Re: Updated GCC vs Clang diagnostics

[Lawrence Crowl <crowl@google.com>]

On 4/12/12, Ian Lance Taylor <iant@google.com> wrote:
> Lawrence Crowl <crowl@google.com> writes:
> > On 4/12/12, Manuel López-Ibáñez <lopezibanez@gmail.com> wrote:
> > > So given your ideal implementation, if the user-visible
> > > result was exactly like the one in Clang, will you be happy
> > > with any of the three things: ranges, color and fix-it hints?
> >
> > There are many issues with color.  Does your reader have
> > any color deficiencies?  Does your software address them?
> > Does the system software render colors well?  Is color contrast
> > sufficient?  Is greyscale contrast sufficient?  Color is low
> > on my list of desirables.
>
> It would be terrible if an error message could not be understood
> without color.  But nobody is suggesting that.

Agreed, no one is suggesting that.

However, without care, the message might be harder to understand
_with_ color.  At a minimum, one should be able to turn the
color off.  As I understand it, that option is in the plan.

> The question at hand is whether color can be used to enhance an
> error message that can be understood without color.  For example,
> whether color can be added to current error messages without any
> other changes.

Yes, color can enhance the messages.  I don't think we disagree
on that.  My point was that color is a harder problem that many
people understand.  For instance, there is no set of colors that
meet web contrast standards against both black and white backgrounds.

As I understand the plan, the colors will be user-configurable,
which goes a long way to addressing the problem because the user
can choose colors that work for them.  It would be nice if the
default configuration worked for a large set of folks.

> I personally think it would be an excellent idea.  Even clang's C++
> error messages can be long.  A simple use of color is an excellent
> way to draw the eye to the more important parts of the message.
> If the color is not available, then it doesn't help, but the
> error message can be understood without it.

Let me try to be clear.  I have no objection to the work as long as
I can turn it off.  If the issues I mention above are unaddressed,
it is likely that I will turn it off, which is why the feature is
low on my list of desirables.  If other folks desire it, I'm happy
to let them have it.  I'm even happy to add an environment variable
so that they can have it.  But, responding to the survey question,
for me color is not a priority.

-- 
Lawrence Crowl