use crate::ty::codec::{TyDecoder, TyEncoder};
use crate::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable};
use crate::ty::sty::{ClosureArgs, GeneratorArgs, InlineConstArgs};
use crate::ty::visit::{TypeVisitable, TypeVisitableExt, TypeVisitor};
use crate::ty::{self, Lift, List, ParamConst, Ty, TyCtxt};
use rustc_data_structures::intern::Interned;
use rustc_errors::{DiagnosticArgValue, IntoDiagnosticArg};
use rustc_hir::def_id::DefId;
use rustc_macros::HashStable;
use rustc_serialize::{self, Decodable, Encodable};
use rustc_span::sym;
use rustc_type_ir::WithCachedTypeInfo;
use smallvec::SmallVec;
use core::intrinsics;
use std::cmp::Ordering;
use std::marker::PhantomData;
use std::mem;
use std::num::NonZeroUsize;
use std::ops::{ControlFlow, Deref};
#[derive(Copy, Clone, PartialEq, Eq, Hash)]
pub struct GenericArg<'tcx> {
ptr: NonZeroUsize,
marker: PhantomData<(Ty<'tcx>, ty::Region<'tcx>, ty::Const<'tcx>)>,
}
impl<'tcx> IntoDiagnosticArg for GenericArg<'tcx> {
fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
self.to_string().into_diagnostic_arg()
}
}
const TAG_MASK: usize = 0b11;
const TYPE_TAG: usize = 0b00;
const REGION_TAG: usize = 0b01;
const CONST_TAG: usize = 0b10;
#[derive(Debug, TyEncodable, TyDecodable, PartialEq, Eq, PartialOrd, Ord, HashStable)]
pub enum GenericArgKind<'tcx> {
Lifetime(ty::Region<'tcx>),
Type(Ty<'tcx>),
Const(ty::Const<'tcx>),
}
impl<'tcx> GenericArgKind<'tcx> {
#[inline]
fn pack(self) -> GenericArg<'tcx> {
let (tag, ptr) = match self {
GenericArgKind::Lifetime(lt) => {
assert_eq!(mem::align_of_val(&*lt.0.0) & TAG_MASK, 0);
(REGION_TAG, lt.0.0 as *const ty::RegionKind<'tcx> as usize)
}
GenericArgKind::Type(ty) => {
assert_eq!(mem::align_of_val(&*ty.0.0) & TAG_MASK, 0);
(TYPE_TAG, ty.0.0 as *const WithCachedTypeInfo<ty::TyKind<'tcx>> as usize)
}
GenericArgKind::Const(ct) => {
assert_eq!(mem::align_of_val(&*ct.0.0) & TAG_MASK, 0);
(CONST_TAG, ct.0.0 as *const ty::ConstData<'tcx> as usize)
}
};
GenericArg { ptr: unsafe { NonZeroUsize::new_unchecked(ptr | tag) }, marker: PhantomData }
}
}
impl<'tcx> Ord for GenericArg<'tcx> {
fn cmp(&self, other: &GenericArg<'tcx>) -> Ordering {
self.unpack().cmp(&other.unpack())
}
}
impl<'tcx> PartialOrd for GenericArg<'tcx> {
fn partial_cmp(&self, other: &GenericArg<'tcx>) -> Option<Ordering> {
Some(self.cmp(&other))
}
}
impl<'tcx> From<ty::Region<'tcx>> for GenericArg<'tcx> {
#[inline]
fn from(r: ty::Region<'tcx>) -> GenericArg<'tcx> {
GenericArgKind::Lifetime(r).pack()
}
}
impl<'tcx> From<Ty<'tcx>> for GenericArg<'tcx> {
#[inline]
fn from(ty: Ty<'tcx>) -> GenericArg<'tcx> {
GenericArgKind::Type(ty).pack()
}
}
impl<'tcx> From<ty::Const<'tcx>> for GenericArg<'tcx> {
#[inline]
fn from(c: ty::Const<'tcx>) -> GenericArg<'tcx> {
GenericArgKind::Const(c).pack()
}
}
impl<'tcx> From<ty::Term<'tcx>> for GenericArg<'tcx> {
fn from(value: ty::Term<'tcx>) -> Self {
match value.unpack() {
ty::TermKind::Ty(t) => t.into(),
ty::TermKind::Const(c) => c.into(),
}
}
}
impl<'tcx> GenericArg<'tcx> {
#[inline]
pub fn unpack(self) -> GenericArgKind<'tcx> {
