Almost everything in LibJS includes Cell.h, don't force all code to
include AK/TypeCasts.h + AK/String.h. Instead include them where they
are actually used and required.
These were an ad-hoc way to implement special behaviour when reading or
writing to specific object properties. Because these were effectively
replaced by the abillity to override the internal methods of Object,
they are no longer needed.
It's way too easy to get this wrong: for the IsArray abstract operation,
Value::is_array() needs to be called. Since we have RTTI, the virtual
Object::is_array() method is not needed anymore - if we need to know
whether something is *actually* a JS::Array (we currently check in more
cases than we should, I think) and not a Proxy with an Array target, we
should do that in a way that doesn't look like an abstract operation.
This is a huge patch, I know. In hindsight this perhaps could've been
done slightly more incremental, but I started and then fixed everything
until it worked, and here we are. I tried splitting of some completely
unrelated changes into separate commits, however. Anyway.
This is a rewrite of most of Object, and by extension large parts of
Array, Proxy, Reflect, String, TypedArray, and some other things.
What we already had worked fine for about 90% of things, but getting the
last 10% right proved to be increasingly difficult with the current code
that sort of grew organically and is only very loosely based on the
spec - this became especially obvious when we started fixing a large
number of test262 failures.
Key changes include:
- 1:1 matching function names and parameters of all object-related
functions, to avoid ambiguity. Previously we had things like put(),
which the spec doesn't have - as a result it wasn't always clear which
need to be used.
- Better separation between object abstract operations and internal
methods - the former are always the same, the latter can be overridden
(and are therefore virtual). The internal methods (i.e. [[Foo]] in the
spec) are now prefixed with 'internal_' for clarity - again, it was
previously not always clear which AO a certain method represents,
get() could've been both Get and [[Get]] (I don't know which one it
was closer to right now).
Note that some of the old names have been kept until all code relying
on them is updated, but they are now simple wrappers around the
closest matching standard abstract operation.
- Simplifications of the storage layer: functions that write values to
storage are now prefixed with 'storage_' to make their purpose clear,
and as they are not part of the spec they should not contain any steps
specified by it. Much functionality is now covered by the layers above
it and was removed (e.g. handling of accessors, attribute checks).
- PropertyAttributes has been greatly simplified, and is being replaced
by PropertyDescriptor - a concept similar to the current
implementation, but more aligned with the actual spec. See the commit
message of the previous commit where it was introduced for details.
- As a bonus, and since I had to look at the spec a whole lot anyway, I
introduced more inline comments with the exact steps from the spec -
this makes it super easy to verify correctness.
- East-const all the things.
As a result of all of this, things are much more correct but a bit
slower now. Retaining speed wasn't a consideration at all, I have done
no profiling of the new code - there might be low hanging fruits, which
we can then harvest separately.
Special thanks to Idan for helping me with this by tracking down bugs,
updating everything outside of LibJS to work with these changes (LibWeb,
Spreadsheet, HackStudio), as well as providing countless patches to fix
regressions I introduced - there still are very few (we got it down to
5), but we also get many new passing test262 tests in return. :^)
Co-authored-by: Idan Horowitz <idan.horowitz@gmail.com>
We were doing a *lot* of string-to-int conversion while creating a new
global object. This happened because Object::put() would try to convert
the property name (string) to an integer to see if it refers to an
indexed property.
Sidestep this issue by using PropertyName for the CommonPropertyNames
struct on VM (vm.names.foo), and giving PropertyName a flag that tells
us whether it's a string that *may be* a number.
All CommonPropertyNames are set up so they are known to not be numbers.
This was missing from Value::is_array(), which is equivalent to the
spec's IsArray() abstract operation - it treats a Proxy value with an
Array target object as being an Array.
It can throw, so needs both the global object and an exception check
now.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
The previous handling of the name and message properties specifically
was breaking websites that created their own error types and relied on
the error prototype working correctly - not assuming an JS::Error this
object, that is.
The way it works now, and it is supposed to work, is:
- Error.prototype.name and Error.prototype.message just have initial
string values and are no longer getters/setters
- When constructing an error with a message, we create a regular
property on the newly created object, so a lookup of the message
property will either get it from the object directly or go though the
prototype chain
- Internal m_name/m_message properties are no longer needed and removed
This makes printing errors slightly more complicated, as we can no
longer rely on the (safe) internal properties, and cannot trust a
property lookup either - get_without_side_effects() is used to solve
this, it's not perfect but something we can revisit later.
I did some refactoring along the way, there was some really old stuff in
there - accessing vm.call_frame().arguments[0] is not something we (have
to) do anymore :^)
Fixes#6245.
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
