diff --git a/.gitignore b/.gitignore
index b5f25c9c..00a267f1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,6 @@
 /build
 /vendor
 /tmp
-/examples/wordpress
+/projects/wordpress
 /.php-cs-fixer.cache
 *.o
\ No newline at end of file
diff --git a/src/Php/CompilerBase.php b/src/Php/CompilerBase.php
index 843b9277..b2f56923 100644
--- a/src/Php/CompilerBase.php
+++ b/src/Php/CompilerBase.php
@@ -59,6 +59,8 @@ class CompilerBase extends \PhpAot\Core\Translator
     public const string NAMESPACE_SEPARATOR = '__';
 
     public const string PREFIX = 'php_';
+    public const string OP_ISSET = 'isset';
+    public const string OP_EMPTY = 'empty';
     protected string $phpxDir = '~/workspace/projects/phpx';
     protected string $lang = 'PHP';
     protected string $cppCompiler = 'g++';
@@ -311,6 +313,8 @@ class CompilerBase extends \PhpAot\Core\Translator
                 return $this->parseAssignOpBitwiseXor($expr);
             case 'Expr_AssignOp_Pow':
                 return $this->parseAssignOpPow($expr);
+            case 'Expr_AssignOp_Coalesce':
+                return $this->parseAssignOpCoalesce($expr);
             case 'Expr_BinaryOp_Mul':
                 return $this->parseBinaryOpMul($expr);
             case 'Expr_BinaryOp_Concat':
@@ -1713,6 +1717,11 @@ class CompilerBase extends \PhpAot\Core\Translator
         $this->error("{$msg} in {$this->file}:{$node->getStartLine()}");
     }
 
+    protected function errorUndefinedVariable(Variable $node): never
+    {
+        $this->fatalError($node, "The variable `{$node->name}` is undefined");
+    }
+
     protected function dump(NodeAbstract $v): void
     {
         if ($this->debugLine == $v->getStartLine()) {
@@ -1734,7 +1743,7 @@ class CompilerBase extends \PhpAot\Core\Translator
                 if ($write) {
                     $this->addLocalVar($var, self::TYPE_ARRAY);
                 } else {
-                    $this->fatalError($node->var, "The variable `{$node->var->name}` is undefined");
+                    $this->errorUndefinedVariable($node->var);
                 }
             } else {
                 $type = $this->getVarType($var);
@@ -1835,9 +1844,9 @@ class CompilerBase extends \PhpAot\Core\Translator
         return false;
     }
 
-    protected function foundStrayCode(): never
+    protected function foundStrayCode(Node $node): never
     {
-        $this->error("All execution code must be within a function; there is no allowance for stray code.");
+        $this->fatalError($node, "All execution code must be within a function, found stray code");
     }
 
     protected function parseFuncCall(Node\Expr\FuncCall $expr, bool $silent = false): string
@@ -2825,11 +2834,24 @@ class CompilerBase extends \PhpAot\Core\Translator
         return $this->parseVarCheckExpr($expr->expr, 'empty');
     }
 
+    /**
+     * 左值只能为变量、数组、对象属性、对象静态属性
+     * @param NodeAbstract $expr
+     * @return void
+     */
+    protected function checkLeftValue(NodeAbstract $expr): void
+    {
+        if (!$this->isVarExpr($expr) && !$this->isArrayDimFetch($expr) && !$this->isPropertyFetch($expr) && !$this->isStaticPropertyFetch($expr)) {
+            $this->fatalError($expr, 'The left value of assignment operation can only be variable, array item, object property, class static property');
+        }
+    }
+
     protected function parseVarCheckExpr(NodeAbstract $expr, string $op): string
     {
         if ($this->isVarExpr($expr)) {
             if ($op === 'isset') {
-                return $this->hasVar($this->parseIdentifier($expr)) ? 'true' : 'false';
+                $var = $this->parseIdentifier($expr);
+                return $this->hasVar($var) ? 'php::exists(' . $var . ')' : 'false';
             }
             return 'php::' . $op . '(' . $this->parseExpr($expr) . ')';
         }
@@ -3466,4 +3488,26 @@ class CompilerBase extends \PhpAot\Core\Translator
 
