[PATCH] caret diagnostics

[Tom Tromey]

>>>>> "Joseph" == Joseph S Myers <joseph@codesourcery.com> writes:

Joseph> (b) to print GCS-compliant ranges in text that IDEs can parse
Joseph> to highlight the relevant text in their editors

Joseph> Caret diagnostics are only one of the styles in which the
Joseph> accurate location information can be used, and implementing an
Joseph> individial style is only a small part of the solution.

Yes, I agree, we need multiple things: accurate locations from the
front ends (ideally macro-expansion-aware), start- and end-locations,
better diagnostic output of various kinds, perhaps smarter location
handling in the optimizations, and of course finally column output in
dwarf.  I hope that covers the 80% of stuff we all seem to agree on.

I'm sympathetic to the idea that switching to caret output by default
will break things.  However, I don't think that GCS-style ranges are
necessarily any more reality-proof, because I am skeptical that most
tool developers read this document when deciding how to parse GCC's
output.  (I'm guessing that plain column output is ok, since libcpp
already does that.)

I'd like to see carets on by default as part of a major release -- say
GCC 5.0.  (First mention!!)

Manuel's idea that we should enable column- or caret-output in the
development (but not release) GCC is worthy of consideration.  We
certainly aren't seeing much progress on this front as-is, maybe this
change would inspire GCC developers a bit.  It will also help root out
the non-GCS-complaint tools ;)

Tom