Provided by: dwarfdump_20120410-2_amd64 bug

NAME

       dwarfdump - dumps DWARF debug information of an ELF object

SYNOPSIS

       dwarfdump [options] objectfilename

DESCRIPTION

       The  dwarfdump  command  prints or checks DWARF sections as requested by specific options.
       With no options (but with the required objectfilename  )  all  sections  print  (but  some
       sections  cannot  be  printed  independently  safely, so those are only printed at offsets
       where the .debug_info section refers to those sections).

       As of June 2011 the printing options and the checking options are mutually  exclusive  (if
       checking  options  are  selected  the  section details are not printed).   When errors are
       encountered dwarfdump does attempt to print sufficient context so that one can  understand
       exactly  where  the error is in the DWARF.  This change makes checking really large object
       files much easier.

       The format is intended to be human readable.  If a script is to parse the output,  the  -d
       option is useful.

       Not all sections actually exist in any given object file.

       The  format  may  change from release to release, so it is unwise to depend too heavily on
       the format.

       Frame information (.debug_frame and .eh_frame) is heavily dependent on the ABI/ISA of  the
       object  file.   By  default  we  use  a  generic  set of register names handling up to 100
       registers named r0-100.  The '-R'  option  uses  a  built-in  generic  register  name  set
       handling  up to 1200 registers named r0-r1199.  The '-x abi=<abi>' description below shows
       how to name an abi and use that to guide the -f or -F processing.  Unless the cpu for  the
       object  file being dumped has many registers, do not use -R or -x abi=generic as those can
       be needlessly slow dumping frame sections. Instead, use the correct abi (if it  exists  in
       dwarfdump.conf)  or  a  generic  such  as  -x abi=generic100 or -x abi=generic500.  To get
       MIPS/IRIX register names names and call the old version 2 libdwarf frame interface use the
       option '-x abi=mips'.  Without '-R' or '-x abi=<abi>' dwarfdump ignores the dwarfdump.conf
       file and uses compiled-in generic set of register names.  If no '-x name=<path>' is given,
       dwarfdump    looks    for    "./dwarfdump.conf",    "$HOME/.dwarfdump.conf",    "<install-
       prefix>/lib/dwarfdump.conf" and takes the first it finds.  If one or more '-x name=<path>'
       is given the last of these is used and all other such files are ignored.

       Some  -k  (checking)  options  print so-called harmless errors.  These are compiler errors
       that do not cause any known problem and are only detected inside libdwarf  itself.   These
       are  difficult  to properly report in dwarfdump and any error strings may not appear close
       to the time the error was encountered.

URI STYLE INPUT STRINGS

       The <objectfilename> and the options taking name strings look for URIs and  translate  the
       URI strings to characters by default (see -x, -c<compiler name>, -S, -u).  So any single %
       character is treated as if the following two characters are hex  digits  representing  the
       underlying  true  character.  Various characters are meaningful to shells (such as bash or
       sh) and to getopt (such as the space character) If the URI translation  does  anything  it
       prints  the  before  and after of the URI translation on standard output, so inspection of
       the first lines of output will show if URI did anything.  The  actual  options  themselves
       are  assumed  to be non-URI.  So in the option '-cS&T' the -c portion must be non-URI, but
       the & character might cause input issues so '-cS%26T' could be used instead.  To  actually
       input a single % character (in a name, for example), double it to %% on the command line.

       Options  -U  (turning off URI interpretation) and -q (making finding URI sequences silent)
       give finer control of URI interpretation.  PP As an example, to get a string'a b' make the
       string 'a%20b' (here the quote  (') is for exposition not part of the string, though quote
       is certainly problematic in a name).  Instead of escaping " quotes in  the  string,   type
       %25, as in
          'a "b'  should be typed   'a%20%25b' Any characters can be typed in URI style, not just
       characters which are problematic to the shell or getopt.  We strongly suggest you not type
       URI-style  characters  where  such are not needed or use the % character itself in command
       line strings unless you must.

PRINTING OPTIONS

       -a     Print each section as independently  as  possible.  Sections  that  can  safely  be
              printed independently (like .debug_abbrev) have relevant info printed in the report
              (sometimes dependent on -v).

       -b     Print the .debug_abbrev section. Because the DWARF specfications do  not  rule  out
              garbage  data  areas in .debug_abbrev (if they are not referenced from .debug_info)
              any garbage bytes can result in this print failing.

       -c     Print locations lists.

       -f     Print the .debug_frame section.

       -F     Print the .eh_frame section.

       -i     Print  the .debug_info section.

       -l     Print the .debug_info section and the associated line section data.

       -m     Print the .debug_macinfo section.

       -N     Print .debug_ranges section.  Because the  DWARF  specfications  do  not  rule  out
              garbage  data  areas in .debug_ranges (if they are not referenced from .debug_info)
              any garbage bytes can result in this print failing.

