A dev cell carries its body's signature word beside the body, every call through a cell (and every function value taken from one) compares it with the word the site was compiled for, and the session lists the stale callers by file and line on the reply. Both backends, both installers; release builds have neither the word nor the compare.
FIX.org, NEXT.md, DISCUSS.org, docs/DISCUSS.md and the session handoff at the
root are one TODO.org now: 293 entries under seven subsystem headings, each
carrying an org keyword that says where it stands. A DONE entry is a few lines
saying what was decided and what that rules out; the reasoning that would not
compress — the embedding spike and the four reports the hand-written x86
backend was built from — moved into docs/BUILT.md instead, and its entries
point there in one line.
Every entry was checked against the tree before it got a keyword, and the
prose was wrong in both directions. Things the deleted files called open were
built: the first-evaluation stall, main being redefinable, macro parameter
lists, the type-limit constants, the array constructors, the byte fills,
inc/dec, the discard's fontification, the Emacs buffers, rt_die's _exit, the
backtrace surface, and the acceptance failure that could print and still exit
zero. Things they called done were not: the backend reports' no-plan buckets
had gone stale in the other direction, the value-dependent defvar was
superseded rather than built, and macro-expansion source locations are on an
unmerged lane, so that entry is NEXT and names the branch.
Every comment that cited one of the five by name now cites a heading that
exists, in TODO.org or in docs/BUILT.md. The session reports under
docs/handoffs/ keep naming the files they worked on, because rewriting them
would falsify what those sessions did; each carries a note saying where the
content went.
Three from a review of the commit before this one, and the first is a dev
loop defect. Naming the widening thunk thick/<count so far> put traversal
order into a symbol, and Session.compatible compares a reload's functions
against the running program's by name -- so swapping two calls in a body
renamed nothing the programmer can see and reported "thick/0 changes
signature, from [i32] i32 to [i64] i64. Restart to change it." The name is
the signature again, written by thick_enc: every type self-delimiting, an
atom as its length and then its spelling, so the boundaries mangle_ty loses
are in the string rather than inferred from the separators. mangle_ty is
untouched -- it is load-bearing for the instantiation names a backtrace, a
Reach edge and a dev cell show -- and the memo stays keyed on the types.
fn-thunk-reload.flan is the pair of widenings and test_session reorders them.
The second was a silent miscompile. bind_ty's Fn-pattern-against-CFn-argument
arm was structural, so it matched nested function positions too, and the
catch-up pass that builds the thunk compares the whole substituted parameter
list -- false when the mismatch is inside one, and the fallthrough handed the
argument over unchanged: one word where the instance declares two, 255 on
both backends with nothing said anywhere. The widening is a value the caller
builds around the whole argument and there is nowhere inside one to build it,
so the arm is admitted at the top of an argument's type and nowhere else, and
the catch-up arm is total over the pair rather than guarded -- bind_ty's
fallthrough is Types.fits, which admits Never, so a binding can still succeed
over a pair the two words cannot bridge. fn-generic-nested.flan is the
parameter position and fn-generic-nested-return.flan the return one.
And the third closes the hole the escaping inversion was for. A match arm
binds the case's fields to slots and the store that fills them is inside the
branch, not in any form escape_check reads as a binding, so (match o (Some f)
f ...) handed back through a name what a case-field read cannot hand back at
all -- sound only because Some_ denies suspects. An arm's slots of function
type are suspect now, for the same reason the read itself is.
