diff options
7 files changed, 67 insertions, 56 deletions
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs index f7b98d935d4..1056644b813 100644 --- a/compiler/rustc_middle/src/thir.rs +++ b/compiler/rustc_middle/src/thir.rs @@ -783,8 +783,12 @@ pub enum PatKind<'tcx> { var: LocalVarId, ty: Ty<'tcx>, subpattern: Option<Box<Pat<'tcx>>>, + /// Is this the leftmost occurrence of the binding, i.e., is `var` the /// `HirId` of this pattern? + /// + /// (The same binding can occur multiple times in different branches of + /// an or-pattern, but only one of them will be primary.) is_primary: bool, }, diff --git a/compiler/rustc_mir_build/src/builder/block.rs b/compiler/rustc_mir_build/src/builder/block.rs index 7c76e02fcef..a71196f79d7 100644 --- a/compiler/rustc_mir_build/src/builder/block.rs +++ b/compiler/rustc_mir_build/src/builder/block.rs @@ -199,19 +199,15 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { None, Some((Some(&destination), initializer_span)), ); - this.visit_primary_bindings( - pattern, - UserTypeProjections::none(), - &mut |this, _, _, node, span, _, _| { - this.storage_live_binding( - block, - node, - span, - OutsideGuard, - ScheduleDrops::Yes, - ); - }, - ); + this.visit_primary_bindings(pattern, &mut |this, node, span| { + this.storage_live_binding( + block, + node, + span, + OutsideGuard, + ScheduleDrops::Yes, + ); + }); let else_block_span = this.thir[*else_block].span; let (matching, failure) = this.in_if_then_scope(last_remainder_scope, else_block_span, |this| { @@ -295,20 +291,16 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { }); debug!("ast_block_stmts: pattern={:?}", pattern); - this.visit_primary_bindings( - pattern, - UserTypeProjections::none(), - &mut |this, _, _, node, span, _, _| { - this.storage_live_binding( - block, - node, - span, - OutsideGuard, - ScheduleDrops::Yes, - ); - this.schedule_drop_for_binding(node, span, OutsideGuard); - }, - ) + this.visit_primary_bindings(pattern, &mut |this, node, span| { + this.storage_live_binding( + block, + node, + span, + OutsideGuard, + ScheduleDrops::Yes, + ); + this.schedule_drop_for_binding(node, span, OutsideGuard); + }) } // Enter the visibility scope, after evaluating the initializer. diff --git a/compiler/rustc_mir_build/src/builder/matches/mod.rs b/compiler/rustc_mir_build/src/builder/matches/mod.rs index 89faf705d19..60cd8a2c89c 100644 --- a/compiler/rustc_mir_build/src/builder/matches/mod.rs +++ b/compiler/rustc_mir_build/src/builder/matches/mod.rs @@ -755,7 +755,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { guard: Option<ExprId>, opt_match_place: Option<(Option<&Place<'tcx>>, Span)>, ) -> Option<SourceScope> { - self.visit_primary_bindings( + self.visit_primary_bindings_special( pattern, UserTypeProjections::none(), &mut |this, name, mode, var, span, ty, user_ty| { @@ -846,12 +846,34 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } } - /// Visit all of the primary bindings in a patterns, that is, visit the - /// leftmost occurrence of each variable bound in a pattern. A variable - /// will occur more than once in an or-pattern. + /// Visits all of the "primary" bindings in a pattern, i.e. the leftmost + /// occurrence of each variable bound by the pattern. + /// See [`PatKind::Binding::is_primary`] for more context. + /// + /// This variant provides only the limited subset of binding data needed + /// by its callers, and should be a "pure" visit without side-effects. pub(super) fn visit_primary_bindings( &mut self, pattern: &Pat<'tcx>, + f: &mut impl FnMut(&mut Self, LocalVarId, Span), + ) { + pattern.walk_always(|pat| { + if let PatKind::Binding { var, is_primary: true, .. } = pat.kind { + f(self, var, pat.span); + } + }) + } + + /// Visits all of the "primary" bindings in a pattern, while