let ptr = self.ptr.get();
unsafe {
match ptr & TAG_MASK {
REGION_TAG => GenericArgKind::Lifetime(ty::Region(Interned::new_unchecked(
&*((ptr & !TAG_MASK) as *const ty::RegionKind<'tcx>),
))),
TYPE_TAG => GenericArgKind::Type(Ty(Interned::new_unchecked(
&*((ptr & !TAG_MASK) as *const WithCachedTypeInfo<ty::TyKind<'tcx>>),
))),
CONST_TAG => GenericArgKind::Const(ty::Const(Interned::new_unchecked(
&*((ptr & !TAG_MASK) as *const ty::ConstData<'tcx>),
))),
_ => intrinsics::unreachable(),
}
}
}
#[inline]
pub fn as_type(self) -> Option<Ty<'tcx>> {
match self.unpack() {
GenericArgKind::Type(ty) => Some(ty),
_ => None,
}
}
#[inline]
pub fn as_region(self) -> Option<ty::Region<'tcx>> {
match self.unpack() {
GenericArgKind::Lifetime(re) => Some(re),
_ => None,
}
}
#[inline]
pub fn as_const(self) -> Option<ty::Const<'tcx>> {
match self.unpack() {
GenericArgKind::Const(ct) => Some(ct),
_ => None,
}
}
pub fn expect_region(self) -> ty::Region<'tcx> {
self.as_region().unwrap_or_else(|| bug!("expected a region, but found another kind"))
}
pub fn expect_ty(self) -> Ty<'tcx> {
self.as_type().unwrap_or_else(|| bug!("expected a type, but found another kind"))
}
pub fn expect_const(self) -> ty::Const<'tcx> {
self.as_const().unwrap_or_else(|| bug!("expected a const, but found another kind"))
}
pub fn is_non_region_infer(self) -> bool {
match self.unpack() {
GenericArgKind::Lifetime(_) => false,
GenericArgKind::Type(ty) => ty.is_ty_or_numeric_infer(),
GenericArgKind::Const(ct) => ct.is_ct_infer(),
}
}
}
impl<'a, 'tcx> Lift<'tcx> for GenericArg<'a> {
type Lifted = GenericArg<'tcx>;
fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
match self.unpack() {
GenericArgKind::Lifetime(lt) => tcx.lift(lt).map(|lt| lt.into()),
GenericArgKind::Type(ty) => tcx.lift(ty).map(|ty| ty.into()),
GenericArgKind::Const(ct) => tcx.lift(ct).map(|ct| ct.into()),
}
}
}
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for GenericArg<'tcx> {
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
folder: &mut F,
) -> Result<Self, F::Error> {
match self.unpack() {
GenericArgKind::Lifetime(lt) => lt.try_fold_with(folder).map(Into::into),
GenericArgKind::Type(ty) => ty.try_fold_with(folder).map(Into::into),
GenericArgKind::Const(ct) => ct.try_fold_with(folder).map(Into::into),
}
}
}
impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for GenericArg<'tcx> {
fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
match self.unpack() {
GenericArgKind::Lifetime(lt) => lt.visit_with(visitor),
GenericArgKind::Type(ty) => ty.visit_with(visitor),
GenericArgKind::Const(ct) => ct.visit_with(visitor),
}
}
}
impl<'tcx, E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<E> for GenericArg<'tcx> {
fn encode(&self, e: &mut E) {
self.unpack().encode(e)
}
}
impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<D> for GenericArg<'tcx> {
fn decode(d: &mut D) -> GenericArg<'tcx> {
GenericArgKind::decode(d).pack()
}
}
pub type GenericArgs<'tcx> = List<GenericArg<'tcx>>;
pub type GenericArgsRef<'tcx> = &'tcx GenericArgs<'tcx>;
