A struct declaration with variables is now absorbed into the 'declaration'
rule, like any other variable declaration.
A struct declaration without variables is now reduced to the
'struct_declaration_without_vars' rule.
They both are reduced to a 'declaration_statement' in the end.
In a declaration with multiple variables, the variables must be created
before the initializer of the next variable is parsed. This is required
for initializers such as:
float a = 1, b = a, c = b + 1;
A requisite for this is that the type information is parsed in the same
rule as the first variable (as a variable_def_typed) so it is
immediately available to declare the first variable. Then, the next
untyped variable declaration is parsed, and the type from the first
variable can be used to declare the second, before the third is parsed,
and so on.
Basically, declare_vars() is separated in three functions:
1. check_invalid_in_out_modifiers(), which is to be called once per
declaration and emits an error when in or out modifiers are used for
these non-parameter variables.
2. declare_var(), which now handles one variable at the time and doesn't
free any memory.
3. initialize_vars(), which takes care of preparing the initialization
instructions of several variables and frees their struct
parse_variable_def, using exclusively free_parse_variable_def().
This allows to declare variables individually before the initializer of
the next variable in the same declaration is parsed, which is used in
the following patches.
Also, simplifies memory management.
In SM1 we can expect all variables to always belong to a single regset.
structs in particular, should always be allocated to HLSL_REGSET_NUM,
since they are only allowed if all their components are numeric.
We are not covering the structs case because of the use of
hlsl_type_get_regset(), which is currently not defined for structs.
So the current shader
struct
{
float4 a;
float4 b;
} apple;
float4 main() : sv_target
{
return apple.a + apple.b;
}
fails with
vkd3d/libs/vkd3d-shader/hlsl.c:224: Aborting, reached unreachable code.
The solution is to iterate over all regsets to find the one where the
variable is allocated (if any), and ignore all others.
This only affects clip and cull distances. The HLSL compiler emits these using
dcl_input, but the previous shader (vertex or TES) will write them as a SPIRV
builtin, and hence we want to read this as a SPIRV builtin as well.
This fixes validation errors in Wine's test_clip_distance().
lower_narrowing_casts() currently creates a new cast calling
hlsl_new_cast(). This cast may be redundant, but it is not folded, which
is making SM1 emit an unnecessary fixme in some shaders:
Aborting due to not yet implemented feature: SM1 "cast" expression.
Other passes that call hlsl_new_cast() are lower_int_division() and
lower_int_modulus(), so the new fold_redundant_casts() pass is called
after these as well.
