php-in-php: JIT SessionCreateIdRuntime — route session_create_id() through VmSession PHP not LLVM (#1492)

[PurHur]

Category

php-in-php · stdlib · php-src-strict

Problem

session_create_id() JIT uses lib/JIT/Builtin/SessionCreateIdRuntime.php (~287 lines LLVM) with hex table + entropy logic duplicated from VM, although ext/standard/VmSession.php already implements php-src semantics (php_session_create_id).

Workers should route JIT/AOT through compiled PHP helpers (same pattern as #9495 SessionStorageRuntime, #9411 SessionGcRuntime).

php-src reference

• php/php-src ext/session/session.c — php_session_create_id, prefix handling
• php/php-src ext/session/session.stub.php — session_create_id(?string $prefix = null): string

Repro (parity guard during migration)

<?php
$id = session_create_id();
var_export(is_string($id));
echo "\n";
var_export(strlen($id) >= 22 && strlen($id) <= 32);
echo "\n";
$id2 = session_create_id('phpc-');
var_export(str_starts_with($id2, 'phpc-'));
echo "\n";

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
wc -l lib/JIT/Builtin/SessionCreateIdRuntime.php
php bin/vm.php repro.php
php bin/jit.php repro.php
'

Check	VM (SSOT)	JIT today (gap)
returns string	OK	must match after migration
length in php-src range	OK	must match
optional $prefix	verify VM	must match

Scope (PHP-in-PHP first)

Path	Work
ext/standard/SessionCreateIdJitHelper.php (new)	wrap VmSession::createId()
lib/JIT/Builtin/SessionCreateIdRuntime.php	thin bridge; delete hex/entropy LLVM
lib/JIT/Builtin/Type.php / session batch	register helper link
Tests	test/compliance/cases/stdlib/session_create_id_jit.phpt

Forbidden: new session ID logic in runtime/*.c.

Done when (php-src-strict)

• JIT/AOT repro matches VM/Zend on string type, length, prefix
• SessionCreateIdRuntime.php ≤ thin trampoline; PR notes LLVM lines removed
• ./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter session_create_id_jit' green
• Session lifecycle compliance (Stdlib: session_abort()/session_reset()/session_create_id() — PHP 7+ session lifecycle APIs (ext/session) #6002, php-in-php: JIT SessionLifecycleRuntime — route session_start/write_close/destroy through VmSession PHP not ~460-line LLVM (#1492) #9446) unchanged

Related

• Stdlib: session_abort()/session_reset()/session_create_id() — PHP 7+ session lifecycle APIs (ext/session) #6002 · php-in-php: JIT SessionLifecycleRuntime — route session_start/write_close/destroy through VmSession PHP not ~460-line LLVM (#1492) #9446 session lifecycle · php-in-php: JIT SessionStorageRuntime — route session file I/O through VmSession PHP not ~1.1k-line LLVM (#1492) #9495 SessionStorageRuntime · North star Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: PHP Runtime → PHP — starting this run.

[PurHur]

Merged via #10861.

PHP path: ext/standard/SessionCreateIdJitHelper.php → VmSession::createId() (php-src ext/session/session.c).

LLVM shrink: SessionCreateIdRuntime.php 287 → 235 LOC — removed hex-table / __compiler_random_bytes entropy loop; thin ABI bridges only.

Verification: SessionCreateIdRuntimeShrinkTest (3/3), compliance session_create_id* JIT+VM (4/4), session_create_id_jit.phpt idok/prefixed on VM+JIT, make bootstrap-selfhost-vm-driver-execute-probe OK.