refactor(backend): 将命令构建方法从修改字符串改为返回标志字符串

- 将 Clang 和 GccLikeBackend 中的 addPICFlag 方法重构为 getPICFlag
- 将 addPlatformLinkFlags 方法重构为 getPlatformLinkFlags
- 将 addPlatformFullLinkFlags 方法重构为 getPlatformFullLinkFlags
- 修改调用方式从传引用改为直接拼接返回的标志字符串
- 统一 Windows 平台的特殊处理逻辑
- 保持原有功能不变但改进代码结构

src/Php/Backend/Clang.php

@@ -85,49 +85,52 @@ class Clang extends GccLikeBackend
         return '-fsanitize=' . $sanitizer;
     }
 
-    protected function addPICFlag(array $config, string &$cmd): void
+    protected function getPICFlag(array $config): string
     {
         if ($this->platform instanceof Windows) {
-            return;
+            return '';
         }
         if ((!empty($config['build_mode']) && $config['build_mode'] === 'ext') || !empty($config['pic'])) {
-            $cmd .= ' -fPIC';
+            return ' -fPIC';
         }
+        return '';
     }
 
-    protected function addPlatformLinkFlags(array $config, string &$cmd): void
+    protected function getPlatformLinkFlags(array $config): string
     {
         if ($this->platform instanceof Windows) {
+            $flags = '';
             if (!empty($config['debug'])) {
-                $cmd .= ' /DEBUG';
+                $flags .= ' /DEBUG';
             }
             if (!empty($config['no_console'])) {
-                $cmd .= ' ' . $this->platform->getSubsystemOptions(true);
+                $flags .= ' ' . $this->platform->getSubsystemOptions(true);
             }
-            $cmd .= ' ' . $this->platform->getCrtConfig();
+            $flags .= ' ' . $this->platform->getCrtConfig();
 
             if (!empty($config['build_mode']) && $config['build_mode'] === 'ext') {
-                $cmd .= ' /DLL';
+                $flags .= ' /DLL';
             }
-            return;
+            return $flags;
         }
 
-        parent::addPlatformLinkFlags($config, $cmd);
+        return parent::getPlatformLinkFlags($config);
     }
 
-    protected function addPlatformFullLinkFlags(array $options, string &$cmd): void
+    protected function getPlatformFullLinkFlags(array $options): string
     {
         if ($this->platform instanceof Windows) {
+            $flags = '';
             if (!empty($options['debug'])) {
-                $cmd .= ' /DEBUG';
+                $flags .= ' /DEBUG';
             }
             if (!empty($options['no_console'])) {
-                $cmd .= ' ' . $this->platform->getSubsystemOptions(true);
+                $flags .= ' ' . $this->platform->getSubsystemOptions(true);
             }
-            $cmd .= ' ' . $this->platform->getCrtConfig();
-            return;
+            $flags .= ' ' . $this->platform->getCrtConfig();
+            return $flags;
         }
 
-        parent::addPlatformFullLinkFlags($options, $cmd);
+        return parent::getPlatformFullLinkFlags($options);
     }
 }

src/Php/Backend/GccLikeBackend.php

@@ -50,42 +50,51 @@ abstract class GccLikeBackend extends CompilerBackend
         };
     }
 
-    /** 添加 PIC 标志 */
-    protected function addPICFlag(array $config, string &$cmd): void
+    /** 获取 PIC 标志 */
+    protected function getPICFlag(array $config): string
     {
         if ((!empty($config['build_mode']) && $config['build_mode'] === 'ext') || !empty($config['pic'])) {
-            $cmd .= ' -fPIC';
+            return ' -fPIC';
         }
+        return '';
     }
 
-    /** 添加平台特定的链接选项 */
-    protected function addPlatformLinkFlags(array $config, string &$cmd): void
+    /** 获取平台特定的链接选项 */
+    protected function getPlatformLinkFlags(array $config): string
     {
+        $flags = '';
+
         if ((!empty($config['build_mode']) && $config['build_mode'] === 'ext') || !empty($config['shared'])) {
-            $cmd .= ' ' . $this->platform->getSharedLinkFlag();
+            $flags .= ' ' . $this->platform->getSharedLinkFlag();
 
             if ($this->platform instanceof \PhpAot\Php\Platform\Macos && !empty($config['install_name'])) {
-                $cmd .= ' ' . $this->platform->getCurrentInstallNameOption($config['install_name']);
+                $flags .= ' ' . $this->platform->getCurrentInstallNameOption($config['install_name']);
             }
         }
 
         if (!empty($config['rpath'])) {
             foreach ($config['rpath'] as $path) {
-                $cmd .= ' -Wl,-rpath,' . escapeshellarg($path);
+                $flags .= ' -Wl,-rpath,' . escapeshellarg($path);
             }
         }
+
+        return $flags;
     }
 
-    /** 添加平台特定的完整链接选项 */
-    protected function addPlatformFullLinkFlags(array $options, string &$cmd): void
+    /** 获取平台特定的完整链接选项 */
+    protected function getPlatformFullLinkFlags(array $options): string
     {
+        $flags = '';
+
         if (!empty($options['shared'])) {
-            $cmd .= ' ' . $this->platform->getSharedLinkFlag();
+            $flags .= ' ' . $this->platform->getSharedLinkFlag();
         }
 
         if (!empty($options['rpath'])) {
-            $cmd .= ' ' . $this->platform->getRpathOptions($options['rpath']);
+            $flags .= ' ' . $this->platform->getRpathOptions($options['rpath']);
         }
+
+        return $flags;
     }
 
     // ──── 抽象方法实现 ────
@@ -259,7 +268,7 @@ abstract class GccLikeBackend extends CompilerBackend
             $cmd .= ' --target=' . $config['target_platform'];
         }
 
-        $this->addPICFlag($config, $cmd);
+        $cmd .= $this->getPICFlag($config);
 
         if (!empty($config['enable_profiler'])) {
             $cmd .= ' -DPPROF_ON=1';
@@ -289,7 +298,7 @@ abstract class GccLikeBackend extends CompilerBackend
     {
         $cmd = '';
 
-        $this->addPlatformLinkFlags($config, $cmd);
+        $cmd .= $this->getPlatformLinkFlags($config);
 
         if (!empty($config['sanitize'])) {
             $cmd .= ' ' . $this->formatSanitizerFlag($config['sanitize']);
@@ -344,7 +353,7 @@ abstract class GccLikeBackend extends CompilerBackend
     {
         $cmd = '';
 
-        $this->addPlatformFullLinkFlags($options, $cmd);
+        $cmd .= $this->getPlatformFullLinkFlags($options);
 
         if (!empty($options['sanitize'])) {
             $cmd .= ' -fsanitize=' . $options['sanitize'];