[clang] [libcxx] [Clang] Add __builtin_invoke and use it in libc++ (PR #116709)

[Nikolas Klauser via cfe-commits]

================
@@ -6540,67 +6540,70 @@ ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
   return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc);
 }
 
-static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, const TypeSourceInfo *Lhs,
-                                    const TypeSourceInfo *Rhs, SourceLocation KeyLoc) {
-  QualType LhsT = Lhs->getType();
-  QualType RhsT = Rhs->getType();
+bool Sema::BuiltinIsBaseOf(SourceLocation RhsTLoc, QualType LhsT,
+                           QualType RhsT) {
+  // C++0x [meta.rel]p2
+  // Base is a base class of Derived without regard to cv-qualifiers or
+  // Base and Derived are not unions and name the same class type without
+  // regard to cv-qualifiers.
+
+  const RecordType *lhsRecord = LhsT->getAs<RecordType>();
+  const RecordType *rhsRecord = RhsT->getAs<RecordType>();
+  if (!rhsRecord || !lhsRecord) {
+    const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>();
+    const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>();
+    if (!LHSObjTy || !RHSObjTy)
+      return false;
 
-  assert(!LhsT->isDependentType() && !RhsT->isDependentType() &&
-         "Cannot evaluate traits of dependent types");
+    ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface();
+    ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface();
+    if (!BaseInterface || !DerivedInterface)
+      return false;
 
-  switch(BTT) {
-  case BTT_IsBaseOf: {
-    // C++0x [meta.rel]p2
-    // Base is a base class of Derived without regard to cv-qualifiers or
-    // Base and Derived are not unions and name the same class type without
-    // regard to cv-qualifiers.
-
-    const RecordType *lhsRecord = LhsT->getAs<RecordType>();
-    const RecordType *rhsRecord = RhsT->getAs<RecordType>();
-    if (!rhsRecord || !lhsRecord) {
-      const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>();
-      const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>();
-      if (!LHSObjTy || !RHSObjTy)
-        return false;
+    if (RequireCompleteType(RhsTLoc, RhsT,
+                            diag::err_incomplete_type_used_in_type_trait_expr))
+      return false;
 
-      ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface();
-      ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface();
-      if (!BaseInterface || !DerivedInterface)
-        return false;
+    return BaseInterface->isSuperClassOf(DerivedInterface);
+  }
 
-      if (Self.RequireCompleteType(
-              Rhs->getTypeLoc().getBeginLoc(), RhsT,
-              diag::err_incomplete_type_used_in_type_trait_expr))
-        return false;
+  assert(Context.hasSameUnqualifiedType(LhsT, RhsT) ==
+         (lhsRecord == rhsRecord));
 
-      return BaseInterface->isSuperClassOf(DerivedInterface);
-    }
+  // Unions are never base classes, and never have base classes.
+  // It doesn't matter if they are complete or not. See PR#41843
+  if (lhsRecord && lhsRecord->getDecl()->isUnion())
+    return false;
+  if (rhsRecord && rhsRecord->getDecl()->isUnion())
+    return false;
+
+  if (lhsRecord == rhsRecord)
+    return true;
 
-    assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)
-             == (lhsRecord == rhsRecord));
+  // C++0x [meta.rel]p2:
+  //   If Base and Derived are class types and are different types
+  //   (ignoring possible cv-qualifiers) then Derived shall be a
+  //   complete type.
+  if (RequireCompleteType(RhsTLoc, RhsT,
+                          diag::err_incomplete_type_used_in_type_trait_expr))
+    return false;
 
-    // Unions are never base classes, and never have base classes.
-    // It doesn't matter if they are complete or not. See PR#41843
-    if (lhsRecord && lhsRecord->getDecl()->isUnion())
-      return false;
-    if (rhsRecord && rhsRecord->getDecl()->isUnion())
-      return false;
+  return cast<CXXRecordDecl>(rhsRecord->getDecl())
+    ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl()));
+}
 
-    if (lhsRecord == rhsRecord)
-      return true;
+static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, const TypeSourceInfo *Lhs,
----------------
philnik777 wrote:

I think so. This allows me to use them in `BuiltinInvoke` above and be very close to the wording in the standard. I guess it would be possible to call `BuildTypeTrait` instead, but that seems much less readable to me (and would require me to find a `TypeSourceInfo` somewhere).

https://github.com/llvm/llvm-project/pull/116709