This also means that for now Lua-style multi-assignments are disabled, those should be easy to enable by making some changes to the assignment_statement grammar so that it doesn't recognize single assignments, but for now this is low priority because it adds a significant amount of complexity to do this right with functions that have multiple return values.
The generated object code can definitely use an optimization pass but that's something left for later when more things are working. Right now it creates one opcode more than necessary for all member accesses (instead of using the offset in the store command it calculates an actual address of the variable in another address register) and can create one too many for non-constant expressions being assigned to local variables (a move between two registers because the emitted expression on the right hand side does not know that it can emit to the actual variable's register.)
- create proper variable data from the function prototype instead of assuming that there's just 3 pointers.
- added a printable name to VMScriptFunction for error output during gameplay in case something goes wrong.
All break and continue statements were collected in one list, and each loop statement taking hold of that entire list, including the breaks and continues from previous outer loops.
Changed it so that loop statements contain the jump addresses themselves and set a pointer in FCompileContext, so that the jump point can be set directly in the loop statement - and an error printed if there is none in the resolving stage, not the emitting one.
Consolidated the identical backpatching code of the three loop statement nodes into a subfunction.
- disable generation of the parser's trace file in debug builds.
This increases parsing time by a factor of 15 and is only needed when debugging a problem in the grammar.
- handle all binary operators which are already implemented in the code generator.
- implemented sizeof/alignof operators in code generator.
- rewrote RequestAddress so that its return value is not the writability of an address but the mere existence. Also changed it to not output errors itself because those cannot be dealt with by the calling function.
- added the '>>>' (unsigned shift) operator. Although, with unsigned numbers available, this is technically not really needed, DECORATE supports this so ZScript should, too, if only for the benefit of making conversion tools easier to handle.
- fixed: FxBinary::ResolveLR' check for numeric operations was incomplete. Like far too many other places it just assumed that everything with ValueType->GetRegType() == REGT_INT is a numeric type, but for names this is not the case.
These were previously faked with the inverse plus a boolean not. Although this works, it either leads to sub-optimal code generation or some fudging to avoid the inefficient handling.
Just adding proper handling to the parser seems the easiest and most straightforward way to get around this. The code generator already can deal with these operations properly so there's no good reason to do it differently.
- added a descriptive name to all types for error messages.
- added a generic type cast node to the code generator.
- added a few more cast operations to the 'cast' VM instruction.
- extended FxClassTypeCast to handle all possible input that can be cast to a class pointer, not just names.
ZDoom only uses these types in a very few isolated places, and even those can be removed without problems, so it's very doubtful that having support for these types is of any benefit - on the other hand, having them will most likely introduce more code than is saved in the data by using them...
