Rollup merge of #139852 - makai410:smir-refactor, r=celinval

StableMIR: Implement `CompilerInterface`

This PR implements part of [the document](https://hackmd.io/``@celinaval/H1lJBGse0).``

With `TablesWrapper` wrapped by `CompilerInterface`, the stable-mir's TLV stores a pointer to `CompilerInterface`, while the rustc-specific TLV stores a pointer to tables.

5 files changed, 511 insertions, 211 deletions

diff --git a/compiler/rustc_smir/src/lib.rs b/compiler/rustc_smir/src/lib.rs
index 77e5f3423d1..771ff98d58d 100644
--- a/compiler/rustc_smir/src/lib.rs
+++ b/compiler/rustc_smir/src/lib.rs
@@ -19,7 +19,6 @@
 
 pub mod rustc_internal;
 
-// Make this module private for now since external users should not call these directly.
-mod rustc_smir;
+pub mod rustc_smir;
 
 pub mod stable_mir;
diff --git a/compiler/rustc_smir/src/rustc_internal/mod.rs b/compiler/rustc_smir/src/rustc_internal/mod.rs
index 146ba17d14f..bca9e24e046 100644
--- a/compiler/rustc_smir/src/rustc_internal/mod.rs
+++ b/compiler/rustc_smir/src/rustc_internal/mod.rs
@@ -18,9 +18,10 @@ use rustc_span::def_id::{CrateNum, DefId};
 use scoped_tls::scoped_thread_local;
 use stable_mir::Error;
 use stable_mir::abi::Layout;
+use stable_mir::compiler_interface::SmirInterface;
 use stable_mir::ty::IndexedVal;
 
-use crate::rustc_smir::context::TablesWrapper;
+use crate::rustc_smir::context::SmirCtxt;
 use crate::rustc_smir::{Stable, Tables};
 use crate::stable_mir;
 
@@ -196,12 +197,12 @@ pub fn crate_num(item: &stable_mir::Crate) -> CrateNum {
 // datastructures and stable MIR datastructures
 scoped_thread_local! (static TLV: Cell<*const ()>);
 
-pub(crate) fn init<'tcx, F, T>(tables: &TablesWrapper<'tcx>, f: F) -> T
+pub(crate) fn init<'tcx, F, T>(cx: &SmirCtxt<'tcx>, f: F) -> T
 where
     F: FnOnce() -> T,
 {
     assert!(!TLV.is_set());
-    let ptr = tables as *const _ as *const ();
+    let ptr = cx as *const _ as *const ();
     TLV.set(&Cell::new(ptr), || f())
 }
 
@@ -212,8 +213,8 @@ pub(crate) fn with_tables<R>(f: impl for<'tcx> FnOnce(&mut Tables<'tcx>) -> R) -
     TLV.with(|tlv| {
         let ptr = tlv.get();
         assert!(!ptr.is_null());
-        let wrapper = ptr as *const TablesWrapper<'_>;
-        let mut tables = unsafe { (*wrapper).0.borrow_mut() };
+        let context = ptr as *const SmirCtxt<'_>;
+        let mut tables = unsafe { (*context).0.borrow_mut() };
         f(&mut *tables)
     })
 }
@@ -222,7 +223,7 @@ pub fn run<F, T>(tcx: TyCtxt<'_>, f: F) -> Result<T, Error>
 where
     F: FnOnce() -> T,
 {
-    let tables = TablesWrapper(RefCell::new(Tables {
+    let tables = SmirCtxt(RefCell::new(Tables {
         tcx,
         def_ids: IndexMap::default(),
         alloc_ids: IndexMap::default(),
@@ -233,7 +234,12 @@ where
         mir_consts: IndexMap::default(),
         layouts: IndexMap::default(),
     }));
-    stable_mir::compiler_interface::run(&tables, || init(&tables, f))
+
+    let interface = SmirInterface { cx: tables };
+
+    // Pass the `SmirInterface` to compiler_interface::run
+    // and initialize the rustc-specific TLS with tables.
+    stable_mir::compiler_interface::run(&interface, || init(&interface.cx, f))
 }
 
 /// Instantiate and run the compiler with the provided arguments and callback.
diff --git a/compiler/rustc_smir/src/rustc_smir/context.rs b/compiler/rustc_smir/src/rustc_smir/context.rs
index 240f6f7fe45..9a4cac243bd 100644
--- a/compiler/rustc_smir/src/rustc_smir/context.rs
+++ b/compiler/rustc_smir/src/rustc_smir/context.rs
@@ -1,7 +1,4 @@
-//! Implementation of `[stable_mir::compiler_interface::Context]` trait.
-//!
-//! This trait is currently the main interface between the Rust compiler,
-//! and the `stable_mir` crate.
+//! Implementation of StableMIR Context.
 
 #![allow(rustc::usage_of_qualified_ty)]
 
@@ -20,7 +17,6 @@ use rustc_middle::ty::{
 use rustc_middle::{mir, ty};
 use rustc_span::def_id::LOCAL_CRATE;
 use stable_mir::abi::{FnAbi, Layout, LayoutShape};
-use stable_mir::compiler_interface::Context;
 use stable_mir::mir::alloc::GlobalAlloc;
 use stable_mir::mir::mono::{InstanceDef, StaticDef};
 use stable_mir::mir::{BinOp, Body, Place, UnOp};
@@ -37,8 +33,14 @@ use crate::rustc_smir::builder::BodyBuilder;
 use crate::rustc_smir::{Stable, Tables, alloc, filter_def_ids, new_item_kind, smir_crate};
 use crate::stable_mir;
 
-impl<'tcx> Context for TablesWrapper<'tcx> {
-    fn target_info(&self) -> MachineInfo {
+/// Provides direct access to rustc's internal queries.
+///
+/// The [`crate::stable_mir::compiler_interface::SmirInterface`] must go through
+/// this context to obtain rustc-level information.
+pub struct SmirCtxt<'tcx>(pub RefCell<Tables<'tcx>>);
+
+impl<'tcx> SmirCtxt<'tcx> {
+    pub fn target_info(&self) -> MachineInfo {
         let mut tables = self.0.borrow_mut();
         MachineInfo {
             endian: tables.tcx.data_layout.endian.stable(&mut *tables),
@@ -48,31 +50,35 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    fn entry_fn(&self) -> Option<stable_mir::CrateItem> {
+    pub fn entry_fn(&self) -> Option<stable_mir::CrateItem> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         Some(tables.crate_item(tcx.entry_fn(())?.0))
     }
 
-    fn all_local_items(&self) -> stable_mir::CrateItems {
+    /// Retrieve all items of the local crate that have a MIR associated with them.
+    pub fn all_local_items(&self) -> stable_mir::CrateItems {
         let mut tables = self.0.borrow_mut();
         tables.tcx.mir_keys(()).iter().map(|item| tables.crate_item(item.to_def_id())).collect()
     }
 
-    fn mir_body(&self, item: stable_mir::DefId) -> stable_mir::mir::Body {
+    /// Retrieve the body of a function.
+    /// This function will panic if the body is not available.
+    pub fn mir_body(&self, item: stable_mir::DefId) -> stable_mir::mir::Body {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[item];
         tables.tcx.instance_mir(rustc_middle::ty::InstanceKind::Item(def_id)).stable(&mut tables)
     }
 
-    fn has_body(&self, def: DefId) -> bool {
+    /// Check whether the body of a function is available.
+    pub fn has_body(&self, def: DefId) -> bool {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let def_id = def.internal(&mut *tables, tcx);
         tables.item_has_body(def_id)
     }
 
-    fn foreign_modules(&self, crate_num: CrateNum) -> Vec<stable_mir::ty::ForeignModuleDef> {
+    pub fn foreign_modules(&self, crate_num: CrateNum) -> Vec<stable_mir::ty::ForeignModuleDef> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         tcx.foreign_modules(crate_num.internal(&mut *tables, tcx))
@@ -81,21 +87,23 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .collect()
     }
 
-    fn crate_functions(&self, crate_num: CrateNum) -> Vec<FnDef> {
+    /// Retrieve all functions defined in this crate.
+    pub fn crate_functions(&self, crate_num: CrateNum) -> Vec<FnDef> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let krate = crate_num.internal(&mut *tables, tcx);
         filter_def_ids(tcx, krate, |def_id| tables.to_fn_def(def_id))
     }
 
