[Clang][AST] Don't use canonical type when checking dependence in Type::isOverloadable

clang/docs/ReleaseNotes.rst

@@ -138,6 +138,8 @@ Bug Fixes to Attribute Support
 Bug Fixes to C++ Support
 ^^^^^^^^^^^^^^^^^^^^^^^^
 
+- Fixed a crash when an expression with a dependent ``__typeof__`` type is used as the operand of a unary operator. (#GH97646)
+
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 

clang/include/clang/AST/Type.h

@@ -8434,7 +8434,7 @@ inline bool Type::isUndeducedType() const {
 /// Determines whether this is a type for which one can define
 /// an overloaded operator.
 inline bool Type::isOverloadableType() const {
-  if (!CanonicalType->isDependentType())
+  if (!isDependentType())
     return isRecordType() || isEnumeralType();
   return !isArrayType() && !isFunctionType() && !isAnyPointerType() &&
          !isMemberPointerType();

clang/test/SemaCXX/decltype.cpp

@@ -139,6 +139,14 @@ namespace GH58674 {
   }
 }
 
+namespace GH97646 {
+  template<bool B>
+  void f() {
+    decltype(B) x = false;
+    !x;
+  }
+}
+
 template<typename>
 class conditional {
 };

clang/test/SemaCXX/typeof_unqual.cpp → clang/test/SemaCXX/typeof.cpp

@@ -3,3 +3,11 @@
 typeof_unqual(int) u = 12; // expected-error {{expected function body after function declarator}}
 __typeof_unqual(int) _u = 12;
 __typeof_unqual__(int) __u = 12;
+
+namespace GH97646 {
+  template<bool B>
+  void f() {
+    __typeof__(B) x = false;
+    !x;
+  }
+}