2 use crate::ty::subst::SubstsRef;
3 use crate::ty::{CanonicalUserTypeAnnotation, Ty};
10 // There are two visitors, one for immutable and one for mutable references,
11 // but both are generated by the following macro. The code is written according
12 // to the following conventions:
14 // - introduce a `visit_foo` and a `super_foo` method for every MIR type
15 // - `visit_foo`, by default, calls `super_foo`
16 // - `super_foo`, by default, destructures the `foo` and calls `visit_foo`
18 // This allows you as a user to override `visit_foo` for types are
19 // interested in, and invoke (within that method) call
20 // `self.super_foo` to get the default behavior. Just as in an OO
21 // language, you should never call `super` methods ordinarily except
22 // in that circumstance.
24 // For the most part, we do not destructure things external to the
25 // MIR, e.g., types, spans, etc, but simply visit them and stop. This
26 // avoids duplication with other visitors like `TypeFoldable`.
30 // The code is written in a very deliberate style intended to minimize
31 // the chance of things being overlooked. You'll notice that we always
32 // use pattern matching to reference fields and we ensure that all
33 // matches are exhaustive.
35 // For example, the `super_basic_block_data` method begins like this:
38 // fn super_basic_block_data(&mut self,
40 // data: & $($mutability)? BasicBlockData<'tcx>) {
41 // let BasicBlockData {
47 // for statement in statements {
48 // self.visit_statement(block, statement);
55 // Here we used `let BasicBlockData { <fields> } = *data` deliberately,
56 // rather than writing `data.statements` in the body. This is because if one
57 // adds a new field to `BasicBlockData`, one will be forced to revise this code,
58 // and hence one will (hopefully) invoke the correct visit methods (if any).
60 // For this to work, ALL MATCHES MUST BE EXHAUSTIVE IN FIELDS AND VARIANTS.
61 // That means you never write `..` to skip over fields, nor do you write `_`
62 // to skip over variants in a `match`.
64 // The only place that `_` is acceptable is to match a field (or
65 // variant argument) that does not require visiting, as in
66 // `is_cleanup` above.
68 macro_rules! body_cache_type {
69 (mut $a:lifetime, $tcx:lifetime) => {
70 &mut BodyAndCache<$tcx>
72 ($a:lifetime, $tcx:lifetime) => {
73 ReadOnlyBodyAndCache<$a, $tcx>
77 macro_rules! make_mir_visitor {
78 ($visitor_trait_name:ident, $($mutability:ident)?) => {
79 pub trait $visitor_trait_name<'tcx> {
80 // Override these, and call `self.super_xxx` to revert back to the
85 body: body_cache_type!($($mutability)? '_, 'tcx)
87 self.super_body(body);
90 fn visit_basic_block_data(&mut self,
92 data: & $($mutability)? BasicBlockData<'tcx>) {
93 self.super_basic_block_data(block, data);
96 fn visit_source_scope_data(&mut self,
97 scope_data: & $($mutability)? SourceScopeData) {
98 self.super_source_scope_data(scope_data);
101 fn visit_statement(&mut self,
102 statement: & $($mutability)? Statement<'tcx>,
103 location: Location) {
104 self.super_statement(statement, location);
107 fn visit_assign(&mut self,
108 place: & $($mutability)? Place<'tcx>,
109 rvalue: & $($mutability)? Rvalue<'tcx>,
110 location: Location) {
111 self.super_assign(place, rvalue, location);
