Fix rdar://5921025 a crash on the included testcase.

llvm-svn: 50885
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 373727a..9a7d692 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2183,7 +2183,8 @@
   else if (FieldDecl *FD = dyn_cast<FieldDecl>(d)) {
     // If the alignment is less than or equal to 8 bits, the packed attribute
     // has no effect.
-    if (Context.getTypeAlign(FD->getType()) <= 8)
+    if (!FD->getType()->isIncompleteType() &&
+        Context.getTypeAlign(FD->getType()) <= 8)
       Diag(rawAttr->getLoc(), 
            diag::warn_attribute_ignored_for_field_of_type,
            rawAttr->getName()->getName(), FD->getType().getAsString());
diff --git a/clang/test/Sema/struct-packed-align.c b/clang/test/Sema/struct-packed-align.c
index f718343..f759e37 100644
--- a/clang/test/Sema/struct-packed-align.c
+++ b/clang/test/Sema/struct-packed-align.c
@@ -62,3 +62,10 @@
 
 extern int g1[sizeof(struct as3) == 16 ? 1 : -1];
 extern int g2[__alignof(struct as3) == 8 ? 1 : -1];
+
+
+// rdar://5921025
+struct packedtest {
+  int ted_likes_cheese;
+  void *args[] __attribute__((packed));
+};