IGNORE_DECLARATIONS: Usage?

[per42]

I understand IGNORE_DECLARATIONS prunes typedefs from _fake_typedefs.h, which are anyway deliberately incorrect (fake). But that leaves my cython declarations with undeclared data types:

cdef extern from "components/offset_filter.h":
    ctypedef bool Comp_Success
    cdef struct If_Signal_Array:
        size_t count
        uint16_t items[1]

I still need those types to be declared. They can be dummy since the cython generated c code will include the correct headers. By removing the used types in IGNORE_DECLARATIONS, it almost works:

    ...
    ctypedef int size_t
    ctypedef _Bool bool
    ctypedef int uint16_t
    ...

_Bool needs to be replaced by bint, so I added filter for that in parse(). I noticed by accident that size_t is understood by Cython, but that is undocumented so probably best to typedef to int

    ...
    ctypedef int size_t
    ctypedef bint bool
    ctypedef int uint16_t
    ...

An alternative is to manually prepend the generated pxd with:

cdef extern:
    ctypedef bint _Bool

It seems I am missing some step here. What is the intended usage for dealing with standard types?

[tarruda]

It seems I am missing some step here. What is the intended usage for dealing with standard types?

The idea is that the standard types are already understood by cython, which is why IGNORE_DECLARATION exists.

[per42]

That makes perfect sense. I am new on Cython, but as far as I can tell from the documentation, these types are not standard Cython types. Perhaps it depends on the build, like size_t was available for me.

C:\Users\per.rosengren\code\zforce-application-simulator>\Anaconda2_32\python.exe setup.py build_ext -i --compiler=mingw32
Compiling zforce_app_sim/components/offset_filter.pyx because it changed.
[1/1] Cythonizing zforce_app_sim/components/offset_filter.pyx

Error compiling Cython file:
------------------------------------------------------------
...
cdef extern from "components/offset_filter.h":

    ctypedef bool Comp_Success
            ^
------------------------------------------------------------

zforce_app_sim\api\components\bar.pxd:3:13: 'bool' is not a type identifier

Error compiling Cython file:
------------------------------------------------------------
...
        If_Signals_signalCapacity
        If_TrackedObject_Array_capacity

    cdef struct If_Signal_Array:
        size_t count
        uint16_t items[1]
       ^
------------------------------------------------------------

zforce_app_sim\api\components\bar.pxd:16:8: 'uint16_t' is not a type identifier

With the pyx:

cdef extern from "components/offset_filter.h":

    ctypedef bool Comp_Success

    ctypedef void* Comp_Instance

    cdef enum If_Config:
        If_SyncedScan_programCapacity
        If_SyncedScan_jobCapacity
        If_Frame_syncedCapacity
        If_Signals_signalCapacity
        If_TrackedObject_Array_capacity

    cdef struct If_Signal_Array:
        size_t count
        uint16_t items[1]

    cdef struct If_Signals:
        If_Signal_Array signal
        uint_fast16_t timestamp

    Comp_Success Comp_SignalFilter_SignalsIn(Comp_Instance instance, If_Signals* signal)

    Comp_Success Comp_SignalFilter_SignalsOut(Comp_Instance instance, If_Signals* signal)

    void Comp_OffsetFilter_Run(Comp_Instance instance)

    If_Signal_Array* Comp_OffsetFilter_signalOffsets(Comp_Instance instance)