Since #784, an array whose elements are proven present passes each element
itself to its callback instead of the optional element value. A callback
whose parameter is a structural supertype of the element
(`refs.find((r: { pos: number }) => ...)` over a wider record) has no
adapter from the plain element record, so lowering rejected it with SC2011.
Before #784 the optional element ABI converted it through a union retag.
The optional-read prepass now treats a site as present only when the
callback's element parameter accepts the stored element through a
mechanical conversion. Otherwise the site keeps the optional element visit,
as before #784. Unannotated and generic parameters are unaffected, so every
site #784 made precise stays precise.
- Synchronize all published packages and the compiler surface manifest at v0.2.7.
- Record native features, runtime performance improvements, and compatibility fixes since v0.2.6; leave Unreleased empty.
- Verify version and manifest contracts, compatibility output, and cross-target library conformance locally; use CI for full validation.
The method-replacement census marks a method name as an observed slot
when some write might replace it, and calls of observed methods go
through a checked property lookup whose result converts back to the
declared return type. Two kinds of data writes over-approximated that:
- A computed write into a string-keyed dictionary marked every method in
the program unless the dictionary's values were primitives. Class
instances have no implicit index signature, so such a dictionary is a
class view only when the class declares the index signature, and then
every method must be assignable to its value type. Any value type no
function can inhabit now qualifies: primitives, or non-callable object
types that require a property functions lack, or weak types sharing no
property with functions.
- A named write like `this.literal = token` marked `literal` for every
class. The write can only replace a method when the written property
can hold a function, so property writes are now judged by the written
property's type (prefetched in one batch).
Compiling vercel-labs/tsc-ts failed after the canary promotion: one
`changedProjects[id] = {...}` write marked every method, OptionNameMap.get
and the JSON parser's literal() calls returned unknown, and their Map-typed
results could not convert back (SC1100/SC1101, 61 errors).
Also skip abstract methods when materializing observed prototype slots.
An abstract declaration emits no prototype member, so lookup continues
to the ancestors; building its value instead threw an uncaught
PoisonError out of the reachability fixed point (the tsc-ts crash).
Tests: corpus 3171 (fails with SC1100/SC1101 before this change) matches
Node in the plain and sanitized lanes; the 112 corpus programs matching
abstract|prototype|method|callback pass; class-dynamic-dispatch unit
tests pass. tsc-ts now builds and type-checks itself with output
identical to tsgo 7.0.2.
The TypeScript 7 parity job needs baselines for the console corpus
programs this PR adds (4294-console-line-sizes, 4295-console-template-
parts, and 4296-console-glued-long-parts from the overflow fix).
Recorded with SCRIPTC_UPDATE_BASELINES=1 pnpm exec vitest run
packages/compiler/test/ts7/order-parity.test.ts. The re-recorded file
added only these three and #763's 3170, with no existing entry changed.
The 3170 entry is left to #763. These are inserted at their sorted
position, apart from 3170, so the hunks stay independent when the stack
is rebased.
node scripts/test-ts7.mjs --baselines-only now reports only 3170, which
the rebased base branch provides.
scr_console_capacity compared the raw tag with SCR_ARG_STR, but string
parts of a concatenation argument carry SCR_ARG_GLUE. A glued string part
therefore reserved only 32 bytes while scr_console_render, which masks
with SCR_ARG_KIND, copied its full length, overflowing the on-stack (or
heap) line buffer for any glued part longer than 32 bytes.
Mask with SCR_ARG_KIND in the capacity loop and in the single-string
fast path, the two remaining kind tests in scr_console.c.
Tests: corpus 4296 logs template literals and `+` chains with glued
string parts of 31..70000 bytes, several long parts per argument, and
multi-byte UTF-8 parts. Before this change the --sanitize build aborted
with an AddressSanitizer stack-buffer-overflow; it now matches Node in
the plain and sanitized lanes.
console.log(`${method} ${path} ${status}`) used to build the joined string
first (one string per number, scr_str_concat_parts, then releases), and
the console then copied that string into the line it writes. The LLVM
backend now flattens a strConcat argument with stringParts and passes
each part as a ScrLogArg:
- Later parts carry SCR_ARG_GLUE, so no separating space is added.
- A number conversion passes the raw double as SCR_ARG_NUM (String()
spelling, so -0 prints "0"; a bare number argument keeps inspect's
"-0").
- A boolean conversion passes the bool.
The runtime renders the parts directly into the line buffer. Parts are
evaluated in source order through emitStringInputs, which applies the
same borrowing rules as concatenation. Calls that use the new tags go to
new scr_console_log_parts / scr_console_error_parts entry points, so a
program object linked against an older runtime pack fails at link time
instead of misprinting.
