Inline JS-to-JS frames no longer live in the raw execution context
vector, so LibWeb callers that need to inspect or pop contexts now go
through VM helpers instead of peeking into that storage directly.
This keeps the execution context bookkeeping encapsulated while
preserving existing microtask and realm-entry checks.
The proposal has not seemed to progress for a while, and there is
a open issue about module imports which breaks HTML integration.
While we could probably make an AD-HOC change to fix that issue,
it is deep enough in the JS engine that I am not particularly
keen on making that change.
Until other browsers begin to make positive signals about shipping
ShadowRealms, let's remove our implementation for now.
There is still some cleanup that can be done with regard to the
HTML integration, but there are a few more items that need to be
untangled there.
The additional data being passed will be used in an upcoming commit.
Allows splitting the churn of modified function signatures from the
logically meaningful code change.
No behavior change.
Delete AST.cpp, AST.h, ASTDump.cpp, ScopeRecord.h, and the dead
get_builtin(MemberExpression const&) from Builtins.cpp.
Extract ImportEntry and ExportEntry into a new ModuleEntry.h,
since they are data types used by the module system, not AST
node types.
Inline ModuleRequest's sorting constructor and
SourceRange::filename().
Remove the dead annex_b_function_declarations field from
EvalDeclarationData, which was only populated by the C++ parser.
When an async function is resumed from a microtask and hits another
await with a non-thenable value (primitive or already-settled native
promise), and the microtask queue is empty, we can resolve the await
synchronously without suspending. No other microtask can observe the
difference in execution order, making this optimization safe.
This avoids the overhead of creating a GC::Function for the microtask
job, enqueuing/dequeuing from the microtask queue, and the execution
context push/pop that comes with it.
A new VM host hook, host_promise_job_queue_is_empty, is added so both
the standalone js binary and LibWeb can provide the appropriate check
for their respective job queue implementations.
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).
Replace alloca-based execution context allocation with InterpreterStack
bump allocation across all call sites: bytecode call instructions,
AbstractOperations call/construct, script evaluation, module evaluation,
and LibWeb module script evaluation.
Also replace the native stack space check with an InterpreterStack
exhaustion check, and remove the now-unused alloca macros from
ExecutionContext.h.
Every function call allocates an ExecutionContext with a trailing array
of Values for registers, locals, constants, and arguments. Previously,
the constructor would initialize all slots to js_special_empty_value(),
but constant slots were then immediately overwritten by the interpreter
copying in values from the Executable before execution began.
To eliminate this redundant initialization, we rearrange the layout from
[registers | constants | locals] to [registers | locals | constants].
This groups registers and locals together at the front, allowing us to
initialize only those slots while leaving constant slots uninitialized
until they're populated with their actual values.
This reduces the per-call initialization cost from O(registers + locals
+ constants) to O(registers + locals).
Also tightens up the types involved (size_t -> u32) and adds VERIFYs to
guard against overflow when computing the combined slot counts, and to
ensure the total fits within the 29-bit operand index field.
This allows Promises (including internal ones, like in Streams) and
FinalizationRegistry to work while scripting is disabled.
These were removed in the spec in support of WebDriver BiDi being able
to enable and disable scripting.
https://github.com/whatwg/html/commit/905b7218
This allows Fetch to work while scripting is disabled, due to its use
of Streams. This was noticeable if you disabled scripting in the UI,
or had a sandboxed iframe with scripting disabled.
There is more work to use job settings instead of realm inside these
hooks, but that's a separate issue.
Fixes https://github.com/LadybirdBrowser/ladybird/issues/7409
Fixes https://github.com/LadybirdBrowser/ladybird/issues/3729
We once again ignore any mention of atomic operations on
[[ArrayBufferByteLengthData]]. This commit also fixes a couple bugs
where we forget to set Data Blocks as Shared.
The microtask is conceptually global and fires pending observers at the
agent level. As such, it doesn't make sense for it to be associated with
any specific document.
We need to prevent these mutation observers from being garbage
collected, and since they are only part of SimilarOriginWindowAgent and
themselves as part of the intrusive list, nobody is visiting them.
