[PATCH] D71576: [c++20] Add deprecation warnings for the expression forms deprecated by P1120R0.

[Reid Kleckner via Phabricator via cfe-commits]

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

I have no blocking concerns, just some idle thoughts. Up to you if you want Aaron's feedback before landing.



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Comment at: clang/include/clang/Basic/DiagnosticSemaKinds.td:6235
+  "%plural{2:with|4:from|:and}0 "
+  "%select{enumeration|floating-point}1 type %3 is deprecated">,
+  InGroup<DeprecatedEnumFloatConversion>;
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I'm surprised we don't have a TableGen facility to say `Warning<warn_foo.Text + " is deprecated">`, but I don't see an alternative.


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Comment at: clang/lib/AST/Type.cpp:1865-1866
   // enumeration type in the sense required here.
   // C++0x: However, if the underlying type of the enum is fixed, it is
   // considered complete.
   if (const auto *ET = dyn_cast<EnumType>(CanonicalType))
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Is this C++11 comment still relevant? I assume that `isComplete` handles this case by returning true, and a forward decl can tell us if the enum is scoped.


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Comment at: clang/test/SemaCXX/warn-enum-compare.cpp:79
 
-  while (B1 == B2); // expected-warning  {{comparison of two values with different enumeration types ('name1::Baz' and 'name2::Baz')}}
-  while (name1::B2 == name2::B3); // expected-warning  {{comparison of two values with different enumeration types ('name1::Baz' and 'name2::Baz')}}
----------------
It seems more technically correct to say that two values are being compared, but I don't see how to keep the diagnostic as well factored as you have it.


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  https://reviews.llvm.org/D71576/new/

https://reviews.llvm.org/D71576