-    fn crate_statics(&self, crate_num: CrateNum) -> Vec<StaticDef> {
+    /// Retrieve all static items defined in this crate.
+    pub fn crate_statics(&self, crate_num: CrateNum) -> Vec<StaticDef> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let krate = crate_num.internal(&mut *tables, tcx);
         filter_def_ids(tcx, krate, |def_id| tables.to_static(def_id))
     }
 
-    fn foreign_module(
+    pub fn foreign_module(
         &self,
         mod_def: stable_mir::ty::ForeignModuleDef,
     ) -> stable_mir::ty::ForeignModule {
@@ -105,7 +113,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         mod_def.stable(&mut *tables)
     }
 
-    fn foreign_items(&self, mod_def: stable_mir::ty::ForeignModuleDef) -> Vec<ForeignDef> {
+    pub fn foreign_items(&self, mod_def: stable_mir::ty::ForeignModuleDef) -> Vec<ForeignDef> {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[mod_def.def_id()];
         tables
@@ -119,12 +127,12 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .collect()
     }
 
-    fn all_trait_decls(&self) -> stable_mir::TraitDecls {
+    pub fn all_trait_decls(&self) -> stable_mir::TraitDecls {
         let mut tables = self.0.borrow_mut();
         tables.tcx.all_traits().map(|trait_def_id| tables.trait_def(trait_def_id)).collect()
     }
 
-    fn trait_decls(&self, crate_num: CrateNum) -> stable_mir::TraitDecls {
+    pub fn trait_decls(&self, crate_num: CrateNum) -> stable_mir::TraitDecls {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         tcx.traits(crate_num.internal(&mut *tables, tcx))
@@ -133,14 +141,14 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .collect()
     }
 
-    fn trait_decl(&self, trait_def: &stable_mir::ty::TraitDef) -> stable_mir::ty::TraitDecl {
+    pub fn trait_decl(&self, trait_def: &stable_mir::ty::TraitDef) -> stable_mir::ty::TraitDecl {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[trait_def.0];
         let trait_def = tables.tcx.trait_def(def_id);
         trait_def.stable(&mut *tables)
     }
 
-    fn all_trait_impls(&self) -> stable_mir::ImplTraitDecls {
+    pub fn all_trait_impls(&self) -> stable_mir::ImplTraitDecls {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         iter::once(LOCAL_CRATE)
@@ -150,7 +158,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .collect()
     }
 
-    fn trait_impls(&self, crate_num: CrateNum) -> stable_mir::ImplTraitDecls {
+    pub fn trait_impls(&self, crate_num: CrateNum) -> stable_mir::ImplTraitDecls {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         tcx.trait_impls_in_crate(crate_num.internal(&mut *tables, tcx))
@@ -159,21 +167,21 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .collect()
     }
 
-    fn trait_impl(&self, impl_def: &stable_mir::ty::ImplDef) -> stable_mir::ty::ImplTrait {
+    pub fn trait_impl(&self, impl_def: &stable_mir::ty::ImplDef) -> stable_mir::ty::ImplTrait {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[impl_def.0];
         let impl_trait = tables.tcx.impl_trait_ref(def_id).unwrap();
         impl_trait.stable(&mut *tables)
     }
 
-    fn generics_of(&self, def_id: stable_mir::DefId) -> stable_mir::ty::Generics {
+    pub fn generics_of(&self, def_id: stable_mir::DefId) -> stable_mir::ty::Generics {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[def_id];
         let generics = tables.tcx.generics_of(def_id);
         generics.stable(&mut *tables)
     }
 
-    fn predicates_of(&self, def_id: stable_mir::DefId) -> stable_mir::ty::GenericPredicates {
+    pub fn predicates_of(&self, def_id: stable_mir::DefId) -> stable_mir::ty::GenericPredicates {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[def_id];
         let GenericPredicates { parent, predicates } = tables.tcx.predicates_of(def_id);
@@ -191,7 +199,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    fn explicit_predicates_of(
+    pub fn explicit_predicates_of(
         &self,
         def_id: stable_mir::DefId,
     ) -> stable_mir::ty::GenericPredicates {
@@ -212,17 +220,20 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    fn local_crate(&self) -> stable_mir::Crate {
+    /// Get information about the local crate.
+    pub fn local_crate(&self) -> stable_mir::Crate {
         let tables = self.0.borrow();
         smir_crate(tables.tcx, LOCAL_CRATE)
     }
 
-    fn external_crates(&self) -> Vec<stable_mir::Crate> {
+    /// Retrieve a list of all external crates.
+    pub fn external_crates(&self) -> Vec<stable_mir::Crate> {
         let tables = self.0.borrow();
         tables.tcx.crates(()).iter().map(|crate_num| smir_crate(tables.tcx, *crate_num)).collect()
     }
 
-    fn find_crates(&self, name: &str) -> Vec<stable_mir::Crate> {
+    /// Find a crate with the given name.
+    pub fn find_crates(&self, name: &str) -> Vec<stable_mir::Crate> {
         let tables = self.0.borrow();
         let crates: Vec<stable_mir::Crate> = [LOCAL_CRATE]
             .iter()
@@ -235,7 +246,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         crates
     }
 
-    fn def_name(&self, def_id: stable_mir::DefId, trimmed: bool) -> Symbol {
+    /// Returns the name of given `DefId`.
+    pub fn def_name(&self, def_id: stable_mir::DefId, trimmed: bool) -> Symbol {
         let tables = self.0.borrow();
         if trimmed {
             with_forced_trimmed_paths!(tables.tcx.def_path_str(tables[def_id]))
@@ -244,7 +256,14 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    fn tool_attrs(
+    /// Return registered tool attributes with the given attribute name.
+    ///
+    /// FIXME(jdonszelmann): may panic on non-tool attributes. After more attribute work, non-tool
+    /// attributes will simply return an empty list.
+    ///
+    /// Single segmented name like `#[clippy]` is specified as `&["clippy".to_string()]`.
+    /// Multi-segmented name like `#[rustfmt::skip]` is specified as `&["rustfmt".to_string(), "skip".to_string()]`.
+    pub fn tool_attrs(
         &self,
         def_id: stable_mir::DefId,
         attr: &[stable_mir::Symbol],
@@ -268,7 +287,11 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .collect()
     }
 
-    fn all_tool_attrs(&self, def_id: stable_mir::DefId) -> Vec<stable_mir::crate_def::Attribute> {
+    /// Get all tool attributes of a definition.
+    pub fn all_tool_attrs(
+        &self,
+        def_id: stable_mir::DefId,
+    ) -> Vec<stable_mir::crate_def::Attribute> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let did = tables[def_id];
@@ -292,12 +315,14 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .collect()
     }
 
-    fn span_to_string(&self, span: stable_mir::ty::Span) -> String {
+    /// Returns printable, human readable form of `Span`.
+    pub fn span_to_string(&self, span: stable_mir::ty::Span) -> String {
         let tables = self.0.borrow();
         tables.tcx.sess.source_map().span_to_diagnostic_string(tables[span])
     }
 
-    fn get_filename(&self, span: &Span) -> Filename {
+    /// Return filename from given `Span`, for diagnostic purposes.
+    pub fn get_filename(&self, span: &Span) -> Filename {
         let tables = self.0.borrow();
         tables
             .tcx
@@ -308,23 +333,27 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .to_string()
     }
 
-    fn get_lines(&self, span: &Span) -> LineInfo {
+    /// Return lines corresponding to this `Span`.
+    pub fn get_lines(&self, span: &Span) -> LineInfo {
         let tables = self.0.borrow();
         let lines = &tables.tcx.sess.source_map().span_to_location_info(tables[*span]);
         LineInfo { start_line: lines.1, start_col: lines.2, end_line: lines.3, end_col: lines.4 }
     }
 
-    fn item_kind(&self, item: CrateItem) -> ItemKind {
+    /// Returns the `kind` of given `DefId`.
+    pub fn item_kind(&self, item: CrateItem) -> ItemKind {
         let tables = self.0.borrow();
         new_item_kind(tables.tcx.def_kind(tables[item.0]))
     }
 