Tests: corpus 4295 covers -0/NaN/exponent spellings inside templates
next to bare arguments, empty parts, more than 16 parts, evaluation
order, a later part reassigning an earlier string, union and optional
values, and async code. A new co-located IR unit test checks the
emitted tags and entry points.
Linux sandbox, ns per line (median of 9 launches, 200k lines), prev =
stack tip, cand = this commit (with the previous one). All outputs
byte-identical to Node.
probe target node prev cand
p-str pipe 4022 1364 1149
p-str file 3376 849 744
p-str null 2360 330 247
p-args pipe 6687 1441 1343
p-args file 5135 969 821
p-args null 3831 389 292
p-write pipe 2866 1244 1168
p-write file 2329 839 782
p-write null 1622 309 275
p-err pipe 4656 3253 1073
p-err file 3659 2099 721
p-err null 2749 591 219
log-lines pipe 5007 1476 1314
log-lines file 3949 965 877
log-lines null 3145 446 378
Every console.log/error/warn line and process.stdout/stderr.write chunk
is still submitted before the call returns, as in Node. On POSIX
executables, each one now goes out as exactly one write(2) on fd 1 or 2.
Before, it went through C stdio, which cost a copy into the stdio
buffer, one stream call per argument, separator, and newline, and a
flush. stderr is unbuffered, so console.error made one write(2) per
piece: 3 writes per line on average in the probe.
- The line renders into a 2 KiB stack buffer (heap above that). A large
single string goes out with writev and no copy.
- Short writes continue and EINTR retries. Other errors (EAGAIN, EPIPE,
EBADF) return errno with the rest dropped, which is what the stdio
flush did. console still ignores them, and SIGPIPE behavior is
unchanged.
- Runtime-internal bytes still in the C stdout buffer are flushed first
(__fpending on Linux, the FILE fields on Darwin, an unconditional
flush elsewhere), so stdout order and merged 2>&1 order are kept.
- Windows, WASI, and library artifacts keep the C stream path, now fed
one formatted chunk per call.
Tests: corpus 4294 covers line sizes across the stack buffer and the
64 KiB stdio buffer. New console-io harness cases cover stdout and
stderr merged into one pipe and into one file (byte-compared with
Node), and console.log after the stdout reader closes (EPIPE).
Linux sandbox, ns per line (median of 9 launches, 200k lines; scriptc
includes ~1 ms startup). All outputs byte-identical to Node.
probe target node prev cand
p-str pipe 4040 1323 1239
p-str file 3092 849 790
p-str null 2193 319 283
p-args pipe 6168 1440 1228
p-args file 4896 925 802
p-args null 3916 389 292
p-write pipe 2889 1328 1197
p-write file 2267 809 769
p-write null 1577 297 265
p-err pipe 4672 3253 1132
p-err file 3478 2042 717
p-err null 2614 562 232
log-lines pipe 4958 1490 1356
log-lines file 3885 966 877
log-lines null 2983 425 368
strace -c (pipe): p-err went from 600,000 to 200,000 write calls. The
other probes stay at one write per line.
The TypeScript 7 parity job reported tests/corpus/3170-number-conversion-
fast-paths.ts as missing a baseline. Recorded with
SCRIPTC_UPDATE_BASELINES=1 pnpm exec vitest run
packages/compiler/test/ts7/order-parity.test.ts: the re-recorded file
added only this program (and the later stack's console programs, which
belong to #764), with no existing entry changed. The entry is inserted
at its sorted position in the stack's baseline block so it does not
overlap the #764 entries when the stack is rebased.
node scripts/test-ts7.mjs --baselines-only passes.
The bootstrap-seed build rejected `host.rcHelpers ?? []` in shapes.ts
(SC2011: `Set<string> | never[]` has no static representation) and the
spread of that union into a string[] literal (SC1090). A small helper copies
the set's keys into a plain array (empty when inline RC is off), which both
callers iterate; emitInlineRcHelpers still sorts its copy. Behavior is
unchanged.
The default build's largest size contributor on the stack was H23's
-falign-functions=64 on every x86-64 runtime unit (2-11 KB per program;
results/h45-size-budget). Release and library flavors now keep the
compiler's default function alignment; the opt-in speed flavor keeps the
blanket 64-byte alignment. Vendored archives stay 64-byte aligned
(lre_exec keeps its pinned placement) except libunicode.c, whose small
table helpers were most of the regex programs' padding. The runtime-first
link order is unchanged.
Docs and usage text describe speed without the reverted runtime profile.
