php-in-php: VmHrtime/VmDns — delete host ext/ffi clock_gettime/getaddrinfo shims (bootstrap)

[PurHur]

Category

php-in-php | bootstrap

Problem

hrtime() and DNS hostname builtins (gethostbyname(), gethostbynamel(), …) use host ext/ffi in ext/standard/VmHrtime.php and VmDns.php. Self-host / AOT bundles that omit Zend FFI cannot provide monotonic timing or libc resolver calls — breaking perf probes (hrtime) and any compile-time / runtime path that resolves hostnames.

JIT already exposes __compiler_hrtime_* in lib/JIT/Builtin/StringHrtime.php; VM should share the same native path without instantiating FFI::cdef in PHP.

php-src reference

• php/php-src ext/standard/hrtime.c — clock_gettime(CLOCK_MONOTONIC)
• php/php-src ext/standard/dns.c — php_dns_* / getaddrinfo
• libc: clock_gettime, getaddrinfo — thin AOT syscall ABI only if PHP lowering cannot reach them

Repro

A — hrtime

<?php
var_export(is_array(hrtime()));
var_export(hrtime(true) > 0);

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php repro.php
php repro.php
'

B — DNS

<?php
var_export(gethostbyname('localhost'));

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php repro.php'

Bootstrap gap: grep extension_loaded('ffi') in VmHrtime.php / VmDns.php — when false, behavior is degraded or absent; document in PR.

Scope (this repo)

Module	Path
VM	ext/standard/VmHrtime.php, VmDns.php — route through existing JIT/native symbols or new thin __compiler_* in linked runtime
JIT/AOT	lib/JIT/Builtin/StringHrtime.php (reuse)
Builtins	ext/standard/hrtime.php, DNS wrappers in Module.php
Tests	test/compliance/cases/stdlib/hrtime_native.phpt, gethostbyname_native.phpt

PHP-in-PHP first: port resolver logic to ext/standard/ PHP where possible; keep C as syscall trampoline only.

Done when

• Repro A passes on VM without host ext/ffi (monotonic array + positive int ns)
• gethostbyname('localhost') returns 127.0.0.1 or ::1 without FFI
• PR body lists lines removed from VmHrtime.php / VmDns.php FFI blocks
• ./script/ci-fast.sh --filter hrtime green

Verification

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter hrtime'
make bootstrap-selfhost-link

Related

• Stdlib: hrtime() — TypeError for non-bool as_number + JIT clock_gettime parity (ext/standard/hrtime.c) #4583 hrtime TypeError parity · php-in-php: hrtime() VM — remove host \hrtime() delegation (ext/standard/hrtime.c) #5174 / Stdlib: hrtime() — monotonic high-resolution clock (ext/standard parity) #3195 hrtime history · Stdlib: gethostbyname() / dns_get_record() / checkdnsrr() — DNS lookups (ext/standard/dns.c parity) #3258 DNS API · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492