This is an active proposal at stage 3 of the TC39 proposal process.
See: https://tc39.es/proposal-dynamic-code-brand-checks/
See: https://github.com/tc39/proposal-dynamic-code-brand-checks
This proposal essentially adds support for the TrustedScript type from
the Trusted Types specification to eval and Function. This in turn
pipes support for the type into the CSP hook to check if the CSP allows
dynamic code compilation.
However, it currently doesn't support ShadowRealms, so the
implementation here is a close approximation, using PerformEval as the
basis.
See: https://github.com/tc39/proposal-dynamic-code-brand-checks/issues/19
This is required to support the new function signature for the CSP
hook, and will allow us to slot in Trusted Types support in the future.
This is better because:
- Better data locality
- Allocate vector for registers+constants+locals+arguments in one go
instead of allocating two vectors separately
The special empty value (that we use for array holes, Optional<Value>
when empty and a few other other placeholder/sentinel tasks) still
exists, but you now create one via JS::js_special_empty_value() and
check for it with Value::is_special_empty_value().
The main idea here is to make it very unlikely to accidentally create an
unexpected special empty value.
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
