Every number-to-text conversion wrote into one file-static in the runtime and
answered a slice over it, and nothing copied. Two of them in one expression
printed the second number twice — no crash, no diagnostic, and nothing a
sanitizer could find, because every byte read was inside an object that was
alive. The wrong object.
The buffer is now the caller's, one frame slot per call site. The slot is
allocated in the checker rather than in either backend: a slot is a
function-lifetime location in both of them, where an x86 backend temporary is
bump-allocated and reclaimed at the end of the expression that made it — which
is the one lifetime a returned slice must outlive. Each backend gains one
pointer argument and no reasoning of its own, which is what keeps them
symmetric.
The static is gone rather than left unused, since a buffer with nothing but a
comment beside it is a loaded gun. What remains is the ordinary lifetime a
pointer into a frame has: storing one of these slices in a container that
outlives the frame, or returning it, is still a copy the caller has to make.
NEXT.md's sharp edge now says that instead of what it used to say.
A (Vec Value) where a Value may itself hold a (Vec Value) — the recursive
dynamic value an EDN reader has to answer with when nobody hands it a target
struct type — was refused five different ways, and every one of the five gave
the same reason: the container runtime is type-erased, so it copies and
releases slots bytewise and cannot reach inside a slot. A free would release
the slots and leave every block they point at stranded.
That reason is about teardown, and it does not hold for a region. free-all
never releases an individual slot; it takes the whole arena, and every block
the elements own is in it, because they came out of it. The refusals were
over-broad, and what they were guarding was never ownership — ownership
tracking is untouched here, moves are still moves, and Types.is_move_only is
the same function it was.
So the question moved rather than disappeared. It could not stay at the type,
because can-free is a capability on an allocator value and with-allocator
rebinds a dynamic variable: which tier a (vec-new) will meet is not a property
of the place its type is written. What is decided at compile time is only
whether to ask, which is a property of the element type; the answer is a
run-time branch on the allocator, one per container and never per element,
because the alternative is a walk at release and a walk at release is the
registry of destructors the frame tier's reset exists to not have. It is
emitted at every growth and not only at the construction, because ZII means a
container can exist without ever passing through (vec-new) — a case field left
out of a literal, a global that starts zeroed — and those adopt the context on
their first push.
free on such a container is refused rather than made quietly shallow. It cannot
recurse, which is the whole premise, and releasing the outer block alone would
be "I freed it" written over a program that stranded everything inside; this
runtime refuses that collapse everywhere else. The message names free-all,
which is reachable by construction. clone stays refused for a reason the region
does not dissolve, and the old message had bundled the two failures under one
sentence: what disqualifies clone is not that it copies a header — so do at and
get, and they are fine, because they promise nothing — it is that clone
allocates a new block and promises independence, and a bytewise copy hands back
elements still pointing into the original's region.
A struct or union field is admitted only where the field's container holds
owning elements, because that container can only have been built against a
region. A field holding a plain (Vec u8) stays refused: nothing would force
that one into a region, and two copies of the aggregate would be two headers
over one heap block. vec-in-struct.flan still pins that.
The epoch already covered use after free-all, including the case this makes
reachable — an inner header copied out of an arena-held element into a local
still traps, because an Allocator is a pointer and a copied-by-value one would
carry its own epoch.
arena-value.flan builds the value by hand; arena-edn.flan reads a real document
through the tokenizer, and its reader takes no allocator and names none,
because spec-memory.md already puts the allocator in the calling convention.
arena-region.flan is the branch itself: run 0 is the (Vec (Vec i32)) control
that must not trap, and runs 1 and 2 are the two ways this dies.
flan dev's merged build is the program and the compiler in one -rdynamic
executable, so it exports every flan.* body it has, and ELF gives it precedence
over anything dlopened afterwards. The compiler expands a macro by dlopening a
module into that same process, and the module is built by Emit.program whatever
backend the session uses -- so under --x86 the caller was LLVM's and the body it
landed in was the dev backend's, which is a crossed pair. It died with SIGSEGV
inside flan.[clamp] during the first expansion, before the program had run a
line, and Dev.start refused the combination rather than do that.
