A test was recently added to the SWIG test suite that checks if overflows are correctly detected. It was added for guile, which allows arbitrarily big integers, so a check if the integer is inside the range of a long is possible. Since the scheme languages in SWIG share a lot of code, the test was added for chicken as well. But the test currently fails, and I am wondering how to proceed.
Currently, SWIG chicken accepts either a fixnum or a flonum to any integer parameter, and does no checking at all for overflow. (It uses C_num_to_int to convert. Thus, a direct cast from int to double.) The question is, which types (if any) should SWIG check for overflow? Testing for the double/flonum -> long overflows could be made, using something like double arg1d = C_flonum_magnitude(scm1); if ((double)C_WORD_MIN > arg1d || (double)C_WORD_MAX < arg1d) SWIG_Chicken_Barf(...) int arg1 = (int) arg1d; Also, casts from fixnums to shorts could also be checked for overflow. Casts from fixnums to ints or longs would not check for overflow... since any overflow chicken would convert to a flonum. Or, we could skip overflow detection and leave the code like it is right now. In that case, I would remove the tests for overflow from the chicken portion of the test suite. John PS: I recently commited some changes to configure.in to no longer check chicken-config and use csc instead. _______________________________________________ Chicken-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/chicken-users