114 fn visit_terminator(&mut self,
115 terminator: & $($mutability)? Terminator<'tcx>,
116 location: Location) {
117 self.super_terminator(terminator, location);
120 fn visit_terminator_kind(&mut self,
121 kind: & $($mutability)? TerminatorKind<'tcx>,
122 location: Location) {
123 self.super_terminator_kind(kind, location);
126 fn visit_assert_message(&mut self,
127 msg: & $($mutability)? AssertMessage<'tcx>,
128 location: Location) {
129 self.super_assert_message(msg, location);
132 fn visit_rvalue(&mut self,
133 rvalue: & $($mutability)? Rvalue<'tcx>,
134 location: Location) {
135 self.super_rvalue(rvalue, location);
138 fn visit_operand(&mut self,
139 operand: & $($mutability)? Operand<'tcx>,
140 location: Location) {
141 self.super_operand(operand, location);
144 fn visit_ascribe_user_ty(&mut self,
145 place: & $($mutability)? Place<'tcx>,
146 variance: & $($mutability)? ty::Variance,
147 user_ty: & $($mutability)? UserTypeProjection,
148 location: Location) {
149 self.super_ascribe_user_ty(place, variance, user_ty, location);
152 fn visit_retag(&mut self,
153 kind: & $($mutability)? RetagKind,
154 place: & $($mutability)? Place<'tcx>,
155 location: Location) {
156 self.super_retag(kind, place, location);
159 fn visit_place(&mut self,
160 place: & $($mutability)? Place<'tcx>,
161 context: PlaceContext,
162 location: Location) {
163 self.super_place(place, context, location);
166 fn visit_place_base(&mut self,
167 local: & $($mutability)? Local,
168 context: PlaceContext,
169 location: Location) {
170 self.super_place_base(local, context, location);
173 visit_place_fns!($($mutability)?);
175 fn visit_constant(&mut self,
176 constant: & $($mutability)? Constant<'tcx>,
177 location: Location) {
178 self.super_constant(constant, location);
181 fn visit_span(&mut self,
182 span: & $($mutability)? Span) {
183 self.super_span(span);
186 fn visit_source_info(&mut self,
187 source_info: & $($mutability)? SourceInfo) {
188 self.super_source_info(source_info);
191 fn visit_ty(&mut self,
192 ty: $(& $mutability)? Ty<'tcx>,
197 fn visit_user_type_projection(
199 ty: & $($mutability)? UserTypeProjection,
201 self.super_user_type_projection(ty);
204 fn visit_user_type_annotation(
206 index: UserTypeAnnotationIndex,
207 ty: & $($mutability)? CanonicalUserTypeAnnotation<'tcx>,
209 self.super_user_type_annotation(index, ty);
212 fn visit_region(&mut self,
213 region: & $($mutability)? ty::Region<'tcx>,
215 self.super_region(region);
218 fn visit_const(&mut self,
219 constant: & $($mutability)? &'tcx ty::Const<'tcx>,
221 self.super_const(constant);
224 fn visit_substs(&mut self,
225 substs: & $($mutability)? SubstsRef<'tcx>,
227 self.super_substs(substs);
230 fn visit_local_decl(&mut self,
232 local_decl: & $($mutability)? LocalDecl<'tcx>) {
233 self.super_local_decl(local, local_decl);
236 fn visit_var_debug_info(&mut self,
237 var_debug_info: & $($mutability)* VarDebugInfo<'tcx>) {
238 self.super_var_debug_info(var_debug_info);
241 fn visit_local(&mut self,
242 _local: & $($mutability)? Local,
243 _context: PlaceContext,
244 _location: Location) {
247 fn visit_source_scope(&mut self,
248 scope: & $($mutability)? SourceScope) {
249 self.super_source_scope(scope);
252 // The `super_xxx` methods comprise the default behavior and are
253 // not meant to be overridden.
