Previously, default argument values would only show up when accessing
the argument by parameter name. This patch makes us write them back
into the call frame so they can be accessed via VM::argument() as well.
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.
Some of the code assumed that chars were always signed while that is
not the case on ARM hosts.
Also, some of the code tried to use EOF (-1) in a way similar to what
fgetc() does, however instead of storing the characters in an int
variable a char was used.
While this seemed to work it also meant that character 0xFF would be
incorrectly seen as an end-of-file.
Careful reading of fgetc() reveals that fgetc() stores character
data in an int where valid characters are in the range of 0-255 and
the EOF value is explicitly outside of that range (usually -1).
As mentioned on Discord earlier, we'll add these to all new functions
going forward - this is the backfill. Reasons:
- It makes you look at the spec, implementing based on MDN or V8
behavior is a no-go
- It makes finding the various functions that are non-compliant easier,
in the future everything should either have such a comment or, if it's
not from the spec at all, a comment explaining why that is the case
- It makes it easier to check whether a certain abstract operation is
implemented in LibJS, not all of them use the same name as the spec.
E.g. RejectPromise() is Promise::reject()
- It makes it easier to reason about vm.arguments(), e.g. when the
function has a rest parameter
- It makes it easier to see whether a certain function is from a
proposal or Annex B
Also:
- Add arguments to all functions and abstract operations that already
had a comment
- Fix some outdated section numbers
- Replace some ecma-international.org URLs with tc39.es
While this implementation should be complete it is based on HashMap's
iterator, which currently follows bucket-order instead of the required
insertion order. This can be simply fixed by replacing the underlying
HashMap member in Map with an enhanced one that maintains a linked
list in insertion order.
This will allow us to use these traits for other hash-based containers
(like Map). This commit also adds a special case for negative zero
values, because while the equality check used same_value_zero which is
negative/positive zero insensitive, the hash was not.
This counter is increased each time a synchronous execution sequence
completes, and will allow us to emulate the abstract operations
AddToKeptObjects & ClearKeptObjects efficiently.
