Spell out the ini files, sys_temp_dir and xdebug.mode of the current process on spawned PHP command lines

bin/phpstan

@@ -25,6 +25,7 @@ use Symfony\Component\Console\Helper\ProgressBar;
 
 	define('__PHPSTAN_RUNNING__', true);
 
+	require_once __DIR__ . '/../src/Process/InheritedPhpConfig.php';
 	require_once __DIR__ . '/../src/Turbo/TurboExtensionEnabler.php';
 	require_once __DIR__ . '/../src/Turbo/TurboExtensionSelector.php';
 	require_once __DIR__ . '/../src/Turbo/TurboProcessRestarter.php';

src/Command/BisectCommand.php

@@ -10,6 +10,7 @@
 use PHPStan\Command\Bisect\BinarySearch;
 use PHPStan\File\FileReader;
 use PHPStan\Internal\HttpClientFactory;
+use PHPStan\Process\InheritedPhpConfig;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Helper\ProgressBar;
 use Symfony\Component\Console\Input\InputArgument;
@@ -19,6 +20,7 @@
 use Symfony\Component\Console\Style\SymfonyStyle;
 use Throwable;
 use function array_filter;
+use function array_map;
 use function array_merge;
 use function array_values;
 use function chmod;
@@ -416,9 +418,16 @@ public function buildAnalyseArgs(InputInterface $input): string
 
 	private function runAnalysis(string $pharPath, string $analyseArgs): int
 	{
+		// every bisect step is a full analysis of its own, and a child process
+		// inherits nothing of our command line - without this each of them
+		// would run with an Xdebug the user turned off for us, see
+		// InheritedPhpConfig
+		$phpArgs = implode(' ', array_map(static fn (string $arg): string => escapeshellarg($arg), InheritedPhpConfig::getArgs()));
+
 		$command = sprintf(
-			'%s %s analyse %s',
+			'%s %s %s analyse %s',
 			escapeshellarg(PHP_BINARY),
+			$phpArgs,
 			escapeshellarg($pharPath),
 			$analyseArgs,
 		);

src/Command/FixerApplication.php

@@ -27,6 +27,7 @@
 use PHPStan\Parallel\ForkParallelChecker;
 use PHPStan\PhpDoc\StubFilesProvider;
 use PHPStan\Process\ForkedProcessPromise;
+use PHPStan\Process\InheritedPhpConfig;
 use PHPStan\Process\ProcessCanceledException;
 use PHPStan\Process\ProcessCrashedException;
 use PHPStan\Process\ProcessHelper;
@@ -43,12 +44,14 @@
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 use Throwable;
+use function array_map;
 use function array_merge;
 use function count;
 use function defined;
 use function escapeshellarg;
 use function get_class;
 use function http_build_query;
+use function implode;
 use function ini_get;
 use function is_file;
 use function parse_url;
@@ -302,7 +305,11 @@ private function getFixerProcess(OutputInterface $output, int $serverPort): Proc
 			}
 		}
 
-		return new Process(sprintf('%s -d memory_limit=%s %s --port %d', escapeshellarg(PHP_BINARY), escapeshellarg(ini_get('memory_limit')), escapeshellarg($pharPath), $serverPort), env: $env, fds: []);
+		// the PHPStan Pro process is a child like a worker is - it inherits
+		// nothing of our command line either, see InheritedPhpConfig
+		$phpArgs = implode(' ', array_map(static fn (string $arg): string => escapeshellarg($arg), InheritedPhpConfig::getArgs()));
+
+		return new Process(sprintf('%s %s -d memory_limit=%s %s --port %d', escapeshellarg(PHP_BINARY), $phpArgs, escapeshellarg(ini_get('memory_limit')), escapeshellarg($pharPath), $serverPort), env: $env, fds: []);
 	}
 
 	/**

src/Parallel/ForkParallelChecker.php

@@ -6,11 +6,13 @@
 use PHPStan\Command\Output;
 use PHPStan\DependencyInjection\AutowiredService;
 use PHPStan\Diagnose\DiagnoseExtension;
+use PHPStan\Process\InheritedPhpConfig;
 use PHPStan\Process\ProcessHelper;
 use PHPStan\Turbo\TurboExtensionEnabler;
 use PHPStan\Turbo\TurboProcessRestarter;
 use function function_exists;
 use function getmypid;
+use function implode;
 use function opcache_get_status;
 use function sprintf;
 use function str_starts_with;
@@ -68,8 +70,10 @@ public function print(Output $output): void
 		$output->writeLineFormatted('Mechanism:                 spawn (react/child-process)');
 		$output->writeLineFormatted(sprintf('Reason fork not used:      %s', $reason));
 
