Auto merge of #18003 - ChayimFriedman2:addr_of-static-mut, r=Veykril

Do not report missing unsafe on `addr_of[_mut]!(EXTERN_OR_MUT_STATIC)`

The compiler no longer does as well; see rust-lang/rust#125834.

Also require unsafe when accessing `extern` `static` (other than by `addr_of!()`).

Fixes #17978.

Author: bors

crates/hir-ty/src/diagnostics/unsafe_check.rs

@@ -5,6 +5,7 @@ use hir_def::{
     body::Body,
     hir::{Expr, ExprId, UnaryOp},
     resolver::{resolver_for_expr, ResolveValueResult, Resolver, ValueNs},
+    type_ref::Rawness,
     DefWithBodyId,
 };
 
@@ -87,12 +88,20 @@ fn walk_unsafe(
             let g = resolver.update_to_inner_scope(db.upcast(), def, current);
             let value_or_partial = resolver.resolve_path_in_value_ns(db.upcast(), path);
             if let Some(ResolveValueResult::ValueNs(ValueNs::StaticId(id), _)) = value_or_partial {
-                if db.static_data(id).mutable {
+                let static_data = db.static_data(id);
+                if static_data.mutable || static_data.is_extern {
                     unsafe_expr_cb(UnsafeExpr { expr: current, inside_unsafe_block });
                 }
             }
             resolver.reset_to_guard(g);
         }
+        Expr::Ref { expr, rawness: Rawness::RawPtr, mutability: _ } => {
+            if let Expr::Path(_) = body.exprs[*expr] {
+                // Do not report unsafe for `addr_of[_mut]!(EXTERN_OR_MUT_STATIC)`,
+                // see https://github.com/rust-lang/rust/pull/125834.
+                return;
+            }
+        }
         Expr::MethodCall { .. } => {
             if infer
                 .method_resolution(current)

crates/ide-diagnostics/src/handlers/missing_unsafe.rs

@@ -163,6 +163,56 @@ fn main() {
         );
     }
 
+    #[test]
+    fn missing_unsafe_diagnostic_with_extern_static() {
+        check_diagnostics(
+            r#"
+//- minicore: copy
+
+extern "C" {
+    static EXTERN: i32;
+    static mut EXTERN_MUT: i32;
+}
+
+fn main() {
+    let _x = EXTERN;
+           //^^^^^^💡 error: this operation is unsafe and requires an unsafe function or block
+    let _x = EXTERN_MUT;
+           //^^^^^^^^^^💡 error: this operation is unsafe and requires an unsafe function or block
+    unsafe {
+        let _x = EXTERN;
+        let _x = EXTERN_MUT;
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn no_unsafe_diagnostic_with_addr_of_static() {
+        check_diagnostics(
+            r#"
+//- minicore: copy, addr_of
+
+use core::ptr::{addr_of, addr_of_mut};
+
+extern "C" {
+    static EXTERN: i32;
+    static mut EXTERN_MUT: i32;
+}
+static mut STATIC_MUT: i32 = 0;
+
+fn main() {
+    let _x = addr_of!(EXTERN);
+    let _x = addr_of!(EXTERN_MUT);
+    let _x = addr_of!(STATIC_MUT);
+    let _x = addr_of_mut!(EXTERN_MUT);
+    let _x = addr_of_mut!(STATIC_MUT);
+}
+"#,
+        );
+    }
+
     #[test]
     fn no_missing_unsafe_diagnostic_with_safe_intrinsic() {
         check_diagnostics(

crates/ide/src/hover/tests.rs

@@ -483,8 +483,8 @@ fn main() {
                                 file_id: FileId(
                                     1,
                                 ),
-                                full_range: 632..867,
-                                focus_range: 693..699,
+                                full_range: 633..868,
+                                focus_range: 694..700,
                                 name: "FnOnce",
                                 kind: Trait,
                                 container_name: "function",
@@ -8479,8 +8479,8 @@ impl Iterator for S {
                                 file_id: FileId(
                                     1,
                                 ),
-                                full_range: 7801..8043,
-                                focus_range: 7866..7872,
+                                full_range: 7802..8044,
+                                focus_range: 7867..7873,
                                 name: "Future",
                                 kind: Trait,
                                 container_name: "future",
@@ -8493,8 +8493,8 @@ impl Iterator for S {
                                 file_id: FileId(
                                     1,
                                 ),
-                                full_range: 8673..9172,
-                                focus_range: 8750..8758,
+                                full_range: 8674..9173,
+                                focus_range: 8751..8759,
                                 name: "Iterator",
                                 kind: Trait,
                                 container_name: "iterator",

crates/test-utils/src/minicore.rs

@@ -65,6 +65,7 @@
 //!     todo: panic
 //!     unimplemented: panic
 //!     column:
+//!     addr_of:
 
 #![rustc_coherence_is_core]
 
@@ -421,6 +422,17 @@ pub mod ptr {
     }
     // endregion:coerce_unsized
     // endregion:non_null
+
+    // region:addr_of
+    #[rustc_macro_transparency = "semitransparent"]
+    pub macro addr_of($place:expr) {
+        &raw const $place
+    }
+    #[rustc_macro_transparency = "semitransparent"]
+    pub macro addr_of_mut($place:expr) {
+        &raw mut $place
+    }
+    // endregion:addr_of
 }
 
 pub mod ops {