Segmentation fault ./forsp examples/demo.fp

[clvBerlin]

The problem
Using gcc (Ubuntu 15.2.0-16ubuntu1) 15.2.0 under WSL of Windows11 with the forsp demo.fp I got a segmentation fault.

I'm quite sure, that lots of compiler versions and forsp programs will show the same problem.

The solution
I fixed read_list as follows:
...

  obj_t *evaluate_first = read();
  return make_pair(evaluate_first, read_list());
  // return make_pair(read(), read_list());

The reason
The order of evaluation is unspecified in C. So even the next compiler version on the same platform might decide to evaluate read_list before evaluating read. This leads to a stack overflow which in turn leads to undefined behaviour.