1 files changed, 104 insertions, 0 deletions
diff --git a/libdw/dwarf_siblingof.c b/libdw/dwarf_siblingof.c
new file mode 100644
index 00000000..90081c64
--- /dev/null
+++ b/libdw/dwarf_siblingof.c
@@ -0,0 +1,104 @@
+/* Return sibling of given DIE.
+   Copyright (C) 2003, 2004 Red Hat, Inc.
+   Written by Ulrich Drepper <drepper@redhat.com>, 2003.
+
+   This program is Open Source software; you can redistribute it and/or
+   modify it under the terms of the Open Software License version 1.0 as
+   published by the Open Source Initiative.
+
+   You should have received a copy of the Open Software License along
+   with this program; if not, you may obtain a copy of the Open Software
+   License version 1.0 from http://www.opensource.org/licenses/osl.php or
+   by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
+   3001 King Ranch Road, Ukiah, CA 95482.   */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libdwP.h"
+#include <dwarf.h>
+#include <string.h>
+
+
+int
+dwarf_siblingof (die, result)
+     Dwarf_Die *die;
+     Dwarf_Die *result;
+{
+  /* Ignore previous errors.  */
+  if (die == NULL)
+    return -1;
+
+  unsigned int level = 0;
+
+  /* Copy of the current DIE.  */
+  Dwarf_Die this_die = *die;
+  /* Temporary attributes we create.  */
+  Dwarf_Attribute sibattr;
+  /* Copy of the CU in the request.  */
+  sibattr.cu = this_die.cu;
+  /* That's the address we start looking.  */
+  unsigned char *addr = this_die.addr;
+
+  /* Search for the beginning of the next die on this level.  We
+     must not return the dies for children of the given die.  */
+  do
+    {
+      /* Find the end of the DIE or the sibling attribute.  */
+      addr = __libdw_find_attr (&this_die, DW_AT_sibling, &sibattr.code,
+				&sibattr.form);
+      if (sibattr.code == DW_AT_sibling)
+	{
+	  Dwarf_Off offset;
+	  sibattr.valp = addr;
+	  if (dwarf_formref (&sibattr, &offset) != 0)
+	    /* Something went wrong.  */
+	    return -1;
+
+	  /* Compute the next address.  */
+	  addr = ((unsigned char *)
+		  sibattr.cu->dbg->sectiondata[IDX_debug_info]->d_buf
+		  + sibattr.cu->start + offset);
+	}
+      else if (unlikely (addr == NULL)
+	       || unlikely (this_die.abbrev == (Dwarf_Abbrev *) -1l))
+	return -1;
+      else if (this_die.abbrev->has_children)
+	/* This abbreviation has children.  */
+	++level;
+
+      /* Check that we are not yet at the end.  */
+      while (*addr == '\0')
+	{
+	  if (level-- == 0)
+	    /* No more sibling at all.  */
+	    return 1;
+
+	  ++addr;
+	}
+
+      /* Initialize the 'current DIE'.  */
+      this_die.addr = addr;
+      this_die.abbrev = NULL;
+    }
+  while (level > 0);
+
+  /* Maybe we reached the end of the CU.  */
+  if (addr
+      >= ((unsigned char *) sibattr.cu->dbg->sectiondata[IDX_debug_info]->d_buf
+	  + sibattr.cu->end))
+    return 1;
+
+  /* Clear the entire DIE structure.  This signals we have not yet
+     determined any of the information.  */
+  memset (result, '\0', sizeof (Dwarf_Die));
+
+  /* We have the address.  */
+  result->addr = addr;
+
+  /* Same CU as the parent.  */
+  result->cu = sibattr.cu;
+
+  return 0;
+}