impl<'tcx> GenericArgs<'tcx> {
pub fn into_type_list(&self, tcx: TyCtxt<'tcx>) -> &'tcx List<Ty<'tcx>> {
tcx.mk_type_list_from_iter(self.iter().map(|arg| match arg.unpack() {
GenericArgKind::Type(ty) => ty,
_ => bug!("`into_type_list` called on generic arg with non-types"),
}))
}
pub fn as_closure(&'tcx self) -> ClosureArgs<'tcx> {
ClosureArgs { args: self }
}
pub fn as_generator(&'tcx self) -> GeneratorArgs<'tcx> {
GeneratorArgs { args: self }
}
pub fn as_inline_const(&'tcx self) -> InlineConstArgs<'tcx> {
InlineConstArgs { args: self }
}
pub fn identity_for_item(tcx: TyCtxt<'tcx>, def_id: impl Into<DefId>) -> GenericArgsRef<'tcx> {
Self::for_item(tcx, def_id.into(), |param, _| tcx.mk_param_from_def(param))
}
pub fn for_item<F>(tcx: TyCtxt<'tcx>, def_id: DefId, mut mk_kind: F) -> GenericArgsRef<'tcx>
where
F: FnMut(&ty::GenericParamDef, &[GenericArg<'tcx>]) -> GenericArg<'tcx>,
{
let defs = tcx.generics_of(def_id);
let count = defs.count();
let mut args = SmallVec::with_capacity(count);
Self::fill_item(&mut args, tcx, defs, &mut mk_kind);
tcx.mk_args(&args)
}
pub fn extend_to<F>(
&self,
tcx: TyCtxt<'tcx>,
def_id: DefId,
mut mk_kind: F,
) -> GenericArgsRef<'tcx>
where
F: FnMut(&ty::GenericParamDef, &[GenericArg<'tcx>]) -> GenericArg<'tcx>,
{
Self::for_item(tcx, def_id, |param, args| {
self.get(param.index as usize).cloned().unwrap_or_else(|| mk_kind(param, args))
})
}
pub fn fill_item<F>(
args: &mut SmallVec<[GenericArg<'tcx>; 8]>,
tcx: TyCtxt<'tcx>,
defs: &ty::Generics,
mk_kind: &mut F,
) where
F: FnMut(&ty::GenericParamDef, &[GenericArg<'tcx>]) -> GenericArg<'tcx>,
{
if let Some(def_id) = defs.parent {
let parent_defs = tcx.generics_of(def_id);
Self::fill_item(args, tcx, parent_defs, mk_kind);
}
Self::fill_single(args, defs, mk_kind)
}
pub fn fill_single<F>(
args: &mut SmallVec<[GenericArg<'tcx>; 8]>,
defs: &ty::Generics,
mk_kind: &mut F,
) where
F: FnMut(&ty::GenericParamDef, &[GenericArg<'tcx>]) -> GenericArg<'tcx>,
{
args.reserve(defs.params.len());
for param in &defs.params {
let kind = mk_kind(param, args);
assert_eq!(param.index as usize, args.len(), "{args:#?}, {defs:#?}");
args.push(kind);
}
}
pub fn extend_with_error(
tcx: TyCtxt<'tcx>,
def_id: DefId,
original_args: &[GenericArg<'tcx>],
) -> GenericArgsRef<'tcx> {
ty::GenericArgs::for_item(tcx, def_id, |def, args| {
if let Some(arg) = original_args.get(def.index as usize) {
*arg
} else {
def.to_error(tcx, args)
}
})
}
#[inline]
pub fn types(&'tcx self) -> impl DoubleEndedIterator<Item = Ty<'tcx>> + 'tcx {
self.iter().filter_map(|k| k.as_type())
}
#[inline]
pub fn regions(&'tcx self) -> impl DoubleEndedIterator<Item = ty::Region<'tcx>> + 'tcx {
self.iter().filter_map(|k| k.as_region())
}
#[inline]
pub fn consts(&'tcx self) -> impl DoubleEndedIterator<Item = ty::Const<'tcx>> + 'tcx {
self.iter().filter_map(|k| k.as_const())
}
#[inline]
pub fn non_erasable_generics(
&'tcx self,
tcx: TyCtxt<'tcx>,
def_id: DefId,
) -> impl DoubleEndedIterator<Item = GenericArgKind<'tcx>> + 'tcx {
let generics = tcx.generics_of(def_id);
