Drew T
2.4 KiB
§141 — The §134 class is CLOSED: every line-shape decision now routes through cdecl._mask (P30 S39)
§134 ("multi-line / comment / string blindness in a hand-rolled line scanner") had been fixed individually in six tools, each time by patching that tool. The standing note said the real fix is routing every line-shape decision through the ONE masking oracle rather than writing a seventh regex. Done — the last two holdouts are migrated:
progress.py.strip_comments — was a private two-line regex stripping /*…*/ and //…, not
string-aware. Every caller is a line-shape decision on its output: the {-vs-; scan that
separates a definition from a declaration, the count('{') - count('}') body-depth walk, and the
empty-vs-real body test. So a brace inside a string literal mis-buckets a function in the fn-count
metric. Demonstrated:
void f(void) { puts("}"); x = 1; }
old regex -> body-depth walk = -1 (unbalanced: the string's brace was counted)
cdecl._mask-> body-depth walk = 0 (correct)
Metrics were identical before and after on today's corpus (341,365 / 353,717; REAL 339,510,
empty 896, stubs 12,345) — i.e. no live source currently trips it. That is what a latent defect looks
like: harmless until the day someone banks a function containing "{", and then silently wrong.
lint_symbol_refs.strip_comments_strings — was correct (char-by-char, escape-aware) but was a
SECOND implementation of the same masking. Deleted in favour of cdecl._mask. One behavioural
difference existed and was checked rather than assumed: _mask blanks the quote DELIMITERS too,
where the private scanner kept them — irrelevant, because every token the linter hunts
(func_<ADDR>, D_<ADDR>, and the bare 2nd arg of INCLUDE_ASM("...", func_X)) lives outside the
quotes either way. Gated on the linter's own output being byte-identical across the change, not on
the two masks being byte-identical — the right gate is the tool's answer, not its internals.
The general law (R33): when the same defect class has been patched N times in N tools, the fix is not the N+1th patch — it is deleting N−1 implementations. A private copy of a shared decision is a divergence waiting to happen, and it diverges silently.
Symptom line for the index: "a scanner miscounts braces/semicolons" · "two tools disagree about what a line is".