docs: update CURRENT_TASK with Box Theory PHI plan (defer/finalize) and MIR v0.5 type meta; add parity tooling and PyVM scaffolding

impl(pyvm/llvmlite):
- add tools/parity.sh; tools/pyvm_runner.py; src/llvm_py/pyvm/*
- emit string const as handle type in MIR JSON; add dst_type hints
- unify '+' to concat_hh with from_i64/from_i8_string bridges; console print via to_i8p_h
- add runtime bridges: nyash.box.from_i64, nyash.string.to_i8p_h

tests:
- add apps/tests/min_str_cat_loop (minimal repro for string cat loop)

CURRENT_TASK.md

@@ -1,25 +1,19 @@
-# Current Task (2025-09-11) — Phase 15 LLVM（主経路） + llvmlite Harness（検証・将来主役）
+# Current Task (2025-09-13 改定) — Phase 15 llvmlite（既定）+ PyVM（新規）
 
 Summary
-- LLVM AOT（Rust/inkwell）は引き続き主経路。ただし「反復速度・仕様変更耐性」を担保するため、Python/llvmlite ハーネスを正式導入し、代表ケースで両者の等価性を検証する。
+- JIT/Cranelift は一時停止。Rust/inkwell LLVM は参照のみ。
-- VM/Cranelift/Interpreter は MIR14 非対応。MIR 正規化（Resolver・LoopForm規約）を Rust 側で担保し、ハーネスにも同じ形を供給する。
+- 既定の実行/ビルド経路は Python/llvmlite ハーネス（MIR JSON→.o→NyRT link）。
-- 代表ケース（apps/selfhost/tools/dep_tree_min_string.nyash）で `.o`（および必要時 EXE）を安定生成。Harness ON/OFF で機能同値を確認。
+- 2本目の実行経路として PyVM（Python MIR VM）を導入し、llvmlite との機能同値で安定化する。
 
-Quick Status — 2025‑09‑13（compressed, post‑harness fixes）
+Quick Status — 2025‑09‑13（post‑harness hardening）
-- Harness ON（llvmlite）で .ll verify green → .o → link 成立（dep_tree_min_string）
+- llvmlite（ハーネス）で verify green → .o → link が代表ケースで成立（dep_tree_min_string）
-- Resolver‑only 統一（vmap 直読排除）。PHI は BB 先頭に集約・i64（ハンドル）固定／pointer incoming は pred 終端直前で boxing（GEP+from_i8_string）
+- Resolver‑only/Sealed SSA/文字列ハンドル不変を強化。PHIはBB先頭・pred終端でboxing/cast。
-- 降下順序: preds 優先の擬似トポロジカル順に block 降下。非 PHI 命令は「現在 BB」末尾に挿入（dominance 安定）
+- IRダンプ/PHIガード/deny-directチェックが利用可能（NYASH_LLVM_DUMP_IR, NYASH_LLVM_PHI_STRICT, tools/llvmlite_check_deny_direct.sh）。
-- 文字列: ‘+’ は string タグ/ptr 検出時のみ concat_hh、len/eq 対応、substring/lastIndexOf は handle 版（_hii/_hh）を NyRT に実装・使用
-- const(string): Global を保持→使用側で GEP→i8* に正規化。MIR main→private、ny_main ラッパ生成
-- by‑name 定数: メソッド名の i8* は定数 GEP を採用（順序依存を排除）
-- 比較/検証: compare_harness_on_off.sh で ON/OFF の Exit 一致（現状 JSON は双方空。最終 JSON 一致は次フェーズで詰め）
 
-Focus Shift — Python/llvmlite Only（2025‑09‑13）
+Focus Shift — llvmlite（既定）+ PyVM（新規）
-- Rust/inkwell 側は当面「保守」へ。開発・詰めは Nyash スクリプト＋Python/llvmlite のみで進行。
+- Rust/inkwell は保守のみ。Python（llvmlite/PyVM）中心で開発。
-- 追加スモーク: apps/tests/esc_dirname_smoke.nyash（esc_json/dirname の最小 2 行出力）。
+- 追加スモーク: esc_dirname_smoke / dep_tree_min_string を llvmlite と PyVM の両方で常時維持。
-- 追加トレース: `NYASH_LLVM_TRACE_FINAL=1` で println 直前に `nyash.debug.trace_handle(i64)` を呼び、最終ハンドルを観測。
+- 追跡: `NYASH_LLVM_TRACE_FINAL=1`（最終ハンドル）、`NYASH_LLVM_TRACE_PHI=1`（PHIログ）
-- Lifetime ヒント（軽量）: `def_blocks`（value_id → 定義ブロック集合）を Builder が収集、Resolver は現ブロック定義済みの i64 を優先再利用（PHI 過剰化を抑制）。
-- const(string) 改善: 即時 `from_i8_string` で i64 ハンドル化（後段連鎖の 0 落ちを軽減）。
 
 Hot Update — 2025‑09‑13（Harness 配線・フォールバック廃止）
 - Runner（LLVMモード）にハーネス配線を追加。`NYASH_LLVM_USE_HARNESS=1` のとき:
@@ -39,14 +33,43 @@ Hot Update — 2025‑09‑13（Resolver‑only 統一 + Harness ON green）
   - `main` 衝突回避: MIR 由来 `main` は private にし、`ny_main()` ラッパを自動生成（NyRT `main` と整合）。
 - 代表ケース（dep_tree_min_string）: Harness ON で `.ll verify green → .o` を確認し、NyRT とリンクして EXE 生成成功。
 
-Next（short, refreshed — Py/llvmlite 線）
+Next（short — Py/llvmlite + PyVM）
-1) スモーク確定: esc_dirname_smoke の 2 行出力を ON/OFF 完全一致に（行比較）。
+1) PyVM スキャフォールド: `tools/pyvm_runner.py` と `src/llvm_py/pyvm/` 追加（最小命令+boxcall）。
-2) dep_tree_min_string の最終 JSON 一致（`{` 以降の diff=空）。
+2) ランナー統合: `NYASH_VM_USE_PY=1` → MIR(JSON) を PyVM に渡して実行。
-   - `NYASH_LLVM_TRACE_FINAL=1`＋`NYASH_LLVM_TRACE_VALUES=1` で println 引数ハンドルの鎖を観測し、synth‑zero 起点を特定→ Resolver/PHI で局所是正。
+3) パリティ基盤: 汎用パリティスクリプト `tools/parity.sh` を追加（stdout+exit code 比較、pyvm/vm/llvmlite 任意ペア）。
-   - PHI/snapshot は「pred で materialize→無ければ snap→最後に synth(0)」の順を徹底。None を入れない。
+4) 型メタ導入（MIR v0.5 互換）: JSON MIR に String の handle/ptr 種別を明示し、llvmlite/PyVM で推測を排除。
-3) CI/補助
+5) スモーク拡充: esc_dirname_smoke / dep_tree_min_string の両経路一致（終了コード+JSON）。
-   - スモークを compare_harness_on_off.sh からも容易に呼べるよう維持（必要なら行比較モード追加）。
+
-   - Deny‑Direct（`vmap.get(` 直読の抑止）を継続チェック。
+Hot Update — MIR v0.5 Type Metadata（2025‑09‑14 着手）
+- 背景: 文字列を i64 として曖昧に扱っており、llvmlite で handle/ptr の推測が必要→不安定の温床。
+- 追加仕様（後方互換、最小差分）:
+  - Const(string): `{"value": {"type": {"kind":"handle","box_type":"StringBox"}, "value":"..."}}`
+    - 既存の `type:"string"` 表記は併記しない（受け側は新表示を優先、無ければ従来推測）。
+  - BoxCall/ExternCall: 可能な範囲で `dst_type` を付与（例: substring→StringBox(handle), length/lastIndexOf→i64）。
+- 実装計画:
+  - A) 共有エミッタ `src/runner/mir_json_emit.rs` を拡張（string const/最小メソッドの `dst_type`）。
+  - B) Python 側: `llvm_builder.py` が `dst_type` を検知して `resolver.mark_string(dst)` を行う（型タグの明示化）。
+  - C) Console 出力の安定化: 当面は既存のポインタAPI/ハンドルAPIを維持。型メタ普及後に handle→ptr ブリッジ導入を検討。
+- 受け入れ（第一段）：
+  - JSON に string const の型メタが出ること
+  - Python 側で `dst_type` により string ハンドルのタグ付けが行われること
+  - `tools/parity.sh` が esc_dirname_smoke で実行できること（完全一致は第二段で目標）
+
+Hot Update — Box Theory PHI（2025‑09‑14 追加予定）
+- 背景: ループの PHI が snapshot 未構築時に 0 合成へ落ちる（forward 参照をその場 resolve しているため）。
+- 方針（箱理論に基づく簡素化）:
+  - Block=箱（BoxScope）。各ブロック末尾の `block_end_values` を箱として扱う。
+  - PHI は即時解決せず defer 収集 → 全ブロック降下後に finalize で箱（pred の snapshot）から値を取り出して配線。
+  - ブロック間は String は常に handle(i64) 固定。pointer PHI は禁止。必要な boxing（ptr→handle）は pred 末端（terminator 直前）で挿入。
+  - ‘+’ は常に concat_hh(handle,handle)。i64 プリミティブは from_i64 で昇格、リテラルは from_i8_string。
+- 実装計画:
+  - A) `llvm_builder.py`: `lower_phi` を defer 化、`finalize_phis` を追加（incoming=(pred_bid,val_id) を materialize）。
+  - B) `llvm_builder.py`: `block_end_values` の網羅性を補強（関数引数/const/新規 dst/phi dst/循環値が確実に入る）。
+  - C) `resolver._value_at_end_i64`: pred 末端での局所 boxing/cast を強制、未定義→0 合成を抑制（strict 時は警告）。
+- 受け入れ（第二段）：
+  - 最小再現 `apps/tests/min_str_cat_loop/main.nyash` で PyVM と llvmlite の parity 緑（`xxx`）
+  - `apps/tests/esc_dirname_smoke.nyash` で parity 緑（1行目の 0 が解消）
+  - `tools/parity.sh` で stdout 完全一致＋終了コード一致
 
 Compact Roadmap（2025‑09‑13 改定）
 - Focus A（Rust LLVM 維持）: Flow hardening, PHI(sealed) 安定化, LoopForm 仕様遵守。

apps/tests/min_str_cat_loop/main.nyash

@@ -0,0 +1,17 @@
+// Minimal repro: string concatenation in a loop should yield "xxx"
+
+static box Main {
+  main(args) {
+    local console = new ConsoleBox()
+    local out = ""
+    local i = 0
+    local n = 3
+    loop(i < n) {
+      out = out + "x"
+      i = i + 1
+    }
+    console.println(out)
+    return 0
+  }
+}
+

crates/nyrt/src/lib.rs

@@ -79,7 +79,9 @@ pub extern "C" fn nyash_string_concat_hh_export(a_h: i64, b_h: i64) -> i64 {
     };
     let s = format!("{}{}", to_s(a_h), to_s(b_h));
     let arc: std::sync::Arc<dyn NyashBox> = std::sync::Arc::new(StringBox::new(s));
-    handles::to_handle(arc) as i64
+    let h = handles::to_handle(arc) as i64;
+    eprintln!("[TRACE] concat_hh -> {}", h);
+    h
 }
 
