Files

nyash-codex 083be99214 test(joinir): Phase 129 P2 - add post-if return var fixture + VM smoke

- Add phase129_if_only_post_if_return_var_min.hako
  - Pattern: x=1; if flag==1 { x=2 }; print(x)
  - Tests join_k continuation env merge

- Add phase129_if_only_post_if_return_var_vm.sh
  - Expected output: 2 (x updated in then branch)
  - Dev-only: NYASH_JOINIR_DEV=1 HAKO_JOINIR_STRICT=1

Note: Currently passes via fallback path (non-Normalized)
P1 implementation (join_k materialization) is next step

2025-12-18 07:18:00 +09:00

5.5 KiB

Raw Blame History

Phase 129: Materialize join_k Continuation + LLVM Parity

Goal

Materialize join_k as a real JoinFunction (not just a concept)
Achieve VM+LLVM EXE parity for Phase 128 if-only partial assign pattern
Verify structural properties: join_k exists, PHI禁止 (no PHI in Normalized)

Background

Phase 128 added basic Assign(int literal) support to Normalized builder, but:

join_k was mentioned in comments but not actually materialized
The If lowering doesn't generate a join continuation
post-if statements (e.g., return x after if) aren't supported in Normalized path

Phase 129 fixes this by actually generating join_k as a JoinFunction.

Design

join_k Continuation Pattern

if cond {
  x = 2  // then: env_then = env with x=2
} else {
  // else: env_else = env (unchanged)
}
print(x)  // post-if: needs env from both branches

Normalized Lowering:

then:
  x = Const(2)
  env_then[x] = new_vid
  TailCall(join_k, env_then)

else:
  // no assignment
  env_else = env (original)
  TailCall(join_k, env_else)

join_k(env_phi):
  // env_phi is the merged environment
  // post-if statements use env_phi
  print(env_phi[x])
  Ret

Key Properties (SSOT)

join_k is a JoinFunction: Not a concept, but actual function in JoinModule
then/else end with TailCall(join_k): Not Ret, not direct post-if
env merging is explicit: env_phi parameter receives merged environment
PHI禁止: No PHI instructions in Normalized (env update + continuation only)

Structural Verification

verify_normalized_structure() enforces:

If node exists → join_k exists (as JoinFunction)
then/else don't end with Ret (they tail-call join_k)
join_k has env parameter (for merged environment)
No PHI instructions (structural check)

Scope

In-Scope (Phase 129)

If-only patterns (no loops)
Assign(int literal) RHS only (Phase 128 baseline)
post-if statements: print/return (minimal set)
VM + LLVM EXE parity (both must work)

Out-of-Scope

Loop patterns (Phase 130+)
Assign(complex expr) RHS (Phase 130+)
Nested if (Phase 130+)

Implementation Plan

P0: LLVM EXE smoke for Phase 128 ✅

Add phase128_if_only_partial_assign_normalized_llvm_exe.sh
Verify VM+LLVM parity for Phase 128 baseline
Regression: phase103, phase118

Status: DONE (commit e7ad3d31b)

P1: Materialize join_k Continuation

Target: src/mir/control_tree/normalized_shadow/builder.rs

Changes:

lower_if_node: Generate join_k function
- Create JoinFunction with env parameter
- then: TailCall(join_k, env_then)
- else: TailCall(join_k, env_else)
- join_k body: process post-if statements
verify_normalized_structure: Add join_k checks
- If exists → join_k exists (by name or structure)
- then/else end with TailCall (not Ret)
- join_k has params (env fields)
- No PHI instructions anywhere

Acceptance:

cargo test --lib PASS
Phase 128 VM smoke PASS
Phase 129 LLVM EXE smoke PASS (new fixture)

P2: Post-If Return Var Fixture

New fixture: apps/tests/phase129_if_only_post_if_return_var_min.hako

x=1; flag=1; if flag==1 { x=2 }; print(x); return "OK"

Expected: 2 (x updated in then branch)

VM smoke: phase129_if_only_post_if_return_var_vm.sh

NYASH_JOINIR_DEV=1 HAKO_JOINIR_STRICT=1
Verify join_k continuation works