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add cast kind of from_exposed_addr (int-to-ptr casts)

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This commit is contained in:
Ralf Jung
2022-06-02 09:05:37 -04:00
parent 5e6bb83268
commit fafccdced3
10 changed files with 93 additions and 39 deletions
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34
compiler/rustc_const_eval/src/interpret/cast.rs
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@@ -37,6 +37,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
self.write_immediate(res, dest)?;
}
PointerFromExposedAddress => {
let src = self.read_immediate(src)?;
let res = self.pointer_from_exposed_address_cast(&src, cast_ty)?;
self.write_immediate(res, dest)?;
}
Misc => {
let src = self.read_immediate(src)?;
let res = self.misc_cast(&src, cast_ty)?;
@@ -201,6 +207,24 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Ok(self.cast_from_int_like(scalar, src.layout, cast_ty)?.into())
}
pub fn pointer_from_exposed_address_cast(
&mut self,
src: &ImmTy<'tcx, M::PointerTag>,
cast_ty: Ty<'tcx>,
) -> InterpResult<'tcx, Immediate<M::PointerTag>> {
assert!(src.layout.ty.is_integral());
assert_matches!(cast_ty.kind(), ty::RawPtr(_));
// First cast to usize.
let scalar = src.to_scalar()?;
let addr = self.cast_from_int_like(scalar, src.layout, self.tcx.types.usize)?;
let addr = addr.to_machine_usize(self)?;
// Then turn address into pointer.
let ptr = M::ptr_from_addr_cast(&self, addr);
Ok(Scalar::from_maybe_pointer(ptr, self).into())
}
pub fn cast_from_int_like(
&self,
scalar: Scalar<M::PointerTag>, // input value (there is no ScalarTy so we separate data+layout)
@@ -225,16 +249,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Scalar::from_uint(v, size)
}
RawPtr(_) => {
assert!(src_layout.ty.is_integral());
let size = self.pointer_size();
let addr = u64::try_from(size.truncate(v)).unwrap();
let ptr = M::ptr_from_addr_cast(&self, addr);
Scalar::from_maybe_pointer(ptr, self)
}
Float(FloatTy::F32) if signed => Scalar::from_f32(Single::from_i128(v as i128).value),
Float(FloatTy::F64) if signed => Scalar::from_f64(Double::from_i128(v as i128).value),
Float(FloatTy::F32) => Scalar::from_f32(Single::from_u128(v).value),