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from __future__ import print_function
import cffi
ffi = cffi.FFI()
ffi.cdef("""
int my_algo(int);
typedef ... va_list;
extern "Python" int f(int, va_list *);
int fetch_int(va_list *);
double fetch_double(va_list *);
void *fetch_ptr(va_list *);
""")
ffi.set_source("_extern_python_cffi", """
#include <stdarg.h>
static int f(int, va_list *);
static int f1(int n, ...)
{
va_list ap;
va_start(ap, n);
int res = f(n, &ap);
va_end(ap);
return res;
}
static int fetch_int(va_list *va) { return va_arg((*va), int); }
static double fetch_double(va_list *va) { return va_arg((*va), double); }
static void * fetch_ptr(va_list *va) { return va_arg((*va), void *); }
static int my_algo(int n) {
return f1(3, n, n+1, n+2) + f1(1, &n) + f1(2, 12.3, 45.6);
}
""")
ffi.compile()
from _extern_python_cffi import ffi, lib
@ffi.def_extern()
def f(n, va):
if n == 3:
x = lib.fetch_int(va)
y = lib.fetch_int(va)
z = lib.fetch_int(va)
print(x, y, z)
elif n == 1:
ptr = lib.fetch_ptr(va)
print('ptr to:', ffi.cast("int *", ptr)[0])
elif n == 2:
x = lib.fetch_double(va)
y = lib.fetch_double(va)
print(x, y)
else:
raise AssertionError(n)
return 14
print(lib.my_algo(10))
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