Merging upstream version 1.73.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 758 insertions, 6 deletions

diff --git a/compiler/rustc_smir/src/stable_mir/mir/body.rs b/compiler/rustc_smir/src/stable_mir/mir/body.rs
index 468e915d1..c16bd6cbd 100644
--- a/compiler/rustc_smir/src/stable_mir/mir/body.rs
+++ b/compiler/rustc_smir/src/stable_mir/mir/body.rs
@@ -1,4 +1,8 @@
-use crate::stable_mir::ty::Ty;
+use crate::rustc_internal::Opaque;
+use crate::stable_mir::ty::{
+    AdtDef, ClosureDef, Const, GeneratorDef, GenericArgs, Movability, Region,
+};
+use crate::stable_mir::{self, ty::Ty};
 
 #[derive(Clone, Debug)]
 pub struct Body {
@@ -130,18 +134,225 @@ pub enum AsyncGeneratorKind {
     Fn,
 }
 
+pub(crate) type LocalDefId = Opaque;
+pub(crate) type CounterValueReference = Opaque;
+pub(crate) type InjectedExpressionId = Opaque;
+pub(crate) type ExpressionOperandId = Opaque;
+
+/// The FakeReadCause describes the type of pattern why a FakeRead statement exists.
+#[derive(Clone, Debug)]
+pub enum FakeReadCause {
+    ForMatchGuard,
+    ForMatchedPlace(LocalDefId),
+    ForGuardBinding,
+    ForLet(LocalDefId),
+    ForIndex,
+}
+
+/// Describes what kind of retag is to be performed
+#[derive(Clone, Debug)]
+pub enum RetagKind {
+    FnEntry,
+    TwoPhase,
+    Raw,
+    Default,
+}
+
+#[derive(Clone, Debug)]
+pub enum Variance {
+    Covariant,
+    Invariant,
+    Contravariant,
+    Bivariant,
+}
+
+#[derive(Clone, Debug)]
+pub enum Op {
+    Subtract,
+    Add,
+}
+
+#[derive(Clone, Debug)]
+pub enum CoverageKind {
+    Counter {
+        function_source_hash: usize,
+        id: CounterValueReference,
+    },
+    Expression {
+        id: InjectedExpressionId,
+        lhs: ExpressionOperandId,
+        op: Op,
+        rhs: ExpressionOperandId,
+    },
+    Unreachable,
+}
+
+#[derive(Clone, Debug)]
+pub struct CodeRegion {
+    pub file_name: String,
+    pub start_line: usize,
+    pub start_col: usize,
+    pub end_line: usize,
+    pub end_col: usize,
+}
+
+#[derive(Clone, Debug)]
+pub struct Coverage {
+    pub kind: CoverageKind,
+    pub code_region: Option<CodeRegion>,
+}
+
+#[derive(Clone, Debug)]
+pub struct CopyNonOverlapping {
+    pub src: Operand,
+    pub dst: Operand,
+    pub count: Operand,
+}
+
+#[derive(Clone, Debug)]
+pub enum NonDivergingIntrinsic {
+    Assume(Operand),
+    CopyNonOverlapping(CopyNonOverlapping),
+}
+
 #[derive(Clone, Debug)]
 pub enum Statement {
     Assign(Place, Rvalue),
+    FakeRead(FakeReadCause, Place),
+    SetDiscriminant { place: Place, variant_index: VariantIdx },
+    Deinit(Place),
+    StorageLive(Local),
+    StorageDead(Local),
+    Retag(RetagKind, Place),
+    PlaceMention(Place),
+    AscribeUserType { place: Place, projections: UserTypeProjection, variance: Variance },
+    Coverage(Coverage),
+    Intrinsic(NonDivergingIntrinsic),
+    ConstEvalCounter,
     Nop,
 }
 
