diff options
Diffstat (limited to 'src/librustc/mir/mod.rs')
| -rw-r--r-- | src/librustc/mir/mod.rs | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs index 64a1729982a..c36e401e8d6 100644 --- a/src/librustc/mir/mod.rs +++ b/src/librustc/mir/mod.rs @@ -1253,6 +1253,15 @@ pub enum StatementKind<'tcx> { /// (The starting point(s) arise implicitly from borrows.) EndRegion(region::Scope), + /// Encodes a user's type assertion. These need to be preserved intact so that NLL can respect + /// them. For example: + /// + /// let (a, b): (T, U) = y; + /// + /// Here we would insert a `UserAssertTy<(T, U)>(y)` instruction to check that the type of `y` + /// is the right thing. + UserAssertTy(Ty<'tcx>, Local), + /// No-op. Useful for deleting instructions without affecting statement indices. Nop, } @@ -1324,6 +1333,7 @@ impl<'tcx> Debug for Statement<'tcx> { InlineAsm { ref asm, ref outputs, ref inputs } => { write!(fmt, "asm!({:?} : {:?} : {:?})", asm, outputs, inputs) }, + UserAssertTy(ref ty, ref local) => write!(fmt, "UserAssertTy({:?}, {:?})", ty, local), Nop => write!(fmt, "nop"), } } @@ -2184,6 +2194,7 @@ EnumTypeFoldableImpl! { (StatementKind::InlineAsm) { asm, outputs, inputs }, (StatementKind::Validate)(a, b), (StatementKind::EndRegion)(a), + (StatementKind::UserAssertTy)(a, b), (StatementKind::Nop), } } |