llvm-project

6344e3aa - Make result variables obey their dynamic values in subsequent expressions (#168611)

Make result variables obey their dynamic values in subsequent expressions (#168611) When you run an expression and the result has a dynamic type that is different from the expression's static result type, we print the result variable using the dynamic type, but at present when you use the result variable in an expression later on, we only give you access to the static type. For instance: ``` (lldb) expr MakeADerivedReportABase() (Derived *) $0 = 0x00000001007e93e0 (lldb) expr $0->method_from_derived() ^ error: no member named 'method_from_derived' in 'Base' (lldb) ``` The static return type of that function is `Base *`, but we printed that the result was a `Derived *` and then only used the `Base *` part of it in subsequent expressions. That's not very helpful, and forces you to guess and then cast the result types to their dynamic type in order to be able to access the full type you were returned, which is inconvenient. This patch makes lldb retain the dynamic type of the result variable (and ditto for persistent result variables). It also adds more testing of expression result variables with various types of dynamic values, to ensure we can access both the ivars and methods of the type we print the result as.