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Updated: July 2014

c++filt (1g)


c++filt - Demangle C++ and Java symbols.


c++filt [-_|--strip-underscore]
[-s format|--format=format]
[--help]  [--version]  [symbol...]


GNU Development Tools                                  C++FILT(1)

     c++filt - Demangle C++ and Java symbols.

     c++filt [-_|--strip-underscore]
             [-s format|--format=format]
             [--help]  [--version]  [symbol...]

     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

             c++filt -n _Z1fv

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

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GNU Development Tools                                  C++FILT(1)

             c++filt -n _Z1fv,

     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

         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.

         Do not remove the initial underscore.

         When demangling the name of a function, do not display
         the types of the function's parameters.

         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".

         Do not include implementation details (if any) in the
         demangled output.

     -s format
         c++filt can decode various methods of mangling, used by

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GNU Development Tools                                  C++FILT(1)

         different compilers.  The argument to this option
         selects which method it uses:

             Automatic selection based on executable (the default

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

             the one used by the Lucid compiler (lcc)

             the one specified by the C++ Annotated Reference

             the one used by the HP compiler (aCC)

             the one used by the EDG compiler

             the one used by the GNU C++ compiler (g++) with the
             V3 ABI.

             the one used by the GNU Java compiler (gcj)

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

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

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

         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

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GNU Development Tools                                  C++FILT(1)


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

     See attributes(5) for descriptions of the following

     |Availability   | developer/gnu-binutils |
     |Stability      | Uncommitted            |
     the Info entries for binutils.

     Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997,
     1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
     2008, 2009, 2010, 2011, 2012 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".

     This software was built from source available at  The original
     community source was downloaded from

     Further information about this software can be found on the
     open source community website at

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