Enum rustc_middle::ty::instance::InstanceDef [−][src]
pub enum InstanceDef<'tcx> {
Item(WithOptConstParam<DefId>),
Intrinsic(DefId),
VtableShim(DefId),
ReifyShim(DefId),
FnPtrShim(DefId, Ty<'tcx>),
Virtual(DefId, usize),
ClosureOnceShim {
call_once: DefId,
track_caller: bool,
},
DropGlue(DefId, Option<Ty<'tcx>>),
CloneShim(DefId, Ty<'tcx>),
}
Variants
Item(WithOptConstParam<DefId>)
A user-defined callable item.
This includes:
fn
items- closures
- generators
Tuple Fields of Item
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.
Tuple Fields of Intrinsic
0: DefId
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.
Tuple Fields of VtableShim
0: DefId
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).
Tuple Fields of ReifyShim
0: DefId
<fn() as FnTrait>::call_*
(generated FnTrait
implementation for fn()
pointers).
DefId
is FnTrait::call_*
.
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).
<[FnMut closure] as FnOnce>::call_once
.
The DefId
is the ID of the call_once
method in FnOnce
.
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.
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
Returns the DefId
of instances which might not require codegen locally.
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.
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.
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
type Lifted = InstanceDef<'tcx>
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
This method tests for !=
.
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
fn super_visit_with<__F: TypeVisitor<'tcx>>(
&self,
__folder: &mut __F
) -> ControlFlow<__F::BreakTy>
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. Read more
Returns true
if this self
has any regions that escape binder
(and
hence are not bound by it). Read more
“Free” regions in this context means that it has any region that is not (a) erased or (b) late-bound. Read more
True if there are any un-erased free regions.
Indicates whether this value definitely references only ‘global’ generic parameters that are the same regardless of what fn we are in. This is used for caching. Read more
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. Read more
True if there are any late-bound regions
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. Read more
Auto Trait Implementations
impl<'tcx> !RefUnwindSafe for InstanceDef<'tcx>
impl<'tcx> !Send for InstanceDef<'tcx>
impl<'tcx> !Sync for InstanceDef<'tcx>
impl<'tcx> Unpin for InstanceDef<'tcx>
impl<'tcx> !UnwindSafe for InstanceDef<'tcx>
Blanket Implementations
Mutably borrows from an owned value. Read more
impl<Ctxt, T> DepNodeParams<Ctxt> for T where
Ctxt: DepContext,
T: for<'a> HashStable<StableHashingContext<'a>> + Debug,
impl<Ctxt, T> DepNodeParams<Ctxt> for T where
Ctxt: DepContext,
T: for<'a> HashStable<StableHashingContext<'a>> + Debug,
This method turns the parameters of a DepNodeConstructor into an opaque Fingerprint to be used in DepNode. Not all DepNodeParams support being turned into a Fingerprint (they don’t need to if the corresponding DepNode is anonymous). Read more
This method tries to recover the query key from the given DepNode
,
something which is needed when forcing DepNode
s during red-green
evaluation. The query system will only call this method if
fingerprint_style()
is not FingerprintStyle::Opaque
.
It is always valid to return None
here, in which case incremental
compilation will treat the query as having changed instead of forcing it. Read more
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: 24 bytes
Size for each variant:
Item
: 19 bytesIntrinsic
: 11 bytesVtableShim
: 11 bytesReifyShim
: 11 bytesFnPtrShim
: 23 bytesVirtual
: 23 bytesClosureOnceShim
: 11 bytesDropGlue
: 23 bytesCloneShim
: 23 bytes