Using a struct with function pointers instead of switching on an enum
makes it much easier to add languages and, more importantly,
sub-languages like glsl's shader stage variants.
The end goal is to allow generic and/or template functions, but this
allows types to be specified parametrically, eg vectors of specific type
and width, with widths of one becoming scalars.
Matrices are currently completely broken as I haven't decided on how to
represent the columns (rows is represented by width (column-major
storage)), and bools are only partially supported (need to sort out
32-bit vs 64-bit bools).
No semantics yet, but qfcc can parse some of QF's shaders. The grammar
mostly follows that in the OpenGL Shading Language, Version 4.60.7 spec,
but with a few less tokens.
This gets the types such that either there is only one definition, or C
sees the same name for what is essentially the same type despite there
being multiple local definitions.
It just feels cleaner than unnecessarily copying token chains. It turns
out that the core problem was just order of operations in next_token:
moving the pending_macro code to after arg/macro detection seems to be
correct (even bare `G LPAREN() 0)` is *not* expanding `G`, as expected).
I got tired of the way the separate token types for macro expansion and
the rest of the preprocessor parser were handled. This makes them a
little more unified. Macro expansion seems to be slightly broken again
in that min/max/bound mess up badly, and __VA_OPT__ does things in the
wrong order, but I wanted to get this in as a checkpoint.
__VA_ARGS__ seems to be working but __VA_OPT__ still needs a lot of work
for dealing with its expansions, but basic error checking and simple
expansions seem to work.
Macros now store their arguments and have a cursor pointing to the next
token to take from their expansion list. While not checked yet, this
will make avoiding recursive macro invocations much easier. More
importantly, it's a step closer to correct argument expansion (though
token pasting is currently broken).
Or at least mostly so. The __QFCC__ define isn't visible, and it seems
undef might not be working properly (ruamoko/lib/types.r doesn't
compile). Of course, there's still the issue of whether it's compiling
correctly.
Really, function-type macros expand too, but incorrectly as the
parameters are not parsed and thus not expanded, but this gets the basic
handling implemented, including # and ## processing.
This will be used for unifying preprocessing and parsing, the idea being
that the tokens will be recorded for later expansion via macros, without
the need to retokenize.
