unix/modffi: Support passing float/double args.

tests/unix/ffi_float.py

@@ -24,3 +24,11 @@ print('%.6f' % strtof('1.23', None))
 
 strtod = libc.func("d", "strtod", "sp")
 print('%.6f' % strtod('1.23', None))
+
+# test passing double and float args
+libm = ffi_open(('libm.so', 'libc.so.0', 'libc.so.6', 'libc.dylib'))
+tgamma = libm.func('d', 'tgamma', 'd')
+tgammaf = libm.func('f', 'tgammaf', 'f')
+for fun in (tgamma, tgammaf):
+    for val in (0.5, 1, 1.0, 1.5, 4, 4.0):
+        print('%.6f' % fun(val))

tests/unix/ffi_float.py.exp

@@ -1,2 +1,14 @@
 1.230000
 1.230000
+1.772454
+1.000000
+1.000000
+0.886227
+6.000000
+6.000000
+1.772454
+1.000000
+1.000000
+0.886227
+6.000000
+6.000000

unix/modffi.c

@@ -356,6 +356,14 @@ STATIC mp_obj_t ffifunc_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw,
         mp_obj_t a = args[i];
         if (*argtype == 'O') {
             values[i] = (ffi_arg)a;
+        #if MICROPY_PY_BUILTINS_FLOAT
+        } else if (*argtype == 'f') {
+            float *p = (float*)&values[i];
+            *p = mp_obj_get_float(a);
+        } else if (*argtype == 'd') {
+            double *p = (double*)&values[i];
+            *p = mp_obj_get_float(a);
+        #endif
         } else if (a == mp_const_none) {
             values[i] = 0;
         } else if (MP_OBJ_IS_INT(a)) {