Chapter 10. c++filt

c++filt [-_|--strip-underscores]
        [-j|--java]
        [-n|--no-strip-underscores]
        [-p|--no-params]
        [-s format|--format=format]
        [--help]  [--version]  [symbol…]

The C++ and Java languages provides function overloading, which means that you can write many functions with the same name (providing each takes parameters of different types). All C++ and Java function names are encoded into a low-level assembly label (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 the linker can keep these overloaded functions from clashing.

Every alphanumeric word (consisting of letters, digits, underscores, dollars, or periods) seen in the input is a potential label. If the label decodes into a C++ name, the C++ name replaces the low-level name in the output.

You can use c++filt to decipher individual symbols:

c++filt symbol

If no symbol arguments are given, c++filt reads symbol names from the standard input and writes the demangled names to the standard output. All results are printed on the standard output.

-_, -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 underscore. 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.

-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.

Warning: c++filt is a new utility, and the details of its user interface are subject to change in future releases. In particular, a command-line option may be required in the the future to decode a name passed as an argument on the command line; in other words,

c++filt symbol

may in a future release become

c++filt option symbol

Notes

[1]

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