Fix bug using dwarf_next_unit to iterate over .debug_types

	* libdw_findcu.c (findcu_cb): Move earlier.
	(__libdw_intern_next_unit): Add new CU to search tree here...
	(__libdw_findcu): ... not here.

	* typeiter.c: New file.
	* run-typeiter.sh: New file.
	* testfile59.bz2: New file.
	* Makefile.am (noinst_PROGRAMS): Add typeiter.
	(TESTS): Add run-typeiter.sh.
	(EXTRA_DIST): Add run-typeiter.sh, testfile59.bz2.
	(typeiter_LDADD): New variable.

If you call dwarf_next_unit to iterate over .debug_types, then call
dwarf_offdie_types, you can see a failure if some earlier call
happened to call __libdw_intern_next_unit via dwarf_formref_die.

What happens is that __libdw_intern_next_unit updates the Dwarf's
next_tu_offset, but does not add the TU to the TU search tree.  So,
the call to dwarf_offdie_types does not find the TU in the tree, and
will not search any more, causing a failure.

This fix changes __libdw_intern_next_unit to add the TU to the search
tree, rather than relying on __libdw_findcu to do it.

1 files changed, 98 insertions, 0 deletions

diff --git a/tests/typeiter.c b/tests/typeiter.c
new file mode 100644
index 00000000..184b00be
--- /dev/null
+++ b/tests/typeiter.c
@@ -0,0 +1,98 @@
+/* Copyright (C) 2012 Red Hat, Inc.
+   This file is part of Red Hat elfutils.
+
+   Red Hat elfutils is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by the
+   Free Software Foundation; version 2 of the License.
+
+   Red Hat elfutils is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with Red Hat elfutils; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
+
+   Red Hat elfutils is an included package of the Open Invention Network.
+   An included package of the Open Invention Network is a package for which
+   Open Invention Network licensees cross-license their patents.  No patent
+   license is granted, either expressly or impliedly, by designation as an
+   included package.  Should you wish to participate in the Open Invention
+   Network licensing program, please visit www.openinventionnetwork.com
+   <http://www.openinventionnetwork.com>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <fcntl.h>
+#include ELFUTILS_HEADER(dw)
+#include <stdio.h>
+#include <unistd.h>
+#include <dwarf.h>
+
+int
+main (int argc, char *argv[])
+{
+  for (int i = 1; i < argc; ++i)
+    {
+      int fd = open (argv[i], O_RDONLY);
+
+      Dwarf *dbg = dwarf_begin (fd, DWARF_C_READ);
+      if (dbg != NULL)
+	{
+	  Dwarf_Off off = 0;
+	  size_t cuhl;
+	  Dwarf_Off noff;
+
+	  while (dwarf_nextcu (dbg, off, &noff, &cuhl, NULL, NULL, NULL) == 0)
+	    {
+	      Dwarf_Die die_mem;
+	      Dwarf_Die *die = dwarf_offdie (dbg, off + cuhl, &die_mem);
+
+	      Dwarf_Die iter_mem;
+	      Dwarf_Die *iter = &iter_mem;
+	      dwarf_child (die, &iter_mem);
+
+	      while (1)
+		{
+		  if (dwarf_tag (iter) == DW_TAG_variable)
+		    {
+		      Dwarf_Attribute attr_mem;
+		      Dwarf_Die form_mem;
+		      dwarf_formref_die (dwarf_attr (iter, DW_AT_type,
+						     &attr_mem),
+					 &form_mem);
+		    }
+
+		  if (dwarf_siblingof (iter, &iter_mem) != 0)
+		    break;
+		}
+
+	      off = noff;
+	    }
+
+	  off = 0;
+	  uint64_t type_sig;
+
+	  while (dwarf_next_unit (dbg, off, &noff, &cuhl, NULL, NULL, NULL,
+				  NULL, &type_sig, NULL) == 0)
+	    {
+	      Dwarf_Die die_mem;
+	      Dwarf_Die *die = dwarf_offdie_types (dbg, off + cuhl, &die_mem);
+
+	      if (die == NULL)
+		printf ("fail\n");
+	      else
+		printf ("ok\n");
+
+	      off = noff;
+	    }
+
+	  dwarf_end (dbg);
+	}
+
+      close (fd);
+    }
+}