-    fn is_foreign_item(&self, item: DefId) -> bool {
+    /// Returns whether this is a foreign item.
+    pub fn is_foreign_item(&self, item: DefId) -> bool {
         let tables = self.0.borrow();
         tables.tcx.is_foreign_item(tables[item])
     }
 
-    fn foreign_item_kind(&self, def: ForeignDef) -> ForeignItemKind {
+    /// Returns the kind of a given foreign item.
+    pub fn foreign_item_kind(&self, def: ForeignDef) -> ForeignItemKind {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[def.def_id()];
         let tcx = tables.tcx;
@@ -339,32 +368,37 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    fn adt_kind(&self, def: AdtDef) -> AdtKind {
+    /// Returns the kind of a given algebraic data type.
+    pub fn adt_kind(&self, def: AdtDef) -> AdtKind {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         def.internal(&mut *tables, tcx).adt_kind().stable(&mut *tables)
     }
 
-    fn adt_is_box(&self, def: AdtDef) -> bool {
+    /// Returns if the ADT is a box.
+    pub fn adt_is_box(&self, def: AdtDef) -> bool {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         def.internal(&mut *tables, tcx).is_box()
     }
 
-    fn adt_is_simd(&self, def: AdtDef) -> bool {
+    /// Returns whether this ADT is simd.
+    pub fn adt_is_simd(&self, def: AdtDef) -> bool {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         def.internal(&mut *tables, tcx).repr().simd()
     }
 
-    fn adt_is_cstr(&self, def: AdtDef) -> bool {
+    /// Returns whether this definition is a C string.
+    pub fn adt_is_cstr(&self, def: AdtDef) -> bool {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let def_id = def.0.internal(&mut *tables, tcx);
         tables.tcx.is_lang_item(def_id, LangItem::CStr)
     }
 
-    fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig {
+    /// Retrieve the function signature for the given generic arguments.
+    pub fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let def_id = def.0.internal(&mut *tables, tcx);
@@ -373,7 +407,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         sig.stable(&mut *tables)
     }
 
-    fn intrinsic(&self, def: DefId) -> Option<IntrinsicDef> {
+    /// Retrieve the intrinsic definition if the item corresponds one.
+    pub fn intrinsic(&self, def: DefId) -> Option<IntrinsicDef> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let def_id = def.internal(&mut *tables, tcx);
@@ -381,14 +416,16 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         intrinsic.map(|_| IntrinsicDef(def))
     }
 
-    fn intrinsic_name(&self, def: IntrinsicDef) -> Symbol {
+    /// Retrieve the plain function name of an intrinsic.
+    pub fn intrinsic_name(&self, def: IntrinsicDef) -> Symbol {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let def_id = def.0.internal(&mut *tables, tcx);
         tcx.intrinsic(def_id).unwrap().name.to_string()
     }
 
-    fn closure_sig(&self, args: &GenericArgs) -> PolyFnSig {
+    /// Retrieve the closure signature for the given generic arguments.
+    pub fn closure_sig(&self, args: &GenericArgs) -> PolyFnSig {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let args_ref = args.internal(&mut *tables, tcx);
@@ -396,25 +433,28 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         sig.stable(&mut *tables)
     }
 
-    fn adt_variants_len(&self, def: AdtDef) -> usize {
+    /// The number of variants in this ADT.
+    pub fn adt_variants_len(&self, def: AdtDef) -> usize {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         def.internal(&mut *tables, tcx).variants().len()
     }
 
-    fn variant_name(&self, def: VariantDef) -> Symbol {
+    /// The name of a variant.
+    pub fn variant_name(&self, def: VariantDef) -> Symbol {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         def.internal(&mut *tables, tcx).name.to_string()
     }
 
-    fn variant_fields(&self, def: VariantDef) -> Vec<FieldDef> {
+    pub fn variant_fields(&self, def: VariantDef) -> Vec<FieldDef> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         def.internal(&mut *tables, tcx).fields.iter().map(|f| f.stable(&mut *tables)).collect()
     }
 
-    fn eval_target_usize(&self, cnst: &MirConst) -> Result<u64, Error> {
+    /// Evaluate constant as a target usize.
+    pub fn eval_target_usize(&self, cnst: &MirConst) -> Result<u64, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let mir_const = cnst.internal(&mut *tables, tcx);
@@ -422,7 +462,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .try_eval_target_usize(tables.tcx, ty::TypingEnv::fully_monomorphized())
             .ok_or_else(|| Error::new(format!("Const `{cnst:?}` cannot be encoded as u64")))
     }
-    fn eval_target_usize_ty(&self, cnst: &TyConst) -> Result<u64, Error> {
+    pub fn eval_target_usize_ty(&self, cnst: &TyConst) -> Result<u64, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let mir_const = cnst.internal(&mut *tables, tcx);
@@ -431,7 +471,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .ok_or_else(|| Error::new(format!("Const `{cnst:?}` cannot be encoded as u64")))
     }
 
-    fn try_new_const_zst(&self, ty: Ty) -> Result<MirConst, Error> {
+    /// Create a new zero-sized constant.
+    pub fn try_new_const_zst(&self, ty: Ty) -> Result<MirConst, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let ty_internal = ty.internal(&mut *tables, tcx);
@@ -456,7 +497,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .stable(&mut *tables))
     }
 
-    fn new_const_str(&self, value: &str) -> MirConst {
+    /// Create a new constant that represents the given string value.
+    pub fn new_const_str(&self, value: &str) -> MirConst {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let ty = ty::Ty::new_static_str(tcx);
@@ -467,12 +509,14 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         mir::Const::from_value(val, ty).stable(&mut tables)
     }
 
-    fn new_const_bool(&self, value: bool) -> MirConst {
+    /// Create a new constant that represents the given boolean value.
+    pub fn new_const_bool(&self, value: bool) -> MirConst {
         let mut tables = self.0.borrow_mut();
         mir::Const::from_bool(tables.tcx, value).stable(&mut tables)
     }
 
-    fn try_new_const_uint(&self, value: u128, uint_ty: UintTy) -> Result<MirConst, Error> {
+    /// Create a new constant that represents the given value.
+    pub fn try_new_const_uint(&self, value: u128, uint_ty: UintTy) -> Result<MirConst, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let ty = ty::Ty::new_uint(tcx, uint_ty.internal(&mut *tables, tcx));
@@ -487,7 +531,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         Ok(mir::Const::from_scalar(tcx, mir::interpret::Scalar::Int(scalar), ty)
             .stable(&mut tables))
     }
-    fn try_new_ty_const_uint(
+    pub fn try_new_ty_const_uint(
         &self,
         value: u128,
         uint_ty: UintTy,
@@ -509,27 +553,35 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .stable(&mut *tables))
     }
 
-    fn new_rigid_ty(&self, kind: RigidTy) -> stable_mir::ty::Ty {
+    /// Create a new type from the given kind.
+    pub fn new_rigid_ty(&self, kind: RigidTy) -> stable_mir::ty::Ty {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let internal_kind = kind.internal(&mut *tables, tcx);
         tables.tcx.mk_ty_from_kind(internal_kind).stable(&mut *tables)
     }
 
-    fn new_box_ty(&self, ty: stable_mir::ty::Ty) -> stable_mir::ty::Ty {
+    /// Create a new box type, `Box<T>`, for the given inner type `T`.
+    pub fn new_box_ty(&self, ty: stable_mir::ty::Ty) -> stable_mir::ty::Ty {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let inner = ty.internal(&mut *tables, tcx);
         ty::Ty::new_box(tables.tcx, inner).stable(&mut *tables)
     }
 
-    fn def_ty(&self, item: stable_mir::DefId) -> stable_mir::ty::Ty {
+    /// Returns the type of given crate item.
+    pub fn def_ty(&self, item: stable_mir::DefId) -> stable_mir::ty::Ty {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         tcx.type_of(item.internal(&mut *tables, tcx)).instantiate_identity().stable(&mut *tables)
     }
 
