Wave 3 close-out: land remaining language + debug_backtrace (#1380 finish line)

[PurHur]

Problem

Wave 3 tracker #1380 is nearly complete on master (May 2026). Stdlib 13/13 ✅. Language 12/13 — only #1354 (PHP 8 attributes) remains.

Issue	Topic	Status
#1354	PHP 8 attributes	📋 open — no PR yet
#1360	readonly classes	✅ closed via #1473
#1366	WeakReference / WeakMap	✅ closed via #1478
#1378	debug_backtrace	✅ closed via #1404

Batch 67 audit (2026-05-24): PRs #1404, #1473, #1478 merged. No open PRs blocking wave-3 close.

Goal

Single finish-line pass:

1. Rebase Stdlib: debug_backtrace() VM minimal stack trace (closes #1378) #1404, feat(lang): readonly classes (#1360) #1473, feat(lang): WeakReference / WeakMap VM stub (#1366) #1478 onto master and land ✅ batch 67
2. Implement Language: PHP 8 attributes (#[Attr] on classes, methods, properties) #1354 minimum viable (parse + store; runtime ignore or reflection stub)
3. Sync Roadmap wave 3: full PHP language + stdlib gaps tracker (#1354–#1379) #1380 body + docs/roadmap-wave3.md counts → 13/13 language
4. Regenerate docs/capabilities-syntax.md / docs/capabilities.md if attributes touch capability rows

Scope

• Rebase queue (Stdlib: debug_backtrace() VM minimal stack trace (closes #1378) #1404, feat(lang): readonly classes (#1360) #1473, feat(lang): WeakReference / WeakMap VM stub (#1366) #1478) — merged batch 67
• Language: PHP 8 attributes (#[Attr] on classes, methods, properties) #1354 attributes implementation
• Close Roadmap wave 3: full PHP language + stdlib gaps tracker (#1354–#1379) #1380 when 13/13 language lands
• No new wave-4 issues unless audit finds net-new gaps
• Self-host: note which landed features unblock M2/M3 (Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492)

Implementation hints

Issue	First files to touch
#1354	lib/Compiler.php, lib/Lint/UnsupportedRegistry.php, php-cfg attribute nodes

Verify (local / Docker only)

php script/capability-syntax.php
php script/capability-matrix.php
./script/ci-fast.sh
docker run --rm -v "$(pwd):/compiler" -w /compiler php-compiler:22.04-dev ./script/ci-local.sh

No GitHub Actions.

Acceptance criteria

• Roadmap wave 3: full PHP language + stdlib gaps tracker (#1354–#1379) #1380 progress table shows 13/13 language, 13/13 stdlib
• CAPABILITY_SYNTAX_CHECK=1 passes in ci-local.sh
• Wave 3 section in ROADMAP 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 marked complete

Dependencies

• Roadmap wave 3: full PHP language + stdlib gaps tracker (#1354–#1379) #1380 umbrella
• Dependencies: php-parser token map for PHP 8.2+ host runs #113 host php-parser tokens (attributes on PHP 8.2+ host)
• Orthogonal: long-standing Language: Closures and anonymous functions #72, Language: Typed properties, union types, and readonly (PHP 8+) #169, Language: throw expressions and Exception object propagation #195 (outside wave 3 table)

Links

• docs/roadmap-wave3.md
• 🗺️ ROADMAP: Self-host + web-capable PHP subset (living) #78 ROADMAP Phase 1 Language / Phase 2 Stdlib

[PurHur]

Process note (from #1769 batch 66)

When any #1354–#1379 child closes, refresh #1380 body from docs/roadmap-wave3.md (counts + PR links). #1769 body-sync pass ✅ 2026-05-24; re-run on next wave-3 merge.

Still open for wave-3 finish line:

Item	PR	Blocker
#1378 debug_backtrace	#1404	rebase
#1360 readonly classes	#1473	rebase conflicts
#1366 WeakRef/WeakMap	#1478	open
#1354 attributes	—	no PR

[PurHur]

Batch 67 status refresh

Wave-3 finish line is one issue away:

Track	Done	Open
Stdlib	13/13 ✅	—
Language	12/13	#1354 attributes only

Merged today: #1404, #1473, #1478. #1380 body synced to match.

Next measurable step: open implementation PR for #1354, then close #1380 + this epic.

[PurHur]

PM: Wave 3 language item #1858 ✅ closed (#1883). Remaining language polish: #1354 attributes + #1885 nested return <call>() (PR #1873 candidate). Open PR #1873 is orthogonal to spine blocker #1880.

[PurHur]

Wave 3 close-out status (batch 87)

• Language: 11/12 on master — only Language: PHP 8 attributes (#[Attr] on classes, methods, properties) #1354 (attributes) open; VM: nested return <call>() loses callee result across function frames #1885 ✅ (Compiler: return-call slot reuse for nested return <call>() (#1885) #1897).
• Stdlib wave 3 (Stdlib: parse_str() — VM + LLVM JIT/AOT #1367–Stdlib: set_error_handler() — VM + LLVM JIT/AOT #1379): 13/13 ✅ on master.
• Gate follow-on: CI: Default NESTED_RETURN_COMPLIANCE_GATE=1 in ci-fast after #1885 #1888 (nested return compliance default-on), CI: Default ATTRIBUTES_COMPLIANCE_GATE=1 in ci-fast after #1354 lands #1904 (attributes gate after Language: PHP 8 attributes (#[Attr] on classes, methods, properties) #1354).

docs/roadmap-wave3.md on master matches this; regen checks: php script/check-wave3-roadmap-sync.php.

[PurHur]

Wave 3 finish line — batch 90 close-out

Language 13/13 ✅ on master:

• #1354 closed via #1925 / #1912
• PHPTs: test/compliance/cases/language/attribute_*.phpt

Stdlib 13/13 ✅ (unchanged).

Docs synced: docs/roadmap-wave3.md — language + stdlib tables show 0 open.

Remaining follow-up (not this issue):

• #1904 — ATTRIBUTES_COMPLIANCE_GATE default-on in ci-fast
• #1380 — umbrella close when PM confirms

Acceptance: wave 3 table complete; closing this finish-line tracker.

[PurHur]

Wave 3 language+stdlib complete on master (#1925). Follow-ups: #1904 (CI gate), #1380 (umbrella).