       -p     Print the .debug_pubnames section.

       -r     Print the .debug_aranges section.

       -s     Print .debug_string section.

       -ta    Print the IRIX only sections .debug_static_funcs and .debug_static_vars.

       -tf    Print the IRIX only section .debug_static_funcs.

       -tv    Print the IRIX only section .debug_static_vars.

       -w     Print the IRIX-only .debug_weaknames section.

       -y     Print the .debug_pubtypes section (and .debug_typenames, an SGI IRIX-only section).

       Having dwarfdump print relocations may help establish whether  dwarfdump  understands  any
       relocations that might exist.

       -o     Print all relocation records as well as we can manage.

       -oi    Print .rel*debug_info relocations.

       -ol    Print .rel*debug_line relocation.

       -op    Print .rel*debug_pubnames relocation.

       -oa    Has no effect.

       -or    Print .rel*debug_aranges relocations.

       -of    Print .rel*debug_frame relocations.

       -oo    Print .rel*debug_loc relocations.

       -oR    Print .rel*debug_ranges relocations.

       -g     Normally  used only for testing libdwarf, this tells dwarfdump to print .debug_info
              and use an older dwarf_loclist() interface function (a function that cannot  handle
              all current location lists).

       -V     Print a dwarfdump date/version string and stop.

CHECKING OPTIONS

       -cg    Restricts  checking  to compilers whose producer string starts with 'GNU' and turns
              off -cs .

       -cs    Restricts checking to compilers whose producer string starts with  'SN'  and  turns
              off -cg .

       -cname Restricts  checking  to  compilers  whose producer string contains 'name' (not case
              sensitive).  The 'name' is read as a URI string.

       -ka : Turns on all checking options except -kxe (-kxe might
                           be slow enough one mignt not want to use it routinely.)

       -kb : Checks for certain abbreviations section errors when reading
                           DIEs.

       -kc    Checks for errors in constants in debug_info.

       -kd    Turns on full reporting of error totals per  producer.   (the  default  shows  less
              detail).

       -ke    Turns on reading pubnames and checking for fde errors.

       -kf    Turns on checking for FDE errors.

       -kF    Turns on checking for line table errors.

       -kg    Turns on checking for unused gaps in .debug_info (these gaps are not an error, just
              a waste of space).

       -ki    Causes a summary of checking results per compiler (producer) to be printed  at  the
              end.

       -kl    Turns on locations list checking.

       -km    Turns on checking of ranges.

       -kM    Turns on checking of aranges.

       -kr    Turns on DIE tag-attr combinations checking.

       -kR    Turns on reading DIEs and checking for forward declarations rom DW_AT_specification
              attributes.  (which are not an error but  can  be  a  source  of  inefficiency  for
              debuggers).

       -ks    Turns on extra reporting for some DIE errors checking detects .

       -kS    Turns on checking DIE references for circular references.

       -kt    Turns on tag-tag combinations checking.

       -kx    Turns on check_frames.

       -kxe   Turns off basic check_frames and turns on extended frame checking.

       -ky    Turns on type_offset, decl_file checking,

OPTION MODIFIERS

       -C     Normally  when checking for tag-tag or tag-attribute combinations both the standard
              combinations and some common extensions are allowed.  With -C  the  extensions  are
              taken out of the allowed class of combinations.

       -d     When  printing DIEs, put all the attributes for each DIE on the same (long) line as
              the TAG.  This makes searching for DIE information (as with grep) much  simpler  as
              the entire DIE is on one line.

       -D     Turns  off  the  display of section offsets and attribute values in printed output.
              So the .debug_info output isjust TAGs and Attributes.  For pubnames (and the  like)
              it  removes  offsets  from the output.  For locations lists it removes offsets from
              the output, but that is useless since the attribute values don't  show  so  neither
              does the location data.

       -e     Turns  on  truncation  of  attribute and tag names. For example DW_TAG_foo  becomes
              foo .    Not compatible with checking, only useful for printing DIEs.

       -G     When printing, add global offsets to the offsets printed.

       -H number
              When printing or checking .debug_info, this terminates the  search  after  'number'
              compilation  units.   When  printing  frame  information  this  terminates  the FDE
              reporting after 'number' FDEs and the CIE reporting (which occurs if one  adds  -v)
              after 'number' CIEs.  Example   '-H 1'

       -M     When  printing, this means one want to have the FORM show for each attribute.  If a
              -v is also added (or more than one) then details of any form indirection  are  also
              shown.

       -n     When  printing  frames,  this turns off the search for function names.  In a really
              large object the search can take more time than one wants to wait, so  this  avoids
              the search.

       -Q     Suppresses section data printing (set automatically with a checking option).

