Auto merge of #124241 - matthiaskrgr:rollup-xhu90xr, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - #123840 (Add an intrinsic for `ptr::from_raw_parts(_mut)`)
 - #124224 (cleanup: unnecessary clone during lower generics args)
 - #124229 (Add gnullvm targets to manifest)
 - #124231 (remove from reviewers)
 - #124235 (Move some tests)

r? `@ghost`
`@rustbot` modify labels: rollup

4 files changed, 69 insertions, 3 deletions

diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs
index 8e8d78226c3..24832086b16 100644
--- a/compiler/rustc_mir_transform/src/gvn.rs
+++ b/compiler/rustc_mir_transform/src/gvn.rs
@@ -885,6 +885,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
                 AggregateKind::Adt(did, ..) => tcx.def_kind(did) != DefKind::Enum,
                 // Coroutines are never ZST, as they at least contain the implicit states.
                 AggregateKind::Coroutine(..) => false,
+                AggregateKind::RawPtr(..) => bug!("MIR for RawPtr aggregate must have 2 fields"),
             };
 
             if is_zst {
@@ -910,6 +911,8 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
             }
             // Do not track unions.
             AggregateKind::Adt(_, _, _, _, Some(_)) => return None,
+            // FIXME: Do the extra work to GVN `from_raw_parts`
+            AggregateKind::RawPtr(..) => return None,
         };
 
         let fields: Option<Vec<_>> = fields
diff --git a/compiler/rustc_mir_transform/src/instsimplify.rs b/compiler/rustc_mir_transform/src/instsimplify.rs
index ff786d44d6a..fd768cc96ae 100644
--- a/compiler/rustc_mir_transform/src/instsimplify.rs
+++ b/compiler/rustc_mir_transform/src/instsimplify.rs
@@ -36,6 +36,7 @@ impl<'tcx> MirPass<'tcx> for InstSimplify {
                         ctx.simplify_bool_cmp(&statement.source_info, rvalue);
                         ctx.simplify_ref_deref(&statement.source_info, rvalue);
                         ctx.simplify_len(&statement.source_info, rvalue);
+                        ctx.simplify_ptr_aggregate(&statement.source_info, rvalue);
                         ctx.simplify_cast(rvalue);
                     }
                     _ => {}
@@ -58,8 +59,17 @@ struct InstSimplifyContext<'tcx, 'a> {
 
 impl<'tcx> InstSimplifyContext<'tcx, '_> {
     fn should_simplify(&self, source_info: &SourceInfo, rvalue: &Rvalue<'tcx>) -> bool {
+        self.should_simplify_custom(source_info, "Rvalue", rvalue)
+    }
+
+    fn should_simplify_custom(
+        &self,
+        source_info: &SourceInfo,
+        label: &str,
+        value: impl std::fmt::Debug,
+    ) -> bool {
         self.tcx.consider_optimizing(|| {
-            format!("InstSimplify - Rvalue: {rvalue:?} SourceInfo: {source_info:?}")
+            format!("InstSimplify - {label}: {value:?} SourceInfo: {source_info:?}")
         })
     }
 
@@ -111,7 +121,7 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
         if a.const_.ty().is_bool() { a.const_.try_to_bool() } else { None }
     }
 
-    /// Transform "&(*a)" ==> "a".
+    /// Transform `&(*a)` ==> `a`.
     fn simplify_ref_deref(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Ref(_, _, place) = rvalue {
             if let Some((base, ProjectionElem::Deref)) = place.as_ref().last_projection() {
@@ -131,7 +141,7 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
         }
     }
 
-    /// Transform "Len([_; N])" ==> "N".
+    /// Transform `Len([_; N])` ==> `N`.
     fn simplify_len(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::Len(ref place) = *rvalue {
             let place_ty = place.ty(self.local_decls, self.tcx).ty;
@@ -147,6 +157,30 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
         }
     }
 
+    /// Transform `Aggregate(RawPtr, [p, ()])` ==> `Cast(PtrToPtr, p)`.
+    fn simplify_ptr_aggregate(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
+        if let Rvalue::Aggregate(box AggregateKind::RawPtr(pointee_ty, mutability), fields) = rvalue
+        {
+            let meta_ty = fields.raw[1].ty(self.local_decls, self.tcx);
+            if meta_ty.is_unit() {
+                // The mutable borrows we're holding prevent printing `rvalue` here
+                if !self.should_simplify_custom(
+                    source_info,
+                    "Aggregate::RawPtr",
+                    (&pointee_ty, *mutability, &fields),
+                ) {
+                    return;
+                }
+
+                let mut fields = std::mem::take(fields);
+                let _meta = fields.pop().unwrap();
+                let data = fields.pop().unwrap();
+                let ptr_ty = Ty::new_ptr(self.tcx, *pointee_ty, *mutability);
+                *rvalue = Rvalue::Cast(CastKind::PtrToPtr, data, ptr_ty);
+            }
+        }
+    }
+
     fn simplify_ub_check(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
         if let Rvalue::NullaryOp(NullOp::UbChecks, _) = *rvalue {
             let const_ = Const::from_bool(self.tcx, self.tcx.sess.ub_checks());
diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs
index 2744026a7c9..b8dbf8a759f 100644
--- a/compiler/rustc_mir_transform/src/known_panics_lint.rs
+++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs
@@ -603,6 +603,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
                         AggregateKind::Adt(_, variant, _, _, _) => variant,
                         AggregateKind::Array(_)
                         | AggregateKind::Tuple
+                        | AggregateKind::RawPtr(_, _)
                         | AggregateKind::Closure(_, _)
                         | AggregateKind::Coroutine(_, _)
                         | AggregateKind::CoroutineClosure(_, _) => VariantIdx::ZERO,
diff --git a/compiler/rustc_mir_transform/src/lower_intrinsics.rs b/compiler/rustc_mir_transform/src/lower_intrinsics.rs
index 7e8920604c1..da63fcf23d9 100644
--- a/compiler/rustc_mir_transform/src/lower_intrinsics.rs
+++ b/compiler/rustc_mir_transform/src/lower_intrinsics.rs
@@ -287,6 +287,34 @@ impl<'tcx> MirPass<'tcx> for LowerIntrinsics {
                             terminator.kind = TerminatorKind::Unreachable;
                         }
                     }
+                    sym::aggregate_raw_ptr => {
+                        let Ok([data, meta]) = <[_; 2]>::try_from(std::mem::take(args)) else {
+                            span_bug!(
+                                terminator.source_info.span,
+                                "Wrong number of arguments for aggregate_raw_ptr intrinsic",
+                            );
+                        };
+                        let target = target.unwrap();
+                        let pointer_ty = generic_args.type_at(0);
+                        let kind = if let ty::RawPtr(pointee_ty, mutability) = pointer_ty.kind() {
+                            AggregateKind::RawPtr(*pointee_ty, *mutability)
+                        } else {
+                            span_bug!(
+                                terminator.source_info.span,
+                                "Return type of aggregate_raw_ptr intrinsic must be a raw pointer",
+                            );
+                        };
+                        let fields = [data.node, meta.node];
+                        block.statements.push(Statement {
+                            source_info: terminator.source_info,
+                            kind: StatementKind::Assign(Box::new((
+                                *destination,
+                                Rvalue::Aggregate(Box::new(kind), fields.into()),
+                            ))),
+                        });
+
+                        terminator.kind = TerminatorKind::Goto { target };
+                    }
                     _ => {}
                 }
             }