BFM-decomp/cookbook/C0135.md

§124 — A "not matched" verdict can mean the definition is there under a DIFFERENT C NAME: the asm-label alias blind spot (P30 SESSION-28, func_8016191C ×137)

Symptom. A family sweep reports no matched unit for func_XXXXXXXX in <ov> and skips every member — even though corpus.stubs says the exemplar is not a stub (i.e. the invariant says it IS matched). The two statements look contradictory; they are both true.

Cause. family_remap.extract_unit looked for a definition head literally named func_<ADDR>. But a body whose byte-true signature conflicts with the fleet-canonical declaration on both §73 axes at once (return AND params) is banked zero-touch by the §37 asm-label alias — the C identifier differs and a GNU asm label binds the emitted symbol:

extern void func_8016191C(void *a0, s32 a1);                 /* the fleet canon, in engine_core.h */
int aF8016191C(int param_1, unsigned int param_2) __asm__("func_8016191C");
int aF8016191C(int param_1, unsigned int param_2) { ... }

extract_unit matched nothing, returned None, and every caller reads None as "not matched."

Measured (P30). That single blind spot was the ENTIRE no matched unit skip class: one exemplar × 137 same-address members, 24 ins each = 3,288 ins, every member still an INCLUDE_ASM stub and otherwise sweep-ready. After the fix: 137 banked / 0 failed, R22 140/140. Fourth consecutive time a "structural" residual resolved to our own tooling (R35).

The fix, and the two traps inside it.

1. Resolve <ident>(...) __asm__("func_<ADDR>"); → <ident> and accept that as the definition head. Re-derive the pattern PER FILE — one file's alias must never leak into the next file's scan.
2. Carry the alias DECLARATION into the unit. Without it the sibling TU emits the symbol aF8016191C and the body never lands at func_<ADDR> — it would link, build, and be wrong. Let the preceding-decl backscan walk past the alias line (so the function's own externs are carried exactly as for a plain definition), then guard start <= alias_ln <= end against double-emitting it.
3. R32: an alias declaration with no findable definition must refuse LOUDLY. Falling through to _macro_unit re-reports "not matched" — the exact silent skip the fix exists to delete.

Do NOT "fix" this at the source. The tempting alternative is to widen the shared header (extern void → extern s32), delete the alias, and rename the definition back. That addresses only §73's RETURN axis while the decl and body also disagree on PARAMS, so it still conflicts — and it is a T2 fleet-shared edit where the alias is T0 draft-only. Fix the reader, not the source.

The general law. corpus.stubs (the invariant) and a source scanner can disagree, and when they do the scanner is wrong — the invariant is derived from the build, the scanner is a text model of it (R33). Any place that turns "I could not find the text" into "it is not matched" is a silent-skip defect waiting to be measured.

§124a — a family sweep's 0 matched-exemplar families may be a FILTER, not a wall

family_sweep --hseq defaults to --band substantial. A mid/tiny family therefore returns [hseq] 0 matched-exemplar families (band=substantial); 0 candidate members — which reads exactly like "nothing to do here." Pass --band all (or the family's band) before concluding anything. Same shape as §53 (the missing carve) and §116 (the wrong opt level): a 0 from the wrong invocation is not evidence. Check the band the family map assigned before you spend a probe on the residual.