Move the compiler interface defs to its own module

Separate items that are exposed in the `stable_mir` crate to be used
by the compiler from items that we expect to be used by tool developers.

compiler/rustc_smir/src/rustc_internal/mod.rs

@@ -181,7 +181,7 @@ pub fn run<F, T>(tcx: TyCtxt<'_>, f: F) -> Result<T, Error>
         instances: IndexMap::default(),
         constants: IndexMap::default(),
     }));
-    stable_mir::run(&tables, || init(&tables, f))
+    stable_mir::compiler_interface::run(&tables, || init(&tables, f))
 }
 
 #[macro_export]

compiler/rustc_smir/src/rustc_smir/context.rs

@@ -1,4 +1,4 @@
-//! Implementation of `[stable_mir::compiler::Context]` trait.
+//! Implementation of `[stable_mir::compiler_interface::Context]` trait.
 //!
 //! This trait is currently the main interface between the Rust compiler,
 //! and the `stable_mir` crate.
@@ -6,6 +6,7 @@
 use rustc_middle::ty::print::{with_forced_trimmed_paths, with_no_trimmed_paths};
 use rustc_middle::ty::{GenericPredicates, Instance, ParamEnv, ScalarInt, ValTree};
 use rustc_span::def_id::LOCAL_CRATE;
+use stable_mir::compiler_interface::Context;
 use stable_mir::mir::alloc::GlobalAlloc;
 use stable_mir::mir::mono::{InstanceDef, StaticDef};
 use stable_mir::mir::Body;
@@ -13,7 +14,7 @@
     AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, Const, FnDef, GenericArgs, LineInfo,
     RigidTy, Span, TyKind,
 };
-use stable_mir::{self, Context, Crate, CrateItem, Error, Filename, ItemKind, Symbol};
+use stable_mir::{self, Crate, CrateItem, Error, Filename, ItemKind, Symbol};
 use std::cell::RefCell;
 
 use crate::rustc_internal::{internal, RustcInternal};

