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

[Jason Merrill <jason at redhat dot com>]

On Wed, Feb 7, 2018 at 1:12 PM, David Malcolm <dmalcolm@redhat.com> wrote:
> On Wed, 2018-02-07 at 12:21 -0500, Jason Merrill wrote:
>> On Fri, Jan 26, 2018 at 1:12 PM, David Malcolm <dmalcolm@redhat.com>
>> wrote:
>> > 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)
>>
>> Yes.
>
> Thanks; committed (r257456).
>
> FWIW, I've filed PR c++/84269 so I remember to fix the missing
> suggestion for "memset" (in gcc 9 stage1).

Did you have a reaction to my comment about the suggested keyword
being pretty far from the actual identifier?  Do we want to lower the
cutoff for suggestions at all?

Jason