1 nm 命令查看符号

$nm -h
Usage: nm [option(s)] [file(s)]
 List symbols in [file(s)] (a.out by default).
 The options are:
  -a, --debug-syms       Display debugger-only symbols
  -A, --print-file-name  Print name of the input file before every symbol
  -B                     Same as --format=bsd
  -C, --demangle[=STYLE] Decode low-level symbol names into user-level names
                          The STYLE, if specified, can be `auto' (the default),
                          `gnu', `lucid', `arm', `hp', `edg', `gnu-v3', `java'
                          or `gnat'
      --no-demangle      Do not demangle low-level symbol names
      --recurse-limit    Enable a demangling recursion limit.  This is the default.
      --no-recurse-limit Disable a demangling recursion limit.
  -D, --dynamic          Display dynamic symbols instead of normal symbols
      --defined-only     Display only defined symbols
  -e                     (ignored)
  -f, --format=FORMAT    Use the output format FORMAT.  FORMAT can be `bsd',
                           `sysv' or `posix'.  The default is `bsd'
  -g, --extern-only      Display only external symbols
  -l, --line-numbers     Use debugging information to find a filename and
                           line number for each symbol
  -n, --numeric-sort     Sort symbols numerically by address
  -o                     Same as -A
  -p, --no-sort          Do not sort the symbols
  -P, --portability      Same as --format=posix
  -r, --reverse-sort     Reverse the sense of the sort
      --plugin NAME      Load the specified plugin
  -S, --print-size       Print size of defined symbols
  -s, --print-armap      Include index for symbols from archive members
      --size-sort        Sort symbols by size
      --special-syms     Include special symbols in the output
      --synthetic        Display synthetic symbols as well
  -t, --radix=RADIX      Use RADIX for printing symbol values
      --target=BFDNAME   Specify the target object format as BFDNAME
  -u, --undefined-only   Display only undefined symbols
      --with-symbol-versions  Display version strings after symbol names
  -X 32_64               (ignored)
  @FILE                  Read options from FILE
  -h, --help             Display this information
  -V, --version          Display this program's version number

$nm -D liborc.so  |grep hdfs
                 U _ZN4hdfs10FileSystem3NewERPNS_9IoServiceERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKNS_7OptionsE
                 U _ZN4hdfs12ConfigParser20LoadDefaultResourcesEv
                 U _ZN4hdfs12ConfigParserC1Ev
                 U _ZN4hdfs12ConfigParserD1Ev
                 U _ZN4hdfs3URI17parse_from_stringERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE
                 U _ZN4hdfs3URIC1Ev
00000000001166b8 W _ZN4hdfs3URID1Ev
00000000001166b8 W _ZN4hdfs3URID2Ev
0000000000116800 W _ZN4hdfs6StatusD1Ev
0000000000116800 W _ZN4hdfs6StatusD2Ev
                 U _ZN4hdfs7OptionsC1Ev
0000000000117550 W _ZN4hdfs7OptionsD1Ev
0000000000117550 W _ZN4hdfs7OptionsD2Ev
                 U _ZN4hdfs8StatInfoC1Ev
                 U _ZN4hdfs9IoService3NewEv
                 U _ZNK4hdfs12ConfigParser11get_optionsERNS_7OptionsE
                 U _ZNK4hdfs12ConfigParser17ValidateResourcesB5cxx11Ev
                 U _ZNK4hdfs3URI3strB5cxx11Eb
                 U _ZNK4hdfs3URI8get_hostB5cxx11Eb
                 U _ZNK4hdfs3URI8get_pathB5cxx11Eb
                 U _ZNK4hdfs3URI8get_portEv
                 U _ZNK4hdfs3URI8has_portEv
                 U _ZNK4hdfs6Status8ToStringB5cxx11Ev
0000000000117340 W _ZNSt8_Rb_treeINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESt4pairIKS5_St6vectorIN4hdfs12NamenodeInfoESaISA_EEESt10_Select1stISD_ESt4lessIS5_ESaISD_EE8_M_eraseEPSt13_Rb_tree_nodeISD_E
0000000000116d08 W _ZNSt8_Rb_treeISt4pairINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES6_ES0_IKS7_N4hdfs5TokenEESt10_Select1stISB_ESt4lessIS7_ESaISB_EE8_M_eraseEPSt13_Rb_tree_nodeISB_E
000000000016efd0 V _ZTIN4hdfs15uri_parse_errorE
00000000001204d0 V _ZTSN4hdfs15uri_parse_errorE
# 如果第一列没有显示，就是该符号没有实现
$c++filt _ZN4hdfs12ConfigParserC1Ev
hdfs::ConfigParser::ConfigParser()

2 c++filt 命令还原符号

$c++filt -h
Usage: c++filt [options] [mangled names]
Options are:
  [-_|--strip-underscore]     Ignore first leading underscore
  [-n|--no-strip-underscore]  Do not ignore a leading underscore (default)
  [-p|--no-params]            Do not display function arguments
  [-i|--no-verbose]           Do not show implementation details (if any)
  [-R|--recurse-limit]        Enable a limit on recursion whilst demangling.  [Default]
  ]-r|--no-recurse-limit]     Disable a limit on recursion whilst demangling
  [-t|--types]                Also attempt to demangle type encodings
  [-s|--format {none,auto,gnu-v3,java,gnat,dlang,rust}]
  [@<file>]                   Read extra options from <file>
  [-h|--help]                 Display this information
  [-v|--version]              Show the version information

$c++filt _ZTVSt17_Nested_exceptionIN4Hdfs12HdfsCanceledEE
vtable for std::_Nested_exception<Hdfs::HdfsException>

**【参考】
GCC详解-Binutils工具之c++filt