show a more informative error when accessing a private class

Author: withinboredom

Zend/zend_compile.c

@@ -9171,7 +9171,7 @@ static void zend_compile_class_decl(znode *result, zend_ast *ast, bool toplevel)
 			// - public
 			// - private
 			// - protected
-			int propFlags = decl->attr & (ZEND_ACC_PUBLIC|ZEND_ACC_PROTECTED|ZEND_ACC_PRIVATE);
+			int propFlags = (decl->attr & (ZEND_ACC_PUBLIC|ZEND_ACC_PROTECTED|ZEND_ACC_PRIVATE)) | ZEND_ACC_INNER_CLASS_REFERENCE;
 
 			// there are two things we need to inject into the nested parent:
 			// - a static property that contains the name of the nested class

Zend/zend_compile.h

@@ -253,7 +253,7 @@ typedef struct _zend_oparray_context {
 /* or IS_CONSTANT_VISITED_MARK                            |     |     |     */
 #define ZEND_CLASS_CONST_IS_CASE         (1 << 6)  /*     |     |     |  X  */
 /*                                                        |     |     |     */
-/* Property Flags (unused: 13...)                         |     |     |     */
+/* Property Flags (unused: 14...)                         |     |     |     */
 /* ===========                                            |     |     |     */
 /*                                                        |     |     |     */
 /* Promoted property / parameter                          |     |     |     */
@@ -267,6 +267,9 @@ typedef struct _zend_oparray_context {
 #define ZEND_ACC_PROTECTED_SET           (1 << 11) /*     |     |  X  |     */
 #define ZEND_ACC_PRIVATE_SET             (1 << 12) /*     |     |  X  |     */
 /*                                                        |     |     |     */
+/* Property is a reference                                |     |  X  |     */
+#define ZEND_ACC_INNER_CLASS_REFERENCE   (1 << 13) /*     |     |  X  |     */
+/*                                                        |     |     |     */
 /* Class Flags (unused: 31)                               |     |     |     */
 /* ===========                                            |     |     |     */
 /*                                                        |     |     |     */

Zend/zend_object_handlers.c

@@ -298,7 +298,11 @@ static zend_never_inline zend_property_info *zend_get_parent_private_property(ze
 
 static ZEND_COLD zend_never_inline void zend_bad_property_access(const zend_property_info *property_info, const zend_class_entry *ce, const zend_string *member) /* {{{ */
 {
-	zend_throw_error(NULL, "Cannot access %s property %s::$%s", zend_visibility_string(property_info->flags), ZSTR_VAL(ce->name), ZSTR_VAL(member));
+	if (property_info->flags & ZEND_ACC_INNER_CLASS_REFERENCE) {
+		zend_throw_error(NULL, "Cannot access %s inner class %s::%s", zend_visibility_string(property_info->flags), ZSTR_VAL(ce->name), ZSTR_VAL(member));
+	} else {
+		zend_throw_error(NULL, "Cannot access %s property %s::$%s", zend_visibility_string(property_info->flags), ZSTR_VAL(ce->name), ZSTR_VAL(member));
+	}
 }
 /* }}} */
 

Zend/zend_vm_def.h

@@ -9825,6 +9825,13 @@ ZEND_VM_HANDLER(209, ZEND_INIT_PARENT_PROPERTY_HOOK_CALL, CONST, UNUSED|NUM, NUM
 		HANDLE_EXCEPTION();
 	}
 	if (prop_info->flags & ZEND_ACC_PRIVATE) {
+		// break here
+		if (prop_info->flags & ZEND_ACC_INNER_CLASS_REFERENCE) {
+			zend_throw_error(NULL, "Cannot access private inner class %s::%s", ZSTR_VAL(parent_ce->name), ZSTR_VAL(property_name));
+			UNDEF_RESULT();
+			HANDLE_EXCEPTION();
+		}
+
 		zend_throw_error(NULL, "Cannot access private property %s::$%s", ZSTR_VAL(parent_ce->name), ZSTR_VAL(property_name));
 		UNDEF_RESULT();
 		HANDLE_EXCEPTION();

Zend/zend_vm_execute.h

@@ -21,7 +21,7 @@ new Foo::Bar();
 --EXPECTF--
 Inner
 
-Fatal error: Uncaught Error: Cannot access private property Foo::$Bar in %s:%d
+Fatal error: Uncaught Error: Cannot access private inner class Foo::Bar in %s:%d
 Stack trace:
 #0 {main}
   thrown in %s on line %d