It has been like this initially but was changed when ZDoom gained an overly complicated polymorphic class descriptor object that required a lot of support code. All these complications have long been removed but these methods remained. Since they prevent a class from being moved to the script side entirely they had to be removed.
This was the last major blocker to make Weapon a purely scripted class, the only remaining native method is Serialize which is of no concern for the coming work.
This stuff is now kept locally in the bot code so that it doesn't infest the rest of the engine.
And please don't read the new botsupp.txt file as some new means to configure bots! This was merely done to get this data out of the way.
The bots are still broken beyond repair and virtually unusable, even if proper data is provided for all weapons.
Since the only thing it gets used for is swapping out PlayerPawns it can safely skip all global variables that never point to a live player, which allowed to remove quite a bit of code here that stood in the way of scriptifying more content
Null pointers must be allowed and non-object pointers which are not null must be explicitly checked for because the code could crash on them when performing a static_cast on an incorrect type.
For the varargs functions that used the Type field to validate their parameters, now a hidden additional argument is passed which contains a byte array with the type info for the current call's arguments. Since this is static per call location it can be better prepared once when the code is being compiled instead of being put in a runtime created array for each invocation. Everything else uses the per-function instance of the same data.
The only thing that still needed the type field with a VMValue is the defaults array, so this uses a different struct type now to store its data.
Currently used for loading parameters into registers.
For checking parameters of native functions some more work is needed to get the info to the function. Currently it doesn't receive the function descriptor.
src/scripting/vm/jit_call.cpp:164:38: warning: offset of on non-standard-layout type 'VMScriptFunction' [-Winvalid-offsetof]
src/scripting/vm/jit_load.cpp:87:50: warning: offset of on non-standard-layout type 'DObject' [-Winvalid-offsetof]
src/scripting/vm/jit_load.cpp:96:50: warning: offset of on non-standard-layout type 'DObject' [-Winvalid-offsetof]
src/scripting/vm/jit_load.cpp:257:53: warning: offset of on non-standard-layout type 'DObject' [-Winvalid-offsetof]
The amount of support code for this minor optimization was quite large and this stood in the way of streamlining the VM's calling convention, so it was preferable to remove it before moving on.
With a proper count value available this can be done properly. The only relevant targets are the jumps immediately succeeding the IJMP instructions, nothing else.