Re: [PATCH] C++: avoid most reserved words as misspelling suggestions (PR c++/81610 and PR c++/80567)

[David Malcolm <dmalcolm at redhat dot com>]

On Mon, 2017-12-11 at 17:24 -0500, Jason Merrill wrote:
> On Wed, Nov 22, 2017 at 10:36 AM, David Malcolm <dmalcolm@redhat.com>
> wrote:

Original post:
  https://gcc.gnu.org/ml/gcc-patches/2017-11/msg02048.html

> > PR c++/81610 and PR c++/80567 report problems where the C++
> > frontend
> > suggested "if", "for" and "else" as corrections for misspelled
> > variable
> > names.

I've now marked these PRs as regressions: the nonsensical suggestions
are only offered by trunk, not by gcc 7 and earlier.

> Hmm, what about cases where people are actually misspelling keywords?
> Don't we want to handle that?
> 
> fi (true) { }
> retrun 42;

I'd prefer not to.

gcc 7 and earlier don't attempt to correct the spelling of the "fi" and
"retrun" above.

trunk currently does offer "return" as a suggestion, but it was by
accident, and I'm wary of attempting to support these corrections: is
"fi" meant to be an "if", or a function call that's missing its decl,
or a name lookup issue?  ...etc

> In the PRs you mention, the actual identifiers are 1) missing
> includes, which we should check first, and 2) pretty far from the
> suggested keywords.

The C++ FE is missing a suggestion about which #include to use for
"memset", but I'd prefer to treat that as a follow-up patch (and
probably for next stage 1).

In the meantime, is this patch OK for trunk? (as a regression fix)

Thanks
Dave