Make the list of pending mutation observers a GC::RootVector so we keep
them alive until they have been processed in the microtask.
Restores 1400+ WPT subtest passes in `dom/nodes/Element-classlist.html`.
In the current spec, MutationObservers are explicitly added to the
pending mutation observers list, and they are removed when that list is
cleared in the "notify mutation observers" microtask.
This solves some issues with slotchange events.
As noted, we delay actually emptying the list of pending mutation
observers until after we're finished with the "clone", because we can't
actually copy or move the intrusive list. As far as I am aware, this
should not affect behaviour because only one microtask can run at once.
We have a couple of ways to designate spec notes and (our) developer
notes in comments, but we never really settled on a single approach. As
a result, we have a bit of a mixed bag of note comments on our hands.
To the extent that I could find them, I changed developer notes to
`// NB: ...` and changed spec notes to `// NOTE: ...`. The rationale for
this is that in most web specs, notes are prefixed by `NOTE: ...` so
this makes it easier to copy paste verbatim. The choice for `NB: ...` is
pretty arbitrary, but it makes it stand out from the regular spec notes
and it was already in wide use in our codebase.
This commit adds the toResizableBuffer() and toFixedLengthBuffer()
methods to WebAssembly.Memory. This includes the necessary hook to
HostResizeArrayBuffer. Some modifications to function signatures in
LibWeb/WebAssembly/Memory.h were also made (changing the return type
from WebIDL::ExceptionOr to JS::ThrowCompletionOr) to allow the use of
some code in the aforementioned hook.
Note: the hook for HostGrowSharedArrayBuffer isn't implemented, since
LibJS doesn't seem to have complete support for growable
SharedArrayBuffers; the relevant methods/getters don't even exist on
the prototype, let alone HostGrowSharedArrayBuffer!
This should help pass the WebAssembly.Memory WPT tests included in
Interop 2025, except those pertaining to growable SharedArrayBuffers.
This has quite a lot of fall out. But the majority of it is just type or
UDL substitution, where the changes just fall through to other function
calls.
By changing property key storage to UTF-16, the main affected areas are:
* NativeFunction names must now be UTF-16
* Bytecode identifiers must now be UTF-16
* Module/binding names must now be UTF-16
It turns out it was a mistake to make this a virtual since
ServiceWorkerAgents are effectively the exact same as
DedicatedWorkerAgents and SharedWorkerAgents just with [[CanBlock]]
set to false.
This helps unwind a niggly depedency where the VM owns and constructs
the Heap and the Agent. But the agent wants to have customized
construction that depends on the heap. Solve this by defering
the initialization of the Agent to after we have constructed the
VM and the heap.
To allow for adding the concept of a WorkerAgent to be reused
between shared and dedicated workers. An event loop is the
commonality between the different agent types, though, there
are some differences between those event loops which we customize
on the construction of the HTML::EventLoop.
This is better because:
- Better data locality
- Allocate vector for registers+constants+locals+arguments in one go
instead of allocating two vectors separately
similar-origin window agents have the [[CanBlock]] flag set to false.
Achieve this by hooking up JS's concept with an agent to HTML::Agent.
For now, this is only hooked up to the similar-origin window agent
case but should be extended to the other agent types in the future.
These callbacks are evaluated synchronously via JS::Call. We do not need
to construct an expensive RootVector container just to immediately
invoke the callbacks.
Stylistically, this also helps indicate where the actual arguments start
at the call sites, by wrapping the arguments in braces.
Before this change, Agent held on to all of the live MutationObserver
objects via GC::Root. This prevented them from ever getting
garbage-collected.
Instead of roots, we now use a simple IntrusiveList and remove them
from it in the finalizer for MutationObserver.
This fixes a massive GC leak on Speedometer.
We added these methods to propagate OOM errors at process startup, but
we longer fret about these tiny OOM failures. Requiring that these init
methods be called prohibits using these strings in processes that have
not set up a MainThreadVM. So let's just remove them and initialize the
strings in a sane manner.
In doing so, this also standardizes how we initialize strings whose C++
variable name differs from their string value. Instead of special-casing
these strings, we just include their string value in the x-macro list.
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.
