Re: error messages with ranges

[Chris Lattner]

On Oct 16, 2009, at 9:51 AM, Gabriel Dos Reis wrote:

> On Fri, Oct 16, 2009 at 3:47 AM, Richard Stallman <address@hidden> wrote:
> > How about something like this:
> >
> >    exprs.c:47:15: error: invalid operands to binary expression  
> > ('int *' and '_Complex float')
> >    ::Argument locations: 47:8-47:14, 47:17-47:24
> >
> > If the brace notation you've proposed becomes a de facto standard,
> > we may as well go along with it.  But I think this proposal
> > is better intrinsically, since it is less clutter and no harder to  
> > parse.
>
> I like the non-braced version.
>
> However, I would like you clarify the '::Argument locations:' marker.
> Do you intend the double colons '::' as token to introduce
> some form of meta data for tools? (In this case, it is to introduce
> locus, but is it an escape for more general tags?)

FWIW, clang uses ranges for a lot of things other than arguments.

Here are some other examples:

$ clang -fsyntax-only t.c
  t.c:12:8: error: called object type 'int' is not a function or  
function pointer
  (P-Q)();
  ~~~~~^
$ clang t.c
t.c:5:28: warning: use of GNU old-style field designator extension
struct point origin = { x: 0.0, y: 0.0 };
                        ~~ ^
                        .x =

This is probably mangled by my email client, but you can see examples  
as intended here:
http://clang.llvm.org/diagnostics.html

The brace sequence is not normally seen by humans, only by IDEs and  
tools.  It being terse and simple is important, but beauty is not very  
important.

-Chris