[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-10 Thread Zoe Carver via Phabricator via cfe-commits 
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGa89ac0dd185d: Update __is_unsigned builtin to match the 
Standard. (authored by zoecarver).

Repository:
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Files:
  clang/docs/LanguageExtensions.rst
  clang/lib/Sema/SemaExprCXX.cpp
  clang/test/SemaCXX/type-traits.cpp


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1440,6 +1441,7 @@
   int t25[F(__is_signed(IntArNB))];
   int t26[F(__is_signed(Union))];
   int t27[F(__is_signed(UnionAr))];
+  int t28[F(__is_signed(UnsignedEnum))];
 }
 
 void is_unsigned()
@@ -1450,7 +1452,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int t07[T(__is_unsigned(Enum))];
 
   int t10[F(__is_unsigned(void))];
   int t11[F(__is_unsigned(cvoid))];
@@ -1468,6 +1469,9 @@
   int t24[F(__is_unsigned(Derives))];
   int t25[F(__is_unsigned(ClassType))];
   int t26[F(__is_unsigned(IntArNB))];
+  int t27[F(__is_unsigned(Enum))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
+  int t29[F(__is_unsigned(SignedEnum))];
 }
 
 typedef Int& IntRef;
Index: clang/lib/Sema/SemaExprCXX.cpp
===
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -4856,9 +4856,11 @@
   case UTT_IsSigned:
 // Enum types should always return false.
 // Floating points should always return true.
-return !T->isEnumeralType() && (T->isFloatingType() || 
T->isSignedIntegerType());
+return T->isFloatingType() ||
+   (T->isSignedIntegerType() && !T->isEnumeralType());
   case UTT_IsUnsigned:
-return T->isUnsignedIntegerType();
+// Enum types should always return false.
+return T->isUnsignedIntegerType() && !T->isEnumeralType();
 
 // Type trait expressions which query classes regarding their construction,
 // destruction, and copying. Rather than being based directly on the
Index: clang/docs/LanguageExtensions.rst
===
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -1194,7 +1194,9 @@
 * ``__is_sealed`` (Microsoft):
   Synonym for ``__is_final``.
 * ``__is_signed`` (C++, Embarcadero):
-  Returns false for enumeration types, and returns true for floating-point 
types. Note, before Clang 10, returned true for enumeration types if the 
underlying type was signed, and returned false for floating-point types.
+  Returns false for enumeration types, and returns true for floating-point
+  types. Note, before Clang 10, returned true for enumeration types if the
+  underlying type was signed, and returned false for floating-point types.
 * ``__is_standard_layout`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivial`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivially_assignable`` (C++, GNU, Microsoft)
@@ -1202,10 +1204,9 @@
 * ``__is_trivially_copyable`` (C++, GNU, Microsoft)
 * ``__is_trivially_destructible`` (C++, MSVC 2013)
 * ``__is_union`` (C++, GNU, Microsoft, Embarcadero)
-* ``__is_unsigned`` (C++, Embarcadero)
-  Note that this currently returns true for enumeration types if the underlying
-  type is unsigned, in violation of the requirements for ``std::is_unsigned``.
-  This behavior is likely to change in a future version of Clang.
+* ``__is_unsigned`` (C++, Embarcadero):
+  Returns false for enumeration types. Note, before Clang 13, returned true for
+  enumeration types if the underlying type was unsigned.
 * ``__is_void`` (C++, Embarcadero)
 * ``__is_volatile`` (C++, Embarcadero)
 * ``__reference_binds_to_temporary(T, U)`` (Clang):  Determines whether a


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1440,6 +1441,7 @@
   int t25[F(__is_signed(IntArNB))];
   int t26[F(__is_signed(Union))];
   int t27[F(__is_signed(UnionAr))];
+  int t28[F(__is_signed(UnsignedEnum))];
 }
 
 void is_unsigned()
@@ -1450,7 +1452,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int

[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-10 Thread Zoe Carver via Phabricator via cfe-commits 
zoecarver updated this revision to Diff 329761.
zoecarver added a comment.

- Fix review comments: add colon, reflow line, and fix typo.


