Use zend_std_build_properties() to access zend_object.properties

The zend_object.properties HashTable needs to be built just in time by calling
rebuild_object_properties() on the object before accessing it. Normally this is
done automatically in zend_std_get_properties(), but we do it manually in a few
places.

In this change I introduce an inline variant of zend_std_build_properties(), and
refactor these places to use it instead of calling rebuild_object_properties()
manually.

rebuild_object_properties() renamed as rebuild_object_properties_internal(), to
enforce usage of zend_std_get_properties() or zend_std_build_properties_ex().

Closes phpGH-14996

Author: arnaud-lb

UPGRADING.INTERNALS

@@ -94,6 +94,11 @@ PHP 8.4 INTERNALS UPGRADE NOTES
 
 * Added zend_hash_get_current_pos_ex() variant of zend_hash_get_current_pos().
 
+* Renamed rebuild_object_properties() to rebuild_object_properties_internal().
+  This function should not be used outside of zend_std_get_properties_ex() and
+  zend_std_get_properties(). Use zend_std_get_properties_ex() or
+  zend_std_get_properties() instead.
+
 ========================
 2. Build system changes
 ========================

Zend/zend_API.c

@@ -31,6 +31,7 @@
 #include "zend_inheritance.h"
 #include "zend_ini.h"
 #include "zend_enum.h"
+#include "zend_object_handlers.h"
 #include "zend_observer.h"
 
 #include <stdarg.h>
@@ -1764,10 +1765,7 @@ ZEND_API void object_properties_load(zend_object *object, HashTable *properties)
 						ZSTR_VAL(object->ce->name), property_info != ZEND_WRONG_PROPERTY_INFO ? zend_get_unmangled_property_name(key): "");
 				}
 
-				if (!object->properties) {
-					rebuild_object_properties(object);
-				}
-				prop = zend_hash_update(object->properties, key, prop);
+				prop = zend_hash_update(zend_std_get_properties_ex(object), key, prop);
 				zval_add_ref(prop);
 			}
 		} else {
@@ -1779,10 +1777,7 @@ ZEND_API void object_properties_load(zend_object *object, HashTable *properties)
 					ZSTR_VAL(object->ce->name), h);
 			}
 
-			if (!object->properties) {
-				rebuild_object_properties(object);
-			}
-			prop = zend_hash_index_update(object->properties, h, prop);
+			prop = zend_hash_index_update(zend_std_get_properties_ex(object), h, prop);
 			zval_add_ref(prop);
 		}
 	} ZEND_HASH_FOREACH_END();

Zend/zend_object_handlers.c

@@ -62,7 +62,7 @@
   called, we cal __call handler.
 */
 
-ZEND_API void rebuild_object_properties(zend_object *zobj) /* {{{ */
+ZEND_API void rebuild_object_properties_internal(zend_object *zobj) /* {{{ */
 {
 	if (!zobj->properties) {
 		zend_property_info *prop_info;
@@ -130,7 +130,7 @@ ZEND_API HashTable *zend_std_build_object_properties_array(zend_object *zobj) /*
 ZEND_API HashTable *zend_std_get_properties(zend_object *zobj) /* {{{ */
 {
 	if (!zobj->properties) {
-		rebuild_object_properties(zobj);
+		rebuild_object_properties_internal(zobj);
 	}
 	return zobj->properties;
 }
@@ -1124,10 +1124,7 @@ found:;
 			}
 
 			Z_TRY_ADDREF_P(value);
-			if (!zobj->properties) {
-				rebuild_object_properties(zobj);
-			}
-			variable_ptr = zend_hash_add_new(zobj->properties, name, value);
+			variable_ptr = zend_hash_add_new(zend_std_get_properties_ex(zobj), name, value);
 		}
 	}
 
@@ -1312,7 +1309,7 @@ ZEND_API zval *zend_std_get_property_ptr_ptr(zend_object *zobj, zend_string *nam
 				}
 			}
 			if (UNEXPECTED(!zobj->properties)) {
-				rebuild_object_properties(zobj);
+				rebuild_object_properties_internal(zobj);
 			}
 			if (UNEXPECTED(type == BP_VAR_RW || type == BP_VAR_R)) {
 				zend_error(E_WARNING, "Undefined property: %s::$%s", ZSTR_VAL(zobj->ce->name), ZSTR_VAL(name));
@@ -2028,13 +2025,9 @@ ZEND_API int zend_std_compare_objects(zval *o1, zval *o2) /* {{{ */
 		Z_UNPROTECT_RECURSION_P(o1);
 		return 0;
 	} else {
-		if (!zobj1->properties) {
-			rebuild_object_properties(zobj1);
-		}
-		if (!zobj2->properties) {
-			rebuild_object_properties(zobj2);
-		}
-		return zend_compare_symbol_tables(zobj1->properties, zobj2->properties);
+		return zend_compare_symbol_tables(
+				zend_std_get_properties_ex(zobj1),
+				zend_std_get_properties_ex(zobj2));
 	}
 }
 /* }}} */

Zend/zend_object_handlers.h

@@ -267,7 +267,16 @@ ZEND_API zend_function *zend_std_get_method(zend_object **obj_ptr, zend_string *
 ZEND_API zend_string *zend_std_get_class_name(const zend_object *zobj);
 ZEND_API int zend_std_compare_objects(zval *o1, zval *o2);
 ZEND_API zend_result zend_std_get_closure(zend_object *obj, zend_class_entry **ce_ptr, zend_function **fptr_ptr, zend_object **obj_ptr, bool check_only);
-ZEND_API void rebuild_object_properties(zend_object *zobj);
+/* Use zend_std_get_properties_ex() */
+ZEND_API void rebuild_object_properties_internal(zend_object *zobj);
+
+static inline HashTable *zend_std_get_properties_ex(zend_object *object)
+{
+	if (!object->properties) {
+		rebuild_object_properties_internal(object);
+	}
+	return object->properties;
+}
 
 ZEND_API HashTable *zend_std_build_object_properties_array(zend_object *zobj);
 

Zend/zend_vm_def.h

@@ -2495,9 +2495,6 @@ ZEND_VM_C_LABEL(fast_assign_obj):
 				}
 
 				if (!zobj->ce->__set && (zobj->ce->ce_flags & ZEND_ACC_ALLOW_DYNAMIC_PROPERTIES)) {
-					if (EXPECTED(zobj->properties == NULL)) {
-						rebuild_object_properties(zobj);
-					}
 					if (OP_DATA_TYPE == IS_CONST) {
 						if (UNEXPECTED(Z_OPT_REFCOUNTED_P(value))) {
 							Z_ADDREF_P(value);
@@ -2521,8 +2518,8 @@ ZEND_VM_C_LABEL(fast_assign_obj):
 						} else if (OP_DATA_TYPE == IS_CV) {
 							Z_TRY_ADDREF_P(value);
 						}
-						}
-					zend_hash_add_new(zobj->properties, name, value);
+					}
+					zend_hash_add_new(zend_std_get_properties_ex(zobj), name, value);
 					if (UNEXPECTED(RETURN_VALUE_USED(opline))) {
 						ZVAL_COPY(EX_VAR(opline->result.var), value);
 					}