-    fn def_ty_with_args(&self, item: stable_mir::DefId, args: &GenericArgs) -> stable_mir::ty::Ty {
+    /// Returns the type of given definition instantiated with the given arguments.
+    pub fn def_ty_with_args(
+        &self,
+        item: stable_mir::DefId,
+        args: &GenericArgs,
+    ) -> stable_mir::ty::Ty {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let args = args.internal(&mut *tables, tcx);
@@ -544,33 +596,38 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .stable(&mut *tables)
     }
 
-    fn mir_const_pretty(&self, cnst: &stable_mir::ty::MirConst) -> String {
+    /// Returns literal value of a const as a string.
+    pub fn mir_const_pretty(&self, cnst: &stable_mir::ty::MirConst) -> String {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         cnst.internal(&mut *tables, tcx).to_string()
     }
 
-    fn span_of_an_item(&self, def_id: stable_mir::DefId) -> Span {
+    /// `Span` of an item.
+    pub fn span_of_an_item(&self, def_id: stable_mir::DefId) -> Span {
         let mut tables = self.0.borrow_mut();
         tables.tcx.def_span(tables[def_id]).stable(&mut *tables)
     }
 
-    fn ty_pretty(&self, ty: stable_mir::ty::Ty) -> String {
+    /// Obtain the representation of a type.
+    pub fn ty_pretty(&self, ty: stable_mir::ty::Ty) -> String {
         let tables = self.0.borrow_mut();
         tables.types[ty].to_string()
     }
 
-    fn ty_kind(&self, ty: stable_mir::ty::Ty) -> TyKind {
+    /// Obtain the representation of a type.
+    pub fn ty_kind(&self, ty: stable_mir::ty::Ty) -> TyKind {
         let mut tables = self.0.borrow_mut();
         tables.types[ty].kind().stable(&mut *tables)
     }
 
-    fn ty_const_pretty(&self, ct: stable_mir::ty::TyConstId) -> String {
+    pub fn ty_const_pretty(&self, ct: stable_mir::ty::TyConstId) -> String {
         let tables = self.0.borrow_mut();
         tables.ty_consts[ct].to_string()
     }
 
-    fn rigid_ty_discriminant_ty(&self, ty: &RigidTy) -> stable_mir::ty::Ty {
+    /// Get the discriminant Ty for this Ty if there's one.
+    pub fn rigid_ty_discriminant_ty(&self, ty: &RigidTy) -> stable_mir::ty::Ty {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let internal_kind = ty.internal(&mut *tables, tcx);
@@ -578,7 +635,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         internal_ty.discriminant_ty(tables.tcx).stable(&mut *tables)
     }
 
-    fn instance_body(&self, def: InstanceDef) -> Option<Body> {
+    /// Get the body of an Instance which is already monomorphized.
+    pub fn instance_body(&self, def: InstanceDef) -> Option<Body> {
         let mut tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         tables
@@ -586,63 +644,74 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .then(|| BodyBuilder::new(tables.tcx, instance).build(&mut *tables))
     }
 
-    fn instance_ty(&self, def: InstanceDef) -> stable_mir::ty::Ty {
+    /// Get the instance type with generic instantiations applied and lifetimes erased.
+    pub fn instance_ty(&self, def: InstanceDef) -> stable_mir::ty::Ty {
         let mut tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         assert!(!instance.has_non_region_param(), "{instance:?} needs further instantiation");
         instance.ty(tables.tcx, ty::TypingEnv::fully_monomorphized()).stable(&mut *tables)
     }
 
-    fn instance_args(&self, def: InstanceDef) -> GenericArgs {
+    /// Get the instantiation types.
+    pub fn instance_args(&self, def: InstanceDef) -> GenericArgs {
         let mut tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         instance.args.stable(&mut *tables)
     }
 
-    fn instance_abi(&self, def: InstanceDef) -> Result<FnAbi, Error> {
+    /// Get an instance ABI.
+    pub fn instance_abi(&self, def: InstanceDef) -> Result<FnAbi, Error> {
         let mut tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         Ok(tables.fn_abi_of_instance(instance, List::empty())?.stable(&mut *tables))
     }
 
-    fn fn_ptr_abi(&self, fn_ptr: PolyFnSig) -> Result<FnAbi, Error> {
+    /// Get the ABI of a function pointer.
+    pub fn fn_ptr_abi(&self, fn_ptr: PolyFnSig) -> Result<FnAbi, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let sig = fn_ptr.internal(&mut *tables, tcx);
         Ok(tables.fn_abi_of_fn_ptr(sig, List::empty())?.stable(&mut *tables))
     }
 
-    fn instance_def_id(&self, def: InstanceDef) -> stable_mir::DefId {
+    /// Get the instance.
+    pub fn instance_def_id(&self, def: InstanceDef) -> stable_mir::DefId {
         let mut tables = self.0.borrow_mut();
         let def_id = tables.instances[def].def_id();
         tables.create_def_id(def_id)
     }
 
-    fn instance_mangled_name(&self, instance: InstanceDef) -> Symbol {
+    /// Get the instance mangled name.
+    pub fn instance_mangled_name(&self, instance: InstanceDef) -> Symbol {
         let tables = self.0.borrow_mut();
         let instance = tables.instances[instance];
         tables.tcx.symbol_name(instance).name.to_string()
     }
 
-    fn is_empty_drop_shim(&self, def: InstanceDef) -> bool {
+    /// Check if this is an empty DropGlue shim.
+    pub fn is_empty_drop_shim(&self, def: InstanceDef) -> bool {
         let tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         matches!(instance.def, ty::InstanceKind::DropGlue(_, None))
     }
 
-    fn is_empty_async_drop_ctor_shim(&self, def: InstanceDef) -> bool {
+    /// Check if this is an empty AsyncDropGlueCtor shim.
+    pub fn is_empty_async_drop_ctor_shim(&self, def: InstanceDef) -> bool {
         let tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         matches!(instance.def, ty::InstanceKind::AsyncDropGlueCtorShim(_, None))
     }
 
-    fn mono_instance(&self, def_id: stable_mir::DefId) -> stable_mir::mir::mono::Instance {
+    /// Convert a non-generic crate item into an instance.
+    /// This function will panic if the item is generic.
+    pub fn mono_instance(&self, def_id: stable_mir::DefId) -> stable_mir::mir::mono::Instance {
         let mut tables = self.0.borrow_mut();
         let def_id = tables[def_id];
         Instance::mono(tables.tcx, def_id).stable(&mut *tables)
     }
 
-    fn requires_monomorphization(&self, def_id: stable_mir::DefId) -> bool {
+    /// Item requires monomorphization.
+    pub fn requires_monomorphization(&self, def_id: stable_mir::DefId) -> bool {
         let tables = self.0.borrow();
         let def_id = tables[def_id];
         let generics = tables.tcx.generics_of(def_id);
@@ -650,7 +719,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         result
     }
 
-    fn resolve_instance(
+    /// Resolve an instance from the given function definition and generic arguments.
+    pub fn resolve_instance(
         &self,
         def: stable_mir::ty::FnDef,
         args: &stable_mir::ty::GenericArgs,
@@ -670,7 +740,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    fn resolve_drop_in_place(&self, ty: stable_mir::ty::Ty) -> stable_mir::mir::mono::Instance {
+    /// Resolve an instance for drop_in_place for the given type.
+    pub fn resolve_drop_in_place(&self, ty: stable_mir::ty::Ty) -> stable_mir::mir::mono::Instance {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let internal_ty = ty.internal(&mut *tables, tcx);
@@ -678,7 +749,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         instance.stable(&mut *tables)
     }
 
-    fn resolve_for_fn_ptr(
+    /// Resolve instance for a function pointer.
+    pub fn resolve_for_fn_ptr(
         &self,
         def: FnDef,
         args: &GenericArgs,
@@ -696,7 +768,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         .stable(&mut *tables)
     }
 
-    fn resolve_closure(
+    /// Resolve instance for a closure with the requested type.
+    pub fn resolve_closure(
         &self,
         def: ClosureDef,
         args: &GenericArgs,
@@ -713,7 +786,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         )
     }
 
-    fn eval_instance(&self, def: InstanceDef, const_ty: Ty) -> Result<Allocation, Error> {
+    /// Try to evaluate an instance into a constant.
+    pub fn eval_instance(&self, def: InstanceDef, const_ty: Ty) -> Result<Allocation, Error> {
         let mut tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         let tcx = tables.tcx;
@@ -733,21 +807,24 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             .map_err(|e| e.stable(&mut *tables))?
     }
 
