bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #122598 - Nadrieril:full-derefpats, r=matthewjasper

Browse source 
deref patterns: lower deref patterns to MIR

This lowers deref patterns to MIR. This is a bit tricky because this is the first kind of pattern that requires storing a value in a temporary. Thanks to https://github.com/rust-lang/rust/pull/123324 false edges are no longer a problem.

The thing I'm not confident about is the handling of fake borrows. This PR ignores any fake borrows inside a deref pattern. We are guaranteed to at least fake borrow the place of the first pointer value, which could be enough, but I'm not certain.
This commit is contained in:
León Orell Valerian Liehr 2024-04-23 17:25:15 +02:00 • committed by GitHub
commit 332cac2c6d
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
51 changed files with 764 additions and 301 deletions
Download patch file Download diff file Expand all files Collapse all files

2
compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs
View file

@ -29,7 +29,7 @@ impl<'tcx> MirPass<'tcx> for CleanupPostBorrowck {
for statement in basic_block.statements.iter_mut() {
match statement.kind {
StatementKind::AscribeUserType(..)
| StatementKind::Assign(box (_, Rvalue::Ref(_, BorrowKind::Fake, _)))
| StatementKind::Assign(box (_, Rvalue::Ref(_, BorrowKind::Fake(_), _)))
| StatementKind::Coverage(
// These kinds of coverage statements are markers inserted during
// MIR building, and are not needed after InstrumentCoverage.

2
compiler/rustc_mir_transform/src/promote_consts.rs
View file

@ -384,7 +384,7 @@ impl<'tcx> Validator<'_, 'tcx> {
match kind {
// Reject these borrow types just to be safe.
// FIXME(RalfJung): could we allow them? Should we? No point in it until we have a usecase.
BorrowKind::Fake | BorrowKind::Mut { kind: MutBorrowKind::ClosureCapture } => {
BorrowKind::Fake(_) | BorrowKind::Mut { kind: MutBorrowKind::ClosureCapture } => {
return Err(Unpromotable);
}