self.iter().enumerate().filter_map(|(i, k)| match k.unpack() {
_ if Some(i) == generics.host_effect_index => None,
ty::GenericArgKind::Lifetime(_) => None,
generic => Some(generic),
})
}
#[inline]
#[track_caller]
pub fn type_at(&self, i: usize) -> Ty<'tcx> {
self[i].as_type().unwrap_or_else(|| bug!("expected type for param #{} in {:?}", i, self))
}
#[inline]
#[track_caller]
pub fn region_at(&self, i: usize) -> ty::Region<'tcx> {
self[i]
.as_region()
.unwrap_or_else(|| bug!("expected region for param #{} in {:?}", i, self))
}
#[inline]
#[track_caller]
pub fn const_at(&self, i: usize) -> ty::Const<'tcx> {
self[i].as_const().unwrap_or_else(|| bug!("expected const for param #{} in {:?}", i, self))
}
#[inline]
#[track_caller]
pub fn type_for_def(&self, def: &ty::GenericParamDef) -> GenericArg<'tcx> {
self.type_at(def.index as usize).into()
}
pub fn rebase_onto(
&self,
tcx: TyCtxt<'tcx>,
source_ancestor: DefId,
target_args: GenericArgsRef<'tcx>,
) -> GenericArgsRef<'tcx> {
let defs = tcx.generics_of(source_ancestor);
tcx.mk_args_from_iter(target_args.iter().chain(self.iter().skip(defs.count())))
}
pub fn truncate_to(&self, tcx: TyCtxt<'tcx>, generics: &ty::Generics) -> GenericArgsRef<'tcx> {
tcx.mk_args_from_iter(self.iter().take(generics.count()))
}
pub fn host_effect_param(&'tcx self) -> Option<ty::Const<'tcx>> {
self.consts().rfind(|x| matches!(x.kind(), ty::ConstKind::Param(p) if p.name == sym::host))
}
pub fn print_as_list(&self) -> String {
let v = self.iter().map(|arg| arg.to_string()).collect::<Vec<_>>();
format!("[{}]", v.join(", "))
}
}
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for GenericArgsRef<'tcx> {
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
folder: &mut F,
) -> Result<Self, F::Error> {
match self.len() {
1 => {
let param0 = self[0].try_fold_with(folder)?;
if param0 == self[0] { Ok(self) } else { Ok(folder.interner().mk_args(&[param0])) }
}
2 => {
let param0 = self[0].try_fold_with(folder)?;
let param1 = self[1].try_fold_with(folder)?;
if param0 == self[0] && param1 == self[1] {
Ok(self)
} else {
Ok(folder.interner().mk_args(&[param0, param1]))
}
}
0 => Ok(self),
_ => ty::util::fold_list(self, folder, |tcx, v| tcx.mk_args(v)),
}
}
}
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<Ty<'tcx>> {
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
folder: &mut F,
) -> Result<Self, F::Error> {
match self.len() {
2 => {
let param0 = self[0].try_fold_with(folder)?;
let param1 = self[1].try_fold_with(folder)?;
if param0 == self[0] && param1 == self[1] {
Ok(self)
} else {
Ok(folder.interner().mk_type_list(&[param0, param1]))
}
}
_ => ty::util::fold_list(self, folder, |tcx, v| tcx.mk_type_list(v)),
}
}
}
impl<'tcx, T: TypeVisitable<TyCtxt<'tcx>>> TypeVisitable<TyCtxt<'tcx>> for &'tcx ty::List<T> {
#[inline]
fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
self.iter().try_for_each(|t| t.visit_with(visitor))
}
}
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
#[derive(Encodable, Decodable, HashStable)]
pub struct EarlyBinder<T> {
value: T,
}
