1 files changed, 41 insertions, 0 deletions
diff --git a/gcc/expr.c b/gcc/expr.c
index 0739b05..cfc6ed1 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -5924,6 +5924,47 @@ get_inner_reference (tree exp, HOST_WIDE_INT *pbitsize,
   return exp;
 }
 
+/* Given an expression EXP that may be a COMPONENT_REF or an ARRAY_REF,
+   look for whether EXP or any nested component-refs within EXP is marked
+   as PACKED.  */
+
+bool
+contains_packed_reference (tree exp)
+{
+  bool packed_p = false;
+
+  while (1)
+    {
+      switch (TREE_CODE (exp))
+	{
+	case COMPONENT_REF:
+	  {
+	    tree field = TREE_OPERAND (exp, 1);
+	    packed_p = DECL_PACKED (field) 
+		       || TYPE_PACKED (TREE_TYPE (field))
+		       || TYPE_PACKED (TREE_TYPE (exp));
+	    if (packed_p)
+	      goto done;
+	  }
+	  break;
+
+	case BIT_FIELD_REF:
+	case ARRAY_REF:
+	case ARRAY_RANGE_REF:
+	case REALPART_EXPR:
+	case IMAGPART_EXPR:
+	case VIEW_CONVERT_EXPR:
+	  break;
+
+	default:
+	  goto done;
+	}
+      exp = TREE_OPERAND (exp, 0);
+    }
+ done:
+  return packed_p;
+}
+
 /* Return a tree of sizetype representing the size, in bytes, of the element
    of EXP, an ARRAY_REF.  */