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Move some queries from rustc::ty to librustc_passes.

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This commit is contained in:
Camille GILLOT 2020-01-01 19:10:11 +01:00
parent bfd04876b9
commit 6d5170c960
3 changed files with 374 additions and 354 deletions
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356
src/librustc/ty/mod.rs
View File

@ -18,7 +18,6 @@ use crate::middle::resolve_lifetime::ObjectLifetimeDefault;
use crate::mir::interpret::ErrorHandled;
use crate::mir::GeneratorLayout;
use crate::mir::ReadOnlyBodyAndCache;
use crate::session::CrateDisambiguator;
use crate::session::DataTypeKind;
use crate::traits::{self, Reveal};
use crate::ty;
@ -31,7 +30,6 @@ use rustc_data_structures::captures::Captures;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::fx::FxIndexMap;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::svh::Svh;
use rustc_data_structures::sync::{self, par_iter, Lrc, ParallelIterator};
use rustc_hir as hir;
use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
@ -2423,70 +2421,6 @@ impl<'tcx> AdtDef {
pub fn sized_constraint(&self, tcx: TyCtxt<'tcx>) -> &'tcx [Ty<'tcx>] {
tcx.adt_sized_constraint(self.did).0
}
fn sized_constraint_for_ty(&self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Vec<Ty<'tcx>> {
let result = match ty.kind {
Bool | Char | Int(..) | Uint(..) | Float(..) | RawPtr(..) | Ref(..) | FnDef(..)
| FnPtr(_) | Array(..) | Closure(..) | Generator(..) | Never => vec![],
Str | Dynamic(..) | Slice(_) | Foreign(..) | Error | GeneratorWitness(..) => {
// these are never sized - return the target type
vec![ty]
}
Tuple(ref tys) => match tys.last() {
None => vec![],
Some(ty) => self.sized_constraint_for_ty(tcx, ty.expect_ty()),
},
Adt(adt, substs) => {
// recursive case
let adt_tys = adt.sized_constraint(tcx);
debug!("sized_constraint_for_ty({:?}) intermediate = {:?}", ty, adt_tys);
adt_tys
.iter()
.map(|ty| ty.subst(tcx, substs))
.flat_map(|ty| self.sized_constraint_for_ty(tcx, ty))
.collect()
}
Projection(..) | Opaque(..) => {
// must calculate explicitly.
// FIXME: consider special-casing always-Sized projections
vec![ty]
}
UnnormalizedProjection(..) => bug!("only used with chalk-engine"),
Param(..) => {
// perf hack: if there is a `T: Sized` bound, then
// we know that `T` is Sized and do not need to check
// it on the impl.
let sized_trait = match tcx.lang_items().sized_trait() {
Some(x) => x,
_ => return vec![ty],
};
let sized_predicate = Binder::dummy(TraitRef {
def_id: sized_trait,
substs: tcx.mk_substs_trait(ty, &[]),
})
.to_predicate();
let predicates = tcx.predicates_of(self.did).predicates;
if predicates.iter().any(|(p, _)| *p == sized_predicate) {
vec![]
} else {
vec![ty]
}
}
Placeholder(..) | Bound(..) | Infer(..) => {
bug!("unexpected type `{:?}` in sized_constraint_for_ty", ty)
}
};
debug!("sized_constraint_for_ty({:?}) = {:?}", ty, result);
result
}
}
impl<'tcx> FieldDef {
@ -2742,57 +2676,6 @@ impl<'tcx> TyCtxt<'tcx> {
is_associated_item.then(|| self.associated_item(def_id))
}
fn associated_item_from_trait_item_ref(
self,
parent_def_id: DefId,
parent_vis: &hir::Visibility<'_>,
trait_item_ref: &hir::TraitItemRef,
) -> AssocItem {
let def_id = self.hir().local_def_id(trait_item_ref.id.hir_id);
let (kind, has_self) = match trait_item_ref.kind {
hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self),
hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
hir::AssocItemKind::OpaqueTy => bug!("only impls can have opaque types"),
};
AssocItem {
ident: trait_item_ref.ident,
kind,
// Visibility of trait items is inherited from their traits.
