Stdlib: max_memory_limit INI missing on PROFILE=8.5 — memory_limit ceiling (main/ini)

[PurHur]

Category

stdlib · php-src-strict · PHP 8.5 · INI · pillar 4 correctness

Problem

PHP 8.5 adds INI directive max_memory_limit (INI_SYSTEM, default -1) as a ceiling for memory_limit. Under PHP_COMPILER_PROFILE=8.5, ini_get('max_memory_limit') returns false (unknown directive).

Verified 2026-07-26:

Repro	Zend 8.5	VM PROFILE=8.5
ini_get('max_memory_limit')	"-1" (string)	false

php-src reference

• php.watch PHP 8.5 max_memory_limit
• php-src main/ini / Zend INI registration for max_memory_limit

PHP implementation target

• INI table in PHP (ext/standard / runtime INI helpers already used for memory_limit) — register max_memory_limit when profile ≥ 8.5
• Enforce ceiling when ini_set('memory_limit', …) would exceed it (warning + clamp), matching Zend
• PHP-in-PHP; no new runtime/*.c unless an existing thin INI ABI is required

Repro

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
PHP_COMPILER_PROFILE=8.5 php bin/vm.php test/repro/maintainer_gap_max_memory_limit_ini_85.php'

Done when

• PROFILE=8.5: ini_get('max_memory_limit') returns string (default "-1")
• Setting memory_limit above the ceiling warns and clamps like Zend (when ceiling ≠ -1)
• Unknown / absent on profile < 8.5 (ini_get false) — php-src-strict
• test/repro/maintainer_gap_max_memory_limit_ini_85.php exits 0; compliance .phpt
• PHP-in-PHP

[PurHur]

claim: worker-lane-A — starting this run

Gate probe (pre-claim):

• make bootstrap-selfhost-link: OK
• php script/bootstrap-inventory.php --check: OK 6561/6561
• Implementing max_memory_limit INI for PROFILE=8.5 (php-src-strict)

[PurHur]

Merged #23238

Verification:

• PHP_COMPILER_PROFILE=8.5 php bin/vm.php test/repro/maintainer_gap_max_memory_limit_ini_85.php → default-ok
• PHP_COMPILER_PROFILE=8.4 php bin/vm.php test/repro/maintainer_gap_max_memory_limit_ini_absent.php → absent-ok
• PHP_COMPILER_PROFILE=8.5 php bin/vm.php -d max_memory_limit=64M test/repro/maintainer_gap_max_memory_limit_ini_85_ceiling.php → ceiling-ok
• phpunit --filter max_memory_limit (VM+JIT, exclude llvm AOT): OK 6 tests
• inventory --check: OK 6561/6561

PHP-in-PHP in VmIni / IniJitHelper; php-src ref main/main.c OnChangeMemoryLimit / OnChangeMaxMemoryLimit.