feat(php): 添加抽象方法支持和调用保护

- 在 ClassDef 中添加 abstractMethods 数组存储抽象方法
- 实现 addAbstractMethod 和 hasAbstractMethod 方法
- 添加 getMethodFlags 方法统一获取方法标志
- 在 Preprocessor 中解析并添加抽象方法到类定义
- 实现 guardAbstractMethod 防止调用抽象方法
- 在父类方法调用中添加抽象方法检查
- 更新单元测试验证抽象方法调用错误处理

phpunit/code/parent-abstract-method.php

@@ -0,0 +1,20 @@
+<?php
+
+abstract class AbsBase {
+    abstract function show();
+}
+
+class Child extends AbsBase {
+    function show() {
+        echo "Call to function show()\n";
+    }
+    function error() {
+        parent::show();
+    }
+}
+
+function main() {
+    $t = new Child();
+    $t->show();
+    $t->error();
+}

phpunit/src/ClassTest.php

@@ -11,4 +11,9 @@ class ClassTest extends \BaseTest
     {
         $this->exec('Cannot access protected property `settings` of class `DevConfig`', 'protected-property.php');
     }
+
+    public function testCallAbstractParentMethod()
+    {
+        $this->exec('Cannot call abstract method `AbsBase::show()`', 'parent-abstract-method.php');
+    }
 }

src/Php/CompilerBase.php

@@ -5209,8 +5209,9 @@ class CompilerBase extends \PhpAot\Core\Translator
         }
         $classDef = $this->getClass($class);
         while (true) {
-            if ($classDef->hasMethod($method)) {
-                return $classDef->getMethod($method)->flags;
+            $flags = $classDef->getMethodFlags($method);
+            if ($flags !== 0) {
+                return $flags;
             }
             if (!$classDef->extends || !$this->hasClass($classDef->extends)) {
                 return 0;
@@ -5219,6 +5220,14 @@ class CompilerBase extends \PhpAot\Core\Translator
         }
     }
 
+    protected function guardAbstractMethod(string $class, string $method, Node $expr): void
+    {
+        $flags = $this->getMethodFlags($class, $method);
+        if ($flags & Modifiers::ABSTRACT) {
+            $this->fatalError($expr, "Cannot call abstract method `{$class}::{$method}()`");
+        }
+    }
+
     /**
      * Determine whether a method call can be devirtualized to a direct native call.
      *
@@ -5392,6 +5401,7 @@ class CompilerBase extends \PhpAot\Core\Translator
         }
         $parentClass = $this->classDef->extends;
         $method = $this->parseIdentifier($expr->name);
+        $this->guardAbstractMethod($parentClass, $method, $expr);
         // TODO 是否转为 native 调用
         if (empty($expr->args)) {
             return 'this_.call(' . $this->getMethodPtr($parentClass, $method) . ')';

src/Php/Entity/ClassDef.php

@@ -43,6 +43,11 @@ class ClassDef extends ClassLikeDef
      * @var array<string, int|string|null>
      */
     public array $enumCases = [];
+    /**
+     * Abstract method name (lowercase) => flags
+     * @var array<string, int>
+     */
+    public array $abstractMethods = [];
     public ?Trait_ $trait = null;
 
     /**
@@ -74,11 +79,33 @@ class ClassDef extends ClassLikeDef
         $this->methods[strtolower($method->name)] = $method;
     }
 
+    public function addAbstractMethod(string $name, int $flags): void
+    {
+        $this->abstractMethods[strtolower($name)] = $flags;
+    }
+
     public function hasMethod(string $method): bool
     {
         return isset($this->methods[strtolower($method)]);
     }
 
+    public function hasAbstractMethod(string $method): bool
+    {
+        return isset($this->abstractMethods[strtolower($method)]);
+    }
+
+    /**
+     * Returns method flags for concrete or abstract methods. Returns 0 if not found.
+     */
+    public function getMethodFlags(string $method): int
+    {
+        $lower = strtolower($method);
+        if (isset($this->methods[$lower])) {
+            return $this->methods[$lower]->flags;
+        }
+        return $this->abstractMethods[$lower] ?? 0;
+    }
+
     public function hasProperty(string $property): bool
     {
         return isset($this->properties[$property]);

src/Php/Preprocessor.php

@@ -616,6 +616,7 @@ class Preprocessor extends CompilerBase
                     }
                 }
             }
+            $this->classDef->addAbstractMethod($name, $flags);
         }
 
         $fullClassName = $this->getFullClassName();