Let's not have to know off-hand that we need to update Environments.cpp
when adding a new WebUI. It's more obvious just below where we define
the URLs.
Avoid expensive cross-hierarchy dynamic_cast from JS::Object to
UniversalGlobalScopeMixin on every microtask checkpoint.
Since UniversalGlobalScopeMixin is not in the JS::Object
inheritance chain, as<UniversalGlobalScopeMixin>(JS::Object&)
falls through to dynamic_cast, which is very costly. Profiling
showed this taking ~14% of total CPU time.
Add EnvironmentSettingsObject::universal_global_scope() backed
by a pointer cached eagerly during initialization.
entry_realm() was using the topmost execution context, but the spec
defines the entry execution context as the most recently pushed *realm*
execution context — the one owned by the environment settings object.
In a synchronous cross-window call, JS function calls push additional
execution contexts above the entry realm, causing the wrong realm to
be returned. Fix this by walking the stack to find the context that
matches its environment settings object's realm execution context.
Previously, destroyed-document tasks were forced to be runnable to
prevent them from leaking in the task queue. Instead, discard them
during task selection so their callbacks never run with stale state.
This used to cause issues with a couple of `spin_until()`s in the past,
but since we've removed some of them that had to do with the document
lifecycle, let's see if we can stick closer to the spec now.
Replace the 16-byte Variant<Empty, GC::Ref<Script>, GC::Ref<Module>>
with a simple 8-byte GC::Ptr<Cell> that points to either a Script or
Module (or is null for Empty).
A helper function script_or_module_from_cell() converts back to the
full ScriptOrModule variant when needed (e.g. in
VM::get_active_script_or_module).
This field was only used by LibWeb to prevent GC collection of the
EnvironmentSettingsObject while its execution context is on the stack.
This is unnecessary because the ESO is already reachable through the
realm's host_defined pointer: EC -> realm -> host_defined ->
PrincipalHostDefined -> environment_settings_object.
Shrinks ExecutionContext from 152 to 144 bytes.
Fixes the included imported test. Note that this required a minor
edit of the WPT import to work with our test harness setup to
try and create a non secure context setup as both file:// and
localhost are considered secure contexts.
This is somewhat awkward as the spec refers to 'is secure context'
with respect to these objects 'relevant settings object'. A natural
way of implementing this could be storing a pointer to the relevant
settings object like the JS representations of these objects do
(and then changing is_secure_context to accept this representation
too), but for now it seems much simpler to just store a boolean for
this purpose and sidestep both problems above.
Instead of passing through window's associated document's URL as
an extra argument to starting up a worker. This will allow for
improving the representation of 'outside settings' when setting
up a Worker.
As a stopgap until we have things wired up fully, consider
WorkerGlobalScope as a SecureContext so that IDL marked with
[SecureContext] is still exposed.
Remove 11 heavy includes from Document.h that were only needed for
pointer/reference types (already forward-declared in Forward.h), and
extract the nested ViewportClient interface to a standalone header.
This reduces Document.h's recompilation cascade from ~1228 files to
~717 files (42% reduction). Headers like BrowsingContext.h that were
previously transitively included see even larger improvements (from
~1228 down to ~73 dependents).
After removing the unwind context stack, ExecutionContextRareData only
held two GC::Ptr fields — both trivially destructible. The indirection
cost more than it saved: a GC cell allocation per EC, an extra pointer
chase on every source range lookup, and unnecessary complexity.
Replace the rare data cell with two inline fields on ExecutionContext:
cached_source_range and context_owner.
This ensures that we are explicitly declaring the allocator to use when
allocating a cell(-inheriting) type, instead of silently falling back
to size-based allocation.
Since this is done in allocate_cell, this will only be detected for
types that are actively being allocated. However, since that means
they're _not_ being allocated, that means it's safe to not declare
an allocator to use for those. For example, the base TypedArray<T>,
which is never directly allocated and only the defined specializations
are ever allocated.
187f8c54 made `HTML::Task` runnable for destroyed documents, and this
change aligns microtask behavior with that. This is required for an
upcoming change that switches Fetch to be unbuffered by default. During
navigation, fetching the new document is initiated by the previous
document, which means we need to allow microtasks created in the
previous document's realm to run even after that document has been
destroyed.
Exactly one place seems to define these at the moment: service worker
clients. Since we don't have a type for these and just use
EnvironmentSettingsObject, I've put it there.
This is required to store Content Security Policies, as their
Directives are implemented as subclasses with overridden virtual
functions. Thus, they cannot be stored as generic Directive classes, as
it'll lose the ability to call overridden functions when they are
copied.
This makes it more convenient to use the 'relvant agent' concept,
instead of the awkward dynamic casts we needed to do for every call
site.
mutation_observers is also changed to hold a GC::Root instead of raw
GC::Ptr. Somehow this was not causing problems before, but trips up CI
after these changes.
There are essentially 3 URL parsing AOs defined by the spec:
1. Parse a URL
2. Encoding parse a URL
3. Encoding parse a URL and serialize the result
Further, these are replicated between the Document and the ESO.
This patch defines these methods in accordance with the spec and updates
existing users to invoke the correct method. In places where the correct
method is ambiguous, we use the encoding parser to preserve existing ad-
hoc behavior.
There was a bug in the HTML proposal where a synthetic realm settings
object's principal realm was a shadow realm if there were nested shadow
realms, which this assertion catches more directly (rather than later
down the track, where it is used).
We were meant to also assert for this case, but we were previously
returning early.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
Now that the heap has no knowledge about a JavaScript realm and is
purely for managing the memory of the heap, it does not make sense
to name this function to say that it is a non-realm variant.
The main motivation behind this is to remove JS specifics of the Realm
from the implementation of the Heap.
As a side effect of this change, this is a bit nicer to read than the
previous approach, and in my opinion, also makes it a little more clear
that this method is specific to a JavaScript Realm.
