Treat attribute argument lists like normal argument lists

Allow trailing comma. Syntactically allow unpacking, but forbid it
during compilation.

The trailing comma test-case is adopted from GH-5796.

Author: nikic

Zend/tests/attributes/026_unpack_in_args.phpt

@@ -0,0 +1,11 @@
+--TEST--
+Cannot use unpacking in attribute argument list
+--FILE--
+<?php
+
+<<MyAttribute(...[1, 2, 3])>>
+class Foo { }
+
+?>
+--EXPECTF--
+Fatal error: Cannot use unpacking in attribute argument list in %s on line %d

Zend/tests/attributes/027_trailing_comma_args.phpt

@@ -0,0 +1,30 @@
+--TEST--
+Trailing comma in attribute argument list
+--FILE--
+<?php
+
+<<MyAttribute(
+	"there",
+	"are",
+	"many",
+	"arguments",
+)>>
+class Foo { }
+
+$ref = new \ReflectionClass(Foo::class);
+$attr = $ref->getAttributes()[0];
+var_dump($attr->getName(), $attr->getArguments());
+
+?>
+--EXPECT--
+string(11) "MyAttribute"
+array(4) {
+  [0]=>
+  string(5) "there"
+  [1]=>
+  string(3) "are"
+  [2]=>
+  string(4) "many"
+  [3]=>
+  string(9) "arguments"
+}

Zend/tests/varSyntax/globalNonSimpleVariableError.phpt

@@ -7,4 +7,4 @@ global $$foo->bar;
 
 ?>
 --EXPECTF--
-Parse error: syntax error, unexpected '->' (T_OBJECT_OPERATOR), expecting ',' or ';' in %s on line %d
+Parse error: syntax error, unexpected '->' (T_OBJECT_OPERATOR), expecting ';' or ',' in %s on line %d

Zend/zend_compile.c

@@ -5743,6 +5743,11 @@ static void zend_compile_attributes(HashTable **attributes, zend_ast *ast, uint3
 			ZEND_ASSERT(args->kind == ZEND_AST_ARG_LIST);
 
 			for (j = 0; j < args->children; j++) {
+				if (args->child[j]->kind == ZEND_AST_UNPACK) {
+					zend_error_noreturn(E_COMPILE_ERROR,
+						"Cannot use unpacking in attribute argument list");
+				}
+
 				zend_const_expr_to_zval(&attr->argv[j], args->child[j]);
 			}
 		}

Zend/zend_language_parser.y

@@ -260,7 +260,7 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %type <ast> identifier type_expr_without_static union_type_without_static
 %type <ast> inline_function union_type
 %type <ast> attributed_statement attributed_class_statement attributed_parameter
-%type <ast> attribute_arguments attribute_decl attribute attributes
+%type <ast> attribute_decl attribute attributes
 
 %type <num> returns_ref function fn is_reference is_variadic variable_modifiers
 %type <num> method_modifiers non_empty_member_modifiers member_modifier optional_visibility_modifier
@@ -317,20 +317,11 @@ name:
 	|	T_NS_SEPARATOR namespace_name				{ $$ = $2; $$->attr = ZEND_NAME_FQ; }
 ;
 
-attribute_arguments:
-		expr
-			{ $$ = zend_ast_create_list(1, ZEND_AST_ARG_LIST, $1); }
-	|	attribute_arguments ',' expr
-			{ $$ = zend_ast_list_add($1, $3); }
-;
-
 attribute_decl:
 		class_name
 			{ $$ = zend_ast_create(ZEND_AST_ATTRIBUTE, $1, NULL); }
-	|	class_name '(' ')'
-			{ $$ = zend_ast_create(ZEND_AST_ATTRIBUTE, $1, NULL); }
-	|	class_name '(' attribute_arguments ')'
-			{ $$ = zend_ast_create(ZEND_AST_ATTRIBUTE, $1, $3); }
+	|	class_name argument_list
+			{ $$ = zend_ast_create(ZEND_AST_ATTRIBUTE, $1, $2); }
 ;
 
 attribute: