1 use crate::ty::subst::SubstsRef;
2 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 base: & $($mutability)? PlaceBase<'tcx>,
168 context: PlaceContext,
169 location: Location) {
170 self.super_place_base(base, 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::Len(path) => {
576 PlaceContext::NonMutatingUse(NonMutatingUseContext::Inspect),
581 Rvalue::Cast(_cast_kind, operand, ty) => {
582 self.visit_operand(operand, location);
583 self.visit_ty(ty, TyContext::Location(location));
586 Rvalue::BinaryOp(_bin_op, lhs, rhs)
587 | Rvalue::CheckedBinaryOp(_bin_op, lhs, rhs) => {
588 self.visit_operand(lhs, location);
589 self.visit_operand(rhs, location);
592 Rvalue::UnaryOp(_un_op, op) => {
593 self.visit_operand(op, location);
596 Rvalue::Discriminant(place) => {
599 PlaceContext::NonMutatingUse(NonMutatingUseContext::Inspect),
604 Rvalue::NullaryOp(_op, ty) => {
605 self.visit_ty(ty, TyContext::Location(location));
608 Rvalue::Aggregate(kind, operands) => {
609 let kind = &$($mutability)? **kind;
611 AggregateKind::Array(ty) => {
612 self.visit_ty(ty, TyContext::Location(location));
614 AggregateKind::Tuple => {
623 self.visit_substs(substs, location);
625 AggregateKind::Closure(
629 self.visit_substs(closure_substs, location);
631 AggregateKind::Generator(
636 self.visit_substs(generator_substs, location);
640 for operand in operands {
641 self.visit_operand(operand, location);
647 fn super_operand(&mut self,
648 operand: & $($mutability)? Operand<'tcx>,
649 location: Location) {
651 Operand::Copy(place) => {
654 PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
658 Operand::Move(place) => {
661 PlaceContext::NonMutatingUse(NonMutatingUseContext::Move),
665 Operand::Constant(constant) => {
666 self.visit_constant(constant, location);
671 fn super_ascribe_user_ty(&mut self,
672 place: & $($mutability)? Place<'tcx>,
673 _variance: & $($mutability)? ty::Variance,
674 user_ty: & $($mutability)? UserTypeProjection,
675 location: Location) {
678 PlaceContext::NonUse(NonUseContext::AscribeUserTy),
681 self.visit_user_type_projection(user_ty);
684 fn super_retag(&mut self,
685 _kind: & $($mutability)? RetagKind,
686 place: & $($mutability)? Place<'tcx>,
687 location: Location) {
690 PlaceContext::MutatingUse(MutatingUseContext::Retag),
695 fn super_place_base(&mut self,
696 place_base: & $($mutability)? PlaceBase<'tcx>,
697 context: PlaceContext,
698 location: Location) {
700 PlaceBase::Local(local) => {
701 self.visit_local(local, context, location);
703 PlaceBase::Static(box Static { kind: _, ty, def_id: _ }) => {
704 self.visit_ty(& $($mutability)? *ty, TyContext::Location(location));
709 fn super_local_decl(&mut self,
711 local_decl: & $($mutability)? LocalDecl<'tcx>) {
722 self.visit_ty(ty, TyContext::LocalDecl {
724 source_info: *source_info,
726 for (user_ty, _) in & $($mutability)? user_ty.contents {
727 self.visit_user_type_projection(user_ty);
729 self.visit_source_info(source_info);
732 fn super_var_debug_info(&mut self,
733 var_debug_info: & $($mutability)? VarDebugInfo<'tcx>) {
740 self.visit_source_info(source_info);
741 let location = START_BLOCK.start_location();
744 PlaceContext::NonUse(NonUseContext::VarDebugInfo),
749 fn super_source_scope(&mut self,
750 _scope: & $($mutability)? SourceScope) {
753 fn super_constant(&mut self,
754 constant: & $($mutability)? Constant<'tcx>,
755 location: Location) {
762 self.visit_span(span);
763 drop(user_ty); // no visit method for this
764 self.visit_const(literal, location);
767 fn super_span(&mut self, _span: & $($mutability)? Span) {
770 fn super_source_info(&mut self, source_info: & $($mutability)? SourceInfo) {
776 self.visit_span(span);
777 self.visit_source_scope(scope);
780 fn super_user_type_projection(
782 _ty: & $($mutability)? UserTypeProjection,
786 fn super_user_type_annotation(
788 _index: UserTypeAnnotationIndex,
789 ty: & $($mutability)? CanonicalUserTypeAnnotation<'tcx>,
791 self.visit_span(& $($mutability)? ty.span);
792 self.visit_ty(& $($mutability)? ty.inferred_ty, TyContext::UserTy(ty.span));
795 fn super_ty(&mut self, _ty: $(& $mutability)? Ty<'tcx>) {
798 fn super_region(&mut self, _region: & $($mutability)? ty::Region<'tcx>) {
801 fn super_const(&mut self, _const: & $($mutability)? &'tcx ty::Const<'tcx>) {
804 fn super_substs(&mut self, _substs: & $($mutability)? SubstsRef<'tcx>) {
807 // Convenience methods
811 body: body_cache_type!($($mutability)? '_, 'tcx),
814 let basic_block = & $($mutability)? body[location.block];
815 if basic_block.statements.len() == location.statement_index {
816 if let Some(ref $($mutability)? terminator) = basic_block.terminator {
817 self.visit_terminator(terminator, location)
820 let statement = & $($mutability)?
