Merge from rustc

9 files changed, 130 insertions, 44 deletions

diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
index 90884adb28c..5f4408ebbc6 100644
--- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
+++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs
@@ -37,7 +37,7 @@ fn eval_body_using_ecx<'mir, 'tcx>(
             || matches!(
                 ecx.tcx.def_kind(cid.instance.def_id()),
                 DefKind::Const
-                    | DefKind::Static(_)
+                    | DefKind::Static { .. }
                     | DefKind::ConstParam
                     | DefKind::AnonConst
                     | DefKind::InlineConst
@@ -59,7 +59,7 @@ fn eval_body_using_ecx<'mir, 'tcx>(
     };
 
     let ret = if let InternKind::Static(_) = intern_kind {
-        create_static_alloc(ecx, cid.instance.def_id(), layout)?
+        create_static_alloc(ecx, cid.instance.def_id().expect_local(), layout)?
     } else {
         ecx.allocate(layout, MemoryKind::Stack)?
     };
@@ -380,7 +380,11 @@ pub fn eval_in_interpreter<'mir, 'tcx>(
         }
         Ok(mplace) => {
             // Since evaluation had no errors, validate the resulting constant.
+
+            // Temporarily allow access to the static_root_ids for the purpose of validation.
+            let static_root_ids = ecx.machine.static_root_ids.take();
             let res = const_validate_mplace(&ecx, &mplace, cid);
+            ecx.machine.static_root_ids = static_root_ids;
 
             let alloc_id = mplace.ptr().provenance.unwrap().alloc_id();
 
diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs
index f104b836716..dd835279df3 100644
--- a/compiler/rustc_const_eval/src/const_eval/machine.rs
+++ b/compiler/rustc_const_eval/src/const_eval/machine.rs
@@ -8,6 +8,7 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::fx::IndexEntry;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::LangItem;
 use rustc_middle::mir;
 use rustc_middle::mir::AssertMessage;
@@ -59,8 +60,10 @@ pub struct CompileTimeInterpreter<'mir, 'tcx> {
     /// Whether to check alignment during evaluation.
     pub(super) check_alignment: CheckAlignment,
 
-    /// Used to prevent reads from a static's base allocation, as that may allow for self-initialization.
-    pub(crate) static_root_alloc_id: Option<AllocId>,
+    /// If `Some`, we are evaluating the initializer of the static with the given `LocalDefId`,
+    /// storing the result in the given `AllocId`.
+    /// Used to prevent reads from a static's base allocation, as that may allow for self-initialization loops.
+    pub(crate) static_root_ids: Option<(AllocId, LocalDefId)>,
 }
 
 #[derive(Copy, Clone)]
@@ -94,7 +97,7 @@ impl<'mir, 'tcx> CompileTimeInterpreter<'mir, 'tcx> {
             stack: Vec::new(),
             can_access_mut_global,
             check_alignment,
-            static_root_alloc_id: None,
+            static_root_ids: None,
         }
     }
 }
@@ -749,7 +752,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
         ecx: &InterpCx<'mir, 'tcx, Self>,
         alloc_id: AllocId,
     ) -> InterpResult<'tcx> {
-        if Some(alloc_id) == ecx.machine.static_root_alloc_id {
+        if Some(alloc_id) == ecx.machine.static_root_ids.map(|(id, _)| id) {
             Err(ConstEvalErrKind::RecursiveStatic.into())
         } else {
             Ok(())
diff --git a/compiler/rustc_const_eval/src/errors.rs b/compiler/rustc_const_eval/src/errors.rs
index 249c02b75f7..46790264359 100644
--- a/compiler/rustc_const_eval/src/errors.rs
+++ b/compiler/rustc_const_eval/src/errors.rs
@@ -25,10 +25,13 @@ pub(crate) struct DanglingPtrInFinal {
     pub kind: InternKind,
 }
 
-#[derive(Diagnostic)]
+#[derive(LintDiagnostic)]
 #[diag(const_eval_mutable_ptr_in_final)]
 pub(crate) struct MutablePtrInFinal {
-    #[primary_span]
+    // rust-lang/rust#122153: This was marked as `#[primary_span]` under
+    // `derive(Diagnostic)`. Since we expect we may hard-error in future, we are
+    // keeping the field (and skipping it under `derive(LintDiagnostic)`).
+    #[skip_arg]
     pub span: Span,
     pub kind: InternKind,
 }
diff --git a/compiler/rustc_const_eval/src/interpret/intern.rs b/compiler/rustc_const_eval/src/interpret/intern.rs
index 82ce9ecd21d..c30a1362417 100644
--- a/compiler/rustc_const_eval/src/interpret/intern.rs
+++ b/compiler/rustc_const_eval/src/interpret/intern.rs
@@ -13,12 +13,17 @@
 //! but that would require relying on type information, and given how many ways Rust has to lie
 //! about type information, we want to avoid doing that.
 
