Files
oxc-guard 60fa13878c release(crates): oxc v0.149.0 (#26397)
### 💥 BREAKING CHANGES

- 66744f0 parser: [**BREAKING**] Rename `panicked` to `fatal_error` in `ParserReturn` (#26382) (overlookmotel)
- 2c9a947 parser: [**BREAKING**] Reduce `MAX_LEN` to 256 bytes below `u32::MAX` (#26352) (overlookmotel)

### 🚀 Features

- 32bdc5b allocator: Construct `ArenaHashSet` with any `Default` hasher (#26372) (Dunqing)
- a17de58 minifier: Process of return/throw in non last position and fix async * inlining (#26214) (Armano)
- bfb4c57 parser: Distinguish unapplied no-side-effects comments (#26120) (碳苯 Carbon)
- 1d9b9d3 ast: Add `GetNodeId` trait (#26145) (camc314)

### 🐛 Bug Fixes

- b156333 codegen: Order accessibility before abstract on accessors (#26392) (camc314)
- 116c8b8 transformer/class-properties: Keep private methods in class-expression scope (#26308) (Changsu Seong)
- 1400a0f parser: Require a string source after `export ... from` (#26389) (camc314)
- 2da73b7 codegen: Print matching quoted import names as identifiers (#26386) (camc314)
- 0a81d29 codegen: Preserve private-in left operand precedence (#26383) (camc314)
- 9a02337 parser: Correctly round large nondecimal literals (#26379) (camc314)
- 3d95477 transformer: Gate async-only rewrites by owning transform (#26326) (Dunqing)
- f45a9ee transformer: Limit arguments capture to lowered async functions (#26317) (Dunqing)
- 789969f transformer: Gate this capture by owning async transform (#26227) (Dunqing)
- affeb14 minifier: Mangle class private members in Node API (#26118) (碳苯 Carbon)
- 8b35abd semantic: Detect duplicate private class elements (#26361) (camc314)
- 457ed57 semantic: Reject await and yield in rest parameter defaults (#26359) (camc314)
- 4b89c7b semantic: Reject jumps across arrow functions (#26357) (camc314)
- c966aca parser: Do not omit `<` token opening type argument list (#26328) (overlookmotel)
- f07dca5 ast_visit: Add the trimmed prefix length to translation table offsets (#26173) (Bharadwaj Pendyala)
- 3ab9bd1 parser: Do not re-lex template substitution tail after fatal error (#26230) (overlookmotel)
- 07851b9 parser: Fix debug assert failure when lexer error with tokens enabled (#26229) (overlookmotel)
- 00dea7a allocator: Gate `Allocator::data_end_ptr` behind fixed_size feature (#26248) (camc314)
- 853ffab ecmascript: Avoid `charAt` panic on 32-bit (#26244) (camc314)
- 34feccb runtime: Remove stale regenerator exports (#26243) (camc314)

### ⚡ Performance

- 34a242e minifier: Use `Ident` for property mangler (#26334) (sapphi-red)
- 5303f5c minifier: Unify merging of last expression into target sequence (#26264) (Armano)
- 2ca7d29 minifier: Consume nodes in minimize_statements in reverse order (#26258) (Armano)
- d2354b4 mangler: Use `Ident` for variable names to keep (#26333) (sapphi-red)
- 5b3e335 minifier: Use `Ident` instead of `Str` in `KeepVar` (#26332) (sapphi-red)
- 51366fb minifier: Use `IdentHashSet` in `PrivateMemberUsageStack` (#26331) (sapphi-red)
- d19c42a minifier: Merge nested if stmt in place instead of creating dummies (#26351) (Armano)
- 356def6 parser: Shrink annotation comment ranges (#26356) (overlookmotel)
- a5be474 parser: Shave instruction off `parse_jsx_element_name` (#26355) (overlookmotel)
- 9780663 parser: Remove fatal error guard from `parse_jsx_element_name` (#26354) (overlookmotel)
- 766e12f parser: Remove `token` field from `LexerCheckpoint` (#26350) (overlookmotel)

### 📚 Documentation

- d4b4e61 transformer: Document ES2015 target floor (#26378) (Dunqing)
- 67dd054 ast_visit: Correct out-of-date comments on `Utf8ToUtf16` converter (#26285) (overlookmotel)
- a8ed2a7 minifier: Fix stale validation instructions (#26251) (camc314)
2026-09-07 14:29:34 +00:00
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Oxc Allocator

A high-performance memory allocator using bump-based arena allocation for fast AST node creation.

Overview

Oxc uses a bump-based memory arena for faster AST allocations. This crate provides an [Allocator] that manages memory efficiently by allocating objects in a single contiguous memory region, avoiding the overhead of individual heap allocations.

Key Features

  • Bump allocation: Fast allocation by simply incrementing a pointer
  • Arena-based memory management: All allocations live for the same lifetime
  • Zero-copy data structures: Efficient Box, Vec, String, and HashMap implementations
  • Optimal for AST operations: Perfect for parse-transform-emit workflows

Architecture

The allocator is designed specifically for AST processing workflows where:

  1. A large number of nodes are allocated during parsing
  2. All nodes have the same lifetime (tied to the AST)
  3. Memory is released all at once when the AST is dropped

This approach is significantly faster than using the system allocator for AST operations.

Features

  • serialize - Enables serialization support for Box and Vec with serde and oxc_estree.
  • pool - Enables AllocatorPool.
  • bitset - Enables BitSet.
  • from_raw_parts - Adds unsafe from_raw_parts method (not recommended for general use).
  • fixed_size - Makes AllocatorPool create large fixed-size allocators, instead of flexibly-sized ones. Only supported on 64-bit little-endian platforms at present. Usage of this feature is not advisable, and it will be removed as soon as we're able to.
  • track_allocations - Count allocations and reallocations. For internal use only. The APIs provided by this feature are sketchy at best, and possibly undefined behavior. Do not enable this feature under any circumstances in production code.
  • disable_track_allocations - Disables track_allocations feature. Purpose is to prevent --all-features enabling allocation tracking.