This is an editorial change in the ECMA-262 spec. See:
12d3687
This AO is meant to replace usages of IteratorNext followed by
IteratorValue with a single operation.
This allows, for example:
ThrowCompletionOr<Optional<Value>> foo()
{
return OptionalNone {};
}
The constructors and constraints here are lifted verbatim from
AK::Optional.
This helps us avoid from needing to construct a Function<T> when
invoking `create_heap_function` with a lambda.
Co-Authored-By: Ali Mohammad Pur <mpfard@serenityos.org>
perform_call() wants a ReadonlySpan<Value>, so just grab a slice of the
current register window instead of making a MarkedVector.
10% speed-up on this function call microbenchmark:
function callee(a, b, c) { }
function caller(callee) {
for (let i = 0; i < 10_000_000; ++i)
callee(1, 2, 3)
}
caller(callee)
Value::Value(double) already converts double to int when it is safe, no
need to check for this here explicitly. While this technically removes
an optimization, I doubt that it will regress performance in any
measurable way.
For parameters that exist strictly as "locals", we can save time and
space by not adding them to the function environment.
This is a speed-up across the board on basically every test.
For example, ~11% on Octane/typescript.js :^)
This commit effectively just does a bulk update of this function to the
spec. Since there have been so many spec changes, no specific change was
made in mind, and many FIXMEs have been left for where we are still out
of date.
These changes also appear to include a normative change to the temporal
spec which was previously resulting in timeouts for some tests, and is
now resulting in a timeout.
Furthermore, this also resolves some crashes by protecting against
division by zero, instead throwing a RangeError. This can only happen
when a custom calender is provided which returns funky values. See:
https://github.com/tc39/proposal-temporal/commit/ed85e9
Diff Tests:
+8 ✅ -4 💀 -4 💥️
The spec has moved along quite a bit since this was originally
implemented. Catch up on at least some of these changes, and leave
FIXMEs for what is missing.
No change to test262.
Previously, constructing a `UnsignedBigInteger::from_base()` could
produce an incorrect result if the input string contained a valid
Base36 digit that was out of range of the given base. The same method
would also crash if the input string contained an invalid Base36 digit.
An error is now returned in both these cases.
Constructing a BigFraction from string is now also fallible, so that we
can handle the case where we are given an input string with invalid
digits.
`JsonValue::to_byte_string` has peculiar type-erasure semantics which is
not usually intended. Unfortunately, it also has a very stereotypical
name which does not warn about unexpected behavior. So let's prefix it
with `deprecated_` to make new code use `as_string` if it just wants to
get string value or `serialized<StringBuilder>` if it needs to do proper
serialization.
This is a normative change in the ECMA-262 spec. See:
22de374
The issue noted here has been fixed in the same way that we previously
worked around it. Update the spec notes to match.
Without a key function, the vtable for this class can be emitted into
every shared object or executable that needs it. This can cause bugs and
bad behavior when trying to access the vtable or RTTI for the class.
This is most easily seen when trying to call ``is<JS::Date>``, which
currently will do a dynamic_cast. Based on compiler, linker and loader
choices about ordering, it's possible that the code checking the RTTI
and the code that created the object could have a different vtable and
type_info in mind, causing false negatives for the ``is`` check.
There was recently a normative change to this AO in ECMA-262. See:
5eaee2f
It turns out we already implemented this to align with web-reality
before it was codified in the spec. This was a bit difficult to reason
without spec text and with a somewhat ad-hoc implementation. So this
patch aligns our implementation with the spec. There should not be any
behavior change.
JS::modulo was yielding a result of '0' for the input:
```
modulo(1., 18446744073709551616.)
```
Instead of the expected '1'.
As far as I can tell the reason for this is that the repeated calls to
fmod is losing precision in the calculation, leading to the wrong
result. Fix this by only calling fmod once, and preserving the negative
value behaviour by an 'if' check.
Without this, the LibWeb text test:
`/Streams/ReadableByteStream-enqueue-respond.html`
Would hang forever after using this function in the IDL conversion of a
u64 in ConvertToInt.
This should also be more efficient :^)
Instead of returning HeapBlock memory to the kernel (or a non-type
specific shared cache), we now keep a BlockAllocator per CellAllocator
and implement "deallocation" by basically informing the kernel that we
don't need the physical memory right now.
This is done with MADV_FREE or MADV_DONTNEED if available, but for other
platforms (including SerenityOS) we munmap and then re-mmap the memory
to achieve the same effect. It's definitely clunky, so I've added a
FIXME about implementing the madvise options on SerenityOS too.
The important outcome of this change is that GC types that use a
type-specific allocator become immune to use-after-free type confusion
attacks, since their virtual addresses will only ever be re-used for
the same exact type again and again.
Fixes#22274
When resolving a rope, we've already taken care to resolve it to
a UTF-8 byte stream. There's no need to do a separate pass just for
validating the data again.
This was noticeable in some profiles. I made a simple microbenchmark
that gets a 30% speed-up:
("x" + "y".repeat(100_000_000)).trimStart()
Instead of using a StringBuilder, add a String::repeated(String, N)
overload that takes advantage of knowing it's already all UTF-8.
This makes the following microbenchmark go 4x faster:
"foo".repeat(100_000_000)
And for single character strings, we can even go 10x faster:
"x".repeat(100_000_000)
We can now implement steps related to resizable ArrayBuffer objects. We
can also implement a couple of missing SharedArrayBuffer checks.
The original implementation of this proposal did not have any tests, so
tests are added here for the whole implementation.
In: https://tc39.es/ecma262/#sec-%typedarray%-intrinsic-object
The spec says:
> is a constructor function object that all of the TypedArray
> constructor objects inherit from.
From what I understand from this, it effectively just means is that the
prototype for the constructor should simply be set to
TypedArrayConstructor. We _were_ doing that, but also inheriting from
it in C++.
This meant we were invoking TypedArrayConstructor::initialize for each
of the typed arrays. This is not actually what we want, since it means
that the 'of' and 'from' functions were being defined as native
properties in both the concrete typed array (e.g Uint8Array), and the
abstract TypedArray. Instead, the properties should only be defined and
inherited from the abstract TypedArray class.
Diff Tests:
+4 ✅ -4 ❌
Co-Authored-By: Andreas Kling <kling@serenityos.org>