vis: Visibility::from_hir(parent_vis, trait_item_ref.id.hir_id, self),
defaultness: trait_item_ref.defaultness,
def_id,
container: TraitContainer(parent_def_id),
method_has_self_argument: has_self,
}
}
fn associated_item_from_impl_item_ref(
self,
parent_def_id: DefId,
impl_item_ref: &hir::ImplItemRef<'_>,
) -> AssocItem {
let def_id = self.hir().local_def_id(impl_item_ref.id.hir_id);
let (kind, has_self) = match impl_item_ref.kind {
hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self),
hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
hir::AssocItemKind::OpaqueTy => (ty::AssocKind::OpaqueTy, false),
};
AssocItem {
ident: impl_item_ref.ident,
kind,
// Visibility of trait impl items doesn't matter.
vis: ty::Visibility::from_hir(&impl_item_ref.vis, impl_item_ref.id.hir_id, self),
defaultness: impl_item_ref.defaultness,
def_id,
container: ImplContainer(parent_def_id),
method_has_self_argument: has_self,
}
}
pub fn field_index(self, hir_id: hir::HirId, tables: &TypeckTables<'_>) -> usize {
tables.field_indices().get(hir_id).cloned().expect("no index for a field")
}
@ -3070,105 +2953,9 @@ impl Iterator for AssocItemsIterator<'_> {
}
}
fn associated_item(tcx: TyCtxt<'_>, def_id: DefId) -> AssocItem {
let id = tcx.hir().as_local_hir_id(def_id).unwrap();
let parent_id = tcx.hir().get_parent_item(id);
let parent_def_id = tcx.hir().local_def_id(parent_id);
let parent_item = tcx.hir().expect_item(parent_id);
match parent_item.kind {
hir::ItemKind::Impl(.., ref impl_item_refs) => {
if let Some(impl_item_ref) = impl_item_refs.iter().find(|i| i.id.hir_id == id) {
let assoc_item =
tcx.associated_item_from_impl_item_ref(parent_def_id, impl_item_ref);
debug_assert_eq!(assoc_item.def_id, def_id);
return assoc_item;
}
}
hir::ItemKind::Trait(.., ref trait_item_refs) => {
if let Some(trait_item_ref) = trait_item_refs.iter().find(|i| i.id.hir_id == id) {
let assoc_item = tcx.associated_item_from_trait_item_ref(
parent_def_id,
&parent_item.vis,
trait_item_ref,
);
debug_assert_eq!(assoc_item.def_id, def_id);
return assoc_item;
}
}
_ => {}
}
span_bug!(
parent_item.span,
"unexpected parent of trait or impl item or item not found: {:?}",
parent_item.kind
)
}
#[derive(Clone, HashStable)]
pub struct AdtSizedConstraint<'tcx>(pub &'tcx [Ty<'tcx>]);
/// Calculates the `Sized` constraint.
///
/// In fact, there are only a few options for the types in the constraint:
/// - an obviously-unsized type
/// - a type parameter or projection whose Sizedness can't be known
/// - a tuple of type parameters or projections, if there are multiple
/// such.
/// - a Error, if a type contained itself. The representability
/// check should catch this case.