 // String.eq_hh(lhs_h, rhs_h) -> i64 (0/1)
@@ -120,7 +122,9 @@ pub extern "C" fn nyash_string_substring_hii_export(h: i64, start: i64, end: i64
     let (st_u, en_u) = (st as usize, en as usize);
     let sub = s.get(st_u.min(s.len())..en_u.min(s.len())).unwrap_or("");
     let arc: std::sync::Arc<dyn NyashBox> = std::sync::Arc::new(StringBox::new(sub.to_string()));
-    handles::to_handle(arc) as i64
+    let nh = handles::to_handle(arc) as i64;
+    eprintln!("[TRACE] substring_hii -> {}", nh);
+    nh
 }
 
 // String.lastIndexOf_hh(haystack_h, needle_h) -> i64
@@ -159,7 +163,9 @@ pub extern "C" fn nyash_box_from_i8_string(ptr: *const i8) -> i64 {
         Err(_) => return 0,
     };
     let arc: std::sync::Arc<dyn NyashBox> = std::sync::Arc::new(StringBox::new(s));
-    handles::to_handle(arc) as i64
+    let h = handles::to_handle(arc) as i64;
+    eprintln!("[TRACE] from_i8_string -> {}", h);
+    h
 }
 
 // box.from_f64(val) -> handle
@@ -171,6 +177,15 @@ pub extern "C" fn nyash_box_from_f64(val: f64) -> i64 {
     handles::to_handle(arc) as i64
 }
 
+// box.from_i64(val) -> handle
+// Helper: build an IntegerBox and return a handle
+#[export_name = "nyash.box.from_i64"]
+pub extern "C" fn nyash_box_from_i64(val: i64) -> i64 {
+    use nyash_rust::{box_trait::{NyashBox, IntegerBox}, jit::rt::handles};
+    let arc: std::sync::Arc<dyn NyashBox> = std::sync::Arc::new(IntegerBox::new(val));
+    handles::to_handle(arc) as i64
+}
+
 // env.box.new(type_name: *const i8) -> handle (i64)
 // Minimal shim for Core-13 pure AOT: constructs Box via registry by name (no args)
 #[export_name = "nyash.env.box.new"]

crates/nyrt/src/plugin/string.rs

@@ -83,7 +83,7 @@ pub extern "C" fn nyash_string_concat_is(a: i64, b: *const i8) -> *mut i8 {
 // Exported as: nyash.string.substring_sii(i8* s, i64 start, i64 end) -> i8*
 #[export_name = "nyash.string.substring_sii"]
 pub extern "C" fn nyash_string_substring_sii(s: *const i8, start: i64, end: i64) -> *mut i8 {
-    use std::ffi::CStr;
+use std::ffi::CStr;
     if s.is_null() {
         return std::ptr::null_mut();
     }
@@ -121,3 +121,34 @@ pub extern "C" fn nyash_string_lastindexof_ss(s: *const i8, needle: *const i8) -
         pos as i64
     } else { -1 }
 }
+
+// Exported as: nyash.string.to_i8p_h(i64 handle) -> i8*
+#[export_name = "nyash.string.to_i8p_h"]
+pub extern "C" fn nyash_string_to_i8p_h(handle: i64) -> *mut i8 {
+    use nyash_rust::jit::rt::handles;
+    if handle <= 0 {
+        // return "0" for consistency with existing fallback behavior
+        let s = handle.to_string();
+        let mut bytes = s.into_bytes();
+        bytes.push(0);
+        let boxed = bytes.into_boxed_slice();
+        let raw = Box::into_raw(boxed) as *mut u8;
+        return raw as *mut i8;
+    }
+    if let Some(obj) = handles::get(handle as u64) {
+        let s = obj.to_string_box().value;
+        let mut bytes = s.into_bytes();
+        bytes.push(0);
+        let boxed = bytes.into_boxed_slice();
+        let raw = Box::into_raw(boxed) as *mut u8;
+        raw as *mut i8
+    } else {
+        // not found -> print numeric handle string
+        let s = handle.to_string();
+        let mut bytes = s.into_bytes();
+        bytes.push(0);
+        let boxed = bytes.into_boxed_slice();
+        let raw = Box::into_raw(boxed) as *mut u8;
+        raw as *mut i8
+    }
+}

docs/development/roadmap/phases/phase-15/README.md

@@ -14,26 +14,26 @@ MIR 13命令の美しさを最大限に活かし、外部コンパイラ依存
 4. **エコシステムの自立**: Nyashだけで完結する開発環境
 5. **劇的なコード圧縮**: 75%削減で保守性・可読性の革命
 
-## 🚀 実装戦略（2025年9月更新）
+## 🚀 実装戦略（2025年9月更新・改定）
 
-### Phase 15.2: LLVM層の独立化（実装中）
+### Phase 15.2: LLVM（llvmlite）安定化 + PyVM導入
-- **Python/llvmlite実装を正式採用**（開発速度10倍、~2400行）
+- JIT/Cranelift は一時停止（古い/非対応）。Rust/inkwell は参照のみ。
-- nyash-llvm-compiler crateの分離（Rust版も継続）
+- 既定のコンパイル経路は **Python/llvmlite**（harness）のみ
-- MIR JSON/バイナリ入力 → ネイティブEXE出力
+  - MIR(JSON) → LLVM IR → .o → NyRTリンク → EXE
-- プラグイン全方向ビルド戦略（.so/.o/.a同時生成）
+  - Resolver-only / Sealed SSA / 文字列ハンドル不変 を強化
-- 独立したツールとして配布可能
+- 新規: **PyVM（Python MIR VM）** を導入し、2本目の実行経路を確保
+  - 最小命令: const/binop/compare/phi/branch/jump/ret + 最小 boxcall（Console/File/Path/String）
+  - ランナー統合: `NYASH_VM_USE_PY=1` で MIR(JSON) を PyVM に渡して実行
+  - 代表スモーク（esc_dirname_smoke / dep_tree_min_string）で llvmlite とパリティ確認
 
-### Phase 15.3: Nyashコンパイラ実装
+### Phase 15.3: NyashコンパイラMVP（後段）
-- NyashでNyashパーサー実装（800行目標）
+- PyVM 安定後、Nyash製パーサ/レクサ（サブセット）と MIR ビルダを段階導入
-- AST→MIR変換（2500行目標）
+- フラグでRustフォールバックと併存（例: `NYASH_USE_NY_COMPILER=1`）
-- **循環依存なし**：nyrtがStringBox/ArrayBoxをC ABI経由で提供
+- JIT不要、PyVM/llvmlite のパリティで正しさを担保
-- ブートストラップでセルフホスティング達成！
 
-### Phase 15.4: VM層のNyash化（革新的）
+### Phase 15.4: VM層のNyash化（PyVMからの置換）
-- MIR解釈エンジンをNyashで実装（~5000行予想）
+- PyVM を足場に、VMコアを Nyash 実装へ段階移植（命令サブセットから）
-- 動的ディスパッチ（MapBox）で13命令処理
+- 動的ディスパッチで13命令処理を目標に拡張
-- コンパイル不要の即座実行
-- デバッグ・開発効率の劇的向上
 
 詳細：[セルフホスティング戦略 2025年9月版](implementation/self-hosting-strategy-2025-09.md)
 
@@ -71,7 +71,7 @@ MIR 13命令の美しさを最大限に活かし、外部コンパイラ依存
 この究極のシンプルさにより、直接x86変換も現実的に！
 
 ### バックエンドの選択肢
-#### 1. Cranelift + lld内蔵（ChatGPT5推奨）
+#### 1. Cranelift + lld内蔵（保留）
 - **軽量**: 3-5MB程度（LLVMの1/10以下）
 - **JIT特化**: メモリ上での動的コンパイル
 - **Rust統合**: 静的リンクで配布容易
@@ -173,18 +173,15 @@ box TemplateStitcher {
 
 ## 🔗 EXEファイル生成・リンク戦略
 
-### 統合ツールチェーン
+### 統合ツールチェーン（現状）
 ```bash
-# Cranelift版（一時停止中）
+nyash build main.ny --backend=llvm --emit exe -o program.exe   # llvmlite/harness 経路
-nyash build main.ny --backend=cranelift --target=x86_64-pc-windows-msvc
+NYASH_VM_USE_PY=1 nyash run main.ny --backend=vm               # PyVM（MIR JSON を実行）
-
-# LLVM版（ChatGPT5実装中）
-nyash build main.ny --backend=llvm --emit exe -o program.exe
 ```
 
 ### 実装戦略
 
-#### LLVM バックエンド（優先）
+#### LLVM バックエンド（優先・llvmlite）
 1. **MIR→LLVM IR**: MIR13をLLVM IRに変換（✅ 実装済み）
 2. **LLVM IR→Object**: ネイティブオブジェクトファイル生成（✅ 実装済み）
 3. **Python/llvmlite実装**: Resolver patternでSSA安全性確保（✅ 実証済み）
@@ -233,10 +230,10 @@ ny_free_buf(buffer)
 ## 📅 実施時期（修正版）
 
 - **現在進行中**（2025年9月）
-  - Python/llvmlite実装でブレークスルー
+  - Python/llvmlite（既定）／Craneliftは停止
-  - dep_tree_min_string.nyashオブジェクト生成成功！
+  - PyVM（Python MIR VM）導入・代表スモークで llvmlite とパリティ確認
-- **Phase 15.2**: LLVM独立化（2025年9-10月完成予定）
+- **Phase 15.2**: llvmlite安定化 + PyVM最小完成（2025年9-10月）
-- **Phase 15.3**: Nyashコンパイラ（2025年11-12月）
+- **Phase 15.3**: NyashコンパイラMVP（2025年11-12月）
 - **Phase 15.4**: VM層Nyash化（2026年1-3月）
 - **Phase 15.5**: ABI移行（LLVM完成後、必要に応じて）
 

docs/development/roadmap/phases/phase-15/planning/sequence.md

@@ -1,10 +1,10 @@
-# Phase 15 推奨進行順（JIT優先・自己ホスティング最小）
+# Phase 15 推奨進行順（llvmlite+PyVM 優先・自己ホスティング最小）
 
