add and use PyTypeObject_DEREF for dereferencing things

Author: Christopher Doris

src/C/consts.jl

@@ -322,6 +322,70 @@ end
     tp_versions_used::Cushort = 0
 end
 
+# shortened struct for dereferencing purposes, only includes fields common to all
+# supported python versions
+@kwdef struct PyTypeObject_DEREF
+    ob_base::PyVarObject = PyVarObject()
+    name::Cstring = C_NULL  # USED
+
+    basicsize::Py_ssize_t = 0
+    itemsize::Py_ssize_t = 0
+
+    dealloc::Ptr{Cvoid} = C_NULL
+    vectorcall_offset::Py_ssize_t = 0
+    getattr::Ptr{Cvoid} = C_NULL
+    setattr::Ptr{Cvoid} = C_NULL
+    as_async::Ptr{Cvoid} = C_NULL
+    repr::Ptr{Cvoid} = C_NULL
+
+    as_number::Ptr{PyNumberMethods} = C_NULL
+    as_sequence::Ptr{PySequenceMethods} = C_NULL
+    as_mapping::Ptr{PyMappingMethods} = C_NULL
+
+    hash::Ptr{Cvoid} = C_NULL
+    call::Ptr{Cvoid} = C_NULL
+    str::Ptr{Cvoid} = C_NULL
+    getattro::Ptr{Cvoid} = C_NULL
+    setattro::Ptr{Cvoid} = C_NULL
+
+    as_buffer::Ptr{PyBufferProcs} = C_NULL  # KEEP
+
+    flags::Culong = 0  # USED
+
+    doc::Cstring = C_NULL
+
+    traverse::Ptr{Cvoid} = C_NULL
+
+    clear::Ptr{Cvoid} = C_NULL
+
+    richcompare::Ptr{Cvoid} = C_NULL
+
+    weaklistoffset::Py_ssize_t = 0
+
+    iter::Ptr{Cvoid} = C_NULL
+    iternext::Ptr{Cvoid} = C_NULL
+
+    methods::Ptr{PyMethodDef} = C_NULL
+    members::Ptr{PyMemberDef} = C_NULL
+    getset::Ptr{PyGetSetDef} = C_NULL
+    base::PyPtr = C_NULL
+    dict::PyPtr = C_NULL
+    descr_get::Ptr{Cvoid} = C_NULL
+    descr_set::Ptr{Cvoid} = C_NULL
+    dictoffset::Py_ssize_t = 0
+    init::Ptr{Cvoid} = C_NULL
+    alloc::Ptr{Cvoid} = C_NULL  # USED
+    new::Ptr{Cvoid} = C_NULL
+    free::Ptr{Cvoid} = C_NULL # USED
+    is_gc::Ptr{Cvoid} = C_NULL
+    bases::PyPtr = C_NULL
+    mro::PyPtr = C_NULL
+    cache::PyPtr = C_NULL
+    subclasses::PyPtr = C_NULL
+    weaklist::PyPtr = C_NULL
+    del::Ptr{Cvoid} = C_NULL
+end
+
 @kwdef struct PySimpleObject{T}
     ob_base::PyObject = PyObject()
     value::T

src/C/extras.jl

@@ -8,24 +8,24 @@ Py_TypeCheck(o, t) = Base.GC.@preserve o t PyType_IsSubtype(Py_Type(asptr(o)), a
 Py_TypeCheckFast(o, f::Integer) = Base.GC.@preserve o PyType_IsSubtypeFast(Py_Type(asptr(o)), f)
 
 PyType_IsSubtypeFast(t, f::Integer) =
-    Base.GC.@preserve t Cint(!iszero(UnsafePtr{PyTypeObject}(asptr(t)).flags[] & f))
+    Base.GC.@preserve t Cint(!iszero(UnsafePtr{PyTypeObject_DEREF}(asptr(t)).flags[] & f))
 
 PyMemoryView_GET_BUFFER(m) = Base.GC.@preserve m Ptr{Py_buffer}(UnsafePtr{PyMemoryViewObject}(asptr(m)).view)
 
 PyType_CheckBuffer(t) = Base.GC.@preserve t begin
-    p = UnsafePtr{PyTypeObject}(asptr(t)).as_buffer[]
+    p = UnsafePtr{PyTypeObject_DEREF}(asptr(t)).as_buffer[]
     return p != C_NULL && p.get[!] != C_NULL
 end
 
 PyObject_CheckBuffer(o) = Base.GC.@preserve o PyType_CheckBuffer(Py_Type(asptr(o)))
 
 PyObject_GetBuffer(_o, b, flags) = Base.GC.@preserve _o begin
     o = asptr(_o)
-    p = UnsafePtr{PyTypeObject}(Py_Type(o)).as_buffer[]
+    p = UnsafePtr{PyTypeObject_DEREF}(Py_Type(o)).as_buffer[]
     if p == C_NULL || p.get[!] == C_NULL
         PyErr_SetString(
             POINTERS.PyExc_TypeError,
-            "a bytes-like object is required, not '$(String(UnsafePtr{PyTypeObject}(Py_Type(o)).name[]))'",
+            "a bytes-like object is required, not '$(String(UnsafePtr{PyTypeObject_DEREF}(Py_Type(o)).name[]))'",
         )
         return Cint(-1)
     end
@@ -36,7 +36,7 @@ PyBuffer_Release(_b) = begin
     b = UnsafePtr(Base.unsafe_convert(Ptr{Py_buffer}, _b))
     o = b.obj[]
     o == C_NULL && return
-    p = UnsafePtr{PyTypeObject}(Py_Type(o)).as_buffer[]
+    p = UnsafePtr{PyTypeObject_DEREF}(Py_Type(o)).as_buffer[]
     if (p != C_NULL && p.release[!] != C_NULL)
         ccall(p.release[!], Cvoid, (PyPtr, Ptr{Py_buffer}), o, b)
     end

src/JlWrap/C.jl

@@ -21,7 +21,7 @@ const PYJLVALUES = []
 const PYJLFREEVALUES = Int[]
 
 function _pyjl_new(t::C.PyPtr, ::C.PyPtr, ::C.PyPtr)
-    o = ccall(UnsafePtr{C.PyTypeObject}(t).alloc[!], C.PyPtr, (C.PyPtr, C.Py_ssize_t), t, 0)
+    o = ccall(UnsafePtr{C.PyTypeObject_DEREF}(t).alloc[!], C.PyPtr, (C.PyPtr, C.Py_ssize_t), t, 0)
     o == C.PyNULL && return C.PyNULL
     UnsafePtr{PyJuliaValueObject}(o).weaklist[] = C.PyNULL
     UnsafePtr{PyJuliaValueObject}(o).value[] = 0
@@ -35,7 +35,7 @@ function _pyjl_dealloc(o::C.PyPtr)
         push!(PYJLFREEVALUES, idx)
     end
     UnsafePtr{PyJuliaValueObject}(o).weaklist[!] == C.PyNULL || C.PyObject_ClearWeakRefs(o)
-    ccall(UnsafePtr{C.PyTypeObject}(C.Py_Type(o)).free[!], Cvoid, (C.PyPtr,), o)
+    ccall(UnsafePtr{C.PyTypeObject_DEREF}(C.Py_Type(o)).free[!], Cvoid, (C.PyPtr,), o)
     nothing
 end