257 $($mutability)? body: body_cache_type!($($mutability)? '_, 'tcx)
259 let span = body.span;
260 if let Some(yield_ty) = &$($mutability)? body.yield_ty {
261 self.visit_ty(yield_ty, TyContext::YieldTy(SourceInfo {
263 scope: OUTERMOST_SOURCE_SCOPE,
267 // for best performance, we want to use an iterator rather
268 // than a for-loop, to avoid calling `body::Body::invalidate` for
270 macro_rules! basic_blocks {
271 (mut) => (body.basic_blocks_mut().iter_enumerated_mut());
272 () => (body.basic_blocks().iter_enumerated());
274 for (bb, data) in basic_blocks!($($mutability)?) {
275 self.visit_basic_block_data(bb, data);
278 let body: & $($mutability)? Body<'_> = & $($mutability)? body;
279 for scope in &$($mutability)? body.source_scopes {
280 self.visit_source_scope_data(scope);
283 self.visit_ty(&$($mutability)? body.return_ty(), TyContext::ReturnTy(SourceInfo {
285 scope: OUTERMOST_SOURCE_SCOPE,
288 for local in body.local_decls.indices() {
289 self.visit_local_decl(local, & $($mutability)? body.local_decls[local]);
292 macro_rules! type_annotations {
293 (mut) => (body.user_type_annotations.iter_enumerated_mut());
294 () => (body.user_type_annotations.iter_enumerated());
297 for (index, annotation) in type_annotations!($($mutability)?) {
298 self.visit_user_type_annotation(
303 for var_debug_info in &$($mutability)? body.var_debug_info {
304 self.visit_var_debug_info(var_debug_info);
307 self.visit_span(&$($mutability)? body.span);
310 fn super_basic_block_data(&mut self,
312 data: & $($mutability)? BasicBlockData<'tcx>) {
320 for statement in statements {
321 let location = Location { block: block, statement_index: index };
322 self.visit_statement(statement, location);
326 if let Some(terminator) = terminator {
327 let location = Location { block: block, statement_index: index };
328 self.visit_terminator(terminator, location);
332 fn super_source_scope_data(&mut self, scope_data: & $($mutability)? SourceScopeData) {
333 let SourceScopeData {
339 self.visit_span(span);
340 if let Some(parent_scope) = parent_scope {
341 self.visit_source_scope(parent_scope);
345 fn super_statement(&mut self,
346 statement: & $($mutability)? Statement<'tcx>,
347 location: Location) {
353 self.visit_source_info(source_info);
355 StatementKind::Assign(
356 box(ref $($mutability)? place, ref $($mutability)? rvalue)
358 self.visit_assign(place, rvalue, location);
360 StatementKind::FakeRead(_, place) => {
363 PlaceContext::NonMutatingUse(NonMutatingUseContext::Inspect),
367 StatementKind::SetDiscriminant { place, .. } => {
370 PlaceContext::MutatingUse(MutatingUseContext::Store),
374 StatementKind::StorageLive(local) => {
377 PlaceContext::NonUse(NonUseContext::StorageLive),
381 StatementKind::StorageDead(local) => {
384 PlaceContext::NonUse(NonUseContext::StorageDead),
388 StatementKind::InlineAsm(asm) => {
389 for output in & $($mutability)? asm.outputs[..] {
392 PlaceContext::MutatingUse(MutatingUseContext::AsmOutput),
396 for (span, input) in & $($mutability)? asm.inputs[..] {
397 self.visit_span(span);
398 self.visit_operand(input, location);
401 StatementKind::Retag(kind, place) => {
402 self.visit_retag(kind, place, location);
404 StatementKind::AscribeUserType(
405 box(ref $($mutability)? place, ref $($mutability)? user_ty),
408 self.visit_ascribe_user_ty(place, variance, user_ty, location);
410 StatementKind::Nop => {}
414 fn super_assign(&mut self,
415 place: &$($mutability)? Place<'tcx>,
416 rvalue: &$($mutability)? Rvalue<'tcx>,
417 location: Location) {
420 PlaceContext::MutatingUse(MutatingUseContext::Store),