-		// what a spawned worker's command line adds on top of the php.ini
-		// (see ProcessHelper); the extension path is on the turbo lines
+		// what a spawned worker's command line spells out for it (see
+		// ProcessHelper); the extension path is on the turbo lines
+		$output->writeLineFormatted(sprintf('Worker php options:        %s', implode(' ', InheritedPhpConfig::getArgs())));
+
 		$parentPid = getmypid();
 		$output->writeLineFormatted('Worker -d entries:');
 		foreach (ProcessHelper::resolveWorkerIniEntries(TurboProcessRestarter::getOpcacheArgs(), PHP_OS_FAMILY, $parentPid === false ? 0 : $parentPid, 1) as $iniEntry) {

src/Process/InheritedPhpConfig.php

@@ -0,0 +1,102 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Process;
+
+use function get_cfg_var;
+use function ini_get;
+use function is_string;
+use function php_ini_loaded_file;
+use function php_ini_scanned_files;
+use function sys_get_temp_dir;
+use function trim;
+
+/**
+ * The PHP command-line options a child PHP process needs so that it runs with
+ * the PHP configuration of the process starting it - the spawned workers of
+ * ProcessHelper, the re-executed main process of TurboProcessRestarter, and
+ * the PHPStan Pro process of FixerApplication.
+ *
+ * The environment carries over to a child on its own, so PHPRC and
+ * PHP_INI_SCAN_DIR - what composer/xdebug-handler sets up for a persistent
+ * restart - need nothing from here. The command line carries over to nothing,
+ * and repeating just `-c`, as the worker command used to, reproduces the main
+ * php.ini and nothing else:
+ *
+ * - The ini scan directory is read again. That matches the spawning process
+ *   when it read it too, and contradicts it when it did not - `php -n`, or a
+ *   `-c` pointing elsewhere, then gives the worker every extension and setting
+ *   the main process was deliberately started without.
+ * - `-d` entries are dropped. `php -d xdebug.mode=off vendor/bin/phpstan` turns
+ *   Xdebug off for the main process alone: xdebug-handler sees an inactive
+ *   Xdebug and rightly does not restart, so no PHPRC is set up either, and every
+ *   worker loads Xdebug again from the scan directory in whatever mode the ini
+ *   says - the analysis runs under an active Xdebug, several times slower, with
+ *   nothing on screen saying so
+ *   (https://github.com/phpstan/phpstan/issues/15189).
+ *
+ * PHP does not record which directives came from the command line, so `-d`
+ * entries cannot be repeated as a group - only the two that matter to a PHPStan
+ * process are: xdebug.mode, whose value decides how fast the whole run is, and
+ * sys_temp_dir, which decides where the result cache lives.
+ */
+final class InheritedPhpConfig
+{
+
+	/**
+	 * @return list<string>
+	 */
+	public static function getArgs(): array
+	{
+		return self::resolveArgs(php_ini_loaded_file(), php_ini_scanned_files(), sys_get_temp_dir(), self::getXdebugMode());
+	}
+
+	/**
+	 * The xdebug.mode in effect, or false when nothing set it.
+	 *
+	 * ini_get() answers only for a loaded Xdebug - for any other PHP the
+	 * directive is not registered and only the raw ini entry exists, which is
+	 * what a child loading Xdebug when we do not would be configured by.
+	 */
+	private static function getXdebugMode(): string|false
+	{
+		$mode = ini_get('xdebug.mode');
+		if ($mode !== false) {
+			return $mode;
+		}
+
+		$mode = get_cfg_var('xdebug.mode');
+
+		return is_string($mode) ? $mode : false;
+	}
+
+	/**
+	 * @param string|false $loadedIniFile php_ini_loaded_file() of the spawning process
+	 * @param string|false $scannedIniFiles php_ini_scanned_files() of the spawning process
+	 * @param string $tempDir sys_get_temp_dir() of the spawning process
+	 * @param string|false $xdebugMode see getXdebugMode()
+	 * @return list<string>
+	 */
+	public static function resolveArgs(string|false $loadedIniFile, string|false $scannedIniFiles, string $tempDir, string|false $xdebugMode): array
+	{
+		$args = [];
+		if ($scannedIniFiles === false || trim($scannedIniFiles) === '') {
+			// -n only suppresses the scan directory here: an explicit -c is
+			// still honored next to it, the way xdebug-handler restarts
+			$args[] = '-n';
+		}
+		if ($loadedIniFile !== false && $loadedIniFile !== '') {
+			$args[] = '-c';
+			$args[] = $loadedIniFile;
+		}
+		$args[] = '-d';
+		// quote value so PHP will parse it as a string when the path contains a bitwise operator like ~
+		$args[] = "sys_temp_dir='" . $tempDir . "'";
+		if ($xdebugMode !== false) {
+			$args[] = '-d';
+			$args[] = 'xdebug.mode=' . $xdebugMode;
+		}
+
+		return $args;
+	}
+
+}

src/Process/ProcessHelper.php

@@ -12,9 +12,7 @@
 use function implode;
 use function ini_get;
 use function is_bool;
-use function php_ini_loaded_file;
 use function sprintf;
-use function sys_get_temp_dir;
 use const PHP_BINARY;
 use const PHP_OS_FAMILY;
 
