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interpret: make read functions generic over operand type

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This commit is contained in:
Ralf Jung 2023-07-25 22:19:18 +02:00
parent 00fb45dccd
commit 77ff1b83cd
19 changed files with 130 additions and 128 deletions
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2
compiler/rustc_const_eval/src/const_eval/machine.rs
View file

@ -216,7 +216,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
let mut msg_place = self.deref_operand(&args[0])?;
while msg_place.layout.ty.is_ref() {
msg_place = self.deref_operand(&msg_place.into())?;
msg_place = self.deref_operand(&msg_place)?;
}
let msg = Symbol::intern(self.read_str(&msg_place)?);

6
compiler/rustc_const_eval/src/const_eval/valtrees.rs
View file

@ -86,7 +86,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
Ok(ty::ValTree::zst())
}
ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => {
let Ok(val) = ecx.read_immediate(&place.into()) else {
let Ok(val) = ecx.read_immediate(place) else {
return Err(ValTreeCreationError::Other);
};
let val = val.to_scalar();
@ -102,7 +102,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
ty::FnPtr(_) | ty::RawPtr(_) => Err(ValTreeCreationError::NonSupportedType),
ty::Ref(_, _, _) => {
let Ok(derefd_place)= ecx.deref_operand(&place.into()) else {
let Ok(derefd_place)= ecx.deref_operand(place) else {
return Err(ValTreeCreationError::Other);
};
debug!(?derefd_place);
@ -130,7 +130,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
bug!("uninhabited types should have errored and never gotten converted to valtree")
}
let Ok(variant) = ecx.read_discriminant(&place.into()) else {
let Ok(variant) = ecx.read_discriminant(place) else {
return Err(ValTreeCreationError::Other);
};
branches(ecx, place, def.variant(variant).fields.len(), def.is_enum().then_some(variant), num_nodes)

2
compiler/rustc_const_eval/src/interpret/cast.rs
View file

@ -56,7 +56,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}
CastKind::FnPtrToPtr | CastKind::PtrToPtr => {
let src = self.read_immediate(&src)?;
let src = self.read_immediate(src)?;
let res = self.ptr_to_ptr(&src, cast_ty)?;
self.write_immediate(res, dest)?;
}

