Don't use custom object handlers for enum properties

Instead mark name/value as readonly and the class as
NO_DYNAMIC_PROPERTIES. This gives us the desired limitations
using native features.

In fact, this also fixes a bug where opcache cache slot merging
might result in a write to the name/value properties being
allowed. The readonly implementation handles this case correctly.

Author: nikic

Zend/tests/enum/no-dynamic-properties.phpt

@@ -17,4 +17,4 @@ try {
 
 ?>
 --EXPECT--
-Enum properties are immutable
+Cannot create dynamic property Foo::$baz

Zend/tests/enum/no-pass-properties-by-ref.phpt

@@ -22,5 +22,5 @@ var_dump(Foo::Bar->value);
 
 ?>
 --EXPECT--
-Cannot acquire reference to property Foo::$value
+Cannot modify readonly property Foo::$value
 int(0)

Zend/tests/enum/no-return-properties-by-ref.phpt

@@ -23,5 +23,5 @@ var_dump(Foo::Bar->value);
 
 ?>
 --EXPECT--
-Cannot acquire reference to property Foo::$value
+Cannot modify readonly property Foo::$value
 int(0)

Zend/tests/enum/no-unset-propertes.phpt

@@ -32,6 +32,6 @@ try {
 
 ?>
 --EXPECT--
-Enum properties are immutable
-Enum properties are immutable
-Enum properties are immutable
+Cannot unset readonly property Foo::$name
+Cannot unset readonly property IntFoo::$name
+Cannot unset readonly property IntFoo::$value

Zend/tests/enum/no-write-properties-cache-slot.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Readonly enum properties should not be writable via cache slot merging
+--FILE--
+<?php
+
+enum Test {
+    case A;
+
+    public function modify() {
+        // Cache slots for the read and write are merged.
+        var_dump($this->name);
+        $this->name = 'foobar';
+    }
+}
+
+try {
+    Test::A->modify();
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+var_dump(Test::A->name);
+
+?>
+--EXPECT--
+string(1) "A"
+Enum properties are immutable
+string(1) "A"

Zend/tests/enum/no-write-properties-through-foreach-reference.phpt

@@ -18,5 +18,5 @@ var_dump(Foo::Bar->value);
 
 ?>
 --EXPECT--
-Cannot acquire reference to property Foo::$value
+Cannot modify readonly property Foo::$value
 int(0)

Zend/tests/enum/no-write-properties-through-references.phpt

@@ -19,5 +19,5 @@ var_dump(Foo::Bar->value);
 
 ?>
 --EXPECT--
-Cannot acquire reference to property Foo::$value
+Cannot modify readonly property Foo::$value
 int(0)

Zend/tests/enum/no-write-properties.phpt

@@ -32,6 +32,6 @@ try {
 
 ?>
 --EXPECT--
-Enum properties are immutable
-Enum properties are immutable
-Enum properties are immutable
+Cannot modify readonly property Foo::$name
+Cannot modify readonly property Foo::$name
+Cannot create dynamic property Foo::$value

Zend/zend_enum.c

@@ -119,32 +119,6 @@ void zend_verify_enum(zend_class_entry *ce)
 	zend_verify_enum_interfaces(ce);
 }
 