impl<'tcx, T> !TypeFoldable<TyCtxt<'tcx>> for ty::EarlyBinder<T> {}
impl<'tcx, T> !TypeVisitable<TyCtxt<'tcx>> for ty::EarlyBinder<T> {}
impl<T> EarlyBinder<T> {
pub fn bind(value: T) -> EarlyBinder<T> {
EarlyBinder { value }
}
pub fn as_ref(&self) -> EarlyBinder<&T> {
EarlyBinder { value: &self.value }
}
pub fn map_bound_ref<F, U>(&self, f: F) -> EarlyBinder<U>
where
F: FnOnce(&T) -> U,
{
self.as_ref().map_bound(f)
}
pub fn map_bound<F, U>(self, f: F) -> EarlyBinder<U>
where
F: FnOnce(T) -> U,
{
let value = f(self.value);
EarlyBinder { value }
}
pub fn try_map_bound<F, U, E>(self, f: F) -> Result<EarlyBinder<U>, E>
where
F: FnOnce(T) -> Result<U, E>,
{
let value = f(self.value)?;
Ok(EarlyBinder { value })
}
pub fn rebind<U>(&self, value: U) -> EarlyBinder<U> {
EarlyBinder { value }
}
pub fn skip_binder(self) -> T {
self.value
}
}
impl<T> EarlyBinder<Option<T>> {
pub fn transpose(self) -> Option<EarlyBinder<T>> {
self.value.map(|value| EarlyBinder { value })
}
}
impl<T, U> EarlyBinder<(T, U)> {
pub fn transpose_tuple2(self) -> (EarlyBinder<T>, EarlyBinder<U>) {
let EarlyBinder { value: (lhs, rhs) } = self;
(EarlyBinder { value: lhs }, EarlyBinder { value: rhs })
}
}
impl<'tcx, 's, I: IntoIterator> EarlyBinder<I>
where
I::Item: TypeFoldable<TyCtxt<'tcx>>,
{
pub fn iter_instantiated(
self,
tcx: TyCtxt<'tcx>,
args: &'s [GenericArg<'tcx>],
) -> IterInstantiated<'s, 'tcx, I> {
IterInstantiated { it: self.value.into_iter(), tcx, args }
}
pub fn instantiate_identity_iter(self) -> I::IntoIter {
self.value.into_iter()
}
}
pub struct IterInstantiated<'s, 'tcx, I: IntoIterator> {
it: I::IntoIter,
tcx: TyCtxt<'tcx>,
args: &'s [GenericArg<'tcx>],
}
impl<'tcx, I: IntoIterator> Iterator for IterInstantiated<'_, 'tcx, I>
where
I::Item: TypeFoldable<TyCtxt<'tcx>>,
{
type Item = I::Item;
fn next(&mut self) -> Option<Self::Item> {
Some(EarlyBinder { value: self.it.next()? }.instantiate(self.tcx, self.args))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.it.size_hint()
}
}
impl<'tcx, I: IntoIterator> DoubleEndedIterator for IterInstantiated<'_, 'tcx, I>
where
I::IntoIter: DoubleEndedIterator,
I::Item: TypeFoldable<TyCtxt<'tcx>>,
{
fn next_back(&mut self) -> Option<Self::Item> {
Some(EarlyBinder { value: self.it.next_back()? }.instantiate(self.tcx, self.args))
}
}
impl<'tcx, I: IntoIterator> ExactSizeIterator for IterInstantiated<'_, 'tcx, I>
where
I::IntoIter: ExactSizeIterator,
I::Item: TypeFoldable<TyCtxt<'tcx>>,
{
}
impl<'tcx, 's, I: IntoIterator> EarlyBinder<I>
where
I::Item: Deref,
<I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
{
pub fn iter_instantiated_copied(
self,
tcx: TyCtxt<'tcx>,
args: &'s [GenericArg<'tcx>],
) -> IterInstantiatedCopied<'s, 'tcx, I> {
IterInstantiatedCopied { it: self.value.into_iter(), tcx, args }
}
pub fn instantiate_identity_iter_copied(
self,
) -> impl Iterator<Item = <I::Item as Deref>::Target> {
self.value.into_iter().map(|v| *v)
}
}
pub struct IterInstantiatedCopied<'a, 'tcx, I: IntoIterator> {
it: I::IntoIter,
tcx: TyCtxt<'tcx>,
args: &'a [GenericArg<'tcx>],
}