31
compiler/rustc_const_eval/src/interpret/discriminant.rs
View file

@ -5,8 +5,7 @@ use rustc_middle::{mir, ty};
use rustc_target::abi::{self, TagEncoding};
use rustc_target::abi::{VariantIdx, Variants};
use super::place::Writeable;
use super::{ImmTy, InterpCx, InterpResult, Machine, OpTy, Scalar};
use super::{ImmTy, InterpCx, InterpResult, Machine, Readable, Scalar, Writeable};
impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// Writes the discriminant of the given variant.
@ -97,11 +96,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
#[instrument(skip(self), level = "trace")]
pub fn read_discriminant(
&self,
op: &OpTy<'tcx, M::Provenance>,
op: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, VariantIdx> {
trace!("read_discriminant_value {:#?}", op.layout);
let ty = op.layout().ty;
trace!("read_discriminant_value {:#?}", op.layout());
// Get type and layout of the discriminant.
let discr_layout = self.layout_of(op.layout.ty.discriminant_ty(*self.tcx))?;
let discr_layout = self.layout_of(ty.discriminant_ty(*self.tcx))?;
trace!("discriminant type: {:?}", discr_layout.ty);
// We use "discriminant" to refer to the value associated with a particular enum variant.
@ -109,20 +109,19 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// declared list of variants -- they can differ with explicitly assigned discriminants.
// We use "tag" to refer to how the discriminant is encoded in memory, which can be either
// straight-forward (`TagEncoding::Direct`) or with a niche (`TagEncoding::Niche`).
let (tag_scalar_layout, tag_encoding, tag_field) = match op.layout.variants {
let (tag_scalar_layout, tag_encoding, tag_field) = match op.layout().variants {
Variants::Single { index } => {
// Do some extra checks on enums.
if op.layout.ty.is_enum() {
if ty.is_enum() {
// Hilariously, `Single` is used even for 0-variant enums.
// (See https://github.com/rust-lang/rust/issues/89765).
if matches!(op.layout.ty.kind(), ty::Adt(def, ..) if def.variants().is_empty())
{
if matches!(ty.kind(), ty::Adt(def, ..) if def.variants().is_empty()) {
throw_ub!(UninhabitedEnumVariantRead(index))
}
// For consisteny with `write_discriminant`, and to make sure that
// `project_downcast` cannot fail due to strange layouts, we declare immediate UB
// for uninhabited variants.
if op.layout.for_variant(self, index).abi.is_uninhabited() {
if op.layout().for_variant(self, index).abi.is_uninhabited() {
throw_ub!(UninhabitedEnumVariantRead(index))
}
}
@ -168,7 +167,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
self.cast_from_int_like(scalar, tag_val.layout, discr_layout.ty).unwrap();
let discr_bits = discr_val.assert_bits(discr_layout.size);
// Convert discriminant to variant index, and catch invalid discriminants.
let index = match *op.layout.ty.kind() {
let index = match *ty.kind() {
ty::Adt(adt, _) => {
adt.discriminants(*self.tcx).find(|(_, var)| var.val == discr_bits)
}
@ -222,12 +221,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
.checked_add(variant_index_relative)
.expect("overflow computing absolute variant idx"),
);
let variants = op
.layout
.ty
.ty_adt_def()
.expect("tagged layout for non adt")
.variants();
let variants =
ty.ty_adt_def().expect("tagged layout for non adt").variants();
assert!(variant_index < variants.next_index());
variant_index
} else {
@ -242,7 +237,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}
};
// For consisteny with `write_discriminant`, and to make sure that `project_downcast` cannot fail due to strange layouts, we declare immediate UB for uninhabited variants.
if op.layout.for_variant(self, index).abi.is_uninhabited() {
if op.layout().for_variant(self, index).abi.is_uninhabited() {
throw_ub!(UninhabitedEnumVariantRead(index))
}
Ok(index)

2
compiler/rustc_const_eval/src/interpret/intern.rs
View file

@ -170,7 +170,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: CompileTimeMachine<'mir, 'tcx, const_eval::Memory
let tcx = self.ecx.tcx;
let ty = mplace.layout.ty;
if let ty::Ref(_, referenced_ty, ref_mutability) = *ty.kind() {
let value = self.ecx.read_immediate(&mplace.into())?;
let value = self.ecx.read_immediate(mplace)?;
let mplace = self.ecx.ref_to_mplace(&value)?;
assert_eq!(mplace.layout.ty, referenced_ty);
// Handle trait object vtables.

16
compiler/rustc_const_eval/src/interpret/intrinsics.rs
View file

@ -226,7 +226,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}
sym::discriminant_value => {
let place = self.deref_operand(&args[0])?;
let variant = self.read_discriminant(&place.into())?;
let variant = self.read_discriminant(&place)?;
let discr = self.discriminant_for_variant(place.layout, variant)?;
self.write_scalar(discr, dest)?;
}
@ -445,7 +445,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
input_len
);
self.copy_op(
&self.project_index(&input, index)?.into(),
&self.project_index(&input, index)?,
dest,
/*allow_transmute*/ false,
)?;
@ -610,7 +610,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
count: &OpTy<'tcx, <M as Machine<'mir, 'tcx>>::Provenance>,
nonoverlapping: bool,
) -> InterpResult<'tcx> {
let count = self.read_target_usize(&count)?;
let count = self.read_target_usize(count)?;
let layout = self.layout_of(src.layout.ty.builtin_deref(true).unwrap().ty)?;
let (size, align) = (layout.size, layout.align.abi);
// `checked_mul` enforces a too small bound (the correct one would probably be target_isize_max),
@ -622,8 +622,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
)
})?;
let src = self.read_pointer(&src)?;
let dst = self.read_pointer(&dst)?;
let src = self.read_pointer(src)?;
let dst = self.read_pointer(dst)?;
self.mem_copy(src, align, dst, align, size, nonoverlapping)
}
@ -636,9 +636,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
) -> InterpResult<'tcx> {
let layout = self.layout_of(dst.layout.ty.builtin_deref(true).unwrap().ty)?;
let dst = self.read_pointer(&dst)?;
let byte = self.read_scalar(&byte)?.to_u8()?;
let count = self.read_target_usize(&count)?;
let dst = self.read_pointer(dst)?;
let byte = self.read_scalar(byte)?.to_u8()?;
let count = self.read_target_usize(count)?;
// `checked_mul` enforces a too small bound (the correct one would probably be target_isize_max),
// but no actual allocation can be big enough for the difference to be noticeable.

