The only remaining explicit use of `typedef` in the codegen (from my
search) is in `addForwardStructFormat` which from what I understand
won't do anything in NIFC.
The remaining followup from #24259. A body for building the type doesn't
seem necessary here since the types with array fields are generally
atomic/already built from `getTypeDescAux`.
follows up #24259
This is the remaining missing use of `StructInitializer` in
`getDefaultValue` after #24259 and #24302. The only remaining direct C
code in getDefaultValue is [this
line](922f7dfd71/compiler/ccgexprs.nim (L3525))
which creates a global array variable, which isn't implemented yet. Next
steps would be all remaining variable and `typedef` declarations, then
hopefully we can move on to general statements and expressions.
`StructInitializer` is now used for most braced initializers in the C
generation, mostly in `genBracedInit`, `getNullValueAux`,
`getDefaultValue`. The exceptions are:
* the default case branch initializer for objects uses C99 designated
initializers with field names, which are not implemented for
`StructInitializer` yet (`siNamedStruct`)
* the uses in `ccgliterals` are untouched so all of ccgliterals can be
done separately and in 1 go
There is one case where `genBracedInit` does not use cbuilder, which is
the global literal variable for openarrays. The reason for this is
simply that variables with C array type are not implemented, which I
thought would be best to leave out of this PR.
For the simplicity of the implementation, code in `getNullValueAuxT`
that reset the initializer back to its initial state if the `Sup` field
did not have any fields itself, is now disabled. This was so the
compiler does not generate `{}` for the Sup field, i.e. `{{}}`, but
every call to `getNullValueAuxT` still generates `{}` if the struct
doesn't have any fields, so I don't know if it really breaks anything.
The case where the Sup field doesn't have any fields but the struct does
also would have generated `{{}, field}`.
Worst case, we can implement either the "resetting" or just disable the
generation of the `Sup` field if there are no fields total. But a better
fix might be to always generate `{0}` if the struct has no fields, in
line with the `char dummy` field that gets added for all objects with no
fields. This doesn't seem necessary for now but might be for the NIFC
output, in which case we can probably keep the logic contained inside
cbuilder (if no fields generated for `siOrderedStruct`/`siNamedStruct`,
we add a `0` for the `dummy` field). This would stipulate that all uses
of struct initializers are exhaustive for every field in structs.
The only remaining use of `struct` after this is in
`genConstSeq`/`genConstSeqV2` which use `genBracedInit`, I figured these
should be done in the PR that adapts `genBracedInit` in general to
cbuilder.
`cbuilder` is now split into `cbuilderbase`, `cbuilderexprs`,
`cbuilderdecls`, with all the struct builder code up to this point going
in `cbuilderdecls`.
Variable builders are added, with local, global and constant variables
implemented, but not threadvars.
A builder for struct (braced) initializers is added. The field names
have to be passed to build each field (so they can be used in `oconstr`
in nifc), but they're not used in the output code if a flag
`orderCompliant` is enabled, which means the initializer list is
generated in order of the built fields. The version which uses the names
on C is not implemented (C99 designated initializers), so this flag has
to be enabled for now.
The struct builders now generate the struct as an inline expression if a
name isn't provided rather than a statement. This means we can now use
`addSimpleStruct` etc for the type of fields, but we can't replace
`addFieldWithStructType` because of `#pragma pack(pop)`.
Doc comments are added to every usable proc but may still not be
sufficient.