The speed posture's inline scr_union_release fast path predates the
runtime change that buffers a surviving union box as a cycle candidate
only when its arm_trace can reach a cycle. It still enqueued every
surviving box: sound (an untraced box visits nothing and the runtime death
path reads the header), but it gave back that change's collector savings
under --optimization=speed. The fast path now loads arm_trace and returns
when it is NULL, exactly like scr_union_release; scr_runtime.h pins the
offset.
Re-lands perf/h02-runtime-lto (6d373317, b62448f3) behind the speed
posture.
- Runtime packs gain an executable `speed` flavor whenever the host LLVM
helper can run. Its static units are emitted through the helper's
`runtime-unit` command (promoted unit-local symbols, object and import
bitcode from one module); its SCR_DYNAMIC variants reference the release
objects. Release, dev, and library flavors and the vendor archives are
built exactly as before (the rebuilt macOS pack's flavors and archives
are identical to the baseline's).
- Speed program builds load the speed flavor's bitcode and pass it to the
helper (`--import-bitcode`); release builds never do.
loadRuntimeBitcode only reads a real speed flavor, never release.
- The helper drops the emitter's inert sanitize_address attributes only
when it imports, so release modules reach the pipeline unchanged.
- Tests: runtime-pack.test.ts covers speed-variant bitcode selection,
verification, and that release-flavor bitcode is never imported;
native-codegen.test.ts covers helper arguments and cache keys.
Release executables stay byte-identical to the stack tip with the rebuilt
helper (14/14 workloads, macOS).
Re-lands perf/h30-inline-rc (00051ca0, 40398773, 07972360) behind the
speed posture. With inline RC on, every mirrored runtime RC family
retains inline and releases inline down to the rc == 1 / new cycle
candidate slow path (shapes.ts INLINE_RC_FAMILIES). Release emission is
unchanged: ShapeHost.rcHelpers is null unless LlvmTargetOptions.inlineRc
is set, and every retain/release (including capture boxes) stays a
runtime call; the %ScrMapRc type is only emitted with inline RC.
- index.ts and native/prepare.ts pass inlineRc for speed executables,
speed object/asm emission, and speed library profiles.
- scr_runtime.h keeps H30's static asserts for the mirrored header and
trace-slot offsets (no code change; the rebuilt macOS pack's manifest is
identical to the baseline's).
- Tests: shapes.test.ts pins release symbols and H30's speed fast paths
and header offsets; emitter.test.ts pins that release IR is unchanged
and speed routes releases through the helpers. The differential harness
gains `// @optimization: speed` (and a SCRIPTC_TEST_OPTIMIZATION=speed
lane); corpus 4032 pins every mirrored family under speed.
Release executables stay byte-identical to the stack tip (14/14
workloads, macOS).
Speed is a third native optimization posture next to release (default,
-O2) and dev (-O0). It is optimized exactly like release at the C/LLVM
level and is the switch for optimizations that trade executable size and
build time for run-time speed, so the default release build stays inside
the binary-size budget.
- backend/optimization.ts: the NativeOptimization type, its -O class, and
cache-key helpers. Release keeps its historical key shapes (absent).
- CLI: build/run/cache warm accept speed; usage text names the trade.
Bootstrap's routed executable cache mirrors the posture.
- Early executable cache keys and native-feature validation include speed,
so release, dev, and speed entries never satisfy one another.
- Runtime packs: an optional executable `speed` flavor (-O2, only beside
release). Speed links it when present and the release objects otherwise;
library modes link their release flavor. The sanitizer lane follows the
same flavor key.
- Library profiles accept "speed".
- WASI release-only linker flags apply to speed too.
- bench-runtime: --baseline-optimization/--candidate-optimization and a
per-contender cold_build_ms.
Release executables are byte-identical to the stack tip for all 14
benchmark workloads (macOS arm64, sha256 of executables built from both
trees).
Upstream native workers (095b6193) run one runtime instance per thread and
make the timer heap thread-local (SCR_TL). The timer slot index added for
O(1) handle lookups indexes that heap, so it becomes thread-local too;
scr_timers_teardown already frees it during worker context shutdown.
The RegExp constructor cache stores retained templates that live instances
borrow and that are never evicted. Its table is thread-local, and worker
executables leave it empty (constructions compile privately as before),
because a worker context has no teardown point after every borrowing
instance. Ordinary executables are unchanged.
stderr is unbuffered, so the piecewise stdio calls issued one write(2)
per argument, separator and newline (two syscalls per simple line), and
the line was not atomic against other writers sharing the descriptor.