+use hir::def::DefKind;
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir as hir;
-use rustc_middle::mir::interpret::{CtfeProvenance, InterpResult};
+use rustc_middle::mir::interpret::{ConstAllocation, CtfeProvenance, InterpResult};
+use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::TyAndLayout;
+use rustc_session::lint;
+use rustc_span::def_id::LocalDefId;
+use rustc_span::sym;
 
 use super::{AllocId, Allocation, InterpCx, MPlaceTy, Machine, MemoryKind, PlaceTy};
 use crate::const_eval;
@@ -33,7 +38,19 @@ pub trait CompileTimeMachine<'mir, 'tcx: 'mir, T> = Machine<
         FrameExtra = (),
         AllocExtra = (),
         MemoryMap = FxIndexMap<AllocId, (MemoryKind<T>, Allocation)>,
-    >;
+    > + HasStaticRootDefId;
+
+pub trait HasStaticRootDefId {
+    /// Returns the `DefId` of the static item that is currently being evaluated.
+    /// Used for interning to be able to handle nested allocations.
+    fn static_def_id(&self) -> Option<LocalDefId>;
+}
+
+impl HasStaticRootDefId for const_eval::CompileTimeInterpreter<'_, '_> {
+    fn static_def_id(&self) -> Option<LocalDefId> {
+        Some(self.static_root_ids?.1)
+    }
+}
 
 /// Intern an allocation. Returns `Err` if the allocation does not exist in the local memory.
 ///
@@ -67,10 +84,35 @@ fn intern_shallow<'rt, 'mir, 'tcx, T, M: CompileTimeMachine<'mir, 'tcx, T>>(
     }
     // link the alloc id to the actual allocation
     let alloc = ecx.tcx.mk_const_alloc(alloc);
-    ecx.tcx.set_alloc_id_memory(alloc_id, alloc);
+    if let Some(static_id) = ecx.machine.static_def_id() {
+        intern_as_new_static(ecx.tcx, static_id, alloc_id, alloc);
+    } else {
+        ecx.tcx.set_alloc_id_memory(alloc_id, alloc);
+    }
     Ok(alloc.0.0.provenance().ptrs().iter().map(|&(_, prov)| prov))
 }
 
+/// Creates a new `DefId` and feeds all the right queries to make this `DefId`
+/// appear as if it were a user-written `static` (though it has no HIR).
+fn intern_as_new_static<'tcx>(
+    tcx: TyCtxtAt<'tcx>,
+    static_id: LocalDefId,
+    alloc_id: AllocId,
+    alloc: ConstAllocation<'tcx>,
+) {
+    let feed = tcx.create_def(
+        static_id,
+        sym::nested,
+        DefKind::Static { mutability: alloc.0.mutability, nested: true },
+    );
+    tcx.set_nested_alloc_id_static(alloc_id, feed.def_id());
+    feed.codegen_fn_attrs(tcx.codegen_fn_attrs(static_id).clone());
+    feed.eval_static_initializer(Ok(alloc));
+    feed.generics_of(tcx.generics_of(static_id).clone());
+    feed.def_ident_span(tcx.def_ident_span(static_id));
+    feed.explicit_predicates_of(tcx.explicit_predicates_of(static_id));
+}
+
 /// How a constant value should be interned.
 #[derive(Copy, Clone, Debug, PartialEq, Hash, Eq)]
 pub enum InternKind {
@@ -221,10 +263,13 @@ pub fn intern_const_alloc_recursive<
         })?);
     }
     if found_bad_mutable_pointer {
-        return Err(ecx
-            .tcx
-            .dcx()
-            .emit_err(MutablePtrInFinal { span: ecx.tcx.span, kind: intern_kind }));
+        let err_diag = MutablePtrInFinal { span: ecx.tcx.span, kind: intern_kind };
+        ecx.tcx.emit_node_span_lint(
+            lint::builtin::CONST_EVAL_MUTABLE_PTR_IN_FINAL_VALUE,
+            ecx.best_lint_scope(),
+            err_diag.span,
+            err_diag,
+        )
     }
 
     Ok(())
diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs
index 305f7ade101..b260112c783 100644
--- a/compiler/rustc_const_eval/src/interpret/machine.rs
+++ b/compiler/rustc_const_eval/src/interpret/machine.rs
@@ -443,7 +443,8 @@ pub trait Machine<'mir, 'tcx: 'mir>: Sized {
         _machine: &mut Self,
         _alloc_extra: &mut Self::AllocExtra,
         _prov: (AllocId, Self::ProvenanceExtra),
-        _range: AllocRange,
+        _size: Size,
+        _align: Align,
     ) -> InterpResult<'tcx> {
         Ok(())
     }
diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs
index cf7f165b87c..86aad2e1642 100644
--- a/compiler/rustc_const_eval/src/interpret/memory.rs
+++ b/compiler/rustc_const_eval/src/interpret/memory.rs
@@ -15,6 +15,7 @@ use std::ptr;
 
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
+use rustc_hir::def::DefKind;
 use rustc_middle::mir::display_allocation;
 use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TyCtxt};
 use rustc_target::abi::{Align, HasDataLayout, Size};
@@ -352,7 +353,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             &mut self.machine,
             &mut alloc.extra,
             (alloc_id, prov),
-            alloc_range(Size::ZERO, size),
+            size,
+            alloc.align,
         )?;
 
         // Don't forget to remember size and align of this now-dead allocation
@@ -761,19 +763,36 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // be held throughout the match.
         match self.tcx.try_get_global_alloc(id) {
             Some(GlobalAlloc::Static(def_id)) => {
-                assert!(self.tcx.is_static(def_id));
                 // Thread-local statics do not have a constant address. They *must* be accessed via
                 // `ThreadLocalRef`; we can never have a pointer to them as a regular constant value.
                 assert!(!self.tcx.is_thread_local_static(def_id));
-                // Use size and align of the type.
-                let ty = self
-                    .tcx
-                    .type_of(def_id)
-                    .no_bound_vars()
-                    .expect("statics should not have generic parameters");
-                let layout = self.tcx.layout_of(ParamEnv::empty().and(ty)).unwrap();
-                assert!(layout.is_sized());
-                (layout.size, layout.align.abi, AllocKind::LiveData)
+
+                let DefKind::Static { nested, .. } = self.tcx.def_kind(def_id) else {
+                    bug!("GlobalAlloc::Static is not a static")
+                };
+
+                let (size, align) = if nested {
+                    // Nested anonymous statics are untyped, so let's get their
+                    // size and alignment from the allocaiton itself. This always
+                    // succeeds, as the query is fed at DefId creation time, so no
+                    // evaluation actually occurs.
+                    let alloc = self.tcx.eval_static_initializer(def_id).unwrap();
+                    (alloc.0.size(), alloc.0.align)
+                } else {
+                    // Use size and align of the type for everything else. We need
+                    // to do that to
+                    // * avoid cycle errors in case of self-referential statics,
+                    // * be able to get information on extern statics.
+                    let ty = self
+                        .tcx
+                        .type_of(def_id)
+                        .no_bound_vars()
+                        .expect("statics should not have generic parameters");
+                    let layout = self.tcx.layout_of(ParamEnv::empty().and(ty)).unwrap();
+                    assert!(layout.is_sized());
+                    (layout.size, layout.align.abi)
+                };
+                (size, align, AllocKind::LiveData)
             }
             Some(GlobalAlloc::Memory(alloc)) => {
                 // Need to duplicate the logic here, because the global allocations have
diff --git a/compiler/rustc_const_eval/src/interpret/mod.rs b/compiler/rustc_const_eval/src/interpret/mod.rs
index a15e52d07e6..2ed879ca72b 100644
--- a/compiler/rustc_const_eval/src/interpret/mod.rs
+++ b/compiler/rustc_const_eval/src/interpret/mod.rs
@@ -22,7 +22,7 @@ pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in
 