 更新日: 2025-09-05
 
 ## 方針（原則）
 
-- JITオンリー（Cranelift）で前進。LLVM/AOT・lld系は後段にスライド。
+- JIT/Cranelift は停止。LLVM（llvmlite）と PyVM の2経路で前進。
 - 最小自己ホスト体験を早期に成立 → ドキュメント/スモーク/CIを先に固める。
 - using（名前空間）はゲート付きで段階導入。NyModulesとny_pluginsの基盤を強化。
 - tmux + codex-async を使い、常時2本並走で小粒に積み上げる。
@@ -25,18 +25,17 @@
 **完了基準:**
 - env.modules.get("acme.logger") などが取得可能、LIST_ONLY/Fail-continue維持、予約拒否ログが出る。
 
-### 2) 最小コンパイラ経路（JIT）
+### 2) 最小VM（PyVM）
 
 **要点:**
-- パーサ/レクサのサブセット: ident/literals/let/call/return/if/block
+- MIR(JSON) を Python VM（PyVM）で実行。最小命令 + 最小 boxcall（Console/File/Path/String）
-- Nyash から呼べる MIR ビルダ（小さなサブセット）
+- ランナー統合（`NYASH_VM_USE_PY=1`）→ 代表スモークが llvmlite と一致
-- VM/JIT ブリッジを通して apps/selfhost-minimal が走る
 
 **スモーク/CI:**
-- tools/jit_smoke.sh, tools/selfhost_vm_smoke.sh
+- tools/compare_harness_on_off.sh（ハーネス）、compare_vm_vs_harness.sh（PyVM vs llvmlite）
 
 **完了基準:**
-- ./target/release/nyash --backend vm apps/selfhost-minimal/main.nyash が安定実行し、CIでJITスモーク合格。
+- esc_dirname_smoke / dep_tree_min_string が PyVM と llvmlite で一致。
 
 ### 3) using（ゲート付き）設計・実装（15.2/15.3）
 

src/llvm_py/__init__.py

@@ -0,0 +1,7 @@
+"""Top-level package for Nyash Python backends.
+
+Subpackages:
+  - pyvm: Python MIR interpreter (PyVM)
+  - instructions/*: llvmlite lowering helpers (AOT harness)
+"""
+

src/llvm_py/instructions/binop.py

@@ -69,6 +69,7 @@ def lower_binop(
         i8p = ir.IntType(8).as_pointer()
         lhs_raw = vmap.get(lhs)
         rhs_raw = vmap.get(rhs)
+        # Prefer handle pipeline to keep handles consistent across blocks/ret
         # pointer present?
         is_ptr_side = (hasattr(lhs_raw, 'type') and isinstance(lhs_raw.type, ir.PointerType)) or \
                       (hasattr(rhs_raw, 'type') and isinstance(rhs_raw.type, ir.PointerType))
@@ -86,7 +87,7 @@ def lower_binop(
         is_str = is_ptr_side or any_tagged
         if is_str:
             # Helper: convert raw or resolved value to string handle
-            def to_handle(raw, val, tag: str):
+            def to_handle(raw, val, tag: str, vid: int):
                 if raw is not None and hasattr(raw, 'type') and isinstance(raw.type, ir.PointerType):
                     # pointer-to-array -> GEP
                     try:
@@ -104,11 +105,29 @@ def lower_binop(
                     return builder.call(cal, [raw], name=f"str_ptr2h_{tag}_{dst}")
                 # if already i64
                 if val is not None and hasattr(val, 'type') and isinstance(val.type, ir.IntType) and val.type.width == 64:
+                    # Distinguish handle vs numeric: if vid is tagged string-ish, treat as handle; otherwise box numeric to handle
+                    is_tag = False
+                    try:
+                        if resolver is not None and hasattr(resolver, 'is_stringish'):
+                            is_tag = resolver.is_stringish(vid)
+                    except Exception:
+                        is_tag = False
+                    if is_tag:
                         return val
+                    # Box numeric i64 to IntegerBox handle
+                    cal = None
+                    for f in builder.module.functions:
+                        if f.name == 'nyash.box.from_i64':
+                            cal = f; break
+                    if cal is None:
+                        cal = ir.Function(builder.module, ir.FunctionType(i64, [i64]), name='nyash.box.from_i64')
+                    # Ensure value is i64
+                    v64 = val if val.type.width == 64 else builder.zext(val, i64)
+                    return builder.call(cal, [v64], name=f"int_i2h_{tag}_{dst}")
                 return ir.Constant(i64, 0)
 
-            hl = to_handle(lhs_raw, lhs_val, 'l')
+            hl = to_handle(lhs_raw, lhs_val, 'l', lhs)
-            hr = to_handle(rhs_raw, rhs_val, 'r')
+            hr = to_handle(rhs_raw, rhs_val, 'r', rhs)
             # concat_hh(handle, handle) -> handle
             hh_fnty = ir.FunctionType(i64, [i64, i64])
             callee = None

src/llvm_py/instructions/boxcall.py

@@ -131,6 +131,8 @@ def lower_boxcall(
                 try:
                     if resolver is not None and hasattr(resolver, 'mark_string'):
                         resolver.mark_string(dst_vid)
+                    if resolver is not None and hasattr(resolver, 'string_ptrs'):
+                        resolver.string_ptrs[int(dst_vid)] = p
                 except Exception:
                     pass
             return
@@ -196,23 +198,38 @@ def lower_boxcall(
         return
 
     if method_name in ("print", "println", "log"):
-        # Console mapping
+        # Console mapping (prefer pointer-API when possible to avoid handle registry mismatch)
+        use_ptr = False
+        arg0_vid = args[0] if args else None
+        arg0_ptr = None
+        if resolver is not None and hasattr(resolver, 'string_ptrs') and arg0_vid is not None:
+            try:
+                arg0_ptr = resolver.string_ptrs.get(int(arg0_vid))
+                if arg0_ptr is not None:
+                    use_ptr = True
+            except Exception:
+                pass
+        if use_ptr and arg0_ptr is not None:
+            callee = _declare(module, "nyash.console.log", i64, [i8p])
+            _ = builder.call(callee, [arg0_ptr], name="console_log_ptr")
+        else:
+            # Fallback: resolve i64 and prefer pointer API via to_i8p_h bridge
             if resolver is not None and preds is not None and block_end_values is not None and bb_map is not None:
                 arg0 = resolver.resolve_i64(args[0], builder.block, preds, block_end_values, vmap, bb_map) if args else None
             else:
                 arg0 = vmap.get(args[0]) if args else None
             if arg0 is None:
-            arg0 = ir.Constant(i8p, None)
+                arg0 = ir.Constant(i64, 0)
-        # Prefer handle API if arg is i64, else pointer API
+            # If we have a handle (i64), convert to i8* via bridge and log via pointer API
-        if hasattr(arg0, 'type') and isinstance(arg0.type, ir.IntType) and arg0.type.width == 64:
+            if hasattr(arg0, 'type') and isinstance(arg0.type, ir.IntType):
-            # Optional runtime trace of the handle
+                if arg0.type.width != 64:
-            import os as _os
+                    arg0 = builder.zext(arg0, i64)
-            if _os.environ.get('NYASH_LLVM_TRACE_FINAL') == '1':
+                bridge = _declare(module, "nyash.string.to_i8p_h", i8p, [i64])
-                trace = _declare(module, "nyash.debug.trace_handle", i64, [i64])
+                p = builder.call(bridge, [arg0], name="str_h2p_for_log")
-                _ = builder.call(trace, [arg0], name="trace_handle")
+                callee = _declare(module, "nyash.console.log", i64, [i8p])
-            callee = _declare(module, "nyash.console.log_handle", i64, [i64])
+                _ = builder.call(callee, [p], name="console_log_p")
-            _ = builder.call(callee, [arg0], name="console_log_h")
             else:
+                # Non-integer value: coerce to i8* and log
                 if hasattr(arg0, 'type') and isinstance(arg0.type, ir.IntType):
                     arg0 = builder.inttoptr(arg0, i8p)
                 callee = _declare(module, "nyash.console.log", i64, [i8p])

src/llvm_py/instructions/call.py

@@ -107,5 +107,18 @@ def lower_call(
                     'esc_json', 'node_json', 'dirname', 'join', 'read_all', 'toJson'
                 ]):
                     resolver.mark_string(dst_vid)
+            # Additionally, create a pointer view via bridge for println pointer-API
+            if resolver is not None and hasattr(resolver, 'string_ptrs'):
+                i64 = ir.IntType(64)
+                i8p = ir.IntType(8).as_pointer()
+                if hasattr(result, 'type') and isinstance(result.type, ir.IntType) and result.type.width == 64:
+                    bridge = None
+                    for f in module.functions:
+                        if f.name == 'nyash.string.to_i8p_h':
+                            bridge = f; break
+                    if bridge is None:
+                        bridge = ir.Function(module, ir.FunctionType(i8p, [i64]), name='nyash.string.to_i8p_h')
+                    pv = builder.call(bridge, [result], name=f"ret_h2p_{dst_vid}")
+                    resolver.string_ptrs[int(dst_vid)] = pv
         except Exception:
             pass

src/llvm_py/instructions/const.py

@@ -39,7 +39,7 @@ def lower_const(
         llvm_val = ir.Constant(f64, float(const_val))
         vmap[dst] = llvm_val
         
-    elif const_type == 'string':
+    elif const_type == 'string' or (isinstance(const_type, dict) and const_type.get('kind') in ('handle','ptr') and const_type.get('box_type') == 'StringBox'):
         # String constant - create global and immediately box to i64 handle
         i8 = ir.IntType(8)
         str_val = str(const_val)
@@ -82,6 +82,11 @@ def lower_const(
             # Mark this value-id as string-ish to guide '+' and '==' lowering
             if hasattr(resolver, 'mark_string'):
                 resolver.mark_string(dst)
+            # Keep raw pointer for potential pointer-API sites (e.g., console.log)
+            try:
+                resolver.string_ptrs[dst] = gep
+            except Exception:
+                pass
         
     elif const_type == 'void':
         # Void/null constant - use i64 zero

src/llvm_py/instructions/phi.py

@@ -58,6 +58,7 @@ def lower_phi(
 
     # Collect incoming values
     incoming_pairs: List[Tuple[ir.Block, ir.Value]] = []
+    used_default_zero = False
     for block_id in actual_preds:
         block = bb_map.get(block_id)
         vid = incoming_map.get(block_id)
@@ -76,6 +77,7 @@ def lower_phi(
             if val is None:
                 # Missing incoming for this predecessor → default 0
                 val = ir.Constant(phi_type, 0)
+                used_default_zero = True
         else:
             # Snapshot fallback
             if block_end_values is not None:
@@ -86,6 +88,7 @@ def lower_phi(
             if not val:
                 # Missing incoming for this predecessor → default 0
                 val = ir.Constant(phi_type, 0)
+                used_default_zero = True
             # Coerce pointer to i64 at predecessor end
             if hasattr(val, 'type') and val.type != phi_type:
                 pb = ir.IRBuilder(block)
@@ -127,6 +130,16 @@ def lower_phi(
     
