1 files changed, 302 insertions, 0 deletions
diff --git a/compiler/rustc_public/src/lib.rs b/compiler/rustc_public/src/lib.rs
new file mode 100644
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+++ b/compiler/rustc_public/src/lib.rs
@@ -0,0 +1,302 @@
+//! The WIP public interface to rustc internals.
+//!
+//! For more information see <https://github.com/rust-lang/project-stable-mir>
+//!
+//! # Note
+//!
+//! This API is still completely unstable and subject to change.
+
+#![allow(rustc::usage_of_ty_tykind)]
+#![doc(
+    html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
+    test(attr(allow(unused_variables), deny(warnings)))
+)]
+#![feature(sized_hierarchy)]
+//!
+//! This crate shall contain all type definitions and APIs that we expect third-party tools to invoke to
+//! interact with the compiler.
+//!
+//! The goal is to eventually be published on
+//! [crates.io](https://crates.io).
+
+use std::fmt::Debug;
+use std::{fmt, io};
+
+pub(crate) use rustc_public_bridge::IndexedVal;
+use rustc_public_bridge::Tables;
+use rustc_public_bridge::context::SmirCtxt;
+/// Export the rustc_internal APIs. Note that this module has no stability
+/// guarantees and it is not taken into account for semver.
+#[cfg(feature = "rustc_internal")]
+pub mod rustc_internal;
+use serde::Serialize;
+
+use crate::compiler_interface::with;
+pub use crate::crate_def::{CrateDef, CrateDefItems, CrateDefType, DefId};
+pub use crate::error::*;
+use crate::mir::mono::StaticDef;
+use crate::mir::{Body, Mutability};
+use crate::ty::{AssocItem, FnDef, ForeignModuleDef, ImplDef, ProvenanceMap, Span, TraitDef, Ty};
+use crate::unstable::Stable;
+
+pub mod abi;
+mod alloc;
+pub(crate) mod unstable;
+#[macro_use]
+pub mod crate_def;
+pub mod compiler_interface;
+#[macro_use]
+pub mod error;
+pub mod mir;
+pub mod target;
+pub mod ty;
+pub mod visitor;
+
+/// Use String for now but we should replace it.
+pub type Symbol = String;
+
+/// The number that identifies a crate.
+pub type CrateNum = usize;
+
+impl Debug for DefId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("DefId").field("id", &self.0).field("name", &self.name()).finish()
+    }
+}
+
+impl IndexedVal for DefId {
+    fn to_val(index: usize) -> Self {
+        DefId(index)
+    }
+
+    fn to_index(&self) -> usize {
+        self.0
+    }
+}
+
+/// A list of crate items.
+pub type CrateItems = Vec<CrateItem>;
+
+/// A list of trait decls.
+pub type TraitDecls = Vec<TraitDef>;
+
+/// A list of impl trait decls.
+pub type ImplTraitDecls = Vec<ImplDef>;
+
+/// A list of associated items.
+pub type AssocItems = Vec<AssocItem>;
+
+/// Holds information about a crate.
+#[derive(Clone, PartialEq, Eq, Debug, Serialize)]
+pub struct Crate {
+    pub id: CrateNum,
+    pub name: Symbol,
+    pub is_local: bool,
+}
+
+impl Crate {
+    /// The list of foreign modules in this crate.
+    pub fn foreign_modules(&self) -> Vec<ForeignModuleDef> {
+        with(|cx| cx.foreign_modules(self.id))
+    }
+
+    /// The list of traits declared in this crate.
+    pub fn trait_decls(&self) -> TraitDecls {
+        with(|cx| cx.trait_decls(self.id))
+    }
+
+    /// The list of trait implementations in this crate.
+    pub fn trait_impls(&self) -> ImplTraitDecls {
+        with(|cx| cx.trait_impls(self.id))
+    }
+
+    /// Return a list of function definitions from this crate independent on their visibility.
+    pub fn fn_defs(&self) -> Vec<FnDef> {
+        with(|cx| cx.crate_functions(self.id))
+    }
+
+    /// Return a list of static items defined in this crate independent on their visibility.
+    pub fn statics(&self) -> Vec<StaticDef> {
+        with(|cx| cx.crate_statics(self.id))
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash, Serialize)]
+pub enum ItemKind {
+    Fn,
+    Static,
+    Const,
+    Ctor(CtorKind),
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash, Serialize)]
+pub enum CtorKind {
+    Const,
+    Fn,
+}
+
+pub type Filename = String;
+
+crate_def_with_ty! {
+    /// Holds information about an item in a crate.
+    #[derive(Serialize)]
+    pub CrateItem;
+}
+
+impl CrateItem {
+    /// This will return the body of an item or panic if it's not available.
+    pub fn expect_body(&self) -> mir::Body {
+        with(|cx| cx.mir_body(self.0))
+    }
+
+    /// Return the body of an item if available.
+    pub fn body(&self) -> Option<mir::Body> {
+        with(|cx| cx.has_body(self.0).then(|| cx.mir_body(self.0)))
+    }
+
+    /// Check if a body is available for this item.
+    pub fn has_body(&self) -> bool {
+        with(|cx| cx.has_body(self.0))
+    }
+
+    pub fn span(&self) -> Span {
+        with(|cx| cx.span_of_an_item(self.0))
+    }
+
+    pub fn kind(&self) -> ItemKind {
+        with(|cx| cx.item_kind(*self))
+    }
+
+    pub fn requires_monomorphization(&self) -> bool {
+        with(|cx| cx.requires_monomorphization(self.0))
+    }
+
+    pub fn ty(&self) -> Ty {
+        with(|cx| cx.def_ty(self.0))
+    }
+
+    pub fn is_foreign_item(&self) -> bool {
+        with(|cx| cx.is_foreign_item(self.0))
+    }
+
+    /// Emit MIR for this item body.
+    pub fn emit_mir<W: io::Write>(&self, w: &mut W) -> io::Result<()> {
+        self.body()
+            .ok_or_else(|| io::Error::other(format!("No body found for `{}`", self.name())))?
+            .dump(w, &self.name())
+    }
+}
+
+/// Return the function where execution starts if the current
+/// crate defines that. This is usually `main`, but could be
+/// `start` if the crate is a no-std crate.
+pub fn entry_fn() -> Option<CrateItem> {
+    with(|cx| cx.entry_fn())
+}
+
+/// Access to the local crate.
+pub fn local_crate() -> Crate {
+    with(|cx| cx.local_crate())
+}
+
+/// Try to find a crate or crates if multiple crates exist from given name.
+pub fn find_crates(name: &str) -> Vec<Crate> {
+    with(|cx| cx.find_crates(name))
+}
+
+/// Try to find a crate with the given name.
+pub fn external_crates() -> Vec<Crate> {
+    with(|cx| cx.external_crates())
+}
+
+/// Retrieve all items in the local crate that have a MIR associated with them.
+pub fn all_local_items() -> CrateItems {
+    with(|cx| cx.all_local_items())
+}
+
+pub fn all_trait_decls() -> TraitDecls {
+    with(|cx| cx.all_trait_decls())
+}
+
+pub fn all_trait_impls() -> ImplTraitDecls {
+    with(|cx| cx.all_trait_impls())
+}
+
+/// A type that provides internal information but that can still be used for debug purpose.
+#[derive(Clone, PartialEq, Eq, Hash, Serialize)]
+pub struct Opaque(String);
+
+impl std::fmt::Display for Opaque {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl std::fmt::Debug for Opaque {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+pub fn opaque<T: Debug>(value: &T) -> Opaque {
+    Opaque(format!("{value:?}"))
+}
+
+macro_rules! bridge_impl {
+    ($name: ident, $ty: ty) => {
+        impl rustc_public_bridge::bridge::$name<compiler_interface::BridgeTys> for $ty {
+            fn new(def: crate::DefId) -> Self {
+                Self(def)
+            }
+        }
+    };
+}
+
+bridge_impl!(CrateItem, crate::CrateItem);
+bridge_impl!(AdtDef, crate::ty::AdtDef);
+bridge_impl!(ForeignModuleDef, crate::ty::ForeignModuleDef);
+bridge_impl!(ForeignDef, crate::ty::ForeignDef);
+bridge_impl!(FnDef, crate::ty::FnDef);
+bridge_impl!(ClosureDef, crate::ty::ClosureDef);
+bridge_impl!(CoroutineDef, crate::ty::CoroutineDef);
+bridge_impl!(CoroutineClosureDef, crate::ty::CoroutineClosureDef);
+bridge_impl!(AliasDef, crate::ty::AliasDef);
+bridge_impl!(ParamDef, crate::ty::ParamDef);
+bridge_impl!(BrNamedDef, crate::ty::BrNamedDef);
+bridge_impl!(TraitDef, crate::ty::TraitDef);
+bridge_impl!(GenericDef, crate::ty::GenericDef);
+bridge_impl!(ConstDef, crate::ty::ConstDef);
+bridge_impl!(ImplDef, crate::ty::ImplDef);
+bridge_impl!(RegionDef, crate::ty::RegionDef);
+bridge_impl!(CoroutineWitnessDef, crate::ty::CoroutineWitnessDef);
+bridge_impl!(AssocDef, crate::ty::AssocDef);
+bridge_impl!(OpaqueDef, crate::ty::OpaqueDef);
+bridge_impl!(StaticDef, crate::mir::mono::StaticDef);
+
+impl rustc_public_bridge::bridge::Prov<compiler_interface::BridgeTys> for crate::ty::Prov {
+    fn new(aid: crate::mir::alloc::AllocId) -> Self {
+        Self(aid)
+    }
+}
+
+impl rustc_public_bridge::bridge::Allocation<compiler_interface::BridgeTys>
+    for crate::ty::Allocation
+{
+    fn new<'tcx>(
+        bytes: Vec<Option<u8>>,
+        ptrs: Vec<(usize, rustc_middle::mir::interpret::AllocId)>,
+        align: u64,
+        mutability: rustc_middle::mir::Mutability,
+        tables: &mut Tables<'tcx, compiler_interface::BridgeTys>,
+        cx: &SmirCtxt<'tcx, compiler_interface::BridgeTys>,
+    ) -> Self {
+        Self {
+            bytes,
+            provenance: ProvenanceMap {
+                ptrs: ptrs.iter().map(|(i, aid)| (*i, tables.prov(*aid))).collect(),
+            },
+            align,
+            mutability: mutability.stable(tables, cx),
+        }
+    }
+}