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`.
Chris Tate