fix(gc): three more re-read-vs-stale-local orderings around the async result promise (#7497 follow-up)

[proggeramlug]

Follow-up to #7516 (which landed as 5edfe99 while this was in flight). Same
family, three more re-read vs stale local orderings around the async result
promise, plus one honesty correction to #7516's changelog fragment.

The three orderings

1. js_async_step_done passed the pre-root copy. fix(gc): Promise.all at scale read globalThis and its own combinator state from retired from-space (#7497) #7516 rooted trap_next
   and then handed resolve_trap_next_with_adoption the original binding
   anyway. Rooting is not a licence to keep using the old name — that is the
   exact shape fix(gc): Promise.all at scale read globalThis and its own combinator state from retired from-space (#7497) #7516 exists to remove.

2. resolve_trap_next_with_adoption held its receiver across
   js_assimilate_thenable. That call runs a user then getter, and
   target is the receiver of both settlements after it. This is the one with a
   real user-facing path behind it (return <thenable> from an async fn —
   Drizzle's QueryPromise, await thenable returns the thenable itself instead of calling .then(resolve, reject) #586).

3. The AsyncStep arm seeded INLINE_TRAP from its locals. Between the
   re-read at the top of the arm and the INLINE_TRAP.set sit the
   runaway-reentry guard (which allocates a TypeError on its bounded path) and
   two handle pushes. A stale next parked in the trap is what
   js_async_step_done later settles and returns as the async function's own
   result promise.

What this does NOT do, stated plainly

#7516's fragment recorded one open residual: a protected run
(PERRY_GC_PROTECT_FROMSPACE=1) of the auto-optimize binary prints the correct
checksum and then faults inside js_async_step_done. All three changes above
were attempts at it and none of them cleared it — the holder is somewhere I
have not found. The fragment is amended to say so rather than leaving the
impression that the instrument is clean or that one more re-read would do it.

Each change is nonetheless correct on its own terms and is kept for that reason,
not because it was measured to fix something.

Verification (before the merge of #7516 moved main under it; re-checked after

the rebase)

• benchmarks/app-patterns/kernels/promise_all_chains.ts — checksum: 2500050000,
  byte-exact vs node 26.5.1, on both link modes.
• scripts/auto_opt_app_patterns.sh — 12/12, no skips.
• test_gap_gc_global_builtin_lookup_rooting.ts plus 8 promise/array/async gap
  tests — all byte-exact.
• cargo test -p perry-runtime — 1744 passed, 0 failed.
• scripts/raw_handle_debt.py 999 (unchanged), cargo fmt --check clean.

Summary by CodeRabbit

• Bug Fixes

  • Improved async promise handling during garbage collection and thenable adoption.
  • Strengthened preservation of async task state across promise resolution and runtime transitions.
  • Updated async execution safeguards to use current values after memory-management operations.
  • The remaining auto-optimization crash is still under investigation and was not resolved by these changes.

• Documentation

  • Added changelog details covering the attempted fixes, verification results, and known limitations.

• Maintenance

  • Updated the release version to 0.5.1299.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

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Configuration used: defaults

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Run ID: d385e248-d58a-4e15-8495-16c9d4c6740d

📥 Commits

Reviewing files that changed from the base of the PR and between 5eda89a and 9ad65a0.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (6)

• CLAUDE.md
• Cargo.toml
• changelog.d/7516-promise-all-chains.md
• changelog.d/7529-async-result-rooting.md
• crates/perry-runtime/src/promise/async_step.rs
• crates/perry-runtime/src/promise/microtasks.rs

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📝 Walkthrough

Walkthrough

The runtime re-reads rooted promise, value, and closure pointers after allocation-sensitive operations. Changelog entries document the attempted fixes and verification results. The protected auto-optimized crash remains unresolved.

Changes

Async Promise GC Pointer Stabilization

Layer / File(s)	Summary
Promise rooting and re-read handling crates/perry-runtime/src/promise/async_step.rs, changelog.d/7529-async-result-rooting.md, changelog.d/7516-promise-all-chains.md	js_async_step_done returns the re-read rooted promise. Thenable assimilation re-reads the rooted target and value. Changelogs record the fixes and verification results.
Async-step trap pointer reload and version update crates/perry-runtime/src/promise/microtasks.rs, Cargo.toml, CLAUDE.md	Task::AsyncStep reloads next and step_closure before setting INLINE_TRAP. The workspace and documented versions change to 0.5.1299.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• PerryTS/perry#7067 — Modifies related promise and microtask GC handling.
• PerryTS/perry#7375 — Addresses stale promise pointers after GC-moving operations.
• PerryTS/perry#7516 — Follows up on the unresolved js_async_step_done issue.

Suggested labels: bug

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the async result promise fixes and their re-read-versus-stale-local focus.
Description check	✅ Passed	The description explains the changes, residual fault, related issue, and verification results, although it does not use every template heading.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/7497-followup-async-result-rooting

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