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

[Martin Sebor <msebor at gmail dot com>]

On 02/13/2018 01:59 PM, Manuel López-Ibáñez wrote:
> On 13 Feb 2018 5:58 pm, "Martin Sebor" <msebor@gmail.com
> <mailto:msebor@gmail.com>> wrote:
>
>
>     I wanted to make the _n() functions like warning_n() more
>     robust by letting them accept a tree argument (as well as
>     offset_int and wide_int) in addition to HOST_WIDE_INT but
>     I can't do it if they can't work with these types.
>
>
> There must be a tree-diagnostics.c where you can add those functions and
> then call the general diagnostic functions. Same for RTL.

I don't see how to do that.

Here's a sketch of what I tried to do:

  struct IntegerConverter
  {
    union {
      tree t;
      unsigned HOST_WIDE_INT hwi;
      // buffer for offset_int, wide_int, etc.
    } value;

    IntegerConverter (tree t)
    {
      value.t = t;
    }

    IntegerConverter (unsigned HOST_WIDE_INT x)
    {
      value.x = x;
    }

    ...
  };

  void error_n (int, const IntegerConverter &, const char*, ...);
  ...

With that, the call

  error_n (loc, t, "%E thing", "%E things", t);

works when t is a tree, and the call to the same function

  error_n (loc, i, "%wu thing", "%wu things", i);

also works when i is a HOST_WIDE_INT.  I chose this approach
to avoid introducing additional overloads of the error_n()
functions.

> Note that pretty-printer.c works in the same way.

It works that way for arguments passed through the ellipsis.
I was trying to use tree (indirectly) in the signature of
the _n() functions and for that I need "tree.h" etc. in
diagnostic-core.h and be able to call functions from
the header in diagnostic-core.c.  I suppose I could make
the calls indirectly somehow but I can't avoid including
GCC headers in diagnostic-core.h.

Martin