[PATCH] D44883: [Sema] Extend -Wself-assign and -Wself-assign-field to warn on overloaded self-assignment (classes)

[John McCall via Phabricator via cfe-commits]

rjmccall added inline comments.


================
Comment at: lib/Sema/SemaExpr.cpp:12093
+    break;
+  }
+
----------------
lebedev.ri wrote:
> rjmccall wrote:
> > I think doing this here can result in double-warning if the overload resolves to a builtin operator.  Now, it might not actually be possible for that to combine with the requirements for self-assignment, but still, I think the right place to diagnose this for C++ is the same place we call DiagnoseSelfMove in CreateOverloadedBinOp.
> > 
> > Can CheckIdentityFieldAssignment just be integrated with DiagnoseSelfAssignment so that callers don't need to do call both?
> > I think the right place to diagnose this for C++ is the same place we call DiagnoseSelfMove in CreateOverloadedBinOp.
> 
> ```
>         switch (Opc) {
>         case BO_Assign:
>         case BO_DivAssign:
>         case BO_SubAssign:
>         case BO_AndAssign:
>         case BO_OrAssign:
>         case BO_XorAssign:
>           DiagnoseSelfAssignment(Args[0], Args[1], OpLoc);
>           CheckIdentityFieldAssignment(Args[0], Args[1], OpLoc);
>           break;
>         default:
>           break;
>         }
> 
>         // Check for a self move.
>         if (Op == OO_Equal)
>           DiagnoseSelfMove(Args[0], Args[1], OpLoc);
> ```
> 
> 
> ^ That does not appear to work. Pretty much all these tests start to fail.
> 
Okay.  It's possible that my suggestion is wrong.  Can you explain more how they fail?


Repository:
  rC Clang

https://reviews.llvm.org/D44883