`scriptc build --profile-use` prints one line on stderr with the number of
functions the profile annotated, the number whose control flow changed since
it was collected (mismatched), and the number it has no record of. When more
than 10% of the functions the profile describes are mismatched, it also prints
a warning to collect the profile again. The build still succeeds.
Both the compiler library's build and the native compiler's build report the
match. Cached builds report the match of the build that produced them: the
native codegen and object caches store it beside the cached objects, and the
executable cache stores it in its entry.
The native toolchain manifest's lib_diagnostics path is relative to the
platform package's dist/bin. installNativeCli copies the manifest into the
scriptc package's bin and relocates each asset path, but lib_diagnostics
was not in the list, so it pointed at a missing file under the scriptc
package and npm installs did not use the prebuilt lib diagnostics. It is
now relocated with the other assets.
With --cpu-dispatch, an x86-64 executable carries two copies of each
program function: the baseline code and a copy compiled for x86-64-v3.
main reads CPUID and XGETBV once. Calls between the program's functions
go to the caller's copy. A function that is also named outside the
copies (a function value, a call from main, a runtime callback or a
coroutine body) keeps a dispatcher under its own name, which tests the
level and tail-calls one copy. Functions without such a use get no
dispatcher, so their copies have the callers the original had and LLVM
inlines them the same way.
The executable still runs on any x86-64 CPU. SCRIPTC_CPU_LEVEL caps the
level at run time. The option is off by default, applies to executables
without a --target-cpu level, and is part of the executable cache key.
bench:runtime takes --baseline-cpu-dispatch and --candidate-cpu-dispatch,
and the LLVM differential suite runs each program at levels 0 and 3 with
SCRIPTC_CPU_DISPATCH=1.
A pipeline stage that arrives as an untyped value now follows Node's
stage ladder for more shapes. As the first stage, a function is a source
function: the pipeline calls it with { signal } while it is set up and
pumps its result, which must be iterable (ERR_INVALID_RETURN_VALUE
otherwise), and a { readable, writable } pair pumps its readable side.
After the first stage, the pipeline call is lowered once per combination
of its first three untyped stages being functions or not, and a typeof
test picks the branch at run time. A function stage is called with the
previous stage and { signal }; before the last stage its result must be
async iterable, and as the last stage a promise resolves the pipeline's
value and an async iterable feeds the PassThrough pipeline() returns
(SCR_PIPE_DEST_DYN). Any other value that is not a stream becomes
Duplex.from of it, which the next stage reads from without the previous
stage being piped into it, and Duplex.from's ERR_INVALID_ARG_TYPE for
the values it rejects.
An untyped stage followed by an untyped function stage hands its value to
that stage through a cell created per pipeline call, so the function
receives the previous stage's own iterator, as Node's makeAsyncIterable
answers it, instead of an async generator over it.
Untyped web streams, pairs after the first stage, and function stages
that return a stream throw the not-supported error.
RUNTIME_ABI_VERSION goes from 45 to 46 for the new stream exports.
The sanitized lane's -fsanitize=address link needs the attribute to
instrument the emitted functions. Without a sanitizer pass it is not
inert: LLVM does not shrink-wrap functions that carry it, so every call
saved and restored all of a function's callee-saved registers on entry,
including on paths that return before any call, and it blocks
speculative loads. The LLVM helper already dropped it for builds that
import runtime bitcode (speed); release builds kept it.
- The new sanitizeAttributes option (default true for direct emission)
is set from --sanitize wherever objectAudit is.
- Without it and without a target CPU level, attribute group #0 holds a
string attribute LLVM ignores, since a group cannot be empty.
A TCP socket's write() answered nothing in typed code and true through
untyped values, and a 'drain' listener never fired. Node 24 answers
false when the bytes the write leaves unsent reach the socket's
65536-byte high-water mark (writeOrBuffer computes it after the socket
writes), sets needDrain, and emits 'drain' when the write buffer
empties; writes to an ended or destroyed socket answer false.
The runtime's write entry points now return that answer, record
needDrain, and fire the socket's 'drain' listeners from the flush that
empties the buffer, unless the write half is ending or the socket is
gone. writableLength reads the unsent bytes and writableNeedDrain the
flag. on('drain') and once('drain') register on the typed path and
through untyped values, and socket.write() may be used as a value.
The fallback node:net declarations type write() as boolean, add the
'drain' event and both properties.
RUNTIME_ABI_VERSION goes from 43 to 44: the socket write entry points
return a boolean.
