Cleanup a few internal compiler deps (#3739)

Some of this code was broken by the toolchain update. Instead of
changing it, replace it by StableMIR APIs.

Related to #3731 

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 and MIT licenses.

kani-compiler/src/codegen_cprover_gotoc/codegen/ty_stable.rs

@@ -7,8 +7,9 @@
 //! `typ.rs`.
 
 use crate::codegen_cprover_gotoc::GotocCtx;
+use crate::kani_middle::abi::LayoutOf;
 use cbmc::goto_program::Type;
-use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
+use rustc_middle::ty::layout::{LayoutOf as _, TyAndLayout};
 use rustc_smir::rustc_internal;
 use stable_mir::mir::mono::Instance;
 use stable_mir::mir::{Local, Operand, Place, Rvalue};
@@ -36,7 +37,7 @@ impl<'tcx> GotocCtx<'tcx> {
     }
 
     pub fn is_zst_stable(&self, ty: Ty) -> bool {
-        self.is_zst(rustc_internal::internal(self.tcx, ty))
+        LayoutOf::new(ty).is_zst()
     }
 
     pub fn layout_of_stable(&self, ty: Ty) -> TyAndLayout<'tcx> {
@@ -113,14 +114,15 @@ impl<'tcx> GotocCtx<'tcx> {
     /// This should be replaced by StableMIR `pretty_ty()` after
     /// <https://github.com/rust-lang/rust/pull/118364> is merged.
     pub fn pretty_ty(&self, ty: Ty) -> String {
-        rustc_internal::internal(self.tcx, ty).to_string()
+        ty.to_string()
     }
 
     pub fn requires_caller_location(&self, instance: Instance) -> bool {
         let instance_internal = rustc_internal::internal(self.tcx, instance);
         instance_internal.def.requires_caller_location(self.tcx)
     }
 }
+
 /// If given type is a Ref / Raw ref, return the pointee type.
 pub fn pointee_type(mir_type: Ty) -> Option<Ty> {
     match mir_type.kind() {

kani-compiler/src/kani_middle/abi.rs

@@ -24,6 +24,11 @@ impl LayoutOf {
         self.layout.is_sized()
     }
 
+    /// Return whether this is a zero-sized type
+    pub fn is_zst(&self) -> bool {
+        self.is_sized() && self.layout.size.bytes() == 0
+    }
+
     /// Return whether the type is unsized and its tail is a foreign item.
     ///
     /// This will also return `true` if the type is foreign.

kani-compiler/src/kani_middle/attributes.rs

@@ -622,8 +622,9 @@ impl<'tcx> KaniAttributes<'tcx> {
                 ),
             );
         } else {
-            let instance = Instance::mono(tcx, self.item);
-            if !super::fn_abi(tcx, instance).args.is_empty() {
+            let instance = rustc_internal::stable(Instance::mono(tcx, self.item));
+            let fn_abi = instance.fn_abi().unwrap();
+            if !fn_abi.args.is_empty() {
                 tcx.dcx().span_err(span, "functions used as harnesses cannot have any arguments");
             }
         }

kani-compiler/src/kani_middle/mod.rs

@@ -7,17 +7,8 @@ use std::collections::HashSet;
 
 use crate::kani_queries::QueryDb;
 use rustc_hir::{def::DefKind, def_id::DefId as InternalDefId, def_id::LOCAL_CRATE};
-use rustc_middle::span_bug;
-use rustc_middle::ty::layout::{
-    FnAbiError, FnAbiOf, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, HasTyCtxt, LayoutError,
-    LayoutOfHelpers, TyAndLayout,
-};
-use rustc_middle::ty::{self, Instance as InstanceInternal, Ty as TyInternal, TyCtxt};
+use rustc_middle::ty::TyCtxt;
 use rustc_smir::rustc_internal;
-use rustc_span::Span;
-use rustc_span::source_map::respan;
-use rustc_target::abi::call::FnAbi;
-use rustc_target::abi::{HasDataLayout, TargetDataLayout};
 use stable_mir::CrateDef;
 use stable_mir::mir::mono::MonoItem;
 use stable_mir::ty::{FnDef, RigidTy, Span as SpanStable, Ty, TyKind};
@@ -155,80 +146,6 @@ impl SourceLocation {
     }
 }
 
-/// Get the FnAbi of a given instance with no extra variadic arguments.
-/// TODO: Get rid of this. Use instance.fn_abi() instead.
-/// <https://github.com/model-checking/kani/issues/1365>
-pub fn fn_abi<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    instance: InstanceInternal<'tcx>,
-) -> &'tcx FnAbi<'tcx, TyInternal<'tcx>> {
-    let helper = CompilerHelpers { tcx };
-    helper.fn_abi_of_instance(instance, ty::List::empty())
-}
-
-struct CompilerHelpers<'tcx> {
-    tcx: TyCtxt<'tcx>,
-}
-
-impl<'tcx> HasParamEnv<'tcx> for CompilerHelpers<'tcx> {
-    fn param_env(&self) -> ty::ParamEnv<'tcx> {
-        ty::ParamEnv::reveal_all()
-    }
-}
-
-impl<'tcx> HasTyCtxt<'tcx> for CompilerHelpers<'tcx> {
-    fn tcx(&self) -> TyCtxt<'tcx> {
-        self.tcx
-    }
-}
-
-impl HasDataLayout for CompilerHelpers<'_> {
-    fn data_layout(&self) -> &TargetDataLayout {
-        self.tcx.data_layout()
-    }
-}
-
-impl<'tcx> LayoutOfHelpers<'tcx> for CompilerHelpers<'tcx> {
-    type LayoutOfResult = TyAndLayout<'tcx>;
-
-    #[inline]
-    fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: TyInternal<'tcx>) -> ! {
-        span_bug!(span, "failed to get layout for `{}`: {}", ty, err)
-    }
-}
-
-/// Implement error handling for extracting function ABI information.
-impl<'tcx> FnAbiOfHelpers<'tcx> for CompilerHelpers<'tcx> {
-    type FnAbiOfResult = &'tcx FnAbi<'tcx, TyInternal<'tcx>>;
-
-    #[inline]
-    fn handle_fn_abi_err(
-        &self,
-        err: FnAbiError<'tcx>,
-        span: Span,
-        fn_abi_request: FnAbiRequest<'tcx>,
-    ) -> ! {
-        if let FnAbiError::Layout(LayoutError::SizeOverflow(_)) = err {
-            self.tcx.dcx().emit_fatal(respan(span, err))
-        } else {
-            match fn_abi_request {
-                FnAbiRequest::OfFnPtr { sig, extra_args } => {
-                    span_bug!(
-                        span,
-                        "Error: {err:?}\n while running `fn_abi_of_fn_ptr. ({sig}, {extra_args:?})`",
-                    );
-                }
-                FnAbiRequest::OfInstance { instance, extra_args } => {
-                    span_bug!(
-                        span,
-                        "Error: {err:?}\n while running `fn_abi_of_instance. ({instance}, {extra_args:?})`",
-                    );
-                }
-            }
-        }
-    }
-}
-
 /// Try to convert an internal `DefId` to a `FnDef`.
 pub fn stable_fn_def(tcx: TyCtxt, def_id: InternalDefId) -> Option<FnDef> {
     if let TyKind::RigidTy(RigidTy::FnDef(def, _)) =