Commits on Apr 28, 2024

1. Fix use-after-move in console implementation …

   Summary:
   Changelog: [Internal]
   
   In the new CDP backend, calling any `console` method a second time involves a call to a moved-from `std::function`. This shouldn't work, and indeed results in an exception on some platforms, but isn't strictly an error according to the C++ standard: moving from a `std::function` leaves it in an [unspecified state](https://en.cppreference.com/w/cpp/utility/functional/function/function#:~:text=the%20call%20too.-,other,is%20in%20a%20valid%20but%20unspecified%20state%20right%20after%20the%20call.,-5), not necessarily an empty state, so (in particular) it's perfectly legal for the implementation to perform a copy instead of a move and leave the original variable intact.
   
   (See [Compiler Explorer](https://godbolt.org/z/qoo5Mnd68) for proof that libc++ and libstdc++ differ on this - the former performs a copy, while the latter actually performs a move, resulting in a `std::bad_function_call` exception later.)
   
   In the code in question, we're right to want to avoid a copy of the `body` function into the argument of `delegateExecutorSync` - only one copy of this function needs to exist at a time. But the correct way to avoid this copy is to capture `body` by reference, as we can do that repeatedly with no ill effects. (`delegateExecutorSync` is, as its name suggests, synchronous, so there are no lifetime issues.) Doing this also allows us to remove the use of `mutable` so the capturing is by *const* reference.
   
   Differential Revision: D56673529

   

   motiz88 authored and facebook-github-bot committed Apr 28, 2024
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