LibJS: Implement the Dynamic Code Brand Checks stage 3 proposal

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 commit is contained in:
Luke Wilde 2024-12-03 10:56:21 +00:00 committed by Andrew Kaster
parent 2368641de5
commit 3d43462ccd
Notes: github-actions[bot] 2025-07-09 21:54:06 +00:00
12 changed files with 176 additions and 111 deletions

View file

@ -41,15 +41,22 @@ ThrowCompletionOr<GC::Ref<Object>> AsyncFunctionConstructor::construct(FunctionO
{
auto& vm = this->vm();
ReadonlySpan<Value> arguments = vm.running_execution_context().arguments;
ReadonlySpan<Value> parameter_args = arguments;
if (!parameter_args.is_empty())
parameter_args = parameter_args.slice(0, parameter_args.size() - 1);
// 1. Let C be the active function object.
auto* constructor = vm.active_function_object();
// 2. If bodyArg is not present, set bodyArg to the empty String.
// NOTE: This does that, as well as the string extraction done inside of CreateDynamicFunction
auto extracted = TRY(extract_parameter_arguments_and_body(vm, vm.running_execution_context().arguments));
Value body_arg = &vm.empty_string();
if (!arguments.is_empty())
body_arg = arguments.last();
// 3. Return ? CreateDynamicFunction(C, NewTarget, async, parameterArgs, bodyArg).
return TRY(FunctionConstructor::create_dynamic_function(vm, *constructor, &new_target, FunctionKind::Async, extracted.parameters, extracted.body));
return TRY(FunctionConstructor::create_dynamic_function(vm, *constructor, &new_target, FunctionKind::Async, parameter_args, body_arg));
}
}