Add support for readonly classes

Zend/tests/readonly_classes/readonly_class_duplicated_modifier.phpt

@@ -0,0 +1,12 @@
+--TEST--
+The readonly class modifier can only be added once
+--FILE--
+<?php
+
+readonly readonly class Foo
+{
+}
+
+?>
+--EXPECTF--
+Fatal error: Multiple readonly modifiers are not allowed in %s on line %d

Zend/tests/readonly_classes/readonly_class_dynamic_property.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Readonly classes cannot use dynamic properties
+--FILE--
+<?php
+
+readonly class Foo
+{
+}
+
+$foo = new Foo();
+
+try {
+    $foo->bar = 1;
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+?>
+--EXPECT--
+Cannot create dynamic property Foo::$bar

Zend/tests/readonly_classes/readonly_class_dynamic_property_attribute.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Readonly classes cannot apply the #[AllowDynamicProperties] attribute
+--FILE--
+<?php
+
+#[AllowDynamicProperties]
+readonly class Foo
+{
+}
+
+?>
+--EXPECTF--
+Fatal error: Cannot apply #[AllowDynamicProperties] to readonly class Foo in %s on line %d

Zend/tests/readonly_classes/readonly_class_final_modifier.phpt

@@ -0,0 +1,16 @@
+--TEST--
+The readonly and final class modifiers can be defined in the same time
+--FILE--
+<?php
+
+final readonly class Foo
+{
+}
+
+readonly class Bar extends Foo
+{
+}
+
+?>
+--EXPECTF--
+Fatal error: Class Bar cannot extend final class Foo in %s on line %d

Zend/tests/readonly_classes/readonly_class_inheritance_error1.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Non-readonly class cannot extend a readonly class
+--FILE--
+<?php
+
+readonly class Foo
+{
+}
+
+class Bar extends Foo
+{
+}
+
+?>
+--EXPECTF--
+Fatal error: Non-readonly class Bar cannot extend readonly class Foo in %s on line %d

Zend/tests/readonly_classes/readonly_class_inheritance_error2.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Readonly class cannot extend a non-readonly class
+--FILE--
+<?php
+
+class Foo
+{
+}
+
+readonly class Bar extends Foo
+{
+}
+
+?>
+--EXPECTF--
+Fatal error: Readonly class Bar cannot extend non-readonly class Foo in %s on line %d

Zend/tests/readonly_classes/readonly_class_inheritance_success.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Readonly class can extend a readonly class
+--FILE--
+<?php
+
+readonly class Foo
+{
+}
+
+readonly class Bar extends Foo
+{
+}
+
+?>
+--EXPECT--

Zend/tests/readonly_classes/readonly_class_missing_type1.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Normal properties of a readonly class must have type
+--FILE--
+<?php
+
+readonly class Foo
+{
+    public $bar;
+}
+
+?>
+--EXPECTF--
+Fatal error: Readonly property Foo::$bar must have type in %s on line %d

Zend/tests/readonly_classes/readonly_class_missing_type2.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Promoted properties of a readonly class must have type
+--FILE--
+<?php
+
+readonly class Foo
+{
+    public function __construct(
+        private $bar
+    ) {}
+}
+
+?>
+--EXPECTF--
+Fatal error: Readonly property Foo::$bar must have type in %s on line %d

Zend/tests/readonly_classes/readonly_class_property1.phpt

@@ -0,0 +1,25 @@
+--TEST--
+Normal properties of a readonly class are implicitly declared as readonly
+--FILE--
+<?php
+
+readonly class Foo
+{
+    public int $bar;
+
+    public function __construct() {
+        $this->bar = 1;
+    }
+}
+
+$foo = new Foo();
+
+try {
+    $foo->bar = 2;
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+?>
+--EXPECT--
+Cannot modify readonly property Foo::$bar

Zend/tests/readonly_classes/readonly_class_property2.phpt

@@ -0,0 +1,23 @@
+--TEST--
+Promoted properties of a readonly class are implicitly declared as readonly
+--FILE--
+<?php
+
+readonly class Foo
+{
+    public function __construct(
+        public int $bar
+    ) {}
+}
+
+$foo = new Foo(1);
+
+try {
+    $foo->bar = 2;
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+
+?>
+--EXPECT--
+Cannot modify readonly property Foo::$bar

