Re: [Bug-gnulib] too many FOO_exit_failure variables

[Bruno Haible]

Paul Eggert wrote:

>         xalloc_exit_failure = 2;
>         xmemcoll_exit_failure = 2;
>
> This doesn't scale well as the number of modules grows.

Sure it does. O(N) lines of code for N modules. If it were O(N^2) I'd
agree that it doesn't scale well.

> How about if we have just a single exit_failure variable, so that
> programs worried about fatal-error exit status can set just that
> variable.

How could this accomodate programs which consider xmalloc() failures
fatal - there's no way to continue if memory is tight - but which
want to gracefully recover from xmemcoll() failures?

Right now you can set

           xalloc_exit_failure = 2;
           xmemcoll_exit_failure = 0;

to achieve this behaviour (and add some fallback code to xmemcoll.c
for this case). With a single exit_failure variable, you can't.


An alternative to such a global *_exit_failure variable per module is
[except for 'xalloc'] to pass the desired error handling behaviour as an
argument. Like this (in the 'pipe' module):

extern pid_t create_pipe_out (const char *progname,
                              const char *prog_path, char **prog_argv,
                              const char *prog_stdout, bool null_stderr,
                              bool exit_on_error,
                              int fd[1]);

The idea here is that the callee provides the error message but the
caller determines whether error(0, ...) or error(EXIT_FAILURE, ...)
is called.

Bruno