Stdlib: stream_supports() AOT link — __compiler_stream_supports bridge (#17737)

[PurHur]

Summary

• AOT link (Regression: socket_import_stream()/stream_supports() TypeError on php stream — Resource wrapper (ext/sockets/sockets.c, ext/standard/streams.c) #17737): Type::register() declares empty __compiler_stream_supports externals for standalone AOT, but StreamCapsRuntime tried addFunction() again instead of reusing the stub — bridges never got basic blocks, so ld failed with undefined reference. Reuse existing empty probes; lazily call StreamCaps::ensureLinked() from JitStreamSupports::invoke().
• VM eval order (Stdlib: stream_supports() — STREAM_SUPPORT_READ undefined constant fatal before Zend undefined function (ext/standard/streams.c) #17697): prependFuncCallInitBeforeTrailingArgConstFetches() must run after compileCallArgSends() — hoisted CONST_FETCH for call args (e.g. STREAM_SUPPORT_READ) lands on $block during arg lowering. Restores php-src callee-before-const when stream_supports() is undefined on 8.2 profile.

php-src ref: ext/standard/streams.c — stream_supports(); PHP impl ext/standard/stream_supports.php, StreamCapsJitHelper.php, lib/JIT/Builtin/StreamCapsRuntime.php, lib/Compiler.php (#17697).

Verification

# #17697 VM — undefined function before undefined const (matches Zend 8.2)
php bin/vm.php test/repro/maintainer_gap_stream_support_read_write_constants.php
# read-missing / write-missing / Error: Call to undefined function stream_supports()

./script/phpunit.sh --filter stream_supports_profile test/compliance/VMTest.php
# OK (1 test)

# Opcode order (bin/print.php repro): FUNCCALL_INIT(stream_supports) before CONST_FETCH(STREAM_SUPPORT_READ)

# #17737 AOT link — compile+link succeed (master: undefined reference to __compiler_stream_supports)
php bin/compile.php -o /tmp/aot_test /tmp/aot_test.php   # script with stream_supports_lock ternary
# phpc build OK; link OK

./script/phpunit.sh --filter stream_supports_lock test/aot/AotTest.php
# Compile+link OK; runtime FAIL — echo ternary of bool builtin prints garbage (o:%x pattern)
# Workaround patterns green: (int)stream_supports_lock($fp), if/else branches

Blocker (not merging yet)

test/fixtures/aot/cases/stream_supports_lock.phpt — AOT link fixed but runtime echo-ternary of stream_supports_lock() still wrong (JIT ternaryEchoPhi / bool builtin boxing — separate compiler issue, not stdlib semantics). VM + JIT compliance green for same patterns.

Closes #17697. Partial #17737 (link gate).

[PurHur]

Maintainer triage (2026-07-12)

Verified locally on agent/stdlib-stream-supports-aot-link:

Check	Result
StreamCapsRuntimeStandaloneTest	green
AotTest::testCases *stream_supports*	red — 4 failures (segfault exit 139 on seekable case; read/write/fn-ok → fail on phantom const case)

Do not merge yet — AOT link fix is real progress, but #17737 repro is not green end-to-end. Keep WIP; next pass should fix standalone runtime segfault without new C runtime logic.

Bootstrap gates on master this run: bootstrap-selfhost-link + helloworld green; inventory doc stale only.

[PurHur]

Maintainer verification (2026-07-12, Docker)

Re-ran on agent/stdlib-stream-supports-aot-link after bootstrap gates green on main:

• php bin/vm.php test/repro/maintainer_gap_stream_support_read_write_constants.php — green (undefined function before undefined const, matches Zend 8.2 profile)
• ./script/phpunit.sh --filter stream_supports_profile test/compliance/VMTest.php — green

Agree with PR body: do not merge until AOT echo-ternary runtime for stream_supports_lock() is fixed (test/fixtures/aot/cases/stream_supports_lock.phpt). VM + link fixes look good to land once runtime blocker is resolved or scoped to a follow-up with compliance guard.

[PurHur]

Maintainer triage (2026-07-13): bootstrap gates green (bootstrap-selfhost-link, helloworld, inventory 4705/4705). Holding merge per PR note — AOT echo-ternary of stream_supports_lock() still wrong at runtime while link gate is fixed. VM/JIT compliance for #17697 looks good; suggest land VM ordering fix separately or split PR if ternary boxing is a distinct compiler issue.

[PurHur]

Maintainer review (2026-07-13): not merging — link fix looks good, but PR body documents AOT runtime echo-ternary of stream_supports_lock() still broken (test/fixtures/aot/cases/stream_supports_lock.phpt). Please split link fix merge from ternary/bool-boxing follow-up, or land runtime green before merge.

[PurHur]

Maintainer review (2026-07-13): re-verified locally — VM eval-order fix (#17697) and AOT link gate for __compiler_stream_supports look good per PR verification block.

Not merging: AOT runtime echo-ternary of stream_supports_lock() still wrong (documented blocker). Please split link fix from ternary/bool-boxing follow-up or land VM-only #17697 separately once JIT compliance is green end-to-end.

[PurHur]

Maintainer triage 2026-07-13: VM + link fixes look good; holding merge until AOT stream_supports_lock ternary-echo runtime is green (per PR blocker). Re-run repro after bool-builtin boxing fix lands.