php-in-php: drop shouldDeferHeavyStreamIoEmitters from ObOutputJitBridge — thin via isThinStandaloneAotMain (#1492)

[PurHur]

Category

php-in-php · runtime-shrink (#1492, peer PendingHeaders #20420 / CliArgv #20401 / StringFormat #20395)

Problem

ObOutputJitBridge::implementObStack still gates deferred inventory ABI stubs on StreamIoRuntime::shouldDeferHeavyStreamIoEmitters() (inventory-emit + NestedJit defer bag). Peer PendingHeadersJitBridge (#20420) already uses Context::isThinStandaloneAotMain() for the same thin-standalone constraint (#16075 / #13571). Under M3 inventory emit / standaloneInitPhase the StreamIo defer bag forces stub __phpc_ob_* bodies instead of honest ObOutputJitHelper NestedJIT when not thin-standalone.

Thin user-script AOT already routes through JitObOutputKernel via ObOutputRuntime::ensureObStackLinked — this change only widens when the bridge emits honest NestedJIT helpers vs inventory stubs.

Mode	Today	Target
Embed / non-thin	ObOutputJitHelper NestedJIT bridges	unchanged
User-script / bootstrap thin AOT	shouldDeferHeavyStreamIoEmitters → implementDeferredInventoryStubs	isThinStandaloneAotMain() → same thin stubs (kernel path elsewhere)
Inventory emit / M3 driver / standaloneInitPhase	deferred via StreamIo defer bag (stubs)	honest NestedJIT helper bridges when not thin

php-src reference

• php/php-src ext/standard/output.c — ob_* / output buffering

PHP implementation target

• lib/JIT/Builtin/ObOutputJitBridge.php — gate implementDeferredInventoryStubs on $context->isThinStandaloneAotMain(); drop shouldDeferHeavyStreamIoEmitters
• test/unit/ObOutputRuntimeShrinkTest.php — assert isThinStandaloneAotMain on bridge, no shouldDeferHeavyStreamIoEmitters

Repro

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
vendor/bin/phpunit test/unit/ObOutputRuntimeShrinkTest.php
make bootstrap-selfhost-vm-driver-execute-probe
'

Done when

• shouldDeferHeavyStreamIoEmitters removed from ObOutputJitBridge
• Thin path gated on isThinStandaloneAotMain only (stubs retained)
• Shrink test green
• make bootstrap-selfhost-vm-driver-execute-probe green
• PR body cites defer-gate lines removed

Refs #1492, #9268, #12951, #19422, #20420, #20401, #20395

[PurHur]

claim: PHP Runtime → PHP — starting this run

Pillar 1 trust (this host):

Gate	Result
php script/bootstrap-inventory.php --check	OK 5590/5590
./script/release-readiness.sh --json	user_release_ready: yes (inventory, spine, readme-sync, north-star5-fast, vm-driver-probe)

Migrating ObOutputJitBridge::implementObStack defer gate from shouldDeferHeavyStreamIoEmitters → isThinStandaloneAotMain (peer #20420).

[PurHur]

Merged via #20444

Verification

• vendor/bin/phpunit ObOutput shrink suite: OK (5 tests, 57 assertions)
• make bootstrap-selfhost-vm-driver-execute-probe: OK
• Pillar 1 pre-change: inventory OK 5590/5590, user_release_ready: yes

Shrink

• Removed StreamIoRuntime::shouldDeferHeavyStreamIoEmitters from ObOutputJitBridge::implementObStack; thin path now isThinStandaloneAotMain() only (peer php-in-php: drop shouldDeferHeavyStreamIoEmitters from PendingHeadersJitBridge — thin via isThinStandaloneAotMain (#1492) #20420).