Repository:
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CHANGES SINCE LAST ACTION
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Files:
  clang/docs/LanguageExtensions.rst
  clang/lib/Sema/SemaExprCXX.cpp
  clang/test/SemaCXX/type-traits.cpp


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1440,6 +1441,7 @@
   int t25[F(__is_signed(IntArNB))];
   int t26[F(__is_signed(Union))];
   int t27[F(__is_signed(UnionAr))];
+  int t28[F(__is_signed(UnsignedEnum))];
 }
 
 void is_unsigned()
@@ -1450,7 +1452,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int t07[T(__is_unsigned(Enum))];
 
   int t10[F(__is_unsigned(void))];
   int t11[F(__is_unsigned(cvoid))];
@@ -1468,6 +1469,9 @@
   int t24[F(__is_unsigned(Derives))];
   int t25[F(__is_unsigned(ClassType))];
   int t26[F(__is_unsigned(IntArNB))];
+  int t27[F(__is_unsigned(Enum))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
+  int t29[F(__is_unsigned(SignedEnum))];
 }
 
 typedef Int& IntRef;
Index: clang/lib/Sema/SemaExprCXX.cpp
===
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -4831,9 +4831,11 @@
   case UTT_IsSigned:
 // Enum types should always return false.
 // Floating points should always return true.
-return !T->isEnumeralType() && (T->isFloatingType() || 
T->isSignedIntegerType());
+return T->isFloatingType() ||
+   (T->isSignedIntegerType() && !T->isEnumeralType());
   case UTT_IsUnsigned:
-return T->isUnsignedIntegerType();
+// Enum types should always return false.
+return T->isUnsignedIntegerType() && !T->isEnumeralType();
 
 // Type trait expressions which query classes regarding their construction,
 // destruction, and copying. Rather than being based directly on the
Index: clang/docs/LanguageExtensions.rst
===
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -1194,7 +1194,9 @@
 * ``__is_sealed`` (Microsoft):
   Synonym for ``__is_final``.
 * ``__is_signed`` (C++, Embarcadero):
-  Returns false for enumeration types, and returns true for floating-point 
types. Note, before Clang 10, returned true for enumeration types if the 
underlying type was signed, and returned false for floating-point types.
+  Returns false for enumeration types, and returns true for floating-point
+  types. Note, before Clang 10, returned true for enumeration types if the
+  underlying type was signed, and returned false for floating-point types.
 * ``__is_standard_layout`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivial`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivially_assignable`` (C++, GNU, Microsoft)
@@ -1202,10 +1204,9 @@
 * ``__is_trivially_copyable`` (C++, GNU, Microsoft)
 * ``__is_trivially_destructible`` (C++, MSVC 2013)
 * ``__is_union`` (C++, GNU, Microsoft, Embarcadero)
-* ``__is_unsigned`` (C++, Embarcadero)
-  Note that this currently returns true for enumeration types if the underlying
-  type is unsigned, in violation of the requirements for ``std::is_unsigned``.
-  This behavior is likely to change in a future version of Clang.
+* ``__is_unsigned`` (C++, Embarcadero):
+  Returns false for enumeration types. Note, before Clang 13, returned true for
+  enumeration types if the underlying type was unsigned.
 * ``__is_void`` (C++, Embarcadero)
 * ``__is_volatile`` (C++, Embarcadero)
 * ``__reference_binds_to_temporary(T, U)`` (Clang):  Determines whether a


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1440,6 +1441,7 @@
   int t25[F(__is_signed(IntArNB))];
   int t26[F(__is_signed(Union))];
   int t27[F(__is_signed(UnionAr))];
+  int t28[F(__is_signed(UnsignedEnum))];
 }
 
 void is_unsigned()
@@ -1450,7 +1452,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int t07[T(__is_unsigned(Enum))];
 
   int t10[F(__is_unsigned(void))];
   int t11[F(__is_unsigned(cvoid))];
@@ -1468,6

[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-10 Thread Zoe Carver via Phabricator via cfe-commits 
zoecarver added a comment.

Sorry for the delay in updating. All review comments have been addressed. 
Thanks!


