Added support for empty arg list. Added AST evaluation test case.

Author: kooldev

Zend/zend_language_parser.y

@@ -322,6 +322,8 @@ attribute_arguments:
 attribute_decl:
 		class_name_reference
 			{ $$ = zend_ast_create(ZEND_AST_ATTRIBUTE, $1, NULL); }
+	|	class_name_reference '(' ')'
+			{ $$ = zend_ast_create(ZEND_AST_ATTRIBUTE, $1, NULL); }
 	|	class_name_reference '(' attribute_arguments ')'
 			{ $$ = zend_ast_create(ZEND_AST_ATTRIBUTE, $1, $3); }
 ;

ext/reflection/tests/attributes/ast.phpt

@@ -0,0 +1,68 @@
+--TEST--
+Attributes can deal with AST nodes.
+--FILE--
+<?php
+
+define('V1', strtoupper(php_sapi_name()));
+
+<<A1([V1 => V1])>>
+class C1
+{
+	public const BAR = 'bar';
+}
+
+$ref = new \ReflectionClass(C1::class);
+$attr = $ref->getAttributes();
+var_dump(count($attr));
+
+$args = $attr[0]->getArguments();
+var_dump(count($args), $args[0][V1] === V1);
+
+echo "\n";
+
+<<A1(V1, 1 + 2, C1::class)>>
+class C2 { }
+
+$ref = new \ReflectionClass(C2::class);
+$attr = $ref->getAttributes();
+var_dump(count($attr));
+
+$args = $attr[0]->getArguments();
+var_dump(count($args));
+var_dump($args[0] === V1);
+var_dump($args[1] === 3);
+var_dump($args[2] === C1::class);
+
+echo "\n";
+
+<<A1(self::FOO, C1::BAR)>>
+class C3
+{
+	private const FOO = 'foo';
+}
+
+$ref = new \ReflectionClass(C3::class);
+$attr = $ref->getAttributes();
+var_dump(count($attr));
+
+$args = $attr[0]->getArguments();
+var_dump(count($args));
+var_dump($args[0] === 'foo');
+var_dump($args[1] === C1::BAR);
+
+?>
+--EXPECT--
+int(1)
+int(1)
+bool(true)
+
+int(1)
+int(3)
+bool(true)
+bool(true)
+bool(true)
+
+int(1)
+int(2)
+bool(true)
+bool(true)