Enum rustc_middle::mir::Rvalue

pub enum Rvalue<'tcx> {
    Use(Operand<'tcx>),
    Repeat(Operand<'tcx>, Const<'tcx>),
    Ref(Region<'tcx>, BorrowKind, Place<'tcx>),
    ThreadLocalRef(DefId),
    AddressOf(Mutability, Place<'tcx>),
    Len(Place<'tcx>),
    Cast(CastKind, Operand<'tcx>, Ty<'tcx>),
    BinaryOp(BinOp, Box<(Operand<'tcx>, Operand<'tcx>)>),
    CheckedBinaryOp(BinOp, Box<(Operand<'tcx>, Operand<'tcx>)>),
    NullaryOp(NullOp, Ty<'tcx>),
    UnaryOp(UnOp, Operand<'tcx>),
    Discriminant(Place<'tcx>),
    Aggregate(Box<AggregateKind<'tcx>>, Vec<Operand<'tcx>>),
    ShallowInitBox(Operand<'tcx>, Ty<'tcx>),
}

Rvalues The various kinds of rvalues that can appear in MIR.

Not all of these are allowed at every MirPhase. Check the documentation there to see which ones you do not have to worry about. The MIR validator will generally enforce such restrictions, causing an ICE if they are violated.

Variants

Use(Operand<'tcx>)

x (either a move or copy, depending on type of x)

Repeat(Operand<'tcx>, Const<'tcx>)

[x; 32]

Ref(Region<'tcx>, BorrowKind, Place<'tcx>)

&x or &mut x

ThreadLocalRef(DefId)

Accessing a thread local static. This is inherently a runtime operation, even if llvm treats it as an access to a static. This Rvalue yields a reference to the thread local static.

AddressOf(Mutability, Place<'tcx>)

Create a raw pointer to the given place Can be generated by raw address of expressions (&raw const x), or when casting a reference to a raw pointer.

Len(Place<'tcx>)

length of a [X] or [X;n] value

Cast(CastKind, Operand<'tcx>, Ty<'tcx>)

BinaryOp(BinOp, Box<(Operand<'tcx>, Operand<'tcx>)>)

CheckedBinaryOp(BinOp, Box<(Operand<'tcx>, Operand<'tcx>)>)

NullaryOp(NullOp, Ty<'tcx>)

UnaryOp(UnOp, Operand<'tcx>)

Discriminant(Place<'tcx>)

Read the discriminant of an ADT.

Undefined (i.e., no effort is made to make it defined, but there’s no reason why it cannot be defined to return, say, a 0) if ADT is not an enum.

Aggregate(Box<AggregateKind<'tcx>>, Vec<Operand<'tcx>>)

Creates an aggregate value, like a tuple or struct. This is only needed because we want to distinguish dest = Foo { x: ..., y: ... } from dest.x = ...; dest.y = ...; in the case that Foo has a destructor. These rvalues can be optimized away after type-checking and before lowering.

ShallowInitBox(Operand<'tcx>, Ty<'tcx>)

Transmutes a *mut u8 into shallow-initialized Box<T>.

This is different a normal transmute because dataflow analysis will treat the box as initialized but its content as uninitialized.

Implementations

impl<'tcx> Rvalue<'tcx>

pub fn ty<D>(&self, local_decls: &D, tcx: TyCtxt<'tcx>) -> Ty<'tcx> where
    D: HasLocalDecls<'tcx>, 

pub fn initialization_state(&self) -> RvalueInitializationState

Returns true if this rvalue is deeply initialized (most rvalues) or whether its only shallowly initialized (Rvalue::Box).

