Stdlib: filter_var() — full ext/filter parity (filters, flags, options array, warnings)

[PurHur]

Category

stdlib · php-src-strict · spec refresh 2026-06-20

Problem

filter_var() currently implements a very small subset (validate int + validate email) and restricts $options to null|int only. Zend/php-src supports many filters, options arrays, and flag semantics (including FILTER_NULL_ON_FAILURE, FILTER_FLAG_*, FILTER_REQUIRE_ARRAY, default behavior, and correct return types + warnings).

Concrete dispatch failure (2026-06-20 probe)

FILTER_VALIDATE_IP constant resolves to 275, but filter_var('127.0.0.1', FILTER_VALIDATE_IP) emits Warning: filter_var(): Unknown filter with ID 275 and returns false. Zend returns '127.0.0.1.

Related narrow issues: #9588 (named FILTER_* constants rejected at compile), #4934 (FILTER_VALIDATE_BOOL), #9860 (JIT email path).

php-src reference

• php/php-src ext/filter/filter.c — PHP_FUNCTION(filter_var) + filter dispatch table
• php/php-src ext/filter/logical_filters.c — validation implementations
• php/php-src ext/filter/sanitizing_filters.c
• php/php-src ext/filter/php_filter.h — FILTER_* and FILTER_FLAG_* constants
• PHPTs: ext/filter/tests/filter_var*.phpt, ext/filter/tests/bug*.phpt

Repro (today)

<?php
declare(strict_types=1);

// 1) FILTER_VALIDATE_IP — constant known, dispatch missing
var_export(filter_var('127.0.0.1', FILTER_VALIDATE_IP));
echo "\n";
var_export(filter_var('not-an-ip', FILTER_VALIDATE_IP));
echo "\n";

// 2) Options array should be accepted for validate int.
var_export(filter_var('42', FILTER_VALIDATE_INT, ['options' => ['min_range' => 50]]));
echo "\n";

// 3) URL validation is missing.
var_export(filter_var('https://example.com', FILTER_VALIDATE_URL));
echo "\n";

// 4) FILTER_NULL_ON_FAILURE should return null instead of false.
var_export(filter_var('not-an-int', FILTER_VALIDATE_INT, FILTER_NULL_ON_FAILURE));
echo "\n";

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php repro.php
php bin/vm.php repro.php 2>&1
'

Expected (Zend):

• IP validate: '127.0.0.1' / false
• false for the min_range case
• URL validate success string or false
• null for FILTER_NULL_ON_FAILURE case

VM today: IP case warns Unknown filter with ID 275; others partial/missing.

Scope (this repo)

Path	Work
ext/filter/ or ext/standard/	Register full filter dispatch table
ext/standard/filter_var.php, VmFilter.php	VM SSOT per filter
lib/JIT/	defer until VM parity; note in matrix
Tests	test/compliance/cases/stdlib/filter_var_validate_ip.phpt + umbrella PHPTs

PHP-in-PHP: implement filters in ext/ + shared validation helpers; #9860 shrinks JIT email LLVM after VM parity.

Done when

• filter_var('127.0.0.1', FILTER_VALIDATE_IP) returns validated string (no unknown-filter warning)
• Options arrays + FILTER_NULL_ON_FAILURE behave per Zend on a starter filter set (int, bool, ip, url, email)
• ./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter filter_var' green for new PHPTs
• php script/capability-matrix.php updated

Related

• Stdlib: filter_var() FILTER_* named filter constants rejected — LogicException not validated value (ext/filter/filter.c) #9588, Stdlib: filter_var() FILTER_VALIDATE_BOOL — bool validation parity (ext/filter/filter.c) #4934, php-in-php: JIT StringFilterEmail — route FILTER_VALIDATE_EMAIL through VmFilter PHP not ~343-line LLVM (#4742, #1492) #9860, Stdlib: filter_var() — bool/float/object value types on JIT path (ext/filter/filter.c) #4742, Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: cursor-agent-lane-c — batch (issues #4403)

[PurHur]

Merged via #12577.

Fix: FILTER_VALIDATE_IP (275) now dispatches in filter_var() VM + JIT via VmFilter::isValidIpAddress() (VmInetPure::inet_pton SSOT) and FilterIpJitHelper.

Verification:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php test/repro-maintainer/parity_filter_validate_ip.php'
./script/docker-exec.sh -- bash -lc './vendor/bin/phpunit --filter filter_var_validate_ip'