hakorune/docs/releases/21.0-full-selfhosting.md

# Phase 21.0 — Full Self‑Hosting (Release Notes)

Date: 2025‑11‑06
Status: COMPLETE

## Summary
Hakorune can now build Hakorune end‑to‑end under the defined DoD:
- S1/S2 (deterministic v1 emit): const/compare/threeblock‑collect repeat 3× with identical normalized hash.
- PRIMARY (no‑fallback): hv1 inline minimal reps (Option‑A/B) are green.
- S3 (llvmlite + Nyash Kernel): link + run representatives pass with expected return codes.

## What changed
- v1 → llvmlite harness direct path
  - tools/ny_mir_builder.sh now feeds v1 JSON straight to the Python harness and links against libnyash_kernel.a.
- Python LLVM builder fixes
  - compare: supports `cmp` (Lt/Le/Gt/Ge/Eq/Ne) and normalizes to `<, <=, >, >=, ==, !=`.
  - ret: synthesizes a small PHI at block head to avoid ret=0 on multi‑pred blocks.
  - mir_call: accepts both nested and flat shapes.
- Using/alias (prod)
  - modules mapping is considered first; missing aliases added for `selfhost.vm.hakorune-vm.str_cast` and `selfhost.vm.helpers.method_alias_policy`.
  - Duplicate `using` lines cleaned in extern_provider.

## How to verify (quick)
- One‑shot (S1/S2 + PRIMARY + S3 auto):
  ```bash
  bash tools/smokes/v2/profiles/quick/core/phase2100/run_all.sh
  ```
- S3 only (auto when LLVM18/llvmlite present):
  ```bash
  NYASH_LLVM_S3=1 bash tools/smokes/v2/profiles/quick/core/phase2100/run_all.sh
  ```

## Environment
- LLVM 18 (llvm-config-18) + llvmlite (Python 3)
- For faster runs: prebuild
  ```bash
  cargo build --release --features llvm
  cargo build --release -p nyash-llvm-compiler
  cargo build --release -p nyash_kernel
  ```

## Next
- Optional: broaden reps and harden typeops/extern coverage in follow‑on phases.