Combining these two groups of data has been the cause of many hard to detect errors because it allowed liberal casting between types that are used for completely different things.
This is an incredibly costly way to do a debug check as it infests the entire VM design from top to bottom. These tags are basically useless for anything else but validating object pointers being passed to native functions (i.e. mismatches between definition and declaration) and that simply does not justify a feature that costs execution time in non-debug builds and added memory overhead everywhere.
Note that this commit does not remove the tags, it only discontinues their use.
This makes VMValue a real POD type with no hacky overloads and eliminates a lot of destructor code in all places that call a VM function. Due to the way this had to be handled, none of these destructors could be skipped because any value could have been a string.
This required some minor changes in functions that passed a temporary FString into the VM to ensure that the temporary object lives long enough to be handled. The code generator had already been changed to deal with this in a previous commit.
This is easily offset by the code savings and reduced maintenance needs elsewhere.
Note that the Strife status bar does not draw the health bars yet. I tried to replace the hacky custom texture with a single fill operation but had to find out that all the coordinate mangling for the status bar is being done deep in the video code. This needs to be fixed before this can be made to work.
Currently this is not usable in mods because they cannot initialize custom status bars yet.
- keep string registers which are being used as function parameters allocated until after the function call returns. This is for allowing to pass strings by reference which would avoid some costly constructor/destructor loops in the call instruction.
This method was chosen because it avoids adding variable declarations to the global namespace which would have required a lot more work while polluting the grammar.
This way the global variables can be handled by a small bit of special coding in the struct generator.
Both files can now be included independently without causing problems.
This also required moving some inline functions into separate files and splitting off the GC definitions from dobject.h to ensure that r_defs does not need to pull in any part of the object hierarchy.
- block creation of actors with the 'new' instruction. Unlike the above these cannot be made abstract because without ConstructNative they cannot be serialized.
It now uses a dedicated opcode instead of piggybacking on OP_CALL and it passes data that is closer to the VM. Symbols should be avoided at this level.
It also will skip the scope instruction if the code generator detects that both calling function and the self pointer type have the same scope, this assumes that subclasses cannot flip between UI and Play.
They are not needed for OP_NEW_K which can evaluate the class relations at compile time and for OP_NEW the calling function can also be checked at compile time, passing only the scope value itself.
This will store class meta properties in a separate memory block so that it won't have to muck around with PClass - which made the implementation from the scripting branch relatively useless because extending the data wasn't particularly easy and also not well implemented. This can now be handled just like the defaults.
