Language: AOT throw/catch with user-defined class (007 ValidationError execute)

[PurHur]

Problem

examples/007-ThrowsWeb/example.php uses an empty user class ValidationError with throw new ValidationError() / catch (ValidationError $e). VM + phpc serve are green (#2076 ✅, #2084 ✅).

Native AOT link/execute still skips in ThrowsWebAotExecuteTest / ExamplesCompileTest::test007ThrowsWebAotLink via PhpcBuild::isUserClassAotBlocked() — gates #2101 ✅ wired but THROWSWEB_AOT_* remain opt-in (#2135).

This is the language blocker for 007 AOT, distinct from gate-flip issues.

Goal

THROWSWEB_AOT_LINK_GATE=1 ./phpc build --project examples/007-ThrowsWeb
THROWSWEB_AOT_SMOKE_GATE=1 vendor/bin/phpunit --filter ThrowsWebAotExecute

Both green on php-compiler:22.04-dev without skip messages.

Implementation hints

Layer	Files	Notes
AOT compile	lib/AOT/, lib/Compiler.php	Lower empty class + new + throw + typed catch
Objects	lib/JIT/Builtin/Type/Object_.php, linker	Avoid __object__ unsupported native type for empty classes
Try/catch	lib/JIT/TryCatchHelper.php (AOT path)	Reuse VM lowering from #2084
Lint	lib/Lint/UnsupportedRegistry.php	Allow empty class in project entry
Tests	test/unit/ThrowsWebAotExecuteTest.php	Remove skip when build succeeds

Minimal v1 scope

• Single-file project (example.php only) — no methods on ValidationError
• No inheritance (Compiler: Class inheritance (extends) and interfaces #101 deferred)
• Pair with Language: throw expressions and Exception object propagation #195 for Exception builtin later; 007 only needs user empty class

Acceptance criteria

• phpc build --project examples/007-ThrowsWeb exits 0 with LLVM 9
• Built binary with CGI POST email=bad prints invalid (case-insensitive)
• ThrowsWebAotExecuteTest runs (not skipped) when THROWSWEB_AOT_SMOKE_GATE=1
• Unblocks CI: Default THROWSWEB_AOT_LINK_GATE + THROWSWEB_AOT_SMOKE_GATE in ci-local after #2101 #2135 default-on flip and Testing: examples-aot-smoke.sh 007 slice (EXAMPLES_AOT_SMOKE_ONLY=007) #2104 aot-smoke slice

Verification (local / Docker only)

make docker-build-22
./script/docker-exec.sh -- bash -lc '
  source script/php-env.sh
  THROWSWEB_AOT_LINK_GATE=1 THROWSWEB_AOT_SMOKE_GATE=1 \
    vendor/bin/phpunit --filter ThrowsWebAotExecute
'

Do not require GitHub Actions.

Dependencies

• Testing: try/catch compliance PHPT pack (phase 1 of #57) #2084 ✅ — VM try/catch
• Language: throw expressions and Exception object propagation #195 — broader throw/Exception (can land after 007 slice)
• Language: Class methods and property access in JIT #58 — methods (not required for empty class)
• Testing: THROWSWEB_AOT_LINK_GATE + THROWSWEB_AOT_SMOKE_GATE (007-ThrowsWeb) #2101 ✅ — gate wiring only
• CI: Default THROWSWEB_AOT_LINK_GATE + THROWSWEB_AOT_SMOKE_GATE in ci-local after #2101 #2135 — ci-local default-on (after this issue green)

Links

• Example: examples/007-ThrowsWeb/
• ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 Phase 1 Language + Phase 3 Web AOT
• Epic self-host: orthogonal (Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492)

[PurHur]

Run status (issue #2157)

Opened PR https://github.com/PurHur/php-compiler/pull/new/issue-2157-aot-throws-user-class — not merge-ready.

Green

• AOT link for examples/007-ThrowsWeb after vendor patches (php-llvm empty functionType fix).
• VM + GET AOT smoke paths.

Still red

• THROWSWEB_AOT_SMOKE_GATE=1 vendor/bin/phpunit --filter ThrowsWebAotExecute — POST exits 134 (abort) before HTML; catch path not completing.

Landmarks in branch

• Defer try/catch dispatch IR until emitThrow (avoid stale class ids).
• Standalone class registry + phpc_jit_object_is_instance_lcname.
• Skip binding caught exception variable in standalone (007 catch body does not use $e).

Next step: trace why emitThrow still hits uncaught abort (handler stack empty at compile time vs pending throw not set).