refactor(allocator): do not make Allocator::bump field public

[overlookmotel]

Follow-on after #12555.

Avoid making bump field of Allocator public when track_allocations feature is enabled, by moving the field offset calculations to next to Allocator's definition.

[overlookmotel]

• refactor(allocator): move allocation tracking code into own module #12937
• refactor(allocator): do not make Allocator::bump field public #12936 👈 (View in Graphite)
• main

---

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• 0-merge - adds this PR to the back of the merge queue
• hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

This stack of pull requests is managed by Graphite. Learn more about stacking.

[Copilot]

Pull Request Overview

This PR refactors the Allocator struct to avoid exposing the bump field publicly when the track_allocations feature is enabled. The field offset calculations for allocation tracking are moved from the Alloc trait implementation to constants defined next to the Allocator struct.

Key changes:

• Remove conditional public visibility of the bump field in Allocator
• Add pre-calculated offset constants NUM_ALLOC_FIELD_OFFSET and NUM_REALLOC_FIELD_OFFSET
• Simplify allocation tracking code by using these constants instead of inline calculations

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
crates/oxc_allocator/src/allocator.rs	Removes public visibility of bump field and adds offset constants for allocation tracking
crates/oxc_allocator/src/alloc.rs	Updates allocation tracking code to use pre-calculated offset constants

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #12936 will not alter performance

_{Comparing 08-09-refactor_allocator_do_not_make_allocator_bump_field_public (ff1d93b) with main (2c303f5)¹}

Summary

✅ 34 untouched benchmarks

Footnotes

1. No successful run was found on main (ff1d93b) during the generation of this report, so 2c303f5 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[overlookmotel]

Merge activity

• Aug 9, 2:17 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Aug 9, 2:17 PM UTC: overlookmotel added this pull request to the Graphite merge queue.
• Aug 9, 2:29 PM UTC: Merged by the Graphite merge queue.