preparing + /// additional user-type-annotation data needed by `declare_bindings`. + /// + /// This also has the side-effect of pushing all user type annotations + /// onto `canonical_user_type_annotations`, so that they end up in MIR + /// even if they aren't associated with any bindings. + #[instrument(level = "debug", skip(self, f))] + fn visit_primary_bindings_special( + &mut self, + pattern: &Pat<'tcx>, pattern_user_ty: UserTypeProjections, f: &mut impl FnMut( &mut Self, @@ -863,17 +885,18 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { UserTypeProjections, ), ) { - debug!( - "visit_primary_bindings: pattern={:?} pattern_user_ty={:?}", - pattern, pattern_user_ty - ); + // Avoid having to write the full method name at each recursive call. + let visit_subpat = |this: &mut Self, subpat, user_tys, f: &mut _| { + this.visit_primary_bindings_special(subpat, user_tys, f) + }; + match pattern.kind { PatKind::Binding { name, mode, var, ty, ref subpattern, is_primary, .. } => { if is_primary { f(self, name, mode, var, pattern.span, ty, pattern_user_ty.clone()); } if let Some(subpattern) = subpattern.as_ref() { - self.visit_primary_bindings(subpattern, pattern_user_ty, f); + visit_subpat(self, subpattern, pattern_user_ty, f); } } @@ -882,17 +905,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let from = u64::try_from(prefix.len()).unwrap(); let to = u64::try_from(suffix.len()).unwrap(); for subpattern in prefix.iter() { - self.visit_primary_bindings(subpattern, pattern_user_ty.clone().index(), f); + visit_subpat(self, subpattern, pattern_user_ty.clone().index(), f); } if let Some(subpattern) = slice { - self.visit_primary_bindings( - subpattern, - pattern_user_ty.clone().subslice(from, to), - f, - ); + visit_subpat(self, subpattern, pattern_user_ty.clone().subslice(from, to), f); } for subpattern in suffix.iter() { - self.visit_primary_bindings(subpattern, pattern_user_ty.clone().index(), f); + visit_subpat(self, subpattern, pattern_user_ty.clone().index(), f); } } @@ -903,11 +922,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { | PatKind::Error(_) => {} PatKind::Deref { ref subpattern } => { - self.visit_primary_bindings(subpattern, pattern_user_ty.deref(), f); + visit_subpat(self, subpattern, pattern_user_ty.deref(), f); } PatKind::DerefPattern { ref subpattern, .. } => { - self.visit_primary_bindings(subpattern, UserTypeProjections::none(), f); + visit_subpat(self, subpattern, UserTypeProjections::none(), f); } PatKind::AscribeUserType { @@ -925,18 +944,18 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let base_user_ty = self.canonical_user_type_annotations.push(annotation.clone()); let subpattern_user_ty = pattern_user_ty.push_user_type(base_user_ty); - self.visit_primary_bindings(subpattern, subpattern_user_ty, f) + visit_subpat(self, subpattern, subpattern_user_ty, f) } PatKind::ExpandedConstant { ref subpattern, .. } => { - self.visit_primary_bindings(subpattern, pattern_user_ty, f) + visit_subpat(self, subpattern, pattern_user_ty, f) } PatKind::Leaf { ref subpatterns } => { for subpattern in subpatterns { let subpattern_user_ty = pattern_user_ty.clone().leaf(subpattern.field); debug!("visit_primary_bindings: subpattern_user_ty={:?}", subpattern_user_ty); - self.visit_primary_bindings(&subpattern.pattern, subpattern_user_ty, f); + visit_subpat(self, &subpattern.pattern, subpattern_user_ty, f); } } @@ -944,7 +963,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { for subpattern in subpatterns { let subpattern_user_ty = pattern_user_ty.clone().variant(adt_def, variant_index, subpattern.field); - self.visit_primary_bindings(&subpattern.pattern, subpattern_user_ty, f); + visit_subpat(self, &subpattern.pattern, subpattern_user_ty, f); } } PatKind::Or { ref pats } => { @@ -953,7 +972,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // `let (x | y) = ...