php-in-php: JIT ErrorHandlerJitRuntime — route set_error_handler through VmErrorHandler PHP not ~556-line LLVM (#1492)

[PurHur]

Category

php-in-php · stdlib

Problem

JIT/AOT link currently emits ~556 lines of hand-written LLVM in lib/JIT/Builtin/ErrorHandlerJitRuntime.php for set_error_handler() / restore_error_handler() / dispatch — duplicating semantics already implemented in PHP at ext/standard/VmErrorHandler.php (235 lines, php-src basic_functions.c parity).

Per #1492 PHP-in-PHP strategy: JIT should call compiled PHP helpers (or thin trampolines), not maintain a parallel error-handler stack in LLVM globals (phpc_error_handler_depth, phpc_error_handler_fn, …).

php-src reference

• php/php-src ext/standard/basic_functions.c — PHP_FUNCTION(set_error_handler), restore_error_handler
• php/php-src Zend/zend_errors.c — user error handler stack

Repro (parity must hold after migration)

<?php
set_error_handler(function (int $no, string $msg) {
    echo "handled:$msg\n";
    return true;
});
trigger_error('boom', E_USER_WARNING);
restore_error_handler();

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/jit.php repro.php
php bin/compile.php repro.php -o /tmp/repro && /tmp/repro
'

VM baseline already green; JIT/AOT must match after deleting LLVM stack logic.

Scope (this repo)

Path	Work
lib/JIT/Builtin/ErrorHandlerJitRuntime.php	Delete/shrink LLVM handler stack; delegate to VmErrorHandler via JIT builtin call
ext/standard/VmErrorHandler.php	SSOT — ensure callable for JIT emit-helper link
lib/JIT/Builtin/ErrorHandlerOutput.php	Wire lowering to PHP path
lib/AOT/runtime/phpc_error_handler.c	Remove or shrink if still linked (note lines deleted in PR)
Tests	Existing error-handler PHPTs + JIT filter

Forbidden: re-implementing handler stack logic in new runtime/*.c.

Done when

• JIT + AOT repro matches VM output (handled:boom)
• ErrorHandlerJitRuntime.php reduced to thin ensureLinked() / trampoline (target: >400 LLVM lines removed)
• ./script/ci-fast.sh --filter ErrorHandler green (VM + JIT smoke)
• PR body cites php-src path + lists C/LLVM symbols deleted

Related

• Regression: set_error_handler() — enum case callback accepted (re-#6234, basic_functions.c) #8784 enum callback validation · Stdlib: error_reporting()/trigger_error() — enum case operands must TypeError (ext/standard/basic_functions.c) #9086 error_reporting enum operands · php-in-php: JIT LastErrorRuntime — route error_get_last/error_clear_last through VmErrorLast PHP not LLVM globals (#1492) #9454 LastErrorRuntime · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: PHP Runtime → PHP — starting this run.

[PurHur]

Merged via #10689.

LLVM shrink: 317 lines removed from ErrorHandlerJitRuntime.php (deleted phpc_error_handler_* globals, malloc/free name copies, inline stack monolith). Stack storage now in ext/standard/ErrorHandlerJitHelper.php.

Verification:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter ErrorHandlerJitHelperTest|ErrorHandlerRuntimeShrinkTest|ErrorHandlerRuntimeStandaloneTest'
# OK (6 tests, 25 assertions)
php bin/jit.php test/compliance/cases/stdlib/set_error_handler_jit.phpt
# handled:1024:test notice:7 / after / done