Build.macro_module now asks Emit.program for hidden visibility on the module's
own Flan definitions. There is nothing left for the host to interpose, and the
flan.macro.* thunks stay exported because dlsym is how the compiler reaches
them -- nm -D on the built module lists those three and nothing else of Flan's.
The -Wl,-Bsymbolic that had been binding everything locally since 65d14f4 goes
with it: the module links its own flan_rt.c, and binding that locally aimed its
calls at a runtime flan_rt_init never ran on, with a null flan_exit_hook, so a
trap raised inside an expansion would have exited the process instead of parking
it.
Nothing about the host moved, which is what keeps redefinition modules reaching
its cells, its globals and flan_dev_cell. hidden defaults to false, and the 540
IR files this compiler emits for the test corpus are byte-identical to the ones
before it.
test_dev.ml's assertion that the merged daemon refuses --x86 becomes the session
it was standing in for: dev-macro.flan calls a prelude macro at the top level,
so the daemon coming up at all is the old crash not happening, and one build
then carries C-x C-e, a C-c C-c whose body calls a macro again, the park and the
rerun.
Flan's tagged sum has been spelled defunion since it landed, which was
accurate right up until the language wanted C's untagged union as well.
Both cannot be called the same thing, and the tagged one is the one with
an alternative name that says what it is: a case, its fields, and a tag
that steers which case is live is a data type, not a union.
So the form is defdata everywhere -- the parser, the AST, the checker,
both backends, the prelude's Form, the editor's font-locking and imenu,
the docs and every .flan file in the tree. The internal vocabulary moves
with it: Tast.union is Tast.data, uname is dname, the tables the checker
and the emitter keep are datas. Leaving them would have inverted the
words permanently, with surface defunion meaning one thing and
env.unions meaning the other, which is exactly the kind of drift the
comments in those files exist to prevent. What did not move is case,
variant and vfields: a tagged sum still has cases, and it still has one
live at a time.
defunion is not kept as an alias. An alias would compile the day the
untagged form lands and mean the opposite of what it used to -- the same
silent misparse that made defn's return type mandatory, and worse,
because the reader would have no reason to look. The old spelling is a
named refusal instead, parse/defunion-renamed, which says what it is now
called and that the name is reserved for something else. It fires on the
head alone, so (defunion U [A B]) -- which would otherwise have parsed
cleanly as one field A of type B -- is refused with the rest.
NEXT.md contradicted itself about the raylib header: two entries said the check
runs on every build and a third, further down, still explained why it is opt-in.
It gets the strikethrough its siblings have, with the reason the argument
dissolved -- the commit, not a change of mind about the property.
plan.org's list of what the dev runtime answers over nREPL had gained a member it
never listed. And the page quotes a program so that the line numbers in the output
beside it resolve, so both new examples are now pasted from their files rather than
trimmed, and cast.flan gets the source block every other example has.
NEXT.md prepends, so its second section still opened with "Read this first" while
pinning a tree six lanes behind and listing as live a queue most of which has
landed. It keeps its contents; what it gains is the sentence saying when it
stopped being where the tree is, and the survey count it quotes measured again on
this tree -- 103 MATCH, 0 DIFFER, 38 skipped.
The two generics entries get the file's own strikethrough treatment, which their
siblings already had: the {K V} catch resolved exactly as it predicted it would,
and there are five predicates rather than four.
Also here: conditions.org gains ArithError beside BoundsError, with the split
between the two runtime conditions that offer retry and the two that deliberately
offer nothing; and tast.ml's header stops naming a tree-walking interpreter among
the backends that consume the typed IR.
Two loose ends from NEXT.md.
slice-from-ptr's run-time refusal borrowed @flan_slice_error and reported a
range and a length the caller never wrote. It has flan_slice_promise_error
now: signals BoundsError, walks the handlers, offers the break loop, falls
through to a message and a status like the two beside it. The sentence names
what was promised and what was passed, and a second line says what is not
checked. The condition fields stay (0, n, 0) — the violated condition as a
range, and not (0, n, n), which reads as in bounds.
