[clang][Interp] Handle ObjCBoxedExprs

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -2649,6 +2649,14 @@ bool ByteCodeExprGen<Emitter>::VisitShuffleVectorExpr(
   return true;
 }
 
+template <class Emitter>
+bool ByteCodeExprGen<Emitter>::VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
+  if (!E->isExpressibleAsConstantInitializer())
+    return this->emitInvalid(E);
+
+  return this->delegate(E->getSubExpr());
+}
+
 template <class Emitter> bool ByteCodeExprGen<Emitter>::discard(const Expr *E) {
   OptionScope<Emitter> Scope(this, /*NewDiscardResult=*/true,
                              /*NewInitializing=*/false);

clang/lib/AST/Interp/ByteCodeExprGen.h

@@ -127,6 +127,7 @@ class ByteCodeExprGen : public ConstStmtVisitor<ByteCodeExprGen<Emitter>, bool>,
   bool VisitAddrLabelExpr(const AddrLabelExpr *E);
   bool VisitConvertVectorExpr(const ConvertVectorExpr *E);
   bool VisitShuffleVectorExpr(const ShuffleVectorExpr *E);
+  bool VisitObjCBoxedExpr(const ObjCBoxedExpr *E);
 
 protected:
   bool visitExpr(const Expr *E) override;

clang/test/AST/Interp/objc.mm

@@ -10,3 +10,4 @@ @interface A {
 @interface NSString
 @end
 constexpr NSString *t0 = @"abc";
+constexpr NSString *t1 = @("abc");