Stdlib: mb_trim()/mb_ltrim()/mb_rtrim() named parameters rejected — LogicException not trimmed string (ext/mbstring/mbstring.c)

[PurHur]

Category

stdlib · php-src-strict

Problem

PHP 8.4 mb_trim(), mb_ltrim(), and mb_rtrim() accept named parameters characters: and encoding: per php-src stubs. Positional calls work; named characters: (and encoding:) throw LogicException: Too many arguments to function call instead of trimming.

Root cause: Internal builtin metadata does not expose php-src parameter names to lib/VM/NamedArgs.php, so named slots are treated as excess arguments.

php-src reference

• php/php-src ext/mbstring/mbstring.stub.php — mb_trim(string $string, ?string $characters = null, ?string $encoding = null)
• php/php-src ext/mbstring/mbstring.c — php_mb_trim / mb_trim_common

Repro (failure today)

<?php
$s = '--héllo--';
var_dump(mb_trim($s, '-'));              // OK: string(6) "héllo"
var_dump(mb_trim($s, characters: '-'));  // FAIL: LogicException

Also in repo: test/repro/maintainer_gap_mb_trim_named_characters.php

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

Implementation hints (PHP-in-PHP)

• Register php-src parameter names on mb_trim / mb_ltrim / mb_rtrim Internal builtins (same pattern as other named-arg-aware stdlib)
• ext/mbstring/VmMbstring.php — runTrimBuiltin() already handles positional characters / encoding; wire named resolution before arg count check
• Mirror in ext/mbstring/JitMbTrim.php for JIT/AOT when in scope
• No new C runtime

Scope

• ext/mbstring/mb_trim.php, mb_ltrim.php, mb_rtrim.php
• ext/mbstring/VmMbstring.php, JitMbTrim.php
• lib/VM/NamedArgs.php (if shared Internal metadata fix)

Done when

• mb_trim($s, characters: '-') returns trimmed string under VM (php-src-strict)
• encoding: named arg works; mb_ltrim / mb_rtrim agree
• Positional calls unchanged
• Smallest compliance guard or repro script green

Verification

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

[PurHur]

claim: PHP Compiler STD Lib — starting this run

[PurHur]

Merged via #9855.

Verification (all green):

• VM repro: php bin/vm.php test/repro/maintainer_gap_mb_trim_named_characters.php
• Compliance + AOT: php vendor/bin/phpunit --filter mb_trim_named_characters → OK (3 tests, 7 assertions)
• AOT lint: php bin/compile.php -l test/repro/maintainer_gap_mb_trim_named_characters.php

Fix: BuiltinParamNames entries for mb_trim/mb_ltrim/mb_rtrim + sparse named-arg slots in VmMbstring::runTrimBuiltin().