impl<'tcx, I: IntoIterator> Iterator for IterInstantiatedCopied<'_, 'tcx, I>
where
I::Item: Deref,
<I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
{
type Item = <I::Item as Deref>::Target;
fn next(&mut self) -> Option<Self::Item> {
self.it.next().map(|value| EarlyBinder { value: *value }.instantiate(self.tcx, self.args))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.it.size_hint()
}
}
impl<'tcx, I: IntoIterator> DoubleEndedIterator for IterInstantiatedCopied<'_, 'tcx, I>
where
I::IntoIter: DoubleEndedIterator,
I::Item: Deref,
<I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
{
fn next_back(&mut self) -> Option<Self::Item> {
self.it
.next_back()
.map(|value| EarlyBinder { value: *value }.instantiate(self.tcx, self.args))
}
}
impl<'tcx, I: IntoIterator> ExactSizeIterator for IterInstantiatedCopied<'_, 'tcx, I>
where
I::IntoIter: ExactSizeIterator,
I::Item: Deref,
<I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
{
}
pub struct EarlyBinderIter<T> {
t: T,
}
impl<T: IntoIterator> EarlyBinder<T> {
pub fn transpose_iter(self) -> EarlyBinderIter<T::IntoIter> {
EarlyBinderIter { t: self.value.into_iter() }
}
}
impl<T: Iterator> Iterator for EarlyBinderIter<T> {
type Item = EarlyBinder<T::Item>;
fn next(&mut self) -> Option<Self::Item> {
self.t.next().map(|value| EarlyBinder { value })
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.t.size_hint()
}
}
impl<'tcx, T: TypeFoldable<TyCtxt<'tcx>>> ty::EarlyBinder<T> {
pub fn instantiate(self, tcx: TyCtxt<'tcx>, args: &[GenericArg<'tcx>]) -> T {
let mut folder = ArgFolder { tcx, args, binders_passed: 0 };
self.value.fold_with(&mut folder)
}
pub fn instantiate_identity(self) -> T {
self.value
}
pub fn no_bound_vars(self) -> Option<T> {
if !self.value.has_param() { Some(self.value) } else { None }
}
}
struct ArgFolder<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
args: &'a [GenericArg<'tcx>],
binders_passed: u32,
}
impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for ArgFolder<'a, 'tcx> {
#[inline]
fn interner(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
&mut self,
t: ty::Binder<'tcx, T>,
) -> ty::Binder<'tcx, T> {
self.binders_passed += 1;
let t = t.super_fold_with(self);
self.binders_passed -= 1;
t
}
fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
#[cold]
#[inline(never)]
fn region_param_out_of_range(data: ty::EarlyBoundRegion, args: &[GenericArg<'_>]) -> ! {
bug!(
"Region parameter out of range when substituting in region {} (index={}, args = {:?})",
data.name,
data.index,
args,
)
}
#[cold]
#[inline(never)]
fn region_param_invalid(data: ty::EarlyBoundRegion, other: GenericArgKind<'_>) -> ! {
bug!(
"Unexpected parameter {:?} when substituting in region {} (index={})",
other,
data.name,
data.index
)
}
match *r {
ty::ReEarlyBound(data) => {
let rk = self.args.get(data.index as usize).map(|k| k.unpack());
match rk {
Some(GenericArgKind::Lifetime(lt)) => self.shift_region_through_binders(lt),
Some(other) => region_param_invalid(data, other),
None => region_param_out_of_range(data, self.args),
}
}
ty::ReLateBound(..)
