diagonalize_list.c

qcc crashes when using the diagonalize macro with a list of scalars

qcc crashes when using the diagonalize macro with a list of scalars

The following macro:

macro testdiag (scalar a, double expr)
{
    foreach() {
        double _d;
        diagonalize(a)
            _d = expr;
        a[] *= _d ;
    }
}

can be called with success with, e.g.:

testdiag (u, u[1] + u[-1] - 2.*u[]);

However, writing:

macro testdiag_list (scalar * list, double * expr)
{
    foreach() {
        for (int i = 0; i < list_len (list); i++) {
            scalar a = list[i];
            double _d;

the argument of diagonalize() must be a simple identifier

            diagonalize(a) // comment this line to avoid qcc segfault
                _d = expr[i];
            a[] *= _d ;
        }
    }
}

results in qcc segfaulting when called with:

scalar * list_scalars = {u};
testdiag_list (list_scalars, (double[]){u[1] + u[-1] - 2.*u[]});

int main()
{
    init_grid (16);
    periodic (right);
    scalar u[];

    foreach()
        u[] = 1.;

    scalar * list_scalars = {u};

    testdiag (u, u[1] + u[-1] - 2.*u[]);
    testdiag_list (list_scalars, (double[]){u[1] + u[-1] - 2.*u[]});
}