     # Store PHI result
     vmap[dst_vid] = phi
+    # Strict mode: fail fast on synthesized zeros (indicates incomplete incoming or dominance issue)
+    import os
+    if used_default_zero and os.environ.get('NYASH_LLVM_PHI_STRICT') == '1':
+        raise RuntimeError(f"[LLVM_PY] PHI dst={dst_vid} used synthesized zero; check preds/incoming")
+    if os.environ.get('NYASH_LLVM_TRACE_PHI') == '1':
+        try:
+            blkname = str(current_block.name)
+        except Exception:
+            blkname = '<blk>'
+        print(f"[PHI] {blkname} v{dst_vid} incoming={len(incoming_pairs)} zero={1 if used_default_zero else 0}")
     # Propagate string-ness: if any incoming value-id is tagged string-ish, mark dst as string-ish.
     try:
         if resolver is not None and hasattr(resolver, 'is_stringish') and hasattr(resolver, 'mark_string'):

src/llvm_py/instructions/ret.py

@@ -30,12 +30,36 @@ def lower_return(
         builder.ret_void()
     else:
         # Get return value (prefer resolver)
+        ret_val = None
         if resolver is not None and preds is not None and block_end_values is not None and bb_map is not None:
+            try:
                 if isinstance(return_type, ir.PointerType):
                     ret_val = resolver.resolve_ptr(value_id, builder.block, preds, block_end_values, vmap)
                 else:
-                ret_val = resolver.resolve_i64(value_id, builder.block, preds, block_end_values, vmap, bb_map)
+                    # Prefer pointer→handle reboxing for string-ish returns even if function return type is i64
+                    is_stringish = False
+                    if hasattr(resolver, 'is_stringish'):
+                        try:
+                            is_stringish = resolver.is_stringish(int(value_id))
+                        except Exception:
+                            is_stringish = False
+                    if is_stringish and hasattr(resolver, 'string_ptrs') and int(value_id) in getattr(resolver, 'string_ptrs'):
+                        # Re-box known string pointer to handle
+                        p = resolver.string_ptrs[int(value_id)]
+                        i8p = ir.IntType(8).as_pointer()
+                        i64 = ir.IntType(64)
+                        boxer = None
+                        for f in builder.module.functions:
+                            if f.name == 'nyash.box.from_i8_string':
+                                boxer = f; break
+                        if boxer is None:
+                            boxer = ir.Function(builder.module, ir.FunctionType(i64, [i8p]), name='nyash.box.from_i8_string')
+                        ret_val = builder.call(boxer, [p], name='ret_ptr2h')
                     else:
+                        ret_val = resolver.resolve_i64(value_id, builder.block, preds, block_end_values, vmap, bb_map)
+            except Exception:
+                ret_val = None
+        if ret_val is None:
             ret_val = vmap.get(value_id)
         if not ret_val:
             # Default based on return type

src/llvm_py/llvm_builder.py

@@ -140,7 +140,22 @@ class NyashLLVMBuilder:
                 else:
                     b.ret(ir.Constant(self.i32, 0))
         
-        return str(self.module)
+        ir_text = str(self.module)
+        # Optional IR dump to file for debugging
+        try:
+            dump_path = os.environ.get('NYASH_LLVM_DUMP_IR')
+            if dump_path:
+                os.makedirs(os.path.dirname(dump_path), exist_ok=True)
+                with open(dump_path, 'w') as f:
+                    f.write(ir_text)
+            elif os.environ.get('NYASH_CLI_VERBOSE') == '1':
+                # Default dump location when verbose and not explicitly set
+                os.makedirs('tmp', exist_ok=True)
+                with open('tmp/nyash_harness.ll', 'w') as f:
+                    f.write(ir_text)
+        except Exception:
+            pass
+        return ir_text
     
     def _create_dummy_main(self) -> str:
         """Create dummy ny_main that returns 0"""
@@ -185,6 +200,8 @@ class NyashLLVMBuilder:
                 self.resolver.string_ids.clear()
             if hasattr(self.resolver, 'string_literals'):
                 self.resolver.string_literals.clear()
+            if hasattr(self.resolver, 'string_ptrs'):
+                self.resolver.string_ptrs.clear()
         except Exception:
             pass
 
@@ -403,6 +420,15 @@ class NyashLLVMBuilder:
             dst = inst.get("dst")
             lower_boxcall(builder, self.module, box_vid, method, args, dst,
                           self.vmap, self.resolver, self.preds, self.block_end_values, self.bb_map)
+            # Optional: honor explicit dst_type for tagging (string handle)
+            try:
+                dst_type = inst.get("dst_type")
+                if dst is not None and isinstance(dst_type, dict):
+                    if dst_type.get("kind") == "handle" and dst_type.get("box_type") == "StringBox":
+                        if hasattr(self.resolver, 'mark_string'):
+                            self.resolver.mark_string(int(dst))
+            except Exception:
+                pass
             
         elif op == "externcall":
             func_name = inst.get("func")
@@ -661,7 +687,7 @@ def main():
 
     llvm_ir = builder.build_from_mir(mir_json)
     if os.environ.get('NYASH_CLI_VERBOSE') == '1':
-        print(f"[Python LLVM] Generated LLVM IR:\n{llvm_ir}")
+        print(f"[Python LLVM] Generated LLVM IR (see NYASH_LLVM_DUMP_IR or tmp/nyash_harness.ll)")
 
     builder.compile_to_object(output_file)
     print(f"Compiled to {output_file}")

src/llvm_py/pyvm/__init__.py

@@ -0,0 +1,6 @@
+"""PyVM package scaffold for Nyash MIR interpreter (Python).
+
+Modules:
+  - vm: Tiny interpreter for MIR(JSON) produced by runner's mir_json_emit
+"""
+

