feat(closure): 添加闭包功能支持并完善相关测试用例

- 添加了嵌套lambda表达式的支持，实现类中的闭包嵌套功能
- 实现了preg_replace_callback中lambda表达式的使用场景
- 支持在lambda内部使用静态变量的功能
- 完善了闭包自调用的实现逻辑
- 添加了四个新的闭包测试用例(closure_007-010)
- 在编译器基类中增加了inClosure状态标识
- 修复了return语句在闭包中的处理逻辑
- 更新了闭包函数体的返回值处理方式

src/Php/CompilerBase.php

@@ -191,6 +191,7 @@ class CompilerBase extends \PhpAot\Core\Translator
     protected array $beforeStmtLines = [];
     protected array $afterStmtLines = [];
     protected bool $inLoop = false;
+    protected bool $inClosure = false;
 
     /**
      * 赋值表达式的左值，写操作，右值为读操作.
@@ -895,7 +896,7 @@ class CompilerBase extends \PhpAot\Core\Translator
                     $result = $this->parseEcho($v);
                     break;
                 case 'Stmt_Return':
-                    $result = $this->parseReturn($v) . ';';
+                    $result = $this->parseReturn($v);
                     break;
                 case 'Stmt_For':
                     $this->inLoop = true;
@@ -1244,7 +1245,7 @@ class CompilerBase extends \PhpAot\Core\Translator
     protected function parseReturn(mixed $v): string
     {
         if ($v->expr === null) {
-            if ($this->functionDef->returnType === self::TYPE_VOID) {
+            if ($this->functionDef->returnType === self::TYPE_VOID and !$this->inClosure) {
                 return 'return;';
             } else {
                 return 'return ' . self::VALUE_NULL . ';';
@@ -3522,10 +3523,14 @@ class CompilerBase extends \PhpAot\Core\Translator
             . self::TYPE_OBJECT . ' &this_, '
             . self::TYPE_ARGS . ' &vars_) ' .
             '-> ' . self::TYPE_VAR . ' {' . PHP_EOL;
+
         $oriLocalVars = $this->localVars;
         $this->localVars = [];
         $oriArgs = $this->arguments;
         $this->arguments = [];
+        $oriInClosure = $this->inClosure;
+        $this->inClosure = true;
+
         $this->indentLevel++;
 
         $fnBodyCode = '';
@@ -3550,7 +3555,7 @@ class CompilerBase extends \PhpAot\Core\Translator
         $fnCode .= $fnBodyCode;
 
         if (!$this->isReturnStmtInLastLine($expr->stmts)) {
-            $fnCode .= 'return '.self::VALUE_NAN. ';' . PHP_EOL;
+            $fnCode .= 'return ' . self::VALUE_NULL . ';' . PHP_EOL;
         }
 
         $this->indentLevel--;
@@ -3559,6 +3564,7 @@ class CompilerBase extends \PhpAot\Core\Translator
         $this->beforeStmtLines[] = $fnCode;
         $this->localVars = $oriLocalVars;
         $this->arguments = $oriArgs;
+        $this->inClosure = $oriInClosure;
 
         $useVars = [];
         foreach ($expr->uses as $useItem) {

tests/zend/closures/closure_007.phpt

@@ -0,0 +1,41 @@
+--TEST--
+Closure 007: Nested lambdas in classes
+--FILE--
+<?php
+
+class A {
+    private $x = 0;
+
+    function getClosureGetter () {
+        return function () {
+            return function () {
+                $this->x++;
+            };
+        };
+    }
+
+    function printX () {
+        echo $this->x."\n";
+    }
+}
+
+function main() {
+    $a = new A;
+    $a->printX();
+    $getClosure = $a->getClosureGetter();
+    $a->printX();
+    $closure = $getClosure();
+    $a->printX();
+    $closure();
+    $a->printX();
+
+    echo "Done\n";
+}
+
+?>
+--EXPECT--
+0
+0
+0
+1
+Done

tests/zend/closures/closure_008.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Closure 008: Use in preg_replace_callback()
+--FILE--
+<?php
+
+function replace_spaces($text) {
+    $lambda = function ($matches) {
+        return str_replace(' ', '&nbsp;', $matches[1]).' ';
+    };
+    return preg_replace_callback('/( +) /', $lambda, $text);
+}
+
+function main() {
+    echo replace_spaces("1 2 3\n");
+    echo replace_spaces("1  2  3\n");
+    echo replace_spaces("1   2   3\n");
+    echo "Done\n";
+}
+?>
+--EXPECT--
+1 2 3
+1&nbsp; 2&nbsp; 3
+1&nbsp;&nbsp; 2&nbsp;&nbsp; 3
+Done

tests/zend/closures/closure_009.phpt

@@ -0,0 +1,33 @@
+--TEST--
+Closure 009: Using static vars inside lambda
+--FILE--
+<?php
+function main() {
+    $a = 1;
+    $x = function ($x) use ($a) {
+      static $n = 0;
+      $n++;
+      $a = $n.':'.$a;
+      echo $x.':'.$a."\n";
+    };
+    $y = function ($x) use (&$a) {
+      static $n = 0;
+      $n++;
+      $a = $n.':'.$a;
+      echo $x.':'.$a."\n";
+    };
+    $x(1);
+    $x(2);
+    $x(3);
+    $y(4);
+    $y(5);
+    $y(6);
+}
+?>
+--EXPECT--
+1:1:1
+2:2:1
+3:3:1
+4:1:1
+5:2:1:1
+6:3:2:1:1

tests/zend/closures/closure_010.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Closure 010: Closure calls itself
+--FILE--
+<?php
+function main() {
+    $i = 3;
+    $lambda = function ($lambda) use (&$i) {
+        if ($i==0) return;
+        echo $i--."\n";
+        $lambda($lambda);
+    };
+    $lambda($lambda);
+    echo "$i\n";
+}
+?>
+--EXPECT--
+3
+2
+1
+0