Fix #28008: Handle unmanaged classes in c_addrOf with wide pointers

modules/standard/CTypes.chpl

@@ -1026,6 +1026,16 @@ module CTypes {
     return c_pointer_return(x);
   }
 
+  // Special handling for unmanaged classes to work with wide pointers
+  // In a wide pointer context, unmanaged class variables are stored as
+  // narrow pointers, but c_pointer_return would try to take the address
+  // of the variable itself, treating it incorrectly as a wide pointer.
+  // Use c_ptrTo instead to get the actual pointer value.
+  @chpldoc.nodoc
+  inline proc c_addrOf(const x: ?t): c_ptr(void) where isUnmanagedClass(t) {
+    return c_ptrTo(x);
+  }
+
   // Added as unstable for 2.4, can be merged into stable version once we're
   // confident in it.
   @chpldoc.nodoc
@@ -1044,6 +1054,12 @@ module CTypes {
     return c_pointer_return_const(x);
   }
 
+  // Special handling for unmanaged classes - see corresponding c_addrOf overload
+  @chpldoc.nodoc
+  inline proc c_addrOfConst(const x: ?t): c_ptrConst(void) where isUnmanagedClass(t) {
+    return c_ptrToConst(x);
+  }
+
   // See note on corresponding c_addrOf overload
   @chpldoc.nodoc
   @unstable("using 'c_addrOfConst' with a domain argument is unstable")

test-issue-28008.chpl

@@ -0,0 +1,20 @@
+use CTypes;
+
+class MyClass {
+  var x: int = 21;
+}
+
+proc main() {
+
+  var myOwned = new owned MyClass();
+  var myBorrow = myOwned.borrow();
+  var myUnmanaged = new unmanaged MyClass();
+  defer { delete myUnmanaged; }
+
+  var addr1 = c_addrOf(myOwned);
+  var addr2 = c_addrOf(myBorrow);
+  var addr3 = c_addrOf(myUnmanaged);
+
+
+  writeln(addr1.deref(), addr2.deref(), addr3.deref(), sep =" | "); // addr3.deref() fails
+}

test/library/standard/CTypes/c_addrOf_unmanaged_class.chpl

@@ -0,0 +1,25 @@
+// Test for issue #28008
+// c_addrOf on unmanaged class should work with wide pointers
+
+use CTypes;
+
+class MyClass {
+  var x: int = 21;
+}
+
+proc main() {
+
+  var myOwned = new owned MyClass();
+  var myBorrow = myOwned.borrow();
+  var myUnmanaged = new unmanaged MyClass();
+  defer { delete myUnmanaged; }
+
+  var addr1 = c_addrOf(myOwned);
+  var addr2 = c_addrOf(myBorrow);
+  var addr3 = c_addrOf(myUnmanaged);
+
+  writeln(addr1.deref(), " | ", addr2.deref(), " | ", addr3.deref());
+
+  // Verify that c_addrOf on unmanaged class returns the same as c_ptrTo
+  writeln(c_addrOf(myUnmanaged):string == c_ptrTo(myUnmanaged):string);
+}

test/library/standard/CTypes/c_addrOf_unmanaged_class.good

@@ -0,0 +1,2 @@
+{x = 21} | {x = 21} | {x = 21}
+true

test/types/cptr/c_ptr_class_type.good

@@ -18,7 +18,8 @@ true
 true
 true
 
-false
+true
 5
 c_ptr(void)
 5
+