[clang][Interp] Don't diagnose ObjCIvarDecls as invalid reads

Author: tbaederr

clang/lib/AST/Interp/Interp.cpp

@@ -18,6 +18,7 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTDiagnostic.h"
 #include "clang/AST/CXXInheritance.h"
+#include "clang/AST/DeclObjC.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
 #include "llvm/ADT/APSInt.h"
@@ -101,6 +102,11 @@ static void diagnoseNonConstVariable(InterpState &S, CodePtr OpPC,
     return;
   }
 
+  // Rather random, but this is to match the diagnostic output of the current
+  // interpreter.
+  if (isa<ObjCIvarDecl>(VD))
+    return;
+
   if (VD->getType()->isIntegralOrEnumerationType()) {
     S.FFDiag(Loc, diag::note_constexpr_ltor_non_const_int, 1) << VD;
     S.Note(VD->getLocation(), diag::note_declared_at);

clang/test/AST/Interp/objc.mm

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify=expected,both %s
+// RUN: %clang_cc1 -verify=ref,both %s
+
+@interface A {
+  int a;
+  static_assert(a, ""); // both-error {{static assertion expression is not an integral constant expression}}
+}
+@end