[Clang] Fixes __builtin_is_implicit_lifetime for types with deleted ctrs (#161163)

We failed to check that the trivial constructor where eligible (this
implies non deleted).

Fixes #160610

Author: cor3ntin

clang/docs/ReleaseNotes.rst

@@ -432,6 +432,7 @@ Bug Fixes to C++ Support
 - Fix an assertion failure when taking the address on a non-type template parameter argument of
   object type. (#GH151531)
 - Suppress ``-Wdouble-promotion`` when explicitly asked for with C++ list initialization (#GH33409).
+- Fix the result of `__builtin_is_implicit_lifetime` for types with a user-provided constructor. (#GH160610)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^

clang/lib/Sema/SemaTypeTraits.cpp

@@ -1163,13 +1163,16 @@ static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
     //   - it has at least one trivial eligible constructor and a trivial,
     //     non-deleted destructor.
     const CXXDestructorDecl *Dtor = RD->getDestructor();
-    if (UnqualT->isAggregateType())
-      if (Dtor && !Dtor->isUserProvided())
-        return true;
-    if (RD->hasTrivialDestructor() && (!Dtor || !Dtor->isDeleted()))
-      if (RD->hasTrivialDefaultConstructor() ||
-          RD->hasTrivialCopyConstructor() || RD->hasTrivialMoveConstructor())
-        return true;
+    if (UnqualT->isAggregateType() && (!Dtor || !Dtor->isUserProvided()))
+      return true;
+    if (RD->hasTrivialDestructor() && (!Dtor || !Dtor->isDeleted())) {
+      for (CXXConstructorDecl *Ctr : RD->ctors()) {
+        if (Ctr->isIneligibleOrNotSelected() || Ctr->isDeleted())
+          continue;
+        if (Ctr->isTrivial())
+          return true;
+      }
+    }
     return false;
   }
   case UTT_IsIntangibleType:

clang/test/SemaCXX/type-traits.cpp

@@ -2038,6 +2038,49 @@ void is_implicit_lifetime(int n) {
   static_assert(__builtin_is_implicit_lifetime(int * __restrict));
 }
 
+namespace GH160610 {
+class NonAggregate {
+public:
+    NonAggregate() = default;
+
+    NonAggregate(const NonAggregate&)            = delete;
+    NonAggregate& operator=(const NonAggregate&) = delete;
+private:
+    int num;
+};
+
+class DataMemberInitializer {
+public:
+    DataMemberInitializer() = default;
+
+    DataMemberInitializer(const DataMemberInitializer&)            = delete;
+    DataMemberInitializer& operator=(const DataMemberInitializer&) = delete;
+private:
+    int num = 0;
+};
+
+class UserProvidedConstructor {
+public:
+    UserProvidedConstructor() {}
+
+    UserProvidedConstructor(const UserProvidedConstructor&)            = delete;
+    UserProvidedConstructor& operator=(const UserProvidedConstructor&) = delete;
+};
+
+static_assert(__builtin_is_implicit_lifetime(NonAggregate));
+static_assert(!__builtin_is_implicit_lifetime(DataMemberInitializer));
+static_assert(!__builtin_is_implicit_lifetime(UserProvidedConstructor));
+
+#if __cplusplus >= 202002L
+template <typename T>
+class Tpl {
+    Tpl() requires false = default ;
+};
+static_assert(!__builtin_is_implicit_lifetime(Tpl<int>));
+
+#endif
+}
+
 void is_signed()
 {
   //static_assert(__is_signed(char));