-// FIXME this is incomplete
 #[derive(Clone, Debug)]
 pub enum Rvalue {
-    Use(Operand),
+    /// Creates a pointer with the indicated mutability to the place.
+    ///
+    /// This is generated by pointer casts like `&v as *const _` or raw address of expressions like
+    /// `&raw v` or `addr_of!(v)`.
+    AddressOf(Mutability, Place),
+
+    /// Creates an aggregate value, like a tuple or struct.
+    ///
+    /// This is needed because dataflow analysis needs to distinguish
+    /// `dest = Foo { x: ..., y: ... }` from `dest.x = ...; dest.y = ...;` in the case that `Foo`
+    /// has a destructor.
+    ///
+    /// Disallowed after deaggregation for all aggregate kinds except `Array` and `Generator`. After
+    /// generator lowering, `Generator` aggregate kinds are disallowed too.
+    Aggregate(AggregateKind, Vec<Operand>),
+
+    /// * `Offset` has the same semantics as [`offset`](pointer::offset), except that the second
+    ///   parameter may be a `usize` as well.
+    /// * The comparison operations accept `bool`s, `char`s, signed or unsigned integers, floats,
+    ///   raw pointers, or function pointers and return a `bool`. The types of the operands must be
+    ///   matching, up to the usual caveat of the lifetimes in function pointers.
+    /// * Left and right shift operations accept signed or unsigned integers not necessarily of the
+    ///   same type and return a value of the same type as their LHS. Like in Rust, the RHS is
+    ///   truncated as needed.
+    /// * The `Bit*` operations accept signed integers, unsigned integers, or bools with matching
+    ///   types and return a value of that type.
+    /// * The remaining operations accept signed integers, unsigned integers, or floats with
+    ///   matching types and return a value of that type.
+    BinaryOp(BinOp, Operand, Operand),
+
+    /// Performs essentially all of the casts that can be performed via `as`.
+    ///
+    /// This allows for casts from/to a variety of types.
+    Cast(CastKind, Operand, Ty),
+
+    /// Same as `BinaryOp`, but yields `(T, bool)` with a `bool` indicating an error condition.
+    ///
+    /// For addition, subtraction, and multiplication on integers the error condition is set when
+    /// the infinite precision result would not be equal to the actual result.
     CheckedBinaryOp(BinOp, Operand, Operand),
+
+    /// A CopyForDeref is equivalent to a read from a place.
+    /// When such a read happens, it is guaranteed that the only use of the returned value is a
+    /// deref operation, immediately followed by one or more projections.
+    CopyForDeref(Place),
+
+    /// Computes the discriminant of the place, returning it as an integer of type
+    /// [`discriminant_ty`]. Returns zero for types without discriminant.
+    ///
+    /// The validity requirements for the underlying value are undecided for this rvalue, see
+    /// [#91095]. Note too that the value of the discriminant is not the same thing as the
+    /// variant index; use [`discriminant_for_variant`] to convert.
+    ///
+    /// [`discriminant_ty`]: rustc_middle::ty::Ty::discriminant_ty
+    /// [#91095]: https://github.com/rust-lang/rust/issues/91095
+    /// [`discriminant_for_variant`]: rustc_middle::ty::Ty::discriminant_for_variant
+    Discriminant(Place),
+
+    /// Yields the length of the place, as a `usize`.
+    ///
+    /// If the type of the place is an array, this is the array length. For slices (`[T]`, not
+    /// `&[T]`) this accesses the place's metadata to determine the length. This rvalue is
+    /// ill-formed for places of other types.
+    Len(Place),
+
+    /// Creates a reference to the place.
+    Ref(Region, BorrowKind, Place),
+
+    /// Creates an array where each element is the value of the operand.
+    ///
+    /// This is the cause of a bug in the case where the repetition count is zero because the value
+    /// is not dropped, see [#74836].
+    ///
+    /// Corresponds to source code like `[x; 32]`.
+    ///
+    /// [#74836]: https://github.com/rust-lang/rust/issues/74836
+    Repeat(Operand, Const),
+
+    /// Transmutes a `*mut u8` into shallow-initialized `Box<T>`.
+    ///
+    /// This is different from a normal transmute because dataflow analysis will treat the box as
+    /// initialized but its content as uninitialized. Like other pointer casts, this in general
+    /// affects alias analysis.
+    ShallowInitBox(Operand, Ty),
+
+    /// Creates a pointer/reference to the given thread local.
+    ///
+    /// The yielded type is a `*mut T` if the static is mutable, otherwise if the static is extern a
+    /// `*const T`, and if neither of those apply a `&T`.
+    ///
+    /// **Note:** This is a runtime operation that actually executes code and is in this sense more
+    /// like a function call. Also, eliminating dead stores of this rvalue causes `fn main() {}` to
+    /// SIGILL for some reason that I (JakobDegen) never got a chance to look into.
+    ///
+    /// **Needs clarification**: Are there weird additional semantics here related to the runtime
+    /// nature of this operation?
+    ThreadLocalRef(stable_mir::CrateItem),
+
+    /// Computes a value as described by the operation.
+    NullaryOp(NullOp, Ty),
+
+    /// Exactly like `BinaryOp`, but less operands.
+    ///
+    /// Also does two's-complement arithmetic. Negation requires a signed integer or a float;
+    /// bitwise not requires a signed integer, unsigned integer, or bool. Both operation kinds
+    /// return a value with the same type as their operand.
     UnaryOp(UnOp, Operand),
+
+    /// Yields the operand unchanged
+    Use(Operand),
+}
+
+#[derive(Clone, Debug)]
+pub enum AggregateKind {
+    Array(Ty),
+    Tuple,
+    Adt(AdtDef, VariantIdx, GenericArgs, Option<UserTypeAnnotationIndex>, Option<FieldIdx>),
+    Closure(ClosureDef, GenericArgs),
+    Generator(GeneratorDef, GenericArgs, Movability),
 }
 