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[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-08 Thread Richard Smith - zygoloid via Phabricator via cfe-commits 
rsmith added a comment.

LGTM too, once the remaining pending comments are addressed.


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[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-08 Thread Richard Smith - zygoloid via Phabricator via cfe-commits 
rsmith added inline comments.



Comment at: clang/docs/LanguageExtensions.rst:1207
 * ``__is_union`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_unsigned`` (C++, Embarcadero)
+  Returns false for enumeration types. Note, before Clang 13, returned true for

Please add a trailing colon to this line to match the other lines with 
additional text after the parentheses.



Comment at: clang/lib/Sema/SemaExprCXX.cpp:4834
 // Floating points should always return true.
-return !T->isEnumeralType() && (T->isFloatingType() || 
T->isSignedIntegerType());
+return T->isFloatingType() || (T->isSignedIntegerType() && 
!T->isEnumeralType());
   case UTT_IsUnsigned:

Please reflow this line so it fits in 80 columns.


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[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-07 Thread Arthur O'Dwyer via Phabricator via cfe-commits 
Quuxplusone added a comment.

LGTM now, mod the (important!) typo in the test.




Comment at: clang/test/SemaCXX/type-traits.cpp:1444
   int t27[F(__is_signed(UnionAr))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
 }

s/is_unsigned/is_signed/


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[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-07 Thread Zoe Carver via Phabricator via cfe-commits 
zoecarver updated this revision to Diff 328905.
zoecarver added a comment.

- Address Arthur's comments.


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Files:
  clang/docs/LanguageExtensions.rst
  clang/lib/Sema/SemaExprCXX.cpp
  clang/test/SemaCXX/type-traits.cpp


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1440,6 +1441,7 @@
   int t25[F(__is_signed(IntArNB))];
   int t26[F(__is_signed(Union))];
   int t27[F(__is_signed(UnionAr))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
 }
 
 void is_unsigned()
@@ -1450,7 +1452,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int t07[T(__is_unsigned(Enum))];
 
   int t10[F(__is_unsigned(void))];
   int t11[F(__is_unsigned(cvoid))];
@@ -1468,6 +1469,9 @@
   int t24[F(__is_unsigned(Derives))];
   int t25[F(__is_unsigned(ClassType))];
   int t26[F(__is_unsigned(IntArNB))];
+  int t27[F(__is_unsigned(Enum))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
+  int t29[F(__is_unsigned(SignedEnum))];
 }
 
 typedef Int& IntRef;
Index: clang/lib/Sema/SemaExprCXX.cpp
===
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -4831,9 +4831,10 @@
   case UTT_IsSigned:
 // Enum types should always return false.
 // Floating points should always return true.
-return !T->isEnumeralType() && (T->isFloatingType() || 
T->isSignedIntegerType());
+return T->isFloatingType() || (T->isSignedIntegerType() && 
!T->isEnumeralType());
   case UTT_IsUnsigned:
-return T->isUnsignedIntegerType();
+// Enum types should always return false.
+return T->isUnsignedIntegerType() && !T->isEnumeralType();
 
 // Type trait expressions which query classes regarding their construction,
 // destruction, and copying. Rather than being based directly on the
Index: clang/docs/LanguageExtensions.rst
===
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -1194,7 +1194,9 @@
 * ``__is_sealed`` (Microsoft):
   Synonym for ``__is_final``.
 * ``__is_signed`` (C++, Embarcadero):
-  Returns false for enumeration types, and returns true for floating-point 
types. Note, before Clang 10, returned true for enumeration types if the 
underlying type was signed, and returned false for floating-point types.
+  Returns false for enumeration types, and returns true for floating-point
+  types. Note, before Clang 10, returned true for enumeration types if the
+  underlying type was signed, and returned false for floating-point types.
 * ``__is_standard_layout`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivial`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivially_assignable`` (C++, GNU, Microsoft)
@@ -1203,9 +1205,8 @@
 * ``__is_trivially_destructible`` (C++, MSVC 2013)
 * ``__is_union`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_unsigned`` (C++, Embarcadero)
-  Note that this currently returns true for enumeration types if the underlying
-  type is unsigned, in violation of the requirements for ``std::is_unsigned``.
-  This behavior is likely to change in a future version of Clang.
+  Returns false for enumeration types. Note, before Clang 13, returned true for
+  enumeration types if the underlying type was unsigned.
 * ``__is_void`` (C++, Embarcadero)
 * ``__is_volatile`` (C++, Embarcadero)
 * ``__reference_binds_to_temporary(T, U)`` (Clang):  Determines whether a