A pipeline whose first stage is a checked-dynamic value now checks it at
run time, as Node's stage ladder does: a stream is piped as before, and a
string or a value with a Symbol.asyncIterator or Symbol.iterator method is
pumped into the next stage through an async generator over its iterator.
A typed Set, Map, generator or async generator object as the first stage
takes the same path. This covers the callback and stream/promises forms,
with or without function stages and pipeline options.
A write whose callback fails synchronously no longer sets needDrain, so no
'drain' follows the error and a pumped source stops at the failed write,
as in Node.
RUNTIME_ABI_VERSION goes from 37 to 42 for scr_stream_dyn_iterable_source.
Object.freeze, Object.seal and Object.preventExtensions of a class
instance held in an untyped value threw SC2020 at run time. Node changes
the instance itself: writes through its typed references then throw the
read-only TypeError in strict mode code, adding properties through any
reference fails, and Object.isFrozen, isSealed and isExtensible report
the state through either reference.
- In a program that freezes, seals or prevents extensions of an untyped
value that is not a fresh literal, every class hierarchy that can be held
there gets the integrity word that static Object.freeze already uses, and
with it the existing write checks.
- The runtime applies the operation to the instance's checked view and
commits the view. The commit of such a hierarchy stores the view's
integrity state in the word (scr_dyn_class_view_integrity) and makes the
instance's property bag not extensible with it. A hierarchy without the
word still throws SC2020.
- These commits replace and remove the bag's field entries whatever their
attributes, so a sealed or frozen view does not leave stale field values
in the bag.
- The analysis behind records and arrays now starts from these calls only,
rather than from every untyped freeze the lowering emits, such as the
frozen strings array of a tagged template.
- Programs without such calls compile as before. The runtime ABI moves to
v38.
Corpus 7407 covers freeze, seal and preventExtensions through unknown of
classes and subclasses, writes through typed and untyped references and
through methods, properties added before and after the operation, and the
integrity queries, and matches Node.
Refs #1374
Co-authored-by: blurname <50226652+blurname@users.noreply.github.com>
Release builds compile for the x86-64 baseline, so LLVM vectorizes with
SSE2 only. `--target-cpu=<baseline|x86-64-v2|x86-64-v3|x86-64-v4|native>`
compiles the program's code for a higher level: every emitted function
carries the level as its `target-cpu`, so LLVM can use AVX2, BMI2, FMA or
AVX-512. The executable then runs only on CPUs of that level.
- `native` resolves to the highest level the build machine supports, read
from /proc/cpuinfo on Linux and `sysctl machdep.cpu` on macOS.
- The level is part of the executable cache key; `baseline` and builds
without the option produce the same output and keys as before.
- The runtime pack keeps its baseline code.
- Targets other than x86-64 refuse a level (SC3002). The CLI's cached
bootstrap route leaves builds with the option to the full compiler.
- `bench:runtime` takes `--baseline-target-cpu` and `--candidate-target-cpu`.
A checked-dynamic method call looked its name up in the method table on
every call: a strlen, a hash and a byte comparison of the name.
The compiler now gives each method-name constant an i32 slot that starts
at -1 and passes it with the call (scr_dyn_invoke_prepared_id, and the
Buffer method entries, which forward it). The first call stores the
name's id in the slot, and later calls read it. Ids stay the runtime's
own, so the slot holds whatever this runtime's table says. Names are
still matched by content on the first call, and the slot is written with
a relaxed atomic store, since every thread writes the same id.
The runtime ABI is now 28.
A 'message' listener with a typed parameter received each message as a
checked-dynamic value: the port decoded the message into dyn objects, the
listener's thunk matched the value against each union arm, read every
field again to build the record, and the dyn objects were then released.
For bench/channel-messages that was about a third of the delivery time.
- A closure registered with on, once, addListener, prependListener or
prependOnceListener for 'message' gets a typed message entry when its
parameter is a number, boolean, string, a record of those without union
fields, or a boxed union of those arms with null or undefined. The
entry builds the parameter from the message's nodes and calls the
closure.
- The entry handles a message only when it has the parameter's exact
layout: the union arm the checked conversion picks, and a record's
declared keys in declaration order with no others. Any other message
runs through the thunk on the decoded value, as before, so undeclared
keys, other orders and mismatches behave as they did.
- Ports, workers and parentPort deliver a message through the entries
when no value in it is reached twice and it holds no ports or native
handles. Listeners without an entry share one decoded value, made when
the first of them runs.
- The message readers are runtime entry points, so the runtime ABI is now
27.
Corpus 7130 and 7131 check typed listeners on MessageChannel ports, a
worker and parentPort against Node: exact layouts, extra keys, shared
values, nested records, untyped listeners beside typed ones, once
listeners and a transferred port.