2
compiler/rustc_const_eval/src/interpret/mod.rs
View file

@ -24,7 +24,7 @@ pub use self::eval_context::{Frame, FrameInfo, InterpCx, LocalState, LocalValue,
pub use self::intern::{intern_const_alloc_recursive, InternKind};
pub use self::machine::{compile_time_machine, AllocMap, Machine, MayLeak, StackPopJump};
pub use self::memory::{AllocKind, AllocRef, AllocRefMut, FnVal, Memory, MemoryKind};
pub use self::operand::{ImmTy, Immediate, OpTy, Operand};
pub use self::operand::{ImmTy, Immediate, OpTy, Operand, Readable};
pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy, Writeable};
pub use self::projection::Projectable;
pub use self::terminator::FnArg;

81
compiler/rustc_const_eval/src/interpret/operand.rs
View file

@ -180,20 +180,6 @@ impl<'tcx, Prov: Provenance> From<MPlaceTy<'tcx, Prov>> for OpTy<'tcx, Prov> {
}
}
impl<'tcx, Prov: Provenance> From<&'_ MPlaceTy<'tcx, Prov>> for OpTy<'tcx, Prov> {
#[inline(always)]
fn from(mplace: &MPlaceTy<'tcx, Prov>) -> Self {
OpTy { op: Operand::Indirect(**mplace), layout: mplace.layout, align: Some(mplace.align) }
}
}
impl<'tcx, Prov: Provenance> From<&'_ mut MPlaceTy<'tcx, Prov>> for OpTy<'tcx, Prov> {
#[inline(always)]
fn from(mplace: &mut MPlaceTy<'tcx, Prov>) -> Self {
OpTy { op: Operand::Indirect(**mplace), layout: mplace.layout, align: Some(mplace.align) }
}
}
impl<'tcx, Prov: Provenance> From<ImmTy<'tcx, Prov>> for OpTy<'tcx, Prov> {
#[inline(always)]
fn from(val: ImmTy<'tcx, Prov>) -> Self {
@ -201,20 +187,6 @@ impl<'tcx, Prov: Provenance> From<ImmTy<'tcx, Prov>> for OpTy<'tcx, Prov> {
}
}
impl<'tcx, Prov: Provenance> From<&'_ ImmTy<'tcx, Prov>> for OpTy<'tcx, Prov> {
#[inline(always)]
fn from(val: &ImmTy<'tcx, Prov>) -> Self {
OpTy { op: Operand::Immediate(val.imm), layout: val.layout, align: None }
}
}
impl<'tcx, Prov: Provenance> From<&'_ mut ImmTy<'tcx, Prov>> for OpTy<'tcx, Prov> {
#[inline(always)]
fn from(val: &mut ImmTy<'tcx, Prov>) -> Self {
OpTy { op: Operand::Immediate(val.imm), layout: val.layout, align: None }
}
}
impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> {
#[inline]
pub fn from_scalar(val: Scalar<Prov>, layout: TyAndLayout<'tcx>) -> Self {
@ -341,7 +313,7 @@ impl<'tcx, Prov: Provenance> Projectable<'tcx, Prov> for ImmTy<'tcx, Prov> {
&self,
_ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
Ok(self.into())
Ok(self.clone().into())
}
}
@ -400,6 +372,31 @@ impl<'tcx, Prov: Provenance + 'static> Projectable<'tcx, Prov> for OpTy<'tcx, Pr
}
}
pub trait Readable<'tcx, Prov: Provenance>: Projectable<'tcx, Prov> {
fn as_mplace_or_imm(&self) -> Either<MPlaceTy<'tcx, Prov>, ImmTy<'tcx, Prov>>;
}
impl<'tcx, Prov: Provenance + 'static> Readable<'tcx, Prov> for OpTy<'tcx, Prov> {
#[inline(always)]
fn as_mplace_or_imm(&self) -> Either<MPlaceTy<'tcx, Prov>, ImmTy<'tcx, Prov>> {
self.as_mplace_or_imm()
}
}