Render the line first and emit it with a single fwrite, as Node writes
one chunk.
clearTimeout/clearInterval, refresh, ref/unref and hasRef scanned the
whole timer heap for the handle, so arming and clearing many timers was
quadratic (1e5 cancels: 1.0 s vs Node 46 ms). An id-to-slot hash kept
exact by every heap write makes the lookup O(1); heap order is unchanged.
exec/test rescanned the whole subject for ASCII (and re-converted a
non-ASCII subject to UTF-16) on every call, so lastIndex-driven exec
loops and sticky tokenizers were quadratic (1e5 matches: 7.9 s vs Node
43 ms). A single-entry cache keeps the last long subject's decoding; it
retains the subject so the address cannot be recycled and the string is
never appended in place. Only exec/test use it (no user code runs while
their input is live).
new RegExp recompiled its pattern on every construction (22x Node). A
bounded never-evicting cache keyed by (flags, source) shares bytecode
through the literal-template mechanism; invalid patterns still throw on
every construction.
`i in arr` with a non-literal number key boxed the typed array into the
checked-dynamic tree and materialized every element per evaluation, so
`for (...) if (i in arr)` loops were quadratic (1e4 elements: 5.3 s vs
Node 0.7 ms). A number key over an array receiver now lowers to arrayHas
(scr_arr_has), the query the literal fold and Object.hasOwn already use;
the key is stabilized first to keep JS evaluation order.
`k in dict` with a runtime string key over an index-signature record
snapshotted and scanned every overflow key per probe (1e4 keys: 436 ms,
1e5: timeout). The helper now ends in recordOvfHas (scr_map_has_str).
- scr_net: scr_net_sock_writev_native sends ordered slices with one
sendmsg when the bytes would go out immediately (plain socket, nothing
buffered); every other state takes the per-slice write_raw path, so
buffering, transports, and teardown are unchanged.
- scr_http: end(data) before the head, write() before the head, chunk
framing, and the final chunk now leave as one write (head + body +
framing), as Node does. A typical response was a head segment plus a
body segment; it is now one segment and one syscall.
- scr_net: stop reading after a short read (libuv UV_HANDLE_READ_PARTIAL);
the level-triggered poller reports later bytes or EOF. Removes the
EAGAIN read per request (0.7 per request on http-api). TLS transports
keep draining.
- scr_http: Date header formatted once per second; head built in one
pass without snprintf; request headers parsed with geometric array
growth and one shared string when the name is already lowercase.
The bytes on the wire are unchanged (the runner digests every response
against Node).
The bootstrap-seed build rejected the compound `value ^= value >> 30n` and
`value ^= value >> 27n` on bigint in string-key-hash.ts (SC1043), while the
plain `^` form on the next line compiles. Spell both as `value = value ^
(...)`. The hash is unchanged.
On 64-bit little-endian targets ScrStr's capacity word is split into a
32-bit cap and a 32-bit cached Map key hash (header stays 24 bytes).
Heap strings fill the hash on first lookup; every in-place mutation path
(unique concat, split scratch reuse, regrow, spare reuse) clears it.
Immortal strings are never written: compiler literals and the runtime's
one-character/empty statics carry the hash precomputed (string-key-hash.ts
mirrors scr_key_hash; both sides pin the same vectors).
scr_key_hash seeds by length multiplicatively: XORing the length into the
low bits cancelled against the last byte ("ab" and "abc" collided).
Map string lookups inline the probe into each getter and reject linear
entries by hash; set specializes its probe/overwrite by lookup kind with a
shared append path.
Tests: runtime map.test.ts (pinned vectors, statics, in-place append
invalidation), string-key-hash.test.ts, corpus 3141-map-string-key-hash
(plain + sanitized; mutation-checked against both invalidation paths).
The bootstrap-seed build rejected `"receiver" in expr` / `"args" in expr`
on the IR expression union in constant-callbacks.ts (SC1090: `in` on an
object union). A switch over the six data-intrinsic kinds now returns their
operands (receiver first; none for mapNew/setNew, as before) and replaces
the DATA_INTRINSICS set. Behavior is unchanged.
Upstream native workers (095b6193) compile the runtime with -DSCR_WORKERS,
which makes scr_cyc_live and scr_weak_dispose_hook thread-local, and the
small-object allocator is compiled out there. The inline allocation paths
address those as ordinary globals, so worker programs keep the out-of-line
runtime calls, exactly like thread-instanced libraries.
A worker-threads test pins that worker LLVM references neither the
allocator state nor the thread-local counters, and that worker programs
keep the fiber path for async bodies (the entry 07 adaptation).
