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 C++FILT(1)                    binutils-2.33.1                    C++FILT(1)
 GNU Development Tools                                 GNU Development Tools

                                 2019-10-12



 NAME
      cxxfilt - demangle C++ and Java symbols

 SYNOPSIS
      c++filt [-_|--strip-underscore]
              [-n|--no-strip-underscore]
              [-p|--no-params]
              [-t|--types]
              [-i|--no-verbose]
              [-r|--no-recurse-limit]
              [-R|--recurse-limit]
              [-s format|--format=format]
              [--help]  [--version]  [symbol...]

 DESCRIPTION
      The C++ and Java languages provide function overloading, which means
      that you can write many functions with the same name, providing that
      each function takes parameters of different types.  In order to be
      able to distinguish these similarly named functions C++ and Java
      encode them into a low-level assembler name which uniquely identifies
      each different version.  This process is known as mangling. The
      c++filt [1] program does the inverse mapping: it decodes (demangles)
      low-level names into user-level names so that they can be read.

      Every alphanumeric word (consisting of letters, digits, underscores,
      dollars, or periods) seen in the input is a potential mangled name.
      If the name decodes into a C++ name, the C++ name replaces the low-
      level name in the output, otherwise the original word is output.  In
      this way you can pass an entire assembler source file, containing
      mangled names, through c++filt and see the same source file containing
      demangled names.

      You can also use c++filt to decipher individual symbols by passing
      them on the command line:

              c++filt <symbol>

      If no symbol arguments are given, c++filt reads symbol names from the
      standard input instead.  All the results are printed on the standard
      output.  The difference between reading names from the command line
      versus reading names from the standard input is that command-line
      arguments are expected to be just mangled names and no checking is
      performed to separate them from surrounding text.  Thus for example:

              c++filt -n _Z1fv

      will work and demangle the name to "f()" whereas:

              c++filt -n _Z1fv,



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 C++FILT(1)                    binutils-2.33.1                    C++FILT(1)
 GNU Development Tools                                 GNU Development Tools

                                 2019-10-12



      will not work.  (Note the extra comma at the end of the mangled name
      which makes it invalid).  This command however will work:

              echo _Z1fv, | c++filt -n

      and will display "f(),", i.e., the demangled name followed by a
      trailing comma.  This behaviour is because when the names are read
      from the standard input it is expected that they might be part of an
      assembler source file where there might be extra, extraneous
      characters trailing after a mangled name.  For example:

                  .type   _Z1fv, @function

 OPTIONS
      -_
      --strip-underscore
          On some systems, both the C and C++ compilers put an underscore in
          front of every name.  For example, the C name "foo" gets the low-
          level name "_foo".  This option removes the initial underscore.
          Whether c++filt removes the underscore by default is target
          dependent.

      -n
      --no-strip-underscore
          Do not remove the initial underscore.

      -p
      --no-params
          When demangling the name of a function, do not display the types
          of the function's parameters.

      -t
      --types
          Attempt to demangle types as well as function names.  This is
          disabled by default since mangled types are normally only used
          internally in the compiler, and they can be confused with non-
          mangled names.  For example, a function called "a" treated as a
          mangled type name would be demangled to "signed char".

      -i
      --no-verbose
          Do not include implementation details (if any) in the demangled
          output.

      -r
      -R
      --recurse-limit
      --no-recurse-limit
      --recursion-limit



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 C++FILT(1)                    binutils-2.33.1                    C++FILT(1)
 GNU Development Tools                                 GNU Development Tools

                                 2019-10-12



      --no-recursion-limit
          Enables or disables a limit on the amount of recursion performed
          whilst demangling strings.  Since the name mangling formats allow
          for an inifinite level of recursion it is possible to create
          strings whose decoding will exhaust the amount of stack space
          available on the host machine, triggering a memory fault.  The
          limit tries to prevent this from happening by restricting
          recursion to 2048 levels of nesting.

          The default is for this limit to be enabled, but disabling it may
          be necessary in order to demangle truly complicated names.  Note
          however that if the recursion limit is disabled then stack
          exhaustion is possible and any bug reports about such an event
          will be rejected.

          The -r option is a synonym for the --no-recurse-limit option.  The
          -R option is a synonym for the --recurse-limit option.

      -s format
      --format=format
          c++filt can decode various methods of mangling, used by different
          compilers.  The argument to this option selects which method it
          uses:

          "auto"
              Automatic selection based on executable (the default method)

          "gnu"
              the one used by the GNU C++ compiler (g++)

          "lucid"
              the one used by the Lucid compiler (lcc)

          "arm"
              the one specified by the C++ Annotated Reference Manual

          "hp"
              the one used by the HP compiler (aCC)

          "edg"
              the one used by the EDG compiler

          "gnu-v3"
              the one used by the GNU C++ compiler (g++) with the V3 ABI.

          "java"
              the one used by the GNU Java compiler (gcj)

          "gnat"



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 C++FILT(1)                    binutils-2.33.1                    C++FILT(1)
 GNU Development Tools                                 GNU Development Tools

                                 2019-10-12



              the one used by the GNU Ada compiler (GNAT).

      --help
          Print a summary of the options to c++filt and exit.

      --version
          Print the version number of c++filt and exit.

      @file
          Read command-line options from file.  The options read are
          inserted in place of the original @file option.  If file does not
          exist, or cannot be read, then the option will be treated
          literally, and not removed.

          Options in file are separated by whitespace.  A whitespace
          character may be included in an option by surrounding the entire
          option in either single or double quotes.  Any character
          (including a backslash) may be included by prefixing the character
          to be included with a backslash.  The file may itself contain
          additional @file options; any such options will be processed
          recursively.

 FOOTNOTES
      1.  MS-DOS does not allow "+" characters in file names, so on MS-DOS
          this program is named CXXFILT.

 SEE ALSO
      the Info entries for binutils.

 COPYRIGHT
      Copyright (c) 1991-2019 Free Software Foundation, Inc.

      Permission is granted to copy, distribute and/or modify this document
      under the terms of the GNU Free Documentation License, Version 1.3 or
      any later version published by the Free Software Foundation; with no
      Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
      Texts.  A copy of the license is included in the section entitled "GNU
      Free Documentation License".














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