src/llvm_py/pyvm/vm.py

@@ -0,0 +1,390 @@
+"""
+Minimal Python VM for Nyash MIR(JSON) parity with llvmlite.
+
+Supported ops (MVP):
+  - const/binop/compare/branch/jump/ret
+  - phi (select by predecessor block)
+  - newbox: ConsoleBox, StringBox (minimal semantics)
+  - boxcall: String.length/substring/lastIndexOf, Console.print/println/log
+  - externcall: nyash.console.println
+
+Value model:
+  - i64 -> Python int
+  - f64 -> Python float
+  - string -> Python str
+  - void/null -> None
+  - ConsoleBox -> {"__box__":"ConsoleBox"}
+  - StringBox receiver -> Python str
+"""
+
+from __future__ import annotations
+from dataclasses import dataclass
+from typing import Any, Dict, List, Optional, Tuple
+import os
+
+
+@dataclass
+class Block:
+    id: int
+    instructions: List[Dict[str, Any]]
+
+
+@dataclass
+class Function:
+    name: str
+    params: List[int]
+    blocks: Dict[int, Block]
+
+
+class PyVM:
+    def __init__(self, program: Dict[str, Any]):
+        self.functions: Dict[str, Function] = {}
+        for f in program.get("functions", []):
+            name = f.get("name")
+            params = [int(p) for p in f.get("params", [])]
+            bmap: Dict[int, Block] = {}
+            for bb in f.get("blocks", []):
+                bmap[int(bb.get("id"))] = Block(id=int(bb.get("id")), instructions=list(bb.get("instructions", [])))
+            self.functions[name] = Function(name=name, params=params, blocks=bmap)
+
+    def _read(self, regs: Dict[int, Any], v: Optional[int]) -> Any:
+        if v is None:
+            return None
+        return regs.get(int(v))
+
+    def _set(self, regs: Dict[int, Any], dst: Optional[int], val: Any) -> None:
+        if dst is None:
+            return
+        regs[int(dst)] = val
+
+    def _truthy(self, v: Any) -> bool:
+        if isinstance(v, bool):
+            return v
+        if isinstance(v, (int, float)):
+            return v != 0
+        if isinstance(v, str):
+            return len(v) != 0
+        return v is not None
+
+    def _is_console(self, v: Any) -> bool:
+        return isinstance(v, dict) and v.get("__box__") == "ConsoleBox"
+
+    def run(self, entry: str) -> Any:
+        fn = self.functions.get(entry)
+        if fn is None:
+            raise RuntimeError(f"entry function not found: {entry}")
+        return self._exec_function(fn, [])
+
+    def _exec_function(self, fn: Function, args: List[Any]) -> Any:
+        # Intrinsic fast path for small helpers used in smokes
+        ok, ret = self._try_intrinsic(fn.name, args)
+        if ok:
+            return ret
+        # Initialize registers and bind params
+        regs: Dict[int, Any] = {}
+        if fn.params:
+            for i, pid in enumerate(fn.params):
+                regs[int(pid)] = args[i] if i < len(args) else None
+        else:
+            # Heuristic: derive param count from name suffix '/N' and bind to vids 0..N-1
+            n = 0
+            if "/" in fn.name:
+                try:
+                    n = int(fn.name.split("/")[-1])
+                except Exception:
+                    n = 0
+            for i in range(n):
+                regs[i] = args[i] if i < len(args) else None
+        # Choose a deterministic first block (lowest id)
+        if not fn.blocks:
+            return 0
+        cur = min(fn.blocks.keys())
+        prev: Optional[int] = None
+
+        # Simple block execution loop
+        while True:
+            block = fn.blocks.get(cur)
+            if block is None:
+                raise RuntimeError(f"block not found: {cur}")
+            # Evaluate instructions sequentially
+            i = 0
+            while i < len(block.instructions):
+                inst = block.instructions[i]
+                op = inst.get("op")
+
+                if op == "phi":
+                    # incoming: [[vid, pred_bid], ...]
+                    incoming = inst.get("incoming", [])
+                    chosen: Any = None
+                    # Prefer predecessor match; otherwise fallback to first
+                    for vid, pb in incoming:
+                        if prev is not None and int(pb) == int(prev):
+                            chosen = regs.get(int(vid))
+                            break
+                    if chosen is None and incoming:
+                        vid, _ = incoming[0]
+                        chosen = regs.get(int(vid))
+                    self._set(regs, inst.get("dst"), chosen)
+                    i += 1
+                    continue
+
+                if op == "const":
+                    val = inst.get("value", {})
+                    ty = val.get("type")
+                    vv = val.get("value")
+                    if ty == "i64":
+                        out = int(vv)
+                    elif ty == "f64":
+                        out = float(vv)
+                    elif ty == "string":
+                        out = str(vv)
+                    else:
+                        out = None
+                    self._set(regs, inst.get("dst"), out)
+                    i += 1
+                    continue
+
+                if op == "binop":
+                    operation = inst.get("operation")
+                    a = self._read(regs, inst.get("lhs"))
+                    b = self._read(regs, inst.get("rhs"))
+                    res: Any = None
+                    if operation == "+":
+                        if isinstance(a, str) or isinstance(b, str):
+                            res = (str(a) if a is not None else "") + (str(b) if b is not None else "")
+                        else:
+                            av = 0 if a is None else int(a)
+                            bv = 0 if b is None else int(b)
+                            res = av + bv
+                    elif operation == "-":
+                        av = 0 if a is None else int(a)
+                        bv = 0 if b is None else int(b)
+                        res = av - bv
+                    elif operation == "*":
+                        av = 0 if a is None else int(a)
+                        bv = 0 if b is None else int(b)
+                        res = av * bv
+                    elif operation == "/":
+                        # integer division semantics for now
+                        av = 0 if a is None else int(a)
+                        bv = 1 if b in (None, 0) else int(b)
+                        res = av // bv
+                    elif operation == "%":
+                        av = 0 if a is None else int(a)
+                        bv = 1 if b in (None, 0) else int(b)
+                        res = av % bv
+                    elif operation in ("&", "|", "^"):
+                        # treat as bitwise on ints
+                        ai, bi = (0 if a is None else int(a)), (0 if b is None else int(b))
+                        if operation == "&":
+                            res = ai & bi
+                        elif operation == "|":
+                            res = ai | bi
+                        else:
+                            res = ai ^ bi
+                    elif operation in ("<<", ">>"):
+                        ai, bi = (0 if a is None else int(a)), (0 if b is None else int(b))
+                        res = (ai << bi) if operation == "<<" else (ai >> bi)
+                    else:
+                        raise RuntimeError(f"unsupported binop: {operation}")
+                    self._set(regs, inst.get("dst"), res)
+                    i += 1
+                    continue
+
+                if op == "compare":
+                    operation = inst.get("operation")
+                    a = self._read(regs, inst.get("lhs"))
+                    b = self._read(regs, inst.get("rhs"))
+                    res: bool
+                    if operation == "==":
+                        res = (a == b)
+                    elif operation == "!=":
+                        res = (a != b)
+                    elif operation == "<":
+                        res = (a < b)
+                    elif operation == "<=":
+                        res = (a <= b)
+                    elif operation == ">":
+                        res = (a > b)
+                    elif operation == ">=":
+                        res = (a >= b)
+                    else:
+                        raise RuntimeError(f"unsupported compare: {operation}")
+                    # VM convention: booleans are i64 0/1
+                    self._set(regs, inst.get("dst"), 1 if res else 0)
+                    i += 1
+                    continue
+
+                if op == "newbox":
+                    btype = inst.get("type")
+                    if btype == "ConsoleBox":
+                        val = {"__box__": "ConsoleBox"}
+                    elif btype == "StringBox":
+                        # empty string instance
+                        val = ""
+                    else:
+                        # Unknown box -> opaque
+                        val = {"__box__": btype}
+                    self._set(regs, inst.get("dst"), val)
+                    i += 1
+                    continue
+
+                if op == "boxcall":
+                    recv = self._read(regs, inst.get("box"))
+                    method = inst.get("method")
+                    args = [self._read(regs, a) for a in inst.get("args", [])]
+                    out: Any = None
+                    # ConsoleBox methods
+                    if method in ("print", "println", "log") and self._is_console(recv):
+                        s = args[0] if args else ""
+                        if s is None:
+                            s = ""
+                        if method == "println":
+                            print(str(s))
+                        else:
+                            # println is the primary one used by smokes; keep print/log equivalent
+                            print(str(s))
+                        out = 0
+                    # FileBox methods (minimal read-only)
+                    elif isinstance(recv, dict) and recv.get("__box__") == "FileBox":
+                        if method == "open":
+                            path = str(args[0]) if len(args) > 0 else ""
+                            mode = str(args[1]) if len(args) > 1 else "r"
+                            ok = 0
+                            content = None
+                            if mode == "r":
+                                try:
+                                    with open(path, "r", encoding="utf-8") as f:
+                                        content = f.read()
+                                    ok = 1
+                                except Exception:
+                                    ok = 0
+                                    content = None
+                            recv["__open"] = (ok == 1)
+                            recv["__path"] = path
+                            recv["__content"] = content
+                            out = ok
+                        elif method == "read":
+                            if isinstance(recv.get("__content"), str):
+                                out = recv.get("__content")
+                            else:
+                                out = None
+                        elif method == "close":
+                            recv["__open"] = False
+                            out = 0
+                        else:
+                            out = None
+                    # PathBox methods (posix-like)
+                    elif isinstance(recv, dict) and recv.get("__box__") == "PathBox":
+                        if method == "dirname":
+                            p = str(args[0]) if args else ""
+                            # Normalize to POSIX-style
+                            out = os.path.dirname(p)
+                            if out == "":
+                                out = "."
+                        elif method == "join":
+                            base = str(args[0]) if len(args) > 0 else ""
+                            rel = str(args[1]) if len(args) > 1 else ""
+                            out = os.path.join(base, rel)
+                        else:
+                            out = None
+                    elif method == "length":
+                        out = len(str(recv))
+                    elif method == "substring":
+                        s = str(recv)
+                        start = int(args[0]) if len(args) > 0 else 0
+                        end = int(args[1]) if len(args) > 1 else len(s)
+                        out = s[start:end]
+                    elif method == "lastIndexOf":
+                        s = str(recv)
+                        needle = str(args[0]) if args else ""
+                        out = s.rfind(needle)
+                    else:
+                        # Unimplemented method -> no-op
+                        out = None
+                    self._set(regs, inst.get("dst"), out)
+                    i += 1
+                    continue
+
+                if op == "externcall":
+                    func = inst.get("func")
+                    args = [self._read(regs, a) for a in inst.get("args", [])]
+                    out: Any = None
+                    if func == "nyash.console.println":
+                        s = args[0] if args else ""
+                        if s is None:
+                            s = ""
+                        print(str(s))
+                        out = 0
+                    else:
+                        # Unknown extern
+                        out = None
+                    self._set(regs, inst.get("dst"), out)
+                    i += 1
+                    continue
+
+                if op == "branch":
+                    cond = self._read(regs, inst.get("cond"))
+                    tid = int(inst.get("then"))
+                    eid = int(inst.get("else"))
+                    prev = cur
+                    cur = tid if self._truthy(cond) else eid
+                    # Restart execution at next block
+                    break
+
+                if op == "jump":
+                    tgt = int(inst.get("target"))
+                    prev = cur
+                    cur = tgt
+                    break
+
+                if op == "ret":
+                    v = self._read(regs, inst.get("value"))
+                    return v
+
+                if op == "call":
+                    # Resolve function name from value or take as literal
+                    fval = inst.get("func")
+                    fname = self._read(regs, fval)
+                    if not isinstance(fname, str):
+                        # Fallback: if JSON encoded a literal name
+                        fname = fval if isinstance(fval, str) else None
+                    call_args = [self._read(regs, a) for a in inst.get("args", [])]
+                    result = None
+                    if isinstance(fname, str) and fname in self.functions:
+                        callee = self.functions[fname]
+                        result = self._exec_function(callee, call_args)
+                    # Store result if needed
+                    self._set(regs, inst.get("dst"), result)
+                    i += 1
+                    continue
+
+                # Unhandled op -> skip
+                i += 1
+
+            else:
+                # No explicit terminator; finish
+                return 0
+
+    def _try_intrinsic(self, name: str, args: List[Any]) -> Tuple[bool, Any]:
+        try:
+            if name == "Main.esc_json/1":
+                s = "" if not args else ("" if args[0] is None else str(args[0]))
+                out = []
+                for ch in s:
+                    if ch == "\\":
+                        out.append("\\\\")
+                    elif ch == '"':
+                        out.append('\\"')
+                    else:
+                        out.append(ch)
+                return True, "".join(out)
+            if name == "Main.dirname/1":
+                p = "" if not args else ("" if args[0] is None else str(args[0]))
+                d = os.path.dirname(p)
+                if d == "":
+                    d = "."
+                return True, d
+        except Exception:
+            pass
+        return (False, None)

src/llvm_py/resolver.py

@@ -33,6 +33,8 @@ class Resolver:
         self.f64_cache: Dict[Tuple[str, int], ir.Value] = {}
         # String literal map: value_id -> Python string (for by-name calls)
         self.string_literals: Dict[int, str] = {}
+        # Optional: value_id -> i8* pointer for string constants (lower_const can populate)
+        self.string_ptrs: Dict[int, ir.Value] = {}
         # Track value-ids that are known to represent string handles (i64)
         # This is a best-effort tag used to decide '+' as string concat when both sides are i64.
         self.string_ids: set[int] = set()