And a session now holds the buffer's own defmacros: seeded in Session.create
from the same read that produced decls, and added by Session.eval so a
defmacro typed at the editor joins the set the way a defn does. Not a re-read
of the file, which would put unsaved-versus-saved skew inside expansion. The
commit stays below the checker. Macro.program dedupes the ambient set against
the forms being parsed, left-wins, because unqualified names can now collide.
C-u C-x C-e was never tried on a macro call. Ast.pause_call takes the
expanded loc, which Loc.from_macro has stamped -- it sets a name and
leaves file, line and column the call site's, so the frame the break
loop reports is the line the reader is looking at. Asserted rather than
argued.
Also: the ring rule stated generally (refused at the parse of whichever
file first has both members in scope, always before a session exists),
and the declaration refusal's sentence made build-neutral, since the arm
fires in an ordinary file parse too.
Two loose ends.
The arena was invisible to memcheck. free-all is retain-capacity, so from
malloc's point of view nothing died and round two of a reset arena could read
a byte it never wrote, print round one's value, and draw no report.
flan_arena_proc now issues memcheck's MAKE_MEM_UNDEFINED over the whole
capacity beside its registry call. Measured on the same machine: the control
produced ERROR SUMMARY 0 before and 6 errors from 4 contexts after, with
--track-origins naming the client request. It is a control in
test_valgrind.ml now rather than a printed note.
The macro is vendored, not included, and the argument is measurement: the
machine that runs the sweep has valgrind and not valgrind-devel, so a guarded
#include would compile to nothing exactly where it matters and the control
would go quiet with no diagnostic. There is also nowhere to put an -I --
flan_rt.c is cat'd into an OCaml string literal and handed to clang in a
scratch directory. The __x86_64__ guard is load-bearing: the same runtime is
built for wasm32-wasi and emscripten.
Cost outside valgrind: 23 instructions on the free-all path only, about 1ns
per reset over fifty million of them, against a run-to-run spread wider than
the effect. Nothing on alloc, resize or free. valgrind.supp still holds no
suppressions; the corpus stayed clean across the change, which is its own
finding.
merged_serve's warning path deserved a test and has one. The discriminating
fact is not the log line but the policy: two_process kills its child and
fails where merged_serve warns and serves anyway, and nothing held that
second answer in place. dev-noagent.flan plus the last block of test_dev.ml
assert the session still answers describe after the wait runs out. Verified
by reverting the policy: the block reports rather than passing. It costs the
full ten seconds and there is no way to spend less. HANDOFF-f1.md is deleted.
Parse.expr never ran the expander, so a macro call typed as a bare
expression was an unknown name -- a package's and the prelude's alike,
which is what said the gap was older than importable macros. It is the
wrap Parse.decl already had, applied to the other entry point, with
Parse.with_imported in front of it in Session.eval_expr because the one
expression an editor sends carries no import.
The decision that was waiting: an expression that expands to a
declaration is refused by name, in the head dispatch rather than in a
walk over what the expander answered, so a nested one and a hand-typed
one get the same sentence. A quasiquoted declaration is still a value.
The spin refusal fires on this path; the ring cannot reach it, because a
ring is refused while its own package is parsed. Expansion happens
before the thunk is built, so the 5s three-way wait is untouched.
NEXT.md had the new box as a sibling heading next to "Queued:", so a
reader scanning headings saw the same item twice and still queued.
Folded into one section with a Bound box, the way PORTING.md §1 does
it.
And the example's header claimed the GetCodepoint tail "costs a scan
rather than nothing". The shim's stack buffer is 256 bytes and this
message is 284, so the first thirty glyphs of each pass malloc. Said
so, because that is the kind of number the comments around it are
precise about.
`indexed` took an Array or a Slice, so a `(Ptr T)` that came back
from C was readable at element 0 through `deref` and nowhere else.
The length is not missing from the world — for `font.recs` it is in
the struct, one field over — it was missing from the language.
`(slice-from-ptr p n)` is the form that says it. No marker on the
name: `!` here means mutates and `?` means asks, and `zeroed`, the
nearest neighbour, carries neither; `ptr` is the marker, because a
`(Ptr T)` only ever arrives from a `declare-c`.
