Mac OS X Manual Page For c++filt(1)

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

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

DESCRIPTION
The C++ and Java languages provide function overloading, which means that you can write many func-tions functions
tions 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 userlevel
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 com-mand command
mand 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()," ie 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. eg:

.type _Z1fv, @function

OPTIONS
-_
--strip-underscores
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 under-score. underscore.
score. Whether c++filt removes the underscore by default is target dependent.

-j
--java
Prints demangled names using Java syntax. The default is to use C++ syntax.

-n
--no-strip-underscores
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-man-gled non-mangled
gled names. eg 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.

-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 liter-ally, literally,
ally, 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.