[PATCH] D104892: [clang] Stop providing builtin overload candidate for relational function pointer comparisons

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith accepted this revision.
rsmith added a comment.
This revision is now accepted and ready to land.

A couple of comments on test coverage but otherwise this looks great, thanks! It'll be instructive to see if people ask for the warning to not be on by default...



================
Comment at: clang/test/CXX/expr/expr.const/p2-0x.cpp:517
   constexpr void (*pf)() = &f, (*pg)() = &g;
-  constexpr bool u13 = pf < pg; // expected-error {{constant expression}} expected-note {{comparison has unspecified value}}
-  constexpr bool u14 = pf == pg;
----------------
Can you undo this change now? We should retain some test coverage ensuring that we fail constant evaluation in this case.


================
Comment at: clang/test/FixIt/fixit.cpp:298-303
     (void)(&t<int>==p); // expected-error {{use '> ='}}
-    (void)(&t<int>>=p); // expected-error {{use '> >'}}
 #if __cplusplus < 201103L
-    (void)(&t<S<int>>>=p); // expected-error {{use '> >'}}
     (Shr)&t<S<int>>>>=p; // expected-error {{use '> >'}}
 #endif
----------------
We should retain some test coverage that we produce a proper fixit when splitting `>>=` into `>` `>=`. If you want to move this test away from function pointer comparison, we can test the same thing with variable templates these days.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D104892/new/

https://reviews.llvm.org/D104892