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remove some provenance-related machine hooks that Miri no longer needs

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This commit is contained in:
Ralf Jung 2022-07-23 10:15:37 -04:00
parent 47ba935965
commit 665a7e8f56
4 changed files with 17 additions and 46 deletions
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23
compiler/rustc_const_eval/src/interpret/machine.rs
View File

@ -135,9 +135,6 @@ pub trait Machine<'mir, 'tcx>: Sized {
/// Whether to enforce integers and floats being initialized.
fn enforce_number_init(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool;
/// Whether to enforce integers and floats not having provenance.
fn enforce_number_no_provenance(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool;
/// Whether function calls should be [ABI](CallAbi)-checked.
fn enforce_abi(_ecx: &InterpCx<'mir, 'tcx, Self>) -> bool {
true
@ -300,13 +297,6 @@ fn ptr_from_addr_cast(
addr: u64,
) -> InterpResult<'tcx, Pointer<Option<Self::Provenance>>>;
/// Hook for returning a pointer from a transmute-like operation on an addr.
/// This is only needed to support Miri's (unsound) "allow-ptr-int-transmute" flag.
fn ptr_from_addr_transmute(
ecx: &InterpCx<'mir, 'tcx, Self>,
addr: u64,
) -> Pointer<Option<Self::Provenance>>;
/// Marks a pointer as exposed, allowing it's provenance
/// to be recovered. "Pointer-to-int cast"
fn expose_ptr(
@ -469,11 +459,6 @@ fn enforce_number_init(_ecx: &InterpCx<$mir, $tcx, Self>) -> bool {
true
}
#[inline(always)]
fn enforce_number_no_provenance(_ecx: &InterpCx<$mir, $tcx, Self>) -> bool {
true
}
#[inline(always)]
fn checked_binop_checks_overflow(_ecx: &InterpCx<$mir, $tcx, Self>) -> bool {
true
@ -518,14 +503,6 @@ fn adjust_alloc_base_pointer(
ptr
}
#[inline(always)]
fn ptr_from_addr_transmute(
_ecx: &InterpCx<$mir, $tcx, Self>,
addr: u64,
) -> Pointer<Option<AllocId>> {
Pointer::from_addr(addr)
}
#[inline(always)]
fn ptr_from_addr_cast(
_ecx: &InterpCx<$mir, $tcx, Self>,

2
compiler/rustc_const_eval/src/interpret/memory.rs
View File

@ -1186,7 +1186,7 @@ pub fn scalar_to_ptr(
Err(ptr) => ptr.into(),
Ok(bits) => {
let addr = u64::try_from(bits).unwrap();
M::ptr_from_addr_transmute(&self, addr)
Pointer::from_addr(addr)
}
},
)

20
compiler/rustc_const_eval/src/interpret/operand.rs
View File

@ -363,17 +363,11 @@ fn read_immediate_from_mplace_raw(
Abi::Scalar(s) if force => Some(s.primitive()),
_ => None,
};
let read_provenance = |s: abi::Primitive, size| {
// Should be just `s.is_ptr()`, but we support a Miri flag that accepts more
// questionable ptr-int transmutes.
let number_may_have_provenance = !M::enforce_number_no_provenance(self);
s.is_ptr() || (number_may_have_provenance && size == self.pointer_size())
};
if let Some(s) = scalar_layout {
let size = s.size(self);
assert_eq!(size, mplace.layout.size, "abi::Scalar size does not match layout size");
let scalar =
alloc.read_scalar(alloc_range(Size::ZERO, size), read_provenance(s, size))?;
let scalar = alloc
.read_scalar(alloc_range(Size::ZERO, size), /*read_provenance*/ s.is_ptr())?;
return Ok(Some(ImmTy { imm: scalar.into(), layout: mplace.layout }));
}
let scalar_pair_layout = match mplace.layout.abi {
@ -391,10 +385,12 @@ fn read_immediate_from_mplace_raw(
let (a_size, b_size) = (a.size(self), b.size(self));
let b_offset = a_size.align_to(b.align(self).abi);
assert!(b_offset.bytes() > 0); // in `operand_field` we use the offset to tell apart the fields
let a_val =
alloc.read_scalar(alloc_range(Size::ZERO, a_size), read_provenance(a, a_size))?;
let b_val =
alloc.read_scalar(alloc_range(b_offset, b_size), read_provenance(b, b_size))?;
let a_val = alloc.read_scalar(
alloc_range(Size::ZERO, a_size),
/*read_provenance*/ a.is_ptr(),
)?;
let b_val = alloc
.read_scalar(alloc_range(b_offset, b_size), /*read_provenance*/ b.is_ptr())?;
return Ok(Some(ImmTy {
imm: Immediate::ScalarPair(a_val, b_val),
layout: mplace.layout,

18
compiler/rustc_const_eval/src/interpret/validity.rs
View File

@ -517,15 +517,13 @@ fn try_visit_primitive(
{ "{:x}", value } expected { "initialized bytes" }
);
}
if M::enforce_number_no_provenance(self.ecx) {
// As a special exception we *do* match on a `Scalar` here, since we truly want
// to know its underlying representation (and *not* cast it to an integer).
let is_ptr = value.check_init().map_or(false, |v| matches!(v, Scalar::Ptr(..)));
if is_ptr {
throw_validation_failure!(self.path,
{ "{:x}", value } expected { "plain (non-pointer) bytes" }
)
}
// As a special exception we *do* match on a `Scalar` here, since we truly want
// to know its underlying representation (and *not* cast it to an integer).
let is_ptr = value.check_init().map_or(false, |v| matches!(v, Scalar::Ptr(..)));
if is_ptr {
throw_validation_failure!(self.path,
{ "{:x}", value } expected { "plain (non-pointer) bytes" }
)
}
Ok(true)
}
@ -906,7 +904,7 @@ fn visit_aggregate(
match alloc.check_bytes(
alloc_range(Size::ZERO, size),
/*allow_uninit*/ !M::enforce_number_init(self.ecx),
/*allow_ptr*/ !M::enforce_number_no_provenance(self.ecx),
/*allow_ptr*/ false,
) {
// In the happy case, we needn't check anything else.
Ok(()) => {}