[clang][Interp] Handle objc strings

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -1637,6 +1637,12 @@ bool ByteCodeExprGen<Emitter>::VisitStringLiteral(const StringLiteral *E) {
   return true;
 }
 
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitObjCStringLiteral(
+    const ObjCStringLiteral *E) {
+  return this->delegate(E->getString());
+}
+
 template <class Emitter>
 bool ByteCodeExprGen<Emitter>::VisitSYCLUniqueStableNameExpr(
     const SYCLUniqueStableNameExpr *E) {

clang/lib/AST/Interp/ByteCodeExprGen.h

@@ -90,6 +90,7 @@ class ByteCodeExprGen : public ConstStmtVisitor<ByteCodeExprGen<Emitter>, bool>,
   bool VisitOpaqueValueExpr(const OpaqueValueExpr *E);
   bool VisitAbstractConditionalOperator(const AbstractConditionalOperator *E);
   bool VisitStringLiteral(const StringLiteral *E);
+  bool VisitObjCStringLiteral(const ObjCStringLiteral *E);
   bool VisitSYCLUniqueStableNameExpr(const SYCLUniqueStableNameExpr *E);
   bool VisitCharacterLiteral(const CharacterLiteral *E);
   bool VisitCompoundAssignOperator(const CompoundAssignOperator *E);

clang/lib/AST/Interp/Context.cpp

@@ -164,7 +164,8 @@ std::optional<PrimType> Context::classify(QualType T) const {
       T->isFunctionType() || T->isSpecificBuiltinType(BuiltinType::BoundMember))
     return PT_FnPtr;
 
-  if (T->isReferenceType() || T->isPointerType())
+  if (T->isReferenceType() || T->isPointerType() ||
+      T->isObjCObjectPointerType())
     return PT_Ptr;
 
   if (const auto *AT = T->getAs<AtomicType>())

clang/test/AST/Interp/objc.mm

@@ -6,3 +6,7 @@ @interface A {
   static_assert(a, ""); // both-error {{static assertion expression is not an integral constant expression}}
 }
 @end
+
+@interface NSString
+@end
+constexpr NSString *t0 = @"abc";