ty: cv.ty(), kind })) } } diff --git a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs index 8d6f8efb6..5105f059f 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs @@ -71,9 +71,9 @@ use std::ops::RangeInclusive; /// Recursively expand this pattern into its subpatterns. Only useful for or-patterns. fn expand_or_pat<'p, 'tcx>(pat: &'p Pat<'tcx>) -> Vec<&'p Pat<'tcx>> { fn expand<'p, 'tcx>(pat: &'p Pat<'tcx>, vec: &mut Vec<&'p Pat<'tcx>>) { - if let PatKind::Or { pats } = pat.kind.as_ref() { - for pat in pats { - expand(pat, vec); + if let PatKind::Or { pats } = &pat.kind { + for pat in pats.iter() { + expand(&pat, vec); } } else { vec.push(pat) @@ -252,10 +252,14 @@ impl IntRange { let kind = if lo == hi { PatKind::Constant { value: lo_const } } else { - PatKind::Range(PatRange { lo: lo_const, hi: hi_const, end: RangeEnd::Included }) + PatKind::Range(Box::new(PatRange { + lo: lo_const, + hi: hi_const, + end: RangeEnd::Included, + })) }; - Pat { ty, span: DUMMY_SP, kind: Box::new(kind) } + Pat { ty, span: DUMMY_SP, kind } } /// Lint on likely incorrect range patterns (#63987) @@ -1297,7 +1301,7 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { let mkpat = |pat| DeconstructedPat::from_pat(cx, pat); let ctor; let fields; - match pat.kind.as_ref() { + match &pat.kind { PatKind::AscribeUserType { subpattern, .. } => return mkpat(subpattern), PatKind::Binding { subpattern: Some(subpat), .. } => return mkpat(subpat), PatKind::Binding { subpattern: None, .. } | PatKind::Wild => { @@ -1342,9 +1346,9 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { fields = Fields::singleton(cx, pat); } ty::Adt(adt, _) => { - ctor = match pat.kind.as_ref() { + ctor = match pat.kind { PatKind::Leaf { .. } => Single, - PatKind::Variant { variant_index, .. } => Variant(*variant_index), + PatKind::Variant { variant_index, .. } => Variant(variant_index), _ => bug!(), }; let variant = &adt.variant(ctor.variant_index_for_adt(*adt)); @@ -1402,7 +1406,7 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { } } } - &PatKind::Range(PatRange { lo, hi, end }) => { + &PatKind::Range(box PatRange { lo, hi, end }) => { let ty = lo.ty(); ctor = if let Some(int_range) = IntRange::from_range( cx.tcx, @@ -1429,7 +1433,8 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { FixedLen(prefix.len() + suffix.len()) }; ctor = Slice(Slice::new(array_len, kind)); - fields = Fields::from_iter(cx, prefix.iter().chain(suffix).map(mkpat)); + fields = + Fields::from_iter(cx, prefix.iter().chain(suffix.iter()).map(|p| mkpat(&*p))); } PatKind::Or { .. } => { ctor = Or; @@ -1442,15 +1447,15 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { pub(crate) fn to_pat(&self, cx: &MatchCheckCtxt<'p, 'tcx>) -> Pat<'tcx> { let is_wildcard = |pat: &Pat<'_>| { - matches!(*pat.kind, PatKind::Binding { subpattern: None, .. } | PatKind::Wild) + matches!(pat.kind, PatKind::Binding { subpattern: None, .. } | PatKind::Wild) }; - let mut subpatterns = self.iter_fields().map(|p| p.to_pat(cx)); - let pat = match &self.ctor { + let mut subpatterns = self.iter_fields().map(|p| Box::new(p.to_pat(cx))); + let kind = match &self.ctor { Single | Variant(_) => match self.ty.kind() { ty::Tuple(..) => PatKind::Leaf { subpatterns: subpatterns .enumerate() - .map(|(i, p)| FieldPat { field: Field::new(i), pattern: p }) + .map(|(i, pattern)| FieldPat { field: Field::new(i), pattern }) .collect(), }, ty::Adt(adt_def, _) if adt_def.is_box() => { @@ -1485,7 +1490,7 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { FixedLen(_) => PatKind::Slice { prefix: subpatterns.collect(), slice: None, - suffix: vec![], + suffix: Box::new([]), }, VarLen(prefix, _) => { let mut subpatterns = subpatterns.peekable(); @@ -1504,14 +1509,18 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { subpatterns.next(); } } - let suffix: Vec<_> = subpatterns.collect(); + let suffix: Box<[_]> = subpatterns.collect(); let wild = Pat::wildcard_from_ty(self.ty); - PatKind::Slice { prefix, slice: Some(wild), suffix } + PatKind::Slice { + prefix: prefix.into_boxed_slice(), + slice: Some(Box::new(wild)), + suffix, + } } } } &Str(value) => PatKind::Constant { value }, - &FloatRange(lo, hi, end) => PatKind::Range(PatRange { lo, hi, end }), + &FloatRange(lo, hi, end) => PatKind::Range(Box::new(PatRange { lo, hi, end })), IntRange(range) => return range.to_pat(cx.tcx, self.ty), Wildcard | NonExhaustive => PatKind::Wild, Missing { .. } => bug!( @@ -1523,7 +1532,7 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> { } }; - Pat { ty: self.ty, span: DUMMY_SP, kind: Box::new(pat) } + Pat { ty: self.ty, span: DUMMY_SP, kind } } pub(super) fn is_or_pat(&self) -> bool { diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs index a13748a2d..0edf6a983 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs @@ -29,27 +29,27 @@ use rustc_span::{Span, Symbol}; use std::cmp::Ordering; #[derive(Clone, Debug)] -pub(crate) enum PatternError { +enum PatternError { AssocConstInPattern(Span), ConstParamInPattern(Span), StaticInPattern(Span), NonConstPath(Span), } -pub(crate) struct PatCtxt<'a, 'tcx> { - pub(crate) tcx: TyCtxt<'tcx>, - pub(crate) param_env: ty::ParamEnv<'tcx>, - pub(crate) typeck_results: &'a ty::TypeckResults<'tcx>, - pub(crate) errors: Vec<PatternError>, +struct PatCtxt<'a, 'tcx> { + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + typeck_results: &'a ty::TypeckResults<'tcx>, + errors: Vec<PatternError>, include_lint_checks: bool, } -pub(crate) fn pat_from_hir<'a, 'tcx>( +pub(super) fn pat_from_hir<'a, 'tcx>( tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, typeck_results: &'a ty::TypeckResults<'tcx>, pat: &'tcx hir::Pat<'tcx>, -) -> Pat<'tcx> { +) -> Box<Pat<'tcx>> { let mut pcx = PatCtxt::new(tcx, param_env, typeck_results); let result = pcx.lower_pattern(pat); if !pcx.errors.is_empty() { @@ -61,7 +61,7 @@ pub(crate) fn pat_from_hir<'a, 'tcx>( } impl<'a, 'tcx> PatCtxt<'a, 'tcx> { - pub(crate) fn new( + fn new( tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, typeck_results: &'a ty::TypeckResults<'tcx>, @@ -69,12 +69,12 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { PatCtxt { tcx, param_env, typeck_results, errors: vec![], include_lint_checks: false } } - pub(crate) fn include_lint_checks(&mut self) -> &mut Self { + fn include_lint_checks(&mut self) -> &mut Self { self.include_lint_checks = true; self } - pub(crate) fn lower_pattern(&mut self, pat: &'tcx hir::Pat<'tcx>) -> Pat<'tcx> { + fn lower_pattern(&mut self, pat: &'tcx hir::Pat<'tcx>) -> Box<Pat<'tcx>> { // When implicit dereferences have been inserted in this pattern, the unadjusted lowered // pattern has the type that results *after* dereferencing. For example, in this code: // @@ -97,13 +97,13 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { let unadjusted_pat = self.lower_pattern_unadjusted(pat); self.typeck_results.pat_adjustments().get(pat.hir_id).unwrap_or(&vec![]).iter().rev().fold( unadjusted_pat, - |pat, ref_ty| { + |pat: Box<_>, ref_ty| { debug!