bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Simplify last prepare_vtable_segments loop even more

Browse source
This commit is contained in:
Maybe Waffle 2023-07-19 10:34:35 +00:00
parent d567f0fc68
commit d87db8eb3f
1 changed files with 21 additions and 24 deletions
Download patch file Download diff file Expand all files Collapse all files

45
compiler/rustc_trait_selection/src/traits/vtable.rs
View file

@ -113,7 +113,7 @@ fn prepare_vtable_segments_inner<'tcx, T>(
// Loop run #1: Emitting the slice [D C] (in reverse order). No one has a next-sibling node. // Loop run #1: Emitting the slice [D C] (in reverse order). No one has a next-sibling node.
// Loop run #1: Stack after exiting out is []. Now the function exits. // Loop run #1: Stack after exiting out is []. Now the function exits.
loop { 'outer: loop {
// dive deeper into the stack, recording the path // dive deeper into the stack, recording the path
'diving_in: loop { 'diving_in: loop {
let &(inner_most_trait_ref, _, _) = stack.last().unwrap(); let &(inner_most_trait_ref, _, _) = stack.last().unwrap();
@ -151,32 +151,29 @@ fn prepare_vtable_segments_inner<'tcx, T>(
emit_vptr_on_new_entry = true; emit_vptr_on_new_entry = true;
// emit innermost item, move to next sibling and stop there if possible, otherwise jump to outer level. // emit innermost item, move to next sibling and stop there if possible, otherwise jump to outer level.
'exiting_out: loop { while let Some((inner_most_trait_ref, emit_vptr, mut siblings)) = stack.pop() {
if let Some((inner_most_trait_ref, emit_vptr, siblings)) = stack.last_mut() { segment_visitor(VtblSegment::TraitOwnEntries {
segment_visitor(VtblSegment::TraitOwnEntries { trait_ref: inner_most_trait_ref,
trait_ref: *inner_most_trait_ref, emit_vptr,
emit_vptr: *emit_vptr, })?;
})?;
match siblings.find(|&sibling| visited.insert(sibling.to_predicate(tcx))) { if let Some(next_inner_most_trait_ref) =
Some(next_inner_most_trait_ref) => { siblings.find(|&sibling| visited.insert(sibling.to_predicate(tcx)))
// We're throwing away potential constness of super traits here. {
// FIXME: handle ~const super traits // We're throwing away potential constness of super traits here.
let next_inner_most_trait_ref = // FIXME: handle ~const super traits
next_inner_most_trait_ref.map_bound(|t| t.trait_ref); let next_inner_most_trait_ref =
*inner_most_trait_ref = next_inner_most_trait_ref; next_inner_most_trait_ref.map_bound(|t| t.trait_ref);
*emit_vptr = emit_vptr_on_new_entry;
break 'exiting_out; stack.push((next_inner_most_trait_ref, emit_vptr_on_new_entry, siblings));
}
None => { // just pushed a new trait onto the stack, so we need to go through its super traits
stack.pop(); continue 'outer;
continue 'exiting_out;
}
}
} }
// all done
return ControlFlow::Continue(());
} }
// the stack is empty, all done
return ControlFlow::Continue(());
} }
} }