[RFC] Allow __debugInfo() on enums

Zend/tests/enum/debugInfo/backed_enum_value.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Enum with __debugInfo() magic method - backed enum value accessible
+--FILE--
+<?php
+
+enum Foo: string {
+	case Bar = "Baz";
+
+	public function __debugInfo() {
+		return [ __CLASS__ . '::' . $this->name . ' = ' . $this->value ];
+	}
+}
+
+var_dump(Foo::Bar);
+
+?>
+--EXPECTF--
+object(Foo)#%d (1) {
+  [0]=>
+  string(14) "Foo::Bar = Baz"
+}

Zend/tests/enum/debugInfo/magic_method.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Enum supports __debugInfo() magic method
+--FILE--
+<?php
+
+enum Foo {
+	case Bar;
+
+	public function __debugInfo() {
+		return [$this->name . ' is a case of the ' . __CLASS__ . ' enum'];
+	}
+}
+
+var_dump(Foo::Bar);
+
+?>
+--EXPECTF--
+object(Foo)#%d (1) {
+  [0]=>
+  string(29) "Bar is a case of the Foo enum"
+}

Zend/tests/enum/debugInfo/missing_magic.phpt

@@ -0,0 +1,14 @@
+--TEST--
+When an enum does not have __debugInfo() it is printed nicely
+--FILE--
+<?php
+
+enum Foo {
+	case Bar;
+}
+
+var_dump(Foo::Bar);
+
+?>
+--EXPECT--
+enum(Foo::Bar)

Zend/tests/enum/debugInfo/param_validation.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Enum with __debugInfo() magic method - param validation
+--FILE--
+<?php
+
+enum Foo {
+	case Bar;
+
+	public function __debugInfo(mixed $arg): array {
+		return [];
+	}
+}
+
+var_dump(Foo::Bar);
+
+?>
+--EXPECTF--
+Fatal error: Method Foo::__debugInfo() cannot take arguments in %s on line %d

Zend/tests/enum/debugInfo/return_validation.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Enum with __debugInfo() magic method - return validation
+--FILE--
+<?php
+
+enum Foo {
+	case Bar;
+
+	public function __debugInfo(): int {
+		return 5;
+	}
+}
+
+var_dump(Foo::Bar);
+
+?>
+--EXPECTF--
+Fatal error: Foo::__debugInfo(): Return type must be ?array when declared in %s on line %d

Zend/tests/enum/debugInfo/visibility_validation.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Enum with __debugInfo() magic method - visibility validation
+--FILE--
+<?php
+
+enum Foo {
+	case Bar;
+
+	private function __debugInfo(): array {
+		return [];
+	}
+}
+
+var_dump(Foo::Bar);
+
+?>
+--EXPECTF--
+Warning: The magic method Foo::__debugInfo() must have public visibility in %s on line %d
+object(Foo)#%d (0) {
+}

Zend/zend_enum.c

@@ -91,7 +91,7 @@ static void zend_verify_enum_properties(const zend_class_entry *ce)
 
 static void zend_verify_enum_magic_methods(const zend_class_entry *ce)
 {
-	// Only __get, __call and __invoke are allowed
+	// Only __get, __call, __debugInfo and __invoke are allowed
 
 	ZEND_ENUM_DISALLOW_MAGIC_METHOD(constructor, "__construct");
 	ZEND_ENUM_DISALLOW_MAGIC_METHOD(destructor, "__destruct");
@@ -101,7 +101,6 @@ static void zend_verify_enum_magic_methods(const zend_class_entry *ce)
 	ZEND_ENUM_DISALLOW_MAGIC_METHOD(__unset, "__unset");
 	ZEND_ENUM_DISALLOW_MAGIC_METHOD(__isset, "__isset");
 	ZEND_ENUM_DISALLOW_MAGIC_METHOD(__tostring, "__toString");
-	ZEND_ENUM_DISALLOW_MAGIC_METHOD(__debugInfo, "__debugInfo");
 	ZEND_ENUM_DISALLOW_MAGIC_METHOD(__serialize, "__serialize");
 	ZEND_ENUM_DISALLOW_MAGIC_METHOD(__unserialize, "__unserialize");
 

ext/standard/var.c

@@ -168,7 +168,7 @@ PHPAPI void php_var_dump(zval *struc, int level) /* {{{ */
 			break;
 		case IS_OBJECT: {
 			zend_class_entry *ce = Z_OBJCE_P(struc);
-			if (ce->ce_flags & ZEND_ACC_ENUM) {
+			if (ce->ce_flags & ZEND_ACC_ENUM && ce->__debugInfo == NULL) {
 				zval *case_name_zval = zend_enum_fetch_case_name(Z_OBJ_P(struc));
 				php_printf("%senum(%s::%s)\n", COMMON, ZSTR_VAL(ce->name), Z_STRVAL_P(case_name_zval));
 				return;