Stdlib: getmxrr() — MX record lookup (ext/standard/dns.c parity)

[PurHur]

Category

stdlib

Problem

getmxrr(string $hostname, array &$mxhosts, array &$weight = null): bool is missing. Mail routing and hostname validation code depends on MX lookups; function_exists('getmxrr') is false under bin/vm.php (host PHP has it).

Split from #3258 (A/AAAA/dns_get_record family) so MX work can land independently.

php-src reference

• php/php-src ext/standard/dns.c — PHP_FUNCTION(getmxrr)
• php/php-src ext/standard/basic_functions.c — registration alongside checkdnsrr

Repro (failure today)

<?php
$hosts = [];
$weights = [];
$ok = getmxrr('example.com', $hosts, $weights);
var_export($ok);
echo "\n", count($hosts), "\n";

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php repro.php'
# Fatal: Call to undefined function getmxrr()

Zend (reference):

php repro.php
# bool(true) and non-empty $hosts on typical resolver

Scope (this repo)

• ext/standard/getmxrr.php (new) — VM via host getmxrr() initially (same pattern as gethostbyname in Stdlib: gethostbyname() / dns_get_record() / checkdnsrr() — DNS lookups (ext/standard/dns.c parity) #3258)
• ext/standard/Module.php — register builtin
• Optional JIT: document VM-only v1 in docs/capabilities.md

Done when

• Repro runs without undefined-function fatal on VM
• $mxhosts populated as string list; $weights as int list when passed (Zend subset)
• Returns false when no MX records (match Zend on test hostname)
• ./script/ci-fast.sh --filter getmxrr green

Verification

./script/ci-fast.sh --filter getmxrr

Related

• Stdlib: gethostbyname() / dns_get_record() / checkdnsrr() — DNS lookups (ext/standard/dns.c parity) #3258 — dns_get_record / checkdnsrr / gethostbyname

[PurHur]

Closed with #4125 in #7941 — getmxrr() registered alongside dns_get_mx(), shared VmDns::dnsGetMx() + VmDnsMx by-ref population.

[PurHur]

claim: PHP Compiler STD Lib — starting this run

Implemented getmxrr() JIT/AOT via shared JitDnsGetMx materializer (same path as dns_get_mx). PR #8051 — VM + JIT + AOT verification green in Docker.

[PurHur]

Merged via #8051.

Verification (Docker):

• vendor/bin/phpunit test/unit/GetmxrrBuiltinTest.php — OK (3 tests, includes AOT lint)
• vendor/bin/phpunit --filter getmxrr test/ — OK (VM + JIT getmxrr_jit.phpt)
• vendor/bin/phpunit test/aot/AotTest.php --filter getmxrr — OK (AOT getmxrr.phpt)
• dns_get_mx regression tests unchanged

getmxrr() now shares JitDnsGetMx compile-time MX materializer with dns_get_mx(); no new C runtime.