Bootstrap: extension_loaded('hash'/'json') false while in-tree handlers are active (ext/standard/info.c)

[PurHur]

Category

bootstrap | stdlib

Problem

In-tree modules register builtins (hash(), json_encode(), json_decode(), …) but extension_loaded('hash') and extension_loaded('json') return false, and those names are missing from get_loaded_extensions().

Framework/feature probes and self-host scripts gate on extension_loaded() exactly like Zend — false negatives cause fallback paths or fatal misconfiguration even when functions work.

Verified 2026-06-07:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php -r "var_export(function_exists(\"hash\")); echo \"\\n\";
var_export(extension_loaded(\"hash\")); echo \"\\n\";
var_export(in_array(\"hash\", get_loaded_extensions(), true)); echo \"\\n\";
var_export(function_exists(\"json_encode\")); echo \"\\n\";
var_export(extension_loaded(\"json\")); echo \"\\n\";"'
# true / false / false / true / false

php-src reference

• php/php-src ext/standard/info.c — PHP_FUNCTION(extension_loaded), get_loaded_extensions
• Module registration: ext/hash/hash.c, ext/json/json.c — zend_module_entry names

Repro

<?php
declare(strict_types=1);

foreach (['hash', 'json', 'date', 'random'] as $ext) {
    echo $ext, ': fn=', (int) function_exists($ext === 'hash' ? 'hash' : ($ext === 'json' ? 'json_encode' : $ext)), 
         ' loaded=', (int) extension_loaded($ext), "\n";
}
print_r(get_loaded_extensions());

Zend: extension_loaded('hash') true when ext/hash enabled; list includes module names.

VM today: functions may work while extension_loaded is false (see probe above).

Scope (this repo)

Layer	Path	Notes
Module registry	ext/*/Module.php, runtime loader in lib/Runtime.php	Track logical extension names when modules register
Builtins	ext/standard/extension_loaded.php, get_loaded_extensions.php	Read registry, not host extension_loaded()
Bootstrap	script/bootstrap-inventory.php probes	align with M5 vendor/self-host gates
Tests	test/compliance/cases/stdlib/extension_loaded_in_tree.phpt	hash/json/date at minimum

PHP-in-PHP first: registry table in PHP (ext/standard/ModuleRegistry.php or similar), not new C module list.

Umbrella: #4839 full registry parity — implement this slice first (modules that already have handlers).

Done when

• extension_loaded('hash') and extension_loaded('json') true when respective handlers registered
• get_loaded_extensions() includes hash, json, standard, types, … matching active in-tree modules
• extension_loaded('nonexistent') still false
• ./script/ci-fast.sh --filter extension_loaded_in_tree green
• Document registry in capability matrix / bootstrap inventory

Verification

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter extension_loaded_in_tree'
php script/bootstrap-inventory.php --check

Links

• Stdlib: get_loaded_extensions() — full module registry parity (phase 2 of #3204) #4839 full list · php-in-php: phpversion($extension) — must resolve registered ext/* modules (zip, spl, filter, …) (ext/standard/info.c) #6372 phpversion($ext) · Bootstrap: ext/random module skeleton — register Random\\Randomizer before handlers (phase 0 of #3722) #7102 ext/random skeleton · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: agent-lane-c — starting this run

[PurHur]

Merged via #7195

Fix: ext/standard/ModuleRegistry.php registers logical extension names when Runtime::load() loads each in-tree module; ext/standard/Module also registers bundled json and date. VmInfo + JIT StringInfo read the registry instead of a hardcoded four-name list.

Verification:
```bash
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter extension_loaded_in_tree'

OK (2 tests, 2 assertions) — VM + JIT

php bin/vm.php -r "var_export(extension_loaded('hash')); echo "\n"; var_export(extension_loaded('json'));"

true / true

```