[clang] __is_trivially_equality_comparable should return false for ar…

…rays

When comparing two arrays, their pointers are compared instead of their elements, which means that they are not trivially equality comparable

Fixes #63371

Reviewed By: cor3ntin

Spies: cor3ntin, cfe-commits

Differential Revision: https://reviews.llvm.org/D153737

clang/lib/AST/Type.cpp

@@ -2684,7 +2684,7 @@ bool QualType::isTriviallyEqualityComparableType(
     const ASTContext &Context) const {
   QualType CanonicalType = getCanonicalType();
   if (CanonicalType->isIncompleteType() || CanonicalType->isDependentType() ||
-      CanonicalType->isEnumeralType())
+      CanonicalType->isEnumeralType() || CanonicalType->isArrayType())
     return false;
 
   if (const auto *RD = CanonicalType->getAsCXXRecordDecl()) {

clang/test/SemaCXX/type-traits.cpp

@@ -3110,7 +3110,7 @@ static_assert(!__is_trivially_equality_comparable(ForwardDeclared), ""); // expe
 static_assert(!__is_trivially_equality_comparable(void), "");
 static_assert(__is_trivially_equality_comparable(int), "");
 static_assert(!__is_trivially_equality_comparable(int[]), "");
-static_assert(__is_trivially_equality_comparable(int[3]), "");
+static_assert(!__is_trivially_equality_comparable(int[3]), "");
 static_assert(!__is_trivially_equality_comparable(float), "");
 static_assert(!__is_trivially_equality_comparable(double), "");
 static_assert(!__is_trivially_equality_comparable(long double), "");
@@ -3134,6 +3134,13 @@ struct TriviallyEqualityComparable {
 };
 static_assert(__is_trivially_equality_comparable(TriviallyEqualityComparable), "");
 
+struct TriviallyEqualityComparableContainsArray {
+  int a[4];
+
+  bool operator==(const TriviallyEqualityComparableContainsArray&) const = default;
+};
+static_assert(__is_trivially_equality_comparable(TriviallyEqualityComparableContainsArray));
+
 struct TriviallyEqualityComparableNonTriviallyCopyable {
   TriviallyEqualityComparableNonTriviallyCopyable(const TriviallyEqualityComparableNonTriviallyCopyable&);
   ~TriviallyEqualityComparableNonTriviallyCopyable();