bjoernager/rust
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Rollup merge of #102778 - nbdd0121:mir, r=tmiasko

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Fix MIR inlining of asm_unwind

The MIR inlining currently doesn't handle inline asm's unwind edge correctly.

This code will cause ICE:
```rust
struct D;

impl Drop for D {
    fn drop(&mut self) {}
}

#[inline(always)]
fn foo() {
    let _d = D;
    unsafe { std::arch::asm!("", options(may_unwind)) };
}

pub fn main() {
    foo();
}
```

This PR fixes this issue. I also take the opportunity to extract common code into a method.
This commit is contained in:
Matthias Krüger 2022-10-08 14:38:19 +02:00 • committed by GitHub
commit 2f2664923b
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3 changed files with 86 additions and 25 deletions
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44
compiler/rustc_mir_transform/src/inline.rs
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@ -977,6 +977,21 @@ impl Integrator<'_, '_> {
trace!("mapping block `{:?}` to `{:?}`", block, new);
new
}
fn map_unwind(&self, unwind: Option<BasicBlock>) -> Option<BasicBlock> {
if self.in_cleanup_block {
if unwind.is_some() {
bug!("cleanup on cleanup block");
}
return unwind;
}
match unwind {
Some(target) => Some(self.map_block(target)),
// Add an unwind edge to the original call's cleanup block
None => self.cleanup_block,
}
}
}
impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
@ -1085,35 +1100,17 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
TerminatorKind::Drop { ref mut target, ref mut unwind, .. }
| TerminatorKind::DropAndReplace { ref mut target, ref mut unwind, .. } => {
*target = self.map_block(*target);
if let Some(tgt) = *unwind {
*unwind = Some(self.map_block(tgt));
} else if !self.in_cleanup_block {
// Unless this drop is in a cleanup block, add an unwind edge to
// the original call's cleanup block
*unwind = self.cleanup_block;
}
*unwind = self.map_unwind(*unwind);
}
TerminatorKind::Call { ref mut target, ref mut cleanup, .. } => {
if let Some(ref mut tgt) = *target {
*tgt = self.map_block(*tgt);
}
if let Some(tgt) = *cleanup {
*cleanup = Some(self.map_block(tgt));
} else if !self.in_cleanup_block {
// Unless this call is in a cleanup block, add an unwind edge to
// the original call's cleanup block
*cleanup = self.cleanup_block;
}
*cleanup = self.map_unwind(*cleanup);
}
TerminatorKind::Assert { ref mut target, ref mut cleanup, .. } => {
*target = self.map_block(*target);
if let Some(tgt) = *cleanup {
*cleanup = Some(self.map_block(tgt));
} else if !self.in_cleanup_block {
// Unless this assert is in a cleanup block, add an unwind edge to
// the original call's cleanup block
*cleanup = self.cleanup_block;
}
*cleanup = self.map_unwind(*cleanup);
}
TerminatorKind::Return => {
terminator.kind = if let Some(tgt) = self.callsite.target {
@ -1141,11 +1138,8 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
TerminatorKind::InlineAsm { ref mut destination, ref mut cleanup, .. } => {
if let Some(ref mut tgt) = *destination {
*tgt = self.map_block(*tgt);
} else if !self.in_cleanup_block {
// Unless this inline asm is in a cleanup block, add an unwind edge to
// the original call's cleanup block
*cleanup = self.cleanup_block;
}
*cleanup = self.map_unwind(*cleanup);
}
}
}