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1440,6 +1441,7 @@
   int t25[F(__is_signed(IntArNB))];
   int t26[F(__is_signed(Union))];
   int t27[F(__is_signed(UnionAr))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
 }
 
 void is_unsigned()
@@ -1450,7 +1452,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int t07[T(__is_unsigned(Enum))];
 
   int t10[F(__is_unsigned(void))];
   int t11[F(__is_unsigned(cvoid))];
@@ -1468,6 +1469,9 @@
   int t24[F(__is_unsigned(Derives))];
   int t25[F(__is_unsigned(ClassType))];
   int t26[F(__is_unsigned(IntArNB))];
+  int

[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-07 Thread Zoe Carver via Phabricator via cfe-commits 
zoecarver added inline comments.



Comment at: clang/lib/Sema/SemaExprCXX.cpp:4837
+// Enum types should always return false (same as UTT_IsSigned).
+return !T->isEnumeralType() && T->isUnsignedIntegerType();
 

Quuxplusone wrote:
> FWIW, I'd lose the parenthetical comment, and I'd write the conditions as 
> respectively
> 
> return T->isUnsignedIntegerType() && !T->isEnumeralType();
> 
> return T->isFloatingType() || (T->isSignedIntegerType() && 
> !T->isEnumeralType());
> 
> both because "T not being an enum type" is expected to be usually true, and 
> because I think `(!x && y)` runs the risk of being misread as `!(x && y)`, 
> whereas `(x && !y)` is easy on the brain.
Fair enough. I originally was thinking, if we have to perform this check 
roughly 50% of this time, either way, it makes sense to do the much faster 
check first. But, if we assume that we almost never receive an enum type, then 
what you're saying makes sense. I'll fix it. 


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[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-05 Thread Arthur O'Dwyer via Phabricator via cfe-commits 
Quuxplusone added a comment.






Comment at: clang/lib/Sema/SemaExprCXX.cpp:4837
+// Enum types should always return false (same as UTT_IsSigned).
+return !T->isEnumeralType() && T->isUnsignedIntegerType();
 

FWIW, I'd lose the parenthetical comment, and I'd write the conditions as 
respectively

return T->isUnsignedIntegerType() && !T->isEnumeralType();

return T->isFloatingType() || (T->isSignedIntegerType() && 
!T->isEnumeralType());

both because "T not being an enum type" is expected to be usually true, and 
because I think `(!x && y)` runs the risk of being misread as `!(x && y)`, 
whereas `(x && !y)` is easy on the brain.



Comment at: clang/test/SemaCXX/type-traits.cpp:1472
+  int t27[F(__is_unsigned(Enum))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
 }

I think you should check `F(__is_unsigned(SignedEnum))` here, too, just for the 
record.
And `F(__is_signed(UnsignedEnum))` in the other place.


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[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-05 Thread Zoe Carver via Phabricator via cfe-commits 
zoecarver added inline comments.



Comment at: clang/docs/LanguageExtensions.rst:1199
+  types. Note, before Clang 10, returned true for enumeration types if the
+  underlying type was signed, and returned false for floating-point types.
 * ``__is_standard_layout`` (C++, GNU, Microsoft, Embarcadero)

Just re-flowing the line here, which I neglected to do in the other commit. 


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[PATCH] D98104: Update __is_unsigned builtin to match the Standard.

2021-03-05 Thread Zoe Carver via Phabricator via cfe-commits 
zoecarver created this revision.
zoecarver added reviewers: ldionne, rsmith, tmatheson.
zoecarver requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

Updates __is_unsigned to have the same behavior as the standard
specifies. This is in line with 511dbd8, which applied the same change
to __is_signed.

Refs D67897 .