423 self.visit_rvalue(rvalue, location);
426 fn super_terminator(&mut self,
427 terminator: &$($mutability)? Terminator<'tcx>,
428 location: Location) {
429 let Terminator { source_info, kind } = terminator;
431 self.visit_source_info(source_info);
432 self.visit_terminator_kind(kind, location);
435 fn super_terminator_kind(&mut self,
436 kind: & $($mutability)? TerminatorKind<'tcx>,
437 source_location: Location) {
439 TerminatorKind::Goto { .. } |
440 TerminatorKind::Resume |
441 TerminatorKind::Abort |
442 TerminatorKind::Return |
443 TerminatorKind::GeneratorDrop |
444 TerminatorKind::Unreachable |
445 TerminatorKind::FalseEdges { .. } |
446 TerminatorKind::FalseUnwind { .. } => {
449 TerminatorKind::SwitchInt {
455 self.visit_operand(discr, source_location);
456 self.visit_ty(switch_ty, TyContext::Location(source_location));
459 TerminatorKind::Drop {
466 PlaceContext::MutatingUse(MutatingUseContext::Drop),
471 TerminatorKind::DropAndReplace {
479 PlaceContext::MutatingUse(MutatingUseContext::Drop),
482 self.visit_operand(value, source_location);
485 TerminatorKind::Call {
492 self.visit_operand(func, source_location);
494 self.visit_operand(arg, source_location);
496 if let Some((destination, _)) = destination {
499 PlaceContext::MutatingUse(MutatingUseContext::Call),
505 TerminatorKind::Assert {
512 self.visit_operand(cond, source_location);
513 self.visit_assert_message(msg, source_location);
516 TerminatorKind::Yield {
521 self.visit_operand(value, source_location);
527 fn super_assert_message(&mut self,
528 msg: & $($mutability)? AssertMessage<'tcx>,
529 location: Location) {
530 use crate::mir::interpret::PanicInfo::*;
532 BoundsCheck { len, index } => {
533 self.visit_operand(len, location);
534 self.visit_operand(index, location);
536 Panic { .. } | Overflow(_) | OverflowNeg | DivisionByZero | RemainderByZero |
537 ResumedAfterReturn(_) | ResumedAfterPanic(_) => {
543 fn super_rvalue(&mut self,
544 rvalue: & $($mutability)? Rvalue<'tcx>,
545 location: Location) {
547 Rvalue::Use(operand) => {
548 self.visit_operand(operand, location);
551 Rvalue::Repeat(value, _) => {
552 self.visit_operand(value, location);
555 Rvalue::Ref(r, bk, path) => {
556 self.visit_region(r, location);
558 BorrowKind::Shared => PlaceContext::NonMutatingUse(
559 NonMutatingUseContext::SharedBorrow
561 BorrowKind::Shallow => PlaceContext::NonMutatingUse(
562 NonMutatingUseContext::ShallowBorrow
564 BorrowKind::Unique => PlaceContext::NonMutatingUse(
565 NonMutatingUseContext::UniqueBorrow
567 BorrowKind::Mut { .. } =>
568 PlaceContext::MutatingUse(MutatingUseContext::Borrow),
570 self.visit_place(path, ctx, location);
573 Rvalue::AddressOf(m, path) => {
575 Mutability::Mut => PlaceContext::MutatingUse(
576 MutatingUseContext::AddressOf
578 Mutability::Not => PlaceContext::NonMutatingUse(
579 NonMutatingUseContext::AddressOf
582 self.visit_place(path, ctx, location);
585 Rvalue::Len(path) => {
588 PlaceContext::NonMutatingUse(NonMutatingUseContext::Inspect),
593 Rvalue::Cast(_cast_kind, operand, ty) => {
594 self.visit_operand(operand, location);
595 self.visit_ty(ty, TyContext::Location(location));
598 Rvalue::BinaryOp(_bin_op, lhs, rhs)
599 | Rvalue::CheckedBinaryOp(_bin_op, lhs, rhs) => {
600 self.visit_operand(lhs, location);
601 self.visit_operand(rhs, location);
604 Rvalue::UnaryOp(_un_op, op) => {
605 self.visit_operand(op, location);
608 Rvalue::Discriminant(place) => {
611 PlaceContext::NonMutatingUse(NonMutatingUseContext::Inspect),
616 Rvalue::NullaryOp(_op, ty) => {
617 self.visit_ty(ty, TyContext::Location(location));
