re PR ipa/59775 (internal compiler error: Segmentation fault)

	PR ipa/59775
	* tree.c (get_binfo_at_offset): Look harder for virtual bases.

From-SVN: r206694

gcc/ChangeLog

+2014-01-16  Jan Hubicka  <jh@suse.cz>
+
+	PR ipa/59775
+	* tree.c (get_binfo_at_offset): Look harder for virtual bases.
+
 2014-01-16  Bernd Schmidt  <bernds@codesourcery.com>
 
 	PR middle-end/56791

gcc/testsuite/ChangeLog

+2014-01-16  Jan Hubicka  <jh@suse.cz>
+
+	PR ipa/59775
+	* g++.dg/torture/pr59775.C: New testcase.
+
 2014-01-16  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/58344

gcc/testsuite/g++.dg/torture/pr59775.C

+// { dg-do compile }
+struct A
+{
+  virtual void foo () = 0;
+  void bar () { foo (); }
+  bool a;
+};
+struct B : public virtual A
+{
+  virtual void foo ();
+};
+struct C : public B
+{
+  C ();
+};
+void
+baz ()
+{
+  C c;
+  c.bar ();
+}

gcc/tree.c

@@ -11995,16 +11995,35 @@ get_binfo_at_offset (tree binfo, HOST_WIDE_INT offset, tree expected_type)
 	 represented in the binfo for the derived class.  */
       else if (offset != 0)
 	{
-	  tree base_binfo, found_binfo = NULL_TREE;
-	  for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
-	    if (types_same_for_odr (TREE_TYPE (base_binfo), TREE_TYPE (fld)))
-	      {
-		found_binfo = base_binfo;
-		break;
-	      }
-	  if (!found_binfo)
-	    return NULL_TREE;
-	  binfo = found_binfo;
+	  tree base_binfo, binfo2 = binfo;
+
+	  /* Find BINFO corresponding to FLD.  This is bit harder
+	     by a fact that in virtual inheritance we may need to walk down
+	     the non-virtual inheritance chain.  */
+	  while (true)
+	    {
+	      tree containing_binfo = NULL, found_binfo = NULL;
+	      for (i = 0; BINFO_BASE_ITERATE (binfo2, i, base_binfo); i++)
+		if (types_same_for_odr (TREE_TYPE (base_binfo), TREE_TYPE (fld)))
+		  {
+		    found_binfo = base_binfo;
+		    break;
+		  }
+		else
+		  if (BINFO_OFFSET (base_binfo) - BINFO_OFFSET (binfo) < pos
+		      && (!containing_binfo
+			  || (BINFO_OFFSET (containing_binfo)
+			      < BINFO_OFFSET (base_binfo))))
+		    containing_binfo = base_binfo;
+	      if (found_binfo)
+		{
+		  binfo = found_binfo;
+		  break;
+		}
+	      if (!containing_binfo)
+		return NULL_TREE;
+	      binfo2 = containing_binfo;
+	    }
 	}
 
       type = TREE_TYPE (fld);