bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Add CastKind::Transmute to MIR

Browse source 
Updates `interpret`, `codegen_ssa`, and `codegen_cranelift` to consume the new cast instead of the intrinsic.

Includes `CastTransmute` for custom MIR building, to be able to test the extra UB.
This commit is contained in:
Scott McMurray 2023-02-24 18:32:52 -08:00
parent a266f11990
commit 64cce5fc7d
55 changed files with 955 additions and 190 deletions
Download patch file Download diff file Expand all files Collapse all files

27
compiler/rustc_const_eval/src/transform/validate.rs
View file

@ -621,6 +621,33 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
);
}
}
CastKind::Transmute => {
if let MirPhase::Runtime(..) = self.mir_phase {
// Unlike `mem::transmute`, a MIR `Transmute` is well-formed
// for any two `Sized` types, just potentially UB to run.
if !op_ty.is_sized(self.tcx, self.param_env) {
self.fail(
location,
format!("Cannot transmute from non-`Sized` type {op_ty:?}"),
);
}
if !target_type.is_sized(self.tcx, self.param_env) {
self.fail(
location,
format!("Cannot transmute to non-`Sized` type {target_type:?}"),
);
}
} else {
self.fail(
location,
format!(
"Transmute is not supported in non-runtime phase {:?}.",
self.mir_phase
),
);
}
}
}
}
Rvalue::Repeat(_, _)