fn adt_sized_constraint(tcx: TyCtxt<'_>, def_id: DefId) -> AdtSizedConstraint<'_> {
let def = tcx.adt_def(def_id);
let result = tcx.mk_type_list(
def.variants
.iter()
.flat_map(|v| v.fields.last())
.flat_map(|f| def.sized_constraint_for_ty(tcx, tcx.type_of(f.did))),
);
debug!("adt_sized_constraint: {:?} => {:?}", def, result);
AdtSizedConstraint(result)
}
fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] {
let id = tcx.hir().as_local_hir_id(def_id).unwrap();
let item = tcx.hir().expect_item(id);
match item.kind {
hir::ItemKind::Trait(.., ref trait_item_refs) => tcx.arena.alloc_from_iter(
trait_item_refs
.iter()
.map(|trait_item_ref| trait_item_ref.id)
.map(|id| tcx.hir().local_def_id(id.hir_id)),
),
hir::ItemKind::Impl(.., ref impl_item_refs) => tcx.arena.alloc_from_iter(
impl_item_refs
.iter()
.map(|impl_item_ref| impl_item_ref.id)
.map(|id| tcx.hir().local_def_id(id.hir_id)),
),
hir::ItemKind::TraitAlias(..) => &[],
_ => span_bug!(item.span, "associated_item_def_ids: not impl or trait"),
}
}
fn def_span(tcx: TyCtxt<'_>, def_id: DefId) -> Span {
tcx.hir().span_if_local(def_id).unwrap()
}
/// If the given `DefId` describes an item belonging to a trait,
/// returns the `DefId` of the trait that the trait item belongs to;
/// otherwise, returns `None`.
fn trait_of_item(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
tcx.opt_associated_item(def_id).and_then(|associated_item| match associated_item.container {
TraitContainer(def_id) => Some(def_id),
ImplContainer(_) => None,
})
}
/// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition.
pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
if let Some(hir_id) = tcx.hir().as_local_hir_id(def_id) {
@ -3181,151 +2968,12 @@ pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
None
}
/// See `ParamEnv` struct definition for details.
fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ParamEnv<'_> {
// The param_env of an impl Trait type is its defining function's param_env
if let Some(parent) = is_impl_trait_defn(tcx, def_id) {
return param_env(tcx, parent);
}
// Compute the bounds on Self and the type parameters.
let InstantiatedPredicates { predicates } = tcx.predicates_of(def_id).instantiate_identity(tcx);
// Finally, we have to normalize the bounds in the environment, in
// case they contain any associated type projections. This process
// can yield errors if the put in illegal associated types, like
// `<i32 as Foo>::Bar` where `i32` does not implement `Foo`. We
// report these errors right here; this doesn't actually feel
// right to me, because constructing the environment feels like a
// kind of a "idempotent" action, but I'm not sure where would be
// a better place. In practice, we construct environments for
// every fn once during type checking, and we'll abort if there
// are any errors at that point, so after type checking you can be
// sure that this will succeed without errors anyway.
let unnormalized_env = ty::ParamEnv::new(
tcx.intern_predicates(&predicates),
traits::Reveal::UserFacing,
tcx.sess.opts.debugging_opts.chalk.then_some(def_id),
);
let body_id = tcx.hir().as_local_hir_id(def_id).map_or(hir::DUMMY_HIR_ID, |id| {
tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id)
});
let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id);
traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause)
}
fn crate_disambiguator(tcx: TyCtxt<'_>, crate_num: CrateNum) -> CrateDisambiguator {
assert_eq!(crate_num, LOCAL_CRATE);
tcx.sess.local_crate_disambiguator()
}
fn original_crate_name(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Symbol {
assert_eq!(crate_num, LOCAL_CRATE);
tcx.crate_name.clone()
}
fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh {
assert_eq!(crate_num, LOCAL_CRATE);
tcx.hir().crate_hash
}
fn instance_def_size_estimate<'tcx>(tcx: TyCtxt<'tcx>, instance_def: InstanceDef<'tcx>) -> usize {
match instance_def {
InstanceDef::Item(..) | InstanceDef::DropGlue(..) => {
let mir = tcx.instance_mir(instance_def);
mir.basic_blocks().iter().map(|bb| bb.statements.len()).sum()
}
// Estimate the size of other compiler-generated shims to be 1.
_ => 1,
}
}
/// If `def_id` is an issue 33140 hack impl, returns its self type; otherwise, returns `None`.