 pub use self::eval_context::{format_interp_error, Frame, FrameInfo, InterpCx, StackPopCleanup};
 pub use self::intern::{
-    intern_const_alloc_for_constprop, intern_const_alloc_recursive, InternKind,
+    intern_const_alloc_for_constprop, intern_const_alloc_recursive, HasStaticRootDefId, InternKind,
 };
 pub use self::machine::{compile_time_machine, AllocMap, Machine, MayLeak, StackPopJump};
 pub use self::memory::{AllocKind, AllocRef, AllocRefMut, FnVal, Memory, MemoryKind};
diff --git a/compiler/rustc_const_eval/src/interpret/util.rs b/compiler/rustc_const_eval/src/interpret/util.rs
index 3427368421f..086475f72c5 100644
--- a/compiler/rustc_const_eval/src/interpret/util.rs
+++ b/compiler/rustc_const_eval/src/interpret/util.rs
@@ -1,11 +1,11 @@
 use crate::const_eval::CompileTimeEvalContext;
 use crate::interpret::{MemPlaceMeta, MemoryKind};
+use rustc_hir::def_id::LocalDefId;
 use rustc_middle::mir::interpret::{AllocId, Allocation, InterpResult, Pointer};
 use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{
     self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
 };
-use rustc_span::def_id::DefId;
 use std::ops::ControlFlow;
 
 use super::MPlaceTy;
@@ -89,13 +89,13 @@ pub(crate) fn take_static_root_alloc<'mir, 'tcx: 'mir>(
 
 pub(crate) fn create_static_alloc<'mir, 'tcx: 'mir>(
     ecx: &mut CompileTimeEvalContext<'mir, 'tcx>,
-    static_def_id: DefId,
+    static_def_id: LocalDefId,
     layout: TyAndLayout<'tcx>,
 ) -> InterpResult<'tcx, MPlaceTy<'tcx>> {
     let alloc = Allocation::try_uninit(layout.size, layout.align.abi)?;
-    let alloc_id = ecx.tcx.reserve_and_set_static_alloc(static_def_id);
-    assert_eq!(ecx.machine.static_root_alloc_id, None);
-    ecx.machine.static_root_alloc_id = Some(alloc_id);
+    let alloc_id = ecx.tcx.reserve_and_set_static_alloc(static_def_id.into());
+    assert_eq!(ecx.machine.static_root_ids, None);
+    ecx.machine.static_root_ids = Some((alloc_id, static_def_id));
     assert!(ecx.memory.alloc_map.insert(alloc_id, (MemoryKind::Stack, alloc)).is_none());
     Ok(ecx.ptr_with_meta_to_mplace(Pointer::from(alloc_id).into(), MemPlaceMeta::None, layout))
 }
diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 972424bccfa..d18600ce7d7 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -457,15 +457,6 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
                         // Special handling for pointers to statics (irrespective of their type).
                         assert!(!self.ecx.tcx.is_thread_local_static(did));
                         assert!(self.ecx.tcx.is_static(did));
-                        let is_mut =
-                            matches!(self.ecx.tcx.def_kind(did), DefKind::Static(Mutability::Mut))
-                                || !self
-                                    .ecx
-                                    .tcx
-                                    .type_of(did)
-                                    .no_bound_vars()
-                                    .expect("statics should not have generic parameters")
-                                    .is_freeze(*self.ecx.tcx, ty::ParamEnv::reveal_all());
                         // Mode-specific checks
                         match self.ctfe_mode {
                             Some(
@@ -490,8 +481,28 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
                             }
                             None => {}
                         }
-                        // Return alloc mutability
-                        if is_mut { Mutability::Mut } else { Mutability::Not }
+                        // Return alloc mutability. For "root" statics we look at the type to account for interior
+                        // mutability; for nested statics we have no type and directly use the annotated mutability.
+                        let DefKind::Static { mutability, nested } = self.ecx.tcx.def_kind(did)
+                        else {
+                            bug!()
+                        };
+                        match (mutability, nested) {
+                            (Mutability::Mut, _) => Mutability::Mut,
+                            (Mutability::Not, true) => Mutability::Not,
+                            (Mutability::Not, false)
+                                if !self
+                                    .ecx
+                                    .tcx
+                                    .type_of(did)
+                                    .no_bound_vars()
+                                    .expect("statics should not have generic parameters")
+                                    .is_freeze(*self.ecx.tcx, ty::ParamEnv::reveal_all()) =>
+                            {
+                                Mutability::Mut
+                            }
+                            (Mutability::Not, false) => Mutability::Not,
+                        }
                     }
                     GlobalAlloc::Memory(alloc) => alloc.inner().mutability,
                     GlobalAlloc::Function(..) | GlobalAlloc::VTable(..) => {