Auto merge of #129582 - nbdd0121:unwind, r=nnethercote · rust-lang/rust@06d261d (original) (raw)
`@@ -51,11 +51,20 @@ impl<'tcx> crate::MirPass<'tcx> for AbortUnwindingCalls {
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`` // This will filter to functions with extern "C-unwind" ABIs, for
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`// example.
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`for block in body.basic_blocks.as_mut() {
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let Some(terminator) = &mut block.terminator else { continue };
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let span = terminator.source_info.span;
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// If we see an UnwindResume terminator inside a function that cannot unwind, we need
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// to replace it with UnwindTerminate.
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if let TerminatorKind::UnwindResume = &terminator.kind
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&& !body_can_unwind
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{
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terminator.kind = TerminatorKind::UnwindTerminate(UnwindTerminateReason::Abi);
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}
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`if block.is_cleanup {
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`continue;
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`}
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``
`-
let Some(terminator) = &block.terminator else { continue };
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``
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let span = terminator.source_info.span;
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`let call_can_unwind = match &terminator.kind {
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`TerminatorKind::Call { func, .. } => {
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`@@ -87,14 +96,18 @@ impl<'tcx> crate::MirPass<'tcx> for AbortUnwindingCalls {
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`if !call_can_unwind {
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`// If this function call can't unwind, then there's no need for it
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`// to have a landing pad. This means that we can remove any cleanup
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``
`-
// registered for it.
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// registered for it (and turn it into UnwindAction::Unreachable).
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`let cleanup = block.terminator_mut().unwind_mut().unwrap();
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`*cleanup = UnwindAction::Unreachable;
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} else if !body_can_unwind {
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} else if !body_can_unwind
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&& matches!(terminator.unwind(), Some(UnwindAction::Continue))
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{
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`// Otherwise if this function can unwind, then if the outer function
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`// can also unwind there's nothing to do. If the outer function
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``
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// can't unwind, however, we need to change the landing pad for this
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// function call to one that aborts.
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// can't unwind, however, we need to ensure that any UnwindAction::Continue
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// is replaced with terminate. For those with UnwindAction::Cleanup,
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// cleanup will still happen, and terminate will happen afterwards handled by
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// the UnwindResume -> UnwindTerminate terminator replacement.
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`let cleanup = block.terminator_mut().unwind_mut().unwrap();
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`*cleanup = UnwindAction::Terminate(UnwindTerminateReason::Abi);
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`}
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