Implemented Default Value in list() syntax

Zend/tests/list_default_001.phpt

@@ -0,0 +1,46 @@
+--TEST--
+Testing list() default value: basic
+--FILE--
+<?php
+
+// empty
+list($a=1) = array();
+var_dump($a);
+
+list($a=1, $b=2) = array();
+var_dump($a, $b);
+
+list($a, $b=2) = array();
+var_dump($a, $b);
+
+echo "---------\n";
+
+list($a=1) = array(2);
+var_dump($a);
+
+list($a=1, $b=2) = array(1 => 3);
+var_dump($a, $b);
+
+list($a, $b=2, $c) = array();
+var_dump($a, $b, $c);
+
+?>
+--EXPECTF--
+int(1)
+int(1)
+int(2)
+
+Notice: Undefined offset: 0 in %s on line %s
+NULL
+int(2)
+---------
+int(2)
+int(1)
+int(3)
+
+Notice: Undefined offset: %d in %s on line %s
+
+Notice: Undefined offset: %d in %s on line %s
+NULL
+int(2)
+NULL

Zend/tests/list_default_002.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Testing list() default value: nested list
+--FILE--
+<?php
+
+list($a, list($b=1, $c), $d=99) = [1, [1 => new stdclass]];
+var_dump($a, $b, $c, $d);
+
+?>
+--EXPECT--
+int(1)
+int(1)
+object(stdClass)#1 (0) {
+}
+int(99)

Zend/tests/list_default_003.phpt

@@ -0,0 +1,30 @@
+--TEST--
+Testing list() default value: non array
+--FILE--
+<?php
+
+list($a, $b=2) = 1;
+var_dump($a, $b);
+
+list($a, $b=2) = null;
+var_dump($a, $b);
+
+list($a, $b=2) = "rule the world!";
+var_dump($a, $b);
+
+
+list($a=10, list($b, $c=20), $d) = null;
+var_dump($a, $b, $c, $d);
+
+?>
+--EXPECT--
+NULL
+int(2)
+NULL
+int(2)
+NULL
+int(2)
+int(10)
+NULL
+int(20)
+NULL

Zend/tests/list_default_004.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Testing list() nested with empty array and default value
+--FILE--
+<?php
+
+list($a, list($b, list(list($c=100, $d)))) = array();
+var_dump($a, $b, $c, $d);
+
+?>
+--EXPECTF--
+Notice: Undefined offset: 0 in %s on line %d
+
+Notice: Undefined offset: 1 in %s on line %d
+NULL
+NULL
+int(100)
+NULL

Zend/tests/list_default_005.phpt

@@ -0,0 +1,47 @@
+--TEST--
+Testing list() assign with non-variable with default value
+--FILE--
+<?php
+
+list($a[1], $b[3]=99) = [1];
+var_dump($a, $b);
+
+
+$obj = new stdclass;
+
+list($a, $obj->prop1, $obj->prop2='default') = [];
+var_dump($a, $obj);
+
+$obj2 = new stdclass;
+
+list($a, list($obj2->prop1, $obj2->prop2='default2')) = [1, [1]];
+var_dump($a, $obj2);
+
+?>
+--EXPECTF--
+array(1) {
+  [1]=>
+  int(1)
+}
+array(1) {
+  [3]=>
+  int(99)
+}
+
+Notice: Undefined offset: 0 in %s on line %d
+
+Notice: Undefined offset: 1 in %s on line %d
+NULL
+object(stdClass)#1 (2) {
+  ["prop1"]=>
+  NULL
+  ["prop2"]=>
+  string(7) "default"
+}
+int(1)
+object(stdClass)#2 (2) {
+  ["prop1"]=>
+  int(1)
+  ["prop2"]=>
+  string(8) "default2"
+}

