Add a ZEND_UNCOMPARABLE value

To explicitly indicate that objects are uncomparable. For now
this has no functional difference from the usual 1 return value,
but makes intent clearer.

Zend/zend_object_handlers.c

@@ -1617,7 +1617,7 @@ ZEND_API int zend_std_compare_objects(zval *o1, zval *o2) /* {{{ */
 				return ret;
 			}
 		}
-		return 1;
+		return ZEND_UNCOMPARABLE;
 	}
 
 	zobj1 = Z_OBJ_P(o1);
@@ -1627,7 +1627,7 @@ ZEND_API int zend_std_compare_objects(zval *o1, zval *o2) /* {{{ */
 		return 0; /* the same object */
 	}
 	if (zobj1->ce != zobj2->ce) {
-		return 1; /* different classes */
+		return ZEND_UNCOMPARABLE; /* different classes */
 	}
 	if (!zobj1->properties && !zobj2->properties) {
 		zend_property_info *info;

Zend/zend_operators.h

@@ -401,6 +401,12 @@ again:
 	return result;
 }
 
+/* Indicate that two values cannot be compared. This value should be returned for both orderings
+ * of the operands. This implies that all of ==, <, <= and >, >= will return false, because we
+ * canonicalize >/>= to </<= with swapped operands. */
+// TODO: Use a different value to allow an actual distinction here.
+#define ZEND_UNCOMPARABLE 1
+
 ZEND_API int ZEND_FASTCALL zend_compare(zval *op1, zval *op2);
 
 ZEND_API int ZEND_FASTCALL compare_function(zval *result, zval *op1, zval *op2);

ext/date/php_date.c

@@ -1903,7 +1903,7 @@ static int date_object_compare_date(zval *d1, zval *d2) /* {{{ */
 
 	if (!o1->time || !o2->time) {
 		php_error_docref(NULL, E_WARNING, "Trying to compare an incomplete DateTime or DateTimeImmutable object");
-		return 1;
+		return ZEND_UNCOMPARABLE;
 	}
 	if (!o1->time->sse_uptodate) {
 		timelib_update_ts(o1->time, o1->time->tz_info);
@@ -2040,7 +2040,7 @@ static int date_object_compare_timezone(zval *tz1, zval *tz2) /* {{{ */
 
 	if (o1->type != o2->type) {
 		php_error_docref(NULL, E_WARNING, "Trying to compare different kinds of DateTimeZone objects");
-		return 1;
+		return ZEND_UNCOMPARABLE;
 	}
 
 	switch (o1->type) {
@@ -3901,7 +3901,7 @@ static int date_interval_compare_objects(zval *o1, zval *o2) {
 	 * smaller, equal or greater depending on the point in time at which the interval starts. As
 	 * such, we treat DateInterval objects are non-comparable and emit a warning. */
 	zend_error(E_WARNING, "Cannot compare DateInterval objects");
-	return 1;
+	return ZEND_UNCOMPARABLE;
 }
 
 /* {{{ date_interval_read_property */

ext/intl/breakiterator/breakiterator_class.cpp

@@ -84,9 +84,6 @@ static int BreakIterator_compare_objects(zval *object1,
 							*bio2;
 
 	ZEND_COMPARE_OBJECTS_FALLBACK(object1, object2);
-	if (Z_TYPE_P(object1) != Z_TYPE_P(object2)) {
-		return 1; /* object and non-object */
-	}
 
 	bio1 = Z_INTL_BREAKITERATOR_P(object1);
 	bio2 = Z_INTL_BREAKITERATOR_P(object2);

ext/intl/timezone/timezone_class.cpp

@@ -285,7 +285,7 @@ static int TimeZone_compare_objects(zval *object1, zval *object2)
 		}
 	}
 
-	return 1;
+	return ZEND_UNCOMPARABLE;
 }
 /* }}} */
 

ext/pdo/pdo_dbh.c

@@ -1298,7 +1298,7 @@ out:
 
 static int dbh_compare(zval *object1, zval *object2)
 {
-	return -1;
+	return ZEND_UNCOMPARABLE;
 }
 
 static HashTable *dbh_get_gc(zend_object *object, zval **gc_data, int *gc_count)

ext/pdo/pdo_stmt.c

@@ -2165,7 +2165,7 @@ out:
 
 static int dbstmt_compare(zval *object1, zval *object2)
 {
-	return -1;
+	return ZEND_UNCOMPARABLE;
 }
 
 zend_object_handlers pdo_dbstmt_object_handlers;
@@ -2585,7 +2585,7 @@ static zend_string *row_get_classname(const zend_object *object)
 
 static int row_compare(zval *object1, zval *object2)
 {
-	return -1;
+	return ZEND_UNCOMPARABLE;
 }
 
 void pdo_row_free_storage(zend_object *std)

ext/simplexml/simplexml.c

@@ -1297,10 +1297,10 @@ static int sxe_objects_compare(zval *object1, zval *object2) /* {{{ */
 		} else if (sxe1->document->ptr == sxe2->document->ptr) {
 			return 0;
 		}
+		return 1;
 	} else {
 		return !(sxe1->node == sxe2->node);
 	}
-	return 1;
 }
 /* }}} */
 

ext/spl/spl_observer.c

@@ -345,7 +345,7 @@ static int spl_object_storage_compare_objects(zval *o1, zval *o2) /* {{{ */
 	zo2 = (zend_object *)Z_OBJ_P(o2);
 
 	if (zo1->ce != spl_ce_SplObjectStorage || zo2->ce != spl_ce_SplObjectStorage) {
-		return 1;
+		return ZEND_UNCOMPARABLE;
 	}
 
 	return zend_hash_compare(&(Z_SPLOBJSTORAGE_P(o1))->storage, &(Z_SPLOBJSTORAGE_P(o2))->storage, (compare_func_t)spl_object_storage_compare_info, 0);