This is a small step in the right direction although the amount of
different checks is becoming unsustainable. In the future we probably
want to have the current_scope handle all declarations.
Combining these into one list helps reduce the size of MatchState, and
as a result, reduces the amount of memory consumed during execution of
very large regex matches.
Doing this also allows us to remove a few regex byte code instructions:
ClearNamedCaptureGroup, SaveLeftNamedCaptureGroup, and NamedReference.
Named groups now behave the same as unnamed groups for these operations.
Note that SaveRightNamedCaptureGroup still exists to cache the matched
group name.
This also removes the recursion level from the MatchState, as it can
exist as a local variable in Matcher::execute instead.
The check for stack space in VM from push_execution_context has been
moved to a method on VM called did_reach_stack_space_limit. This
allows us to check the stack size in other places besides
push_execution_context.
We can now verify that we have enough space on the stack before calling
flatten_into_array to ensure that we don't cause a stack overflow error
when calling the function with a large depth.
When overriding visit_edges() in a JS::Object subclass, we must make
sure to call the base class visit_edges(), or the object's Shape (and
any properties) will not get marked.
Making userspace provide a global string ID was silly, and made the API
extremely difficult to use correctly in a global profiling context.
Instead, simply make the kernel do the string ID allocation for us.
This also allows us to convert the string storage to a Vector in the
kernel (and an array in the JSON profile data.)
When appending two strings together to form a new string, if both of the
strings are already UTF-16, create the new string as UTF-16 as well.
This shaves about 0.5 seconds off the following test262 test:
RegExp/property-escapes/generated/General_Category_-_Decimal_Number.js
The test262 tests under RegExp/property-escapes/generated will invoke
Reflect.apply with up to 10,000 arguments at a time. In LibJS, when the
call stack reached VM::call_internal, we transfer those arguments from
a MarkedValueList to the execution context's arguments Vector.
Because these types differ (MarkedValueList is a Vector<Value, 32>), the
arguments are copied rather than moved. By changing the arguments vector
to a MarkedValueList, we can properly move the passed arguments over.
This shaves about 2 seconds off the following test262 test (from 15sec):
RegExp/property-escapes/generated/General_Category_-_Decimal_Number.js