Zend/tests/list_default_006.phpt

@@ -0,0 +1,55 @@
+--TEST--
+Testing list() assign with default different expressions
+--FILE--
+<?php
+
+list($a, $b='str') = [1];
+var_dump($a, $b);
+
+
+list($a, $b=new stdclass) = [1];
+var_dump($a, $b);
+
+list($a, $b=new stdclass) = [1, 2];
+var_dump($a, $b);
+
+list($a, $b=function () {return true;}) = [1];
+var_dump($a, $b);
+
+list($a, $b=function () {return true;}) = [1, 2];
+var_dump($a, $b);
+
+echo "----------\n";
+
+function test_func($str)
+{
+	var_dump($str);
+	return "Yes Sir!";
+}
+
+list($a, $b=test_func("call me!")) = [1];
+var_dump($a, $b);
+
+list($a, $b=test_func("call me!")) = [1, 2];
+var_dump($a, $b);
+
+?>
+--EXPECTF--
+int(1)
+string(3) "str"
+int(1)
+object(stdClass)#1 (0) {
+}
+int(1)
+int(2)
+int(1)
+object(Closure)#1 (0) {
+}
+int(1)
+int(2)
+----------
+string(8) "call me!"
+int(1)
+string(8) "Yes Sir!"
+int(1)
+int(2)

Zend/tests/list_default_007.phpt

@@ -0,0 +1,60 @@
+--TEST--
+Testing list() default value in foreach context
+--FILE--
+<?php
+
+
+$arr = [
+	[],
+	[1],
+	[1, 2],
+	[1, 2, 3]
+];
+
+foreach($arr as $key => list($one, $two ='default')) {
+	echo "$key => $one, $two\n";
+}
+
+echo "-----------\n";
+
+foreach($arr as $key => list($one='ONE')) {
+	echo "$key => $one\n";
+}
+
+echo "-----------\n";
+
+foreach($arr as $key => list($one=strlen('ONE'))) {
+	echo "$key => $one\n";
+}
+
+function say_sth($str) {
+	echo "Beep\n";
+	return $str;
+}
+
+foreach($arr as $key => list($one=say_sth('ONE'))) {
+	echo "$key => $one\n";
+}
+
+?>
+--EXPECTF--
+Notice: Undefined offset: %d in %s on line %d
+0 => , default
+1 => 1, default
+2 => 1, 2
+3 => 1, 2
+-----------
+0 => ONE
+1 => 1
+2 => 1
+3 => 1
+-----------
+0 => 3
+1 => 1
+2 => 1
+3 => 1
+Beep
+0 => ONE
+1 => 1
+2 => 1
+3 => 1

Zend/zend_ast.c

@@ -1074,6 +1074,14 @@ static void zend_ast_export_ex(smart_str *str, zend_ast *ast, int priority, int
 			zend_ast_export_list(str, (zend_ast_list*)ast, 1, 20, indent);
 			smart_str_appendc(str, ')');
 			break;
+		case ZEND_AST_LIST_ELEM:
+			zend_ast_export_ex(str, ast->child[0], priority, indent);
+
+			if (ast->child[1]) {
+				smart_str_appendc(str, '=');
+				zend_ast_export_ex(str, ast->child[1], priority, indent);
+			}
+			break;
 		case ZEND_AST_ARRAY:
 			smart_str_appendc(str, '[');
 			zend_ast_export_list(str, (zend_ast_list*)ast, 1, 20, indent);

Zend/zend_ast.h

@@ -116,6 +116,7 @@ enum _zend_ast_kind {
 	ZEND_AST_INSTANCEOF,
 	ZEND_AST_YIELD,
 	ZEND_AST_COALESCE,
+	ZEND_AST_LIST_ELEM,
 
