[PurHur]

Summary

• Align CompilerVersion::advertisesReadonlyBuiltin() with the forward-profile pattern used by advertisesZendThreadId(): on PHP_COMPILER_PROFILE=8.4, function_exists('readonly') is now true.
• Reference 8.4.0-dev profile (no forward profile) still withholds readonly from introspection to match Zend 8.2 phantom gate.

Root cause

advertisesReadonlyBuiltin() only checked stable CompilerVersion::VERSION >= 8.4.0, so forward-profile callers could invoke readonly($o) but function_exists('readonly') returned false.

php-src reference

• ext/standard/basic_functions.c — PHP_FUNCTION(readonly) registration on PHP 8.4+

PHP implementation

• lib/CompilerVersion.php — introspection gate
• ext/standard/BuiltinIntrospectionPolicy.php — unchanged (already routes through gate)

C runtime shrink

No new C; introspection-only PHP gate fix.

Verification

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
PHP_COMPILER_PROFILE=8.4 php bin/vm.php test/repro-maintainer/issue_readonly_function.php'
# true
# Cannot modify readonly object of class stdClass
# reapply: Object is already readonly

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
PHP_COMPILER_PROFILE=8.4 vendor/bin/phpunit --filter testReadonlyAdvertisedOnForwardProfile84 test/unit/ForwardProfilePhantomIntrospectionTest.php'
# OK (1 test, 5 assertions)

./script/ci-fast.sh
# exit 0

Closes #17693

Made with Cursor