Zend/tests/readonly_classes/readonly_class_property3.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Declaring static property for a readonly class is forbidden
+--FILE--
+<?php
+
+readonly class Foo
+{
+    public static int $bar;
+}
+
+?>
+--EXPECTF--
+Fatal error: Readonly class Foo cannot declare static properties in %s on line %d

Zend/tests/readonly_classes/readonly_enum.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Enums cannot be readonly
+--FILE--
+<?php
+
+readonly enum Foo
+{
+}
+
+?>
+--EXPECTF--
+Parse error: syntax error, unexpected token "enum", expecting "abstract" or "final" or "readonly" or "class" in %s on line %d

Zend/tests/readonly_classes/readonly_interface.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Interfaces cannot be readonly
+--FILE--
+<?php
+
+readonly interface Foo
+{
+}
+
+?>
+--EXPECTF--
+Parse error: syntax error, unexpected token "interface", expecting "abstract" or "final" or "readonly" or "class" in %s on line %d

Zend/tests/readonly_classes/readonly_trait.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Traits cannot be readonly
+--FILE--
+<?php
+
+readonly trait Foo
+{
+}
+
+?>
+--EXPECTF--
+Parse error: syntax error, unexpected token "trait", expecting "abstract" or "final" or "readonly" or "class" in %s on line %d

Zend/zend_ast.c

@@ -1715,6 +1715,9 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 				if (decl->flags & ZEND_ACC_FINAL) {
 					smart_str_appends(str, "final ");
 				}
+				if (decl->flags & ZEND_ACC_READONLY_CLASS) {
+					smart_str_appends(str, "readonly ");
+				}
 				smart_str_appends(str, "class ");
 			}
 			smart_str_appendl(str, ZSTR_VAL(decl->name), ZSTR_LEN(decl->name));

Zend/zend_attributes.c

@@ -71,6 +71,11 @@ static void validate_allow_dynamic_properties(
 	if (scope->ce_flags & ZEND_ACC_INTERFACE) {
 		zend_error_noreturn(E_ERROR, "Cannot apply #[AllowDynamicProperties] to interface");
 	}
+	if (scope->ce_flags & ZEND_ACC_READONLY_CLASS) {
+		zend_error_noreturn(E_ERROR, "Cannot apply #[AllowDynamicProperties] to readonly class %s",
+			ZSTR_VAL(scope->name)
+		);
+	}
 	scope->ce_flags |= ZEND_ACC_ALLOW_DYNAMIC_PROPERTIES;
 }
 

Zend/zend_compile.c

@@ -797,6 +797,10 @@ uint32_t zend_add_class_modifier(uint32_t flags, uint32_t new_flag) /* {{{ */
 		zend_throw_exception(zend_ce_compile_error, "Multiple final modifiers are not allowed", 0);
 		return 0;
 	}
+	if ((flags & ZEND_ACC_READONLY_CLASS) && (new_flag & ZEND_ACC_READONLY_CLASS)) {
+		zend_throw_exception(zend_ce_compile_error, "Multiple readonly modifiers are not allowed", 0);
+		return 0;
+	}
 	if ((new_flags & ZEND_ACC_EXPLICIT_ABSTRACT_CLASS) && (new_flags & ZEND_ACC_FINAL)) {
 		zend_throw_exception(zend_ce_compile_error,
 			"Cannot use the final modifier on an abstract class", 0);
@@ -6673,6 +6677,7 @@ static void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast, uint32
 		if (property_flags) {
 			zend_op_array *op_array = CG(active_op_array);
 			zend_class_entry *scope = op_array->scope;
+
 			bool is_ctor =
 				scope && zend_is_constructor(op_array->function_name);
 			if (!is_ctor) {
@@ -6699,6 +6704,10 @@ static void zend_compile_params(zend_ast *ast, zend_ast *return_type_ast, uint32
 					ZSTR_VAL(scope->name), ZSTR_VAL(name), ZSTR_VAL(str));
 			}
 
+			if (!(property_flags & ZEND_ACC_READONLY) && (scope->ce_flags & ZEND_ACC_READONLY_CLASS)) {
+				property_flags |= ZEND_ACC_READONLY;
+			}
+
 			/* Recompile the type, as it has different memory management requirements. */
 			zend_type type = ZEND_TYPE_INIT_NONE(0);
 			if (type_ast) {
@@ -7241,6 +7250,12 @@ static void zend_compile_prop_decl(zend_ast *ast, zend_ast *type_ast, uint32_t f
 		zend_error_noreturn(E_COMPILE_ERROR, "Properties cannot be declared abstract");
 	}
 
