php-in-php: drop always-on Builtin\Type getrandom after NestedJIT urandom migration (#29531 shape)

[PurHur]

Category

php-in-php · runtime-shrink (#1492, peer #32110 sprintf / #29531 random_bytes)

Problem

Always-on Builtin\Type still registers libc getrandom(3) (Type::register() addFunction('getrandom')) even though:

1. User-script random_bytes() already lives in PHP (RandomBytesJitHelper / StringRandomBytes / __compiler_random_bytes) — not this always-on libc row.
2. NestedJIT JitRandomBytesKernel already reads /dev/urandom via module-local open/read (LibcExtern::ensurePosixFd, php-in-php: drop always-on LibcExtern open/close/read/write after NestedJIT declares module-locally (#31764 shape) #31817 / php-in-php: RandomBytesJitHelper → @random_bytes NestedJIT leaf; delete phpc_random_bytes_kernel (re-#29364 / gethostname) #29531). It does not call getrandom(3).
3. There are zero lookupFunction('getrandom') consumers under lib/ + ext/. The always-on row is dead C surface on every JIT/AOT module.

Path	Today	Target
User-script random_bytes()	PHP helpers (RandomBytesJitHelper / StringRandomBytes)	unchanged
NestedJIT kernel	/dev/urandom via open/read	unchanged
Builtin\Type	always-on libc getrandom	drop declare
VM	VmRandomPure / VmRandomNative (no getrandom FFI, #8921 / #12181)	unchanged

php-src reference

• php/php-src ext/standard/random.c — php_random_bytes() (getrandom / /dev/urandom fallback)
• php/php-src ext/random/random.c — PHP_FUNCTION(random_bytes)

PHP implementation target

• lib/JIT/Builtin/Type.php — drop always-on libc getrandom declare
• test/unit/GetrandomRuntimeShrinkTest.php — assert Type no longer addFunction('getrandom'); no NestedJIT lookupFunction('getrandom') remains

Repro

./script/phpunit.sh --filter 'GetrandomRuntimeShrinkTest|StringRandomBytesRuntimeShrinkTest|VmRandomPureRuntimeShrinkTest'

Done when

• Builtin\Type has no always-on libc getrandom declare
• No NestedJIT lookupFunction('getrandom') remains
• User-script random_bytes() still goes through PHP helpers / /dev/urandom kernel
• php-src-strict; user-script random_bytes() behavior unchanged
• exit/abort always-on decls remain (live consumers)

[PurHur]

claim: PHP Runtime → PHP — starting this run

Dropping the dead always-on Builtin\Type libc getrandom(3) declare. User-script random_bytes() stays on PHP helpers; NestedJIT already uses /dev/urandom via open/read (#29531).

[PurHur]

Merged in #32140

Dropped the dead always-on libc getrandom(3) declare from lib/JIT/Builtin/Type.php. User-script random_bytes() stays on PHP helpers; NestedJIT still uses /dev/urandom via open/read.

Verification:

• ./script/phpunit.sh --filter GetrandomRuntimeShrinkTest — OK (3 tests, 11 assertions)
• related random_bytes shrink tests — OK (20 tests, 73 assertions)
• php bin/vm.php -r 'echo strlen(random_bytes(16))' via docker-exec — 16