pocketpy/include/pocketpy/cffi.h

#pragma once

#include "common.h"
#include "vm.h"
#include "_generated.h"

namespace pkpy {

#define PY_CLASS(T, mod, name)                  \
    static Type _type(VM* vm) {                 \
        PK_LOCAL_STATIC const std::pair<StrName, StrName> _path(#mod, #name); \
        return PK_OBJ_GET(Type, vm->_modules[_path.first]->attr()[_path.second]); \
    }                                                                       \
    static void _check_type(VM* vm, PyObject* val){                         \
        if(!vm->isinstance(val, T::_type(vm))){                             \
            vm->TypeError("expected '" #mod "." #name "', got " + OBJ_NAME(vm->_t(val)).escape());  \
        }                                                                   \
    }                                                                       \
    static PyObject* register_class(VM* vm, PyObject* mod, Type base=0) {   \
        if(OBJ_NAME(mod) != #mod) {                                         \
            Str msg = fmt("register_class() failed: ", OBJ_NAME(mod), " != ", #mod); \
            throw std::runtime_error(msg.str());                            \
        }                                                                   \
        PyObject* type = vm->new_type_object(mod, #name, base);             \
        T::_register(vm, mod, type);                                        \
        return type;                                                        \
    }                                                                       

#define VAR_T(T, ...) vm->heap.gcnew<T>(T::_type(vm), __VA_ARGS__)

struct VoidP{
    PY_CLASS(VoidP, c, void_p)

    void* ptr;
    VoidP(const void* ptr): ptr(const_cast<void*>(ptr)){}

    bool operator==(const VoidP& other) const {
        return ptr == other.ptr;
    }
    bool operator!=(const VoidP& other) const {
        return ptr != other.ptr;
    }
    bool operator<(const VoidP& other) const { return ptr < other.ptr; }
    bool operator<=(const VoidP& other) const { return ptr <= other.ptr; }
    bool operator>(const VoidP& other) const { return ptr > other.ptr; }
    bool operator>=(const VoidP& other) const { return ptr >= other.ptr; }

    Str hex() const{
        std::stringstream ss; // hex
        ss << std::hex << reinterpret_cast<intptr_t>(ptr);
        return "0x" + ss.str();
    }

    static void _register(VM* vm, PyObject* mod, PyObject* type);
};

inline PyObject* py_var(VM* vm, const void* p){
    return VAR_T(VoidP, p);
}

#define POINTER_VAR(Tp, NAME)    \
    inline PyObject* py_var(VM* vm, Tp val){    \
        const static std::pair<StrName, StrName> P("c", NAME);      \
        PyObject* type = vm->_modules[P.first]->attr(P.second);     \
        return vm->heap.gcnew<VoidP>(PK_OBJ_GET(Type, type), val);  \
    }

POINTER_VAR(char*, "char_p")
// const char* is special, need to rethink about it
POINTER_VAR(const unsigned char*, "uchar_p")
POINTER_VAR(const short*, "short_p")
POINTER_VAR(const unsigned short*, "ushort_p")
POINTER_VAR(const int*, "int_p")
POINTER_VAR(const unsigned int*, "uint_p")
POINTER_VAR(const long*, "long_p")
POINTER_VAR(const unsigned long*, "ulong_p")
POINTER_VAR(const long long*, "longlong_p")
POINTER_VAR(const unsigned long long*, "ulonglong_p")
POINTER_VAR(const float*, "float_p")
POINTER_VAR(const double*, "double_p")
POINTER_VAR(const bool*, "bool_p")

#undef POINTER_VAR


struct C99Struct{
    PY_CLASS(C99Struct, c, struct)

    static constexpr int INLINE_SIZE = 24;

    char _inlined[INLINE_SIZE];
    char* p;
    int size;

    C99Struct(int new_size, bool zero_init=true){
        this->size = new_size;
        if(size <= INLINE_SIZE){
            p = _inlined;
        }else{
            p = (char*)malloc(size);
        }
        if(zero_init) memset(p, 0, size);
    }

    C99Struct(void* p, int size): C99Struct(size, false){
        if(p != nullptr) memcpy(this->p, p, size);
    }

    C99Struct(const C99Struct& other): C99Struct(other.p, other.size){}
    ~C99Struct(){ if(p!=_inlined) free(p); }

    static void _register(VM* vm, PyObject* mod, PyObject* type);
};

static_assert(sizeof(Py_<C99Struct>) <= 64);
static_assert(sizeof(Py_<Tuple>) <= 64);

/***********************************************/
template<typename Tp>
Tp to_void_p(VM* vm, PyObject* var){
    static_assert(std::is_pointer_v<Tp>);
    if(var == vm->None) return nullptr;     // None can be casted to any pointer implicitly
    VoidP& p = CAST(VoidP&, var);
    return reinterpret_cast<Tp>(p.ptr);
}
/*****************************************************************/
void add_module_c(VM* vm);

}   // namespace pkpy