Implement object type annotation

RFC: https://wiki.php.net/rfc/object-typehint

Author: brzuchal

NEWS

@@ -8,6 +8,7 @@ PHP                                                                        NEWS
   . Fixed bug #74761 (Unary operator expected error on some systems). (petk)
   . Allow loading PHP/Zend extensions by name in ini files (extension=<name>).
     (francois at tekwire dot net)
+  . Added object type annotation. (brzuchal)
 
 - OpenSSL:
   . Fixed bug #74798 (pkcs7_en/decrypt does not work if \x0a is used in content).

UPGRADING

@@ -41,6 +41,7 @@ PHP 7.2 UPGRADE NOTES
   . Minimum supported Windows versions are Windows 7/Server 2008 R2.
   . Initial trait property value compatibility check will no longer perform
     any casts. (Bug #74269)
+  . "object" (in any case) can no longer be used as a class name.
 
 - BCMath:
   . The bcmod() function no longer truncates fractional numbers to integers. As
@@ -101,6 +102,8 @@ PHP 7.2 UPGRADE NOTES
     (https://wiki.php.net/rfc/allow-abstract-function-override)
   . A trailing comma in group use statements is now allowed.
     (https://wiki.php.net/rfc/list-syntax-trailing-commas)
+  . The "object" type annotation is now supported.
+    (https://wiki.php.net/rfc/object-typehint)
 
 - DBA:
   . Implemented support for the LMDB backend.

Zend/tests/bug26698.phpt

@@ -5,7 +5,7 @@ Bug #26698 (Thrown exceptions while evaluting argument to pass as parameter cras
 
 ini_set("report_memleaks", 0);  // the exception thrown in this test results in a memory leak, which is fine
 
-class Object
+class ObjectOne
 {
 	function getNone()
 	{
@@ -23,7 +23,7 @@ class Proxy
 	{
 		try
 		{
-			$res = new Object();
+			$res = new ObjectOne();
 			$this->three($res->getNone());
 		}
 		catch(Exception $e)
@@ -36,7 +36,7 @@ class Proxy
 	{
 		try
 		{
-			$res = new Object();
+			$res = new ObjectOne();
 			$this->three(1, $res->getNone());
 		}
 		catch(Exception $e)
@@ -49,7 +49,7 @@ class Proxy
 	{
 		try
 		{
-			$res = new Object();
+			$res = new ObjectOne();
 			$this->three(1, 2, $res->getNone());
 		}
 		catch(Exception $e)

Zend/tests/bug28444.phpt

@@ -9,7 +9,7 @@ function my_error_handler($errno, $errstr, $errfile, $errline) {
 
 set_error_handler('my_error_handler');
 
-class Object
+class ObjectOne
 {
 	public $x;
 
@@ -26,7 +26,7 @@ class Overloaded
 
 	function __construct($x)
 	{
-		$this->x = new Object($x);
+		$this->x = new ObjectOne($x);
 	}
 
 	function __get($prop)
@@ -47,7 +47,7 @@ var_dump($y->x->x);
 var_dump($y->x->x = 3);
 var_dump($y->y = 3);
 var_dump($y->y);
-var_dump($y->z = new Object(4));
+var_dump($y->z = new ObjectOne(4));
 var_dump($y->z->x);
 $t = $y->z;
 var_dump($t->x = 5);
@@ -56,7 +56,7 @@ var_dump($y->z->x = 6);
 ?>
 ===DONE===
 --EXPECTF--
-object(Object)#%d (1) {
+object(ObjectOne)#%d (1) {
   ["x"]=>
   int(2)
 }
@@ -66,9 +66,9 @@ Overloaded::__set(y,3)
 int(3)
 Overloaded::__get(y)
 int(3)
-string(55) "Object of class Object could not be converted to string"
+string(58) "Object of class ObjectOne could not be converted to string"
 Overloaded::__set(z,)
-object(Object)#%d (1) {
+object(ObjectOne)#%d (1) {
   ["x"]=>
   int(4)
 }

Zend/tests/bug60598.phpt

@@ -6,7 +6,7 @@ define('OBJECT_COUNT', 10000);
 
 $containers = array();
 
-class Object {
+class ObjectOne {
     protected $_guid = 0;
     public function __construct() {
 		global $containers;
@@ -20,7 +20,7 @@ class Object {
 }
 
 for ($i = 0; $i < OBJECT_COUNT; ++$i) {
-    new Object();
+    new ObjectOne();
 }
 
 // You probably won't see this because of the "zend_mm_heap corrupted"

Zend/tests/object_types/invalid_default_value.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Object type can only default to null
+--FILE--
+<?php
+
+function test(object $obj = 42) { }
+
+?>
+--EXPECTF--
+Fatal error: Default value for parameters with a object type can only be NULL in %s on line %d

Zend/tests/object_types/missing_return_type_inheritance_in_class.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Missing class method a object return type during inheritance
+--FILE--
+<?php
+
+class One {
+    public function a() : object {}
+}
+
+class Two extends One {
+    public function a() {}
+}
+
+--EXPECTF--
+Fatal error: Declaration of Two::a() must be compatible with One::a(): object in %s on line 9

Zend/tests/object_types/missing_return_type_inheritance_in_interface.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Missing interface method a object return type during inheritance
+--FILE--
+<?php
+
+interface One {
+    public function a() : object;
+}
+
+interface Two extends One {
+    public function a();
+}
+
+--EXPECTF--
+Fatal error: Declaration of Two::a() must be compatible with One::a(): object in %s on line %d

Zend/tests/object_types/return_type_in_class.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Adding a class method object return type
+--FILE--
+<?php
+
+interface One {
+    public function a() : object;
+}
+
+class Two implements One {
+    public function a() : object {}
+}
+
+$three = new class extends Two {
+    public function a() : object {
+        return 12345;
+    }
+};
+$three->a();
+--EXPECTF--
+
+Fatal error: Uncaught TypeError: Return value of class@anonymous::a() must be an object, integer returned in %s:13
+Stack trace:
+#0 %s(16): class@anonymous->a()
+#1 {main}
+  thrown in %s on line 13

Zend/tests/object_types/return_type_in_function.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Adding a function object return type
+--FILE--
+<?php
+
+function a() : object {
+	return 12345;
+}
+a();
+--EXPECTF--
+
+Fatal error: Uncaught TypeError: Return value of a() must be an object, integer returned in %s:4
+Stack trace:
+#0 %s(6): a()
+#1 {main}
+  thrown in %s on line 4