///
/// See [`ImplOverlapKind::Issue33140`] for more details.
fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Ty<'_>> {
debug!("issue33140_self_ty({:?})", def_id);
let trait_ref = tcx
.impl_trait_ref(def_id)
.unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id));
debug!("issue33140_self_ty({:?}), trait-ref={:?}", def_id, trait_ref);
let is_marker_like = tcx.impl_polarity(def_id) == ty::ImplPolarity::Positive
&& tcx.associated_item_def_ids(trait_ref.def_id).is_empty();
// Check whether these impls would be ok for a marker trait.
if !is_marker_like {
debug!("issue33140_self_ty - not marker-like!");
return None;
}
// impl must be `impl Trait for dyn Marker1 + Marker2 + ...`
if trait_ref.substs.len() != 1 {
debug!("issue33140_self_ty - impl has substs!");
return None;
}
let predicates = tcx.predicates_of(def_id);
if predicates.parent.is_some() || !predicates.predicates.is_empty() {
debug!("issue33140_self_ty - impl has predicates {:?}!", predicates);
return None;
}
let self_ty = trait_ref.self_ty();
let self_ty_matches = match self_ty.kind {
ty::Dynamic(ref data, ty::ReStatic) => data.principal().is_none(),
_ => false,
};
if self_ty_matches {
debug!("issue33140_self_ty - MATCHES!");
Some(self_ty)
} else {
debug!("issue33140_self_ty - non-matching self type");
None
}
}
/// Check if a function is async.
fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync {
let hir_id = tcx
.hir()
.as_local_hir_id(def_id)
.unwrap_or_else(|| bug!("asyncness: expected local `DefId`, got `{:?}`", def_id));
let node = tcx.hir().get(hir_id);
let fn_like = hir_map::blocks::FnLikeNode::from_node(node).unwrap_or_else(|| {
bug!("asyncness: expected fn-like node but got `{:?}`", def_id);
});
fn_like.asyncness()
}
pub fn provide(providers: &mut ty::query::Providers<'_>) {
context::provide(providers);
erase_regions::provide(providers);
layout::provide(providers);
*providers = ty::query::Providers {
asyncness,
associated_item,
associated_item_def_ids,
adt_sized_constraint,
def_span,
param_env,
trait_of_item,
crate_disambiguator,
original_crate_name,
crate_hash,
trait_impls_of: trait_def::trait_impls_of_provider,
instance_def_size_estimate,
issue33140_self_ty,
..*providers
};
*providers =
ty::query::Providers { trait_impls_of: trait_def::trait_impls_of_provider, ..*providers };
}
/// A map for the local crate mapping each type to a vector of its

3
src/librustc_passes/lib.rs
View File

@ -5,6 +5,7 @@
//! This API is completely unstable and subject to change.
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
#![feature(bool_to_option)]
#![feature(in_band_lifetimes)]
#![feature(nll)]
#![feature(slice_patterns)]
@ -30,6 +31,7 @@ pub mod loops;
mod reachable;
mod region;
pub mod stability;
mod ty;
pub fn provide(providers: &mut Providers<'_>) {
check_const::provide(providers);
@ -42,4 +44,5 @@ pub fn provide(providers: &mut Providers<'_>) {
reachable::provide(providers);
region::provide(providers);
stability::provide(providers);
ty::provide(providers);
}

369
src/librustc_passes/ty.rs Normal file
View File

@ -0,0 +1,369 @@
use rustc::hir::map as hir_map;
use rustc::session::CrateDisambiguator;
use rustc::traits::{self};
use rustc::ty::subst::Subst;
use rustc::ty::{self, ToPredicate, Ty, TyCtxt};
use rustc_data_structures::svh::Svh;
use rustc_hir as hir;
use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
use rustc_span::symbol::Symbol;
use rustc_span::Span;
fn sized_constraint_for_ty(tcx: TyCtxt<'tcx>, adtdef: &ty::AdtDef, ty: Ty<'tcx>) -> Vec<Ty<'tcx>> {
use ty::TyKind::*;
let result = match ty.kind {
Bool | Char | Int(..) | Uint(..) | Float(..) | RawPtr(..) | Ref(..) | FnDef(..)