 #[derive(Clone, Debug)]
@@ -153,12 +364,115 @@ pub enum Operand {
 
 #[derive(Clone, Debug)]
 pub struct Place {
-    pub local: usize,
+    pub local: Local,
     pub projection: String,
 }
 
 #[derive(Clone, Debug)]
+pub struct UserTypeProjection {
+    pub base: UserTypeAnnotationIndex,
+    pub projection: String,
+}
+
+pub type Local = usize;
+
+type FieldIdx = usize;
+
+/// The source-order index of a variant in a type.
+pub type VariantIdx = usize;
+
+type UserTypeAnnotationIndex = usize;
+
+#[derive(Clone, Debug)]
 pub struct SwitchTarget {
     pub value: u128,
     pub target: usize,
 }
+
+#[derive(Clone, Debug)]
+pub enum BorrowKind {
+    /// Data must be immutable and is aliasable.
+    Shared,
+
+    /// The immediately borrowed place must be immutable, but projections from
+    /// it don't need to be. For example, a shallow borrow of `a.b` doesn't
+    /// conflict with a mutable borrow of `a.b.c`.
+    Shallow,
+
+    /// Data is mutable and not aliasable.
+    Mut {
+        /// `true` if this borrow arose from method-call auto-ref
+        kind: MutBorrowKind,
+    },
+}
+
+#[derive(Clone, Debug)]
+pub enum MutBorrowKind {
+    Default,
+    TwoPhaseBorrow,
+    ClosureCapture,
+}
+
+#[derive(Clone, Debug)]
+pub enum Mutability {
+    Not,
+    Mut,
+}
+
+#[derive(Clone, Debug)]
+pub enum Safety {
+    Unsafe,
+    Normal,
+}
+
+#[derive(Clone, Debug)]
+pub enum PointerCoercion {
+    /// Go from a fn-item type to a fn-pointer type.
+    ReifyFnPointer,
+
+    /// Go from a safe fn pointer to an unsafe fn pointer.
+    UnsafeFnPointer,
+
+    /// Go from a non-capturing closure to an fn pointer or an unsafe fn pointer.
+    /// It cannot convert a closure that requires unsafe.
+    ClosureFnPointer(Safety),
+
+    /// Go from a mut raw pointer to a const raw pointer.
+    MutToConstPointer,
+
+    /// Go from `*const [T; N]` to `*const T`
+    ArrayToPointer,
+
+    /// Unsize a pointer/reference value, e.g., `&[T; n]` to
+    /// `&[T]`. Note that the source could be a thin or fat pointer.
+    /// This will do things like convert thin pointers to fat
+    /// pointers, or convert structs containing thin pointers to
+    /// structs containing fat pointers, or convert between fat
+    /// pointers.
+    Unsize,
+}
+
+#[derive(Clone, Debug)]
+pub enum CastKind {
+    PointerExposeAddress,
+    PointerFromExposedAddress,
+    PointerCoercion(PointerCoercion),
+    DynStar,
+    IntToInt,
+    FloatToInt,
+    FloatToFloat,
+    IntToFloat,
+    PtrToPtr,
+    FnPtrToPtr,
+    Transmute,
+}
+
+#[derive(Clone, Debug)]
+pub enum NullOp {
+    /// Returns the size of a value of that type.
+    SizeOf,
+    /// Returns the minimum alignment of a type.
+    AlignOf,
+    /// Returns the offset of a field.
+    OffsetOf(Vec<FieldIdx>),
+}
diff --git a/compiler/rustc_smir/src/stable_mir/mod.rs b/compiler/rustc_smir/src/stable_mir/mod.rs
index 5e599a77b..19061742b 100644
--- a/compiler/rustc_smir/src/stable_mir/mod.rs
+++ b/compiler/rustc_smir/src/stable_mir/mod.rs
@@ -15,7 +15,7 @@ use std::cell::Cell;
 