compiler/stable_mir/src/compiler_interface.rs

@@ -0,0 +1,163 @@
+//! Define the interface with the Rust compiler.
+//!
+//! StableMIR users should not use any of the items in this module directly.
+//! These APIs have no stability guarantee.
+
+use crate::mir::alloc::{AllocId, GlobalAlloc};
+use crate::mir::mono::{Instance, InstanceDef, StaticDef};
+use crate::mir::Body;
+use crate::ty::{
+    AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, Const, FnDef, GenericArgs,
+    GenericPredicates, Generics, ImplDef, ImplTrait, LineInfo, RigidTy, Span, TraitDecl, TraitDef,
+    Ty, TyKind,
+};
+use crate::{
+    mir, Crate, CrateItem, CrateItems, DefId, Error, Filename, ImplTraitDecls, ItemKind, Symbol,
+    TraitDecls,
+};
+use std::cell::Cell;
+
+/// 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;
+    fn mir_body(&self, item: DefId) -> mir::Body;
+    fn all_trait_decls(&self) -> TraitDecls;
+    fn trait_decl(&self, trait_def: &TraitDef) -> TraitDecl;
+    fn all_trait_impls(&self) -> 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;
+    /// Get information about the local crate.
+    fn local_crate(&self) -> Crate;
+    /// Retrieve a list of all external crates.
+    fn external_crates(&self) -> Vec<Crate>;
+
+    /// Find a crate with the given name.
+    fn find_crates(&self, name: &str) -> Vec<Crate>;
+
+    /// Returns the name of given `DefId`
+    fn def_name(&self, def_id: DefId, trimmed: bool) -> Symbol;
+
+    /// Returns printable, human readable form of `Span`
+    fn span_to_string(&self, span: Span) -> String;
+
+    /// Return filename from given `Span`, for diagnostic purposes
+    fn get_filename(&self, span: &Span) -> Filename;
+
+    /// Return lines corresponding to this `Span`
+    fn get_lines(&self, span: &Span) -> LineInfo;
+
+    /// Returns the `kind` of given `DefId`
+    fn item_kind(&self, item: CrateItem) -> ItemKind;
+
+    /// Returns whether this is a foreign item.
+    fn is_foreign_item(&self, item: CrateItem) -> bool;
+
+    /// Returns the kind of a given algebraic data type
+    fn adt_kind(&self, def: AdtDef) -> AdtKind;
+
+    /// Returns if the ADT is a box.
+    fn adt_is_box(&self, def: AdtDef) -> bool;
+
+    /// Evaluate constant as a target usize.
+    fn eval_target_usize(&self, cnst: &Const) -> Result<u64, Error>;
+
+    /// Create a target usize constant for the given value.
+    fn usize_to_const(&self, val: u64) -> Result<Const, Error>;
+
+    /// Create a new type from the given kind.
+    fn new_rigid_ty(&self, kind: RigidTy) -> Ty;
+
+    /// Returns the type of given crate item.
+    fn def_ty(&self, item: DefId) -> Ty;
+
+    /// Returns literal value of a const as a string.
+    fn const_literal(&self, cnst: &Const) -> String;
+
+    /// `Span` of an item
+    fn span_of_an_item(&self, def_id: DefId) -> Span;
+
+    /// Obtain the representation of a type.
+    fn ty_kind(&self, ty: Ty) -> TyKind;
+
+    /// Get the body of an Instance.
+    /// FIXME: Monomorphize the body.
+    fn instance_body(&self, instance: InstanceDef) -> Option<Body>;
+
+    /// Get the instance type with generic substitutions applied and lifetimes erased.
+    fn instance_ty(&self, instance: InstanceDef) -> Ty;
+
+    /// Get the instance.
+    fn instance_def_id(&self, instance: InstanceDef) -> DefId;
+
+    /// Get the instance mangled name.
+    fn instance_mangled_name(&self, instance: InstanceDef) -> Symbol;
+
+    /// Convert a non-generic crate item into an instance.
+    /// This function will panic if the item is generic.
+    fn mono_instance(&self, item: CrateItem) -> Instance;
+
+    /// Item requires monomorphization.
+    fn requires_monomorphization(&self, def_id: DefId) -> bool;
+
+    /// Resolve an instance from the given function definition and generic arguments.
+    fn resolve_instance(&self, def: FnDef, args: &GenericArgs) -> Option<Instance>;
+
+    /// Resolve an instance for drop_in_place for the given type.
+    fn resolve_drop_in_place(&self, ty: Ty) -> Instance;
+
+    /// Resolve instance for a function pointer.
+    fn resolve_for_fn_ptr(&self, def: FnDef, args: &GenericArgs) -> Option<Instance>;
+
+    /// Resolve instance for a closure with the requested type.
+    fn resolve_closure(
+        &self,
+        def: ClosureDef,
+        args: &GenericArgs,
+        kind: ClosureKind,
+    ) -> Option<Instance>;
+
+    /// Evaluate a static's initializer.
+    fn eval_static_initializer(&self, def: StaticDef) -> Result<Allocation, Error>;
+
+    /// Retrieve global allocation for the given allocation ID.
+    fn global_alloc(&self, id: AllocId) -> GlobalAlloc;
+
+    /// 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;
+}
+
+// A thread local variable that stores a pointer to the tables mapping between TyCtxt
+// datastructures and stable MIR datastructures
+scoped_thread_local! (static TLV: Cell<*const ()>);
+
+pub fn run<F, T>(context: &dyn Context, f: F) -> Result<T, Error>
+where
+    F: FnOnce() -> T,
+{
+    if TLV.is_set() {
+        Err(Error::from("StableMIR already running"))
+    } else {
+        let ptr: *const () = &context as *const &_ as _;
+        TLV.set(&Cell::new(ptr), || Ok(f()))
+    }
+}
+
+/// Execute the given function with access the compiler [Context].
+///
+/// I.e., This function will load the current context 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 {
+    assert!(TLV.is_set());
+    TLV.with(|tlv| {
+        let ptr = tlv.get();
+        assert!(!ptr.is_null());
+        f(unsafe { *(ptr as *const &dyn Context) })
+    })
+}

compiler/stable_mir/src/lib.rs

@@ -17,38 +17,30 @@
 //! The goal is to eventually be published on
 //! [crates.io](https://crates.io).
 
