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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-07 05:48:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-07 05:48:48 +0000 |
commit | ef24de24a82fe681581cc130f342363c47c0969a (patch) | |
tree | 0d494f7e1a38b95c92426f58fe6eaa877303a86c /compiler/rustc_mir_dataflow/src/drop_flag_effects.rs | |
parent | Releasing progress-linux version 1.74.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-ef24de24a82fe681581cc130f342363c47c0969a.tar.xz rustc-ef24de24a82fe681581cc130f342363c47c0969a.zip |
Merging upstream version 1.75.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compiler/rustc_mir_dataflow/src/drop_flag_effects.rs')
-rw-r--r-- | compiler/rustc_mir_dataflow/src/drop_flag_effects.rs | 83 |
1 files changed, 1 insertions, 82 deletions
diff --git a/compiler/rustc_mir_dataflow/src/drop_flag_effects.rs b/compiler/rustc_mir_dataflow/src/drop_flag_effects.rs index 0d466bbe5..163d74cc9 100644 --- a/compiler/rustc_mir_dataflow/src/drop_flag_effects.rs +++ b/compiler/rustc_mir_dataflow/src/drop_flag_effects.rs @@ -1,6 +1,6 @@ use crate::elaborate_drops::DropFlagState; use rustc_middle::mir::{self, Body, Location, Terminator, TerminatorKind}; -use rustc_middle::ty::{self, TyCtxt}; +use rustc_middle::ty::TyCtxt; use rustc_target::abi::VariantIdx; use super::indexes::MovePathIndex; @@ -55,60 +55,6 @@ pub fn on_all_children_bits<'tcx, F>( ) where F: FnMut(MovePathIndex), { - #[inline] - fn is_terminal_path<'tcx>( - tcx: TyCtxt<'tcx>, - body: &Body<'tcx>, - move_data: &MoveData<'tcx>, - path: MovePathIndex, - ) -> bool { - let place = move_data.move_paths[path].place; - - // When enumerating the child fragments of a path, don't recurse into - // paths (1.) past arrays, slices, and pointers, nor (2.) into a type - // that implements `Drop`. - // - // Places behind references or arrays are not tracked by elaboration - // and are always assumed to be initialized when accessible. As - // references and indexes can be reseated, trying to track them can - // only lead to trouble. - // - // Places behind ADT's with a Drop impl are not tracked by - // elaboration since they can never have a drop-flag state that - // differs from that of the parent with the Drop impl. - // - // In both cases, the contents can only be accessed if and only if - // their parents are initialized. This implies for example that there - // is no need to maintain separate drop flags to track such state. - // - // FIXME: we have to do something for moving slice patterns. - let ty = place.ty(body, tcx).ty; - match ty.kind() { - ty::Adt(def, _) if (def.has_dtor(tcx) && !def.is_box()) || def.is_union() => { - debug!( - "place_contents_drop_state_cannot_differ place: {:?} ty: {:?} Drop => true", - place, ty - ); - true - } - ty::Array(..) => { - debug!( - "place_contents_drop_state_cannot_differ place: {:?} ty: {:?} => false", - place, ty - ); - false - } - ty::Slice(..) | ty::Ref(..) | ty::RawPtr(..) => { - debug!( - "place_contents_drop_state_cannot_differ place: {:?} ty: {:?} refd => true", - place, ty - ); - true - } - _ => false, - } - } - fn on_all_children_bits<'tcx, F>( tcx: TyCtxt<'tcx>, body: &Body<'tcx>, @@ -120,10 +66,6 @@ pub fn on_all_children_bits<'tcx, F>( { each_child(move_path_index); - if is_terminal_path(tcx, body, move_data, move_path_index) { - return; - } - let mut next_child_index = move_data.move_paths[move_path_index].first_child; while let Some(child_index) = next_child_index { on_all_children_bits(tcx, body, move_data, child_index, each_child); @@ -133,29 +75,6 @@ pub fn on_all_children_bits<'tcx, F>( on_all_children_bits(tcx, body, move_data, move_path_index, &mut each_child); } -pub fn on_all_drop_children_bits<'tcx, F>( - tcx: TyCtxt<'tcx>, - body: &Body<'tcx>, - ctxt: &MoveDataParamEnv<'tcx>, - path: MovePathIndex, - mut each_child: F, -) where - F: FnMut(MovePathIndex), -{ - on_all_children_bits(tcx, body, &ctxt.move_data, path, |child| { - let place = &ctxt.move_data.move_paths[path].place; - let ty = place.ty(body, tcx).ty; - debug!("on_all_drop_children_bits({:?}, {:?} : {:?})", path, place, ty); - - let erased_ty = tcx.erase_regions(ty); - if erased_ty.needs_drop(tcx, ctxt.param_env) { - each_child(child); - } else { - debug!("on_all_drop_children_bits - skipping") - } - }) -} - pub fn drop_flag_effects_for_function_entry<'tcx, F>( tcx: TyCtxt<'tcx>, body: &Body<'tcx>, |