Repository:
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Files:
  clang/docs/LanguageExtensions.rst
  clang/lib/Sema/SemaExprCXX.cpp
  clang/test/SemaCXX/type-traits.cpp


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1450,7 +1451,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int t07[T(__is_unsigned(Enum))];
 
   int t10[F(__is_unsigned(void))];
   int t11[F(__is_unsigned(cvoid))];
@@ -1468,6 +1468,8 @@
   int t24[F(__is_unsigned(Derives))];
   int t25[F(__is_unsigned(ClassType))];
   int t26[F(__is_unsigned(IntArNB))];
+  int t27[F(__is_unsigned(Enum))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
 }
 
 typedef Int& IntRef;
Index: clang/lib/Sema/SemaExprCXX.cpp
===
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -4833,7 +4833,8 @@
 // Floating points should always return true.
 return !T->isEnumeralType() && (T->isFloatingType() || 
T->isSignedIntegerType());
   case UTT_IsUnsigned:
-return T->isUnsignedIntegerType();
+// Enum types should always return false (same as UTT_IsSigned).
+return !T->isEnumeralType() && T->isUnsignedIntegerType();
 
 // Type trait expressions which query classes regarding their construction,
 // destruction, and copying. Rather than being based directly on the
Index: clang/docs/LanguageExtensions.rst
===
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -1194,7 +1194,9 @@
 * ``__is_sealed`` (Microsoft):
   Synonym for ``__is_final``.
 * ``__is_signed`` (C++, Embarcadero):
-  Returns false for enumeration types, and returns true for floating-point 
types. Note, before Clang 10, returned true for enumeration types if the 
underlying type was signed, and returned false for floating-point types.
+  Returns false for enumeration types, and returns true for floating-point
+  types. Note, before Clang 10, returned true for enumeration types if the
+  underlying type was signed, and returned false for floating-point types.
 * ``__is_standard_layout`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivial`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_trivially_assignable`` (C++, GNU, Microsoft)
@@ -1203,9 +1205,8 @@
 * ``__is_trivially_destructible`` (C++, MSVC 2013)
 * ``__is_union`` (C++, GNU, Microsoft, Embarcadero)
 * ``__is_unsigned`` (C++, Embarcadero)
-  Note that this currently returns true for enumeration types if the underlying
-  type is unsigned, in violation of the requirements for ``std::is_unsigned``.
-  This behavior is likely to change in a future version of Clang.
+  Returns false for enumeration types. Note, before Clang 13, returned true for
+  enumeration types if the underlying type was unsigned.
 * ``__is_void`` (C++, Embarcadero)
 * ``__is_volatile`` (C++, Embarcadero)
 * ``__reference_binds_to_temporary(T, U)`` (Clang):  Determines whether a


Index: clang/test/SemaCXX/type-traits.cpp
===
--- clang/test/SemaCXX/type-traits.cpp
+++ clang/test/SemaCXX/type-traits.cpp
@@ -13,6 +13,7 @@
 // PODs
 enum Enum { EV };
 enum SignedEnum : signed int { };
+enum UnsignedEnum : unsigned int { };
 struct POD { Enum e; int i; float f; NonPOD* p; };
 struct Empty {};
 struct IncompleteStruct;
@@ -1450,7 +1451,6 @@
   int t04[T(__is_unsigned(unsigned int))];
   int t05[T(__is_unsigned(unsigned long))];
   int t06[T(__is_unsigned(unsigned long long))];
-  int t07[T(__is_unsigned(Enum))];
 
   int t10[F(__is_unsigned(void))];
   int t11[F(__is_unsigned(cvoid))];
@@ -1468,6 +1468,8 @@
   int t24[F(__is_unsigned(Derives))];
   int t25[F(__is_unsigned(ClassType))];
   int t26[F(__is_unsigned(IntArNB))];
+  int t27[F(__is_unsigned(Enum))];
+  int t28[F(__is_unsigned(UnsignedEnum))];
 }
 
 typedef Int& IntRef;
Index: clang/lib/Sema/SemaExprCXX.cpp
===
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -4833,7 +4833,8 @@
 // Floating points should always return