Allow validation of complex nested statics

Author: oli-obk

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -465,16 +465,6 @@ 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 { mt: 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(
@@ -500,7 +490,24 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
                             None => {}
                         }
                         // Return alloc mutability
-                        if is_mut { Mutability::Mut } else { Mutability::Not }
+                        if let DefKind::Static { mt, nested } = self.ecx.tcx.def_kind(did) {
+                            if nested {
+                                mt
+                            } else 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::Not
+                            } else {
+                                mt
+                            }
+                        } else {
+                            Mutability::Not
+                        }
                     }
                     GlobalAlloc::Memory(alloc) => alloc.inner().mutability,
                     GlobalAlloc::Function(..) | GlobalAlloc::VTable(..) => {

tests/ui/statics/nested_struct.rs

@@ -0,0 +1,19 @@
+//@ check-pass
+
+pub struct Lint {
+    pub name: &'static str,
+    pub desc: &'static str,
+    pub report_in_external_macro: bool,
+    pub is_loaded: bool,
+    pub crate_level_only: bool,
+}
+
+static FOO: &Lint = &Lint {
+    name: &"foo",
+    desc: "desc",
+    report_in_external_macro: false,
+    is_loaded: true,
+    crate_level_only: false,
+};
+
+fn main() {}