-    fn eval_static_initializer(&self, def: StaticDef) -> Result<Allocation, Error> {
+    /// Evaluate a static's initializer.
+    pub fn eval_static_initializer(&self, def: StaticDef) -> Result<Allocation, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let def_id = def.0.internal(&mut *tables, tcx);
         tables.tcx.eval_static_initializer(def_id).stable(&mut *tables)
     }
 
-    fn global_alloc(&self, alloc: stable_mir::mir::alloc::AllocId) -> GlobalAlloc {
+    /// Retrieve global allocation for the given allocation ID.
+    pub fn global_alloc(&self, alloc: stable_mir::mir::alloc::AllocId) -> GlobalAlloc {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let alloc_id = alloc.internal(&mut *tables, tcx);
         tables.tcx.global_alloc(alloc_id).stable(&mut *tables)
     }
 
-    fn vtable_allocation(
+    /// Retrieve the id for the virtual table.
+    pub fn vtable_allocation(
         &self,
         global_alloc: &GlobalAlloc,
     ) -> Option<stable_mir::mir::alloc::AllocId> {
@@ -765,7 +842,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         Some(alloc_id.stable(&mut *tables))
     }
 
-    fn krate(&self, def_id: stable_mir::DefId) -> Crate {
+    pub fn krate(&self, def_id: stable_mir::DefId) -> Crate {
         let tables = self.0.borrow();
         smir_crate(tables.tcx, tables[def_id].krate)
     }
@@ -773,7 +850,7 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
     /// Retrieve the instance name for diagnostic messages.
     ///
     /// This will return the specialized name, e.g., `Vec<char>::new`.
-    fn instance_name(&self, def: InstanceDef, trimmed: bool) -> Symbol {
+    pub fn instance_name(&self, def: InstanceDef, trimmed: bool) -> Symbol {
         let tables = self.0.borrow_mut();
         let instance = tables.instances[def];
         if trimmed {
@@ -787,7 +864,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         }
     }
 
-    fn ty_layout(&self, ty: Ty) -> Result<Layout, Error> {
+    /// Get the layout of a type.
+    pub fn ty_layout(&self, ty: Ty) -> Result<Layout, Error> {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let ty = ty.internal(&mut *tables, tcx);
@@ -795,19 +873,22 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         Ok(layout.stable(&mut *tables))
     }
 
-    fn layout_shape(&self, id: Layout) -> LayoutShape {
+    /// Get the layout shape.
+    pub fn layout_shape(&self, id: Layout) -> LayoutShape {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         id.internal(&mut *tables, tcx).0.stable(&mut *tables)
     }
 
-    fn place_pretty(&self, place: &Place) -> String {
+    /// Get a debug string representation of a place.
+    pub fn place_pretty(&self, place: &Place) -> String {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         format!("{:?}", place.internal(&mut *tables, tcx))
     }
 
-    fn binop_ty(&self, bin_op: BinOp, rhs: Ty, lhs: Ty) -> Ty {
+    /// Get the resulting type of binary operation.
+    pub fn binop_ty(&self, bin_op: BinOp, rhs: Ty, lhs: Ty) -> Ty {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let rhs_internal = rhs.internal(&mut *tables, tcx);
@@ -816,7 +897,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         ty.stable(&mut *tables)
     }
 
-    fn unop_ty(&self, un_op: UnOp, arg: Ty) -> Ty {
+    /// Get the resulting type of unary operation.
+    pub fn unop_ty(&self, un_op: UnOp, arg: Ty) -> Ty {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let arg_internal = arg.internal(&mut *tables, tcx);
@@ -824,7 +906,8 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         ty.stable(&mut *tables)
     }
 
-    fn associated_items(&self, def_id: stable_mir::DefId) -> stable_mir::AssocItems {
+    /// Get all associated items of a definition.
+    pub fn associated_items(&self, def_id: stable_mir::DefId) -> stable_mir::AssocItems {
         let mut tables = self.0.borrow_mut();
         let tcx = tables.tcx;
         let def_id = tables[def_id];
@@ -840,8 +923,6 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
     }
 }
 
-pub(crate) struct TablesWrapper<'tcx>(pub RefCell<Tables<'tcx>>);
-
 /// Implement error handling for extracting function ABI information.
 impl<'tcx> FnAbiOfHelpers<'tcx> for Tables<'tcx> {
     type FnAbiOfResult = Result<&'tcx rustc_target::callconv::FnAbi<'tcx, ty::Ty<'tcx>>, Error>;
diff --git a/compiler/rustc_smir/src/rustc_smir/mod.rs b/compiler/rustc_smir/src/rustc_smir/mod.rs
index dea8f54a670..b5003baaf63 100644
--- a/compiler/rustc_smir/src/rustc_smir/mod.rs
+++ b/compiler/rustc_smir/src/rustc_smir/mod.rs
@@ -25,7 +25,7 @@ use crate::stable_mir;
 
 mod alloc;
 mod builder;
-pub(crate) mod context;
+pub mod context;
 mod convert;
 
 pub struct Tables<'tcx> {
diff --git a/compiler/rustc_smir/src/stable_mir/compiler_interface.rs b/compiler/rustc_smir/src/stable_mir/compiler_interface.rs
index 33d950bb951..cd61907dc6b 100644
--- a/compiler/rustc_smir/src/stable_mir/compiler_interface.rs
+++ b/compiler/rustc_smir/src/stable_mir/compiler_interface.rs
@@ -5,6 +5,7 @@
 
 use std::cell::Cell;
 
+use rustc_smir::context::SmirCtxt;
 use stable_mir::abi::{FnAbi, Layout, LayoutShape};
 use stable_mir::crate_def::Attribute;
 use stable_mir::mir::alloc::{AllocId, GlobalAlloc};
@@ -22,47 +23,116 @@ use stable_mir::{
     ItemKind, Symbol, TraitDecls, mir,
 };
 
-use crate::stable_mir;
+use crate::{rustc_smir, stable_mir};
+
+/// Stable public API for querying compiler information.
+///
+/// All queries are delegated to an internal [`SmirCtxt`] that provides
+/// similar APIs but based on internal rustc constructs.
+///
+/// Do not use this directly. This is currently used in the macro expansion.
+pub(crate) struct SmirInterface<'tcx> {
+    pub(crate) cx: SmirCtxt<'tcx>,
+}
+
+impl<'tcx> SmirInterface<'tcx> {
+    pub(crate) fn entry_fn(&self) -> Option<CrateItem> {
+        self.cx.entry_fn()
+    }
 
-/// This trait defines the interface between stable_mir and the Rust compiler.
-/// Do not use this directly.
-pub trait Context {
-    fn entry_fn(&self) -> Option<CrateItem>;
     /// Retrieve all items of the local crate that have a MIR associated with them.
-    fn all_local_items(&self) -> CrateItems;
+    pub(crate) fn all_local_items(&self) -> CrateItems {
+        self.cx.all_local_items()
+    }
+
     /// Retrieve the body of a function.
     /// This function will panic if the body is not available.
-    fn mir_body(&self, item: DefId) -> mir::Body;
+    pub(crate) fn mir_body(&self, item: DefId) -> mir::Body {
+        self.cx.mir_body(item)
+    }
+
     /// Check whether the body of a function is available.
-    fn has_body(&self, item: DefId) -> bool;
-    fn foreign_modules(&self, crate_num: CrateNum) -> Vec<ForeignModuleDef>;
+    pub(crate) fn has_body(&self, item: DefId) -> bool {
+        self.cx.has_body(item)
+    }
+
+    pub(crate) fn foreign_modules(&self, crate_num: CrateNum) -> Vec<ForeignModuleDef> {
+        self.cx.foreign_modules(crate_num)
+    }
 
     /// Retrieve all functions defined in this crate.
-    fn crate_functions(&self, crate_num: CrateNum) -> Vec<FnDef>;
+    pub(crate) fn crate_functions(&self, crate_num: CrateNum) -> Vec<FnDef> {
+        self.cx.crate_functions(crate_num)
+    }
 