-static zval *zend_enum_read_property(zend_object *zobj, zend_string *name, int type, void **cache_slot, zval *rv) /* {{{ */
-{
-	if (type == BP_VAR_W || type == BP_VAR_RW || type == BP_VAR_UNSET) {
-		zend_throw_error(NULL, "Cannot acquire reference to property %s::$%s", ZSTR_VAL(zobj->ce->name), ZSTR_VAL(name));
-		return &EG(uninitialized_zval);
-	}
-
-	return zend_std_read_property(zobj, name, type, cache_slot, rv);
-}
-
-static ZEND_COLD zval *zend_enum_write_property(zend_object *object, zend_string *member, zval *value, void **cache_slot)
-{
-	ZEND_ENUM_PROPERTY_ERROR();
-	return &EG(uninitialized_zval);
-}
-
-static ZEND_COLD void zend_enum_unset_property(zend_object *object, zend_string *member, void **cache_slot)
-{
-	ZEND_ENUM_PROPERTY_ERROR();
-}
-
-static zval *zend_enum_get_property_ptr_ptr(zend_object *zobj, zend_string *name, int type, void **cache_slot)
-{
-	return NULL;
-}
-
 static int zend_implement_unit_enum(zend_class_entry *interface, zend_class_entry *class_type)
 {
 	if (class_type->ce_flags & ZEND_ACC_ENUM) {
@@ -186,10 +160,6 @@ void zend_register_enum_ce(void)
 	zend_ce_backed_enum->interface_gets_implemented = zend_implement_backed_enum;
 
 	memcpy(&enum_handlers, &std_object_handlers, sizeof(zend_object_handlers));
-	enum_handlers.read_property = zend_enum_read_property;
-	enum_handlers.write_property = zend_enum_write_property;
-	enum_handlers.unset_property = zend_enum_unset_property;
-	enum_handlers.get_property_ptr_ptr = zend_enum_get_property_ptr_ptr;
 	enum_handlers.clone_obj = NULL;
 	enum_handlers.compare = zend_objects_not_comparable;
 }
@@ -359,16 +329,18 @@ void zend_enum_register_funcs(zend_class_entry *ce)
 
 void zend_enum_register_props(zend_class_entry *ce)
 {
+	ce->ce_flags |= ZEND_ACC_NO_DYNAMIC_PROPERTIES;
+
 	zval name_default_value;
 	ZVAL_UNDEF(&name_default_value);
 	zend_type name_type = ZEND_TYPE_INIT_CODE(IS_STRING, 0, 0);
-	zend_declare_typed_property(ce, ZSTR_KNOWN(ZEND_STR_NAME), &name_default_value, ZEND_ACC_PUBLIC, NULL, name_type);
+	zend_declare_typed_property(ce, ZSTR_KNOWN(ZEND_STR_NAME), &name_default_value, ZEND_ACC_PUBLIC | ZEND_ACC_READONLY, NULL, name_type);
 
 	if (ce->enum_backing_type != IS_UNDEF) {
 		zval value_default_value;
 		ZVAL_UNDEF(&value_default_value);
 		zend_type value_type = ZEND_TYPE_INIT_CODE(ce->enum_backing_type, 0, 0);
-		zend_declare_typed_property(ce, ZSTR_KNOWN(ZEND_STR_VALUE), &value_default_value, ZEND_ACC_PUBLIC, NULL, value_type);
+		zend_declare_typed_property(ce, ZSTR_KNOWN(ZEND_STR_VALUE), &value_default_value, ZEND_ACC_PUBLIC | ZEND_ACC_READONLY, NULL, value_type);
 	}
 }
 

ext/reflection/tests/ReflectionEnumUnitCase_getEnum.phpt

@@ -31,7 +31,7 @@ Class [ <user> final class Foo implements UnitEnum ] {
   }
 
   - Properties [1] {
-    Property [ public string $name ]
+    Property [ public readonly string $name ]
   }
 
   - Methods [0] {

ext/reflection/tests/ReflectionEnum_toString.phpt

@@ -31,7 +31,7 @@ Class [ <user> final class Foo implements UnitEnum ] {
   }
 
   - Properties [1] {
-    Property [ public string $name ]
+    Property [ public readonly string $name ]
   }
 
   - Methods [0] {

ext/reflection/tests/ReflectionProperty_setValue_readonly.phpt

@@ -19,5 +19,5 @@ var_dump(Foo::Bar->value);
 
 ?>
 --EXPECT--
-Enum properties are immutable
+Cannot modify readonly property Foo::$value
 int(0)