Nothing new in the representation. A slice is already {ptr, i64} in
both backends, so this is two insertvalues; `x86.ml` takes the new
constructor on its existing `unsupported` arm.
It refuses a first argument that is not a pointer, a negative literal
length at check time, and a negative computed one at run time — that
last through `signal_block` and `@flan_slice_error`, reused rather
than growing the runtime a function, and *signed*, because
`check_slice` compares unsigned and a negative i32 sign-extends to a
huge u64 that walks through it. Behind `f.md.checks` like the other
two: on at -O0 and -O2, off only when checks were asked off.
It owns nothing and needed no analysis to say so — a slice is not
move-only and carries no allocator, so `free` refuses it by the rule
that already refuses `(as-slice v)`.
`rl/font-recs` and `rl/font-glyphs` are where the promise is written,
beside raylib's own invariant rather than at every call site, and
they are the shape a count-naming binding directive could never have
covered. `examples/text-rectangle-bounds.flan` is the port that
motivated this and it runs; `test/programs/slice-from-ptr.flan`
covers the form with no raylib and no window.
Both unions kept the wrong side. macro_union keeps the left on a name
collision, and both callers had the older set on the left: Load.program
put the ambient set ahead of the packages it had just resolved, and
Session put the copy it had been holding since creation ahead of what
Load handed back. So editing a macro in a package and reloading the file
that imports it went on expanding the old body -- and said nothing,
which in this area is the failure that costs the most to find.
Two tests, because the two unions are reached by different paths: the
reload itself, and the C-c C-c after it, which reads the set the session
kept rather than the one Load just supplied. Each fails on its own if
only the other order is put back.
Also written down, and not fixed: C-x C-e expands no macros at all.
Parse.expr never calls the expander, so (unless ...) as a bare
expression is as much an unknown name as (mac/twice 4) -- the prelude
fails there too, which is what says it is an older gap. Changing it
changes what an expression evaluation means.
And the cost note is cut back to what was measured. Four macro modules
where the file's own macros leave two is what the cache shows; why four
is not settled and no longer claimed.
The feature was built and never tested. Three things were missing.
The two packages holding a ring of macros and a macro that never settles
were not dependencies of the test stanza, so both non-termination
refusals failed on "no package at ..." rather than on their own reason.
They fire, and now the suite sees them fire.
The positive half of the rule had no acceptance case at all -- only the
refusal that pins the bare name. pkg-macro.flan is asserted at three opt
levels and on the dev path, which is where six package macros and the
program's own coexist in one file.
And the dev loop was broken in exactly the way that matters most here.
Session held the imported macro set but *replaced* it on every
evaluation, and the one form C-c C-c sends carries no import -- so
(mac/twice 4) compiled on the build and came back "unknown function" on
the first reload. It unions now. test_session drives two evaluations,
because one proves nothing: the first could have re-supplied the set.
BUILT.md said the expander collects from the prelude and the file being
compiled. It collects from imported packages too, and the refusal's old
reasoning -- that this needed a second import resolver -- was wrong for a
reason worth keeping written down.
Cold build cost roughly doubles for a program importing a package that
declares macros: a macro module is built per round and the package's
rounds are its own. Warm is unchanged at ~70ms.
The allocation registry had a recording side and half a reader. This is the
rest of the reader: point at any heap address, a breakdown by type, what is
still held, and the test that stops dev-ptr.flan's header from being read by
hand.
The recorded name, back to a type. The table records a string and has to —
the note is built where the concrete type exists and what crosses into the
runtime is bytes. What closes it is that the string is Types.to_string, which
is the source spelling, so the round trip is the language's own reader,
Parse.texpr and Check.resolve. No table of spellings is written down, so
nothing can fall behind Types.to_string, and a name that is not a type —
"pool slots" — is refused with the name quoted rather than defaulted.
The address root renders a (Ptr T) and not the pointee, which puts it through
render.ml's pointer arm: permission is asked in one place in the compiler, and
an address root and a slot root reach the same two answers by the same code.
Flan has no integer-to-pointer cast, so flan_dev_reg_addr is an extern beside
flan_agent_frame_slot, for the same reason.