620 Rvalue::Aggregate(kind, operands) => {
621 let kind = &$($mutability)? **kind;
623 AggregateKind::Array(ty) => {
624 self.visit_ty(ty, TyContext::Location(location));
626 AggregateKind::Tuple => {
635 self.visit_substs(substs, location);
637 AggregateKind::Closure(
641 self.visit_substs(closure_substs, location);
643 AggregateKind::Generator(
648 self.visit_substs(generator_substs, location);
652 for operand in operands {
653 self.visit_operand(operand, location);
659 fn super_operand(&mut self,
660 operand: & $($mutability)? Operand<'tcx>,
661 location: Location) {
663 Operand::Copy(place) => {
666 PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
670 Operand::Move(place) => {
673 PlaceContext::NonMutatingUse(NonMutatingUseContext::Move),
677 Operand::Constant(constant) => {
678 self.visit_constant(constant, location);
683 fn super_ascribe_user_ty(&mut self,
684 place: & $($mutability)? Place<'tcx>,
685 _variance: & $($mutability)? ty::Variance,
686 user_ty: & $($mutability)? UserTypeProjection,
687 location: Location) {
690 PlaceContext::NonUse(NonUseContext::AscribeUserTy),
693 self.visit_user_type_projection(user_ty);
696 fn super_retag(&mut self,
697 _kind: & $($mutability)? RetagKind,
698 place: & $($mutability)? Place<'tcx>,
699 location: Location) {
702 PlaceContext::MutatingUse(MutatingUseContext::Retag),
707 fn super_place_base(&mut self,
708 local: & $($mutability)? Local,
709 context: PlaceContext,
710 location: Location) {
711 self.visit_local(local, context, location);
714 fn super_local_decl(&mut self,
716 local_decl: & $($mutability)? LocalDecl<'tcx>) {
727 self.visit_ty(ty, TyContext::LocalDecl {
729 source_info: *source_info,
731 for (user_ty, _) in & $($mutability)? user_ty.contents {
732 self.visit_user_type_projection(user_ty);
734 self.visit_source_info(source_info);
737 fn super_var_debug_info(&mut self,
738 var_debug_info: & $($mutability)? VarDebugInfo<'tcx>) {
745 self.visit_source_info(source_info);
746 let location = START_BLOCK.start_location();
749 PlaceContext::NonUse(NonUseContext::VarDebugInfo),
754 fn super_source_scope(&mut self,
755 _scope: & $($mutability)? SourceScope) {
758 fn super_constant(&mut self,
759 constant: & $($mutability)? Constant<'tcx>,
760 location: Location) {
767 self.visit_span(span);
768 drop(user_ty); // no visit method for this
769 self.visit_const(literal, location);
772 fn super_span(&mut self, _span: & $($mutability)? Span) {
775 fn super_source_info(&mut self, source_info: & $($mutability)? SourceInfo) {
781 self.visit_span(span);
782 self.visit_source_scope(scope);
785 fn super_user_type_projection(
787 _ty: & $($mutability)? UserTypeProjection,
791 fn super_user_type_annotation(
793 _index: UserTypeAnnotationIndex,
794 ty: & $($mutability)? CanonicalUserTypeAnnotation<'tcx>,
796 self.visit_span(& $($mutability)? ty.span);
797 self.visit_ty(& $($mutability)? ty.inferred_ty, TyContext::UserTy(ty.span));
800 fn super_ty(&mut self, _ty: $(& $mutability)? Ty<'tcx>) {
803 fn super_region(&mut self, _region: & $($mutability)? ty::Region<'tcx>) {
806 fn super_const(&mut self, _const: & $($mutability)? &'tcx ty::Const<'tcx>) {
809 fn super_substs(&mut self, _substs: & $($mutability)? SubstsRef<'tcx>) {
812 // Convenience methods
816 body: body_cache_type!($($mutability)? '_, 'tcx),
819 let basic_block = & $($mutability)? body[location.block];
820 if basic_block.statements.len() == location.statement_index {
821 if let Some(ref $($mutability)? terminator) = basic_block.terminator {
822 self.visit_terminator(terminator, location)
825 let statement = & $($mutability)?
