Iterator-Collection RC Ownership Contract

6 sections

100%
Section 1 Root Cause Analysis & Design Section 2 Fix Iterator elem_dec_fn (List, Map, Set) Section 3 Fix For-Yield RC Scoping Section 4 For-Do / For-Yield Parity Audit Section 5 Comprehensive Test Matrix Section 6 Verification & Merge Gate
Overview

Establish a correct, complete, and tested ownership contract between iterators and their source collections in the Ori compiler's AOT pipeline. Currently, the contract has two critical bugs: (1) iterator elem_dec_fn is hardcoded NULL, so element cleanup fails when ori_iter_drop does the final buffer RC dec; (2) the for-yield lowering doesn't properly scope the source collection's lifetime, causing the AIMS pipeline to emit a spurious extra RcDec (double-free). This plan fixes both bugs and audits the full for-do/for-yield parity to prevent similar issues.

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In Progress

1 sections
Section 2 In Progress

Fix Iterator elem_dec_fn (List, Map, Set)

Replace NULL elem_dec_fn/key_dec_fn/val_dec_fn with the real per-element drop functions in emit_list_iter() and emit_map_iter(), ensuring correct element cleanup regardless of which RcDec reaches zero

26/26 tasks
✓

Completed

5 sections
Section 1 Complete

Root Cause Analysis & Design

Document the full causal chain from codegen through runtime that produces leaked elements and double-frees in iterator-based loops, establishing the shared understanding needed for Sections 02-06

19/19 tasks
Section 3 Complete

Fix For-Yield RC Scoping

Eliminate the spurious extra RcDec on the source collection in for-yield by properly scoping the collection variable so it dies at the Jump to header, matching the for-do pattern. Also fix the clear_mutable_names() workaround that breaks outer mutable variable assignment in for-yield AOT.

32/32 tasks
Section 4 Complete

For-Do / For-Yield Parity Audit

Systematic comparison of for-do and for-yield ARC IR across all 6 implemented element types (5 list + 1 map; Set<str> deferred until type exists), verifying identical RC semantics

22/22 tasks
Section 5 Complete

Comprehensive Test Matrix

Combinatorial test coverage: 6 implemented element types x 8 iteration patterns x 2 loop variants (93 tests: 81 active + 12 ignored catch bug; Set<str> deferred until type exists)

18/18 tasks
Section 6 Complete

Verification & Merge Gate

Full verification pass confirming all fixes are correct, no regressions exist, and the branch is ready to merge

35/35 tasks