 use crate::rustc_smir::Tables;
 
-use self::ty::{Ty, TyKind};
+use self::ty::{ImplDef, ImplTrait, TraitDecl, TraitDef, Ty, TyKind};
 
 pub mod mir;
 pub mod ty;
@@ -32,6 +32,12 @@ pub type DefId = usize;
 /// A list of crate items.
 pub type CrateItems = Vec<CrateItem>;
 
+/// A list of trait decls.
+pub type TraitDecls = Vec<TraitDef>;
+
+/// A list of impl trait decls.
+pub type ImplTraitDecls = Vec<ImplDef>;
+
 /// Holds information about a crate.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct Crate {
@@ -79,11 +85,31 @@ pub fn all_local_items() -> CrateItems {
     with(|cx| cx.all_local_items())
 }
 
+pub fn all_trait_decls() -> TraitDecls {
+    with(|cx| cx.all_trait_decls())
+}
+
+pub fn trait_decl(trait_def: &TraitDef) -> TraitDecl {
+    with(|cx| cx.trait_decl(trait_def))
+}
+
+pub fn all_trait_impls() -> ImplTraitDecls {
+    with(|cx| cx.all_trait_impls())
+}
+
+pub fn trait_impl(trait_impl: &ImplDef) -> ImplTrait {
+    with(|cx| cx.trait_impl(trait_impl))
+}
+
 pub trait Context {
     fn entry_fn(&mut self) -> Option<CrateItem>;
     /// Retrieve all items of the local crate that have a MIR associated with them.
     fn all_local_items(&mut self) -> CrateItems;
     fn mir_body(&mut self, item: &CrateItem) -> mir::Body;
+    fn all_trait_decls(&mut self) -> TraitDecls;
+    fn trait_decl(&mut self, trait_def: &TraitDef) -> TraitDecl;
+    fn all_trait_impls(&mut self) -> ImplTraitDecls;
+    fn trait_impl(&mut self, trait_impl: &ImplDef) -> ImplTrait;
     /// Get information about the local crate.
     fn local_crate(&self) -> Crate;
     /// Retrieve a list of all external crates.
diff --git a/compiler/rustc_smir/src/stable_mir/ty.rs b/compiler/rustc_smir/src/stable_mir/ty.rs
index 3181af46e..7a6601f09 100644
--- a/compiler/rustc_smir/src/stable_mir/ty.rs
+++ b/compiler/rustc_smir/src/stable_mir/ty.rs
@@ -1,4 +1,10 @@
-use super::with;
+use rustc_middle::mir::interpret::{alloc_range, AllocRange, ConstValue, Pointer};
+
+use super::{mir::Mutability, mir::Safety, with, DefId};
+use crate::{
+    rustc_internal::{opaque, Opaque},
+    rustc_smir::{Stable, Tables},
+};
 
 #[derive(Copy, Clone, Debug)]
 pub struct Ty(pub usize);
@@ -9,9 +15,21 @@ impl Ty {
     }
 }
 
