Self-host: Unsupported expression CFG batch tracker (post-#2254 triage)

[PurHur]

Category

bootstrap

Milestone

M3/M5 — CFG expression lowering backlog (parent #1492 / stmt sibling #2276)

Problem

lib/Compiler.php ends compileExpr() with:

throw new \LogicException("Unsupported expression: " . $expr->getType());

docs/bootstrap-inventory.md lists Unsupported expression: among recurring CFG warnings. #2276 tracks Unknown Stmt Type: batches; this issue tracks expression kinds from triage.

May 2026 harness note: static lint sweep is currently clean:

./script/docker-exec.sh -- bash -lc './phpc lint --bootstrap-inventory --check'
# 0 unsupported / 701 scanned

./script/docker-exec.sh -- bash -lc 'php script/bootstrap-inventory-triage.php --top 10'
# (no CFG gaps when lint is clean)

The live M3 blocker is native Runtime parse spine at execute time (#2566), not static unsupported expressions. Reprioritize this tracker after emit-TU ladder green unless a new triage run surfaces expression kinds blocking a specific inventory file.

php-src reference

• Zend/zend_compile.c — zend_compile_expr() switch over zend_ast kinds
• Zend/zend_ast.c — expression AST node catalog (reference when mapping php-cfg Expr_* gaps)

Repro (refresh batch table)

./script/docker-exec.sh -- bash -lc 'php script/bootstrap-inventory-triage.php --top 30 | grep -i "Unsupported expression" || true'
./script/docker-exec.sh -- bash -lc './phpc lint --bootstrap-inventory --json 2>/dev/null | python3 -c "import json,sys; d=json.load(sys.stdin); print(list(d.get(\"unsupported\",{}).keys())[:15])" || true'

When a spine file regresses, capture one failing path:

./script/docker-exec.sh -- bash -lc './phpc lint --bootstrap-inventory path/to/file.php 2>&1 | head -20'

Scope

Module	Path
Expression lowering	lib/Compiler.php — compileExpr()
Triage	script/bootstrap-inventory-triage.php
Lint SSOT	./phpc lint --bootstrap-inventory
Patches	patches/ + script/apply-patches.sh for php-cfg gaps

Batch table (living — edit when inventory regresses)

Expr kind (php-cfg)	Example spine symptom	Child issue	Status
(baseline May 2026)	0 unsupported expr	—	✅ clean
Expr_Throw in ??	coalesce throw	#3462	📋 filed
(add rows from triage)		open per-class when ≥3 files

Rule: Do not implement lowering in this umbrella — open focused child issues per Expr_* when a batch blocks ≥3 inventory files or M3 link.

Done when

• phpc lint --bootstrap-inventory --check stays green on master (regression guard)
• When triage shows Unsupported expression: rows, top 3 kinds have linked child issues with repro + php-src ref
• Each closed batch: inventory regen + --check + note in this table
• No duplicate work with Self-host: Unknown Stmt Type lowering batch tracker (post-#2254 triage) #2276 (stmt) or Language features wave 2: JIT/syntax gaps tracker (#1222–#1235) #1238 (language wave-2)

Verification

./script/docker-exec.sh -- bash -lc 'php script/bootstrap-inventory.php --check'
./script/docker-exec.sh -- bash -lc 'php script/bootstrap-inventory-triage.php --top 20'

Links

• Parent: Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 self-host epic
• Stmt sibling: Self-host: Unknown Stmt Type lowering batch tracker (post-#2254 triage) #2276
• Coordinator: Self-host: CFG lowering batch coordination (stmt/expr/op trackers) #2362

[PurHur]

Coordination meta: execution order and PR checklist — #2362. Triage SSOT: #2254 ✅. ROADMAP #78.

[PurHur]

Backlog-architect 2026-05-27: Inventory lint + triage are clean (0 CFG gaps). M0–M4 bootstrap ladder green. Do not prioritize until a regression surfaces expression kinds blocking a named gate — focus #2849 / #2865 (M5 cold boot) and #2866 (argv full revision) first.

[PurHur]

Deprioritized (2026-05-28): ./phpc lint --bootstrap-inventory --check reports 0 unsupported expressions on 725 files. Critical path is #2879 / #2880 / #2878. Re-open triage when a bootstrap probe surfaces Unsupported expression: on an inventory file.

[PurHur]

claim: worker-lane-a — starting this run (bootstrap inventory PHPDoc/lint blockers from triage)

[PurHur]

Run update (worker-lane-a): Triage showed 4 PHPDoc/PHPTypes parse failures blocking `phpc lint --bootstrap-inventory --check` (not `Unsupported expression:` kinds). PR fixes:

File	Gap	Fix
`lib/JIT.php`	prose after `@return array<…>`	description on separate line
`ext/standard/VmReflection.php`	trait/implements map prose	same
`lib/JIT/Builtin/StringUcwords.php`	`@return mixed …` prose	same
`lib/JIT/NamedArgs.php`	union inside array shape	`array<string,mixed>` + `list<Operand

Verify: `./phpc lint --bootstrap-inventory --check` → 0 unsupported (989 scanned); triage → no CFG gaps.

[PurHur]

claim: cursor-agent-lane-c — verifying PR #3871 and merging if green

[PurHur]

Merged via PR #3871 (squash).

Lane C queue scan: no new non-stdlib n % 3 == 2 issues without open PRs (stdlib tickets owned by STD Lib automation). Continued in-flight PR #3871.

Verification (this run):

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && ./phpc lint --bootstrap-inventory --check'
# bootstrap-inventory: 0 files with unsupported syntax (989 scanned)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php script/bootstrap-inventory-triage.php --top 10'
# (no CFG gaps — lint --bootstrap-inventory is clean)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php script/check-bootstrap-inventory-lint-sync.php'
# check-bootstrap-inventory-lint-sync: OK (0 file(s) with unsupported syntax in snapshot)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit test/unit/JIT/NamedArgsTest.php'
# OK (2 tests, 4 assertions)

Note: php script/bootstrap-inventory.php --check still reports stale docs/bootstrap-inventory.md on master (pre-existing; orthogonal to PHPDoc lint fix).