diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/build/scope.rs')
| -rw-r--r-- | compiler/rustc_mir_build/src/build/scope.rs | 93 |
1 files changed, 77 insertions, 16 deletions
diff --git a/compiler/rustc_mir_build/src/build/scope.rs b/compiler/rustc_mir_build/src/build/scope.rs index e63fbeeac66..636e47b7ad2 100644 --- a/compiler/rustc_mir_build/src/build/scope.rs +++ b/compiler/rustc_mir_build/src/build/scope.rs @@ -89,7 +89,7 @@ use rustc_index::{IndexSlice, IndexVec}; use rustc_middle::middle::region; use rustc_middle::mir::*; use rustc_middle::thir::{ExprId, LintLevel}; -use rustc_middle::{bug, span_bug}; +use rustc_middle::{bug, span_bug, ty}; use rustc_session::lint::Level; use rustc_span::source_map::Spanned; use rustc_span::{DUMMY_SP, Span}; @@ -151,6 +151,9 @@ struct DropData { /// Whether this is a value Drop or a StorageDead. kind: DropKind, + + /// Whether this is a backwards-incompatible drop lint + backwards_incompatible_lint: bool, } #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] @@ -274,8 +277,12 @@ impl DropTree { // represents the block in the tree that should be jumped to once all // of the required drops have been performed. let fake_source_info = SourceInfo::outermost(DUMMY_SP); - let fake_data = - DropData { source_info: fake_source_info, local: Local::MAX, kind: DropKind::Storage }; + let fake_data = DropData { + source_info: fake_source_info, + local: Local::MAX, + kind: DropKind::Storage, + backwards_incompatible_lint: false, + }; let drops = IndexVec::from_raw(vec![DropNode { data: fake_data, next: DropIdx::MAX }]); Self { drops, entry_points: Vec::new(), existing_drops_map: FxHashMap::default() } } @@ -763,7 +770,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let local = place.as_local().unwrap_or_else(|| bug!("projection in tail call args")); - Some(DropData { source_info, local, kind: DropKind::Value }) + Some(DropData { + source_info, + local, + kind: DropKind::Value, + backwards_incompatible_lint: false, + }) } Operand::Constant(_) => None, }) @@ -1019,9 +1031,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { if local.index() <= self.arg_count { span_bug!( span, - "`schedule_drop` called with local {:?} and arg_count {}", + "`schedule_drop` called with body argument {:?} \ + but its storage does not require a drop", local, - self.arg_count, ) } false @@ -1089,6 +1101,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { source_info: SourceInfo { span: scope_end, scope: scope.source_scope }, local, kind: drop_kind, + backwards_incompatible_lint: false, }); return; @@ -1098,6 +1111,45 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { span_bug!(span, "region scope {:?} not in scope to drop {:?}", region_scope, local); } + /// Schedule emission of a backwards incompatible drop lint hint. + /// Applicable only to temporary values for now. + pub(crate) fn schedule_backwards_incompatible_drop( + &mut self, + span: Span, + region_scope: region::Scope, + local: Local, + ) { + if !self.local_decls[local].ty.has_significant_drop(self.tcx, ty::TypingEnv { + typing_mode: ty::TypingMode::non_body_analysis(), + param_env: self.param_env, + }) { + return; + } + for scope in self.scopes.scopes.iter_mut().rev() { + // Since we are inserting linting MIR statement, we have to invalidate the caches + scope.invalidate_cache(); + if scope.region_scope == region_scope { + let region_scope_span = region_scope.span(self.tcx, self.region_scope_tree); + let scope_end = self.tcx.sess.source_map().end_point(region_scope_span); + + scope.drops.push(DropData { + source_info: SourceInfo { span: scope_end, scope: scope.source_scope }, + local, + kind: DropKind::Value, + backwards_incompatible_lint: true, + }); + + return; + } + } + span_bug!( + span, + "region scope {:?} not in scope to drop {:?} for linting", + region_scope, + local + ); + } + /// Indicates that the "local operand" stored in `local` is /// *moved* at some point during execution (see `local_scope` for /// more information about what a "local operand" is -- in short, @@ -1378,16 +1430,25 @@ fn build_scope_drops<'tcx>( continue; } - unwind_drops.add_entry_point(block, unwind_to); - - let next = cfg.start_new_block(); - cfg.terminate(block, source_info, TerminatorKind::Drop { - place: local.into(), - target: next, - unwind: UnwindAction::Continue, - replace: false, - }); - block = next; + if drop_data.backwards_incompatible_lint { + cfg.push(block, Statement { + source_info, + kind: StatementKind::BackwardIncompatibleDropHint { + place: Box::new(local.into()), + reason: BackwardIncompatibleDropReason::Edition2024, + }, + }); + } else { + unwind_drops.add_entry_point(block, unwind_to); + let next = cfg.start_new_block(); + cfg.terminate(block, source_info, TerminatorKind::Drop { + place: local.into(), + target: next, + unwind: UnwindAction::Continue, + replace: false, + }); + block = next; + } } DropKind::Storage => { if storage_dead_on_unwind { |