Language: Generators (yield and yield from)

[PurHur]

Category

language

Problem (updated May 2026)

VM generators landed — yield, keyed yield (#3085), and yield from iterate via GeneratorState + foreach. JIT and AOT remain no per docs/capabilities-syntax.md; bin/jit.php falls back to VM via Block::requiresVmLowering.

This umbrella issue tracks remaining parity; implement via child issues:

• JIT: #3074
• AOT: #3115

Do not duplicate VM work here.

php-src reference

• Zend/zend_compile.c — zend_compile_generator(), yield / yield from opcodes
• Zend/zend_generators.c — Generator object, send/throw, delegate

Repro (today)

<?php
function gen(): Generator {
    yield 1;
    yield 'a' => 2;
    yield from [3, 4];
}
echo implode(',', iterator_to_array(gen()));

# VM — passes
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php repro.php'

# JIT — VM fallback (no native yield IR)
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/jit.php repro.php'

# AOT — blocked
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/compile.php -o /tmp/gen repro.php && /tmp/gen'

Expected (Zend): 1,2,3,4
Actual (JIT/AOT): no LLVM suspend/resume; AOT may error at compile or runtime stub.

Existing compliance: test/compliance/cases/language/generator_*.phpt (VM).

Scope (this repo) — closure criteria for umbrella

• #3074 closed — JIT yield opcodes
• #3115 closed — AOT suspend/resume
• php script/capability-syntax.php — Generators row JIT/AOT yes
• docs/generators-jit-aot.md updated

Done when (this issue)

All generator compliance PHPTs pass under VM + JIT + AOT without VM fallback; child issues closed.

Dependencies

• Language: Implement foreach (CFG → VM → JIT) #53 ✅ foreach (iterator protocol)
• feat(generators): SSOT VM-fallback, keyed-yield fix, JIT stub (#167) #3085 ✅ keyed yield VM
• Child: Language: Generator JIT lowering (yield opcodes) #3074, Language: Generator AOT lowering (yield / suspend resume) #3115

De-duplication

Issue	Role
#167	Umbrella — close when JIT+AOT land
#3074	JIT lowering (claim this for JIT work)
#3115	AOT lowering (claim this for AOT work)
#72	Closures — separate capture model

Links

• Wave 2: #1238
• Epic: #2483
• North star: #1492

[PurHur]

Harness-safe verification note

This issue currently shows raw docker run -v \"$(pwd):/compiler\" ... in the Verification section. On Runforge/harness hosts that bind-mount is often empty.

Preferred verification for contributors (local/Docker only):

make test-harness
# targeted:
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && ./script/ci-fast.sh --filter Generator'

(Please keep the acceptance criteria VM-first; track any JIT work as a follow-up issue once VM/compliance is green.)