     /// Retrieve all static items defined in this crate.
-    fn crate_statics(&self, crate_num: CrateNum) -> Vec<StaticDef>;
-    fn foreign_module(&self, mod_def: ForeignModuleDef) -> ForeignModule;
-    fn foreign_items(&self, mod_def: ForeignModuleDef) -> Vec<ForeignDef>;
-    fn all_trait_decls(&self) -> TraitDecls;
-    fn trait_decls(&self, crate_num: CrateNum) -> TraitDecls;
-    fn trait_decl(&self, trait_def: &TraitDef) -> TraitDecl;
-    fn all_trait_impls(&self) -> ImplTraitDecls;
-    fn trait_impls(&self, crate_num: CrateNum) -> ImplTraitDecls;
-    fn trait_impl(&self, trait_impl: &ImplDef) -> ImplTrait;
-    fn generics_of(&self, def_id: DefId) -> Generics;
-    fn predicates_of(&self, def_id: DefId) -> GenericPredicates;
-    fn explicit_predicates_of(&self, def_id: DefId) -> GenericPredicates;
+    pub(crate) fn crate_statics(&self, crate_num: CrateNum) -> Vec<StaticDef> {
+        self.cx.crate_statics(crate_num)
+    }
+
+    pub(crate) fn foreign_module(&self, mod_def: ForeignModuleDef) -> ForeignModule {
+        self.cx.foreign_module(mod_def)
+    }
+
+    pub(crate) fn foreign_items(&self, mod_def: ForeignModuleDef) -> Vec<ForeignDef> {
+        self.cx.foreign_items(mod_def)
+    }
+
+    pub(crate) fn all_trait_decls(&self) -> TraitDecls {
+        self.cx.all_trait_decls()
+    }
+
+    pub(crate) fn trait_decls(&self, crate_num: CrateNum) -> TraitDecls {
+        self.cx.trait_decls(crate_num)
+    }
+
+    pub(crate) fn trait_decl(&self, trait_def: &TraitDef) -> TraitDecl {
+        self.cx.trait_decl(trait_def)
+    }
+
+    pub(crate) fn all_trait_impls(&self) -> ImplTraitDecls {
+        self.cx.all_trait_impls()
+    }
+
+    pub(crate) fn trait_impls(&self, crate_num: CrateNum) -> ImplTraitDecls {
+        self.cx.trait_impls(crate_num)
+    }
+
+    pub(crate) fn trait_impl(&self, trait_impl: &ImplDef) -> ImplTrait {
+        self.cx.trait_impl(trait_impl)
+    }
+
+    pub(crate) fn generics_of(&self, def_id: DefId) -> Generics {
+        self.cx.generics_of(def_id)
+    }
+
+    pub(crate) fn predicates_of(&self, def_id: DefId) -> GenericPredicates {
+        self.cx.predicates_of(def_id)
+    }
+
+    pub(crate) fn explicit_predicates_of(&self, def_id: DefId) -> GenericPredicates {
+        self.cx.explicit_predicates_of(def_id)
+    }
+
     /// Get information about the local crate.
-    fn local_crate(&self) -> Crate;
+    pub(crate) fn local_crate(&self) -> Crate {
+        self.cx.local_crate()
+    }
+
     /// Retrieve a list of all external crates.
-    fn external_crates(&self) -> Vec<Crate>;
+    pub(crate) fn external_crates(&self) -> Vec<Crate> {
+        self.cx.external_crates()
+    }
 
     /// Find a crate with the given name.
-    fn find_crates(&self, name: &str) -> Vec<Crate>;
+    pub(crate) fn find_crates(&self, name: &str) -> Vec<Crate> {
+        self.cx.find_crates(name)
+    }
 
-    /// Returns the name of given `DefId`
-    fn def_name(&self, def_id: DefId, trimmed: bool) -> Symbol;
+    /// Returns the name of given `DefId`.
+    pub(crate) fn def_name(&self, def_id: DefId, trimmed: bool) -> Symbol {
+        self.cx.def_name(def_id, trimmed)
+    }
 
     /// Return registered tool attributes with the given attribute name.
     ///
@@ -71,218 +141,362 @@ pub trait Context {
     ///
     /// Single segmented name like `#[clippy]` is specified as `&["clippy".to_string()]`.
     /// Multi-segmented name like `#[rustfmt::skip]` is specified as `&["rustfmt".to_string(), "skip".to_string()]`.
-    fn tool_attrs(&self, def_id: DefId, attr: &[Symbol]) -> Vec<Attribute>;
+    pub(crate) fn tool_attrs(&self, def_id: DefId, attr: &[Symbol]) -> Vec<Attribute> {
+        self.cx.tool_attrs(def_id, attr)
+    }
 
     /// Get all tool attributes of a definition.
-    fn all_tool_attrs(&self, def_id: DefId) -> Vec<Attribute>;
+    pub(crate) fn all_tool_attrs(&self, def_id: DefId) -> Vec<Attribute> {
+        self.cx.all_tool_attrs(def_id)
+    }
 
-    /// Returns printable, human readable form of `Span`
-    fn span_to_string(&self, span: Span) -> String;
+    /// Returns printable, human readable form of `Span`.
+    pub(crate) fn span_to_string(&self, span: Span) -> String {
+        self.cx.span_to_string(span)
+    }
 
-    /// Return filename from given `Span`, for diagnostic purposes
-    fn get_filename(&self, span: &Span) -> Filename;
+    /// Return filename from given `Span`, for diagnostic purposes.
+    pub(crate) fn get_filename(&self, span: &Span) -> Filename {
+        self.cx.get_filename(span)
+    }
 
-    /// Return lines corresponding to this `Span`
-    fn get_lines(&self, span: &Span) -> LineInfo;
+    /// Return lines corresponding to this `Span`.
+    pub(crate) fn get_lines(&self, span: &Span) -> LineInfo {
+        self.cx.get_lines(span)
+    }
 
-    /// Returns the `kind` of given `DefId`
-    fn item_kind(&self, item: CrateItem) -> ItemKind;
+    /// Returns the `kind` of given `DefId`.
+    pub(crate) fn item_kind(&self, item: CrateItem) -> ItemKind {
+        self.cx.item_kind(item)
+    }
 
     /// Returns whether this is a foreign item.
-    fn is_foreign_item(&self, item: DefId) -> bool;
+    pub(crate) fn is_foreign_item(&self, item: DefId) -> bool {
+        self.cx.is_foreign_item(item)
+    }
 
     /// Returns the kind of a given foreign item.
-    fn foreign_item_kind(&self, def: ForeignDef) -> ForeignItemKind;
+    pub(crate) fn foreign_item_kind(&self, def: ForeignDef) -> ForeignItemKind {
+        self.cx.foreign_item_kind(def)
+    }
 
-    /// Returns the kind of a given algebraic data type
-    fn adt_kind(&self, def: AdtDef) -> AdtKind;
+    /// Returns the kind of a given algebraic data type.
+    pub(crate) fn adt_kind(&self, def: AdtDef) -> AdtKind {
+        self.cx.adt_kind(def)
+    }
 
     /// Returns if the ADT is a box.
-    fn adt_is_box(&self, def: AdtDef) -> bool;
+    pub(crate) fn adt_is_box(&self, def: AdtDef) -> bool {
+        self.cx.adt_is_box(def)
+    }
 
     /// Returns whether this ADT is simd.
-    fn adt_is_simd(&self, def: AdtDef) -> bool;
+    pub(crate) fn adt_is_simd(&self, def: AdtDef) -> bool {
+        self.cx.adt_is_simd(def)
+    }
 
     /// Returns whether this definition is a C string.
-    fn adt_is_cstr(&self, def: AdtDef) -> bool;
+    pub(crate) fn adt_is_cstr(&self, def: AdtDef) -> bool {
+        self.cx.adt_is_cstr(def)
+    }
 
     /// Retrieve the function signature for the given generic arguments.
-    fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig;
+    pub(crate) fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig {
+        self.cx.fn_sig(def, args)
+    }
 
     /// Retrieve the intrinsic definition if the item corresponds one.
-    fn intrinsic(&self, item: DefId) -> Option<IntrinsicDef>;
+    pub(crate) fn intrinsic(&self, item: DefId) -> Option<IntrinsicDef> {
+        self.cx.intrinsic(item)
+    }
 