@@ -23,11 +21,11 @@
  * and SpawnedProcessPromise).
  *
  * Besides the worker command and its options it spells out the PHP
- * configuration the worker runs with. The php.ini is inherited through
- * `-c`, but command-line `-d` entries are not, so whatever the spawning
- * process got that way - the turbo extension and the OPcache setup of the
- * TurboProcessRestarter restart - is repeated here; see
- * resolveWorkerIniEntries() for the set and the reasoning.
+ * configuration the worker runs with. Nothing of a command line is inherited
+ * by a child process, so whatever the spawning process got that way is
+ * repeated here: the php.ini situation it runs with (InheritedPhpConfig), and
+ * the turbo extension and the OPcache setup of the TurboProcessRestarter
+ * restart - see resolveWorkerIniEntries() for that set and the reasoning.
  */
 final class ProcessHelper
 {
@@ -46,15 +44,10 @@ public static function getWorkerCommand(
 		InputInterface $input,
 	): string
 	{
-		$phpIni = php_ini_loaded_file();
-		$phpCmd = $phpIni === false ? escapeshellarg(PHP_BINARY) : sprintf('%s -c %s', escapeshellarg(PHP_BINARY), escapeshellarg($phpIni));
-
-		$processCommandArray = [
-			$phpCmd,
-			'-d',
-			// quote value so PHP will parse it as a string when the path contains a bitwise operator like ~
-			'sys_temp_dir=' . escapeshellarg("'" . sys_get_temp_dir() . "'"),
-		];
+		$processCommandArray = [escapeshellarg(PHP_BINARY)];
+		foreach (InheritedPhpConfig::getArgs() as $inheritedArg) {
+			$processCommandArray[] = escapeshellarg($inheritedArg);
+		}
 
 		if ($input->getOption('memory-limit') === null) {
 			$processCommandArray[] = '-d';

src/Turbo/TurboProcessRestarter.php

@@ -2,6 +2,7 @@
 
 namespace PHPStan\Turbo;
 
+use PHPStan\Process\InheritedPhpConfig;
 use function explode;
 use function extension_loaded;
 use function function_exists;
@@ -11,7 +12,6 @@
 use function is_string;
 use function max;
 use function pcntl_exec;
-use function php_ini_loaded_file;
 use function strtolower;
 use function trim;
 use const PHP_BINARY;
@@ -129,14 +129,37 @@ public static function restartIfSuitable(array $argv): void
 			return;
 		}
 
-		$args = [];
-		$phpIni = php_ini_loaded_file();
-		if ($phpIni !== false) {
-			$args[] = '-c';
-			$args[] = $phpIni;
-		}
+		pcntl_exec(PHP_BINARY, self::resolveRestartArgs(
+			InheritedPhpConfig::getArgs(),
+			$opcacheArgs,
+			$extensionPath,
+			ini_get('memory_limit'),
+			$argv,
+		));
+		// pcntl_exec() returns only on failure — continue as we are
+	}
+
+	/**
+	 * The whole command line of the restarted process, php options first.
+	 *
+	 * The restart replaces the process, so everything the current command line
+	 * gave it and a child process does not inherit has to be spelled out again
+	 * - the php.ini situation and the Xdebug mode of InheritedPhpConfig just as
+	 * much as the OPcache setup this restart exists for. Without the former,
+	 * `php -d xdebug.mode=off vendor/bin/phpstan` restarted into a process with
+	 * Xdebug active again, which xdebug-handler then had to restart a second
+	 * time.
+	 *
+	 * @param list<string> $inheritedArgs InheritedPhpConfig::getArgs()
+	 * @param list<string> $opcacheArgs getOpcacheArgs()
+	 * @param list<string> $argv the current $_SERVER['argv'], php options already stripped from it
+	 * @return list<string>
+	 */
+	public static function resolveRestartArgs(array $inheritedArgs, array $opcacheArgs, ?string $extensionPath, string $memoryLimit, array $argv): array
+	{
+		$args = $inheritedArgs;
 		$args[] = '-d';
-		$args[] = 'memory_limit=' . ini_get('memory_limit');
+		$args[] = 'memory_limit=' . $memoryLimit;
 		foreach ($opcacheArgs as $opcacheArg) {
 			$args[] = '-d';
 			$args[] = $opcacheArg;
@@ -153,8 +176,7 @@ public static function restartIfSuitable(array $argv): void
 			$args[] = $arg;
 		}
 
-		pcntl_exec(PHP_BINARY, $args);
-		// pcntl_exec() returns only on failure — continue as we are
+		return $args;
 	}
 
 	/**