Index: cfe/trunk/lib/Sema/SemaChecking.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp
+++ cfe/trunk/lib/Sema/SemaChecking.cpp
@@ -12097,6 +12097,8 @@
     if (ME->isArrow())
       BaseType = BaseType->getPointeeType();
     RecordDecl *RD = BaseType->getAs<RecordType>()->getDecl();
+    if (RD->isInvalidDecl())
+      return;
 
     ValueDecl *MD = ME->getMemberDecl();
     auto *FD = dyn_cast<FieldDecl>(MD);
Index: cfe/trunk/test/Sema/address-packed.c
===================================================================
--- cfe/trunk/test/Sema/address-packed.c
+++ cfe/trunk/test/Sema/address-packed.c
@@ -329,3 +329,12 @@
   uint32_t *p32;
   p32 = &a[0].x; // no-warning
 }
+
+struct Invalid0 {
+  void *x;
+  struct fwd f; // expected-error {{incomplete type}} expected-note {{forward declaration}}
+} __attribute__((packed));
+
+void *g14(struct Invalid0 *ivl) {
+  return &(ivl->x);
+}