         return 'php::newClosure(' . $tmpVar . ', { ' . implode(', ', $useVars) . ' })';
     }
+
+    protected function parseAssignOpCoalesce(Node\Expr\AssignOp\Coalesce $expr): string
+    {
+        $this->checkLeftValue($expr->var);
+        $isset = $this->parseVarCheckExpr($expr->var, self::OP_ISSET);
+
+        $inAssignExpr = $this->inAssignExpr;
+        $this->inAssignExpr = true;
+        $var = $this->parseIdentifier($expr->var);
+        $this->inAssignExpr = $inAssignExpr;
+
+        $right = $this->parseExpr($expr->expr);
+        if ($this->isVarExpr($expr->expr) and !$this->hasVar($right)) {
+            $this->errorUndefinedVariable($expr->expr);
+        }
+        if ($this->isVarExpr($expr->var) and !$this->hasVar($var)) {
+            $this->addLocalVar($var, $this->detectExprType($expr->expr));
+        }
+        return 'if (!' . $isset . ') {' . PHP_EOL .
+            $this->getIndent() . $var . ' = ' . $right . ';' . PHP_EOL .
+            '}' . PHP_EOL;
+    }
 }
diff --git a/src/Php/Preprocessor.php b/src/Php/Preprocessor.php
index cce1fb40..7b777f60 100644
--- a/src/Php/Preprocessor.php
+++ b/src/Php/Preprocessor.php
@@ -106,7 +106,7 @@ class Preprocessor extends CompilerBase
                     $this->parseConstDef($v);
                     break;
                 case 'Stmt_Expression':
-                    $this->foundStrayCode();
+                    $this->foundStrayCode($v);
                 default:
                     $this->fatalError($v, 'Unsupported statement: ' . $type);
             }
@@ -144,7 +144,7 @@ class Preprocessor extends CompilerBase
                 case 'Stmt_Const':
                     break;
                 case 'Stmt_Expression':
-                    $this->foundStrayCode();
+                    $this->foundStrayCode($v2);
                 default:
                     abort($v2);
             }
@@ -178,7 +178,7 @@ class Preprocessor extends CompilerBase
                     $code .= $this->prepareFunction($v) . PHP_EOL;
                     break;
                 case 'Stmt_Expression':
-                    $this->foundStrayCode();
+                    $this->foundStrayCode($v);
                 default:
                     abort($v);
             }
diff --git a/tests/aot/assign_coalesce_001.phpt b/tests/aot/assign_coalesce_001.phpt
new file mode 100644
index 00000000..4dcdd2b8
--- /dev/null
+++ b/tests/aot/assign_coalesce_001.phpt
@@ -0,0 +1,15 @@
+--TEST--
+assign coalesce
+--FILE--
+<?php
+$a = 123;
+$a ??= 456;
+var_dump($a);
+
+$b = null;
+$b ??= 'foo';
+var_dump($b);
+?>
+--EXPECT--
+int(123)
+string(3) "foo"
diff --git a/tests/zend/coalesce/assign_coalesce_001.phpt b/tests/zend/coalesce/assign_coalesce_001.phpt
new file mode 100644
index 00000000..fce688f0
--- /dev/null
+++ b/tests/zend/coalesce/assign_coalesce_001.phpt
@@ -0,0 +1,119 @@
+--TEST--
+Coalesce assign (??=): Basic behavior
+--FILE--
+<?php
+// Identity function used to track single-evaluation
+function id($arg) {
+    return $arg;
+}
+
+class Test {
+    public static $foo;
+    public static $bar;
+}
+
+function main() {
+    // Refcounted values
+    $foo = "fo";
+    $foo .= "o";
+    $bar = "ba";
+    $bar .= "r";
+    echo "Simple variables:\n";
+    $a = 123;
+    $a ??= 456;
+    var_dump($a);
+
+    $b = null;
+    $b ??= $foo;
+    var_dump($b);
+
+    $c = $foo;
+    $c ??= $bar;
+    var_dump($c);
+
+    $d ??= $foo;
+    var_dump($c);
+
+    echo "\nArrays:\n";
+    $ary = [];
+    $ary["foo"] ??= 123;
+    $ary[$foo] ??= $bar;
+    $ary[$bar] ??= $foo;
+    var_dump($ary);
+
+    echo "\nArrays (identity):\n";
+    $ary = [];
+    $ary[id($foo)] ??= 123;
+    $ary[id($foo)] ??= $bar;
+    $ary[id($bar)] ??= $foo;
+    var_dump($ary);
+
+    echo "\nObjects:\n";
+    $obj = new stdClass;
+    $obj->foo ??= 123;
+    $obj->$foo ??= $bar;
+    $obj->$bar ??= $foo;
+    var_dump($obj);
+
+    $obj = new stdClass;
+    $obj->{id($foo)} ??= 123;
+    $obj->{id($foo)} ??= $bar;
+    $obj->{id($bar)} ??= $foo;
+    var_dump($obj);
+
+    echo "\nStatic props:\n";
+    Test::$foo ??= 123;
+    Test::$$foo ??= $bar;
+    Test::$$bar ??= $foo;
+    var_dump(Test::$foo, Test::$bar);
+
+    Test::$foo = null;
+    Test::$bar = null;
+    Test::${id($foo)} ??= 123;
+    Test::${id($foo)} ??= $bar;
+    Test::${id($bar)} ??= $foo;
+    var_dump(Test::$foo, Test::$bar);
+}
+?>
+--EXPECT--
+Simple variables:
+int(123)
+string(3) "foo"
+string(3) "foo"
+string(3) "foo"
+
+Arrays:
+array(2) {
+  ["foo"]=>
+  int(123)
+  ["bar"]=>
+  string(3) "foo"
+}
+
+Arrays (identity):
+array(2) {
+  ["foo"]=>
+  int(123)
+  ["bar"]=>
+  string(3) "foo"
+}
+
+Objects:
+object(stdClass)#1 (2) {
+  ["foo"]=>
+  int(123)
+  ["bar"]=>
+  string(3) "foo"
+}
+object(stdClass)#2 (2) {
+  ["foo"]=>
+  int(123)
+  ["bar"]=>
+  string(3) "foo"
+}
+
+Static props:
+int(123)
+string(3) "foo"
+int(123)
+string(3) "foo"
diff --git a/tests/zend/use_function/basic.phpt b/tests/zend/use_function/basic.phpt
new file mode 100644
index 00000000..57370716
--- /dev/null
+++ b/tests/zend/use_function/basic.phpt
@@ -0,0 +1,28 @@
+--TEST--
+import namespaced function
+--FILE--
+<?php
+
+namespace foo\bar {
+    function baz() {
+        return 'foo.bar.baz';
+    }
+    function qux() {
+        return baz();
+    }
+}
+
+namespace {
+    use function foo\bar\baz, foo\bar\qux;
+    function main() {
+        var_dump(baz());
+        var_dump(qux());
+        echo "Done\n";
+    }
+}
+
+?>
+--EXPECT--
+string(11) "foo.bar.baz"
+string(11) "foo.bar.baz"
+Done