feat(compiler): add compiler command validation and path resolution

- Implemented isCommandExecutable method to check if compiler commands are executable
- Added getCommandProgram method to extract program name from quoted/argumented commands
- Created isPathLikeCommand helper for path-based command detection
- Added compiler toolchain validation in Translator prepare phase
- Implemented proper PATH environment lookup with extension handling on Windows
- Added comprehensive unit tests for command parsing and executability checks
- Enhanced error reporting when compiler/linker executables are not found
- Moved file collection before compiler validation in translation process

phpunit/src/FactoryTest.php

@@ -11,6 +11,48 @@ use PhpAot\Php\Platform\Macos;
 
 class FactoryTest extends TestCase
 {
+    private string|false $originalPath;
+    private string $tmpDir;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->originalPath = getenv('PATH');
+        $this->tmpDir = sys_get_temp_dir() . '/compiler_factory_test_' . uniqid();
+        mkdir($this->tmpDir, 0777, true);
+    }
+
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+        if ($this->originalPath === false) {
+            putenv('PATH');
+        } else {
+            putenv('PATH=' . $this->originalPath);
+        }
+        $this->removeDirectory($this->tmpDir);
+    }
+
+    private function removeDirectory(string $dir): void
+    {
+        if (!is_dir($dir)) {
+            return;
+        }
+        foreach (array_diff(scandir($dir), ['.', '..']) as $file) {
+            $path = $dir . DIRECTORY_SEPARATOR . $file;
+            is_dir($path) ? $this->removeDirectory($path) : unlink($path);
+        }
+        rmdir($dir);
+    }
+
+    private function createFakeExecutable(string $name): string
+    {
+        $path = $this->tmpDir . DIRECTORY_SEPARATOR . $name;
+        file_put_contents($path, "#!/bin/sh\nexit 0\n");
+        chmod($path, 0755);
+        return $path;
+    }
+
     /**
      * 测试 PlatformFactory 自动检测
      */
@@ -172,4 +214,28 @@ class FactoryTest extends TestCase
         
         $this->assertSame($platform, $retrievedPlatform);
     }
+
+    public function testCompilerCommandProgramParsesArgumentsAndQuotes(): void
+    {
+        $this->assertSame('clang++', CompilerFactory::getCommandProgram('clang++ -stdlib=libc++'));
+        $this->assertSame('/opt/llvm/bin/clang++', CompilerFactory::getCommandProgram('"/opt/llvm/bin/clang++" -O2'));
+        $this->assertSame('C:\\LLVM\\bin\\clang++.exe', CompilerFactory::getCommandProgram('"C:\\LLVM\\bin\\clang++.exe" -O2'));
+        $this->assertSame('', CompilerFactory::getCommandProgram('   '));
+    }
+
+    public function testCompilerCommandExecutableUsesPathAndIgnoresArguments(): void
+    {
+        $this->createFakeExecutable('fake-g++');
+        putenv('PATH=' . $this->tmpDir);
+
+        $this->assertTrue(CompilerFactory::isCommandExecutable('fake-g++ -std=c++20'));
+        $this->assertFalse(CompilerFactory::isCommandExecutable('missing-g++ -std=c++20'));
+    }
+
+    public function testCompilerCommandExecutableAcceptsQuotedAbsolutePath(): void
+    {
+        $compiler = $this->createFakeExecutable('quoted-clang++');
+
+        $this->assertTrue(CompilerFactory::isCommandExecutable('"' . $compiler . '" -O2'));
+    }
 }

