W25 Step B-0: cfg.cpp local extern → helper-own-header include

SonicField · SonicField · commit d0e80314dd4a · 2026-04-22T12:45:20.000-07:00
Per W25 spec §3 Step B + theologian [chat L2170] case-classification
guidance. First B-0 test case to validate Step B pattern on smallest
§1b TU before scaling to heavier ones.

CASE: Class C2 (file-pair-scoped helper, NOT in canonical hir_c_api.h).

  cfg.cpp had 1 lint-pattern extern:
    extern "C" size_t hir_cfg_get_rpo_c(void *cfg, void **out, size_t capacity);

  hir_cfg_get_rpo_c is declared in hir_cfg_rpo_c.h:18 + defined in
  hir_cfg_rpo_c.c:19 — its own file pair, not part of hir_c_api.h's
  canonical surface (it's a parallel C implementation of CFG RPO traversal
  alongside the C++ hir_cfg_get_rpo).

FIX: replace local extern with #include of helper's canonical header.

  - "cinderx/Jit/hir/cfg.h" (kept)
  - "cinderx/Jit/hir/hir_basic_block_c.h" (kept — §1b dual-include
    works post-W25 Step A)
  - "cinderx/Jit/hir/hir_cfg_rpo_c.h" (NEW — replaces local extern)

NO call-site changes (hir_cfg_get_rpo_c name same in both contexts).
NO canonical hir_c_api.h expansion needed (helper stays in own header).

CASE-CLASSIFICATION REPORT for spec amendment:
  Class C2 pattern is COMMON — 5+ §1b/non-§1b TUs use this same
  hir_cfg_get_rpo_c local extern (cfg.cpp, licm_c.c, pass_output_type_c.c
  twice, refcount_env_bridge.cpp, dominator_c.c). Step B for these
  TUs is straightforward: replace local extern with #include of
  helper's own header.

  Spec §3 Step B should enumerate Class C2 explicitly:
    Class A (canonical match in hir_c_api.h): #include hir_c_api.h
    Class B (name mismatch): caller-rewrite + #include hir_c_api.h
    Class C2 (file-pair helper with own header): #include helper's header
    Class C1 (function not in any header): add to canonical OR move to
      a helper header

testkeeper x86_64 compile-only PASS verified pre-commit at binary
timestamp 1776887068.

NEXT: testkeeper ARM64 pydebug --clean + 8-test gate. Then scale to
B-1 (other small §1b TUs: ssaify_c.c 1 extern, hir_basic_block_c.c
1 extern, licm_c.c 3, resolve_kwargs_c.c 5).

Authorization chain:
  - W25 spec §3 Step B: theologian L2017
  - 4-step revised sequencing + B-0 endorsement: theologian L2170
  - QUERY-BEFORE-PIVOT: generalist L2168 → theologian L2170 ack
  - Supervisor delegation to theologian: chat L2169
diff --git a/Python/jit/hir/cfg.cpp b/Python/jit/hir/cfg.cpp
@@ -2,8 +2,7 @@
 
 #include "cinderx/Jit/hir/cfg.h"
 #include "cinderx/Jit/hir/hir_basic_block_c.h"
-
-extern "C" size_t hir_cfg_get_rpo_c(void *cfg, void **out, size_t capacity);
+#include "cinderx/Jit/hir/hir_cfg_rpo_c.h"
 
 namespace jit::hir {
 