 	ZEND_AST_STATIC,
 	ZEND_AST_WHILE,

Zend/zend_compile.c

@@ -2461,23 +2461,46 @@ static void zend_compile_list_assign(znode *result, zend_ast *ast, znode *expr_n
 	zend_bool has_elems = 0;
 
 	for (i = 0; i < list->children; ++i) {
-		zend_ast *var_ast = list->child[i];
-		znode fetch_result, dim_node;
+		zend_ast *list_elm_ast = list->child[i];
+		zend_ast *var_ast, *default_ast;
+
+		znode fetch_result, dim_node, default_node;
+		zend_op *opline;
 
-		if (var_ast == NULL) {
+		if (list_elm_ast  == NULL) {
 			continue;
 		}
+
 		has_elems = 1;
 
+		var_ast = list_elm_ast->child[0];
+		default_ast = list_elm_ast->child[1];
+
 		dim_node.op_type = IS_CONST;
 		ZVAL_LONG(&dim_node.u.constant, i);
 
 		if (expr_node->op_type == IS_CONST) {
 			Z_TRY_ADDREF(expr_node->u.constant);
 		}
 
-		zend_emit_op(&fetch_result, ZEND_FETCH_LIST, expr_node, &dim_node);
-		zend_emit_assign_znode(var_ast, &fetch_result);
+		opline = zend_emit_op(&fetch_result, ZEND_FETCH_LIST, expr_node, &dim_node);
+
+		if (default_ast) {
+			uint32_t opnum_skip_jmp;
+
+			zend_emit_assign_znode(var_ast, &fetch_result);
+
+			opnum_skip_jmp = zend_emit_jump(0);
+
+			opline->extended_value = get_next_op_number(CG(active_op_array));
+
+			zend_compile_expr(&default_node, default_ast);
+			zend_emit_assign_znode(var_ast, &default_node);
+
+			zend_update_jump_target_to_next(opnum_skip_jmp);
+		} else {
+			zend_emit_assign_znode(var_ast, &fetch_result);
+		}
 	}
 
 	if (!has_elems) {
@@ -2531,11 +2554,15 @@ zend_bool zend_list_has_assign_to(zend_ast *list_ast, zend_string *name) /* {{{
 	zend_ast_list *list = zend_ast_get_list(list_ast);
 	uint32_t i;
 	for (i = 0; i < list->children; i++) {
-		zend_ast *var_ast = list->child[i];
-		if (!var_ast) {
+		zend_ast *elm_ast = list->child[i];
+		zend_ast *var_ast;
+
+		if (!elm_ast) {
 			continue;
 		}
 
+		var_ast = elm_ast->child[0];
+
 		/* Recursively check nested list()s */
 		if (var_ast->kind == ZEND_AST_LIST && zend_list_has_assign_to(var_ast, name)) {
 			return 1;

Zend/zend_language_parser.y

@@ -1177,8 +1177,9 @@ assignment_list:
 ;
 
 assignment_list_element:
-		variable						{ $$ = $1; }
-	|	T_LIST '(' assignment_list ')'	{ $$ = $3; }
+		variable						{ $$ = zend_ast_create_ex(ZEND_AST_LIST_ELEM, 0, $1, NULL); }
+	|	variable '=' expr				{ $$ = zend_ast_create_ex(ZEND_AST_LIST_ELEM, 0, $1, $3); }
+	|	T_LIST '(' assignment_list ')'	{ $$ = zend_ast_create_ex(ZEND_AST_LIST_ELEM, 0, $3, NULL); }
 	|	/* empty */						{ $$ = NULL; }
 ;
 

Zend/zend_opcode.c

@@ -685,6 +685,11 @@ ZEND_API int pass_two(zend_op_array *op_array)
 					opline->opcode = ZEND_GENERATOR_RETURN;
 				}
 				break;
+			case ZEND_FETCH_LIST:
+				if (opline->extended_value != 0) {
+					opline->extended_value = ZEND_OPLINE_NUM_TO_OFFSET(op_array, opline, opline->extended_value);
+				}
+				break;
 		}
 		if (opline->op1_type == IS_CONST) {
 			ZEND_PASS_TWO_UPDATE_CONSTANT(op_array, opline->op1);