     /// Retrieve the plain function name of an intrinsic.
-    fn intrinsic_name(&self, def: IntrinsicDef) -> Symbol;
+    pub(crate) fn intrinsic_name(&self, def: IntrinsicDef) -> Symbol {
+        self.cx.intrinsic_name(def)
+    }
 
     /// Retrieve the closure signature for the given generic arguments.
-    fn closure_sig(&self, args: &GenericArgs) -> PolyFnSig;
+    pub(crate) fn closure_sig(&self, args: &GenericArgs) -> PolyFnSig {
+        self.cx.closure_sig(args)
+    }
 
     /// The number of variants in this ADT.
-    fn adt_variants_len(&self, def: AdtDef) -> usize;
+    pub(crate) fn adt_variants_len(&self, def: AdtDef) -> usize {
+        self.cx.adt_variants_len(def)
+    }
 
     /// The name of a variant.
-    fn variant_name(&self, def: VariantDef) -> Symbol;
-    fn variant_fields(&self, def: VariantDef) -> Vec<FieldDef>;
+    pub(crate) fn variant_name(&self, def: VariantDef) -> Symbol {
+        self.cx.variant_name(def)
+    }
+
+    pub(crate) fn variant_fields(&self, def: VariantDef) -> Vec<FieldDef> {
+        self.cx.variant_fields(def)
+    }
 
     /// Evaluate constant as a target usize.
-    fn eval_target_usize(&self, cnst: &MirConst) -> Result<u64, Error>;
-    fn eval_target_usize_ty(&self, cnst: &TyConst) -> Result<u64, Error>;
+    pub(crate) fn eval_target_usize(&self, cnst: &MirConst) -> Result<u64, Error> {
+        self.cx.eval_target_usize(cnst)
+    }
+
+    pub(crate) fn eval_target_usize_ty(&self, cnst: &TyConst) -> Result<u64, Error> {
+        self.cx.eval_target_usize_ty(cnst)
+    }
 
     /// Create a new zero-sized constant.
-    fn try_new_const_zst(&self, ty: Ty) -> Result<MirConst, Error>;
+    pub(crate) fn try_new_const_zst(&self, ty: Ty) -> Result<MirConst, Error> {
+        self.cx.try_new_const_zst(ty)
+    }
 
     /// Create a new constant that represents the given string value.
-    fn new_const_str(&self, value: &str) -> MirConst;
+    pub(crate) fn new_const_str(&self, value: &str) -> MirConst {
+        self.cx.new_const_str(value)
+    }
 
     /// Create a new constant that represents the given boolean value.
-    fn new_const_bool(&self, value: bool) -> MirConst;
+    pub(crate) fn new_const_bool(&self, value: bool) -> MirConst {
+        self.cx.new_const_bool(value)
+    }
 
     /// Create a new constant that represents the given value.
-    fn try_new_const_uint(&self, value: u128, uint_ty: UintTy) -> Result<MirConst, Error>;
-    fn try_new_ty_const_uint(&self, value: u128, uint_ty: UintTy) -> Result<TyConst, Error>;
+    pub(crate) fn try_new_const_uint(
+        &self,
+        value: u128,
+        uint_ty: UintTy,
+    ) -> Result<MirConst, Error> {
+        self.cx.try_new_const_uint(value, uint_ty)
+    }
+
+    pub(crate) fn try_new_ty_const_uint(
+        &self,
+        value: u128,
+        uint_ty: UintTy,
+    ) -> Result<TyConst, Error> {
+        self.cx.try_new_ty_const_uint(value, uint_ty)
+    }
 
     /// Create a new type from the given kind.
-    fn new_rigid_ty(&self, kind: RigidTy) -> Ty;
+    pub(crate) fn new_rigid_ty(&self, kind: RigidTy) -> Ty {
+        self.cx.new_rigid_ty(kind)
+    }
 
     /// Create a new box type, `Box<T>`, for the given inner type `T`.
-    fn new_box_ty(&self, ty: Ty) -> Ty;
+    pub(crate) fn new_box_ty(&self, ty: Ty) -> Ty {
+        self.cx.new_box_ty(ty)
+    }
 
     /// Returns the type of given crate item.
-    fn def_ty(&self, item: DefId) -> Ty;
+    pub(crate) fn def_ty(&self, item: DefId) -> Ty {
+        self.cx.def_ty(item)
+    }
 
     /// Returns the type of given definition instantiated with the given arguments.
-    fn def_ty_with_args(&self, item: DefId, args: &GenericArgs) -> Ty;
+    pub(crate) fn def_ty_with_args(&self, item: DefId, args: &GenericArgs) -> Ty {
+        self.cx.def_ty_with_args(item, args)
+    }
 
     /// Returns literal value of a const as a string.
-    fn mir_const_pretty(&self, cnst: &MirConst) -> String;
+    pub(crate) fn mir_const_pretty(&self, cnst: &MirConst) -> String {
+        self.cx.mir_const_pretty(cnst)
+    }
 
-    /// `Span` of an item
-    fn span_of_an_item(&self, def_id: DefId) -> Span;
+    /// `Span` of an item.
+    pub(crate) fn span_of_an_item(&self, def_id: DefId) -> Span {
+        self.cx.span_of_an_item(def_id)
+    }
 
-    fn ty_const_pretty(&self, ct: TyConstId) -> String;
+    pub(crate) fn ty_const_pretty(&self, ct: TyConstId) -> String {
+        self.cx.ty_const_pretty(ct)
+    }
 
     /// Obtain the representation of a type.
-    fn ty_pretty(&self, ty: Ty) -> String;
+    pub(crate) fn ty_pretty(&self, ty: Ty) -> String {
+        self.cx.ty_pretty(ty)
+    }
 
     /// Obtain the representation of a type.
-    fn ty_kind(&self, ty: Ty) -> TyKind;
+    pub(crate) fn ty_kind(&self, ty: Ty) -> TyKind {
+        self.cx.ty_kind(ty)
+    }
 
-    // Get the discriminant Ty for this Ty if there's one.
-    fn rigid_ty_discriminant_ty(&self, ty: &RigidTy) -> Ty;
+    /// Get the discriminant Ty for this Ty if there's one.
+    pub(crate) fn rigid_ty_discriminant_ty(&self, ty: &RigidTy) -> Ty {
+        self.cx.rigid_ty_discriminant_ty(ty)
+    }
 
     /// Get the body of an Instance which is already monomorphized.
-    fn instance_body(&self, instance: InstanceDef) -> Option<Body>;
+    pub(crate) fn instance_body(&self, instance: InstanceDef) -> Option<Body> {
+        self.cx.instance_body(instance)
+    }
 
     /// Get the instance type with generic instantiations applied and lifetimes erased.
-    fn instance_ty(&self, instance: InstanceDef) -> Ty;
+    pub(crate) fn instance_ty(&self, instance: InstanceDef) -> Ty {
+        self.cx.instance_ty(instance)
+    }
 
     /// Get the instantiation types.
-    fn instance_args(&self, def: InstanceDef) -> GenericArgs;
+    pub(crate) fn instance_args(&self, def: InstanceDef) -> GenericArgs {
+        self.cx.instance_args(def)
+    }
 
     /// Get the instance.
-    fn instance_def_id(&self, instance: InstanceDef) -> DefId;
+    pub(crate) fn instance_def_id(&self, instance: InstanceDef) -> DefId {
+        self.cx.instance_def_id(instance)
+    }
 
     /// Get the instance mangled name.
-    fn instance_mangled_name(&self, instance: InstanceDef) -> Symbol;
+    pub(crate) fn instance_mangled_name(&self, instance: InstanceDef) -> Symbol {
+        self.cx.instance_mangled_name(instance)
+    }
 
     /// Check if this is an empty DropGlue shim.
-    fn is_empty_drop_shim(&self, def: InstanceDef) -> bool;
+    pub(crate) fn is_empty_drop_shim(&self, def: InstanceDef) -> bool {
+        self.cx.is_empty_drop_shim(def)
+    }
 
