Show the file cache directory in diagnose, use it from PHP 8.3 only

PHP 8.3 is the oldest version the turbo extension is built for, and the
range the file cache was measured on.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: 2 people

src/Turbo/TurboDiagnoseExtension.php

@@ -10,6 +10,9 @@
 use function php_uname;
 use function phpversion;
 use function sprintf;
+use function strlen;
+use function strpos;
+use function substr;
 use const PHP_DEBUG;
 use const PHP_MAJOR_VERSION;
 use const PHP_MINOR_VERSION;
@@ -69,9 +72,37 @@ public function print(Output $output): void
 			'<info>Turbo trusted types:</info> %s',
 			$this->describeTrustedTypes(),
 		));
+		$output->writeLineFormatted(sprintf(
+			'<info>OPcache file cache:</info> %s',
+			$this->describeFileCache(),
+		));
 		$output->writeLineFormatted('');
 	}
 
+	/**
+	 * Where TurboProcessRestarter keeps the persistent OPcache file cache, so it
+	 * can be found and deleted.
+	 */
+	private function describeFileCache(): string
+	{
+		$fileCache = ini_get('opcache.file_cache');
+		if ($fileCache !== false && $fileCache !== '') {
+			return $fileCache;
+		}
+
+		// without the restart (no pcntl), only the spawned workers get one
+		foreach (TurboProcessRestarter::getOpcacheArgs() as $opcacheArg) {
+			$prefix = 'opcache.file_cache=';
+			if (strpos($opcacheArg, $prefix) !== 0 || $opcacheArg === $prefix) {
+				continue;
+			}
+
+			return sprintf('%s (spawned workers)', substr($opcacheArg, strlen($prefix)));
+		}
+
+		return 'off';
+	}
+
 	private function describeTrustedTypes(): string
 	{
 		if (TurboExtensionEnabler::isTrustingOwnTypes()) {

src/Turbo/TurboProcessRestarter.php

@@ -42,6 +42,7 @@
 use function unlink;
 use const PHP_BINARY;
 use const PHP_OS_FAMILY;
+use const PHP_VERSION_ID;
 
 /**
  * Restarts the main PHPStan process via pcntl_exec() when the process it
@@ -303,7 +304,9 @@ public static function getOpcacheArgs(): array
 	 * and has no build to key the directory by. Not in CI (see
 	 * resolveContinuousIntegration()): an empty temp dir at the start of every
 	 * job would make the cache pure cost, and with a file cache the
-	 * extension's trusted-types pass is off. Not on Windows either: every
+	 * extension's trusted-types pass is off. Not on PHP older than the oldest
+	 * one the extension is built for (TurboExtensionSelector::MINIMUM_PHP_VERSION_ID):
+	 * the file cache was only measured on that range. Not on Windows either: every
 	 * spawned worker there gets its own opcache.cache_id (see ProcessHelper),
 	 * and OPcache then keeps a separate file cache per worker that no later
 	 * run reuses: 2 GB after one benchmark run on a GitHub runner, and cold
@@ -316,6 +319,9 @@ private static function getFileCacheDirectory(): ?string
 		}
 
 		self::$fileCacheDirectoryResolved = true;
+		if (PHP_VERSION_ID < TurboExtensionSelector::MINIMUM_PHP_VERSION_ID) {
+			return null;
+		}
 		if (PHP_OS_FAMILY === 'Windows' || !function_exists('posix_geteuid') || !class_exists('Phar', false)) {
 			return null;
 		}