+#[derive(Debug, Clone)]
+pub struct Const {
+    pub literal: ConstantKind,
+}
+
+type Ident = Opaque;
+pub(crate) type Region = Opaque;
+type Span = Opaque;
+
 #[derive(Clone, Debug)]
 pub enum TyKind {
     RigidTy(RigidTy),
+    Alias(AliasKind, AliasTy),
+    Param(ParamTy),
+    Bound(usize, BoundTy),
 }
 
 #[derive(Clone, Debug)]
@@ -21,6 +39,19 @@ pub enum RigidTy {
     Int(IntTy),
     Uint(UintTy),
     Float(FloatTy),
+    Adt(AdtDef, GenericArgs),
+    Foreign(ForeignDef),
+    Str,
+    Array(Ty, Const),
+    Slice(Ty),
+    RawPtr(Ty, Mutability),
+    Ref(Region, Ty, Mutability),
+    FnDef(FnDef, GenericArgs),
+    FnPtr(PolyFnSig),
+    Closure(ClosureDef, GenericArgs),
+    Generator(GeneratorDef, GenericArgs, Movability),
+    Dynamic(Vec<Binder<ExistentialPredicate>>, Region, DynKind),
+    Never,
     Tuple(Vec<Ty>),
 }
 
@@ -49,3 +80,384 @@ pub enum FloatTy {
     F32,
     F64,
 }
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Movability {
+    Static,
+    Movable,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct ForeignDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct FnDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct ClosureDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct GeneratorDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct ParamDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct BrNamedDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct AdtDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct AliasDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct TraitDef(pub(crate) DefId);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct ConstDef(pub(crate) DefId);
+
+impl TraitDef {
+    pub fn trait_decl(&self) -> TraitDecl {
+        with(|cx| cx.trait_decl(self))
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct ImplDef(pub(crate) DefId);
+
+impl ImplDef {
+    pub fn trait_impl(&self) -> ImplTrait {
+        with(|cx| cx.trait_impl(self))
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct GenericArgs(pub Vec<GenericArgKind>);
+
+#[derive(Clone, Debug)]
+pub enum GenericArgKind {
+    Lifetime(Region),
+    Type(Ty),
+    Const(Const),
+}
+
+#[derive(Clone, Debug)]
+pub enum TermKind {
+    Type(Ty),
+    Const(Const),
+}
+
+#[derive(Clone, Debug)]
+pub enum AliasKind {
+    Projection,
+    Inherent,
+    Opaque,
+    Weak,
+}
+
+#[derive(Clone, Debug)]
+pub struct AliasTy {
+    pub def_id: AliasDef,
+    pub args: GenericArgs,
+}
+
+pub type PolyFnSig = Binder<FnSig>;
+
+#[derive(Clone, Debug)]
+pub struct FnSig {
+    pub inputs_and_output: Vec<Ty>,
+    pub c_variadic: bool,
+    pub unsafety: Safety,
+    pub abi: Abi,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum Abi {
+    Rust,
+    C { unwind: bool },
+    Cdecl { unwind: bool },
+    Stdcall { unwind: bool },
+    Fastcall { unwind: bool },
+    Vectorcall { unwind: bool },
+    Thiscall { unwind: bool },
+    Aapcs { unwind: bool },
+    Win64 { unwind: bool },
+    SysV64 { unwind: bool },
+    PtxKernel,
+    Msp430Interrupt,
+    X86Interrupt,
+    AmdGpuKernel,
+    EfiApi,
+    AvrInterrupt,
+    AvrNonBlockingInterrupt,
+    CCmseNonSecureCall,
+    Wasm,
+    System { unwind: bool },
+    RustIntrinsic,
+    RustCall,
+    PlatformIntrinsic,
+    Unadjusted,
+    RustCold,
+    RiscvInterruptM,
+    RiscvInterruptS,
+}
+
+#[derive(Clone, Debug)]
+pub struct Binder<T> {
+    pub value: T,
+    pub bound_vars: Vec<BoundVariableKind>,
+}
+
+#[derive(Clone, Debug)]
+pub struct EarlyBinder<T> {
+    pub value: T,
+}
+
+#[derive(Clone, Debug)]
+pub enum BoundVariableKind {
+    Ty(BoundTyKind),
+    Region(BoundRegionKind),