src/Php/Backend/CompilerFactory.php

@@ -110,10 +110,69 @@ class CompilerFactory
         ];
     }
 
+    public static function isCommandExecutable(string $command): bool
+    {
+        $program = self::getCommandProgram($command);
+        if ($program === '') {
+            return false;
+        }
+
+        if (self::isPathLikeCommand($program)) {
+            return is_file($program) && is_executable($program);
+        }
+
+        $path = getenv('PATH');
+        if ($path === false || $path === '') {
+            return false;
+        }
+
+        $extensions = [''];
+        if (DIRECTORY_SEPARATOR === '\\') {
+            $pathext = getenv('PATHEXT') ?: '.COM;.EXE;.BAT;.CMD';
+            $extensions = array_filter(array_map('strtolower', explode(';', $pathext)));
+            if (preg_match('/\.[A-Za-z0-9]+$/', $program)) {
+                array_unshift($extensions, '');
+            }
+        }
+
+        foreach (explode(PATH_SEPARATOR, $path) as $dir) {
+            if ($dir === '') {
+                continue;
+            }
+            foreach ($extensions as $extension) {
+                $candidate = rtrim($dir, DIRECTORY_SEPARATOR . '/\\') . DIRECTORY_SEPARATOR . $program . $extension;
+                if (is_file($candidate) && is_executable($candidate)) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    public static function getCommandProgram(string $command): string
+    {
+        $command = trim($command);
+        if ($command === '') {
+            return '';
+        }
+
+        if ($command[0] === '"' || $command[0] === "'") {
+            $quote = $command[0];
+            $end = strpos($command, $quote, 1);
+            if ($end !== false) {
+                return substr($command, 1, $end - 1);
+            }
+        }
+
+        $firstToken = strtok($command, " \t\r\n");
+        return $firstToken === false ? '' : $firstToken;
+    }
+
     private static function normalizeCompilerName(string $compilerName): string
     {
-        $firstToken = strtok(trim($compilerName), ' ');
-        if ($firstToken === false || $firstToken === '') {
+        $firstToken = self::getCommandProgram($compilerName);
+        if ($firstToken === '') {
             return '';
         }
 
@@ -122,4 +181,11 @@ class CompilerFactory
 
         return preg_replace('/\.exe$/', '', $name);
     }
+
+    private static function isPathLikeCommand(string $program): bool
+    {
+        return str_contains($program, '/')
+            || str_contains($program, '\\')
+            || preg_match('/^[A-Za-z]:[\/\\\\]/', $program) === 1;
+    }
 }

src/Php/Translator.php

@@ -636,6 +636,9 @@ class Translator extends Preprocessor
 
     public function prepare(string $path): array
     {
+        $files = $this->getFiles($path);
+        $this->validateCompilerToolchain();
+
         // shell_exec 和 define 已通过 php::fn:: 直接调用，无需动态符号表
 
         // 根据平台检查库文件（仅在构建二进制文件时需要）
@@ -648,7 +651,6 @@ class Translator extends Preprocessor
             }
         }
 
-        $files = $this->getFiles($path);
         $files = $this->filterIgnoredFiles($files);
         // 分析 PHP 文件，预处理
         foreach ($files as $k => $file) {
@@ -668,6 +670,30 @@ class Translator extends Preprocessor
         return $files;
     }
 
+    protected function validateCompilerToolchain(): void
+    {
+        $backend = $this->getCompilerBackend();
+        $compilerCommand = $backend->getCompilerCommand();
+        if (!CompilerFactory::isCommandExecutable($compilerCommand)) {
+            $program = CompilerFactory::getCommandProgram($compilerCommand);
+            $this->error(
+                "C/C++ compiler executable not found: {$program}\n" .
+                "Configured compiler command: {$compilerCommand}\n" .
+                "Install a supported compiler or set `cpp-compiler` in project.yml / PHPX_CC / CXX."
+            );
+        }
+
+        $linkerCommand = $backend->getLinkerCommand();
+        if ($linkerCommand !== $compilerCommand && !CompilerFactory::isCommandExecutable($linkerCommand)) {
+            $program = CompilerFactory::getCommandProgram($linkerCommand);
+            $this->error(
+                "Linker executable not found: {$program}\n" .
+                "Configured linker command: {$linkerCommand}\n" .
+                "Install the required linker or update compiler configuration."
+            );
+        }
+    }
+
     protected function shouldIgnoreFile(string $file): bool
     {
         foreach ($this->ignorePaths as $ignorePath) {