* dwarf.c (read_and_display_attr_value): Prefix values that are

        displayed in hexadecimal with 0x.
        For the DW_AT_import attribute display the abbreviation number and
        tag of the imported DIE.
        (process_debug_info): Warn about lengths that reserved by the
        DWARF3 specification.
        Provide more information when corrupted DIEs are detected.
        Warn if DIE corruption makes the sibling level negative.

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index ccb34b71ef54a4e461cbf5bcd35d9107608dc5e5..fe0ed8fc2aab0b5a269806b70179cee75c9ef2e8 100644 (file)
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,14 @@
+2008-01-03  Nick Clifton  <nickc@redhat.com>
+
+       * dwarf.c (read_and_display_attr_value): Prefix values that are
+       displayed in hexadecimal with 0x.
+       For the DW_AT_import attribute display the abbreviation number and
+       tag of the imported DIE.
+       (process_debug_info): Warn about lengths that reserved by the
+       DWARF3 specification.
+       Provide more information when corrupted DIEs are detected.
+       Warn if DIE corruption makes the sibling level negative.
+
 For older changes see ChangeLog-2007
 \f
 Local Variables:

diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index 6fa270db1ea7e3c37044a21534bdc661a841d582..093832d5e5bffc17992cfe4b4c43d227c79b4a31 100644 (file)
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -1004,15 +1004,16 @@ decode_location_expression (unsigned char * data,
 }
 
 static unsigned char *
-read_and_display_attr_value (unsigned long attribute,
-                            unsigned long form,
-                            unsigned char *data,
-                            unsigned long cu_offset,
-                            unsigned long pointer_size,
-                            unsigned long offset_size,
-                            int dwarf_version,
-                            debug_info *debug_info_p,
-                            int do_loc)
+read_and_display_attr_value (unsigned long   attribute,
+                            unsigned long   form,
+                            unsigned char * data,
+                            unsigned long   cu_offset,
+                            unsigned long   pointer_size,
+                            unsigned long   offset_size,
+                            int             dwarf_version,
+                            debug_info *    debug_info_p,
+                            int             do_loc,
+                            unsigned char * section_start)
 {
   unsigned long uvalue = 0;
   unsigned char *block_start = NULL;
@@ -1087,14 +1088,15 @@ read_and_display_attr_value (unsigned long attribute,
       return read_and_display_attr_value (attribute, form, data,
                                          cu_offset, pointer_size,
                                          offset_size, dwarf_version,
-                                         debug_info_p, do_loc);
+                                         debug_info_p, do_loc,
+                                         section_start);
     }
 
   switch (form)
     {
     case DW_FORM_ref_addr:
       if (!do_loc)
-       printf (" <#%lx>", uvalue);
+       printf (" <0x%lx>", uvalue);
       break;
 
     case DW_FORM_ref1:
@@ -1102,13 +1104,13 @@ read_and_display_attr_value (unsigned long attribute,
     case DW_FORM_ref4:
     case DW_FORM_ref_udata:
       if (!do_loc)
-       printf (" <%lx>", uvalue + cu_offset);
+       printf (" <0x%lx>", uvalue + cu_offset);
       break;
 
     case DW_FORM_data4:
     case DW_FORM_addr:
       if (!do_loc)
-       printf (" %#lx", uvalue);
+       printf (" 0x%lx", uvalue);
       break;
 
     case DW_FORM_flag:
@@ -1125,8 +1127,8 @@ read_and_display_attr_value (unsigned long attribute,
       if (!do_loc)
        {
          uvalue = byte_get (data, 4);
-         printf (" %lx", uvalue);
-         printf (" %lx", (unsigned long) byte_get (data + 4, 4));
+         printf (" 0x%lx", uvalue);
+         printf (" 0x%lx", (unsigned long) byte_get (data + 4, 4));
        }
       if ((do_loc || do_debug_loc || do_debug_ranges)
          && num_debug_info_entries == 0)
@@ -1196,7 +1198,6 @@ read_and_display_attr_value (unsigned long attribute,
       break;
     }
 
-  /* For some attributes we can display further information.  */
   if ((do_loc || do_debug_loc || do_debug_ranges)
       && num_debug_info_entries == 0)
     {
@@ -1268,6 +1269,7 @@ read_and_display_attr_value (unsigned long attribute,
   if (do_loc)
     return data;
 
+  /* For some attributes we can display further information.  */
   printf ("\t");
 
   switch (attribute)
@@ -1472,6 +1474,28 @@ read_and_display_attr_value (unsigned long attribute,
        }
       break;
 