     /// Check if this is an empty AsyncDropGlueCtor shim.
-    fn is_empty_async_drop_ctor_shim(&self, def: InstanceDef) -> bool;
+    pub(crate) fn is_empty_async_drop_ctor_shim(&self, def: InstanceDef) -> bool {
+        self.cx.is_empty_async_drop_ctor_shim(def)
+    }
 
     /// Convert a non-generic crate item into an instance.
     /// This function will panic if the item is generic.
-    fn mono_instance(&self, def_id: DefId) -> Instance;
+    pub(crate) fn mono_instance(&self, def_id: DefId) -> Instance {
+        self.cx.mono_instance(def_id)
+    }
 
     /// Item requires monomorphization.
-    fn requires_monomorphization(&self, def_id: DefId) -> bool;
+    pub(crate) fn requires_monomorphization(&self, def_id: DefId) -> bool {
+        self.cx.requires_monomorphization(def_id)
+    }
 
     /// Resolve an instance from the given function definition and generic arguments.
-    fn resolve_instance(&self, def: FnDef, args: &GenericArgs) -> Option<Instance>;
+    pub(crate) fn resolve_instance(&self, def: FnDef, args: &GenericArgs) -> Option<Instance> {
+        self.cx.resolve_instance(def, args)
+    }
 
     /// Resolve an instance for drop_in_place for the given type.
-    fn resolve_drop_in_place(&self, ty: Ty) -> Instance;
+    pub(crate) fn resolve_drop_in_place(&self, ty: Ty) -> Instance {
+        self.cx.resolve_drop_in_place(ty)
+    }
 
     /// Resolve instance for a function pointer.
-    fn resolve_for_fn_ptr(&self, def: FnDef, args: &GenericArgs) -> Option<Instance>;
+    pub(crate) fn resolve_for_fn_ptr(&self, def: FnDef, args: &GenericArgs) -> Option<Instance> {
+        self.cx.resolve_for_fn_ptr(def, args)
+    }
 
     /// Resolve instance for a closure with the requested type.
-    fn resolve_closure(
+    pub(crate) fn resolve_closure(
         &self,
         def: ClosureDef,
         args: &GenericArgs,
         kind: ClosureKind,
-    ) -> Option<Instance>;
+    ) -> Option<Instance> {
+        self.cx.resolve_closure(def, args, kind)
+    }
 
     /// Evaluate a static's initializer.
-    fn eval_static_initializer(&self, def: StaticDef) -> Result<Allocation, Error>;
+    pub(crate) fn eval_static_initializer(&self, def: StaticDef) -> Result<Allocation, Error> {
+        self.cx.eval_static_initializer(def)
+    }
 
     /// Try to evaluate an instance into a constant.
-    fn eval_instance(&self, def: InstanceDef, const_ty: Ty) -> Result<Allocation, Error>;
+    pub(crate) fn eval_instance(
+        &self,
+        def: InstanceDef,
+        const_ty: Ty,
+    ) -> Result<Allocation, Error> {
+        self.cx.eval_instance(def, const_ty)
+    }
 
     /// Retrieve global allocation for the given allocation ID.
-    fn global_alloc(&self, id: AllocId) -> GlobalAlloc;
+    pub(crate) fn global_alloc(&self, id: AllocId) -> GlobalAlloc {
+        self.cx.global_alloc(id)
+    }
 
     /// Retrieve the id for the virtual table.
-    fn vtable_allocation(&self, global_alloc: &GlobalAlloc) -> Option<AllocId>;
-    fn krate(&self, def_id: DefId) -> Crate;
-    fn instance_name(&self, def: InstanceDef, trimmed: bool) -> Symbol;
+    pub(crate) fn vtable_allocation(&self, global_alloc: &GlobalAlloc) -> Option<AllocId> {
+        self.cx.vtable_allocation(global_alloc)
+    }
+
+    pub(crate) fn krate(&self, def_id: DefId) -> Crate {
+        self.cx.krate(def_id)
+    }
+
+    pub(crate) fn instance_name(&self, def: InstanceDef, trimmed: bool) -> Symbol {
+        self.cx.instance_name(def, trimmed)
+    }
 
     /// Return information about the target machine.
-    fn target_info(&self) -> MachineInfo;
+    pub(crate) fn target_info(&self) -> MachineInfo {
+        self.cx.target_info()
+    }
 
     /// Get an instance ABI.
-    fn instance_abi(&self, def: InstanceDef) -> Result<FnAbi, Error>;
+    pub(crate) fn instance_abi(&self, def: InstanceDef) -> Result<FnAbi, Error> {
+        self.cx.instance_abi(def)
+    }
 
     /// Get the ABI of a function pointer.
-    fn fn_ptr_abi(&self, fn_ptr: PolyFnSig) -> Result<FnAbi, Error>;
+    pub(crate) fn fn_ptr_abi(&self, fn_ptr: PolyFnSig) -> Result<FnAbi, Error> {
+        self.cx.fn_ptr_abi(fn_ptr)
+    }
 
     /// Get the layout of a type.
-    fn ty_layout(&self, ty: Ty) -> Result<Layout, Error>;
+    pub(crate) fn ty_layout(&self, ty: Ty) -> Result<Layout, Error> {
+        self.cx.ty_layout(ty)
+    }
 
     /// Get the layout shape.
-    fn layout_shape(&self, id: Layout) -> LayoutShape;
+    pub(crate) fn layout_shape(&self, id: Layout) -> LayoutShape {
+        self.cx.layout_shape(id)
+    }
 
     /// Get a debug string representation of a place.
-    fn place_pretty(&self, place: &Place) -> String;
+    pub(crate) fn place_pretty(&self, place: &Place) -> String {
+        self.cx.place_pretty(place)
+    }
 
     /// Get the resulting type of binary operation.
-    fn binop_ty(&self, bin_op: BinOp, rhs: Ty, lhs: Ty) -> Ty;
+    pub(crate) fn binop_ty(&self, bin_op: BinOp, rhs: Ty, lhs: Ty) -> Ty {
+        self.cx.binop_ty(bin_op, rhs, lhs)
+    }
 
     /// Get the resulting type of unary operation.
-    fn unop_ty(&self, un_op: UnOp, arg: Ty) -> Ty;
+    pub(crate) fn unop_ty(&self, un_op: UnOp, arg: Ty) -> Ty {
+        self.cx.unop_ty(un_op, arg)
+    }
 
     /// Get all associated items of a definition.
-    fn associated_items(&self, def_id: DefId) -> AssocItems;
+    pub(crate) fn associated_items(&self, def_id: DefId) -> AssocItems {
+        self.cx.associated_items(def_id)
+    }
 }
 
-// A thread local variable that stores a pointer to the tables mapping between TyCtxt
-// datastructures and stable MIR datastructures
+// A thread local variable that stores a pointer to [`SmirInterface`].
 scoped_tls::scoped_thread_local!(static TLV: Cell<*const ()>);
 
-pub fn run<F, T>(context: &dyn Context, f: F) -> Result<T, Error>
+pub(crate) fn run<'tcx, T, F>(interface: &SmirInterface<'tcx>, f: F) -> Result<T, Error>
 where
     F: FnOnce() -> T,
 {
     if TLV.is_set() {
         Err(Error::from("StableMIR already running"))
     } else {
-        let ptr: *const () = (&raw const context) as _;
+        let ptr: *const () = (interface as *const SmirInterface<'tcx>) as *const ();
         TLV.set(&Cell::new(ptr), || Ok(f()))
     }
 }
 
-/// Execute the given function with access the compiler [Context].
+/// Execute the given function with access the [`SmirInterface`].
 ///
-/// I.e., This function will load the current context and calls a function with it.
+/// I.e., This function will load the current interface and calls a function with it.
 /// Do not nest these, as that will ICE.
-pub(crate) fn with<R>(f: impl FnOnce(&dyn Context) -> R) -> R {
+pub(crate) fn with<R>(f: impl FnOnce(&SmirInterface<'_>) -> R) -> R {
     assert!(TLV.is_set());
     TLV.with(|tlv| {
         let ptr = tlv.get();
         assert!(!ptr.is_null());
-        f(unsafe { *(ptr as *const &dyn Context) })
+        f(unsafe { &*(ptr as *const SmirInterface<'_>) })
     })
 }