Ignore DWARF debug information with a version of 0 - assume that it is padding.

	PR 19872
bfd	* dwarf2.c (parse_comp_unit): Skip warning about unrecognised
	version number if the version is zero.

bin	* dwarf.c (display_debug_aranges): Skip warning about unrecognised
	version number if the version is zero.

2 files changed, 27 insertions, 13 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 9b87780..42d112f 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2016-04-04  Nick Clifton  <nickc@redhat.com>
+
+	PR 19872
+	* dwarf2.c (parse_comp_unit): Skip warning about unrecognised
+	version number if the version is zero.
+
 2016-04-01  Alan Modra  <amodra@gmail.com>
 
 	PR 19886
diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index addfbf5..33370ac 100644
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -2757,11 +2757,18 @@ parse_comp_unit (struct dwarf2_debug *stash,
 
   if (version != 2 && version != 3 && version != 4)
     {
-      (*_bfd_error_handler)
-	(_("Dwarf Error: found dwarf version '%u', this reader"
-	   " only handles version 2, 3 and 4 information."), version);
-      bfd_set_error (bfd_error_bad_value);
-      return 0;
+      /* PR 19872: A version number of 0 probably means that there is padding
+	 at the end of the .debug_info section.  Gold puts it there when
+	 performing an incremental link, for example.  So do not generate
+	 an error, just return a NULL.  */
+      if (version)
+	{
+	  (*_bfd_error_handler)
+	    (_("Dwarf Error: found dwarf version '%u', this reader"
+	       " only handles version 2, 3 and 4 information."), version);
+	  bfd_set_error (bfd_error_bad_value);
+	}
+      return NULL;
     }
 
   if (addr_size > sizeof (bfd_vma))
@@ -2772,7 +2779,7 @@ parse_comp_unit (struct dwarf2_debug *stash,
 	 addr_size,
 	 (unsigned int) sizeof (bfd_vma));
       bfd_set_error (bfd_error_bad_value);
-      return 0;
+      return NULL;
     }
 
   if (addr_size != 2 && addr_size != 4 && addr_size != 8)
@@ -2781,22 +2788,23 @@ parse_comp_unit (struct dwarf2_debug *stash,
 	("Dwarf Error: found address size '%u', this reader"
 	 " can only handle address sizes '2', '4' and '8'.", addr_size);
       bfd_set_error (bfd_error_bad_value);
-      return 0;
+      return NULL;
     }
 
   /* Read the abbrevs for this compilation unit into a table.  */
   abbrevs = read_abbrevs (abfd, abbrev_offset, stash);
   if (! abbrevs)
-    return 0;
+    return NULL;
 
   abbrev_number = safe_read_leb128 (abfd, info_ptr, &bytes_read, FALSE, end_ptr);
   info_ptr += bytes_read;
   if (! abbrev_number)
     {
-      (*_bfd_error_handler) (_("Dwarf Error: Bad abbrev number: %u."),
-			     abbrev_number);
-      bfd_set_error (bfd_error_bad_value);
-      return 0;
+      /* PR 19872: An abbrev number of 0 probably means that there is padding
+	 at the end of the .debug_abbrev section.  Gold puts it there when
+	 performing an incremental link, for example.  So do not generate
+	 an error, just return a NULL.  */
+      return NULL;
     }
 
   abbrev = lookup_abbrev (abbrev_number, abbrevs);
@@ -2805,7 +2813,7 @@ parse_comp_unit (struct dwarf2_debug *stash,
       (*_bfd_error_handler) (_("Dwarf Error: Could not find abbrev number %u."),
 			     abbrev_number);
       bfd_set_error (bfd_error_bad_value);
-      return 0;
+      return NULL;
     }
 
   amt = sizeof (struct comp_unit);