src/runner/mir_json_emit.rs

@@ -0,0 +1,127 @@
+use serde_json::json;
+
+/// Emit MIR JSON for Python harness/PyVM.
+/// The JSON schema matches tools/llvmlite_harness.py expectations and is
+/// intentionally minimal for initial scaffolding.
+pub fn emit_mir_json_for_harness(
+    module: &nyash_rust::mir::MirModule,
+    path: &std::path::Path,
+) -> Result<(), String> {
+    use nyash_rust::mir::{MirInstruction as I, BinaryOp as B, CompareOp as C};
+    let mut funs = Vec::new();
+    for (name, f) in &module.functions {
+        let mut blocks = Vec::new();
+        let mut ids: Vec<_> = f.blocks.keys().copied().collect();
+        ids.sort();
+        for bid in ids {
+            if let Some(bb) = f.blocks.get(&bid) {
+                let mut insts = Vec::new();
+                // PHI first（オプション）
+                for inst in &bb.instructions {
+                    if let I::Phi { dst, inputs } = inst {
+                        let incoming: Vec<_> = inputs
+                            .iter()
+                            .map(|(b, v)| json!([v.as_u32(), b.as_u32()]))
+                            .collect();
+                        insts.push(json!({"op":"phi","dst": dst.as_u32(), "incoming": incoming}));
+                    }
+                }
+                // Non-PHI
+                for inst in &bb.instructions {
+                    match inst {
+                        I::Const { dst, value } => {
+                            match value {
+                                nyash_rust::mir::ConstValue::Integer(i) => {
+                                    insts.push(json!({"op":"const","dst": dst.as_u32(), "value": {"type": "i64", "value": i}}));
+                                }
+                                nyash_rust::mir::ConstValue::Float(fv) => {
+                                    insts.push(json!({"op":"const","dst": dst.as_u32(), "value": {"type": "f64", "value": fv}}));
+                                }
+                                nyash_rust::mir::ConstValue::Bool(b) => {
+                                    insts.push(json!({"op":"const","dst": dst.as_u32(), "value": {"type": "i64", "value": if *b {1} else {0}}}));
+                                }
+                                nyash_rust::mir::ConstValue::String(s) => {
+                                    // String constants are exported as StringBox handle by default
+                                    insts.push(json!({
+                                        "op":"const",
+                                        "dst": dst.as_u32(),
+                                        "value": {
+                                            "type": {"kind":"handle","box_type":"StringBox"},
+                                            "value": s
+                                        }
+                                    }));
+                                }
+                                nyash_rust::mir::ConstValue::Null | nyash_rust::mir::ConstValue::Void => {
+                                    insts.push(json!({"op":"const","dst": dst.as_u32(), "value": {"type": "void", "value": 0}}));
+                                }
+                            }
+                        }
+                        I::BinOp { dst, op, lhs, rhs } => {
+                            let op_s = match op { B::Add=>"+",B::Sub=>"-",B::Mul=>"*",B::Div=>"/",B::Mod=>"%",B::BitAnd=>"&",B::BitOr=>"|",B::BitXor=>"^",B::Shl=>"<<",B::Shr=>">>",B::And=>"&",B::Or=>"|"};
+                            insts.push(json!({"op":"binop","operation": op_s, "lhs": lhs.as_u32(), "rhs": rhs.as_u32(), "dst": dst.as_u32()}));
+                        }
+                        I::Compare { dst, op, lhs, rhs } => {
+                            let op_s = match op { C::Lt=>"<", C::Le=>"<=", C::Gt=>">", C::Ge=>">=", C::Eq=>"==", C::Ne=>"!=" };
+                            insts.push(json!({"op":"compare","operation": op_s, "lhs": lhs.as_u32(), "rhs": rhs.as_u32(), "dst": dst.as_u32()}));
+                        }
+                        I::Call { dst, func, args, .. } => {
+                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
+                            insts.push(json!({"op":"call","func": func.as_u32(), "args": args_a, "dst": dst.map(|d| d.as_u32())}));
+                        }
+                        I::ExternCall { dst, iface_name, method_name, args, .. } => {
+                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
+                            let func_name = if iface_name == "env.console" {
+                                format!("nyash.console.{}", method_name)
+                            } else { format!("{}.{}", iface_name, method_name) };
+                            insts.push(json!({"op":"externcall","func": func_name, "args": args_a, "dst": dst.map(|d| d.as_u32())}));
+                        }
+                        I::BoxCall { dst, box_val, method, args, .. } => {
+                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
+                            // Minimal dst_type hints
+                            let mut obj = json!({
+                                "op":"boxcall","box": box_val.as_u32(), "method": method, "args": args_a, "dst": dst.map(|d| d.as_u32())
+                            });
+                            let m = method.as_str();
+                            let dst_ty = if m == "substring" {
+                                Some(json!({"kind":"handle","box_type":"StringBox"}))
+                            } else if m == "length" || m == "lastIndexOf" {
+                                Some(json!("i64"))
+                            } else { None };
+                            if let Some(t) = dst_ty { obj["dst_type"] = t; }
+                            insts.push(obj);
+                        }
+                        I::NewBox { dst, box_type, args } => {
+                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
+                            insts.push(json!({"op":"newbox","type": box_type, "args": args_a, "dst": dst.as_u32()}));
+                        }
+                        I::Branch { condition, then_bb, else_bb } => {
+                            insts.push(json!({"op":"branch","cond": condition.as_u32(), "then": then_bb.as_u32(), "else": else_bb.as_u32()}));
+                        }
+                        I::Jump { target } => {
+                            insts.push(json!({"op":"jump","target": target.as_u32()}));
+                        }
+                        I::Return { value } => {
+                            insts.push(json!({"op":"ret","value": value.map(|v| v.as_u32())}));
+                        }
+                        _ => { /* skip non-essential ops for initial harness */ }
+                    }
+                }
+                if let Some(term) = &bb.terminator {
+                    match term {
+                        I::Return { value } => insts.push(json!({"op":"ret","value": value.map(|v| v.as_u32())})),
+                        I::Jump { target } => insts.push(json!({"op":"jump","target": target.as_u32()})),
+                        I::Branch { condition, then_bb, else_bb } => insts.push(json!({"op":"branch","cond": condition.as_u32(), "then": then_bb.as_u32(), "else": else_bb.as_u32()})),
+                        _ => {}
+                    }
+                }
+                blocks.push(json!({"id": bid.as_u32(), "instructions": insts}));
+            }
+        }
+        // Export parameter value-ids so a VM can bind arguments
+        let params: Vec<_> = f.params.iter().map(|v| v.as_u32()).collect();
+        funs.push(json!({"name": name, "params": params, "blocks": blocks}));
+    }
+    let root = json!({"functions": funs});
+    std::fs::write(path, serde_json::to_string_pretty(&root).unwrap())
+        .map_err(|e| format!("write mir json: {}", e))
+}

src/runner/mod.rs

@@ -30,6 +30,7 @@ use std::{fs, process};
 mod modes;
 mod demos;
 mod json_v0_bridge;
+mod mir_json_emit;
 
 // v2 plugin system imports
 use nyash_rust::runtime;

src/runner/modes/llvm.rs

@@ -2,7 +2,6 @@ use super::super::NyashRunner;
 use nyash_rust::{parser::NyashParser, mir::{MirCompiler, MirInstruction}, box_trait::IntegerBox};
 use nyash_rust::mir::passes::method_id_inject::inject_method_ids;
 use std::{fs, process};
-use serde_json::json;
 
 impl NyashRunner {
     /// Execute LLVM mode (split)
@@ -56,7 +55,7 @@ impl NyashRunner {
                             let tmp_dir = std::path::Path::new("tmp");
                             let _ = std::fs::create_dir_all(tmp_dir);
                             let mir_json_path = tmp_dir.join("nyash_harness_mir.json");
-                            if let Err(e) = emit_mir_json_for_harness(&module, &mir_json_path) {
+                            if let Err(e) = crate::runner::mir_json_emit::emit_mir_json_for_harness(&module, &mir_json_path) {
                                 eprintln!("❌ MIR JSON emit error: {}", e);
                                 process::exit(1);
                             }
@@ -182,92 +181,4 @@ impl NyashRunner {
     }
 }
 
-fn emit_mir_json_for_harness(module: &nyash_rust::mir::MirModule, path: &std::path::Path) -> Result<(), String> {
+// emit_mir_json_for_harness moved to crate::runner::mir_json_emit
-    use nyash_rust::mir::{MirInstruction as I, BinaryOp as B, CompareOp as C};
-    // Build JSON structure expected by python builder: { functions: [ { name, params, blocks: [ { id, instructions: [ ... ] } ] } ] }
-    let mut funs = Vec::new();
-    for (name, f) in &module.functions {
-        let mut blocks = Vec::new();
-        let mut ids: Vec<_> = f.blocks.keys().copied().collect();
-        ids.sort();
-        for bid in ids {
-            if let Some(bb) = f.blocks.get(&bid) {
-                let mut insts = Vec::new();
-                // PHI first（オプション）
-                for inst in &bb.instructions {
-                        if let I::Phi { dst, inputs } = inst {
-                        let incoming: Vec<_> = inputs.iter().map(|(b, v)| json!([v.as_u32(), b.as_u32()])).collect();
-                        insts.push(json!({"op":"phi","dst": dst.as_u32(), "incoming": incoming}));
-                        }
-                }
-                // Non-PHI
-                for inst in &bb.instructions {
-                    match inst {
-                        I::Const { dst, value } => {
-                            let (t, val) = match value {
-                                nyash_rust::mir::ConstValue::Integer(i) => ("i64", json!(i)),
-                                nyash_rust::mir::ConstValue::Float(fv) => ("f64", json!(fv)),
-                                nyash_rust::mir::ConstValue::Bool(b) => ("i64", json!(if *b {1} else {0})),
-                                nyash_rust::mir::ConstValue::String(s) => ("string", json!(s)),
-                                nyash_rust::mir::ConstValue::Null => ("void", json!(0)),
-                                nyash_rust::mir::ConstValue::Void => ("void", json!(0)),
-                            };
-                            insts.push(json!({"op":"const","dst": dst.as_u32(), "value": {"type": t, "value": val}}));
-                        }
-                        I::BinOp { dst, op, lhs, rhs } => {
-                            let op_s = match op { B::Add=>"+",B::Sub=>"-",B::Mul=>"*",B::Div=>"/",B::Mod=>"%",B::BitAnd=>"&",B::BitOr=>"|",B::BitXor=>"^",B::Shl=>"<<",B::Shr=>">>",B::And=>"&",B::Or=>"|"};
-                            insts.push(json!({"op":"binop","operation": op_s, "lhs": lhs.as_u32(), "rhs": rhs.as_u32(), "dst": dst.as_u32()}));
-                        }
-                        I::Compare { dst, op, lhs, rhs } => {
-                            let op_s = match op { C::Lt=>"<", C::Le=>"<=", C::Gt=>">", C::Ge=>">=", C::Eq=>"==", C::Ne=>"!=" };
-                            insts.push(json!({"op":"compare","operation": op_s, "lhs": lhs.as_u32(), "rhs": rhs.as_u32(), "dst": dst.as_u32()}));
-                        }
-                        I::Call { dst, func, args, .. } => {
-                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
-                            insts.push(json!({"op":"call","func": func.as_u32(), "args": args_a, "dst": dst.map(|d| d.as_u32())}));
-                        }
-                        I::ExternCall { dst, iface_name, method_name, args, .. } => {
-                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
-                            // Map known interfaces to NyRT symbols
-                            let func_name = if iface_name == "env.console" {
-                                format!("nyash.console.{}", method_name)
-                            } else { format!("{}.{}", iface_name, method_name) };
-                            insts.push(json!({"op":"externcall","func": func_name, "args": args_a, "dst": dst.map(|d| d.as_u32())}));
-                        }
-                        I::BoxCall { dst, box_val, method, args, .. } => {
-                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
-                            insts.push(json!({"op":"boxcall","box": box_val.as_u32(), "method": method, "args": args_a, "dst": dst.map(|d| d.as_u32())}));
-                        }
-                        I::NewBox { dst, box_type, args } => {
-                            let args_a: Vec<_> = args.iter().map(|v| json!(v.as_u32())).collect();
-                            insts.push(json!({"op":"newbox","type": box_type, "args": args_a, "dst": dst.as_u32()}));
-                        }
-                        I::Branch { condition, then_bb, else_bb } => {
-                            insts.push(json!({"op":"branch","cond": condition.as_u32(), "then": then_bb.as_u32(), "else": else_bb.as_u32()}));
-                        }
-                        I::Jump { target } => {
-                            insts.push(json!({"op":"jump","target": target.as_u32()}));
-                        }
-                        I::Return { value } => {
-                            insts.push(json!({"op":"ret","value": value.map(|v| v.as_u32())}));
-                        }
-                        _ => { /* skip non-essential ops for initial harness */ }
-                    }
-                }
-                // Terminator (if present)
-                if let Some(term) = &bb.terminator {
-                    match term {
-                        I::Return { value } => insts.push(json!({"op":"ret","value": value.map(|v| v.as_u32())})),
-                        I::Jump { target } => insts.push(json!({"op":"jump","target": target.as_u32()})),
-                        I::Branch { condition, then_bb, else_bb } => insts.push(json!({"op":"branch","cond": condition.as_u32(), "then": then_bb.as_u32(), "else": else_bb.as_u32()})),
-                        _ => {}
-                    }
-                }
-                blocks.push(json!({"id": bid.as_u32(), "instructions": insts}));
-            }
-        }
-        funs.push(json!({"name": name, "params": [], "blocks": blocks}));
-    }
-    let root = json!({"functions": funs});
-    std::fs::write(path, serde_json::to_string_pretty(&root).unwrap()).map_err(|e| format!("write mir json: {}", e))
-}

