feat(plugin): serve ProcessExecutor as a proxy stub

Composer reaches this class two ways: the object graph hands one out through
Composer::getLoop()->getProcessExecutor(), and plugins write
`new ProcessExecutor($io)` freely. Both bind to a Rust-side entity, so the
timeout the run shares -- seeded from process-timeout and rewritten while the
run is in flight -- has one value instead of one per world, and the executor
can still be passed to the classes that take one (`new Filesystem($process)`).

Three things the stub generator was missing came with it:

- By-ref parameters. The call carries their positions and the answer carries
  what each holds afterwards; a position the answer omits was never assigned
  to, which is what PHP does with an untouched by-ref parameter.
  ProcessExecutor::execute is the only one on a proxied class.
- Argument arity, reproduced where the real body reads func_num_args().
  execute($cmd) forwards the child's output and execute($cmd, $out) captures
  it, and nothing but the argument count separates the two.
- Static methods that cannot run in the worker. One that reads a static
  property the Rust side owns, or that reaches a guarded class, forwards
  through __shirabeCallStatic instead of being materialized. That also fixes
  Filesystem::isLocalPath and getPlatformPath, whose materialized bodies
  called the guarded Composer\Util\Platform.

The async surface stays an explicit error. executeAsync resolves its promise
with a Symfony Process, whose proc_open() resource and pipes belong to
whichever process called start(), so a Rust-side spawn has none to hand back;
running the real start() in the worker needs a promise representation that
crosses the boundary unresolved.

The fixture project drives the whole synchronous surface from plugin code and
compares the trace against upstream Composer byte for byte.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 176 insertions, 0 deletions

