NAME
cxxfilt - Demangle C++ and Java symbols.
SYNOPSIS
c++filt [
-_|
--strip-underscore]
[
-n|
--no-strip-underscore]
[
-p|
--no-params]
[
-t|
--types]
[
-i|
--no-verbose]
[
-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.
- -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) 1991-2016 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".