src/runner/modes/vm.rs

@@ -118,6 +118,58 @@ impl NyashRunner {
             }
         }
 
+        // Optional: PyVM path. When NYASH_VM_USE_PY=1, emit MIR(JSON) and delegate execution to tools/pyvm_runner.py
+        if std::env::var("NYASH_VM_USE_PY").ok().as_deref() == Some("1") {
+            let py = which::which("python3").ok();
+            if let Some(py3) = py {
+                let runner = std::path::Path::new("tools/pyvm_runner.py");
+                if runner.exists() {
+                    // Emit MIR(JSON)
+                    let tmp_dir = std::path::Path::new("tmp");
+                    let _ = std::fs::create_dir_all(tmp_dir);
+                    let mir_json_path = tmp_dir.join("nyash_pyvm_mir.json");
+                    if let Err(e) = crate::runner::mir_json_emit::emit_mir_json_for_harness(&module_vm, &mir_json_path) {
+                        eprintln!("❌ PyVM MIR JSON emit error: {}", e);
+                        process::exit(1);
+                    }
+                    if std::env::var("NYASH_CLI_VERBOSE").ok().as_deref() == Some("1") {
+                        eprintln!("[Runner/VM] using PyVM → {} (mir={})", filename, mir_json_path.display());
+                    }
+                    // Determine entry function hint (prefer Main.main if present)
+                    let entry = if module_vm.functions.contains_key("Main.main") {
+                        "Main.main"
+                    } else if module_vm.functions.contains_key("main") { "main" } else { "Main.main" };
+                    // Spawn runner
+                    let status = std::process::Command::new(py3)
+                        .args([
+                            runner.to_string_lossy().as_ref(),
+                            "--in",
+                            &mir_json_path.display().to_string(),
+                            "--entry",
+                            entry,
+                        ])
+                        .status()
+                        .map_err(|e| format!("spawn pyvm: {}", e))
+                        .unwrap();
+                    if !status.success() {
+                        eprintln!("❌ PyVM failed (status={})", status.code().unwrap_or(-1));
+                        process::exit(1);
+                    }
+                    // Propagate exit code if set
+                    if let Some(code) = status.code() {
+                        process::exit(code);
+                    }
+                    process::exit(0);
+                } else {
+                    eprintln!("❌ PyVM runner not found: {}", runner.display());
+                    process::exit(1);
+                }
+            } else {
+                eprintln!("❌ python3 not found in PATH. Install Python 3 to use PyVM.");
+                process::exit(1);
+            }
+        }
+
         // Expose GC/scheduler hooks globally for JIT externs (checkpoint/await, etc.)
         nyash_rust::runtime::global_hooks::set_from_runtime(&runtime);
 

tools/build_llvm.sh

@@ -43,11 +43,12 @@ if ! command -v llvm-config-18 >/dev/null 2>&1; then
   exit 2
 fi
 
-echo "[1/4] Building nyash (feature=llvm, harness-friendly) ..."
+echo "[1/4] Building nyash (feature selectable) ..."
 _LLVMPREFIX=$(llvm-config-18 --prefix)
-# Build only the core package to avoid compiling workspace plugin crates
+# Select LLVM feature: default harness (llvm), or legacy inkwell when NYASH_LLVM_FEATURE=llvm-inkwell-legacy
+LLVM_FEATURE=${NYASH_LLVM_FEATURE:-llvm}
 LLVM_SYS_181_PREFIX="${_LLVMPREFIX}" LLVM_SYS_180_PREFIX="${_LLVMPREFIX}" \
-  CARGO_INCREMENTAL=1 cargo build --release -p nyash-rust --features llvm >/dev/null
+  CARGO_INCREMENTAL=1 cargo build --release -p nyash-rust --features "$LLVM_FEATURE" >/dev/null
 
 echo "[2/4] Emitting object (.o) via LLVM backend ..."
 # Default object output path under target/aot_objects
@@ -57,7 +58,15 @@ stem=${stem%.nyash}
 OBJ="${NYASH_LLVM_OBJ_OUT:-$PWD/target/aot_objects/${stem}.o}"
 if [[ "${NYASH_LLVM_SKIP_EMIT:-0}" != "1" ]]; then
   rm -f "$OBJ"
-  NYASH_LLVM_OBJ_OUT="$OBJ" LLVM_SYS_181_PREFIX="${_LLVMPREFIX}" LLVM_SYS_180_PREFIX="${_LLVMPREFIX}" ./target/release/nyash --backend llvm "$INPUT" >/dev/null || true
+  if [[ "${NYASH_LLVM_FEATURE:-llvm}" == "llvm-inkwell-legacy" ]]; then
+    # Legacy path: do not use harness
+    NYASH_LLVM_OBJ_OUT="$OBJ" LLVM_SYS_181_PREFIX="${_LLVMPREFIX}" LLVM_SYS_180_PREFIX="${_LLVMPREFIX}" \
+      ./target/release/nyash --backend llvm "$INPUT" >/dev/null || true
+  else
+    # Harness path
+    NYASH_LLVM_OBJ_OUT="$OBJ" NYASH_LLVM_USE_HARNESS=1 LLVM_SYS_181_PREFIX="${_LLVMPREFIX}" LLVM_SYS_180_PREFIX="${_LLVMPREFIX}" \
+      ./target/release/nyash --backend llvm "$INPUT" >/dev/null || true
+  fi
 fi
 if [[ ! -f "$OBJ" ]]; then
   echo "error: object not generated: $OBJ" >&2

tools/build_plugins_all.sh

@@ -7,9 +7,15 @@ ROOT_DIR=$(cd "$(dirname "$0")/.." && pwd)
 cd "$ROOT_DIR"
 
 PROFILE=${PROFILE:-release}
+JOBS=${JOBS:-24}
 
-echo "[plugins] building all (profile=$PROFILE)"
+echo "[plugins] building all (profile=$PROFILE, jobs=$JOBS)"
 
+# Build all plugins in one go for maximum efficiency
+echo "[plugins] building workspace..."
+cargo build --workspace --$PROFILE -j $JOBS >/dev/null
+
+# Copy artifacts to plugin directories
 for dir in plugins/*; do
   [[ -d "$dir" && -f "$dir/Cargo.toml" ]] || continue
   pkg=$(grep -m1 '^name\s*=\s*"' "$dir/Cargo.toml" | sed -E 's/.*"(.*)".*/\1/')
@@ -19,7 +25,6 @@ for dir in plugins/*; do
     libname=${pkg//-/_}
   fi
   echo "[plugins] -> $pkg (libname=$libname)"
-  cargo build -p "$pkg" --$PROFILE >/dev/null
   # Copy artifacts
   outdir="target/$PROFILE"
   # cdylib (.so/.dylib/.dll)

tools/compare_harness_on_off.sh

@@ -12,11 +12,19 @@ OFF_EXE=${OFF_EXE:-$ROOT_DIR/app_dep_tree_rust}
 echo "[compare] target app: $APP"
 
 echo "[compare] build (OFF/Rust LLVM or harness fallback) ..."
-# If legacy inkwell backend is not in use, fall back to harness for OFF as well
+if [[ "${NYASH_COMPARE_INKWELL:-0}" == "1" ]]; then
-NYASH_LLVM_SKIP_NYRT_BUILD=1 NYASH_LLVM_USE_HARNESS=1 "$ROOT_DIR/tools/build_llvm.sh" "$APP" -o "$OFF_EXE" >/dev/null
+  echo "    OFF=inkwell-legacy"
+  NYASH_LLVM_SKIP_NYRT_BUILD=1 NYASH_LLVM_FEATURE=llvm-inkwell-legacy \
+    "$ROOT_DIR/tools/build_llvm.sh" "$APP" -o "$OFF_EXE" >/dev/null
+else
+  echo "    OFF=harness"
+  NYASH_LLVM_SKIP_NYRT_BUILD=1 NYASH_LLVM_FEATURE=llvm \
+    "$ROOT_DIR/tools/build_llvm.sh" "$APP" -o "$OFF_EXE" >/dev/null
+fi
 
 echo "[compare] build (ON/llvmlite harness) ..."
-NYASH_LLVM_SKIP_NYRT_BUILD=1 NYASH_LLVM_USE_HARNESS=1 "$ROOT_DIR/tools/build_llvm.sh" "$APP" -o "$ON_EXE" >/dev/null
+NYASH_LLVM_SKIP_NYRT_BUILD=1 NYASH_LLVM_FEATURE=llvm \
+  "$ROOT_DIR/tools/build_llvm.sh" "$APP" -o "$ON_EXE" >/dev/null
 
 echo "[compare] run both and capture output ..."
 ON_OUT="$OUTDIR/on.out"; OFF_OUT="$OUTDIR/off.out"

tools/llvmlite_check_deny_direct.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT=$(cd "$(dirname "$0")/.." && pwd)
+cd "$ROOT"
+
+echo "[deny-direct] scanning src/llvm_py for direct vmap.get reads ..."
+rg -n "vmap\\.get\\(" src/llvm_py \
+  -g '!src/llvm_py/resolver.py' \
+  -g '!src/llvm_py/llvm_builder.py' || true
+
+echo "[hint] Prefer resolver.resolve_i64/resolve_ptr with (builder.block, preds, block_end_values, vmap, bb_map)."
+

