[PATCH] adjust warning_n() to take uhwi (PR 84207)

[Manuel López-Ibáñez]

On 14 Feb 2018 8:16 pm, "Pedro Alves" <palves@redhat.com> wrote:

Instead of a class that has to have a constructor for every type
you want to pass as plural selector to the _n functions, which
increases coupling, I'd suggest using a conversion function, and
overload that.  I.e., something like, in the core diagnostics code:

static inline unsigned HOST_WIDE_INT
as_plural_form (unsigned HOST_WIDE_INT val)
{
  return val;
}

/* In some tree-diagnostics header.  */

static inline unsigned HOST_WIDE_INT
as_plural_form (tree t)
{
   // extract & return a HWI
}

/* In some whatever-other-type-diagnostics header.  */

static inline unsigned HOST_WIDE_INT
as_plural_form (whatever_other_type v)
{
   // like above
}

and then you call error_n and other similar functions like this:

    error_n (loc, u, "%u thing", "%u things", u);
    error_n (loc, as_plural_form (u), "%u thing", "%u things", u);
    error_n (loc, as_plural_form (t), "%E thing", "%E things", t);
    error_n (loc, as_plural_form (i), "%wu thing", "%wu things", i);

This is similar in spirit to std::to_string, etc.


If that's desired, why not simply have GCC::to_uhwi() ? It would likely be
useful in other contexts.

Cheers,

Manuel.