Language: Generator return type void accepted — must fatal at compile time (Zend/zend_compile.c) #11666

Summary

Functions that yield with a declared : void return type compile and run on VM; Zend/php-src rejects them at compile time with Generator return type must be a supertype of Generator, void given.

php-src reference

• php/php-src Zend/zend_compile.c — generator return type validation (zend_handle_generator_func_return_type)
• php/php-src Zend/zend_generators.c — generator object semantics

Repro

test/repro/maintainer_gap_generator_void_return.php

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

Zend: compile-time fatal (exit 255)

VM: prints 1 (exit 0)

Expected (php-src-strict)

Compile-time fatal — generators cannot declare void return type.

Implementation hints

• Fix in lib/ compile-time return-type validation for generator functions (PHP lowering)
• No new C runtime branches

Done when

• Repro fails at compile time on VM/JIT/AOT consistent with Zend
• Targeted compliance guard under test/compliance/ or test/repro/