+    Const,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum BoundTyKind {
+    Anon,
+    Param(ParamDef, String),
+}
+
+#[derive(Clone, Debug)]
+pub enum BoundRegionKind {
+    BrAnon(Option<Span>),
+    BrNamed(BrNamedDef, String),
+    BrEnv,
+}
+
+#[derive(Clone, Debug)]
+pub enum DynKind {
+    Dyn,
+    DynStar,
+}
+
+#[derive(Clone, Debug)]
+pub enum ExistentialPredicate {
+    Trait(ExistentialTraitRef),
+    Projection(ExistentialProjection),
+    AutoTrait(TraitDef),
+}
+
+#[derive(Clone, Debug)]
+pub struct ExistentialTraitRef {
+    pub def_id: TraitDef,
+    pub generic_args: GenericArgs,
+}
+
+#[derive(Clone, Debug)]
+pub struct ExistentialProjection {
+    pub def_id: TraitDef,
+    pub generic_args: GenericArgs,
+    pub term: TermKind,
+}
+
+#[derive(Clone, Debug)]
+pub struct ParamTy {
+    pub index: u32,
+    pub name: String,
+}
+
+#[derive(Clone, Debug)]
+pub struct BoundTy {
+    pub var: usize,
+    pub kind: BoundTyKind,
+}
+
+pub type Bytes = Vec<Option<u8>>;
+pub type Size = usize;
+pub type Prov = Opaque;
+pub type Align = u64;
+pub type Promoted = u32;
+pub type InitMaskMaterialized = Vec<u64>;
+
+/// Stores the provenance information of pointers stored in memory.
+#[derive(Clone, Debug)]
+pub struct ProvenanceMap {
+    /// Provenance in this map applies from the given offset for an entire pointer-size worth of
+    /// bytes. Two entries in this map are always at least a pointer size apart.
+    pub ptrs: Vec<(Size, Prov)>,
+}
+
+#[derive(Clone, Debug)]
+pub struct Allocation {
+    pub bytes: Bytes,
+    pub provenance: ProvenanceMap,
+    pub align: Align,
+    pub mutability: Mutability,
+}
+
+impl Allocation {
+    /// Creates new empty `Allocation` from given `Align`.
+    fn new_empty_allocation(align: rustc_target::abi::Align) -> Allocation {
+        Allocation {
+            bytes: Vec::new(),
+            provenance: ProvenanceMap { ptrs: Vec::new() },
+            align: align.bytes(),
+            mutability: Mutability::Not,
+        }
+    }
+}
+
+// We need this method instead of a Stable implementation
+// because we need to get `Ty` of the const we are trying to create, to do that
+// we need to have access to `ConstantKind` but we can't access that inside Stable impl.
+pub fn new_allocation<'tcx>(
+    const_kind: &rustc_middle::mir::ConstantKind<'tcx>,
+    const_value: ConstValue<'tcx>,
+    tables: &mut Tables<'tcx>,
+) -> Allocation {
+    match const_value {
+        ConstValue::Scalar(scalar) => {
+            let size = scalar.size();
+            let align = tables
+                .tcx
+                .layout_of(rustc_middle::ty::ParamEnv::reveal_all().and(const_kind.ty()))
+                .unwrap()
+                .align;
+            let mut allocation = rustc_middle::mir::interpret::Allocation::uninit(size, align.abi);
+            allocation
+                .write_scalar(&tables.tcx, alloc_range(rustc_target::abi::Size::ZERO, size), scalar)
+                .unwrap();
+            allocation.stable(tables)
+        }
+        ConstValue::ZeroSized => {
+            let align = tables
+                .tcx
+                .layout_of(rustc_middle::ty::ParamEnv::empty().and(const_kind.ty()))
+                .unwrap()
+                .align;
+            Allocation::new_empty_allocation(align.abi)
+        }
+        ConstValue::Slice { data, start, end } => {
+            let alloc_id = tables.tcx.create_memory_alloc(data);
+            let ptr = Pointer::new(alloc_id, rustc_target::abi::Size::from_bytes(start));
+            let scalar_ptr = rustc_middle::mir::interpret::Scalar::from_pointer(ptr, &tables.tcx);