+	if ((ce->ce_flags & ZEND_ACC_READONLY_CLASS) && (flags & ZEND_ACC_STATIC)) {
+		zend_error_noreturn(E_COMPILE_ERROR, "Readonly class %s cannot declare static properties",
+			ZSTR_VAL(ce->name)
+		);
+	}
+
 	for (i = 0; i < children; ++i) {
 		zend_property_info *info;
 		zend_ast *prop_ast = list->child[i];
@@ -7306,6 +7321,10 @@ static void zend_compile_prop_decl(zend_ast *ast, zend_ast *type_ast, uint32_t f
 			ZVAL_UNDEF(&value_zv);
 		}
 
+		if ((ce->ce_flags & ZEND_ACC_READONLY_CLASS)) {
+			flags |= ZEND_ACC_READONLY;
+		}
+
 		if (flags & ZEND_ACC_READONLY) {
 			if (!ZEND_TYPE_IS_SET(type)) {
 				zend_error_noreturn(E_COMPILE_ERROR, "Readonly property %s::$%s must have type",

Zend/zend_compile.h

@@ -240,7 +240,7 @@ typedef struct _zend_oparray_context {
 /* or IS_CONSTANT_VISITED_MARK                            |     |     |     */
 #define ZEND_CLASS_CONST_IS_CASE         (1 << 6)  /*     |     |     |  X  */
 /*                                                        |     |     |     */
-/* Class Flags (unused: 16,21,30,31)                      |     |     |     */
+/* Class Flags (unused: 21,30,31)                         |     |     |     */
 /* ===========                                            |     |     |     */
 /*                                                        |     |     |     */
 /* Special class types                                    |     |     |     */
@@ -273,6 +273,9 @@ typedef struct _zend_oparray_context {
 /* without triggering a deprecation warning               |     |     |     */
 #define ZEND_ACC_ALLOW_DYNAMIC_PROPERTIES (1 << 15) /* X  |     |     |     */
 /*                                                        |     |     |     */
+/* Readonly class                                         |     |     |     */
+#define ZEND_ACC_READONLY_CLASS          (1 << 16) /*  X  |     |     |     */
+/*                                                        |     |     |     */
 /* Parent class is resolved (CE).                         |     |     |     */
 #define ZEND_ACC_RESOLVED_PARENT         (1 << 17) /*  X  |     |     |     */
 /*                                                        |     |     |     */

Zend/zend_inheritance.c

@@ -1430,6 +1430,13 @@ ZEND_API void zend_do_inheritance_ex(zend_class_entry *ce, zend_class_entry *par
 		}
 	}
 
+	if (UNEXPECTED((ce->ce_flags & ZEND_ACC_READONLY_CLASS) != (parent_ce->ce_flags & ZEND_ACC_READONLY_CLASS))) {
+		zend_error_noreturn(E_COMPILE_ERROR, "%s class %s cannot extend %s class %s",
+			ce->ce_flags & ZEND_ACC_READONLY_CLASS ? "Readonly" : "Non-readonly", ZSTR_VAL(ce->name),
+			parent_ce->ce_flags & ZEND_ACC_READONLY_CLASS ? "readonly" : "non-readonly", ZSTR_VAL(parent_ce->name)
+		);
+	}
+
 	if (ce->parent_name) {
 		zend_string_release_ex(ce->parent_name, 0);
 	}

Zend/zend_language_parser.y

@@ -595,6 +595,7 @@ class_modifiers:
 class_modifier:
 		T_ABSTRACT 		{ $$ = ZEND_ACC_EXPLICIT_ABSTRACT_CLASS; }
 	|	T_FINAL 		{ $$ = ZEND_ACC_FINAL; }
+	|	T_READONLY 		{ $$ = ZEND_ACC_READONLY_CLASS|ZEND_ACC_NO_DYNAMIC_PROPERTIES; }
 ;
 
 trait_declaration_statement:

build/gen_stub.php

@@ -1797,6 +1797,10 @@ private function getFlagsAsString(): string
             $flags[] = "ZEND_ACC_ABSTRACT";
         }
 
+        if ($this->flags & Class_::MODIFIER_READONLY) {
+            $flags[] = "ZEND_ACC_READONLY_CLASS";
+        }
+
         if ($this->isDeprecated) {
             $flags[] = "ZEND_ACC_DEPRECATED";
         }