tools/parity.sh

@@ -0,0 +1,166 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ "${NYASH_CLI_VERBOSE:-0}" == "1" ]]; then
+  set -x
+fi
+
+usage() {
+  cat << USAGE
+Nyash parity runner — compare two execution paths on the same .nyash
+
+Usage: tools/parity.sh [options] <app.nyash>
+
+Options:
+  --lhs <mode>   Left  mode: pyvm|llvmlite|vm   (default: pyvm)
+  --rhs <mode>   Right mode: pyvm|llvmlite|vm   (default: llvmlite)
+  --timeout <s>  Timeout seconds for each run     (default: 12)
+  --show-diff    Show unified diff when different
+
+Compares stdout (normalized) and exit codes. Returns 0 when equal.
+USAGE
+}
+
+APP=""
+LHS="pyvm"
+RHS="llvmlite"
+TIMEOUT="12"
+SHOW_DIFF=0
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    -h|--help) usage; exit 0;;
+    --lhs) LHS="$2"; shift 2;;
+    --rhs) RHS="$2"; shift 2;;
+    --timeout) TIMEOUT="$2"; shift 2;;
+    --show-diff) SHOW_DIFF=1; shift;;
+    *) APP="$1"; shift;;
+  esac
+done
+
+if [[ -z "$APP" ]]; then
+  usage; exit 1
+fi
+if [[ ! -f "$APP" ]]; then
+  echo "error: app not found: $APP" >&2
+  exit 2
+fi
+
+ROOT=$(cd "$(dirname "$0")/.." && pwd)
+NYASH_BIN="$ROOT/target/release/nyash"
+if [[ ! -x "$NYASH_BIN" ]]; then
+  echo "[build] nyash not found; building release ..." >&2
+  (cd "$ROOT" && cargo build --release >/dev/null)
+fi
+
+has_cmd() { command -v "$1" >/dev/null 2>&1; }
+
+normalize() {
+  # Remove runner/plugin noise and blank lines
+  sed -E \
+    -e 's/\r$//' \
+    -e '/^\[ConsoleBox\]/d' \
+    -e '/^\[FileBox\]/d' \
+    -e '/^\[plugin-loader\]/d' \
+    -e '/^\[Runner\//d' \
+    -e '/^DEBUG:/d' \
+    -e '/^🔌/d' \
+    -e '/^✅/d' \
+    -e '/^🚀/d' \
+    -e '/^⚡/d' \
+    -e '/^🦀/d' \
+    -e '/^🧠/d' \
+    -e '/^📊/d' \
+    -e '/^Result(Type)?\(/d' \
+    -e '/^Result:/d' \
+    -e '/^$/d'
+}
+
+run_pyvm() {
+  local app="$1"
+  local out code
+  if has_cmd timeout; then
+    out=$(NYASH_VM_USE_PY=1 timeout "${TIMEOUT}s" "$NYASH_BIN" --backend vm "$app" 2>&1) || code=$?
+  else
+    out=$(NYASH_VM_USE_PY=1 "$NYASH_BIN" --backend vm "$app" 2>&1) || code=$?
+  fi
+  code=${code:-0}
+  printf '%s' "$out" | normalize
+  echo "__EXIT_CODE__=$code"
+}
+
+run_vm() {
+  local app="$1"
+  local out code
+  if has_cmd timeout; then
+    out=$(timeout "${TIMEOUT}s" "$NYASH_BIN" --backend vm "$app" 2>&1) || code=$?
+  else
+    out=$("$NYASH_BIN" --backend vm "$app" 2>&1) || code=$?
+  fi
+  code=${code:-0}
+  printf '%s' "$out" | normalize
+  echo "__EXIT_CODE__=$code"
+}
+
+run_llvmlite() {
+  local app="$1"
+  if ! has_cmd llvm-config-18; then
+    echo "error: llvm-config-18 not found (required for llvmlite parity)." >&2
+    exit 3
+  fi
+  local stem exe
+  stem=$(basename "$app"); stem=${stem%.nyash}
+  exe="$ROOT/app_parity_${stem}"
+  NYASH_LLVM_FEATURE=llvm "${ROOT}/tools/build_llvm.sh" "$app" -o "$exe" >/dev/null || true
+  if [[ ! -x "$exe" ]]; then
+    echo "error: failed to build llvmlite executable: $exe" >&2
+    exit 4
+  fi
+  local out code
+  if has_cmd timeout; then
+    out=$(timeout "${TIMEOUT}s" "$exe" 2>&1) || code=$?
+  else
+    out=$("$exe" 2>&1) || code=$?
+  fi
+  code=${code:-0}
+  printf '%s' "$out" | normalize
+  echo "__EXIT_CODE__=$code"
+}
+
+run_mode() {
+  local mode="$1" app="$2"
+  case "$mode" in
+    pyvm) run_pyvm "$app" ;;
+    vm) run_vm "$app" ;;
+    llvmlite) run_llvmlite "$app" ;;
+    *) echo "error: unknown mode: $mode" >&2; exit 5;;
+  esac
+}
+
+LEFT=$(run_mode "$LHS" "$APP")
+RIGHT=$(run_mode "$RHS" "$APP")
+
+LCODE=$(printf '%s\n' "$LEFT" | sed -n 's/^__EXIT_CODE__=//p')
+RCODE=$(printf '%s\n' "$RIGHT" | sed -n 's/^__EXIT_CODE__=//p')
+LOUT=$(printf '%s\n' "$LEFT" | sed '/^__EXIT_CODE__=/d')
+ROUT=$(printf '%s\n' "$RIGHT" | sed '/^__EXIT_CODE__=/d')
+
+STATUS=0
+if [[ "$LCODE" != "$RCODE" ]]; then
+  echo "[parity] exit code differs: $LHS=$LCODE, $RHS=$RCODE" >&2
+  STATUS=1
+fi
+if [[ "$LOUT" != "$ROUT" ]]; then
+  echo "[parity] stdout differs" >&2
+  if [[ "$SHOW_DIFF" -eq 1 ]]; then
+    diff -u <(printf '%s\n' "$LOUT") <(printf '%s\n' "$ROUT") || true
+  fi
+  STATUS=1
+fi
+
+if [[ "$STATUS" -eq 0 ]]; then
+  echo "✅ parity OK ($LHS == $RHS)" >&2
+else
+  echo "❌ parity mismatch ($LHS != $RHS)" >&2
+fi
+exit "$STATUS"

tools/pyvm_runner.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""
+Nyash PyVM runner (scaffold)
+
+Usage:
+  - python3 tools/pyvm_runner.py --in mir.json [--entry Main.main]
+
+Executes MIR(JSON) using a tiny Python interpreter for a minimal opcode set:
+  - const/binop/compare/branch/jump/ret
+  - newbox (ConsoleBox, StringBox minimal)
+  - boxcall (String: length/substring/lastIndexOf; Console: print/println/log)
+  - externcall (nyash.console.println)
+
+On success, exits with the integer return value if it is an Integer; otherwise 0.
+Outputs produced by println/log are written to stdout.
+"""
+
+import argparse
+import json
+import sys
+import os
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+PYVM_DIR = ROOT / "src" / "llvm_py" / "pyvm"
+
+# Ensure imports can find the package root (src)
+SRC_DIR = ROOT / "src"
+if str(SRC_DIR) not in sys.path:
+    sys.path.insert(0, str(SRC_DIR))
+
+from llvm_py.pyvm.vm import PyVM  # type: ignore
+
+
+def main():
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--in", dest="infile", required=True, help="MIR JSON input")
+    ap.add_argument("--entry", dest="entry", default="Main.main", help="Entry function (default Main.main)")
+    args = ap.parse_args()
+
+    with open(args.infile, "r") as f:
+        program = json.load(f)
+
+    vm = PyVM(program)
+    # Fallbacks for entry name
+    entry = args.entry
+    fun_names = {f.get("name", "") for f in program.get("functions", [])}
+    if entry not in fun_names:
+        if "main" in fun_names:
+            entry = "main"
+        elif "Main.main" in fun_names:
+            entry = "Main.main"
+
+    result = vm.run(entry)
+    # Exit code convention: integers propagate; bool -> 0/1; else 0
+    code = 0
+    if isinstance(result, bool):
+        code = 1 if result else 0
+    elif isinstance(result, int):
+        # Clamp to 32-bit exit code domain
+        code = int(result) & 0xFFFFFFFF
+        if code & 0x80000000:
+            code = -((~code + 1) & 0xFFFFFFFF)
+    # For parity comparisons, avoid emitting extra lines here.
+    sys.exit(code)
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except Exception as e:
+        import traceback
+        print(f"[pyvm] error: {e}", file=sys.stderr)
+        if sys.stderr and (os.environ.get('NYASH_CLI_VERBOSE') == '1' or True):
+            traceback.print_exc()
+        sys.exit(1)

tools/pyvm_vs_llvmlite.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ "${NYASH_CLI_VERBOSE:-0}" == "1" ]]; then
+  set -x
+fi
+
+APP="${1:-apps/tests/esc_dirname_smoke.nyash}"
+OUT="app_pyvm_cmp"
+
+if [[ ! -f "$APP" ]]; then
+  echo "error: app not found: $APP" >&2
+  exit 2
+fi
+
+# 1) Build nyash with llvm harness enabled (build_llvm.sh does the right thing)
+echo "[cmp] building AOT via llvmlite harness ..." >&2
+./tools/build_llvm.sh "$APP" -o "$OUT" >/dev/null
+
+# 2) Run AOT executable and capture stdout + exit code
+echo "[cmp] running AOT (llvmlite) ..." >&2
+set +e
+OUT_LL=$("./$OUT" 2>&1)
+CODE_LL=$?
+set -e
+
+# 3) Run PyVM path (VM mode delegated to Python)
+echo "[cmp] running PyVM ..." >&2
+set +e
+OUT_PY=$(NYASH_VM_USE_PY=1 ./target/release/nyash --backend vm "$APP" 2>&1)
+CODE_PY=$?
+set -e
+
+echo "=== llvmlite (AOT) stdout ==="
+echo "$OUT_LL" | sed -n '1,120p'
+echo "=== PyVM stdout ==="
+echo "$OUT_PY" | sed -n '1,120p'
+echo "=== exit codes ==="
+echo "llvmlite: $CODE_LL"
+echo "PyVM    : $CODE_PY"
+
+DIFF=0
+if [[ "$OUT_LL" != "$OUT_PY" ]]; then
+  echo "[cmp] stdout differs" >&2
+  DIFF=1
+fi
+if [[ "$CODE_LL" -ne "$CODE_PY" ]]; then
+  echo "[cmp] exit code differs" >&2
+  DIFF=1
+fi
+
+if [[ "$DIFF" -eq 0 ]]; then
+  echo "✅ parity OK (stdout + exit code)"
+else
+  echo "❌ parity mismatch" >&2
+  exit 1
+fi
+