Trait Implementations

impl<'tcx> Clone for Rvalue<'tcx>

fn clone(&self) -> Rvalue<'tcx>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'tcx> Debug for Rvalue<'tcx>

fn fmt(&self, fmt: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'tcx, __D: TyDecoder<'tcx>> Decodable<__D> for Rvalue<'tcx>

fn decode(__decoder: &mut __D) -> Self

impl<'tcx, __E: TyEncoder<'tcx>> Encodable<__E> for Rvalue<'tcx>

fn encode(&self, __encoder: &mut __E) -> Result<(), <__E as Encoder>::Error>

impl<'tcx> Hash for Rvalue<'tcx>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for Rvalue<'tcx>

fn hash_stable(
    &self,
    __hcx: &mut StableHashingContext<'__ctx>,
    __hasher: &mut StableHasher
)

impl<'tcx> PartialEq<Rvalue<'tcx>> for Rvalue<'tcx>

fn eq(&self, other: &Rvalue<'tcx>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rvalue<'tcx>) -> bool

This method tests for !=.

impl<'tcx> TypeFoldable<'tcx> for Rvalue<'tcx>

fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
    self,
    folder: &mut F
) -> Result<Self, F::Error>

Traverses the type in question, typically by calling try_fold_with on each field/element. This is true even for types of interest such as Ty. This should only be called within TypeFolder methods, when non-custom traversals are desired for types of interest.

fn super_visit_with<V: TypeVisitor<'tcx>>(
    &self,
    visitor: &mut V
) -> ControlFlow<V::BreakTy>

Traverses the type in question, typically by calling visit_with on each field/element. This is true even for types of interest such as Ty. This should only be called within TypeVisitor methods, when non-custom traversals are desired for types of interest.

fn try_fold_with<F: FallibleTypeFolder<'tcx>>(
    self,
    folder: &mut F
) -> Result<Self, F::Error>

The main entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f).

fn fold_with<F: TypeFolder<'tcx, Error = !>>(self, folder: &mut F) -> Self

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

fn super_fold_with<F: TypeFolder<'tcx, Error = !>>(self, folder: &mut F) -> Self

A convenient alternative to try_super_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_super_fold_with.

fn visit_with<V: TypeVisitor<'tcx>>(
    &self,
    visitor: &mut V
) -> ControlFlow<V::BreakTy>

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v).

fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool

Returns true if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free.

fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool

Returns true if this self has any regions that escape binder (and hence are not bound by it).

fn has_escaping_bound_vars(&self) -> bool

fn has_type_flags(&self, flags: TypeFlags) -> bool

fn has_projections(&self) -> bool

fn has_opaque_types(&self) -> bool

fn references_error(&self) -> bool

fn error_reported(&self) -> Option<ErrorGuaranteed>

fn has_param_types_or_consts(&self) -> bool

fn has_infer_regions(&self) -> bool

fn has_infer_types(&self) -> bool

fn has_infer_types_or_consts(&self) -> bool

fn needs_infer(&self) -> bool

fn has_placeholders(&self) -> bool

fn needs_subst(&self) -> bool

fn has_free_regions(&self) -> bool

“Free” regions in this context means that it has any region that is not (a) erased or (b) late-bound.

fn has_erased_regions(&self) -> bool

fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.

fn is_global(&self) -> bool

Indicates whether this value references only ‘global’ generic parameters that are the same regardless of what fn we are in. This is used for caching.

fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

fn still_further_specializable(&self) -> bool

Indicates whether this value still has parameters/placeholders/inference variables which could be replaced later, in a way that would change the results of impl specialization.

impl<'tcx> StructuralPartialEq for Rvalue<'tcx>

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 40 bytes

Size for each variant:

• Use: 31 bytes
• Repeat: 39 bytes
• Ref: 31 bytes
• ThreadLocalRef: 11 bytes
• AddressOf: 23 bytes
• Len: 23 bytes
• Cast: 39 bytes
• BinaryOp: 15 bytes
• CheckedBinaryOp: 15 bytes
• NullaryOp: 15 bytes
• UnaryOp: 31 bytes
• Discriminant: 23 bytes
• Aggregate: 39 bytes
• ShallowInitBox: 39 bytes