aaron.ballman added inline comments.
================
Comment at: clang/test/SemaCXX/cxx2b-deducing-this.cpp:192
+ f(); // expected-error{{call to non-static member function
without an object argument}}
+ f(Over_Call_Func_Example{}); // expected-error{{call to non-static
member function without an object argument}}
+ Over_Call_Func_Example{}.f(); // ok
----------------
aaron.ballman wrote:
> cor3ntin wrote:
> > aaron.ballman wrote:
> > > cor3ntin wrote:
> > > > aaron.ballman wrote:
> > > > > Errr, this diagnostic seems likely to be hard for users to act on:
> > > > > this non-static member function has an object argument! And it's even
> > > > > the right type!
> > > > >
> > > > > If the model for the feature is "these are just static functions with
> > > > > funky lookup rules", I kind of wonder if this should be accepted
> > > > > instead of rejected. But if it needs to be rejected, I think we
> > > > > should have a better diagnostic, perhaps along the lines of "a call
> > > > > to an explicit object member function cannot specify the explicit
> > > > > object argument" with a fix-it to remove that argument. WDYT?
> > > > UGH, phab is confused, I'm no longer sure which diag you are concerned
> > > > about...
> > > ```
> > > static void h() {
> > > f(); // expected-error{{call to non-static member function
> > > without an object argument}}
> > > f(Over_Call_Func_Example{}); // expected-error{{call to
> > > non-static member function without an object argument}}
> > > Over_Call_Func_Example{}.f(); // ok
> > > }
> > > ```
> > > from around line 214 in the latest patch; the second error seems hard to
> > > understand because there is an object argument being passed, it's just
> > > not the form allowed.
> > You have a rewording suggestion?
> How about we split it into two diagnostics:
> ```
> static void h() {
> f(); // expected-error{{call to non-static member function without an
> object argument}}
> f(Over_Call_Func_Example{}); // expected-error{{cannot pass an explicit
> object as an argument to the call; did you mean to use '.'?}}
> Over_Call_Func_Example{}.f(); // ok
> }
> ```
> the idea being: if the call is to an explicit object function and the user
> provided an extra argument to the call whose type and position matches the
> explicit object parameter, we tell the users "that's now how you use this"
> and best-case give them a fix-it to move the argument to before the call and
> add a `.`?
@cor3ntin and I discussed this suggestion off-list and came to the conclusion
that it would be ideal to improve the error here (and perhaps have a note that
points to the `this` in the declaration of `f()` + a fixit) but it would be
difficult to come up with a heuristic for in all cases. Consider a declaration
like `void f(this auto, Over_Call_Func_Example);` which is called with
`f(Over_Call_Func_Example{});` from within a static function as a corollary
test case to the above.
Let's punt on this for now.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D140828/new/
https://reviews.llvm.org/D140828
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