826 basic_block.statements[location.statement_index];
827 self.visit_statement(statement, location)
834 macro_rules! visit_place_fns {
836 fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
840 place: &mut Place<'tcx>,
841 context: PlaceContext,
844 self.visit_place_base(&mut place.local, context, location);
846 if let Some(new_projection) = self.process_projection(&place.projection) {
847 place.projection = self.tcx().intern_place_elems(&new_projection);
851 fn process_projection(
853 projection: &'a [PlaceElem<'tcx>],
854 ) -> Option<Vec<PlaceElem<'tcx>>> {
855 let mut projection = Cow::Borrowed(projection);
857 for i in 0..projection.len() {
858 if let Some(elem) = projection.get(i) {
859 if let Some(elem) = self.process_projection_elem(elem) {
860 // This converts the borrowed projection into `Cow::Owned(_)` and returns a
861 // clone of the projection so we can mutate and reintern later.
862 let vec = projection.to_mut();
869 Cow::Borrowed(_) => None,
870 Cow::Owned(vec) => Some(vec),
874 fn process_projection_elem(
876 _elem: &PlaceElem<'tcx>,
877 ) -> Option<PlaceElem<'tcx>> {
886 projection: &[PlaceElem<'tcx>],
887 context: PlaceContext,
890 self.super_projection(local, projection, context, location);
893 fn visit_projection_elem(
896 proj_base: &[PlaceElem<'tcx>],
897 elem: &PlaceElem<'tcx>,
898 context: PlaceContext,
901 self.super_projection_elem(local, proj_base, elem, context, location);
907 context: PlaceContext,
910 let mut context = context;
912 if !place.projection.is_empty() {
913 context = if context.is_mutating_use() {
914 PlaceContext::MutatingUse(MutatingUseContext::Projection)
916 PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
920 self.visit_place_base(&place.local, context, location);
922 self.visit_projection(&place.local,
931 projection: &[PlaceElem<'tcx>],
932 context: PlaceContext,
935 let mut cursor = projection;
936 while let [proj_base @ .., elem] = cursor {
938 self.visit_projection_elem(local, cursor, elem, context, location);
942 fn super_projection_elem(
945 _proj_base: &[PlaceElem<'tcx>],
946 elem: &PlaceElem<'tcx>,
947 _context: PlaceContext,
951 ProjectionElem::Field(_field, ty) => {
952 self.visit_ty(ty, TyContext::Location(location));
954 ProjectionElem::Index(local) => {
957 PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
961 ProjectionElem::Deref |
962 ProjectionElem::Subslice { from: _, to: _, from_end: _ } |
963 ProjectionElem::ConstantIndex { offset: _,
966 ProjectionElem::Downcast(_, _) => {
973 make_mir_visitor!(Visitor,);
974 make_mir_visitor!(MutVisitor, mut);
976 pub trait MirVisitable<'tcx> {
977 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>);
980 impl<'tcx> MirVisitable<'tcx> for Statement<'tcx> {
981 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>) {
982 visitor.visit_statement(self, location)
986 impl<'tcx> MirVisitable<'tcx> for Terminator<'tcx> {
987 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>) {
988 visitor.visit_terminator(self, location)
992 impl<'tcx> MirVisitable<'tcx> for Option<Terminator<'tcx>> {
993 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>) {
994 visitor.visit_terminator(self.as_ref().unwrap(), location)
998 /// Extra information passed to `visit_ty` and friends to give context
999 /// about where the type etc appears.
1001 pub enum TyContext {
1003 /// The index of the local variable we are visiting.
1006 /// The source location where this local variable was declared.
1007 source_info: SourceInfo,
1010 /// The inferred type of a user type annotation.
1013 /// The return type of the function.
