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C++FILT(1)		     GNU Development Tools		    C++FILT(1)

NAME
       c++filt - 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,

       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
       --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"
	       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) 1991-2020 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".

binutils-2.34			  2022-09-06			    C++FILT(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | FOOTNOTES | SEE ALSO | COPYRIGHT

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