Enum rustc_middle::ty::instance::InstanceDef

pub enum InstanceDef<'tcx> {
    Item(WithOptConstParam<DefId>),
    Intrinsic(DefId),
    VtableShim(DefId),
    ReifyShim(DefId),
    FnPtrShim(DefId, Ty<'tcx>),
    Virtual(DefId, usize),
    ClosureOnceShim {
        call_once: DefId,
    },
    DropGlue(DefId, Option<Ty<'tcx>>),
    CloneShim(DefId, Ty<'tcx>),
}

Variants

Item(WithOptConstParam<DefId>)

A user-defined callable item.

This includes:

• fn items
• closures
• generators

Intrinsic(DefId)

An intrinsic fn item (with "rust-intrinsic" or "platform-intrinsic" ABI).

Alongside Virtual, this is the only InstanceDef that does not have its own callable MIR. Instead, codegen and const eval “magically” evaluate calls to intrinsics purely in the caller.

VtableShim(DefId)

<T as Trait>::method where method receives unsizeable self: Self (part of the unsized_locals feature).

The generated shim will take Self via *mut Self - conceptually this is &owned Self - and dereference the argument to call the original function.

ReifyShim(DefId)

fn() pointer where the function itself cannot be turned into a pointer.

One example is <dyn Trait as Trait>::fn, where the shim contains a virtual call, which codegen supports only via a direct call to the <dyn Trait as Trait>::fn instance (an InstanceDef::Virtual).

Another example is functions annotated with #[track_caller], which must have their implicit caller location argument populated for a call. Because this is a required part of the function’s ABI but can’t be tracked as a property of the function pointer, we use a single “caller location” (the definition of the function itself).

FnPtrShim(DefId, Ty<'tcx>)

<fn() as FnTrait>::call_* (generated FnTrait implementation for fn() pointers).

DefId is FnTrait::call_*.

Virtual(DefId, usize)

Dynamic dispatch to <dyn Trait as Trait>::fn.

This InstanceDef does not have callable MIR. Calls to Virtual instances must be codegen’d as virtual calls through the vtable.

If this is reified to a fn pointer, a ReifyShim is used (see ReifyShim above for more details on that).

ClosureOnceShim

<[FnMut closure] as FnOnce>::call_once.

The DefId is the ID of the call_once method in FnOnce.

Fields of ClosureOnceShim

call_once: DefId

DropGlue(DefId, Option<Ty<'tcx>>)

core::ptr::drop_in_place::<T>.

The DefId is for core::ptr::drop_in_place. The Option<Ty<'tcx>> is either Some(T), or None for empty drop glue.

CloneShim(DefId, Ty<'tcx>)

Compiler-generated <T as Clone>::clone implementation.

For all types that automatically implement Copy, a trivial Clone impl is provided too. Additionally, arrays, tuples, and closures get a Clone shim even if they aren’t Copy.

The DefId is for Clone::clone, the Ty is the type T with the builtin Clone impl.

Implementations

impl<'tcx> InstanceDef<'tcx>

pub fn def_id(self) -> DefId

pub fn with_opt_param(self) -> WithOptConstParam<DefId>

pub fn attrs(&self, tcx: TyCtxt<'tcx>) -> Attributes<'tcx>

pub fn requires_inline(&self, tcx: TyCtxt<'tcx>) -> bool

Returns true if the LLVM version of this instance is unconditionally marked with inline. This implies that a copy of this instance is generated in every codegen unit. Note that this is only a hint. See the documentation for generates_cgu_internal_copy for more information.

pub fn generates_cgu_internal_copy(&self, tcx: TyCtxt<'tcx>) -> bool

Returns true if the machine code for this instance is instantiated in each codegen unit that references it. Note that this is only a hint! The compiler can globally decide to not do this in order to speed up compilation. CGU-internal copies are only exist to enable inlining. If inlining is not performed (e.g. at -Copt-level=0) then the time for generating them is wasted and it’s better to create a single copy with external linkage.

pub fn requires_caller_location(&self, tcx: TyCtxt<'_>) -> bool

pub fn has_polymorphic_mir_body(&self) -> bool

Returns true when the MIR body associated with this instance should be monomorphized by its users (e.g. codegen or miri) by substituting the substs from Instance (see Instance::substs_for_mir_body).

Otherwise, returns false only for some kinds of shims where the construction of the MIR body should perform necessary substitutions.

Trait Implementations

impl<'tcx> Clone for InstanceDef<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for InstanceDef<'tcx>

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

Formats the value using the given formatter.

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

fn decode(__decoder: &mut __D) -> Result<Self, <__D as Decoder>::Error>

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

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

impl<'tcx> Hash for InstanceDef<'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 InstanceDef<'tcx>

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

impl<'a, 'tcx> Lift<'tcx> for InstanceDef<'a>

type Lifted = InstanceDef<'tcx>

fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted>

impl<'tcx> Ord for InstanceDef<'tcx>

fn cmp(&self, other: &InstanceDef<'tcx>) -> Ordering

This method returns an Ordering between self and other.

#[must_use]

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<'tcx> PartialEq<InstanceDef<'tcx>> for InstanceDef<'tcx>

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

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

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

This method tests for !=.

impl<'tcx> PartialOrd<InstanceDef<'tcx>> for InstanceDef<'tcx>

fn partial_cmp(&self, other: &InstanceDef<'tcx>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'tcx> TypeFoldable<'tcx> for InstanceDef<'tcx>

fn super_fold_with<__F: TypeFolder<'tcx>>(self, __folder: &mut __F) -> Self

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

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

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

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 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> Copy for InstanceDef<'tcx>

impl<'tcx> Eq for InstanceDef<'tcx>

impl<'tcx> StructuralEq for InstanceDef<'tcx>

impl<'tcx> StructuralPartialEq for InstanceDef<'tcx>