The private copy of the LLVM text had no extension. Builds that compile it
with the C driver (sanitize builds, targets without the LLVM helper) passed
it to clang directly when the native cache was off, and clang read it as a
linker input, so the build failed. The copy is now named with `.ll`.
Those builds also record the output directory in their native cache proof.
Renaming the private copies to the shared names after the native build
changed that directory, so every unchanged repeat missed the proof and
relinked the executable. The shared names are now installed before the
native build, which compiles and caches copies in a private directory
outside the output directory.
Readable, Writable, Duplex, Transform and PassThrough take the
objectMode option, and a Duplex, Transform or PassThrough the
readableObjectMode and writableObjectMode options, as true or false
literals in an options object literal or in an options value. An
object-mode side holds any value that converts to a checked-dynamic
value: push, unshift, write, end, pipe, pipeline, for await, 'data'
listeners, Readable.from and the transform callback carry values in
TypeScript and JavaScript, and constructor-function streams and options
held in variables do the same. The object-mode high-water mark counts
values and defaults to 16. A readable buffer that mixes strings, Buffers
and other values holds them all, and push(undefined) and other values on
a byte-mode stream report ERR_INVALID_ARG_TYPE through 'error', as in
Node.
In typed code a write or transform callback, or a _write or _transform
method, may declare its chunk with any such type, which converts when
the callback runs. Writes pass the encoding argument to _write and
_transform as Node does: undefined when absent, null when a callback
took its place, otherwise the value unchanged. A parameter declared
string | null | undefined receives that value and one declared string
receives "" for undefined and null. write(chunk, encoding) on a
byte-mode stream encodes a string chunk with any known encoding and
throws ERR_UNKNOWN_ENCODING for an unknown one. Readable.from takes
typed Maps and Sets of any such value, and arrays that mix strings and
Buffers.
for await over a readable-only stream that will emit 'close' now ends
after 'close', as Node's eos does. Buffered writes that complete inside
clearBuffer run their callbacks in order, and 'finish' waits for a
deferred afterWrite that carries a callback, as Node's pendingcb does,
unless a _final callback schedules it.
The 'data' listener adapters take three slots and write and transform
callbacks read their chunk and encoding through runtime accessors, so
RUNTIME_ABI_VERSION is now 26.
Cipheriv and Decipheriv values are Transforms, as in Node: they can be
written and ended, piped into, used as pipeline() and stream/promises
pipeline stages, composed, read, iterated with for await, read by
stream/consumers, passed to finished(), and listened to, and their stream
properties read as in Node. Each chunk goes through the cipher's
update(), and the end pushes final() or reports its error through
'error'; writing after final() throws out of write(). The stream unit
builds a cipher's Transform on its first stream use from operations the
cipher's handle provides (ScrDynHandleOps.transform), so programs that
use ciphers without streams link as before. The cipher is a
collector-headered object behind a traced handle: its Transform's steps
hold it, and the pair is reclaimed as a cycle. Through untyped values, in
a program that uses streams, a cipher's stream properties and its on,
once, off, pipe, unpipe, read, pause, resume, setEncoding, write, end,
destroy, cork and uncork members run on its Transform; other stream
members throw a coded SC2020 error.
A Transform holds a write's callback while its readable side is at the
high-water mark and runs it at the next read, and runs it on a tick once
the readable side has ended, as Transform._write does. write() on a
PassThrough, a Transform, a Hash or a cipher used to return true however
much the readable side buffered. zlib streams applied the rule already
and keep their timing.
pipeline() accepts function stages anywhere among its streams, so runs of
async generator stages can sit on both sides of a stream. A stage can be
named by a function declaration, or a const bound to a function
expression, that nothing reassigns; its body lowers again at the
pipeline with its source typed by the pipeline. The source can also be
an array, a string, a synchronous generator object, or a synchronous
generator function without parameters: an async generator steps the
source's iterator and yields each element, and the next stage receives
each element on the same tick as with Node's for await over the source.
The runtime's function-stage entry points take a bitmask of the function
positions and one (next, read, return) helper triple for each generator
pumped into a stream, so RUNTIME_ABI_VERSION is now 25. In JavaScript,
the chunks a stage receives from the previous stage's generator read as
the strings or Buffers it yields, so their string and Buffer methods
compile.
Corpus 7055-7059 cover cipher streams in TypeScript and JavaScript, their
errors, close order and backpressure, the pipeline stages and sources
with their tick order, and Transform backpressure.
