[PATCH] D149154: [clang][Interp] Emit diagnostic when comparing function pointers

[Aaron Ballman via Phabricator via cfe-commits]

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

LGTM



================
Comment at: clang/lib/AST/Interp/Interp.h:652-653
+  const SourceInfo &Loc = S.Current->getSource(OpPC);
+  S.FFDiag(Loc, diag::note_constexpr_pointer_comparison_unspecified)
+      << LS << RS;
+  return false;
----------------
tbaeder wrote:
> aaron.ballman wrote:
> > Can we pass in the result of `getType()` instead of doing this string conversion dance?
> Well the diagnostic doesn't print the result of the LHS/RHS:
> ```
> ./array.cpp:202:18: error: constexpr variable 'u13' must be initialized by a constant expression
>   202 |   constexpr bool u13 = pf < pg; // ref-warning {{ordered comparison of function pointers}}
>       |                  ^     ~~~~~~~
> ./array.cpp:202:27: note: comparison between '&f' and '&g' has unspecified value
>   202 |   constexpr bool u13 = pf < pg; // ref-warning {{ordered comparison of function pointers}}
>       |                           ^
> ```
> 
> I'm not exactly a fan of how the code looks though. I might add a helper function for this later.
Ah of course, good point. And yeah, a helper function for this would probably not be a bad idea.


Repository:
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  https://reviews.llvm.org/D149154/new/

https://reviews.llvm.org/D149154