| FnPtr(_) | Array(..) | Closure(..) | Generator(..) | Never => vec![],
Str | Dynamic(..) | Slice(_) | Foreign(..) | Error | GeneratorWitness(..) => {
// these are never sized - return the target type
vec![ty]
}
Tuple(ref tys) => match tys.last() {
None => vec![],
Some(ty) => sized_constraint_for_ty(tcx, adtdef, ty.expect_ty()),
},
Adt(adt, substs) => {
// recursive case
let adt_tys = adt.sized_constraint(tcx);
debug!("sized_constraint_for_ty({:?}) intermediate = {:?}", ty, adt_tys);
adt_tys
.iter()
.map(|ty| ty.subst(tcx, substs))
.flat_map(|ty| sized_constraint_for_ty(tcx, adtdef, ty))
.collect()
}
Projection(..) | Opaque(..) => {
// must calculate explicitly.
// FIXME: consider special-casing always-Sized projections
vec![ty]
}
UnnormalizedProjection(..) => bug!("only used with chalk-engine"),
Param(..) => {
// perf hack: if there is a `T: Sized` bound, then
// we know that `T` is Sized and do not need to check
// it on the impl.
let sized_trait = match tcx.lang_items().sized_trait() {
Some(x) => x,
_ => return vec![ty],
};
let sized_predicate = ty::Binder::dummy(ty::TraitRef {
def_id: sized_trait,
substs: tcx.mk_substs_trait(ty, &[]),
})
.to_predicate();
let predicates = tcx.predicates_of(adtdef.did).predicates;
if predicates.iter().any(|(p, _)| *p == sized_predicate) { vec![] } else { vec![ty] }
}
Placeholder(..) | Bound(..) | Infer(..) => {
bug!("unexpected type `{:?}` in sized_constraint_for_ty", ty)
}
};
debug!("sized_constraint_for_ty({:?}) = {:?}", ty, result);
result
}
fn associated_item_from_trait_item_ref(
tcx: TyCtxt<'_>,
parent_def_id: DefId,
parent_vis: &hir::Visibility<'_>,
trait_item_ref: &hir::TraitItemRef,
) -> ty::AssocItem {
let def_id = tcx.hir().local_def_id(trait_item_ref.id.hir_id);
let (kind, has_self) = match trait_item_ref.kind {
hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self),
hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
hir::AssocItemKind::OpaqueTy => bug!("only impls can have opaque types"),
};
ty::AssocItem {
ident: trait_item_ref.ident,
kind,
// Visibility of trait items is inherited from their traits.
vis: ty::Visibility::from_hir(parent_vis, trait_item_ref.id.hir_id, tcx),
defaultness: trait_item_ref.defaultness,
def_id,
container: ty::TraitContainer(parent_def_id),
method_has_self_argument: has_self,
}
}
fn associated_item_from_impl_item_ref(
tcx: TyCtxt<'_>,
parent_def_id: DefId,
impl_item_ref: &hir::ImplItemRef<'_>,
) -> ty::AssocItem {
let def_id = tcx.hir().local_def_id(impl_item_ref.id.hir_id);
let (kind, has_self) = match impl_item_ref.kind {
hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self),
hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
hir::AssocItemKind::OpaqueTy => (ty::AssocKind::OpaqueTy, false),
};
ty::AssocItem {
ident: impl_item_ref.ident,
kind,
// Visibility of trait impl items doesn't matter.