821 basic_block.statements[location.statement_index];
822 self.visit_statement(statement, location)
829 macro_rules! visit_place_fns {
831 fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
835 place: &mut Place<'tcx>,
836 context: PlaceContext,
839 self.visit_place_base(&mut place.base, context, location);
841 if let Some(new_projection) = self.process_projection(&place.projection) {
842 place.projection = self.tcx().intern_place_elems(&new_projection);
846 fn process_projection(
848 projection: &'a [PlaceElem<'tcx>],
849 ) -> Option<Vec<PlaceElem<'tcx>>> {
850 let mut projection = Cow::Borrowed(projection);
852 for i in 0..projection.len() {
853 if let Some(elem) = projection.get(i) {
854 if let Some(elem) = self.process_projection_elem(elem) {
855 // This converts the borrowed projection into `Cow::Owned(_)` and returns a
856 // clone of the projection so we can mutate and reintern later.
857 let vec = projection.to_mut();
864 Cow::Borrowed(_) => None,
865 Cow::Owned(vec) => Some(vec),
869 fn process_projection_elem(
871 _elem: &PlaceElem<'tcx>,
872 ) -> Option<PlaceElem<'tcx>> {
880 base: &PlaceBase<'tcx>,
881 projection: &[PlaceElem<'tcx>],
882 context: PlaceContext,
885 self.super_projection(base, projection, context, location);
888 fn visit_projection_elem(
890 base: &PlaceBase<'tcx>,
891 proj_base: &[PlaceElem<'tcx>],
892 elem: &PlaceElem<'tcx>,
893 context: PlaceContext,
896 self.super_projection_elem(base, proj_base, elem, context, location);
902 context: PlaceContext,
905 let mut context = context;
907 if !place.projection.is_empty() {
908 context = if context.is_mutating_use() {
909 PlaceContext::MutatingUse(MutatingUseContext::Projection)
911 PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
915 self.visit_place_base(&place.base, context, location);
917 self.visit_projection(&place.base,
925 base: &PlaceBase<'tcx>,
926 projection: &[PlaceElem<'tcx>],
927 context: PlaceContext,
930 let mut cursor = projection;
931 while let [proj_base @ .., elem] = cursor {
933 self.visit_projection_elem(base, cursor, elem, context, location);
937 fn super_projection_elem(
939 _base: &PlaceBase<'tcx>,
940 _proj_base: &[PlaceElem<'tcx>],
941 elem: &PlaceElem<'tcx>,
942 _context: PlaceContext,
946 ProjectionElem::Field(_field, ty) => {
947 self.visit_ty(ty, TyContext::Location(location));
949 ProjectionElem::Index(local) => {
952 PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
956 ProjectionElem::Deref |
957 ProjectionElem::Subslice { from: _, to: _ } |
958 ProjectionElem::ConstantIndex { offset: _,
961 ProjectionElem::Downcast(_, _) => {
968 make_mir_visitor!(Visitor,);
969 make_mir_visitor!(MutVisitor,mut);
971 pub trait MirVisitable<'tcx> {
972 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>);
975 impl<'tcx> MirVisitable<'tcx> for Statement<'tcx> {
976 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>)
978 visitor.visit_statement(self, location)
982 impl<'tcx> MirVisitable<'tcx> for Terminator<'tcx> {
983 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>)
985 visitor.visit_terminator(self, location)
989 impl<'tcx> MirVisitable<'tcx> for Option<Terminator<'tcx>> {
990 fn apply(&self, location: Location, visitor: &mut dyn Visitor<'tcx>)
992 visitor.visit_terminator(self.as_ref().unwrap(), location)
996 /// Extra information passed to `visit_ty` and friends to give context
997 /// about where the type etc appears.