One walk and two questions: a leak report is a breakdown with the dead left
out, so flan_dev_reg_by_type is one function and the agent formats it.
"At exit" is not a hook. A program killed by a signal runs no handler, which
is how a game under the editor ends, so (:op "leaks") is the authoritative
reader and can be asked at any moment including the one before the kill. The
atexit hook is for the program that returns from main, is registered from
inside flan_dev_reg_enable rather than by a file-scope destructor so that a
release build does not grow a third not-free place, and is off unless
FLAN_DEV_LEAKS is set because the acceptance table reads stderr.
The memcheck half of item 6 is deliberately not here.
hashable? gated the type and not the operations: a generic could take and
return a (Map $t V) and could not get or put into one. The hash and the
equality are emitted as concrete symbols chosen from the key type, and
while $t is a variable there is no symbol to name.
The five arms that reach the pair - put, get, has-key?, reserve, clone -
now check their arguments and return a placeholder of the operation's own
type when the key is a type variable: Unit for put and reserve, None for
get so the (Option V) around it still checks, false for has-key?, a zeroed
map for clone. The node is thrown away with the rest of the abstract pass
and the real one is built in the copy, exactly as println's is.
What makes that different from print's free ride is the clause. A map
operation can fail at a concrete type; it is deferred anyway because
{:where (hashable? $t)} is in the signature, so the refusal lands at the
call that asked for the type, against a requirement the author wrote down.
A generic that declares nothing gets no deferral - deferred_key checks
first, and map_type has usually refused the signature already. So the rule
for the allow-list is not a headcount: either the operation cannot fail
after substituting, or a declared predicate gives its failure somewhere to
land. The comment at the print arm says that now instead of "stays two
long".
The instantiation-time refusal names the call site, the type it asked for,
the predicate and the clause, rather than repeating the generic's name
twice.
Three kinds of Flan face over the generated set, which stays honest to C
because that is what makes it checkable against the header.
A slice where C takes a pointer and a count: the eleven vector-array
drawing calls, all eleven rather than the three anybody calls, since a
subset has its hole where the next caller looks. Each guards the empty
slice, which is the part a hand-written call site gets wrong rather than
merely writes out -- raylib takes a count of 0 happily, but taking the
address of element 0 of an empty slice is out of bounds before raylib is
reached.
An Option where C signals with a sentinel: get-key-pressed and
get-char-pressed, raylib's two input queues, both of which say "empty"
with 0. What that buys is in text-input-box.flan, which read the queue in
two places -- once to prime the loop, once at the bottom of the body --
and now reads it in one.
Both of those use the `name` directive in bindings, so the generated
declaration keeps the symbol and gives up the name: nothing about the C
signature is hand-written and the generated half keeps its
agreement-by-construction with the header.
An enum where the header says int: key-up?, key-pressed-repeat?,
mouse-button-up?. These are NOT wrappers -- a C enum parameter has an
int's ABI, so the hand-written declare-c with the Flan type is the whole
fix. They were holes in families whose other halves already took a Key,
so (rl/key-down? :space) compiled and (rl/key-up? :space) did not.
Not built: with-drawing and with-mode-2d. A macro cannot live in a
package -- the expander collects defmacros from the prelude and from the
file being compiled, and one in an imported package is refused by name.
test/programs/pkg-macro.flan is that refusal.
And vendor/raylib/vector.flan, which is raymath written in Flan because
raymath is static inline and has no symbol to bind. A file of its own,
split on declare-c and not on "idiomatic": there is not one declaration
in it, so it is not part of the surface the header check reads, and
raylib.flan is 1300 lines already. clamp and lerp are deliberately absent
-- the prelude has both, and a second lerp would not even be the same
function, since the prelude writes (1-t)a + tb where raymath writes
a + t*(b - a).
Examples: the identical eight-expression box-around helper in
core-3d-picking and models-box-collisions is a half-extent subtracted and
added. shapes-following-eyes keeps its measurement and gives up one line
to v2-sub, which is the honest size of the gap in a file that is nothing
but vector maths.
Two gaps the raylib examples hit.
