The flip: FUNCTION/XFUNCTION/FUN::fun/delim_check and the module
interfaces take `const UTF8 * const fargs[]`. Double-const is
load-bearing: C++ qualification conversion needs const at both pointer
levels, so builder-side `UTF8 *[]` arrays convert implicitly — the
evaluator, the JIT marshaller, and every owner site need zero casts,
and slot reassignment inside bodies becomes a compile error for free.
The conversions: the flip landed first so the compiler enumerated every
violation; this commit is that inventory worked to zero — ~250 sites
across funceval, funceval2, functions, funmath, help, mail, session,
powers, levels, predicates, conf, walkdb, stringutil, timeutil/
date_scan (regenerated, one-line diff), exp3, and mux_main, each
classified per docs/campaign-2136-const-fargs.md's four recipes.
New idioms (functions.h): trim_space_sep_n() — non-destructive trim for
(pointer, length) consumers, so trim-then-scan sites need no copy at
all; FargVec — the argv counterpart of FargCopy for CS_ARGV handlers.
countwords() and DecodeListOfIntegers() rewritten non-destructive.
The flip deleted more than it added: #2157's fun_munge list1 copy, the
engine_com help-topic copy, fun_index's in-place NUL write, and five
const_casts (process_sex x4, sha1_helper). const_cast budget: zero
added.
Trap recorded in the brief: an old-signature definition doesn't fail
the build — it becomes a C++ overload, and the new-signature symbol
stays undefined until dlopen(RTLD_NOW). delim_check, the conn_bridge
bridges, the dbt_spike stub, and exp3::Call were all silently shadowed;
muxscript was the only host that noticed, because netmux's own net.cpp
resolved the flat-namespace lookup. After any signature flip, grep the
old spelling.
Verified: make test EXPECT_CONFIG="jit=yes" (35 passed / 0 failed) and
make test-scenario, including the new tests/scenario/sidefx_fargs.py
that live-probes the class-3 wrappers smoke never touches (pemit/
trigger/link/tel/wipe/destroy).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