impl<'tcx, Prov: Provenance + 'static> Readable<'tcx, Prov> for MPlaceTy<'tcx, Prov> {
#[inline(always)]
fn as_mplace_or_imm(&self) -> Either<MPlaceTy<'tcx, Prov>, ImmTy<'tcx, Prov>> {
Left(self.clone())
}
}
impl<'tcx, Prov: Provenance> Readable<'tcx, Prov> for ImmTy<'tcx, Prov> {
#[inline(always)]
fn as_mplace_or_imm(&self) -> Either<MPlaceTy<'tcx, Prov>, ImmTy<'tcx, Prov>> {
Right(self.clone())
}
}
impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// Try reading an immediate in memory; this is interesting particularly for `ScalarPair`.
/// Returns `None` if the layout does not permit loading this as a value.
@ -472,7 +469,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// ConstProp needs it, though.
pub fn read_immediate_raw(
&self,
src: &OpTy<'tcx, M::Provenance>,
src: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, Either<MPlaceTy<'tcx, M::Provenance>, ImmTy<'tcx, M::Provenance>>> {
Ok(match src.as_mplace_or_imm() {
Left(ref mplace) => {
@ -492,14 +489,18 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
#[inline(always)]
pub fn read_immediate(
&self,
op: &OpTy<'tcx, M::Provenance>,
op: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, ImmTy<'tcx, M::Provenance>> {
if !matches!(
op.layout.abi,
op.layout().abi,
Abi::Scalar(abi::Scalar::Initialized { .. })
| Abi::ScalarPair(abi::Scalar::Initialized { .. }, abi::Scalar::Initialized { .. })
) {
span_bug!(self.cur_span(), "primitive read not possible for type: {:?}", op.layout.ty);
span_bug!(
self.cur_span(),
"primitive read not possible for type: {:?}",
op.layout().ty
);
}
let imm = self.read_immediate_raw(op)?.right().unwrap();
if matches!(*imm, Immediate::Uninit) {
@ -511,7 +512,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// Read a scalar from a place
pub fn read_scalar(
&self,
op: &OpTy<'tcx, M::Provenance>,
op: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, Scalar<M::Provenance>> {
Ok(self.read_immediate(op)?.to_scalar())
}
@ -522,16 +523,22 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
/// Read a pointer from a place.
pub fn read_pointer(
&self,
op: &OpTy<'tcx, M::Provenance>,
op: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, Pointer<Option<M::Provenance>>> {
self.read_scalar(op)?.to_pointer(self)
}
/// Read a pointer-sized unsigned integer from a place.
pub fn read_target_usize(&self, op: &OpTy<'tcx, M::Provenance>) -> InterpResult<'tcx, u64> {
pub fn read_target_usize(
&self,
op: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, u64> {
self.read_scalar(op)?.to_target_usize(self)
}
/// Read a pointer-sized signed integer from a place.
pub fn read_target_isize(&self, op: &OpTy<'tcx, M::Provenance>) -> InterpResult<'tcx, i64> {
pub fn read_target_isize(
&self,
op: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, i64> {
self.read_scalar(op)?.to_target_isize(self)
}