+    case DW_AT_import:
+      {
+       unsigned long abbrev_number;
+       abbrev_entry * entry;
+
+       if (form == DW_FORM_ref1
+           || form == DW_FORM_ref2
+           || form == DW_FORM_ref4)
+         uvalue += cu_offset;
+
+       abbrev_number = read_leb128 (section_start + uvalue, NULL, 0);
+       
+       printf ("[Abbrev Number: %ld", abbrev_number);
+       for (entry = first_abbrev; entry != NULL; entry = entry->next)
+         if (entry->entry == abbrev_number)
+           break;
+       if (entry != NULL)
+         printf (" (%s)", get_TAG_name (entry->tag));
+       printf ("]");
+      }
+      break;
+
     default:
       break;
     }
@@ -1634,22 +1658,23 @@ get_AT_name (unsigned long attribute)
 }
 
 static unsigned char *
-read_and_display_attr (unsigned long attribute,
-                      unsigned long form,
-                      unsigned char *data,
-                      unsigned long cu_offset,
-                      unsigned long pointer_size,
-                      unsigned long offset_size,
-                      int dwarf_version,
-                      debug_info *debug_info_p,
-                      int do_loc)
+read_and_display_attr (unsigned long   attribute,
+                      unsigned long   form,
+                      unsigned char * data,
+                      unsigned long   cu_offset,
+                      unsigned long   pointer_size,
+                      unsigned long   offset_size,
+                      int             dwarf_version,
+                      debug_info *    debug_info_p,
+                      int             do_loc,
+                      unsigned char * section_start)
 {
   if (!do_loc)
     printf ("   %-18s:", get_AT_name (attribute));
   data = read_and_display_attr_value (attribute, form, data, cu_offset,
                                      pointer_size, offset_size,
                                      dwarf_version, debug_info_p,
-                                     do_loc);
+                                     do_loc, section_start);
   if (!do_loc)
     printf ("\n");
   return data;
@@ -1689,6 +1714,11 @@ process_debug_info (struct dwarf_section *section, void *file,
              length = byte_get (section_begin + 4, 8);
              section_begin += length + 12;
            }
+         else if (length >= 0xfffffff0 && length < 0xffffffff)
+           {
+             warn (_("Reserved length value (%lx) found in section %s\n"), length, section->name);
+             return 0;
+           }
          else
            section_begin += length + 4;
 
@@ -1802,8 +1832,8 @@ process_debug_info (struct dwarf_section *section, void *file,
       if (cu_offset + compunit.cu_length + initial_length_size
          > section->size)
        {
-         warn (_("Debug info is corrupted, length is invalid (section is %lu bytes)\n"),
-               (unsigned long)section->size);
+         warn (_("Debug info is corrupted, length of CU at %lx extends beyond end of section (length = %lx)\n"),
+               cu_offset, compunit.cu_length);
          break;
        }
       tags = hdrptr;
@@ -1820,8 +1850,9 @@ process_debug_info (struct dwarf_section *section, void *file,
       /* Process the abbrevs used by this compilation unit. DWARF
         sections under Mach-O have non-zero addresses.  */
       if (compunit.cu_abbrev_offset >= debug_displays [abbrev].section.size)
-       warn (_("Debug info is corrupted, abbrev offset is invalid (section is %lu bytes)\n"),
-             (unsigned long)debug_displays [abbrev].section.size);
+       warn (_("Debug info is corrupted, abbrev offset (%lx) is larger than abbrev section size (%lx)\n"),
+             (unsigned long) compunit.cu_abbrev_offset,
+             (unsigned long) debug_displays [abbrev].section.size);
       else
        process_abbrev_section
          ((unsigned char *) debug_displays [abbrev].section.start
@@ -1834,25 +1865,38 @@ process_debug_info (struct dwarf_section *section, void *file,
        {
          unsigned int bytes_read;
          unsigned long abbrev_number;
+         unsigned long die_offset;
          abbrev_entry *entry;
          abbrev_attr *attr;
 
+         die_offset = tags - section_begin;
+
          abbrev_number = read_leb128 (tags, & bytes_read, 0);
          tags += bytes_read;
 
-         /* A null DIE marks the end of a list of children.  */
+         /* A null DIE marks the end of a list of siblings.  */
          if (abbrev_number == 0)
            {
              --level;
+             if (level < 0)
+               {
+                 static unsigned num_bogus_warns = 0;
+
+                 if (num_bogus_warns < 3)
+                   {
+                     warn (_("Bogus end-of-siblings marker detected at offset %lx in .debug_info section\n"),
+                           die_offset);
+                     num_bogus_warns ++;
+                     if (num_bogus_warns == 3)
+                       warn (_("Further warnings about bogus end-of-sibling markers suppressed\n"));
+                   }
+               }
              continue;
            }
 
          if (!do_loc)
            printf (_(" <%d><%lx>: Abbrev Number: %lu"),
-                   level,
-                   (unsigned long) (tags - section_begin
-                                    - bytes_read),
-                   abbrev_number);
+                   level, die_offset, abbrev_number);
  
          /* Scan through the abbreviation list until we reach the
             correct entry.  */
@@ -1904,8 +1948,8 @@ process_debug_info (struct dwarf_section *section, void *file,
                                            compunit.cu_pointer_size,
                                            offset_size,
                                            compunit.cu_version,
-                                           &debug_information [unit],
-                                           do_loc);
+                                           debug_information + unit,
+                                           do_loc, section->start);
            }
  
          if (entry->children)