vis: ty::Visibility::from_hir(&impl_item_ref.vis, impl_item_ref.id.hir_id, tcx),
defaultness: impl_item_ref.defaultness,
def_id,
container: ty::ImplContainer(parent_def_id),
method_has_self_argument: has_self,
}
}
fn associated_item(tcx: TyCtxt<'_>, def_id: DefId) -> ty::AssocItem {
let id = tcx.hir().as_local_hir_id(def_id).unwrap();
let parent_id = tcx.hir().get_parent_item(id);
let parent_def_id = tcx.hir().local_def_id(parent_id);
let parent_item = tcx.hir().expect_item(parent_id);
match parent_item.kind {
hir::ItemKind::Impl(.., ref impl_item_refs) => {
if let Some(impl_item_ref) = impl_item_refs.iter().find(|i| i.id.hir_id == id) {
let assoc_item =
associated_item_from_impl_item_ref(tcx, parent_def_id, impl_item_ref);
debug_assert_eq!(assoc_item.def_id, def_id);
return assoc_item;
}
}
hir::ItemKind::Trait(.., ref trait_item_refs) => {
if let Some(trait_item_ref) = trait_item_refs.iter().find(|i| i.id.hir_id == id) {
let assoc_item = associated_item_from_trait_item_ref(
tcx,
parent_def_id,
&parent_item.vis,
trait_item_ref,
);
debug_assert_eq!(assoc_item.def_id, def_id);
return assoc_item;
}
}
_ => {}
}
span_bug!(
parent_item.span,
"unexpected parent of trait or impl item or item not found: {:?}",
parent_item.kind
)
}
/// Calculates the `Sized` constraint.
///
/// In fact, there are only a few options for the types in the constraint:
/// - an obviously-unsized type
/// - a type parameter or projection whose Sizedness can't be known
/// - a tuple of type parameters or projections, if there are multiple
/// such.
/// - a Error, if a type contained itself. The representability
/// check should catch this case.
fn adt_sized_constraint(tcx: TyCtxt<'_>, def_id: DefId) -> ty::AdtSizedConstraint<'_> {
let def = tcx.adt_def(def_id);
let result = tcx.mk_type_list(
def.variants
.iter()
.flat_map(|v| v.fields.last())
.flat_map(|f| sized_constraint_for_ty(tcx, def, tcx.type_of(f.did))),
);
debug!("adt_sized_constraint: {:?} => {:?}", def, result);
ty::AdtSizedConstraint(result)
}
fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] {
let id = tcx.hir().as_local_hir_id(def_id).unwrap();
let item = tcx.hir().expect_item(id);
match item.kind {
hir::ItemKind::Trait(.., ref trait_item_refs) => tcx.arena.alloc_from_iter(
trait_item_refs
.iter()
.map(|trait_item_ref| trait_item_ref.id)
.map(|id| tcx.hir().local_def_id(id.hir_id)),
),
hir::ItemKind::Impl(.., ref impl_item_refs) => tcx.arena.alloc_from_iter(
impl_item_refs
.iter()
.map(|impl_item_ref| impl_item_ref.id)
.map(|id| tcx.hir().local_def_id(id.hir_id)),
),
hir::ItemKind::TraitAlias(..) => &[],
_ => span_bug!(item.span, "associated_item_def_ids: not impl or trait"),
}
}
fn def_span(tcx: TyCtxt<'_>, def_id: DefId) -> Span {
tcx.hir().span_if_local(def_id).unwrap()
}
/// If the given `DefId` describes an item belonging to a trait,
/// returns the `DefId` of the trait that the trait item belongs to;
/// otherwise, returns `None`.
fn trait_of_item(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
tcx.opt_associated_item(def_id).and_then(|associated_item| match associated_item.container {
ty::TraitContainer(def_id) => Some(def_id),
ty::ImplContainer(_) => None,
})
}
/// See `ParamEnv` struct definition for details.
fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
// The param_env of an impl Trait type is its defining function's param_env
if let Some(parent) = ty::is_impl_trait_defn(tcx, def_id) {
return param_env(tcx, parent);
}
// Compute the bounds on Self and the type parameters.
let ty::InstantiatedPredicates { predicates } =
tcx.predicates_of(def_id).instantiate_identity(tcx);
// Finally, we have to normalize the bounds in the environment, in
// case they contain any associated type projections. This process
// can yield errors if the put in illegal associated types, like
// `<i32 as Foo>::Bar` where `i32` does not implement `Foo`. We
// report these errors right here; this doesn't actually feel
// right to me, because constructing the environment feels like a
// kind of a "idempotent" action, but I'm not sure where would be
// a better place. In practice, we construct environments for
// every fn once during type checking, and we'll abort if there
// are any errors at that point, so after type checking you can be
// sure that this will succeed without errors anyway.