+            let scalar_len = rustc_middle::mir::interpret::Scalar::from_target_usize(
+                (end - start) as u64,
+                &tables.tcx,
+            );
+            let layout = tables
+                .tcx
+                .layout_of(rustc_middle::ty::ParamEnv::reveal_all().and(const_kind.ty()))
+                .unwrap();
+            let mut allocation =
+                rustc_middle::mir::interpret::Allocation::uninit(layout.size, layout.align.abi);
+            allocation
+                .write_scalar(
+                    &tables.tcx,
+                    alloc_range(rustc_target::abi::Size::ZERO, tables.tcx.data_layout.pointer_size),
+                    scalar_ptr,
+                )
+                .unwrap();
+            allocation
+                .write_scalar(
+                    &tables.tcx,
+                    alloc_range(tables.tcx.data_layout.pointer_size, scalar_len.size()),
+                    scalar_len,
+                )
+                .unwrap();
+            allocation.stable(tables)
+        }
+        ConstValue::ByRef { alloc, offset } => {
+            let ty_size = tables
+                .tcx
+                .layout_of(rustc_middle::ty::ParamEnv::reveal_all().and(const_kind.ty()))
+                .unwrap()
+                .size;
+            allocation_filter(&alloc.0, alloc_range(offset, ty_size), tables)
+        }
+    }
+}
+
+/// Creates an `Allocation` only from information within the `AllocRange`.
+pub fn allocation_filter<'tcx>(
+    alloc: &rustc_middle::mir::interpret::Allocation,
+    alloc_range: AllocRange,
+    tables: &mut Tables<'tcx>,
+) -> Allocation {
+    let mut bytes: Vec<Option<u8>> = alloc
+        .inspect_with_uninit_and_ptr_outside_interpreter(
+            alloc_range.start.bytes_usize()..alloc_range.end().bytes_usize(),
+        )
+        .iter()
+        .copied()
+        .map(Some)
+        .collect();
+    for (i, b) in bytes.iter_mut().enumerate() {
+        if !alloc
+            .init_mask()
+            .get(rustc_target::abi::Size::from_bytes(i + alloc_range.start.bytes_usize()))
+        {
+            *b = None;
+        }
+    }
+    let mut ptrs = Vec::new();
+    for (offset, prov) in alloc
+        .provenance()
+        .ptrs()
+        .iter()
+        .filter(|a| a.0 >= alloc_range.start && a.0 <= alloc_range.end())
+    {
+        ptrs.push((offset.bytes_usize() - alloc_range.start.bytes_usize(), opaque(prov)));
+    }
+    Allocation {
+        bytes: bytes,
+        provenance: ProvenanceMap { ptrs },
+        align: alloc.align.bytes(),
+        mutability: alloc.mutability.stable(tables),
+    }
+}
+
+#[derive(Clone, Debug)]
+pub enum ConstantKind {
+    Allocated(Allocation),
+    Unevaluated(UnevaluatedConst),
+    ParamCt(Opaque),
+}
+
+#[derive(Clone, Debug)]
+pub struct UnevaluatedConst {
+    pub ty: Ty,
+    pub def: ConstDef,
+    pub args: GenericArgs,
+    pub promoted: Option<Promoted>,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum TraitSpecializationKind {
+    None,
+    Marker,
+    AlwaysApplicable,
+}
+
+#[derive(Clone, Debug)]
+pub struct TraitDecl {
+    pub def_id: TraitDef,
+    pub unsafety: Safety,
+    pub paren_sugar: bool,
+    pub has_auto_impl: bool,
+    pub is_marker: bool,
+    pub is_coinductive: bool,
+    pub skip_array_during_method_dispatch: bool,
+    pub specialization_kind: TraitSpecializationKind,
+    pub must_implement_one_of: Option<Vec<Ident>>,
+    pub implement_via_object: bool,
+    pub deny_explicit_impl: bool,
+}
+
+pub type ImplTrait = EarlyBinder<TraitRef>;
+
+#[derive(Clone, Debug)]
+pub struct TraitRef {
+    pub def_id: TraitDef,
+    pub args: GenericArgs,
+}