("{:?}: wrapping pattern with type {:?}", pat, ref_ty); - Pat { + Box::new(Pat { span: pat.span, ty: *ref_ty, - kind: Box::new(PatKind::Deref { subpattern: pat }), - } + kind: PatKind::Deref { subpattern: pat }, + }) }, ) } @@ -113,7 +113,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { expr: &'tcx hir::Expr<'tcx>, ) -> (PatKind<'tcx>, Option<Ascription<'tcx>>) { match self.lower_lit(expr) { - PatKind::AscribeUserType { ascription, subpattern: Pat { kind: box kind, .. } } => { + PatKind::AscribeUserType { ascription, subpattern: box Pat { kind, .. } } => { (kind, Some(ascription)) } kind => (kind, None), @@ -134,7 +134,9 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { match (end, cmp) { // `x..y` where `x < y`. // Non-empty because the range includes at least `x`. - (RangeEnd::Excluded, Some(Ordering::Less)) => PatKind::Range(PatRange { lo, hi, end }), + (RangeEnd::Excluded, Some(Ordering::Less)) => { + PatKind::Range(Box::new(PatRange { lo, hi, end })) + } // `x..y` where `x >= y`. The range is empty => error. (RangeEnd::Excluded, _) => { struct_span_err!( @@ -149,7 +151,9 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { // `x..=y` where `x == y`. (RangeEnd::Included, Some(Ordering::Equal)) => PatKind::Constant { value: lo }, // `x..=y` where `x < y`. - (RangeEnd::Included, Some(Ordering::Less)) => PatKind::Range(PatRange { lo, hi, end }), + (RangeEnd::Included, Some(Ordering::Less)) => { + PatKind::Range(Box::new(PatRange { lo, hi, end })) + } // `x..=y` where `x > y` hence the range is empty => error. (RangeEnd::Included, _) => { let mut err = struct_span_err!( @@ -196,8 +200,9 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { } } - fn lower_pattern_unadjusted(&mut self, pat: &'tcx hir::Pat<'tcx>) -> Pat<'tcx> { + fn lower_pattern_unadjusted(&mut self, pat: &'tcx hir::Pat<'tcx>) -> Box<Pat<'tcx>> { let mut ty = self.typeck_results.node_type(pat.hir_id); + let mut span = pat.span; let kind = match pat.kind { hir::PatKind::Wild => PatKind::Wild, @@ -228,7 +233,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { // constants somewhere. Have them on the range pattern. for end in &[lo, hi] { if let Some((_, Some(ascription))) = end { - let subpattern = Pat { span: pat.span, ty, kind: Box::new(kind) }; + let subpattern = Box::new(Pat { span: pat.span, ty, kind }); kind = PatKind::AscribeUserType { ascription: ascription.clone(), subpattern }; } @@ -258,6 +263,10 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { } hir::PatKind::Binding(_, id, ident, ref sub) => { + if let Some(ident_span) = ident.span.find_ancestor_inside(span) { + span = span.with_hi(ident_span.hi()); + } + let bm = *self .typeck_results .pat_binding_modes() @@ -322,14 +331,14 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { hir::PatKind::Or(ref pats) => PatKind::Or { pats: self.lower_patterns(pats) }, }; - Pat { span: pat.span, ty, kind: Box::new(kind) } + Box::new(Pat { span, ty, kind }) } fn lower_tuple_subpats( &mut self, pats: &'tcx [hir::Pat<'tcx>], expected_len: usize, - gap_pos: Option<usize>, + gap_pos: hir::DotDotPos, ) -> Vec<FieldPat<'tcx>> { pats.iter() .enumerate_and_adjust(expected_len, gap_pos) @@ -340,11 +349,14 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { .collect() } - fn lower_patterns(&mut self, pats: &'tcx [hir::Pat<'tcx>]) -> Vec<Pat<'tcx>> { + fn lower_patterns(&mut self, pats: &'tcx [hir::Pat<'tcx>]) -> Box<[Box<Pat<'tcx>>]> { pats.iter().map(|p| self.lower_pattern(p)).collect() } - fn lower_opt_pattern(&mut self, pat: &'tcx Option<&'tcx hir::Pat<'tcx>>) -> Option<Pat<'tcx>> { + fn lower_opt_pattern( + &mut self, + pat: &'tcx Option<&'tcx hir::Pat<'tcx>>, + ) -> Option<Box<Pat<'tcx>>> { pat.as_ref().map(|p| self.lower_pattern(p)) } @@ -436,12 +448,12 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { if let Some(user_ty) = self.user_substs_applied_to_ty_of_hir_id(hir_id) { debug!("lower_variant_or_leaf: kind={:?} user_ty={:?} span={:?}", kind, user_ty, span); let annotation = CanonicalUserTypeAnnotation { - user_ty, + user_ty: Box::new(user_ty), span, inferred_ty: self.typeck_results.node_type(hir_id), }; kind = PatKind::AscribeUserType { - subpattern: Pat { span, ty, kind: Box::new(kind) }, + subpattern: Box::new(Pat { span, ty, kind }), ascription: Ascription { annotation, variance: ty::Variance::Covariant }, }; } @@ -453,11 +465,11 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { /// it to `const_to_pat`. Any other path (like enum variants without fields) /// is converted to the corresponding pattern via `lower_variant_or_leaf`. #[instrument(skip(self), level = "debug")] - fn lower_path(&mut self, qpath: &hir::QPath<'_>, id: hir::HirId, span: Span) -> Pat<'tcx> { + fn lower_path(&mut self, qpath: &hir::QPath<'_>, id: hir::HirId, span: Span) -> Box<Pat<'tcx>> { let ty = self.typeck_results.node_type(id); let res = self.typeck_results.qpath_res(qpath, id); - let pat_from_kind = |kind| Pat { span, ty, kind: Box::new(kind) }; + let pat_from_kind = |kind| Box::new(Pat { span, ty, kind }); let (def_id, is_associated_const) = match res { Res::Def(DefKind::Const, def_id) => (def_id, false), @@ -469,7 +481,12 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { // Use `Reveal::All` here because patterns are always monomorphic even if their function // isn't. let param_env_reveal_all = self.param_env.with_reveal_all_normalized(self.tcx); - let substs = self.typeck_results.node_substs(id); + // N.B. There is no guarantee that substs collected in typeck results are fully normalized, + // so they need to be normalized in order to pass to `Instance::resolve`, which will ICE + // if given unnormalized types. + let substs = self + .tcx + .normalize_erasing_regions(param_env_reveal_all, self.typeck_results.node_substs(id)); let instance = match ty::Instance::resolve(self.tcx, param_env_reveal_all, def_id, substs) { Ok(Some(i)) => i, Ok(None) => { @@ -505,13 +522,13 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { let user_provided_types = self.typeck_results().user_provided_types(); if let Some(&user_ty) = user_provided_types.get(id) { let annotation = CanonicalUserTypeAnnotation { - user_ty, + user_ty: Box::new(user_ty), span, inferred_ty: self.typeck_results().node_type(id), }; - Pat { + Box::new(Pat { span, - kind: Box::new(PatKind::AscribeUserType { + kind: PatKind::AscribeUserType { subpattern: pattern, ascription: Ascription { annotation, @@ -519,9 +536,9 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { /// `variance` field documentation for details. variance: ty::Variance::Contravariant, }, - }), + }, ty: const_.ty(), - } + }) } else { pattern } @@ -553,23 +570,19 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { let value = value.eval(self.tcx, self.param_env); match value { - mir::ConstantKind::Ty(c) => { - match c.kind() { - ConstKind::Param(_) => { - self.errors.push(PatternError::ConstParamInPattern(span)); - return PatKind::Wild; - } - ConstKind::Unevaluated(_) => { - // If we land here it means the const can't be evaluated because it's `TooGeneric`. - self.tcx - .sess - .span_err(span, "constant pattern depends on a generic parameter"); - return PatKind::Wild; - } - _ => bug!("Expected either ConstKind::Param or ConstKind::Unevaluated"), + mir::ConstantKind::Ty(c) => match c.kind() { + ConstKind::Param(_) => { + self.errors.push(PatternError::ConstParamInPattern(span)); + return PatKind::Wild; } + _ => bug!("Expected ConstKind::Param"), + }, + mir::ConstantKind::Val(_, _) => self.const_to_pat(value, id, span, false).kind, + mir::ConstantKind::Unevaluated(..) => { + // If we land here it means the const can't be evaluated because it's `TooGeneric`. + self.tcx.sess.span_err(span, "constant pattern depends on a generic parameter"); + return PatKind::Wild; } - mir::ConstantKind::Val(_, _) => *self.const_to_pat(value, id, span, false).kind, } } @@ -580,7 +593,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { fn lower_lit(&mut self, expr: &'tcx hir::Expr<'tcx>) -> PatKind<'tcx> { let (lit, neg) = match expr.kind { hir::ExprKind::Path(ref qpath) => { - return *self.lower_path(qpath, expr.hir_id, expr.span).kind; + return self.lower_path(qpath, expr.hir_id, expr.span).kind; } hir::ExprKind::ConstBlock(ref anon_const) => { return self.lower_inline_const(anon_const, expr.hir_id, expr.span); @@ -598,7 +611,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { let lit_input = LitToConstInput { lit: &lit.node, ty: self.typeck_results.expr_ty(expr), neg }; match self.tcx.at(expr.span).lit_to_mir_constant(lit_input) { - Ok(constant) => *self.const_to_pat(constant, expr.hir_id, lit.span, false).kind, + Ok(constant) => self.const_to_pat(constant, expr.hir_id, lit.span, false).kind, Err(LitToConstError::Reported) => PatKind::Wild, Err(LitToConstError::TypeError) => bug!("lower_lit: had type error"), } @@ -615,7 +628,7 @@ impl<'tcx> UserAnnotatedTyHelpers<'tcx> for PatCtxt<'_, 'tcx> { } } -pub(crate) trait PatternFoldable<'tcx>: Sized { +trait PatternFoldable<'tcx>: Sized { fn fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self { self.super_fold_with(folder) } @@ -623,7 +636,7 @@ pub(crate) trait PatternFoldable<'tcx>: Sized { fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self; } -pub(crate) trait PatternFolder<'tcx>: Sized { +trait PatternFolder<'tcx>: Sized { fn fold_pattern(&mut self, pattern: &Pat<'tcx>) -> Pat<'tcx> { pattern.super_fold_with(self) } @@ -646,6 +659,12 @@ impl<'tcx, T: PatternFoldable<'tcx>> PatternFoldable<'tcx> for Vec<T> { } } +impl<'tcx, T: PatternFoldable<'tcx>> PatternFoldable<'tcx> for Box<[T]> { + fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self { + self.iter().map(|t| t.fold_with(folder)).collect() + } +} + impl<'tcx, T: PatternFoldable<'tcx>> PatternFoldable<'tcx> for Option<T> { fn super_fold_with<F: PatternFolder<'tcx>>(&self, folder: &mut F) -> Self { self.as_ref().map(|t| t.fold_with(folder)) @@ -732,7 +751,7 @@ impl<'tcx> PatternFoldable<'tcx> for PatKind<'tcx> { PatKind::Deref { subpattern: subpattern.fold_with(folder) } } PatKind::Constant { value } => PatKind::Constant { value }, - PatKind::Range(range) => PatKind::Range(range), + PatKind::Range(ref range) => PatKind::Range(range.clone()), PatKind::Slice { ref prefix, ref slice, ref suffix } => PatKind::Slice { prefix: prefix.fold_with(folder), slice: slice.fold_with(folder), diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs index 0a660ef30..115d34ff8 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs @@ -364,8 +364,8 @@ impl<'a, 'p, 'tcx> fmt::Debug for PatCtxt<'a, 'p, 'tcx> { /// A row of a matrix. Rows of len 1 are very common, which is why `SmallVec[_; 2]` /// works well. #[derive(Clone)] -struct PatStack<'p, 'tcx> { - pats: SmallVec<[&'p DeconstructedPat<'p, 'tcx>; 2]>, +pub(crate) struct PatStack<'p, 'tcx> { + pub(crate) pats: SmallVec<[&'p DeconstructedPat<'p, 'tcx>; 2]>, } impl<'p, 'tcx> PatStack<'p, 'tcx> { @@ -403,6 +403,21 @@ impl<'p, 'tcx> PatStack<'p, 'tcx> { }) } + // Recursively expand all patterns into their subpatterns and push each `PatStack` to matrix. + fn expand_and_extend<'a>(&'a self, matrix: &mut Matrix<'p, 'tcx>) { + if !self.is_empty() && self.head().is_or_pat() { + for pat in self.head().iter_fields() { + let mut new_patstack = PatStack::from_pattern(pat); + new_patstack.pats.extend_from_slice(&self.pats[1..]); + if !new_patstack.is_empty() && new_patstack.head().is_or_pat() { + new_patstack.expand_and_extend(matrix); + } else if !new_patstack.is_empty() { + matrix.push(new_patstack); + } + } + } + } + /// This computes `S(self.head().ctor(), self)`. See top of the file for explanations. /// /// Structure patterns with a partial wild pattern (Foo { a: 42, .. }) have their missing @@ -436,7 +451,7 @@ impl<'p, 'tcx> fmt::Debug for PatStack<'p, 'tcx> { /// A 2D matrix. #[derive(Clone)] pub(super) struct Matrix<'p, 'tcx> { - patterns: Vec<PatStack<'p, 'tcx>>, + pub patterns: Vec<PatStack<'p, 'tcx>>, } impl<'p, 'tcx> Matrix<'p, 'tcx> { @@ -453,7 +468,7 @@ impl<'p, 'tcx> Matrix<'p, 'tcx> { /// expands it. fn push(&mut self, row: PatStack<'p, 'tcx>) { if !row.is_empty() && row.head().is_or_pat() { - self.patterns.extend(row.expand_or_pat()); + row.expand_and_extend(self); } else { self.patterns.push(row); } @@ -739,8 +754,8 @@ fn lint_non_exhaustive_omitted_patterns<'p, 'tcx>( hir_id: HirId, witnesses: Vec<DeconstructedPat<'p, 'tcx>>, ) { - let joined_patterns = joined_uncovered_patterns(cx, &witnesses); cx.tcx.struct_span_lint_hir(NON_EXHAUSTIVE_OMITTED_PATTERNS, hir_id, sp, |build| { + let joined_patterns = joined_uncovered_patterns(cx, &witnesses); let mut lint = build.build("some variants are not matched explicitly"); lint.span_label(sp, pattern_not_covered_label(&witnesses, &joined_patterns)); lint.help( @@ -776,7 +791,7 @@ fn lint_non_exhaustive_omitted_patterns<'p, 'tcx>( /// `is_under_guard` is used to inform if the pattern has a guard. If it /// has one it must not be inserted into the matrix. This shouldn't be /// relied on for soundness. -#[instrument(level = "debug", skip(cx, matrix, hir_id))] +#[instrument(level = "debug", skip(cx, matrix, hir_id), ret)] fn is_useful<'p, 'tcx>( cx: &MatchCheckCtxt<'p, 'tcx>, matrix: &Matrix<'p, 'tcx>, @@ -902,7 +917,6 @@ fn is_useful<'p, 'tcx>( v.head().set_reachable(); } - debug!(?ret); ret } |