22
compiler/rustc_const_eval/src/interpret/place.rs
View file

@ -18,7 +18,7 @@ use rustc_target::abi::{self, Abi, Align, FieldIdx, HasDataLayout, Size, FIRST_V
use super::{
alloc_range, mir_assign_valid_types, AllocId, AllocRef, AllocRefMut, CheckInAllocMsg,
ConstAlloc, ImmTy, Immediate, InterpCx, InterpResult, Machine, MemoryKind, OpTy, Operand,
Pointer, Projectable, Provenance, Scalar,
Pointer, Projectable, Provenance, Readable, Scalar,
};
#[derive(Copy, Clone, Hash, PartialEq, Eq, Debug)]
@ -246,7 +246,7 @@ impl<'tcx, Prov: Provenance + 'static> Projectable<'tcx, Prov> for MPlaceTy<'tcx
&self,
_ecx: &InterpCx<'mir, 'tcx, M>,
) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
Ok(self.into())
Ok(self.clone().into())
}
}
@ -442,7 +442,7 @@ where
#[instrument(skip(self), level = "debug")]
pub fn deref_operand(
&self,
src: &OpTy<'tcx, M::Provenance>,
src: &impl Readable<'tcx, M::Provenance>,
) -> InterpResult<'tcx, MPlaceTy<'tcx, M::Provenance>> {
let val = self.read_immediate(src)?;
trace!("deref to {} on {:?}", val.layout.ty, *val);
@ -766,7 +766,7 @@ where
#[instrument(skip(self), level = "debug")]
pub fn copy_op(
&mut self,
src: &OpTy<'tcx, M::Provenance>,
src: &impl Readable<'tcx, M::Provenance>,
dest: &impl Writeable<'tcx, M::Provenance>,
allow_transmute: bool,
) -> InterpResult<'tcx> {
@ -787,19 +787,19 @@ where
#[instrument(skip(self), level = "debug")]
fn copy_op_no_validate(
&mut self,
src: &OpTy<'tcx, M::Provenance>,
src: &impl Readable<'tcx, M::Provenance>,
dest: &impl Writeable<'tcx, M::Provenance>,
allow_transmute: bool,
) -> InterpResult<'tcx> {
// We do NOT compare the types for equality, because well-typed code can
// actually "transmute" `&mut T` to `&T` in an assignment without a cast.
let layout_compat =
mir_assign_valid_types(*self.tcx, self.param_env, src.layout, dest.layout());
mir_assign_valid_types(*self.tcx, self.param_env, src.layout(), dest.layout());
if !allow_transmute && !layout_compat {
span_bug!(
self.cur_span(),
"type mismatch when copying!\nsrc: {:?},\ndest: {:?}",
src.layout.ty,
src.layout().ty,
dest.layout().ty,
);
}
@ -813,13 +813,13 @@ where
// actually sized, due to a trivially false where-clause
// predicate like `where Self: Sized` with `Self = dyn Trait`.
// See #102553 for an example of such a predicate.
if src.layout.is_unsized() {
throw_inval!(SizeOfUnsizedType(src.layout.ty));
if src.layout().is_unsized() {
throw_inval!(SizeOfUnsizedType(src.layout().ty));
}
if dest.layout().is_unsized() {
throw_inval!(SizeOfUnsizedType(dest.layout().ty));
}
assert_eq!(src.layout.size, dest.layout().size);
assert_eq!(src.layout().size, dest.layout().size);
// Yay, we got a value that we can write directly.
return if layout_compat {
self.write_immediate_no_validate(*src_val, dest)
@ -831,7 +831,7 @@ where
let dest_mem = dest.force_mplace(self)?;
self.write_immediate_to_mplace_no_validate(
*src_val,
src.layout,
src.layout(),
dest_mem.align,
*dest_mem,
)