From e6b2b764ecf08e3144274383e8f95e51fcaa6963 Mon Sep 17 00:00:00 2001
From: Scott McMurray <scottmcm@users.noreply.github.com>
Date: Thu, 11 Apr 2024 14:44:02 -0700
Subject: Add `AggregateKind::RawPtr` and enough support to compile

---
 compiler/rustc_middle/src/mir/pretty.rs |  9 +++++++++
 compiler/rustc_middle/src/mir/syntax.rs | 15 +++++++++++++++
 compiler/rustc_middle/src/mir/tcx.rs    |  1 +
 compiler/rustc_middle/src/mir/visit.rs  |  3 +++
 4 files changed, 28 insertions(+)

(limited to 'compiler/rustc_middle/src')

diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index a3cdcec9ec0..8291404ebf3 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -1094,6 +1094,15 @@ impl<'tcx> Debug for Rvalue<'tcx> {
 
                         struct_fmt.finish()
                     }),
+
+                    AggregateKind::RawPtr(pointee_ty, mutability) => {
+                        let kind_str = match mutability {
+                            Mutability::Mut => "mut",
+                            Mutability::Not => "const",
+                        };
+                        with_no_trimmed_paths!(write!(fmt, "*{kind_str} {pointee_ty} from "))?;
+                        fmt_tuple(fmt, "")
+                    }
                 }
             }
 
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index 97c3eb55638..db13bb9a3e8 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -1351,6 +1351,21 @@ pub enum AggregateKind<'tcx> {
     Closure(DefId, GenericArgsRef<'tcx>),
     Coroutine(DefId, GenericArgsRef<'tcx>),
     CoroutineClosure(DefId, GenericArgsRef<'tcx>),
+
+    /// Construct a raw pointer from the data pointer and metadata.
+    ///
+    /// The `Ty` here is the type of the *pointee*, not the pointer itself.
+    /// The `Mutability` indicates whether this produces a `*const` or `*mut`.
+    ///
+    /// The [`Rvalue::Aggregate`] operands for thus must be
+    ///
+    /// 0. A raw pointer of matching mutability with any [`core::ptr::Thin`] pointee
+    /// 1. A value of the appropriate [`core::ptr::Pointee::Metadata`] type
+    ///
+    /// *Both* operands must always be included, even the unit value if this is
+    /// creating a thin pointer. If you're just converting between thin pointers,
+    /// you may want an [`Rvalue::Cast`] with [`CastKind::PtrToPtr`] instead.
+    RawPtr(Ty<'tcx>, Mutability),
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, Hash, HashStable)]
diff --git a/compiler/rustc_middle/src/mir/tcx.rs b/compiler/rustc_middle/src/mir/tcx.rs
index 506003ff7c0..abe99f3e95c 100644
--- a/compiler/rustc_middle/src/mir/tcx.rs
+++ b/compiler/rustc_middle/src/mir/tcx.rs
@@ -206,6 +206,7 @@ impl<'tcx> Rvalue<'tcx> {
                 AggregateKind::CoroutineClosure(did, args) => {
                     Ty::new_coroutine_closure(tcx, did, args)
                 }
+                AggregateKind::RawPtr(ty, mutability) => Ty::new_ptr(tcx, ty, mutability),
             },
             Rvalue::ShallowInitBox(_, ty) => Ty::new_box(tcx, ty),
             Rvalue::CopyForDeref(ref place) => place.ty(local_decls, tcx).ty,
diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs
index 4f7b2f7cbe4..fc1ab0f12ac 100644
--- a/compiler/rustc_middle/src/mir/visit.rs
+++ b/compiler/rustc_middle/src/mir/visit.rs
@@ -751,6 +751,9 @@ macro_rules! make_mir_visitor {
                             ) => {
                                 self.visit_args(coroutine_closure_args, location);
                             }
+                            AggregateKind::RawPtr(ty, _) => {
+                                self.visit_ty($(& $mutability)? *ty, TyContext::Location(location));
+                            }
                         }
 
                         for operand in operands {
-- 
cgit 1.4.1-3-g733a5