-use crate::mir::mono::{InstanceDef, StaticDef};
+use self::ty::{ImplDef, ImplTrait, IndexedVal, Span, TraitDecl, TraitDef, Ty};
+pub(crate) use crate::compiler_interface::with;
+pub use crate::crate_def::CrateDef;
+pub use crate::crate_def::DefId;
+use crate::mir::pretty::function_name;
 use crate::mir::Body;
+use crate::mir::Mutability;
+pub use error::*;
 use std::fmt;
 use std::fmt::Debug;
-use std::{cell::Cell, io};
+use std::io;
-
-use self::ty::{
-    GenericPredicates, Generics, ImplDef, ImplTrait, IndexedVal, LineInfo, Span, TraitDecl,
-    TraitDef, Ty, TyKind,
-};
 
 #[macro_use]
 extern crate scoped_tls;
 
 #[macro_use]
 pub mod crate_def;
+pub mod compiler_interface;
 #[macro_use]
 pub mod error;
 pub mod mir;
 pub mod ty;
 pub mod visitor;
 
-pub use crate::crate_def::CrateDef;
-pub use crate::crate_def::DefId;
-use crate::mir::alloc::{AllocId, GlobalAlloc};
-use crate::mir::pretty::function_name;
-use crate::mir::Mutability;
-use crate::ty::{AdtDef, AdtKind, Allocation, ClosureDef, ClosureKind, Const, RigidTy};
-pub use error::*;
-use mir::mono::Instance;
-use ty::{FnDef, GenericArgs};
-
 /// Use String for now but we should replace it.
 pub type Symbol = String;
 
@@ -179,149 +171,6 @@ pub fn trait_impl(trait_impl: &ImplDef) -> ImplTrait {
     with(|cx| cx.trait_impl(trait_impl))
 }
 