1014 ReturnTy(SourceInfo),
1016 YieldTy(SourceInfo),
1018 /// A type found at some location.
1022 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1023 pub enum NonMutatingUseContext {
1024 /// Being inspected in some way, like loading a len.
1026 /// Consumed as part of an operand.
1028 /// Consumed as part of an operand.
1036 /// AddressOf for *const pointer.
1038 /// Used as base for another place, e.g., `x` in `x.y`. Will not mutate the place.
1039 /// For example, the projection `x.y` is not marked as a mutation in these cases:
1047 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1048 pub enum MutatingUseContext {
1049 /// Appears as LHS of an assignment.
1051 /// Can often be treated as a `Store`, but needs to be separate because
1052 /// ASM is allowed to read outputs as well, so a `Store`-`AsmOutput` sequence
1053 /// cannot be simplified the way a `Store`-`Store` can be.
1055 /// Destination of a call.
1061 /// AddressOf for *mut pointer.
1063 /// Used as base for another place, e.g., `x` in `x.y`. Could potentially mutate the place.
1064 /// For example, the projection `x.y` is marked as a mutation in these cases:
1070 /// Retagging, a "Stacked Borrows" shadow state operation
1074 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1075 pub enum NonUseContext {
1076 /// Starting a storage live range.
1078 /// Ending a storage live range.
1080 /// User type annotation assertions for NLL.
1082 /// The data of an user variable, for debug info.
1086 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1087 pub enum PlaceContext {
1088 NonMutatingUse(NonMutatingUseContext),
1089 MutatingUse(MutatingUseContext),
1090 NonUse(NonUseContext),
1094 /// Returns `true` if this place context represents a drop.
1095 pub fn is_drop(&self) -> bool {
1097 PlaceContext::MutatingUse(MutatingUseContext::Drop) => true,
1102 /// Returns `true` if this place context represents a borrow.
1103 pub fn is_borrow(&self) -> bool {
1105 PlaceContext::NonMutatingUse(NonMutatingUseContext::SharedBorrow)
1106 | PlaceContext::NonMutatingUse(NonMutatingUseContext::ShallowBorrow)
1107 | PlaceContext::NonMutatingUse(NonMutatingUseContext::UniqueBorrow)
1108 | PlaceContext::MutatingUse(MutatingUseContext::Borrow) => true,
1113 /// Returns `true` if this place context represents a storage live or storage dead marker.
1114 pub fn is_storage_marker(&self) -> bool {
1116 PlaceContext::NonUse(NonUseContext::StorageLive)
1117 | PlaceContext::NonUse(NonUseContext::StorageDead) => true,
1122 /// Returns `true` if this place context represents a storage live marker.
1123 pub fn is_storage_live_marker(&self) -> bool {
1125 PlaceContext::NonUse(NonUseContext::StorageLive) => true,
1130 /// Returns `true` if this place context represents a storage dead marker.
1131 pub fn is_storage_dead_marker(&self) -> bool {
1133 PlaceContext::NonUse(NonUseContext::StorageDead) => true,
1138 /// Returns `true` if this place context represents a use that potentially changes the value.
1139 pub fn is_mutating_use(&self) -> bool {
1141 PlaceContext::MutatingUse(..) => true,
1146 /// Returns `true` if this place context represents a use that does not change the value.
1147 pub fn is_nonmutating_use(&self) -> bool {
1149 PlaceContext::NonMutatingUse(..) => true,
1154 /// Returns `true` if this place context represents a use.
1155 pub fn is_use(&self) -> bool {
1157 PlaceContext::NonUse(..) => false,
1162 /// Returns `true` if this place context represents an assignment statement.
1163 pub fn is_place_assignment(&self) -> bool {
1165 PlaceContext::MutatingUse(MutatingUseContext::Store)
1166 | PlaceContext::MutatingUse(MutatingUseContext::Call)
1167 | PlaceContext::MutatingUse(MutatingUseContext::AsmOutput) => true,