Emitted record and class constructors called scr_rt_calloc/scr_cyc_alloc
with a constant size, so the size class, the zeroing length and the
collector header setup were recomputed per object behind a call (plus an
empty scr_obj_alloc_note call and a variable-length memset). llvm/alloc.ts
now emits the fast paths inline: pop the class free list (clearing only
the bytes the helper does not store itself) or bump, with the old calls as
the cold slow path. Releases inline the weak-dispose hook check, the live
count, and the free-list push; blocks outside the reservation still go to
scr_rt_free.
The emitted IR does not know which runtime it links against (the sanitized
lane only differs at link time), so the runtime now defines scr_sa in
every build. Where the allocator is compiled out (ASan, SCR_RC_AUDIT,
wasm32, Windows, 32-bit, thread-instanced libraries) it stays all-zero and
the inline paths always take the slow path, which keeps the RC-audit
object notes. ScrSaState's layout is pinned with static asserts. Inline
emission is additionally gated off for 32-bit, WASI, Windows triples and
thread-instanced libraries.
Runtime callers with hot constant-size allocations (union boxes, arrays,
boxes, closures, dyn nodes) use new static inline twins
scr_cyc_alloc_inline/scr_cyc_free_inline; scr_cyc_live is exported.
The ABI guard now recognizes function-pointer extern data
(scr_weak_dispose_hook). New corpus program 4410 pins recycled-block
clearing, size classes, objects above the largest class, cycles and weak
observers.
`new Item()` now calls the borrowed constructor body, so no retain transfers the fresh instance into it: the snapshot body retains twice, not three times.
layouts.ts and classes.ts imported NullableRefFields type-only, so the
self-hosted layout stage never saw the class declaration and rejected
`NullableRefFields | undefined`. They now import the class itself, and the
field record names the object variant directly instead of an intersection
type.
The bootstrap-seed build compiles the compiler with scriptc, which rejected
`for (const index of parameters.get(fn.name) ?? [])` in the emitter: the
`Set<number> | never[]` union has no static representation (SC2011). Read
the set once and iterate it only when present. Behavior is unchanged.
A whole-value read of a nullable-pointer field allocated a heap box per
read, so list walks (`p = p.next`) regressed: 0.07 s -> 0.35 s on a 100k
list walked 200 times. Such reads now retain the instance pointer into
the current frame and wrap it in a private stack box with that
independent owner:
- local union storage accepts nullable field reads and copies of another
binding of the same union as sources (the payload is retained; scalar
and unit arms own nothing; retains branch on the tag because not every
retain entry point is NULL-tolerant);
- arguments to projection-only parameters of calls and constructors.
The list walk now takes 0.05 s (baseline 0.07 s). Corpus 4061 adds a copy
that outlives a store to the field and copies across string, number,
-0 and undefined arms.
A class field typed `C | null` or `C | undefined` (one unit arm plus one
emitted class arm) now holds the instance pointer itself: NULL is the unit
arm. The struct slot stays `ptr`, so layouts are unchanged.
- Teardown, trace and gcFree use the slot's storage type (the class arm);
every class retain/release/visit entry point is NULL-tolerant.
- Projections of a field read (tag tests, narrowing, truthiness, unionDisc,
nullish, borrowed equality operands) use a private stack box over the
borrowed pointer; whole-value reads build an owned heap box (or the
immortal unit instance); generic borrowed receivers get that owned box.
- Stores take the payload of a wrap directly, or the retained payload of
a borrowed union; a store of a union binding is a projection use, so
constructor parameters stored this way are projection-only.
- `new` calls the borrowed constructor body when the lifetime analysis
allows it, so projection-only arguments become private stack boxes.
- The dyn bridges (materialize, commit, symbol fields) convert between
the pointer and a temporary union.
alloc-trees no longer allocates a union box per tree edge. Corpus 4061
pins tests, narrowing, nullish, optional chaining, equality with
mutation, escapes, reassignment, subclass instances, unionDisc, `any`
reads/writes, JSON, console output, cycles, and a 300k chain teardown.
macOS arm64 (H23 runner, --layouts=4 --runs=16, vs perf/harness):
alloc-trees -45.5%, records-sort -72.8%, numeric-kernels -29.4%,
ast-interp -21.3%, word-graph -12.4%; template-render +1.9% and
functional-pipeline +0.8% (both within 2%); geomean -17.6%.
Accepting nullish and unionEq as projection uses also proves parameters
projection-only, so callers pass private stack boxes to them. The narrowed
nullish shape now always borrows a binding (no code runs between the read
and the payload extraction), and unionEq routes proven parameters through
the borrowed receiver path, so a stack box never reaches union RC entry
points. Found by the Linux corpus (free(): invalid pointer in 1535 and
others); pinned by a stack-unions unit test and corpus 4060.
Malte Ubl