-/// 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;
-    fn mir_body(&self, item: DefId) -> mir::Body;
-    fn all_trait_decls(&self) -> TraitDecls;
-    fn trait_decl(&self, trait_def: &TraitDef) -> TraitDecl;
-    fn all_trait_impls(&self) -> 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;
-    /// Get information about the local crate.
-    fn local_crate(&self) -> Crate;
-    /// Retrieve a list of all external crates.
-    fn external_crates(&self) -> Vec<Crate>;
-
-    /// Find a crate with the given name.
-    fn find_crates(&self, name: &str) -> Vec<Crate>;
-
-    /// Returns the name of given `DefId`
-    fn def_name(&self, def_id: DefId, trimmed: bool) -> Symbol;
-
-    /// Returns printable, human readable form of `Span`
-    fn span_to_string(&self, span: Span) -> String;
-
-    /// Return filename from given `Span`, for diagnostic purposes
-    fn get_filename(&self, span: &Span) -> Filename;
-
-    /// Return lines corresponding to this `Span`
-    fn get_lines(&self, span: &Span) -> LineInfo;
-
-    /// Returns the `kind` of given `DefId`
-    fn item_kind(&self, item: CrateItem) -> ItemKind;
-
-    /// Returns whether this is a foreign item.
-    fn is_foreign_item(&self, item: CrateItem) -> bool;
-
-    /// Returns the kind of a given algebraic data type
-    fn adt_kind(&self, def: AdtDef) -> AdtKind;
-
-    /// Returns if the ADT is a box.
-    fn adt_is_box(&self, def: AdtDef) -> bool;
-
-    /// Evaluate constant as a target usize.
-    fn eval_target_usize(&self, cnst: &Const) -> Result<u64, Error>;
-
-    /// Create a target usize constant for the given value.
-    fn usize_to_const(&self, val: u64) -> Result<Const, Error>;
-
-    /// Create a new type from the given kind.
-    fn new_rigid_ty(&self, kind: RigidTy) -> Ty;
-
-    /// Returns the type of given crate item.
-    fn def_ty(&self, item: DefId) -> Ty;
-
-    /// Returns literal value of a const as a string.
-    fn const_literal(&self, cnst: &Const) -> String;
-
-    /// `Span` of an item
-    fn span_of_an_item(&self, def_id: DefId) -> Span;
-
-    /// Obtain the representation of a type.
-    fn ty_kind(&self, ty: Ty) -> TyKind;
-
-    /// Get the body of an Instance.
-    /// FIXME: Monomorphize the body.
-    fn instance_body(&self, instance: InstanceDef) -> Option<Body>;
-
-    /// Get the instance type with generic substitutions applied and lifetimes erased.
-    fn instance_ty(&self, instance: InstanceDef) -> Ty;
-
-    /// Get the instance.
-    fn instance_def_id(&self, instance: InstanceDef) -> DefId;
-
-    /// Get the instance mangled name.
-    fn instance_mangled_name(&self, instance: InstanceDef) -> Symbol;
-
-    /// Convert a non-generic crate item into an instance.
-    /// This function will panic if the item is generic.
-    fn mono_instance(&self, item: CrateItem) -> Instance;
-
-    /// Item requires monomorphization.
-    fn requires_monomorphization(&self, def_id: DefId) -> bool;
-
-    /// Resolve an instance from the given function definition and generic arguments.
-    fn resolve_instance(&self, def: FnDef, args: &GenericArgs) -> Option<Instance>;
-
-    /// Resolve an instance for drop_in_place for the given type.
-    fn resolve_drop_in_place(&self, ty: Ty) -> Instance;
-
-    /// Resolve instance for a function pointer.
-    fn resolve_for_fn_ptr(&self, def: FnDef, args: &GenericArgs) -> Option<Instance>;
-
-    /// Resolve instance for a closure with the requested type.
-    fn resolve_closure(
-        &self,
-        def: ClosureDef,
-        args: &GenericArgs,
-        kind: ClosureKind,
-    ) -> Option<Instance>;
-
-    /// Evaluate a static's initializer.
-    fn eval_static_initializer(&self, def: StaticDef) -> Result<Allocation, Error>;
-
-    /// Retrieve global allocation for the given allocation ID.
-    fn global_alloc(&self, id: AllocId) -> GlobalAlloc;
-
-    /// 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;
-}
-
-// A thread local variable that stores a pointer to the tables mapping between TyCtxt
-// datastructures and stable MIR datastructures
-scoped_thread_local! (static TLV: Cell<*const ()>);
-
-pub fn run<F, T>(context: &dyn Context, f: F) -> Result<T, Error>
-where
-    F: FnOnce() -> T,
-{
-    if TLV.is_set() {
-        Err(Error::from("StableMIR already running"))
-    } else {
-        let ptr: *const () = &context as *const &_ as _;
-        TLV.set(&Cell::new(ptr), || Ok(f()))
-    }
-}
-
-/// Loads the current context and calls a function with it.
-/// Do not nest these, as that will ICE.
-pub fn with<R>(f: impl FnOnce(&dyn Context) -> R) -> R {
-    assert!(TLV.is_set());
-    TLV.with(|tlv| {
-        let ptr = tlv.get();
-        assert!(!ptr.is_null());
-        f(unsafe { *(ptr as *const &dyn Context) })
-    })
-}
-
 /// A type that provides internal information but that can still be used for debug purpose.
 #[derive(Clone, PartialEq, Eq, Hash)]
 pub struct Opaque(String);