`, the primary binding of `y` occurs in // the right subpattern for subpattern in pats.iter() { - self.visit_primary_bindings(subpattern, pattern_user_ty.clone(), f); + visit_subpat(self, subpattern, pattern_user_ty.clone(), f); } } } diff --git a/tests/mir-opt/building/user_type_annotations.let_else.built.after.mir b/tests/mir-opt/building/user_type_annotations.let_else.built.after.mir index 4029930c855..3a515787c10 100644 --- a/tests/mir-opt/building/user_type_annotations.let_else.built.after.mir +++ b/tests/mir-opt/building/user_type_annotations.let_else.built.after.mir @@ -3,7 +3,6 @@ | User Type Annotations | 0: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:35:20: 35:45, inferred_ty: (u32, u64, &char) | 1: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:35:20: 35:45, inferred_ty: (u32, u64, &char) -| 2: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:35:20: 35:45, inferred_ty: (u32, u64, &char) | fn let_else() -> () { let mut _0: (); @@ -51,7 +50,7 @@ fn let_else() -> () { } bb4: { - AscribeUserType(_5, +, UserTypeProjection { base: UserType(2), projs: [] }); + AscribeUserType(_5, +, UserTypeProjection { base: UserType(1), projs: [] }); _2 = copy (_5.0: u32); _3 = copy (_5.1: u64); _4 = copy (_5.2: &char); diff --git a/tests/mir-opt/building/user_type_annotations.let_else_bindless.built.after.mir b/tests/mir-opt/building/user_type_annotations.let_else_bindless.built.after.mir index ffac242e54e..52a6d904d45 100644 --- a/tests/mir-opt/building/user_type_annotations.let_else_bindless.built.after.mir +++ b/tests/mir-opt/building/user_type_annotations.let_else_bindless.built.after.mir @@ -3,7 +3,6 @@ | User Type Annotations | 0: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:40:20: 40:45, inferred_ty: (u32, u64, &char) | 1: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:40:20: 40:45, inferred_ty: (u32, u64, &char) -| 2: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:40:20: 40:45, inferred_ty: (u32, u64, &char) | fn let_else_bindless() -> () { let mut _0: (); @@ -42,7 +41,7 @@ fn let_else_bindless() -> () { } bb4: { - AscribeUserType(_2, +, UserTypeProjection { base: UserType(2), projs: [] }); + AscribeUserType(_2, +, UserTypeProjection { base: UserType(1), projs: [] }); StorageDead(_4); StorageDead(_2); _0 = const (); diff --git a/tests/mir-opt/building/user_type_annotations.let_uninit.built.after.mir b/tests/mir-opt/building/user_type_annotations.let_uninit.built.after.mir index d86cbc5b192..76b5938b87d 100644 --- a/tests/mir-opt/building/user_type_annotations.let_uninit.built.after.mir +++ b/tests/mir-opt/building/user_type_annotations.let_uninit.built.after.mir @@ -2,7 +2,6 @@ | User Type Annotations | 0: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:15:20: 15:45, inferred_ty: (u32, u64, &char) -| 1: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:15:20: 15:45, inferred_ty: (u32, u64, &char) | fn let_uninit() -> () { let mut _0: (); diff --git a/tests/mir-opt/building/user_type_annotations.let_uninit_bindless.built.after.mir b/tests/mir-opt/building/user_type_annotations.let_uninit_bindless.built.after.mir index a85bdacad23..0cd12558771 100644 --- a/tests/mir-opt/building/user_type_annotations.let_uninit_bindless.built.after.mir +++ b/tests/mir-opt/building/user_type_annotations.let_uninit_bindless.built.after.mir @@ -2,7 +2,6 @@ | User Type Annotations | 0: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:20:20: 20:45, inferred_ty: (u32, u64, &char) -| 1: user_ty: Canonical { value: Ty((u32, u64, &'static char)), max_universe: U0, variables: [] }, span: $DIR/user_type_annotations.rs:20:20: 20:45, inferred_ty: (u32, u64, &char) | fn let_uninit_bindless() -> () { let mut _0: (); |