Now that module loading is implemented this just works :^).
Since ShadowRealm explicitly passed a null ScriptOrModule we attempt to
get the top most ScriptOrModule in HostImportModuleDynamically.
This won't work in general as the web specifies other behavior but for
LibJS there must always be an active script to call
HostImportModuleDynamically.
This also refactors interpreter creation to follow
InitializeHostDefinedRealm, but I couldn't fit it in the title :^)
This allows us to follow the spec much more closely rather than being
completely ad-hoc with just the parse node instead of having all the
surrounding data such as the realm of the parse node.
The interpreter creation refactor creates the global execution context
once and doesn't take it off the stack. This allows LibWeb to take the
global execution context and manually handle it, following the HTML
spec. The HTML spec calls this the "realm execution context" of the
environment settings object.
It also allows us to specify the globalThis type, as it can be
different from the global object type. For example, on the web, Window
global objects use a WindowProxy global this value to enforce the same
origin policy on operations like [[GetOwnProperty]].
Finally, it allows us to directly call Program::execute in perform_eval
and perform_shadow_realm_eval as this moves
global_declaration_instantiation into Interpreter::run
(ScriptEvaluation) as per the spec.
Note that this doesn't evalulate Source Text Modules yet or refactor
the bytecode interpreter, that's work for future us :^)
This patch was originally build by Luke for the environment settings
object change but was also needed for modules. So I (davidot) have
modified it with the new completion changes and setup for that.
Co-authored-by: davidot <davidot@serenityos.org>
This is another major milestone on our journey towards removing global
VM exception state :^)
Does pretty much exactly what it says on the tin: updating
ASTNode::execute() to return a Completion instead of a plain value. This
will *also* allow us to eventually remove the non-standard unwinding
mechanism and purely rely on the various completion types.
In the end this is a nicer API than having separate has_{value,target}()
and having to check those first, and then making another Optional from
the unwrapped value:
completion.has_value() ? completion.value() : Optional<Value> {}
// ^^^^^^^^^^^^^^^^^^
// Implicit creation of non-empty Optional<Value>
This way we need to unwrap the optional ourselves, but can easily pass
it to something else as well.
This is in anticipation of the AST using completions :^)
Well... sort of. This adds the function itself and all the scaffolding
from the ShadowRealm API (and basically completes its implementation).
However, we do not nearly have enough support for modules and imports,
so we currently pretend whatever was attempted to be imported failed -
once we have HostImportModuleDynamically it should be relatively easy to
complete the implementation.