diff --git a/crates/shirabe-php-rpc/php/stubs/Composer/Util/ProcessExecutor.php b/crates/shirabe-php-rpc/php/stubs/Composer/Util/ProcessExecutor.php
new file mode 100644
index 00000000..dfa1f0d2
--- /dev/null
+++ b/crates/shirabe-php-rpc/php/stubs/Composer/Util/ProcessExecutor.php
@@ -0,0 +1,176 @@
+<?php
+
+// Generated by scripts/plugin-stub-generator; do not edit by hand.
+// Proxy stub for Composer\Util\ProcessExecutor: the public surface forwards to the Rust-side entity over RPC.
+
+namespace Composer\Util;
+
+use Composer\IO\IOInterface;
+use React\Promise\PromiseInterface;
+
+class ProcessExecutor implements \ShirabeRustStub
+{
+    /** @var int */
+    protected $__rhandle;
+    /** @var int */
+    protected $__epoch;
+
+    /**
+     * Binds a stub the registry built for an existing entity. Proxy instantiation bypasses
+     * the constructor, which belongs to plugin code building a new entity instead.
+     */
+    public function __shirabeBind(int $rhandle, int $epoch): void
+    {
+        $this->__rhandle = $rhandle;
+        $this->__epoch = $epoch;
+    }
+
+    public function __destruct()
+    {
+        \ShirabeRustObjectRegistry::release($this->__rhandle);
+    }
+
+    public function __shirabeRustHandleDescriptor(): array
+    {
+        return [
+            '__rhandle' => $this->__rhandle,
+            '__class' => static::class,
+            '__epoch' => $this->__epoch,
+        ];
+    }
+
+    public function __clone()
+    {
+        // PHP has already shallow-copied this stub, so both copies would point at one
+        // entity and release it twice. The Rust side clones the entity instead, applying
+        // whatever __clone semantics the real class defines, and this copy rebinds to the
+        // fresh handle. Entities without clone semantics answer with an explicit error.
+        [$this->__rhandle, $this->__epoch] = \ShirabeRpcRuntime::callRust($this->__rhandle, '__shirabeClone', []);
+        \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
+    }
+
+    public function __get($name)
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, '__get', [$name]);
+    }
+
+    public function __set($name, $value): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, '__set', [$name, $value]);
+    }
+
+    public function __isset($name): bool
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, '__isset', [$name]);
+    }
+
+    public function __unset($name): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, '__unset', [$name]);
+    }
+
+    public function __construct(?IOInterface $io = null)
+    {
+        [$this->__rhandle, $this->__epoch] = \ShirabeRpcRuntime::callRust(0, '__shirabeConstruct', [static::class, [$io]]);
+        \ShirabeRustObjectRegistry::adopt($this->__rhandle, $this);
+    }
+
+    private const STATUS_QUEUED = 1;
+    private const STATUS_STARTED = 2;
+    private const STATUS_COMPLETED = 3;
+    private const STATUS_FAILED = 4;
+    private const STATUS_ABORTED = 5;
+    private const BUILTIN_CMD_COMMANDS = [
+        'assoc', 'break', 'call', 'cd', 'chdir', 'cls', 'color', 'copy', 'date',
+        'del', 'dir', 'echo', 'endlocal', 'erase', 'exit', 'for', 'ftype', 'goto',
+        'help', 'if', 'label', 'md', 'mkdir', 'mklink', 'move', 'path', 'pause',
+        'popd', 'prompt', 'pushd', 'rd', 'rem', 'ren', 'rename', 'rmdir', 'set',
+        'setlocal', 'shift', 'start', 'time', 'title', 'type', 'ver', 'vol',
+    ];
+    private const GIT_CMDS_NEED_GIT_DIR = [
+        ['show'],
+        ['log'],
+        ['branch'],
+        ['remote', 'set-url'],
+    ];
+
+    // Forwarded rather than materialized: it reads the static property $timeout, whose value the Rust side owns.
+    public static function getTimeout(): int
+    {
+        return \ShirabeRpcRuntime::callRust(0, '__shirabeCallStatic', [self::class, 'getTimeout', []]);
+    }
+
+    // Forwarded rather than materialized: it reads the static property $timeout, whose value the Rust side owns.
+    public static function setTimeout(int $timeout): void
+    {
+        \ShirabeRpcRuntime::callRust(0, '__shirabeCallStatic', [self::class, 'setTimeout', [$timeout]]);
+    }
+
+    // Forwarded rather than materialized: it references Composer\Util\Platform, which a guard shadows in the worker.
+    public static function escape($argument): string
+    {
+        return \ShirabeRpcRuntime::callRust(0, '__shirabeCallStatic', [self::class, 'escape', [$argument]]);
+    }
+
+    public function execute($command, &$output = null, ?string $cwd = null): int
+    {
+        $__args = [$command, $output, $cwd];
+        array_splice($__args, func_num_args());
+        $__out = [];
+        $__result = \ShirabeRpcRuntime::callRust($this->__rhandle, 'execute', $__args, [1], $__out);
+        if (array_key_exists(1, $__out)) {
+            $output = $__out[1];
+        }
+        return $__result;
+    }
+
+    public function executeTty($command, ?string $cwd = null): int
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'executeTty', [$command, $cwd]);
+    }
+
+    public function executeAsync($command, ?string $cwd = null): PromiseInterface
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'executeAsync', [$command, $cwd]);
+    }
+
+    public function setMaxJobs(int $maxJobs): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, 'setMaxJobs', [$maxJobs]);
+    }
+
+    public function resetMaxJobs(): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, 'resetMaxJobs', []);
+    }
+
+    public function wait($index = null): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, 'wait', [$index]);
+    }
+
+    public function enableAsync(): void
+    {
+        \ShirabeRpcRuntime::callRust($this->__rhandle, 'enableAsync', []);
+    }
+
+    public function countActiveJobs($index = null): int
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'countActiveJobs', [$index]);
+    }
+
+    public function splitLines(?string $output): array
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'splitLines', [$output]);
+    }
+
+    public function getErrorOutput(): string
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'getErrorOutput', []);
+    }
+
+    public function requiresGitDirEnv($command): bool
+    {
+        return \ShirabeRpcRuntime::callRust($this->__rhandle, 'requiresGitDirEnv', [$command]);
+    }
+}