       -R     When  printing  frames  for  ABIs  with  lots  of registers, this allows up to 1200
              registers to be named (like R999) without choosing an ABI  with,  for  example  '-x
              abi=ppc'

       -v     Increases  the detail shown when printing.  In some sections, using more -v options
              will increase the detail (one to three are useful) or  may  change  the  report  to
              show,  for  example,  the  actual line-data-commands instead of the resultant line-
              table.

SELECTIVE ENTRY PRINTING

       These -S options stand alone and basic print information about the  compilation  unit  and
       DIE where the string(s) appear.  At most one of each of the following is effective (so for
       example one can only have one 'match', but one  can  have  a  'match',  an  'any',  and  a
       'regex').   Any -S causes the .debug_info section to be inspected.  No checking options or
       printing options should be supplied with -S.

       -S match=string
              When printing DIEs for each tag value  or  attribute  name  that  matches  'string'
              exactly print the compilation unit information and its section offset.  Any CU with
              no match is not printed.  The 'string' is read as a URI string.

       -S any=string
              When printing DIEs for each tag value or  attribute  name  that  contains  'string'
              somewhere  in  the  tag  or attribute (case insensitive) print the compilation unit
              information and its section offset.  Any CU with no  match  is  not  printed.   The
              'string' is read as a URI string.

       -S regex=string
              When  printing DIEs for each tag value or attribute name where the 'string' reqular
              expression matches print the compilation unit information and its  section  offset.
              Any CU with no match is not printed.  The 'string' is read as a URI string.

       The  string  cannot  have spaces or other characters which are meaningful to getopt(3) and
       the shell will strip off quotes and other characters.  So the string is assumed to  be  in
       URI  style  and  is translated.  In other words, to match 'a b' make the -S string 'a%20b'
       Instead of escaping " quotes in the string,  type %25, as in
          'a "b'  should be typed   'a%20%25b' (the ' are for exposition here, not  part  of  the
       strings).   Any  characters  can  be  typed  in  URI  style, not just characters which are
       problematic to the shell or getopt.

       The -S any= and -S regex= options are only usable if the library  functions  required  are
       found at configure time.

       The  -W  option  is  a  modifier  to  the -S option, and increases the amount of output -W
       prints.  Now we show the -W in context with a -S option.

       -S match=string1 -W
              Prints the parent tree and the children tree for the DIEs that -S matches.

       -S match=string2 -Wp
              Prints the parent tree for the DIEs that -S matches.

       -S match=string3 -Wc
              Prints the parent tree for the DIEs that -S matches.

OTHER OPTIONS

       -# number
              This option controls internal debugging output,  higher  numbers  mean  more  debug
              actions. See the source code.

       -x name=/p/a/t/h.conf
              The file path given is the name of a file assumed to be a dwarfdump.conf-like file.
              The file path is read as a URI string.

       -x abi=ppc
              Selects the abi  (from  a  dwarfdump.conf  file)  to  be  used  in  printing  frame
              information (here using ppc as an example).  The abi is read as a URI string.

       -P     When  checking this adds the list of compilation-unit names seen for each producer-
              compiler to the printed checking results.

       -q     When a URI is found and translated while reading the command line, be  quiet  about
              the  URI  translation.  That  is,   don't  print the original and translated option
              strings.

       -E     Turns on printing object-internal header data for some systems (for Unix/Linux does
              nothing).

       -u cuname
              Turns  on  selective  printing  of  DIEs  (printing  like -i).  Only the DIEs for a
              compilation unit that match the name provided are printed.  If the compilation unit
              is  ./a/b/c.c  the 'cuname' you provide should be c.c as the characters through the
              final path-separating / are ignored.  If 'cuname' begins with a / then  the  entire
              name  string  of a compilation unit must match 'cuname'.  The 'cuname' is read as a
              URI string.

       -U     Turn off the URI interpretation of the command line strings entirely.  Must  be  be
              on the command line before any URI strings encountered to be fully effective.

       -z     No longer suported.

FILES

       dwarfdump

       dwarfdump.conf

       $(HOME)/.dwarfdump.conf

       $(HOME)/dwarfdump.conf

       <install-prefix>/lib/dwarfdump.conf

NOTES

       In  some  cases compilers use DW_FORM_data1 (for example) and in such cases the signedness
       of the value must be taken from context. Rather than attempt  to  determine  the  context,
       dwarfdump  prints  the  value with both signednesses whenever there is ambiguity about the
       correct interpretation.  For example, "DW_AT_const_value           176(as signed =  -80)".
       For  normal  DWARF  consumers that correctly and fully evaluate all attributes there is no
       ambiguity of signedness: the ambiguity for dwarfdump is due to dwarfdump  evaluating  DIEs
       in a simple order and not keeping track of much context.

BUGS

       Support for DWARF3 is being completed but may not be complete.

                                                                                      DWARFDUMP()