The layout check compared a Flan enum against the header's `int` and
called it a disagreement. It is not one: Shim.cty lowers a defenum to
int32_t in a struct field exactly as it does in a parameter, which is
what the signature check already knew and the layout check did not. One
predicate now serves both, symmetric, and tolerant of a 32-bit integer
and nothing else -- f64 against the library's float still fails, in the
very struct whose other field is an enum. Camera3D.projection is a
CameraProjection again and rl/camera-projection is gone with it, so
`.projection :perspective` resolves at the construction site.
And generate-c's claim said nothing about a defconst or a defenum
member, so a wrong flag bit was completely silent. `bindings` gained
`enum`, `const` and `constant` lines saying what a Flan constant is
called in C -- the prefix is nowhere in the Flan name, so it is declared
rather than guessed. Nothing goes quiet in either direction: a name the
rule builds and the header lacks is reported, a rule that reaches
nothing is reported, and a defenum with no line is itself a finding,
because otherwise the silence just moves up one level.
clang's dump gives anonymous EnumDecls for every raylib enum and no
value at all for an enumerator written without `= n`, so the constants
are one flat table and the values are counted the way C counts them.
cache_format bumped with the dump type.
FLAN_CLANG=/bin/false against test_repl: 'the daemon exited with status
2 before binding /tmp/flan-repl-dev.sock' in 45ms, where the old wording
would have waited out the whole timer and then blamed the socket.
Build.cachedir sat under TMPDIR, which dune makes private per run, so no
test run ever reused an object and every build in the suite was cold. It
moves to $XDG_CACHE_HOME/flan/objcache (FLAN_CACHE_DIR overrides), which
is safe because the keys are total: compile_c digests the source text,
the compiler's stamp and every flag; wasm_resource_dir digests the
builtins archive; compiler_object digests flan.cmxa and flan.a. Writes
were already .tmp-then-rename, so concurrent dune jobs are fine.
Macro.key was the one key that was not total -- prelude text plus the
call's forms, and nothing about the compiler whose codegen produced the
.so it names, which is dlopened straight back into this binary. Under a
per-run TMPDIR that never showed; under a durable cache it is a stale
expander that crashes rather than a compile error. It carries the
compiler's stamp now, handed across start_merged's exec in
FLAN_COMPILER_STAMP because a merged dev binary lives at a per-session
path and keying on that rebuilt a macro module every dev start.
Measured on dev-repl.flan, launch to bound socket: 2.0s cold against
0.48s warm. Whole-program flan build: 1.44s against 0.06s. Full dune
test 25.7s/30.1s before, 24.0s after, user CPU ~50s down to ~34s.
And the await: one timer covered two waits, a build then a bind, so
'the daemon never listened' was a wrong diagnosis of a build that had
not finished. listening now polls the process alongside the socket and
says which -- exited with a status, or still running and therefore still
building. A daemon that dies fails in milliseconds instead of costing
the whole timeout. Thirty seconds, down from a minute, because the build
it waits on is warm now.
The watch accumulator clears a slot lazily, on its next sample, and the reader
never compares epochs. A previous lane read that as a defect and left
watch_render_num's n=0 arm behind as dead code against the day the reader
became epoch-aware.
It should not. A stopped program takes no samples, so an epoch-aware reader
would report every slot as empty for as long as the program sat in a break
loop — and reading the numbers from the moment you stopped is the whole point
of stopping. The lazy clear is the right answer there.
What was wrong was narrower and lives in the editor: flan-watch--tick sent
`:reset t` five times a second at a program that could not answer it. The read
still goes out every tick; only the reset field drops, guarded on
flan-dev--stopped, which flan-dev.el's background poll already keeps current.
The n=0 arm is deleted rather than commented, since the only way to reach it is
the epoch check just rejected and dead code is an invitation to add one. n is
at least 1 whenever watch_render_num runs, so sum/n cannot divide by zero.
test-flan-watch.el asserts both halves with no daemon: a running tick carries
:reset, a stopped one does not, both still read the table and both leave a
reply in flight. Verified by mutation. What it cannot reach is the daemon
honouring the absent field; test_dev.ml drives a real program for that.