A build now names the functions of the program's own files that compile
to the dynamic tier and likely run often, so a slow program with a little
untyped code says where the time goes:
warning SC6101: 3 functions that likely run often use untyped values, which runs slower than typed code:
advance (nbody.js:22): untyped JavaScript file, in a loop
...
- The functions come from the tier assignment lowering already makes
(Lowerer.dynamicFunctions). Without a profile, a function counts as
likely hot when a dynamic operation runs inside one of its loops, when
a loop calls it, or when it calls itself (lowering/dynamic-tier.ts).
- A function is named only when its source says why its values are
untyped: an `any` (for a for...of variable, the value it iterates), an
untyped JSON.parse result, or an untyped JavaScript file. Generated
%dyn.* helpers, module top levels and functions that are dynamic for an
operation without a static lowering are left out.
- At most five functions are named, most likely hot first, with the
total; dynamic-tier code in npm packages is counted per package on one
line. All of the warning's text is in diagnostics/dynamic-tier.ts.
- SC6101 opens the SC61xx band, performance notes, with a new
"performance" category in the diagnostics envelope; SC60xx stay the
divergences.
- scriptc build prints it after the divergence warnings, and the
executable cache stores it with the entry, so a cached build (including
the CLI's routed fast path) repeats it. scriptc coverage reports it, and
a comment-only edit no longer replays a verdict that carries it, since
its text holds line numbers.
- --no-dynamic-tier-warning leaves it out of build and coverage;
coverage --fail-on=dynamic fails on it.
- Docs: coverage.mdx (Dynamic tier, Gating builds and CI, the envelope
categories) and cli.mdx.
The frontend, lowering and LLVM emission of an optimized executable build run in a child
process when no earlier build of the same invocation emitted its native program object.
The parent passes the LLVM text to the native helper as the file the child wrote, so the
helper runs after the pages the frontend used are released. Later builds of the
invocation find most native partitions cached and peak in the frontend, so they, along
with development builds and builds with SCRIPTC_FRONTEND_PROCESS=0, prepare their input
in-process. The child runs with the parent's Node options without --eval, --print and
their code, or inspector, watch and test runner options. With SCRIPTC_TIMING=1, it
reports its phases on the parent's clock.
ScrArr stores len and cap as 32-bit fields and no longer stores the
state pointer. The dense states share the values' allocation and run
backward from its end: the state of slot i is at
data + cap * (slot width + 1) - 1 - i. Removing slots from the front
(shift, splice(0, n)) advances data and lowers cap, which leaves every
remaining state at its address; the head room size, needed only to free
or reallocate the block, is kept in the vacated slot before data. On
64-bit targets the header goes from 64 to 48 bytes, and from 36 to 32
bytes on wasm32. Array lengths were already limited to 2^32 - 1.
The emitted code loads len and cap as i32 and zero-extends them, and
computes state addresses from data and cap. Runtime loops compute the
end of the states once per call. Local array reads load data once for
both the state and value paths. A local or strict element read whose
index is a loop's induction variable reads slots above the hole-free
prefix through the runtime: an inline state check there makes LLVM keep
-1 - i as a second induction variable, which costs a register in the
loop.
Bulk operations do not read back states they just wrote: an append to
an array whose hole-free prefix reaches its length moves the prefix bound
to the new length, a copy from below the source's prefix writes value
states without reading the source's, and releasing a string array skips
the state checks below the prefix. Copies of up to eight slots and of
short state runs use overlapping word moves instead of a call. Emitted
element access computes the state address only on the state-checked
path. Without these, programs that build many small arrays with split or
slice ran 2-4% slower than with the separate state pointer.
Integer loops over an array's length compare the counter with the i32
length field in 32 bits; the counter never exceeds 2^32 - 1 there. The
array-length stability proof accepts Map and Set reads (get, has, size)
and checked union extractions (`x!`), which run no user code, so loops
that look up maps keep the dense fast copy, which tests the hole-free
prefix once before the loop.
Small constructions with the small allocator request 6 slots, so their
blocks stay 112 bytes, now with 7 inline slots (6 after a collector
header). With 96-byte blocks of 5 slots, programs that free and reuse
many small arrays ran 15-20% slower.
RUNTIME_ABI_VERSION goes from 22 to 23.
Release builds now emit the string retain and the dyn retain and release
fast paths inline. The dyn release decides the cases scr_dyn_release
decides by kind and calls scr_dyn_release_survivor for capsules and
handles. String releases and the other families stay runtime calls, as
string-heavy programs have many release sites. The speed posture keeps
every fast path and gains the dyn release. The runtime ABI version moves
to 21 because program objects call the new runtime entry point.
Chris Tate