| ty::ReFree(_)
| ty::ReStatic
| ty::RePlaceholder(_)
| ty::ReErased
| ty::ReError(_) => r,
ty::ReVar(_) => bug!("unexpected region: {r:?}"),
}
}
fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
if !t.has_param() {
return t;
}
match *t.kind() {
ty::Param(p) => self.ty_for_param(p, t),
_ => t.super_fold_with(self),
}
}
fn fold_const(&mut self, c: ty::Const<'tcx>) -> ty::Const<'tcx> {
if let ty::ConstKind::Param(p) = c.kind() {
self.const_for_param(p, c)
} else {
c.super_fold_with(self)
}
}
}
impl<'a, 'tcx> ArgFolder<'a, 'tcx> {
fn ty_for_param(&self, p: ty::ParamTy, source_ty: Ty<'tcx>) -> Ty<'tcx> {
let opt_ty = self.args.get(p.index as usize).map(|k| k.unpack());
let ty = match opt_ty {
Some(GenericArgKind::Type(ty)) => ty,
Some(kind) => self.type_param_expected(p, source_ty, kind),
None => self.type_param_out_of_range(p, source_ty),
};
self.shift_vars_through_binders(ty)
}
#[cold]
#[inline(never)]
fn type_param_expected(&self, p: ty::ParamTy, ty: Ty<'tcx>, kind: GenericArgKind<'tcx>) -> ! {
bug!(
"expected type for `{:?}` ({:?}/{}) but found {:?} when substituting, args={:?}",
p,
ty,
p.index,
kind,
self.args,
)
}
#[cold]
#[inline(never)]
fn type_param_out_of_range(&self, p: ty::ParamTy, ty: Ty<'tcx>) -> ! {
bug!(
"type parameter `{:?}` ({:?}/{}) out of range when substituting, args={:?}",
p,
ty,
p.index,
self.args,
)
}
fn const_for_param(&self, p: ParamConst, source_ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
let opt_ct = self.args.get(p.index as usize).map(|k| k.unpack());
let ct = match opt_ct {
Some(GenericArgKind::Const(ct)) => ct,
Some(kind) => self.const_param_expected(p, source_ct, kind),
None => self.const_param_out_of_range(p, source_ct),
};
self.shift_vars_through_binders(ct)
}
#[cold]
#[inline(never)]
fn const_param_expected(
&self,
p: ty::ParamConst,
ct: ty::Const<'tcx>,
kind: GenericArgKind<'tcx>,
) -> ! {
bug!(
"expected const for `{:?}` ({:?}/{}) but found {:?} when substituting args={:?}",
p,
ct,
p.index,
kind,
self.args,
)
}
#[cold]
#[inline(never)]
fn const_param_out_of_range(&self, p: ty::ParamConst, ct: ty::Const<'tcx>) -> ! {
bug!(
"const parameter `{:?}` ({:?}/{}) out of range when substituting args={:?}",
p,
ct,
p.index,
self.args,
)
}
fn shift_vars_through_binders<T: TypeFoldable<TyCtxt<'tcx>>>(&self, val: T) -> T {
debug!(
"shift_vars(val={:?}, binders_passed={:?}, has_escaping_bound_vars={:?})",
val,
self.binders_passed,
val.has_escaping_bound_vars()
);
if self.binders_passed == 0 || !val.has_escaping_bound_vars() {
return val;
}
let result = ty::fold::shift_vars(TypeFolder::interner(self), val, self.binders_passed);
debug!("shift_vars: shifted result = {:?}", result);
result
}
fn shift_region_through_binders(&self, region: ty::Region<'tcx>) -> ty::Region<'tcx> {
if self.binders_passed == 0 || !region.has_escaping_bound_vars() {
return region;
}
ty::fold::shift_region(self.tcx, region, self.binders_passed)
}
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
#[derive(HashStable, TypeFoldable, TypeVisitable)]
pub struct UserArgs<'tcx> {
pub args: GenericArgsRef<'tcx>,
pub user_self_ty: Option<UserSelfTy<'tcx>>,
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
#[derive(HashStable, TypeFoldable, TypeVisitable)]
pub struct UserSelfTy<'tcx> {
pub impl_def_id: DefId,
pub self_ty: Ty<'tcx>,
}