let unnormalized_env = ty::ParamEnv::new(
tcx.intern_predicates(&predicates),
traits::Reveal::UserFacing,
tcx.sess.opts.debugging_opts.chalk.then_some(def_id),
);
let body_id = tcx.hir().as_local_hir_id(def_id).map_or(hir::DUMMY_HIR_ID, |id| {
tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id)
});
let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id);
traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause)
}
fn crate_disambiguator(tcx: TyCtxt<'_>, crate_num: CrateNum) -> CrateDisambiguator {
assert_eq!(crate_num, LOCAL_CRATE);
tcx.sess.local_crate_disambiguator()
}
fn original_crate_name(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Symbol {
assert_eq!(crate_num, LOCAL_CRATE);
tcx.crate_name.clone()
}
fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh {
assert_eq!(crate_num, LOCAL_CRATE);
tcx.hir().crate_hash
}
fn instance_def_size_estimate<'tcx>(
tcx: TyCtxt<'tcx>,
instance_def: ty::InstanceDef<'tcx>,
) -> usize {
use ty::InstanceDef;
match instance_def {
InstanceDef::Item(..) | InstanceDef::DropGlue(..) => {
let mir = tcx.instance_mir(instance_def);
mir.basic_blocks().iter().map(|bb| bb.statements.len()).sum()
}
// Estimate the size of other compiler-generated shims to be 1.
_ => 1,
}
}
/// If `def_id` is an issue 33140 hack impl, returns its self type; otherwise, returns `None`.
///
/// See [`ImplOverlapKind::Issue33140`] for more details.
fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Ty<'_>> {
debug!("issue33140_self_ty({:?})", def_id);
let trait_ref = tcx
.impl_trait_ref(def_id)
.unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id));
debug!("issue33140_self_ty({:?}), trait-ref={:?}", def_id, trait_ref);
let is_marker_like = tcx.impl_polarity(def_id) == ty::ImplPolarity::Positive
&& tcx.associated_item_def_ids(trait_ref.def_id).is_empty();
// Check whether these impls would be ok for a marker trait.
if !is_marker_like {
debug!("issue33140_self_ty - not marker-like!");
return None;
}
// impl must be `impl Trait for dyn Marker1 + Marker2 + ...`
if trait_ref.substs.len() != 1 {
debug!("issue33140_self_ty - impl has substs!");
return None;
}
let predicates = tcx.predicates_of(def_id);
if predicates.parent.is_some() || !predicates.predicates.is_empty() {
debug!("issue33140_self_ty - impl has predicates {:?}!", predicates);
return None;
}
let self_ty = trait_ref.self_ty();
let self_ty_matches = match self_ty.kind {
ty::Dynamic(ref data, ty::ReStatic) => data.principal().is_none(),
_ => false,
};
if self_ty_matches {
debug!("issue33140_self_ty - MATCHES!");
Some(self_ty)
} else {
debug!("issue33140_self_ty - non-matching self type");
None
}
}
/// Check if a function is async.
fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync {
let hir_id = tcx
.hir()
.as_local_hir_id(def_id)
.unwrap_or_else(|| bug!("asyncness: expected local `DefId`, got `{:?}`", def_id));
let node = tcx.hir().get(hir_id);
let fn_like = hir_map::blocks::FnLikeNode::from_node(node).unwrap_or_else(|| {
bug!("asyncness: expected fn-like node but got `{:?}`", def_id);
});
fn_like.asyncness()
}
pub fn provide(providers: &mut ty::query::Providers<'_>) {
*providers = ty::query::Providers {
asyncness,
associated_item,
associated_item_def_ids,
adt_sized_constraint,
def_span,
param_env,
trait_of_item,
crate_disambiguator,
original_crate_name,
crate_hash,
instance_def_size_estimate,
issue33140_self_ty,
..*providers
};
}