Struct rustc_mir_build::build::scope::DropTree
source · struct DropTree {
drops: IndexVec<DropIdx, (DropData, DropIdx)>,
previous_drops: FxHashMap<(DropIdx, Local, DropKind), DropIdx>,
entry_points: Vec<(DropIdx, BasicBlock)>,
}
Expand description
A tree of drops that we have deferred lowering. It’s used for:
- Drops on unwind paths
- Drops on generator drop paths (when a suspended generator is dropped)
- Drops on return and loop exit paths
- Drops on the else path in an
if let
chain
Once no more nodes could be added to the tree, we lower it to MIR in one go
in build_mir
.
Fields§
§drops: IndexVec<DropIdx, (DropData, DropIdx)>
Drops in the tree.
previous_drops: FxHashMap<(DropIdx, Local, DropKind), DropIdx>
Map for finding the inverse of the next_drop
relation:
previous_drops[(drops[i].1, drops[i].0.local, drops[i].0.kind)] == i
entry_points: Vec<(DropIdx, BasicBlock)>
Edges into the DropTree
that need to be added once it’s lowered.
Implementations§
source§impl DropTree
impl DropTree
fn new() -> Self
fn add_drop(&mut self, drop: DropData, next: DropIdx) -> DropIdx
fn add_entry(&mut self, from: BasicBlock, to: DropIdx)
sourcefn build_mir<'tcx, T: DropTreeBuilder<'tcx>>(
&mut self,
cfg: &mut CFG<'tcx>,
blocks: &mut IndexVec<DropIdx, Option<BasicBlock>>
)
fn build_mir<'tcx, T: DropTreeBuilder<'tcx>>( &mut self, cfg: &mut CFG<'tcx>, blocks: &mut IndexVec<DropIdx, Option<BasicBlock>> )
Builds the MIR for a given drop tree.
blocks
should have the same length as self.drops
, and may have its
first value set to some already existing block.
sourcefn assign_blocks<'tcx, T: DropTreeBuilder<'tcx>>(
&mut self,
cfg: &mut CFG<'tcx>,
blocks: &mut IndexVec<DropIdx, Option<BasicBlock>>
)
fn assign_blocks<'tcx, T: DropTreeBuilder<'tcx>>( &mut self, cfg: &mut CFG<'tcx>, blocks: &mut IndexVec<DropIdx, Option<BasicBlock>> )
Assign blocks for all of the drops in the drop tree that need them.
fn link_blocks<'tcx>( &self, cfg: &mut CFG<'tcx>, blocks: &IndexSlice<DropIdx, Option<BasicBlock>> )
Trait Implementations§
Auto Trait Implementations§
impl RefUnwindSafe for DropTree
impl !Send for DropTree
impl !Sync for DropTree
impl Unpin for DropTree
impl UnwindSafe for DropTree
Blanket Implementations§
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
Layout§
Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...)
attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.
Size: 80 bytes