Language: JIT support for non-void function return types

[PurHur]

Category

language

Problem

User-defined functions with non-void return types (: string, : ?int, etc.) must compile in JIT and AOT, not only VM. docs/capabilities-syntax.md still lists Method return types: JIT = no (#55).

MiniWebApp Router helpers, template functions, and self-host lib/ code rely on typed returns:

function greet(string $name): string { return 'Hello '.$name; }
function route(string $path): ?string { return null; }

php-src reference

• Zend/zend_compile.c — zend_compile_return, return type enforcement
• Zend/zend_execute.c — ZEND_RETURN, ZEND_RETURN_VALUE
• Zend/zend_type.c — return type validation

Repro (today)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php -r "function f(): string { return \"ok\"; } echo f();"
php bin/jit.php -r "function f(): string { return \"ok\"; } echo f();"
'

Zend / VM target: prints ok. JIT gap: confirm whether bin/jit.php prints ok, fatals, or segfaults; this issue closes when JIT + AOT match VM.

AOT slice:

# Write /tmp/ret.php with greet() above, then:
php bin/compile.php /tmp/ret.php /tmp/ret-out && /tmp/ret-out

Scope (this repo)

Layer	Files	Notes
Compiler	lib/Compiler.php	TYPE_RETURN value operand for user functions
VM	lib/VM.php	Already supports returns for many paths — regression guard
JIT	lib/JIT.php, lib/JIT.pre	OpCode::TYPE_RETURN LLVM ret with boxed __value__* per type
AOT	lib/AOT/	Same ABI as JIT
Caps	script/capability-syntax.php	Flip JIT row for method return types
Tests	test/compliance/cases/function_return_*.phpt	string, int, bool, null, array

v1 types: void, string, int, bool, float, array, ?T for same. Defer: object, union/intersection returns.

Done when

• JIT repro prints ok for : string return (no LogicException / segfault)
• Compliance PHPTs for VM + JIT (@group llvm) on return types above
• AOT linked binary runs return-type fixture
• docs/capabilities-syntax.md — method return types JIT = yes (subset documented)
• examples/003-MiniWebApp JIT project gate unblocked where blocked only by returns (Testing: JIT smoke for phpc build --project on 003-MiniWebApp #587)

Verification

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter function_return'
make test-harness ARGS='--filter function_return'  # LLVM hosts

Dependencies

• Language: Class methods and property access in JIT #58 / Language: Visibility, constructors, and destructors #145 — OOP methods (parallel JIT dispatch work)
• Language: include/require in JIT and AOT (multi-file applications) #54 — multi-file includes for helper functions
• Does not duplicate Compiler: Return type declarations on user functions (VM + JIT) #205 (declarations) — this is codegen/ABI

Links

• ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 Phase 2
• Testing: MiniWebApp VM OOP e2e — phpc serve Router when #58/#145/#54 land #2059 MiniWebApp OOP (return types on Router methods)

[PurHur]

claim: worker-lane-b-automation — starting this run

[PurHur]

PR opened: native JIT return lowering + compliance/AOT tests. IR verify green for string/int/bool/float/array/nullable/method returns. MCJIT execute still blocked by #2055 in harness; AOT greet(): string fixture runs.