I was investigating how qcc dealt with field fields and got segfaults
from qfprogs due to the lack of type encodings. While the resulting
output is not guaranteed to be correct (especially if trying to dump
progs compiled by some other extended compiler), at least it's better
than segfaulting or any other UB.
There's still the problem of defining implementations, but this gets a
lot of things working so long as the return type is one of the parameter
types rather than computed.
While much is broken, especially textures, e4m8.map successfully imports
into blender 4.2-ish, and even the entity relation lines seem to work
(which surprised me as those were the first sign of trouble).
And document type expressions to a certain extent. A lot of work needs
to be done as there's a lot of bitrot in the information in the doc (eg,
integer is now int, array declarations, etc).
A working call isn't produced yet, but the generic function does seem to
be selected correctly preferring a minimum of type promotions, though I
suspect I'll need to do more work on the selection process.
Mainly to prevent promotion between different vector and matrix sizes,
but also to be consistent in that double doesn't promote to itself (same
as other scalar types). Also fix up type_rows and type_cols for matrices
and make type_assignable, type_promotes, and type_compatible null-safe
(always false if either src or dst is null).
With this, genFType and genDType functions are now treated separately
and expanding to all components (single row or column matrices are not
supported (at this stage, anyway) for generic parameters).
That is, `@generic(...) { ... };`, which is handy for bulk declarations
(such as for glsl). This proved to be a lot harder than expected, I
suspect handling of specifiers needs a lot of work.
I never did like all those cryptic parameters, especially when they were
just 0 and 1. Now the individual specifier creation functions take only
those parameters they need (if any) and there's no possibility of
conflicting parameters. Also, it's clearer what the new specifier does.
It doesn't properly differentiate between (treats genDType as being the
same as genFType):
@generic(genFType=@vector(float)) genFType radians(genFType degrees);
@generic(genDType=@vector(double)) genDType radians(genDType degrees);
but this is due to problems with how the type is built from
@vector(float) and @vector(double). However, I thought it was about time
I got some of this into git.
Also, `@generic(...) { ... };` blocks don't work properly (they lose the
generic info): need to get a little smarter about handling generic scope
in `external_def_list`.
This fits in nicely with the rest of the generic type system and makes
it a little more useful. The idea is it will take a return type (already
does since type functions always require a parameter at this stage) and
a parameter list (not implemented yet). It currently resolves to the
basic void (...) function type for QC.
It turns out they're not needed as the difficulty of quakec function
declarations (function fields) is taken care of by qc_function_spec.
Also, they made it difficult to think about function declarations.
While they might be ok, I expect them to cause some issues when doing
compile-time evaluations of type expressions, so use of dags seems to be
a premature optimization. However, as the "no dags" flag is propagated
to parent expression nodes, it may prove useful in other contexts.
The expression grammar has been tidied up and some basic checks are made
of parameters to the type functions. Also, type parameters are looked up
so parsing now works properly. However, the type parameters are not used
correctly, so function generation doesn't work.
The semantics are only partially implemented (generic types not yet
generated), but the generic scope for function declarations seems to be
working as intended in that it gets inserted in the scope chain and
removed at the end of the declaration.
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).
