rustc_public/unstable/
mod.rs

1//! Module that collects the things that have no stability guarantees.
2//!
3//! We want to keep rustc_public's IR definitions and logic separate from
4//! any sort of conversion and usage of internal rustc code. So we
5//! restrict the usage of internal items to be inside this module.
6
7use std::marker::PointeeSized;
8
9use rustc_hir::def::DefKind;
10use rustc_middle::ty::{List, Ty, TyCtxt};
11use rustc_middle::{mir, ty};
12use rustc_public_bridge::Tables;
13use rustc_public_bridge::context::CompilerCtxt;
14
15use super::compiler_interface::BridgeTys;
16use crate::{CtorKind, ItemKind};
17
18pub(crate) mod convert;
19mod internal_cx;
20
21/// Trait that defines the methods that are fine to call from [`RustcInternal`].
22///
23/// This trait is only for [`RustcInternal`]. Any other other access to rustc's internals
24/// should go through [`rustc_public_bridge::context::CompilerCtxt`].
25#[cfg_attr(not(feature = "rustc_internal"), allow(unreachable_pub))]
26pub trait InternalCx<'tcx>: Copy + Clone {
27    fn tcx(self) -> TyCtxt<'tcx>;
28
29    fn lift<T: ty::Lift<TyCtxt<'tcx>>>(self, value: T) -> Option<T::Lifted>;
30
31    fn mk_args_from_iter<I, T>(self, iter: I) -> T::Output
32    where
33        I: Iterator<Item = T>,
34        T: ty::CollectAndApply<ty::GenericArg<'tcx>, ty::GenericArgsRef<'tcx>>;
35
36    fn mk_pat(self, v: ty::PatternKind<'tcx>) -> ty::Pattern<'tcx>;
37
38    fn mk_poly_existential_predicates(
39        self,
40        eps: &[ty::PolyExistentialPredicate<'tcx>],
41    ) -> &'tcx List<ty::PolyExistentialPredicate<'tcx>>;
42
43    fn mk_type_list(self, v: &[Ty<'tcx>]) -> &'tcx List<Ty<'tcx>>;
44
45    fn lifetimes_re_erased(self) -> ty::Region<'tcx>;
46
47    fn mk_bound_variable_kinds_from_iter<I, T>(self, iter: I) -> T::Output
48    where
49        I: Iterator<Item = T>,
50        T: ty::CollectAndApply<ty::BoundVariableKind, &'tcx List<ty::BoundVariableKind>>;
51
52    fn mk_place_elems(self, v: &[mir::PlaceElem<'tcx>]) -> &'tcx List<mir::PlaceElem<'tcx>>;
53
54    fn adt_def(self, def_id: rustc_hir::def_id::DefId) -> ty::AdtDef<'tcx>;
55}
56
57/// Trait used to convert between an internal MIR type to a rustc_public's IR type.
58///
59/// This trait is currently exposed to users so they can have interoperability
60/// between internal MIR and rustc_public's IR constructs.
61/// However, they should be used seldom and they have no influence in this crate semver.
62#[doc(hidden)]
63#[cfg_attr(not(feature = "rustc_internal"), allow(unreachable_pub))]
64pub trait Stable<'tcx>: PointeeSized {
65    /// The stable representation of the type implementing Stable.
66    type T;
67    /// Converts an object to the equivalent rustc_public's IR representation.
68    fn stable<'cx>(
69        &self,
70        tables: &mut Tables<'cx, BridgeTys>,
71        cx: &CompilerCtxt<'cx, BridgeTys>,
72    ) -> Self::T;
73}
74
75/// Trait used to translate a rustc_public's IR construct to its rustc counterpart.
76///
77/// This is basically a mirror of [Stable].
78///
79/// This trait is currently exposed to users so they can have interoperability
80/// between internal MIR and rustc_public's IR constructs.
81/// They should be used seldom as they have no stability guarantees.
82#[doc(hidden)]
83#[cfg_attr(not(feature = "rustc_internal"), allow(unreachable_pub))]
84pub trait RustcInternal {
85    type T<'tcx>;
86    fn internal<'tcx>(
87        &self,
88        tables: &mut Tables<'_, BridgeTys>,
89        tcx: impl InternalCx<'tcx>,
90    ) -> Self::T<'tcx>;
91}
92
93pub(crate) fn new_item_kind(kind: DefKind) -> ItemKind {
94    match kind {
95        DefKind::Mod
96        | DefKind::Struct
97        | DefKind::Union
98        | DefKind::Enum
99        | DefKind::Variant
100        | DefKind::Trait
101        | DefKind::TyAlias
102        | DefKind::ForeignTy
103        | DefKind::TraitAlias
104        | DefKind::AssocTy
105        | DefKind::TyParam
106        | DefKind::ConstParam
107        | DefKind::Macro(_)
108        | DefKind::ExternCrate
109        | DefKind::Use
110        | DefKind::ForeignMod
111        | DefKind::OpaqueTy
112        | DefKind::Field
113        | DefKind::LifetimeParam
114        | DefKind::Impl { .. }
115        | DefKind::GlobalAsm => {
116            unreachable!("Not a valid item kind: {kind:?}");
117        }
118        DefKind::Closure | DefKind::AssocFn | DefKind::Fn | DefKind::SyntheticCoroutineBody => {
119            ItemKind::Fn
120        }
121        DefKind::Const | DefKind::InlineConst | DefKind::AssocConst | DefKind::AnonConst => {
122            ItemKind::Const
123        }
124        DefKind::Static { .. } => ItemKind::Static,
125        DefKind::Ctor(_, rustc_hir::def::CtorKind::Const) => ItemKind::Ctor(CtorKind::Const),
126        DefKind::Ctor(_, rustc_hir::def::CtorKind::Fn) => ItemKind::Ctor(CtorKind::Fn),
127    }
128}