1001 /// The index of the local variable we are visiting.
1004 /// The source location where this local variable was declared.
1005 source_info: SourceInfo,
1008 /// The inferred type of a user type annotation.
1011 /// The return type of the function.
1012 ReturnTy(SourceInfo),
1014 YieldTy(SourceInfo),
1016 /// A type found at some location.
1020 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1021 pub enum NonMutatingUseContext {
1022 /// Being inspected in some way, like loading a len.
1024 /// Consumed as part of an operand.
1026 /// Consumed as part of an operand.
1034 /// Used as base for another place, e.g., `x` in `x.y`. Will not mutate the place.
1035 /// For example, the projection `x.y` is not marked as a mutation in these cases:
1043 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1044 pub enum MutatingUseContext {
1045 /// Appears as LHS of an assignment.
1047 /// Can often be treated as a `Store`, but needs to be separate because
1048 /// ASM is allowed to read outputs as well, so a `Store`-`AsmOutput` sequence
1049 /// cannot be simplified the way a `Store`-`Store` can be.
1051 /// Destination of a call.
1057 /// Used as base for another place, e.g., `x` in `x.y`. Could potentially mutate the place.
1058 /// For example, the projection `x.y` is marked as a mutation in these cases:
1064 /// Retagging, a "Stacked Borrows" shadow state operation
1068 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1069 pub enum NonUseContext {
1070 /// Starting a storage live range.
1072 /// Ending a storage live range.
1074 /// User type annotation assertions for NLL.
1076 /// The data of an user variable, for debug info.
1080 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
1081 pub enum PlaceContext {
1082 NonMutatingUse(NonMutatingUseContext),
1083 MutatingUse(MutatingUseContext),
1084 NonUse(NonUseContext),
1088 /// Returns `true` if this place context represents a drop.
1089 pub fn is_drop(&self) -> bool {
1091 PlaceContext::MutatingUse(MutatingUseContext::Drop) => true,
1096 /// Returns `true` if this place context represents a borrow.
1097 pub fn is_borrow(&self) -> bool {
1099 PlaceContext::NonMutatingUse(NonMutatingUseContext::SharedBorrow) |
1100 PlaceContext::NonMutatingUse(NonMutatingUseContext::ShallowBorrow) |
1101 PlaceContext::NonMutatingUse(NonMutatingUseContext::UniqueBorrow) |
1102 PlaceContext::MutatingUse(MutatingUseContext::Borrow) => true,
1107 /// Returns `true` if this place context represents a storage live or storage dead marker.
1108 pub fn is_storage_marker(&self) -> bool {
1110 PlaceContext::NonUse(NonUseContext::StorageLive) |
1111 PlaceContext::NonUse(NonUseContext::StorageDead) => true,
1116 /// Returns `true` if this place context represents a storage live marker.
1117 pub fn is_storage_live_marker(&self) -> bool {
1119 PlaceContext::NonUse(NonUseContext::StorageLive) => true,
1124 /// Returns `true` if this place context represents a storage dead marker.
1125 pub fn is_storage_dead_marker(&self) -> bool {
1127 PlaceContext::NonUse(NonUseContext::StorageDead) => true,
1132 /// Returns `true` if this place context represents a use that potentially changes the value.
1133 pub fn is_mutating_use(&self) -> bool {
1135 PlaceContext::MutatingUse(..) => true,
1140 /// Returns `true` if this place context represents a use that does not change the value.
1141 pub fn is_nonmutating_use(&self) -> bool {
1143 PlaceContext::NonMutatingUse(..) => true,
1148 /// Returns `true` if this place context represents a use.
1149 pub fn is_use(&self) -> bool {
1151 PlaceContext::NonUse(..) => false,
1156 /// Returns `true` if this place context represents an assignment statement.
1157 pub fn is_place_assignment(&self) -> bool {
1159 PlaceContext::MutatingUse(MutatingUseContext::Store) |
1160 PlaceContext::MutatingUse(MutatingUseContext::Call) |
1161 PlaceContext::MutatingUse(MutatingUseContext::AsmOutput) => true,