Rollup merge of #119094 - celinval:smir-layout, r=compiler-errors

Add function ABI and type layout to StableMIR

This change introduces a new module to StableMIR named `abi` with information from `rustc_target::abi` and `rustc_abi`, that allow users to retrieve more low level information required to perform bit-precise analysis.

The layout of a type can be retrieved via `Ty::layout`, and the instance ABI can be retrieved via `Instance::fn_abi()`.

To properly handle errors while retrieve layout information, we had to implement a few layout related traits.

r? ```@compiler-errors```

compiler/rustc_smir/src/rustc_internal/internal.rs

@@ -7,6 +7,7 @@
 use crate::rustc_smir::Tables;
 use rustc_middle::ty::{self as rustc_ty, Ty as InternalTy};
 use rustc_span::Symbol;
+use stable_mir::abi::Layout;
 use stable_mir::mir::alloc::AllocId;
 use stable_mir::mir::mono::{Instance, MonoItem, StaticDef};
 use stable_mir::mir::{Mutability, Safety};
@@ -460,6 +461,14 @@ impl<'tcx> RustcInternal<'tcx> for Span {
     }
 }
 
+impl<'tcx> RustcInternal<'tcx> for Layout {
+    type T = rustc_target::abi::Layout<'tcx>;
+
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        tables.layouts[*self]
+    }
+}
+
 impl<'tcx, T> RustcInternal<'tcx> for &T
 where
     T: RustcInternal<'tcx>,

compiler/rustc_smir/src/rustc_internal/mod.rs

@@ -12,6 +12,7 @@ use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::{CrateNum, DefId};
 use rustc_span::Span;
 use scoped_tls::scoped_thread_local;
+use stable_mir::abi::Layout;
 use stable_mir::ty::IndexedVal;
 use stable_mir::Error;
 use std::cell::Cell;
@@ -136,6 +137,10 @@ impl<'tcx> Tables<'tcx> {
     pub(crate) fn static_def(&mut self, did: DefId) -> stable_mir::mir::mono::StaticDef {
         stable_mir::mir::mono::StaticDef(self.create_def_id(did))
     }
+
+    pub(crate) fn layout_id(&mut self, layout: rustc_target::abi::Layout<'tcx>) -> Layout {
+        self.layouts.create_or_fetch(layout)
+    }
 }
 
 pub fn crate_num(item: &stable_mir::Crate) -> CrateNum {
@@ -180,6 +185,7 @@ where
         types: IndexMap::default(),
         instances: IndexMap::default(),
         constants: IndexMap::default(),
+        layouts: IndexMap::default(),
     }));
     stable_mir::compiler_interface::run(&tables, || init(&tables, f))
 }

compiler/rustc_smir/src/rustc_smir/context.rs

@@ -3,12 +3,19 @@
 //! This trait is currently the main interface between the Rust compiler,
 //! and the `stable_mir` crate.
 
+#![allow(rustc::usage_of_qualified_ty)]
+
+use rustc_abi::HasDataLayout;
 use rustc_middle::ty;
+use rustc_middle::ty::layout::{
+    FnAbiOf, FnAbiOfHelpers, HasParamEnv, HasTyCtxt, LayoutOf, LayoutOfHelpers,
+};
 use rustc_middle::ty::print::{with_forced_trimmed_paths, with_no_trimmed_paths};
 use rustc_middle::ty::{
-    GenericPredicates, Instance, ParamEnv, ScalarInt, TypeVisitableExt, ValTree,
+    GenericPredicates, Instance, List, ParamEnv, ScalarInt, TyCtxt, TypeVisitableExt, ValTree,
 };
 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};
@@ -280,7 +287,6 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         tables.tcx.mk_ty_from_kind(internal_kind).stable(&mut *tables)
     }
 
-    #[allow(rustc::usage_of_qualified_ty)]
     fn new_box_ty(&self, ty: stable_mir::ty::Ty) -> stable_mir::ty::Ty {
         let mut tables = self.0.borrow_mut();
         let inner = ty.internal(&mut *tables);
@@ -335,6 +341,12 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
         instance.ty(tables.tcx, ParamEnv::reveal_all()).stable(&mut *tables)
     }
 
+    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 instance_def_id(&self, def: InstanceDef) -> stable_mir::DefId {
         let mut tables = self.0.borrow_mut();
         let def_id = tables.instances[def].def_id();
@@ -473,6 +485,65 @@ impl<'tcx> Context for TablesWrapper<'tcx> {
             )
         }
     }
+
+    fn ty_layout(&self, ty: Ty) -> Result<Layout, Error> {
+        let mut tables = self.0.borrow_mut();
+        let ty = ty.internal(&mut *tables);
+        let layout = tables.layout_of(ty)?.layout;
+        Ok(layout.stable(&mut *tables))
+    }
+
+    fn layout_shape(&self, id: Layout) -> LayoutShape {
+        let mut tables = self.0.borrow_mut();
+        id.internal(&mut *tables).0.stable(&mut *tables)
+    }
 }
 
 pub 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::abi::call::FnAbi<'tcx, ty::Ty<'tcx>>, Error>;
+
+    #[inline]
+    fn handle_fn_abi_err(
+        &self,
+        err: ty::layout::FnAbiError<'tcx>,
+        _span: rustc_span::Span,
+        fn_abi_request: ty::layout::FnAbiRequest<'tcx>,
+    ) -> Error {
+        Error::new(format!("Failed to get ABI for `{fn_abi_request:?}`: {err:?}"))
+    }
+}
+
+impl<'tcx> LayoutOfHelpers<'tcx> for Tables<'tcx> {
+    type LayoutOfResult = Result<ty::layout::TyAndLayout<'tcx>, Error>;
+
+    #[inline]
+    fn handle_layout_err(
+        &self,
+        err: ty::layout::LayoutError<'tcx>,
+        _span: rustc_span::Span,
+        ty: ty::Ty<'tcx>,
+    ) -> Error {
+        Error::new(format!("Failed to get layout for `{ty}`: {err}"))
+    }
+}
+
+impl<'tcx> HasParamEnv<'tcx> for Tables<'tcx> {
+    fn param_env(&self) -> ty::ParamEnv<'tcx> {
+        ty::ParamEnv::reveal_all()
+    }
+}
+
+impl<'tcx> HasTyCtxt<'tcx> for Tables<'tcx> {
+    fn tcx(&self) -> TyCtxt<'tcx> {
+        self.tcx
+    }
+}
+
+impl<'tcx> HasDataLayout for Tables<'tcx> {
+    fn data_layout(&self) -> &rustc_abi::TargetDataLayout {
+        self.tcx.data_layout()
+    }
+}