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.

7 files changed, 210 insertions, 38 deletions

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 98b67f4a..f96c0d1b 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,9 @@
+2012-03-19  Tom Tromey  <tromey@redhat.com>
+
+	* libdw_findcu.c (findcu_cb): Move earlier.
+	(__libdw_intern_next_unit): Add new CU to search tree here...
+	(__libdw_findcu): ... not here.
+
 2012-01-31  Mark Wielaard  <mjw@redhat.com>
 
 	* dwarf_formudata.c (dwarf_formudata): Handle DW_FORM_sec_offset.
diff --git a/libdw/libdw_findcu.c b/libdw/libdw_findcu.c
index 8e5f9e9b..83c96baf 100644
--- a/libdw/libdw_findcu.c
+++ b/libdw/libdw_findcu.c
@@ -56,6 +56,31 @@
 #include <search.h>
 #include "libdwP.h"
 
+static int
+findcu_cb (const void *arg1, const void *arg2)
+{
+  struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1;
+  struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2;
+
+  /* Find out which of the two arguments is the search value.  It has
+     end offset 0.  */
+  if (cu1->end == 0)
+    {
+      if (cu1->start < cu2->start)
+	return -1;
+      if (cu1->start >= cu2->end)
+	return 1;
+    }
+  else
+    {
+      if (cu2->start < cu1->start)
+	return 1;
+      if (cu2->start >= cu1->end)
+	return -1;
+    }
+
+  return 0;
+}
 
 struct Dwarf_CU *
 internal_function
@@ -65,6 +90,7 @@ __libdw_intern_next_unit (dbg, debug_types)
 {
   Dwarf_Off *const offsetp
     = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset;
+  void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree;
 
   Dwarf_Off oldoff = *offsetp;
   uint16_t version;
@@ -105,34 +131,16 @@ __libdw_intern_next_unit (dbg, debug_types)
   newp->lines = NULL;
   newp->locs = NULL;
 
-  return newp;
-}
-
-
-static int
-findcu_cb (const void *arg1, const void *arg2)
-{
-  struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1;
-  struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2;
-
-  /* Find out which of the two arguments is the search value.  It has
-     end offset 0.  */
-  if (cu1->end == 0)
+  /* Add the new entry to the search tree.  */
+  if (tsearch (newp, tree, findcu_cb) == NULL)
     {
-      if (cu1->start < cu2->start)
-	return -1;
-      if (cu1->start >= cu2->end)
-	return 1;
-    }
-  else
-    {
-      if (cu2->start < cu1->start)
-	return 1;
-      if (cu2->start >= cu1->end)
-	return -1;
+      /* Something went wrong.  Undo the operation.  */
+      *offsetp = oldoff;
+      __libdw_seterrno (DWARF_E_NOMEM);
+      return NULL;
     }
 
-  return 0;
+  return newp;
 }
 
 struct Dwarf_CU *
@@ -160,20 +168,10 @@ __libdw_findcu (dbg, start, debug_types)
   /* No.  Then read more CUs.  */
   while (1)
     {
-      Dwarf_Off oldoff = *next_offset;
       struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, debug_types);
       if (newp == NULL)
 	return NULL;
 
-      /* Add the new entry to the search tree.  */
-      if (tsearch (newp, tree, findcu_cb) == NULL)
-	{
-	  /* Something went wrong.  Undo the operation.  */
-	  *next_offset = oldoff;
-	  __libdw_seterrno (DWARF_E_NOMEM);
-	  return NULL;
-	}
-
       /* Is this the one we are looking for?  */
       if (start < *next_offset)
 	// XXX Match exact offset.
diff --git a/tests/ChangeLog b/tests/ChangeLog
index a7825911..8d2b83f1 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,13 @@
+2012-03-21  Tom Tromey  <tromey@redhat.com>
+
+	* 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.
+
 2012-02-21  Kurt Roeckx  <kurt@roeckx.be>
 
 	* run-alldts.sh: testrun ./alldts.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 3074c893..f2c211b5 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -58,7 +58,7 @@ noinst_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \
 		  dwfl-addr-sect dwfl-bug-report early-offscn \
 		  dwfl-bug-getmodules dwarf-getmacros addrcfi \
 		  test-flag-nobits dwarf-getstring rerequest_tag \
-		  alldts md5-sha1-test
+		  alldts md5-sha1-test typeiter
 asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \
 	    asm-tst6 asm-tst7 asm-tst8 asm-tst9
 
@@ -86,7 +86,7 @@ TESTS = run-arextract.sh run-arsymtest.sh newfile test-nlist \
 	run-disasm-x86.sh run-disasm-x86-64.sh \
 	run-early-offscn.sh run-dwarf-getmacros.sh \
 	run-test-flag-nobits.sh run-prelink-addr-test.sh \
-	run-dwarf-getstring.sh run-rerequest_tag.sh
+	run-dwarf-getstring.sh run-rerequest_tag.sh run-typeiter.sh
 # run-show-ciefde.sh
 
 if !STANDALONE
@@ -161,7 +161,8 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh \
 	     testfile55-32.bz2 testfile55-32.debug.bz2 \
 	     testfile55-32.prelink.bz2 testfile55-64.bz2 \
 	     testfile55-64.debug.bz2 testfile55-64.prelink.bz2 \
-	     testfile56.bz2 testfile57.bz2 testfile58.bz2
+	     testfile56.bz2 testfile57.bz2 testfile58.bz2 \
+	     run-typeiter.sh testfile59.bz2
 
 installed_TESTS_ENVIRONMENT = libdir=$(DESTDIR)$(libdir) \
 			      bindir=$(DESTDIR)$(bindir) \
@@ -258,6 +259,7 @@ test_flag_nobits_LDADD = $(libelf) $(libmudflap)
 rerequest_tag_LDADD = $(libdw) $(libmudflap)
 alldts_LDADD = $(libebl) $(libelf) $(libmudflap)
 md5_sha1_test_LDADD = $(libeu)
+typeiter_LDADD = $(libdw) $(libelf) $(libmudflap)
 
 if GCOV
 check: check-am coverage
diff --git a/tests/run-typeiter.sh b/tests/run-typeiter.sh
new file mode 100755
index 00000000..4f650ca6
--- /dev/null
+++ b/tests/run-typeiter.sh
@@ -0,0 +1,58 @@
+#! /bin/sh
+# 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>.
+
+. $srcdir/test-subr.sh
+
+# struct s1
+# {
+#   char c;
+#   short s;
+#   int i;
+#   long l;
+#   float f;
+#   double d;
+# };
+# 
+# s1 S1;
+# 
+# int func (s1 *p)
+# {
+#   return p->i;
+# }
+# 
+# int main()
+# {
+#   return func (&S1);
+# }
+#
+# g++ -gdwarf-4 -g -fdebug-types-section
+
+testfiles testfile59
+
+testrun_compare ./typeiter testfile59 <<\EOF
+ok
+EOF
+
+exit 0
diff --git a/tests/testfile59.bz2 b/tests/testfile59.bz2
new file mode 100755
index 00000000..bcee648c
--- /dev/null
+++ b/tests/testfile59.bz2
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);
+    }
+}