Struct rustc_middle::middle::region::Scope
source · pub struct Scope {
pub id: ItemLocalId,
pub data: ScopeData,
}
Expand description
Represents a statically-describable scope that can be used to bound the lifetime/region for values.
Node(node_id)
: Any AST node that has any scope at all has the
Node(node_id)
scope. Other variants represent special cases not
immediately derivable from the abstract syntax tree structure.
DestructionScope(node_id)
represents the scope of destructors
implicitly-attached to node_id
that run immediately after the
expression for node_id
itself. Not every AST node carries a
DestructionScope
, but those that are terminating_scopes
do;
see discussion with ScopeTree
.
Remainder { block, statement_index }
represents
the scope of user code running immediately after the initializer
expression for the indexed statement, until the end of the block.
So: the following code can be broken down into the scopes beneath:
let a = f().g( 'b: { let x = d(); let y = d(); x.h(y) } ) ;
+-+ (D12.)
+-+ (D11.)
+---------+ (R10.)
+-+ (D9.)
+----------+ (M8.)
+----------------------+ (R7.)
+-+ (D6.)
+----------+ (M5.)
+-----------------------------------+ (M4.)
+--------------------------------------------------+ (M3.)
+--+ (M2.)
+-----------------------------------------------------------+ (M1.)
(M1.): Node scope of the whole `let a = ...;` statement.
(M2.): Node scope of the `f()` expression.
(M3.): Node scope of the `f().g(..)` expression.
(M4.): Node scope of the block labeled `'b:`.
(M5.): Node scope of the `let x = d();` statement
(D6.): DestructionScope for temporaries created during M5.
(R7.): Remainder scope for block `'b:`, stmt 0 (let x = ...).
(M8.): Node scope of the `let y = d();` statement.
(D9.): DestructionScope for temporaries created during M8.
(R10.): Remainder scope for block `'b:`, stmt 1 (let y = ...).
(D11.): DestructionScope for temporaries and bindings from block `'b:`.
(D12.): DestructionScope for temporaries created during M1 (e.g., f()).
Note that while the above picture shows the destruction scopes as following their corresponding node scopes, in the internal data structures of the compiler the destruction scopes are represented as enclosing parents. This is sound because we use the enclosing parent relationship just to ensure that referenced values live long enough; phrased another way, the starting point of each range is not really the important thing in the above picture, but rather the ending point.
Fields§
§id: ItemLocalId
§data: ScopeData
Implementations§
source§impl Scope
impl Scope
sourcepub fn item_local_id(&self) -> ItemLocalId
pub fn item_local_id(&self) -> ItemLocalId
Returns an item-local ID associated with this scope.
N.B., likely to be replaced as API is refined; e.g., pnkfelix
anticipates fn entry_node_id
and fn each_exit_node_id
.
pub fn hir_id(&self, scope_tree: &ScopeTree) -> Option<HirId>
Trait Implementations§
source§impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for Scope
impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for Scope
fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher, )
source§impl Ord for Scope
impl Ord for Scope
source§impl PartialOrd for Scope
impl PartialOrd for Scope
source§impl<'a> ToStableHashKey<StableHashingContext<'a>> for Scope
impl<'a> ToStableHashKey<StableHashingContext<'a>> for Scope
type KeyType = Scope
fn to_stable_hash_key(&self, _: &StableHashingContext<'a>) -> Scope
source§impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Scope
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Scope
source§fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
_: &mut F,
) -> Result<Self, F::Error>
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, _: &mut F, ) -> Result<Self, F::Error>
source§impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Scope
impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Scope
source§fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
fn visit_with<F: TypeVisitor<TyCtxt<'tcx>>>(&self, _: &mut F) -> F::Result
impl Copy for Scope
impl Eq for Scope
impl StructuralPartialEq for Scope
Auto Trait Implementations§
impl DynSend for Scope
impl DynSync for Scope
impl Freeze for Scope
impl RefUnwindSafe for Scope
impl Send for Scope
impl Sync for Scope
impl Unpin for Scope
impl UnwindSafe for Scope
Blanket Implementations§
source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T
fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'a mut [T]
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impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
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fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'a mut [T]
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
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T: Clone,
impl<T> CloneToUninit for Twhere
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bound by binder
or bound by some binder outside of binder
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fn has_coroutines(&self) -> bool
fn references_error(&self) -> bool
fn has_non_region_param(&self) -> bool
fn has_infer_regions(&self) -> bool
fn has_infer_types(&self) -> bool
fn has_non_region_infer(&self) -> bool
fn has_infer(&self) -> bool
fn has_placeholders(&self) -> bool
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fn has_param(&self) -> bool
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fn has_free_regions(&self) -> bool
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Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...)
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Size: 8 bytes